freebsd-skq/sys/compat/svr4/svr4_socket.c
John Baldwin e0569c0798 Clean up the svr4 socket cache and streams code some to make it more easily
locked.
- Move all the svr4 socket cache code into svr4_socket.c, specifically
  move svr4_delete_socket() over from streams.c.  Make the socket cache
  entry structure and svr4_head private to svr4_socket.c as a result.
- Add a mutex to protect the svr4 socket cache.
- Change svr4_find_socket() to copy the sockaddr_un struct into a
  caller-supplied sockaddr_un rather than giving the caller a pointer to
  our internal one.  This removes the one case where code outside of
  svr4_socket.c could access data in the cache.
- Add an eventhandler for process_exit and process_exec to purge the cache
  of any entries for the exiting or execing process.
- Add methods to init and destroy the socket cache and call them from the
  svr4 ABI module's event handler.
- Conditionally grab Giant around socreate() in streamsopen().
- Use fdclose() instead of inlining it in streamsopen() when handling
  socreate() failure.
- Only allocate a stream structure and attach it to a socket in
  streamsopen().  Previously, if a svr4 program performed a stream
  operation on an arbitrary socket not opened via the streams device,
  we would attach streams state data to it and change f_ops of the
  associated struct file while it was in use.  The latter was especially
  not safe, and if a program wants a stream object it should open it via
  the streams device anyway.
- Don't bother locking so_emuldata in the streams code now that we only
  touch it right after creating a socket (in streamsopen()) or when
  tearing it down when the file is closed.
- Remove D_NEEDGIANT from the streams device as it is no longer needed.
2006-07-21 20:40:13 +00:00

242 lines
6.9 KiB
C

/*-
* Copyright (c) 1998 Mark Newton
* Copyright (c) 1996 Christos Zoulas.
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Christos Zoulas.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
*/
/*
* In SVR4 unix domain sockets are referenced sometimes
* (in putmsg(2) for example) as a [device, inode] pair instead of a pathname.
* Since there is no iname() routine in the kernel, and we need access to
* a mapping from inode to pathname, we keep our own table. This is a simple
* linked list that contains the pathname, the [device, inode] pair, the
* file corresponding to that socket and the process. When the
* socket gets closed we remove the item from the list. The list gets loaded
* every time a stat(2) call finds a socket.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/queue.h>
#include <sys/eventhandler.h>
#include <sys/file.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysproto.h>
#include <sys/un.h>
#include <sys/stat.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <compat/svr4/svr4.h>
#include <compat/svr4/svr4_types.h>
#include <compat/svr4/svr4_util.h>
#include <compat/svr4/svr4_socket.h>
#include <compat/svr4/svr4_signal.h>
#include <compat/svr4/svr4_sockmod.h>
#include <compat/svr4/svr4_proto.h>
struct svr4_sockcache_entry {
struct proc *p; /* Process for the socket */
void *cookie; /* Internal cookie used for matching */
struct sockaddr_un sock;/* Pathname for the socket */
dev_t dev; /* Device where the socket lives on */
ino_t ino; /* Inode where the socket lives on */
TAILQ_ENTRY(svr4_sockcache_entry) entries;
};
static TAILQ_HEAD(, svr4_sockcache_entry) svr4_head;
static struct mtx svr4_sockcache_lock;
static eventhandler_tag svr4_sockcache_exit_tag, svr4_sockcache_exec_tag;
static void svr4_purge_sockcache(void *arg, struct proc *p);
int
svr4_find_socket(td, fp, dev, ino, saun)
struct thread *td;
struct file *fp;
dev_t dev;
ino_t ino;
struct sockaddr_un *saun;
{
struct svr4_sockcache_entry *e;
void *cookie = ((struct socket *)fp->f_data)->so_emuldata;
DPRINTF(("svr4_find_socket: [%p,%d,%d]: ", td, dev, ino));
mtx_lock(&svr4_sockcache_lock);
TAILQ_FOREACH(e, &svr4_head, entries)
if (e->p == td->td_proc && e->dev == dev && e->ino == ino) {
#ifdef DIAGNOSTIC
if (e->cookie != NULL && e->cookie != cookie)
panic("svr4 socket cookie mismatch");
#endif
e->cookie = cookie;
DPRINTF(("%s\n", e->sock.sun_path));
*saun = e->sock;
mtx_unlock(&svr4_sockcache_lock);
return (0);
}
mtx_unlock(&svr4_sockcache_lock);
DPRINTF(("not found\n"));
return (ENOENT);
}
int
svr4_add_socket(td, path, st)
struct thread *td;
const char *path;
struct stat *st;
{
struct svr4_sockcache_entry *e;
int len, error;
e = malloc(sizeof(*e), M_TEMP, M_WAITOK);
e->cookie = NULL;
e->dev = st->st_dev;
e->ino = st->st_ino;
e->p = td->td_proc;
if ((error = copyinstr(path, e->sock.sun_path,
sizeof(e->sock.sun_path), &len)) != 0) {
DPRINTF(("svr4_add_socket: copyinstr failed %d\n", error));
free(e, M_TEMP);
return error;
}
e->sock.sun_family = AF_LOCAL;
e->sock.sun_len = len;
mtx_lock(&svr4_sockcache_lock);
TAILQ_INSERT_HEAD(&svr4_head, e, entries);
mtx_unlock(&svr4_sockcache_lock);
DPRINTF(("svr4_add_socket: %s [%p,%d,%d]\n", e->sock.sun_path,
td->td_proc, e->dev, e->ino));
return 0;
}
void
svr4_delete_socket(p, fp)
struct proc *p;
struct file *fp;
{
struct svr4_sockcache_entry *e;
void *cookie = ((struct socket *)fp->f_data)->so_emuldata;
mtx_lock(&svr4_sockcache_lock);
TAILQ_FOREACH(e, &svr4_head, entries)
if (e->p == p && e->cookie == cookie) {
TAILQ_REMOVE(&svr4_head, e, entries);
mtx_unlock(&svr4_sockcache_lock);
DPRINTF(("svr4_delete_socket: %s [%p,%d,%d]\n",
e->sock.sun_path, p, (int)e->dev, e->ino));
free(e, M_TEMP);
return;
}
mtx_unlock(&svr4_sockcache_lock);
}
void
svr4_purge_sockcache(arg, p)
void *arg;
struct proc *p;
{
struct svr4_sockcache_entry *e, *ne;
mtx_lock(&svr4_sockcache_lock);
TAILQ_FOREACH_SAFE(e, &svr4_head, entries, ne) {
if (e->p == p) {
TAILQ_REMOVE(&svr4_head, e, entries);
DPRINTF(("svr4_purge_sockcache: %s [%p,%d,%d]\n",
e->sock.sun_path, p, (int)e->dev, e->ino));
free(e, M_TEMP);
}
}
mtx_unlock(&svr4_sockcache_lock);
}
void
svr4_sockcache_init(void)
{
TAILQ_INIT(&svr4_head);
mtx_init(&svr4_sockcache_lock, "svr4 socket cache", NULL, MTX_DEF);
svr4_sockcache_exit_tag = EVENTHANDLER_REGISTER(process_exit,
svr4_purge_sockcache, NULL, EVENTHANDLER_PRI_ANY);
svr4_sockcache_exec_tag = EVENTHANDLER_REGISTER(process_exec,
svr4_purge_sockcache, NULL, EVENTHANDLER_PRI_ANY);
}
void
svr4_sockcache_destroy(void)
{
KASSERT(TAILQ_EMPTY(&svr4_head),
("%s: sockcache entries still around", __func__));
EVENTHANDLER_DEREGISTER(process_exec, svr4_sockcache_exec_tag);
EVENTHANDLER_DEREGISTER(process_exit, svr4_sockcache_exit_tag);
mtx_destroy(&svr4_sockcache_lock);
}
int
svr4_sys_socket(td, uap)
struct thread *td;
struct svr4_sys_socket_args *uap;
{
switch (uap->type) {
case SVR4_SOCK_DGRAM:
uap->type = SOCK_DGRAM;
break;
case SVR4_SOCK_STREAM:
uap->type = SOCK_STREAM;
break;
case SVR4_SOCK_RAW:
uap->type = SOCK_RAW;
break;
case SVR4_SOCK_RDM:
uap->type = SOCK_RDM;
break;
case SVR4_SOCK_SEQPACKET:
uap->type = SOCK_SEQPACKET;
break;
default:
return EINVAL;
}
return socket(td, (struct socket_args *)uap);
}