xref: /freebsd/sys/kern/sys_socket.c (revision e4e9813eb92cd7c4d4b819a8fbed5cbd3d92f5d8)
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/mac.h>
42 #include <sys/proc.h>
43 #include <sys/protosw.h>
44 #include <sys/sigio.h>
45 #include <sys/signal.h>
46 #include <sys/signalvar.h>
47 #include <sys/socket.h>
48 #include <sys/socketvar.h>
49 #include <sys/filio.h>			/* XXX */
50 #include <sys/sockio.h>
51 #include <sys/stat.h>
52 #include <sys/uio.h>
53 #include <sys/ucred.h>
54 
55 #include <net/if.h>
56 #include <net/route.h>
57 
58 struct	fileops socketops = {
59 	.fo_read = soo_read,
60 	.fo_write = soo_write,
61 	.fo_ioctl = soo_ioctl,
62 	.fo_poll = soo_poll,
63 	.fo_kqfilter = soo_kqfilter,
64 	.fo_stat = soo_stat,
65 	.fo_close = soo_close,
66 	.fo_flags = DFLAG_PASSABLE
67 };
68 
69 /* ARGSUSED */
70 int
71 soo_read(fp, uio, active_cred, flags, td)
72 	struct file *fp;
73 	struct uio *uio;
74 	struct ucred *active_cred;
75 	struct thread *td;
76 	int flags;
77 {
78 	struct socket *so = fp->f_data;
79 	int error;
80 
81 	NET_LOCK_GIANT();
82 #ifdef MAC
83 	SOCK_LOCK(so);
84 	error = mac_check_socket_receive(active_cred, so);
85 	SOCK_UNLOCK(so);
86 	if (error) {
87 		NET_UNLOCK_GIANT();
88 		return (error);
89 	}
90 #endif
91 	error = soreceive(so, 0, uio, 0, 0, 0);
92 	NET_UNLOCK_GIANT();
93 	return (error);
94 }
95 
96 /* ARGSUSED */
97 int
98 soo_write(fp, uio, active_cred, flags, td)
99 	struct file *fp;
100 	struct uio *uio;
101 	struct ucred *active_cred;
102 	struct thread *td;
103 	int flags;
104 {
105 	struct socket *so = fp->f_data;
106 	int error;
107 
108 	NET_LOCK_GIANT();
109 #ifdef MAC
110 	SOCK_LOCK(so);
111 	error = mac_check_socket_send(active_cred, so);
112 	SOCK_UNLOCK(so);
113 	if (error) {
114 		NET_UNLOCK_GIANT();
115 		return (error);
116 	}
117 #endif
118 	error = sosend(so, 0, uio, 0, 0, 0, uio->uio_td);
119 	if (error == EPIPE && (so->so_options & SO_NOSIGPIPE) == 0) {
120 		PROC_LOCK(uio->uio_td->td_proc);
121 		psignal(uio->uio_td->td_proc, SIGPIPE);
122 		PROC_UNLOCK(uio->uio_td->td_proc);
123 	}
124 	NET_UNLOCK_GIANT();
125 	return (error);
126 }
127 
128 int
129 soo_ioctl(fp, cmd, data, active_cred, td)
130 	struct file *fp;
131 	u_long cmd;
132 	void *data;
133 	struct ucred *active_cred;
134 	struct thread *td;
135 {
136 	struct socket *so = fp->f_data;
137 	int error = 0;
138 
139 	NET_LOCK_GIANT();
140 	switch (cmd) {
141 
142 	case FIONBIO:
143 		SOCK_LOCK(so);
144 		if (*(int *)data)
145 			so->so_state |= SS_NBIO;
146 		else
147 			so->so_state &= ~SS_NBIO;
148 		SOCK_UNLOCK(so);
149 		break;
150 
151 	case FIOASYNC:
152 		/*
153 		 * XXXRW: This code separately acquires SOCK_LOCK(so)
154 		 * and SOCKBUF_LOCK(&so->so_rcv) even though they are
155 		 * the same mutex to avoid introducing the assumption
156 		 * that they are the same.
157 		 */
158 		if (*(int *)data) {
159 			SOCK_LOCK(so);
160 			so->so_state |= SS_ASYNC;
161 			SOCK_UNLOCK(so);
162 			SOCKBUF_LOCK(&so->so_rcv);
163 			so->so_rcv.sb_flags |= SB_ASYNC;
164 			SOCKBUF_UNLOCK(&so->so_rcv);
165 			SOCKBUF_LOCK(&so->so_snd);
166 			so->so_snd.sb_flags |= SB_ASYNC;
167 			SOCKBUF_UNLOCK(&so->so_snd);
168 		} else {
169 			SOCK_LOCK(so);
170 			so->so_state &= ~SS_ASYNC;
171 			SOCK_UNLOCK(so);
172 			SOCKBUF_LOCK(&so->so_rcv);
173 			so->so_rcv.sb_flags &= ~SB_ASYNC;
174 			SOCKBUF_UNLOCK(&so->so_rcv);
175 			SOCKBUF_LOCK(&so->so_snd);
176 			so->so_snd.sb_flags &= ~SB_ASYNC;
177 			SOCKBUF_UNLOCK(&so->so_snd);
178 		}
179 		break;
180 
181 	case FIONREAD:
182 		/* Unlocked read. */
183 		*(int *)data = so->so_rcv.sb_cc;
184 		break;
185 
186 	case FIOSETOWN:
187 		error = fsetown(*(int *)data, &so->so_sigio);
188 		break;
189 
190 	case FIOGETOWN:
191 		*(int *)data = fgetown(&so->so_sigio);
192 		break;
193 
194 	case SIOCSPGRP:
195 		error = fsetown(-(*(int *)data), &so->so_sigio);
196 		break;
197 
198 	case SIOCGPGRP:
199 		*(int *)data = -fgetown(&so->so_sigio);
200 		break;
201 
202 	case SIOCATMARK:
203 		/* Unlocked read. */
204 		*(int *)data = (so->so_rcv.sb_state & SBS_RCVATMARK) != 0;
205 		break;
206 	default:
207 		/*
208 		 * Interface/routing/protocol specific ioctls:
209 		 * interface and routing ioctls should have a
210 		 * different entry since a socket's unnecessary
211 		 */
212 		if (IOCGROUP(cmd) == 'i')
213 			error = ifioctl(so, cmd, data, td);
214 		else if (IOCGROUP(cmd) == 'r')
215 			error = rtioctl(cmd, data);
216 		else
217 			error = ((*so->so_proto->pr_usrreqs->pru_control)
218 			    (so, cmd, data, 0, td));
219 		break;
220 	}
221 	NET_UNLOCK_GIANT();
222 	return(error);
223 }
224 
225 int
226 soo_poll(fp, events, active_cred, td)
227 	struct file *fp;
228 	int events;
229 	struct ucred *active_cred;
230 	struct thread *td;
231 {
232 	struct socket *so = fp->f_data;
233 	int error;
234 
235 	NET_LOCK_GIANT();
236 #ifdef MAC
237 	SOCK_LOCK(so);
238 	error = mac_check_socket_poll(active_cred, so);
239 	SOCK_UNLOCK(so);
240 	if (error) {
241 		NET_UNLOCK_GIANT();
242 		return (error);
243 	}
244 #endif
245 	error = sopoll(so, events, fp->f_cred, td);
246 	NET_UNLOCK_GIANT();
247 
248 	return (error);
249 }
250 
251 int
252 soo_stat(fp, ub, active_cred, td)
253 	struct file *fp;
254 	struct stat *ub;
255 	struct ucred *active_cred;
256 	struct thread *td;
257 {
258 	struct socket *so = fp->f_data;
259 	int error;
260 
261 	bzero((caddr_t)ub, sizeof (*ub));
262 	ub->st_mode = S_IFSOCK;
263 	NET_LOCK_GIANT();
264 #ifdef MAC
265 	SOCK_LOCK(so);
266 	error = mac_check_socket_stat(active_cred, so);
267 	SOCK_UNLOCK(so);
268 	if (error) {
269 		NET_UNLOCK_GIANT();
270 		return (error);
271 	}
272 #endif
273 	/*
274 	 * If SBS_CANTRCVMORE is set, but there's still data left in the
275 	 * receive buffer, the socket is still readable.
276 	 *
277 	 * XXXRW: perhaps should lock socket buffer so st_size result
278 	 * is consistent.
279 	 */
280 	/* Unlocked read. */
281 	if ((so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0 ||
282 	    so->so_rcv.sb_cc != 0)
283 		ub->st_mode |= S_IRUSR | S_IRGRP | S_IROTH;
284 	if ((so->so_snd.sb_state & SBS_CANTSENDMORE) == 0)
285 		ub->st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;
286 	ub->st_size = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
287 	ub->st_uid = so->so_cred->cr_uid;
288 	ub->st_gid = so->so_cred->cr_gid;
289 	error = (*so->so_proto->pr_usrreqs->pru_sense)(so, ub);
290 	NET_UNLOCK_GIANT();
291 	return (error);
292 }
293 
294 /*
295  * API socket close on file pointer.  We call soclose() to close the
296  * socket (including initiating closing protocols).  soclose() will
297  * sorele() the file reference but the actual socket will not go away
298  * until the socket's ref count hits 0.
299  */
300 /* ARGSUSED */
301 int
302 soo_close(fp, td)
303 	struct file *fp;
304 	struct thread *td;
305 {
306 	int error = 0;
307 	struct socket *so;
308 
309 	NET_LOCK_GIANT();
310 	so = fp->f_data;
311 	fp->f_ops = &badfileops;
312 	fp->f_data = NULL;
313 
314 	if (so)
315 		error = soclose(so);
316 	NET_UNLOCK_GIANT();
317 	return (error);
318 }
319