xref: /freebsd/sys/kern/sys_socket.c (revision 84dfba8d183d31e3412639ecb4b8ad4433cf7e80)
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/if_var.h>
54 #include <net/route.h>
55 #include <net/vnet.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_chmod = invfo_chmod,
69 	.fo_chown = invfo_chown,
70 	.fo_sendfile = invfo_sendfile,
71 	.fo_flags = DFLAG_PASSABLE
72 };
73 
74 /* ARGSUSED */
75 int
76 soo_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
77     int flags, struct thread *td)
78 {
79 	struct socket *so = fp->f_data;
80 	int error;
81 
82 #ifdef MAC
83 	error = mac_socket_check_receive(active_cred, so);
84 	if (error)
85 		return (error);
86 #endif
87 	error = soreceive(so, 0, uio, 0, 0, 0);
88 	return (error);
89 }
90 
91 /* ARGSUSED */
92 int
93 soo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
94     int flags, struct thread *td)
95 {
96 	struct socket *so = fp->f_data;
97 	int error;
98 
99 #ifdef MAC
100 	error = mac_socket_check_send(active_cred, 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 		tdsignal(uio->uio_td, 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 FIONWRITE:
174 		/* Unlocked read. */
175 		*(int *)data = so->so_snd.sb_cc;
176 		break;
177 
178 	case FIONSPACE:
179 		if ((so->so_snd.sb_hiwat < so->so_snd.sb_cc) ||
180 		    (so->so_snd.sb_mbmax < so->so_snd.sb_mbcnt))
181 			*(int *)data = 0;
182 		else
183 			*(int *)data = sbspace(&so->so_snd);
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: interface and
209 		 * routing ioctls should have a different entry since a
210 		 * socket is unnecessary.
211 		 */
212 		if (IOCGROUP(cmd) == 'i')
213 			error = ifioctl(so, cmd, data, td);
214 		else if (IOCGROUP(cmd) == 'r') {
215 			CURVNET_SET(so->so_vnet);
216 			error = rtioctl_fib(cmd, data, so->so_fibnum);
217 			CURVNET_RESTORE();
218 		} else {
219 			CURVNET_SET(so->so_vnet);
220 			error = ((*so->so_proto->pr_usrreqs->pru_control)
221 			    (so, cmd, data, 0, td));
222 			CURVNET_RESTORE();
223 		}
224 		break;
225 	}
226 	return (error);
227 }
228 
229 int
230 soo_poll(struct file *fp, int events, struct ucred *active_cred,
231     struct thread *td)
232 {
233 	struct socket *so = fp->f_data;
234 #ifdef MAC
235 	int error;
236 
237 	error = mac_socket_check_poll(active_cred, so);
238 	if (error)
239 		return (error);
240 #endif
241 	return (sopoll(so, events, fp->f_cred, td));
242 }
243 
244 int
245 soo_stat(struct file *fp, struct stat *ub, struct ucred *active_cred,
246     struct thread *td)
247 {
248 	struct socket *so = fp->f_data;
249 #ifdef MAC
250 	int error;
251 #endif
252 
253 	bzero((caddr_t)ub, sizeof (*ub));
254 	ub->st_mode = S_IFSOCK;
255 #ifdef MAC
256 	error = mac_socket_check_stat(active_cred, so);
257 	if (error)
258 		return (error);
259 #endif
260 	/*
261 	 * If SBS_CANTRCVMORE is set, but there's still data left in the
262 	 * receive buffer, the socket is still readable.
263 	 */
264 	SOCKBUF_LOCK(&so->so_rcv);
265 	if ((so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0 ||
266 	    so->so_rcv.sb_cc != 0)
267 		ub->st_mode |= S_IRUSR | S_IRGRP | S_IROTH;
268 	ub->st_size = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
269 	SOCKBUF_UNLOCK(&so->so_rcv);
270 	/* Unlocked read. */
271 	if ((so->so_snd.sb_state & SBS_CANTSENDMORE) == 0)
272 		ub->st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;
273 	ub->st_uid = so->so_cred->cr_uid;
274 	ub->st_gid = so->so_cred->cr_gid;
275 	return (*so->so_proto->pr_usrreqs->pru_sense)(so, ub);
276 }
277 
278 /*
279  * API socket close on file pointer.  We call soclose() to close the socket
280  * (including initiating closing protocols).  soclose() will sorele() the
281  * file reference but the actual socket will not go away until the socket's
282  * ref count hits 0.
283  */
284 /* ARGSUSED */
285 int
286 soo_close(struct file *fp, struct thread *td)
287 {
288 	int error = 0;
289 	struct socket *so;
290 
291 	so = fp->f_data;
292 	fp->f_ops = &badfileops;
293 	fp->f_data = NULL;
294 
295 	if (so)
296 		error = soclose(so);
297 	return (error);
298 }
299