xref: /freebsd/sys/kern/sys_socket.c (revision f856af0466c076beef4ea9b15d088e1119a945b8)
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(fp, uio, active_cred, flags, td)
73 	struct file *fp;
74 	struct uio *uio;
75 	struct ucred *active_cred;
76 	struct thread *td;
77 	int flags;
78 {
79 	struct socket *so = fp->f_data;
80 	int error;
81 
82 	NET_LOCK_GIANT();
83 #ifdef MAC
84 	SOCK_LOCK(so);
85 	error = mac_check_socket_receive(active_cred, so);
86 	SOCK_UNLOCK(so);
87 	if (error) {
88 		NET_UNLOCK_GIANT();
89 		return (error);
90 	}
91 #endif
92 	error = soreceive(so, 0, uio, 0, 0, 0);
93 	NET_UNLOCK_GIANT();
94 	return (error);
95 }
96 
97 /* ARGSUSED */
98 int
99 soo_write(fp, uio, active_cred, flags, td)
100 	struct file *fp;
101 	struct uio *uio;
102 	struct ucred *active_cred;
103 	struct thread *td;
104 	int flags;
105 {
106 	struct socket *so = fp->f_data;
107 	int error;
108 
109 	NET_LOCK_GIANT();
110 #ifdef MAC
111 	SOCK_LOCK(so);
112 	error = mac_check_socket_send(active_cred, so);
113 	SOCK_UNLOCK(so);
114 	if (error) {
115 		NET_UNLOCK_GIANT();
116 		return (error);
117 	}
118 #endif
119 	error = sosend(so, 0, uio, 0, 0, 0, uio->uio_td);
120 	if (error == EPIPE && (so->so_options & SO_NOSIGPIPE) == 0) {
121 		PROC_LOCK(uio->uio_td->td_proc);
122 		psignal(uio->uio_td->td_proc, SIGPIPE);
123 		PROC_UNLOCK(uio->uio_td->td_proc);
124 	}
125 	NET_UNLOCK_GIANT();
126 	return (error);
127 }
128 
129 int
130 soo_ioctl(fp, cmd, data, active_cred, td)
131 	struct file *fp;
132 	u_long cmd;
133 	void *data;
134 	struct ucred *active_cred;
135 	struct thread *td;
136 {
137 	struct socket *so = fp->f_data;
138 	int error = 0;
139 
140 	NET_LOCK_GIANT();
141 	switch (cmd) {
142 
143 	case FIONBIO:
144 		SOCK_LOCK(so);
145 		if (*(int *)data)
146 			so->so_state |= SS_NBIO;
147 		else
148 			so->so_state &= ~SS_NBIO;
149 		SOCK_UNLOCK(so);
150 		break;
151 
152 	case FIOASYNC:
153 		/*
154 		 * XXXRW: This code separately acquires SOCK_LOCK(so)
155 		 * and SOCKBUF_LOCK(&so->so_rcv) even though they are
156 		 * the same mutex to avoid introducing the assumption
157 		 * that they are the same.
158 		 */
159 		if (*(int *)data) {
160 			SOCK_LOCK(so);
161 			so->so_state |= SS_ASYNC;
162 			SOCK_UNLOCK(so);
163 			SOCKBUF_LOCK(&so->so_rcv);
164 			so->so_rcv.sb_flags |= SB_ASYNC;
165 			SOCKBUF_UNLOCK(&so->so_rcv);
166 			SOCKBUF_LOCK(&so->so_snd);
167 			so->so_snd.sb_flags |= SB_ASYNC;
168 			SOCKBUF_UNLOCK(&so->so_snd);
169 		} else {
170 			SOCK_LOCK(so);
171 			so->so_state &= ~SS_ASYNC;
172 			SOCK_UNLOCK(so);
173 			SOCKBUF_LOCK(&so->so_rcv);
174 			so->so_rcv.sb_flags &= ~SB_ASYNC;
175 			SOCKBUF_UNLOCK(&so->so_rcv);
176 			SOCKBUF_LOCK(&so->so_snd);
177 			so->so_snd.sb_flags &= ~SB_ASYNC;
178 			SOCKBUF_UNLOCK(&so->so_snd);
179 		}
180 		break;
181 
182 	case FIONREAD:
183 		/* Unlocked read. */
184 		*(int *)data = so->so_rcv.sb_cc;
185 		break;
186 
187 	case FIOSETOWN:
188 		error = fsetown(*(int *)data, &so->so_sigio);
189 		break;
190 
191 	case FIOGETOWN:
192 		*(int *)data = fgetown(&so->so_sigio);
193 		break;
194 
195 	case SIOCSPGRP:
196 		error = fsetown(-(*(int *)data), &so->so_sigio);
197 		break;
198 
199 	case SIOCGPGRP:
200 		*(int *)data = -fgetown(&so->so_sigio);
201 		break;
202 
203 	case SIOCATMARK:
204 		/* Unlocked read. */
205 		*(int *)data = (so->so_rcv.sb_state & SBS_RCVATMARK) != 0;
206 		break;
207 	default:
208 		/*
209 		 * Interface/routing/protocol specific ioctls:
210 		 * interface and routing ioctls should have a
211 		 * different entry since a socket's unnecessary
212 		 */
213 		if (IOCGROUP(cmd) == 'i')
214 			error = ifioctl(so, cmd, data, td);
215 		else if (IOCGROUP(cmd) == 'r')
216 			error = rtioctl(cmd, data);
217 		else
218 			error = ((*so->so_proto->pr_usrreqs->pru_control)
219 			    (so, cmd, data, 0, td));
220 		break;
221 	}
222 	NET_UNLOCK_GIANT();
223 	return(error);
224 }
225 
226 int
227 soo_poll(fp, events, active_cred, td)
228 	struct file *fp;
229 	int events;
230 	struct ucred *active_cred;
231 	struct thread *td;
232 {
233 	struct socket *so = fp->f_data;
234 	int error;
235 
236 	NET_LOCK_GIANT();
237 #ifdef MAC
238 	SOCK_LOCK(so);
239 	error = mac_check_socket_poll(active_cred, so);
240 	SOCK_UNLOCK(so);
241 	if (error) {
242 		NET_UNLOCK_GIANT();
243 		return (error);
244 	}
245 #endif
246 	error = sopoll(so, events, fp->f_cred, td);
247 	NET_UNLOCK_GIANT();
248 
249 	return (error);
250 }
251 
252 int
253 soo_stat(fp, ub, active_cred, td)
254 	struct file *fp;
255 	struct stat *ub;
256 	struct ucred *active_cred;
257 	struct thread *td;
258 {
259 	struct socket *so = fp->f_data;
260 	int error;
261 
262 	bzero((caddr_t)ub, sizeof (*ub));
263 	ub->st_mode = S_IFSOCK;
264 	NET_LOCK_GIANT();
265 #ifdef MAC
266 	SOCK_LOCK(so);
267 	error = mac_check_socket_stat(active_cred, so);
268 	SOCK_UNLOCK(so);
269 	if (error) {
270 		NET_UNLOCK_GIANT();
271 		return (error);
272 	}
273 #endif
274 	/*
275 	 * If SBS_CANTRCVMORE is set, but there's still data left in the
276 	 * receive buffer, the socket is still readable.
277 	 *
278 	 * XXXRW: perhaps should lock socket buffer so st_size result
279 	 * is consistent.
280 	 */
281 	/* Unlocked read. */
282 	if ((so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0 ||
283 	    so->so_rcv.sb_cc != 0)
284 		ub->st_mode |= S_IRUSR | S_IRGRP | S_IROTH;
285 	if ((so->so_snd.sb_state & SBS_CANTSENDMORE) == 0)
286 		ub->st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;
287 	ub->st_size = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
288 	ub->st_uid = so->so_cred->cr_uid;
289 	ub->st_gid = so->so_cred->cr_gid;
290 	error = (*so->so_proto->pr_usrreqs->pru_sense)(so, ub);
291 	NET_UNLOCK_GIANT();
292 	return (error);
293 }
294 
295 /*
296  * API socket close on file pointer.  We call soclose() to close the
297  * socket (including initiating closing protocols).  soclose() will
298  * sorele() the file reference but the actual socket will not go away
299  * until the socket's ref count hits 0.
300  */
301 /* ARGSUSED */
302 int
303 soo_close(fp, td)
304 	struct file *fp;
305 	struct thread *td;
306 {
307 	int error = 0;
308 	struct socket *so;
309 
310 	NET_LOCK_GIANT();
311 	so = fp->f_data;
312 	fp->f_ops = &badfileops;
313 	fp->f_data = NULL;
314 
315 	if (so)
316 		error = soclose(so);
317 	NET_UNLOCK_GIANT();
318 	return (error);
319 }
320