1 /*-
2 * Copyright (c) 1982, 1986, 1989, 1991, 1993
3 * The Regents of the University of California.
4 * Copyright (c) 2004-2009 Robert N. M. Watson
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 4. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94
32 */
33
34 /*
35 * UNIX Domain (Local) Sockets
36 *
37 * This is an implementation of UNIX (local) domain sockets. Each socket has
38 * an associated struct unpcb (UNIX protocol control block). Stream sockets
39 * may be connected to 0 or 1 other socket. Datagram sockets may be
40 * connected to 0, 1, or many other sockets. Sockets may be created and
41 * connected in pairs (socketpair(2)), or bound/connected to using the file
42 * system name space. For most purposes, only the receive socket buffer is
43 * used, as sending on one socket delivers directly to the receive socket
44 * buffer of a second socket.
45 *
46 * The implementation is substantially complicated by the fact that
47 * "ancillary data", such as file descriptors or credentials, may be passed
48 * across UNIX domain sockets. The potential for passing UNIX domain sockets
49 * over other UNIX domain sockets requires the implementation of a simple
50 * garbage collector to find and tear down cycles of disconnected sockets.
51 *
52 * TODO:
53 * SEQPACKET, RDM
54 * rethink name space problems
55 * need a proper out-of-band
56 */
57
58 #include <sys/cdefs.h>
59 __FBSDID("$FreeBSD: releng/8.3/sys/kern/uipc_usrreq.c 225827 2011-09-28 08:47:17Z bz $");
60
61 #include "opt_ddb.h"
62
63 #include <sys/param.h>
64 #include <sys/domain.h>
65 #include <sys/fcntl.h>
66 #include <sys/malloc.h> /* XXX must be before <sys/file.h> */
67 #include <sys/eventhandler.h>
68 #include <sys/file.h>
69 #include <sys/filedesc.h>
70 #include <sys/kernel.h>
71 #include <sys/lock.h>
72 #include <sys/mbuf.h>
73 #include <sys/mount.h>
74 #include <sys/mutex.h>
75 #include <sys/namei.h>
76 #include <sys/proc.h>
77 #include <sys/protosw.h>
78 #include <sys/queue.h>
79 #include <sys/resourcevar.h>
80 #include <sys/rwlock.h>
81 #include <sys/socket.h>
82 #include <sys/socketvar.h>
83 #include <sys/signalvar.h>
84 #include <sys/stat.h>
85 #include <sys/sx.h>
86 #include <sys/sysctl.h>
87 #include <sys/systm.h>
88 #include <sys/taskqueue.h>
89 #include <sys/un.h>
90 #include <sys/unpcb.h>
91 #include <sys/vnode.h>
92
93 #include <net/vnet.h>
94
95 #ifdef DDB
96 #include <ddb/ddb.h>
97 #endif
98
99 #include <security/mac/mac_framework.h>
100
101 #include <vm/uma.h>
102
103 /*
104 * Locking key:
105 * (l) Locked using list lock
106 * (g) Locked using linkage lock
107 */
108
109 static uma_zone_t unp_zone;
110 static unp_gen_t unp_gencnt; /* (l) */
111 static u_int unp_count; /* (l) Count of local sockets. */
112 static ino_t unp_ino; /* Prototype for fake inode numbers. */
113 static int unp_rights; /* (g) File descriptors in flight. */
114 static struct unp_head unp_shead; /* (l) List of stream sockets. */
115 static struct unp_head unp_dhead; /* (l) List of datagram sockets. */
116
117 struct unp_defer {
118 SLIST_ENTRY(unp_defer) ud_link;
119 struct file *ud_fp;
120 };
121 static SLIST_HEAD(, unp_defer) unp_defers;
122 static int unp_defers_count;
123
124 static const struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL };
125
126 /*
127 * Garbage collection of cyclic file descriptor/socket references occurs
128 * asynchronously in a taskqueue context in order to avoid recursion and
129 * reentrance in the UNIX domain socket, file descriptor, and socket layer
130 * code. See unp_gc() for a full description.
131 */
132 static struct task unp_gc_task;
133
134 /*
135 * The close of unix domain sockets attached as SCM_RIGHTS is
136 * postponed to the taskqueue, to avoid arbitrary recursion depth.
137 * The attached sockets might have another sockets attached.
138 */
139 static struct task unp_defer_task;
140
141 /*
142 * Both send and receive buffers are allocated PIPSIZ bytes of buffering for
143 * stream sockets, although the total for sender and receiver is actually
144 * only PIPSIZ.
145 *
146 * Datagram sockets really use the sendspace as the maximum datagram size,
147 * and don't really want to reserve the sendspace. Their recvspace should be
148 * large enough for at least one max-size datagram plus address.
149 */
150 #ifndef PIPSIZ
151 #define PIPSIZ 8192
152 #endif
153 static u_long unpst_sendspace = PIPSIZ;
154 static u_long unpst_recvspace = PIPSIZ;
155 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */
156 static u_long unpdg_recvspace = 4*1024;
157
158 SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW, 0, "Local domain");
159 SYSCTL_NODE(_net_local, SOCK_STREAM, stream, CTLFLAG_RW, 0, "SOCK_STREAM");
160 SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram, CTLFLAG_RW, 0, "SOCK_DGRAM");
161
162 SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW,
163 &unpst_sendspace, 0, "Default stream send space.");
164 SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW,
165 &unpst_recvspace, 0, "Default stream receive space.");
166 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW,
167 &unpdg_sendspace, 0, "Default datagram send space.");
168 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW,
169 &unpdg_recvspace, 0, "Default datagram receive space.");
170 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0,
171 "File descriptors in flight.");
172 SYSCTL_INT(_net_local, OID_AUTO, deferred, CTLFLAG_RD,
173 &unp_defers_count, 0,
174 "File descriptors deferred to taskqueue for close.");
175
176 /*-
177 * Locking and synchronization:
178 *
179 * Three types of locks exit in the local domain socket implementation: a
180 * global list mutex, a global linkage rwlock, and per-unpcb mutexes. Of the
181 * global locks, the list lock protects the socket count, global generation
182 * number, and stream/datagram global lists. The linkage lock protects the
183 * interconnection of unpcbs, the v_socket and unp_vnode pointers, and can be
184 * held exclusively over the acquisition of multiple unpcb locks to prevent
185 * deadlock.
186 *
187 * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer,
188 * allocated in pru_attach() and freed in pru_detach(). The validity of that
189 * pointer is an invariant, so no lock is required to dereference the so_pcb
190 * pointer if a valid socket reference is held by the caller. In practice,
191 * this is always true during operations performed on a socket. Each unpcb
192 * has a back-pointer to its socket, unp_socket, which will be stable under
193 * the same circumstances.
194 *
195 * This pointer may only be safely dereferenced as long as a valid reference
196 * to the unpcb is held. Typically, this reference will be from the socket,
197 * or from another unpcb when the referring unpcb's lock is held (in order
198 * that the reference not be invalidated during use). For example, to follow
199 * unp->unp_conn->unp_socket, you need unlock the lock on unp, not unp_conn,
200 * as unp_socket remains valid as long as the reference to unp_conn is valid.
201 *
202 * Fields of unpcbss are locked using a per-unpcb lock, unp_mtx. Individual
203 * atomic reads without the lock may be performed "lockless", but more
204 * complex reads and read-modify-writes require the mutex to be held. No
205 * lock order is defined between unpcb locks -- multiple unpcb locks may be
206 * acquired at the same time only when holding the linkage rwlock
207 * exclusively, which prevents deadlocks.
208 *
209 * Blocking with UNIX domain sockets is a tricky issue: unlike most network
210 * protocols, bind() is a non-atomic operation, and connect() requires
211 * potential sleeping in the protocol, due to potentially waiting on local or
212 * distributed file systems. We try to separate "lookup" operations, which
213 * may sleep, and the IPC operations themselves, which typically can occur
214 * with relative atomicity as locks can be held over the entire operation.
215 *
216 * Another tricky issue is simultaneous multi-threaded or multi-process
217 * access to a single UNIX domain socket. These are handled by the flags
218 * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or
219 * binding, both of which involve dropping UNIX domain socket locks in order
220 * to perform namei() and other file system operations.
221 */
222 static struct rwlock unp_link_rwlock;
223 static struct mtx unp_list_lock;
224 static struct mtx unp_defers_lock;
225
226 #define UNP_LINK_LOCK_INIT() rw_init(&unp_link_rwlock, \
227 "unp_link_rwlock")
228
229 #define UNP_LINK_LOCK_ASSERT() rw_assert(&unp_link_rwlock, \
230 RA_LOCKED)
231 #define UNP_LINK_UNLOCK_ASSERT() rw_assert(&unp_link_rwlock, \
232 RA_UNLOCKED)
233
234 #define UNP_LINK_RLOCK() rw_rlock(&unp_link_rwlock)
235 #define UNP_LINK_RUNLOCK() rw_runlock(&unp_link_rwlock)
236 #define UNP_LINK_WLOCK() rw_wlock(&unp_link_rwlock)
237 #define UNP_LINK_WUNLOCK() rw_wunlock(&unp_link_rwlock)
238 #define UNP_LINK_WLOCK_ASSERT() rw_assert(&unp_link_rwlock, \
239 RA_WLOCKED)
240
241 #define UNP_LIST_LOCK_INIT() mtx_init(&unp_list_lock, \
242 "unp_list_lock", NULL, MTX_DEF)
243 #define UNP_LIST_LOCK() mtx_lock(&unp_list_lock)
244 #define UNP_LIST_UNLOCK() mtx_unlock(&unp_list_lock)
245
246 #define UNP_DEFERRED_LOCK_INIT() mtx_init(&unp_defers_lock, \
247 "unp_defer", NULL, MTX_DEF)
248 #define UNP_DEFERRED_LOCK() mtx_lock(&unp_defers_lock)
249 #define UNP_DEFERRED_UNLOCK() mtx_unlock(&unp_defers_lock)
250
251 #define UNP_PCB_LOCK_INIT(unp) mtx_init(&(unp)->unp_mtx, \
252 "unp_mtx", "unp_mtx", \
253 MTX_DUPOK|MTX_DEF|MTX_RECURSE)
254 #define UNP_PCB_LOCK_DESTROY(unp) mtx_destroy(&(unp)->unp_mtx)
255 #define UNP_PCB_LOCK(unp) mtx_lock(&(unp)->unp_mtx)
256 #define UNP_PCB_UNLOCK(unp) mtx_unlock(&(unp)->unp_mtx)
257 #define UNP_PCB_LOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_OWNED)
258
259 static int uipc_connect2(struct socket *, struct socket *);
260 static int uipc_ctloutput(struct socket *, struct sockopt *);
261 static int unp_connect(struct socket *, struct sockaddr *,
262 struct thread *);
263 static int unp_connect2(struct socket *so, struct socket *so2, int);
264 static void unp_disconnect(struct unpcb *unp, struct unpcb *unp2);
265 static void unp_dispose(struct mbuf *);
266 static void unp_shutdown(struct unpcb *);
267 static void unp_drop(struct unpcb *, int);
268 static void unp_gc(__unused void *, int);
269 static void unp_scan(struct mbuf *, void (*)(struct file *));
270 static void unp_discard(struct file *);
271 static void unp_freerights(struct file **, int);
272 static void unp_init(void);
273 static int unp_internalize(struct mbuf **, struct thread *);
274 static void unp_internalize_fp(struct file *);
275 static int unp_externalize(struct mbuf *, struct mbuf **);
276 static int unp_externalize_fp(struct file *);
277 static struct mbuf *unp_addsockcred(struct thread *, struct mbuf *);
278 static void unp_process_defers(void * __unused, int);
279
280 /*
281 * Definitions of protocols supported in the LOCAL domain.
282 */
283 static struct domain localdomain;
284 static struct pr_usrreqs uipc_usrreqs_dgram, uipc_usrreqs_stream;
285 static struct protosw localsw[] = {
286 {
287 .pr_type = SOCK_STREAM,
288 .pr_domain = &localdomain,
289 .pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS,
290 .pr_ctloutput = &uipc_ctloutput,
291 .pr_usrreqs = &uipc_usrreqs_stream
292 },
293 {
294 .pr_type = SOCK_DGRAM,
295 .pr_domain = &localdomain,
296 .pr_flags = PR_ATOMIC|PR_ADDR|PR_RIGHTS,
297 .pr_usrreqs = &uipc_usrreqs_dgram
298 },
299 };
300
301 static struct domain localdomain = {
302 .dom_family = AF_LOCAL,
303 .dom_name = "local",
304 .dom_init = unp_init,
305 .dom_externalize = unp_externalize,
306 .dom_dispose = unp_dispose,
307 .dom_protosw = localsw,
308 .dom_protoswNPROTOSW = &localsw[sizeof(localsw)/sizeof(localsw[0])]
309 };
310 DOMAIN_SET(local);
311
312 static void
313 uipc_abort(struct socket *so)
314 {
315 struct unpcb *unp, *unp2;
316
317 unp = sotounpcb(so);
318 KASSERT(unp != NULL, ("uipc_abort: unp == NULL"));
319
320 UNP_LINK_WLOCK();
321 UNP_PCB_LOCK(unp);
322 unp2 = unp->unp_conn;
323 if (unp2 != NULL) {
324 UNP_PCB_LOCK(unp2);
325 unp_drop(unp2, ECONNABORTED);
326 UNP_PCB_UNLOCK(unp2);
327 }
328 UNP_PCB_UNLOCK(unp);
329 UNP_LINK_WUNLOCK();
330 }
331
332 static int
333 uipc_accept(struct socket *so, struct sockaddr **nam)
334 {
335 struct unpcb *unp, *unp2;
336 const struct sockaddr *sa;
337
338 /*
339 * Pass back name of connected socket, if it was bound and we are
340 * still connected (our peer may have closed already!).
341 */
342 unp = sotounpcb(so);
343 KASSERT(unp != NULL, ("uipc_accept: unp == NULL"));
344
345 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
346 UNP_LINK_RLOCK();
347 unp2 = unp->unp_conn;
348 if (unp2 != NULL && unp2->unp_addr != NULL) {
349 UNP_PCB_LOCK(unp2);
350 sa = (struct sockaddr *) unp2->unp_addr;
351 bcopy(sa, *nam, sa->sa_len);
352 UNP_PCB_UNLOCK(unp2);
353 } else {
354 sa = &sun_noname;
355 bcopy(sa, *nam, sa->sa_len);
356 }
357 UNP_LINK_RUNLOCK();
358 return (0);
359 }
360
361 static int
362 uipc_attach(struct socket *so, int proto, struct thread *td)
363 {
364 u_long sendspace, recvspace;
365 struct unpcb *unp;
366 int error;
367
368 KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL"));
369 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
370 switch (so->so_type) {
371 case SOCK_STREAM:
372 sendspace = unpst_sendspace;
373 recvspace = unpst_recvspace;
374 break;
375
376 case SOCK_DGRAM:
377 sendspace = unpdg_sendspace;
378 recvspace = unpdg_recvspace;
379 break;
380
381 default:
382 panic("uipc_attach");
383 }
384 error = soreserve(so, sendspace, recvspace);
385 if (error)
386 return (error);
387 }
388 unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO);
389 if (unp == NULL)
390 return (ENOBUFS);
391 LIST_INIT(&unp->unp_refs);
392 UNP_PCB_LOCK_INIT(unp);
393 unp->unp_socket = so;
394 so->so_pcb = unp;
395 unp->unp_refcount = 1;
396
397 UNP_LIST_LOCK();
398 unp->unp_gencnt = ++unp_gencnt;
399 unp_count++;
400 LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead : &unp_shead,
401 unp, unp_link);
402 UNP_LIST_UNLOCK();
403
404 return (0);
405 }
406
407 static int
408 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
409 {
410 struct sockaddr_un *soun = (struct sockaddr_un *)nam;
411 struct vattr vattr;
412 int error, namelen, vfslocked;
413 struct nameidata nd;
414 struct unpcb *unp;
415 struct vnode *vp;
416 struct mount *mp;
417 char *buf;
418
419 unp = sotounpcb(so);
420 KASSERT(unp != NULL, ("uipc_bind: unp == NULL"));
421
422 if (soun->sun_len > sizeof(struct sockaddr_un))
423 return (EINVAL);
424 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path);
425 if (namelen <= 0)
426 return (EINVAL);
427
428 /*
429 * We don't allow simultaneous bind() calls on a single UNIX domain
430 * socket, so flag in-progress operations, and return an error if an
431 * operation is already in progress.
432 *
433 * Historically, we have not allowed a socket to be rebound, so this
434 * also returns an error. Not allowing re-binding simplifies the
435 * implementation and avoids a great many possible failure modes.
436 */
437 UNP_PCB_LOCK(unp);
438 if (unp->unp_vnode != NULL) {
439 UNP_PCB_UNLOCK(unp);
440 return (EINVAL);
441 }
442 if (unp->unp_flags & UNP_BINDING) {
443 UNP_PCB_UNLOCK(unp);
444 return (EALREADY);
445 }
446 unp->unp_flags |= UNP_BINDING;
447 UNP_PCB_UNLOCK(unp);
448
449 buf = malloc(namelen + 1, M_TEMP, M_WAITOK);
450 bcopy(soun->sun_path, buf, namelen);
451 buf[namelen] = 0;
452
453 restart:
454 vfslocked = 0;
455 NDINIT(&nd, CREATE, MPSAFE | NOFOLLOW | LOCKPARENT | SAVENAME,
456 UIO_SYSSPACE, buf, td);
457 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */
458 error = namei(&nd);
459 if (error)
460 goto error;
461 vp = nd.ni_vp;
462 vfslocked = NDHASGIANT(&nd);
463 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
464 NDFREE(&nd, NDF_ONLY_PNBUF);
465 if (nd.ni_dvp == vp)
466 vrele(nd.ni_dvp);
467 else
468 vput(nd.ni_dvp);
469 if (vp != NULL) {
470 vrele(vp);
471 error = EADDRINUSE;
472 goto error;
473 }
474 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH);
475 if (error)
476 goto error;
477 VFS_UNLOCK_GIANT(vfslocked);
478 goto restart;
479 }
480 VATTR_NULL(&vattr);
481 vattr.va_type = VSOCK;
482 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask);
483 #ifdef MAC
484 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
485 &vattr);
486 #endif
487 if (error == 0)
488 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
489 NDFREE(&nd, NDF_ONLY_PNBUF);
490 vput(nd.ni_dvp);
491 if (error) {
492 vn_finished_write(mp);
493 goto error;
494 }
495 vp = nd.ni_vp;
496 ASSERT_VOP_ELOCKED(vp, "uipc_bind");
497 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK);
498
499 UNP_LINK_WLOCK();
500 UNP_PCB_LOCK(unp);
501 vp->v_socket = unp->unp_socket;
502 unp->unp_vnode = vp;
503 unp->unp_addr = soun;
504 unp->unp_flags &= ~UNP_BINDING;
505 UNP_PCB_UNLOCK(unp);
506 UNP_LINK_WUNLOCK();
507 VOP_UNLOCK(vp, 0);
508 vn_finished_write(mp);
509 VFS_UNLOCK_GIANT(vfslocked);
510 free(buf, M_TEMP);
511 return (0);
512
513 error:
514 VFS_UNLOCK_GIANT(vfslocked);
515 UNP_PCB_LOCK(unp);
516 unp->unp_flags &= ~UNP_BINDING;
517 UNP_PCB_UNLOCK(unp);
518 free(buf, M_TEMP);
519 return (error);
520 }
521
522 static int
523 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
524 {
525 int error;
526
527 KASSERT(td == curthread, ("uipc_connect: td != curthread"));
528 UNP_LINK_WLOCK();
529 error = unp_connect(so, nam, td);
530 UNP_LINK_WUNLOCK();
531 return (error);
532 }
533
534 static void
535 uipc_close(struct socket *so)
536 {
537 struct unpcb *unp, *unp2;
538
539 unp = sotounpcb(so);
540 KASSERT(unp != NULL, ("uipc_close: unp == NULL"));
541
542 UNP_LINK_WLOCK();
543 UNP_PCB_LOCK(unp);
544 unp2 = unp->unp_conn;
545 if (unp2 != NULL) {
546 UNP_PCB_LOCK(unp2);
547 unp_disconnect(unp, unp2);
548 UNP_PCB_UNLOCK(unp2);
549 }
550 UNP_PCB_UNLOCK(unp);
551 UNP_LINK_WUNLOCK();
552 }
553
554 static int
555 uipc_connect2(struct socket *so1, struct socket *so2)
556 {
557 struct unpcb *unp, *unp2;
558 int error;
559
560 UNP_LINK_WLOCK();
561 unp = so1->so_pcb;
562 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL"));
563 UNP_PCB_LOCK(unp);
564 unp2 = so2->so_pcb;
565 KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL"));
566 UNP_PCB_LOCK(unp2);
567 error = unp_connect2(so1, so2, PRU_CONNECT2);
568 UNP_PCB_UNLOCK(unp2);
569 UNP_PCB_UNLOCK(unp);
570 UNP_LINK_WUNLOCK();
571 return (error);
572 }
573
574 static void
575 uipc_detach(struct socket *so)
576 {
577 struct unpcb *unp, *unp2;
578 struct sockaddr_un *saved_unp_addr;
579 struct vnode *vp;
580 int freeunp, local_unp_rights;
581
582 unp = sotounpcb(so);
583 KASSERT(unp != NULL, ("uipc_detach: unp == NULL"));
584
585 UNP_LINK_WLOCK();
586 UNP_LIST_LOCK();
587 UNP_PCB_LOCK(unp);
588 LIST_REMOVE(unp, unp_link);
589 unp->unp_gencnt = ++unp_gencnt;
590 --unp_count;
591 UNP_LIST_UNLOCK();
592
593 /*
594 * XXXRW: Should assert vp->v_socket == so.
595 */
596 if ((vp = unp->unp_vnode) != NULL) {
597 unp->unp_vnode->v_socket = NULL;
598 unp->unp_vnode = NULL;
599 }
600 unp2 = unp->unp_conn;
601 if (unp2 != NULL) {
602 UNP_PCB_LOCK(unp2);
603 unp_disconnect(unp, unp2);
604 UNP_PCB_UNLOCK(unp2);
605 }
606
607 /*
608 * We hold the linkage lock exclusively, so it's OK to acquire
609 * multiple pcb locks at a time.
610 */
611 while (!LIST_EMPTY(&unp->unp_refs)) {
612 struct unpcb *ref = LIST_FIRST(&unp->unp_refs);
613
614 UNP_PCB_LOCK(ref);
615 unp_drop(ref, ECONNRESET);
616 UNP_PCB_UNLOCK(ref);
617 }
618 local_unp_rights = unp_rights;
619 UNP_LINK_WUNLOCK();
620 unp->unp_socket->so_pcb = NULL;
621 saved_unp_addr = unp->unp_addr;
622 unp->unp_addr = NULL;
623 unp->unp_refcount--;
624 freeunp = (unp->unp_refcount == 0);
625 if (saved_unp_addr != NULL)
626 free(saved_unp_addr, M_SONAME);
627 if (freeunp) {
628 UNP_PCB_LOCK_DESTROY(unp);
629 uma_zfree(unp_zone, unp);
630 } else
631 UNP_PCB_UNLOCK(unp);
632 if (vp) {
633 int vfslocked;
634
635 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
636 vrele(vp);
637 VFS_UNLOCK_GIANT(vfslocked);
638 }
639 if (local_unp_rights)
640 taskqueue_enqueue(taskqueue_thread, &unp_gc_task);
641 }
642
643 static int
644 uipc_disconnect(struct socket *so)
645 {
646 struct unpcb *unp, *unp2;
647
648 unp = sotounpcb(so);
649 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL"));
650
651 UNP_LINK_WLOCK();
652 UNP_PCB_LOCK(unp);
653 unp2 = unp->unp_conn;
654 if (unp2 != NULL) {
655 UNP_PCB_LOCK(unp2);
656 unp_disconnect(unp, unp2);
657 UNP_PCB_UNLOCK(unp2);
658 }
659 UNP_PCB_UNLOCK(unp);
660 UNP_LINK_WUNLOCK();
661 return (0);
662 }
663
664 static int
665 uipc_listen(struct socket *so, int backlog, struct thread *td)
666 {
667 struct unpcb *unp;
668 int error;
669
670 unp = sotounpcb(so);
671 KASSERT(unp != NULL, ("uipc_listen: unp == NULL"));
672
673 UNP_PCB_LOCK(unp);
674 if (unp->unp_vnode == NULL) {
675 UNP_PCB_UNLOCK(unp);
676 return (EINVAL);
677 }
678
679 SOCK_LOCK(so);
680 error = solisten_proto_check(so);
681 if (error == 0) {
682 cru2x(td->td_ucred, &unp->unp_peercred);
683 unp->unp_flags |= UNP_HAVEPCCACHED;
684 solisten_proto(so, backlog);
685 }
686 SOCK_UNLOCK(so);
687 UNP_PCB_UNLOCK(unp);
688 return (error);
689 }
690
691 static int
692 uipc_peeraddr(struct socket *so, struct sockaddr **nam)
693 {
694 struct unpcb *unp, *unp2;
695 const struct sockaddr *sa;
696
697 unp = sotounpcb(so);
698 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL"));
699
700 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
701 UNP_LINK_RLOCK();
702 /*
703 * XXX: It seems that this test always fails even when connection is
704 * established. So, this else clause is added as workaround to
705 * return PF_LOCAL sockaddr.
706 */
707 unp2 = unp->unp_conn;
708 if (unp2 != NULL) {
709 UNP_PCB_LOCK(unp2);
710 if (unp2->unp_addr != NULL)
711 sa = (struct sockaddr *) unp2->unp_addr;
712 else
713 sa = &sun_noname;
714 bcopy(sa, *nam, sa->sa_len);
715 UNP_PCB_UNLOCK(unp2);
716 } else {
717 sa = &sun_noname;
718 bcopy(sa, *nam, sa->sa_len);
719 }
720 UNP_LINK_RUNLOCK();
721 return (0);
722 }
723
724 static int
725 uipc_rcvd(struct socket *so, int flags)
726 {
727 struct unpcb *unp, *unp2;
728 struct socket *so2;
729 u_int mbcnt, sbcc;
730 u_long newhiwat;
731
732 unp = sotounpcb(so);
733 KASSERT(unp != NULL, ("uipc_rcvd: unp == NULL"));
734
735 if (so->so_type == SOCK_DGRAM)
736 panic("uipc_rcvd DGRAM?");
737
738 if (so->so_type != SOCK_STREAM)
739 panic("uipc_rcvd unknown socktype");
740
741 /*
742 * Adjust backpressure on sender and wakeup any waiting to write.
743 *
744 * The unp lock is acquired to maintain the validity of the unp_conn
745 * pointer; no lock on unp2 is required as unp2->unp_socket will be
746 * static as long as we don't permit unp2 to disconnect from unp,
747 * which is prevented by the lock on unp. We cache values from
748 * so_rcv to avoid holding the so_rcv lock over the entire
749 * transaction on the remote so_snd.
750 */
751 SOCKBUF_LOCK(&so->so_rcv);
752 mbcnt = so->so_rcv.sb_mbcnt;
753 sbcc = so->so_rcv.sb_cc;
754 SOCKBUF_UNLOCK(&so->so_rcv);
755 UNP_PCB_LOCK(unp);
756 unp2 = unp->unp_conn;
757 if (unp2 == NULL) {
758 UNP_PCB_UNLOCK(unp);
759 return (0);
760 }
761 so2 = unp2->unp_socket;
762 SOCKBUF_LOCK(&so2->so_snd);
763 so2->so_snd.sb_mbmax += unp->unp_mbcnt - mbcnt;
764 newhiwat = so2->so_snd.sb_hiwat + unp->unp_cc - sbcc;
765 (void)chgsbsize(so2->so_cred->cr_uidinfo, &so2->so_snd.sb_hiwat,
766 newhiwat, RLIM_INFINITY);
767 sowwakeup_locked(so2);
768 unp->unp_mbcnt = mbcnt;
769 unp->unp_cc = sbcc;
770 UNP_PCB_UNLOCK(unp);
771 return (0);
772 }
773
774 static int
775 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
776 struct mbuf *control, struct thread *td)
777 {
778 struct unpcb *unp, *unp2;
779 struct socket *so2;
780 u_int mbcnt_delta, sbcc;
781 u_int newhiwat;
782 int error = 0;
783
784 unp = sotounpcb(so);
785 KASSERT(unp != NULL, ("uipc_send: unp == NULL"));
786
787 if (flags & PRUS_OOB) {
788 error = EOPNOTSUPP;
789 goto release;
790 }
791 if (control != NULL && (error = unp_internalize(&control, td)))
792 goto release;
793 if ((nam != NULL) || (flags & PRUS_EOF))
794 UNP_LINK_WLOCK();
795 else
796 UNP_LINK_RLOCK();
797 switch (so->so_type) {
798 case SOCK_DGRAM:
799 {
800 const struct sockaddr *from;
801
802 unp2 = unp->unp_conn;
803 if (nam != NULL) {
804 UNP_LINK_WLOCK_ASSERT();
805 if (unp2 != NULL) {
806 error = EISCONN;
807 break;
808 }
809 error = unp_connect(so, nam, td);
810 if (error)
811 break;
812 unp2 = unp->unp_conn;
813 }
814
815 /*
816 * Because connect() and send() are non-atomic in a sendto()
817 * with a target address, it's possible that the socket will
818 * have disconnected before the send() can run. In that case
819 * return the slightly counter-intuitive but otherwise
820 * correct error that the socket is not connected.
821 */
822 if (unp2 == NULL) {
823 error = ENOTCONN;
824 break;
825 }
826 /* Lockless read. */
827 if (unp2->unp_flags & UNP_WANTCRED)
828 control = unp_addsockcred(td, control);
829 UNP_PCB_LOCK(unp);
830 if (unp->unp_addr != NULL)
831 from = (struct sockaddr *)unp->unp_addr;
832 else
833 from = &sun_noname;
834 so2 = unp2->unp_socket;
835 SOCKBUF_LOCK(&so2->so_rcv);
836 if (sbappendaddr_locked(&so2->so_rcv, from, m, control)) {
837 sorwakeup_locked(so2);
838 m = NULL;
839 control = NULL;
840 } else {
841 SOCKBUF_UNLOCK(&so2->so_rcv);
842 error = ENOBUFS;
843 }
844 if (nam != NULL) {
845 UNP_LINK_WLOCK_ASSERT();
846 UNP_PCB_LOCK(unp2);
847 unp_disconnect(unp, unp2);
848 UNP_PCB_UNLOCK(unp2);
849 }
850 UNP_PCB_UNLOCK(unp);
851 break;
852 }
853
854 case SOCK_STREAM:
855 if ((so->so_state & SS_ISCONNECTED) == 0) {
856 if (nam != NULL) {
857 UNP_LINK_WLOCK_ASSERT();
858 error = unp_connect(so, nam, td);
859 if (error)
860 break; /* XXX */
861 } else {
862 error = ENOTCONN;
863 break;
864 }
865 }
866
867 /* Lockless read. */
868 if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
869 error = EPIPE;
870 break;
871 }
872
873 /*
874 * Because connect() and send() are non-atomic in a sendto()
875 * with a target address, it's possible that the socket will
876 * have disconnected before the send() can run. In that case
877 * return the slightly counter-intuitive but otherwise
878 * correct error that the socket is not connected.
879 *
880 * Locking here must be done carefully: the linkage lock
881 * prevents interconnections between unpcbs from changing, so
882 * we can traverse from unp to unp2 without acquiring unp's
883 * lock. Socket buffer locks follow unpcb locks, so we can
884 * acquire both remote and lock socket buffer locks.
885 */
886 unp2 = unp->unp_conn;
887 if (unp2 == NULL) {
888 error = ENOTCONN;
889 break;
890 }
891 so2 = unp2->unp_socket;
892 UNP_PCB_LOCK(unp2);
893 SOCKBUF_LOCK(&so2->so_rcv);
894 if (unp2->unp_flags & UNP_WANTCRED) {
895 /*
896 * Credentials are passed only once on SOCK_STREAM.
897 */
898 unp2->unp_flags &= ~UNP_WANTCRED;
899 control = unp_addsockcred(td, control);
900 }
901 /*
902 * Send to paired receive port, and then reduce send buffer
903 * hiwater marks to maintain backpressure. Wake up readers.
904 */
905 if (control != NULL) {
906 if (sbappendcontrol_locked(&so2->so_rcv, m, control))
907 control = NULL;
908 } else
909 sbappend_locked(&so2->so_rcv, m);
910 mbcnt_delta = so2->so_rcv.sb_mbcnt - unp2->unp_mbcnt;
911 unp2->unp_mbcnt = so2->so_rcv.sb_mbcnt;
912 sbcc = so2->so_rcv.sb_cc;
913 sorwakeup_locked(so2);
914
915 SOCKBUF_LOCK(&so->so_snd);
916 if ((int)so->so_snd.sb_hiwat >= (int)(sbcc - unp2->unp_cc))
917 newhiwat = so->so_snd.sb_hiwat - (sbcc - unp2->unp_cc);
918 else
919 newhiwat = 0;
920 (void)chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat,
921 newhiwat, RLIM_INFINITY);
922 so->so_snd.sb_mbmax -= mbcnt_delta;
923 SOCKBUF_UNLOCK(&so->so_snd);
924 unp2->unp_cc = sbcc;
925 UNP_PCB_UNLOCK(unp2);
926 m = NULL;
927 break;
928
929 default:
930 panic("uipc_send unknown socktype");
931 }
932
933 /*
934 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown.
935 */
936 if (flags & PRUS_EOF) {
937 UNP_PCB_LOCK(unp);
938 socantsendmore(so);
939 unp_shutdown(unp);
940 UNP_PCB_UNLOCK(unp);
941 }
942
943 if ((nam != NULL) || (flags & PRUS_EOF))
944 UNP_LINK_WUNLOCK();
945 else
946 UNP_LINK_RUNLOCK();
947
948 if (control != NULL && error != 0)
949 unp_dispose(control);
950
951 release:
952 if (control != NULL)
953 m_freem(control);
954 if (m != NULL)
955 m_freem(m);
956 return (error);
957 }
958
959 static int
960 uipc_sense(struct socket *so, struct stat *sb)
961 {
962 struct unpcb *unp, *unp2;
963 struct socket *so2;
964
965 unp = sotounpcb(so);
966 KASSERT(unp != NULL, ("uipc_sense: unp == NULL"));
967
968 sb->st_blksize = so->so_snd.sb_hiwat;
969 UNP_LINK_RLOCK();
970 UNP_PCB_LOCK(unp);
971 unp2 = unp->unp_conn;
972 if (so->so_type == SOCK_STREAM && unp2 != NULL) {
973 so2 = unp2->unp_socket;
974 sb->st_blksize += so2->so_rcv.sb_cc;
975 }
976 sb->st_dev = NODEV;
977 if (unp->unp_ino == 0)
978 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino;
979 sb->st_ino = unp->unp_ino;
980 UNP_PCB_UNLOCK(unp);
981 UNP_LINK_RUNLOCK();
982 return (0);
983 }
984
985 static int
986 uipc_shutdown(struct socket *so)
987 {
988 struct unpcb *unp;
989
990 unp = sotounpcb(so);
991 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL"));
992
993 UNP_LINK_WLOCK();
994 UNP_PCB_LOCK(unp);
995 socantsendmore(so);
996 unp_shutdown(unp);
997 UNP_PCB_UNLOCK(unp);
998 UNP_LINK_WUNLOCK();
999 return (0);
1000 }
1001
1002 static int
1003 uipc_sockaddr(struct socket *so, struct sockaddr **nam)
1004 {
1005 struct unpcb *unp;
1006 const struct sockaddr *sa;
1007
1008 unp = sotounpcb(so);
1009 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL"));
1010
1011 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
1012 UNP_PCB_LOCK(unp);
1013 if (unp->unp_addr != NULL)
1014 sa = (struct sockaddr *) unp->unp_addr;
1015 else
1016 sa = &sun_noname;
1017 bcopy(sa, *nam, sa->sa_len);
1018 UNP_PCB_UNLOCK(unp);
1019 return (0);
1020 }
1021
1022 static struct pr_usrreqs uipc_usrreqs_dgram = {
1023 .pru_abort = uipc_abort,
1024 .pru_accept = uipc_accept,
1025 .pru_attach = uipc_attach,
1026 .pru_bind = uipc_bind,
1027 .pru_connect = uipc_connect,
1028 .pru_connect2 = uipc_connect2,
1029 .pru_detach = uipc_detach,
1030 .pru_disconnect = uipc_disconnect,
1031 .pru_listen = uipc_listen,
1032 .pru_peeraddr = uipc_peeraddr,
1033 .pru_rcvd = uipc_rcvd,
1034 .pru_send = uipc_send,
1035 .pru_sense = uipc_sense,
1036 .pru_shutdown = uipc_shutdown,
1037 .pru_sockaddr = uipc_sockaddr,
1038 .pru_soreceive = soreceive_dgram,
1039 .pru_close = uipc_close,
1040 };
1041
1042 static struct pr_usrreqs uipc_usrreqs_stream = {
1043 .pru_abort = uipc_abort,
1044 .pru_accept = uipc_accept,
1045 .pru_attach = uipc_attach,
1046 .pru_bind = uipc_bind,
1047 .pru_connect = uipc_connect,
1048 .pru_connect2 = uipc_connect2,
1049 .pru_detach = uipc_detach,
1050 .pru_disconnect = uipc_disconnect,
1051 .pru_listen = uipc_listen,
1052 .pru_peeraddr = uipc_peeraddr,
1053 .pru_rcvd = uipc_rcvd,
1054 .pru_send = uipc_send,
1055 .pru_sense = uipc_sense,
1056 .pru_shutdown = uipc_shutdown,
1057 .pru_sockaddr = uipc_sockaddr,
1058 .pru_soreceive = soreceive_generic,
1059 .pru_close = uipc_close,
1060 };
1061
1062 static int
1063 uipc_ctloutput(struct socket *so, struct sockopt *sopt)
1064 {
1065 struct unpcb *unp;
1066 struct xucred xu;
1067 int error, optval;
1068
1069 if (sopt->sopt_level != 0)
1070 return (EINVAL);
1071
1072 unp = sotounpcb(so);
1073 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL"));
1074 error = 0;
1075 switch (sopt->sopt_dir) {
1076 case SOPT_GET:
1077 switch (sopt->sopt_name) {
1078 case LOCAL_PEERCRED:
1079 UNP_PCB_LOCK(unp);
1080 if (unp->unp_flags & UNP_HAVEPC)
1081 xu = unp->unp_peercred;
1082 else {
1083 if (so->so_type == SOCK_STREAM)
1084 error = ENOTCONN;
1085 else
1086 error = EINVAL;
1087 }
1088 UNP_PCB_UNLOCK(unp);
1089 if (error == 0)
1090 error = sooptcopyout(sopt, &xu, sizeof(xu));
1091 break;
1092
1093 case LOCAL_CREDS:
1094 /* Unlocked read. */
1095 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0;
1096 error = sooptcopyout(sopt, &optval, sizeof(optval));
1097 break;
1098
1099 case LOCAL_CONNWAIT:
1100 /* Unlocked read. */
1101 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0;
1102 error = sooptcopyout(sopt, &optval, sizeof(optval));
1103 break;
1104
1105 default:
1106 error = EOPNOTSUPP;
1107 break;
1108 }
1109 break;
1110
1111 case SOPT_SET:
1112 switch (sopt->sopt_name) {
1113 case LOCAL_CREDS:
1114 case LOCAL_CONNWAIT:
1115 error = sooptcopyin(sopt, &optval, sizeof(optval),
1116 sizeof(optval));
1117 if (error)
1118 break;
1119
1120 #define OPTSET(bit) do { \
1121 UNP_PCB_LOCK(unp); \
1122 if (optval) \
1123 unp->unp_flags |= bit; \
1124 else \
1125 unp->unp_flags &= ~bit; \
1126 UNP_PCB_UNLOCK(unp); \
1127 } while (0)
1128
1129 switch (sopt->sopt_name) {
1130 case LOCAL_CREDS:
1131 OPTSET(UNP_WANTCRED);
1132 break;
1133
1134 case LOCAL_CONNWAIT:
1135 OPTSET(UNP_CONNWAIT);
1136 break;
1137
1138 default:
1139 break;
1140 }
1141 break;
1142 #undef OPTSET
1143 default:
1144 error = ENOPROTOOPT;
1145 break;
1146 }
1147 break;
1148
1149 default:
1150 error = EOPNOTSUPP;
1151 break;
1152 }
1153 return (error);
1154 }
1155
1156 static int
1157 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1158 {
1159 struct sockaddr_un *soun = (struct sockaddr_un *)nam;
1160 struct vnode *vp;
1161 struct socket *so2, *so3;
1162 struct unpcb *unp, *unp2, *unp3;
1163 int error, len, vfslocked;
1164 struct nameidata nd;
1165 char buf[SOCK_MAXADDRLEN];
1166 struct sockaddr *sa;
1167
1168 UNP_LINK_WLOCK_ASSERT();
1169
1170 unp = sotounpcb(so);
1171 KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
1172
1173 if (nam->sa_len > sizeof(struct sockaddr_un))
1174 return (EINVAL);
1175 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path);
1176 if (len <= 0)
1177 return (EINVAL);
1178 bcopy(soun->sun_path, buf, len);
1179 buf[len] = 0;
1180
1181 UNP_PCB_LOCK(unp);
1182 if (unp->unp_flags & UNP_CONNECTING) {
1183 UNP_PCB_UNLOCK(unp);
1184 return (EALREADY);
1185 }
1186 UNP_LINK_WUNLOCK();
1187 unp->unp_flags |= UNP_CONNECTING;
1188 UNP_PCB_UNLOCK(unp);
1189
1190 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
1191 NDINIT(&nd, LOOKUP, MPSAFE | FOLLOW | LOCKLEAF, UIO_SYSSPACE, buf,
1192 td);
1193 error = namei(&nd);
1194 if (error)
1195 vp = NULL;
1196 else
1197 vp = nd.ni_vp;
1198 ASSERT_VOP_LOCKED(vp, "unp_connect");
1199 vfslocked = NDHASGIANT(&nd);
1200 NDFREE(&nd, NDF_ONLY_PNBUF);
1201 if (error)
1202 goto bad;
1203
1204 if (vp->v_type != VSOCK) {
1205 error = ENOTSOCK;
1206 goto bad;
1207 }
1208 #ifdef MAC
1209 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD);
1210 if (error)
1211 goto bad;
1212 #endif
1213 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td);
1214 if (error)
1215 goto bad;
1216 VFS_UNLOCK_GIANT(vfslocked);
1217
1218 unp = sotounpcb(so);
1219 KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
1220
1221 /*
1222 * Lock linkage lock for two reasons: make sure v_socket is stable,
1223 * and to protect simultaneous locking of multiple pcbs.
1224 */
1225 UNP_LINK_WLOCK();
1226 so2 = vp->v_socket;
1227 if (so2 == NULL) {
1228 error = ECONNREFUSED;
1229 goto bad2;
1230 }
1231 if (so->so_type != so2->so_type) {
1232 error = EPROTOTYPE;
1233 goto bad2;
1234 }
1235 if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
1236 if (so2->so_options & SO_ACCEPTCONN) {
1237 CURVNET_SET(so2->so_vnet);
1238 so3 = sonewconn(so2, 0);
1239 CURVNET_RESTORE();
1240 } else
1241 so3 = NULL;
1242 if (so3 == NULL) {
1243 error = ECONNREFUSED;
1244 goto bad2;
1245 }
1246 unp = sotounpcb(so);
1247 unp2 = sotounpcb(so2);
1248 unp3 = sotounpcb(so3);
1249 UNP_PCB_LOCK(unp);
1250 UNP_PCB_LOCK(unp2);
1251 UNP_PCB_LOCK(unp3);
1252 if (unp2->unp_addr != NULL) {
1253 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len);
1254 unp3->unp_addr = (struct sockaddr_un *) sa;
1255 sa = NULL;
1256 }
1257
1258 /*
1259 * The connecter's (client's) credentials are copied from its
1260 * process structure at the time of connect() (which is now).
1261 */
1262 cru2x(td->td_ucred, &unp3->unp_peercred);
1263 unp3->unp_flags |= UNP_HAVEPC;
1264
1265 /*
1266 * The receiver's (server's) credentials are copied from the
1267 * unp_peercred member of socket on which the former called
1268 * listen(); uipc_listen() cached that process's credentials
1269 * at that time so we can use them now.
1270 */
1271 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED,
1272 ("unp_connect: listener without cached peercred"));
1273 memcpy(&unp->unp_peercred, &unp2->unp_peercred,
1274 sizeof(unp->unp_peercred));
1275 unp->unp_flags |= UNP_HAVEPC;
1276 if (unp2->unp_flags & UNP_WANTCRED)
1277 unp3->unp_flags |= UNP_WANTCRED;
1278 UNP_PCB_UNLOCK(unp3);
1279 UNP_PCB_UNLOCK(unp2);
1280 UNP_PCB_UNLOCK(unp);
1281 #ifdef MAC
1282 mac_socketpeer_set_from_socket(so, so3);
1283 mac_socketpeer_set_from_socket(so3, so);
1284 #endif
1285
1286 so2 = so3;
1287 }
1288 unp = sotounpcb(so);
1289 KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
1290 unp2 = sotounpcb(so2);
1291 KASSERT(unp2 != NULL, ("unp_connect: unp2 == NULL"));
1292 UNP_PCB_LOCK(unp);
1293 UNP_PCB_LOCK(unp2);
1294 error = unp_connect2(so, so2, PRU_CONNECT);
1295 UNP_PCB_UNLOCK(unp2);
1296 UNP_PCB_UNLOCK(unp);
1297 bad2:
1298 UNP_LINK_WUNLOCK();
1299 if (vfslocked)
1300 /*
1301 * Giant has been previously acquired. This means filesystem
1302 * isn't MPSAFE. Do it once again.
1303 */
1304 mtx_lock(&Giant);
1305 bad:
1306 if (vp != NULL)
1307 vput(vp);
1308 VFS_UNLOCK_GIANT(vfslocked);
1309 free(sa, M_SONAME);
1310 UNP_LINK_WLOCK();
1311 UNP_PCB_LOCK(unp);
1312 unp->unp_flags &= ~UNP_CONNECTING;
1313 UNP_PCB_UNLOCK(unp);
1314 return (error);
1315 }
1316
1317 static int
1318 unp_connect2(struct socket *so, struct socket *so2, int req)
1319 {
1320 struct unpcb *unp;
1321 struct unpcb *unp2;
1322
1323 unp = sotounpcb(so);
1324 KASSERT(unp != NULL, ("unp_connect2: unp == NULL"));
1325 unp2 = sotounpcb(so2);
1326 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL"));
1327
1328 UNP_LINK_WLOCK_ASSERT();
1329 UNP_PCB_LOCK_ASSERT(unp);
1330 UNP_PCB_LOCK_ASSERT(unp2);
1331
1332 if (so2->so_type != so->so_type)
1333 return (EPROTOTYPE);
1334 unp->unp_conn = unp2;
1335
1336 switch (so->so_type) {
1337 case SOCK_DGRAM:
1338 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink);
1339 soisconnected(so);
1340 break;
1341
1342 case SOCK_STREAM:
1343 unp2->unp_conn = unp;
1344 if (req == PRU_CONNECT &&
1345 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT))
1346 soisconnecting(so);
1347 else
1348 soisconnected(so);
1349 soisconnected(so2);
1350 break;
1351
1352 default:
1353 panic("unp_connect2");
1354 }
1355 return (0);
1356 }
1357
1358 static void
1359 unp_disconnect(struct unpcb *unp, struct unpcb *unp2)
1360 {
1361 struct socket *so;
1362
1363 KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL"));
1364
1365 UNP_LINK_WLOCK_ASSERT();
1366 UNP_PCB_LOCK_ASSERT(unp);
1367 UNP_PCB_LOCK_ASSERT(unp2);
1368
1369 unp->unp_conn = NULL;
1370 switch (unp->unp_socket->so_type) {
1371 case SOCK_DGRAM:
1372 LIST_REMOVE(unp, unp_reflink);
1373 so = unp->unp_socket;
1374 SOCK_LOCK(so);
1375 so->so_state &= ~SS_ISCONNECTED;
1376 SOCK_UNLOCK(so);
1377 break;
1378
1379 case SOCK_STREAM:
1380 soisdisconnected(unp->unp_socket);
1381 unp2->unp_conn = NULL;
1382 soisdisconnected(unp2->unp_socket);
1383 break;
1384 }
1385 }
1386
1387 /*
1388 * unp_pcblist() walks the global list of struct unpcb's to generate a
1389 * pointer list, bumping the refcount on each unpcb. It then copies them out
1390 * sequentially, validating the generation number on each to see if it has
1391 * been detached. All of this is necessary because copyout() may sleep on
1392 * disk I/O.
1393 */
1394 static int
1395 unp_pcblist(SYSCTL_HANDLER_ARGS)
1396 {
1397 int error, i, n;
1398 int freeunp;
1399 struct unpcb *unp, **unp_list;
1400 unp_gen_t gencnt;
1401 struct xunpgen *xug;
1402 struct unp_head *head;
1403 struct xunpcb *xu;
1404
1405 head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead);
1406
1407 /*
1408 * The process of preparing the PCB list is too time-consuming and
1409 * resource-intensive to repeat twice on every request.
1410 */
1411 if (req->oldptr == NULL) {
1412 n = unp_count;
1413 req->oldidx = 2 * (sizeof *xug)
1414 + (n + n/8) * sizeof(struct xunpcb);
1415 return (0);
1416 }
1417
1418 if (req->newptr != NULL)
1419 return (EPERM);
1420
1421 /*
1422 * OK, now we're committed to doing something.
1423 */
1424 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK);
1425 UNP_LIST_LOCK();
1426 gencnt = unp_gencnt;
1427 n = unp_count;
1428 UNP_LIST_UNLOCK();
1429
1430 xug->xug_len = sizeof *xug;
1431 xug->xug_count = n;
1432 xug->xug_gen = gencnt;
1433 xug->xug_sogen = so_gencnt;
1434 error = SYSCTL_OUT(req, xug, sizeof *xug);
1435 if (error) {
1436 free(xug, M_TEMP);
1437 return (error);
1438 }
1439
1440 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK);
1441
1442 UNP_LIST_LOCK();
1443 for (unp = LIST_FIRST(head), i = 0; unp && i < n;
1444 unp = LIST_NEXT(unp, unp_link)) {
1445 UNP_PCB_LOCK(unp);
1446 if (unp->unp_gencnt <= gencnt) {
1447 if (cr_cansee(req->td->td_ucred,
1448 unp->unp_socket->so_cred)) {
1449 UNP_PCB_UNLOCK(unp);
1450 continue;
1451 }
1452 unp_list[i++] = unp;
1453 unp->unp_refcount++;
1454 }
1455 UNP_PCB_UNLOCK(unp);
1456 }
1457 UNP_LIST_UNLOCK();
1458 n = i; /* In case we lost some during malloc. */
1459
1460 error = 0;
1461 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO);
1462 for (i = 0; i < n; i++) {
1463 unp = unp_list[i];
1464 UNP_PCB_LOCK(unp);
1465 unp->unp_refcount--;
1466 if (unp->unp_refcount != 0 && unp->unp_gencnt <= gencnt) {
1467 xu->xu_len = sizeof *xu;
1468 xu->xu_unpp = unp;
1469 /*
1470 * XXX - need more locking here to protect against
1471 * connect/disconnect races for SMP.
1472 */
1473 if (unp->unp_addr != NULL)
1474 bcopy(unp->unp_addr, &xu->xu_addr,
1475 unp->unp_addr->sun_len);
1476 if (unp->unp_conn != NULL &&
1477 unp->unp_conn->unp_addr != NULL)
1478 bcopy(unp->unp_conn->unp_addr,
1479 &xu->xu_caddr,
1480 unp->unp_conn->unp_addr->sun_len);
1481 bcopy(unp, &xu->xu_unp, sizeof *unp);
1482 sotoxsocket(unp->unp_socket, &xu->xu_socket);
1483 UNP_PCB_UNLOCK(unp);
1484 error = SYSCTL_OUT(req, xu, sizeof *xu);
1485 } else {
1486 freeunp = (unp->unp_refcount == 0);
1487 UNP_PCB_UNLOCK(unp);
1488 if (freeunp) {
1489 UNP_PCB_LOCK_DESTROY(unp);
1490 uma_zfree(unp_zone, unp);
1491 }
1492 }
1493 }
1494 free(xu, M_TEMP);
1495 if (!error) {
1496 /*
1497 * Give the user an updated idea of our state. If the
1498 * generation differs from what we told her before, she knows
1499 * that something happened while we were processing this
1500 * request, and it might be necessary to retry.
1501 */
1502 xug->xug_gen = unp_gencnt;
1503 xug->xug_sogen = so_gencnt;
1504 xug->xug_count = unp_count;
1505 error = SYSCTL_OUT(req, xug, sizeof *xug);
1506 }
1507 free(unp_list, M_TEMP);
1508 free(xug, M_TEMP);
1509 return (error);
1510 }
1511
1512 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD,
1513 (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb",
1514 "List of active local datagram sockets");
1515 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD,
1516 (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb",
1517 "List of active local stream sockets");
1518
1519 static void
1520 unp_shutdown(struct unpcb *unp)
1521 {
1522 struct unpcb *unp2;
1523 struct socket *so;
1524
1525 UNP_LINK_WLOCK_ASSERT();
1526 UNP_PCB_LOCK_ASSERT(unp);
1527
1528 unp2 = unp->unp_conn;
1529 if (unp->unp_socket->so_type == SOCK_STREAM && unp2 != NULL) {
1530 so = unp2->unp_socket;
1531 if (so != NULL)
1532 socantrcvmore(so);
1533 }
1534 }
1535
1536 static void
1537 unp_drop(struct unpcb *unp, int errno)
1538 {
1539 struct socket *so = unp->unp_socket;
1540 struct unpcb *unp2;
1541
1542 UNP_LINK_WLOCK_ASSERT();
1543 UNP_PCB_LOCK_ASSERT(unp);
1544
1545 so->so_error = errno;
1546 unp2 = unp->unp_conn;
1547 if (unp2 == NULL)
1548 return;
1549 UNP_PCB_LOCK(unp2);
1550 unp_disconnect(unp, unp2);
1551 UNP_PCB_UNLOCK(unp2);
1552 }
1553
1554 static void
1555 unp_freerights(struct file **rp, int fdcount)
1556 {
1557 int i;
1558 struct file *fp;
1559
1560 for (i = 0; i < fdcount; i++) {
1561 fp = *rp;
1562 *rp++ = NULL;
1563 unp_discard(fp);
1564 }
1565 }
1566
1567 static int
1568 unp_externalize(struct mbuf *control, struct mbuf **controlp)
1569 {
1570 struct thread *td = curthread; /* XXX */
1571 struct cmsghdr *cm = mtod(control, struct cmsghdr *);
1572 int i;
1573 int *fdp;
1574 struct file **rp;
1575 struct file *fp;
1576 void *data;
1577 socklen_t clen = control->m_len, datalen;
1578 int error, newfds;
1579 int f;
1580 u_int newlen;
1581
1582 UNP_LINK_UNLOCK_ASSERT();
1583
1584 error = 0;
1585 if (controlp != NULL) /* controlp == NULL => free control messages */
1586 *controlp = NULL;
1587 while (cm != NULL) {
1588 if (sizeof(*cm) > clen || cm->cmsg_len > clen) {
1589 error = EINVAL;
1590 break;
1591 }
1592 data = CMSG_DATA(cm);
1593 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
1594 if (cm->cmsg_level == SOL_SOCKET
1595 && cm->cmsg_type == SCM_RIGHTS) {
1596 newfds = datalen / sizeof(struct file *);
1597 rp = data;
1598
1599 /* If we're not outputting the descriptors free them. */
1600 if (error || controlp == NULL) {
1601 unp_freerights(rp, newfds);
1602 goto next;
1603 }
1604 FILEDESC_XLOCK(td->td_proc->p_fd);
1605 /* if the new FD's will not fit free them. */
1606 if (!fdavail(td, newfds)) {
1607 FILEDESC_XUNLOCK(td->td_proc->p_fd);
1608 error = EMSGSIZE;
1609 unp_freerights(rp, newfds);
1610 goto next;
1611 }
1612
1613 /*
1614 * Now change each pointer to an fd in the global
1615 * table to an integer that is the index to the local
1616 * fd table entry that we set up to point to the
1617 * global one we are transferring.
1618 */
1619 newlen = newfds * sizeof(int);
1620 *controlp = sbcreatecontrol(NULL, newlen,
1621 SCM_RIGHTS, SOL_SOCKET);
1622 if (*controlp == NULL) {
1623 FILEDESC_XUNLOCK(td->td_proc->p_fd);
1624 error = E2BIG;
1625 unp_freerights(rp, newfds);
1626 goto next;
1627 }
1628
1629 fdp = (int *)
1630 CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1631 for (i = 0; i < newfds; i++) {
1632 if (fdalloc(td, 0, &f))
1633 panic("unp_externalize fdalloc failed");
1634 fp = *rp++;
1635 td->td_proc->p_fd->fd_ofiles[f] = fp;
1636 unp_externalize_fp(fp);
1637 *fdp++ = f;
1638 }
1639 FILEDESC_XUNLOCK(td->td_proc->p_fd);
1640 } else {
1641 /* We can just copy anything else across. */
1642 if (error || controlp == NULL)
1643 goto next;
1644 *controlp = sbcreatecontrol(NULL, datalen,
1645 cm->cmsg_type, cm->cmsg_level);
1646 if (*controlp == NULL) {
1647 error = ENOBUFS;
1648 goto next;
1649 }
1650 bcopy(data,
1651 CMSG_DATA(mtod(*controlp, struct cmsghdr *)),
1652 datalen);
1653 }
1654 controlp = &(*controlp)->m_next;
1655
1656 next:
1657 if (CMSG_SPACE(datalen) < clen) {
1658 clen -= CMSG_SPACE(datalen);
1659 cm = (struct cmsghdr *)
1660 ((caddr_t)cm + CMSG_SPACE(datalen));
1661 } else {
1662 clen = 0;
1663 cm = NULL;
1664 }
1665 }
1666
1667 m_freem(control);
1668 return (error);
1669 }
1670
1671 static void
1672 unp_zone_change(void *tag)
1673 {
1674
1675 uma_zone_set_max(unp_zone, maxsockets);
1676 }
1677
1678 static void
1679 unp_init(void)
1680 {
1681
1682 #ifdef VIMAGE
1683 if (!IS_DEFAULT_VNET(curvnet))
1684 return;
1685 #endif
1686 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL,
1687 NULL, NULL, UMA_ALIGN_PTR, 0);
1688 if (unp_zone == NULL)
1689 panic("unp_init");
1690 uma_zone_set_max(unp_zone, maxsockets);
1691 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change,
1692 NULL, EVENTHANDLER_PRI_ANY);
1693 LIST_INIT(&unp_dhead);
1694 LIST_INIT(&unp_shead);
1695 SLIST_INIT(&unp_defers);
1696 TASK_INIT(&unp_gc_task, 0, unp_gc, NULL);
1697 TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL);
1698 UNP_LINK_LOCK_INIT();
1699 UNP_LIST_LOCK_INIT();
1700 UNP_DEFERRED_LOCK_INIT();
1701 }
1702
1703 static int
1704 unp_internalize(struct mbuf **controlp, struct thread *td)
1705 {
1706 struct mbuf *control = *controlp;
1707 struct proc *p = td->td_proc;
1708 struct filedesc *fdescp = p->p_fd;
1709 struct cmsghdr *cm = mtod(control, struct cmsghdr *);
1710 struct cmsgcred *cmcred;
1711 struct file **rp;
1712 struct file *fp;
1713 struct timeval *tv;
1714 int i, fd, *fdp;
1715 void *data;
1716 socklen_t clen = control->m_len, datalen;
1717 int error, oldfds;
1718 u_int newlen;
1719
1720 UNP_LINK_UNLOCK_ASSERT();
1721
1722 error = 0;
1723 *controlp = NULL;
1724 while (cm != NULL) {
1725 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET
1726 || cm->cmsg_len > clen) {
1727 error = EINVAL;
1728 goto out;
1729 }
1730 data = CMSG_DATA(cm);
1731 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
1732
1733 switch (cm->cmsg_type) {
1734 /*
1735 * Fill in credential information.
1736 */
1737 case SCM_CREDS:
1738 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred),
1739 SCM_CREDS, SOL_SOCKET);
1740 if (*controlp == NULL) {
1741 error = ENOBUFS;
1742 goto out;
1743 }
1744 cmcred = (struct cmsgcred *)
1745 CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1746 cmcred->cmcred_pid = p->p_pid;
1747 cmcred->cmcred_uid = td->td_ucred->cr_ruid;
1748 cmcred->cmcred_gid = td->td_ucred->cr_rgid;
1749 cmcred->cmcred_euid = td->td_ucred->cr_uid;
1750 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups,
1751 CMGROUP_MAX);
1752 for (i = 0; i < cmcred->cmcred_ngroups; i++)
1753 cmcred->cmcred_groups[i] =
1754 td->td_ucred->cr_groups[i];
1755 break;
1756
1757 case SCM_RIGHTS:
1758 oldfds = datalen / sizeof (int);
1759 /*
1760 * Check that all the FDs passed in refer to legal
1761 * files. If not, reject the entire operation.
1762 */
1763 fdp = data;
1764 FILEDESC_SLOCK(fdescp);
1765 for (i = 0; i < oldfds; i++) {
1766 fd = *fdp++;
1767 if ((unsigned)fd >= fdescp->fd_nfiles ||
1768 fdescp->fd_ofiles[fd] == NULL) {
1769 FILEDESC_SUNLOCK(fdescp);
1770 error = EBADF;
1771 goto out;
1772 }
1773 fp = fdescp->fd_ofiles[fd];
1774 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) {
1775 FILEDESC_SUNLOCK(fdescp);
1776 error = EOPNOTSUPP;
1777 goto out;
1778 }
1779
1780 }
1781
1782 /*
1783 * Now replace the integer FDs with pointers to the
1784 * associated global file table entry..
1785 */
1786 newlen = oldfds * sizeof(struct file *);
1787 *controlp = sbcreatecontrol(NULL, newlen,
1788 SCM_RIGHTS, SOL_SOCKET);
1789 if (*controlp == NULL) {
1790 FILEDESC_SUNLOCK(fdescp);
1791 error = E2BIG;
1792 goto out;
1793 }
1794 fdp = data;
1795 rp = (struct file **)
1796 CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1797 for (i = 0; i < oldfds; i++) {
1798 fp = fdescp->fd_ofiles[*fdp++];
1799 *rp++ = fp;
1800 unp_internalize_fp(fp);
1801 }
1802 FILEDESC_SUNLOCK(fdescp);
1803 break;
1804
1805 case SCM_TIMESTAMP:
1806 *controlp = sbcreatecontrol(NULL, sizeof(*tv),
1807 SCM_TIMESTAMP, SOL_SOCKET);
1808 if (*controlp == NULL) {
1809 error = ENOBUFS;
1810 goto out;
1811 }
1812 tv = (struct timeval *)
1813 CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1814 microtime(tv);
1815 break;
1816
1817 default:
1818 error = EINVAL;
1819 goto out;
1820 }
1821
1822 controlp = &(*controlp)->m_next;
1823 if (CMSG_SPACE(datalen) < clen) {
1824 clen -= CMSG_SPACE(datalen);
1825 cm = (struct cmsghdr *)
1826 ((caddr_t)cm + CMSG_SPACE(datalen));
1827 } else {
1828 clen = 0;
1829 cm = NULL;
1830 }
1831 }
1832
1833 out:
1834 m_freem(control);
1835 return (error);
1836 }
1837
1838 static struct mbuf *
1839 unp_addsockcred(struct thread *td, struct mbuf *control)
1840 {
1841 struct mbuf *m, *n, *n_prev;
1842 struct sockcred *sc;
1843 const struct cmsghdr *cm;
1844 int ngroups;
1845 int i;
1846
1847 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX);
1848 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET);
1849 if (m == NULL)
1850 return (control);
1851
1852 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *));
1853 sc->sc_uid = td->td_ucred->cr_ruid;
1854 sc->sc_euid = td->td_ucred->cr_uid;
1855 sc->sc_gid = td->td_ucred->cr_rgid;
1856 sc->sc_egid = td->td_ucred->cr_gid;
1857 sc->sc_ngroups = ngroups;
1858 for (i = 0; i < sc->sc_ngroups; i++)
1859 sc->sc_groups[i] = td->td_ucred->cr_groups[i];
1860
1861 /*
1862 * Unlink SCM_CREDS control messages (struct cmsgcred), since just
1863 * created SCM_CREDS control message (struct sockcred) has another
1864 * format.
1865 */
1866 if (control != NULL)
1867 for (n = control, n_prev = NULL; n != NULL;) {
1868 cm = mtod(n, struct cmsghdr *);
1869 if (cm->cmsg_level == SOL_SOCKET &&
1870 cm->cmsg_type == SCM_CREDS) {
1871 if (n_prev == NULL)
1872 control = n->m_next;
1873 else
1874 n_prev->m_next = n->m_next;
1875 n = m_free(n);
1876 } else {
1877 n_prev = n;
1878 n = n->m_next;
1879 }
1880 }
1881
1882 /* Prepend it to the head. */
1883 m->m_next = control;
1884 return (m);
1885 }
1886
1887 static struct unpcb *
1888 fptounp(struct file *fp)
1889 {
1890 struct socket *so;
1891
1892 if (fp->f_type != DTYPE_SOCKET)
1893 return (NULL);
1894 if ((so = fp->f_data) == NULL)
1895 return (NULL);
1896 if (so->so_proto->pr_domain != &localdomain)
1897 return (NULL);
1898 return sotounpcb(so);
1899 }
1900
1901 static void
1902 unp_discard(struct file *fp)
1903 {
1904 struct unp_defer *dr;
1905
1906 if (unp_externalize_fp(fp)) {
1907 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK);
1908 dr->ud_fp = fp;
1909 UNP_DEFERRED_LOCK();
1910 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link);
1911 UNP_DEFERRED_UNLOCK();
1912 atomic_add_int(&unp_defers_count, 1);
1913 taskqueue_enqueue(taskqueue_thread, &unp_defer_task);
1914 } else
1915 (void) closef(fp, (struct thread *)NULL);
1916 }
1917
1918 static void
1919 unp_process_defers(void *arg __unused, int pending)
1920 {
1921 struct unp_defer *dr;
1922 SLIST_HEAD(, unp_defer) drl;
1923 int count;
1924
1925 SLIST_INIT(&drl);
1926 for (;;) {
1927 UNP_DEFERRED_LOCK();
1928 if (SLIST_FIRST(&unp_defers) == NULL) {
1929 UNP_DEFERRED_UNLOCK();
1930 break;
1931 }
1932 SLIST_SWAP(&unp_defers, &drl, unp_defer);
1933 UNP_DEFERRED_UNLOCK();
1934 count = 0;
1935 while ((dr = SLIST_FIRST(&drl)) != NULL) {
1936 SLIST_REMOVE_HEAD(&drl, ud_link);
1937 closef(dr->ud_fp, NULL);
1938 free(dr, M_TEMP);
1939 count++;
1940 }
1941 atomic_add_int(&unp_defers_count, -count);
1942 }
1943 }
1944
1945 static void
1946 unp_internalize_fp(struct file *fp)
1947 {
1948 struct unpcb *unp;
1949
1950 UNP_LINK_WLOCK();
1951 if ((unp = fptounp(fp)) != NULL) {
1952 unp->unp_file = fp;
1953 unp->unp_msgcount++;
1954 }
1955 fhold(fp);
1956 unp_rights++;
1957 UNP_LINK_WUNLOCK();
1958 }
1959
1960 static int
1961 unp_externalize_fp(struct file *fp)
1962 {
1963 struct unpcb *unp;
1964 int ret;
1965
1966 UNP_LINK_WLOCK();
1967 if ((unp = fptounp(fp)) != NULL) {
1968 unp->unp_msgcount--;
1969 ret = 1;
1970 } else
1971 ret = 0;
1972 unp_rights--;
1973 UNP_LINK_WUNLOCK();
1974 return (ret);
1975 }
1976
1977 /*
1978 * unp_defer indicates whether additional work has been defered for a future
1979 * pass through unp_gc(). It is thread local and does not require explicit
1980 * synchronization.
1981 */
1982 static int unp_marked;
1983 static int unp_unreachable;
1984
1985 static void
1986 unp_accessable(struct file *fp)
1987 {
1988 struct unpcb *unp;
1989
1990 if ((unp = fptounp(fp)) == NULL)
1991 return;
1992 if (unp->unp_gcflag & UNPGC_REF)
1993 return;
1994 unp->unp_gcflag &= ~UNPGC_DEAD;
1995 unp->unp_gcflag |= UNPGC_REF;
1996 unp_marked++;
1997 }
1998
1999 static void
2000 unp_gc_process(struct unpcb *unp)
2001 {
2002 struct socket *soa;
2003 struct socket *so;
2004 struct file *fp;
2005
2006 /* Already processed. */
2007 if (unp->unp_gcflag & UNPGC_SCANNED)
2008 return;
2009 fp = unp->unp_file;
2010
2011 /*
2012 * Check for a socket potentially in a cycle. It must be in a
2013 * queue as indicated by msgcount, and this must equal the file
2014 * reference count. Note that when msgcount is 0 the file is NULL.
2015 */
2016 if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp &&
2017 unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) {
2018 unp->unp_gcflag |= UNPGC_DEAD;
2019 unp_unreachable++;
2020 return;
2021 }
2022
2023 /*
2024 * Mark all sockets we reference with RIGHTS.
2025 */
2026 so = unp->unp_socket;
2027 SOCKBUF_LOCK(&so->so_rcv);
2028 unp_scan(so->so_rcv.sb_mb, unp_accessable);
2029 SOCKBUF_UNLOCK(&so->so_rcv);
2030
2031 /*
2032 * Mark all sockets in our accept queue.
2033 */
2034 ACCEPT_LOCK();
2035 TAILQ_FOREACH(soa, &so->so_comp, so_list) {
2036 SOCKBUF_LOCK(&soa->so_rcv);
2037 unp_scan(soa->so_rcv.sb_mb, unp_accessable);
2038 SOCKBUF_UNLOCK(&soa->so_rcv);
2039 }
2040 ACCEPT_UNLOCK();
2041 unp->unp_gcflag |= UNPGC_SCANNED;
2042 }
2043
2044 static int unp_recycled;
2045 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0,
2046 "Number of unreachable sockets claimed by the garbage collector.");
2047
2048 static int unp_taskcount;
2049 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0,
2050 "Number of times the garbage collector has run.");
2051
2052 static void
2053 unp_gc(__unused void *arg, int pending)
2054 {
2055 struct unp_head *heads[] = { &unp_dhead, &unp_shead, NULL };
2056 struct unp_head **head;
2057 struct file *f, **unref;
2058 struct unpcb *unp;
2059 int i, total;
2060
2061 unp_taskcount++;
2062 UNP_LIST_LOCK();
2063 /*
2064 * First clear all gc flags from previous runs.
2065 */
2066 for (head = heads; *head != NULL; head++)
2067 LIST_FOREACH(unp, *head, unp_link)
2068 unp->unp_gcflag = 0;
2069
2070 /*
2071 * Scan marking all reachable sockets with UNPGC_REF. Once a socket
2072 * is reachable all of the sockets it references are reachable.
2073 * Stop the scan once we do a complete loop without discovering
2074 * a new reachable socket.
2075 */
2076 do {
2077 unp_unreachable = 0;
2078 unp_marked = 0;
2079 for (head = heads; *head != NULL; head++)
2080 LIST_FOREACH(unp, *head, unp_link)
2081 unp_gc_process(unp);
2082 } while (unp_marked);
2083 UNP_LIST_UNLOCK();
2084 if (unp_unreachable == 0)
2085 return;
2086
2087 /*
2088 * Allocate space for a local list of dead unpcbs.
2089 */
2090 unref = malloc(unp_unreachable * sizeof(struct file *),
2091 M_TEMP, M_WAITOK);
2092
2093 /*
2094 * Iterate looking for sockets which have been specifically marked
2095 * as as unreachable and store them locally.
2096 */
2097 UNP_LINK_RLOCK();
2098 UNP_LIST_LOCK();
2099 for (total = 0, head = heads; *head != NULL; head++)
2100 LIST_FOREACH(unp, *head, unp_link)
2101 if ((unp->unp_gcflag & UNPGC_DEAD) != 0) {
2102 f = unp->unp_file;
2103 if (unp->unp_msgcount == 0 || f == NULL ||
2104 f->f_count != unp->unp_msgcount)
2105 continue;
2106 unref[total++] = f;
2107 fhold(f);
2108 KASSERT(total <= unp_unreachable,
2109 ("unp_gc: incorrect unreachable count."));
2110 }
2111 UNP_LIST_UNLOCK();
2112 UNP_LINK_RUNLOCK();
2113
2114 /*
2115 * Now flush all sockets, free'ing rights. This will free the
2116 * struct files associated with these sockets but leave each socket
2117 * with one remaining ref.
2118 */
2119 for (i = 0; i < total; i++) {
2120 struct socket *so;
2121
2122 so = unref[i]->f_data;
2123 CURVNET_SET(so->so_vnet);
2124 sorflush(so);
2125 CURVNET_RESTORE();
2126 }
2127
2128 /*
2129 * And finally release the sockets so they can be reclaimed.
2130 */
2131 for (i = 0; i < total; i++)
2132 fdrop(unref[i], NULL);
2133 unp_recycled += total;
2134 free(unref, M_TEMP);
2135 }
2136
2137 static void
2138 unp_dispose(struct mbuf *m)
2139 {
2140
2141 if (m)
2142 unp_scan(m, unp_discard);
2143 }
2144
2145 static void
2146 unp_scan(struct mbuf *m0, void (*op)(struct file *))
2147 {
2148 struct mbuf *m;
2149 struct file **rp;
2150 struct cmsghdr *cm;
2151 void *data;
2152 int i;
2153 socklen_t clen, datalen;
2154 int qfds;
2155
2156 while (m0 != NULL) {
2157 for (m = m0; m; m = m->m_next) {
2158 if (m->m_type != MT_CONTROL)
2159 continue;
2160
2161 cm = mtod(m, struct cmsghdr *);
2162 clen = m->m_len;
2163
2164 while (cm != NULL) {
2165 if (sizeof(*cm) > clen || cm->cmsg_len > clen)
2166 break;
2167
2168 data = CMSG_DATA(cm);
2169 datalen = (caddr_t)cm + cm->cmsg_len
2170 - (caddr_t)data;
2171
2172 if (cm->cmsg_level == SOL_SOCKET &&
2173 cm->cmsg_type == SCM_RIGHTS) {
2174 qfds = datalen / sizeof (struct file *);
2175 rp = data;
2176 for (i = 0; i < qfds; i++)
2177 (*op)(*rp++);
2178 }
2179
2180 if (CMSG_SPACE(datalen) < clen) {
2181 clen -= CMSG_SPACE(datalen);
2182 cm = (struct cmsghdr *)
2183 ((caddr_t)cm + CMSG_SPACE(datalen));
2184 } else {
2185 clen = 0;
2186 cm = NULL;
2187 }
2188 }
2189 }
2190 m0 = m0->m_act;
2191 }
2192 }
2193
2194 #ifdef DDB
2195 static void
2196 db_print_indent(int indent)
2197 {
2198 int i;
2199
2200 for (i = 0; i < indent; i++)
2201 db_printf(" ");
2202 }
2203
2204 static void
2205 db_print_unpflags(int unp_flags)
2206 {
2207 int comma;
2208
2209 comma = 0;
2210 if (unp_flags & UNP_HAVEPC) {
2211 db_printf("%sUNP_HAVEPC", comma ? ", " : "");
2212 comma = 1;
2213 }
2214 if (unp_flags & UNP_HAVEPCCACHED) {
2215 db_printf("%sUNP_HAVEPCCACHED", comma ? ", " : "");
2216 comma = 1;
2217 }
2218 if (unp_flags & UNP_WANTCRED) {
2219 db_printf("%sUNP_WANTCRED", comma ? ", " : "");
2220 comma = 1;
2221 }
2222 if (unp_flags & UNP_CONNWAIT) {
2223 db_printf("%sUNP_CONNWAIT", comma ? ", " : "");
2224 comma = 1;
2225 }
2226 if (unp_flags & UNP_CONNECTING) {
2227 db_printf("%sUNP_CONNECTING", comma ? ", " : "");
2228 comma = 1;
2229 }
2230 if (unp_flags & UNP_BINDING) {
2231 db_printf("%sUNP_BINDING", comma ? ", " : "");
2232 comma = 1;
2233 }
2234 }
2235
2236 static void
2237 db_print_xucred(int indent, struct xucred *xu)
2238 {
2239 int comma, i;
2240
2241 db_print_indent(indent);
2242 db_printf("cr_version: %u cr_uid: %u cr_ngroups: %d\n",
2243 xu->cr_version, xu->cr_uid, xu->cr_ngroups);
2244 db_print_indent(indent);
2245 db_printf("cr_groups: ");
2246 comma = 0;
2247 for (i = 0; i < xu->cr_ngroups; i++) {
2248 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]);
2249 comma = 1;
2250 }
2251 db_printf("\n");
2252 }
2253
2254 static void
2255 db_print_unprefs(int indent, struct unp_head *uh)
2256 {
2257 struct unpcb *unp;
2258 int counter;
2259
2260 counter = 0;
2261 LIST_FOREACH(unp, uh, unp_reflink) {
2262 if (counter % 4 == 0)
2263 db_print_indent(indent);
2264 db_printf("%p ", unp);
2265 if (counter % 4 == 3)
2266 db_printf("\n");
2267 counter++;
2268 }
2269 if (counter != 0 && counter % 4 != 0)
2270 db_printf("\n");
2271 }
2272
2273 DB_SHOW_COMMAND(unpcb, db_show_unpcb)
2274 {
2275 struct unpcb *unp;
2276
2277 if (!have_addr) {
2278 db_printf("usage: show unpcb <addr>\n");
2279 return;
2280 }
2281 unp = (struct unpcb *)addr;
2282
2283 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket,
2284 unp->unp_vnode);
2285
2286 db_printf("unp_ino: %d unp_conn: %p\n", unp->unp_ino,
2287 unp->unp_conn);
2288
2289 db_printf("unp_refs:\n");
2290 db_print_unprefs(2, &unp->unp_refs);
2291
2292 /* XXXRW: Would be nice to print the full address, if any. */
2293 db_printf("unp_addr: %p\n", unp->unp_addr);
2294
2295 db_printf("unp_cc: %d unp_mbcnt: %d unp_gencnt: %llu\n",
2296 unp->unp_cc, unp->unp_mbcnt,
2297 (unsigned long long)unp->unp_gencnt);
2298
2299 db_printf("unp_flags: %x (", unp->unp_flags);
2300 db_print_unpflags(unp->unp_flags);
2301 db_printf(")\n");
2302
2303 db_printf("unp_peercred:\n");
2304 db_print_xucred(2, &unp->unp_peercred);
2305
2306 db_printf("unp_refcount: %u\n", unp->unp_refcount);
2307 }
2308 #endif
Cache object: 118fb0ab23084ed7615f52b9d4d8b24d
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