xref: /freebsd/sys/kern/sys_socket.c (revision f3bb407b7c1b3faa88d0580541f01a8e6fb6cc68)
1 /*-
2  * Copyright (c) 1982, 1986, 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)sys_socket.c	8.1 (Berkeley) 6/10/93
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include "opt_mac.h"
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/file.h>
40 #include <sys/filedesc.h>
41 #include <sys/proc.h>
42 #include <sys/protosw.h>
43 #include <sys/sigio.h>
44 #include <sys/signal.h>
45 #include <sys/signalvar.h>
46 #include <sys/socket.h>
47 #include <sys/socketvar.h>
48 #include <sys/filio.h>			/* XXX */
49 #include <sys/sockio.h>
50 #include <sys/stat.h>
51 #include <sys/uio.h>
52 #include <sys/ucred.h>
53 
54 #include <net/if.h>
55 #include <net/route.h>
56 
57 #include <security/mac/mac_framework.h>
58 
59 struct fileops	socketops = {
60 	.fo_read = soo_read,
61 	.fo_write = soo_write,
62 	.fo_ioctl = soo_ioctl,
63 	.fo_poll = soo_poll,
64 	.fo_kqfilter = soo_kqfilter,
65 	.fo_stat = soo_stat,
66 	.fo_close = soo_close,
67 	.fo_flags = DFLAG_PASSABLE
68 };
69 
70 /* ARGSUSED */
71 int
72 soo_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
73     int flags, struct thread *td)
74 {
75 	struct socket *so = fp->f_data;
76 	int error;
77 
78 	NET_LOCK_GIANT();
79 #ifdef MAC
80 	SOCK_LOCK(so);
81 	error = mac_check_socket_receive(active_cred, so);
82 	SOCK_UNLOCK(so);
83 	if (error) {
84 		NET_UNLOCK_GIANT();
85 		return (error);
86 	}
87 #endif
88 	error = soreceive(so, 0, uio, 0, 0, 0);
89 	NET_UNLOCK_GIANT();
90 	return (error);
91 }
92 
93 /* ARGSUSED */
94 int
95 soo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
96     int flags, struct thread *td)
97 {
98 	struct socket *so = fp->f_data;
99 	int error;
100 
101 	NET_LOCK_GIANT();
102 #ifdef MAC
103 	SOCK_LOCK(so);
104 	error = mac_check_socket_send(active_cred, so);
105 	SOCK_UNLOCK(so);
106 	if (error) {
107 		NET_UNLOCK_GIANT();
108 		return (error);
109 	}
110 #endif
111 	error = sosend(so, 0, uio, 0, 0, 0, uio->uio_td);
112 	if (error == EPIPE && (so->so_options & SO_NOSIGPIPE) == 0) {
113 		PROC_LOCK(uio->uio_td->td_proc);
114 		psignal(uio->uio_td->td_proc, SIGPIPE);
115 		PROC_UNLOCK(uio->uio_td->td_proc);
116 	}
117 	NET_UNLOCK_GIANT();
118 	return (error);
119 }
120 
121 int
122 soo_ioctl(struct file *fp, u_long cmd, void *data, struct ucred *active_cred,
123     struct thread *td)
124 {
125 	struct socket *so = fp->f_data;
126 	int error = 0;
127 
128 	NET_LOCK_GIANT();
129 	switch (cmd) {
130 
131 	case FIONBIO:
132 		SOCK_LOCK(so);
133 		if (*(int *)data)
134 			so->so_state |= SS_NBIO;
135 		else
136 			so->so_state &= ~SS_NBIO;
137 		SOCK_UNLOCK(so);
138 		break;
139 
140 	case FIOASYNC:
141 		/*
142 		 * XXXRW: This code separately acquires SOCK_LOCK(so) and
143 		 * SOCKBUF_LOCK(&so->so_rcv) even though they are the same
144 		 * mutex to avoid introducing the assumption that they are
145 		 * the same.
146 		 */
147 		if (*(int *)data) {
148 			SOCK_LOCK(so);
149 			so->so_state |= SS_ASYNC;
150 			SOCK_UNLOCK(so);
151 			SOCKBUF_LOCK(&so->so_rcv);
152 			so->so_rcv.sb_flags |= SB_ASYNC;
153 			SOCKBUF_UNLOCK(&so->so_rcv);
154 			SOCKBUF_LOCK(&so->so_snd);
155 			so->so_snd.sb_flags |= SB_ASYNC;
156 			SOCKBUF_UNLOCK(&so->so_snd);
157 		} else {
158 			SOCK_LOCK(so);
159 			so->so_state &= ~SS_ASYNC;
160 			SOCK_UNLOCK(so);
161 			SOCKBUF_LOCK(&so->so_rcv);
162 			so->so_rcv.sb_flags &= ~SB_ASYNC;
163 			SOCKBUF_UNLOCK(&so->so_rcv);
164 			SOCKBUF_LOCK(&so->so_snd);
165 			so->so_snd.sb_flags &= ~SB_ASYNC;
166 			SOCKBUF_UNLOCK(&so->so_snd);
167 		}
168 		break;
169 
170 	case FIONREAD:
171 		/* Unlocked read. */
172 		*(int *)data = so->so_rcv.sb_cc;
173 		break;
174 
175 	case FIOSETOWN:
176 		error = fsetown(*(int *)data, &so->so_sigio);
177 		break;
178 
179 	case FIOGETOWN:
180 		*(int *)data = fgetown(&so->so_sigio);
181 		break;
182 
183 	case SIOCSPGRP:
184 		error = fsetown(-(*(int *)data), &so->so_sigio);
185 		break;
186 
187 	case SIOCGPGRP:
188 		*(int *)data = -fgetown(&so->so_sigio);
189 		break;
190 
191 	case SIOCATMARK:
192 		/* Unlocked read. */
193 		*(int *)data = (so->so_rcv.sb_state & SBS_RCVATMARK) != 0;
194 		break;
195 	default:
196 		/*
197 		 * Interface/routing/protocol specific ioctls: interface and
198 		 * routing ioctls should have a different entry since a
199 		 * socket is unnecessary.
200 		 */
201 		if (IOCGROUP(cmd) == 'i')
202 			error = ifioctl(so, cmd, data, td);
203 		else if (IOCGROUP(cmd) == 'r')
204 			error = rtioctl(cmd, data);
205 		else
206 			error = ((*so->so_proto->pr_usrreqs->pru_control)
207 			    (so, cmd, data, 0, td));
208 		break;
209 	}
210 	NET_UNLOCK_GIANT();
211 	return(error);
212 }
213 
214 int
215 soo_poll(struct file *fp, int events, struct ucred *active_cred,
216     struct thread *td)
217 {
218 	struct socket *so = fp->f_data;
219 	int error;
220 
221 	NET_LOCK_GIANT();
222 #ifdef MAC
223 	SOCK_LOCK(so);
224 	error = mac_check_socket_poll(active_cred, so);
225 	SOCK_UNLOCK(so);
226 	if (error) {
227 		NET_UNLOCK_GIANT();
228 		return (error);
229 	}
230 #endif
231 	error = sopoll(so, events, fp->f_cred, td);
232 	NET_UNLOCK_GIANT();
233 
234 	return (error);
235 }
236 
237 int
238 soo_stat(struct file *fp, struct stat *ub, struct ucred *active_cred,
239     struct thread *td)
240 {
241 	struct socket *so = fp->f_data;
242 	int error;
243 
244 	bzero((caddr_t)ub, sizeof (*ub));
245 	ub->st_mode = S_IFSOCK;
246 	NET_LOCK_GIANT();
247 #ifdef MAC
248 	SOCK_LOCK(so);
249 	error = mac_check_socket_stat(active_cred, so);
250 	SOCK_UNLOCK(so);
251 	if (error) {
252 		NET_UNLOCK_GIANT();
253 		return (error);
254 	}
255 #endif
256 	/*
257 	 * If SBS_CANTRCVMORE is set, but there's still data left in the
258 	 * receive buffer, the socket is still readable.
259 	 *
260 	 * XXXRW: perhaps should lock socket buffer so st_size result is
261 	 * consistent.
262 	 */
263 	/* Unlocked read. */
264 	if ((so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0 ||
265 	    so->so_rcv.sb_cc != 0)
266 		ub->st_mode |= S_IRUSR | S_IRGRP | S_IROTH;
267 	if ((so->so_snd.sb_state & SBS_CANTSENDMORE) == 0)
268 		ub->st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;
269 	ub->st_size = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
270 	ub->st_uid = so->so_cred->cr_uid;
271 	ub->st_gid = so->so_cred->cr_gid;
272 	error = (*so->so_proto->pr_usrreqs->pru_sense)(so, ub);
273 	NET_UNLOCK_GIANT();
274 	return (error);
275 }
276 
277 /*
278  * API socket close on file pointer.  We call soclose() to close the socket
279  * (including initiating closing protocols).  soclose() will sorele() the
280  * file reference but the actual socket will not go away until the socket's
281  * ref count hits 0.
282  */
283 /* ARGSUSED */
284 int
285 soo_close(struct file *fp, struct thread *td)
286 {
287 	int error = 0;
288 	struct socket *so;
289 
290 	NET_LOCK_GIANT();
291 	so = fp->f_data;
292 	fp->f_ops = &badfileops;
293 	fp->f_data = NULL;
294 
295 	if (so)
296 		error = soclose(so);
297 	NET_UNLOCK_GIANT();
298 	return (error);
299 }
300