xref: /freebsd/sys/kern/sys_socket.c (revision 35a04710d7286aa9538917fd7f8e417dbee95b82)
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 #ifdef MAC
77 	int error;
78 
79 	SOCK_LOCK(so);
80 	error = mac_socket_check_receive(active_cred, so);
81 	SOCK_UNLOCK(so);
82 	if (error)
83 		return (error);
84 #endif
85 	return (soreceive(so, 0, uio, 0, 0, 0));
86 }
87 
88 /* ARGSUSED */
89 int
90 soo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
91     int flags, struct thread *td)
92 {
93 	struct socket *so = fp->f_data;
94 	int error;
95 
96 #ifdef MAC
97 	SOCK_LOCK(so);
98 	error = mac_socket_check_send(active_cred, so);
99 	SOCK_UNLOCK(so);
100 	if (error)
101 		return (error);
102 #endif
103 	error = sosend(so, 0, uio, 0, 0, 0, uio->uio_td);
104 	if (error == EPIPE && (so->so_options & SO_NOSIGPIPE) == 0) {
105 		PROC_LOCK(uio->uio_td->td_proc);
106 		psignal(uio->uio_td->td_proc, SIGPIPE);
107 		PROC_UNLOCK(uio->uio_td->td_proc);
108 	}
109 	return (error);
110 }
111 
112 int
113 soo_ioctl(struct file *fp, u_long cmd, void *data, struct ucred *active_cred,
114     struct thread *td)
115 {
116 	struct socket *so = fp->f_data;
117 	int error = 0;
118 
119 	switch (cmd) {
120 	case FIONBIO:
121 		SOCK_LOCK(so);
122 		if (*(int *)data)
123 			so->so_state |= SS_NBIO;
124 		else
125 			so->so_state &= ~SS_NBIO;
126 		SOCK_UNLOCK(so);
127 		break;
128 
129 	case FIOASYNC:
130 		/*
131 		 * XXXRW: This code separately acquires SOCK_LOCK(so) and
132 		 * SOCKBUF_LOCK(&so->so_rcv) even though they are the same
133 		 * mutex to avoid introducing the assumption that they are
134 		 * the same.
135 		 */
136 		if (*(int *)data) {
137 			SOCK_LOCK(so);
138 			so->so_state |= SS_ASYNC;
139 			SOCK_UNLOCK(so);
140 			SOCKBUF_LOCK(&so->so_rcv);
141 			so->so_rcv.sb_flags |= SB_ASYNC;
142 			SOCKBUF_UNLOCK(&so->so_rcv);
143 			SOCKBUF_LOCK(&so->so_snd);
144 			so->so_snd.sb_flags |= SB_ASYNC;
145 			SOCKBUF_UNLOCK(&so->so_snd);
146 		} else {
147 			SOCK_LOCK(so);
148 			so->so_state &= ~SS_ASYNC;
149 			SOCK_UNLOCK(so);
150 			SOCKBUF_LOCK(&so->so_rcv);
151 			so->so_rcv.sb_flags &= ~SB_ASYNC;
152 			SOCKBUF_UNLOCK(&so->so_rcv);
153 			SOCKBUF_LOCK(&so->so_snd);
154 			so->so_snd.sb_flags &= ~SB_ASYNC;
155 			SOCKBUF_UNLOCK(&so->so_snd);
156 		}
157 		break;
158 
159 	case FIONREAD:
160 		/* Unlocked read. */
161 		*(int *)data = so->so_rcv.sb_cc;
162 		break;
163 
164 	case FIOSETOWN:
165 		error = fsetown(*(int *)data, &so->so_sigio);
166 		break;
167 
168 	case FIOGETOWN:
169 		*(int *)data = fgetown(&so->so_sigio);
170 		break;
171 
172 	case SIOCSPGRP:
173 		error = fsetown(-(*(int *)data), &so->so_sigio);
174 		break;
175 
176 	case SIOCGPGRP:
177 		*(int *)data = -fgetown(&so->so_sigio);
178 		break;
179 
180 	case SIOCATMARK:
181 		/* Unlocked read. */
182 		*(int *)data = (so->so_rcv.sb_state & SBS_RCVATMARK) != 0;
183 		break;
184 	default:
185 		/*
186 		 * Interface/routing/protocol specific ioctls: interface and
187 		 * routing ioctls should have a different entry since a
188 		 * socket is unnecessary.
189 		 */
190 		if (IOCGROUP(cmd) == 'i')
191 			error = ifioctl(so, cmd, data, td);
192 		else if (IOCGROUP(cmd) == 'r')
193 			error = rtioctl(cmd, data);
194 		else
195 			error = ((*so->so_proto->pr_usrreqs->pru_control)
196 			    (so, cmd, data, 0, td));
197 		break;
198 	}
199 	return (error);
200 }
201 
202 int
203 soo_poll(struct file *fp, int events, struct ucred *active_cred,
204     struct thread *td)
205 {
206 	struct socket *so = fp->f_data;
207 #ifdef MAC
208 	int error;
209 
210 	SOCK_LOCK(so);
211 	error = mac_socket_check_poll(active_cred, so);
212 	SOCK_UNLOCK(so);
213 	if (error)
214 		return (error);
215 #endif
216 	return (sopoll(so, events, fp->f_cred, td));
217 }
218 
219 int
220 soo_stat(struct file *fp, struct stat *ub, struct ucred *active_cred,
221     struct thread *td)
222 {
223 	struct socket *so = fp->f_data;
224 #ifdef MAC
225 	int error;
226 #endif
227 
228 	bzero((caddr_t)ub, sizeof (*ub));
229 	ub->st_mode = S_IFSOCK;
230 #ifdef MAC
231 	SOCK_LOCK(so);
232 	error = mac_socket_check_stat(active_cred, so);
233 	SOCK_UNLOCK(so);
234 	if (error)
235 		return (error);
236 #endif
237 	/*
238 	 * If SBS_CANTRCVMORE is set, but there's still data left in the
239 	 * receive buffer, the socket is still readable.
240 	 *
241 	 * XXXRW: perhaps should lock socket buffer so st_size result is
242 	 * consistent.
243 	 */
244 	/* Unlocked read. */
245 	if ((so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0 ||
246 	    so->so_rcv.sb_cc != 0)
247 		ub->st_mode |= S_IRUSR | S_IRGRP | S_IROTH;
248 	if ((so->so_snd.sb_state & SBS_CANTSENDMORE) == 0)
249 		ub->st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;
250 	ub->st_size = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
251 	ub->st_uid = so->so_cred->cr_uid;
252 	ub->st_gid = so->so_cred->cr_gid;
253 	return (*so->so_proto->pr_usrreqs->pru_sense)(so, ub);
254 }
255 
256 /*
257  * API socket close on file pointer.  We call soclose() to close the socket
258  * (including initiating closing protocols).  soclose() will sorele() the
259  * file reference but the actual socket will not go away until the socket's
260  * ref count hits 0.
261  */
262 /* ARGSUSED */
263 int
264 soo_close(struct file *fp, struct thread *td)
265 {
266 	int error = 0;
267 	struct socket *so;
268 
269 	so = fp->f_data;
270 	fp->f_ops = &badfileops;
271 	fp->f_data = NULL;
272 
273 	if (so)
274 		error = soclose(so);
275 	return (error);
276 }
277