xref: /freebsd/sys/kern/sys_socket.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
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_truncate = soo_truncate,
63 	.fo_ioctl = soo_ioctl,
64 	.fo_poll = soo_poll,
65 	.fo_kqfilter = soo_kqfilter,
66 	.fo_stat = soo_stat,
67 	.fo_close = soo_close,
68 	.fo_flags = DFLAG_PASSABLE
69 };
70 
71 /* ARGSUSED */
72 int
73 soo_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
74     int flags, struct thread *td)
75 {
76 	struct socket *so = fp->f_data;
77 #ifdef MAC
78 	int error;
79 
80 	SOCK_LOCK(so);
81 	error = mac_socket_check_receive(active_cred, so);
82 	SOCK_UNLOCK(so);
83 	if (error)
84 		return (error);
85 #endif
86 	return (soreceive(so, 0, uio, 0, 0, 0));
87 }
88 
89 /* ARGSUSED */
90 int
91 soo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
92     int flags, struct thread *td)
93 {
94 	struct socket *so = fp->f_data;
95 	int error;
96 
97 #ifdef MAC
98 	SOCK_LOCK(so);
99 	error = mac_socket_check_send(active_cred, so);
100 	SOCK_UNLOCK(so);
101 	if (error)
102 		return (error);
103 #endif
104 	error = sosend(so, 0, uio, 0, 0, 0, uio->uio_td);
105 	if (error == EPIPE && (so->so_options & SO_NOSIGPIPE) == 0) {
106 		PROC_LOCK(uio->uio_td->td_proc);
107 		psignal(uio->uio_td->td_proc, SIGPIPE);
108 		PROC_UNLOCK(uio->uio_td->td_proc);
109 	}
110 	return (error);
111 }
112 
113 int
114 soo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
115     struct thread *td)
116 {
117 
118 	return (EINVAL);
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 	switch (cmd) {
129 	case FIONBIO:
130 		SOCK_LOCK(so);
131 		if (*(int *)data)
132 			so->so_state |= SS_NBIO;
133 		else
134 			so->so_state &= ~SS_NBIO;
135 		SOCK_UNLOCK(so);
136 		break;
137 
138 	case FIOASYNC:
139 		/*
140 		 * XXXRW: This code separately acquires SOCK_LOCK(so) and
141 		 * SOCKBUF_LOCK(&so->so_rcv) even though they are the same
142 		 * mutex to avoid introducing the assumption that they are
143 		 * the same.
144 		 */
145 		if (*(int *)data) {
146 			SOCK_LOCK(so);
147 			so->so_state |= SS_ASYNC;
148 			SOCK_UNLOCK(so);
149 			SOCKBUF_LOCK(&so->so_rcv);
150 			so->so_rcv.sb_flags |= SB_ASYNC;
151 			SOCKBUF_UNLOCK(&so->so_rcv);
152 			SOCKBUF_LOCK(&so->so_snd);
153 			so->so_snd.sb_flags |= SB_ASYNC;
154 			SOCKBUF_UNLOCK(&so->so_snd);
155 		} else {
156 			SOCK_LOCK(so);
157 			so->so_state &= ~SS_ASYNC;
158 			SOCK_UNLOCK(so);
159 			SOCKBUF_LOCK(&so->so_rcv);
160 			so->so_rcv.sb_flags &= ~SB_ASYNC;
161 			SOCKBUF_UNLOCK(&so->so_rcv);
162 			SOCKBUF_LOCK(&so->so_snd);
163 			so->so_snd.sb_flags &= ~SB_ASYNC;
164 			SOCKBUF_UNLOCK(&so->so_snd);
165 		}
166 		break;
167 
168 	case FIONREAD:
169 		/* Unlocked read. */
170 		*(int *)data = so->so_rcv.sb_cc;
171 		break;
172 
173 	case FIOSETOWN:
174 		error = fsetown(*(int *)data, &so->so_sigio);
175 		break;
176 
177 	case FIOGETOWN:
178 		*(int *)data = fgetown(&so->so_sigio);
179 		break;
180 
181 	case SIOCSPGRP:
182 		error = fsetown(-(*(int *)data), &so->so_sigio);
183 		break;
184 
185 	case SIOCGPGRP:
186 		*(int *)data = -fgetown(&so->so_sigio);
187 		break;
188 
189 	case SIOCATMARK:
190 		/* Unlocked read. */
191 		*(int *)data = (so->so_rcv.sb_state & SBS_RCVATMARK) != 0;
192 		break;
193 	default:
194 		/*
195 		 * Interface/routing/protocol specific ioctls: interface and
196 		 * routing ioctls should have a different entry since a
197 		 * socket is unnecessary.
198 		 */
199 		if (IOCGROUP(cmd) == 'i')
200 			error = ifioctl(so, cmd, data, td);
201 		else if (IOCGROUP(cmd) == 'r')
202 			error = rtioctl(cmd, data);
203 		else
204 			error = ((*so->so_proto->pr_usrreqs->pru_control)
205 			    (so, cmd, data, 0, td));
206 		break;
207 	}
208 	return (error);
209 }
210 
211 int
212 soo_poll(struct file *fp, int events, struct ucred *active_cred,
213     struct thread *td)
214 {
215 	struct socket *so = fp->f_data;
216 #ifdef MAC
217 	int error;
218 
219 	SOCK_LOCK(so);
220 	error = mac_socket_check_poll(active_cred, so);
221 	SOCK_UNLOCK(so);
222 	if (error)
223 		return (error);
224 #endif
225 	return (sopoll(so, events, fp->f_cred, td));
226 }
227 
228 int
229 soo_stat(struct file *fp, struct stat *ub, struct ucred *active_cred,
230     struct thread *td)
231 {
232 	struct socket *so = fp->f_data;
233 #ifdef MAC
234 	int error;
235 #endif
236 
237 	bzero((caddr_t)ub, sizeof (*ub));
238 	ub->st_mode = S_IFSOCK;
239 #ifdef MAC
240 	SOCK_LOCK(so);
241 	error = mac_socket_check_stat(active_cred, so);
242 	SOCK_UNLOCK(so);
243 	if (error)
244 		return (error);
245 #endif
246 	/*
247 	 * If SBS_CANTRCVMORE is set, but there's still data left in the
248 	 * receive buffer, the socket is still readable.
249 	 *
250 	 * XXXRW: perhaps should lock socket buffer so st_size result is
251 	 * consistent.
252 	 */
253 	/* Unlocked read. */
254 	if ((so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0 ||
255 	    so->so_rcv.sb_cc != 0)
256 		ub->st_mode |= S_IRUSR | S_IRGRP | S_IROTH;
257 	if ((so->so_snd.sb_state & SBS_CANTSENDMORE) == 0)
258 		ub->st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;
259 	ub->st_size = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
260 	ub->st_uid = so->so_cred->cr_uid;
261 	ub->st_gid = so->so_cred->cr_gid;
262 	return (*so->so_proto->pr_usrreqs->pru_sense)(so, ub);
263 }
264 
265 /*
266  * API socket close on file pointer.  We call soclose() to close the socket
267  * (including initiating closing protocols).  soclose() will sorele() the
268  * file reference but the actual socket will not go away until the socket's
269  * ref count hits 0.
270  */
271 /* ARGSUSED */
272 int
273 soo_close(struct file *fp, struct thread *td)
274 {
275 	int error = 0;
276 	struct socket *so;
277 
278 	so = fp->f_data;
279 	fp->f_ops = &badfileops;
280 	fp->f_data = NULL;
281 
282 	if (so)
283 		error = soclose(so);
284 	return (error);
285 }
286