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tools - Fix backup file permissions for hammer-backup.sh
[dragonfly.git] / sys / kern / uipc_usrreq.c
blobc3b927852f463c9e32fc7f491661143c2cd0c732
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. 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 * From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94
30 * $FreeBSD: src/sys/kern/uipc_usrreq.c,v 1.54.2.10 2003/03/04 17:28:09 nectar Exp $
31 */
32
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/domain.h>
37 #include <sys/fcntl.h>
38 #include <sys/malloc.h> /* XXX must be before <sys/file.h> */
39 #include <sys/proc.h>
40 #include <sys/file.h>
41 #include <sys/filedesc.h>
42 #include <sys/mbuf.h>
43 #include <sys/nlookup.h>
44 #include <sys/protosw.h>
45 #include <sys/socket.h>
46 #include <sys/socketvar.h>
47 #include <sys/resourcevar.h>
48 #include <sys/stat.h>
49 #include <sys/mount.h>
50 #include <sys/sysctl.h>
51 #include <sys/un.h>
52 #include <sys/unpcb.h>
53 #include <sys/vnode.h>
54
55 #include <sys/file2.h>
56 #include <sys/spinlock2.h>
57 #include <sys/socketvar2.h>
58 #include <sys/msgport2.h>
59
60 typedef struct unp_defdiscard {
61 struct unp_defdiscard *next;
62 struct file *fp;
63 } *unp_defdiscard_t;
64
65 static MALLOC_DEFINE(M_UNPCB, "unpcb", "unpcb struct");
66 static unp_gen_t unp_gencnt;
67 static u_int unp_count;
68
69 static struct unp_head unp_shead, unp_dhead;
70
71 static struct lwkt_token unp_token = LWKT_TOKEN_INITIALIZER(unp_token);
72 static int unp_defdiscard_nest;
73 static unp_defdiscard_t unp_defdiscard_base;
74
75 /*
76 * Unix communications domain.
77 *
78 * TODO:
79 * RDM
80 * rethink name space problems
81 * need a proper out-of-band
82 * lock pushdown
83 */
84 static struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL };
85 static ino_t unp_ino = 1; /* prototype for fake inode numbers */
86 static struct spinlock unp_ino_spin = SPINLOCK_INITIALIZER(&unp_ino_spin, "unp_ino_spin");
87
88 static int unp_attach (struct socket *, struct pru_attach_info *);
89 static void unp_detach (struct unpcb *);
90 static int unp_bind (struct unpcb *,struct sockaddr *, struct thread *);
91 static int unp_connect (struct socket *,struct sockaddr *,
92 struct thread *);
93 static void unp_disconnect (struct unpcb *);
94 static void unp_shutdown (struct unpcb *);
95 static void unp_drop (struct unpcb *, int);
96 static void unp_gc (void);
97 static int unp_gc_clearmarks(struct file *, void *);
98 static int unp_gc_checkmarks(struct file *, void *);
99 static int unp_gc_checkrefs(struct file *, void *);
100 static int unp_revoke_gc_check(struct file *, void *);
101 static void unp_scan (struct mbuf *, void (*)(struct file *, void *),
102 void *data);
103 static void unp_mark (struct file *, void *data);
104 static void unp_discard (struct file *, void *);
105 static int unp_internalize (struct mbuf *, struct thread *);
106 static int unp_listen (struct unpcb *, struct thread *);
107 static void unp_fp_externalize(struct lwp *lp, struct file *fp, int fd);
108
109 /*
110 * SMP Considerations:
111 *
112 * Since unp_token will be automaticly released upon execution of
113 * blocking code, we need to reference unp_conn before any possible
114 * blocking code to prevent it from being ripped behind our back.
115 *
116 * Any adjustment to unp->unp_conn requires both the global unp_token
117 * AND the per-unp token (lwkt_token_pool_lookup(unp)) to be held.
118 *
119 * Any access to so_pcb to obtain unp requires the pool token for
120 * unp to be held.
121 */
122
123 /* NOTE: unp_token MUST be held */
124 static __inline void
125 unp_reference(struct unpcb *unp)
126 {
127 atomic_add_int(&unp->unp_refcnt, 1);
128 }
129
130 /* NOTE: unp_token MUST be held */
131 static __inline void
132 unp_free(struct unpcb *unp)
133 {
134 KKASSERT(unp->unp_refcnt > 0);
135 if (atomic_fetchadd_int(&unp->unp_refcnt, -1) == 1)
136 unp_detach(unp);
137 }
138
139 /*
140 * NOTE: (so) is referenced from soabort*() and netmsg_pru_abort()
141 * will sofree() it when we return.
142 */
143 static void
144 uipc_abort(netmsg_t msg)
145 {
146 struct unpcb *unp;
147 int error;
148
149 lwkt_gettoken(&unp_token);
150 unp = msg->base.nm_so->so_pcb;
151 if (unp) {
152 unp_drop(unp, ECONNABORTED);
153 unp_free(unp);
154 error = 0;
155 } else {
156 error = EINVAL;
157 }
158 lwkt_reltoken(&unp_token);
159
160 lwkt_replymsg(&msg->lmsg, error);
161 }
162
163 static void
164 uipc_accept(netmsg_t msg)
165 {
166 struct unpcb *unp;
167 int error;
168
169 lwkt_gettoken(&unp_token);
170 unp = msg->base.nm_so->so_pcb;
171 if (unp == NULL) {
172 error = EINVAL;
173 } else {
174 struct unpcb *unp2 = unp->unp_conn;
175
176 /*
177 * Pass back name of connected socket,
178 * if it was bound and we are still connected
179 * (our peer may have closed already!).
180 */
181 if (unp2 && unp2->unp_addr) {
182 unp_reference(unp2);
183 *msg->accept.nm_nam = dup_sockaddr(
184 (struct sockaddr *)unp2->unp_addr);
185 unp_free(unp2);
186 } else {
187 *msg->accept.nm_nam = dup_sockaddr(&sun_noname);
188 }
189 error = 0;
190 }
191 lwkt_reltoken(&unp_token);
192 lwkt_replymsg(&msg->lmsg, error);
193 }
194
195 static void
196 uipc_attach(netmsg_t msg)
197 {
198 struct unpcb *unp;
199 int error;
200
201 lwkt_gettoken(&unp_token);
202 unp = msg->base.nm_so->so_pcb;
203 if (unp)
204 error = EISCONN;
205 else
206 error = unp_attach(msg->base.nm_so, msg->attach.nm_ai);
207 lwkt_reltoken(&unp_token);
208 lwkt_replymsg(&msg->lmsg, error);
209 }
210
211 static void
212 uipc_bind(netmsg_t msg)
213 {
214 struct unpcb *unp;
215 int error;
216
217 lwkt_gettoken(&unp_token);
218 unp = msg->base.nm_so->so_pcb;
219 if (unp)
220 error = unp_bind(unp, msg->bind.nm_nam, msg->bind.nm_td);
221 else
222 error = EINVAL;
223 lwkt_reltoken(&unp_token);
224 lwkt_replymsg(&msg->lmsg, error);
225 }
226
227 static void
228 uipc_connect(netmsg_t msg)
229 {
230 struct unpcb *unp;
231 int error;
232
233 unp = msg->base.nm_so->so_pcb;
234 if (unp) {
235 error = unp_connect(msg->base.nm_so,
236 msg->connect.nm_nam,
237 msg->connect.nm_td);
238 } else {
239 error = EINVAL;
240 }
241 lwkt_replymsg(&msg->lmsg, error);
242 }
243
244 static void
245 uipc_connect2(netmsg_t msg)
246 {
247 struct unpcb *unp;
248 int error;
249
250 unp = msg->connect2.nm_so1->so_pcb;
251 if (unp) {
252 error = unp_connect2(msg->connect2.nm_so1,
253 msg->connect2.nm_so2);
254 } else {
255 error = EINVAL;
256 }
257 lwkt_replymsg(&msg->lmsg, error);
258 }
259
260 /* control is EOPNOTSUPP */
261
262 static void
263 uipc_detach(netmsg_t msg)
264 {
265 struct unpcb *unp;
266 int error;
267
268 lwkt_gettoken(&unp_token);
269 unp = msg->base.nm_so->so_pcb;
270 if (unp) {
271 unp_free(unp);
272 error = 0;
273 } else {
274 error = EINVAL;
275 }
276 lwkt_reltoken(&unp_token);
277 lwkt_replymsg(&msg->lmsg, error);
278 }
279
280 static void
281 uipc_disconnect(netmsg_t msg)
282 {
283 struct unpcb *unp;
284 int error;
285
286 lwkt_gettoken(&unp_token);
287 unp = msg->base.nm_so->so_pcb;
288 if (unp) {
289 unp_disconnect(unp);
290 error = 0;
291 } else {
292 error = EINVAL;
293 }
294 lwkt_reltoken(&unp_token);
295 lwkt_replymsg(&msg->lmsg, error);
296 }
297
298 static void
299 uipc_listen(netmsg_t msg)
300 {
301 struct unpcb *unp;
302 int error;
303
304 lwkt_gettoken(&unp_token);
305 unp = msg->base.nm_so->so_pcb;
306 if (unp == NULL || unp->unp_vnode == NULL)
307 error = EINVAL;
308 else
309 error = unp_listen(unp, msg->listen.nm_td);
310 lwkt_reltoken(&unp_token);
311 lwkt_replymsg(&msg->lmsg, error);
312 }
313
314 static void
315 uipc_peeraddr(netmsg_t msg)
316 {
317 struct unpcb *unp;
318 int error;
319
320 lwkt_gettoken(&unp_token);
321 unp = msg->base.nm_so->so_pcb;
322 if (unp == NULL) {
323 error = EINVAL;
324 } else if (unp->unp_conn && unp->unp_conn->unp_addr) {
325 struct unpcb *unp2 = unp->unp_conn;
326
327 unp_reference(unp2);
328 *msg->peeraddr.nm_nam = dup_sockaddr(
329 (struct sockaddr *)unp2->unp_addr);
330 unp_free(unp2);
331 error = 0;
332 } else {
333 /*
334 * XXX: It seems that this test always fails even when
335 * connection is established. So, this else clause is
336 * added as workaround to return PF_LOCAL sockaddr.
337 */
338 *msg->peeraddr.nm_nam = dup_sockaddr(&sun_noname);
339 error = 0;
340 }
341 lwkt_reltoken(&unp_token);
342 lwkt_replymsg(&msg->lmsg, error);
343 }
344
345 static void
346 uipc_rcvd(netmsg_t msg)
347 {
348 struct unpcb *unp, *unp2;
349 struct socket *so;
350 struct socket *so2;
351 int error;
352
353 /*
354 * so_pcb is only modified with both the global and the unp
355 * pool token held. The unp pointer is invalid until we verify
356 * that it is good by re-checking so_pcb AFTER obtaining the token.
357 */
358 so = msg->base.nm_so;
359 while ((unp = so->so_pcb) != NULL) {
360 lwkt_getpooltoken(unp);
361 if (unp == so->so_pcb)
362 break;
363 lwkt_relpooltoken(unp);
364 }
365 if (unp == NULL) {
366 error = EINVAL;
367 goto done;
368 }
369 /* pool token held */
370
371 switch (so->so_type) {
372 case SOCK_DGRAM:
373 panic("uipc_rcvd DGRAM?");
374 /*NOTREACHED*/
375 case SOCK_STREAM:
376 case SOCK_SEQPACKET:
377 if (unp->unp_conn == NULL)
378 break;
379 unp2 = unp->unp_conn; /* protected by pool token */
380
381 /*
382 * Because we are transfering mbufs directly to the
383 * peer socket we have to use SSB_STOP on the sender
384 * to prevent it from building up infinite mbufs.
385 *
386 * As in several places in this module w ehave to ref unp2
387 * to ensure that it does not get ripped out from under us
388 * if we block on the so2 token or in sowwakeup().
389 */
390 so2 = unp2->unp_socket;
391 unp_reference(unp2);
392 lwkt_gettoken(&so2->so_rcv.ssb_token);
393 if (so->so_rcv.ssb_cc < so2->so_snd.ssb_hiwat &&
394 so->so_rcv.ssb_mbcnt < so2->so_snd.ssb_mbmax
395 ) {
396 atomic_clear_int(&so2->so_snd.ssb_flags, SSB_STOP);
397
398 sowwakeup(so2);
399 }
400 lwkt_reltoken(&so2->so_rcv.ssb_token);
401 unp_free(unp2);
402 break;
403 default:
404 panic("uipc_rcvd unknown socktype");
405 /*NOTREACHED*/
406 }
407 error = 0;
408 lwkt_relpooltoken(unp);
409 done:
410 lwkt_replymsg(&msg->lmsg, error);
411 }
412
413 /* pru_rcvoob is EOPNOTSUPP */
414
415 static void
416 uipc_send(netmsg_t msg)
417 {
418 struct unpcb *unp, *unp2;
419 struct socket *so;
420 struct socket *so2;
421 struct mbuf *control;
422 struct mbuf *m;
423 int error = 0;
424
425 so = msg->base.nm_so;
426 control = msg->send.nm_control;
427 m = msg->send.nm_m;
428
429 /*
430 * so_pcb is only modified with both the global and the unp
431 * pool token held. The unp pointer is invalid until we verify
432 * that it is good by re-checking so_pcb AFTER obtaining the token.
433 */
434 so = msg->base.nm_so;
435 while ((unp = so->so_pcb) != NULL) {
436 lwkt_getpooltoken(unp);
437 if (unp == so->so_pcb)
438 break;
439 lwkt_relpooltoken(unp);
440 }
441 if (unp == NULL) {
442 error = EINVAL;
443 goto done;
444 }
445 /* pool token held */
446
447 if (msg->send.nm_flags & PRUS_OOB) {
448 error = EOPNOTSUPP;
449 goto release;
450 }
451
452 wakeup_start_delayed();
453
454 if (control && (error = unp_internalize(control, msg->send.nm_td)))
455 goto release;
456
457 switch (so->so_type) {
458 case SOCK_DGRAM:
459 {
460 struct sockaddr *from;
461
462 if (msg->send.nm_addr) {
463 if (unp->unp_conn) {
464 error = EISCONN;
465 break;
466 }
467 error = unp_connect(so,
468 msg->send.nm_addr,
469 msg->send.nm_td);
470 if (error)
471 break;
472 } else {
473 if (unp->unp_conn == NULL) {
474 error = ENOTCONN;
475 break;
476 }
477 }
478 unp2 = unp->unp_conn;
479 so2 = unp2->unp_socket;
480 if (unp->unp_addr)
481 from = (struct sockaddr *)unp->unp_addr;
482 else
483 from = &sun_noname;
484
485 unp_reference(unp2);
486
487 lwkt_gettoken(&so2->so_rcv.ssb_token);
488 if (ssb_appendaddr(&so2->so_rcv, from, m, control)) {
489 sorwakeup(so2);
490 m = NULL;
491 control = NULL;
492 } else {
493 error = ENOBUFS;
494 }
495 if (msg->send.nm_addr)
496 unp_disconnect(unp);
497 lwkt_reltoken(&so2->so_rcv.ssb_token);
498
499 unp_free(unp2);
500 break;
501 }
502
503 case SOCK_STREAM:
504 case SOCK_SEQPACKET:
505 /* Connect if not connected yet. */
506 /*
507 * Note: A better implementation would complain
508 * if not equal to the peer's address.
509 */
510 if (!(so->so_state & SS_ISCONNECTED)) {
511 if (msg->send.nm_addr) {
512 error = unp_connect(so,
513 msg->send.nm_addr,
514 msg->send.nm_td);
515 if (error)
516 break; /* XXX */
517 } else {
518 error = ENOTCONN;
519 break;
520 }
521 }
522
523 if (so->so_state & SS_CANTSENDMORE) {
524 error = EPIPE;
525 break;
526 }
527 if (unp->unp_conn == NULL)
528 panic("uipc_send connected but no connection?");
529 unp2 = unp->unp_conn;
530 so2 = unp2->unp_socket;
531
532 unp_reference(unp2);
533
534 /*
535 * Send to paired receive port, and then reduce
536 * send buffer hiwater marks to maintain backpressure.
537 * Wake up readers.
538 */
539 lwkt_gettoken(&so2->so_rcv.ssb_token);
540 if (control) {
541 if (ssb_appendcontrol(&so2->so_rcv, m, control)) {
542 control = NULL;
543 m = NULL;
544 }
545 } else if (so->so_type == SOCK_SEQPACKET) {
546 sbappendrecord(&so2->so_rcv.sb, m);
547 m = NULL;
548 } else {
549 sbappend(&so2->so_rcv.sb, m);
550 m = NULL;
551 }
552
553 /*
554 * Because we are transfering mbufs directly to the
555 * peer socket we have to use SSB_STOP on the sender
556 * to prevent it from building up infinite mbufs.
557 */
558 if (so2->so_rcv.ssb_cc >= so->so_snd.ssb_hiwat ||
559 so2->so_rcv.ssb_mbcnt >= so->so_snd.ssb_mbmax
560 ) {
561 atomic_set_int(&so->so_snd.ssb_flags, SSB_STOP);
562 }
563 lwkt_reltoken(&so2->so_rcv.ssb_token);
564 sorwakeup(so2);
565
566 unp_free(unp2);
567 break;
568
569 default:
570 panic("uipc_send unknown socktype");
571 }
572
573 /*
574 * SEND_EOF is equivalent to a SEND followed by a SHUTDOWN.
575 */
576 if (msg->send.nm_flags & PRUS_EOF) {
577 socantsendmore(so);
578 unp_shutdown(unp);
579 }
580
581 if (control && error != 0)
582 unp_dispose(control);
583 release:
584 lwkt_relpooltoken(unp);
585 wakeup_end_delayed();
586 done:
587
588 if (control)
589 m_freem(control);
590 if (m)
591 m_freem(m);
592 lwkt_replymsg(&msg->lmsg, error);
593 }
594
595 /*
596 * MPSAFE
597 */
598 static void
599 uipc_sense(netmsg_t msg)
600 {
601 struct unpcb *unp;
602 struct socket *so;
603 struct stat *sb;
604 int error;
605
606 so = msg->base.nm_so;
607 sb = msg->sense.nm_stat;
608
609 /*
610 * so_pcb is only modified with both the global and the unp
611 * pool token held. The unp pointer is invalid until we verify
612 * that it is good by re-checking so_pcb AFTER obtaining the token.
613 */
614 while ((unp = so->so_pcb) != NULL) {
615 lwkt_getpooltoken(unp);
616 if (unp == so->so_pcb)
617 break;
618 lwkt_relpooltoken(unp);
619 }
620 if (unp == NULL) {
621 error = EINVAL;
622 goto done;
623 }
624 /* pool token held */
625
626 sb->st_blksize = so->so_snd.ssb_hiwat;
627 sb->st_dev = NOUDEV;
628 if (unp->unp_ino == 0) { /* make up a non-zero inode number */
629 spin_lock(&unp_ino_spin);
630 unp->unp_ino = unp_ino++;
631 spin_unlock(&unp_ino_spin);
632 }
633 sb->st_ino = unp->unp_ino;
634 error = 0;
635 lwkt_relpooltoken(unp);
636 done:
637 lwkt_replymsg(&msg->lmsg, error);
638 }
639
640 static void
641 uipc_shutdown(netmsg_t msg)
642 {
643 struct socket *so;
644 struct unpcb *unp;
645 int error;
646
647 /*
648 * so_pcb is only modified with both the global and the unp
649 * pool token held. The unp pointer is invalid until we verify
650 * that it is good by re-checking so_pcb AFTER obtaining the token.
651 */
652 so = msg->base.nm_so;
653 while ((unp = so->so_pcb) != NULL) {
654 lwkt_getpooltoken(unp);
655 if (unp == so->so_pcb)
656 break;
657 lwkt_relpooltoken(unp);
658 }
659 if (unp) {
660 /* pool token held */
661 socantsendmore(so);
662 unp_shutdown(unp);
663 lwkt_relpooltoken(unp);
664 error = 0;
665 } else {
666 error = EINVAL;
667 }
668 lwkt_replymsg(&msg->lmsg, error);
669 }
670
671 static void
672 uipc_sockaddr(netmsg_t msg)
673 {
674 struct socket *so;
675 struct unpcb *unp;
676 int error;
677
678 /*
679 * so_pcb is only modified with both the global and the unp
680 * pool token held. The unp pointer is invalid until we verify
681 * that it is good by re-checking so_pcb AFTER obtaining the token.
682 */
683 so = msg->base.nm_so;
684 while ((unp = so->so_pcb) != NULL) {
685 lwkt_getpooltoken(unp);
686 if (unp == so->so_pcb)
687 break;
688 lwkt_relpooltoken(unp);
689 }
690 if (unp) {
691 /* pool token held */
692 if (unp->unp_addr) {
693 *msg->sockaddr.nm_nam =
694 dup_sockaddr((struct sockaddr *)unp->unp_addr);
695 }
696 lwkt_relpooltoken(unp);
697 error = 0;
698 } else {
699 error = EINVAL;
700 }
701 lwkt_replymsg(&msg->lmsg, error);
702 }
703
704 struct pr_usrreqs uipc_usrreqs = {
705 .pru_abort = uipc_abort,
706 .pru_accept = uipc_accept,
707 .pru_attach = uipc_attach,
708 .pru_bind = uipc_bind,
709 .pru_connect = uipc_connect,
710 .pru_connect2 = uipc_connect2,
711 .pru_control = pr_generic_notsupp,
712 .pru_detach = uipc_detach,
713 .pru_disconnect = uipc_disconnect,
714 .pru_listen = uipc_listen,
715 .pru_peeraddr = uipc_peeraddr,
716 .pru_rcvd = uipc_rcvd,
717 .pru_rcvoob = pr_generic_notsupp,
718 .pru_send = uipc_send,
719 .pru_sense = uipc_sense,
720 .pru_shutdown = uipc_shutdown,
721 .pru_sockaddr = uipc_sockaddr,
722 .pru_sosend = sosend,
723 .pru_soreceive = soreceive
724 };
725
726 void
727 uipc_ctloutput(netmsg_t msg)
728 {
729 struct socket *so;
730 struct sockopt *sopt;
731 struct unpcb *unp;
732 int error = 0;
733
734 lwkt_gettoken(&unp_token);
735 so = msg->base.nm_so;
736 sopt = msg->ctloutput.nm_sopt;
737 unp = so->so_pcb;
738
739 switch (sopt->sopt_dir) {
740 case SOPT_GET:
741 switch (sopt->sopt_name) {
742 case LOCAL_PEERCRED:
743 if (unp->unp_flags & UNP_HAVEPC)
744 soopt_from_kbuf(sopt, &unp->unp_peercred,
745 sizeof(unp->unp_peercred));
746 else {
747 if (so->so_type == SOCK_STREAM)
748 error = ENOTCONN;
749 else if (so->so_type == SOCK_SEQPACKET)
750 error = ENOTCONN;
751 else
752 error = EINVAL;
753 }
754 break;
755 default:
756 error = EOPNOTSUPP;
757 break;
758 }
759 break;
760 case SOPT_SET:
761 default:
762 error = EOPNOTSUPP;
763 break;
764 }
765 lwkt_reltoken(&unp_token);
766 lwkt_replymsg(&msg->lmsg, error);
767 }
768
769 /*
770 * Both send and receive buffers are allocated PIPSIZ bytes of buffering
771 * for stream sockets, although the total for sender and receiver is
772 * actually only PIPSIZ.
773 *
774 * Datagram sockets really use the sendspace as the maximum datagram size,
775 * and don't really want to reserve the sendspace. Their recvspace should
776 * be large enough for at least one max-size datagram plus address.
777 *
778 * We want the local send/recv space to be significant larger then lo0's
779 * mtu of 16384.
780 */
781 #ifndef PIPSIZ
782 #define PIPSIZ 57344
783 #endif
784 static u_long unpst_sendspace = PIPSIZ;
785 static u_long unpst_recvspace = PIPSIZ;
786 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */
787 static u_long unpdg_recvspace = 4*1024;
788
789 static int unp_rights; /* file descriptors in flight */
790 static struct spinlock unp_spin = SPINLOCK_INITIALIZER(&unp_spin, "unp_spin");
791
792 SYSCTL_DECL(_net_local_seqpacket);
793 SYSCTL_DECL(_net_local_stream);
794 SYSCTL_INT(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW,
795 &unpst_sendspace, 0, "Size of stream socket send buffer");
796 SYSCTL_INT(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW,
797 &unpst_recvspace, 0, "Size of stream socket receive buffer");
798
799 SYSCTL_DECL(_net_local_dgram);
800 SYSCTL_INT(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW,
801 &unpdg_sendspace, 0, "Max datagram socket size");
802 SYSCTL_INT(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW,
803 &unpdg_recvspace, 0, "Size of datagram socket receive buffer");
804
805 SYSCTL_DECL(_net_local);
806 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0,
807 "File descriptors in flight");
808
809 static int
810 unp_attach(struct socket *so, struct pru_attach_info *ai)
811 {
812 struct unpcb *unp;
813 int error;
814
815 lwkt_gettoken(&unp_token);
816
817 if (so->so_snd.ssb_hiwat == 0 || so->so_rcv.ssb_hiwat == 0) {
818 switch (so->so_type) {
819 case SOCK_STREAM:
820 case SOCK_SEQPACKET:
821 error = soreserve(so, unpst_sendspace, unpst_recvspace,
822 ai->sb_rlimit);
823 break;
824
825 case SOCK_DGRAM:
826 error = soreserve(so, unpdg_sendspace, unpdg_recvspace,
827 ai->sb_rlimit);
828 break;
829
830 default:
831 panic("unp_attach");
832 }
833 if (error)
834 goto failed;
835 }
836
837 /*
838 * In order to support sendfile we have to set either SSB_STOPSUPP
839 * or SSB_PREALLOC. Unix domain sockets use the SSB_STOP flow
840 * control mechanism.
841 */
842 if (so->so_type == SOCK_STREAM) {
843 atomic_set_int(&so->so_rcv.ssb_flags, SSB_STOPSUPP);
844 atomic_set_int(&so->so_snd.ssb_flags, SSB_STOPSUPP);
845 }
846
847 unp = kmalloc(sizeof(*unp), M_UNPCB, M_WAITOK | M_ZERO | M_NULLOK);
848 if (unp == NULL) {
849 error = ENOBUFS;
850 goto failed;
851 }
852 unp->unp_refcnt = 1;
853 unp->unp_gencnt = ++unp_gencnt;
854 unp_count++;
855 LIST_INIT(&unp->unp_refs);
856 unp->unp_socket = so;
857 unp->unp_rvnode = ai->fd_rdir; /* jail cruft XXX JH */
858 LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead
859 : &unp_shead, unp, unp_link);
860 so->so_pcb = (caddr_t)unp;
861 soreference(so);
862 error = 0;
863 failed:
864 lwkt_reltoken(&unp_token);
865 return error;
866 }
867
868 static void
869 unp_detach(struct unpcb *unp)
870 {
871 struct socket *so;
872
873 lwkt_gettoken(&unp_token);
874 lwkt_getpooltoken(unp);
875
876 LIST_REMOVE(unp, unp_link); /* both tokens required */
877 unp->unp_gencnt = ++unp_gencnt;
878 --unp_count;
879 if (unp->unp_vnode) {
880 unp->unp_vnode->v_socket = NULL;
881 vrele(unp->unp_vnode);
882 unp->unp_vnode = NULL;
883 }
884 if (unp->unp_conn)
885 unp_disconnect(unp);
886 while (!LIST_EMPTY(&unp->unp_refs))
887 unp_drop(LIST_FIRST(&unp->unp_refs), ECONNRESET);
888 soisdisconnected(unp->unp_socket);
889 so = unp->unp_socket;
890 soreference(so); /* for delayed sorflush */
891 KKASSERT(so->so_pcb == unp);
892 so->so_pcb = NULL; /* both tokens required */
893 unp->unp_socket = NULL;
894 sofree(so); /* remove pcb ref */
895
896 if (unp_rights) {
897 /*
898 * Normally the receive buffer is flushed later,
899 * in sofree, but if our receive buffer holds references
900 * to descriptors that are now garbage, we will dispose
901 * of those descriptor references after the garbage collector
902 * gets them (resulting in a "panic: closef: count < 0").
903 */
904 sorflush(so);
905 unp_gc();
906 }
907 sofree(so);
908 lwkt_relpooltoken(unp);
909 lwkt_reltoken(&unp_token);
910
911 if (unp->unp_addr)
912 kfree(unp->unp_addr, M_SONAME);
913 kfree(unp, M_UNPCB);
914 }
915
916 static int
917 unp_bind(struct unpcb *unp, struct sockaddr *nam, struct thread *td)
918 {
919 struct proc *p = td->td_proc;
920 struct sockaddr_un *soun = (struct sockaddr_un *)nam;
921 struct vnode *vp;
922 struct vattr vattr;
923 int error, namelen;
924 struct nlookupdata nd;
925 char buf[SOCK_MAXADDRLEN];
926
927 lwkt_gettoken(&unp_token);
928 if (unp->unp_vnode != NULL) {
929 error = EINVAL;
930 goto failed;
931 }
932 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path);
933 if (namelen <= 0) {
934 error = EINVAL;
935 goto failed;
936 }
937 strncpy(buf, soun->sun_path, namelen);
938 buf[namelen] = 0; /* null-terminate the string */
939 error = nlookup_init(&nd, buf, UIO_SYSSPACE,
940 NLC_LOCKVP | NLC_CREATE | NLC_REFDVP);
941 if (error == 0)
942 error = nlookup(&nd);
943 if (error == 0 && nd.nl_nch.ncp->nc_vp != NULL)
944 error = EADDRINUSE;
945 if (error)
946 goto done;
947
948 VATTR_NULL(&vattr);
949 vattr.va_type = VSOCK;
950 vattr.va_mode = (ACCESSPERMS & ~p->p_fd->fd_cmask);
951 error = VOP_NCREATE(&nd.nl_nch, nd.nl_dvp, &vp, nd.nl_cred, &vattr);
952 if (error == 0) {
953 if (unp->unp_vnode == NULL) {
954 vp->v_socket = unp->unp_socket;
955 unp->unp_vnode = vp;
956 unp->unp_addr = (struct sockaddr_un *)dup_sockaddr(nam);
957 vn_unlock(vp);
958 } else {
959 vput(vp); /* late race */
960 error = EINVAL;
961 }
962 }
963 done:
964 nlookup_done(&nd);
965 failed:
966 lwkt_reltoken(&unp_token);
967 return (error);
968 }
969
970 static int
971 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
972 {
973 struct proc *p = td->td_proc;
974 struct sockaddr_un *soun = (struct sockaddr_un *)nam;
975 struct vnode *vp;
976 struct socket *so2, *so3;
977 struct unpcb *unp, *unp2, *unp3;
978 int error, len;
979 struct nlookupdata nd;
980 char buf[SOCK_MAXADDRLEN];
981
982 lwkt_gettoken(&unp_token);
983
984 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path);
985 if (len <= 0) {
986 error = EINVAL;
987 goto failed;
988 }
989 strncpy(buf, soun->sun_path, len);
990 buf[len] = 0;
991
992 vp = NULL;
993 error = nlookup_init(&nd, buf, UIO_SYSSPACE, NLC_FOLLOW);
994 if (error == 0)
995 error = nlookup(&nd);
996 if (error == 0)
997 error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp);
998 nlookup_done(&nd);
999 if (error)
1000 goto failed;
1001
1002 if (vp->v_type != VSOCK) {
1003 error = ENOTSOCK;
1004 goto bad;
1005 }
1006 error = VOP_EACCESS(vp, VWRITE, p->p_ucred);
1007 if (error)
1008 goto bad;
1009 so2 = vp->v_socket;
1010 if (so2 == NULL) {
1011 error = ECONNREFUSED;
1012 goto bad;
1013 }
1014 if (so->so_type != so2->so_type) {
1015 error = EPROTOTYPE;
1016 goto bad;
1017 }
1018 if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
1019 if (!(so2->so_options & SO_ACCEPTCONN) ||
1020 (so3 = sonewconn(so2, 0)) == NULL) {
1021 error = ECONNREFUSED;
1022 goto bad;
1023 }
1024 unp = so->so_pcb;
1025 if (unp->unp_conn) { /* race, already connected! */
1026 error = EISCONN;
1027 sofree(so3);
1028 goto bad;
1029 }
1030 unp2 = so2->so_pcb;
1031 unp3 = so3->so_pcb;
1032 if (unp2->unp_addr)
1033 unp3->unp_addr = (struct sockaddr_un *)
1034 dup_sockaddr((struct sockaddr *)unp2->unp_addr);
1035
1036 /*
1037 * unp_peercred management:
1038 *
1039 * The connecter's (client's) credentials are copied
1040 * from its process structure at the time of connect()
1041 * (which is now).
1042 */
1043 cru2x(p->p_ucred, &unp3->unp_peercred);
1044 unp3->unp_flags |= UNP_HAVEPC;
1045 /*
1046 * The receiver's (server's) credentials are copied
1047 * from the unp_peercred member of socket on which the
1048 * former called listen(); unp_listen() cached that
1049 * process's credentials at that time so we can use
1050 * them now.
1051 */
1052 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED,
1053 ("unp_connect: listener without cached peercred"));
1054 memcpy(&unp->unp_peercred, &unp2->unp_peercred,
1055 sizeof(unp->unp_peercred));
1056 unp->unp_flags |= UNP_HAVEPC;
1057
1058 so2 = so3;
1059 }
1060 error = unp_connect2(so, so2);
1061 bad:
1062 vput(vp);
1063 failed:
1064 lwkt_reltoken(&unp_token);
1065 return (error);
1066 }
1067
1068 /*
1069 * Connect two unix domain sockets together.
1070 *
1071 * NOTE: Semantics for any change to unp_conn requires that the per-unp
1072 * pool token also be held.
1073 */
1074 int
1075 unp_connect2(struct socket *so, struct socket *so2)
1076 {
1077 struct unpcb *unp;
1078 struct unpcb *unp2;
1079
1080 lwkt_gettoken(&unp_token);
1081 unp = so->so_pcb;
1082 if (so2->so_type != so->so_type) {
1083 lwkt_reltoken(&unp_token);
1084 return (EPROTOTYPE);
1085 }
1086 unp2 = so2->so_pcb;
1087 lwkt_getpooltoken(unp);
1088 lwkt_getpooltoken(unp2);
1089
1090 unp->unp_conn = unp2;
1091
1092 switch (so->so_type) {
1093 case SOCK_DGRAM:
1094 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink);
1095 soisconnected(so);
1096 break;
1097
1098 case SOCK_STREAM:
1099 case SOCK_SEQPACKET:
1100 unp2->unp_conn = unp;
1101 soisconnected(so);
1102 soisconnected(so2);
1103 break;
1104
1105 default:
1106 panic("unp_connect2");
1107 }
1108 lwkt_relpooltoken(unp2);
1109 lwkt_relpooltoken(unp);
1110 lwkt_reltoken(&unp_token);
1111 return (0);
1112 }
1113
1114 /*
1115 * Disconnect a unix domain socket pair.
1116 *
1117 * NOTE: Semantics for any change to unp_conn requires that the per-unp
1118 * pool token also be held.
1119 */
1120 static void
1121 unp_disconnect(struct unpcb *unp)
1122 {
1123 struct unpcb *unp2;
1124
1125 lwkt_gettoken(&unp_token);
1126 lwkt_getpooltoken(unp);
1127
1128 while ((unp2 = unp->unp_conn) != NULL) {
1129 lwkt_getpooltoken(unp2);
1130 if (unp2 == unp->unp_conn)
1131 break;
1132 lwkt_relpooltoken(unp2);
1133 }
1134 if (unp2 == NULL)
1135 goto done;
1136
1137 unp->unp_conn = NULL;
1138
1139 switch (unp->unp_socket->so_type) {
1140 case SOCK_DGRAM:
1141 LIST_REMOVE(unp, unp_reflink);
1142 soclrstate(unp->unp_socket, SS_ISCONNECTED);
1143 break;
1144
1145 case SOCK_STREAM:
1146 case SOCK_SEQPACKET:
1147 unp_reference(unp2);
1148 unp2->unp_conn = NULL;
1149
1150 soisdisconnected(unp->unp_socket);
1151 soisdisconnected(unp2->unp_socket);
1152
1153 unp_free(unp2);
1154 break;
1155 }
1156 lwkt_relpooltoken(unp2);
1157 done:
1158 lwkt_relpooltoken(unp);
1159 lwkt_reltoken(&unp_token);
1160 }
1161
1162 #ifdef notdef
1163 void
1164 unp_abort(struct unpcb *unp)
1165 {
1166 lwkt_gettoken(&unp_token);
1167 unp_free(unp);
1168 lwkt_reltoken(&unp_token);
1169 }
1170 #endif
1171
1172 static int
1173 prison_unpcb(struct thread *td, struct unpcb *unp)
1174 {
1175 struct proc *p;
1176
1177 if (td == NULL)
1178 return (0);
1179 if ((p = td->td_proc) == NULL)
1180 return (0);
1181 if (!p->p_ucred->cr_prison)
1182 return (0);
1183 if (p->p_fd->fd_rdir == unp->unp_rvnode)
1184 return (0);
1185 return (1);
1186 }
1187
1188 static int
1189 unp_pcblist(SYSCTL_HANDLER_ARGS)
1190 {
1191 int error, i, n;
1192 struct unpcb *unp, **unp_list;
1193 unp_gen_t gencnt;
1194 struct unp_head *head;
1195
1196 head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead);
1197
1198 KKASSERT(curproc != NULL);
1199
1200 /*
1201 * The process of preparing the PCB list is too time-consuming and
1202 * resource-intensive to repeat twice on every request.
1203 */
1204 if (req->oldptr == NULL) {
1205 n = unp_count;
1206 req->oldidx = (n + n/8) * sizeof(struct xunpcb);
1207 return 0;
1208 }
1209
1210 if (req->newptr != NULL)
1211 return EPERM;
1212
1213 lwkt_gettoken(&unp_token);
1214
1215 /*
1216 * OK, now we're committed to doing something.
1217 */
1218 gencnt = unp_gencnt;
1219 n = unp_count;
1220
1221 unp_list = kmalloc(n * sizeof *unp_list, M_TEMP, M_WAITOK);
1222
1223 for (unp = LIST_FIRST(head), i = 0; unp && i < n;
1224 unp = LIST_NEXT(unp, unp_link)) {
1225 if (unp->unp_gencnt <= gencnt && !prison_unpcb(req->td, unp))
1226 unp_list[i++] = unp;
1227 }
1228 n = i; /* in case we lost some during malloc */
1229
1230 error = 0;
1231 for (i = 0; i < n; i++) {
1232 unp = unp_list[i];
1233 if (unp->unp_gencnt <= gencnt) {
1234 struct xunpcb xu;
1235 xu.xu_len = sizeof xu;
1236 xu.xu_unpp = unp;
1237 /*
1238 * XXX - need more locking here to protect against
1239 * connect/disconnect races for SMP.
1240 */
1241 if (unp->unp_addr)
1242 bcopy(unp->unp_addr, &xu.xu_addr,
1243 unp->unp_addr->sun_len);
1244 if (unp->unp_conn && unp->unp_conn->unp_addr)
1245 bcopy(unp->unp_conn->unp_addr,
1246 &xu.xu_caddr,
1247 unp->unp_conn->unp_addr->sun_len);
1248 bcopy(unp, &xu.xu_unp, sizeof *unp);
1249 sotoxsocket(unp->unp_socket, &xu.xu_socket);
1250 error = SYSCTL_OUT(req, &xu, sizeof xu);
1251 }
1252 }
1253 lwkt_reltoken(&unp_token);
1254 kfree(unp_list, M_TEMP);
1255
1256 return error;
1257 }
1258
1259 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD,
1260 (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb",
1261 "List of active local datagram sockets");
1262 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD,
1263 (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb",
1264 "List of active local stream sockets");
1265 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, CTLFLAG_RD,
1266 (caddr_t)(long)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb",
1267 "List of active local seqpacket stream sockets");
1268
1269 static void
1270 unp_shutdown(struct unpcb *unp)
1271 {
1272 struct socket *so;
1273
1274 if ((unp->unp_socket->so_type == SOCK_STREAM ||
1275 unp->unp_socket->so_type == SOCK_SEQPACKET) &&
1276 unp->unp_conn != NULL && (so = unp->unp_conn->unp_socket)) {
1277 socantrcvmore(so);
1278 }
1279 }
1280
1281 static void
1282 unp_drop(struct unpcb *unp, int err)
1283 {
1284 struct socket *so = unp->unp_socket;
1285
1286 so->so_error = err;
1287 unp_disconnect(unp);
1288 }
1289
1290 #ifdef notdef
1291 void
1292 unp_drain(void)
1293 {
1294 lwkt_gettoken(&unp_token);
1295 lwkt_reltoken(&unp_token);
1296 }
1297 #endif
1298
1299 int
1300 unp_externalize(struct mbuf *rights)
1301 {
1302 struct thread *td = curthread;
1303 struct proc *p = td->td_proc; /* XXX */
1304 struct lwp *lp = td->td_lwp;
1305 struct cmsghdr *cm = mtod(rights, struct cmsghdr *);
1306 int *fdp;
1307 int i;
1308 struct file **rp;
1309 struct file *fp;
1310 int newfds = (cm->cmsg_len - (CMSG_DATA(cm) - (u_char *)cm))
1311 / sizeof (struct file *);
1312 int f;
1313
1314 lwkt_gettoken(&unp_token);
1315
1316 /*
1317 * if the new FD's will not fit, then we free them all
1318 */
1319 if (!fdavail(p, newfds)) {
1320 rp = (struct file **)CMSG_DATA(cm);
1321 for (i = 0; i < newfds; i++) {
1322 fp = *rp;
1323 /*
1324 * zero the pointer before calling unp_discard,
1325 * since it may end up in unp_gc()..
1326 */
1327 *rp++ = NULL;
1328 unp_discard(fp, NULL);
1329 }
1330 lwkt_reltoken(&unp_token);
1331 return (EMSGSIZE);
1332 }
1333
1334 /*
1335 * now change each pointer to an fd in the global table to
1336 * an integer that is the index to the local fd table entry
1337 * that we set up to point to the global one we are transferring.
1338 * If sizeof (struct file *) is bigger than or equal to sizeof int,
1339 * then do it in forward order. In that case, an integer will
1340 * always come in the same place or before its corresponding
1341 * struct file pointer.
1342 * If sizeof (struct file *) is smaller than sizeof int, then
1343 * do it in reverse order.
1344 */
1345 if (sizeof (struct file *) >= sizeof (int)) {
1346 fdp = (int *)CMSG_DATA(cm);
1347 rp = (struct file **)CMSG_DATA(cm);
1348 for (i = 0; i < newfds; i++) {
1349 if (fdalloc(p, 0, &f))
1350 panic("unp_externalize");
1351 fp = *rp++;
1352 unp_fp_externalize(lp, fp, f);
1353 *fdp++ = f;
1354 }
1355 } else {
1356 fdp = (int *)CMSG_DATA(cm) + newfds - 1;
1357 rp = (struct file **)CMSG_DATA(cm) + newfds - 1;
1358 for (i = 0; i < newfds; i++) {
1359 if (fdalloc(p, 0, &f))
1360 panic("unp_externalize");
1361 fp = *rp--;
1362 unp_fp_externalize(lp, fp, f);
1363 *fdp-- = f;
1364 }
1365 }
1366
1367 /*
1368 * Adjust length, in case sizeof(struct file *) and sizeof(int)
1369 * differs.
1370 */
1371 cm->cmsg_len = CMSG_LEN(newfds * sizeof(int));
1372 rights->m_len = cm->cmsg_len;
1373
1374 lwkt_reltoken(&unp_token);
1375 return (0);
1376 }
1377
1378 static void
1379 unp_fp_externalize(struct lwp *lp, struct file *fp, int fd)
1380 {
1381 struct file *fx;
1382 int error;
1383
1384 lwkt_gettoken(&unp_token);
1385
1386 if (lp) {
1387 KKASSERT(fd >= 0);
1388 if (fp->f_flag & FREVOKED) {
1389 kprintf("Warning: revoked fp exiting unix socket\n");
1390 fx = NULL;
1391 error = falloc(lp, &fx, NULL);
1392 if (error == 0)
1393 fsetfd(lp->lwp_proc->p_fd, fx, fd);
1394 else
1395 fsetfd(lp->lwp_proc->p_fd, NULL, fd);
1396 fdrop(fx);
1397 } else {
1398 fsetfd(lp->lwp_proc->p_fd, fp, fd);
1399 }
1400 }
1401 spin_lock(&unp_spin);
1402 fp->f_msgcount--;
1403 unp_rights--;
1404 spin_unlock(&unp_spin);
1405 fdrop(fp);
1406
1407 lwkt_reltoken(&unp_token);
1408 }
1409
1410
1411 void
1412 unp_init(void)
1413 {
1414 LIST_INIT(&unp_dhead);
1415 LIST_INIT(&unp_shead);
1416 spin_init(&unp_spin, "unpinit");
1417 }
1418
1419 static int
1420 unp_internalize(struct mbuf *control, struct thread *td)
1421 {
1422 struct proc *p = td->td_proc;
1423 struct filedesc *fdescp;
1424 struct cmsghdr *cm = mtod(control, struct cmsghdr *);
1425 struct file **rp;
1426 struct file *fp;
1427 int i, fd, *fdp;
1428 struct cmsgcred *cmcred;
1429 int oldfds;
1430 u_int newlen;
1431 int error;
1432
1433 KKASSERT(p);
1434 lwkt_gettoken(&unp_token);
1435
1436 fdescp = p->p_fd;
1437 if ((cm->cmsg_type != SCM_RIGHTS && cm->cmsg_type != SCM_CREDS) ||
1438 cm->cmsg_level != SOL_SOCKET ||
1439 CMSG_ALIGN(cm->cmsg_len) != control->m_len) {
1440 error = EINVAL;
1441 goto done;
1442 }
1443
1444 /*
1445 * Fill in credential information.
1446 */
1447 if (cm->cmsg_type == SCM_CREDS) {
1448 cmcred = (struct cmsgcred *)CMSG_DATA(cm);
1449 cmcred->cmcred_pid = p->p_pid;
1450 cmcred->cmcred_uid = p->p_ucred->cr_ruid;
1451 cmcred->cmcred_gid = p->p_ucred->cr_rgid;
1452 cmcred->cmcred_euid = p->p_ucred->cr_uid;
1453 cmcred->cmcred_ngroups = MIN(p->p_ucred->cr_ngroups,
1454 CMGROUP_MAX);
1455 for (i = 0; i < cmcred->cmcred_ngroups; i++)
1456 cmcred->cmcred_groups[i] = p->p_ucred->cr_groups[i];
1457 error = 0;
1458 goto done;
1459 }
1460
1461 /*
1462 * cmsghdr may not be aligned, do not allow calculation(s) to
1463 * go negative.
1464 */
1465 if (cm->cmsg_len < CMSG_LEN(0)) {
1466 error = EINVAL;
1467 goto done;
1468 }
1469
1470 oldfds = (cm->cmsg_len - CMSG_LEN(0)) / sizeof (int);
1471
1472 /*
1473 * check that all the FDs passed in refer to legal OPEN files
1474 * If not, reject the entire operation.
1475 */
1476 fdp = (int *)CMSG_DATA(cm);
1477 for (i = 0; i < oldfds; i++) {
1478 fd = *fdp++;
1479 if ((unsigned)fd >= fdescp->fd_nfiles ||
1480 fdescp->fd_files[fd].fp == NULL) {
1481 error = EBADF;
1482 goto done;
1483 }
1484 if (fdescp->fd_files[fd].fp->f_type == DTYPE_KQUEUE) {
1485 error = EOPNOTSUPP;
1486 goto done;
1487 }
1488 }
1489 /*
1490 * Now replace the integer FDs with pointers to
1491 * the associated global file table entry..
1492 * Allocate a bigger buffer as necessary. But if an cluster is not
1493 * enough, return E2BIG.
1494 */
1495 newlen = CMSG_LEN(oldfds * sizeof(struct file *));
1496 if (newlen > MCLBYTES) {
1497 error = E2BIG;
1498 goto done;
1499 }
1500 if (newlen - control->m_len > M_TRAILINGSPACE(control)) {
1501 if (control->m_flags & M_EXT) {
1502 error = E2BIG;
1503 goto done;
1504 }
1505 MCLGET(control, MB_WAIT);
1506 if (!(control->m_flags & M_EXT)) {
1507 error = ENOBUFS;
1508 goto done;
1509 }
1510
1511 /* copy the data to the cluster */
1512 memcpy(mtod(control, char *), cm, cm->cmsg_len);
1513 cm = mtod(control, struct cmsghdr *);
1514 }
1515
1516 /*
1517 * Adjust length, in case sizeof(struct file *) and sizeof(int)
1518 * differs.
1519 */
1520 cm->cmsg_len = newlen;
1521 control->m_len = CMSG_ALIGN(newlen);
1522
1523 /*
1524 * Transform the file descriptors into struct file pointers.
1525 * If sizeof (struct file *) is bigger than or equal to sizeof int,
1526 * then do it in reverse order so that the int won't get until
1527 * we're done.
1528 * If sizeof (struct file *) is smaller than sizeof int, then
1529 * do it in forward order.
1530 */
1531 if (sizeof (struct file *) >= sizeof (int)) {
1532 fdp = (int *)CMSG_DATA(cm) + oldfds - 1;
1533 rp = (struct file **)CMSG_DATA(cm) + oldfds - 1;
1534 for (i = 0; i < oldfds; i++) {
1535 fp = fdescp->fd_files[*fdp--].fp;
1536 *rp-- = fp;
1537 fhold(fp);
1538 spin_lock(&unp_spin);
1539 fp->f_msgcount++;
1540 unp_rights++;
1541 spin_unlock(&unp_spin);
1542 }
1543 } else {
1544 fdp = (int *)CMSG_DATA(cm);
1545 rp = (struct file **)CMSG_DATA(cm);
1546 for (i = 0; i < oldfds; i++) {
1547 fp = fdescp->fd_files[*fdp++].fp;
1548 *rp++ = fp;
1549 fhold(fp);
1550 spin_lock(&unp_spin);
1551 fp->f_msgcount++;
1552 unp_rights++;
1553 spin_unlock(&unp_spin);
1554 }
1555 }
1556 error = 0;
1557 done:
1558 lwkt_reltoken(&unp_token);
1559 return error;
1560 }
1561
1562 /*
1563 * Garbage collect in-transit file descriptors that get lost due to
1564 * loops (i.e. when a socket is sent to another process over itself,
1565 * and more complex situations).
1566 *
1567 * NOT MPSAFE - TODO socket flush code and maybe closef. Rest is MPSAFE.
1568 */
1569
1570 struct unp_gc_info {
1571 struct file **extra_ref;
1572 struct file *locked_fp;
1573 int defer;
1574 int index;
1575 int maxindex;
1576 };
1577
1578 static void
1579 unp_gc(void)
1580 {
1581 struct unp_gc_info info;
1582 static boolean_t unp_gcing;
1583 struct file **fpp;
1584 int i;
1585
1586 /*
1587 * Only one gc can be in-progress at any given moment
1588 */
1589 spin_lock(&unp_spin);
1590 if (unp_gcing) {
1591 spin_unlock(&unp_spin);
1592 return;
1593 }
1594 unp_gcing = TRUE;
1595 spin_unlock(&unp_spin);
1596
1597 lwkt_gettoken(&unp_token);
1598
1599 /*
1600 * Before going through all this, set all FDs to be NOT defered
1601 * and NOT externally accessible (not marked). During the scan
1602 * a fd can be marked externally accessible but we may or may not
1603 * be able to immediately process it (controlled by FDEFER).
1604 *
1605 * If we loop sleep a bit. The complexity of the topology can cause
1606 * multiple loops. Also failure to acquire the socket's so_rcv
1607 * token can cause us to loop.
1608 */
1609 allfiles_scan_exclusive(unp_gc_clearmarks, NULL);
1610 do {
1611 info.defer = 0;
1612 allfiles_scan_exclusive(unp_gc_checkmarks, &info);
1613 if (info.defer)
1614 tsleep(&info, 0, "gcagain", 1);
1615 } while (info.defer);
1616
1617 /*
1618 * We grab an extra reference to each of the file table entries
1619 * that are not otherwise accessible and then free the rights
1620 * that are stored in messages on them.
1621 *
1622 * The bug in the orginal code is a little tricky, so I'll describe
1623 * what's wrong with it here.
1624 *
1625 * It is incorrect to simply unp_discard each entry for f_msgcount
1626 * times -- consider the case of sockets A and B that contain
1627 * references to each other. On a last close of some other socket,
1628 * we trigger a gc since the number of outstanding rights (unp_rights)
1629 * is non-zero. If during the sweep phase the gc code un_discards,
1630 * we end up doing a (full) closef on the descriptor. A closef on A
1631 * results in the following chain. Closef calls soo_close, which
1632 * calls soclose. Soclose calls first (through the switch
1633 * uipc_usrreq) unp_detach, which re-invokes unp_gc. Unp_gc simply
1634 * returns because the previous instance had set unp_gcing, and
1635 * we return all the way back to soclose, which marks the socket
1636 * with SS_NOFDREF, and then calls sofree. Sofree calls sorflush
1637 * to free up the rights that are queued in messages on the socket A,
1638 * i.e., the reference on B. The sorflush calls via the dom_dispose
1639 * switch unp_dispose, which unp_scans with unp_discard. This second
1640 * instance of unp_discard just calls closef on B.
1641 *
1642 * Well, a similar chain occurs on B, resulting in a sorflush on B,
1643 * which results in another closef on A. Unfortunately, A is already
1644 * being closed, and the descriptor has already been marked with
1645 * SS_NOFDREF, and soclose panics at this point.
1646 *
1647 * Here, we first take an extra reference to each inaccessible
1648 * descriptor. Then, we call sorflush ourself, since we know
1649 * it is a Unix domain socket anyhow. After we destroy all the
1650 * rights carried in messages, we do a last closef to get rid
1651 * of our extra reference. This is the last close, and the
1652 * unp_detach etc will shut down the socket.
1653 *
1654 * 91/09/19, bsy@cs.cmu.edu
1655 */
1656 info.extra_ref = kmalloc(256 * sizeof(struct file *), M_FILE, M_WAITOK);
1657 info.maxindex = 256;
1658
1659 do {
1660 /*
1661 * Look for matches
1662 */
1663 info.index = 0;
1664 allfiles_scan_exclusive(unp_gc_checkrefs, &info);
1665
1666 /*
1667 * For each FD on our hit list, do the following two things
1668 */
1669 for (i = info.index, fpp = info.extra_ref; --i >= 0; ++fpp) {
1670 struct file *tfp = *fpp;
1671 if (tfp->f_type == DTYPE_SOCKET && tfp->f_data != NULL)
1672 sorflush((struct socket *)(tfp->f_data));
1673 }
1674 for (i = info.index, fpp = info.extra_ref; --i >= 0; ++fpp)
1675 closef(*fpp, NULL);
1676 } while (info.index == info.maxindex);
1677
1678 lwkt_reltoken(&unp_token);
1679
1680 kfree((caddr_t)info.extra_ref, M_FILE);
1681 unp_gcing = FALSE;
1682 }
1683
1684 /*
1685 * MPSAFE - NOTE: filehead list and file pointer spinlocked on entry
1686 */
1687 static int
1688 unp_gc_checkrefs(struct file *fp, void *data)
1689 {
1690 struct unp_gc_info *info = data;
1691
1692 if (fp->f_count == 0)
1693 return(0);
1694 if (info->index == info->maxindex)
1695 return(-1);
1696
1697 /*
1698 * If all refs are from msgs, and it's not marked accessible
1699 * then it must be referenced from some unreachable cycle
1700 * of (shut-down) FDs, so include it in our
1701 * list of FDs to remove
1702 */
1703 if (fp->f_count == fp->f_msgcount && !(fp->f_flag & FMARK)) {
1704 info->extra_ref[info->index++] = fp;
1705 fhold(fp);
1706 }
1707 return(0);
1708 }
1709
1710 /*
1711 * MPSAFE - NOTE: filehead list and file pointer spinlocked on entry
1712 */
1713 static int
1714 unp_gc_clearmarks(struct file *fp, void *data __unused)
1715 {
1716 atomic_clear_int(&fp->f_flag, FMARK | FDEFER);
1717 return(0);
1718 }
1719
1720 /*
1721 * MPSAFE - NOTE: filehead list and file pointer spinlocked on entry
1722 */
1723 static int
1724 unp_gc_checkmarks(struct file *fp, void *data)
1725 {
1726 struct unp_gc_info *info = data;
1727 struct socket *so;
1728
1729 /*
1730 * If the file is not open, skip it. Make sure it isn't marked
1731 * defered or we could loop forever, in case we somehow race
1732 * something.
1733 */
1734 if (fp->f_count == 0) {
1735 if (fp->f_flag & FDEFER)
1736 atomic_clear_int(&fp->f_flag, FDEFER);
1737 return(0);
1738 }
1739 /*
1740 * If we already marked it as 'defer' in a
1741 * previous pass, then try process it this time
1742 * and un-mark it
1743 */
1744 if (fp->f_flag & FDEFER) {
1745 atomic_clear_int(&fp->f_flag, FDEFER);
1746 } else {
1747 /*
1748 * if it's not defered, then check if it's
1749 * already marked.. if so skip it
1750 */
1751 if (fp->f_flag & FMARK)
1752 return(0);
1753 /*
1754 * If all references are from messages
1755 * in transit, then skip it. it's not
1756 * externally accessible.
1757 */
1758 if (fp->f_count == fp->f_msgcount)
1759 return(0);
1760 /*
1761 * If it got this far then it must be
1762 * externally accessible.
1763 */
1764 atomic_set_int(&fp->f_flag, FMARK);
1765 }
1766
1767 /*
1768 * either it was defered, or it is externally
1769 * accessible and not already marked so.
1770 * Now check if it is possibly one of OUR sockets.
1771 */
1772 if (fp->f_type != DTYPE_SOCKET ||
1773 (so = (struct socket *)fp->f_data) == NULL) {
1774 return(0);
1775 }
1776 if (so->so_proto->pr_domain != &localdomain ||
1777 !(so->so_proto->pr_flags & PR_RIGHTS)) {
1778 return(0);
1779 }
1780
1781 /*
1782 * So, Ok, it's one of our sockets and it IS externally accessible
1783 * (or was defered). Now we look to see if we hold any file
1784 * descriptors in its message buffers. Follow those links and mark
1785 * them as accessible too.
1786 *
1787 * We are holding multiple spinlocks here, if we cannot get the
1788 * token non-blocking defer until the next loop.
1789 */
1790 info->locked_fp = fp;
1791 if (lwkt_trytoken(&so->so_rcv.ssb_token)) {
1792 unp_scan(so->so_rcv.ssb_mb, unp_mark, info);
1793 lwkt_reltoken(&so->so_rcv.ssb_token);
1794 } else {
1795 atomic_set_int(&fp->f_flag, FDEFER);
1796 ++info->defer;
1797 }
1798 return (0);
1799 }
1800
1801 /*
1802 * Scan all unix domain sockets and replace any revoked file pointers
1803 * found with the dummy file pointer fx. We don't worry about races
1804 * against file pointers being read out as those are handled in the
1805 * externalize code.
1806 */
1807
1808 #define REVOKE_GC_MAXFILES 32
1809
1810 struct unp_revoke_gc_info {
1811 struct file *fx;
1812 struct file *fary[REVOKE_GC_MAXFILES];
1813 int fcount;
1814 };
1815
1816 void
1817 unp_revoke_gc(struct file *fx)
1818 {
1819 struct unp_revoke_gc_info info;
1820 int i;
1821
1822 lwkt_gettoken(&unp_token);
1823 info.fx = fx;
1824 do {
1825 info.fcount = 0;
1826 allfiles_scan_exclusive(unp_revoke_gc_check, &info);
1827 for (i = 0; i < info.fcount; ++i)
1828 unp_fp_externalize(NULL, info.fary[i], -1);
1829 } while (info.fcount == REVOKE_GC_MAXFILES);
1830 lwkt_reltoken(&unp_token);
1831 }
1832
1833 /*
1834 * Check for and replace revoked descriptors.
1835 *
1836 * WARNING: This routine is not allowed to block.
1837 */
1838 static int
1839 unp_revoke_gc_check(struct file *fps, void *vinfo)
1840 {
1841 struct unp_revoke_gc_info *info = vinfo;
1842 struct file *fp;
1843 struct socket *so;
1844 struct mbuf *m0;
1845 struct mbuf *m;
1846 struct file **rp;
1847 struct cmsghdr *cm;
1848 int i;
1849 int qfds;
1850
1851 /*
1852 * Is this a unix domain socket with rights-passing abilities?
1853 */
1854 if (fps->f_type != DTYPE_SOCKET)
1855 return (0);
1856 if ((so = (struct socket *)fps->f_data) == NULL)
1857 return(0);
1858 if (so->so_proto->pr_domain != &localdomain)
1859 return(0);
1860 if ((so->so_proto->pr_flags & PR_RIGHTS) == 0)
1861 return(0);
1862
1863 /*
1864 * Scan the mbufs for control messages and replace any revoked
1865 * descriptors we find.
1866 */
1867 lwkt_gettoken(&so->so_rcv.ssb_token);
1868 m0 = so->so_rcv.ssb_mb;
1869 while (m0) {
1870 for (m = m0; m; m = m->m_next) {
1871 if (m->m_type != MT_CONTROL)
1872 continue;
1873 if (m->m_len < sizeof(*cm))
1874 continue;
1875 cm = mtod(m, struct cmsghdr *);
1876 if (cm->cmsg_level != SOL_SOCKET ||
1877 cm->cmsg_type != SCM_RIGHTS) {
1878 continue;
1879 }
1880 qfds = (cm->cmsg_len - CMSG_LEN(0)) / sizeof(void *);
1881 rp = (struct file **)CMSG_DATA(cm);
1882 for (i = 0; i < qfds; i++) {
1883 fp = rp[i];
1884 if (fp->f_flag & FREVOKED) {
1885 kprintf("Warning: Removing revoked fp from unix domain socket queue\n");
1886 fhold(info->fx);
1887 info->fx->f_msgcount++;
1888 unp_rights++;
1889 rp[i] = info->fx;
1890 info->fary[info->fcount++] = fp;
1891 }
1892 if (info->fcount == REVOKE_GC_MAXFILES)
1893 break;
1894 }
1895 if (info->fcount == REVOKE_GC_MAXFILES)
1896 break;
1897 }
1898 m0 = m0->m_nextpkt;
1899 if (info->fcount == REVOKE_GC_MAXFILES)
1900 break;
1901 }
1902 lwkt_reltoken(&so->so_rcv.ssb_token);
1903
1904 /*
1905 * Stop the scan if we filled up our array.
1906 */
1907 if (info->fcount == REVOKE_GC_MAXFILES)
1908 return(-1);
1909 return(0);
1910 }
1911
1912 /*
1913 * Dispose of the fp's stored in a mbuf.
1914 *
1915 * The dds loop can cause additional fps to be entered onto the
1916 * list while it is running, flattening out the operation and avoiding
1917 * a deep kernel stack recursion.
1918 */
1919 void
1920 unp_dispose(struct mbuf *m)
1921 {
1922 unp_defdiscard_t dds;
1923
1924 lwkt_gettoken(&unp_token);
1925 ++unp_defdiscard_nest;
1926 if (m) {
1927 unp_scan(m, unp_discard, NULL);
1928 }
1929 if (unp_defdiscard_nest == 1) {
1930 while ((dds = unp_defdiscard_base) != NULL) {
1931 unp_defdiscard_base = dds->next;
1932 closef(dds->fp, NULL);
1933 kfree(dds, M_UNPCB);
1934 }
1935 }
1936 --unp_defdiscard_nest;
1937 lwkt_reltoken(&unp_token);
1938 }
1939
1940 static int
1941 unp_listen(struct unpcb *unp, struct thread *td)
1942 {
1943 struct proc *p = td->td_proc;
1944
1945 KKASSERT(p);
1946 lwkt_gettoken(&unp_token);
1947 cru2x(p->p_ucred, &unp->unp_peercred);
1948 unp->unp_flags |= UNP_HAVEPCCACHED;
1949 lwkt_reltoken(&unp_token);
1950 return (0);
1951 }
1952
1953 static void
1954 unp_scan(struct mbuf *m0, void (*op)(struct file *, void *), void *data)
1955 {
1956 struct mbuf *m;
1957 struct file **rp;
1958 struct cmsghdr *cm;
1959 int i;
1960 int qfds;
1961
1962 while (m0) {
1963 for (m = m0; m; m = m->m_next) {
1964 if (m->m_type == MT_CONTROL &&
1965 m->m_len >= sizeof(*cm)) {
1966 cm = mtod(m, struct cmsghdr *);
1967 if (cm->cmsg_level != SOL_SOCKET ||
1968 cm->cmsg_type != SCM_RIGHTS)
1969 continue;
1970 qfds = (cm->cmsg_len - CMSG_LEN(0)) /
1971 sizeof(void *);
1972 rp = (struct file **)CMSG_DATA(cm);
1973 for (i = 0; i < qfds; i++)
1974 (*op)(*rp++, data);
1975 break; /* XXX, but saves time */
1976 }
1977 }
1978 m0 = m0->m_nextpkt;
1979 }
1980 }
1981
1982 /*
1983 * Mark visibility. info->defer is recalculated on every pass.
1984 */
1985 static void
1986 unp_mark(struct file *fp, void *data)
1987 {
1988 struct unp_gc_info *info = data;
1989
1990 if ((fp->f_flag & FMARK) == 0) {
1991 ++info->defer;
1992 atomic_set_int(&fp->f_flag, FMARK | FDEFER);
1993 } else if (fp->f_flag & FDEFER) {
1994 ++info->defer;
1995 }
1996 }
1997
1998 /*
1999 * Discard a fp previously held in a unix domain socket mbuf. To
2000 * avoid blowing out the kernel stack due to contrived chain-reactions
2001 * we may have to defer the operation to a higher procedural level.
2002 *
2003 * Caller holds unp_token
2004 */
2005 static void
2006 unp_discard(struct file *fp, void *data __unused)
2007 {
2008 unp_defdiscard_t dds;
2009
2010 spin_lock(&unp_spin);
2011 fp->f_msgcount--;
2012 unp_rights--;
2013 spin_unlock(&unp_spin);
2014
2015 if (unp_defdiscard_nest) {
2016 dds = kmalloc(sizeof(*dds), M_UNPCB, M_WAITOK|M_ZERO);
2017 dds->fp = fp;
2018 dds->next = unp_defdiscard_base;
2019 unp_defdiscard_base = dds;
2020 } else {
2021 closef(fp, NULL);
2022 }
2023 }
2024
DragonFly BSD