1517 lines
38 KiB
C
1517 lines
38 KiB
C
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/*
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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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*/
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/*
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* SSH2 support by Markus Friedl.
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* Copyright (c) 2000 Markus Friedl. All rights reserved.
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*/
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#include "includes.h"
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RCSID("$OpenBSD: session.c,v 1.12 2000/05/03 18:03:07 markus Exp $");
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#include "xmalloc.h"
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#include "ssh.h"
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#include "pty.h"
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#include "packet.h"
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#include "buffer.h"
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#include "cipher.h"
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#include "mpaux.h"
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#include "servconf.h"
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#include "uidswap.h"
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#include "compat.h"
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#include "channels.h"
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#include "nchan.h"
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#include "bufaux.h"
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#include "ssh2.h"
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#include "auth.h"
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/* types */
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#define TTYSZ 64
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typedef struct Session Session;
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struct Session {
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int used;
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int self;
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int extended;
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struct passwd *pw;
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pid_t pid;
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/* tty */
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char *term;
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int ptyfd, ttyfd, ptymaster;
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int row, col, xpixel, ypixel;
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char tty[TTYSZ];
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/* X11 */
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char *display;
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int screen;
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char *auth_proto;
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char *auth_data;
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int single_connection;
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/* proto 2 */
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int chanid;
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};
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/* func */
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Session *session_new(void);
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void session_set_fds(Session *s, int fdin, int fdout, int fderr);
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void session_pty_cleanup(Session *s);
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void session_proctitle(Session *s);
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void do_exec_pty(Session *s, const char *command, struct passwd * pw);
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void do_exec_no_pty(Session *s, const char *command, struct passwd * pw);
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void
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do_child(const char *command, struct passwd * pw, const char *term,
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const char *display, const char *auth_proto,
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const char *auth_data, const char *ttyname);
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/* import */
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extern ServerOptions options;
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extern char *__progname;
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extern int log_stderr;
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extern int debug_flag;
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/* Local Xauthority file. */
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static char *xauthfile;
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/* data */
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#define MAX_SESSIONS 10
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Session sessions[MAX_SESSIONS];
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/* Flags set in auth-rsa from authorized_keys flags. These are set in auth-rsa.c. */
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int no_port_forwarding_flag = 0;
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int no_agent_forwarding_flag = 0;
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int no_x11_forwarding_flag = 0;
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int no_pty_flag = 0;
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/* RSA authentication "command=" option. */
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char *forced_command = NULL;
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/* RSA authentication "environment=" options. */
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struct envstring *custom_environment = NULL;
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/*
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* Remove local Xauthority file.
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*/
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void
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xauthfile_cleanup_proc(void *ignore)
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{
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debug("xauthfile_cleanup_proc called");
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if (xauthfile != NULL) {
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char *p;
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unlink(xauthfile);
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p = strrchr(xauthfile, '/');
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if (p != NULL) {
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*p = '\0';
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rmdir(xauthfile);
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}
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xfree(xauthfile);
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xauthfile = NULL;
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}
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}
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/*
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* Function to perform cleanup if we get aborted abnormally (e.g., due to a
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* dropped connection).
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*/
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void
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pty_cleanup_proc(void *session)
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{
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Session *s=session;
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if (s == NULL)
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fatal("pty_cleanup_proc: no session");
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debug("pty_cleanup_proc: %s", s->tty);
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if (s->pid != 0) {
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/* Record that the user has logged out. */
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record_logout(s->pid, s->tty);
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}
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/* Release the pseudo-tty. */
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pty_release(s->tty);
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}
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/*
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* Prepares for an interactive session. This is called after the user has
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* been successfully authenticated. During this message exchange, pseudo
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* terminals are allocated, X11, TCP/IP, and authentication agent forwardings
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* are requested, etc.
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*/
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void
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do_authenticated(struct passwd * pw)
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{
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Session *s;
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int type;
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int compression_level = 0, enable_compression_after_reply = 0;
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int have_pty = 0;
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char *command;
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int n_bytes;
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int plen;
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unsigned int proto_len, data_len, dlen;
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/*
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* Cancel the alarm we set to limit the time taken for
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* authentication.
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*/
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alarm(0);
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/*
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* Inform the channel mechanism that we are the server side and that
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* the client may request to connect to any port at all. (The user
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* could do it anyway, and we wouldn\'t know what is permitted except
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* by the client telling us, so we can equally well trust the client
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* not to request anything bogus.)
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*/
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if (!no_port_forwarding_flag)
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channel_permit_all_opens();
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s = session_new();
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s->pw = pw;
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/*
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* We stay in this loop until the client requests to execute a shell
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* or a command.
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*/
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for (;;) {
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int success = 0;
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/* Get a packet from the client. */
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type = packet_read(&plen);
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/* Process the packet. */
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switch (type) {
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case SSH_CMSG_REQUEST_COMPRESSION:
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packet_integrity_check(plen, 4, type);
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compression_level = packet_get_int();
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if (compression_level < 1 || compression_level > 9) {
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packet_send_debug("Received illegal compression level %d.",
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compression_level);
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break;
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}
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/* Enable compression after we have responded with SUCCESS. */
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enable_compression_after_reply = 1;
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success = 1;
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break;
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case SSH_CMSG_REQUEST_PTY:
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if (no_pty_flag) {
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debug("Allocating a pty not permitted for this authentication.");
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break;
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}
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if (have_pty)
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packet_disconnect("Protocol error: you already have a pty.");
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debug("Allocating pty.");
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/* Allocate a pty and open it. */
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if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
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sizeof(s->tty))) {
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error("Failed to allocate pty.");
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break;
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}
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fatal_add_cleanup(pty_cleanup_proc, (void *)s);
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pty_setowner(pw, s->tty);
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/* Get TERM from the packet. Note that the value may be of arbitrary length. */
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s->term = packet_get_string(&dlen);
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packet_integrity_check(dlen, strlen(s->term), type);
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/* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */
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/* Remaining bytes */
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n_bytes = plen - (4 + dlen + 4 * 4);
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if (strcmp(s->term, "") == 0) {
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xfree(s->term);
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s->term = NULL;
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}
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/* Get window size from the packet. */
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s->row = packet_get_int();
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s->col = packet_get_int();
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s->xpixel = packet_get_int();
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s->ypixel = packet_get_int();
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pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
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/* Get tty modes from the packet. */
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tty_parse_modes(s->ttyfd, &n_bytes);
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packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type);
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session_proctitle(s);
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/* Indicate that we now have a pty. */
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success = 1;
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have_pty = 1;
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break;
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case SSH_CMSG_X11_REQUEST_FORWARDING:
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if (!options.x11_forwarding) {
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packet_send_debug("X11 forwarding disabled in server configuration file.");
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break;
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}
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#ifdef XAUTH_PATH
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if (no_x11_forwarding_flag) {
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packet_send_debug("X11 forwarding not permitted for this authentication.");
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break;
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}
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debug("Received request for X11 forwarding with auth spoofing.");
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if (s->display != NULL)
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packet_disconnect("Protocol error: X11 display already set.");
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s->auth_proto = packet_get_string(&proto_len);
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s->auth_data = packet_get_string(&data_len);
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packet_integrity_check(plen, 4 + proto_len + 4 + data_len + 4, type);
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if (packet_get_protocol_flags() & SSH_PROTOFLAG_SCREEN_NUMBER)
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s->screen = packet_get_int();
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else
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s->screen = 0;
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s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
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if (s->display == NULL)
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break;
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/* Setup to always have a local .Xauthority. */
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xauthfile = xmalloc(MAXPATHLEN);
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strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
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temporarily_use_uid(pw->pw_uid);
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if (mkdtemp(xauthfile) == NULL) {
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restore_uid();
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error("private X11 dir: mkdtemp %s failed: %s",
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xauthfile, strerror(errno));
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xfree(xauthfile);
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xauthfile = NULL;
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/* XXXX remove listening channels */
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break;
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}
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strlcat(xauthfile, "/cookies", MAXPATHLEN);
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open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
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restore_uid();
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fatal_add_cleanup(xauthfile_cleanup_proc, NULL);
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success = 1;
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break;
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#else /* XAUTH_PATH */
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packet_send_debug("No xauth program; cannot forward with spoofing.");
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break;
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#endif /* XAUTH_PATH */
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case SSH_CMSG_AGENT_REQUEST_FORWARDING:
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if (no_agent_forwarding_flag || compat13) {
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debug("Authentication agent forwarding not permitted for this authentication.");
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break;
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}
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debug("Received authentication agent forwarding request.");
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auth_input_request_forwarding(pw);
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success = 1;
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break;
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case SSH_CMSG_PORT_FORWARD_REQUEST:
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if (no_port_forwarding_flag) {
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debug("Port forwarding not permitted for this authentication.");
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break;
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}
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debug("Received TCP/IP port forwarding request.");
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channel_input_port_forward_request(pw->pw_uid == 0, options.gateway_ports);
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success = 1;
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break;
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case SSH_CMSG_MAX_PACKET_SIZE:
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if (packet_set_maxsize(packet_get_int()) > 0)
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success = 1;
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break;
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case SSH_CMSG_EXEC_SHELL:
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case SSH_CMSG_EXEC_CMD:
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/* Set interactive/non-interactive mode. */
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packet_set_interactive(have_pty || s->display != NULL,
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options.keepalives);
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if (type == SSH_CMSG_EXEC_CMD) {
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command = packet_get_string(&dlen);
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debug("Exec command '%.500s'", command);
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packet_integrity_check(plen, 4 + dlen, type);
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} else {
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command = NULL;
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packet_integrity_check(plen, 0, type);
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}
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if (forced_command != NULL) {
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command = forced_command;
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debug("Forced command '%.500s'", forced_command);
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}
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if (have_pty)
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do_exec_pty(s, command, pw);
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else
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do_exec_no_pty(s, command, pw);
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if (command != NULL)
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xfree(command);
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/* Cleanup user's local Xauthority file. */
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if (xauthfile)
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xauthfile_cleanup_proc(NULL);
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return;
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default:
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/*
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* Any unknown messages in this phase are ignored,
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* and a failure message is returned.
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*/
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log("Unknown packet type received after authentication: %d", type);
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}
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packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
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packet_send();
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packet_write_wait();
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/* Enable compression now that we have replied if appropriate. */
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if (enable_compression_after_reply) {
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enable_compression_after_reply = 0;
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packet_start_compression(compression_level);
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}
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}
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}
|
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/*
|
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* This is called to fork and execute a command when we have no tty. This
|
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* will call do_child from the child, and server_loop from the parent after
|
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* setting up file descriptors and such.
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*/
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void
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do_exec_no_pty(Session *s, const char *command, struct passwd * pw)
|
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{
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int pid;
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#ifdef USE_PIPES
|
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int pin[2], pout[2], perr[2];
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/* Allocate pipes for communicating with the program. */
|
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if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
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packet_disconnect("Could not create pipes: %.100s",
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strerror(errno));
|
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#else /* USE_PIPES */
|
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int inout[2], err[2];
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/* Uses socket pairs to communicate with the program. */
|
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if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
|
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socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
|
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packet_disconnect("Could not create socket pairs: %.100s",
|
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strerror(errno));
|
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#endif /* USE_PIPES */
|
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if (s == NULL)
|
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fatal("do_exec_no_pty: no session");
|
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|
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session_proctitle(s);
|
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|
|
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/* Fork the child. */
|
||
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if ((pid = fork()) == 0) {
|
||
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/* Child. Reinitialize the log since the pid has changed. */
|
||
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log_init(__progname, options.log_level, options.log_facility, log_stderr);
|
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|
||
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/*
|
||
|
* Create a new session and process group since the 4.4BSD
|
||
|
* setlogin() affects the entire process group.
|
||
|
*/
|
||
|
if (setsid() < 0)
|
||
|
error("setsid failed: %.100s", strerror(errno));
|
||
|
|
||
|
#ifdef USE_PIPES
|
||
|
/*
|
||
|
* Redirect stdin. We close the parent side of the socket
|
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|
* pair, and make the child side the standard input.
|
||
|
*/
|
||
|
close(pin[1]);
|
||
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if (dup2(pin[0], 0) < 0)
|
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perror("dup2 stdin");
|
||
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close(pin[0]);
|
||
|
|
||
|
/* Redirect stdout. */
|
||
|
close(pout[0]);
|
||
|
if (dup2(pout[1], 1) < 0)
|
||
|
perror("dup2 stdout");
|
||
|
close(pout[1]);
|
||
|
|
||
|
/* Redirect stderr. */
|
||
|
close(perr[0]);
|
||
|
if (dup2(perr[1], 2) < 0)
|
||
|
perror("dup2 stderr");
|
||
|
close(perr[1]);
|
||
|
#else /* USE_PIPES */
|
||
|
/*
|
||
|
* Redirect stdin, stdout, and stderr. Stdin and stdout will
|
||
|
* use the same socket, as some programs (particularly rdist)
|
||
|
* seem to depend on it.
|
||
|
*/
|
||
|
close(inout[1]);
|
||
|
close(err[1]);
|
||
|
if (dup2(inout[0], 0) < 0) /* stdin */
|
||
|
perror("dup2 stdin");
|
||
|
if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
|
||
|
perror("dup2 stdout");
|
||
|
if (dup2(err[0], 2) < 0) /* stderr */
|
||
|
perror("dup2 stderr");
|
||
|
#endif /* USE_PIPES */
|
||
|
|
||
|
/* Do processing for the child (exec command etc). */
|
||
|
do_child(command, pw, NULL, s->display, s->auth_proto, s->auth_data, NULL);
|
||
|
/* NOTREACHED */
|
||
|
}
|
||
|
if (pid < 0)
|
||
|
packet_disconnect("fork failed: %.100s", strerror(errno));
|
||
|
s->pid = pid;
|
||
|
#ifdef USE_PIPES
|
||
|
/* We are the parent. Close the child sides of the pipes. */
|
||
|
close(pin[0]);
|
||
|
close(pout[1]);
|
||
|
close(perr[1]);
|
||
|
|
||
|
if (compat20) {
|
||
|
session_set_fds(s, pin[1], pout[0], s->extended ? perr[0] : -1);
|
||
|
} else {
|
||
|
/* Enter the interactive session. */
|
||
|
server_loop(pid, pin[1], pout[0], perr[0]);
|
||
|
/* server_loop has closed pin[1], pout[1], and perr[1]. */
|
||
|
}
|
||
|
#else /* USE_PIPES */
|
||
|
/* We are the parent. Close the child sides of the socket pairs. */
|
||
|
close(inout[0]);
|
||
|
close(err[0]);
|
||
|
|
||
|
/*
|
||
|
* Enter the interactive session. Note: server_loop must be able to
|
||
|
* handle the case that fdin and fdout are the same.
|
||
|
*/
|
||
|
if (compat20) {
|
||
|
session_set_fds(s, inout[1], inout[1], s->extended ? err[1] : -1);
|
||
|
} else {
|
||
|
server_loop(pid, inout[1], inout[1], err[1]);
|
||
|
/* server_loop has closed inout[1] and err[1]. */
|
||
|
}
|
||
|
#endif /* USE_PIPES */
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* This is called to fork and execute a command when we have a tty. This
|
||
|
* will call do_child from the child, and server_loop from the parent after
|
||
|
* setting up file descriptors, controlling tty, updating wtmp, utmp,
|
||
|
* lastlog, and other such operations.
|
||
|
*/
|
||
|
void
|
||
|
do_exec_pty(Session *s, const char *command, struct passwd * pw)
|
||
|
{
|
||
|
FILE *f;
|
||
|
char buf[100], *time_string;
|
||
|
char line[256];
|
||
|
const char *hostname;
|
||
|
int fdout, ptyfd, ttyfd, ptymaster;
|
||
|
int quiet_login;
|
||
|
pid_t pid;
|
||
|
socklen_t fromlen;
|
||
|
struct sockaddr_storage from;
|
||
|
struct stat st;
|
||
|
time_t last_login_time;
|
||
|
|
||
|
if (s == NULL)
|
||
|
fatal("do_exec_pty: no session");
|
||
|
ptyfd = s->ptyfd;
|
||
|
ttyfd = s->ttyfd;
|
||
|
|
||
|
/* Get remote host name. */
|
||
|
hostname = get_canonical_hostname();
|
||
|
|
||
|
/*
|
||
|
* Get the time when the user last logged in. Buf will be set to
|
||
|
* contain the hostname the last login was from.
|
||
|
*/
|
||
|
if (!options.use_login) {
|
||
|
last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
|
||
|
buf, sizeof(buf));
|
||
|
}
|
||
|
|
||
|
/* Fork the child. */
|
||
|
if ((pid = fork()) == 0) {
|
||
|
pid = getpid();
|
||
|
|
||
|
/* Child. Reinitialize the log because the pid has
|
||
|
changed. */
|
||
|
log_init(__progname, options.log_level, options.log_facility, log_stderr);
|
||
|
|
||
|
/* Close the master side of the pseudo tty. */
|
||
|
close(ptyfd);
|
||
|
|
||
|
/* Make the pseudo tty our controlling tty. */
|
||
|
pty_make_controlling_tty(&ttyfd, s->tty);
|
||
|
|
||
|
/* Redirect stdin from the pseudo tty. */
|
||
|
if (dup2(ttyfd, fileno(stdin)) < 0)
|
||
|
error("dup2 stdin failed: %.100s", strerror(errno));
|
||
|
|
||
|
/* Redirect stdout to the pseudo tty. */
|
||
|
if (dup2(ttyfd, fileno(stdout)) < 0)
|
||
|
error("dup2 stdin failed: %.100s", strerror(errno));
|
||
|
|
||
|
/* Redirect stderr to the pseudo tty. */
|
||
|
if (dup2(ttyfd, fileno(stderr)) < 0)
|
||
|
error("dup2 stdin failed: %.100s", strerror(errno));
|
||
|
|
||
|
/* Close the extra descriptor for the pseudo tty. */
|
||
|
close(ttyfd);
|
||
|
|
||
|
/* XXXX ? move to do_child() ??*/
|
||
|
/*
|
||
|
* Get IP address of client. This is needed because we want
|
||
|
* to record where the user logged in from. If the
|
||
|
* connection is not a socket, let the ip address be 0.0.0.0.
|
||
|
*/
|
||
|
memset(&from, 0, sizeof(from));
|
||
|
if (packet_connection_is_on_socket()) {
|
||
|
fromlen = sizeof(from);
|
||
|
if (getpeername(packet_get_connection_in(),
|
||
|
(struct sockaddr *) & from, &fromlen) < 0) {
|
||
|
debug("getpeername: %.100s", strerror(errno));
|
||
|
fatal_cleanup();
|
||
|
}
|
||
|
}
|
||
|
/* Record that there was a login on that terminal. */
|
||
|
record_login(pid, s->tty, pw->pw_name, pw->pw_uid, hostname,
|
||
|
(struct sockaddr *)&from);
|
||
|
|
||
|
/* Check if .hushlogin exists. */
|
||
|
snprintf(line, sizeof line, "%.200s/.hushlogin", pw->pw_dir);
|
||
|
quiet_login = stat(line, &st) >= 0;
|
||
|
|
||
|
/*
|
||
|
* If the user has logged in before, display the time of last
|
||
|
* login. However, don't display anything extra if a command
|
||
|
* has been specified (so that ssh can be used to execute
|
||
|
* commands on a remote machine without users knowing they
|
||
|
* are going to another machine). Login(1) will do this for
|
||
|
* us as well, so check if login(1) is used
|
||
|
*/
|
||
|
if (command == NULL && last_login_time != 0 && !quiet_login &&
|
||
|
!options.use_login) {
|
||
|
/* Convert the date to a string. */
|
||
|
time_string = ctime(&last_login_time);
|
||
|
/* Remove the trailing newline. */
|
||
|
if (strchr(time_string, '\n'))
|
||
|
*strchr(time_string, '\n') = 0;
|
||
|
/* Display the last login time. Host if displayed
|
||
|
if known. */
|
||
|
if (strcmp(buf, "") == 0)
|
||
|
printf("Last login: %s\r\n", time_string);
|
||
|
else
|
||
|
printf("Last login: %s from %s\r\n", time_string, buf);
|
||
|
}
|
||
|
/*
|
||
|
* Print /etc/motd unless a command was specified or printing
|
||
|
* it was disabled in server options or login(1) will be
|
||
|
* used. Note that some machines appear to print it in
|
||
|
* /etc/profile or similar.
|
||
|
*/
|
||
|
if (command == NULL && options.print_motd && !quiet_login &&
|
||
|
!options.use_login) {
|
||
|
/* Print /etc/motd if it exists. */
|
||
|
f = fopen("/etc/motd", "r");
|
||
|
if (f) {
|
||
|
while (fgets(line, sizeof(line), f))
|
||
|
fputs(line, stdout);
|
||
|
fclose(f);
|
||
|
}
|
||
|
}
|
||
|
/* Do common processing for the child, such as execing the command. */
|
||
|
do_child(command, pw, s->term, s->display, s->auth_proto, s->auth_data, s->tty);
|
||
|
/* NOTREACHED */
|
||
|
}
|
||
|
if (pid < 0)
|
||
|
packet_disconnect("fork failed: %.100s", strerror(errno));
|
||
|
s->pid = pid;
|
||
|
|
||
|
/* Parent. Close the slave side of the pseudo tty. */
|
||
|
close(ttyfd);
|
||
|
|
||
|
/*
|
||
|
* Create another descriptor of the pty master side for use as the
|
||
|
* standard input. We could use the original descriptor, but this
|
||
|
* simplifies code in server_loop. The descriptor is bidirectional.
|
||
|
*/
|
||
|
fdout = dup(ptyfd);
|
||
|
if (fdout < 0)
|
||
|
packet_disconnect("dup #1 failed: %.100s", strerror(errno));
|
||
|
|
||
|
/* we keep a reference to the pty master */
|
||
|
ptymaster = dup(ptyfd);
|
||
|
if (ptymaster < 0)
|
||
|
packet_disconnect("dup #2 failed: %.100s", strerror(errno));
|
||
|
s->ptymaster = ptymaster;
|
||
|
|
||
|
/* Enter interactive session. */
|
||
|
if (compat20) {
|
||
|
session_set_fds(s, ptyfd, fdout, -1);
|
||
|
} else {
|
||
|
server_loop(pid, ptyfd, fdout, -1);
|
||
|
/* server_loop _has_ closed ptyfd and fdout. */
|
||
|
session_pty_cleanup(s);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Sets the value of the given variable in the environment. If the variable
|
||
|
* already exists, its value is overriden.
|
||
|
*/
|
||
|
void
|
||
|
child_set_env(char ***envp, unsigned int *envsizep, const char *name,
|
||
|
const char *value)
|
||
|
{
|
||
|
unsigned int i, namelen;
|
||
|
char **env;
|
||
|
|
||
|
/*
|
||
|
* Find the slot where the value should be stored. If the variable
|
||
|
* already exists, we reuse the slot; otherwise we append a new slot
|
||
|
* at the end of the array, expanding if necessary.
|
||
|
*/
|
||
|
env = *envp;
|
||
|
namelen = strlen(name);
|
||
|
for (i = 0; env[i]; i++)
|
||
|
if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
|
||
|
break;
|
||
|
if (env[i]) {
|
||
|
/* Reuse the slot. */
|
||
|
xfree(env[i]);
|
||
|
} else {
|
||
|
/* New variable. Expand if necessary. */
|
||
|
if (i >= (*envsizep) - 1) {
|
||
|
(*envsizep) += 50;
|
||
|
env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
|
||
|
}
|
||
|
/* Need to set the NULL pointer at end of array beyond the new slot. */
|
||
|
env[i + 1] = NULL;
|
||
|
}
|
||
|
|
||
|
/* Allocate space and format the variable in the appropriate slot. */
|
||
|
env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
|
||
|
snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Reads environment variables from the given file and adds/overrides them
|
||
|
* into the environment. If the file does not exist, this does nothing.
|
||
|
* Otherwise, it must consist of empty lines, comments (line starts with '#')
|
||
|
* and assignments of the form name=value. No other forms are allowed.
|
||
|
*/
|
||
|
void
|
||
|
read_environment_file(char ***env, unsigned int *envsize,
|
||
|
const char *filename)
|
||
|
{
|
||
|
FILE *f;
|
||
|
char buf[4096];
|
||
|
char *cp, *value;
|
||
|
|
||
|
f = fopen(filename, "r");
|
||
|
if (!f)
|
||
|
return;
|
||
|
|
||
|
while (fgets(buf, sizeof(buf), f)) {
|
||
|
for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
|
||
|
;
|
||
|
if (!*cp || *cp == '#' || *cp == '\n')
|
||
|
continue;
|
||
|
if (strchr(cp, '\n'))
|
||
|
*strchr(cp, '\n') = '\0';
|
||
|
value = strchr(cp, '=');
|
||
|
if (value == NULL) {
|
||
|
fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
|
||
|
continue;
|
||
|
}
|
||
|
/* Replace the equals sign by nul, and advance value to the value string. */
|
||
|
*value = '\0';
|
||
|
value++;
|
||
|
child_set_env(env, envsize, cp, value);
|
||
|
}
|
||
|
fclose(f);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Performs common processing for the child, such as setting up the
|
||
|
* environment, closing extra file descriptors, setting the user and group
|
||
|
* ids, and executing the command or shell.
|
||
|
*/
|
||
|
void
|
||
|
do_child(const char *command, struct passwd * pw, const char *term,
|
||
|
const char *display, const char *auth_proto,
|
||
|
const char *auth_data, const char *ttyname)
|
||
|
{
|
||
|
const char *shell, *cp = NULL;
|
||
|
char buf[256];
|
||
|
FILE *f;
|
||
|
unsigned int envsize, i;
|
||
|
char **env;
|
||
|
extern char **environ;
|
||
|
struct stat st;
|
||
|
char *argv[10];
|
||
|
|
||
|
f = fopen("/etc/nologin", "r");
|
||
|
if (f) {
|
||
|
/* /etc/nologin exists. Print its contents and exit. */
|
||
|
while (fgets(buf, sizeof(buf), f))
|
||
|
fputs(buf, stderr);
|
||
|
fclose(f);
|
||
|
if (pw->pw_uid != 0)
|
||
|
exit(254);
|
||
|
}
|
||
|
/* Set login name in the kernel. */
|
||
|
if (setlogin(pw->pw_name) < 0)
|
||
|
error("setlogin failed: %s", strerror(errno));
|
||
|
|
||
|
/* Set uid, gid, and groups. */
|
||
|
/* Login(1) does this as well, and it needs uid 0 for the "-h"
|
||
|
switch, so we let login(1) to this for us. */
|
||
|
if (!options.use_login) {
|
||
|
if (getuid() == 0 || geteuid() == 0) {
|
||
|
if (setgid(pw->pw_gid) < 0) {
|
||
|
perror("setgid");
|
||
|
exit(1);
|
||
|
}
|
||
|
/* Initialize the group list. */
|
||
|
if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
|
||
|
perror("initgroups");
|
||
|
exit(1);
|
||
|
}
|
||
|
endgrent();
|
||
|
|
||
|
/* Permanently switch to the desired uid. */
|
||
|
permanently_set_uid(pw->pw_uid);
|
||
|
}
|
||
|
if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
|
||
|
fatal("Failed to set uids to %d.", (int) pw->pw_uid);
|
||
|
}
|
||
|
/*
|
||
|
* Get the shell from the password data. An empty shell field is
|
||
|
* legal, and means /bin/sh.
|
||
|
*/
|
||
|
shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
|
||
|
|
||
|
#ifdef AFS
|
||
|
/* Try to get AFS tokens for the local cell. */
|
||
|
if (k_hasafs()) {
|
||
|
char cell[64];
|
||
|
|
||
|
if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
|
||
|
krb_afslog(cell, 0);
|
||
|
|
||
|
krb_afslog(0, 0);
|
||
|
}
|
||
|
#endif /* AFS */
|
||
|
|
||
|
/* Initialize the environment. */
|
||
|
envsize = 100;
|
||
|
env = xmalloc(envsize * sizeof(char *));
|
||
|
env[0] = NULL;
|
||
|
|
||
|
if (!options.use_login) {
|
||
|
/* Set basic environment. */
|
||
|
child_set_env(&env, &envsize, "USER", pw->pw_name);
|
||
|
child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
|
||
|
child_set_env(&env, &envsize, "HOME", pw->pw_dir);
|
||
|
child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
|
||
|
|
||
|
snprintf(buf, sizeof buf, "%.200s/%.50s",
|
||
|
_PATH_MAILDIR, pw->pw_name);
|
||
|
child_set_env(&env, &envsize, "MAIL", buf);
|
||
|
|
||
|
/* Normal systems set SHELL by default. */
|
||
|
child_set_env(&env, &envsize, "SHELL", shell);
|
||
|
}
|
||
|
if (getenv("TZ"))
|
||
|
child_set_env(&env, &envsize, "TZ", getenv("TZ"));
|
||
|
|
||
|
/* Set custom environment options from RSA authentication. */
|
||
|
while (custom_environment) {
|
||
|
struct envstring *ce = custom_environment;
|
||
|
char *s = ce->s;
|
||
|
int i;
|
||
|
for (i = 0; s[i] != '=' && s[i]; i++);
|
||
|
if (s[i] == '=') {
|
||
|
s[i] = 0;
|
||
|
child_set_env(&env, &envsize, s, s + i + 1);
|
||
|
}
|
||
|
custom_environment = ce->next;
|
||
|
xfree(ce->s);
|
||
|
xfree(ce);
|
||
|
}
|
||
|
|
||
|
snprintf(buf, sizeof buf, "%.50s %d %d",
|
||
|
get_remote_ipaddr(), get_remote_port(), get_local_port());
|
||
|
child_set_env(&env, &envsize, "SSH_CLIENT", buf);
|
||
|
|
||
|
if (ttyname)
|
||
|
child_set_env(&env, &envsize, "SSH_TTY", ttyname);
|
||
|
if (term)
|
||
|
child_set_env(&env, &envsize, "TERM", term);
|
||
|
if (display)
|
||
|
child_set_env(&env, &envsize, "DISPLAY", display);
|
||
|
|
||
|
#ifdef KRB4
|
||
|
{
|
||
|
extern char *ticket;
|
||
|
|
||
|
if (ticket)
|
||
|
child_set_env(&env, &envsize, "KRBTKFILE", ticket);
|
||
|
}
|
||
|
#endif /* KRB4 */
|
||
|
|
||
|
if (xauthfile)
|
||
|
child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
|
||
|
if (auth_get_socket_name() != NULL)
|
||
|
child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
|
||
|
auth_get_socket_name());
|
||
|
|
||
|
/* read $HOME/.ssh/environment. */
|
||
|
if (!options.use_login) {
|
||
|
snprintf(buf, sizeof buf, "%.200s/.ssh/environment", pw->pw_dir);
|
||
|
read_environment_file(&env, &envsize, buf);
|
||
|
}
|
||
|
if (debug_flag) {
|
||
|
/* dump the environment */
|
||
|
fprintf(stderr, "Environment:\n");
|
||
|
for (i = 0; env[i]; i++)
|
||
|
fprintf(stderr, " %.200s\n", env[i]);
|
||
|
}
|
||
|
/*
|
||
|
* Close the connection descriptors; note that this is the child, and
|
||
|
* the server will still have the socket open, and it is important
|
||
|
* that we do not shutdown it. Note that the descriptors cannot be
|
||
|
* closed before building the environment, as we call
|
||
|
* get_remote_ipaddr there.
|
||
|
*/
|
||
|
if (packet_get_connection_in() == packet_get_connection_out())
|
||
|
close(packet_get_connection_in());
|
||
|
else {
|
||
|
close(packet_get_connection_in());
|
||
|
close(packet_get_connection_out());
|
||
|
}
|
||
|
/*
|
||
|
* Close all descriptors related to channels. They will still remain
|
||
|
* open in the parent.
|
||
|
*/
|
||
|
/* XXX better use close-on-exec? -markus */
|
||
|
channel_close_all();
|
||
|
|
||
|
/*
|
||
|
* Close any extra file descriptors. Note that there may still be
|
||
|
* descriptors left by system functions. They will be closed later.
|
||
|
*/
|
||
|
endpwent();
|
||
|
|
||
|
/*
|
||
|
* Close any extra open file descriptors so that we don\'t have them
|
||
|
* hanging around in clients. Note that we want to do this after
|
||
|
* initgroups, because at least on Solaris 2.3 it leaves file
|
||
|
* descriptors open.
|
||
|
*/
|
||
|
for (i = 3; i < 64; i++)
|
||
|
close(i);
|
||
|
|
||
|
/* Change current directory to the user\'s home directory. */
|
||
|
if (chdir(pw->pw_dir) < 0)
|
||
|
fprintf(stderr, "Could not chdir to home directory %s: %s\n",
|
||
|
pw->pw_dir, strerror(errno));
|
||
|
|
||
|
/*
|
||
|
* Must take new environment into use so that .ssh/rc, /etc/sshrc and
|
||
|
* xauth are run in the proper environment.
|
||
|
*/
|
||
|
environ = env;
|
||
|
|
||
|
/*
|
||
|
* Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
|
||
|
* in this order).
|
||
|
*/
|
||
|
if (!options.use_login) {
|
||
|
if (stat(SSH_USER_RC, &st) >= 0) {
|
||
|
if (debug_flag)
|
||
|
fprintf(stderr, "Running /bin/sh %s\n", SSH_USER_RC);
|
||
|
|
||
|
f = popen("/bin/sh " SSH_USER_RC, "w");
|
||
|
if (f) {
|
||
|
if (auth_proto != NULL && auth_data != NULL)
|
||
|
fprintf(f, "%s %s\n", auth_proto, auth_data);
|
||
|
pclose(f);
|
||
|
} else
|
||
|
fprintf(stderr, "Could not run %s\n", SSH_USER_RC);
|
||
|
} else if (stat(SSH_SYSTEM_RC, &st) >= 0) {
|
||
|
if (debug_flag)
|
||
|
fprintf(stderr, "Running /bin/sh %s\n", SSH_SYSTEM_RC);
|
||
|
|
||
|
f = popen("/bin/sh " SSH_SYSTEM_RC, "w");
|
||
|
if (f) {
|
||
|
if (auth_proto != NULL && auth_data != NULL)
|
||
|
fprintf(f, "%s %s\n", auth_proto, auth_data);
|
||
|
pclose(f);
|
||
|
} else
|
||
|
fprintf(stderr, "Could not run %s\n", SSH_SYSTEM_RC);
|
||
|
}
|
||
|
#ifdef XAUTH_PATH
|
||
|
else {
|
||
|
/* Add authority data to .Xauthority if appropriate. */
|
||
|
if (auth_proto != NULL && auth_data != NULL) {
|
||
|
if (debug_flag)
|
||
|
fprintf(stderr, "Running %.100s add %.100s %.100s %.100s\n",
|
||
|
XAUTH_PATH, display, auth_proto, auth_data);
|
||
|
|
||
|
f = popen(XAUTH_PATH " -q -", "w");
|
||
|
if (f) {
|
||
|
fprintf(f, "add %s %s %s\n", display, auth_proto, auth_data);
|
||
|
pclose(f);
|
||
|
} else
|
||
|
fprintf(stderr, "Could not run %s -q -\n", XAUTH_PATH);
|
||
|
}
|
||
|
}
|
||
|
#endif /* XAUTH_PATH */
|
||
|
|
||
|
/* Get the last component of the shell name. */
|
||
|
cp = strrchr(shell, '/');
|
||
|
if (cp)
|
||
|
cp++;
|
||
|
else
|
||
|
cp = shell;
|
||
|
}
|
||
|
/*
|
||
|
* If we have no command, execute the shell. In this case, the shell
|
||
|
* name to be passed in argv[0] is preceded by '-' to indicate that
|
||
|
* this is a login shell.
|
||
|
*/
|
||
|
if (!command) {
|
||
|
if (!options.use_login) {
|
||
|
char buf[256];
|
||
|
|
||
|
/*
|
||
|
* Check for mail if we have a tty and it was enabled
|
||
|
* in server options.
|
||
|
*/
|
||
|
if (ttyname && options.check_mail) {
|
||
|
char *mailbox;
|
||
|
struct stat mailstat;
|
||
|
mailbox = getenv("MAIL");
|
||
|
if (mailbox != NULL) {
|
||
|
if (stat(mailbox, &mailstat) != 0 || mailstat.st_size == 0)
|
||
|
printf("No mail.\n");
|
||
|
else if (mailstat.st_mtime < mailstat.st_atime)
|
||
|
printf("You have mail.\n");
|
||
|
else
|
||
|
printf("You have new mail.\n");
|
||
|
}
|
||
|
}
|
||
|
/* Start the shell. Set initial character to '-'. */
|
||
|
buf[0] = '-';
|
||
|
strncpy(buf + 1, cp, sizeof(buf) - 1);
|
||
|
buf[sizeof(buf) - 1] = 0;
|
||
|
|
||
|
/* Execute the shell. */
|
||
|
argv[0] = buf;
|
||
|
argv[1] = NULL;
|
||
|
execve(shell, argv, env);
|
||
|
|
||
|
/* Executing the shell failed. */
|
||
|
perror(shell);
|
||
|
exit(1);
|
||
|
|
||
|
} else {
|
||
|
/* Launch login(1). */
|
||
|
|
||
|
execl("/usr/bin/login", "login", "-h", get_remote_ipaddr(),
|
||
|
"-p", "-f", "--", pw->pw_name, NULL);
|
||
|
|
||
|
/* Login couldn't be executed, die. */
|
||
|
|
||
|
perror("login");
|
||
|
exit(1);
|
||
|
}
|
||
|
}
|
||
|
/*
|
||
|
* Execute the command using the user's shell. This uses the -c
|
||
|
* option to execute the command.
|
||
|
*/
|
||
|
argv[0] = (char *) cp;
|
||
|
argv[1] = "-c";
|
||
|
argv[2] = (char *) command;
|
||
|
argv[3] = NULL;
|
||
|
execve(shell, argv, env);
|
||
|
perror(shell);
|
||
|
exit(1);
|
||
|
}
|
||
|
|
||
|
Session *
|
||
|
session_new(void)
|
||
|
{
|
||
|
int i;
|
||
|
static int did_init = 0;
|
||
|
if (!did_init) {
|
||
|
debug("session_new: init");
|
||
|
for(i = 0; i < MAX_SESSIONS; i++) {
|
||
|
sessions[i].used = 0;
|
||
|
sessions[i].self = i;
|
||
|
}
|
||
|
did_init = 1;
|
||
|
}
|
||
|
for(i = 0; i < MAX_SESSIONS; i++) {
|
||
|
Session *s = &sessions[i];
|
||
|
if (! s->used) {
|
||
|
s->pid = 0;
|
||
|
s->extended = 0;
|
||
|
s->chanid = -1;
|
||
|
s->ptyfd = -1;
|
||
|
s->ttyfd = -1;
|
||
|
s->term = NULL;
|
||
|
s->pw = NULL;
|
||
|
s->display = NULL;
|
||
|
s->screen = 0;
|
||
|
s->auth_data = NULL;
|
||
|
s->auth_proto = NULL;
|
||
|
s->used = 1;
|
||
|
s->pw = NULL;
|
||
|
debug("session_new: session %d", i);
|
||
|
return s;
|
||
|
}
|
||
|
}
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
void
|
||
|
session_dump(void)
|
||
|
{
|
||
|
int i;
|
||
|
for(i = 0; i < MAX_SESSIONS; i++) {
|
||
|
Session *s = &sessions[i];
|
||
|
debug("dump: used %d session %d %p channel %d pid %d",
|
||
|
s->used,
|
||
|
s->self,
|
||
|
s,
|
||
|
s->chanid,
|
||
|
s->pid);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
int
|
||
|
session_open(int chanid)
|
||
|
{
|
||
|
Session *s = session_new();
|
||
|
debug("session_open: channel %d", chanid);
|
||
|
if (s == NULL) {
|
||
|
error("no more sessions");
|
||
|
return 0;
|
||
|
}
|
||
|
s->pw = auth_get_user();
|
||
|
if (s->pw == NULL)
|
||
|
fatal("no user for session %i", s->self);
|
||
|
debug("session_open: session %d: link with channel %d", s->self, chanid);
|
||
|
s->chanid = chanid;
|
||
|
return 1;
|
||
|
}
|
||
|
|
||
|
Session *
|
||
|
session_by_channel(int id)
|
||
|
{
|
||
|
int i;
|
||
|
for(i = 0; i < MAX_SESSIONS; i++) {
|
||
|
Session *s = &sessions[i];
|
||
|
if (s->used && s->chanid == id) {
|
||
|
debug("session_by_channel: session %d channel %d", i, id);
|
||
|
return s;
|
||
|
}
|
||
|
}
|
||
|
debug("session_by_channel: unknown channel %d", id);
|
||
|
session_dump();
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
Session *
|
||
|
session_by_pid(pid_t pid)
|
||
|
{
|
||
|
int i;
|
||
|
debug("session_by_pid: pid %d", pid);
|
||
|
for(i = 0; i < MAX_SESSIONS; i++) {
|
||
|
Session *s = &sessions[i];
|
||
|
if (s->used && s->pid == pid)
|
||
|
return s;
|
||
|
}
|
||
|
error("session_by_pid: unknown pid %d", pid);
|
||
|
session_dump();
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
int
|
||
|
session_window_change_req(Session *s)
|
||
|
{
|
||
|
s->col = packet_get_int();
|
||
|
s->row = packet_get_int();
|
||
|
s->xpixel = packet_get_int();
|
||
|
s->ypixel = packet_get_int();
|
||
|
packet_done();
|
||
|
pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
|
||
|
return 1;
|
||
|
}
|
||
|
|
||
|
int
|
||
|
session_pty_req(Session *s)
|
||
|
{
|
||
|
unsigned int len;
|
||
|
char *term_modes; /* encoded terminal modes */
|
||
|
|
||
|
if (s->ttyfd != -1)
|
||
|
return 0;
|
||
|
s->term = packet_get_string(&len);
|
||
|
s->col = packet_get_int();
|
||
|
s->row = packet_get_int();
|
||
|
s->xpixel = packet_get_int();
|
||
|
s->ypixel = packet_get_int();
|
||
|
term_modes = packet_get_string(&len);
|
||
|
packet_done();
|
||
|
|
||
|
if (strcmp(s->term, "") == 0) {
|
||
|
xfree(s->term);
|
||
|
s->term = NULL;
|
||
|
}
|
||
|
/* Allocate a pty and open it. */
|
||
|
if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
|
||
|
xfree(s->term);
|
||
|
s->term = NULL;
|
||
|
s->ptyfd = -1;
|
||
|
s->ttyfd = -1;
|
||
|
error("session_pty_req: session %d alloc failed", s->self);
|
||
|
xfree(term_modes);
|
||
|
return 0;
|
||
|
}
|
||
|
debug("session_pty_req: session %d alloc %s", s->self, s->tty);
|
||
|
/*
|
||
|
* Add a cleanup function to clear the utmp entry and record logout
|
||
|
* time in case we call fatal() (e.g., the connection gets closed).
|
||
|
*/
|
||
|
fatal_add_cleanup(pty_cleanup_proc, (void *)s);
|
||
|
pty_setowner(s->pw, s->tty);
|
||
|
/* Get window size from the packet. */
|
||
|
pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
|
||
|
|
||
|
session_proctitle(s);
|
||
|
|
||
|
/* XXX parse and set terminal modes */
|
||
|
xfree(term_modes);
|
||
|
return 1;
|
||
|
}
|
||
|
|
||
|
int
|
||
|
session_subsystem_req(Session *s)
|
||
|
{
|
||
|
unsigned int len;
|
||
|
int success = 0;
|
||
|
char *subsys = packet_get_string(&len);
|
||
|
|
||
|
packet_done();
|
||
|
log("subsystem request for %s", subsys);
|
||
|
|
||
|
xfree(subsys);
|
||
|
return success;
|
||
|
}
|
||
|
|
||
|
int
|
||
|
session_x11_req(Session *s)
|
||
|
{
|
||
|
if (!options.x11_forwarding) {
|
||
|
debug("X11 forwarding disabled in server configuration file.");
|
||
|
return 0;
|
||
|
}
|
||
|
if (xauthfile != NULL) {
|
||
|
debug("X11 fwd already started.");
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
debug("Received request for X11 forwarding with auth spoofing.");
|
||
|
if (s->display != NULL)
|
||
|
packet_disconnect("Protocol error: X11 display already set.");
|
||
|
|
||
|
s->single_connection = packet_get_char();
|
||
|
s->auth_proto = packet_get_string(NULL);
|
||
|
s->auth_data = packet_get_string(NULL);
|
||
|
s->screen = packet_get_int();
|
||
|
packet_done();
|
||
|
|
||
|
s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
|
||
|
if (s->display == NULL) {
|
||
|
xfree(s->auth_proto);
|
||
|
xfree(s->auth_data);
|
||
|
return 0;
|
||
|
}
|
||
|
xauthfile = xmalloc(MAXPATHLEN);
|
||
|
strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
|
||
|
temporarily_use_uid(s->pw->pw_uid);
|
||
|
if (mkdtemp(xauthfile) == NULL) {
|
||
|
restore_uid();
|
||
|
error("private X11 dir: mkdtemp %s failed: %s",
|
||
|
xauthfile, strerror(errno));
|
||
|
xfree(xauthfile);
|
||
|
xauthfile = NULL;
|
||
|
xfree(s->auth_proto);
|
||
|
xfree(s->auth_data);
|
||
|
/* XXXX remove listening channels */
|
||
|
return 0;
|
||
|
}
|
||
|
strlcat(xauthfile, "/cookies", MAXPATHLEN);
|
||
|
open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
|
||
|
restore_uid();
|
||
|
fatal_add_cleanup(xauthfile_cleanup_proc, s);
|
||
|
return 1;
|
||
|
}
|
||
|
|
||
|
void
|
||
|
session_input_channel_req(int id, void *arg)
|
||
|
{
|
||
|
unsigned int len;
|
||
|
int reply;
|
||
|
int success = 0;
|
||
|
char *rtype;
|
||
|
Session *s;
|
||
|
Channel *c;
|
||
|
|
||
|
rtype = packet_get_string(&len);
|
||
|
reply = packet_get_char();
|
||
|
|
||
|
s = session_by_channel(id);
|
||
|
if (s == NULL)
|
||
|
fatal("session_input_channel_req: channel %d: no session", id);
|
||
|
c = channel_lookup(id);
|
||
|
if (c == NULL)
|
||
|
fatal("session_input_channel_req: channel %d: bad channel", id);
|
||
|
|
||
|
debug("session_input_channel_req: session %d channel %d request %s reply %d",
|
||
|
s->self, id, rtype, reply);
|
||
|
|
||
|
/*
|
||
|
* a session is in LARVAL state until a shell
|
||
|
* or programm is executed
|
||
|
*/
|
||
|
if (c->type == SSH_CHANNEL_LARVAL) {
|
||
|
if (strcmp(rtype, "shell") == 0) {
|
||
|
packet_done();
|
||
|
s->extended = 1;
|
||
|
if (s->ttyfd == -1)
|
||
|
do_exec_no_pty(s, NULL, s->pw);
|
||
|
else
|
||
|
do_exec_pty(s, NULL, s->pw);
|
||
|
success = 1;
|
||
|
} else if (strcmp(rtype, "exec") == 0) {
|
||
|
char *command = packet_get_string(&len);
|
||
|
packet_done();
|
||
|
s->extended = 1;
|
||
|
if (s->ttyfd == -1)
|
||
|
do_exec_no_pty(s, command, s->pw);
|
||
|
else
|
||
|
do_exec_pty(s, command, s->pw);
|
||
|
xfree(command);
|
||
|
success = 1;
|
||
|
} else if (strcmp(rtype, "pty-req") == 0) {
|
||
|
success = session_pty_req(s);
|
||
|
} else if (strcmp(rtype, "x11-req") == 0) {
|
||
|
success = session_x11_req(s);
|
||
|
} else if (strcmp(rtype, "subsystem") == 0) {
|
||
|
success = session_subsystem_req(s);
|
||
|
}
|
||
|
}
|
||
|
if (strcmp(rtype, "window-change") == 0) {
|
||
|
success = session_window_change_req(s);
|
||
|
}
|
||
|
|
||
|
if (reply) {
|
||
|
packet_start(success ?
|
||
|
SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
|
||
|
packet_put_int(c->remote_id);
|
||
|
packet_send();
|
||
|
}
|
||
|
xfree(rtype);
|
||
|
}
|
||
|
|
||
|
void
|
||
|
session_set_fds(Session *s, int fdin, int fdout, int fderr)
|
||
|
{
|
||
|
if (!compat20)
|
||
|
fatal("session_set_fds: called for proto != 2.0");
|
||
|
/*
|
||
|
* now that have a child and a pipe to the child,
|
||
|
* we can activate our channel and register the fd's
|
||
|
*/
|
||
|
if (s->chanid == -1)
|
||
|
fatal("no channel for session %d", s->self);
|
||
|
channel_set_fds(s->chanid,
|
||
|
fdout, fdin, fderr,
|
||
|
fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ);
|
||
|
}
|
||
|
|
||
|
void
|
||
|
session_pty_cleanup(Session *s)
|
||
|
{
|
||
|
if (s == NULL || s->ttyfd == -1)
|
||
|
return;
|
||
|
|
||
|
debug("session_pty_cleanup: session %i release %s", s->self, s->tty);
|
||
|
|
||
|
/* Cancel the cleanup function. */
|
||
|
fatal_remove_cleanup(pty_cleanup_proc, (void *)s);
|
||
|
|
||
|
/* Record that the user has logged out. */
|
||
|
record_logout(s->pid, s->tty);
|
||
|
|
||
|
/* Release the pseudo-tty. */
|
||
|
pty_release(s->tty);
|
||
|
|
||
|
/*
|
||
|
* Close the server side of the socket pairs. We must do this after
|
||
|
* the pty cleanup, so that another process doesn't get this pty
|
||
|
* while we're still cleaning up.
|
||
|
*/
|
||
|
if (close(s->ptymaster) < 0)
|
||
|
error("close(s->ptymaster): %s", strerror(errno));
|
||
|
}
|
||
|
|
||
|
void
|
||
|
session_exit_message(Session *s, int status)
|
||
|
{
|
||
|
Channel *c;
|
||
|
if (s == NULL)
|
||
|
fatal("session_close: no session");
|
||
|
c = channel_lookup(s->chanid);
|
||
|
if (c == NULL)
|
||
|
fatal("session_close: session %d: no channel %d",
|
||
|
s->self, s->chanid);
|
||
|
debug("session_exit_message: session %d channel %d pid %d",
|
||
|
s->self, s->chanid, s->pid);
|
||
|
|
||
|
if (WIFEXITED(status)) {
|
||
|
channel_request_start(s->chanid,
|
||
|
"exit-status", 0);
|
||
|
packet_put_int(WEXITSTATUS(status));
|
||
|
packet_send();
|
||
|
} else if (WIFSIGNALED(status)) {
|
||
|
channel_request_start(s->chanid,
|
||
|
"exit-signal", 0);
|
||
|
packet_put_int(WTERMSIG(status));
|
||
|
packet_put_char(WCOREDUMP(status));
|
||
|
packet_put_cstring("");
|
||
|
packet_put_cstring("");
|
||
|
packet_send();
|
||
|
} else {
|
||
|
/* Some weird exit cause. Just exit. */
|
||
|
packet_disconnect("wait returned status %04x.", status);
|
||
|
}
|
||
|
|
||
|
/* disconnect channel */
|
||
|
debug("session_exit_message: release channel %d", s->chanid);
|
||
|
channel_cancel_cleanup(s->chanid);
|
||
|
/*
|
||
|
* emulate a write failure with 'chan_write_failed', nobody will be
|
||
|
* interested in data we write.
|
||
|
* Note that we must not call 'chan_read_failed', since there could
|
||
|
* be some more data waiting in the pipe.
|
||
|
*/
|
||
|
if (c->ostate != CHAN_OUTPUT_CLOSED)
|
||
|
chan_write_failed(c);
|
||
|
s->chanid = -1;
|
||
|
}
|
||
|
|
||
|
void
|
||
|
session_free(Session *s)
|
||
|
{
|
||
|
debug("session_free: session %d pid %d", s->self, s->pid);
|
||
|
if (s->term)
|
||
|
xfree(s->term);
|
||
|
if (s->display)
|
||
|
xfree(s->display);
|
||
|
if (s->auth_data)
|
||
|
xfree(s->auth_data);
|
||
|
if (s->auth_proto)
|
||
|
xfree(s->auth_proto);
|
||
|
s->used = 0;
|
||
|
}
|
||
|
|
||
|
void
|
||
|
session_close(Session *s)
|
||
|
{
|
||
|
session_pty_cleanup(s);
|
||
|
session_free(s);
|
||
|
session_proctitle(s);
|
||
|
}
|
||
|
|
||
|
void
|
||
|
session_close_by_pid(pid_t pid, int status)
|
||
|
{
|
||
|
Session *s = session_by_pid(pid);
|
||
|
if (s == NULL) {
|
||
|
debug("session_close_by_pid: no session for pid %d", s->pid);
|
||
|
return;
|
||
|
}
|
||
|
if (s->chanid != -1)
|
||
|
session_exit_message(s, status);
|
||
|
session_close(s);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* this is called when a channel dies before
|
||
|
* the session 'child' itself dies
|
||
|
*/
|
||
|
void
|
||
|
session_close_by_channel(int id, void *arg)
|
||
|
{
|
||
|
Session *s = session_by_channel(id);
|
||
|
if (s == NULL) {
|
||
|
debug("session_close_by_channel: no session for channel %d", id);
|
||
|
return;
|
||
|
}
|
||
|
/* disconnect channel */
|
||
|
channel_cancel_cleanup(s->chanid);
|
||
|
s->chanid = -1;
|
||
|
|
||
|
debug("session_close_by_channel: channel %d kill %d", id, s->pid);
|
||
|
if (s->pid == 0) {
|
||
|
/* close session immediately */
|
||
|
session_close(s);
|
||
|
} else {
|
||
|
/* notify child, delay session cleanup */
|
||
|
if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
|
||
|
error("session_close_by_channel: kill %d: %s",
|
||
|
s->pid, strerror(errno));
|
||
|
}
|
||
|
}
|
||
|
|
||
|
char *
|
||
|
session_tty_list(void)
|
||
|
{
|
||
|
static char buf[1024];
|
||
|
int i;
|
||
|
buf[0] = '\0';
|
||
|
for(i = 0; i < MAX_SESSIONS; i++) {
|
||
|
Session *s = &sessions[i];
|
||
|
if (s->used && s->ttyfd != -1) {
|
||
|
if (buf[0] != '\0')
|
||
|
strlcat(buf, ",", sizeof buf);
|
||
|
strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
|
||
|
}
|
||
|
}
|
||
|
if (buf[0] == '\0')
|
||
|
strlcpy(buf, "notty", sizeof buf);
|
||
|
return buf;
|
||
|
}
|
||
|
|
||
|
void
|
||
|
session_proctitle(Session *s)
|
||
|
{
|
||
|
if (s->pw == NULL)
|
||
|
error("no user for session %d", s->self);
|
||
|
else
|
||
|
setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
|
||
|
}
|
||
|
|
||
|
void
|
||
|
do_authenticated2(void)
|
||
|
{
|
||
|
/*
|
||
|
* Cancel the alarm we set to limit the time taken for
|
||
|
* authentication.
|
||
|
*/
|
||
|
alarm(0);
|
||
|
server_loop2();
|
||
|
if (xauthfile)
|
||
|
xauthfile_cleanup_proc(NULL);
|
||
|
}
|