1 /* $NetBSD: uipc_usrreq.c,v 1.94.2.3 2009/04/10 20:32:04 snj Exp $ */
2
3 /*-
4 * Copyright (c) 1998, 2000, 2004 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9 * NASA Ames Research Center.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the NetBSD
22 * Foundation, Inc. and its contributors.
23 * 4. Neither the name of The NetBSD Foundation nor the names of its
24 * contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40 /*
41 * Copyright (c) 1982, 1986, 1989, 1991, 1993
42 * The Regents of the University of California. All rights reserved.
43 *
44 * Redistribution and use in source and binary forms, with or without
45 * modification, are permitted provided that the following conditions
46 * are met:
47 * 1. Redistributions of source code must retain the above copyright
48 * notice, this list of conditions and the following disclaimer.
49 * 2. Redistributions in binary form must reproduce the above copyright
50 * notice, this list of conditions and the following disclaimer in the
51 * documentation and/or other materials provided with the distribution.
52 * 3. Neither the name of the University nor the names of its contributors
53 * may be used to endorse or promote products derived from this software
54 * without specific prior written permission.
55 *
56 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
57 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
58 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
59 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
60 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
61 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
62 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
63 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
64 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
65 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
66 * SUCH DAMAGE.
67 *
68 * @(#)uipc_usrreq.c 8.9 (Berkeley) 5/14/95
69 */
70
71 /*
72 * Copyright (c) 1997 Christopher G. Demetriou. All rights reserved.
73 *
74 * Redistribution and use in source and binary forms, with or without
75 * modification, are permitted provided that the following conditions
76 * are met:
77 * 1. Redistributions of source code must retain the above copyright
78 * notice, this list of conditions and the following disclaimer.
79 * 2. Redistributions in binary form must reproduce the above copyright
80 * notice, this list of conditions and the following disclaimer in the
81 * documentation and/or other materials provided with the distribution.
82 * 3. All advertising materials mentioning features or use of this software
83 * must display the following acknowledgement:
84 * This product includes software developed by the University of
85 * California, Berkeley and its contributors.
86 * 4. Neither the name of the University nor the names of its contributors
87 * may be used to endorse or promote products derived from this software
88 * without specific prior written permission.
89 *
90 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
91 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
92 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
93 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
94 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
95 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
96 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
97 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
98 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
99 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
100 * SUCH DAMAGE.
101 *
102 * @(#)uipc_usrreq.c 8.9 (Berkeley) 5/14/95
103 */
104
105 #include <sys/cdefs.h>
106 __KERNEL_RCSID(0, "$NetBSD: uipc_usrreq.c,v 1.94.2.3 2009/04/10 20:32:04 snj Exp $");
107
108 #include <sys/param.h>
109 #include <sys/systm.h>
110 #include <sys/proc.h>
111 #include <sys/filedesc.h>
112 #include <sys/domain.h>
113 #include <sys/protosw.h>
114 #include <sys/socket.h>
115 #include <sys/socketvar.h>
116 #include <sys/unpcb.h>
117 #include <sys/un.h>
118 #include <sys/namei.h>
119 #include <sys/vnode.h>
120 #include <sys/file.h>
121 #include <sys/stat.h>
122 #include <sys/mbuf.h>
123 #include <sys/kauth.h>
124
125 /*
126 * Unix communications domain.
127 *
128 * TODO:
129 * SEQPACKET, RDM
130 * rethink name space problems
131 * need a proper out-of-band
132 */
133 const struct sockaddr_un sun_noname = {
134 .sun_len = sizeof(sun_noname),
135 .sun_family = AF_LOCAL,
136 };
137 ino_t unp_ino; /* prototype for fake inode numbers */
138
139 struct mbuf *unp_addsockcred(struct lwp *, struct mbuf *);
140
141 int
142 unp_output(struct mbuf *m, struct mbuf *control, struct unpcb *unp,
143 struct lwp *l)
144 {
145 struct socket *so2;
146 const struct sockaddr_un *sun;
147
148 so2 = unp->unp_conn->unp_socket;
149 if (unp->unp_addr)
150 sun = unp->unp_addr;
151 else
152 sun = &sun_noname;
153 if (unp->unp_conn->unp_flags & UNP_WANTCRED)
154 control = unp_addsockcred(l, control);
155 if (sbappendaddr(&so2->so_rcv, (const struct sockaddr *)sun, m,
156 control) == 0) {
157 unp_dispose(control);
158 m_freem(control);
159 m_freem(m);
160 so2->so_rcv.sb_overflowed++;
161 return (ENOBUFS);
162 } else {
163 sorwakeup(so2);
164 return (0);
165 }
166 }
167
168 void
169 unp_setsockaddr(struct unpcb *unp, struct mbuf *nam)
170 {
171 const struct sockaddr_un *sun;
172
173 if (unp->unp_addr)
174 sun = unp->unp_addr;
175 else
176 sun = &sun_noname;
177 nam->m_len = sun->sun_len;
178 if (nam->m_len > MLEN)
179 MEXTMALLOC(nam, nam->m_len, M_WAITOK);
180 memcpy(mtod(nam, caddr_t), sun, (size_t)nam->m_len);
181 }
182
183 void
184 unp_setpeeraddr(struct unpcb *unp, struct mbuf *nam)
185 {
186 const struct sockaddr_un *sun;
187
188 if (unp->unp_conn && unp->unp_conn->unp_addr)
189 sun = unp->unp_conn->unp_addr;
190 else
191 sun = &sun_noname;
192 nam->m_len = sun->sun_len;
193 if (nam->m_len > MLEN)
194 MEXTMALLOC(nam, nam->m_len, M_WAITOK);
195 memcpy(mtod(nam, caddr_t), sun, (size_t)nam->m_len);
196 }
197
198 /*ARGSUSED*/
199 int
200 uipc_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam,
201 struct mbuf *control, struct lwp *l)
202 {
203 struct unpcb *unp = sotounpcb(so);
204 struct socket *so2;
205 struct proc *p;
206 u_int newhiwat;
207 int error = 0;
208
209 if (req == PRU_CONTROL)
210 return (EOPNOTSUPP);
211
212 #ifdef DIAGNOSTIC
213 if (req != PRU_SEND && req != PRU_SENDOOB && control)
214 panic("uipc_usrreq: unexpected control mbuf");
215 #endif
216 p = l ? l->l_proc : NULL;
217 if (unp == 0 && req != PRU_ATTACH) {
218 error = EINVAL;
219 goto release;
220 }
221
222 switch (req) {
223
224 case PRU_ATTACH:
225 if (unp != 0) {
226 error = EISCONN;
227 break;
228 }
229 error = unp_attach(so);
230 break;
231
232 case PRU_DETACH:
233 unp_detach(unp);
234 break;
235
236 case PRU_BIND:
237 KASSERT(l != NULL);
238 error = unp_bind(unp, nam, l);
239 break;
240
241 case PRU_LISTEN:
242 if (unp->unp_vnode == 0)
243 error = EINVAL;
244 break;
245
246 case PRU_CONNECT:
247 KASSERT(l != NULL);
248 error = unp_connect(so, nam, l);
249 break;
250
251 case PRU_CONNECT2:
252 error = unp_connect2(so, (struct socket *)nam, PRU_CONNECT2);
253 break;
254
255 case PRU_DISCONNECT:
256 unp_disconnect(unp);
257 break;
258
259 case PRU_ACCEPT:
260 unp_setpeeraddr(unp, nam);
261 /*
262 * Mark the initiating STREAM socket as connected *ONLY*
263 * after it's been accepted. This prevents a client from
264 * overrunning a server and receiving ECONNREFUSED.
265 */
266 if (unp->unp_conn != NULL &&
267 (unp->unp_conn->unp_socket->so_state & SS_ISCONNECTING))
268 soisconnected(unp->unp_conn->unp_socket);
269 break;
270
271 case PRU_SHUTDOWN:
272 socantsendmore(so);
273 unp_shutdown(unp);
274 break;
275
276 case PRU_RCVD:
277 switch (so->so_type) {
278
279 case SOCK_DGRAM:
280 panic("uipc 1");
281 /*NOTREACHED*/
282
283 case SOCK_STREAM:
284 #define rcv (&so->so_rcv)
285 #define snd (&so2->so_snd)
286 if (unp->unp_conn == 0)
287 break;
288 so2 = unp->unp_conn->unp_socket;
289 /*
290 * Adjust backpressure on sender
291 * and wakeup any waiting to write.
292 */
293 snd->sb_mbmax += unp->unp_mbcnt - rcv->sb_mbcnt;
294 unp->unp_mbcnt = rcv->sb_mbcnt;
295 newhiwat = snd->sb_hiwat + unp->unp_cc - rcv->sb_cc;
296 (void)chgsbsize(so2->so_uidinfo,
297 &snd->sb_hiwat, newhiwat, RLIM_INFINITY);
298 unp->unp_cc = rcv->sb_cc;
299 sowwakeup(so2);
300 #undef snd
301 #undef rcv
302 break;
303
304 default:
305 panic("uipc 2");
306 }
307 break;
308
309 case PRU_SEND:
310 /*
311 * Note: unp_internalize() rejects any control message
312 * other than SCM_RIGHTS, and only allows one. This
313 * has the side-effect of preventing a caller from
314 * forging SCM_CREDS.
315 */
316 if (control) {
317 KASSERT(l != NULL);
318 if ((error = unp_internalize(control, l)) != 0) {
319 m_freem(control);
320 m_freem(m);
321 break;
322 }
323 }
324 switch (so->so_type) {
325
326 case SOCK_DGRAM: {
327 if (nam) {
328 if ((so->so_state & SS_ISCONNECTED) != 0)
329 error = EISCONN;
330 else {
331 KASSERT(l != NULL);
332 error = unp_connect(so, nam, l);
333 }
334 } else {
335 if ((so->so_state & SS_ISCONNECTED) == 0)
336 error = ENOTCONN;
337 }
338 if (error) {
339 unp_dispose(control);
340 m_freem(control);
341 m_freem(m);
342 break;
343 }
344 KASSERT(p != NULL);
345 error = unp_output(m, control, unp, l);
346 if (nam)
347 unp_disconnect(unp);
348 break;
349 }
350
351 case SOCK_STREAM:
352 #define rcv (&so2->so_rcv)
353 #define snd (&so->so_snd)
354 if (unp->unp_conn == NULL) {
355 error = ENOTCONN;
356 break;
357 }
358 so2 = unp->unp_conn->unp_socket;
359 if (unp->unp_conn->unp_flags & UNP_WANTCRED) {
360 /*
361 * Credentials are passed only once on
362 * SOCK_STREAM.
363 */
364 unp->unp_conn->unp_flags &= ~UNP_WANTCRED;
365 control = unp_addsockcred(l, control);
366 }
367 /*
368 * Send to paired receive port, and then reduce
369 * send buffer hiwater marks to maintain backpressure.
370 * Wake up readers.
371 */
372 if (control) {
373 if (sbappendcontrol(rcv, m, control) == 0) {
374 unp_dispose(control);
375 m_freem(control);
376 }
377 } else
378 sbappend(rcv, m);
379 snd->sb_mbmax -=
380 rcv->sb_mbcnt - unp->unp_conn->unp_mbcnt;
381 unp->unp_conn->unp_mbcnt = rcv->sb_mbcnt;
382 newhiwat = snd->sb_hiwat -
383 (rcv->sb_cc - unp->unp_conn->unp_cc);
384 (void)chgsbsize(so->so_uidinfo,
385 &snd->sb_hiwat, newhiwat, RLIM_INFINITY);
386 unp->unp_conn->unp_cc = rcv->sb_cc;
387 sorwakeup(so2);
388 #undef snd
389 #undef rcv
390 break;
391
392 default:
393 panic("uipc 4");
394 }
395 break;
396
397 case PRU_ABORT:
398 unp_drop(unp, ECONNABORTED);
399
400 KASSERT(so->so_head == NULL);
401 #ifdef DIAGNOSTIC
402 if (so->so_pcb == 0)
403 panic("uipc 5: drop killed pcb");
404 #endif
405 unp_detach(unp);
406 break;
407
408 case PRU_SENSE:
409 ((struct stat *) m)->st_blksize = so->so_snd.sb_hiwat;
410 if (so->so_type == SOCK_STREAM && unp->unp_conn != 0) {
411 so2 = unp->unp_conn->unp_socket;
412 ((struct stat *) m)->st_blksize += so2->so_rcv.sb_cc;
413 }
414 ((struct stat *) m)->st_dev = NODEV;
415 if (unp->unp_ino == 0)
416 unp->unp_ino = unp_ino++;
417 ((struct stat *) m)->st_atimespec =
418 ((struct stat *) m)->st_mtimespec =
419 ((struct stat *) m)->st_ctimespec = unp->unp_ctime;
420 ((struct stat *) m)->st_ino = unp->unp_ino;
421 return (0);
422
423 case PRU_RCVOOB:
424 error = EOPNOTSUPP;
425 break;
426
427 case PRU_SENDOOB:
428 m_freem(control);
429 m_freem(m);
430 error = EOPNOTSUPP;
431 break;
432
433 case PRU_SOCKADDR:
434 unp_setsockaddr(unp, nam);
435 break;
436
437 case PRU_PEERADDR:
438 unp_setpeeraddr(unp, nam);
439 break;
440
441 default:
442 panic("piusrreq");
443 }
444
445 release:
446 return (error);
447 }
448
449 /*
450 * Unix domain socket option processing.
451 */
452 int
453 uipc_ctloutput(int op, struct socket *so, int level, int optname,
454 struct mbuf **mp)
455 {
456 struct unpcb *unp = sotounpcb(so);
457 struct mbuf *m = *mp;
458 int optval = 0, error = 0;
459
460 if (level != 0) {
461 error = EINVAL;
462 if (op == PRCO_SETOPT && m)
463 (void) m_free(m);
464 } else switch (op) {
465
466 case PRCO_SETOPT:
467 switch (optname) {
468 case LOCAL_CREDS:
469 case LOCAL_CONNWAIT:
470 if (m == NULL || m->m_len != sizeof(int))
471 error = EINVAL;
472 else {
473 optval = *mtod(m, int *);
474 switch (optname) {
475 #define OPTSET(bit) \
476 if (optval) \
477 unp->unp_flags |= (bit); \
478 else \
479 unp->unp_flags &= ~(bit);
480
481 case LOCAL_CREDS:
482 OPTSET(UNP_WANTCRED);
483 break;
484 case LOCAL_CONNWAIT:
485 OPTSET(UNP_CONNWAIT);
486 break;
487 }
488 }
489 break;
490 #undef OPTSET
491
492 default:
493 error = ENOPROTOOPT;
494 break;
495 }
496 if (m)
497 (void) m_free(m);
498 break;
499
500 case PRCO_GETOPT:
501 switch (optname) {
502 case LOCAL_CREDS:
503 *mp = m = m_get(M_WAIT, MT_SOOPTS);
504 m->m_len = sizeof(int);
505 switch (optname) {
506
507 #define OPTBIT(bit) (unp->unp_flags & (bit) ? 1 : 0)
508
509 case LOCAL_CREDS:
510 optval = OPTBIT(UNP_WANTCRED);
511 break;
512 }
513 *mtod(m, int *) = optval;
514 break;
515 #undef OPTBIT
516
517 default:
518 error = ENOPROTOOPT;
519 break;
520 }
521 break;
522 }
523 return (error);
524 }
525
526 /*
527 * Both send and receive buffers are allocated PIPSIZ bytes of buffering
528 * for stream sockets, although the total for sender and receiver is
529 * actually only PIPSIZ.
530 * Datagram sockets really use the sendspace as the maximum datagram size,
531 * and don't really want to reserve the sendspace. Their recvspace should
532 * be large enough for at least one max-size datagram plus address.
533 */
534 #define PIPSIZ 4096
535 u_long unpst_sendspace = PIPSIZ;
536 u_long unpst_recvspace = PIPSIZ;
537 u_long unpdg_sendspace = 2*1024; /* really max datagram size */
538 u_long unpdg_recvspace = 4*1024;
539
540 int unp_rights; /* file descriptors in flight */
541 int unp_rights_ratio = 2; /* limit, fraction of maxfiles */
542
543 int
544 unp_attach(struct socket *so)
545 {
546 struct unpcb *unp;
547 int error;
548
549 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
550 switch (so->so_type) {
551
552 case SOCK_STREAM:
553 error = soreserve(so, unpst_sendspace, unpst_recvspace);
554 break;
555
556 case SOCK_DGRAM:
557 error = soreserve(so, unpdg_sendspace, unpdg_recvspace);
558 break;
559
560 default:
561 panic("unp_attach");
562 }
563 if (error)
564 return (error);
565 }
566 unp = malloc(sizeof(*unp), M_PCB, M_NOWAIT);
567 if (unp == NULL)
568 return (ENOBUFS);
569 memset((caddr_t)unp, 0, sizeof(*unp));
570 unp->unp_socket = so;
571 so->so_pcb = unp;
572 nanotime(&unp->unp_ctime);
573 return (0);
574 }
575
576 void
577 unp_detach(struct unpcb *unp)
578 {
579
580 if (unp->unp_vnode) {
581 unp->unp_vnode->v_socket = 0;
582 vrele(unp->unp_vnode);
583 unp->unp_vnode = 0;
584 }
585 if (unp->unp_conn)
586 unp_disconnect(unp);
587 while (unp->unp_refs)
588 unp_drop(unp->unp_refs, ECONNRESET);
589 soisdisconnected(unp->unp_socket);
590 unp->unp_socket->so_pcb = 0;
591 if (unp->unp_addr)
592 free(unp->unp_addr, M_SONAME);
593 if (unp_rights) {
594 /*
595 * Normally the receive buffer is flushed later,
596 * in sofree, but if our receive buffer holds references
597 * to descriptors that are now garbage, we will dispose
598 * of those descriptor references after the garbage collector
599 * gets them (resulting in a "panic: closef: count < 0").
600 */
601 sorflush(unp->unp_socket);
602 free(unp, M_PCB);
603 unp_gc();
604 } else
605 free(unp, M_PCB);
606 }
607
608 int
609 unp_bind(struct unpcb *unp, struct mbuf *nam, struct lwp *l)
610 {
611 struct sockaddr_un *sun;
612 struct vnode *vp;
613 struct mount *mp;
614 struct vattr vattr;
615 size_t addrlen;
616 struct proc *p;
617 int error;
618 struct nameidata nd;
619
620 if (unp->unp_vnode != 0)
621 return (EINVAL);
622
623 p = l->l_proc;
624 /*
625 * Allocate the new sockaddr. We have to allocate one
626 * extra byte so that we can ensure that the pathname
627 * is nul-terminated.
628 */
629 addrlen = nam->m_len + 1;
630 sun = malloc(addrlen, M_SONAME, M_WAITOK);
631 m_copydata(nam, 0, nam->m_len, (caddr_t)sun);
632 *(((char *)sun) + nam->m_len) = '\0';
633
634 restart:
635 NDINIT(&nd, CREATE, FOLLOW | LOCKPARENT, UIO_SYSSPACE,
636 sun->sun_path, l);
637
638 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */
639 if ((error = namei(&nd)) != 0)
640 goto bad;
641 vp = nd.ni_vp;
642 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
643 VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
644 if (nd.ni_dvp == vp)
645 vrele(nd.ni_dvp);
646 else
647 vput(nd.ni_dvp);
648 vrele(vp);
649 if (vp != NULL) {
650 error = EADDRINUSE;
651 goto bad;
652 }
653 error = vn_start_write(NULL, &mp,
654 V_WAIT | V_SLEEPONLY | V_PCATCH);
655 if (error)
656 goto bad;
657 goto restart;
658 }
659 VATTR_NULL(&vattr);
660 vattr.va_type = VSOCK;
661 vattr.va_mode = ACCESSPERMS & ~(p->p_cwdi->cwdi_cmask);
662 VOP_LEASE(nd.ni_dvp, l, l->l_cred, LEASE_WRITE);
663 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
664 vn_finished_write(mp, 0);
665 if (error)
666 goto bad;
667 vp = nd.ni_vp;
668 vp->v_socket = unp->unp_socket;
669 unp->unp_vnode = vp;
670 unp->unp_addrlen = addrlen;
671 unp->unp_addr = sun;
672 VOP_UNLOCK(vp, 0);
673 return (0);
674
675 bad:
676 free(sun, M_SONAME);
677 return (error);
678 }
679
680 int
681 unp_connect(struct socket *so, struct mbuf *nam, struct lwp *l)
682 {
683 struct sockaddr_un *sun;
684 struct vnode *vp;
685 struct socket *so2, *so3;
686 struct unpcb *unp2, *unp3;
687 size_t addrlen;
688 int error;
689 struct nameidata nd;
690
691 /*
692 * Allocate a temporary sockaddr. We have to allocate one extra
693 * byte so that we can ensure that the pathname is nul-terminated.
694 * When we establish the connection, we copy the other PCB's
695 * sockaddr to our own.
696 */
697 addrlen = nam->m_len + 1;
698 sun = malloc(addrlen, M_SONAME, M_WAITOK);
699 m_copydata(nam, 0, nam->m_len, (caddr_t)sun);
700 *(((char *)sun) + nam->m_len) = '\0';
701
702 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, sun->sun_path, l);
703
704 if ((error = namei(&nd)) != 0)
705 goto bad2;
706 vp = nd.ni_vp;
707 if (vp->v_type != VSOCK) {
708 error = ENOTSOCK;
709 goto bad;
710 }
711 if ((error = VOP_ACCESS(vp, VWRITE, l->l_cred, l)) != 0)
712 goto bad;
713 so2 = vp->v_socket;
714 if (so2 == 0) {
715 error = ECONNREFUSED;
716 goto bad;
717 }
718 if (so->so_type != so2->so_type) {
719 error = EPROTOTYPE;
720 goto bad;
721 }
722 if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
723 if ((so2->so_options & SO_ACCEPTCONN) == 0 ||
724 (so3 = sonewconn(so2, 0)) == 0) {
725 error = ECONNREFUSED;
726 goto bad;
727 }
728 unp2 = sotounpcb(so2);
729 unp3 = sotounpcb(so3);
730 if (unp2->unp_addr) {
731 unp3->unp_addr = malloc(unp2->unp_addrlen,
732 M_SONAME, M_WAITOK);
733 memcpy(unp3->unp_addr, unp2->unp_addr,
734 unp2->unp_addrlen);
735 unp3->unp_addrlen = unp2->unp_addrlen;
736 }
737 unp3->unp_flags = unp2->unp_flags;
738 so2 = so3;
739 }
740 error = unp_connect2(so, so2, PRU_CONNECT);
741 bad:
742 vput(vp);
743 bad2:
744 free(sun, M_SONAME);
745 return (error);
746 }
747
748 int
749 unp_connect2(struct socket *so, struct socket *so2, int req)
750 {
751 struct unpcb *unp = sotounpcb(so);
752 struct unpcb *unp2;
753
754 if (so2->so_type != so->so_type)
755 return (EPROTOTYPE);
756 unp2 = sotounpcb(so2);
757 unp->unp_conn = unp2;
758 switch (so->so_type) {
759
760 case SOCK_DGRAM:
761 unp->unp_nextref = unp2->unp_refs;
762 unp2->unp_refs = unp;
763 soisconnected(so);
764 break;
765
766 case SOCK_STREAM:
767 unp2->unp_conn = unp;
768 if (req == PRU_CONNECT &&
769 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT))
770 soisconnecting(so);
771 else
772 soisconnected(so);
773 soisconnected(so2);
774 break;
775
776 default:
777 panic("unp_connect2");
778 }
779 return (0);
780 }
781
782 void
783 unp_disconnect(struct unpcb *unp)
784 {
785 struct unpcb *unp2 = unp->unp_conn;
786
787 if (unp2 == 0)
788 return;
789 unp->unp_conn = 0;
790 switch (unp->unp_socket->so_type) {
791
792 case SOCK_DGRAM:
793 if (unp2->unp_refs == unp)
794 unp2->unp_refs = unp->unp_nextref;
795 else {
796 unp2 = unp2->unp_refs;
797 for (;;) {
798 if (unp2 == 0)
799 panic("unp_disconnect");
800 if (unp2->unp_nextref == unp)
801 break;
802 unp2 = unp2->unp_nextref;
803 }
804 unp2->unp_nextref = unp->unp_nextref;
805 }
806 unp->unp_nextref = 0;
807 unp->unp_socket->so_state &= ~SS_ISCONNECTED;
808 break;
809
810 case SOCK_STREAM:
811 soisdisconnected(unp->unp_socket);
812 unp2->unp_conn = 0;
813 soisdisconnected(unp2->unp_socket);
814 break;
815 }
816 }
817
818 #ifdef notdef
819 unp_abort(struct unpcb *unp)
820 {
821 unp_detach(unp);
822 }
823 #endif
824
825 void
826 unp_shutdown(struct unpcb *unp)
827 {
828 struct socket *so;
829
830 if (unp->unp_socket->so_type == SOCK_STREAM && unp->unp_conn &&
831 (so = unp->unp_conn->unp_socket))
832 socantrcvmore(so);
833 }
834
835 void
836 unp_drop(struct unpcb *unp, int errno)
837 {
838 struct socket *so = unp->unp_socket;
839
840 so->so_error = errno;
841 unp_disconnect(unp);
842 if (so->so_head) {
843 so->so_pcb = 0;
844 sofree(so);
845 if (unp->unp_addr)
846 free(unp->unp_addr, M_SONAME);
847 free(unp, M_PCB);
848 }
849 }
850
851 #ifdef notdef
852 unp_drain(void)
853 {
854
855 }
856 #endif
857
858 int
859 unp_externalize(struct mbuf *rights, struct lwp *l)
860 {
861 struct cmsghdr *cm = mtod(rights, struct cmsghdr *);
862 struct proc *p = l->l_proc;
863 int i, *fdp;
864 struct file **rp;
865 struct file *fp;
866 int nfds, error = 0;
867
868 nfds = (cm->cmsg_len - CMSG_ALIGN(sizeof(*cm))) /
869 sizeof(struct file *);
870 rp = (struct file **)CMSG_DATA(cm);
871
872 fdp = malloc(nfds * sizeof(int), M_TEMP, M_WAITOK);
873
874 /* Make sure the recipient should be able to see the descriptors.. */
875 if (p->p_cwdi->cwdi_rdir != NULL) {
876 rp = (struct file **)CMSG_DATA(cm);
877 for (i = 0; i < nfds; i++) {
878 fp = *rp++;
879 /*
880 * If we are in a chroot'ed directory, and
881 * someone wants to pass us a directory, make
882 * sure it's inside the subtree we're allowed
883 * to access.
884 */
885 if (fp->f_type == DTYPE_VNODE) {
886 struct vnode *vp = (struct vnode *)fp->f_data;
887 if ((vp->v_type == VDIR) &&
888 !vn_isunder(vp, p->p_cwdi->cwdi_rdir, l)) {
889 error = EPERM;
890 break;
891 }
892 }
893 }
894 }
895
896 restart:
897 rp = (struct file **)CMSG_DATA(cm);
898 if (error != 0) {
899 for (i = 0; i < nfds; i++) {
900 fp = *rp;
901 /*
902 * zero the pointer before calling unp_discard,
903 * since it may end up in unp_gc()..
904 */
905 *rp++ = 0;
906 unp_discard(fp);
907 }
908 goto out;
909 }
910
911 /*
912 * First loop -- allocate file descriptor table slots for the
913 * new descriptors.
914 */
915 for (i = 0; i < nfds; i++) {
916 fp = *rp++;
917 if ((error = fdalloc(p, 0, &fdp[i])) != 0) {
918 /*
919 * Back out what we've done so far.
920 */
921 for (--i; i >= 0; i--)
922 fdremove(p->p_fd, fdp[i]);
923
924 if (error == ENOSPC) {
925 fdexpand(p);
926 error = 0;
927 } else {
928 /*
929 * This is the error that has historically
930 * been returned, and some callers may
931 * expect it.
932 */
933 error = EMSGSIZE;
934 }
935 goto restart;
936 }
937
938 /*
939 * Make the slot reference the descriptor so that
940 * fdalloc() works properly.. We finalize it all
941 * in the loop below.
942 */
943 p->p_fd->fd_ofiles[fdp[i]] = fp;
944 }
945
946 /*
947 * Now that adding them has succeeded, update all of the
948 * descriptor passing state.
949 */
950 rp = (struct file **)CMSG_DATA(cm);
951 for (i = 0; i < nfds; i++) {
952 fp = *rp++;
953 fp->f_msgcount--;
954 unp_rights--;
955 }
956
957 /*
958 * Copy temporary array to message and adjust length, in case of
959 * transition from large struct file pointers to ints.
960 */
961 memcpy(CMSG_DATA(cm), fdp, nfds * sizeof(int));
962 cm->cmsg_len = CMSG_LEN(nfds * sizeof(int));
963 rights->m_len = CMSG_SPACE(nfds * sizeof(int));
964 out:
965 free(fdp, M_TEMP);
966 return (error);
967 }
968
969 int
970 unp_internalize(struct mbuf *control, struct lwp *l)
971 {
972 struct proc *p = l->l_proc;
973 struct filedesc *fdescp = p->p_fd;
974 struct cmsghdr *newcm, *cm = mtod(control, struct cmsghdr *);
975 struct file **rp, **files;
976 struct file *fp;
977 int i, fd, *fdp;
978 int nfds;
979 u_int neededspace;
980 u_int maxmsg;
981
982 /* Sanity check the control message header */
983 if (cm->cmsg_type != SCM_RIGHTS || cm->cmsg_level != SOL_SOCKET ||
984 cm->cmsg_len != control->m_len)
985 return (EINVAL);
986
987 /* Verify that the file descriptors are valid */
988 nfds = (cm->cmsg_len - CMSG_ALIGN(sizeof(*cm))) / sizeof(int);
989
990 maxmsg = maxfiles / unp_rights_ratio;
991 if (unp_rights + nfds > maxmsg)
992 return (EAGAIN);
993
994 fdp = (int *)CMSG_DATA(cm);
995 for (i = 0; i < nfds; i++) {
996 fd = *fdp++;
997 if ((fp = fd_getfile(fdescp, fd)) == NULL)
998 return (EBADF);
999 simple_unlock(&fp->f_slock);
1000 }
1001
1002 /* Make sure we have room for the struct file pointers */
1003 neededspace = CMSG_SPACE(nfds * sizeof(struct file *)) -
1004 control->m_len;
1005 if (neededspace > M_TRAILINGSPACE(control)) {
1006
1007 /* allocate new space and copy header into it */
1008 newcm = malloc(
1009 CMSG_SPACE(nfds * sizeof(struct file *)),
1010 M_MBUF, M_WAITOK);
1011 if (newcm == NULL)
1012 return (E2BIG);
1013 memcpy(newcm, cm, sizeof(struct cmsghdr));
1014 files = (struct file **)CMSG_DATA(newcm);
1015 } else {
1016 /* we can convert in-place */
1017 newcm = NULL;
1018 files = (struct file **)CMSG_DATA(cm);
1019 }
1020
1021 /*
1022 * Transform the file descriptors into struct file pointers, in
1023 * reverse order so that if pointers are bigger than ints, the
1024 * int won't get until we're done.
1025 */
1026 fdp = (int *)CMSG_DATA(cm) + nfds;
1027 rp = files + nfds;
1028 for (i = 0; i < nfds; i++) {
1029 fp = fdescp->fd_ofiles[*--fdp];
1030 simple_lock(&fp->f_slock);
1031 #ifdef DIAGNOSTIC
1032 if (fp->f_iflags & FIF_WANTCLOSE)
1033 panic("unp_internalize: file already closed");
1034 #endif
1035 *--rp = fp;
1036 fp->f_count++;
1037 fp->f_msgcount++;
1038 simple_unlock(&fp->f_slock);
1039 unp_rights++;
1040 }
1041
1042 if (newcm) {
1043 if (control->m_flags & M_EXT)
1044 MEXTREMOVE(control);
1045 MEXTADD(control, newcm,
1046 CMSG_SPACE(nfds * sizeof(struct file *)),
1047 M_MBUF, NULL, NULL);
1048 cm = newcm;
1049 }
1050
1051 /* adjust message & mbuf to note amount of space actually used. */
1052 cm->cmsg_len = CMSG_LEN(nfds * sizeof(struct file *));
1053 control->m_len = CMSG_SPACE(nfds * sizeof(struct file *));
1054
1055 return (0);
1056 }
1057
1058 struct mbuf *
1059 unp_addsockcred(struct lwp *l, struct mbuf *control)
1060 {
1061 struct cmsghdr *cmp;
1062 struct sockcred *sc;
1063 struct mbuf *m, *n;
1064 int len, space, i;
1065
1066 len = CMSG_LEN(SOCKCREDSIZE(kauth_cred_ngroups(l->l_cred)));
1067 space = CMSG_SPACE(SOCKCREDSIZE(kauth_cred_ngroups(l->l_cred)));
1068
1069 m = m_get(M_WAIT, MT_CONTROL);
1070 if (space > MLEN) {
1071 if (space > MCLBYTES)
1072 MEXTMALLOC(m, space, M_WAITOK);
1073 else
1074 m_clget(m, M_WAIT);
1075 if ((m->m_flags & M_EXT) == 0) {
1076 m_free(m);
1077 return (control);
1078 }
1079 }
1080
1081 m->m_len = space;
1082 m->m_next = NULL;
1083 cmp = mtod(m, struct cmsghdr *);
1084 sc = (struct sockcred *)CMSG_DATA(cmp);
1085 cmp->cmsg_len = len;
1086 cmp->cmsg_level = SOL_SOCKET;
1087 cmp->cmsg_type = SCM_CREDS;
1088 sc->sc_uid = kauth_cred_getuid(l->l_cred);
1089 sc->sc_euid = kauth_cred_geteuid(l->l_cred);
1090 sc->sc_gid = kauth_cred_getgid(l->l_cred);
1091 sc->sc_egid = kauth_cred_getegid(l->l_cred);
1092 sc->sc_ngroups = kauth_cred_ngroups(l->l_cred);
1093 for (i = 0; i < sc->sc_ngroups; i++)
1094 sc->sc_groups[i] = kauth_cred_group(l->l_cred, i);
1095
1096 /*
1097 * If a control message already exists, append us to the end.
1098 */
1099 if (control != NULL) {
1100 for (n = control; n->m_next != NULL; n = n->m_next)
1101 ;
1102 n->m_next = m;
1103 } else
1104 control = m;
1105
1106 return (control);
1107 }
1108
1109 int unp_defer, unp_gcing;
1110 extern struct domain unixdomain;
1111
1112 /*
1113 * Comment added long after the fact explaining what's going on here.
1114 * Do a mark-sweep GC of file descriptors on the system, to free up
1115 * any which are caught in flight to an about-to-be-closed socket.
1116 *
1117 * Traditional mark-sweep gc's start at the "root", and mark
1118 * everything reachable from the root (which, in our case would be the
1119 * process table). The mark bits are cleared during the sweep.
1120 *
1121 * XXX For some inexplicable reason (perhaps because the file
1122 * descriptor tables used to live in the u area which could be swapped
1123 * out and thus hard to reach), we do multiple scans over the set of
1124 * descriptors, using use *two* mark bits per object (DEFER and MARK).
1125 * Whenever we find a descriptor which references other descriptors,
1126 * the ones it references are marked with both bits, and we iterate
1127 * over the whole file table until there are no more DEFER bits set.
1128 * We also make an extra pass *before* the GC to clear the mark bits,
1129 * which could have been cleared at almost no cost during the previous
1130 * sweep.
1131 *
1132 * XXX MP: this needs to run with locks such that no other thread of
1133 * control can create or destroy references to file descriptors. it
1134 * may be necessary to defer the GC until later (when the locking
1135 * situation is more hospitable); it may be necessary to push this
1136 * into a separate thread.
1137 */
1138 void
1139 unp_gc(void)
1140 {
1141 struct file *fp, *nextfp;
1142 struct socket *so, *so1;
1143 struct file **extra_ref, **fpp;
1144 int nunref, i;
1145
1146 if (unp_gcing)
1147 return;
1148 unp_gcing = 1;
1149 unp_defer = 0;
1150
1151 /* Clear mark bits */
1152 LIST_FOREACH(fp, &filehead, f_list)
1153 fp->f_flag &= ~(FMARK|FDEFER);
1154
1155 /*
1156 * Iterate over the set of descriptors, marking ones believed
1157 * (based on refcount) to be referenced from a process, and
1158 * marking for rescan descriptors which are queued on a socket.
1159 */
1160 do {
1161 LIST_FOREACH(fp, &filehead, f_list) {
1162 if (fp->f_flag & FDEFER) {
1163 fp->f_flag &= ~FDEFER;
1164 unp_defer--;
1165 #ifdef DIAGNOSTIC
1166 if (fp->f_count == 0)
1167 panic("unp_gc: deferred unreferenced socket");
1168 #endif
1169 } else {
1170 if (fp->f_count == 0)
1171 continue;
1172 if (fp->f_flag & FMARK)
1173 continue;
1174 if (fp->f_count == fp->f_msgcount)
1175 continue;
1176 }
1177 if (fp->f_iflags & FIF_DISCARDED)
1178 continue;
1179 fp->f_flag |= FMARK;
1180
1181 if (fp->f_type != DTYPE_SOCKET ||
1182 (so = (struct socket *)fp->f_data) == 0)
1183 continue;
1184 if (so->so_proto->pr_domain != &unixdomain ||
1185 (so->so_proto->pr_flags&PR_RIGHTS) == 0)
1186 continue;
1187 #ifdef notdef
1188 if (so->so_rcv.sb_flags & SB_LOCK) {
1189 /*
1190 * This is problematical; it's not clear
1191 * we need to wait for the sockbuf to be
1192 * unlocked (on a uniprocessor, at least),
1193 * and it's also not clear what to do
1194 * if sbwait returns an error due to receipt
1195 * of a signal. If sbwait does return
1196 * an error, we'll go into an infinite
1197 * loop. Delete all of this for now.
1198 */
1199 (void) sbwait(&so->so_rcv);
1200 goto restart;
1201 }
1202 #endif
1203 unp_scan(so->so_rcv.sb_mb, unp_mark, 0);
1204 /*
1205 * mark descriptors referenced from sockets queued on the accept queue as well.
1206 */
1207 if (so->so_options & SO_ACCEPTCONN) {
1208 TAILQ_FOREACH(so1, &so->so_q0, so_qe) {
1209 unp_scan(so1->so_rcv.sb_mb, unp_mark, 0);
1210 }
1211 TAILQ_FOREACH(so1, &so->so_q, so_qe) {
1212 unp_scan(so1->so_rcv.sb_mb, unp_mark, 0);
1213 }
1214 }
1215
1216 }
1217 } while (unp_defer);
1218 /*
1219 * Sweep pass. Find unmarked descriptors, and free them.
1220 *
1221 * We grab an extra reference to each of the file table entries
1222 * that are not otherwise accessible and then free the rights
1223 * that are stored in messages on them.
1224 *
1225 * The bug in the original code is a little tricky, so I'll describe
1226 * what's wrong with it here.
1227 *
1228 * It is incorrect to simply unp_discard each entry for f_msgcount
1229 * times -- consider the case of sockets A and B that contain
1230 * references to each other. On a last close of some other socket,
1231 * we trigger a gc since the number of outstanding rights (unp_rights)
1232 * is non-zero. If during the sweep phase the gc code un_discards,
1233 * we end up doing a (full) closef on the descriptor. A closef on A
1234 * results in the following chain. Closef calls soo_close, which
1235 * calls soclose. Soclose calls first (through the switch
1236 * uipc_usrreq) unp_detach, which re-invokes unp_gc. Unp_gc simply
1237 * returns because the previous instance had set unp_gcing, and
1238 * we return all the way back to soclose, which marks the socket
1239 * with SS_NOFDREF, and then calls sofree. Sofree calls sorflush
1240 * to free up the rights that are queued in messages on the socket A,
1241 * i.e., the reference on B. The sorflush calls via the dom_dispose
1242 * switch unp_dispose, which unp_scans with unp_discard. This second
1243 * instance of unp_discard just calls closef on B.
1244 *
1245 * Well, a similar chain occurs on B, resulting in a sorflush on B,
1246 * which results in another closef on A. Unfortunately, A is already
1247 * being closed, and the descriptor has already been marked with
1248 * SS_NOFDREF, and soclose panics at this point.
1249 *
1250 * Here, we first take an extra reference to each inaccessible
1251 * descriptor. Then, if the inaccessible descriptor is a
1252 * socket, we call sorflush in case it is a Unix domain
1253 * socket. After we destroy all the rights carried in
1254 * messages, we do a last closef to get rid of our extra
1255 * reference. This is the last close, and the unp_detach etc
1256 * will shut down the socket.
1257 *
1258 * 91/09/19, bsy@cs.cmu.edu
1259 */
1260 extra_ref = malloc(nfiles * sizeof(struct file *), M_FILE, M_WAITOK);
1261 for (nunref = 0, fp = LIST_FIRST(&filehead), fpp = extra_ref; fp != 0;
1262 fp = nextfp) {
1263 nextfp = LIST_NEXT(fp, f_list);
1264 simple_lock(&fp->f_slock);
1265 if (fp->f_count != 0 &&
1266 fp->f_count == fp->f_msgcount && !(fp->f_flag & FMARK)) {
1267 *fpp++ = fp;
1268 nunref++;
1269 fp->f_count++;
1270 }
1271 simple_unlock(&fp->f_slock);
1272 }
1273 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) {
1274 fp = *fpp;
1275 simple_lock(&fp->f_slock);
1276 FILE_USE(fp);
1277 if (fp->f_type == DTYPE_SOCKET)
1278 sorflush((struct socket *)fp->f_data);
1279 FILE_UNUSE(fp, NULL);
1280 }
1281 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) {
1282 fp = *fpp;
1283 simple_lock(&fp->f_slock);
1284 if (fp->f_iflags & FIF_DISCARDED) {
1285 fp->f_usecount++;
1286 fp->f_msgcount--;
1287 simple_unlock(&fp->f_slock);
1288 unp_rights--;
1289 (void) closef(fp, (struct lwp *)0);
1290 simple_lock(&fp->f_slock);
1291 }
1292 FILE_USE(fp);
1293 (void) closef(fp, (struct lwp *)0);
1294 }
1295 free((caddr_t)extra_ref, M_FILE);
1296 unp_gcing = 0;
1297 }
1298
1299 void
1300 unp_dispose(struct mbuf *m)
1301 {
1302
1303 if (m)
1304 unp_scan(m, unp_discard, 1);
1305 }
1306
1307 void
1308 unp_scan(struct mbuf *m0, void (*op)(struct file *), int discard)
1309 {
1310 struct mbuf *m;
1311 struct file **rp;
1312 struct cmsghdr *cm;
1313 int i;
1314 int qfds;
1315
1316 while (m0) {
1317 for (m = m0; m; m = m->m_next) {
1318 if (m->m_type == MT_CONTROL &&
1319 m->m_len >= sizeof(*cm)) {
1320 cm = mtod(m, struct cmsghdr *);
1321 if (cm->cmsg_level != SOL_SOCKET ||
1322 cm->cmsg_type != SCM_RIGHTS)
1323 continue;
1324 qfds = (cm->cmsg_len - CMSG_ALIGN(sizeof(*cm)))
1325 / sizeof(struct file *);
1326 rp = (struct file **)CMSG_DATA(cm);
1327 for (i = 0; i < qfds; i++) {
1328 struct file *fp = *rp;
1329 if (discard)
1330 *rp = 0;
1331 (*op)(fp);
1332 rp++;
1333 }
1334 break; /* XXX, but saves time */
1335 }
1336 }
1337 m0 = m0->m_nextpkt;
1338 }
1339 }
1340
1341 void
1342 unp_mark(struct file *fp)
1343 {
1344 if (fp == NULL)
1345 return;
1346
1347 if (fp->f_flag & FMARK)
1348 return;
1349
1350 /* If we're already deferred, don't screw up the defer count */
1351 if (fp->f_flag & FDEFER)
1352 return;
1353
1354 /*
1355 * Minimize the number of deferrals... Sockets are the only
1356 * type of descriptor which can hold references to another
1357 * descriptor, so just mark other descriptors, and defer
1358 * unmarked sockets for the next pass.
1359 */
1360 if (fp->f_type == DTYPE_SOCKET) {
1361 unp_defer++;
1362 if (fp->f_count == 0)
1363 panic("unp_mark: queued unref");
1364 fp->f_flag |= FDEFER;
1365 } else {
1366 fp->f_flag |= FMARK;
1367 }
1368 return;
1369 }
1370
1371 void
1372 unp_discard(struct file *fp)
1373 {
1374 if (fp == NULL)
1375 return;
1376
1377 simple_lock(&fp->f_slock);
1378 /*
1379 * closing unix domain sockets may cause a deep
1380 * recursion, so leave them open and mark them
1381 * for the garbage collector to discard them safely.
1382 */
1383 if (fp->f_type == DTYPE_SOCKET && fp->f_count == 1) {
1384 struct socket *so;
1385
1386 so = (struct socket *)fp->f_data;
1387 if (so && so->so_proto->pr_domain == &unixdomain &&
1388 (so->so_proto->pr_flags&PR_RIGHTS) != 0) {
1389 fp->f_iflags |= FIF_DISCARDED;
1390 simple_unlock(&fp->f_slock);
1391 return;
1392 }
1393 }
1394 fp->f_usecount++; /* i.e. FILE_USE(fp) sans locking */
1395 fp->f_msgcount--;
1396 simple_unlock(&fp->f_slock);
1397 unp_rights--;
1398 (void) closef(fp, (struct lwp *)0);
1399 }
Cache object: 141b9eca25fc3da277a5245da5307513
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