Some notable changes, from upstream's release notes: - sshd(8): Remove support for obsolete "host/port" syntax. - ssh(1): When prompting whether to record a new host key, accept the key fingerprint as a synonym for "yes". - ssh-keygen(1): when acting as a CA and signing certificates with an RSA key, default to using the rsa-sha2-512 signature algorithm. - ssh(1), sshd(8), ssh-keygen(1): this release removes the "ssh-rsa" (RSA/SHA1) algorithm from those accepted for certificate signatures. - ssh-sk-helper(8): this is a new binary. It is used by the FIDO/U2F support to provide address-space isolation for token middleware libraries (including the internal one). - ssh(1): this release enables UpdateHostkeys by default subject to some conservative preconditions. - scp(1): this release changes the behaviour of remote to remote copies (e.g. "scp host-a:/path host-b:") to transfer through the local host by default. - scp(1): experimental support for transfers using the SFTP protocol as a replacement for the venerable SCP/RCP protocol that it has traditionally used. Additional integration work is needed to support FIDO/U2F in the base system. Deprecation Notice ------------------ OpenSSH will disable the ssh-rsa signature scheme by default in the next release. Reviewed by: imp MFC after: 1 month Relnotes: Yes Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D29985
4892 lines
133 KiB
C
4892 lines
133 KiB
C
/* $OpenBSD: channels.c,v 1.407 2021/05/19 01:24:05 djm Exp $ */
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/*
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* Author: Tatu Ylonen <ylo@cs.hut.fi>
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* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
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* All rights reserved
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* This file contains functions for generic socket connection forwarding.
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* There is also code for initiating connection forwarding for X11 connections,
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* arbitrary tcp/ip connections, and the authentication agent connection.
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*
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* As far as I am concerned, the code I have written for this software
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* can be used freely for any purpose. Any derived versions of this
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* software must be clearly marked as such, and if the derived work is
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* incompatible with the protocol description in the RFC file, it must be
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* called by a name other than "ssh" or "Secure Shell".
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*
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* SSH2 support added by Markus Friedl.
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* Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
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* Copyright (c) 1999 Dug Song. All rights reserved.
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* Copyright (c) 1999 Theo de Raadt. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "includes.h"
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <sys/ioctl.h>
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#include <sys/un.h>
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#include <sys/socket.h>
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#ifdef HAVE_SYS_TIME_H
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# include <sys/time.h>
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#endif
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <limits.h>
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#include <netdb.h>
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#include <stdarg.h>
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#ifdef HAVE_STDINT_H
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# include <stdint.h>
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#endif
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <termios.h>
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#include <unistd.h>
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#include "openbsd-compat/sys-queue.h"
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#include "xmalloc.h"
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#include "ssh.h"
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#include "ssh2.h"
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#include "ssherr.h"
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#include "sshbuf.h"
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#include "packet.h"
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#include "log.h"
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#include "misc.h"
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#include "channels.h"
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#include "compat.h"
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#include "canohost.h"
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#include "sshkey.h"
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#include "authfd.h"
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#include "pathnames.h"
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#include "match.h"
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/* -- agent forwarding */
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#define NUM_SOCKS 10
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/* -- tcp forwarding */
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/* special-case port number meaning allow any port */
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#define FWD_PERMIT_ANY_PORT 0
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/* special-case wildcard meaning allow any host */
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#define FWD_PERMIT_ANY_HOST "*"
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/* -- X11 forwarding */
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/* Maximum number of fake X11 displays to try. */
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#define MAX_DISPLAYS 1000
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/* Per-channel callback for pre/post select() actions */
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typedef void chan_fn(struct ssh *, Channel *c,
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fd_set *readset, fd_set *writeset);
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/*
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* Data structure for storing which hosts are permitted for forward requests.
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* The local sides of any remote forwards are stored in this array to prevent
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* a corrupt remote server from accessing arbitrary TCP/IP ports on our local
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* network (which might be behind a firewall).
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*/
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/* XXX: streamlocal wants a path instead of host:port */
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/* Overload host_to_connect; we could just make this match Forward */
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/* XXX - can we use listen_host instead of listen_path? */
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struct permission {
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char *host_to_connect; /* Connect to 'host'. */
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int port_to_connect; /* Connect to 'port'. */
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char *listen_host; /* Remote side should listen address. */
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char *listen_path; /* Remote side should listen path. */
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int listen_port; /* Remote side should listen port. */
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Channel *downstream; /* Downstream mux*/
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};
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/*
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* Stores the forwarding permission state for a single direction (local or
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* remote).
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*/
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struct permission_set {
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/*
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* List of all local permitted host/port pairs to allow for the
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* user.
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*/
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u_int num_permitted_user;
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struct permission *permitted_user;
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/*
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* List of all permitted host/port pairs to allow for the admin.
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*/
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u_int num_permitted_admin;
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struct permission *permitted_admin;
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/*
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* If this is true, all opens/listens are permitted. This is the
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* case on the server on which we have to trust the client anyway,
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* and the user could do anything after logging in.
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*/
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int all_permitted;
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};
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/* Master structure for channels state */
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struct ssh_channels {
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/*
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* Pointer to an array containing all allocated channels. The array
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* is dynamically extended as needed.
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*/
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Channel **channels;
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/*
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* Size of the channel array. All slots of the array must always be
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* initialized (at least the type field); unused slots set to NULL
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*/
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u_int channels_alloc;
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/*
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* Maximum file descriptor value used in any of the channels. This is
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* updated in channel_new.
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*/
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int channel_max_fd;
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/*
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* 'channel_pre*' are called just before select() to add any bits
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* relevant to channels in the select bitmasks.
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*
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* 'channel_post*': perform any appropriate operations for
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* channels which have events pending.
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*/
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chan_fn **channel_pre;
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chan_fn **channel_post;
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/* -- tcp forwarding */
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struct permission_set local_perms;
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struct permission_set remote_perms;
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/* -- X11 forwarding */
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/* Saved X11 local (client) display. */
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char *x11_saved_display;
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/* Saved X11 authentication protocol name. */
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char *x11_saved_proto;
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/* Saved X11 authentication data. This is the real data. */
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char *x11_saved_data;
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u_int x11_saved_data_len;
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/* Deadline after which all X11 connections are refused */
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u_int x11_refuse_time;
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/*
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* Fake X11 authentication data. This is what the server will be
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* sending us; we should replace any occurrences of this by the
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* real data.
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*/
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u_char *x11_fake_data;
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u_int x11_fake_data_len;
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/* AF_UNSPEC or AF_INET or AF_INET6 */
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int IPv4or6;
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};
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/* helper */
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static void port_open_helper(struct ssh *ssh, Channel *c, char *rtype);
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static const char *channel_rfwd_bind_host(const char *listen_host);
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/* non-blocking connect helpers */
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static int connect_next(struct channel_connect *);
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static void channel_connect_ctx_free(struct channel_connect *);
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static Channel *rdynamic_connect_prepare(struct ssh *, char *, char *);
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static int rdynamic_connect_finish(struct ssh *, Channel *);
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/* Setup helper */
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static void channel_handler_init(struct ssh_channels *sc);
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/* -- channel core */
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void
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channel_init_channels(struct ssh *ssh)
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{
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struct ssh_channels *sc;
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if ((sc = calloc(1, sizeof(*sc))) == NULL)
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fatal_f("allocation failed");
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sc->channels_alloc = 10;
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sc->channels = xcalloc(sc->channels_alloc, sizeof(*sc->channels));
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sc->IPv4or6 = AF_UNSPEC;
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channel_handler_init(sc);
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ssh->chanctxt = sc;
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}
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Channel *
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channel_by_id(struct ssh *ssh, int id)
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{
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Channel *c;
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if (id < 0 || (u_int)id >= ssh->chanctxt->channels_alloc) {
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logit_f("%d: bad id", id);
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return NULL;
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}
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c = ssh->chanctxt->channels[id];
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if (c == NULL) {
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logit_f("%d: bad id: channel free", id);
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return NULL;
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}
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return c;
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}
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Channel *
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channel_by_remote_id(struct ssh *ssh, u_int remote_id)
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{
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Channel *c;
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u_int i;
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for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
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c = ssh->chanctxt->channels[i];
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if (c != NULL && c->have_remote_id && c->remote_id == remote_id)
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return c;
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}
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return NULL;
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}
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/*
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* Returns the channel if it is allowed to receive protocol messages.
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* Private channels, like listening sockets, may not receive messages.
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*/
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Channel *
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channel_lookup(struct ssh *ssh, int id)
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{
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Channel *c;
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if ((c = channel_by_id(ssh, id)) == NULL)
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return NULL;
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switch (c->type) {
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case SSH_CHANNEL_X11_OPEN:
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case SSH_CHANNEL_LARVAL:
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case SSH_CHANNEL_CONNECTING:
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case SSH_CHANNEL_DYNAMIC:
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case SSH_CHANNEL_RDYNAMIC_OPEN:
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case SSH_CHANNEL_RDYNAMIC_FINISH:
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case SSH_CHANNEL_OPENING:
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case SSH_CHANNEL_OPEN:
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case SSH_CHANNEL_ABANDONED:
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case SSH_CHANNEL_MUX_PROXY:
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return c;
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}
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logit("Non-public channel %d, type %d.", id, c->type);
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return NULL;
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}
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/*
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* Register filedescriptors for a channel, used when allocating a channel or
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* when the channel consumer/producer is ready, e.g. shell exec'd
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*/
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static void
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channel_register_fds(struct ssh *ssh, Channel *c, int rfd, int wfd, int efd,
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int extusage, int nonblock, int is_tty)
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{
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struct ssh_channels *sc = ssh->chanctxt;
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/* Update the maximum file descriptor value. */
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sc->channel_max_fd = MAXIMUM(sc->channel_max_fd, rfd);
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sc->channel_max_fd = MAXIMUM(sc->channel_max_fd, wfd);
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sc->channel_max_fd = MAXIMUM(sc->channel_max_fd, efd);
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if (rfd != -1)
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fcntl(rfd, F_SETFD, FD_CLOEXEC);
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if (wfd != -1 && wfd != rfd)
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fcntl(wfd, F_SETFD, FD_CLOEXEC);
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if (efd != -1 && efd != rfd && efd != wfd)
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fcntl(efd, F_SETFD, FD_CLOEXEC);
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c->rfd = rfd;
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c->wfd = wfd;
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c->sock = (rfd == wfd) ? rfd : -1;
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c->efd = efd;
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c->extended_usage = extusage;
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if ((c->isatty = is_tty) != 0)
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debug2("channel %d: rfd %d isatty", c->self, c->rfd);
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#ifdef _AIX
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/* XXX: Later AIX versions can't push as much data to tty */
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c->wfd_isatty = is_tty || isatty(c->wfd);
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#endif
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/* enable nonblocking mode */
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c->restore_block = 0;
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if (nonblock == CHANNEL_NONBLOCK_STDIO) {
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/*
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* Special handling for stdio file descriptors: do not set
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* non-blocking mode if they are TTYs. Otherwise prepare to
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* restore their blocking state on exit to avoid interfering
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* with other programs that follow.
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*/
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if (rfd != -1 && !isatty(rfd) && fcntl(rfd, F_GETFL) == 0) {
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c->restore_block |= CHANNEL_RESTORE_RFD;
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set_nonblock(rfd);
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}
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if (wfd != -1 && !isatty(wfd) && fcntl(wfd, F_GETFL) == 0) {
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c->restore_block |= CHANNEL_RESTORE_WFD;
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set_nonblock(wfd);
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}
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if (efd != -1 && !isatty(efd) && fcntl(efd, F_GETFL) == 0) {
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c->restore_block |= CHANNEL_RESTORE_EFD;
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set_nonblock(efd);
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}
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} else if (nonblock) {
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if (rfd != -1)
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set_nonblock(rfd);
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if (wfd != -1)
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set_nonblock(wfd);
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if (efd != -1)
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set_nonblock(efd);
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}
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}
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/*
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* Allocate a new channel object and set its type and socket. This will cause
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* remote_name to be freed.
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*/
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Channel *
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channel_new(struct ssh *ssh, char *ctype, int type, int rfd, int wfd, int efd,
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u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
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{
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struct ssh_channels *sc = ssh->chanctxt;
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u_int i, found;
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Channel *c;
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int r;
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/* Try to find a free slot where to put the new channel. */
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for (i = 0; i < sc->channels_alloc; i++) {
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if (sc->channels[i] == NULL) {
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/* Found a free slot. */
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found = i;
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break;
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}
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}
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if (i >= sc->channels_alloc) {
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/*
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* There are no free slots. Take last+1 slot and expand
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* the array.
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*/
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found = sc->channels_alloc;
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if (sc->channels_alloc > CHANNELS_MAX_CHANNELS)
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fatal_f("internal error: channels_alloc %d too big",
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sc->channels_alloc);
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sc->channels = xrecallocarray(sc->channels, sc->channels_alloc,
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sc->channels_alloc + 10, sizeof(*sc->channels));
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sc->channels_alloc += 10;
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debug2("channel: expanding %d", sc->channels_alloc);
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}
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/* Initialize and return new channel. */
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c = sc->channels[found] = xcalloc(1, sizeof(Channel));
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if ((c->input = sshbuf_new()) == NULL ||
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(c->output = sshbuf_new()) == NULL ||
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(c->extended = sshbuf_new()) == NULL)
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fatal_f("sshbuf_new failed");
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if ((r = sshbuf_set_max_size(c->input, CHAN_INPUT_MAX)) != 0)
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fatal_fr(r, "sshbuf_set_max_size");
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c->ostate = CHAN_OUTPUT_OPEN;
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c->istate = CHAN_INPUT_OPEN;
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channel_register_fds(ssh, c, rfd, wfd, efd, extusage, nonblock, 0);
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c->self = found;
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c->type = type;
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c->ctype = ctype;
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c->local_window = window;
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c->local_window_max = window;
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c->local_maxpacket = maxpack;
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c->remote_name = xstrdup(remote_name);
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c->ctl_chan = -1;
|
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c->delayed = 1; /* prevent call to channel_post handler */
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TAILQ_INIT(&c->status_confirms);
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debug("channel %d: new [%s]", found, remote_name);
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return c;
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}
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|
|
static void
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channel_find_maxfd(struct ssh_channels *sc)
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{
|
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u_int i;
|
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int max = 0;
|
|
Channel *c;
|
|
|
|
for (i = 0; i < sc->channels_alloc; i++) {
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c = sc->channels[i];
|
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if (c != NULL) {
|
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max = MAXIMUM(max, c->rfd);
|
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max = MAXIMUM(max, c->wfd);
|
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max = MAXIMUM(max, c->efd);
|
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}
|
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}
|
|
sc->channel_max_fd = max;
|
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}
|
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|
|
int
|
|
channel_close_fd(struct ssh *ssh, Channel *c, int *fdp)
|
|
{
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
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int ret, fd = *fdp;
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|
|
|
if (fd == -1)
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return 0;
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if ((*fdp == c->rfd && (c->restore_block & CHANNEL_RESTORE_RFD) != 0) ||
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(*fdp == c->wfd && (c->restore_block & CHANNEL_RESTORE_WFD) != 0) ||
|
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(*fdp == c->efd && (c->restore_block & CHANNEL_RESTORE_EFD) != 0))
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(void)fcntl(*fdp, F_SETFL, 0); /* restore blocking */
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|
|
ret = close(fd);
|
|
*fdp = -1;
|
|
if (fd == sc->channel_max_fd)
|
|
channel_find_maxfd(sc);
|
|
return ret;
|
|
}
|
|
|
|
/* Close all channel fd/socket. */
|
|
static void
|
|
channel_close_fds(struct ssh *ssh, Channel *c)
|
|
{
|
|
int sock = c->sock, rfd = c->rfd, wfd = c->wfd, efd = c->efd;
|
|
|
|
channel_close_fd(ssh, c, &c->sock);
|
|
if (rfd != sock)
|
|
channel_close_fd(ssh, c, &c->rfd);
|
|
if (wfd != sock && wfd != rfd)
|
|
channel_close_fd(ssh, c, &c->wfd);
|
|
if (efd != sock && efd != rfd && efd != wfd)
|
|
channel_close_fd(ssh, c, &c->efd);
|
|
}
|
|
|
|
static void
|
|
fwd_perm_clear(struct permission *perm)
|
|
{
|
|
free(perm->host_to_connect);
|
|
free(perm->listen_host);
|
|
free(perm->listen_path);
|
|
memset(perm, 0, sizeof(*perm));
|
|
}
|
|
|
|
/* Returns an printable name for the specified forwarding permission list */
|
|
static const char *
|
|
fwd_ident(int who, int where)
|
|
{
|
|
if (who == FORWARD_ADM) {
|
|
if (where == FORWARD_LOCAL)
|
|
return "admin local";
|
|
else if (where == FORWARD_REMOTE)
|
|
return "admin remote";
|
|
} else if (who == FORWARD_USER) {
|
|
if (where == FORWARD_LOCAL)
|
|
return "user local";
|
|
else if (where == FORWARD_REMOTE)
|
|
return "user remote";
|
|
}
|
|
fatal("Unknown forward permission list %d/%d", who, where);
|
|
}
|
|
|
|
/* Returns the forwarding permission list for the specified direction */
|
|
static struct permission_set *
|
|
permission_set_get(struct ssh *ssh, int where)
|
|
{
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
|
|
|
switch (where) {
|
|
case FORWARD_LOCAL:
|
|
return &sc->local_perms;
|
|
break;
|
|
case FORWARD_REMOTE:
|
|
return &sc->remote_perms;
|
|
break;
|
|
default:
|
|
fatal_f("invalid forwarding direction %d", where);
|
|
}
|
|
}
|
|
|
|
/* Returns pointers to the specified forwarding list and its element count */
|
|
static void
|
|
permission_set_get_array(struct ssh *ssh, int who, int where,
|
|
struct permission ***permpp, u_int **npermpp)
|
|
{
|
|
struct permission_set *pset = permission_set_get(ssh, where);
|
|
|
|
switch (who) {
|
|
case FORWARD_USER:
|
|
*permpp = &pset->permitted_user;
|
|
*npermpp = &pset->num_permitted_user;
|
|
break;
|
|
case FORWARD_ADM:
|
|
*permpp = &pset->permitted_admin;
|
|
*npermpp = &pset->num_permitted_admin;
|
|
break;
|
|
default:
|
|
fatal_f("invalid forwarding client %d", who);
|
|
}
|
|
}
|
|
|
|
/* Adds an entry to the spcified forwarding list */
|
|
static int
|
|
permission_set_add(struct ssh *ssh, int who, int where,
|
|
const char *host_to_connect, int port_to_connect,
|
|
const char *listen_host, const char *listen_path, int listen_port,
|
|
Channel *downstream)
|
|
{
|
|
struct permission **permp;
|
|
u_int n, *npermp;
|
|
|
|
permission_set_get_array(ssh, who, where, &permp, &npermp);
|
|
|
|
if (*npermp >= INT_MAX)
|
|
fatal_f("%s overflow", fwd_ident(who, where));
|
|
|
|
*permp = xrecallocarray(*permp, *npermp, *npermp + 1, sizeof(**permp));
|
|
n = (*npermp)++;
|
|
#define MAYBE_DUP(s) ((s == NULL) ? NULL : xstrdup(s))
|
|
(*permp)[n].host_to_connect = MAYBE_DUP(host_to_connect);
|
|
(*permp)[n].port_to_connect = port_to_connect;
|
|
(*permp)[n].listen_host = MAYBE_DUP(listen_host);
|
|
(*permp)[n].listen_path = MAYBE_DUP(listen_path);
|
|
(*permp)[n].listen_port = listen_port;
|
|
(*permp)[n].downstream = downstream;
|
|
#undef MAYBE_DUP
|
|
return (int)n;
|
|
}
|
|
|
|
static void
|
|
mux_remove_remote_forwardings(struct ssh *ssh, Channel *c)
|
|
{
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
|
struct permission_set *pset = &sc->local_perms;
|
|
struct permission *perm;
|
|
int r;
|
|
u_int i;
|
|
|
|
for (i = 0; i < pset->num_permitted_user; i++) {
|
|
perm = &pset->permitted_user[i];
|
|
if (perm->downstream != c)
|
|
continue;
|
|
|
|
/* cancel on the server, since mux client is gone */
|
|
debug("channel %d: cleanup remote forward for %s:%u",
|
|
c->self, perm->listen_host, perm->listen_port);
|
|
if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
|
|
(r = sshpkt_put_cstring(ssh,
|
|
"cancel-tcpip-forward")) != 0 ||
|
|
(r = sshpkt_put_u8(ssh, 0)) != 0 ||
|
|
(r = sshpkt_put_cstring(ssh,
|
|
channel_rfwd_bind_host(perm->listen_host))) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, perm->listen_port)) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0) {
|
|
fatal_fr(r, "channel %i", c->self);
|
|
}
|
|
fwd_perm_clear(perm); /* unregister */
|
|
}
|
|
}
|
|
|
|
/* Free the channel and close its fd/socket. */
|
|
void
|
|
channel_free(struct ssh *ssh, Channel *c)
|
|
{
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
|
char *s;
|
|
u_int i, n;
|
|
Channel *other;
|
|
struct channel_confirm *cc;
|
|
|
|
for (n = 0, i = 0; i < sc->channels_alloc; i++) {
|
|
if ((other = sc->channels[i]) == NULL)
|
|
continue;
|
|
n++;
|
|
/* detach from mux client and prepare for closing */
|
|
if (c->type == SSH_CHANNEL_MUX_CLIENT &&
|
|
other->type == SSH_CHANNEL_MUX_PROXY &&
|
|
other->mux_ctx == c) {
|
|
other->mux_ctx = NULL;
|
|
other->type = SSH_CHANNEL_OPEN;
|
|
other->istate = CHAN_INPUT_CLOSED;
|
|
other->ostate = CHAN_OUTPUT_CLOSED;
|
|
}
|
|
}
|
|
debug("channel %d: free: %s, nchannels %u", c->self,
|
|
c->remote_name ? c->remote_name : "???", n);
|
|
|
|
if (c->type == SSH_CHANNEL_MUX_CLIENT)
|
|
mux_remove_remote_forwardings(ssh, c);
|
|
else if (c->type == SSH_CHANNEL_MUX_LISTENER) {
|
|
free(c->mux_ctx);
|
|
c->mux_ctx = NULL;
|
|
}
|
|
|
|
if (log_level_get() >= SYSLOG_LEVEL_DEBUG3) {
|
|
s = channel_open_message(ssh);
|
|
debug3("channel %d: status: %s", c->self, s);
|
|
free(s);
|
|
}
|
|
|
|
channel_close_fds(ssh, c);
|
|
sshbuf_free(c->input);
|
|
sshbuf_free(c->output);
|
|
sshbuf_free(c->extended);
|
|
c->input = c->output = c->extended = NULL;
|
|
free(c->remote_name);
|
|
c->remote_name = NULL;
|
|
free(c->path);
|
|
c->path = NULL;
|
|
free(c->listening_addr);
|
|
c->listening_addr = NULL;
|
|
while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
|
|
if (cc->abandon_cb != NULL)
|
|
cc->abandon_cb(ssh, c, cc->ctx);
|
|
TAILQ_REMOVE(&c->status_confirms, cc, entry);
|
|
freezero(cc, sizeof(*cc));
|
|
}
|
|
if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
|
|
c->filter_cleanup(ssh, c->self, c->filter_ctx);
|
|
sc->channels[c->self] = NULL;
|
|
freezero(c, sizeof(*c));
|
|
}
|
|
|
|
void
|
|
channel_free_all(struct ssh *ssh)
|
|
{
|
|
u_int i;
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
|
|
|
for (i = 0; i < sc->channels_alloc; i++)
|
|
if (sc->channels[i] != NULL)
|
|
channel_free(ssh, sc->channels[i]);
|
|
|
|
free(sc->channels);
|
|
sc->channels = NULL;
|
|
sc->channels_alloc = 0;
|
|
sc->channel_max_fd = 0;
|
|
|
|
free(sc->x11_saved_display);
|
|
sc->x11_saved_display = NULL;
|
|
|
|
free(sc->x11_saved_proto);
|
|
sc->x11_saved_proto = NULL;
|
|
|
|
free(sc->x11_saved_data);
|
|
sc->x11_saved_data = NULL;
|
|
sc->x11_saved_data_len = 0;
|
|
|
|
free(sc->x11_fake_data);
|
|
sc->x11_fake_data = NULL;
|
|
sc->x11_fake_data_len = 0;
|
|
}
|
|
|
|
/*
|
|
* Closes the sockets/fds of all channels. This is used to close extra file
|
|
* descriptors after a fork.
|
|
*/
|
|
void
|
|
channel_close_all(struct ssh *ssh)
|
|
{
|
|
u_int i;
|
|
|
|
for (i = 0; i < ssh->chanctxt->channels_alloc; i++)
|
|
if (ssh->chanctxt->channels[i] != NULL)
|
|
channel_close_fds(ssh, ssh->chanctxt->channels[i]);
|
|
}
|
|
|
|
/*
|
|
* Stop listening to channels.
|
|
*/
|
|
void
|
|
channel_stop_listening(struct ssh *ssh)
|
|
{
|
|
u_int i;
|
|
Channel *c;
|
|
|
|
for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
|
|
c = ssh->chanctxt->channels[i];
|
|
if (c != NULL) {
|
|
switch (c->type) {
|
|
case SSH_CHANNEL_AUTH_SOCKET:
|
|
case SSH_CHANNEL_PORT_LISTENER:
|
|
case SSH_CHANNEL_RPORT_LISTENER:
|
|
case SSH_CHANNEL_X11_LISTENER:
|
|
case SSH_CHANNEL_UNIX_LISTENER:
|
|
case SSH_CHANNEL_RUNIX_LISTENER:
|
|
channel_close_fd(ssh, c, &c->sock);
|
|
channel_free(ssh, c);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Returns true if no channel has too much buffered data, and false if one or
|
|
* more channel is overfull.
|
|
*/
|
|
int
|
|
channel_not_very_much_buffered_data(struct ssh *ssh)
|
|
{
|
|
u_int i;
|
|
u_int maxsize = ssh_packet_get_maxsize(ssh);
|
|
Channel *c;
|
|
|
|
for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
|
|
c = ssh->chanctxt->channels[i];
|
|
if (c == NULL || c->type != SSH_CHANNEL_OPEN)
|
|
continue;
|
|
if (sshbuf_len(c->output) > maxsize) {
|
|
debug2("channel %d: big output buffer %zu > %u",
|
|
c->self, sshbuf_len(c->output), maxsize);
|
|
return 0;
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/* Returns true if any channel is still open. */
|
|
int
|
|
channel_still_open(struct ssh *ssh)
|
|
{
|
|
u_int i;
|
|
Channel *c;
|
|
|
|
for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
|
|
c = ssh->chanctxt->channels[i];
|
|
if (c == NULL)
|
|
continue;
|
|
switch (c->type) {
|
|
case SSH_CHANNEL_X11_LISTENER:
|
|
case SSH_CHANNEL_PORT_LISTENER:
|
|
case SSH_CHANNEL_RPORT_LISTENER:
|
|
case SSH_CHANNEL_MUX_LISTENER:
|
|
case SSH_CHANNEL_CLOSED:
|
|
case SSH_CHANNEL_AUTH_SOCKET:
|
|
case SSH_CHANNEL_DYNAMIC:
|
|
case SSH_CHANNEL_RDYNAMIC_OPEN:
|
|
case SSH_CHANNEL_CONNECTING:
|
|
case SSH_CHANNEL_ZOMBIE:
|
|
case SSH_CHANNEL_ABANDONED:
|
|
case SSH_CHANNEL_UNIX_LISTENER:
|
|
case SSH_CHANNEL_RUNIX_LISTENER:
|
|
continue;
|
|
case SSH_CHANNEL_LARVAL:
|
|
continue;
|
|
case SSH_CHANNEL_OPENING:
|
|
case SSH_CHANNEL_OPEN:
|
|
case SSH_CHANNEL_RDYNAMIC_FINISH:
|
|
case SSH_CHANNEL_X11_OPEN:
|
|
case SSH_CHANNEL_MUX_CLIENT:
|
|
case SSH_CHANNEL_MUX_PROXY:
|
|
return 1;
|
|
default:
|
|
fatal_f("bad channel type %d", c->type);
|
|
/* NOTREACHED */
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Returns the id of an open channel suitable for keepaliving */
|
|
int
|
|
channel_find_open(struct ssh *ssh)
|
|
{
|
|
u_int i;
|
|
Channel *c;
|
|
|
|
for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
|
|
c = ssh->chanctxt->channels[i];
|
|
if (c == NULL || !c->have_remote_id)
|
|
continue;
|
|
switch (c->type) {
|
|
case SSH_CHANNEL_CLOSED:
|
|
case SSH_CHANNEL_DYNAMIC:
|
|
case SSH_CHANNEL_RDYNAMIC_OPEN:
|
|
case SSH_CHANNEL_RDYNAMIC_FINISH:
|
|
case SSH_CHANNEL_X11_LISTENER:
|
|
case SSH_CHANNEL_PORT_LISTENER:
|
|
case SSH_CHANNEL_RPORT_LISTENER:
|
|
case SSH_CHANNEL_MUX_LISTENER:
|
|
case SSH_CHANNEL_MUX_CLIENT:
|
|
case SSH_CHANNEL_MUX_PROXY:
|
|
case SSH_CHANNEL_OPENING:
|
|
case SSH_CHANNEL_CONNECTING:
|
|
case SSH_CHANNEL_ZOMBIE:
|
|
case SSH_CHANNEL_ABANDONED:
|
|
case SSH_CHANNEL_UNIX_LISTENER:
|
|
case SSH_CHANNEL_RUNIX_LISTENER:
|
|
continue;
|
|
case SSH_CHANNEL_LARVAL:
|
|
case SSH_CHANNEL_AUTH_SOCKET:
|
|
case SSH_CHANNEL_OPEN:
|
|
case SSH_CHANNEL_X11_OPEN:
|
|
return i;
|
|
default:
|
|
fatal_f("bad channel type %d", c->type);
|
|
/* NOTREACHED */
|
|
}
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
/* Returns the state of the channel's extended usage flag */
|
|
const char *
|
|
channel_format_extended_usage(const Channel *c)
|
|
{
|
|
if (c->efd == -1)
|
|
return "closed";
|
|
|
|
switch (c->extended_usage) {
|
|
case CHAN_EXTENDED_WRITE:
|
|
return "write";
|
|
case CHAN_EXTENDED_READ:
|
|
return "read";
|
|
case CHAN_EXTENDED_IGNORE:
|
|
return "ignore";
|
|
default:
|
|
return "UNKNOWN";
|
|
}
|
|
}
|
|
|
|
static char *
|
|
channel_format_status(const Channel *c)
|
|
{
|
|
char *ret = NULL;
|
|
|
|
xasprintf(&ret, "t%d %s%u i%u/%zu o%u/%zu e[%s]/%zu "
|
|
"fd %d/%d/%d sock %d cc %d",
|
|
c->type,
|
|
c->have_remote_id ? "r" : "nr", c->remote_id,
|
|
c->istate, sshbuf_len(c->input),
|
|
c->ostate, sshbuf_len(c->output),
|
|
channel_format_extended_usage(c), sshbuf_len(c->extended),
|
|
c->rfd, c->wfd, c->efd, c->sock, c->ctl_chan);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Returns a message describing the currently open forwarded connections,
|
|
* suitable for sending to the client. The message contains crlf pairs for
|
|
* newlines.
|
|
*/
|
|
char *
|
|
channel_open_message(struct ssh *ssh)
|
|
{
|
|
struct sshbuf *buf;
|
|
Channel *c;
|
|
u_int i;
|
|
int r;
|
|
char *cp, *ret;
|
|
|
|
if ((buf = sshbuf_new()) == NULL)
|
|
fatal_f("sshbuf_new");
|
|
if ((r = sshbuf_putf(buf,
|
|
"The following connections are open:\r\n")) != 0)
|
|
fatal_fr(r, "sshbuf_putf");
|
|
for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
|
|
c = ssh->chanctxt->channels[i];
|
|
if (c == NULL)
|
|
continue;
|
|
switch (c->type) {
|
|
case SSH_CHANNEL_X11_LISTENER:
|
|
case SSH_CHANNEL_PORT_LISTENER:
|
|
case SSH_CHANNEL_RPORT_LISTENER:
|
|
case SSH_CHANNEL_CLOSED:
|
|
case SSH_CHANNEL_AUTH_SOCKET:
|
|
case SSH_CHANNEL_ZOMBIE:
|
|
case SSH_CHANNEL_ABANDONED:
|
|
case SSH_CHANNEL_MUX_LISTENER:
|
|
case SSH_CHANNEL_UNIX_LISTENER:
|
|
case SSH_CHANNEL_RUNIX_LISTENER:
|
|
continue;
|
|
case SSH_CHANNEL_LARVAL:
|
|
case SSH_CHANNEL_OPENING:
|
|
case SSH_CHANNEL_CONNECTING:
|
|
case SSH_CHANNEL_DYNAMIC:
|
|
case SSH_CHANNEL_RDYNAMIC_OPEN:
|
|
case SSH_CHANNEL_RDYNAMIC_FINISH:
|
|
case SSH_CHANNEL_OPEN:
|
|
case SSH_CHANNEL_X11_OPEN:
|
|
case SSH_CHANNEL_MUX_PROXY:
|
|
case SSH_CHANNEL_MUX_CLIENT:
|
|
cp = channel_format_status(c);
|
|
if ((r = sshbuf_putf(buf, " #%d %.300s (%s)\r\n",
|
|
c->self, c->remote_name, cp)) != 0) {
|
|
free(cp);
|
|
fatal_fr(r, "sshbuf_putf");
|
|
}
|
|
free(cp);
|
|
continue;
|
|
default:
|
|
fatal_f("bad channel type %d", c->type);
|
|
/* NOTREACHED */
|
|
}
|
|
}
|
|
if ((ret = sshbuf_dup_string(buf)) == NULL)
|
|
fatal_f("sshbuf_dup_string");
|
|
sshbuf_free(buf);
|
|
return ret;
|
|
}
|
|
|
|
static void
|
|
open_preamble(struct ssh *ssh, const char *where, Channel *c, const char *type)
|
|
{
|
|
int r;
|
|
|
|
if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN)) != 0 ||
|
|
(r = sshpkt_put_cstring(ssh, type)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->self)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0) {
|
|
fatal_r(r, "%s: channel %i: open", where, c->self);
|
|
}
|
|
}
|
|
|
|
void
|
|
channel_send_open(struct ssh *ssh, int id)
|
|
{
|
|
Channel *c = channel_lookup(ssh, id);
|
|
int r;
|
|
|
|
if (c == NULL) {
|
|
logit("channel_send_open: %d: bad id", id);
|
|
return;
|
|
}
|
|
debug2("channel %d: send open", id);
|
|
open_preamble(ssh, __func__, c, c->ctype);
|
|
if ((r = sshpkt_send(ssh)) != 0)
|
|
fatal_fr(r, "channel %i", c->self);
|
|
}
|
|
|
|
void
|
|
channel_request_start(struct ssh *ssh, int id, char *service, int wantconfirm)
|
|
{
|
|
Channel *c = channel_lookup(ssh, id);
|
|
int r;
|
|
|
|
if (c == NULL) {
|
|
logit_f("%d: unknown channel id", id);
|
|
return;
|
|
}
|
|
if (!c->have_remote_id)
|
|
fatal_f("channel %d: no remote id", c->self);
|
|
|
|
debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
|
|
if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_REQUEST)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
|
|
(r = sshpkt_put_cstring(ssh, service)) != 0 ||
|
|
(r = sshpkt_put_u8(ssh, wantconfirm)) != 0) {
|
|
fatal_fr(r, "channel %i", c->self);
|
|
}
|
|
}
|
|
|
|
void
|
|
channel_register_status_confirm(struct ssh *ssh, int id,
|
|
channel_confirm_cb *cb, channel_confirm_abandon_cb *abandon_cb, void *ctx)
|
|
{
|
|
struct channel_confirm *cc;
|
|
Channel *c;
|
|
|
|
if ((c = channel_lookup(ssh, id)) == NULL)
|
|
fatal_f("%d: bad id", id);
|
|
|
|
cc = xcalloc(1, sizeof(*cc));
|
|
cc->cb = cb;
|
|
cc->abandon_cb = abandon_cb;
|
|
cc->ctx = ctx;
|
|
TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
|
|
}
|
|
|
|
void
|
|
channel_register_open_confirm(struct ssh *ssh, int id,
|
|
channel_open_fn *fn, void *ctx)
|
|
{
|
|
Channel *c = channel_lookup(ssh, id);
|
|
|
|
if (c == NULL) {
|
|
logit_f("%d: bad id", id);
|
|
return;
|
|
}
|
|
c->open_confirm = fn;
|
|
c->open_confirm_ctx = ctx;
|
|
}
|
|
|
|
void
|
|
channel_register_cleanup(struct ssh *ssh, int id,
|
|
channel_callback_fn *fn, int do_close)
|
|
{
|
|
Channel *c = channel_by_id(ssh, id);
|
|
|
|
if (c == NULL) {
|
|
logit_f("%d: bad id", id);
|
|
return;
|
|
}
|
|
c->detach_user = fn;
|
|
c->detach_close = do_close;
|
|
}
|
|
|
|
void
|
|
channel_cancel_cleanup(struct ssh *ssh, int id)
|
|
{
|
|
Channel *c = channel_by_id(ssh, id);
|
|
|
|
if (c == NULL) {
|
|
logit_f("%d: bad id", id);
|
|
return;
|
|
}
|
|
c->detach_user = NULL;
|
|
c->detach_close = 0;
|
|
}
|
|
|
|
void
|
|
channel_register_filter(struct ssh *ssh, int id, channel_infilter_fn *ifn,
|
|
channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
|
|
{
|
|
Channel *c = channel_lookup(ssh, id);
|
|
|
|
if (c == NULL) {
|
|
logit_f("%d: bad id", id);
|
|
return;
|
|
}
|
|
c->input_filter = ifn;
|
|
c->output_filter = ofn;
|
|
c->filter_ctx = ctx;
|
|
c->filter_cleanup = cfn;
|
|
}
|
|
|
|
void
|
|
channel_set_fds(struct ssh *ssh, int id, int rfd, int wfd, int efd,
|
|
int extusage, int nonblock, int is_tty, u_int window_max)
|
|
{
|
|
Channel *c = channel_lookup(ssh, id);
|
|
int r;
|
|
|
|
if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
|
|
fatal("channel_activate for non-larval channel %d.", id);
|
|
if (!c->have_remote_id)
|
|
fatal_f("channel %d: no remote id", c->self);
|
|
|
|
channel_register_fds(ssh, c, rfd, wfd, efd, extusage, nonblock, is_tty);
|
|
c->type = SSH_CHANNEL_OPEN;
|
|
c->local_window = c->local_window_max = window_max;
|
|
|
|
if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0)
|
|
fatal_fr(r, "channel %i", c->self);
|
|
}
|
|
|
|
static void
|
|
channel_pre_listener(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
FD_SET(c->sock, readset);
|
|
}
|
|
|
|
static void
|
|
channel_pre_connecting(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
debug3("channel %d: waiting for connection", c->self);
|
|
FD_SET(c->sock, writeset);
|
|
}
|
|
|
|
static void
|
|
channel_pre_open(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
if (c->istate == CHAN_INPUT_OPEN &&
|
|
c->remote_window > 0 &&
|
|
sshbuf_len(c->input) < c->remote_window &&
|
|
sshbuf_check_reserve(c->input, CHAN_RBUF) == 0)
|
|
FD_SET(c->rfd, readset);
|
|
if (c->ostate == CHAN_OUTPUT_OPEN ||
|
|
c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
|
|
if (sshbuf_len(c->output) > 0) {
|
|
FD_SET(c->wfd, writeset);
|
|
} else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
|
|
if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
|
|
debug2("channel %d: "
|
|
"obuf_empty delayed efd %d/(%zu)", c->self,
|
|
c->efd, sshbuf_len(c->extended));
|
|
else
|
|
chan_obuf_empty(ssh, c);
|
|
}
|
|
}
|
|
/** XXX check close conditions, too */
|
|
if (c->efd != -1 && !(c->istate == CHAN_INPUT_CLOSED &&
|
|
c->ostate == CHAN_OUTPUT_CLOSED)) {
|
|
if (c->extended_usage == CHAN_EXTENDED_WRITE &&
|
|
sshbuf_len(c->extended) > 0)
|
|
FD_SET(c->efd, writeset);
|
|
else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
|
|
(c->extended_usage == CHAN_EXTENDED_READ ||
|
|
c->extended_usage == CHAN_EXTENDED_IGNORE) &&
|
|
sshbuf_len(c->extended) < c->remote_window)
|
|
FD_SET(c->efd, readset);
|
|
}
|
|
/* XXX: What about efd? races? */
|
|
}
|
|
|
|
/*
|
|
* This is a special state for X11 authentication spoofing. An opened X11
|
|
* connection (when authentication spoofing is being done) remains in this
|
|
* state until the first packet has been completely read. The authentication
|
|
* data in that packet is then substituted by the real data if it matches the
|
|
* fake data, and the channel is put into normal mode.
|
|
* XXX All this happens at the client side.
|
|
* Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
|
|
*/
|
|
static int
|
|
x11_open_helper(struct ssh *ssh, struct sshbuf *b)
|
|
{
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
|
u_char *ucp;
|
|
u_int proto_len, data_len;
|
|
|
|
/* Is this being called after the refusal deadline? */
|
|
if (sc->x11_refuse_time != 0 &&
|
|
(u_int)monotime() >= sc->x11_refuse_time) {
|
|
verbose("Rejected X11 connection after ForwardX11Timeout "
|
|
"expired");
|
|
return -1;
|
|
}
|
|
|
|
/* Check if the fixed size part of the packet is in buffer. */
|
|
if (sshbuf_len(b) < 12)
|
|
return 0;
|
|
|
|
/* Parse the lengths of variable-length fields. */
|
|
ucp = sshbuf_mutable_ptr(b);
|
|
if (ucp[0] == 0x42) { /* Byte order MSB first. */
|
|
proto_len = 256 * ucp[6] + ucp[7];
|
|
data_len = 256 * ucp[8] + ucp[9];
|
|
} else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
|
|
proto_len = ucp[6] + 256 * ucp[7];
|
|
data_len = ucp[8] + 256 * ucp[9];
|
|
} else {
|
|
debug2("Initial X11 packet contains bad byte order byte: 0x%x",
|
|
ucp[0]);
|
|
return -1;
|
|
}
|
|
|
|
/* Check if the whole packet is in buffer. */
|
|
if (sshbuf_len(b) <
|
|
12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
|
|
return 0;
|
|
|
|
/* Check if authentication protocol matches. */
|
|
if (proto_len != strlen(sc->x11_saved_proto) ||
|
|
memcmp(ucp + 12, sc->x11_saved_proto, proto_len) != 0) {
|
|
debug2("X11 connection uses different authentication protocol.");
|
|
return -1;
|
|
}
|
|
/* Check if authentication data matches our fake data. */
|
|
if (data_len != sc->x11_fake_data_len ||
|
|
timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
|
|
sc->x11_fake_data, sc->x11_fake_data_len) != 0) {
|
|
debug2("X11 auth data does not match fake data.");
|
|
return -1;
|
|
}
|
|
/* Check fake data length */
|
|
if (sc->x11_fake_data_len != sc->x11_saved_data_len) {
|
|
error("X11 fake_data_len %d != saved_data_len %d",
|
|
sc->x11_fake_data_len, sc->x11_saved_data_len);
|
|
return -1;
|
|
}
|
|
/*
|
|
* Received authentication protocol and data match
|
|
* our fake data. Substitute the fake data with real
|
|
* data.
|
|
*/
|
|
memcpy(ucp + 12 + ((proto_len + 3) & ~3),
|
|
sc->x11_saved_data, sc->x11_saved_data_len);
|
|
return 1;
|
|
}
|
|
|
|
static void
|
|
channel_pre_x11_open(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
int ret = x11_open_helper(ssh, c->output);
|
|
|
|
/* c->force_drain = 1; */
|
|
|
|
if (ret == 1) {
|
|
c->type = SSH_CHANNEL_OPEN;
|
|
channel_pre_open(ssh, c, readset, writeset);
|
|
} else if (ret == -1) {
|
|
logit("X11 connection rejected because of wrong authentication.");
|
|
debug2("X11 rejected %d i%d/o%d",
|
|
c->self, c->istate, c->ostate);
|
|
chan_read_failed(ssh, c);
|
|
sshbuf_reset(c->input);
|
|
chan_ibuf_empty(ssh, c);
|
|
sshbuf_reset(c->output);
|
|
chan_write_failed(ssh, c);
|
|
debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
|
|
}
|
|
}
|
|
|
|
static void
|
|
channel_pre_mux_client(struct ssh *ssh,
|
|
Channel *c, fd_set *readset, fd_set *writeset)
|
|
{
|
|
if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
|
|
sshbuf_check_reserve(c->input, CHAN_RBUF) == 0)
|
|
FD_SET(c->rfd, readset);
|
|
if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
|
|
/* clear buffer immediately (discard any partial packet) */
|
|
sshbuf_reset(c->input);
|
|
chan_ibuf_empty(ssh, c);
|
|
/* Start output drain. XXX just kill chan? */
|
|
chan_rcvd_oclose(ssh, c);
|
|
}
|
|
if (c->ostate == CHAN_OUTPUT_OPEN ||
|
|
c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
|
|
if (sshbuf_len(c->output) > 0)
|
|
FD_SET(c->wfd, writeset);
|
|
else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
|
|
chan_obuf_empty(ssh, c);
|
|
}
|
|
}
|
|
|
|
/* try to decode a socks4 header */
|
|
static int
|
|
channel_decode_socks4(Channel *c, struct sshbuf *input, struct sshbuf *output)
|
|
{
|
|
const u_char *p;
|
|
char *host;
|
|
u_int len, have, i, found, need;
|
|
char username[256];
|
|
struct {
|
|
u_int8_t version;
|
|
u_int8_t command;
|
|
u_int16_t dest_port;
|
|
struct in_addr dest_addr;
|
|
} s4_req, s4_rsp;
|
|
int r;
|
|
|
|
debug2("channel %d: decode socks4", c->self);
|
|
|
|
have = sshbuf_len(input);
|
|
len = sizeof(s4_req);
|
|
if (have < len)
|
|
return 0;
|
|
p = sshbuf_ptr(input);
|
|
|
|
need = 1;
|
|
/* SOCKS4A uses an invalid IP address 0.0.0.x */
|
|
if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
|
|
debug2("channel %d: socks4a request", c->self);
|
|
/* ... and needs an extra string (the hostname) */
|
|
need = 2;
|
|
}
|
|
/* Check for terminating NUL on the string(s) */
|
|
for (found = 0, i = len; i < have; i++) {
|
|
if (p[i] == '\0') {
|
|
found++;
|
|
if (found == need)
|
|
break;
|
|
}
|
|
if (i > 1024) {
|
|
/* the peer is probably sending garbage */
|
|
debug("channel %d: decode socks4: too long",
|
|
c->self);
|
|
return -1;
|
|
}
|
|
}
|
|
if (found < need)
|
|
return 0;
|
|
if ((r = sshbuf_get(input, &s4_req.version, 1)) != 0 ||
|
|
(r = sshbuf_get(input, &s4_req.command, 1)) != 0 ||
|
|
(r = sshbuf_get(input, &s4_req.dest_port, 2)) != 0 ||
|
|
(r = sshbuf_get(input, &s4_req.dest_addr, 4)) != 0) {
|
|
debug_r(r, "channels %d: decode socks4", c->self);
|
|
return -1;
|
|
}
|
|
have = sshbuf_len(input);
|
|
p = sshbuf_ptr(input);
|
|
if (memchr(p, '\0', have) == NULL) {
|
|
error("channel %d: decode socks4: unterminated user", c->self);
|
|
return -1;
|
|
}
|
|
len = strlen(p);
|
|
debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
|
|
len++; /* trailing '\0' */
|
|
strlcpy(username, p, sizeof(username));
|
|
if ((r = sshbuf_consume(input, len)) != 0)
|
|
fatal_fr(r, "channel %d: consume", c->self);
|
|
free(c->path);
|
|
c->path = NULL;
|
|
if (need == 1) { /* SOCKS4: one string */
|
|
host = inet_ntoa(s4_req.dest_addr);
|
|
c->path = xstrdup(host);
|
|
} else { /* SOCKS4A: two strings */
|
|
have = sshbuf_len(input);
|
|
p = sshbuf_ptr(input);
|
|
if (memchr(p, '\0', have) == NULL) {
|
|
error("channel %d: decode socks4a: host not nul "
|
|
"terminated", c->self);
|
|
return -1;
|
|
}
|
|
len = strlen(p);
|
|
debug2("channel %d: decode socks4a: host %s/%d",
|
|
c->self, p, len);
|
|
len++; /* trailing '\0' */
|
|
if (len > NI_MAXHOST) {
|
|
error("channel %d: hostname \"%.100s\" too long",
|
|
c->self, p);
|
|
return -1;
|
|
}
|
|
c->path = xstrdup(p);
|
|
if ((r = sshbuf_consume(input, len)) != 0)
|
|
fatal_fr(r, "channel %d: consume", c->self);
|
|
}
|
|
c->host_port = ntohs(s4_req.dest_port);
|
|
|
|
debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
|
|
c->self, c->path, c->host_port, s4_req.command);
|
|
|
|
if (s4_req.command != 1) {
|
|
debug("channel %d: cannot handle: %s cn %d",
|
|
c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
|
|
return -1;
|
|
}
|
|
s4_rsp.version = 0; /* vn: 0 for reply */
|
|
s4_rsp.command = 90; /* cd: req granted */
|
|
s4_rsp.dest_port = 0; /* ignored */
|
|
s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
|
|
if ((r = sshbuf_put(output, &s4_rsp, sizeof(s4_rsp))) != 0)
|
|
fatal_fr(r, "channel %d: append reply", c->self);
|
|
return 1;
|
|
}
|
|
|
|
/* try to decode a socks5 header */
|
|
#define SSH_SOCKS5_AUTHDONE 0x1000
|
|
#define SSH_SOCKS5_NOAUTH 0x00
|
|
#define SSH_SOCKS5_IPV4 0x01
|
|
#define SSH_SOCKS5_DOMAIN 0x03
|
|
#define SSH_SOCKS5_IPV6 0x04
|
|
#define SSH_SOCKS5_CONNECT 0x01
|
|
#define SSH_SOCKS5_SUCCESS 0x00
|
|
|
|
static int
|
|
channel_decode_socks5(Channel *c, struct sshbuf *input, struct sshbuf *output)
|
|
{
|
|
/* XXX use get/put_u8 instead of trusting struct padding */
|
|
struct {
|
|
u_int8_t version;
|
|
u_int8_t command;
|
|
u_int8_t reserved;
|
|
u_int8_t atyp;
|
|
} s5_req, s5_rsp;
|
|
u_int16_t dest_port;
|
|
char dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
|
|
const u_char *p;
|
|
u_int have, need, i, found, nmethods, addrlen, af;
|
|
int r;
|
|
|
|
debug2("channel %d: decode socks5", c->self);
|
|
p = sshbuf_ptr(input);
|
|
if (p[0] != 0x05)
|
|
return -1;
|
|
have = sshbuf_len(input);
|
|
if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
|
|
/* format: ver | nmethods | methods */
|
|
if (have < 2)
|
|
return 0;
|
|
nmethods = p[1];
|
|
if (have < nmethods + 2)
|
|
return 0;
|
|
/* look for method: "NO AUTHENTICATION REQUIRED" */
|
|
for (found = 0, i = 2; i < nmethods + 2; i++) {
|
|
if (p[i] == SSH_SOCKS5_NOAUTH) {
|
|
found = 1;
|
|
break;
|
|
}
|
|
}
|
|
if (!found) {
|
|
debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
|
|
c->self);
|
|
return -1;
|
|
}
|
|
if ((r = sshbuf_consume(input, nmethods + 2)) != 0)
|
|
fatal_fr(r, "channel %d: consume", c->self);
|
|
/* version, method */
|
|
if ((r = sshbuf_put_u8(output, 0x05)) != 0 ||
|
|
(r = sshbuf_put_u8(output, SSH_SOCKS5_NOAUTH)) != 0)
|
|
fatal_fr(r, "channel %d: append reply", c->self);
|
|
c->flags |= SSH_SOCKS5_AUTHDONE;
|
|
debug2("channel %d: socks5 auth done", c->self);
|
|
return 0; /* need more */
|
|
}
|
|
debug2("channel %d: socks5 post auth", c->self);
|
|
if (have < sizeof(s5_req)+1)
|
|
return 0; /* need more */
|
|
memcpy(&s5_req, p, sizeof(s5_req));
|
|
if (s5_req.version != 0x05 ||
|
|
s5_req.command != SSH_SOCKS5_CONNECT ||
|
|
s5_req.reserved != 0x00) {
|
|
debug2("channel %d: only socks5 connect supported", c->self);
|
|
return -1;
|
|
}
|
|
switch (s5_req.atyp){
|
|
case SSH_SOCKS5_IPV4:
|
|
addrlen = 4;
|
|
af = AF_INET;
|
|
break;
|
|
case SSH_SOCKS5_DOMAIN:
|
|
addrlen = p[sizeof(s5_req)];
|
|
af = -1;
|
|
break;
|
|
case SSH_SOCKS5_IPV6:
|
|
addrlen = 16;
|
|
af = AF_INET6;
|
|
break;
|
|
default:
|
|
debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
|
|
return -1;
|
|
}
|
|
need = sizeof(s5_req) + addrlen + 2;
|
|
if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
|
|
need++;
|
|
if (have < need)
|
|
return 0;
|
|
if ((r = sshbuf_consume(input, sizeof(s5_req))) != 0)
|
|
fatal_fr(r, "channel %d: consume", c->self);
|
|
if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
|
|
/* host string length */
|
|
if ((r = sshbuf_consume(input, 1)) != 0)
|
|
fatal_fr(r, "channel %d: consume", c->self);
|
|
}
|
|
if ((r = sshbuf_get(input, &dest_addr, addrlen)) != 0 ||
|
|
(r = sshbuf_get(input, &dest_port, 2)) != 0) {
|
|
debug_r(r, "channel %d: parse addr/port", c->self);
|
|
return -1;
|
|
}
|
|
dest_addr[addrlen] = '\0';
|
|
free(c->path);
|
|
c->path = NULL;
|
|
if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
|
|
if (addrlen >= NI_MAXHOST) {
|
|
error("channel %d: dynamic request: socks5 hostname "
|
|
"\"%.100s\" too long", c->self, dest_addr);
|
|
return -1;
|
|
}
|
|
c->path = xstrdup(dest_addr);
|
|
} else {
|
|
if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
|
|
return -1;
|
|
c->path = xstrdup(ntop);
|
|
}
|
|
c->host_port = ntohs(dest_port);
|
|
|
|
debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
|
|
c->self, c->path, c->host_port, s5_req.command);
|
|
|
|
s5_rsp.version = 0x05;
|
|
s5_rsp.command = SSH_SOCKS5_SUCCESS;
|
|
s5_rsp.reserved = 0; /* ignored */
|
|
s5_rsp.atyp = SSH_SOCKS5_IPV4;
|
|
dest_port = 0; /* ignored */
|
|
|
|
if ((r = sshbuf_put(output, &s5_rsp, sizeof(s5_rsp))) != 0 ||
|
|
(r = sshbuf_put_u32(output, ntohl(INADDR_ANY))) != 0 ||
|
|
(r = sshbuf_put(output, &dest_port, sizeof(dest_port))) != 0)
|
|
fatal_fr(r, "channel %d: append reply", c->self);
|
|
return 1;
|
|
}
|
|
|
|
Channel *
|
|
channel_connect_stdio_fwd(struct ssh *ssh,
|
|
const char *host_to_connect, u_short port_to_connect,
|
|
int in, int out, int nonblock)
|
|
{
|
|
Channel *c;
|
|
|
|
debug_f("%s:%d", host_to_connect, port_to_connect);
|
|
|
|
c = channel_new(ssh, "stdio-forward", SSH_CHANNEL_OPENING, in, out,
|
|
-1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
|
|
0, "stdio-forward", nonblock);
|
|
|
|
c->path = xstrdup(host_to_connect);
|
|
c->host_port = port_to_connect;
|
|
c->listening_port = 0;
|
|
c->force_drain = 1;
|
|
|
|
channel_register_fds(ssh, c, in, out, -1, 0, 1, 0);
|
|
port_open_helper(ssh, c, "direct-tcpip");
|
|
|
|
return c;
|
|
}
|
|
|
|
/* dynamic port forwarding */
|
|
static void
|
|
channel_pre_dynamic(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
const u_char *p;
|
|
u_int have;
|
|
int ret;
|
|
|
|
have = sshbuf_len(c->input);
|
|
debug2("channel %d: pre_dynamic: have %d", c->self, have);
|
|
/* sshbuf_dump(c->input, stderr); */
|
|
/* check if the fixed size part of the packet is in buffer. */
|
|
if (have < 3) {
|
|
/* need more */
|
|
FD_SET(c->sock, readset);
|
|
return;
|
|
}
|
|
/* try to guess the protocol */
|
|
p = sshbuf_ptr(c->input);
|
|
/* XXX sshbuf_peek_u8? */
|
|
switch (p[0]) {
|
|
case 0x04:
|
|
ret = channel_decode_socks4(c, c->input, c->output);
|
|
break;
|
|
case 0x05:
|
|
ret = channel_decode_socks5(c, c->input, c->output);
|
|
break;
|
|
default:
|
|
ret = -1;
|
|
break;
|
|
}
|
|
if (ret < 0) {
|
|
chan_mark_dead(ssh, c);
|
|
} else if (ret == 0) {
|
|
debug2("channel %d: pre_dynamic: need more", c->self);
|
|
/* need more */
|
|
FD_SET(c->sock, readset);
|
|
if (sshbuf_len(c->output))
|
|
FD_SET(c->sock, writeset);
|
|
} else {
|
|
/* switch to the next state */
|
|
c->type = SSH_CHANNEL_OPENING;
|
|
port_open_helper(ssh, c, "direct-tcpip");
|
|
}
|
|
}
|
|
|
|
/* simulate read-error */
|
|
static void
|
|
rdynamic_close(struct ssh *ssh, Channel *c)
|
|
{
|
|
c->type = SSH_CHANNEL_OPEN;
|
|
chan_read_failed(ssh, c);
|
|
sshbuf_reset(c->input);
|
|
chan_ibuf_empty(ssh, c);
|
|
sshbuf_reset(c->output);
|
|
chan_write_failed(ssh, c);
|
|
}
|
|
|
|
/* reverse dynamic port forwarding */
|
|
static void
|
|
channel_before_prepare_select_rdynamic(struct ssh *ssh, Channel *c)
|
|
{
|
|
const u_char *p;
|
|
u_int have, len;
|
|
int r, ret;
|
|
|
|
have = sshbuf_len(c->output);
|
|
debug2("channel %d: pre_rdynamic: have %d", c->self, have);
|
|
/* sshbuf_dump(c->output, stderr); */
|
|
/* EOF received */
|
|
if (c->flags & CHAN_EOF_RCVD) {
|
|
if ((r = sshbuf_consume(c->output, have)) != 0)
|
|
fatal_fr(r, "channel %d: consume", c->self);
|
|
rdynamic_close(ssh, c);
|
|
return;
|
|
}
|
|
/* check if the fixed size part of the packet is in buffer. */
|
|
if (have < 3)
|
|
return;
|
|
/* try to guess the protocol */
|
|
p = sshbuf_ptr(c->output);
|
|
switch (p[0]) {
|
|
case 0x04:
|
|
/* switch input/output for reverse forwarding */
|
|
ret = channel_decode_socks4(c, c->output, c->input);
|
|
break;
|
|
case 0x05:
|
|
ret = channel_decode_socks5(c, c->output, c->input);
|
|
break;
|
|
default:
|
|
ret = -1;
|
|
break;
|
|
}
|
|
if (ret < 0) {
|
|
rdynamic_close(ssh, c);
|
|
} else if (ret == 0) {
|
|
debug2("channel %d: pre_rdynamic: need more", c->self);
|
|
/* send socks request to peer */
|
|
len = sshbuf_len(c->input);
|
|
if (len > 0 && len < c->remote_window) {
|
|
if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_DATA)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
|
|
(r = sshpkt_put_stringb(ssh, c->input)) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0) {
|
|
fatal_fr(r, "channel %i: rdynamic", c->self);
|
|
}
|
|
if ((r = sshbuf_consume(c->input, len)) != 0)
|
|
fatal_fr(r, "channel %d: consume", c->self);
|
|
c->remote_window -= len;
|
|
}
|
|
} else if (rdynamic_connect_finish(ssh, c) < 0) {
|
|
/* the connect failed */
|
|
rdynamic_close(ssh, c);
|
|
}
|
|
}
|
|
|
|
/* This is our fake X11 server socket. */
|
|
static void
|
|
channel_post_x11_listener(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
Channel *nc;
|
|
struct sockaddr_storage addr;
|
|
int r, newsock, oerrno, remote_port;
|
|
socklen_t addrlen;
|
|
char buf[16384], *remote_ipaddr;
|
|
|
|
if (!FD_ISSET(c->sock, readset))
|
|
return;
|
|
|
|
debug("X11 connection requested.");
|
|
addrlen = sizeof(addr);
|
|
newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
|
|
if (c->single_connection) {
|
|
oerrno = errno;
|
|
debug2("single_connection: closing X11 listener.");
|
|
channel_close_fd(ssh, c, &c->sock);
|
|
chan_mark_dead(ssh, c);
|
|
errno = oerrno;
|
|
}
|
|
if (newsock == -1) {
|
|
if (errno != EINTR && errno != EWOULDBLOCK &&
|
|
errno != ECONNABORTED)
|
|
error("accept: %.100s", strerror(errno));
|
|
if (errno == EMFILE || errno == ENFILE)
|
|
c->notbefore = monotime() + 1;
|
|
return;
|
|
}
|
|
set_nodelay(newsock);
|
|
remote_ipaddr = get_peer_ipaddr(newsock);
|
|
remote_port = get_peer_port(newsock);
|
|
snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
|
|
remote_ipaddr, remote_port);
|
|
|
|
nc = channel_new(ssh, "accepted x11 socket",
|
|
SSH_CHANNEL_OPENING, newsock, newsock, -1,
|
|
c->local_window_max, c->local_maxpacket, 0, buf, 1);
|
|
open_preamble(ssh, __func__, nc, "x11");
|
|
if ((r = sshpkt_put_cstring(ssh, remote_ipaddr)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, remote_port)) != 0) {
|
|
fatal_fr(r, "channel %i: reply", c->self);
|
|
}
|
|
if ((r = sshpkt_send(ssh)) != 0)
|
|
fatal_fr(r, "channel %i: send", c->self);
|
|
free(remote_ipaddr);
|
|
}
|
|
|
|
static void
|
|
port_open_helper(struct ssh *ssh, Channel *c, char *rtype)
|
|
{
|
|
char *local_ipaddr = get_local_ipaddr(c->sock);
|
|
int local_port = c->sock == -1 ? 65536 : get_local_port(c->sock);
|
|
char *remote_ipaddr = get_peer_ipaddr(c->sock);
|
|
int remote_port = get_peer_port(c->sock);
|
|
int r;
|
|
|
|
if (remote_port == -1) {
|
|
/* Fake addr/port to appease peers that validate it (Tectia) */
|
|
free(remote_ipaddr);
|
|
remote_ipaddr = xstrdup("127.0.0.1");
|
|
remote_port = 65535;
|
|
}
|
|
|
|
free(c->remote_name);
|
|
xasprintf(&c->remote_name,
|
|
"%s: listening port %d for %.100s port %d, "
|
|
"connect from %.200s port %d to %.100s port %d",
|
|
rtype, c->listening_port, c->path, c->host_port,
|
|
remote_ipaddr, remote_port, local_ipaddr, local_port);
|
|
|
|
open_preamble(ssh, __func__, c, rtype);
|
|
if (strcmp(rtype, "direct-tcpip") == 0) {
|
|
/* target host, port */
|
|
if ((r = sshpkt_put_cstring(ssh, c->path)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->host_port)) != 0)
|
|
fatal_fr(r, "channel %i: reply", c->self);
|
|
} else if (strcmp(rtype, "direct-streamlocal@openssh.com") == 0) {
|
|
/* target path */
|
|
if ((r = sshpkt_put_cstring(ssh, c->path)) != 0)
|
|
fatal_fr(r, "channel %i: reply", c->self);
|
|
} else if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
|
|
/* listen path */
|
|
if ((r = sshpkt_put_cstring(ssh, c->path)) != 0)
|
|
fatal_fr(r, "channel %i: reply", c->self);
|
|
} else {
|
|
/* listen address, port */
|
|
if ((r = sshpkt_put_cstring(ssh, c->path)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, local_port)) != 0)
|
|
fatal_fr(r, "channel %i: reply", c->self);
|
|
}
|
|
if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
|
|
/* reserved for future owner/mode info */
|
|
if ((r = sshpkt_put_cstring(ssh, "")) != 0)
|
|
fatal_fr(r, "channel %i: reply", c->self);
|
|
} else {
|
|
/* originator host and port */
|
|
if ((r = sshpkt_put_cstring(ssh, remote_ipaddr)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, (u_int)remote_port)) != 0)
|
|
fatal_fr(r, "channel %i: reply", c->self);
|
|
}
|
|
if ((r = sshpkt_send(ssh)) != 0)
|
|
fatal_fr(r, "channel %i: send", c->self);
|
|
free(remote_ipaddr);
|
|
free(local_ipaddr);
|
|
}
|
|
|
|
void
|
|
channel_set_x11_refuse_time(struct ssh *ssh, u_int refuse_time)
|
|
{
|
|
ssh->chanctxt->x11_refuse_time = refuse_time;
|
|
}
|
|
|
|
/*
|
|
* This socket is listening for connections to a forwarded TCP/IP port.
|
|
*/
|
|
static void
|
|
channel_post_port_listener(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
Channel *nc;
|
|
struct sockaddr_storage addr;
|
|
int newsock, nextstate;
|
|
socklen_t addrlen;
|
|
char *rtype;
|
|
|
|
if (!FD_ISSET(c->sock, readset))
|
|
return;
|
|
|
|
debug("Connection to port %d forwarding to %.100s port %d requested.",
|
|
c->listening_port, c->path, c->host_port);
|
|
|
|
if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
|
|
nextstate = SSH_CHANNEL_OPENING;
|
|
rtype = "forwarded-tcpip";
|
|
} else if (c->type == SSH_CHANNEL_RUNIX_LISTENER) {
|
|
nextstate = SSH_CHANNEL_OPENING;
|
|
rtype = "forwarded-streamlocal@openssh.com";
|
|
} else if (c->host_port == PORT_STREAMLOCAL) {
|
|
nextstate = SSH_CHANNEL_OPENING;
|
|
rtype = "direct-streamlocal@openssh.com";
|
|
} else if (c->host_port == 0) {
|
|
nextstate = SSH_CHANNEL_DYNAMIC;
|
|
rtype = "dynamic-tcpip";
|
|
} else {
|
|
nextstate = SSH_CHANNEL_OPENING;
|
|
rtype = "direct-tcpip";
|
|
}
|
|
|
|
addrlen = sizeof(addr);
|
|
newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
|
|
if (newsock == -1) {
|
|
if (errno != EINTR && errno != EWOULDBLOCK &&
|
|
errno != ECONNABORTED)
|
|
error("accept: %.100s", strerror(errno));
|
|
if (errno == EMFILE || errno == ENFILE)
|
|
c->notbefore = monotime() + 1;
|
|
return;
|
|
}
|
|
if (c->host_port != PORT_STREAMLOCAL)
|
|
set_nodelay(newsock);
|
|
nc = channel_new(ssh, rtype, nextstate, newsock, newsock, -1,
|
|
c->local_window_max, c->local_maxpacket, 0, rtype, 1);
|
|
nc->listening_port = c->listening_port;
|
|
nc->host_port = c->host_port;
|
|
if (c->path != NULL)
|
|
nc->path = xstrdup(c->path);
|
|
|
|
if (nextstate != SSH_CHANNEL_DYNAMIC)
|
|
port_open_helper(ssh, nc, rtype);
|
|
}
|
|
|
|
/*
|
|
* This is the authentication agent socket listening for connections from
|
|
* clients.
|
|
*/
|
|
static void
|
|
channel_post_auth_listener(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
Channel *nc;
|
|
int r, newsock;
|
|
struct sockaddr_storage addr;
|
|
socklen_t addrlen;
|
|
|
|
if (!FD_ISSET(c->sock, readset))
|
|
return;
|
|
|
|
addrlen = sizeof(addr);
|
|
newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
|
|
if (newsock == -1) {
|
|
error("accept from auth socket: %.100s", strerror(errno));
|
|
if (errno == EMFILE || errno == ENFILE)
|
|
c->notbefore = monotime() + 1;
|
|
return;
|
|
}
|
|
nc = channel_new(ssh, "accepted auth socket",
|
|
SSH_CHANNEL_OPENING, newsock, newsock, -1,
|
|
c->local_window_max, c->local_maxpacket,
|
|
0, "accepted auth socket", 1);
|
|
open_preamble(ssh, __func__, nc, "auth-agent@openssh.com");
|
|
if ((r = sshpkt_send(ssh)) != 0)
|
|
fatal_fr(r, "channel %i", c->self);
|
|
}
|
|
|
|
static void
|
|
channel_post_connecting(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
int err = 0, sock, isopen, r;
|
|
socklen_t sz = sizeof(err);
|
|
|
|
if (!FD_ISSET(c->sock, writeset))
|
|
return;
|
|
if (!c->have_remote_id)
|
|
fatal_f("channel %d: no remote id", c->self);
|
|
/* for rdynamic the OPEN_CONFIRMATION has been sent already */
|
|
isopen = (c->type == SSH_CHANNEL_RDYNAMIC_FINISH);
|
|
if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) == -1) {
|
|
err = errno;
|
|
error("getsockopt SO_ERROR failed");
|
|
}
|
|
if (err == 0) {
|
|
debug("channel %d: connected to %s port %d",
|
|
c->self, c->connect_ctx.host, c->connect_ctx.port);
|
|
channel_connect_ctx_free(&c->connect_ctx);
|
|
c->type = SSH_CHANNEL_OPEN;
|
|
if (isopen) {
|
|
/* no message necessary */
|
|
} else {
|
|
if ((r = sshpkt_start(ssh,
|
|
SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->self)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0)
|
|
fatal_fr(r, "channel %i open confirm", c->self);
|
|
}
|
|
} else {
|
|
debug("channel %d: connection failed: %s",
|
|
c->self, strerror(err));
|
|
/* Try next address, if any */
|
|
if ((sock = connect_next(&c->connect_ctx)) > 0) {
|
|
close(c->sock);
|
|
c->sock = c->rfd = c->wfd = sock;
|
|
channel_find_maxfd(ssh->chanctxt);
|
|
return;
|
|
}
|
|
/* Exhausted all addresses */
|
|
error("connect_to %.100s port %d: failed.",
|
|
c->connect_ctx.host, c->connect_ctx.port);
|
|
channel_connect_ctx_free(&c->connect_ctx);
|
|
if (isopen) {
|
|
rdynamic_close(ssh, c);
|
|
} else {
|
|
if ((r = sshpkt_start(ssh,
|
|
SSH2_MSG_CHANNEL_OPEN_FAILURE)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh,
|
|
SSH2_OPEN_CONNECT_FAILED)) != 0 ||
|
|
(r = sshpkt_put_cstring(ssh, strerror(err))) != 0 ||
|
|
(r = sshpkt_put_cstring(ssh, "")) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0)
|
|
fatal_fr(r, "channel %i: failure", c->self);
|
|
chan_mark_dead(ssh, c);
|
|
}
|
|
}
|
|
}
|
|
|
|
static int
|
|
channel_handle_rfd(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
char buf[CHAN_RBUF];
|
|
ssize_t len;
|
|
int r, force;
|
|
|
|
force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
|
|
|
|
if (c->rfd == -1 || (!force && !FD_ISSET(c->rfd, readset)))
|
|
return 1;
|
|
|
|
errno = 0;
|
|
len = read(c->rfd, buf, sizeof(buf));
|
|
if (len == -1 && (errno == EINTR ||
|
|
((errno == EAGAIN || errno == EWOULDBLOCK) && !force)))
|
|
return 1;
|
|
#ifndef PTY_ZEROREAD
|
|
if (len <= 0) {
|
|
#else
|
|
if ((!c->isatty && len <= 0) ||
|
|
(c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
|
|
#endif
|
|
debug2("channel %d: read<=0 rfd %d len %zd",
|
|
c->self, c->rfd, len);
|
|
if (c->type != SSH_CHANNEL_OPEN) {
|
|
debug2("channel %d: not open", c->self);
|
|
chan_mark_dead(ssh, c);
|
|
return -1;
|
|
} else {
|
|
chan_read_failed(ssh, c);
|
|
}
|
|
return -1;
|
|
}
|
|
if (c->input_filter != NULL) {
|
|
if (c->input_filter(ssh, c, buf, len) == -1) {
|
|
debug2("channel %d: filter stops", c->self);
|
|
chan_read_failed(ssh, c);
|
|
}
|
|
} else if (c->datagram) {
|
|
if ((r = sshbuf_put_string(c->input, buf, len)) != 0)
|
|
fatal_fr(r, "channel %i: put datagram", c->self);
|
|
} else if ((r = sshbuf_put(c->input, buf, len)) != 0)
|
|
fatal_fr(r, "channel %i: put data", c->self);
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
channel_handle_wfd(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
struct termios tio;
|
|
u_char *data = NULL, *buf; /* XXX const; need filter API change */
|
|
size_t dlen, olen = 0;
|
|
int r, len;
|
|
|
|
if (c->wfd == -1 || !FD_ISSET(c->wfd, writeset) ||
|
|
sshbuf_len(c->output) == 0)
|
|
return 1;
|
|
|
|
/* Send buffered output data to the socket. */
|
|
olen = sshbuf_len(c->output);
|
|
if (c->output_filter != NULL) {
|
|
if ((buf = c->output_filter(ssh, c, &data, &dlen)) == NULL) {
|
|
debug2("channel %d: filter stops", c->self);
|
|
if (c->type != SSH_CHANNEL_OPEN)
|
|
chan_mark_dead(ssh, c);
|
|
else
|
|
chan_write_failed(ssh, c);
|
|
return -1;
|
|
}
|
|
} else if (c->datagram) {
|
|
if ((r = sshbuf_get_string(c->output, &data, &dlen)) != 0)
|
|
fatal_fr(r, "channel %i: get datagram", c->self);
|
|
buf = data;
|
|
} else {
|
|
buf = data = sshbuf_mutable_ptr(c->output);
|
|
dlen = sshbuf_len(c->output);
|
|
}
|
|
|
|
if (c->datagram) {
|
|
/* ignore truncated writes, datagrams might get lost */
|
|
len = write(c->wfd, buf, dlen);
|
|
free(data);
|
|
if (len == -1 && (errno == EINTR || errno == EAGAIN ||
|
|
errno == EWOULDBLOCK))
|
|
return 1;
|
|
if (len <= 0)
|
|
goto write_fail;
|
|
goto out;
|
|
}
|
|
|
|
#ifdef _AIX
|
|
/* XXX: Later AIX versions can't push as much data to tty */
|
|
if (c->wfd_isatty)
|
|
dlen = MIN(dlen, 8*1024);
|
|
#endif
|
|
|
|
len = write(c->wfd, buf, dlen);
|
|
if (len == -1 &&
|
|
(errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
|
|
return 1;
|
|
if (len <= 0) {
|
|
write_fail:
|
|
if (c->type != SSH_CHANNEL_OPEN) {
|
|
debug2("channel %d: not open", c->self);
|
|
chan_mark_dead(ssh, c);
|
|
return -1;
|
|
} else {
|
|
chan_write_failed(ssh, c);
|
|
}
|
|
return -1;
|
|
}
|
|
#ifndef BROKEN_TCGETATTR_ICANON
|
|
if (c->isatty && dlen >= 1 && buf[0] != '\r') {
|
|
if (tcgetattr(c->wfd, &tio) == 0 &&
|
|
!(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
|
|
/*
|
|
* Simulate echo to reduce the impact of
|
|
* traffic analysis. We need to match the
|
|
* size of a SSH2_MSG_CHANNEL_DATA message
|
|
* (4 byte channel id + buf)
|
|
*/
|
|
if ((r = sshpkt_msg_ignore(ssh, 4+len)) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0)
|
|
fatal_fr(r, "channel %i: ignore", c->self);
|
|
}
|
|
}
|
|
#endif /* BROKEN_TCGETATTR_ICANON */
|
|
if ((r = sshbuf_consume(c->output, len)) != 0)
|
|
fatal_fr(r, "channel %i: consume", c->self);
|
|
out:
|
|
c->local_consumed += olen - sshbuf_len(c->output);
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
channel_handle_efd_write(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
int r;
|
|
ssize_t len;
|
|
|
|
if (!FD_ISSET(c->efd, writeset) || sshbuf_len(c->extended) == 0)
|
|
return 1;
|
|
|
|
len = write(c->efd, sshbuf_ptr(c->extended),
|
|
sshbuf_len(c->extended));
|
|
debug2("channel %d: written %zd to efd %d", c->self, len, c->efd);
|
|
if (len == -1 && (errno == EINTR || errno == EAGAIN ||
|
|
errno == EWOULDBLOCK))
|
|
return 1;
|
|
if (len <= 0) {
|
|
debug2("channel %d: closing write-efd %d", c->self, c->efd);
|
|
channel_close_fd(ssh, c, &c->efd);
|
|
} else {
|
|
if ((r = sshbuf_consume(c->extended, len)) != 0)
|
|
fatal_fr(r, "channel %i: consume", c->self);
|
|
c->local_consumed += len;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
channel_handle_efd_read(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
char buf[CHAN_RBUF];
|
|
ssize_t len;
|
|
int r, force;
|
|
|
|
force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
|
|
|
|
if (c->efd == -1 || (!force && !FD_ISSET(c->efd, readset)))
|
|
return 1;
|
|
|
|
len = read(c->efd, buf, sizeof(buf));
|
|
debug2("channel %d: read %zd from efd %d", c->self, len, c->efd);
|
|
if (len == -1 && (errno == EINTR || ((errno == EAGAIN ||
|
|
errno == EWOULDBLOCK) && !force)))
|
|
return 1;
|
|
if (len <= 0) {
|
|
debug2("channel %d: closing read-efd %d", c->self, c->efd);
|
|
channel_close_fd(ssh, c, &c->efd);
|
|
} else if (c->extended_usage == CHAN_EXTENDED_IGNORE)
|
|
debug3("channel %d: discard efd", c->self);
|
|
else if ((r = sshbuf_put(c->extended, buf, len)) != 0)
|
|
fatal_fr(r, "channel %i: append", c->self);
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
channel_handle_efd(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
if (c->efd == -1)
|
|
return 1;
|
|
|
|
/** XXX handle drain efd, too */
|
|
|
|
if (c->extended_usage == CHAN_EXTENDED_WRITE)
|
|
return channel_handle_efd_write(ssh, c, readset, writeset);
|
|
else if (c->extended_usage == CHAN_EXTENDED_READ ||
|
|
c->extended_usage == CHAN_EXTENDED_IGNORE)
|
|
return channel_handle_efd_read(ssh, c, readset, writeset);
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
channel_check_window(struct ssh *ssh, Channel *c)
|
|
{
|
|
int r;
|
|
|
|
if (c->type == SSH_CHANNEL_OPEN &&
|
|
!(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
|
|
((c->local_window_max - c->local_window >
|
|
c->local_maxpacket*3) ||
|
|
c->local_window < c->local_window_max/2) &&
|
|
c->local_consumed > 0) {
|
|
if (!c->have_remote_id)
|
|
fatal_f("channel %d: no remote id", c->self);
|
|
if ((r = sshpkt_start(ssh,
|
|
SSH2_MSG_CHANNEL_WINDOW_ADJUST)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->local_consumed)) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0) {
|
|
fatal_fr(r, "channel %i", c->self);
|
|
}
|
|
debug2("channel %d: window %d sent adjust %d", c->self,
|
|
c->local_window, c->local_consumed);
|
|
c->local_window += c->local_consumed;
|
|
c->local_consumed = 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static void
|
|
channel_post_open(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
channel_handle_rfd(ssh, c, readset, writeset);
|
|
channel_handle_wfd(ssh, c, readset, writeset);
|
|
channel_handle_efd(ssh, c, readset, writeset);
|
|
channel_check_window(ssh, c);
|
|
}
|
|
|
|
static u_int
|
|
read_mux(struct ssh *ssh, Channel *c, u_int need)
|
|
{
|
|
char buf[CHAN_RBUF];
|
|
ssize_t len;
|
|
u_int rlen;
|
|
int r;
|
|
|
|
if (sshbuf_len(c->input) < need) {
|
|
rlen = need - sshbuf_len(c->input);
|
|
len = read(c->rfd, buf, MINIMUM(rlen, CHAN_RBUF));
|
|
if (len == -1 && (errno == EINTR || errno == EAGAIN))
|
|
return sshbuf_len(c->input);
|
|
if (len <= 0) {
|
|
debug2("channel %d: ctl read<=0 rfd %d len %zd",
|
|
c->self, c->rfd, len);
|
|
chan_read_failed(ssh, c);
|
|
return 0;
|
|
} else if ((r = sshbuf_put(c->input, buf, len)) != 0)
|
|
fatal_fr(r, "channel %i: append", c->self);
|
|
}
|
|
return sshbuf_len(c->input);
|
|
}
|
|
|
|
static void
|
|
channel_post_mux_client_read(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
u_int need;
|
|
|
|
if (c->rfd == -1 || !FD_ISSET(c->rfd, readset))
|
|
return;
|
|
if (c->istate != CHAN_INPUT_OPEN && c->istate != CHAN_INPUT_WAIT_DRAIN)
|
|
return;
|
|
if (c->mux_pause)
|
|
return;
|
|
|
|
/*
|
|
* Don't not read past the precise end of packets to
|
|
* avoid disrupting fd passing.
|
|
*/
|
|
if (read_mux(ssh, c, 4) < 4) /* read header */
|
|
return;
|
|
/* XXX sshbuf_peek_u32 */
|
|
need = PEEK_U32(sshbuf_ptr(c->input));
|
|
#define CHANNEL_MUX_MAX_PACKET (256 * 1024)
|
|
if (need > CHANNEL_MUX_MAX_PACKET) {
|
|
debug2("channel %d: packet too big %u > %u",
|
|
c->self, CHANNEL_MUX_MAX_PACKET, need);
|
|
chan_rcvd_oclose(ssh, c);
|
|
return;
|
|
}
|
|
if (read_mux(ssh, c, need + 4) < need + 4) /* read body */
|
|
return;
|
|
if (c->mux_rcb(ssh, c) != 0) {
|
|
debug("channel %d: mux_rcb failed", c->self);
|
|
chan_mark_dead(ssh, c);
|
|
return;
|
|
}
|
|
}
|
|
|
|
static void
|
|
channel_post_mux_client_write(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
ssize_t len;
|
|
int r;
|
|
|
|
if (c->wfd == -1 || !FD_ISSET(c->wfd, writeset) ||
|
|
sshbuf_len(c->output) == 0)
|
|
return;
|
|
|
|
len = write(c->wfd, sshbuf_ptr(c->output), sshbuf_len(c->output));
|
|
if (len == -1 && (errno == EINTR || errno == EAGAIN))
|
|
return;
|
|
if (len <= 0) {
|
|
chan_mark_dead(ssh, c);
|
|
return;
|
|
}
|
|
if ((r = sshbuf_consume(c->output, len)) != 0)
|
|
fatal_fr(r, "channel %i: consume", c->self);
|
|
}
|
|
|
|
static void
|
|
channel_post_mux_client(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
channel_post_mux_client_read(ssh, c, readset, writeset);
|
|
channel_post_mux_client_write(ssh, c, readset, writeset);
|
|
}
|
|
|
|
static void
|
|
channel_post_mux_listener(struct ssh *ssh, Channel *c,
|
|
fd_set *readset, fd_set *writeset)
|
|
{
|
|
Channel *nc;
|
|
struct sockaddr_storage addr;
|
|
socklen_t addrlen;
|
|
int newsock;
|
|
uid_t euid;
|
|
gid_t egid;
|
|
|
|
if (!FD_ISSET(c->sock, readset))
|
|
return;
|
|
|
|
debug("multiplexing control connection");
|
|
|
|
/*
|
|
* Accept connection on control socket
|
|
*/
|
|
memset(&addr, 0, sizeof(addr));
|
|
addrlen = sizeof(addr);
|
|
if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
|
|
&addrlen)) == -1) {
|
|
error_f("accept: %s", strerror(errno));
|
|
if (errno == EMFILE || errno == ENFILE)
|
|
c->notbefore = monotime() + 1;
|
|
return;
|
|
}
|
|
|
|
if (getpeereid(newsock, &euid, &egid) == -1) {
|
|
error_f("getpeereid failed: %s", strerror(errno));
|
|
close(newsock);
|
|
return;
|
|
}
|
|
if ((euid != 0) && (getuid() != euid)) {
|
|
error("multiplex uid mismatch: peer euid %u != uid %u",
|
|
(u_int)euid, (u_int)getuid());
|
|
close(newsock);
|
|
return;
|
|
}
|
|
nc = channel_new(ssh, "multiplex client", SSH_CHANNEL_MUX_CLIENT,
|
|
newsock, newsock, -1, c->local_window_max,
|
|
c->local_maxpacket, 0, "mux-control", 1);
|
|
nc->mux_rcb = c->mux_rcb;
|
|
debug3_f("new mux channel %d fd %d", nc->self, nc->sock);
|
|
/* establish state */
|
|
nc->mux_rcb(ssh, nc);
|
|
/* mux state transitions must not elicit protocol messages */
|
|
nc->flags |= CHAN_LOCAL;
|
|
}
|
|
|
|
static void
|
|
channel_handler_init(struct ssh_channels *sc)
|
|
{
|
|
chan_fn **pre, **post;
|
|
|
|
if ((pre = calloc(SSH_CHANNEL_MAX_TYPE, sizeof(*pre))) == NULL ||
|
|
(post = calloc(SSH_CHANNEL_MAX_TYPE, sizeof(*post))) == NULL)
|
|
fatal_f("allocation failed");
|
|
|
|
pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
|
|
pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
|
|
pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
|
|
pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
|
|
pre[SSH_CHANNEL_UNIX_LISTENER] = &channel_pre_listener;
|
|
pre[SSH_CHANNEL_RUNIX_LISTENER] = &channel_pre_listener;
|
|
pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
|
|
pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
|
|
pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
|
|
pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
|
|
pre[SSH_CHANNEL_RDYNAMIC_FINISH] = &channel_pre_connecting;
|
|
pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
|
|
pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
|
|
|
|
post[SSH_CHANNEL_OPEN] = &channel_post_open;
|
|
post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
|
|
post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
|
|
post[SSH_CHANNEL_UNIX_LISTENER] = &channel_post_port_listener;
|
|
post[SSH_CHANNEL_RUNIX_LISTENER] = &channel_post_port_listener;
|
|
post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
|
|
post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
|
|
post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
|
|
post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
|
|
post[SSH_CHANNEL_RDYNAMIC_FINISH] = &channel_post_connecting;
|
|
post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
|
|
post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
|
|
|
|
sc->channel_pre = pre;
|
|
sc->channel_post = post;
|
|
}
|
|
|
|
/* gc dead channels */
|
|
static void
|
|
channel_garbage_collect(struct ssh *ssh, Channel *c)
|
|
{
|
|
if (c == NULL)
|
|
return;
|
|
if (c->detach_user != NULL) {
|
|
if (!chan_is_dead(ssh, c, c->detach_close))
|
|
return;
|
|
|
|
debug2("channel %d: gc: notify user", c->self);
|
|
c->detach_user(ssh, c->self, NULL);
|
|
/* if we still have a callback */
|
|
if (c->detach_user != NULL)
|
|
return;
|
|
debug2("channel %d: gc: user detached", c->self);
|
|
}
|
|
if (!chan_is_dead(ssh, c, 1))
|
|
return;
|
|
debug2("channel %d: garbage collecting", c->self);
|
|
channel_free(ssh, c);
|
|
}
|
|
|
|
enum channel_table { CHAN_PRE, CHAN_POST };
|
|
|
|
static void
|
|
channel_handler(struct ssh *ssh, int table,
|
|
fd_set *readset, fd_set *writeset, time_t *unpause_secs)
|
|
{
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
|
chan_fn **ftab = table == CHAN_PRE ? sc->channel_pre : sc->channel_post;
|
|
u_int i, oalloc;
|
|
Channel *c;
|
|
time_t now;
|
|
|
|
now = monotime();
|
|
if (unpause_secs != NULL)
|
|
*unpause_secs = 0;
|
|
for (i = 0, oalloc = sc->channels_alloc; i < oalloc; i++) {
|
|
c = sc->channels[i];
|
|
if (c == NULL)
|
|
continue;
|
|
if (c->delayed) {
|
|
if (table == CHAN_PRE)
|
|
c->delayed = 0;
|
|
else
|
|
continue;
|
|
}
|
|
if (ftab[c->type] != NULL) {
|
|
/*
|
|
* Run handlers that are not paused.
|
|
*/
|
|
if (c->notbefore <= now)
|
|
(*ftab[c->type])(ssh, c, readset, writeset);
|
|
else if (unpause_secs != NULL) {
|
|
/*
|
|
* Collect the time that the earliest
|
|
* channel comes off pause.
|
|
*/
|
|
debug3_f("chan %d: skip for %d more "
|
|
"seconds", c->self,
|
|
(int)(c->notbefore - now));
|
|
if (*unpause_secs == 0 ||
|
|
(c->notbefore - now) < *unpause_secs)
|
|
*unpause_secs = c->notbefore - now;
|
|
}
|
|
}
|
|
channel_garbage_collect(ssh, c);
|
|
}
|
|
if (unpause_secs != NULL && *unpause_secs != 0)
|
|
debug3_f("first channel unpauses in %d seconds",
|
|
(int)*unpause_secs);
|
|
}
|
|
|
|
/*
|
|
* Create sockets before allocating the select bitmasks.
|
|
* This is necessary for things that need to happen after reading
|
|
* the network-input but before channel_prepare_select().
|
|
*/
|
|
static void
|
|
channel_before_prepare_select(struct ssh *ssh)
|
|
{
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
|
Channel *c;
|
|
u_int i, oalloc;
|
|
|
|
for (i = 0, oalloc = sc->channels_alloc; i < oalloc; i++) {
|
|
c = sc->channels[i];
|
|
if (c == NULL)
|
|
continue;
|
|
if (c->type == SSH_CHANNEL_RDYNAMIC_OPEN)
|
|
channel_before_prepare_select_rdynamic(ssh, c);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Allocate/update select bitmasks and add any bits relevant to channels in
|
|
* select bitmasks.
|
|
*/
|
|
void
|
|
channel_prepare_select(struct ssh *ssh, fd_set **readsetp, fd_set **writesetp,
|
|
int *maxfdp, u_int *nallocp, time_t *minwait_secs)
|
|
{
|
|
u_int n, sz, nfdset;
|
|
|
|
channel_before_prepare_select(ssh); /* might update channel_max_fd */
|
|
|
|
n = MAXIMUM(*maxfdp, ssh->chanctxt->channel_max_fd);
|
|
|
|
nfdset = howmany(n+1, NFDBITS);
|
|
/* Explicitly test here, because xrealloc isn't always called */
|
|
if (nfdset && SIZE_MAX / nfdset < sizeof(fd_mask))
|
|
fatal("channel_prepare_select: max_fd (%d) is too large", n);
|
|
sz = nfdset * sizeof(fd_mask);
|
|
|
|
/* perhaps check sz < nalloc/2 and shrink? */
|
|
if (*readsetp == NULL || sz > *nallocp) {
|
|
*readsetp = xreallocarray(*readsetp, nfdset, sizeof(fd_mask));
|
|
*writesetp = xreallocarray(*writesetp, nfdset, sizeof(fd_mask));
|
|
*nallocp = sz;
|
|
}
|
|
*maxfdp = n;
|
|
memset(*readsetp, 0, sz);
|
|
memset(*writesetp, 0, sz);
|
|
|
|
if (!ssh_packet_is_rekeying(ssh))
|
|
channel_handler(ssh, CHAN_PRE, *readsetp, *writesetp,
|
|
minwait_secs);
|
|
}
|
|
|
|
/*
|
|
* After select, perform any appropriate operations for channels which have
|
|
* events pending.
|
|
*/
|
|
void
|
|
channel_after_select(struct ssh *ssh, fd_set *readset, fd_set *writeset)
|
|
{
|
|
channel_handler(ssh, CHAN_POST, readset, writeset, NULL);
|
|
}
|
|
|
|
/*
|
|
* Enqueue data for channels with open or draining c->input.
|
|
*/
|
|
static void
|
|
channel_output_poll_input_open(struct ssh *ssh, Channel *c)
|
|
{
|
|
size_t len, plen;
|
|
const u_char *pkt;
|
|
int r;
|
|
|
|
if ((len = sshbuf_len(c->input)) == 0) {
|
|
if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
|
|
/*
|
|
* input-buffer is empty and read-socket shutdown:
|
|
* tell peer, that we will not send more data:
|
|
* send IEOF.
|
|
* hack for extended data: delay EOF if EFD still
|
|
* in use.
|
|
*/
|
|
if (CHANNEL_EFD_INPUT_ACTIVE(c))
|
|
debug2("channel %d: "
|
|
"ibuf_empty delayed efd %d/(%zu)",
|
|
c->self, c->efd, sshbuf_len(c->extended));
|
|
else
|
|
chan_ibuf_empty(ssh, c);
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (!c->have_remote_id)
|
|
fatal_f("channel %d: no remote id", c->self);
|
|
|
|
if (c->datagram) {
|
|
/* Check datagram will fit; drop if not */
|
|
if ((r = sshbuf_get_string_direct(c->input, &pkt, &plen)) != 0)
|
|
fatal_fr(r, "channel %i: get datagram", c->self);
|
|
/*
|
|
* XXX this does tail-drop on the datagram queue which is
|
|
* usually suboptimal compared to head-drop. Better to have
|
|
* backpressure at read time? (i.e. read + discard)
|
|
*/
|
|
if (plen > c->remote_window || plen > c->remote_maxpacket) {
|
|
debug("channel %d: datagram too big", c->self);
|
|
return;
|
|
}
|
|
/* Enqueue it */
|
|
if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_DATA)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
|
|
(r = sshpkt_put_string(ssh, pkt, plen)) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0)
|
|
fatal_fr(r, "channel %i: send datagram", c->self);
|
|
c->remote_window -= plen;
|
|
return;
|
|
}
|
|
|
|
/* Enqueue packet for buffered data. */
|
|
if (len > c->remote_window)
|
|
len = c->remote_window;
|
|
if (len > c->remote_maxpacket)
|
|
len = c->remote_maxpacket;
|
|
if (len == 0)
|
|
return;
|
|
if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_DATA)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
|
|
(r = sshpkt_put_string(ssh, sshbuf_ptr(c->input), len)) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0)
|
|
fatal_fr(r, "channel %i: send data", c->self);
|
|
if ((r = sshbuf_consume(c->input, len)) != 0)
|
|
fatal_fr(r, "channel %i: consume", c->self);
|
|
c->remote_window -= len;
|
|
}
|
|
|
|
/*
|
|
* Enqueue data for channels with open c->extended in read mode.
|
|
*/
|
|
static void
|
|
channel_output_poll_extended_read(struct ssh *ssh, Channel *c)
|
|
{
|
|
size_t len;
|
|
int r;
|
|
|
|
if ((len = sshbuf_len(c->extended)) == 0)
|
|
return;
|
|
|
|
debug2("channel %d: rwin %u elen %zu euse %d", c->self,
|
|
c->remote_window, sshbuf_len(c->extended), c->extended_usage);
|
|
if (len > c->remote_window)
|
|
len = c->remote_window;
|
|
if (len > c->remote_maxpacket)
|
|
len = c->remote_maxpacket;
|
|
if (len == 0)
|
|
return;
|
|
if (!c->have_remote_id)
|
|
fatal_f("channel %d: no remote id", c->self);
|
|
if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_EXTENDED_DATA)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, SSH2_EXTENDED_DATA_STDERR)) != 0 ||
|
|
(r = sshpkt_put_string(ssh, sshbuf_ptr(c->extended), len)) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0)
|
|
fatal_fr(r, "channel %i: data", c->self);
|
|
if ((r = sshbuf_consume(c->extended, len)) != 0)
|
|
fatal_fr(r, "channel %i: consume", c->self);
|
|
c->remote_window -= len;
|
|
debug2("channel %d: sent ext data %zu", c->self, len);
|
|
}
|
|
|
|
/* If there is data to send to the connection, enqueue some of it now. */
|
|
void
|
|
channel_output_poll(struct ssh *ssh)
|
|
{
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
|
Channel *c;
|
|
u_int i;
|
|
|
|
for (i = 0; i < sc->channels_alloc; i++) {
|
|
c = sc->channels[i];
|
|
if (c == NULL)
|
|
continue;
|
|
|
|
/*
|
|
* We are only interested in channels that can have buffered
|
|
* incoming data.
|
|
*/
|
|
if (c->type != SSH_CHANNEL_OPEN)
|
|
continue;
|
|
if ((c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
|
|
/* XXX is this true? */
|
|
debug3("channel %d: will not send data after close",
|
|
c->self);
|
|
continue;
|
|
}
|
|
|
|
/* Get the amount of buffered data for this channel. */
|
|
if (c->istate == CHAN_INPUT_OPEN ||
|
|
c->istate == CHAN_INPUT_WAIT_DRAIN)
|
|
channel_output_poll_input_open(ssh, c);
|
|
/* Send extended data, i.e. stderr */
|
|
if (!(c->flags & CHAN_EOF_SENT) &&
|
|
c->extended_usage == CHAN_EXTENDED_READ)
|
|
channel_output_poll_extended_read(ssh, c);
|
|
}
|
|
}
|
|
|
|
/* -- mux proxy support */
|
|
|
|
/*
|
|
* When multiplexing channel messages for mux clients we have to deal
|
|
* with downstream messages from the mux client and upstream messages
|
|
* from the ssh server:
|
|
* 1) Handling downstream messages is straightforward and happens
|
|
* in channel_proxy_downstream():
|
|
* - We forward all messages (mostly) unmodified to the server.
|
|
* - However, in order to route messages from upstream to the correct
|
|
* downstream client, we have to replace the channel IDs used by the
|
|
* mux clients with a unique channel ID because the mux clients might
|
|
* use conflicting channel IDs.
|
|
* - so we inspect and change both SSH2_MSG_CHANNEL_OPEN and
|
|
* SSH2_MSG_CHANNEL_OPEN_CONFIRMATION messages, create a local
|
|
* SSH_CHANNEL_MUX_PROXY channel and replace the mux clients ID
|
|
* with the newly allocated channel ID.
|
|
* 2) Upstream messages are received by matching SSH_CHANNEL_MUX_PROXY
|
|
* channels and processed by channel_proxy_upstream(). The local channel ID
|
|
* is then translated back to the original mux client ID.
|
|
* 3) In both cases we need to keep track of matching SSH2_MSG_CHANNEL_CLOSE
|
|
* messages so we can clean up SSH_CHANNEL_MUX_PROXY channels.
|
|
* 4) The SSH_CHANNEL_MUX_PROXY channels also need to closed when the
|
|
* downstream mux client are removed.
|
|
* 5) Handling SSH2_MSG_CHANNEL_OPEN messages from the upstream server
|
|
* requires more work, because they are not addressed to a specific
|
|
* channel. E.g. client_request_forwarded_tcpip() needs to figure
|
|
* out whether the request is addressed to the local client or a
|
|
* specific downstream client based on the listen-address/port.
|
|
* 6) Agent and X11-Forwarding have a similar problem and are currently
|
|
* not supported as the matching session/channel cannot be identified
|
|
* easily.
|
|
*/
|
|
|
|
/*
|
|
* receive packets from downstream mux clients:
|
|
* channel callback fired on read from mux client, creates
|
|
* SSH_CHANNEL_MUX_PROXY channels and translates channel IDs
|
|
* on channel creation.
|
|
*/
|
|
int
|
|
channel_proxy_downstream(struct ssh *ssh, Channel *downstream)
|
|
{
|
|
Channel *c = NULL;
|
|
struct sshbuf *original = NULL, *modified = NULL;
|
|
const u_char *cp;
|
|
char *ctype = NULL, *listen_host = NULL;
|
|
u_char type;
|
|
size_t have;
|
|
int ret = -1, r;
|
|
u_int id, remote_id, listen_port;
|
|
|
|
/* sshbuf_dump(downstream->input, stderr); */
|
|
if ((r = sshbuf_get_string_direct(downstream->input, &cp, &have))
|
|
!= 0) {
|
|
error_fr(r, "parse");
|
|
return -1;
|
|
}
|
|
if (have < 2) {
|
|
error_f("short message");
|
|
return -1;
|
|
}
|
|
type = cp[1];
|
|
/* skip padlen + type */
|
|
cp += 2;
|
|
have -= 2;
|
|
if (ssh_packet_log_type(type))
|
|
debug3_f("channel %u: down->up: type %u",
|
|
downstream->self, type);
|
|
|
|
switch (type) {
|
|
case SSH2_MSG_CHANNEL_OPEN:
|
|
if ((original = sshbuf_from(cp, have)) == NULL ||
|
|
(modified = sshbuf_new()) == NULL) {
|
|
error_f("alloc");
|
|
goto out;
|
|
}
|
|
if ((r = sshbuf_get_cstring(original, &ctype, NULL)) != 0 ||
|
|
(r = sshbuf_get_u32(original, &id)) != 0) {
|
|
error_fr(r, "parse");
|
|
goto out;
|
|
}
|
|
c = channel_new(ssh, "mux proxy", SSH_CHANNEL_MUX_PROXY,
|
|
-1, -1, -1, 0, 0, 0, ctype, 1);
|
|
c->mux_ctx = downstream; /* point to mux client */
|
|
c->mux_downstream_id = id; /* original downstream id */
|
|
if ((r = sshbuf_put_cstring(modified, ctype)) != 0 ||
|
|
(r = sshbuf_put_u32(modified, c->self)) != 0 ||
|
|
(r = sshbuf_putb(modified, original)) != 0) {
|
|
error_fr(r, "compose");
|
|
channel_free(ssh, c);
|
|
goto out;
|
|
}
|
|
break;
|
|
case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
|
|
/*
|
|
* Almost the same as SSH2_MSG_CHANNEL_OPEN, except then we
|
|
* need to parse 'remote_id' instead of 'ctype'.
|
|
*/
|
|
if ((original = sshbuf_from(cp, have)) == NULL ||
|
|
(modified = sshbuf_new()) == NULL) {
|
|
error_f("alloc");
|
|
goto out;
|
|
}
|
|
if ((r = sshbuf_get_u32(original, &remote_id)) != 0 ||
|
|
(r = sshbuf_get_u32(original, &id)) != 0) {
|
|
error_fr(r, "parse");
|
|
goto out;
|
|
}
|
|
c = channel_new(ssh, "mux proxy", SSH_CHANNEL_MUX_PROXY,
|
|
-1, -1, -1, 0, 0, 0, "mux-down-connect", 1);
|
|
c->mux_ctx = downstream; /* point to mux client */
|
|
c->mux_downstream_id = id;
|
|
c->remote_id = remote_id;
|
|
c->have_remote_id = 1;
|
|
if ((r = sshbuf_put_u32(modified, remote_id)) != 0 ||
|
|
(r = sshbuf_put_u32(modified, c->self)) != 0 ||
|
|
(r = sshbuf_putb(modified, original)) != 0) {
|
|
error_fr(r, "compose");
|
|
channel_free(ssh, c);
|
|
goto out;
|
|
}
|
|
break;
|
|
case SSH2_MSG_GLOBAL_REQUEST:
|
|
if ((original = sshbuf_from(cp, have)) == NULL) {
|
|
error_f("alloc");
|
|
goto out;
|
|
}
|
|
if ((r = sshbuf_get_cstring(original, &ctype, NULL)) != 0) {
|
|
error_fr(r, "parse");
|
|
goto out;
|
|
}
|
|
if (strcmp(ctype, "tcpip-forward") != 0) {
|
|
error_f("unsupported request %s", ctype);
|
|
goto out;
|
|
}
|
|
if ((r = sshbuf_get_u8(original, NULL)) != 0 ||
|
|
(r = sshbuf_get_cstring(original, &listen_host, NULL)) != 0 ||
|
|
(r = sshbuf_get_u32(original, &listen_port)) != 0) {
|
|
error_fr(r, "parse");
|
|
goto out;
|
|
}
|
|
if (listen_port > 65535) {
|
|
error_f("tcpip-forward for %s: bad port %u",
|
|
listen_host, listen_port);
|
|
goto out;
|
|
}
|
|
/* Record that connection to this host/port is permitted. */
|
|
permission_set_add(ssh, FORWARD_USER, FORWARD_LOCAL, "<mux>", -1,
|
|
listen_host, NULL, (int)listen_port, downstream);
|
|
listen_host = NULL;
|
|
break;
|
|
case SSH2_MSG_CHANNEL_CLOSE:
|
|
if (have < 4)
|
|
break;
|
|
remote_id = PEEK_U32(cp);
|
|
if ((c = channel_by_remote_id(ssh, remote_id)) != NULL) {
|
|
if (c->flags & CHAN_CLOSE_RCVD)
|
|
channel_free(ssh, c);
|
|
else
|
|
c->flags |= CHAN_CLOSE_SENT;
|
|
}
|
|
break;
|
|
}
|
|
if (modified) {
|
|
if ((r = sshpkt_start(ssh, type)) != 0 ||
|
|
(r = sshpkt_putb(ssh, modified)) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0) {
|
|
error_fr(r, "send");
|
|
goto out;
|
|
}
|
|
} else {
|
|
if ((r = sshpkt_start(ssh, type)) != 0 ||
|
|
(r = sshpkt_put(ssh, cp, have)) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0) {
|
|
error_fr(r, "send");
|
|
goto out;
|
|
}
|
|
}
|
|
ret = 0;
|
|
out:
|
|
free(ctype);
|
|
free(listen_host);
|
|
sshbuf_free(original);
|
|
sshbuf_free(modified);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* receive packets from upstream server and de-multiplex packets
|
|
* to correct downstream:
|
|
* implemented as a helper for channel input handlers,
|
|
* replaces local (proxy) channel ID with downstream channel ID.
|
|
*/
|
|
int
|
|
channel_proxy_upstream(Channel *c, int type, u_int32_t seq, struct ssh *ssh)
|
|
{
|
|
struct sshbuf *b = NULL;
|
|
Channel *downstream;
|
|
const u_char *cp = NULL;
|
|
size_t len;
|
|
int r;
|
|
|
|
/*
|
|
* When receiving packets from the peer we need to check whether we
|
|
* need to forward the packets to the mux client. In this case we
|
|
* restore the original channel id and keep track of CLOSE messages,
|
|
* so we can cleanup the channel.
|
|
*/
|
|
if (c == NULL || c->type != SSH_CHANNEL_MUX_PROXY)
|
|
return 0;
|
|
if ((downstream = c->mux_ctx) == NULL)
|
|
return 0;
|
|
switch (type) {
|
|
case SSH2_MSG_CHANNEL_CLOSE:
|
|
case SSH2_MSG_CHANNEL_DATA:
|
|
case SSH2_MSG_CHANNEL_EOF:
|
|
case SSH2_MSG_CHANNEL_EXTENDED_DATA:
|
|
case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
|
|
case SSH2_MSG_CHANNEL_OPEN_FAILURE:
|
|
case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
|
|
case SSH2_MSG_CHANNEL_SUCCESS:
|
|
case SSH2_MSG_CHANNEL_FAILURE:
|
|
case SSH2_MSG_CHANNEL_REQUEST:
|
|
break;
|
|
default:
|
|
debug2_f("channel %u: unsupported type %u", c->self, type);
|
|
return 0;
|
|
}
|
|
if ((b = sshbuf_new()) == NULL) {
|
|
error_f("alloc reply");
|
|
goto out;
|
|
}
|
|
/* get remaining payload (after id) */
|
|
cp = sshpkt_ptr(ssh, &len);
|
|
if (cp == NULL) {
|
|
error_f("no packet");
|
|
goto out;
|
|
}
|
|
/* translate id and send to muxclient */
|
|
if ((r = sshbuf_put_u8(b, 0)) != 0 || /* padlen */
|
|
(r = sshbuf_put_u8(b, type)) != 0 ||
|
|
(r = sshbuf_put_u32(b, c->mux_downstream_id)) != 0 ||
|
|
(r = sshbuf_put(b, cp, len)) != 0 ||
|
|
(r = sshbuf_put_stringb(downstream->output, b)) != 0) {
|
|
error_fr(r, "compose muxclient");
|
|
goto out;
|
|
}
|
|
/* sshbuf_dump(b, stderr); */
|
|
if (ssh_packet_log_type(type))
|
|
debug3_f("channel %u: up->down: type %u", c->self, type);
|
|
out:
|
|
/* update state */
|
|
switch (type) {
|
|
case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
|
|
/* record remote_id for SSH2_MSG_CHANNEL_CLOSE */
|
|
if (cp && len > 4) {
|
|
c->remote_id = PEEK_U32(cp);
|
|
c->have_remote_id = 1;
|
|
}
|
|
break;
|
|
case SSH2_MSG_CHANNEL_CLOSE:
|
|
if (c->flags & CHAN_CLOSE_SENT)
|
|
channel_free(ssh, c);
|
|
else
|
|
c->flags |= CHAN_CLOSE_RCVD;
|
|
break;
|
|
}
|
|
sshbuf_free(b);
|
|
return 1;
|
|
}
|
|
|
|
/* -- protocol input */
|
|
|
|
/* Parse a channel ID from the current packet */
|
|
static int
|
|
channel_parse_id(struct ssh *ssh, const char *where, const char *what)
|
|
{
|
|
u_int32_t id;
|
|
int r;
|
|
|
|
if ((r = sshpkt_get_u32(ssh, &id)) != 0) {
|
|
error_r(r, "%s: parse id", where);
|
|
ssh_packet_disconnect(ssh, "Invalid %s message", what);
|
|
}
|
|
if (id > INT_MAX) {
|
|
error_r(r, "%s: bad channel id %u", where, id);
|
|
ssh_packet_disconnect(ssh, "Invalid %s channel id", what);
|
|
}
|
|
return (int)id;
|
|
}
|
|
|
|
/* Lookup a channel from an ID in the current packet */
|
|
static Channel *
|
|
channel_from_packet_id(struct ssh *ssh, const char *where, const char *what)
|
|
{
|
|
int id = channel_parse_id(ssh, where, what);
|
|
Channel *c;
|
|
|
|
if ((c = channel_lookup(ssh, id)) == NULL) {
|
|
ssh_packet_disconnect(ssh,
|
|
"%s packet referred to nonexistent channel %d", what, id);
|
|
}
|
|
return c;
|
|
}
|
|
|
|
int
|
|
channel_input_data(int type, u_int32_t seq, struct ssh *ssh)
|
|
{
|
|
const u_char *data;
|
|
size_t data_len, win_len;
|
|
Channel *c = channel_from_packet_id(ssh, __func__, "data");
|
|
int r;
|
|
|
|
if (channel_proxy_upstream(c, type, seq, ssh))
|
|
return 0;
|
|
|
|
/* Ignore any data for non-open channels (might happen on close) */
|
|
if (c->type != SSH_CHANNEL_OPEN &&
|
|
c->type != SSH_CHANNEL_RDYNAMIC_OPEN &&
|
|
c->type != SSH_CHANNEL_RDYNAMIC_FINISH &&
|
|
c->type != SSH_CHANNEL_X11_OPEN)
|
|
return 0;
|
|
|
|
/* Get the data. */
|
|
if ((r = sshpkt_get_string_direct(ssh, &data, &data_len)) != 0 ||
|
|
(r = sshpkt_get_end(ssh)) != 0)
|
|
fatal_fr(r, "channel %i: get data", c->self);
|
|
|
|
win_len = data_len;
|
|
if (c->datagram)
|
|
win_len += 4; /* string length header */
|
|
|
|
/*
|
|
* The sending side reduces its window as it sends data, so we
|
|
* must 'fake' consumption of the data in order to ensure that window
|
|
* updates are sent back. Otherwise the connection might deadlock.
|
|
*/
|
|
if (c->ostate != CHAN_OUTPUT_OPEN) {
|
|
c->local_window -= win_len;
|
|
c->local_consumed += win_len;
|
|
return 0;
|
|
}
|
|
|
|
if (win_len > c->local_maxpacket) {
|
|
logit("channel %d: rcvd big packet %zu, maxpack %u",
|
|
c->self, win_len, c->local_maxpacket);
|
|
return 0;
|
|
}
|
|
if (win_len > c->local_window) {
|
|
logit("channel %d: rcvd too much data %zu, win %u",
|
|
c->self, win_len, c->local_window);
|
|
return 0;
|
|
}
|
|
c->local_window -= win_len;
|
|
|
|
if (c->datagram) {
|
|
if ((r = sshbuf_put_string(c->output, data, data_len)) != 0)
|
|
fatal_fr(r, "channel %i: append datagram", c->self);
|
|
} else if ((r = sshbuf_put(c->output, data, data_len)) != 0)
|
|
fatal_fr(r, "channel %i: append data", c->self);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
channel_input_extended_data(int type, u_int32_t seq, struct ssh *ssh)
|
|
{
|
|
const u_char *data;
|
|
size_t data_len;
|
|
u_int32_t tcode;
|
|
Channel *c = channel_from_packet_id(ssh, __func__, "extended data");
|
|
int r;
|
|
|
|
if (channel_proxy_upstream(c, type, seq, ssh))
|
|
return 0;
|
|
if (c->type != SSH_CHANNEL_OPEN) {
|
|
logit("channel %d: ext data for non open", c->self);
|
|
return 0;
|
|
}
|
|
if (c->flags & CHAN_EOF_RCVD) {
|
|
if (ssh->compat & SSH_BUG_EXTEOF)
|
|
debug("channel %d: accepting ext data after eof",
|
|
c->self);
|
|
else
|
|
ssh_packet_disconnect(ssh, "Received extended_data "
|
|
"after EOF on channel %d.", c->self);
|
|
}
|
|
|
|
if ((r = sshpkt_get_u32(ssh, &tcode)) != 0) {
|
|
error_fr(r, "parse tcode");
|
|
ssh_packet_disconnect(ssh, "Invalid extended_data message");
|
|
}
|
|
if (c->efd == -1 ||
|
|
c->extended_usage != CHAN_EXTENDED_WRITE ||
|
|
tcode != SSH2_EXTENDED_DATA_STDERR) {
|
|
logit("channel %d: bad ext data", c->self);
|
|
return 0;
|
|
}
|
|
if ((r = sshpkt_get_string_direct(ssh, &data, &data_len)) != 0 ||
|
|
(r = sshpkt_get_end(ssh)) != 0) {
|
|
error_fr(r, "parse data");
|
|
ssh_packet_disconnect(ssh, "Invalid extended_data message");
|
|
}
|
|
|
|
if (data_len > c->local_window) {
|
|
logit("channel %d: rcvd too much extended_data %zu, win %u",
|
|
c->self, data_len, c->local_window);
|
|
return 0;
|
|
}
|
|
debug2("channel %d: rcvd ext data %zu", c->self, data_len);
|
|
/* XXX sshpkt_getb? */
|
|
if ((r = sshbuf_put(c->extended, data, data_len)) != 0)
|
|
error_fr(r, "append");
|
|
c->local_window -= data_len;
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
channel_input_ieof(int type, u_int32_t seq, struct ssh *ssh)
|
|
{
|
|
Channel *c = channel_from_packet_id(ssh, __func__, "ieof");
|
|
int r;
|
|
|
|
if ((r = sshpkt_get_end(ssh)) != 0) {
|
|
error_fr(r, "parse data");
|
|
ssh_packet_disconnect(ssh, "Invalid ieof message");
|
|
}
|
|
|
|
if (channel_proxy_upstream(c, type, seq, ssh))
|
|
return 0;
|
|
chan_rcvd_ieof(ssh, c);
|
|
|
|
/* XXX force input close */
|
|
if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
|
|
debug("channel %d: FORCE input drain", c->self);
|
|
c->istate = CHAN_INPUT_WAIT_DRAIN;
|
|
if (sshbuf_len(c->input) == 0)
|
|
chan_ibuf_empty(ssh, c);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
channel_input_oclose(int type, u_int32_t seq, struct ssh *ssh)
|
|
{
|
|
Channel *c = channel_from_packet_id(ssh, __func__, "oclose");
|
|
int r;
|
|
|
|
if (channel_proxy_upstream(c, type, seq, ssh))
|
|
return 0;
|
|
if ((r = sshpkt_get_end(ssh)) != 0) {
|
|
error_fr(r, "parse data");
|
|
ssh_packet_disconnect(ssh, "Invalid oclose message");
|
|
}
|
|
chan_rcvd_oclose(ssh, c);
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
channel_input_open_confirmation(int type, u_int32_t seq, struct ssh *ssh)
|
|
{
|
|
Channel *c = channel_from_packet_id(ssh, __func__, "open confirmation");
|
|
u_int32_t remote_window, remote_maxpacket;
|
|
int r;
|
|
|
|
if (channel_proxy_upstream(c, type, seq, ssh))
|
|
return 0;
|
|
if (c->type != SSH_CHANNEL_OPENING)
|
|
ssh_packet_disconnect(ssh, "Received open confirmation for "
|
|
"non-opening channel %d.", c->self);
|
|
/*
|
|
* Record the remote channel number and mark that the channel
|
|
* is now open.
|
|
*/
|
|
if ((r = sshpkt_get_u32(ssh, &c->remote_id)) != 0 ||
|
|
(r = sshpkt_get_u32(ssh, &remote_window)) != 0 ||
|
|
(r = sshpkt_get_u32(ssh, &remote_maxpacket)) != 0 ||
|
|
(r = sshpkt_get_end(ssh)) != 0) {
|
|
error_fr(r, "window/maxpacket");
|
|
ssh_packet_disconnect(ssh, "Invalid open confirmation message");
|
|
}
|
|
|
|
c->have_remote_id = 1;
|
|
c->remote_window = remote_window;
|
|
c->remote_maxpacket = remote_maxpacket;
|
|
c->type = SSH_CHANNEL_OPEN;
|
|
if (c->open_confirm) {
|
|
debug2_f("channel %d: callback start", c->self);
|
|
c->open_confirm(ssh, c->self, 1, c->open_confirm_ctx);
|
|
debug2_f("channel %d: callback done", c->self);
|
|
}
|
|
debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
|
|
c->remote_window, c->remote_maxpacket);
|
|
return 0;
|
|
}
|
|
|
|
static char *
|
|
reason2txt(int reason)
|
|
{
|
|
switch (reason) {
|
|
case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
|
|
return "administratively prohibited";
|
|
case SSH2_OPEN_CONNECT_FAILED:
|
|
return "connect failed";
|
|
case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
|
|
return "unknown channel type";
|
|
case SSH2_OPEN_RESOURCE_SHORTAGE:
|
|
return "resource shortage";
|
|
}
|
|
return "unknown reason";
|
|
}
|
|
|
|
int
|
|
channel_input_open_failure(int type, u_int32_t seq, struct ssh *ssh)
|
|
{
|
|
Channel *c = channel_from_packet_id(ssh, __func__, "open failure");
|
|
u_int32_t reason;
|
|
char *msg = NULL;
|
|
int r;
|
|
|
|
if (channel_proxy_upstream(c, type, seq, ssh))
|
|
return 0;
|
|
if (c->type != SSH_CHANNEL_OPENING)
|
|
ssh_packet_disconnect(ssh, "Received open failure for "
|
|
"non-opening channel %d.", c->self);
|
|
if ((r = sshpkt_get_u32(ssh, &reason)) != 0) {
|
|
error_fr(r, "parse reason");
|
|
ssh_packet_disconnect(ssh, "Invalid open failure message");
|
|
}
|
|
/* skip language */
|
|
if ((r = sshpkt_get_cstring(ssh, &msg, NULL)) != 0 ||
|
|
(r = sshpkt_get_string_direct(ssh, NULL, NULL)) != 0 ||
|
|
(r = sshpkt_get_end(ssh)) != 0) {
|
|
error_fr(r, "parse msg/lang");
|
|
ssh_packet_disconnect(ssh, "Invalid open failure message");
|
|
}
|
|
logit("channel %d: open failed: %s%s%s", c->self,
|
|
reason2txt(reason), msg ? ": ": "", msg ? msg : "");
|
|
free(msg);
|
|
if (c->open_confirm) {
|
|
debug2_f("channel %d: callback start", c->self);
|
|
c->open_confirm(ssh, c->self, 0, c->open_confirm_ctx);
|
|
debug2_f("channel %d: callback done", c->self);
|
|
}
|
|
/* Schedule the channel for cleanup/deletion. */
|
|
chan_mark_dead(ssh, c);
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
channel_input_window_adjust(int type, u_int32_t seq, struct ssh *ssh)
|
|
{
|
|
int id = channel_parse_id(ssh, __func__, "window adjust");
|
|
Channel *c;
|
|
u_int32_t adjust;
|
|
u_int new_rwin;
|
|
int r;
|
|
|
|
if ((c = channel_lookup(ssh, id)) == NULL) {
|
|
logit("Received window adjust for non-open channel %d.", id);
|
|
return 0;
|
|
}
|
|
|
|
if (channel_proxy_upstream(c, type, seq, ssh))
|
|
return 0;
|
|
if ((r = sshpkt_get_u32(ssh, &adjust)) != 0 ||
|
|
(r = sshpkt_get_end(ssh)) != 0) {
|
|
error_fr(r, "parse adjust");
|
|
ssh_packet_disconnect(ssh, "Invalid window adjust message");
|
|
}
|
|
debug2("channel %d: rcvd adjust %u", c->self, adjust);
|
|
if ((new_rwin = c->remote_window + adjust) < c->remote_window) {
|
|
fatal("channel %d: adjust %u overflows remote window %u",
|
|
c->self, adjust, c->remote_window);
|
|
}
|
|
c->remote_window = new_rwin;
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
channel_input_status_confirm(int type, u_int32_t seq, struct ssh *ssh)
|
|
{
|
|
int id = channel_parse_id(ssh, __func__, "status confirm");
|
|
Channel *c;
|
|
struct channel_confirm *cc;
|
|
|
|
/* Reset keepalive timeout */
|
|
ssh_packet_set_alive_timeouts(ssh, 0);
|
|
|
|
debug2_f("type %d id %d", type, id);
|
|
|
|
if ((c = channel_lookup(ssh, id)) == NULL) {
|
|
logit_f("%d: unknown", id);
|
|
return 0;
|
|
}
|
|
if (channel_proxy_upstream(c, type, seq, ssh))
|
|
return 0;
|
|
if (sshpkt_get_end(ssh) != 0)
|
|
ssh_packet_disconnect(ssh, "Invalid status confirm message");
|
|
if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
|
|
return 0;
|
|
cc->cb(ssh, type, c, cc->ctx);
|
|
TAILQ_REMOVE(&c->status_confirms, cc, entry);
|
|
freezero(cc, sizeof(*cc));
|
|
return 0;
|
|
}
|
|
|
|
/* -- tcp forwarding */
|
|
|
|
void
|
|
channel_set_af(struct ssh *ssh, int af)
|
|
{
|
|
ssh->chanctxt->IPv4or6 = af;
|
|
}
|
|
|
|
|
|
/*
|
|
* Determine whether or not a port forward listens to loopback, the
|
|
* specified address or wildcard. On the client, a specified bind
|
|
* address will always override gateway_ports. On the server, a
|
|
* gateway_ports of 1 (``yes'') will override the client's specification
|
|
* and force a wildcard bind, whereas a value of 2 (``clientspecified'')
|
|
* will bind to whatever address the client asked for.
|
|
*
|
|
* Special-case listen_addrs are:
|
|
*
|
|
* "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
|
|
* "" (empty string), "*" -> wildcard v4/v6
|
|
* "localhost" -> loopback v4/v6
|
|
* "127.0.0.1" / "::1" -> accepted even if gateway_ports isn't set
|
|
*/
|
|
static const char *
|
|
channel_fwd_bind_addr(struct ssh *ssh, const char *listen_addr, int *wildcardp,
|
|
int is_client, struct ForwardOptions *fwd_opts)
|
|
{
|
|
const char *addr = NULL;
|
|
int wildcard = 0;
|
|
|
|
if (listen_addr == NULL) {
|
|
/* No address specified: default to gateway_ports setting */
|
|
if (fwd_opts->gateway_ports)
|
|
wildcard = 1;
|
|
} else if (fwd_opts->gateway_ports || is_client) {
|
|
if (((ssh->compat & SSH_OLD_FORWARD_ADDR) &&
|
|
strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
|
|
*listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
|
|
(!is_client && fwd_opts->gateway_ports == 1)) {
|
|
wildcard = 1;
|
|
/*
|
|
* Notify client if they requested a specific listen
|
|
* address and it was overridden.
|
|
*/
|
|
if (*listen_addr != '\0' &&
|
|
strcmp(listen_addr, "0.0.0.0") != 0 &&
|
|
strcmp(listen_addr, "*") != 0) {
|
|
ssh_packet_send_debug(ssh,
|
|
"Forwarding listen address "
|
|
"\"%s\" overridden by server "
|
|
"GatewayPorts", listen_addr);
|
|
}
|
|
} else if (strcmp(listen_addr, "localhost") != 0 ||
|
|
strcmp(listen_addr, "127.0.0.1") == 0 ||
|
|
strcmp(listen_addr, "::1") == 0) {
|
|
/*
|
|
* Accept explicit localhost address when
|
|
* GatewayPorts=yes. The "localhost" hostname is
|
|
* deliberately skipped here so it will listen on all
|
|
* available local address families.
|
|
*/
|
|
addr = listen_addr;
|
|
}
|
|
} else if (strcmp(listen_addr, "127.0.0.1") == 0 ||
|
|
strcmp(listen_addr, "::1") == 0) {
|
|
/*
|
|
* If a specific IPv4/IPv6 localhost address has been
|
|
* requested then accept it even if gateway_ports is in
|
|
* effect. This allows the client to prefer IPv4 or IPv6.
|
|
*/
|
|
addr = listen_addr;
|
|
}
|
|
if (wildcardp != NULL)
|
|
*wildcardp = wildcard;
|
|
return addr;
|
|
}
|
|
|
|
static int
|
|
channel_setup_fwd_listener_tcpip(struct ssh *ssh, int type,
|
|
struct Forward *fwd, int *allocated_listen_port,
|
|
struct ForwardOptions *fwd_opts)
|
|
{
|
|
Channel *c;
|
|
int sock, r, success = 0, wildcard = 0, is_client;
|
|
struct addrinfo hints, *ai, *aitop;
|
|
const char *host, *addr;
|
|
char ntop[NI_MAXHOST], strport[NI_MAXSERV];
|
|
in_port_t *lport_p;
|
|
|
|
is_client = (type == SSH_CHANNEL_PORT_LISTENER);
|
|
|
|
if (is_client && fwd->connect_path != NULL) {
|
|
host = fwd->connect_path;
|
|
} else {
|
|
host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
|
|
fwd->listen_host : fwd->connect_host;
|
|
if (host == NULL) {
|
|
error("No forward host name.");
|
|
return 0;
|
|
}
|
|
if (strlen(host) >= NI_MAXHOST) {
|
|
error("Forward host name too long.");
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/* Determine the bind address, cf. channel_fwd_bind_addr() comment */
|
|
addr = channel_fwd_bind_addr(ssh, fwd->listen_host, &wildcard,
|
|
is_client, fwd_opts);
|
|
debug3_f("type %d wildcard %d addr %s", type, wildcard,
|
|
(addr == NULL) ? "NULL" : addr);
|
|
|
|
/*
|
|
* getaddrinfo returns a loopback address if the hostname is
|
|
* set to NULL and hints.ai_flags is not AI_PASSIVE
|
|
*/
|
|
memset(&hints, 0, sizeof(hints));
|
|
hints.ai_family = ssh->chanctxt->IPv4or6;
|
|
hints.ai_flags = wildcard ? AI_PASSIVE : 0;
|
|
hints.ai_socktype = SOCK_STREAM;
|
|
snprintf(strport, sizeof strport, "%d", fwd->listen_port);
|
|
if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
|
|
if (addr == NULL) {
|
|
/* This really shouldn't happen */
|
|
ssh_packet_disconnect(ssh, "getaddrinfo: fatal error: %s",
|
|
ssh_gai_strerror(r));
|
|
} else {
|
|
error_f("getaddrinfo(%.64s): %s", addr,
|
|
ssh_gai_strerror(r));
|
|
}
|
|
return 0;
|
|
}
|
|
if (allocated_listen_port != NULL)
|
|
*allocated_listen_port = 0;
|
|
for (ai = aitop; ai; ai = ai->ai_next) {
|
|
switch (ai->ai_family) {
|
|
case AF_INET:
|
|
lport_p = &((struct sockaddr_in *)ai->ai_addr)->
|
|
sin_port;
|
|
break;
|
|
case AF_INET6:
|
|
lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
|
|
sin6_port;
|
|
break;
|
|
default:
|
|
continue;
|
|
}
|
|
/*
|
|
* If allocating a port for -R forwards, then use the
|
|
* same port for all address families.
|
|
*/
|
|
if (type == SSH_CHANNEL_RPORT_LISTENER &&
|
|
fwd->listen_port == 0 && allocated_listen_port != NULL &&
|
|
*allocated_listen_port > 0)
|
|
*lport_p = htons(*allocated_listen_port);
|
|
|
|
if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
|
|
strport, sizeof(strport),
|
|
NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
|
|
error_f("getnameinfo failed");
|
|
continue;
|
|
}
|
|
/* Create a port to listen for the host. */
|
|
sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
|
|
if (sock == -1) {
|
|
/* this is no error since kernel may not support ipv6 */
|
|
verbose("socket [%s]:%s: %.100s", ntop, strport,
|
|
strerror(errno));
|
|
continue;
|
|
}
|
|
|
|
set_reuseaddr(sock);
|
|
if (ai->ai_family == AF_INET6)
|
|
sock_set_v6only(sock);
|
|
|
|
debug("Local forwarding listening on %s port %s.",
|
|
ntop, strport);
|
|
|
|
/* Bind the socket to the address. */
|
|
if (bind(sock, ai->ai_addr, ai->ai_addrlen) == -1) {
|
|
/*
|
|
* address can be in if use ipv6 address is
|
|
* already bound
|
|
*/
|
|
if (!ai->ai_next)
|
|
error("bind [%s]:%s: %.100s",
|
|
ntop, strport, strerror(errno));
|
|
else
|
|
verbose("bind [%s]:%s: %.100s",
|
|
ntop, strport, strerror(errno));
|
|
|
|
close(sock);
|
|
continue;
|
|
}
|
|
/* Start listening for connections on the socket. */
|
|
if (listen(sock, SSH_LISTEN_BACKLOG) == -1) {
|
|
error("listen [%s]:%s: %.100s", ntop, strport,
|
|
strerror(errno));
|
|
close(sock);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* fwd->listen_port == 0 requests a dynamically allocated port -
|
|
* record what we got.
|
|
*/
|
|
if (type == SSH_CHANNEL_RPORT_LISTENER &&
|
|
fwd->listen_port == 0 &&
|
|
allocated_listen_port != NULL &&
|
|
*allocated_listen_port == 0) {
|
|
*allocated_listen_port = get_local_port(sock);
|
|
debug("Allocated listen port %d",
|
|
*allocated_listen_port);
|
|
}
|
|
|
|
/* Allocate a channel number for the socket. */
|
|
c = channel_new(ssh, "port listener", type, sock, sock, -1,
|
|
CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
|
|
0, "port listener", 1);
|
|
c->path = xstrdup(host);
|
|
c->host_port = fwd->connect_port;
|
|
c->listening_addr = addr == NULL ? NULL : xstrdup(addr);
|
|
if (fwd->listen_port == 0 && allocated_listen_port != NULL &&
|
|
!(ssh->compat & SSH_BUG_DYNAMIC_RPORT))
|
|
c->listening_port = *allocated_listen_port;
|
|
else
|
|
c->listening_port = fwd->listen_port;
|
|
success = 1;
|
|
}
|
|
if (success == 0)
|
|
error_f("cannot listen to port: %d", fwd->listen_port);
|
|
freeaddrinfo(aitop);
|
|
return success;
|
|
}
|
|
|
|
static int
|
|
channel_setup_fwd_listener_streamlocal(struct ssh *ssh, int type,
|
|
struct Forward *fwd, struct ForwardOptions *fwd_opts)
|
|
{
|
|
struct sockaddr_un sunaddr;
|
|
const char *path;
|
|
Channel *c;
|
|
int port, sock;
|
|
mode_t omask;
|
|
|
|
switch (type) {
|
|
case SSH_CHANNEL_UNIX_LISTENER:
|
|
if (fwd->connect_path != NULL) {
|
|
if (strlen(fwd->connect_path) > sizeof(sunaddr.sun_path)) {
|
|
error("Local connecting path too long: %s",
|
|
fwd->connect_path);
|
|
return 0;
|
|
}
|
|
path = fwd->connect_path;
|
|
port = PORT_STREAMLOCAL;
|
|
} else {
|
|
if (fwd->connect_host == NULL) {
|
|
error("No forward host name.");
|
|
return 0;
|
|
}
|
|
if (strlen(fwd->connect_host) >= NI_MAXHOST) {
|
|
error("Forward host name too long.");
|
|
return 0;
|
|
}
|
|
path = fwd->connect_host;
|
|
port = fwd->connect_port;
|
|
}
|
|
break;
|
|
case SSH_CHANNEL_RUNIX_LISTENER:
|
|
path = fwd->listen_path;
|
|
port = PORT_STREAMLOCAL;
|
|
break;
|
|
default:
|
|
error_f("unexpected channel type %d", type);
|
|
return 0;
|
|
}
|
|
|
|
if (fwd->listen_path == NULL) {
|
|
error("No forward path name.");
|
|
return 0;
|
|
}
|
|
if (strlen(fwd->listen_path) > sizeof(sunaddr.sun_path)) {
|
|
error("Local listening path too long: %s", fwd->listen_path);
|
|
return 0;
|
|
}
|
|
|
|
debug3_f("type %d path %s", type, fwd->listen_path);
|
|
|
|
/* Start a Unix domain listener. */
|
|
omask = umask(fwd_opts->streamlocal_bind_mask);
|
|
sock = unix_listener(fwd->listen_path, SSH_LISTEN_BACKLOG,
|
|
fwd_opts->streamlocal_bind_unlink);
|
|
umask(omask);
|
|
if (sock < 0)
|
|
return 0;
|
|
|
|
debug("Local forwarding listening on path %s.", fwd->listen_path);
|
|
|
|
/* Allocate a channel number for the socket. */
|
|
c = channel_new(ssh, "unix listener", type, sock, sock, -1,
|
|
CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
|
|
0, "unix listener", 1);
|
|
c->path = xstrdup(path);
|
|
c->host_port = port;
|
|
c->listening_port = PORT_STREAMLOCAL;
|
|
c->listening_addr = xstrdup(fwd->listen_path);
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
channel_cancel_rport_listener_tcpip(struct ssh *ssh,
|
|
const char *host, u_short port)
|
|
{
|
|
u_int i;
|
|
int found = 0;
|
|
|
|
for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
|
|
Channel *c = ssh->chanctxt->channels[i];
|
|
if (c == NULL || c->type != SSH_CHANNEL_RPORT_LISTENER)
|
|
continue;
|
|
if (strcmp(c->path, host) == 0 && c->listening_port == port) {
|
|
debug2_f("close channel %d", i);
|
|
channel_free(ssh, c);
|
|
found = 1;
|
|
}
|
|
}
|
|
|
|
return found;
|
|
}
|
|
|
|
static int
|
|
channel_cancel_rport_listener_streamlocal(struct ssh *ssh, const char *path)
|
|
{
|
|
u_int i;
|
|
int found = 0;
|
|
|
|
for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
|
|
Channel *c = ssh->chanctxt->channels[i];
|
|
if (c == NULL || c->type != SSH_CHANNEL_RUNIX_LISTENER)
|
|
continue;
|
|
if (c->path == NULL)
|
|
continue;
|
|
if (strcmp(c->path, path) == 0) {
|
|
debug2_f("close channel %d", i);
|
|
channel_free(ssh, c);
|
|
found = 1;
|
|
}
|
|
}
|
|
|
|
return found;
|
|
}
|
|
|
|
int
|
|
channel_cancel_rport_listener(struct ssh *ssh, struct Forward *fwd)
|
|
{
|
|
if (fwd->listen_path != NULL) {
|
|
return channel_cancel_rport_listener_streamlocal(ssh,
|
|
fwd->listen_path);
|
|
} else {
|
|
return channel_cancel_rport_listener_tcpip(ssh,
|
|
fwd->listen_host, fwd->listen_port);
|
|
}
|
|
}
|
|
|
|
static int
|
|
channel_cancel_lport_listener_tcpip(struct ssh *ssh,
|
|
const char *lhost, u_short lport, int cport,
|
|
struct ForwardOptions *fwd_opts)
|
|
{
|
|
u_int i;
|
|
int found = 0;
|
|
const char *addr = channel_fwd_bind_addr(ssh, lhost, NULL, 1, fwd_opts);
|
|
|
|
for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
|
|
Channel *c = ssh->chanctxt->channels[i];
|
|
if (c == NULL || c->type != SSH_CHANNEL_PORT_LISTENER)
|
|
continue;
|
|
if (c->listening_port != lport)
|
|
continue;
|
|
if (cport == CHANNEL_CANCEL_PORT_STATIC) {
|
|
/* skip dynamic forwardings */
|
|
if (c->host_port == 0)
|
|
continue;
|
|
} else {
|
|
if (c->host_port != cport)
|
|
continue;
|
|
}
|
|
if ((c->listening_addr == NULL && addr != NULL) ||
|
|
(c->listening_addr != NULL && addr == NULL))
|
|
continue;
|
|
if (addr == NULL || strcmp(c->listening_addr, addr) == 0) {
|
|
debug2_f("close channel %d", i);
|
|
channel_free(ssh, c);
|
|
found = 1;
|
|
}
|
|
}
|
|
|
|
return found;
|
|
}
|
|
|
|
static int
|
|
channel_cancel_lport_listener_streamlocal(struct ssh *ssh, const char *path)
|
|
{
|
|
u_int i;
|
|
int found = 0;
|
|
|
|
if (path == NULL) {
|
|
error_f("no path specified.");
|
|
return 0;
|
|
}
|
|
|
|
for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
|
|
Channel *c = ssh->chanctxt->channels[i];
|
|
if (c == NULL || c->type != SSH_CHANNEL_UNIX_LISTENER)
|
|
continue;
|
|
if (c->listening_addr == NULL)
|
|
continue;
|
|
if (strcmp(c->listening_addr, path) == 0) {
|
|
debug2_f("close channel %d", i);
|
|
channel_free(ssh, c);
|
|
found = 1;
|
|
}
|
|
}
|
|
|
|
return found;
|
|
}
|
|
|
|
int
|
|
channel_cancel_lport_listener(struct ssh *ssh,
|
|
struct Forward *fwd, int cport, struct ForwardOptions *fwd_opts)
|
|
{
|
|
if (fwd->listen_path != NULL) {
|
|
return channel_cancel_lport_listener_streamlocal(ssh,
|
|
fwd->listen_path);
|
|
} else {
|
|
return channel_cancel_lport_listener_tcpip(ssh,
|
|
fwd->listen_host, fwd->listen_port, cport, fwd_opts);
|
|
}
|
|
}
|
|
|
|
/* protocol local port fwd, used by ssh */
|
|
int
|
|
channel_setup_local_fwd_listener(struct ssh *ssh,
|
|
struct Forward *fwd, struct ForwardOptions *fwd_opts)
|
|
{
|
|
if (fwd->listen_path != NULL) {
|
|
return channel_setup_fwd_listener_streamlocal(ssh,
|
|
SSH_CHANNEL_UNIX_LISTENER, fwd, fwd_opts);
|
|
} else {
|
|
return channel_setup_fwd_listener_tcpip(ssh,
|
|
SSH_CHANNEL_PORT_LISTENER, fwd, NULL, fwd_opts);
|
|
}
|
|
}
|
|
|
|
/* Matches a remote forwarding permission against a requested forwarding */
|
|
static int
|
|
remote_open_match(struct permission *allowed_open, struct Forward *fwd)
|
|
{
|
|
int ret;
|
|
char *lhost;
|
|
|
|
/* XXX add ACLs for streamlocal */
|
|
if (fwd->listen_path != NULL)
|
|
return 1;
|
|
|
|
if (fwd->listen_host == NULL || allowed_open->listen_host == NULL)
|
|
return 0;
|
|
|
|
if (allowed_open->listen_port != FWD_PERMIT_ANY_PORT &&
|
|
allowed_open->listen_port != fwd->listen_port)
|
|
return 0;
|
|
|
|
/* Match hostnames case-insensitively */
|
|
lhost = xstrdup(fwd->listen_host);
|
|
lowercase(lhost);
|
|
ret = match_pattern(lhost, allowed_open->listen_host);
|
|
free(lhost);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* Checks whether a requested remote forwarding is permitted */
|
|
static int
|
|
check_rfwd_permission(struct ssh *ssh, struct Forward *fwd)
|
|
{
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
|
struct permission_set *pset = &sc->remote_perms;
|
|
u_int i, permit, permit_adm = 1;
|
|
struct permission *perm;
|
|
|
|
/* XXX apply GatewayPorts override before checking? */
|
|
|
|
permit = pset->all_permitted;
|
|
if (!permit) {
|
|
for (i = 0; i < pset->num_permitted_user; i++) {
|
|
perm = &pset->permitted_user[i];
|
|
if (remote_open_match(perm, fwd)) {
|
|
permit = 1;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (pset->num_permitted_admin > 0) {
|
|
permit_adm = 0;
|
|
for (i = 0; i < pset->num_permitted_admin; i++) {
|
|
perm = &pset->permitted_admin[i];
|
|
if (remote_open_match(perm, fwd)) {
|
|
permit_adm = 1;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
return permit && permit_adm;
|
|
}
|
|
|
|
/* protocol v2 remote port fwd, used by sshd */
|
|
int
|
|
channel_setup_remote_fwd_listener(struct ssh *ssh, struct Forward *fwd,
|
|
int *allocated_listen_port, struct ForwardOptions *fwd_opts)
|
|
{
|
|
if (!check_rfwd_permission(ssh, fwd)) {
|
|
ssh_packet_send_debug(ssh, "port forwarding refused");
|
|
if (fwd->listen_path != NULL)
|
|
/* XXX always allowed, see remote_open_match() */
|
|
logit("Received request from %.100s port %d to "
|
|
"remote forward to path \"%.100s\", "
|
|
"but the request was denied.",
|
|
ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
|
|
fwd->listen_path);
|
|
else if(fwd->listen_host != NULL)
|
|
logit("Received request from %.100s port %d to "
|
|
"remote forward to host %.100s port %d, "
|
|
"but the request was denied.",
|
|
ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
|
|
fwd->listen_host, fwd->listen_port );
|
|
else
|
|
logit("Received request from %.100s port %d to remote "
|
|
"forward, but the request was denied.",
|
|
ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
|
|
return 0;
|
|
}
|
|
if (fwd->listen_path != NULL) {
|
|
return channel_setup_fwd_listener_streamlocal(ssh,
|
|
SSH_CHANNEL_RUNIX_LISTENER, fwd, fwd_opts);
|
|
} else {
|
|
return channel_setup_fwd_listener_tcpip(ssh,
|
|
SSH_CHANNEL_RPORT_LISTENER, fwd, allocated_listen_port,
|
|
fwd_opts);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Translate the requested rfwd listen host to something usable for
|
|
* this server.
|
|
*/
|
|
static const char *
|
|
channel_rfwd_bind_host(const char *listen_host)
|
|
{
|
|
if (listen_host == NULL) {
|
|
return "localhost";
|
|
} else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) {
|
|
return "";
|
|
} else
|
|
return listen_host;
|
|
}
|
|
|
|
/*
|
|
* Initiate forwarding of connections to port "port" on remote host through
|
|
* the secure channel to host:port from local side.
|
|
* Returns handle (index) for updating the dynamic listen port with
|
|
* channel_update_permission().
|
|
*/
|
|
int
|
|
channel_request_remote_forwarding(struct ssh *ssh, struct Forward *fwd)
|
|
{
|
|
int r, success = 0, idx = -1;
|
|
char *host_to_connect, *listen_host, *listen_path;
|
|
int port_to_connect, listen_port;
|
|
|
|
/* Send the forward request to the remote side. */
|
|
if (fwd->listen_path != NULL) {
|
|
if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
|
|
(r = sshpkt_put_cstring(ssh,
|
|
"streamlocal-forward@openssh.com")) != 0 ||
|
|
(r = sshpkt_put_u8(ssh, 1)) != 0 || /* want reply */
|
|
(r = sshpkt_put_cstring(ssh, fwd->listen_path)) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0 ||
|
|
(r = ssh_packet_write_wait(ssh)) != 0)
|
|
fatal_fr(r, "request streamlocal");
|
|
} else {
|
|
if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
|
|
(r = sshpkt_put_cstring(ssh, "tcpip-forward")) != 0 ||
|
|
(r = sshpkt_put_u8(ssh, 1)) != 0 || /* want reply */
|
|
(r = sshpkt_put_cstring(ssh,
|
|
channel_rfwd_bind_host(fwd->listen_host))) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, fwd->listen_port)) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0 ||
|
|
(r = ssh_packet_write_wait(ssh)) != 0)
|
|
fatal_fr(r, "request tcpip-forward");
|
|
}
|
|
/* Assume that server accepts the request */
|
|
success = 1;
|
|
if (success) {
|
|
/* Record that connection to this host/port is permitted. */
|
|
host_to_connect = listen_host = listen_path = NULL;
|
|
port_to_connect = listen_port = 0;
|
|
if (fwd->connect_path != NULL) {
|
|
host_to_connect = xstrdup(fwd->connect_path);
|
|
port_to_connect = PORT_STREAMLOCAL;
|
|
} else {
|
|
host_to_connect = xstrdup(fwd->connect_host);
|
|
port_to_connect = fwd->connect_port;
|
|
}
|
|
if (fwd->listen_path != NULL) {
|
|
listen_path = xstrdup(fwd->listen_path);
|
|
listen_port = PORT_STREAMLOCAL;
|
|
} else {
|
|
if (fwd->listen_host != NULL)
|
|
listen_host = xstrdup(fwd->listen_host);
|
|
listen_port = fwd->listen_port;
|
|
}
|
|
idx = permission_set_add(ssh, FORWARD_USER, FORWARD_LOCAL,
|
|
host_to_connect, port_to_connect,
|
|
listen_host, listen_path, listen_port, NULL);
|
|
}
|
|
return idx;
|
|
}
|
|
|
|
static int
|
|
open_match(struct permission *allowed_open, const char *requestedhost,
|
|
int requestedport)
|
|
{
|
|
if (allowed_open->host_to_connect == NULL)
|
|
return 0;
|
|
if (allowed_open->port_to_connect != FWD_PERMIT_ANY_PORT &&
|
|
allowed_open->port_to_connect != requestedport)
|
|
return 0;
|
|
if (strcmp(allowed_open->host_to_connect, FWD_PERMIT_ANY_HOST) != 0 &&
|
|
strcmp(allowed_open->host_to_connect, requestedhost) != 0)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Note that in the listen host/port case
|
|
* we don't support FWD_PERMIT_ANY_PORT and
|
|
* need to translate between the configured-host (listen_host)
|
|
* and what we've sent to the remote server (channel_rfwd_bind_host)
|
|
*/
|
|
static int
|
|
open_listen_match_tcpip(struct permission *allowed_open,
|
|
const char *requestedhost, u_short requestedport, int translate)
|
|
{
|
|
const char *allowed_host;
|
|
|
|
if (allowed_open->host_to_connect == NULL)
|
|
return 0;
|
|
if (allowed_open->listen_port != requestedport)
|
|
return 0;
|
|
if (!translate && allowed_open->listen_host == NULL &&
|
|
requestedhost == NULL)
|
|
return 1;
|
|
allowed_host = translate ?
|
|
channel_rfwd_bind_host(allowed_open->listen_host) :
|
|
allowed_open->listen_host;
|
|
if (allowed_host == NULL || requestedhost == NULL ||
|
|
strcmp(allowed_host, requestedhost) != 0)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
open_listen_match_streamlocal(struct permission *allowed_open,
|
|
const char *requestedpath)
|
|
{
|
|
if (allowed_open->host_to_connect == NULL)
|
|
return 0;
|
|
if (allowed_open->listen_port != PORT_STREAMLOCAL)
|
|
return 0;
|
|
if (allowed_open->listen_path == NULL ||
|
|
strcmp(allowed_open->listen_path, requestedpath) != 0)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Request cancellation of remote forwarding of connection host:port from
|
|
* local side.
|
|
*/
|
|
static int
|
|
channel_request_rforward_cancel_tcpip(struct ssh *ssh,
|
|
const char *host, u_short port)
|
|
{
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
|
struct permission_set *pset = &sc->local_perms;
|
|
int r;
|
|
u_int i;
|
|
struct permission *perm = NULL;
|
|
|
|
for (i = 0; i < pset->num_permitted_user; i++) {
|
|
perm = &pset->permitted_user[i];
|
|
if (open_listen_match_tcpip(perm, host, port, 0))
|
|
break;
|
|
perm = NULL;
|
|
}
|
|
if (perm == NULL) {
|
|
debug_f("requested forward not found");
|
|
return -1;
|
|
}
|
|
if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
|
|
(r = sshpkt_put_cstring(ssh, "cancel-tcpip-forward")) != 0 ||
|
|
(r = sshpkt_put_u8(ssh, 0)) != 0 || /* want reply */
|
|
(r = sshpkt_put_cstring(ssh, channel_rfwd_bind_host(host))) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, port)) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0)
|
|
fatal_fr(r, "send cancel");
|
|
|
|
fwd_perm_clear(perm); /* unregister */
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Request cancellation of remote forwarding of Unix domain socket
|
|
* path from local side.
|
|
*/
|
|
static int
|
|
channel_request_rforward_cancel_streamlocal(struct ssh *ssh, const char *path)
|
|
{
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
|
struct permission_set *pset = &sc->local_perms;
|
|
int r;
|
|
u_int i;
|
|
struct permission *perm = NULL;
|
|
|
|
for (i = 0; i < pset->num_permitted_user; i++) {
|
|
perm = &pset->permitted_user[i];
|
|
if (open_listen_match_streamlocal(perm, path))
|
|
break;
|
|
perm = NULL;
|
|
}
|
|
if (perm == NULL) {
|
|
debug_f("requested forward not found");
|
|
return -1;
|
|
}
|
|
if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
|
|
(r = sshpkt_put_cstring(ssh,
|
|
"cancel-streamlocal-forward@openssh.com")) != 0 ||
|
|
(r = sshpkt_put_u8(ssh, 0)) != 0 || /* want reply */
|
|
(r = sshpkt_put_cstring(ssh, path)) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0)
|
|
fatal_fr(r, "send cancel");
|
|
|
|
fwd_perm_clear(perm); /* unregister */
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Request cancellation of remote forwarding of a connection from local side.
|
|
*/
|
|
int
|
|
channel_request_rforward_cancel(struct ssh *ssh, struct Forward *fwd)
|
|
{
|
|
if (fwd->listen_path != NULL) {
|
|
return channel_request_rforward_cancel_streamlocal(ssh,
|
|
fwd->listen_path);
|
|
} else {
|
|
return channel_request_rforward_cancel_tcpip(ssh,
|
|
fwd->listen_host,
|
|
fwd->listen_port ? fwd->listen_port : fwd->allocated_port);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Permits opening to any host/port if permitted_user[] is empty. This is
|
|
* usually called by the server, because the user could connect to any port
|
|
* anyway, and the server has no way to know but to trust the client anyway.
|
|
*/
|
|
void
|
|
channel_permit_all(struct ssh *ssh, int where)
|
|
{
|
|
struct permission_set *pset = permission_set_get(ssh, where);
|
|
|
|
if (pset->num_permitted_user == 0)
|
|
pset->all_permitted = 1;
|
|
}
|
|
|
|
/*
|
|
* Permit the specified host/port for forwarding.
|
|
*/
|
|
void
|
|
channel_add_permission(struct ssh *ssh, int who, int where,
|
|
char *host, int port)
|
|
{
|
|
int local = where == FORWARD_LOCAL;
|
|
struct permission_set *pset = permission_set_get(ssh, where);
|
|
|
|
debug("allow %s forwarding to host %s port %d",
|
|
fwd_ident(who, where), host, port);
|
|
/*
|
|
* Remote forwards set listen_host/port, local forwards set
|
|
* host/port_to_connect.
|
|
*/
|
|
permission_set_add(ssh, who, where,
|
|
local ? host : 0, local ? port : 0,
|
|
local ? NULL : host, NULL, local ? 0 : port, NULL);
|
|
pset->all_permitted = 0;
|
|
}
|
|
|
|
/*
|
|
* Administratively disable forwarding.
|
|
*/
|
|
void
|
|
channel_disable_admin(struct ssh *ssh, int where)
|
|
{
|
|
channel_clear_permission(ssh, FORWARD_ADM, where);
|
|
permission_set_add(ssh, FORWARD_ADM, where,
|
|
NULL, 0, NULL, NULL, 0, NULL);
|
|
}
|
|
|
|
/*
|
|
* Clear a list of permitted opens.
|
|
*/
|
|
void
|
|
channel_clear_permission(struct ssh *ssh, int who, int where)
|
|
{
|
|
struct permission **permp;
|
|
u_int *npermp;
|
|
|
|
permission_set_get_array(ssh, who, where, &permp, &npermp);
|
|
*permp = xrecallocarray(*permp, *npermp, 0, sizeof(**permp));
|
|
*npermp = 0;
|
|
}
|
|
|
|
/*
|
|
* Update the listen port for a dynamic remote forward, after
|
|
* the actual 'newport' has been allocated. If 'newport' < 0 is
|
|
* passed then they entry will be invalidated.
|
|
*/
|
|
void
|
|
channel_update_permission(struct ssh *ssh, int idx, int newport)
|
|
{
|
|
struct permission_set *pset = &ssh->chanctxt->local_perms;
|
|
|
|
if (idx < 0 || (u_int)idx >= pset->num_permitted_user) {
|
|
debug_f("index out of range: %d num_permitted_user %d",
|
|
idx, pset->num_permitted_user);
|
|
return;
|
|
}
|
|
debug("%s allowed port %d for forwarding to host %s port %d",
|
|
newport > 0 ? "Updating" : "Removing",
|
|
newport,
|
|
pset->permitted_user[idx].host_to_connect,
|
|
pset->permitted_user[idx].port_to_connect);
|
|
if (newport <= 0)
|
|
fwd_perm_clear(&pset->permitted_user[idx]);
|
|
else {
|
|
pset->permitted_user[idx].listen_port =
|
|
(ssh->compat & SSH_BUG_DYNAMIC_RPORT) ? 0 : newport;
|
|
}
|
|
}
|
|
|
|
/* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */
|
|
int
|
|
permitopen_port(const char *p)
|
|
{
|
|
int port;
|
|
|
|
if (strcmp(p, "*") == 0)
|
|
return FWD_PERMIT_ANY_PORT;
|
|
if ((port = a2port(p)) > 0)
|
|
return port;
|
|
return -1;
|
|
}
|
|
|
|
/* Try to start non-blocking connect to next host in cctx list */
|
|
static int
|
|
connect_next(struct channel_connect *cctx)
|
|
{
|
|
int sock, saved_errno;
|
|
struct sockaddr_un *sunaddr;
|
|
char ntop[NI_MAXHOST];
|
|
char strport[MAXIMUM(NI_MAXSERV, sizeof(sunaddr->sun_path))];
|
|
|
|
for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
|
|
switch (cctx->ai->ai_family) {
|
|
case AF_UNIX:
|
|
/* unix:pathname instead of host:port */
|
|
sunaddr = (struct sockaddr_un *)cctx->ai->ai_addr;
|
|
strlcpy(ntop, "unix", sizeof(ntop));
|
|
strlcpy(strport, sunaddr->sun_path, sizeof(strport));
|
|
break;
|
|
case AF_INET:
|
|
case AF_INET6:
|
|
if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
|
|
ntop, sizeof(ntop), strport, sizeof(strport),
|
|
NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
|
|
error("connect_next: getnameinfo failed");
|
|
continue;
|
|
}
|
|
break;
|
|
default:
|
|
continue;
|
|
}
|
|
if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
|
|
cctx->ai->ai_protocol)) == -1) {
|
|
if (cctx->ai->ai_next == NULL)
|
|
error("socket: %.100s", strerror(errno));
|
|
else
|
|
verbose("socket: %.100s", strerror(errno));
|
|
continue;
|
|
}
|
|
if (set_nonblock(sock) == -1)
|
|
fatal_f("set_nonblock(%d)", sock);
|
|
if (connect(sock, cctx->ai->ai_addr,
|
|
cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
|
|
debug("connect_next: host %.100s ([%.100s]:%s): "
|
|
"%.100s", cctx->host, ntop, strport,
|
|
strerror(errno));
|
|
saved_errno = errno;
|
|
close(sock);
|
|
errno = saved_errno;
|
|
continue; /* fail -- try next */
|
|
}
|
|
if (cctx->ai->ai_family != AF_UNIX)
|
|
set_nodelay(sock);
|
|
debug("connect_next: host %.100s ([%.100s]:%s) "
|
|
"in progress, fd=%d", cctx->host, ntop, strport, sock);
|
|
cctx->ai = cctx->ai->ai_next;
|
|
return sock;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
static void
|
|
channel_connect_ctx_free(struct channel_connect *cctx)
|
|
{
|
|
free(cctx->host);
|
|
if (cctx->aitop) {
|
|
if (cctx->aitop->ai_family == AF_UNIX)
|
|
free(cctx->aitop);
|
|
else
|
|
freeaddrinfo(cctx->aitop);
|
|
}
|
|
memset(cctx, 0, sizeof(*cctx));
|
|
}
|
|
|
|
/*
|
|
* Return connecting socket to remote host:port or local socket path,
|
|
* passing back the failure reason if appropriate.
|
|
*/
|
|
static int
|
|
connect_to_helper(struct ssh *ssh, const char *name, int port, int socktype,
|
|
char *ctype, char *rname, struct channel_connect *cctx,
|
|
int *reason, const char **errmsg)
|
|
{
|
|
struct addrinfo hints;
|
|
int gaierr;
|
|
int sock = -1;
|
|
char strport[NI_MAXSERV];
|
|
|
|
if (port == PORT_STREAMLOCAL) {
|
|
struct sockaddr_un *sunaddr;
|
|
struct addrinfo *ai;
|
|
|
|
if (strlen(name) > sizeof(sunaddr->sun_path)) {
|
|
error("%.100s: %.100s", name, strerror(ENAMETOOLONG));
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* Fake up a struct addrinfo for AF_UNIX connections.
|
|
* channel_connect_ctx_free() must check ai_family
|
|
* and use free() not freeaddirinfo() for AF_UNIX.
|
|
*/
|
|
ai = xmalloc(sizeof(*ai) + sizeof(*sunaddr));
|
|
memset(ai, 0, sizeof(*ai) + sizeof(*sunaddr));
|
|
ai->ai_addr = (struct sockaddr *)(ai + 1);
|
|
ai->ai_addrlen = sizeof(*sunaddr);
|
|
ai->ai_family = AF_UNIX;
|
|
ai->ai_socktype = socktype;
|
|
ai->ai_protocol = PF_UNSPEC;
|
|
sunaddr = (struct sockaddr_un *)ai->ai_addr;
|
|
sunaddr->sun_family = AF_UNIX;
|
|
strlcpy(sunaddr->sun_path, name, sizeof(sunaddr->sun_path));
|
|
cctx->aitop = ai;
|
|
} else {
|
|
memset(&hints, 0, sizeof(hints));
|
|
hints.ai_family = ssh->chanctxt->IPv4or6;
|
|
hints.ai_socktype = socktype;
|
|
snprintf(strport, sizeof strport, "%d", port);
|
|
if ((gaierr = getaddrinfo(name, strport, &hints, &cctx->aitop))
|
|
!= 0) {
|
|
if (errmsg != NULL)
|
|
*errmsg = ssh_gai_strerror(gaierr);
|
|
if (reason != NULL)
|
|
*reason = SSH2_OPEN_CONNECT_FAILED;
|
|
error("connect_to %.100s: unknown host (%s)", name,
|
|
ssh_gai_strerror(gaierr));
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
cctx->host = xstrdup(name);
|
|
cctx->port = port;
|
|
cctx->ai = cctx->aitop;
|
|
|
|
if ((sock = connect_next(cctx)) == -1) {
|
|
error("connect to %.100s port %d failed: %s",
|
|
name, port, strerror(errno));
|
|
return -1;
|
|
}
|
|
|
|
return sock;
|
|
}
|
|
|
|
/* Return CONNECTING channel to remote host:port or local socket path */
|
|
static Channel *
|
|
connect_to(struct ssh *ssh, const char *host, int port,
|
|
char *ctype, char *rname)
|
|
{
|
|
struct channel_connect cctx;
|
|
Channel *c;
|
|
int sock;
|
|
|
|
memset(&cctx, 0, sizeof(cctx));
|
|
sock = connect_to_helper(ssh, host, port, SOCK_STREAM, ctype, rname,
|
|
&cctx, NULL, NULL);
|
|
if (sock == -1) {
|
|
channel_connect_ctx_free(&cctx);
|
|
return NULL;
|
|
}
|
|
c = channel_new(ssh, ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
|
|
CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
|
|
c->host_port = port;
|
|
c->path = xstrdup(host);
|
|
c->connect_ctx = cctx;
|
|
|
|
return c;
|
|
}
|
|
|
|
/*
|
|
* returns either the newly connected channel or the downstream channel
|
|
* that needs to deal with this connection.
|
|
*/
|
|
Channel *
|
|
channel_connect_by_listen_address(struct ssh *ssh, const char *listen_host,
|
|
u_short listen_port, char *ctype, char *rname)
|
|
{
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
|
struct permission_set *pset = &sc->local_perms;
|
|
u_int i;
|
|
struct permission *perm;
|
|
|
|
for (i = 0; i < pset->num_permitted_user; i++) {
|
|
perm = &pset->permitted_user[i];
|
|
if (open_listen_match_tcpip(perm,
|
|
listen_host, listen_port, 1)) {
|
|
if (perm->downstream)
|
|
return perm->downstream;
|
|
if (perm->port_to_connect == 0)
|
|
return rdynamic_connect_prepare(ssh,
|
|
ctype, rname);
|
|
return connect_to(ssh,
|
|
perm->host_to_connect, perm->port_to_connect,
|
|
ctype, rname);
|
|
}
|
|
}
|
|
error("WARNING: Server requests forwarding for unknown listen_port %d",
|
|
listen_port);
|
|
return NULL;
|
|
}
|
|
|
|
Channel *
|
|
channel_connect_by_listen_path(struct ssh *ssh, const char *path,
|
|
char *ctype, char *rname)
|
|
{
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
|
struct permission_set *pset = &sc->local_perms;
|
|
u_int i;
|
|
struct permission *perm;
|
|
|
|
for (i = 0; i < pset->num_permitted_user; i++) {
|
|
perm = &pset->permitted_user[i];
|
|
if (open_listen_match_streamlocal(perm, path)) {
|
|
return connect_to(ssh,
|
|
perm->host_to_connect, perm->port_to_connect,
|
|
ctype, rname);
|
|
}
|
|
}
|
|
error("WARNING: Server requests forwarding for unknown path %.100s",
|
|
path);
|
|
return NULL;
|
|
}
|
|
|
|
/* Check if connecting to that port is permitted and connect. */
|
|
Channel *
|
|
channel_connect_to_port(struct ssh *ssh, const char *host, u_short port,
|
|
char *ctype, char *rname, int *reason, const char **errmsg)
|
|
{
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
|
struct permission_set *pset = &sc->local_perms;
|
|
struct channel_connect cctx;
|
|
Channel *c;
|
|
u_int i, permit, permit_adm = 1;
|
|
int sock;
|
|
struct permission *perm;
|
|
|
|
permit = pset->all_permitted;
|
|
if (!permit) {
|
|
for (i = 0; i < pset->num_permitted_user; i++) {
|
|
perm = &pset->permitted_user[i];
|
|
if (open_match(perm, host, port)) {
|
|
permit = 1;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (pset->num_permitted_admin > 0) {
|
|
permit_adm = 0;
|
|
for (i = 0; i < pset->num_permitted_admin; i++) {
|
|
perm = &pset->permitted_admin[i];
|
|
if (open_match(perm, host, port)) {
|
|
permit_adm = 1;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!permit || !permit_adm) {
|
|
logit("Received request from %.100s port %d to connect to "
|
|
"host %.100s port %d, but the request was denied.",
|
|
ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), host, port);
|
|
if (reason != NULL)
|
|
*reason = SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED;
|
|
return NULL;
|
|
}
|
|
|
|
memset(&cctx, 0, sizeof(cctx));
|
|
sock = connect_to_helper(ssh, host, port, SOCK_STREAM, ctype, rname,
|
|
&cctx, reason, errmsg);
|
|
if (sock == -1) {
|
|
channel_connect_ctx_free(&cctx);
|
|
return NULL;
|
|
}
|
|
|
|
c = channel_new(ssh, ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
|
|
CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
|
|
c->host_port = port;
|
|
c->path = xstrdup(host);
|
|
c->connect_ctx = cctx;
|
|
|
|
return c;
|
|
}
|
|
|
|
/* Check if connecting to that path is permitted and connect. */
|
|
Channel *
|
|
channel_connect_to_path(struct ssh *ssh, const char *path,
|
|
char *ctype, char *rname)
|
|
{
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
|
struct permission_set *pset = &sc->local_perms;
|
|
u_int i, permit, permit_adm = 1;
|
|
struct permission *perm;
|
|
|
|
permit = pset->all_permitted;
|
|
if (!permit) {
|
|
for (i = 0; i < pset->num_permitted_user; i++) {
|
|
perm = &pset->permitted_user[i];
|
|
if (open_match(perm, path, PORT_STREAMLOCAL)) {
|
|
permit = 1;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (pset->num_permitted_admin > 0) {
|
|
permit_adm = 0;
|
|
for (i = 0; i < pset->num_permitted_admin; i++) {
|
|
perm = &pset->permitted_admin[i];
|
|
if (open_match(perm, path, PORT_STREAMLOCAL)) {
|
|
permit_adm = 1;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!permit || !permit_adm) {
|
|
logit("Received request to connect to path %.100s, "
|
|
"but the request was denied.", path);
|
|
return NULL;
|
|
}
|
|
return connect_to(ssh, path, PORT_STREAMLOCAL, ctype, rname);
|
|
}
|
|
|
|
void
|
|
channel_send_window_changes(struct ssh *ssh)
|
|
{
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
|
struct winsize ws;
|
|
int r;
|
|
u_int i;
|
|
|
|
for (i = 0; i < sc->channels_alloc; i++) {
|
|
if (sc->channels[i] == NULL || !sc->channels[i]->client_tty ||
|
|
sc->channels[i]->type != SSH_CHANNEL_OPEN)
|
|
continue;
|
|
if (ioctl(sc->channels[i]->rfd, TIOCGWINSZ, &ws) == -1)
|
|
continue;
|
|
channel_request_start(ssh, i, "window-change", 0);
|
|
if ((r = sshpkt_put_u32(ssh, (u_int)ws.ws_col)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, (u_int)ws.ws_row)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, (u_int)ws.ws_xpixel)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, (u_int)ws.ws_ypixel)) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0)
|
|
fatal_fr(r, "channel %u; send window-change", i);
|
|
}
|
|
}
|
|
|
|
/* Return RDYNAMIC_OPEN channel: channel allows SOCKS, but is not connected */
|
|
static Channel *
|
|
rdynamic_connect_prepare(struct ssh *ssh, char *ctype, char *rname)
|
|
{
|
|
Channel *c;
|
|
int r;
|
|
|
|
c = channel_new(ssh, ctype, SSH_CHANNEL_RDYNAMIC_OPEN, -1, -1, -1,
|
|
CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
|
|
c->host_port = 0;
|
|
c->path = NULL;
|
|
|
|
/*
|
|
* We need to open the channel before we have a FD,
|
|
* so that we can get SOCKS header from peer.
|
|
*/
|
|
if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->self)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0)
|
|
fatal_fr(r, "channel %i; confirm", c->self);
|
|
return c;
|
|
}
|
|
|
|
/* Return CONNECTING socket to remote host:port or local socket path */
|
|
static int
|
|
rdynamic_connect_finish(struct ssh *ssh, Channel *c)
|
|
{
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
|
struct permission_set *pset = &sc->local_perms;
|
|
struct permission *perm;
|
|
struct channel_connect cctx;
|
|
u_int i, permit_adm = 1;
|
|
int sock;
|
|
|
|
if (pset->num_permitted_admin > 0) {
|
|
permit_adm = 0;
|
|
for (i = 0; i < pset->num_permitted_admin; i++) {
|
|
perm = &pset->permitted_admin[i];
|
|
if (open_match(perm, c->path, c->host_port)) {
|
|
permit_adm = 1;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (!permit_adm) {
|
|
debug_f("requested forward not permitted");
|
|
return -1;
|
|
}
|
|
|
|
memset(&cctx, 0, sizeof(cctx));
|
|
sock = connect_to_helper(ssh, c->path, c->host_port, SOCK_STREAM, NULL,
|
|
NULL, &cctx, NULL, NULL);
|
|
if (sock == -1)
|
|
channel_connect_ctx_free(&cctx);
|
|
else {
|
|
/* similar to SSH_CHANNEL_CONNECTING but we've already sent the open */
|
|
c->type = SSH_CHANNEL_RDYNAMIC_FINISH;
|
|
c->connect_ctx = cctx;
|
|
channel_register_fds(ssh, c, sock, sock, -1, 0, 1, 0);
|
|
}
|
|
return sock;
|
|
}
|
|
|
|
/* -- X11 forwarding */
|
|
|
|
/*
|
|
* Creates an internet domain socket for listening for X11 connections.
|
|
* Returns 0 and a suitable display number for the DISPLAY variable
|
|
* stored in display_numberp , or -1 if an error occurs.
|
|
*/
|
|
int
|
|
x11_create_display_inet(struct ssh *ssh, int x11_display_offset,
|
|
int x11_use_localhost, int single_connection,
|
|
u_int *display_numberp, int **chanids)
|
|
{
|
|
Channel *nc = NULL;
|
|
int display_number, sock;
|
|
u_short port;
|
|
struct addrinfo hints, *ai, *aitop;
|
|
char strport[NI_MAXSERV];
|
|
int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
|
|
|
|
if (chanids == NULL)
|
|
return -1;
|
|
|
|
for (display_number = x11_display_offset;
|
|
display_number < MAX_DISPLAYS;
|
|
display_number++) {
|
|
port = 6000 + display_number;
|
|
memset(&hints, 0, sizeof(hints));
|
|
hints.ai_family = ssh->chanctxt->IPv4or6;
|
|
hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
|
|
hints.ai_socktype = SOCK_STREAM;
|
|
snprintf(strport, sizeof strport, "%d", port);
|
|
if ((gaierr = getaddrinfo(NULL, strport,
|
|
&hints, &aitop)) != 0) {
|
|
error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
|
|
return -1;
|
|
}
|
|
for (ai = aitop; ai; ai = ai->ai_next) {
|
|
if (ai->ai_family != AF_INET &&
|
|
ai->ai_family != AF_INET6)
|
|
continue;
|
|
sock = socket(ai->ai_family, ai->ai_socktype,
|
|
ai->ai_protocol);
|
|
if (sock == -1) {
|
|
if ((errno != EINVAL) && (errno != EAFNOSUPPORT)
|
|
#ifdef EPFNOSUPPORT
|
|
&& (errno != EPFNOSUPPORT)
|
|
#endif
|
|
) {
|
|
error("socket: %.100s", strerror(errno));
|
|
freeaddrinfo(aitop);
|
|
return -1;
|
|
} else {
|
|
debug("x11_create_display_inet: Socket family %d not supported",
|
|
ai->ai_family);
|
|
continue;
|
|
}
|
|
}
|
|
if (ai->ai_family == AF_INET6)
|
|
sock_set_v6only(sock);
|
|
if (x11_use_localhost)
|
|
set_reuseaddr(sock);
|
|
if (bind(sock, ai->ai_addr, ai->ai_addrlen) == -1) {
|
|
debug2_f("bind port %d: %.100s", port,
|
|
strerror(errno));
|
|
close(sock);
|
|
for (n = 0; n < num_socks; n++)
|
|
close(socks[n]);
|
|
num_socks = 0;
|
|
break;
|
|
}
|
|
socks[num_socks++] = sock;
|
|
if (num_socks == NUM_SOCKS)
|
|
break;
|
|
}
|
|
freeaddrinfo(aitop);
|
|
if (num_socks > 0)
|
|
break;
|
|
}
|
|
if (display_number >= MAX_DISPLAYS) {
|
|
error("Failed to allocate internet-domain X11 display socket.");
|
|
return -1;
|
|
}
|
|
/* Start listening for connections on the socket. */
|
|
for (n = 0; n < num_socks; n++) {
|
|
sock = socks[n];
|
|
if (listen(sock, SSH_LISTEN_BACKLOG) == -1) {
|
|
error("listen: %.100s", strerror(errno));
|
|
close(sock);
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
/* Allocate a channel for each socket. */
|
|
*chanids = xcalloc(num_socks + 1, sizeof(**chanids));
|
|
for (n = 0; n < num_socks; n++) {
|
|
sock = socks[n];
|
|
nc = channel_new(ssh, "x11 listener",
|
|
SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
|
|
CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
|
|
0, "X11 inet listener", 1);
|
|
nc->single_connection = single_connection;
|
|
(*chanids)[n] = nc->self;
|
|
}
|
|
(*chanids)[n] = -1;
|
|
|
|
/* Return the display number for the DISPLAY environment variable. */
|
|
*display_numberp = display_number;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
connect_local_xsocket_path(const char *pathname)
|
|
{
|
|
int sock;
|
|
struct sockaddr_un addr;
|
|
|
|
sock = socket(AF_UNIX, SOCK_STREAM, 0);
|
|
if (sock == -1)
|
|
error("socket: %.100s", strerror(errno));
|
|
memset(&addr, 0, sizeof(addr));
|
|
addr.sun_family = AF_UNIX;
|
|
strlcpy(addr.sun_path, pathname, sizeof addr.sun_path);
|
|
if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
|
|
return sock;
|
|
close(sock);
|
|
error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
|
|
return -1;
|
|
}
|
|
|
|
static int
|
|
connect_local_xsocket(u_int dnr)
|
|
{
|
|
char buf[1024];
|
|
snprintf(buf, sizeof buf, _PATH_UNIX_X, dnr);
|
|
return connect_local_xsocket_path(buf);
|
|
}
|
|
|
|
#ifdef __APPLE__
|
|
static int
|
|
is_path_to_xsocket(const char *display, char *path, size_t pathlen)
|
|
{
|
|
struct stat sbuf;
|
|
|
|
if (strlcpy(path, display, pathlen) >= pathlen) {
|
|
error("%s: display path too long", __func__);
|
|
return 0;
|
|
}
|
|
if (display[0] != '/')
|
|
return 0;
|
|
if (stat(path, &sbuf) == 0) {
|
|
return 1;
|
|
} else {
|
|
char *dot = strrchr(path, '.');
|
|
if (dot != NULL) {
|
|
*dot = '\0';
|
|
if (stat(path, &sbuf) == 0) {
|
|
return 1;
|
|
}
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
int
|
|
x11_connect_display(struct ssh *ssh)
|
|
{
|
|
u_int display_number;
|
|
const char *display;
|
|
char buf[1024], *cp;
|
|
struct addrinfo hints, *ai, *aitop;
|
|
char strport[NI_MAXSERV];
|
|
int gaierr, sock = 0;
|
|
|
|
/* Try to open a socket for the local X server. */
|
|
display = getenv("DISPLAY");
|
|
if (!display) {
|
|
error("DISPLAY not set.");
|
|
return -1;
|
|
}
|
|
/*
|
|
* Now we decode the value of the DISPLAY variable and make a
|
|
* connection to the real X server.
|
|
*/
|
|
|
|
#ifdef __APPLE__
|
|
/* Check if display is a path to a socket (as set by launchd). */
|
|
{
|
|
char path[PATH_MAX];
|
|
|
|
if (is_path_to_xsocket(display, path, sizeof(path))) {
|
|
debug("x11_connect_display: $DISPLAY is launchd");
|
|
|
|
/* Create a socket. */
|
|
sock = connect_local_xsocket_path(path);
|
|
if (sock < 0)
|
|
return -1;
|
|
|
|
/* OK, we now have a connection to the display. */
|
|
return sock;
|
|
}
|
|
}
|
|
#endif
|
|
/*
|
|
* Check if it is a unix domain socket. Unix domain displays are in
|
|
* one of the following formats: unix:d[.s], :d[.s], ::d[.s]
|
|
*/
|
|
if (strncmp(display, "unix:", 5) == 0 ||
|
|
display[0] == ':') {
|
|
/* Connect to the unix domain socket. */
|
|
if (sscanf(strrchr(display, ':') + 1, "%u",
|
|
&display_number) != 1) {
|
|
error("Could not parse display number from DISPLAY: "
|
|
"%.100s", display);
|
|
return -1;
|
|
}
|
|
/* Create a socket. */
|
|
sock = connect_local_xsocket(display_number);
|
|
if (sock < 0)
|
|
return -1;
|
|
|
|
/* OK, we now have a connection to the display. */
|
|
return sock;
|
|
}
|
|
/*
|
|
* Connect to an inet socket. The DISPLAY value is supposedly
|
|
* hostname:d[.s], where hostname may also be numeric IP address.
|
|
*/
|
|
strlcpy(buf, display, sizeof(buf));
|
|
cp = strchr(buf, ':');
|
|
if (!cp) {
|
|
error("Could not find ':' in DISPLAY: %.100s", display);
|
|
return -1;
|
|
}
|
|
*cp = 0;
|
|
/*
|
|
* buf now contains the host name. But first we parse the
|
|
* display number.
|
|
*/
|
|
if (sscanf(cp + 1, "%u", &display_number) != 1) {
|
|
error("Could not parse display number from DISPLAY: %.100s",
|
|
display);
|
|
return -1;
|
|
}
|
|
|
|
/* Look up the host address */
|
|
memset(&hints, 0, sizeof(hints));
|
|
hints.ai_family = ssh->chanctxt->IPv4or6;
|
|
hints.ai_socktype = SOCK_STREAM;
|
|
snprintf(strport, sizeof strport, "%u", 6000 + display_number);
|
|
if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
|
|
error("%.100s: unknown host. (%s)", buf,
|
|
ssh_gai_strerror(gaierr));
|
|
return -1;
|
|
}
|
|
for (ai = aitop; ai; ai = ai->ai_next) {
|
|
/* Create a socket. */
|
|
sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
|
|
if (sock == -1) {
|
|
debug2("socket: %.100s", strerror(errno));
|
|
continue;
|
|
}
|
|
/* Connect it to the display. */
|
|
if (connect(sock, ai->ai_addr, ai->ai_addrlen) == -1) {
|
|
debug2("connect %.100s port %u: %.100s", buf,
|
|
6000 + display_number, strerror(errno));
|
|
close(sock);
|
|
continue;
|
|
}
|
|
/* Success */
|
|
break;
|
|
}
|
|
freeaddrinfo(aitop);
|
|
if (!ai) {
|
|
error("connect %.100s port %u: %.100s", buf,
|
|
6000 + display_number, strerror(errno));
|
|
return -1;
|
|
}
|
|
set_nodelay(sock);
|
|
return sock;
|
|
}
|
|
|
|
/*
|
|
* Requests forwarding of X11 connections, generates fake authentication
|
|
* data, and enables authentication spoofing.
|
|
* This should be called in the client only.
|
|
*/
|
|
void
|
|
x11_request_forwarding_with_spoofing(struct ssh *ssh, int client_session_id,
|
|
const char *disp, const char *proto, const char *data, int want_reply)
|
|
{
|
|
struct ssh_channels *sc = ssh->chanctxt;
|
|
u_int data_len = (u_int) strlen(data) / 2;
|
|
u_int i, value;
|
|
const char *cp;
|
|
char *new_data;
|
|
int r, screen_number;
|
|
|
|
if (sc->x11_saved_display == NULL)
|
|
sc->x11_saved_display = xstrdup(disp);
|
|
else if (strcmp(disp, sc->x11_saved_display) != 0) {
|
|
error("x11_request_forwarding_with_spoofing: different "
|
|
"$DISPLAY already forwarded");
|
|
return;
|
|
}
|
|
|
|
cp = strchr(disp, ':');
|
|
if (cp)
|
|
cp = strchr(cp, '.');
|
|
if (cp)
|
|
screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
|
|
else
|
|
screen_number = 0;
|
|
|
|
if (sc->x11_saved_proto == NULL) {
|
|
/* Save protocol name. */
|
|
sc->x11_saved_proto = xstrdup(proto);
|
|
|
|
/* Extract real authentication data. */
|
|
sc->x11_saved_data = xmalloc(data_len);
|
|
for (i = 0; i < data_len; i++) {
|
|
if (sscanf(data + 2 * i, "%2x", &value) != 1) {
|
|
fatal("x11_request_forwarding: bad "
|
|
"authentication data: %.100s", data);
|
|
}
|
|
sc->x11_saved_data[i] = value;
|
|
}
|
|
sc->x11_saved_data_len = data_len;
|
|
|
|
/* Generate fake data of the same length. */
|
|
sc->x11_fake_data = xmalloc(data_len);
|
|
arc4random_buf(sc->x11_fake_data, data_len);
|
|
sc->x11_fake_data_len = data_len;
|
|
}
|
|
|
|
/* Convert the fake data into hex. */
|
|
new_data = tohex(sc->x11_fake_data, data_len);
|
|
|
|
/* Send the request packet. */
|
|
channel_request_start(ssh, client_session_id, "x11-req", want_reply);
|
|
if ((r = sshpkt_put_u8(ssh, 0)) != 0 || /* bool: single connection */
|
|
(r = sshpkt_put_cstring(ssh, proto)) != 0 ||
|
|
(r = sshpkt_put_cstring(ssh, new_data)) != 0 ||
|
|
(r = sshpkt_put_u32(ssh, screen_number)) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0 ||
|
|
(r = ssh_packet_write_wait(ssh)) != 0)
|
|
fatal_fr(r, "send x11-req");
|
|
free(new_data);
|
|
}
|