xref: /freebsd/sys/kern/sys_socket.c (revision ce3adf4362fcca6a43e500b2531f0038adbfbd21)
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_sendfile = invfo_sendfile,
70 	.fo_flags = DFLAG_PASSABLE
71 };
72 
73 /* ARGSUSED */
74 int
75 soo_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
76     int flags, struct thread *td)
77 {
78 	struct socket *so = fp->f_data;
79 	int error;
80 
81 #ifdef MAC
82 	error = mac_socket_check_receive(active_cred, so);
83 	if (error)
84 		return (error);
85 #endif
86 	error = soreceive(so, 0, uio, 0, 0, 0);
87 	return (error);
88 }
89 
90 /* ARGSUSED */
91 int
92 soo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
93     int flags, struct thread *td)
94 {
95 	struct socket *so = fp->f_data;
96 	int error;
97 
98 #ifdef MAC
99 	error = mac_socket_check_send(active_cred, 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 		tdsignal(uio->uio_td, SIGPIPE);
107 		PROC_UNLOCK(uio->uio_td->td_proc);
108 	}
109 	return (error);
110 }
111 
112 int
113 soo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
114     struct thread *td)
115 {
116 
117 	return (EINVAL);
118 }
119 
120 int
121 soo_ioctl(struct file *fp, u_long cmd, void *data, struct ucred *active_cred,
122     struct thread *td)
123 {
124 	struct socket *so = fp->f_data;
125 	int error = 0;
126 
127 	switch (cmd) {
128 	case FIONBIO:
129 		SOCK_LOCK(so);
130 		if (*(int *)data)
131 			so->so_state |= SS_NBIO;
132 		else
133 			so->so_state &= ~SS_NBIO;
134 		SOCK_UNLOCK(so);
135 		break;
136 
137 	case FIOASYNC:
138 		/*
139 		 * XXXRW: This code separately acquires SOCK_LOCK(so) and
140 		 * SOCKBUF_LOCK(&so->so_rcv) even though they are the same
141 		 * mutex to avoid introducing the assumption that they are
142 		 * the same.
143 		 */
144 		if (*(int *)data) {
145 			SOCK_LOCK(so);
146 			so->so_state |= SS_ASYNC;
147 			SOCK_UNLOCK(so);
148 			SOCKBUF_LOCK(&so->so_rcv);
149 			so->so_rcv.sb_flags |= SB_ASYNC;
150 			SOCKBUF_UNLOCK(&so->so_rcv);
151 			SOCKBUF_LOCK(&so->so_snd);
152 			so->so_snd.sb_flags |= SB_ASYNC;
153 			SOCKBUF_UNLOCK(&so->so_snd);
154 		} else {
155 			SOCK_LOCK(so);
156 			so->so_state &= ~SS_ASYNC;
157 			SOCK_UNLOCK(so);
158 			SOCKBUF_LOCK(&so->so_rcv);
159 			so->so_rcv.sb_flags &= ~SB_ASYNC;
160 			SOCKBUF_UNLOCK(&so->so_rcv);
161 			SOCKBUF_LOCK(&so->so_snd);
162 			so->so_snd.sb_flags &= ~SB_ASYNC;
163 			SOCKBUF_UNLOCK(&so->so_snd);
164 		}
165 		break;
166 
167 	case FIONREAD:
168 		/* Unlocked read. */
169 		*(int *)data = so->so_rcv.sb_cc;
170 		break;
171 
172 	case FIONWRITE:
173 		/* Unlocked read. */
174 		*(int *)data = so->so_snd.sb_cc;
175 		break;
176 
177 	case FIONSPACE:
178 		if ((so->so_snd.sb_hiwat < so->so_snd.sb_cc) ||
179 		    (so->so_snd.sb_mbmax < so->so_snd.sb_mbcnt))
180 			*(int *)data = 0;
181 		else
182 			*(int *)data = sbspace(&so->so_snd);
183 		break;
184 
185 	case FIOSETOWN:
186 		error = fsetown(*(int *)data, &so->so_sigio);
187 		break;
188 
189 	case FIOGETOWN:
190 		*(int *)data = fgetown(&so->so_sigio);
191 		break;
192 
193 	case SIOCSPGRP:
194 		error = fsetown(-(*(int *)data), &so->so_sigio);
195 		break;
196 
197 	case SIOCGPGRP:
198 		*(int *)data = -fgetown(&so->so_sigio);
199 		break;
200 
201 	case SIOCATMARK:
202 		/* Unlocked read. */
203 		*(int *)data = (so->so_rcv.sb_state & SBS_RCVATMARK) != 0;
204 		break;
205 	default:
206 		/*
207 		 * Interface/routing/protocol specific ioctls: interface and
208 		 * routing ioctls should have a different entry since a
209 		 * socket is unnecessary.
210 		 */
211 		if (IOCGROUP(cmd) == 'i')
212 			error = ifioctl(so, cmd, data, td);
213 		else if (IOCGROUP(cmd) == 'r') {
214 			CURVNET_SET(so->so_vnet);
215 			error = rtioctl_fib(cmd, data, so->so_fibnum);
216 			CURVNET_RESTORE();
217 		} else {
218 			CURVNET_SET(so->so_vnet);
219 			error = ((*so->so_proto->pr_usrreqs->pru_control)
220 			    (so, cmd, data, 0, td));
221 			CURVNET_RESTORE();
222 		}
223 		break;
224 	}
225 	return (error);
226 }
227 
228 int
229 soo_poll(struct file *fp, int events, struct ucred *active_cred,
230     struct thread *td)
231 {
232 	struct socket *so = fp->f_data;
233 #ifdef MAC
234 	int error;
235 
236 	error = mac_socket_check_poll(active_cred, so);
237 	if (error)
238 		return (error);
239 #endif
240 	return (sopoll(so, events, fp->f_cred, td));
241 }
242 
243 int
244 soo_stat(struct file *fp, struct stat *ub, struct ucred *active_cred,
245     struct thread *td)
246 {
247 	struct socket *so = fp->f_data;
248 #ifdef MAC
249 	int error;
250 #endif
251 
252 	bzero((caddr_t)ub, sizeof (*ub));
253 	ub->st_mode = S_IFSOCK;
254 #ifdef MAC
255 	error = mac_socket_check_stat(active_cred, so);
256 	if (error)
257 		return (error);
258 #endif
259 	/*
260 	 * If SBS_CANTRCVMORE is set, but there's still data left in the
261 	 * receive buffer, the socket is still readable.
262 	 */
263 	SOCKBUF_LOCK(&so->so_rcv);
264 	if ((so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0 ||
265 	    so->so_rcv.sb_cc != 0)
266 		ub->st_mode |= S_IRUSR | S_IRGRP | S_IROTH;
267 	ub->st_size = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
268 	SOCKBUF_UNLOCK(&so->so_rcv);
269 	/* Unlocked read. */
270 	if ((so->so_snd.sb_state & SBS_CANTSENDMORE) == 0)
271 		ub->st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;
272 	ub->st_uid = so->so_cred->cr_uid;
273 	ub->st_gid = so->so_cred->cr_gid;
274 	return (*so->so_proto->pr_usrreqs->pru_sense)(so, ub);
275 }
276 
277 /*
278  * API socket close on file pointer.  We call soclose() to close the socket
279  * (including initiating closing protocols).  soclose() will sorele() the
280  * file reference but the actual socket will not go away until the socket's
281  * ref count hits 0.
282  */
283 /* ARGSUSED */
284 int
285 soo_close(struct file *fp, struct thread *td)
286 {
287 	int error = 0;
288 	struct socket *so;
289 
290 	so = fp->f_data;
291 	fp->f_ops = &badfileops;
292 	fp->f_data = NULL;
293 
294 	if (so)
295 		error = soclose(so);
296 	return (error);
297 }
298