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 * RDM
54 * distinguish datagram size limits from flow control limits in SEQPACKET
55 * rethink name space problems
56 * need a proper out-of-band
57 */
58
59 #include <sys/cdefs.h>
60 __FBSDID("$FreeBSD: releng/10.0/sys/kern/uipc_usrreq.c 255478 2013-09-11 18:22:30Z glebius $");
61
62 #include "opt_ddb.h"
63
64 #include <sys/param.h>
65 #include <sys/capability.h>
66 #include <sys/domain.h>
67 #include <sys/fcntl.h>
68 #include <sys/malloc.h> /* XXX must be before <sys/file.h> */
69 #include <sys/eventhandler.h>
70 #include <sys/file.h>
71 #include <sys/filedesc.h>
72 #include <sys/kernel.h>
73 #include <sys/lock.h>
74 #include <sys/mbuf.h>
75 #include <sys/mount.h>
76 #include <sys/mutex.h>
77 #include <sys/namei.h>
78 #include <sys/proc.h>
79 #include <sys/protosw.h>
80 #include <sys/queue.h>
81 #include <sys/resourcevar.h>
82 #include <sys/rwlock.h>
83 #include <sys/socket.h>
84 #include <sys/socketvar.h>
85 #include <sys/signalvar.h>
86 #include <sys/stat.h>
87 #include <sys/sx.h>
88 #include <sys/sysctl.h>
89 #include <sys/systm.h>
90 #include <sys/taskqueue.h>
91 #include <sys/un.h>
92 #include <sys/unpcb.h>
93 #include <sys/vnode.h>
94
95 #include <net/vnet.h>
96
97 #ifdef DDB
98 #include <ddb/ddb.h>
99 #endif
100
101 #include <security/mac/mac_framework.h>
102
103 #include <vm/uma.h>
104
105 MALLOC_DECLARE(M_FILECAPS);
106
107 /*
108 * Locking key:
109 * (l) Locked using list lock
110 * (g) Locked using linkage lock
111 */
112
113 static uma_zone_t unp_zone;
114 static unp_gen_t unp_gencnt; /* (l) */
115 static u_int unp_count; /* (l) Count of local sockets. */
116 static ino_t unp_ino; /* Prototype for fake inode numbers. */
117 static int unp_rights; /* (g) File descriptors in flight. */
118 static struct unp_head unp_shead; /* (l) List of stream sockets. */
119 static struct unp_head unp_dhead; /* (l) List of datagram sockets. */
120 static struct unp_head unp_sphead; /* (l) List of seqpacket sockets. */
121
122 struct unp_defer {
123 SLIST_ENTRY(unp_defer) ud_link;
124 struct file *ud_fp;
125 };
126 static SLIST_HEAD(, unp_defer) unp_defers;
127 static int unp_defers_count;
128
129 static const struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL };
130
131 /*
132 * Garbage collection of cyclic file descriptor/socket references occurs
133 * asynchronously in a taskqueue context in order to avoid recursion and
134 * reentrance in the UNIX domain socket, file descriptor, and socket layer
135 * code. See unp_gc() for a full description.
136 */
137 static struct timeout_task unp_gc_task;
138
139 /*
140 * The close of unix domain sockets attached as SCM_RIGHTS is
141 * postponed to the taskqueue, to avoid arbitrary recursion depth.
142 * The attached sockets might have another sockets attached.
143 */
144 static struct task unp_defer_task;
145
146 /*
147 * Both send and receive buffers are allocated PIPSIZ bytes of buffering for
148 * stream sockets, although the total for sender and receiver is actually
149 * only PIPSIZ.
150 *
151 * Datagram sockets really use the sendspace as the maximum datagram size,
152 * and don't really want to reserve the sendspace. Their recvspace should be
153 * large enough for at least one max-size datagram plus address.
154 */
155 #ifndef PIPSIZ
156 #define PIPSIZ 8192
157 #endif
158 static u_long unpst_sendspace = PIPSIZ;
159 static u_long unpst_recvspace = PIPSIZ;
160 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */
161 static u_long unpdg_recvspace = 4*1024;
162 static u_long unpsp_sendspace = PIPSIZ; /* really max datagram size */
163 static u_long unpsp_recvspace = PIPSIZ;
164
165 static SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW, 0, "Local domain");
166 static SYSCTL_NODE(_net_local, SOCK_STREAM, stream, CTLFLAG_RW, 0,
167 "SOCK_STREAM");
168 static SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram, CTLFLAG_RW, 0, "SOCK_DGRAM");
169 static SYSCTL_NODE(_net_local, SOCK_SEQPACKET, seqpacket, CTLFLAG_RW, 0,
170 "SOCK_SEQPACKET");
171
172 SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW,
173 &unpst_sendspace, 0, "Default stream send space.");
174 SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW,
175 &unpst_recvspace, 0, "Default stream receive space.");
176 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW,
177 &unpdg_sendspace, 0, "Default datagram send space.");
178 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW,
179 &unpdg_recvspace, 0, "Default datagram receive space.");
180 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, maxseqpacket, CTLFLAG_RW,
181 &unpsp_sendspace, 0, "Default seqpacket send space.");
182 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, recvspace, CTLFLAG_RW,
183 &unpsp_recvspace, 0, "Default seqpacket receive space.");
184 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0,
185 "File descriptors in flight.");
186 SYSCTL_INT(_net_local, OID_AUTO, deferred, CTLFLAG_RD,
187 &unp_defers_count, 0,
188 "File descriptors deferred to taskqueue for close.");
189
190 /*
191 * Locking and synchronization:
192 *
193 * Three types of locks exit in the local domain socket implementation: a
194 * global list mutex, a global linkage rwlock, and per-unpcb mutexes. Of the
195 * global locks, the list lock protects the socket count, global generation
196 * number, and stream/datagram global lists. The linkage lock protects the
197 * interconnection of unpcbs, the v_socket and unp_vnode pointers, and can be
198 * held exclusively over the acquisition of multiple unpcb locks to prevent
199 * deadlock.
200 *
201 * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer,
202 * allocated in pru_attach() and freed in pru_detach(). The validity of that
203 * pointer is an invariant, so no lock is required to dereference the so_pcb
204 * pointer if a valid socket reference is held by the caller. In practice,
205 * this is always true during operations performed on a socket. Each unpcb
206 * has a back-pointer to its socket, unp_socket, which will be stable under
207 * the same circumstances.
208 *
209 * This pointer may only be safely dereferenced as long as a valid reference
210 * to the unpcb is held. Typically, this reference will be from the socket,
211 * or from another unpcb when the referring unpcb's lock is held (in order
212 * that the reference not be invalidated during use). For example, to follow
213 * unp->unp_conn->unp_socket, you need unlock the lock on unp, not unp_conn,
214 * as unp_socket remains valid as long as the reference to unp_conn is valid.
215 *
216 * Fields of unpcbss are locked using a per-unpcb lock, unp_mtx. Individual
217 * atomic reads without the lock may be performed "lockless", but more
218 * complex reads and read-modify-writes require the mutex to be held. No
219 * lock order is defined between unpcb locks -- multiple unpcb locks may be
220 * acquired at the same time only when holding the linkage rwlock
221 * exclusively, which prevents deadlocks.
222 *
223 * Blocking with UNIX domain sockets is a tricky issue: unlike most network
224 * protocols, bind() is a non-atomic operation, and connect() requires
225 * potential sleeping in the protocol, due to potentially waiting on local or
226 * distributed file systems. We try to separate "lookup" operations, which
227 * may sleep, and the IPC operations themselves, which typically can occur
228 * with relative atomicity as locks can be held over the entire operation.
229 *
230 * Another tricky issue is simultaneous multi-threaded or multi-process
231 * access to a single UNIX domain socket. These are handled by the flags
232 * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or
233 * binding, both of which involve dropping UNIX domain socket locks in order
234 * to perform namei() and other file system operations.
235 */
236 static struct rwlock unp_link_rwlock;
237 static struct mtx unp_list_lock;
238 static struct mtx unp_defers_lock;
239
240 #define UNP_LINK_LOCK_INIT() rw_init(&unp_link_rwlock, \
241 "unp_link_rwlock")
242
243 #define UNP_LINK_LOCK_ASSERT() rw_assert(&unp_link_rwlock, \
244 RA_LOCKED)
245 #define UNP_LINK_UNLOCK_ASSERT() rw_assert(&unp_link_rwlock, \
246 RA_UNLOCKED)
247
248 #define UNP_LINK_RLOCK() rw_rlock(&unp_link_rwlock)
249 #define UNP_LINK_RUNLOCK() rw_runlock(&unp_link_rwlock)
250 #define UNP_LINK_WLOCK() rw_wlock(&unp_link_rwlock)
251 #define UNP_LINK_WUNLOCK() rw_wunlock(&unp_link_rwlock)
252 #define UNP_LINK_WLOCK_ASSERT() rw_assert(&unp_link_rwlock, \
253 RA_WLOCKED)
254
255 #define UNP_LIST_LOCK_INIT() mtx_init(&unp_list_lock, \
256 "unp_list_lock", NULL, MTX_DEF)
257 #define UNP_LIST_LOCK() mtx_lock(&unp_list_lock)
258 #define UNP_LIST_UNLOCK() mtx_unlock(&unp_list_lock)
259
260 #define UNP_DEFERRED_LOCK_INIT() mtx_init(&unp_defers_lock, \
261 "unp_defer", NULL, MTX_DEF)
262 #define UNP_DEFERRED_LOCK() mtx_lock(&unp_defers_lock)
263 #define UNP_DEFERRED_UNLOCK() mtx_unlock(&unp_defers_lock)
264
265 #define UNP_PCB_LOCK_INIT(unp) mtx_init(&(unp)->unp_mtx, \
266 "unp_mtx", "unp_mtx", \
267 MTX_DUPOK|MTX_DEF|MTX_RECURSE)
268 #define UNP_PCB_LOCK_DESTROY(unp) mtx_destroy(&(unp)->unp_mtx)
269 #define UNP_PCB_LOCK(unp) mtx_lock(&(unp)->unp_mtx)
270 #define UNP_PCB_UNLOCK(unp) mtx_unlock(&(unp)->unp_mtx)
271 #define UNP_PCB_LOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_OWNED)
272
273 static int uipc_connect2(struct socket *, struct socket *);
274 static int uipc_ctloutput(struct socket *, struct sockopt *);
275 static int unp_connect(struct socket *, struct sockaddr *,
276 struct thread *);
277 static int unp_connectat(int, struct socket *, struct sockaddr *,
278 struct thread *);
279 static int unp_connect2(struct socket *so, struct socket *so2, int);
280 static void unp_disconnect(struct unpcb *unp, struct unpcb *unp2);
281 static void unp_dispose(struct mbuf *);
282 static void unp_shutdown(struct unpcb *);
283 static void unp_drop(struct unpcb *, int);
284 static void unp_gc(__unused void *, int);
285 static void unp_scan(struct mbuf *, void (*)(struct filedescent **, int));
286 static void unp_discard(struct file *);
287 static void unp_freerights(struct filedescent **, int);
288 static void unp_init(void);
289 static int unp_internalize(struct mbuf **, struct thread *);
290 static void unp_internalize_fp(struct file *);
291 static int unp_externalize(struct mbuf *, struct mbuf **, int);
292 static int unp_externalize_fp(struct file *);
293 static struct mbuf *unp_addsockcred(struct thread *, struct mbuf *);
294 static void unp_process_defers(void * __unused, int);
295
296 /*
297 * Definitions of protocols supported in the LOCAL domain.
298 */
299 static struct domain localdomain;
300 static struct pr_usrreqs uipc_usrreqs_dgram, uipc_usrreqs_stream;
301 static struct pr_usrreqs uipc_usrreqs_seqpacket;
302 static struct protosw localsw[] = {
303 {
304 .pr_type = SOCK_STREAM,
305 .pr_domain = &localdomain,
306 .pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS,
307 .pr_ctloutput = &uipc_ctloutput,
308 .pr_usrreqs = &uipc_usrreqs_stream
309 },
310 {
311 .pr_type = SOCK_DGRAM,
312 .pr_domain = &localdomain,
313 .pr_flags = PR_ATOMIC|PR_ADDR|PR_RIGHTS,
314 .pr_ctloutput = &uipc_ctloutput,
315 .pr_usrreqs = &uipc_usrreqs_dgram
316 },
317 {
318 .pr_type = SOCK_SEQPACKET,
319 .pr_domain = &localdomain,
320
321 /*
322 * XXXRW: For now, PR_ADDR because soreceive will bump into them
323 * due to our use of sbappendaddr. A new sbappend variants is needed
324 * that supports both atomic record writes and control data.
325 */
326 .pr_flags = PR_ADDR|PR_ATOMIC|PR_CONNREQUIRED|PR_WANTRCVD|
327 PR_RIGHTS,
328 .pr_ctloutput = &uipc_ctloutput,
329 .pr_usrreqs = &uipc_usrreqs_seqpacket,
330 },
331 };
332
333 static struct domain localdomain = {
334 .dom_family = AF_LOCAL,
335 .dom_name = "local",
336 .dom_init = unp_init,
337 .dom_externalize = unp_externalize,
338 .dom_dispose = unp_dispose,
339 .dom_protosw = localsw,
340 .dom_protoswNPROTOSW = &localsw[sizeof(localsw)/sizeof(localsw[0])]
341 };
342 DOMAIN_SET(local);
343
344 static void
345 uipc_abort(struct socket *so)
346 {
347 struct unpcb *unp, *unp2;
348
349 unp = sotounpcb(so);
350 KASSERT(unp != NULL, ("uipc_abort: unp == NULL"));
351
352 UNP_LINK_WLOCK();
353 UNP_PCB_LOCK(unp);
354 unp2 = unp->unp_conn;
355 if (unp2 != NULL) {
356 UNP_PCB_LOCK(unp2);
357 unp_drop(unp2, ECONNABORTED);
358 UNP_PCB_UNLOCK(unp2);
359 }
360 UNP_PCB_UNLOCK(unp);
361 UNP_LINK_WUNLOCK();
362 }
363
364 static int
365 uipc_accept(struct socket *so, struct sockaddr **nam)
366 {
367 struct unpcb *unp, *unp2;
368 const struct sockaddr *sa;
369
370 /*
371 * Pass back name of connected socket, if it was bound and we are
372 * still connected (our peer may have closed already!).
373 */
374 unp = sotounpcb(so);
375 KASSERT(unp != NULL, ("uipc_accept: unp == NULL"));
376
377 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
378 UNP_LINK_RLOCK();
379 unp2 = unp->unp_conn;
380 if (unp2 != NULL && unp2->unp_addr != NULL) {
381 UNP_PCB_LOCK(unp2);
382 sa = (struct sockaddr *) unp2->unp_addr;
383 bcopy(sa, *nam, sa->sa_len);
384 UNP_PCB_UNLOCK(unp2);
385 } else {
386 sa = &sun_noname;
387 bcopy(sa, *nam, sa->sa_len);
388 }
389 UNP_LINK_RUNLOCK();
390 return (0);
391 }
392
393 static int
394 uipc_attach(struct socket *so, int proto, struct thread *td)
395 {
396 u_long sendspace, recvspace;
397 struct unpcb *unp;
398 int error;
399
400 KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL"));
401 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
402 switch (so->so_type) {
403 case SOCK_STREAM:
404 sendspace = unpst_sendspace;
405 recvspace = unpst_recvspace;
406 break;
407
408 case SOCK_DGRAM:
409 sendspace = unpdg_sendspace;
410 recvspace = unpdg_recvspace;
411 break;
412
413 case SOCK_SEQPACKET:
414 sendspace = unpsp_sendspace;
415 recvspace = unpsp_recvspace;
416 break;
417
418 default:
419 panic("uipc_attach");
420 }
421 error = soreserve(so, sendspace, recvspace);
422 if (error)
423 return (error);
424 }
425 unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO);
426 if (unp == NULL)
427 return (ENOBUFS);
428 LIST_INIT(&unp->unp_refs);
429 UNP_PCB_LOCK_INIT(unp);
430 unp->unp_socket = so;
431 so->so_pcb = unp;
432 unp->unp_refcount = 1;
433
434 UNP_LIST_LOCK();
435 unp->unp_gencnt = ++unp_gencnt;
436 unp_count++;
437 switch (so->so_type) {
438 case SOCK_STREAM:
439 LIST_INSERT_HEAD(&unp_shead, unp, unp_link);
440 break;
441
442 case SOCK_DGRAM:
443 LIST_INSERT_HEAD(&unp_dhead, unp, unp_link);
444 break;
445
446 case SOCK_SEQPACKET:
447 LIST_INSERT_HEAD(&unp_sphead, unp, unp_link);
448 break;
449
450 default:
451 panic("uipc_attach");
452 }
453 UNP_LIST_UNLOCK();
454
455 return (0);
456 }
457
458 static int
459 uipc_bindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
460 {
461 struct sockaddr_un *soun = (struct sockaddr_un *)nam;
462 struct vattr vattr;
463 int error, namelen;
464 struct nameidata nd;
465 struct unpcb *unp;
466 struct vnode *vp;
467 struct mount *mp;
468 cap_rights_t rights;
469 char *buf;
470
471 unp = sotounpcb(so);
472 KASSERT(unp != NULL, ("uipc_bind: unp == NULL"));
473
474 if (soun->sun_len > sizeof(struct sockaddr_un))
475 return (EINVAL);
476 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path);
477 if (namelen <= 0)
478 return (EINVAL);
479
480 /*
481 * We don't allow simultaneous bind() calls on a single UNIX domain
482 * socket, so flag in-progress operations, and return an error if an
483 * operation is already in progress.
484 *
485 * Historically, we have not allowed a socket to be rebound, so this
486 * also returns an error. Not allowing re-binding simplifies the
487 * implementation and avoids a great many possible failure modes.
488 */
489 UNP_PCB_LOCK(unp);
490 if (unp->unp_vnode != NULL) {
491 UNP_PCB_UNLOCK(unp);
492 return (EINVAL);
493 }
494 if (unp->unp_flags & UNP_BINDING) {
495 UNP_PCB_UNLOCK(unp);
496 return (EALREADY);
497 }
498 unp->unp_flags |= UNP_BINDING;
499 UNP_PCB_UNLOCK(unp);
500
501 buf = malloc(namelen + 1, M_TEMP, M_WAITOK);
502 bcopy(soun->sun_path, buf, namelen);
503 buf[namelen] = 0;
504
505 restart:
506 NDINIT_ATRIGHTS(&nd, CREATE, NOFOLLOW | LOCKPARENT | SAVENAME,
507 UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_BINDAT), td);
508 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */
509 error = namei(&nd);
510 if (error)
511 goto error;
512 vp = nd.ni_vp;
513 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
514 NDFREE(&nd, NDF_ONLY_PNBUF);
515 if (nd.ni_dvp == vp)
516 vrele(nd.ni_dvp);
517 else
518 vput(nd.ni_dvp);
519 if (vp != NULL) {
520 vrele(vp);
521 error = EADDRINUSE;
522 goto error;
523 }
524 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH);
525 if (error)
526 goto error;
527 goto restart;
528 }
529 VATTR_NULL(&vattr);
530 vattr.va_type = VSOCK;
531 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask);
532 #ifdef MAC
533 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
534 &vattr);
535 #endif
536 if (error == 0)
537 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
538 NDFREE(&nd, NDF_ONLY_PNBUF);
539 vput(nd.ni_dvp);
540 if (error) {
541 vn_finished_write(mp);
542 goto error;
543 }
544 vp = nd.ni_vp;
545 ASSERT_VOP_ELOCKED(vp, "uipc_bind");
546 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK);
547
548 UNP_LINK_WLOCK();
549 UNP_PCB_LOCK(unp);
550 VOP_UNP_BIND(vp, unp->unp_socket);
551 unp->unp_vnode = vp;
552 unp->unp_addr = soun;
553 unp->unp_flags &= ~UNP_BINDING;
554 UNP_PCB_UNLOCK(unp);
555 UNP_LINK_WUNLOCK();
556 VOP_UNLOCK(vp, 0);
557 vn_finished_write(mp);
558 free(buf, M_TEMP);
559 return (0);
560
561 error:
562 UNP_PCB_LOCK(unp);
563 unp->unp_flags &= ~UNP_BINDING;
564 UNP_PCB_UNLOCK(unp);
565 free(buf, M_TEMP);
566 return (error);
567 }
568
569 static int
570 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
571 {
572
573 return (uipc_bindat(AT_FDCWD, so, nam, td));
574 }
575
576 static int
577 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
578 {
579 int error;
580
581 KASSERT(td == curthread, ("uipc_connect: td != curthread"));
582 UNP_LINK_WLOCK();
583 error = unp_connect(so, nam, td);
584 UNP_LINK_WUNLOCK();
585 return (error);
586 }
587
588 static int
589 uipc_connectat(int fd, struct socket *so, struct sockaddr *nam,
590 struct thread *td)
591 {
592 int error;
593
594 KASSERT(td == curthread, ("uipc_connectat: td != curthread"));
595 UNP_LINK_WLOCK();
596 error = unp_connectat(fd, so, nam, td);
597 UNP_LINK_WUNLOCK();
598 return (error);
599 }
600
601 static void
602 uipc_close(struct socket *so)
603 {
604 struct unpcb *unp, *unp2;
605
606 unp = sotounpcb(so);
607 KASSERT(unp != NULL, ("uipc_close: unp == NULL"));
608
609 UNP_LINK_WLOCK();
610 UNP_PCB_LOCK(unp);
611 unp2 = unp->unp_conn;
612 if (unp2 != NULL) {
613 UNP_PCB_LOCK(unp2);
614 unp_disconnect(unp, unp2);
615 UNP_PCB_UNLOCK(unp2);
616 }
617 UNP_PCB_UNLOCK(unp);
618 UNP_LINK_WUNLOCK();
619 }
620
621 static int
622 uipc_connect2(struct socket *so1, struct socket *so2)
623 {
624 struct unpcb *unp, *unp2;
625 int error;
626
627 UNP_LINK_WLOCK();
628 unp = so1->so_pcb;
629 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL"));
630 UNP_PCB_LOCK(unp);
631 unp2 = so2->so_pcb;
632 KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL"));
633 UNP_PCB_LOCK(unp2);
634 error = unp_connect2(so1, so2, PRU_CONNECT2);
635 UNP_PCB_UNLOCK(unp2);
636 UNP_PCB_UNLOCK(unp);
637 UNP_LINK_WUNLOCK();
638 return (error);
639 }
640
641 static void
642 uipc_detach(struct socket *so)
643 {
644 struct unpcb *unp, *unp2;
645 struct sockaddr_un *saved_unp_addr;
646 struct vnode *vp;
647 int freeunp, local_unp_rights;
648
649 unp = sotounpcb(so);
650 KASSERT(unp != NULL, ("uipc_detach: unp == NULL"));
651
652 UNP_LINK_WLOCK();
653 UNP_LIST_LOCK();
654 UNP_PCB_LOCK(unp);
655 LIST_REMOVE(unp, unp_link);
656 unp->unp_gencnt = ++unp_gencnt;
657 --unp_count;
658 UNP_LIST_UNLOCK();
659
660 /*
661 * XXXRW: Should assert vp->v_socket == so.
662 */
663 if ((vp = unp->unp_vnode) != NULL) {
664 VOP_UNP_DETACH(vp);
665 unp->unp_vnode = NULL;
666 }
667 unp2 = unp->unp_conn;
668 if (unp2 != NULL) {
669 UNP_PCB_LOCK(unp2);
670 unp_disconnect(unp, unp2);
671 UNP_PCB_UNLOCK(unp2);
672 }
673
674 /*
675 * We hold the linkage lock exclusively, so it's OK to acquire
676 * multiple pcb locks at a time.
677 */
678 while (!LIST_EMPTY(&unp->unp_refs)) {
679 struct unpcb *ref = LIST_FIRST(&unp->unp_refs);
680
681 UNP_PCB_LOCK(ref);
682 unp_drop(ref, ECONNRESET);
683 UNP_PCB_UNLOCK(ref);
684 }
685 local_unp_rights = unp_rights;
686 UNP_LINK_WUNLOCK();
687 unp->unp_socket->so_pcb = NULL;
688 saved_unp_addr = unp->unp_addr;
689 unp->unp_addr = NULL;
690 unp->unp_refcount--;
691 freeunp = (unp->unp_refcount == 0);
692 if (saved_unp_addr != NULL)
693 free(saved_unp_addr, M_SONAME);
694 if (freeunp) {
695 UNP_PCB_LOCK_DESTROY(unp);
696 uma_zfree(unp_zone, unp);
697 } else
698 UNP_PCB_UNLOCK(unp);
699 if (vp)
700 vrele(vp);
701 if (local_unp_rights)
702 taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1);
703 }
704
705 static int
706 uipc_disconnect(struct socket *so)
707 {
708 struct unpcb *unp, *unp2;
709
710 unp = sotounpcb(so);
711 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL"));
712
713 UNP_LINK_WLOCK();
714 UNP_PCB_LOCK(unp);
715 unp2 = unp->unp_conn;
716 if (unp2 != NULL) {
717 UNP_PCB_LOCK(unp2);
718 unp_disconnect(unp, unp2);
719 UNP_PCB_UNLOCK(unp2);
720 }
721 UNP_PCB_UNLOCK(unp);
722 UNP_LINK_WUNLOCK();
723 return (0);
724 }
725
726 static int
727 uipc_listen(struct socket *so, int backlog, struct thread *td)
728 {
729 struct unpcb *unp;
730 int error;
731
732 unp = sotounpcb(so);
733 KASSERT(unp != NULL, ("uipc_listen: unp == NULL"));
734
735 UNP_PCB_LOCK(unp);
736 if (unp->unp_vnode == NULL) {
737 UNP_PCB_UNLOCK(unp);
738 return (EINVAL);
739 }
740
741 SOCK_LOCK(so);
742 error = solisten_proto_check(so);
743 if (error == 0) {
744 cru2x(td->td_ucred, &unp->unp_peercred);
745 unp->unp_flags |= UNP_HAVEPCCACHED;
746 solisten_proto(so, backlog);
747 }
748 SOCK_UNLOCK(so);
749 UNP_PCB_UNLOCK(unp);
750 return (error);
751 }
752
753 static int
754 uipc_peeraddr(struct socket *so, struct sockaddr **nam)
755 {
756 struct unpcb *unp, *unp2;
757 const struct sockaddr *sa;
758
759 unp = sotounpcb(so);
760 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL"));
761
762 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
763 UNP_LINK_RLOCK();
764 /*
765 * XXX: It seems that this test always fails even when connection is
766 * established. So, this else clause is added as workaround to
767 * return PF_LOCAL sockaddr.
768 */
769 unp2 = unp->unp_conn;
770 if (unp2 != NULL) {
771 UNP_PCB_LOCK(unp2);
772 if (unp2->unp_addr != NULL)
773 sa = (struct sockaddr *) unp2->unp_addr;
774 else
775 sa = &sun_noname;
776 bcopy(sa, *nam, sa->sa_len);
777 UNP_PCB_UNLOCK(unp2);
778 } else {
779 sa = &sun_noname;
780 bcopy(sa, *nam, sa->sa_len);
781 }
782 UNP_LINK_RUNLOCK();
783 return (0);
784 }
785
786 static int
787 uipc_rcvd(struct socket *so, int flags)
788 {
789 struct unpcb *unp, *unp2;
790 struct socket *so2;
791 u_int mbcnt, sbcc;
792 u_long newhiwat;
793
794 unp = sotounpcb(so);
795 KASSERT(unp != NULL, ("uipc_rcvd: unp == NULL"));
796
797 if (so->so_type != SOCK_STREAM && so->so_type != SOCK_SEQPACKET)
798 panic("uipc_rcvd socktype %d", so->so_type);
799
800 /*
801 * Adjust backpressure on sender and wakeup any waiting to write.
802 *
803 * The unp lock is acquired to maintain the validity of the unp_conn
804 * pointer; no lock on unp2 is required as unp2->unp_socket will be
805 * static as long as we don't permit unp2 to disconnect from unp,
806 * which is prevented by the lock on unp. We cache values from
807 * so_rcv to avoid holding the so_rcv lock over the entire
808 * transaction on the remote so_snd.
809 */
810 SOCKBUF_LOCK(&so->so_rcv);
811 mbcnt = so->so_rcv.sb_mbcnt;
812 sbcc = so->so_rcv.sb_cc;
813 SOCKBUF_UNLOCK(&so->so_rcv);
814 UNP_PCB_LOCK(unp);
815 unp2 = unp->unp_conn;
816 if (unp2 == NULL) {
817 UNP_PCB_UNLOCK(unp);
818 return (0);
819 }
820 so2 = unp2->unp_socket;
821 SOCKBUF_LOCK(&so2->so_snd);
822 so2->so_snd.sb_mbmax += unp->unp_mbcnt - mbcnt;
823 newhiwat = so2->so_snd.sb_hiwat + unp->unp_cc - sbcc;
824 (void)chgsbsize(so2->so_cred->cr_uidinfo, &so2->so_snd.sb_hiwat,
825 newhiwat, RLIM_INFINITY);
826 sowwakeup_locked(so2);
827 unp->unp_mbcnt = mbcnt;
828 unp->unp_cc = sbcc;
829 UNP_PCB_UNLOCK(unp);
830 return (0);
831 }
832
833 static int
834 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
835 struct mbuf *control, struct thread *td)
836 {
837 struct unpcb *unp, *unp2;
838 struct socket *so2;
839 u_int mbcnt_delta, sbcc;
840 u_int newhiwat;
841 int error = 0;
842
843 unp = sotounpcb(so);
844 KASSERT(unp != NULL, ("uipc_send: unp == NULL"));
845
846 if (flags & PRUS_OOB) {
847 error = EOPNOTSUPP;
848 goto release;
849 }
850 if (control != NULL && (error = unp_internalize(&control, td)))
851 goto release;
852 if ((nam != NULL) || (flags & PRUS_EOF))
853 UNP_LINK_WLOCK();
854 else
855 UNP_LINK_RLOCK();
856 switch (so->so_type) {
857 case SOCK_DGRAM:
858 {
859 const struct sockaddr *from;
860
861 unp2 = unp->unp_conn;
862 if (nam != NULL) {
863 UNP_LINK_WLOCK_ASSERT();
864 if (unp2 != NULL) {
865 error = EISCONN;
866 break;
867 }
868 error = unp_connect(so, nam, td);
869 if (error)
870 break;
871 unp2 = unp->unp_conn;
872 }
873
874 /*
875 * Because connect() and send() are non-atomic in a sendto()
876 * with a target address, it's possible that the socket will
877 * have disconnected before the send() can run. In that case
878 * return the slightly counter-intuitive but otherwise
879 * correct error that the socket is not connected.
880 */
881 if (unp2 == NULL) {
882 error = ENOTCONN;
883 break;
884 }
885 /* Lockless read. */
886 if (unp2->unp_flags & UNP_WANTCRED)
887 control = unp_addsockcred(td, control);
888 UNP_PCB_LOCK(unp);
889 if (unp->unp_addr != NULL)
890 from = (struct sockaddr *)unp->unp_addr;
891 else
892 from = &sun_noname;
893 so2 = unp2->unp_socket;
894 SOCKBUF_LOCK(&so2->so_rcv);
895 if (sbappendaddr_locked(&so2->so_rcv, from, m, control)) {
896 sorwakeup_locked(so2);
897 m = NULL;
898 control = NULL;
899 } else {
900 SOCKBUF_UNLOCK(&so2->so_rcv);
901 error = ENOBUFS;
902 }
903 if (nam != NULL) {
904 UNP_LINK_WLOCK_ASSERT();
905 UNP_PCB_LOCK(unp2);
906 unp_disconnect(unp, unp2);
907 UNP_PCB_UNLOCK(unp2);
908 }
909 UNP_PCB_UNLOCK(unp);
910 break;
911 }
912
913 case SOCK_SEQPACKET:
914 case SOCK_STREAM:
915 if ((so->so_state & SS_ISCONNECTED) == 0) {
916 if (nam != NULL) {
917 UNP_LINK_WLOCK_ASSERT();
918 error = unp_connect(so, nam, td);
919 if (error)
920 break; /* XXX */
921 } else {
922 error = ENOTCONN;
923 break;
924 }
925 }
926
927 /* Lockless read. */
928 if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
929 error = EPIPE;
930 break;
931 }
932
933 /*
934 * Because connect() and send() are non-atomic in a sendto()
935 * with a target address, it's possible that the socket will
936 * have disconnected before the send() can run. In that case
937 * return the slightly counter-intuitive but otherwise
938 * correct error that the socket is not connected.
939 *
940 * Locking here must be done carefully: the linkage lock
941 * prevents interconnections between unpcbs from changing, so
942 * we can traverse from unp to unp2 without acquiring unp's
943 * lock. Socket buffer locks follow unpcb locks, so we can
944 * acquire both remote and lock socket buffer locks.
945 */
946 unp2 = unp->unp_conn;
947 if (unp2 == NULL) {
948 error = ENOTCONN;
949 break;
950 }
951 so2 = unp2->unp_socket;
952 UNP_PCB_LOCK(unp2);
953 SOCKBUF_LOCK(&so2->so_rcv);
954 if (unp2->unp_flags & UNP_WANTCRED) {
955 /*
956 * Credentials are passed only once on SOCK_STREAM
957 * and SOCK_SEQPACKET.
958 */
959 unp2->unp_flags &= ~UNP_WANTCRED;
960 control = unp_addsockcred(td, control);
961 }
962 /*
963 * Send to paired receive port, and then reduce send buffer
964 * hiwater marks to maintain backpressure. Wake up readers.
965 */
966 switch (so->so_type) {
967 case SOCK_STREAM:
968 if (control != NULL) {
969 if (sbappendcontrol_locked(&so2->so_rcv, m,
970 control))
971 control = NULL;
972 } else
973 sbappend_locked(&so2->so_rcv, m);
974 break;
975
976 case SOCK_SEQPACKET: {
977 const struct sockaddr *from;
978
979 from = &sun_noname;
980 if (sbappendaddr_locked(&so2->so_rcv, from, m,
981 control))
982 control = NULL;
983 break;
984 }
985 }
986
987 /*
988 * XXXRW: While fine for SOCK_STREAM, this conflates maximum
989 * datagram size and back-pressure for SOCK_SEQPACKET, which
990 * can lead to undesired return of EMSGSIZE on send instead
991 * of more desirable blocking.
992 */
993 mbcnt_delta = so2->so_rcv.sb_mbcnt - unp2->unp_mbcnt;
994 unp2->unp_mbcnt = so2->so_rcv.sb_mbcnt;
995 sbcc = so2->so_rcv.sb_cc;
996 sorwakeup_locked(so2);
997
998 SOCKBUF_LOCK(&so->so_snd);
999 if ((int)so->so_snd.sb_hiwat >= (int)(sbcc - unp2->unp_cc))
1000 newhiwat = so->so_snd.sb_hiwat - (sbcc - unp2->unp_cc);
1001 else
1002 newhiwat = 0;
1003 (void)chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat,
1004 newhiwat, RLIM_INFINITY);
1005 so->so_snd.sb_mbmax -= mbcnt_delta;
1006 SOCKBUF_UNLOCK(&so->so_snd);
1007 unp2->unp_cc = sbcc;
1008 UNP_PCB_UNLOCK(unp2);
1009 m = NULL;
1010 break;
1011
1012 default:
1013 panic("uipc_send unknown socktype");
1014 }
1015
1016 /*
1017 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown.
1018 */
1019 if (flags & PRUS_EOF) {
1020 UNP_PCB_LOCK(unp);
1021 socantsendmore(so);
1022 unp_shutdown(unp);
1023 UNP_PCB_UNLOCK(unp);
1024 }
1025
1026 if ((nam != NULL) || (flags & PRUS_EOF))
1027 UNP_LINK_WUNLOCK();
1028 else
1029 UNP_LINK_RUNLOCK();
1030
1031 if (control != NULL && error != 0)
1032 unp_dispose(control);
1033
1034 release:
1035 if (control != NULL)
1036 m_freem(control);
1037 if (m != NULL)
1038 m_freem(m);
1039 return (error);
1040 }
1041
1042 static int
1043 uipc_sense(struct socket *so, struct stat *sb)
1044 {
1045 struct unpcb *unp, *unp2;
1046 struct socket *so2;
1047
1048 unp = sotounpcb(so);
1049 KASSERT(unp != NULL, ("uipc_sense: unp == NULL"));
1050
1051 sb->st_blksize = so->so_snd.sb_hiwat;
1052 UNP_LINK_RLOCK();
1053 UNP_PCB_LOCK(unp);
1054 unp2 = unp->unp_conn;
1055 if ((so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET) &&
1056 unp2 != NULL) {
1057 so2 = unp2->unp_socket;
1058 sb->st_blksize += so2->so_rcv.sb_cc;
1059 }
1060 sb->st_dev = NODEV;
1061 if (unp->unp_ino == 0)
1062 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino;
1063 sb->st_ino = unp->unp_ino;
1064 UNP_PCB_UNLOCK(unp);
1065 UNP_LINK_RUNLOCK();
1066 return (0);
1067 }
1068
1069 static int
1070 uipc_shutdown(struct socket *so)
1071 {
1072 struct unpcb *unp;
1073
1074 unp = sotounpcb(so);
1075 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL"));
1076
1077 UNP_LINK_WLOCK();
1078 UNP_PCB_LOCK(unp);
1079 socantsendmore(so);
1080 unp_shutdown(unp);
1081 UNP_PCB_UNLOCK(unp);
1082 UNP_LINK_WUNLOCK();
1083 return (0);
1084 }
1085
1086 static int
1087 uipc_sockaddr(struct socket *so, struct sockaddr **nam)
1088 {
1089 struct unpcb *unp;
1090 const struct sockaddr *sa;
1091
1092 unp = sotounpcb(so);
1093 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL"));
1094
1095 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
1096 UNP_PCB_LOCK(unp);
1097 if (unp->unp_addr != NULL)
1098 sa = (struct sockaddr *) unp->unp_addr;
1099 else
1100 sa = &sun_noname;
1101 bcopy(sa, *nam, sa->sa_len);
1102 UNP_PCB_UNLOCK(unp);
1103 return (0);
1104 }
1105
1106 static struct pr_usrreqs uipc_usrreqs_dgram = {
1107 .pru_abort = uipc_abort,
1108 .pru_accept = uipc_accept,
1109 .pru_attach = uipc_attach,
1110 .pru_bind = uipc_bind,
1111 .pru_bindat = uipc_bindat,
1112 .pru_connect = uipc_connect,
1113 .pru_connectat = uipc_connectat,
1114 .pru_connect2 = uipc_connect2,
1115 .pru_detach = uipc_detach,
1116 .pru_disconnect = uipc_disconnect,
1117 .pru_listen = uipc_listen,
1118 .pru_peeraddr = uipc_peeraddr,
1119 .pru_rcvd = uipc_rcvd,
1120 .pru_send = uipc_send,
1121 .pru_sense = uipc_sense,
1122 .pru_shutdown = uipc_shutdown,
1123 .pru_sockaddr = uipc_sockaddr,
1124 .pru_soreceive = soreceive_dgram,
1125 .pru_close = uipc_close,
1126 };
1127
1128 static struct pr_usrreqs uipc_usrreqs_seqpacket = {
1129 .pru_abort = uipc_abort,
1130 .pru_accept = uipc_accept,
1131 .pru_attach = uipc_attach,
1132 .pru_bind = uipc_bind,
1133 .pru_bindat = uipc_bindat,
1134 .pru_connect = uipc_connect,
1135 .pru_connectat = uipc_connectat,
1136 .pru_connect2 = uipc_connect2,
1137 .pru_detach = uipc_detach,
1138 .pru_disconnect = uipc_disconnect,
1139 .pru_listen = uipc_listen,
1140 .pru_peeraddr = uipc_peeraddr,
1141 .pru_rcvd = uipc_rcvd,
1142 .pru_send = uipc_send,
1143 .pru_sense = uipc_sense,
1144 .pru_shutdown = uipc_shutdown,
1145 .pru_sockaddr = uipc_sockaddr,
1146 .pru_soreceive = soreceive_generic, /* XXX: or...? */
1147 .pru_close = uipc_close,
1148 };
1149
1150 static struct pr_usrreqs uipc_usrreqs_stream = {
1151 .pru_abort = uipc_abort,
1152 .pru_accept = uipc_accept,
1153 .pru_attach = uipc_attach,
1154 .pru_bind = uipc_bind,
1155 .pru_bindat = uipc_bindat,
1156 .pru_connect = uipc_connect,
1157 .pru_connectat = uipc_connectat,
1158 .pru_connect2 = uipc_connect2,
1159 .pru_detach = uipc_detach,
1160 .pru_disconnect = uipc_disconnect,
1161 .pru_listen = uipc_listen,
1162 .pru_peeraddr = uipc_peeraddr,
1163 .pru_rcvd = uipc_rcvd,
1164 .pru_send = uipc_send,
1165 .pru_sense = uipc_sense,
1166 .pru_shutdown = uipc_shutdown,
1167 .pru_sockaddr = uipc_sockaddr,
1168 .pru_soreceive = soreceive_generic,
1169 .pru_close = uipc_close,
1170 };
1171
1172 static int
1173 uipc_ctloutput(struct socket *so, struct sockopt *sopt)
1174 {
1175 struct unpcb *unp;
1176 struct xucred xu;
1177 int error, optval;
1178
1179 if (sopt->sopt_level != 0)
1180 return (EINVAL);
1181
1182 unp = sotounpcb(so);
1183 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL"));
1184 error = 0;
1185 switch (sopt->sopt_dir) {
1186 case SOPT_GET:
1187 switch (sopt->sopt_name) {
1188 case LOCAL_PEERCRED:
1189 UNP_PCB_LOCK(unp);
1190 if (unp->unp_flags & UNP_HAVEPC)
1191 xu = unp->unp_peercred;
1192 else {
1193 if (so->so_type == SOCK_STREAM)
1194 error = ENOTCONN;
1195 else
1196 error = EINVAL;
1197 }
1198 UNP_PCB_UNLOCK(unp);
1199 if (error == 0)
1200 error = sooptcopyout(sopt, &xu, sizeof(xu));
1201 break;
1202
1203 case LOCAL_CREDS:
1204 /* Unlocked read. */
1205 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0;
1206 error = sooptcopyout(sopt, &optval, sizeof(optval));
1207 break;
1208
1209 case LOCAL_CONNWAIT:
1210 /* Unlocked read. */
1211 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0;
1212 error = sooptcopyout(sopt, &optval, sizeof(optval));
1213 break;
1214
1215 default:
1216 error = EOPNOTSUPP;
1217 break;
1218 }
1219 break;
1220
1221 case SOPT_SET:
1222 switch (sopt->sopt_name) {
1223 case LOCAL_CREDS:
1224 case LOCAL_CONNWAIT:
1225 error = sooptcopyin(sopt, &optval, sizeof(optval),
1226 sizeof(optval));
1227 if (error)
1228 break;
1229
1230 #define OPTSET(bit) do { \
1231 UNP_PCB_LOCK(unp); \
1232 if (optval) \
1233 unp->unp_flags |= bit; \
1234 else \
1235 unp->unp_flags &= ~bit; \
1236 UNP_PCB_UNLOCK(unp); \
1237 } while (0)
1238
1239 switch (sopt->sopt_name) {
1240 case LOCAL_CREDS:
1241 OPTSET(UNP_WANTCRED);
1242 break;
1243
1244 case LOCAL_CONNWAIT:
1245 OPTSET(UNP_CONNWAIT);
1246 break;
1247
1248 default:
1249 break;
1250 }
1251 break;
1252 #undef OPTSET
1253 default:
1254 error = ENOPROTOOPT;
1255 break;
1256 }
1257 break;
1258
1259 default:
1260 error = EOPNOTSUPP;
1261 break;
1262 }
1263 return (error);
1264 }
1265
1266 static int
1267 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1268 {
1269
1270 return (unp_connectat(AT_FDCWD, so, nam, td));
1271 }
1272
1273 static int
1274 unp_connectat(int fd, struct socket *so, struct sockaddr *nam,
1275 struct thread *td)
1276 {
1277 struct sockaddr_un *soun = (struct sockaddr_un *)nam;
1278 struct vnode *vp;
1279 struct socket *so2, *so3;
1280 struct unpcb *unp, *unp2, *unp3;
1281 struct nameidata nd;
1282 char buf[SOCK_MAXADDRLEN];
1283 struct sockaddr *sa;
1284 cap_rights_t rights;
1285 int error, len;
1286
1287 UNP_LINK_WLOCK_ASSERT();
1288
1289 unp = sotounpcb(so);
1290 KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
1291
1292 if (nam->sa_len > sizeof(struct sockaddr_un))
1293 return (EINVAL);
1294 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path);
1295 if (len <= 0)
1296 return (EINVAL);
1297 bcopy(soun->sun_path, buf, len);
1298 buf[len] = 0;
1299
1300 UNP_PCB_LOCK(unp);
1301 if (unp->unp_flags & UNP_CONNECTING) {
1302 UNP_PCB_UNLOCK(unp);
1303 return (EALREADY);
1304 }
1305 UNP_LINK_WUNLOCK();
1306 unp->unp_flags |= UNP_CONNECTING;
1307 UNP_PCB_UNLOCK(unp);
1308
1309 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
1310 NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF,
1311 UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_CONNECTAT), td);
1312 error = namei(&nd);
1313 if (error)
1314 vp = NULL;
1315 else
1316 vp = nd.ni_vp;
1317 ASSERT_VOP_LOCKED(vp, "unp_connect");
1318 NDFREE(&nd, NDF_ONLY_PNBUF);
1319 if (error)
1320 goto bad;
1321
1322 if (vp->v_type != VSOCK) {
1323 error = ENOTSOCK;
1324 goto bad;
1325 }
1326 #ifdef MAC
1327 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD);
1328 if (error)
1329 goto bad;
1330 #endif
1331 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td);
1332 if (error)
1333 goto bad;
1334
1335 unp = sotounpcb(so);
1336 KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
1337
1338 /*
1339 * Lock linkage lock for two reasons: make sure v_socket is stable,
1340 * and to protect simultaneous locking of multiple pcbs.
1341 */
1342 UNP_LINK_WLOCK();
1343 VOP_UNP_CONNECT(vp, &so2);
1344 if (so2 == NULL) {
1345 error = ECONNREFUSED;
1346 goto bad2;
1347 }
1348 if (so->so_type != so2->so_type) {
1349 error = EPROTOTYPE;
1350 goto bad2;
1351 }
1352 if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
1353 if (so2->so_options & SO_ACCEPTCONN) {
1354 CURVNET_SET(so2->so_vnet);
1355 so3 = sonewconn(so2, 0);
1356 CURVNET_RESTORE();
1357 } else
1358 so3 = NULL;
1359 if (so3 == NULL) {
1360 error = ECONNREFUSED;
1361 goto bad2;
1362 }
1363 unp = sotounpcb(so);
1364 unp2 = sotounpcb(so2);
1365 unp3 = sotounpcb(so3);
1366 UNP_PCB_LOCK(unp);
1367 UNP_PCB_LOCK(unp2);
1368 UNP_PCB_LOCK(unp3);
1369 if (unp2->unp_addr != NULL) {
1370 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len);
1371 unp3->unp_addr = (struct sockaddr_un *) sa;
1372 sa = NULL;
1373 }
1374
1375 /*
1376 * The connector's (client's) credentials are copied from its
1377 * process structure at the time of connect() (which is now).
1378 */
1379 cru2x(td->td_ucred, &unp3->unp_peercred);
1380 unp3->unp_flags |= UNP_HAVEPC;
1381
1382 /*
1383 * The receiver's (server's) credentials are copied from the
1384 * unp_peercred member of socket on which the former called
1385 * listen(); uipc_listen() cached that process's credentials
1386 * at that time so we can use them now.
1387 */
1388 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED,
1389 ("unp_connect: listener without cached peercred"));
1390 memcpy(&unp->unp_peercred, &unp2->unp_peercred,
1391 sizeof(unp->unp_peercred));
1392 unp->unp_flags |= UNP_HAVEPC;
1393 if (unp2->unp_flags & UNP_WANTCRED)
1394 unp3->unp_flags |= UNP_WANTCRED;
1395 UNP_PCB_UNLOCK(unp3);
1396 UNP_PCB_UNLOCK(unp2);
1397 UNP_PCB_UNLOCK(unp);
1398 #ifdef MAC
1399 mac_socketpeer_set_from_socket(so, so3);
1400 mac_socketpeer_set_from_socket(so3, so);
1401 #endif
1402
1403 so2 = so3;
1404 }
1405 unp = sotounpcb(so);
1406 KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
1407 unp2 = sotounpcb(so2);
1408 KASSERT(unp2 != NULL, ("unp_connect: unp2 == NULL"));
1409 UNP_PCB_LOCK(unp);
1410 UNP_PCB_LOCK(unp2);
1411 error = unp_connect2(so, so2, PRU_CONNECT);
1412 UNP_PCB_UNLOCK(unp2);
1413 UNP_PCB_UNLOCK(unp);
1414 bad2:
1415 UNP_LINK_WUNLOCK();
1416 bad:
1417 if (vp != NULL)
1418 vput(vp);
1419 free(sa, M_SONAME);
1420 UNP_LINK_WLOCK();
1421 UNP_PCB_LOCK(unp);
1422 unp->unp_flags &= ~UNP_CONNECTING;
1423 UNP_PCB_UNLOCK(unp);
1424 return (error);
1425 }
1426
1427 static int
1428 unp_connect2(struct socket *so, struct socket *so2, int req)
1429 {
1430 struct unpcb *unp;
1431 struct unpcb *unp2;
1432
1433 unp = sotounpcb(so);
1434 KASSERT(unp != NULL, ("unp_connect2: unp == NULL"));
1435 unp2 = sotounpcb(so2);
1436 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL"));
1437
1438 UNP_LINK_WLOCK_ASSERT();
1439 UNP_PCB_LOCK_ASSERT(unp);
1440 UNP_PCB_LOCK_ASSERT(unp2);
1441
1442 if (so2->so_type != so->so_type)
1443 return (EPROTOTYPE);
1444 unp->unp_conn = unp2;
1445
1446 switch (so->so_type) {
1447 case SOCK_DGRAM:
1448 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink);
1449 soisconnected(so);
1450 break;
1451
1452 case SOCK_STREAM:
1453 case SOCK_SEQPACKET:
1454 unp2->unp_conn = unp;
1455 if (req == PRU_CONNECT &&
1456 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT))
1457 soisconnecting(so);
1458 else
1459 soisconnected(so);
1460 soisconnected(so2);
1461 break;
1462
1463 default:
1464 panic("unp_connect2");
1465 }
1466 return (0);
1467 }
1468
1469 static void
1470 unp_disconnect(struct unpcb *unp, struct unpcb *unp2)
1471 {
1472 struct socket *so;
1473
1474 KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL"));
1475
1476 UNP_LINK_WLOCK_ASSERT();
1477 UNP_PCB_LOCK_ASSERT(unp);
1478 UNP_PCB_LOCK_ASSERT(unp2);
1479
1480 unp->unp_conn = NULL;
1481 switch (unp->unp_socket->so_type) {
1482 case SOCK_DGRAM:
1483 LIST_REMOVE(unp, unp_reflink);
1484 so = unp->unp_socket;
1485 SOCK_LOCK(so);
1486 so->so_state &= ~SS_ISCONNECTED;
1487 SOCK_UNLOCK(so);
1488 break;
1489
1490 case SOCK_STREAM:
1491 case SOCK_SEQPACKET:
1492 soisdisconnected(unp->unp_socket);
1493 unp2->unp_conn = NULL;
1494 soisdisconnected(unp2->unp_socket);
1495 break;
1496 }
1497 }
1498
1499 /*
1500 * unp_pcblist() walks the global list of struct unpcb's to generate a
1501 * pointer list, bumping the refcount on each unpcb. It then copies them out
1502 * sequentially, validating the generation number on each to see if it has
1503 * been detached. All of this is necessary because copyout() may sleep on
1504 * disk I/O.
1505 */
1506 static int
1507 unp_pcblist(SYSCTL_HANDLER_ARGS)
1508 {
1509 int error, i, n;
1510 int freeunp;
1511 struct unpcb *unp, **unp_list;
1512 unp_gen_t gencnt;
1513 struct xunpgen *xug;
1514 struct unp_head *head;
1515 struct xunpcb *xu;
1516
1517 switch ((intptr_t)arg1) {
1518 case SOCK_STREAM:
1519 head = &unp_shead;
1520 break;
1521
1522 case SOCK_DGRAM:
1523 head = &unp_dhead;
1524 break;
1525
1526 case SOCK_SEQPACKET:
1527 head = &unp_sphead;
1528 break;
1529
1530 default:
1531 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1);
1532 }
1533
1534 /*
1535 * The process of preparing the PCB list is too time-consuming and
1536 * resource-intensive to repeat twice on every request.
1537 */
1538 if (req->oldptr == NULL) {
1539 n = unp_count;
1540 req->oldidx = 2 * (sizeof *xug)
1541 + (n + n/8) * sizeof(struct xunpcb);
1542 return (0);
1543 }
1544
1545 if (req->newptr != NULL)
1546 return (EPERM);
1547
1548 /*
1549 * OK, now we're committed to doing something.
1550 */
1551 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK);
1552 UNP_LIST_LOCK();
1553 gencnt = unp_gencnt;
1554 n = unp_count;
1555 UNP_LIST_UNLOCK();
1556
1557 xug->xug_len = sizeof *xug;
1558 xug->xug_count = n;
1559 xug->xug_gen = gencnt;
1560 xug->xug_sogen = so_gencnt;
1561 error = SYSCTL_OUT(req, xug, sizeof *xug);
1562 if (error) {
1563 free(xug, M_TEMP);
1564 return (error);
1565 }
1566
1567 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK);
1568
1569 UNP_LIST_LOCK();
1570 for (unp = LIST_FIRST(head), i = 0; unp && i < n;
1571 unp = LIST_NEXT(unp, unp_link)) {
1572 UNP_PCB_LOCK(unp);
1573 if (unp->unp_gencnt <= gencnt) {
1574 if (cr_cansee(req->td->td_ucred,
1575 unp->unp_socket->so_cred)) {
1576 UNP_PCB_UNLOCK(unp);
1577 continue;
1578 }
1579 unp_list[i++] = unp;
1580 unp->unp_refcount++;
1581 }
1582 UNP_PCB_UNLOCK(unp);
1583 }
1584 UNP_LIST_UNLOCK();
1585 n = i; /* In case we lost some during malloc. */
1586
1587 error = 0;
1588 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO);
1589 for (i = 0; i < n; i++) {
1590 unp = unp_list[i];
1591 UNP_PCB_LOCK(unp);
1592 unp->unp_refcount--;
1593 if (unp->unp_refcount != 0 && unp->unp_gencnt <= gencnt) {
1594 xu->xu_len = sizeof *xu;
1595 xu->xu_unpp = unp;
1596 /*
1597 * XXX - need more locking here to protect against
1598 * connect/disconnect races for SMP.
1599 */
1600 if (unp->unp_addr != NULL)
1601 bcopy(unp->unp_addr, &xu->xu_addr,
1602 unp->unp_addr->sun_len);
1603 if (unp->unp_conn != NULL &&
1604 unp->unp_conn->unp_addr != NULL)
1605 bcopy(unp->unp_conn->unp_addr,
1606 &xu->xu_caddr,
1607 unp->unp_conn->unp_addr->sun_len);
1608 bcopy(unp, &xu->xu_unp, sizeof *unp);
1609 sotoxsocket(unp->unp_socket, &xu->xu_socket);
1610 UNP_PCB_UNLOCK(unp);
1611 error = SYSCTL_OUT(req, xu, sizeof *xu);
1612 } else {
1613 freeunp = (unp->unp_refcount == 0);
1614 UNP_PCB_UNLOCK(unp);
1615 if (freeunp) {
1616 UNP_PCB_LOCK_DESTROY(unp);
1617 uma_zfree(unp_zone, unp);
1618 }
1619 }
1620 }
1621 free(xu, M_TEMP);
1622 if (!error) {
1623 /*
1624 * Give the user an updated idea of our state. If the
1625 * generation differs from what we told her before, she knows
1626 * that something happened while we were processing this
1627 * request, and it might be necessary to retry.
1628 */
1629 xug->xug_gen = unp_gencnt;
1630 xug->xug_sogen = so_gencnt;
1631 xug->xug_count = unp_count;
1632 error = SYSCTL_OUT(req, xug, sizeof *xug);
1633 }
1634 free(unp_list, M_TEMP);
1635 free(xug, M_TEMP);
1636 return (error);
1637 }
1638
1639 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD,
1640 (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb",
1641 "List of active local datagram sockets");
1642 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD,
1643 (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb",
1644 "List of active local stream sockets");
1645 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist,
1646 CTLTYPE_OPAQUE | CTLFLAG_RD,
1647 (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb",
1648 "List of active local seqpacket sockets");
1649
1650 static void
1651 unp_shutdown(struct unpcb *unp)
1652 {
1653 struct unpcb *unp2;
1654 struct socket *so;
1655
1656 UNP_LINK_WLOCK_ASSERT();
1657 UNP_PCB_LOCK_ASSERT(unp);
1658
1659 unp2 = unp->unp_conn;
1660 if ((unp->unp_socket->so_type == SOCK_STREAM ||
1661 (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) {
1662 so = unp2->unp_socket;
1663 if (so != NULL)
1664 socantrcvmore(so);
1665 }
1666 }
1667
1668 static void
1669 unp_drop(struct unpcb *unp, int errno)
1670 {
1671 struct socket *so = unp->unp_socket;
1672 struct unpcb *unp2;
1673
1674 UNP_LINK_WLOCK_ASSERT();
1675 UNP_PCB_LOCK_ASSERT(unp);
1676
1677 so->so_error = errno;
1678 unp2 = unp->unp_conn;
1679 if (unp2 == NULL)
1680 return;
1681 UNP_PCB_LOCK(unp2);
1682 unp_disconnect(unp, unp2);
1683 UNP_PCB_UNLOCK(unp2);
1684 }
1685
1686 static void
1687 unp_freerights(struct filedescent **fdep, int fdcount)
1688 {
1689 struct file *fp;
1690 int i;
1691
1692 KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount));
1693
1694 for (i = 0; i < fdcount; i++) {
1695 fp = fdep[i]->fde_file;
1696 filecaps_free(&fdep[i]->fde_caps);
1697 unp_discard(fp);
1698 }
1699 free(fdep[0], M_FILECAPS);
1700 }
1701
1702 static int
1703 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags)
1704 {
1705 struct thread *td = curthread; /* XXX */
1706 struct cmsghdr *cm = mtod(control, struct cmsghdr *);
1707 int i;
1708 int *fdp;
1709 struct filedesc *fdesc = td->td_proc->p_fd;
1710 struct filedescent *fde, **fdep;
1711 void *data;
1712 socklen_t clen = control->m_len, datalen;
1713 int error, newfds;
1714 u_int newlen;
1715
1716 UNP_LINK_UNLOCK_ASSERT();
1717
1718 error = 0;
1719 if (controlp != NULL) /* controlp == NULL => free control messages */
1720 *controlp = NULL;
1721 while (cm != NULL) {
1722 if (sizeof(*cm) > clen || cm->cmsg_len > clen) {
1723 error = EINVAL;
1724 break;
1725 }
1726 data = CMSG_DATA(cm);
1727 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
1728 if (cm->cmsg_level == SOL_SOCKET
1729 && cm->cmsg_type == SCM_RIGHTS) {
1730 newfds = datalen / sizeof(*fdep);
1731 if (newfds == 0)
1732 goto next;
1733 fdep = data;
1734
1735 /* If we're not outputting the descriptors free them. */
1736 if (error || controlp == NULL) {
1737 unp_freerights(fdep, newfds);
1738 goto next;
1739 }
1740 FILEDESC_XLOCK(fdesc);
1741
1742 /*
1743 * Now change each pointer to an fd in the global
1744 * table to an integer that is the index to the local
1745 * fd table entry that we set up to point to the
1746 * global one we are transferring.
1747 */
1748 newlen = newfds * sizeof(int);
1749 *controlp = sbcreatecontrol(NULL, newlen,
1750 SCM_RIGHTS, SOL_SOCKET);
1751 if (*controlp == NULL) {
1752 FILEDESC_XUNLOCK(fdesc);
1753 error = E2BIG;
1754 unp_freerights(fdep, newfds);
1755 goto next;
1756 }
1757
1758 fdp = (int *)
1759 CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1760 if (fdallocn(td, 0, fdp, newfds) != 0) {
1761 FILEDESC_XUNLOCK(td->td_proc->p_fd);
1762 error = EMSGSIZE;
1763 unp_freerights(fdep, newfds);
1764 m_freem(*controlp);
1765 *controlp = NULL;
1766 goto next;
1767 }
1768 for (i = 0; i < newfds; i++, fdp++) {
1769 fde = &fdesc->fd_ofiles[*fdp];
1770 fde->fde_file = fdep[i]->fde_file;
1771 filecaps_move(&fdep[i]->fde_caps,
1772 &fde->fde_caps);
1773 if ((flags & MSG_CMSG_CLOEXEC) != 0)
1774 fde->fde_flags |= UF_EXCLOSE;
1775 unp_externalize_fp(fde->fde_file);
1776 }
1777 FILEDESC_XUNLOCK(fdesc);
1778 free(fdep[0], M_FILECAPS);
1779 } else {
1780 /* We can just copy anything else across. */
1781 if (error || controlp == NULL)
1782 goto next;
1783 *controlp = sbcreatecontrol(NULL, datalen,
1784 cm->cmsg_type, cm->cmsg_level);
1785 if (*controlp == NULL) {
1786 error = ENOBUFS;
1787 goto next;
1788 }
1789 bcopy(data,
1790 CMSG_DATA(mtod(*controlp, struct cmsghdr *)),
1791 datalen);
1792 }
1793 controlp = &(*controlp)->m_next;
1794
1795 next:
1796 if (CMSG_SPACE(datalen) < clen) {
1797 clen -= CMSG_SPACE(datalen);
1798 cm = (struct cmsghdr *)
1799 ((caddr_t)cm + CMSG_SPACE(datalen));
1800 } else {
1801 clen = 0;
1802 cm = NULL;
1803 }
1804 }
1805
1806 m_freem(control);
1807 return (error);
1808 }
1809
1810 static void
1811 unp_zone_change(void *tag)
1812 {
1813
1814 uma_zone_set_max(unp_zone, maxsockets);
1815 }
1816
1817 static void
1818 unp_init(void)
1819 {
1820
1821 #ifdef VIMAGE
1822 if (!IS_DEFAULT_VNET(curvnet))
1823 return;
1824 #endif
1825 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL,
1826 NULL, NULL, UMA_ALIGN_PTR, 0);
1827 if (unp_zone == NULL)
1828 panic("unp_init");
1829 uma_zone_set_max(unp_zone, maxsockets);
1830 uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached");
1831 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change,
1832 NULL, EVENTHANDLER_PRI_ANY);
1833 LIST_INIT(&unp_dhead);
1834 LIST_INIT(&unp_shead);
1835 LIST_INIT(&unp_sphead);
1836 SLIST_INIT(&unp_defers);
1837 TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL);
1838 TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL);
1839 UNP_LINK_LOCK_INIT();
1840 UNP_LIST_LOCK_INIT();
1841 UNP_DEFERRED_LOCK_INIT();
1842 }
1843
1844 static int
1845 unp_internalize(struct mbuf **controlp, struct thread *td)
1846 {
1847 struct mbuf *control = *controlp;
1848 struct proc *p = td->td_proc;
1849 struct filedesc *fdesc = p->p_fd;
1850 struct bintime *bt;
1851 struct cmsghdr *cm = mtod(control, struct cmsghdr *);
1852 struct cmsgcred *cmcred;
1853 struct filedescent *fde, **fdep, *fdev;
1854 struct file *fp;
1855 struct timeval *tv;
1856 int i, fd, *fdp;
1857 void *data;
1858 socklen_t clen = control->m_len, datalen;
1859 int error, oldfds;
1860 u_int newlen;
1861
1862 UNP_LINK_UNLOCK_ASSERT();
1863
1864 error = 0;
1865 *controlp = NULL;
1866 while (cm != NULL) {
1867 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET
1868 || cm->cmsg_len > clen) {
1869 error = EINVAL;
1870 goto out;
1871 }
1872 data = CMSG_DATA(cm);
1873 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
1874
1875 switch (cm->cmsg_type) {
1876 /*
1877 * Fill in credential information.
1878 */
1879 case SCM_CREDS:
1880 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred),
1881 SCM_CREDS, SOL_SOCKET);
1882 if (*controlp == NULL) {
1883 error = ENOBUFS;
1884 goto out;
1885 }
1886 cmcred = (struct cmsgcred *)
1887 CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1888 cmcred->cmcred_pid = p->p_pid;
1889 cmcred->cmcred_uid = td->td_ucred->cr_ruid;
1890 cmcred->cmcred_gid = td->td_ucred->cr_rgid;
1891 cmcred->cmcred_euid = td->td_ucred->cr_uid;
1892 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups,
1893 CMGROUP_MAX);
1894 for (i = 0; i < cmcred->cmcred_ngroups; i++)
1895 cmcred->cmcred_groups[i] =
1896 td->td_ucred->cr_groups[i];
1897 break;
1898
1899 case SCM_RIGHTS:
1900 oldfds = datalen / sizeof (int);
1901 if (oldfds == 0)
1902 break;
1903 /*
1904 * Check that all the FDs passed in refer to legal
1905 * files. If not, reject the entire operation.
1906 */
1907 fdp = data;
1908 FILEDESC_SLOCK(fdesc);
1909 for (i = 0; i < oldfds; i++) {
1910 fd = *fdp++;
1911 if (fget_locked(fdesc, fd) == NULL) {
1912 FILEDESC_SUNLOCK(fdesc);
1913 error = EBADF;
1914 goto out;
1915 }
1916 fp = fdesc->fd_ofiles[fd].fde_file;
1917 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) {
1918 FILEDESC_SUNLOCK(fdesc);
1919 error = EOPNOTSUPP;
1920 goto out;
1921 }
1922
1923 }
1924
1925 /*
1926 * Now replace the integer FDs with pointers to the
1927 * file structure and capability rights.
1928 */
1929 newlen = oldfds * sizeof(fdep[0]);
1930 *controlp = sbcreatecontrol(NULL, newlen,
1931 SCM_RIGHTS, SOL_SOCKET);
1932 if (*controlp == NULL) {
1933 FILEDESC_SUNLOCK(fdesc);
1934 error = E2BIG;
1935 goto out;
1936 }
1937 fdp = data;
1938 fdep = (struct filedescent **)
1939 CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1940 fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS,
1941 M_WAITOK);
1942 for (i = 0; i < oldfds; i++, fdev++, fdp++) {
1943 fde = &fdesc->fd_ofiles[*fdp];
1944 fdep[i] = fdev;
1945 fdep[i]->fde_file = fde->fde_file;
1946 filecaps_copy(&fde->fde_caps,
1947 &fdep[i]->fde_caps);
1948 unp_internalize_fp(fdep[i]->fde_file);
1949 }
1950 FILEDESC_SUNLOCK(fdesc);
1951 break;
1952
1953 case SCM_TIMESTAMP:
1954 *controlp = sbcreatecontrol(NULL, sizeof(*tv),
1955 SCM_TIMESTAMP, SOL_SOCKET);
1956 if (*controlp == NULL) {
1957 error = ENOBUFS;
1958 goto out;
1959 }
1960 tv = (struct timeval *)
1961 CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1962 microtime(tv);
1963 break;
1964
1965 case SCM_BINTIME:
1966 *controlp = sbcreatecontrol(NULL, sizeof(*bt),
1967 SCM_BINTIME, SOL_SOCKET);
1968 if (*controlp == NULL) {
1969 error = ENOBUFS;
1970 goto out;
1971 }
1972 bt = (struct bintime *)
1973 CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1974 bintime(bt);
1975 break;
1976
1977 default:
1978 error = EINVAL;
1979 goto out;
1980 }
1981
1982 controlp = &(*controlp)->m_next;
1983 if (CMSG_SPACE(datalen) < clen) {
1984 clen -= CMSG_SPACE(datalen);
1985 cm = (struct cmsghdr *)
1986 ((caddr_t)cm + CMSG_SPACE(datalen));
1987 } else {
1988 clen = 0;
1989 cm = NULL;
1990 }
1991 }
1992
1993 out:
1994 m_freem(control);
1995 return (error);
1996 }
1997
1998 static struct mbuf *
1999 unp_addsockcred(struct thread *td, struct mbuf *control)
2000 {
2001 struct mbuf *m, *n, *n_prev;
2002 struct sockcred *sc;
2003 const struct cmsghdr *cm;
2004 int ngroups;
2005 int i;
2006
2007 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX);
2008 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET);
2009 if (m == NULL)
2010 return (control);
2011
2012 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *));
2013 sc->sc_uid = td->td_ucred->cr_ruid;
2014 sc->sc_euid = td->td_ucred->cr_uid;
2015 sc->sc_gid = td->td_ucred->cr_rgid;
2016 sc->sc_egid = td->td_ucred->cr_gid;
2017 sc->sc_ngroups = ngroups;
2018 for (i = 0; i < sc->sc_ngroups; i++)
2019 sc->sc_groups[i] = td->td_ucred->cr_groups[i];
2020
2021 /*
2022 * Unlink SCM_CREDS control messages (struct cmsgcred), since just
2023 * created SCM_CREDS control message (struct sockcred) has another
2024 * format.
2025 */
2026 if (control != NULL)
2027 for (n = control, n_prev = NULL; n != NULL;) {
2028 cm = mtod(n, struct cmsghdr *);
2029 if (cm->cmsg_level == SOL_SOCKET &&
2030 cm->cmsg_type == SCM_CREDS) {
2031 if (n_prev == NULL)
2032 control = n->m_next;
2033 else
2034 n_prev->m_next = n->m_next;
2035 n = m_free(n);
2036 } else {
2037 n_prev = n;
2038 n = n->m_next;
2039 }
2040 }
2041
2042 /* Prepend it to the head. */
2043 m->m_next = control;
2044 return (m);
2045 }
2046
2047 static struct unpcb *
2048 fptounp(struct file *fp)
2049 {
2050 struct socket *so;
2051
2052 if (fp->f_type != DTYPE_SOCKET)
2053 return (NULL);
2054 if ((so = fp->f_data) == NULL)
2055 return (NULL);
2056 if (so->so_proto->pr_domain != &localdomain)
2057 return (NULL);
2058 return sotounpcb(so);
2059 }
2060
2061 static void
2062 unp_discard(struct file *fp)
2063 {
2064 struct unp_defer *dr;
2065
2066 if (unp_externalize_fp(fp)) {
2067 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK);
2068 dr->ud_fp = fp;
2069 UNP_DEFERRED_LOCK();
2070 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link);
2071 UNP_DEFERRED_UNLOCK();
2072 atomic_add_int(&unp_defers_count, 1);
2073 taskqueue_enqueue(taskqueue_thread, &unp_defer_task);
2074 } else
2075 (void) closef(fp, (struct thread *)NULL);
2076 }
2077
2078 static void
2079 unp_process_defers(void *arg __unused, int pending)
2080 {
2081 struct unp_defer *dr;
2082 SLIST_HEAD(, unp_defer) drl;
2083 int count;
2084
2085 SLIST_INIT(&drl);
2086 for (;;) {
2087 UNP_DEFERRED_LOCK();
2088 if (SLIST_FIRST(&unp_defers) == NULL) {
2089 UNP_DEFERRED_UNLOCK();
2090 break;
2091 }
2092 SLIST_SWAP(&unp_defers, &drl, unp_defer);
2093 UNP_DEFERRED_UNLOCK();
2094 count = 0;
2095 while ((dr = SLIST_FIRST(&drl)) != NULL) {
2096 SLIST_REMOVE_HEAD(&drl, ud_link);
2097 closef(dr->ud_fp, NULL);
2098 free(dr, M_TEMP);
2099 count++;
2100 }
2101 atomic_add_int(&unp_defers_count, -count);
2102 }
2103 }
2104
2105 static void
2106 unp_internalize_fp(struct file *fp)
2107 {
2108 struct unpcb *unp;
2109
2110 UNP_LINK_WLOCK();
2111 if ((unp = fptounp(fp)) != NULL) {
2112 unp->unp_file = fp;
2113 unp->unp_msgcount++;
2114 }
2115 fhold(fp);
2116 unp_rights++;
2117 UNP_LINK_WUNLOCK();
2118 }
2119
2120 static int
2121 unp_externalize_fp(struct file *fp)
2122 {
2123 struct unpcb *unp;
2124 int ret;
2125
2126 UNP_LINK_WLOCK();
2127 if ((unp = fptounp(fp)) != NULL) {
2128 unp->unp_msgcount--;
2129 ret = 1;
2130 } else
2131 ret = 0;
2132 unp_rights--;
2133 UNP_LINK_WUNLOCK();
2134 return (ret);
2135 }
2136
2137 /*
2138 * unp_defer indicates whether additional work has been defered for a future
2139 * pass through unp_gc(). It is thread local and does not require explicit
2140 * synchronization.
2141 */
2142 static int unp_marked;
2143 static int unp_unreachable;
2144
2145 static void
2146 unp_accessable(struct filedescent **fdep, int fdcount)
2147 {
2148 struct unpcb *unp;
2149 struct file *fp;
2150 int i;
2151
2152 for (i = 0; i < fdcount; i++) {
2153 fp = fdep[i]->fde_file;
2154 if ((unp = fptounp(fp)) == NULL)
2155 continue;
2156 if (unp->unp_gcflag & UNPGC_REF)
2157 continue;
2158 unp->unp_gcflag &= ~UNPGC_DEAD;
2159 unp->unp_gcflag |= UNPGC_REF;
2160 unp_marked++;
2161 }
2162 }
2163
2164 static void
2165 unp_gc_process(struct unpcb *unp)
2166 {
2167 struct socket *soa;
2168 struct socket *so;
2169 struct file *fp;
2170
2171 /* Already processed. */
2172 if (unp->unp_gcflag & UNPGC_SCANNED)
2173 return;
2174 fp = unp->unp_file;
2175
2176 /*
2177 * Check for a socket potentially in a cycle. It must be in a
2178 * queue as indicated by msgcount, and this must equal the file
2179 * reference count. Note that when msgcount is 0 the file is NULL.
2180 */
2181 if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp &&
2182 unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) {
2183 unp->unp_gcflag |= UNPGC_DEAD;
2184 unp_unreachable++;
2185 return;
2186 }
2187
2188 /*
2189 * Mark all sockets we reference with RIGHTS.
2190 */
2191 so = unp->unp_socket;
2192 SOCKBUF_LOCK(&so->so_rcv);
2193 unp_scan(so->so_rcv.sb_mb, unp_accessable);
2194 SOCKBUF_UNLOCK(&so->so_rcv);
2195
2196 /*
2197 * Mark all sockets in our accept queue.
2198 */
2199 ACCEPT_LOCK();
2200 TAILQ_FOREACH(soa, &so->so_comp, so_list) {
2201 SOCKBUF_LOCK(&soa->so_rcv);
2202 unp_scan(soa->so_rcv.sb_mb, unp_accessable);
2203 SOCKBUF_UNLOCK(&soa->so_rcv);
2204 }
2205 ACCEPT_UNLOCK();
2206 unp->unp_gcflag |= UNPGC_SCANNED;
2207 }
2208
2209 static int unp_recycled;
2210 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0,
2211 "Number of unreachable sockets claimed by the garbage collector.");
2212
2213 static int unp_taskcount;
2214 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0,
2215 "Number of times the garbage collector has run.");
2216
2217 static void
2218 unp_gc(__unused void *arg, int pending)
2219 {
2220 struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead,
2221 NULL };
2222 struct unp_head **head;
2223 struct file *f, **unref;
2224 struct unpcb *unp;
2225 int i, total;
2226
2227 unp_taskcount++;
2228 UNP_LIST_LOCK();
2229 /*
2230 * First clear all gc flags from previous runs.
2231 */
2232 for (head = heads; *head != NULL; head++)
2233 LIST_FOREACH(unp, *head, unp_link)
2234 unp->unp_gcflag = 0;
2235
2236 /*
2237 * Scan marking all reachable sockets with UNPGC_REF. Once a socket
2238 * is reachable all of the sockets it references are reachable.
2239 * Stop the scan once we do a complete loop without discovering
2240 * a new reachable socket.
2241 */
2242 do {
2243 unp_unreachable = 0;
2244 unp_marked = 0;
2245 for (head = heads; *head != NULL; head++)
2246 LIST_FOREACH(unp, *head, unp_link)
2247 unp_gc_process(unp);
2248 } while (unp_marked);
2249 UNP_LIST_UNLOCK();
2250 if (unp_unreachable == 0)
2251 return;
2252
2253 /*
2254 * Allocate space for a local list of dead unpcbs.
2255 */
2256 unref = malloc(unp_unreachable * sizeof(struct file *),
2257 M_TEMP, M_WAITOK);
2258
2259 /*
2260 * Iterate looking for sockets which have been specifically marked
2261 * as as unreachable and store them locally.
2262 */
2263 UNP_LINK_RLOCK();
2264 UNP_LIST_LOCK();
2265 for (total = 0, head = heads; *head != NULL; head++)
2266 LIST_FOREACH(unp, *head, unp_link)
2267 if ((unp->unp_gcflag & UNPGC_DEAD) != 0) {
2268 f = unp->unp_file;
2269 if (unp->unp_msgcount == 0 || f == NULL ||
2270 f->f_count != unp->unp_msgcount)
2271 continue;
2272 unref[total++] = f;
2273 fhold(f);
2274 KASSERT(total <= unp_unreachable,
2275 ("unp_gc: incorrect unreachable count."));
2276 }
2277 UNP_LIST_UNLOCK();
2278 UNP_LINK_RUNLOCK();
2279
2280 /*
2281 * Now flush all sockets, free'ing rights. This will free the
2282 * struct files associated with these sockets but leave each socket
2283 * with one remaining ref.
2284 */
2285 for (i = 0; i < total; i++) {
2286 struct socket *so;
2287
2288 so = unref[i]->f_data;
2289 CURVNET_SET(so->so_vnet);
2290 sorflush(so);
2291 CURVNET_RESTORE();
2292 }
2293
2294 /*
2295 * And finally release the sockets so they can be reclaimed.
2296 */
2297 for (i = 0; i < total; i++)
2298 fdrop(unref[i], NULL);
2299 unp_recycled += total;
2300 free(unref, M_TEMP);
2301 }
2302
2303 static void
2304 unp_dispose(struct mbuf *m)
2305 {
2306
2307 if (m)
2308 unp_scan(m, unp_freerights);
2309 }
2310
2311 static void
2312 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int))
2313 {
2314 struct mbuf *m;
2315 struct cmsghdr *cm;
2316 void *data;
2317 socklen_t clen, datalen;
2318
2319 while (m0 != NULL) {
2320 for (m = m0; m; m = m->m_next) {
2321 if (m->m_type != MT_CONTROL)
2322 continue;
2323
2324 cm = mtod(m, struct cmsghdr *);
2325 clen = m->m_len;
2326
2327 while (cm != NULL) {
2328 if (sizeof(*cm) > clen || cm->cmsg_len > clen)
2329 break;
2330
2331 data = CMSG_DATA(cm);
2332 datalen = (caddr_t)cm + cm->cmsg_len
2333 - (caddr_t)data;
2334
2335 if (cm->cmsg_level == SOL_SOCKET &&
2336 cm->cmsg_type == SCM_RIGHTS) {
2337 (*op)(data, datalen /
2338 sizeof(struct filedescent *));
2339 }
2340
2341 if (CMSG_SPACE(datalen) < clen) {
2342 clen -= CMSG_SPACE(datalen);
2343 cm = (struct cmsghdr *)
2344 ((caddr_t)cm + CMSG_SPACE(datalen));
2345 } else {
2346 clen = 0;
2347 cm = NULL;
2348 }
2349 }
2350 }
2351 m0 = m0->m_act;
2352 }
2353 }
2354
2355 /*
2356 * A helper function called by VFS before socket-type vnode reclamation.
2357 * For an active vnode it clears unp_vnode pointer and decrements unp_vnode
2358 * use count.
2359 */
2360 void
2361 vfs_unp_reclaim(struct vnode *vp)
2362 {
2363 struct socket *so;
2364 struct unpcb *unp;
2365 int active;
2366
2367 ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim");
2368 KASSERT(vp->v_type == VSOCK,
2369 ("vfs_unp_reclaim: vp->v_type != VSOCK"));
2370
2371 active = 0;
2372 UNP_LINK_WLOCK();
2373 VOP_UNP_CONNECT(vp, &so);
2374 if (so == NULL)
2375 goto done;
2376 unp = sotounpcb(so);
2377 if (unp == NULL)
2378 goto done;
2379 UNP_PCB_LOCK(unp);
2380 if (unp->unp_vnode == vp) {
2381 VOP_UNP_DETACH(vp);
2382 unp->unp_vnode = NULL;
2383 active = 1;
2384 }
2385 UNP_PCB_UNLOCK(unp);
2386 done:
2387 UNP_LINK_WUNLOCK();
2388 if (active)
2389 vunref(vp);
2390 }
2391
2392 #ifdef DDB
2393 static void
2394 db_print_indent(int indent)
2395 {
2396 int i;
2397
2398 for (i = 0; i < indent; i++)
2399 db_printf(" ");
2400 }
2401
2402 static void
2403 db_print_unpflags(int unp_flags)
2404 {
2405 int comma;
2406
2407 comma = 0;
2408 if (unp_flags & UNP_HAVEPC) {
2409 db_printf("%sUNP_HAVEPC", comma ? ", " : "");
2410 comma = 1;
2411 }
2412 if (unp_flags & UNP_HAVEPCCACHED) {
2413 db_printf("%sUNP_HAVEPCCACHED", comma ? ", " : "");
2414 comma = 1;
2415 }
2416 if (unp_flags & UNP_WANTCRED) {
2417 db_printf("%sUNP_WANTCRED", comma ? ", " : "");
2418 comma = 1;
2419 }
2420 if (unp_flags & UNP_CONNWAIT) {
2421 db_printf("%sUNP_CONNWAIT", comma ? ", " : "");
2422 comma = 1;
2423 }
2424 if (unp_flags & UNP_CONNECTING) {
2425 db_printf("%sUNP_CONNECTING", comma ? ", " : "");
2426 comma = 1;
2427 }
2428 if (unp_flags & UNP_BINDING) {
2429 db_printf("%sUNP_BINDING", comma ? ", " : "");
2430 comma = 1;
2431 }
2432 }
2433
2434 static void
2435 db_print_xucred(int indent, struct xucred *xu)
2436 {
2437 int comma, i;
2438
2439 db_print_indent(indent);
2440 db_printf("cr_version: %u cr_uid: %u cr_ngroups: %d\n",
2441 xu->cr_version, xu->cr_uid, xu->cr_ngroups);
2442 db_print_indent(indent);
2443 db_printf("cr_groups: ");
2444 comma = 0;
2445 for (i = 0; i < xu->cr_ngroups; i++) {
2446 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]);
2447 comma = 1;
2448 }
2449 db_printf("\n");
2450 }
2451
2452 static void
2453 db_print_unprefs(int indent, struct unp_head *uh)
2454 {
2455 struct unpcb *unp;
2456 int counter;
2457
2458 counter = 0;
2459 LIST_FOREACH(unp, uh, unp_reflink) {
2460 if (counter % 4 == 0)
2461 db_print_indent(indent);
2462 db_printf("%p ", unp);
2463 if (counter % 4 == 3)
2464 db_printf("\n");
2465 counter++;
2466 }
2467 if (counter != 0 && counter % 4 != 0)
2468 db_printf("\n");
2469 }
2470
2471 DB_SHOW_COMMAND(unpcb, db_show_unpcb)
2472 {
2473 struct unpcb *unp;
2474
2475 if (!have_addr) {
2476 db_printf("usage: show unpcb <addr>\n");
2477 return;
2478 }
2479 unp = (struct unpcb *)addr;
2480
2481 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket,
2482 unp->unp_vnode);
2483
2484 db_printf("unp_ino: %ju unp_conn: %p\n", (uintmax_t)unp->unp_ino,
2485 unp->unp_conn);
2486
2487 db_printf("unp_refs:\n");
2488 db_print_unprefs(2, &unp->unp_refs);
2489
2490 /* XXXRW: Would be nice to print the full address, if any. */
2491 db_printf("unp_addr: %p\n", unp->unp_addr);
2492
2493 db_printf("unp_cc: %d unp_mbcnt: %d unp_gencnt: %llu\n",
2494 unp->unp_cc, unp->unp_mbcnt,
2495 (unsigned long long)unp->unp_gencnt);
2496
2497 db_printf("unp_flags: %x (", unp->unp_flags);
2498 db_print_unpflags(unp->unp_flags);
2499 db_printf(")\n");
2500
2501 db_printf("unp_peercred:\n");
2502 db_print_xucred(2, &unp->unp_peercred);
2503
2504 db_printf("unp_refcount: %u\n", unp->unp_refcount);
2505 }
2506 #endif
Cache object: a49c5a3dc43068474982ce4f4d2bf750
|