xref: /freebsd/sys/kern/sys_socket.c (revision aa0a1e58)
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_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 	int error;
77 
78 #ifdef MAC
79 	error = mac_socket_check_receive(active_cred, so);
80 	if (error)
81 		return (error);
82 #endif
83 	error = soreceive(so, 0, uio, 0, 0, 0);
84 	return (error);
85 }
86 
87 /* ARGSUSED */
88 int
89 soo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
90     int flags, struct thread *td)
91 {
92 	struct socket *so = fp->f_data;
93 	int error;
94 
95 #ifdef MAC
96 	error = mac_socket_check_send(active_cred, so);
97 	if (error)
98 		return (error);
99 #endif
100 	error = sosend(so, 0, uio, 0, 0, 0, uio->uio_td);
101 	if (error == EPIPE && (so->so_options & SO_NOSIGPIPE) == 0) {
102 		PROC_LOCK(uio->uio_td->td_proc);
103 		tdsignal(uio->uio_td, SIGPIPE);
104 		PROC_UNLOCK(uio->uio_td->td_proc);
105 	}
106 	return (error);
107 }
108 
109 int
110 soo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
111     struct thread *td)
112 {
113 
114 	return (EINVAL);
115 }
116 
117 int
118 soo_ioctl(struct file *fp, u_long cmd, void *data, struct ucred *active_cred,
119     struct thread *td)
120 {
121 	struct socket *so = fp->f_data;
122 	int error = 0;
123 
124 	switch (cmd) {
125 	case FIONBIO:
126 		SOCK_LOCK(so);
127 		if (*(int *)data)
128 			so->so_state |= SS_NBIO;
129 		else
130 			so->so_state &= ~SS_NBIO;
131 		SOCK_UNLOCK(so);
132 		break;
133 
134 	case FIOASYNC:
135 		/*
136 		 * XXXRW: This code separately acquires SOCK_LOCK(so) and
137 		 * SOCKBUF_LOCK(&so->so_rcv) even though they are the same
138 		 * mutex to avoid introducing the assumption that they are
139 		 * the same.
140 		 */
141 		if (*(int *)data) {
142 			SOCK_LOCK(so);
143 			so->so_state |= SS_ASYNC;
144 			SOCK_UNLOCK(so);
145 			SOCKBUF_LOCK(&so->so_rcv);
146 			so->so_rcv.sb_flags |= SB_ASYNC;
147 			SOCKBUF_UNLOCK(&so->so_rcv);
148 			SOCKBUF_LOCK(&so->so_snd);
149 			so->so_snd.sb_flags |= SB_ASYNC;
150 			SOCKBUF_UNLOCK(&so->so_snd);
151 		} else {
152 			SOCK_LOCK(so);
153 			so->so_state &= ~SS_ASYNC;
154 			SOCK_UNLOCK(so);
155 			SOCKBUF_LOCK(&so->so_rcv);
156 			so->so_rcv.sb_flags &= ~SB_ASYNC;
157 			SOCKBUF_UNLOCK(&so->so_rcv);
158 			SOCKBUF_LOCK(&so->so_snd);
159 			so->so_snd.sb_flags &= ~SB_ASYNC;
160 			SOCKBUF_UNLOCK(&so->so_snd);
161 		}
162 		break;
163 
164 	case FIONREAD:
165 		/* Unlocked read. */
166 		*(int *)data = so->so_rcv.sb_cc;
167 		break;
168 
169 	case FIONWRITE:
170 		/* Unlocked read. */
171 		*(int *)data = so->so_snd.sb_cc;
172 		break;
173 
174 	case FIONSPACE:
175 		if ((so->so_snd.sb_hiwat < so->so_snd.sb_cc) ||
176 		    (so->so_snd.sb_mbmax < so->so_snd.sb_mbcnt))
177 			*(int *)data = 0;
178 		else
179 			*(int *)data = sbspace(&so->so_snd);
180 		break;
181 
182 	case FIOSETOWN:
183 		error = fsetown(*(int *)data, &so->so_sigio);
184 		break;
185 
186 	case FIOGETOWN:
187 		*(int *)data = fgetown(&so->so_sigio);
188 		break;
189 
190 	case SIOCSPGRP:
191 		error = fsetown(-(*(int *)data), &so->so_sigio);
192 		break;
193 
194 	case SIOCGPGRP:
195 		*(int *)data = -fgetown(&so->so_sigio);
196 		break;
197 
198 	case SIOCATMARK:
199 		/* Unlocked read. */
200 		*(int *)data = (so->so_rcv.sb_state & SBS_RCVATMARK) != 0;
201 		break;
202 	default:
203 		/*
204 		 * Interface/routing/protocol specific ioctls: interface and
205 		 * routing ioctls should have a different entry since a
206 		 * socket is unnecessary.
207 		 */
208 		if (IOCGROUP(cmd) == 'i')
209 			error = ifioctl(so, cmd, data, td);
210 		else if (IOCGROUP(cmd) == 'r') {
211 			CURVNET_SET(so->so_vnet);
212 			error = rtioctl_fib(cmd, data, so->so_fibnum);
213 			CURVNET_RESTORE();
214 		} else {
215 			CURVNET_SET(so->so_vnet);
216 			error = ((*so->so_proto->pr_usrreqs->pru_control)
217 			    (so, cmd, data, 0, td));
218 			CURVNET_RESTORE();
219 		}
220 		break;
221 	}
222 	return (error);
223 }
224 
225 int
226 soo_poll(struct file *fp, int events, struct ucred *active_cred,
227     struct thread *td)
228 {
229 	struct socket *so = fp->f_data;
230 #ifdef MAC
231 	int error;
232 
233 	error = mac_socket_check_poll(active_cred, so);
234 	if (error)
235 		return (error);
236 #endif
237 	return (sopoll(so, events, fp->f_cred, td));
238 }
239 
240 int
241 soo_stat(struct file *fp, struct stat *ub, struct ucred *active_cred,
242     struct thread *td)
243 {
244 	struct socket *so = fp->f_data;
245 #ifdef MAC
246 	int error;
247 #endif
248 
249 	bzero((caddr_t)ub, sizeof (*ub));
250 	ub->st_mode = S_IFSOCK;
251 #ifdef MAC
252 	error = mac_socket_check_stat(active_cred, so);
253 	if (error)
254 		return (error);
255 #endif
256 	/*
257 	 * If SBS_CANTRCVMORE is set, but there's still data left in the
258 	 * receive buffer, the socket is still readable.
259 	 */
260 	SOCKBUF_LOCK(&so->so_rcv);
261 	if ((so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0 ||
262 	    so->so_rcv.sb_cc != 0)
263 		ub->st_mode |= S_IRUSR | S_IRGRP | S_IROTH;
264 	ub->st_size = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
265 	SOCKBUF_UNLOCK(&so->so_rcv);
266 	/* Unlocked read. */
267 	if ((so->so_snd.sb_state & SBS_CANTSENDMORE) == 0)
268 		ub->st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;
269 	ub->st_uid = so->so_cred->cr_uid;
270 	ub->st_gid = so->so_cred->cr_gid;
271 	return (*so->so_proto->pr_usrreqs->pru_sense)(so, ub);
272 }
273 
274 /*
275  * API socket close on file pointer.  We call soclose() to close the socket
276  * (including initiating closing protocols).  soclose() will sorele() the
277  * file reference but the actual socket will not go away until the socket's
278  * ref count hits 0.
279  */
280 /* ARGSUSED */
281 int
282 soo_close(struct file *fp, struct thread *td)
283 {
284 	int error = 0;
285 	struct socket *so;
286 
287 	so = fp->f_data;
288 	fp->f_ops = &badfileops;
289 	fp->f_data = NULL;
290 
291 	if (so)
292 		error = soclose(so);
293 	return (error);
294 }
295