xref: /freebsd/sys/kern/sys_socket.c (revision 8fc257994d0ce2396196d7a06d50d20c8015f4b7)
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 	CURVNET_SET(so->so_vnet);
84 	error = soreceive(so, 0, uio, 0, 0, 0);
85 	CURVNET_RESTORE();
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 	CURVNET_SET(so->so_vnet);
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 			error = rtioctl_fib(cmd, data, so->so_fibnum);
215 		else
216 			error = ((*so->so_proto->pr_usrreqs->pru_control)
217 			    (so, cmd, data, 0, td));
218 		break;
219 	}
220 	CURVNET_RESTORE();
221 	return (error);
222 }
223 
224 int
225 soo_poll(struct file *fp, int events, struct ucred *active_cred,
226     struct thread *td)
227 {
228 	struct socket *so = fp->f_data;
229 #ifdef MAC
230 	int error;
231 
232 	error = mac_socket_check_poll(active_cred, so);
233 	if (error)
234 		return (error);
235 #endif
236 	return (sopoll(so, events, fp->f_cred, td));
237 }
238 
239 int
240 soo_stat(struct file *fp, struct stat *ub, struct ucred *active_cred,
241     struct thread *td)
242 {
243 	struct socket *so = fp->f_data;
244 #ifdef MAC
245 	int error;
246 #endif
247 
248 	bzero((caddr_t)ub, sizeof (*ub));
249 	ub->st_mode = S_IFSOCK;
250 #ifdef MAC
251 	error = mac_socket_check_stat(active_cred, so);
252 	if (error)
253 		return (error);
254 #endif
255 	/*
256 	 * If SBS_CANTRCVMORE is set, but there's still data left in the
257 	 * receive buffer, the socket is still readable.
258 	 */
259 	SOCKBUF_LOCK(&so->so_rcv);
260 	if ((so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0 ||
261 	    so->so_rcv.sb_cc != 0)
262 		ub->st_mode |= S_IRUSR | S_IRGRP | S_IROTH;
263 	ub->st_size = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
264 	SOCKBUF_UNLOCK(&so->so_rcv);
265 	/* Unlocked read. */
266 	if ((so->so_snd.sb_state & SBS_CANTSENDMORE) == 0)
267 		ub->st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;
268 	ub->st_uid = so->so_cred->cr_uid;
269 	ub->st_gid = so->so_cred->cr_gid;
270 	return (*so->so_proto->pr_usrreqs->pru_sense)(so, ub);
271 }
272 
273 /*
274  * API socket close on file pointer.  We call soclose() to close the socket
275  * (including initiating closing protocols).  soclose() will sorele() the
276  * file reference but the actual socket will not go away until the socket's
277  * ref count hits 0.
278  */
279 /* ARGSUSED */
280 int
281 soo_close(struct file *fp, struct thread *td)
282 {
283 	int error = 0;
284 	struct socket *so;
285 
286 	so = fp->f_data;
287 	fp->f_ops = &badfileops;
288 	fp->f_data = NULL;
289 
290 	if (so)
291 		error = soclose(so);
292 	return (error);
293 }
294