svr4_socket.c revision 107838 
1/*
2 * Copyright (c) 1998 Mark Newton
3 * Copyright (c) 1996 Christos Zoulas.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 *    must display the following acknowledgement:
16 *	This product includes software developed by Christos Zoulas.
17 * 4. The name of the author may not be used to endorse or promote products
18 *    derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 *
31 * $FreeBSD: head/sys/compat/svr4/svr4_socket.c 107838 2002-12-13 22:27:25Z alfred $
32 */
33
34/*
35 * In SVR4 unix domain sockets are referenced sometimes
36 * (in putmsg(2) for example) as a [device, inode] pair instead of a pathname.
37 * Since there is no iname() routine in the kernel, and we need access to
38 * a mapping from inode to pathname, we keep our own table. This is a simple
39 * linked list that contains the pathname, the [device, inode] pair, the
40 * file corresponding to that socket and the process. When the
41 * socket gets closed we remove the item from the list. The list gets loaded
42 * every time a stat(2) call finds a socket.
43 */
44
45#include <sys/param.h>
46#include <sys/systm.h>
47#include <sys/queue.h>
48#include <sys/file.h>
49#include <sys/socket.h>
50#include <sys/socketvar.h>
51#include <sys/sysproto.h>
52#include <sys/un.h>
53#include <sys/stat.h>
54#include <sys/proc.h>
55#include <sys/malloc.h>
56
57#include <compat/svr4/svr4.h>
58#include <compat/svr4/svr4_types.h>
59#include <compat/svr4/svr4_util.h>
60#include <compat/svr4/svr4_socket.h>
61#include <compat/svr4/svr4_signal.h>
62#include <compat/svr4/svr4_sockmod.h>
63#include <compat/svr4/svr4_proto.h>
64
65struct svr4_sockcache_entry {
66	struct proc *p;		/* Process for the socket		*/
67	void *cookie;		/* Internal cookie used for matching	*/
68	struct sockaddr_un sock;/* Pathname for the socket		*/
69	udev_t dev;		/* Device where the socket lives on	*/
70	ino_t ino;		/* Inode where the socket lives on	*/
71	TAILQ_ENTRY(svr4_sockcache_entry) entries;
72};
73
74extern TAILQ_HEAD(svr4_sockcache_head, svr4_sockcache_entry) svr4_head;
75extern int svr4_str_initialized;
76
77struct sockaddr_un *
78svr4_find_socket(td, fp, dev, ino)
79	struct thread *td;
80	struct file *fp;
81	udev_t dev;
82	ino_t ino;
83{
84	struct svr4_sockcache_entry *e;
85	void *cookie = ((struct socket *) fp->f_data)->so_emuldata;
86
87	if (svr4_str_initialized != 2) {
88		if (atomic_cmpset_acq_int(&svr4_str_initialized, 0, 1)) {
89			DPRINTF(("svr4_find_socket: uninitialized [%p,%d,%d]\n",
90			    td, dev, ino));
91			TAILQ_INIT(&svr4_head);
92			atomic_store_rel_int(&svr4_str_initialized, 2);
93		}
94		return NULL;
95	}
96
97
98	DPRINTF(("svr4_find_socket: [%p,%d,%d]: ", td, dev, ino));
99	TAILQ_FOREACH(e, &svr4_head, entries)
100		if (e->p == td->td_proc && e->dev == dev && e->ino == ino) {
101#ifdef DIAGNOSTIC
102			if (e->cookie != NULL && e->cookie != cookie)
103				panic("svr4 socket cookie mismatch");
104#endif
105			e->cookie = cookie;
106			DPRINTF(("%s\n", e->sock.sun_path));
107			return &e->sock;
108		}
109
110	DPRINTF(("not found\n"));
111	return NULL;
112}
113
114
115/*
116 * svr4_delete_socket() is in sys/dev/streams.c (because it's called by
117 * the streams "soo_close()" routine).
118 */
119int
120svr4_add_socket(td, path, st)
121	struct thread *td;
122	const char *path;
123	struct stat *st;
124{
125	struct svr4_sockcache_entry *e;
126	int len, error;
127
128	/*
129	 * Wait for the TAILQ to be initialized.  Only the very first CPU
130	 * will succeed on the atomic_cmpset().  The other CPU's will spin
131	 * until the first one finishes the initialization.  Once the
132	 * initialization is complete, the condition will always fail
133	 * avoiding expensive atomic operations in the common case.
134	 */
135	while (svr4_str_initialized != 2)
136		if (atomic_cmpset_acq_int(&svr4_str_initialized, 0, 1)) {
137			TAILQ_INIT(&svr4_head);
138			atomic_store_rel_int(&svr4_str_initialized, 2);
139		}
140
141	e = malloc(sizeof(*e), M_TEMP, M_WAITOK);
142	e->cookie = NULL;
143	e->dev = st->st_dev;
144	e->ino = st->st_ino;
145	e->p = td->td_proc;
146
147	if ((error = copyinstr(path, e->sock.sun_path,
148	    sizeof(e->sock.sun_path), &len)) != 0) {
149		DPRINTF(("svr4_add_socket: copyinstr failed %d\n", error));
150		free(e, M_TEMP);
151		return error;
152	}
153
154	e->sock.sun_family = AF_LOCAL;
155	e->sock.sun_len = len;
156
157	TAILQ_INSERT_HEAD(&svr4_head, e, entries);
158	DPRINTF(("svr4_add_socket: %s [%p,%d,%d]\n", e->sock.sun_path,
159		 td->td_proc, e->dev, e->ino));
160	return 0;
161}
162
163
164int
165svr4_sys_socket(td, uap)
166	struct thread *td;
167	struct svr4_sys_socket_args *uap;
168{
169	switch (uap->type) {
170	case SVR4_SOCK_DGRAM:
171		uap->type = SOCK_DGRAM;
172		break;
173
174	case SVR4_SOCK_STREAM:
175		uap->type = SOCK_STREAM;
176		break;
177
178	case SVR4_SOCK_RAW:
179		uap->type = SOCK_RAW;
180		break;
181
182	case SVR4_SOCK_RDM:
183		uap->type = SOCK_RDM;
184		break;
185
186	case SVR4_SOCK_SEQPACKET:
187		uap->type = SOCK_SEQPACKET;
188		break;
189	default:
190		return EINVAL;
191	}
192	return socket(td, (struct socket_args *)uap);
193}
194