xref: /freebsd/sys/kern/sys_socket.c (revision ff0ba87247820afbdfdc1b307c803f7923d0e4d3)
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/domain.h>
38 #include <sys/file.h>
39 #include <sys/filedesc.h>
40 #include <sys/malloc.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/un.h>
54 #include <sys/unpcb.h>
55 #include <sys/user.h>
56 
57 #include <net/if.h>
58 #include <net/if_var.h>
59 #include <net/route.h>
60 #include <net/vnet.h>
61 
62 #include <netinet/in.h>
63 #include <netinet/in_pcb.h>
64 
65 #include <security/mac/mac_framework.h>
66 
67 static fo_rdwr_t soo_read;
68 static fo_rdwr_t soo_write;
69 static fo_ioctl_t soo_ioctl;
70 static fo_poll_t soo_poll;
71 extern fo_kqfilter_t soo_kqfilter;
72 static fo_stat_t soo_stat;
73 static fo_close_t soo_close;
74 static fo_fill_kinfo_t soo_fill_kinfo;
75 
76 struct fileops	socketops = {
77 	.fo_read = soo_read,
78 	.fo_write = soo_write,
79 	.fo_truncate = invfo_truncate,
80 	.fo_ioctl = soo_ioctl,
81 	.fo_poll = soo_poll,
82 	.fo_kqfilter = soo_kqfilter,
83 	.fo_stat = soo_stat,
84 	.fo_close = soo_close,
85 	.fo_chmod = invfo_chmod,
86 	.fo_chown = invfo_chown,
87 	.fo_sendfile = invfo_sendfile,
88 	.fo_fill_kinfo = soo_fill_kinfo,
89 	.fo_flags = DFLAG_PASSABLE
90 };
91 
92 static int
93 soo_read(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_receive(active_cred, so);
101 	if (error)
102 		return (error);
103 #endif
104 	error = soreceive(so, 0, uio, 0, 0, 0);
105 	return (error);
106 }
107 
108 static int
109 soo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
110     int flags, struct thread *td)
111 {
112 	struct socket *so = fp->f_data;
113 	int error;
114 
115 #ifdef MAC
116 	error = mac_socket_check_send(active_cred, so);
117 	if (error)
118 		return (error);
119 #endif
120 	error = sosend(so, 0, uio, 0, 0, 0, uio->uio_td);
121 	if (error == EPIPE && (so->so_options & SO_NOSIGPIPE) == 0) {
122 		PROC_LOCK(uio->uio_td->td_proc);
123 		tdsignal(uio->uio_td, SIGPIPE);
124 		PROC_UNLOCK(uio->uio_td->td_proc);
125 	}
126 	return (error);
127 }
128 
129 static int
130 soo_ioctl(struct file *fp, u_long cmd, void *data, struct ucred *active_cred,
131     struct thread *td)
132 {
133 	struct socket *so = fp->f_data;
134 	int error = 0;
135 
136 	switch (cmd) {
137 	case FIONBIO:
138 		SOCK_LOCK(so);
139 		if (*(int *)data)
140 			so->so_state |= SS_NBIO;
141 		else
142 			so->so_state &= ~SS_NBIO;
143 		SOCK_UNLOCK(so);
144 		break;
145 
146 	case FIOASYNC:
147 		/*
148 		 * XXXRW: This code separately acquires SOCK_LOCK(so) and
149 		 * SOCKBUF_LOCK(&so->so_rcv) even though they are the same
150 		 * mutex to avoid introducing the assumption that they are
151 		 * the same.
152 		 */
153 		if (*(int *)data) {
154 			SOCK_LOCK(so);
155 			so->so_state |= SS_ASYNC;
156 			SOCK_UNLOCK(so);
157 			SOCKBUF_LOCK(&so->so_rcv);
158 			so->so_rcv.sb_flags |= SB_ASYNC;
159 			SOCKBUF_UNLOCK(&so->so_rcv);
160 			SOCKBUF_LOCK(&so->so_snd);
161 			so->so_snd.sb_flags |= SB_ASYNC;
162 			SOCKBUF_UNLOCK(&so->so_snd);
163 		} else {
164 			SOCK_LOCK(so);
165 			so->so_state &= ~SS_ASYNC;
166 			SOCK_UNLOCK(so);
167 			SOCKBUF_LOCK(&so->so_rcv);
168 			so->so_rcv.sb_flags &= ~SB_ASYNC;
169 			SOCKBUF_UNLOCK(&so->so_rcv);
170 			SOCKBUF_LOCK(&so->so_snd);
171 			so->so_snd.sb_flags &= ~SB_ASYNC;
172 			SOCKBUF_UNLOCK(&so->so_snd);
173 		}
174 		break;
175 
176 	case FIONREAD:
177 		/* Unlocked read. */
178 		*(int *)data = sbavail(&so->so_rcv);
179 		break;
180 
181 	case FIONWRITE:
182 		/* Unlocked read. */
183 		*(int *)data = sbavail(&so->so_snd);
184 		break;
185 
186 	case FIONSPACE:
187 		/* Unlocked read. */
188 		if ((so->so_snd.sb_hiwat < sbused(&so->so_snd)) ||
189 		    (so->so_snd.sb_mbmax < so->so_snd.sb_mbcnt))
190 			*(int *)data = 0;
191 		else
192 			*(int *)data = sbspace(&so->so_snd);
193 		break;
194 
195 	case FIOSETOWN:
196 		error = fsetown(*(int *)data, &so->so_sigio);
197 		break;
198 
199 	case FIOGETOWN:
200 		*(int *)data = fgetown(&so->so_sigio);
201 		break;
202 
203 	case SIOCSPGRP:
204 		error = fsetown(-(*(int *)data), &so->so_sigio);
205 		break;
206 
207 	case SIOCGPGRP:
208 		*(int *)data = -fgetown(&so->so_sigio);
209 		break;
210 
211 	case SIOCATMARK:
212 		/* Unlocked read. */
213 		*(int *)data = (so->so_rcv.sb_state & SBS_RCVATMARK) != 0;
214 		break;
215 	default:
216 		/*
217 		 * Interface/routing/protocol specific ioctls: interface and
218 		 * routing ioctls should have a different entry since a
219 		 * socket is unnecessary.
220 		 */
221 		if (IOCGROUP(cmd) == 'i')
222 			error = ifioctl(so, cmd, data, td);
223 		else if (IOCGROUP(cmd) == 'r') {
224 			CURVNET_SET(so->so_vnet);
225 			error = rtioctl_fib(cmd, data, so->so_fibnum);
226 			CURVNET_RESTORE();
227 		} else {
228 			CURVNET_SET(so->so_vnet);
229 			error = ((*so->so_proto->pr_usrreqs->pru_control)
230 			    (so, cmd, data, 0, td));
231 			CURVNET_RESTORE();
232 		}
233 		break;
234 	}
235 	return (error);
236 }
237 
238 static int
239 soo_poll(struct file *fp, int events, struct ucred *active_cred,
240     struct thread *td)
241 {
242 	struct socket *so = fp->f_data;
243 #ifdef MAC
244 	int error;
245 
246 	error = mac_socket_check_poll(active_cred, so);
247 	if (error)
248 		return (error);
249 #endif
250 	return (sopoll(so, events, fp->f_cred, td));
251 }
252 
253 static int
254 soo_stat(struct file *fp, struct stat *ub, struct ucred *active_cred,
255     struct thread *td)
256 {
257 	struct socket *so = fp->f_data;
258 	struct sockbuf *sb;
259 #ifdef MAC
260 	int error;
261 #endif
262 
263 	bzero((caddr_t)ub, sizeof (*ub));
264 	ub->st_mode = S_IFSOCK;
265 #ifdef MAC
266 	error = mac_socket_check_stat(active_cred, so);
267 	if (error)
268 		return (error);
269 #endif
270 	/*
271 	 * If SBS_CANTRCVMORE is set, but there's still data left in the
272 	 * receive buffer, the socket is still readable.
273 	 */
274 	sb = &so->so_rcv;
275 	SOCKBUF_LOCK(sb);
276 	if ((sb->sb_state & SBS_CANTRCVMORE) == 0 || sbavail(sb))
277 		ub->st_mode |= S_IRUSR | S_IRGRP | S_IROTH;
278 	ub->st_size = sbavail(sb) - sb->sb_ctl;
279 	SOCKBUF_UNLOCK(sb);
280 
281 	sb = &so->so_snd;
282 	SOCKBUF_LOCK(sb);
283 	if ((sb->sb_state & SBS_CANTSENDMORE) == 0)
284 		ub->st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;
285 	SOCKBUF_UNLOCK(sb);
286 	ub->st_uid = so->so_cred->cr_uid;
287 	ub->st_gid = so->so_cred->cr_gid;
288 	return (*so->so_proto->pr_usrreqs->pru_sense)(so, ub);
289 }
290 
291 /*
292  * API socket close on file pointer.  We call soclose() to close the socket
293  * (including initiating closing protocols).  soclose() will sorele() the
294  * file reference but the actual socket will not go away until the socket's
295  * ref count hits 0.
296  */
297 static int
298 soo_close(struct file *fp, struct thread *td)
299 {
300 	int error = 0;
301 	struct socket *so;
302 
303 	so = fp->f_data;
304 	fp->f_ops = &badfileops;
305 	fp->f_data = NULL;
306 
307 	if (so)
308 		error = soclose(so);
309 	return (error);
310 }
311 
312 static int
313 soo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
314 {
315 	struct sockaddr *sa;
316 	struct inpcb *inpcb;
317 	struct unpcb *unpcb;
318 	struct socket *so;
319 	int error;
320 
321 	kif->kf_type = KF_TYPE_SOCKET;
322 	so = fp->f_data;
323 	kif->kf_sock_domain = so->so_proto->pr_domain->dom_family;
324 	kif->kf_sock_type = so->so_type;
325 	kif->kf_sock_protocol = so->so_proto->pr_protocol;
326 	kif->kf_un.kf_sock.kf_sock_pcb = (uintptr_t)so->so_pcb;
327 	switch (kif->kf_sock_domain) {
328 	case AF_INET:
329 	case AF_INET6:
330 		if (kif->kf_sock_protocol == IPPROTO_TCP) {
331 			if (so->so_pcb != NULL) {
332 				inpcb = (struct inpcb *)(so->so_pcb);
333 				kif->kf_un.kf_sock.kf_sock_inpcb =
334 				    (uintptr_t)inpcb->inp_ppcb;
335 			}
336 		}
337 		break;
338 	case AF_UNIX:
339 		if (so->so_pcb != NULL) {
340 			unpcb = (struct unpcb *)(so->so_pcb);
341 			if (unpcb->unp_conn) {
342 				kif->kf_un.kf_sock.kf_sock_unpconn =
343 				    (uintptr_t)unpcb->unp_conn;
344 				kif->kf_un.kf_sock.kf_sock_rcv_sb_state =
345 				    so->so_rcv.sb_state;
346 				kif->kf_un.kf_sock.kf_sock_snd_sb_state =
347 				    so->so_snd.sb_state;
348 			}
349 		}
350 		break;
351 	}
352 	error = so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa);
353 	if (error == 0 && sa->sa_len <= sizeof(kif->kf_sa_local)) {
354 		bcopy(sa, &kif->kf_sa_local, sa->sa_len);
355 		free(sa, M_SONAME);
356 	}
357 	error = so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa);
358 	if (error == 0 && sa->sa_len <= sizeof(kif->kf_sa_peer)) {
359 		bcopy(sa, &kif->kf_sa_peer, sa->sa_len);
360 		free(sa, M_SONAME);
361 	}
362 	strncpy(kif->kf_path, so->so_proto->pr_domain->dom_name,
363 	    sizeof(kif->kf_path));
364 	return (0);
365 }
366