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freebsd-dev/sys/dev/iscsi/icl_soft_proxy.c
Gleb Smirnoff 779f106aa1 Listening sockets improvements. 
o Separate fields of struct socket that belong to listening from
  fields that belong to normal dataflow, and unionize them.  This
  shrinks the structure a bit.
  - Take out selinfo's from the socket buffers into the socket. The
    first reason is to support braindamaged scenario when a socket is
    added to kevent(2) and then listen(2) is cast on it. The second
    reason is that there is future plan to make socket buffers pluggable,
    so that for a dataflow socket a socket buffer can be changed, and
    in this case we also want to keep same selinfos through the lifetime
    of a socket.
  - Remove struct struct so_accf. Since now listening stuff no longer
    affects struct socket size, just move its fields into listening part
    of the union.
  - Provide sol_upcall field and enforce that so_upcall_set() may be called
    only on a dataflow socket, which has buffers, and for listening sockets
    provide solisten_upcall_set().

o Remove ACCEPT_LOCK() global.
  - Add a mutex to socket, to be used instead of socket buffer lock to lock
    fields of struct socket that don't belong to a socket buffer.
  - Allow to acquire two socket locks, but the first one must belong to a
    listening socket.
  - Make soref()/sorele() to use atomic(9).  This allows in some situations
    to do soref() without owning socket lock.  There is place for improvement
    here, it is possible to make sorele() also to lock optionally.
  - Most protocols aren't touched by this change, except UNIX local sockets.
    See below for more information.

o Reduce copy-and-paste in kernel modules that accept connections from
  listening sockets: provide function solisten_dequeue(), and use it in
  the following modules: ctl(4), iscsi(4), ng_btsocket(4), ng_ksocket(4),
  infiniband, rpc.

o UNIX local sockets.
  - Removal of ACCEPT_LOCK() global uncovered several races in the UNIX
    local sockets.  Most races exist around spawning a new socket, when we
    are connecting to a local listening socket.  To cover them, we need to
    hold locks on both PCBs when spawning a third one.  This means holding
    them across sonewconn().  This creates a LOR between pcb locks and
    unp_list_lock.
  - To fix the new LOR, abandon the global unp_list_lock in favor of global
    unp_link_lock.  Indeed, separating these two locks didn't provide us any
    extra parralelism in the UNIX sockets.
  - Now call into uipc_attach() may happen with unp_link_lock hold if, we
    are accepting, or without unp_link_lock in case if we are just creating
    a socket.
  - Another problem in UNIX sockets is that uipc_close() basicly did nothing
    for a listening socket.  The vnode remained opened for connections.  This
    is fixed by removing vnode in uipc_close().  Maybe the right way would be
    to do it for all sockets (not only listening), simply move the vnode
    teardown from uipc_detach() to uipc_close()?

Sponsored by:		Netflix
Differential Revision:	https://reviews.freebsd.org/D9770
2017-06-08 21:30:34 +00:00

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/*-
* Copyright (c) 2012 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Edward Tomasz Napierala under sponsorship
* from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
/*-
* Copyright (c) 1982, 1986, 1989, 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* sendfile(2) and related extensions:
* Copyright (c) 1998, David Greenman. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)uipc_syscalls.c 8.4 (Berkeley) 2/21/94
*/
/*
* iSCSI Common Layer, kernel proxy part.
*/
#ifdef ICL_KERNEL_PROXY
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/capsicum.h>
#include <sys/condvar.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sx.h>
#include <sys/systm.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <dev/iscsi/icl.h>
struct icl_listen_sock {
TAILQ_ENTRY(icl_listen_sock) ils_next;
struct icl_listen *ils_listen;
struct socket *ils_socket;
bool ils_running;
int ils_id;
};
struct icl_listen {
TAILQ_HEAD(, icl_listen_sock) il_sockets;
struct sx il_lock;
void (*il_accept)(struct socket *,
struct sockaddr *, int);
};
static MALLOC_DEFINE(M_ICL_PROXY, "ICL_PROXY", "iSCSI common layer proxy");
int
icl_soft_proxy_connect(struct icl_conn *ic, int domain, int socktype,
int protocol, struct sockaddr *from_sa, struct sockaddr *to_sa)
{
struct socket *so;
int error;
int interrupted = 0;
error = socreate(domain, &so, socktype, protocol,
curthread->td_ucred, curthread);
if (error != 0)
return (error);
if (from_sa != NULL) {
error = sobind(so, from_sa, curthread);
if (error != 0) {
soclose(so);
return (error);
}
}
error = soconnect(so, to_sa, curthread);
if (error != 0) {
soclose(so);
return (error);
}
SOCK_LOCK(so);
while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
error = msleep(&so->so_timeo, SOCK_MTX(so), PSOCK | PCATCH,
"icl_connect", 0);
if (error) {
if (error == EINTR || error == ERESTART)
interrupted = 1;
break;
}
}
if (error == 0) {
error = so->so_error;
so->so_error = 0;
}
SOCK_UNLOCK(so);
if (error != 0) {
soclose(so);
return (error);
}
error = icl_soft_handoff_sock(ic, so);
if (error != 0)
soclose(so);
return (error);
}
struct icl_listen *
icl_listen_new(void (*accept_cb)(struct socket *, struct sockaddr *, int))
{
struct icl_listen *il;
il = malloc(sizeof(*il), M_ICL_PROXY, M_ZERO | M_WAITOK);
TAILQ_INIT(&il->il_sockets);
sx_init(&il->il_lock, "icl_listen");
il->il_accept = accept_cb;
return (il);
}
void
icl_listen_free(struct icl_listen *il)
{
struct icl_listen_sock *ils;
sx_xlock(&il->il_lock);
while (!TAILQ_EMPTY(&il->il_sockets)) {
ils = TAILQ_FIRST(&il->il_sockets);
while (ils->ils_running) {
ICL_DEBUG("waiting for accept thread to terminate");
sx_xunlock(&il->il_lock);
SOLISTEN_LOCK(ils->ils_socket);
ils->ils_socket->so_error = ENOTCONN;
SOLISTEN_UNLOCK(ils->ils_socket);
wakeup(&ils->ils_socket->so_timeo);
pause("icl_unlisten", 1 * hz);
sx_xlock(&il->il_lock);
}
TAILQ_REMOVE(&il->il_sockets, ils, ils_next);
soclose(ils->ils_socket);
free(ils, M_ICL_PROXY);
}
sx_xunlock(&il->il_lock);
free(il, M_ICL_PROXY);
}
/*
* XXX: Doing accept in a separate thread in each socket might not be the
* best way to do stuff, but it's pretty clean and debuggable - and you
* probably won't have hundreds of listening sockets anyway.
*/
static void
icl_accept_thread(void *arg)
{
struct icl_listen_sock *ils;
struct socket *head, *so;
struct sockaddr *sa;
int error;
ils = arg;
head = ils->ils_socket;
ils->ils_running = true;
for (;;) {
SOLISTEN_LOCK(head);
error = solisten_dequeue(head, &so, 0);
if (error == ENOTCONN) {
/*
* XXXGL: ENOTCONN is our mark from icl_listen_free().
* Neither socket code, nor msleep(9) may return it.
*/
ICL_DEBUG("terminating");
ils->ils_running = false;
kthread_exit();
return;
}
if (error) {
ICL_WARN("solisten_dequeue error %d", error);
continue;
}
sa = NULL;
error = soaccept(so, &sa);
if (error != 0) {
ICL_WARN("soaccept error %d", error);
if (sa != NULL)
free(sa, M_SONAME);
soclose(so);
continue;
}
(ils->ils_listen->il_accept)(so, sa, ils->ils_id);
}
}
static int
icl_listen_add_tcp(struct icl_listen *il, int domain, int socktype,
int protocol, struct sockaddr *sa, int portal_id)
{
struct icl_listen_sock *ils;
struct socket *so;
struct sockopt sopt;
int error, one = 1;
error = socreate(domain, &so, socktype, protocol,
curthread->td_ucred, curthread);
if (error != 0) {
ICL_WARN("socreate failed with error %d", error);
return (error);
}
sopt.sopt_dir = SOPT_SET;
sopt.sopt_level = SOL_SOCKET;
sopt.sopt_name = SO_REUSEADDR;
sopt.sopt_val = &one;
sopt.sopt_valsize = sizeof(one);
sopt.sopt_td = NULL;
error = sosetopt(so, &sopt);
if (error != 0) {
ICL_WARN("failed to set SO_REUSEADDR with error %d", error);
soclose(so);
return (error);
}
error = sobind(so, sa, curthread);
if (error != 0) {
ICL_WARN("sobind failed with error %d", error);
soclose(so);
return (error);
}
error = solisten(so, -1, curthread);
if (error != 0) {
ICL_WARN("solisten failed with error %d", error);
soclose(so);
return (error);
}
ils = malloc(sizeof(*ils), M_ICL_PROXY, M_ZERO | M_WAITOK);
ils->ils_listen = il;
ils->ils_socket = so;
ils->ils_id = portal_id;
error = kthread_add(icl_accept_thread, ils, NULL, NULL, 0, 0, "iclacc");
if (error != 0) {
ICL_WARN("kthread_add failed with error %d", error);
soclose(so);
free(ils, M_ICL_PROXY);
return (error);
}
sx_xlock(&il->il_lock);
TAILQ_INSERT_TAIL(&il->il_sockets, ils, ils_next);
sx_xunlock(&il->il_lock);
return (0);
}
int
icl_listen_add(struct icl_listen *il, bool rdma, int domain, int socktype,
int protocol, struct sockaddr *sa, int portal_id)
{
if (rdma) {
ICL_DEBUG("RDMA not supported");
return (EOPNOTSUPP);
}
return (icl_listen_add_tcp(il, domain, socktype, protocol, sa,
portal_id));
}
int
icl_listen_remove(struct icl_listen *il, struct sockaddr *sa)
{
/*
* XXX
*/
return (EOPNOTSUPP);
}
#endif /* ICL_KERNEL_PROXY */
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