Disallow writes to filesystems mounted read-only via NULLFS. In this case
[dragonfly.git] / sys / kern / uipc_usrreq.c
CommitLineData
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1/*
2 * Copyright (c) 1982, 1986, 1989, 1991, 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 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94
34 * $FreeBSD: src/sys/kern/uipc_usrreq.c,v 1.54.2.10 2003/03/04 17:28:09 nectar Exp $
efda3bd0 35 * $DragonFly: src/sys/kern/uipc_usrreq.c,v 1.29 2006/09/05 00:55:45 dillon Exp $
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36 */
37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/kernel.h>
41#include <sys/domain.h>
42#include <sys/fcntl.h>
43#include <sys/malloc.h> /* XXX must be before <sys/file.h> */
dadab5e9 44#include <sys/proc.h>
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45#include <sys/file.h>
46#include <sys/filedesc.h>
47#include <sys/mbuf.h>
fad57d0e 48#include <sys/nlookup.h>
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49#include <sys/protosw.h>
50#include <sys/socket.h>
51#include <sys/socketvar.h>
52#include <sys/resourcevar.h>
53#include <sys/stat.h>
fad57d0e 54#include <sys/mount.h>
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MD
55#include <sys/sysctl.h>
56#include <sys/un.h>
57#include <sys/unpcb.h>
58#include <sys/vnode.h>
dadab5e9 59#include <sys/file2.h>
2dd63755 60#include <sys/spinlock2.h>
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61
62#include <vm/vm_zone.h>
63
64static struct vm_zone *unp_zone;
65static unp_gen_t unp_gencnt;
66static u_int unp_count;
67
68static struct unp_head unp_shead, unp_dhead;
69
70/*
71 * Unix communications domain.
72 *
73 * TODO:
74 * SEQPACKET, RDM
75 * rethink name space problems
76 * need a proper out-of-band
77 * lock pushdown
78 */
79static struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL };
80static ino_t unp_ino; /* prototype for fake inode numbers */
81
e4700d00 82static int unp_attach (struct socket *, struct pru_attach_info *);
402ed7e1
RG
83static void unp_detach (struct unpcb *);
84static int unp_bind (struct unpcb *,struct sockaddr *, struct thread *);
85static int unp_connect (struct socket *,struct sockaddr *,
86 struct thread *);
87static void unp_disconnect (struct unpcb *);
88static void unp_shutdown (struct unpcb *);
89static void unp_drop (struct unpcb *, int);
90static void unp_gc (void);
2dd63755
MD
91static int unp_gc_clearmarks(struct file *, void *);
92static int unp_gc_checkmarks(struct file *, void *);
93static int unp_gc_checkrefs(struct file *, void *);
94static void unp_scan (struct mbuf *, void (*)(struct file *, void *),
95 void *data);
96static void unp_mark (struct file *, void *data);
97static void unp_discard (struct file *, void *);
402ed7e1
RG
98static int unp_internalize (struct mbuf *, struct thread *);
99static int unp_listen (struct unpcb *, struct thread *);
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100
101static int
102uipc_abort(struct socket *so)
103{
e606b589 104 struct unpcb *unp = so->so_pcb;
984263bc 105
9dc5418a 106 if (unp == NULL)
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107 return EINVAL;
108 unp_drop(unp, ECONNABORTED);
109 unp_detach(unp);
110 sofree(so);
111 return 0;
112}
113
114static int
115uipc_accept(struct socket *so, struct sockaddr **nam)
116{
e606b589 117 struct unpcb *unp = so->so_pcb;
984263bc 118
9dc5418a 119 if (unp == NULL)
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120 return EINVAL;
121
122 /*
123 * Pass back name of connected socket,
124 * if it was bound and we are still connected
125 * (our peer may have closed already!).
126 */
127 if (unp->unp_conn && unp->unp_conn->unp_addr) {
cfa2ba21 128 *nam = dup_sockaddr((struct sockaddr *)unp->unp_conn->unp_addr);
984263bc 129 } else {
cfa2ba21 130 *nam = dup_sockaddr((struct sockaddr *)&sun_noname);
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MD
131 }
132 return 0;
133}
134
135static int
e4700d00 136uipc_attach(struct socket *so, int proto, struct pru_attach_info *ai)
984263bc 137{
e606b589 138 struct unpcb *unp = so->so_pcb;
984263bc 139
9dc5418a 140 if (unp != NULL)
984263bc 141 return EISCONN;
e4700d00 142 return unp_attach(so, ai);
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143}
144
145static int
dadab5e9 146uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
984263bc 147{
e606b589 148 struct unpcb *unp = so->so_pcb;
984263bc 149
9dc5418a 150 if (unp == NULL)
984263bc 151 return EINVAL;
dadab5e9 152 return unp_bind(unp, nam, td);
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MD
153}
154
155static int
dadab5e9 156uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
984263bc 157{
e606b589 158 struct unpcb *unp = so->so_pcb;
984263bc 159
9dc5418a 160 if (unp == NULL)
984263bc 161 return EINVAL;
dadab5e9 162 return unp_connect(so, nam, td);
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MD
163}
164
165static int
166uipc_connect2(struct socket *so1, struct socket *so2)
167{
e606b589 168 struct unpcb *unp = so1->so_pcb;
984263bc 169
9dc5418a 170 if (unp == NULL)
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171 return EINVAL;
172
173 return unp_connect2(so1, so2);
174}
175
176/* control is EOPNOTSUPP */
177
178static int
179uipc_detach(struct socket *so)
180{
e606b589 181 struct unpcb *unp = so->so_pcb;
984263bc 182
9dc5418a 183 if (unp == NULL)
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184 return EINVAL;
185
186 unp_detach(unp);
187 return 0;
188}
189
190static int
191uipc_disconnect(struct socket *so)
192{
e606b589 193 struct unpcb *unp = so->so_pcb;
984263bc 194
9dc5418a 195 if (unp == NULL)
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196 return EINVAL;
197 unp_disconnect(unp);
198 return 0;
199}
200
201static int
dadab5e9 202uipc_listen(struct socket *so, struct thread *td)
984263bc 203{
e606b589 204 struct unpcb *unp = so->so_pcb;
984263bc 205
9dc5418a 206 if (unp == NULL || unp->unp_vnode == NULL)
984263bc 207 return EINVAL;
dadab5e9 208 return unp_listen(unp, td);
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209}
210
211static int
212uipc_peeraddr(struct socket *so, struct sockaddr **nam)
213{
e606b589 214 struct unpcb *unp = so->so_pcb;
984263bc 215
9dc5418a 216 if (unp == NULL)
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217 return EINVAL;
218 if (unp->unp_conn && unp->unp_conn->unp_addr)
cfa2ba21 219 *nam = dup_sockaddr((struct sockaddr *)unp->unp_conn->unp_addr);
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220 else {
221 /*
222 * XXX: It seems that this test always fails even when
223 * connection is established. So, this else clause is
224 * added as workaround to return PF_LOCAL sockaddr.
225 */
cfa2ba21 226 *nam = dup_sockaddr((struct sockaddr *)&sun_noname);
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227 }
228 return 0;
229}
230
231static int
232uipc_rcvd(struct socket *so, int flags)
233{
e606b589 234 struct unpcb *unp = so->so_pcb;
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235 struct socket *so2;
236 u_long newhiwat;
237
9dc5418a 238 if (unp == NULL)
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239 return EINVAL;
240 switch (so->so_type) {
241 case SOCK_DGRAM:
242 panic("uipc_rcvd DGRAM?");
243 /*NOTREACHED*/
244
245 case SOCK_STREAM:
9dc5418a 246 if (unp->unp_conn == NULL)
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247 break;
248 so2 = unp->unp_conn->unp_socket;
249 /*
250 * Adjust backpressure on sender
251 * and wakeup any waiting to write.
252 */
253 so2->so_snd.sb_mbmax += unp->unp_mbcnt - so->so_rcv.sb_mbcnt;
254 unp->unp_mbcnt = so->so_rcv.sb_mbcnt;
9dc5418a
JH
255 newhiwat =
256 so2->so_snd.sb_hiwat + unp->unp_cc - so->so_rcv.sb_cc;
3e0c844d 257 chgsbsize(so2->so_cred->cr_uidinfo, &so2->so_snd.sb_hiwat,
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258 newhiwat, RLIM_INFINITY);
259 unp->unp_cc = so->so_rcv.sb_cc;
260 sowwakeup(so2);
261 break;
262
263 default:
264 panic("uipc_rcvd unknown socktype");
265 }
266 return 0;
267}
268
269/* pru_rcvoob is EOPNOTSUPP */
270
271static int
272uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
dadab5e9 273 struct mbuf *control, struct thread *td)
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MD
274{
275 int error = 0;
e606b589 276 struct unpcb *unp = so->so_pcb;
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277 struct socket *so2;
278 u_long newhiwat;
279
9dc5418a 280 if (unp == NULL) {
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281 error = EINVAL;
282 goto release;
283 }
284 if (flags & PRUS_OOB) {
285 error = EOPNOTSUPP;
286 goto release;
287 }
288
dadab5e9 289 if (control && (error = unp_internalize(control, td)))
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290 goto release;
291
292 switch (so->so_type) {
293 case SOCK_DGRAM:
294 {
295 struct sockaddr *from;
296
297 if (nam) {
298 if (unp->unp_conn) {
299 error = EISCONN;
300 break;
301 }
dadab5e9 302 error = unp_connect(so, nam, td);
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303 if (error)
304 break;
305 } else {
9dc5418a 306 if (unp->unp_conn == NULL) {
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307 error = ENOTCONN;
308 break;
309 }
310 }
311 so2 = unp->unp_conn->unp_socket;
312 if (unp->unp_addr)
313 from = (struct sockaddr *)unp->unp_addr;
314 else
315 from = &sun_noname;
316 if (sbappendaddr(&so2->so_rcv, from, m, control)) {
317 sorwakeup(so2);
9dc5418a
JH
318 m = NULL;
319 control = NULL;
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MD
320 } else
321 error = ENOBUFS;
322 if (nam)
323 unp_disconnect(unp);
324 break;
325 }
326
327 case SOCK_STREAM:
328 /* Connect if not connected yet. */
329 /*
330 * Note: A better implementation would complain
331 * if not equal to the peer's address.
332 */
9dc5418a 333 if (!(so->so_state & SS_ISCONNECTED)) {
984263bc 334 if (nam) {
dadab5e9 335 error = unp_connect(so, nam, td);
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MD
336 if (error)
337 break; /* XXX */
338 } else {
339 error = ENOTCONN;
340 break;
341 }
342 }
343
344 if (so->so_state & SS_CANTSENDMORE) {
345 error = EPIPE;
346 break;
347 }
9dc5418a 348 if (unp->unp_conn == NULL)
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MD
349 panic("uipc_send connected but no connection?");
350 so2 = unp->unp_conn->unp_socket;
351 /*
352 * Send to paired receive port, and then reduce
353 * send buffer hiwater marks to maintain backpressure.
354 * Wake up readers.
355 */
356 if (control) {
357 if (sbappendcontrol(&so2->so_rcv, m, control))
9dc5418a 358 control = NULL;
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MD
359 } else
360 sbappend(&so2->so_rcv, m);
361 so->so_snd.sb_mbmax -=
362 so2->so_rcv.sb_mbcnt - unp->unp_conn->unp_mbcnt;
363 unp->unp_conn->unp_mbcnt = so2->so_rcv.sb_mbcnt;
364 newhiwat = so->so_snd.sb_hiwat -
365 (so2->so_rcv.sb_cc - unp->unp_conn->unp_cc);
3e0c844d 366 chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat,
984263bc
MD
367 newhiwat, RLIM_INFINITY);
368 unp->unp_conn->unp_cc = so2->so_rcv.sb_cc;
369 sorwakeup(so2);
9dc5418a 370 m = NULL;
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MD
371 break;
372
373 default:
374 panic("uipc_send unknown socktype");
375 }
376
377 /*
9dc5418a 378 * SEND_EOF is equivalent to a SEND followed by a SHUTDOWN.
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MD
379 */
380 if (flags & PRUS_EOF) {
381 socantsendmore(so);
382 unp_shutdown(unp);
383 }
384
385 if (control && error != 0)
386 unp_dispose(control);
387
388release:
389 if (control)
390 m_freem(control);
391 if (m)
392 m_freem(m);
393 return error;
394}
395
396static int
397uipc_sense(struct socket *so, struct stat *sb)
398{
e606b589 399 struct unpcb *unp = so->so_pcb;
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MD
400 struct socket *so2;
401
9dc5418a 402 if (unp == NULL)
984263bc
MD
403 return EINVAL;
404 sb->st_blksize = so->so_snd.sb_hiwat;
9dc5418a 405 if (so->so_type == SOCK_STREAM && unp->unp_conn != NULL) {
984263bc
MD
406 so2 = unp->unp_conn->unp_socket;
407 sb->st_blksize += so2->so_rcv.sb_cc;
408 }
409 sb->st_dev = NOUDEV;
410 if (unp->unp_ino == 0) /* make up a non-zero inode number */
411 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino;
412 sb->st_ino = unp->unp_ino;
413 return (0);
414}
415
416static int
417uipc_shutdown(struct socket *so)
418{
e606b589 419 struct unpcb *unp = so->so_pcb;
984263bc 420
9dc5418a 421 if (unp == NULL)
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MD
422 return EINVAL;
423 socantsendmore(so);
424 unp_shutdown(unp);
425 return 0;
426}
427
428static int
429uipc_sockaddr(struct socket *so, struct sockaddr **nam)
430{
e606b589 431 struct unpcb *unp = so->so_pcb;
984263bc 432
9dc5418a 433 if (unp == NULL)
984263bc
MD
434 return EINVAL;
435 if (unp->unp_addr)
cfa2ba21 436 *nam = dup_sockaddr((struct sockaddr *)unp->unp_addr);
984263bc
MD
437 return 0;
438}
439
440struct pr_usrreqs uipc_usrreqs = {
441 uipc_abort, uipc_accept, uipc_attach, uipc_bind, uipc_connect,
442 uipc_connect2, pru_control_notsupp, uipc_detach, uipc_disconnect,
443 uipc_listen, uipc_peeraddr, uipc_rcvd, pru_rcvoob_notsupp,
444 uipc_send, uipc_sense, uipc_shutdown, uipc_sockaddr,
445 sosend, soreceive, sopoll
446};
447
448int
9dc5418a 449uipc_ctloutput(struct socket *so, struct sockopt *sopt)
984263bc 450{
e606b589 451 struct unpcb *unp = so->so_pcb;
984263bc
MD
452 int error;
453
454 switch (sopt->sopt_dir) {
455 case SOPT_GET:
456 switch (sopt->sopt_name) {
457 case LOCAL_PEERCRED:
458 if (unp->unp_flags & UNP_HAVEPC)
459 error = sooptcopyout(sopt, &unp->unp_peercred,
460 sizeof(unp->unp_peercred));
461 else {
462 if (so->so_type == SOCK_STREAM)
463 error = ENOTCONN;
464 else
465 error = EINVAL;
466 }
467 break;
468 default:
469 error = EOPNOTSUPP;
470 break;
471 }
472 break;
473 case SOPT_SET:
474 default:
475 error = EOPNOTSUPP;
476 break;
477 }
478 return (error);
479}
480
481/*
482 * Both send and receive buffers are allocated PIPSIZ bytes of buffering
483 * for stream sockets, although the total for sender and receiver is
484 * actually only PIPSIZ.
485 * Datagram sockets really use the sendspace as the maximum datagram size,
486 * and don't really want to reserve the sendspace. Their recvspace should
487 * be large enough for at least one max-size datagram plus address.
488 */
489#ifndef PIPSIZ
490#define PIPSIZ 8192
491#endif
492static u_long unpst_sendspace = PIPSIZ;
493static u_long unpst_recvspace = PIPSIZ;
494static u_long unpdg_sendspace = 2*1024; /* really max datagram size */
495static u_long unpdg_recvspace = 4*1024;
496
497static int unp_rights; /* file descriptors in flight */
2dd63755 498static struct spinlock unp_spin = SPINLOCK_INITIALIZER(&unp_spin);
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499
500SYSCTL_DECL(_net_local_stream);
501SYSCTL_INT(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW,
502 &unpst_sendspace, 0, "");
503SYSCTL_INT(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW,
504 &unpst_recvspace, 0, "");
9dc5418a 505
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506SYSCTL_DECL(_net_local_dgram);
507SYSCTL_INT(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW,
508 &unpdg_sendspace, 0, "");
509SYSCTL_INT(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW,
510 &unpdg_recvspace, 0, "");
9dc5418a 511
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MD
512SYSCTL_DECL(_net_local);
513SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, "");
514
515static int
e4700d00 516unp_attach(struct socket *so, struct pru_attach_info *ai)
984263bc 517{
1fd87d54 518 struct unpcb *unp;
984263bc
MD
519 int error;
520
521 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
522 switch (so->so_type) {
523
524 case SOCK_STREAM:
e4700d00
JH
525 error = soreserve(so, unpst_sendspace, unpst_recvspace,
526 ai->sb_rlimit);
984263bc
MD
527 break;
528
529 case SOCK_DGRAM:
e4700d00
JH
530 error = soreserve(so, unpdg_sendspace, unpdg_recvspace,
531 ai->sb_rlimit);
984263bc
MD
532 break;
533
534 default:
535 panic("unp_attach");
536 }
537 if (error)
538 return (error);
539 }
540 unp = zalloc(unp_zone);
541 if (unp == NULL)
542 return (ENOBUFS);
543 bzero(unp, sizeof *unp);
544 unp->unp_gencnt = ++unp_gencnt;
545 unp_count++;
546 LIST_INIT(&unp->unp_refs);
547 unp->unp_socket = so;
e4700d00 548 unp->unp_rvnode = ai->fd_rdir; /* jail cruft XXX JH */
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MD
549 LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead
550 : &unp_shead, unp, unp_link);
551 so->so_pcb = (caddr_t)unp;
552 return (0);
553}
554
555static void
9dc5418a 556unp_detach(struct unpcb *unp)
984263bc
MD
557{
558 LIST_REMOVE(unp, unp_link);
559 unp->unp_gencnt = ++unp_gencnt;
560 --unp_count;
561 if (unp->unp_vnode) {
9dc5418a 562 unp->unp_vnode->v_socket = NULL;
984263bc 563 vrele(unp->unp_vnode);
9dc5418a 564 unp->unp_vnode = NULL;
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MD
565 }
566 if (unp->unp_conn)
567 unp_disconnect(unp);
568 while (!LIST_EMPTY(&unp->unp_refs))
569 unp_drop(LIST_FIRST(&unp->unp_refs), ECONNRESET);
570 soisdisconnected(unp->unp_socket);
9dc5418a 571 unp->unp_socket->so_pcb = NULL;
984263bc
MD
572 if (unp_rights) {
573 /*
574 * Normally the receive buffer is flushed later,
575 * in sofree, but if our receive buffer holds references
576 * to descriptors that are now garbage, we will dispose
577 * of those descriptor references after the garbage collector
578 * gets them (resulting in a "panic: closef: count < 0").
579 */
580 sorflush(unp->unp_socket);
581 unp_gc();
582 }
583 if (unp->unp_addr)
efda3bd0 584 kfree(unp->unp_addr, M_SONAME);
984263bc
MD
585 zfree(unp_zone, unp);
586}
587
588static int
dadab5e9 589unp_bind(struct unpcb *unp, struct sockaddr *nam, struct thread *td)
984263bc 590{
dadab5e9 591 struct proc *p = td->td_proc;
984263bc 592 struct sockaddr_un *soun = (struct sockaddr_un *)nam;
dadab5e9 593 struct vnode *vp;
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MD
594 struct vattr vattr;
595 int error, namelen;
fad57d0e 596 struct nlookupdata nd;
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MD
597 char buf[SOCK_MAXADDRLEN];
598
599 if (unp->unp_vnode != NULL)
600 return (EINVAL);
601 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path);
602 if (namelen <= 0)
fad57d0e 603 return (EINVAL);
984263bc
MD
604 strncpy(buf, soun->sun_path, namelen);
605 buf[namelen] = 0; /* null-terminate the string */
fad57d0e
MD
606 error = nlookup_init(&nd, buf, UIO_SYSSPACE, NLC_LOCKVP|NLC_CREATE);
607 if (error == 0)
608 error = nlookup(&nd);
609 if (error == 0 && nd.nl_ncp->nc_vp != NULL)
610 error = EADDRINUSE;
984263bc 611 if (error)
fad57d0e
MD
612 goto done;
613
984263bc
MD
614 VATTR_NULL(&vattr);
615 vattr.va_type = VSOCK;
616 vattr.va_mode = (ACCESSPERMS & ~p->p_fd->fd_cmask);
fad57d0e
MD
617 error = VOP_NCREATE(nd.nl_ncp, &vp, nd.nl_cred, &vattr);
618 if (error == 0) {
619 vp->v_socket = unp->unp_socket;
620 unp->unp_vnode = vp;
621 unp->unp_addr = (struct sockaddr_un *)dup_sockaddr(nam);
a11aaa81 622 vn_unlock(vp);
fad57d0e
MD
623 }
624done:
625 nlookup_done(&nd);
626 return (error);
984263bc
MD
627}
628
629static int
dadab5e9 630unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
984263bc 631{
dadab5e9
MD
632 struct proc *p = td->td_proc;
633 struct sockaddr_un *soun = (struct sockaddr_un *)nam;
634 struct vnode *vp;
635 struct socket *so2, *so3;
984263bc
MD
636 struct unpcb *unp, *unp2, *unp3;
637 int error, len;
fad57d0e 638 struct nlookupdata nd;
984263bc
MD
639 char buf[SOCK_MAXADDRLEN];
640
dadab5e9
MD
641 KKASSERT(p);
642
984263bc
MD
643 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path);
644 if (len <= 0)
645 return EINVAL;
646 strncpy(buf, soun->sun_path, len);
647 buf[len] = 0;
648
fad57d0e
MD
649 vp = NULL;
650 error = nlookup_init(&nd, buf, UIO_SYSSPACE, NLC_FOLLOW);
651 if (error == 0)
652 error = nlookup(&nd);
653 if (error == 0)
654 error = cache_vget(nd.nl_ncp, nd.nl_cred, LK_EXCLUSIVE, &vp);
655 nlookup_done(&nd);
984263bc
MD
656 if (error)
657 return (error);
fad57d0e 658
984263bc
MD
659 if (vp->v_type != VSOCK) {
660 error = ENOTSOCK;
661 goto bad;
662 }
87de5057 663 error = VOP_ACCESS(vp, VWRITE, p->p_ucred);
984263bc
MD
664 if (error)
665 goto bad;
666 so2 = vp->v_socket;
9dc5418a 667 if (so2 == NULL) {
984263bc
MD
668 error = ECONNREFUSED;
669 goto bad;
670 }
671 if (so->so_type != so2->so_type) {
672 error = EPROTOTYPE;
673 goto bad;
674 }
675 if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
9dc5418a
JH
676 if (!(so2->so_options & SO_ACCEPTCONN) ||
677 (so3 = sonewconn(so2, 0)) == NULL) {
984263bc
MD
678 error = ECONNREFUSED;
679 goto bad;
680 }
e606b589
JH
681 unp = so->so_pcb;
682 unp2 = so2->so_pcb;
683 unp3 = so3->so_pcb;
984263bc
MD
684 if (unp2->unp_addr)
685 unp3->unp_addr = (struct sockaddr_un *)
cfa2ba21 686 dup_sockaddr((struct sockaddr *)unp2->unp_addr);
984263bc
MD
687
688 /*
689 * unp_peercred management:
690 *
691 * The connecter's (client's) credentials are copied
692 * from its process structure at the time of connect()
693 * (which is now).
694 */
695 cru2x(p->p_ucred, &unp3->unp_peercred);
696 unp3->unp_flags |= UNP_HAVEPC;
697 /*
698 * The receiver's (server's) credentials are copied
699 * from the unp_peercred member of socket on which the
700 * former called listen(); unp_listen() cached that
701 * process's credentials at that time so we can use
702 * them now.
703 */
704 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED,
705 ("unp_connect: listener without cached peercred"));
706 memcpy(&unp->unp_peercred, &unp2->unp_peercred,
707 sizeof(unp->unp_peercred));
708 unp->unp_flags |= UNP_HAVEPC;
709
710 so2 = so3;
711 }
712 error = unp_connect2(so, so2);
713bad:
714 vput(vp);
715 return (error);
716}
717
718int
9dc5418a 719unp_connect2(struct socket *so, struct socket *so2)
984263bc 720{
e606b589 721 struct unpcb *unp = so->so_pcb;
1fd87d54 722 struct unpcb *unp2;
984263bc
MD
723
724 if (so2->so_type != so->so_type)
725 return (EPROTOTYPE);
e606b589 726 unp2 = so2->so_pcb;
984263bc
MD
727 unp->unp_conn = unp2;
728 switch (so->so_type) {
729
730 case SOCK_DGRAM:
731 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink);
732 soisconnected(so);
733 break;
734
735 case SOCK_STREAM:
736 unp2->unp_conn = unp;
737 soisconnected(so);
738 soisconnected(so2);
739 break;
740
741 default:
742 panic("unp_connect2");
743 }
744 return (0);
745}
746
747static void
9dc5418a 748unp_disconnect(struct unpcb *unp)
984263bc 749{
1fd87d54 750 struct unpcb *unp2 = unp->unp_conn;
984263bc 751
9dc5418a 752 if (unp2 == NULL)
984263bc 753 return;
984263bc 754
9dc5418a
JH
755 unp->unp_conn = NULL;
756
757 switch (unp->unp_socket->so_type) {
984263bc
MD
758 case SOCK_DGRAM:
759 LIST_REMOVE(unp, unp_reflink);
760 unp->unp_socket->so_state &= ~SS_ISCONNECTED;
761 break;
984263bc
MD
762 case SOCK_STREAM:
763 soisdisconnected(unp->unp_socket);
9dc5418a 764 unp2->unp_conn = NULL;
984263bc
MD
765 soisdisconnected(unp2->unp_socket);
766 break;
767 }
768}
769
770#ifdef notdef
771void
9dc5418a 772unp_abort(struct unpcb *unp)
984263bc
MD
773{
774
775 unp_detach(unp);
776}
777#endif
778
779static int
dadab5e9 780prison_unpcb(struct thread *td, struct unpcb *unp)
984263bc 781{
dadab5e9
MD
782 struct proc *p;
783
784 if (td == NULL)
785 return (0);
786 if ((p = td->td_proc) == NULL)
787 return (0);
41c20dac 788 if (!p->p_ucred->cr_prison)
984263bc
MD
789 return (0);
790 if (p->p_fd->fd_rdir == unp->unp_rvnode)
791 return (0);
792 return (1);
793}
794
795static int
796unp_pcblist(SYSCTL_HANDLER_ARGS)
797{
798 int error, i, n;
799 struct unpcb *unp, **unp_list;
800 unp_gen_t gencnt;
984263bc
MD
801 struct unp_head *head;
802
803 head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead);
804
41c20dac
MD
805 KKASSERT(curproc != NULL);
806
984263bc
MD
807 /*
808 * The process of preparing the PCB list is too time-consuming and
809 * resource-intensive to repeat twice on every request.
810 */
9dc5418a 811 if (req->oldptr == NULL) {
984263bc 812 n = unp_count;
8d7c364e 813 req->oldidx = (n + n/8) * sizeof(struct xunpcb);
984263bc
MD
814 return 0;
815 }
816
9dc5418a 817 if (req->newptr != NULL)
984263bc
MD
818 return EPERM;
819
820 /*
821 * OK, now we're committed to doing something.
822 */
823 gencnt = unp_gencnt;
824 n = unp_count;
825
efda3bd0 826 unp_list = kmalloc(n * sizeof *unp_list, M_TEMP, M_WAITOK);
9dc5418a 827 if (unp_list == NULL)
984263bc
MD
828 return ENOMEM;
829
830 for (unp = LIST_FIRST(head), i = 0; unp && i < n;
831 unp = LIST_NEXT(unp, unp_link)) {
dadab5e9 832 if (unp->unp_gencnt <= gencnt && !prison_unpcb(req->td, unp))
984263bc
MD
833 unp_list[i++] = unp;
834 }
835 n = i; /* in case we lost some during malloc */
836
837 error = 0;
838 for (i = 0; i < n; i++) {
839 unp = unp_list[i];
840 if (unp->unp_gencnt <= gencnt) {
841 struct xunpcb xu;
842 xu.xu_len = sizeof xu;
843 xu.xu_unpp = unp;
844 /*
845 * XXX - need more locking here to protect against
846 * connect/disconnect races for SMP.
847 */
848 if (unp->unp_addr)
849 bcopy(unp->unp_addr, &xu.xu_addr,
850 unp->unp_addr->sun_len);
851 if (unp->unp_conn && unp->unp_conn->unp_addr)
852 bcopy(unp->unp_conn->unp_addr,
853 &xu.xu_caddr,
854 unp->unp_conn->unp_addr->sun_len);
855 bcopy(unp, &xu.xu_unp, sizeof *unp);
856 sotoxsocket(unp->unp_socket, &xu.xu_socket);
857 error = SYSCTL_OUT(req, &xu, sizeof xu);
858 }
859 }
efda3bd0 860 kfree(unp_list, M_TEMP);
984263bc
MD
861 return error;
862}
863
864SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD,
865 (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb",
866 "List of active local datagram sockets");
867SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD,
868 (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb",
869 "List of active local stream sockets");
870
871static void
9dc5418a 872unp_shutdown(struct unpcb *unp)
984263bc
MD
873{
874 struct socket *so;
875
9dc5418a 876 if (unp->unp_socket->so_type == SOCK_STREAM && unp->unp_conn != NULL &&
984263bc
MD
877 (so = unp->unp_conn->unp_socket))
878 socantrcvmore(so);
879}
880
881static void
9dc5418a 882unp_drop(struct unpcb *unp, int errno)
984263bc
MD
883{
884 struct socket *so = unp->unp_socket;
885
886 so->so_error = errno;
887 unp_disconnect(unp);
888}
889
890#ifdef notdef
891void
892unp_drain()
893{
894
895}
896#endif
897
898int
dadab5e9 899unp_externalize(struct mbuf *rights)
984263bc
MD
900{
901 struct proc *p = curproc; /* XXX */
dadab5e9
MD
902 int i;
903 struct cmsghdr *cm = mtod(rights, struct cmsghdr *);
904 int *fdp;
905 struct file **rp;
906 struct file *fp;
984263bc
MD
907 int newfds = (cm->cmsg_len - (CMSG_DATA(cm) - (u_char *)cm))
908 / sizeof (struct file *);
909 int f;
910
911 /*
912 * if the new FD's will not fit, then we free them all
913 */
914 if (!fdavail(p, newfds)) {
915 rp = (struct file **)CMSG_DATA(cm);
916 for (i = 0; i < newfds; i++) {
917 fp = *rp;
918 /*
919 * zero the pointer before calling unp_discard,
920 * since it may end up in unp_gc()..
921 */
922 *rp++ = 0;
2dd63755 923 unp_discard(fp, NULL);
984263bc
MD
924 }
925 return (EMSGSIZE);
926 }
927 /*
928 * now change each pointer to an fd in the global table to
929 * an integer that is the index to the local fd table entry
930 * that we set up to point to the global one we are transferring.
931 * If sizeof (struct file *) is bigger than or equal to sizeof int,
932 * then do it in forward order. In that case, an integer will
933 * always come in the same place or before its corresponding
934 * struct file pointer.
935 * If sizeof (struct file *) is smaller than sizeof int, then
936 * do it in reverse order.
937 */
938 if (sizeof (struct file *) >= sizeof (int)) {
939 fdp = (int *)(cm + 1);
940 rp = (struct file **)CMSG_DATA(cm);
941 for (i = 0; i < newfds; i++) {
942 if (fdalloc(p, 0, &f))
943 panic("unp_externalize");
944 fp = *rp++;
259b8ea0
MD
945 fsetfd(p, fp, f);
946 fdrop(fp);
2dd63755 947 spin_lock_wr(&unp_spin);
984263bc
MD
948 fp->f_msgcount--;
949 unp_rights--;
2dd63755 950 spin_unlock_wr(&unp_spin);
984263bc
MD
951 *fdp++ = f;
952 }
953 } else {
954 fdp = (int *)(cm + 1) + newfds - 1;
955 rp = (struct file **)CMSG_DATA(cm) + newfds - 1;
956 for (i = 0; i < newfds; i++) {
957 if (fdalloc(p, 0, &f))
958 panic("unp_externalize");
959 fp = *rp--;
259b8ea0
MD
960 fsetfd(p, fp, f);
961 fdrop(fp);
2dd63755 962 spin_lock_wr(&unp_spin);
984263bc
MD
963 fp->f_msgcount--;
964 unp_rights--;
2dd63755 965 spin_unlock_wr(&unp_spin);
984263bc
MD
966 *fdp-- = f;
967 }
968 }
969
970 /*
971 * Adjust length, in case sizeof(struct file *) and sizeof(int)
972 * differs.
973 */
974 cm->cmsg_len = CMSG_LEN(newfds * sizeof(int));
975 rights->m_len = cm->cmsg_len;
976 return (0);
977}
978
979void
980unp_init(void)
981{
982 unp_zone = zinit("unpcb", sizeof(struct unpcb), nmbclusters, 0, 0);
9dc5418a 983 if (unp_zone == NULL)
984263bc
MD
984 panic("unp_init");
985 LIST_INIT(&unp_dhead);
986 LIST_INIT(&unp_shead);
2dd63755 987 spin_init(&unp_spin);
984263bc
MD
988}
989
984263bc 990static int
dadab5e9 991unp_internalize(struct mbuf *control, struct thread *td)
984263bc 992{
dadab5e9
MD
993 struct proc *p = td->td_proc;
994 struct filedesc *fdescp;
995 struct cmsghdr *cm = mtod(control, struct cmsghdr *);
996 struct file **rp;
997 struct file *fp;
998 int i, fd, *fdp;
999 struct cmsgcred *cmcred;
984263bc
MD
1000 int oldfds;
1001 u_int newlen;
1002
dadab5e9
MD
1003 KKASSERT(p);
1004 fdescp = p->p_fd;
984263bc
MD
1005 if ((cm->cmsg_type != SCM_RIGHTS && cm->cmsg_type != SCM_CREDS) ||
1006 cm->cmsg_level != SOL_SOCKET || cm->cmsg_len != control->m_len)
1007 return (EINVAL);
1008
1009 /*
1010 * Fill in credential information.
1011 */
1012 if (cm->cmsg_type == SCM_CREDS) {
1013 cmcred = (struct cmsgcred *)(cm + 1);
1014 cmcred->cmcred_pid = p->p_pid;
41c20dac
MD
1015 cmcred->cmcred_uid = p->p_ucred->cr_ruid;
1016 cmcred->cmcred_gid = p->p_ucred->cr_rgid;
984263bc
MD
1017 cmcred->cmcred_euid = p->p_ucred->cr_uid;
1018 cmcred->cmcred_ngroups = MIN(p->p_ucred->cr_ngroups,
1019 CMGROUP_MAX);
1020 for (i = 0; i < cmcred->cmcred_ngroups; i++)
1021 cmcred->cmcred_groups[i] = p->p_ucred->cr_groups[i];
1022 return(0);
1023 }
1024
1025 oldfds = (cm->cmsg_len - sizeof (*cm)) / sizeof (int);
1026 /*
1027 * check that all the FDs passed in refer to legal OPEN files
1028 * If not, reject the entire operation.
1029 */
1030 fdp = (int *)(cm + 1);
1031 for (i = 0; i < oldfds; i++) {
1032 fd = *fdp++;
1033 if ((unsigned)fd >= fdescp->fd_nfiles ||
0679adc4 1034 fdescp->fd_files[fd].fp == NULL)
984263bc 1035 return (EBADF);
0679adc4 1036 if (fdescp->fd_files[fd].fp->f_type == DTYPE_KQUEUE)
984263bc
MD
1037 return (EOPNOTSUPP);
1038 }
1039 /*
1040 * Now replace the integer FDs with pointers to
1041 * the associated global file table entry..
1042 * Allocate a bigger buffer as necessary. But if an cluster is not
1043 * enough, return E2BIG.
1044 */
1045 newlen = CMSG_LEN(oldfds * sizeof(struct file *));
1046 if (newlen > MCLBYTES)
1047 return (E2BIG);
1048 if (newlen - control->m_len > M_TRAILINGSPACE(control)) {
1049 if (control->m_flags & M_EXT)
1050 return (E2BIG);
74f1caca 1051 MCLGET(control, MB_WAIT);
9dc5418a 1052 if (!(control->m_flags & M_EXT))
984263bc
MD
1053 return (ENOBUFS);
1054
1055 /* copy the data to the cluster */
1056 memcpy(mtod(control, char *), cm, cm->cmsg_len);
1057 cm = mtod(control, struct cmsghdr *);
1058 }
1059
1060 /*
1061 * Adjust length, in case sizeof(struct file *) and sizeof(int)
1062 * differs.
1063 */
1064 control->m_len = cm->cmsg_len = newlen;
1065
1066 /*
1067 * Transform the file descriptors into struct file pointers.
1068 * If sizeof (struct file *) is bigger than or equal to sizeof int,
1069 * then do it in reverse order so that the int won't get until
1070 * we're done.
1071 * If sizeof (struct file *) is smaller than sizeof int, then
1072 * do it in forward order.
1073 */
1074 if (sizeof (struct file *) >= sizeof (int)) {
1075 fdp = (int *)(cm + 1) + oldfds - 1;
1076 rp = (struct file **)CMSG_DATA(cm) + oldfds - 1;
1077 for (i = 0; i < oldfds; i++) {
0679adc4 1078 fp = fdescp->fd_files[*fdp--].fp;
984263bc 1079 *rp-- = fp;
2dd63755
MD
1080 fhold(fp);
1081 spin_lock_wr(&unp_spin);
984263bc
MD
1082 fp->f_msgcount++;
1083 unp_rights++;
2dd63755 1084 spin_unlock_wr(&unp_spin);
984263bc
MD
1085 }
1086 } else {
1087 fdp = (int *)(cm + 1);
1088 rp = (struct file **)CMSG_DATA(cm);
1089 for (i = 0; i < oldfds; i++) {
0679adc4 1090 fp = fdescp->fd_files[*fdp++].fp;
984263bc 1091 *rp++ = fp;
2dd63755
MD
1092 fhold(fp);
1093 spin_lock_wr(&unp_spin);
984263bc
MD
1094 fp->f_msgcount++;
1095 unp_rights++;
2dd63755 1096 spin_unlock_wr(&unp_spin);
984263bc
MD
1097 }
1098 }
1099 return (0);
1100}
1101
2dd63755
MD
1102/*
1103 * Garbage collect in-transit file descriptors that get lost due to
1104 * loops (i.e. when a socket is sent to another process over itself,
1105 * and more complex situations).
1106 *
1107 * NOT MPSAFE - TODO socket flush code and maybe closef. Rest is MPSAFE.
1108 */
1109
1110struct unp_gc_info {
1111 struct file **extra_ref;
1112 struct file *locked_fp;
1113 int defer;
1114 int index;
1115 int maxindex;
1116};
984263bc
MD
1117
1118static void
1119unp_gc()
1120{
2dd63755 1121 struct unp_gc_info info;
9dc5418a 1122 static boolean_t unp_gcing;
2dd63755
MD
1123 struct file **fpp;
1124 int i;
9dc5418a 1125
2dd63755
MD
1126 spin_lock_wr(&unp_spin);
1127 if (unp_gcing) {
1128 spin_unlock_wr(&unp_spin);
984263bc 1129 return;
2dd63755 1130 }
9dc5418a 1131 unp_gcing = TRUE;
2dd63755
MD
1132 spin_unlock_wr(&unp_spin);
1133
984263bc
MD
1134 /*
1135 * before going through all this, set all FDs to
1136 * be NOT defered and NOT externally accessible
1137 */
2dd63755
MD
1138 info.defer = 0;
1139 allfiles_scan_exclusive(unp_gc_clearmarks, NULL);
984263bc 1140 do {
2dd63755
MD
1141 allfiles_scan_exclusive(unp_gc_checkmarks, &info);
1142 } while (info.defer);
1143
984263bc
MD
1144 /*
1145 * We grab an extra reference to each of the file table entries
1146 * that are not otherwise accessible and then free the rights
1147 * that are stored in messages on them.
1148 *
1149 * The bug in the orginal code is a little tricky, so I'll describe
1150 * what's wrong with it here.
1151 *
1152 * It is incorrect to simply unp_discard each entry for f_msgcount
1153 * times -- consider the case of sockets A and B that contain
1154 * references to each other. On a last close of some other socket,
1155 * we trigger a gc since the number of outstanding rights (unp_rights)
1156 * is non-zero. If during the sweep phase the gc code un_discards,
1157 * we end up doing a (full) closef on the descriptor. A closef on A
1158 * results in the following chain. Closef calls soo_close, which
1159 * calls soclose. Soclose calls first (through the switch
1160 * uipc_usrreq) unp_detach, which re-invokes unp_gc. Unp_gc simply
1161 * returns because the previous instance had set unp_gcing, and
1162 * we return all the way back to soclose, which marks the socket
1163 * with SS_NOFDREF, and then calls sofree. Sofree calls sorflush
1164 * to free up the rights that are queued in messages on the socket A,
1165 * i.e., the reference on B. The sorflush calls via the dom_dispose
1166 * switch unp_dispose, which unp_scans with unp_discard. This second
1167 * instance of unp_discard just calls closef on B.
1168 *
1169 * Well, a similar chain occurs on B, resulting in a sorflush on B,
1170 * which results in another closef on A. Unfortunately, A is already
1171 * being closed, and the descriptor has already been marked with
1172 * SS_NOFDREF, and soclose panics at this point.
1173 *
1174 * Here, we first take an extra reference to each inaccessible
1175 * descriptor. Then, we call sorflush ourself, since we know
1176 * it is a Unix domain socket anyhow. After we destroy all the
1177 * rights carried in messages, we do a last closef to get rid
1178 * of our extra reference. This is the last close, and the
1179 * unp_detach etc will shut down the socket.
1180 *
1181 * 91/09/19, bsy@cs.cmu.edu
1182 */
efda3bd0 1183 info.extra_ref = kmalloc(256 * sizeof(struct file *), M_FILE, M_WAITOK);
2dd63755
MD
1184 info.maxindex = 256;
1185
1186 do {
1187 /*
1188 * Look for matches
984263bc 1189 */
2dd63755
MD
1190 info.index = 0;
1191 allfiles_scan_exclusive(unp_gc_checkrefs, &info);
1192
984263bc 1193 /*
2dd63755 1194 * For each FD on our hit list, do the following two things
984263bc 1195 */
2dd63755
MD
1196 for (i = info.index, fpp = info.extra_ref; --i >= 0; ++fpp) {
1197 struct file *tfp = *fpp;
1198 if (tfp->f_type == DTYPE_SOCKET && tfp->f_data != NULL)
1199 sorflush((struct socket *)(tfp->f_data));
984263bc 1200 }
2dd63755
MD
1201 for (i = info.index, fpp = info.extra_ref; --i >= 0; ++fpp)
1202 closef(*fpp, NULL);
1203 } while (info.index == info.maxindex);
efda3bd0 1204 kfree((caddr_t)info.extra_ref, M_FILE);
2dd63755
MD
1205 unp_gcing = FALSE;
1206}
1207
1208/*
1209 * MPSAFE - NOTE: filehead list and file pointer spinlocked on entry
1210 */
1211static int
1212unp_gc_checkrefs(struct file *fp, void *data)
1213{
1214 struct unp_gc_info *info = data;
1215
1216 if (fp->f_count == 0)
1217 return(0);
1218 if (info->index == info->maxindex)
1219 return(-1);
1220
984263bc 1221 /*
2dd63755
MD
1222 * If all refs are from msgs, and it's not marked accessible
1223 * then it must be referenced from some unreachable cycle
1224 * of (shut-down) FDs, so include it in our
1225 * list of FDs to remove
984263bc 1226 */
2dd63755
MD
1227 if (fp->f_count == fp->f_msgcount && !(fp->f_flag & FMARK)) {
1228 info->extra_ref[info->index++] = fp;
1229 fhold(fp);
984263bc 1230 }
2dd63755
MD
1231 return(0);
1232}
1233
1234/*
1235 * MPSAFE - NOTE: filehead list and file pointer spinlocked on entry
1236 */
1237static int
1238unp_gc_clearmarks(struct file *fp, void *data __unused)
1239{
1240 fp->f_flag &= ~(FMARK|FDEFER);
1241 return(0);
1242}
1243
1244/*
1245 * MPSAFE - NOTE: filehead list and file pointer spinlocked on entry
1246 */
1247static int
1248unp_gc_checkmarks(struct file *fp, void *data)
1249{
1250 struct unp_gc_info *info = data;
1251 struct socket *so;
1252
1253 /*
1254 * If the file is not open, skip it
1255 */
1256 if (fp->f_count == 0)
1257 return(0);
1258 /*
1259 * If we already marked it as 'defer' in a
1260 * previous pass, then try process it this time
1261 * and un-mark it
1262 */
1263 if (fp->f_flag & FDEFER) {
1264 fp->f_flag &= ~FDEFER;
1265 --info->defer;
1266 } else {
1267 /*
1268 * if it's not defered, then check if it's
1269 * already marked.. if so skip it
1270 */
1271 if (fp->f_flag & FMARK)
1272 return(0);
1273 /*
1274 * If all references are from messages
1275 * in transit, then skip it. it's not
1276 * externally accessible.
1277 */
1278 if (fp->f_count == fp->f_msgcount)
1279 return(0);
1280 /*
1281 * If it got this far then it must be
1282 * externally accessible.
1283 */
1284 fp->f_flag |= FMARK;
1285 }
1286 /*
1287 * either it was defered, or it is externally
1288 * accessible and not already marked so.
1289 * Now check if it is possibly one of OUR sockets.
1290 */
1291 if (fp->f_type != DTYPE_SOCKET ||
1292 (so = (struct socket *)fp->f_data) == NULL)
1293 return(0);
1294 if (so->so_proto->pr_domain != &localdomain ||
1295 !(so->so_proto->pr_flags & PR_RIGHTS))
1296 return(0);
1297#ifdef notdef
1298 XXX note: exclusive fp->f_spin lock held
1299 if (so->so_rcv.sb_flags & SB_LOCK) {
1300 /*
1301 * This is problematical; it's not clear
1302 * we need to wait for the sockbuf to be
1303 * unlocked (on a uniprocessor, at least),
1304 * and it's also not clear what to do
1305 * if sbwait returns an error due to receipt
1306 * of a signal. If sbwait does return
1307 * an error, we'll go into an infinite
1308 * loop. Delete all of this for now.
1309 */
1310 sbwait(&so->so_rcv);
1311 goto restart;
1312 }
1313#endif
1314 /*
1315 * So, Ok, it's one of our sockets and it IS externally
1316 * accessible (or was defered). Now we look
1317 * to see if we hold any file descriptors in its
1318 * message buffers. Follow those links and mark them
1319 * as accessible too.
1320 */
1321 info->locked_fp = fp;
1322/* spin_lock_wr(&so->so_rcv.sb_spin); */
1323 unp_scan(so->so_rcv.sb_mb, unp_mark, info);
1324/* spin_unlock_wr(&so->so_rcv.sb_spin);*/
1325 return (0);
984263bc
MD
1326}
1327
1328void
dadab5e9 1329unp_dispose(struct mbuf *m)
984263bc 1330{
984263bc 1331 if (m)
2dd63755 1332 unp_scan(m, unp_discard, NULL);
984263bc
MD
1333}
1334
1335static int
dadab5e9 1336unp_listen(struct unpcb *unp, struct thread *td)
984263bc 1337{
dadab5e9 1338 struct proc *p = td->td_proc;
984263bc 1339
dadab5e9 1340 KKASSERT(p);
984263bc
MD
1341 cru2x(p->p_ucred, &unp->unp_peercred);
1342 unp->unp_flags |= UNP_HAVEPCCACHED;
1343 return (0);
1344}
1345
1346static void
2dd63755 1347unp_scan(struct mbuf *m0, void (*op)(struct file *, void *), void *data)
984263bc 1348{
dadab5e9
MD
1349 struct mbuf *m;
1350 struct file **rp;
1351 struct cmsghdr *cm;
1352 int i;
984263bc
MD
1353 int qfds;
1354
1355 while (m0) {
2dd63755 1356 for (m = m0; m; m = m->m_next) {
984263bc
MD
1357 if (m->m_type == MT_CONTROL &&
1358 m->m_len >= sizeof(*cm)) {
1359 cm = mtod(m, struct cmsghdr *);
1360 if (cm->cmsg_level != SOL_SOCKET ||
1361 cm->cmsg_type != SCM_RIGHTS)
1362 continue;
1363 qfds = (cm->cmsg_len -
1364 (CMSG_DATA(cm) - (u_char *)cm))
1365 / sizeof (struct file *);
1366 rp = (struct file **)CMSG_DATA(cm);
1367 for (i = 0; i < qfds; i++)
2dd63755 1368 (*op)(*rp++, data);
984263bc
MD
1369 break; /* XXX, but saves time */
1370 }
2dd63755 1371 }
9a275e74 1372 m0 = m0->m_nextpkt;
984263bc
MD
1373 }
1374}
1375
1376static void
2dd63755 1377unp_mark(struct file *fp, void *data)
984263bc 1378{
2dd63755 1379 struct unp_gc_info *info = data;
984263bc 1380
2dd63755
MD
1381 if (info->locked_fp != fp)
1382 spin_lock_wr(&fp->f_spin);
5d3c4ae7
MD
1383 if ((fp->f_flag & FMARK) == 0) {
1384 ++info->defer;
1385 fp->f_flag |= (FMARK|FDEFER);
1386 }
2dd63755
MD
1387 if (info->locked_fp != fp)
1388 spin_unlock_wr(&fp->f_spin);
984263bc
MD
1389}
1390
1391static void
2dd63755 1392unp_discard(struct file *fp, void *data __unused)
984263bc 1393{
2dd63755 1394 spin_lock_wr(&unp_spin);
984263bc
MD
1395 fp->f_msgcount--;
1396 unp_rights--;
2dd63755 1397 spin_unlock_wr(&unp_spin);
3e0c844d 1398 closef(fp, NULL);
984263bc 1399}
2dd63755 1400