xref: /freebsd/sys/kern/sys_socket.c (revision 195ebc7e9e4b129de810833791a19dfb4349d6a9)
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 #include <sys/vimage.h>
54 
55 #include <net/if.h>
56 #include <net/route.h>
57 
58 #include <security/mac/mac_framework.h>
59 
60 struct fileops	socketops = {
61 	.fo_read = soo_read,
62 	.fo_write = soo_write,
63 	.fo_truncate = soo_truncate,
64 	.fo_ioctl = soo_ioctl,
65 	.fo_poll = soo_poll,
66 	.fo_kqfilter = soo_kqfilter,
67 	.fo_stat = soo_stat,
68 	.fo_close = soo_close,
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 	CURVNET_SET(so->so_vnet);
86 	error = soreceive(so, 0, uio, 0, 0, 0);
87 	CURVNET_RESTORE();
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 		psignal(uio->uio_td->td_proc, 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 	CURVNET_SET(so->so_vnet);
129 	switch (cmd) {
130 	case FIONBIO:
131 		SOCK_LOCK(so);
132 		if (*(int *)data)
133 			so->so_state |= SS_NBIO;
134 		else
135 			so->so_state &= ~SS_NBIO;
136 		SOCK_UNLOCK(so);
137 		break;
138 
139 	case FIOASYNC:
140 		/*
141 		 * XXXRW: This code separately acquires SOCK_LOCK(so) and
142 		 * SOCKBUF_LOCK(&so->so_rcv) even though they are the same
143 		 * mutex to avoid introducing the assumption that they are
144 		 * the same.
145 		 */
146 		if (*(int *)data) {
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 		} else {
157 			SOCK_LOCK(so);
158 			so->so_state &= ~SS_ASYNC;
159 			SOCK_UNLOCK(so);
160 			SOCKBUF_LOCK(&so->so_rcv);
161 			so->so_rcv.sb_flags &= ~SB_ASYNC;
162 			SOCKBUF_UNLOCK(&so->so_rcv);
163 			SOCKBUF_LOCK(&so->so_snd);
164 			so->so_snd.sb_flags &= ~SB_ASYNC;
165 			SOCKBUF_UNLOCK(&so->so_snd);
166 		}
167 		break;
168 
169 	case FIONREAD:
170 		/* Unlocked read. */
171 		*(int *)data = so->so_rcv.sb_cc;
172 		break;
173 
174 	case FIOSETOWN:
175 		error = fsetown(*(int *)data, &so->so_sigio);
176 		break;
177 
178 	case FIOGETOWN:
179 		*(int *)data = fgetown(&so->so_sigio);
180 		break;
181 
182 	case SIOCSPGRP:
183 		error = fsetown(-(*(int *)data), &so->so_sigio);
184 		break;
185 
186 	case SIOCGPGRP:
187 		*(int *)data = -fgetown(&so->so_sigio);
188 		break;
189 
190 	case SIOCATMARK:
191 		/* Unlocked read. */
192 		*(int *)data = (so->so_rcv.sb_state & SBS_RCVATMARK) != 0;
193 		break;
194 	default:
195 		/*
196 		 * Interface/routing/protocol specific ioctls: interface and
197 		 * routing ioctls should have a different entry since a
198 		 * socket is unnecessary.
199 		 */
200 		if (IOCGROUP(cmd) == 'i')
201 			error = ifioctl(so, cmd, data, td);
202 		else if (IOCGROUP(cmd) == 'r')
203 			error = rtioctl_fib(cmd, data, so->so_fibnum);
204 		else
205 			error = ((*so->so_proto->pr_usrreqs->pru_control)
206 			    (so, cmd, data, 0, td));
207 		break;
208 	}
209 	CURVNET_RESTORE();
210 	return (error);
211 }
212 
213 int
214 soo_poll(struct file *fp, int events, struct ucred *active_cred,
215     struct thread *td)
216 {
217 	struct socket *so = fp->f_data;
218 #ifdef MAC
219 	int error;
220 
221 	error = mac_socket_check_poll(active_cred, so);
222 	if (error)
223 		return (error);
224 #endif
225 	return (sopoll(so, events, fp->f_cred, td));
226 }
227 
228 int
229 soo_stat(struct file *fp, struct stat *ub, struct ucred *active_cred,
230     struct thread *td)
231 {
232 	struct socket *so = fp->f_data;
233 #ifdef MAC
234 	int error;
235 #endif
236 
237 	bzero((caddr_t)ub, sizeof (*ub));
238 	ub->st_mode = S_IFSOCK;
239 #ifdef MAC
240 	error = mac_socket_check_stat(active_cred, so);
241 	if (error)
242 		return (error);
243 #endif
244 	/*
245 	 * If SBS_CANTRCVMORE is set, but there's still data left in the
246 	 * receive buffer, the socket is still readable.
247 	 */
248 	SOCKBUF_LOCK(&so->so_rcv);
249 	if ((so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0 ||
250 	    so->so_rcv.sb_cc != 0)
251 		ub->st_mode |= S_IRUSR | S_IRGRP | S_IROTH;
252 	ub->st_size = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
253 	SOCKBUF_UNLOCK(&so->so_rcv);
254 	/* Unlocked read. */
255 	if ((so->so_snd.sb_state & SBS_CANTSENDMORE) == 0)
256 		ub->st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;
257 	ub->st_uid = so->so_cred->cr_uid;
258 	ub->st_gid = so->so_cred->cr_gid;
259 	return (*so->so_proto->pr_usrreqs->pru_sense)(so, ub);
260 }
261 
262 /*
263  * API socket close on file pointer.  We call soclose() to close the socket
264  * (including initiating closing protocols).  soclose() will sorele() the
265  * file reference but the actual socket will not go away until the socket's
266  * ref count hits 0.
267  */
268 /* ARGSUSED */
269 int
270 soo_close(struct file *fp, struct thread *td)
271 {
272 	int error = 0;
273 	struct socket *so;
274 
275 	so = fp->f_data;
276 	fp->f_ops = &badfileops;
277 	fp->f_data = NULL;
278 
279 	if (so)
280 		error = soclose(so);
281 	return (error);
282 }
283