xref: /freebsd/sys/kern/sys_socket.c (revision 586f63035fbe5e45cfc971037fd76375661ece26)
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 <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/file.h>
38 #include <sys/filedesc.h>
39 #include <sys/proc.h>
40 #include <sys/protosw.h>
41 #include <sys/sigio.h>
42 #include <sys/signal.h>
43 #include <sys/signalvar.h>
44 #include <sys/socket.h>
45 #include <sys/socketvar.h>
46 #include <sys/filio.h>			/* XXX */
47 #include <sys/sockio.h>
48 #include <sys/stat.h>
49 #include <sys/uio.h>
50 #include <sys/ucred.h>
51 
52 #include <net/if.h>
53 #include <net/route.h>
54 #include <net/vnet.h>
55 
56 #include <security/mac/mac_framework.h>
57 
58 struct fileops	socketops = {
59 	.fo_read = soo_read,
60 	.fo_write = soo_write,
61 	.fo_truncate = soo_truncate,
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_chmod = invfo_chmod,
68 	.fo_chown = invfo_chown,
69 	.fo_flags = DFLAG_PASSABLE
70 };
71 
72 /* ARGSUSED */
73 int
74 soo_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
75     int flags, struct thread *td)
76 {
77 	struct socket *so = fp->f_data;
78 	int error;
79 
80 #ifdef MAC
81 	error = mac_socket_check_receive(active_cred, so);
82 	if (error)
83 		return (error);
84 #endif
85 	error = soreceive(so, 0, uio, 0, 0, 0);
86 	return (error);
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 	error = mac_socket_check_send(active_cred, so);
99 	if (error)
100 		return (error);
101 #endif
102 	error = sosend(so, 0, uio, 0, 0, 0, uio->uio_td);
103 	if (error == EPIPE && (so->so_options & SO_NOSIGPIPE) == 0) {
104 		PROC_LOCK(uio->uio_td->td_proc);
105 		tdsignal(uio->uio_td, SIGPIPE);
106 		PROC_UNLOCK(uio->uio_td->td_proc);
107 	}
108 	return (error);
109 }
110 
111 int
112 soo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
113     struct thread *td)
114 {
115 
116 	return (EINVAL);
117 }
118 
119 int
120 soo_ioctl(struct file *fp, u_long cmd, void *data, struct ucred *active_cred,
121     struct thread *td)
122 {
123 	struct socket *so = fp->f_data;
124 	int error = 0;
125 
126 	switch (cmd) {
127 	case FIONBIO:
128 		SOCK_LOCK(so);
129 		if (*(int *)data)
130 			so->so_state |= SS_NBIO;
131 		else
132 			so->so_state &= ~SS_NBIO;
133 		SOCK_UNLOCK(so);
134 		break;
135 
136 	case FIOASYNC:
137 		/*
138 		 * XXXRW: This code separately acquires SOCK_LOCK(so) and
139 		 * SOCKBUF_LOCK(&so->so_rcv) even though they are the same
140 		 * mutex to avoid introducing the assumption that they are
141 		 * the same.
142 		 */
143 		if (*(int *)data) {
144 			SOCK_LOCK(so);
145 			so->so_state |= SS_ASYNC;
146 			SOCK_UNLOCK(so);
147 			SOCKBUF_LOCK(&so->so_rcv);
148 			so->so_rcv.sb_flags |= SB_ASYNC;
149 			SOCKBUF_UNLOCK(&so->so_rcv);
150 			SOCKBUF_LOCK(&so->so_snd);
151 			so->so_snd.sb_flags |= SB_ASYNC;
152 			SOCKBUF_UNLOCK(&so->so_snd);
153 		} else {
154 			SOCK_LOCK(so);
155 			so->so_state &= ~SS_ASYNC;
156 			SOCK_UNLOCK(so);
157 			SOCKBUF_LOCK(&so->so_rcv);
158 			so->so_rcv.sb_flags &= ~SB_ASYNC;
159 			SOCKBUF_UNLOCK(&so->so_rcv);
160 			SOCKBUF_LOCK(&so->so_snd);
161 			so->so_snd.sb_flags &= ~SB_ASYNC;
162 			SOCKBUF_UNLOCK(&so->so_snd);
163 		}
164 		break;
165 
166 	case FIONREAD:
167 		/* Unlocked read. */
168 		*(int *)data = so->so_rcv.sb_cc;
169 		break;
170 
171 	case FIONWRITE:
172 		/* Unlocked read. */
173 		*(int *)data = so->so_snd.sb_cc;
174 		break;
175 
176 	case FIONSPACE:
177 		if ((so->so_snd.sb_hiwat < so->so_snd.sb_cc) ||
178 		    (so->so_snd.sb_mbmax < so->so_snd.sb_mbcnt))
179 			*(int *)data = 0;
180 		else
181 			*(int *)data = sbspace(&so->so_snd);
182 		break;
183 
184 	case FIOSETOWN:
185 		error = fsetown(*(int *)data, &so->so_sigio);
186 		break;
187 
188 	case FIOGETOWN:
189 		*(int *)data = fgetown(&so->so_sigio);
190 		break;
191 
192 	case SIOCSPGRP:
193 		error = fsetown(-(*(int *)data), &so->so_sigio);
194 		break;
195 
196 	case SIOCGPGRP:
197 		*(int *)data = -fgetown(&so->so_sigio);
198 		break;
199 
200 	case SIOCATMARK:
201 		/* Unlocked read. */
202 		*(int *)data = (so->so_rcv.sb_state & SBS_RCVATMARK) != 0;
203 		break;
204 	default:
205 		/*
206 		 * Interface/routing/protocol specific ioctls: interface and
207 		 * routing ioctls should have a different entry since a
208 		 * socket is unnecessary.
209 		 */
210 		if (IOCGROUP(cmd) == 'i')
211 			error = ifioctl(so, cmd, data, td);
212 		else if (IOCGROUP(cmd) == 'r') {
213 			CURVNET_SET(so->so_vnet);
214 			error = rtioctl_fib(cmd, data, so->so_fibnum);
215 			CURVNET_RESTORE();
216 		} else {
217 			CURVNET_SET(so->so_vnet);
218 			error = ((*so->so_proto->pr_usrreqs->pru_control)
219 			    (so, cmd, data, 0, td));
220 			CURVNET_RESTORE();
221 		}
222 		break;
223 	}
224 	return (error);
225 }
226 
227 int
228 soo_poll(struct file *fp, int events, struct ucred *active_cred,
229     struct thread *td)
230 {
231 	struct socket *so = fp->f_data;
232 #ifdef MAC
233 	int error;
234 
235 	error = mac_socket_check_poll(active_cred, so);
236 	if (error)
237 		return (error);
238 #endif
239 	return (sopoll(so, events, fp->f_cred, td));
240 }
241 
242 int
243 soo_stat(struct file *fp, struct stat *ub, struct ucred *active_cred,
244     struct thread *td)
245 {
246 	struct socket *so = fp->f_data;
247 #ifdef MAC
248 	int error;
249 #endif
250 
251 	bzero((caddr_t)ub, sizeof (*ub));
252 	ub->st_mode = S_IFSOCK;
253 #ifdef MAC
254 	error = mac_socket_check_stat(active_cred, so);
255 	if (error)
256 		return (error);
257 #endif
258 	/*
259 	 * If SBS_CANTRCVMORE is set, but there's still data left in the
260 	 * receive buffer, the socket is still readable.
261 	 */
262 	SOCKBUF_LOCK(&so->so_rcv);
263 	if ((so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0 ||
264 	    so->so_rcv.sb_cc != 0)
265 		ub->st_mode |= S_IRUSR | S_IRGRP | S_IROTH;
266 	ub->st_size = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
267 	SOCKBUF_UNLOCK(&so->so_rcv);
268 	/* Unlocked read. */
269 	if ((so->so_snd.sb_state & SBS_CANTSENDMORE) == 0)
270 		ub->st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;
271 	ub->st_uid = so->so_cred->cr_uid;
272 	ub->st_gid = so->so_cred->cr_gid;
273 	return (*so->so_proto->pr_usrreqs->pru_sense)(so, ub);
274 }
275 
276 /*
277  * API socket close on file pointer.  We call soclose() to close the socket
278  * (including initiating closing protocols).  soclose() will sorele() the
279  * file reference but the actual socket will not go away until the socket's
280  * ref count hits 0.
281  */
282 /* ARGSUSED */
283 int
284 soo_close(struct file *fp, struct thread *td)
285 {
286 	int error = 0;
287 	struct socket *so;
288 
289 	so = fp->f_data;
290 	fp->f_ops = &badfileops;
291 	fp->f_data = NULL;
292 
293 	if (so)
294 		error = soclose(so);
295 	return (error);
296 }
297