uipc_usrreq.c revision 233803
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: stable/9/sys/kern/uipc_usrreq.c 233803 2012-04-02 19:01:32Z trociny $"); 61 62#include "opt_ddb.h" 63 64#include <sys/param.h> 65#include <sys/domain.h> 66#include <sys/fcntl.h> 67#include <sys/malloc.h> /* XXX must be before <sys/file.h> */ 68#include <sys/eventhandler.h> 69#include <sys/file.h> 70#include <sys/filedesc.h> 71#include <sys/kernel.h> 72#include <sys/lock.h> 73#include <sys/mbuf.h> 74#include <sys/mount.h> 75#include <sys/mutex.h> 76#include <sys/namei.h> 77#include <sys/proc.h> 78#include <sys/protosw.h> 79#include <sys/queue.h> 80#include <sys/resourcevar.h> 81#include <sys/rwlock.h> 82#include <sys/socket.h> 83#include <sys/socketvar.h> 84#include <sys/signalvar.h> 85#include <sys/stat.h> 86#include <sys/sx.h> 87#include <sys/sysctl.h> 88#include <sys/systm.h> 89#include <sys/taskqueue.h> 90#include <sys/un.h> 91#include <sys/unpcb.h> 92#include <sys/vnode.h> 93 94#include <net/vnet.h> 95 96#ifdef DDB 97#include <ddb/ddb.h> 98#endif 99 100#include <security/mac/mac_framework.h> 101 102#include <vm/uma.h> 103 104/* 105 * Locking key: 106 * (l) Locked using list lock 107 * (g) Locked using linkage lock 108 */ 109 110static uma_zone_t unp_zone; 111static unp_gen_t unp_gencnt; /* (l) */ 112static u_int unp_count; /* (l) Count of local sockets. */ 113static ino_t unp_ino; /* Prototype for fake inode numbers. */ 114static int unp_rights; /* (g) File descriptors in flight. */ 115static struct unp_head unp_shead; /* (l) List of stream sockets. */ 116static struct unp_head unp_dhead; /* (l) List of datagram sockets. */ 117static struct unp_head unp_sphead; /* (l) List of seqpacket sockets. */ 118 119struct unp_defer { 120 SLIST_ENTRY(unp_defer) ud_link; 121 struct file *ud_fp; 122}; 123static SLIST_HEAD(, unp_defer) unp_defers; 124static int unp_defers_count; 125 126static const struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; 127 128/* 129 * Garbage collection of cyclic file descriptor/socket references occurs 130 * asynchronously in a taskqueue context in order to avoid recursion and 131 * reentrance in the UNIX domain socket, file descriptor, and socket layer 132 * code. See unp_gc() for a full description. 133 */ 134static struct task unp_gc_task; 135 136/* 137 * The close of unix domain sockets attached as SCM_RIGHTS is 138 * postponed to the taskqueue, to avoid arbitrary recursion depth. 139 * The attached sockets might have another sockets attached. 140 */ 141static struct task unp_defer_task; 142 143/* 144 * Both send and receive buffers are allocated PIPSIZ bytes of buffering for 145 * stream sockets, although the total for sender and receiver is actually 146 * only PIPSIZ. 147 * 148 * Datagram sockets really use the sendspace as the maximum datagram size, 149 * and don't really want to reserve the sendspace. Their recvspace should be 150 * large enough for at least one max-size datagram plus address. 151 */ 152#ifndef PIPSIZ 153#define PIPSIZ 8192 154#endif 155static u_long unpst_sendspace = PIPSIZ; 156static u_long unpst_recvspace = PIPSIZ; 157static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 158static u_long unpdg_recvspace = 4*1024; 159static u_long unpsp_sendspace = PIPSIZ; /* really max datagram size */ 160static u_long unpsp_recvspace = PIPSIZ; 161 162SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW, 0, "Local domain"); 163SYSCTL_NODE(_net_local, SOCK_STREAM, stream, CTLFLAG_RW, 0, "SOCK_STREAM"); 164SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram, CTLFLAG_RW, 0, "SOCK_DGRAM"); 165SYSCTL_NODE(_net_local, SOCK_SEQPACKET, seqpacket, CTLFLAG_RW, 0, 166 "SOCK_SEQPACKET"); 167 168SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, 169 &unpst_sendspace, 0, "Default stream send space."); 170SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, 171 &unpst_recvspace, 0, "Default stream receive space."); 172SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, 173 &unpdg_sendspace, 0, "Default datagram send space."); 174SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, 175 &unpdg_recvspace, 0, "Default datagram receive space."); 176SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, maxseqpacket, CTLFLAG_RW, 177 &unpsp_sendspace, 0, "Default seqpacket send space."); 178SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, recvspace, CTLFLAG_RW, 179 &unpsp_recvspace, 0, "Default seqpacket receive space."); 180SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, 181 "File descriptors in flight."); 182SYSCTL_INT(_net_local, OID_AUTO, deferred, CTLFLAG_RD, 183 &unp_defers_count, 0, 184 "File descriptors deferred to taskqueue for close."); 185 186/* 187 * Locking and synchronization: 188 * 189 * Three types of locks exit in the local domain socket implementation: a 190 * global list mutex, a global linkage rwlock, and per-unpcb mutexes. Of the 191 * global locks, the list lock protects the socket count, global generation 192 * number, and stream/datagram global lists. The linkage lock protects the 193 * interconnection of unpcbs, the v_socket and unp_vnode pointers, and can be 194 * held exclusively over the acquisition of multiple unpcb locks to prevent 195 * deadlock. 196 * 197 * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer, 198 * allocated in pru_attach() and freed in pru_detach(). The validity of that 199 * pointer is an invariant, so no lock is required to dereference the so_pcb 200 * pointer if a valid socket reference is held by the caller. In practice, 201 * this is always true during operations performed on a socket. Each unpcb 202 * has a back-pointer to its socket, unp_socket, which will be stable under 203 * the same circumstances. 204 * 205 * This pointer may only be safely dereferenced as long as a valid reference 206 * to the unpcb is held. Typically, this reference will be from the socket, 207 * or from another unpcb when the referring unpcb's lock is held (in order 208 * that the reference not be invalidated during use). For example, to follow 209 * unp->unp_conn->unp_socket, you need unlock the lock on unp, not unp_conn, 210 * as unp_socket remains valid as long as the reference to unp_conn is valid. 211 * 212 * Fields of unpcbss are locked using a per-unpcb lock, unp_mtx. Individual 213 * atomic reads without the lock may be performed "lockless", but more 214 * complex reads and read-modify-writes require the mutex to be held. No 215 * lock order is defined between unpcb locks -- multiple unpcb locks may be 216 * acquired at the same time only when holding the linkage rwlock 217 * exclusively, which prevents deadlocks. 218 * 219 * Blocking with UNIX domain sockets is a tricky issue: unlike most network 220 * protocols, bind() is a non-atomic operation, and connect() requires 221 * potential sleeping in the protocol, due to potentially waiting on local or 222 * distributed file systems. We try to separate "lookup" operations, which 223 * may sleep, and the IPC operations themselves, which typically can occur 224 * with relative atomicity as locks can be held over the entire operation. 225 * 226 * Another tricky issue is simultaneous multi-threaded or multi-process 227 * access to a single UNIX domain socket. These are handled by the flags 228 * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or 229 * binding, both of which involve dropping UNIX domain socket locks in order 230 * to perform namei() and other file system operations. 231 */ 232static struct rwlock unp_link_rwlock; 233static struct mtx unp_list_lock; 234static struct mtx unp_defers_lock; 235 236#define UNP_LINK_LOCK_INIT() rw_init(&unp_link_rwlock, \ 237 "unp_link_rwlock") 238 239#define UNP_LINK_LOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 240 RA_LOCKED) 241#define UNP_LINK_UNLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 242 RA_UNLOCKED) 243 244#define UNP_LINK_RLOCK() rw_rlock(&unp_link_rwlock) 245#define UNP_LINK_RUNLOCK() rw_runlock(&unp_link_rwlock) 246#define UNP_LINK_WLOCK() rw_wlock(&unp_link_rwlock) 247#define UNP_LINK_WUNLOCK() rw_wunlock(&unp_link_rwlock) 248#define UNP_LINK_WLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 249 RA_WLOCKED) 250 251#define UNP_LIST_LOCK_INIT() mtx_init(&unp_list_lock, \ 252 "unp_list_lock", NULL, MTX_DEF) 253#define UNP_LIST_LOCK() mtx_lock(&unp_list_lock) 254#define UNP_LIST_UNLOCK() mtx_unlock(&unp_list_lock) 255 256#define UNP_DEFERRED_LOCK_INIT() mtx_init(&unp_defers_lock, \ 257 "unp_defer", NULL, MTX_DEF) 258#define UNP_DEFERRED_LOCK() mtx_lock(&unp_defers_lock) 259#define UNP_DEFERRED_UNLOCK() mtx_unlock(&unp_defers_lock) 260 261#define UNP_PCB_LOCK_INIT(unp) mtx_init(&(unp)->unp_mtx, \ 262 "unp_mtx", "unp_mtx", \ 263 MTX_DUPOK|MTX_DEF|MTX_RECURSE) 264#define UNP_PCB_LOCK_DESTROY(unp) mtx_destroy(&(unp)->unp_mtx) 265#define UNP_PCB_LOCK(unp) mtx_lock(&(unp)->unp_mtx) 266#define UNP_PCB_UNLOCK(unp) mtx_unlock(&(unp)->unp_mtx) 267#define UNP_PCB_LOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_OWNED) 268 269static int uipc_connect2(struct socket *, struct socket *); 270static int uipc_ctloutput(struct socket *, struct sockopt *); 271static int unp_connect(struct socket *, struct sockaddr *, 272 struct thread *); 273static int unp_connect2(struct socket *so, struct socket *so2, int); 274static void unp_disconnect(struct unpcb *unp, struct unpcb *unp2); 275static void unp_dispose(struct mbuf *); 276static void unp_shutdown(struct unpcb *); 277static void unp_drop(struct unpcb *, int); 278static void unp_gc(__unused void *, int); 279static void unp_scan(struct mbuf *, void (*)(struct file *)); 280static void unp_discard(struct file *); 281static void unp_freerights(struct file **, int); 282static void unp_init(void); 283static int unp_internalize(struct mbuf **, struct thread *); 284static void unp_internalize_fp(struct file *); 285static int unp_externalize(struct mbuf *, struct mbuf **); 286static int unp_externalize_fp(struct file *); 287static struct mbuf *unp_addsockcred(struct thread *, struct mbuf *); 288static void unp_process_defers(void * __unused, int); 289 290/* 291 * Definitions of protocols supported in the LOCAL domain. 292 */ 293static struct domain localdomain; 294static struct pr_usrreqs uipc_usrreqs_dgram, uipc_usrreqs_stream; 295static struct pr_usrreqs uipc_usrreqs_seqpacket; 296static struct protosw localsw[] = { 297{ 298 .pr_type = SOCK_STREAM, 299 .pr_domain = &localdomain, 300 .pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS, 301 .pr_ctloutput = &uipc_ctloutput, 302 .pr_usrreqs = &uipc_usrreqs_stream 303}, 304{ 305 .pr_type = SOCK_DGRAM, 306 .pr_domain = &localdomain, 307 .pr_flags = PR_ATOMIC|PR_ADDR|PR_RIGHTS, 308 .pr_usrreqs = &uipc_usrreqs_dgram 309}, 310{ 311 .pr_type = SOCK_SEQPACKET, 312 .pr_domain = &localdomain, 313 314 /* 315 * XXXRW: For now, PR_ADDR because soreceive will bump into them 316 * due to our use of sbappendaddr. A new sbappend variants is needed 317 * that supports both atomic record writes and control data. 318 */ 319 .pr_flags = PR_ADDR|PR_ATOMIC|PR_CONNREQUIRED|PR_WANTRCVD| 320 PR_RIGHTS, 321 .pr_usrreqs = &uipc_usrreqs_seqpacket, 322}, 323}; 324 325static struct domain localdomain = { 326 .dom_family = AF_LOCAL, 327 .dom_name = "local", 328 .dom_init = unp_init, 329 .dom_externalize = unp_externalize, 330 .dom_dispose = unp_dispose, 331 .dom_protosw = localsw, 332 .dom_protoswNPROTOSW = &localsw[sizeof(localsw)/sizeof(localsw[0])] 333}; 334DOMAIN_SET(local); 335 336static void 337uipc_abort(struct socket *so) 338{ 339 struct unpcb *unp, *unp2; 340 341 unp = sotounpcb(so); 342 KASSERT(unp != NULL, ("uipc_abort: unp == NULL")); 343 344 UNP_LINK_WLOCK(); 345 UNP_PCB_LOCK(unp); 346 unp2 = unp->unp_conn; 347 if (unp2 != NULL) { 348 UNP_PCB_LOCK(unp2); 349 unp_drop(unp2, ECONNABORTED); 350 UNP_PCB_UNLOCK(unp2); 351 } 352 UNP_PCB_UNLOCK(unp); 353 UNP_LINK_WUNLOCK(); 354} 355 356static int 357uipc_accept(struct socket *so, struct sockaddr **nam) 358{ 359 struct unpcb *unp, *unp2; 360 const struct sockaddr *sa; 361 362 /* 363 * Pass back name of connected socket, if it was bound and we are 364 * still connected (our peer may have closed already!). 365 */ 366 unp = sotounpcb(so); 367 KASSERT(unp != NULL, ("uipc_accept: unp == NULL")); 368 369 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 370 UNP_LINK_RLOCK(); 371 unp2 = unp->unp_conn; 372 if (unp2 != NULL && unp2->unp_addr != NULL) { 373 UNP_PCB_LOCK(unp2); 374 sa = (struct sockaddr *) unp2->unp_addr; 375 bcopy(sa, *nam, sa->sa_len); 376 UNP_PCB_UNLOCK(unp2); 377 } else { 378 sa = &sun_noname; 379 bcopy(sa, *nam, sa->sa_len); 380 } 381 UNP_LINK_RUNLOCK(); 382 return (0); 383} 384 385static int 386uipc_attach(struct socket *so, int proto, struct thread *td) 387{ 388 u_long sendspace, recvspace; 389 struct unpcb *unp; 390 int error; 391 392 KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL")); 393 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 394 switch (so->so_type) { 395 case SOCK_STREAM: 396 sendspace = unpst_sendspace; 397 recvspace = unpst_recvspace; 398 break; 399 400 case SOCK_DGRAM: 401 sendspace = unpdg_sendspace; 402 recvspace = unpdg_recvspace; 403 break; 404 405 case SOCK_SEQPACKET: 406 sendspace = unpsp_sendspace; 407 recvspace = unpsp_recvspace; 408 break; 409 410 default: 411 panic("uipc_attach"); 412 } 413 error = soreserve(so, sendspace, recvspace); 414 if (error) 415 return (error); 416 } 417 unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO); 418 if (unp == NULL) 419 return (ENOBUFS); 420 LIST_INIT(&unp->unp_refs); 421 UNP_PCB_LOCK_INIT(unp); 422 unp->unp_socket = so; 423 so->so_pcb = unp; 424 unp->unp_refcount = 1; 425 426 UNP_LIST_LOCK(); 427 unp->unp_gencnt = ++unp_gencnt; 428 unp_count++; 429 switch (so->so_type) { 430 case SOCK_STREAM: 431 LIST_INSERT_HEAD(&unp_shead, unp, unp_link); 432 break; 433 434 case SOCK_DGRAM: 435 LIST_INSERT_HEAD(&unp_dhead, unp, unp_link); 436 break; 437 438 case SOCK_SEQPACKET: 439 LIST_INSERT_HEAD(&unp_sphead, unp, unp_link); 440 break; 441 442 default: 443 panic("uipc_attach"); 444 } 445 UNP_LIST_UNLOCK(); 446 447 return (0); 448} 449 450static int 451uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 452{ 453 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 454 struct vattr vattr; 455 int error, namelen, vfslocked; 456 struct nameidata nd; 457 struct unpcb *unp; 458 struct vnode *vp; 459 struct mount *mp; 460 char *buf; 461 462 unp = sotounpcb(so); 463 KASSERT(unp != NULL, ("uipc_bind: unp == NULL")); 464 465 if (soun->sun_len > sizeof(struct sockaddr_un)) 466 return (EINVAL); 467 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 468 if (namelen <= 0) 469 return (EINVAL); 470 471 /* 472 * We don't allow simultaneous bind() calls on a single UNIX domain 473 * socket, so flag in-progress operations, and return an error if an 474 * operation is already in progress. 475 * 476 * Historically, we have not allowed a socket to be rebound, so this 477 * also returns an error. Not allowing re-binding simplifies the 478 * implementation and avoids a great many possible failure modes. 479 */ 480 UNP_PCB_LOCK(unp); 481 if (unp->unp_vnode != NULL) { 482 UNP_PCB_UNLOCK(unp); 483 return (EINVAL); 484 } 485 if (unp->unp_flags & UNP_BINDING) { 486 UNP_PCB_UNLOCK(unp); 487 return (EALREADY); 488 } 489 unp->unp_flags |= UNP_BINDING; 490 UNP_PCB_UNLOCK(unp); 491 492 buf = malloc(namelen + 1, M_TEMP, M_WAITOK); 493 bcopy(soun->sun_path, buf, namelen); 494 buf[namelen] = 0; 495 496restart: 497 vfslocked = 0; 498 NDINIT(&nd, CREATE, MPSAFE | NOFOLLOW | LOCKPARENT | SAVENAME, 499 UIO_SYSSPACE, buf, td); 500/* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 501 error = namei(&nd); 502 if (error) 503 goto error; 504 vp = nd.ni_vp; 505 vfslocked = NDHASGIANT(&nd); 506 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 507 NDFREE(&nd, NDF_ONLY_PNBUF); 508 if (nd.ni_dvp == vp) 509 vrele(nd.ni_dvp); 510 else 511 vput(nd.ni_dvp); 512 if (vp != NULL) { 513 vrele(vp); 514 error = EADDRINUSE; 515 goto error; 516 } 517 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); 518 if (error) 519 goto error; 520 VFS_UNLOCK_GIANT(vfslocked); 521 goto restart; 522 } 523 VATTR_NULL(&vattr); 524 vattr.va_type = VSOCK; 525 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask); 526#ifdef MAC 527 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, 528 &vattr); 529#endif 530 if (error == 0) 531 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 532 NDFREE(&nd, NDF_ONLY_PNBUF); 533 vput(nd.ni_dvp); 534 if (error) { 535 vn_finished_write(mp); 536 goto error; 537 } 538 vp = nd.ni_vp; 539 ASSERT_VOP_ELOCKED(vp, "uipc_bind"); 540 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); 541 542 UNP_LINK_WLOCK(); 543 UNP_PCB_LOCK(unp); 544 vp->v_socket = unp->unp_socket; 545 unp->unp_vnode = vp; 546 unp->unp_addr = soun; 547 unp->unp_flags &= ~UNP_BINDING; 548 UNP_PCB_UNLOCK(unp); 549 UNP_LINK_WUNLOCK(); 550 VOP_UNLOCK(vp, 0); 551 vn_finished_write(mp); 552 VFS_UNLOCK_GIANT(vfslocked); 553 free(buf, M_TEMP); 554 return (0); 555 556error: 557 VFS_UNLOCK_GIANT(vfslocked); 558 UNP_PCB_LOCK(unp); 559 unp->unp_flags &= ~UNP_BINDING; 560 UNP_PCB_UNLOCK(unp); 561 free(buf, M_TEMP); 562 return (error); 563} 564 565static int 566uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 567{ 568 int error; 569 570 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 571 UNP_LINK_WLOCK(); 572 error = unp_connect(so, nam, td); 573 UNP_LINK_WUNLOCK(); 574 return (error); 575} 576 577static void 578uipc_close(struct socket *so) 579{ 580 struct unpcb *unp, *unp2; 581 582 unp = sotounpcb(so); 583 KASSERT(unp != NULL, ("uipc_close: unp == NULL")); 584 585 UNP_LINK_WLOCK(); 586 UNP_PCB_LOCK(unp); 587 unp2 = unp->unp_conn; 588 if (unp2 != NULL) { 589 UNP_PCB_LOCK(unp2); 590 unp_disconnect(unp, unp2); 591 UNP_PCB_UNLOCK(unp2); 592 } 593 UNP_PCB_UNLOCK(unp); 594 UNP_LINK_WUNLOCK(); 595} 596 597static int 598uipc_connect2(struct socket *so1, struct socket *so2) 599{ 600 struct unpcb *unp, *unp2; 601 int error; 602 603 UNP_LINK_WLOCK(); 604 unp = so1->so_pcb; 605 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL")); 606 UNP_PCB_LOCK(unp); 607 unp2 = so2->so_pcb; 608 KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL")); 609 UNP_PCB_LOCK(unp2); 610 error = unp_connect2(so1, so2, PRU_CONNECT2); 611 UNP_PCB_UNLOCK(unp2); 612 UNP_PCB_UNLOCK(unp); 613 UNP_LINK_WUNLOCK(); 614 return (error); 615} 616 617static void 618uipc_detach(struct socket *so) 619{ 620 struct unpcb *unp, *unp2; 621 struct sockaddr_un *saved_unp_addr; 622 struct vnode *vp; 623 int freeunp, local_unp_rights; 624 625 unp = sotounpcb(so); 626 KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); 627 628 UNP_LINK_WLOCK(); 629 UNP_LIST_LOCK(); 630 UNP_PCB_LOCK(unp); 631 LIST_REMOVE(unp, unp_link); 632 unp->unp_gencnt = ++unp_gencnt; 633 --unp_count; 634 UNP_LIST_UNLOCK(); 635 636 /* 637 * XXXRW: Should assert vp->v_socket == so. 638 */ 639 if ((vp = unp->unp_vnode) != NULL) { 640 unp->unp_vnode->v_socket = NULL; 641 unp->unp_vnode = NULL; 642 } 643 unp2 = unp->unp_conn; 644 if (unp2 != NULL) { 645 UNP_PCB_LOCK(unp2); 646 unp_disconnect(unp, unp2); 647 UNP_PCB_UNLOCK(unp2); 648 } 649 650 /* 651 * We hold the linkage lock exclusively, so it's OK to acquire 652 * multiple pcb locks at a time. 653 */ 654 while (!LIST_EMPTY(&unp->unp_refs)) { 655 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 656 657 UNP_PCB_LOCK(ref); 658 unp_drop(ref, ECONNRESET); 659 UNP_PCB_UNLOCK(ref); 660 } 661 local_unp_rights = unp_rights; 662 UNP_LINK_WUNLOCK(); 663 unp->unp_socket->so_pcb = NULL; 664 saved_unp_addr = unp->unp_addr; 665 unp->unp_addr = NULL; 666 unp->unp_refcount--; 667 freeunp = (unp->unp_refcount == 0); 668 if (saved_unp_addr != NULL) 669 free(saved_unp_addr, M_SONAME); 670 if (freeunp) { 671 UNP_PCB_LOCK_DESTROY(unp); 672 uma_zfree(unp_zone, unp); 673 } else 674 UNP_PCB_UNLOCK(unp); 675 if (vp) { 676 int vfslocked; 677 678 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 679 vrele(vp); 680 VFS_UNLOCK_GIANT(vfslocked); 681 } 682 if (local_unp_rights) 683 taskqueue_enqueue(taskqueue_thread, &unp_gc_task); 684} 685 686static int 687uipc_disconnect(struct socket *so) 688{ 689 struct unpcb *unp, *unp2; 690 691 unp = sotounpcb(so); 692 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 693 694 UNP_LINK_WLOCK(); 695 UNP_PCB_LOCK(unp); 696 unp2 = unp->unp_conn; 697 if (unp2 != NULL) { 698 UNP_PCB_LOCK(unp2); 699 unp_disconnect(unp, unp2); 700 UNP_PCB_UNLOCK(unp2); 701 } 702 UNP_PCB_UNLOCK(unp); 703 UNP_LINK_WUNLOCK(); 704 return (0); 705} 706 707static int 708uipc_listen(struct socket *so, int backlog, struct thread *td) 709{ 710 struct unpcb *unp; 711 int error; 712 713 unp = sotounpcb(so); 714 KASSERT(unp != NULL, ("uipc_listen: unp == NULL")); 715 716 UNP_PCB_LOCK(unp); 717 if (unp->unp_vnode == NULL) { 718 UNP_PCB_UNLOCK(unp); 719 return (EINVAL); 720 } 721 722 SOCK_LOCK(so); 723 error = solisten_proto_check(so); 724 if (error == 0) { 725 cru2x(td->td_ucred, &unp->unp_peercred); 726 unp->unp_flags |= UNP_HAVEPCCACHED; 727 solisten_proto(so, backlog); 728 } 729 SOCK_UNLOCK(so); 730 UNP_PCB_UNLOCK(unp); 731 return (error); 732} 733 734static int 735uipc_peeraddr(struct socket *so, struct sockaddr **nam) 736{ 737 struct unpcb *unp, *unp2; 738 const struct sockaddr *sa; 739 740 unp = sotounpcb(so); 741 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); 742 743 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 744 UNP_LINK_RLOCK(); 745 /* 746 * XXX: It seems that this test always fails even when connection is 747 * established. So, this else clause is added as workaround to 748 * return PF_LOCAL sockaddr. 749 */ 750 unp2 = unp->unp_conn; 751 if (unp2 != NULL) { 752 UNP_PCB_LOCK(unp2); 753 if (unp2->unp_addr != NULL) 754 sa = (struct sockaddr *) unp2->unp_addr; 755 else 756 sa = &sun_noname; 757 bcopy(sa, *nam, sa->sa_len); 758 UNP_PCB_UNLOCK(unp2); 759 } else { 760 sa = &sun_noname; 761 bcopy(sa, *nam, sa->sa_len); 762 } 763 UNP_LINK_RUNLOCK(); 764 return (0); 765} 766 767static int 768uipc_rcvd(struct socket *so, int flags) 769{ 770 struct unpcb *unp, *unp2; 771 struct socket *so2; 772 u_int mbcnt, sbcc; 773 u_long newhiwat; 774 775 unp = sotounpcb(so); 776 KASSERT(unp != NULL, ("uipc_rcvd: unp == NULL")); 777 778 if (so->so_type != SOCK_STREAM && so->so_type != SOCK_SEQPACKET) 779 panic("uipc_rcvd socktype %d", so->so_type); 780 781 /* 782 * Adjust backpressure on sender and wakeup any waiting to write. 783 * 784 * The unp lock is acquired to maintain the validity of the unp_conn 785 * pointer; no lock on unp2 is required as unp2->unp_socket will be 786 * static as long as we don't permit unp2 to disconnect from unp, 787 * which is prevented by the lock on unp. We cache values from 788 * so_rcv to avoid holding the so_rcv lock over the entire 789 * transaction on the remote so_snd. 790 */ 791 SOCKBUF_LOCK(&so->so_rcv); 792 mbcnt = so->so_rcv.sb_mbcnt; 793 sbcc = so->so_rcv.sb_cc; 794 SOCKBUF_UNLOCK(&so->so_rcv); 795 UNP_PCB_LOCK(unp); 796 unp2 = unp->unp_conn; 797 if (unp2 == NULL) { 798 UNP_PCB_UNLOCK(unp); 799 return (0); 800 } 801 so2 = unp2->unp_socket; 802 SOCKBUF_LOCK(&so2->so_snd); 803 so2->so_snd.sb_mbmax += unp->unp_mbcnt - mbcnt; 804 newhiwat = so2->so_snd.sb_hiwat + unp->unp_cc - sbcc; 805 (void)chgsbsize(so2->so_cred->cr_uidinfo, &so2->so_snd.sb_hiwat, 806 newhiwat, RLIM_INFINITY); 807 sowwakeup_locked(so2); 808 unp->unp_mbcnt = mbcnt; 809 unp->unp_cc = sbcc; 810 UNP_PCB_UNLOCK(unp); 811 return (0); 812} 813 814static int 815uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 816 struct mbuf *control, struct thread *td) 817{ 818 struct unpcb *unp, *unp2; 819 struct socket *so2; 820 u_int mbcnt_delta, sbcc; 821 u_int newhiwat; 822 int error = 0; 823 824 unp = sotounpcb(so); 825 KASSERT(unp != NULL, ("uipc_send: unp == NULL")); 826 827 if (flags & PRUS_OOB) { 828 error = EOPNOTSUPP; 829 goto release; 830 } 831 if (control != NULL && (error = unp_internalize(&control, td))) 832 goto release; 833 if ((nam != NULL) || (flags & PRUS_EOF)) 834 UNP_LINK_WLOCK(); 835 else 836 UNP_LINK_RLOCK(); 837 switch (so->so_type) { 838 case SOCK_DGRAM: 839 { 840 const struct sockaddr *from; 841 842 unp2 = unp->unp_conn; 843 if (nam != NULL) { 844 UNP_LINK_WLOCK_ASSERT(); 845 if (unp2 != NULL) { 846 error = EISCONN; 847 break; 848 } 849 error = unp_connect(so, nam, td); 850 if (error) 851 break; 852 unp2 = unp->unp_conn; 853 } 854 855 /* 856 * Because connect() and send() are non-atomic in a sendto() 857 * with a target address, it's possible that the socket will 858 * have disconnected before the send() can run. In that case 859 * return the slightly counter-intuitive but otherwise 860 * correct error that the socket is not connected. 861 */ 862 if (unp2 == NULL) { 863 error = ENOTCONN; 864 break; 865 } 866 /* Lockless read. */ 867 if (unp2->unp_flags & UNP_WANTCRED) 868 control = unp_addsockcred(td, control); 869 UNP_PCB_LOCK(unp); 870 if (unp->unp_addr != NULL) 871 from = (struct sockaddr *)unp->unp_addr; 872 else 873 from = &sun_noname; 874 so2 = unp2->unp_socket; 875 SOCKBUF_LOCK(&so2->so_rcv); 876 if (sbappendaddr_locked(&so2->so_rcv, from, m, control)) { 877 sorwakeup_locked(so2); 878 m = NULL; 879 control = NULL; 880 } else { 881 SOCKBUF_UNLOCK(&so2->so_rcv); 882 error = ENOBUFS; 883 } 884 if (nam != NULL) { 885 UNP_LINK_WLOCK_ASSERT(); 886 UNP_PCB_LOCK(unp2); 887 unp_disconnect(unp, unp2); 888 UNP_PCB_UNLOCK(unp2); 889 } 890 UNP_PCB_UNLOCK(unp); 891 break; 892 } 893 894 case SOCK_SEQPACKET: 895 case SOCK_STREAM: 896 if ((so->so_state & SS_ISCONNECTED) == 0) { 897 if (nam != NULL) { 898 UNP_LINK_WLOCK_ASSERT(); 899 error = unp_connect(so, nam, td); 900 if (error) 901 break; /* XXX */ 902 } else { 903 error = ENOTCONN; 904 break; 905 } 906 } 907 908 /* Lockless read. */ 909 if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 910 error = EPIPE; 911 break; 912 } 913 914 /* 915 * Because connect() and send() are non-atomic in a sendto() 916 * with a target address, it's possible that the socket will 917 * have disconnected before the send() can run. In that case 918 * return the slightly counter-intuitive but otherwise 919 * correct error that the socket is not connected. 920 * 921 * Locking here must be done carefully: the linkage lock 922 * prevents interconnections between unpcbs from changing, so 923 * we can traverse from unp to unp2 without acquiring unp's 924 * lock. Socket buffer locks follow unpcb locks, so we can 925 * acquire both remote and lock socket buffer locks. 926 */ 927 unp2 = unp->unp_conn; 928 if (unp2 == NULL) { 929 error = ENOTCONN; 930 break; 931 } 932 so2 = unp2->unp_socket; 933 UNP_PCB_LOCK(unp2); 934 SOCKBUF_LOCK(&so2->so_rcv); 935 if (unp2->unp_flags & UNP_WANTCRED) { 936 /* 937 * Credentials are passed only once on SOCK_STREAM. 938 */ 939 unp2->unp_flags &= ~UNP_WANTCRED; 940 control = unp_addsockcred(td, control); 941 } 942 /* 943 * Send to paired receive port, and then reduce send buffer 944 * hiwater marks to maintain backpressure. Wake up readers. 945 */ 946 switch (so->so_type) { 947 case SOCK_STREAM: 948 if (control != NULL) { 949 if (sbappendcontrol_locked(&so2->so_rcv, m, 950 control)) 951 control = NULL; 952 } else 953 sbappend_locked(&so2->so_rcv, m); 954 break; 955 956 case SOCK_SEQPACKET: { 957 const struct sockaddr *from; 958 959 from = &sun_noname; 960 if (sbappendaddr_locked(&so2->so_rcv, from, m, 961 control)) 962 control = NULL; 963 break; 964 } 965 } 966 967 /* 968 * XXXRW: While fine for SOCK_STREAM, this conflates maximum 969 * datagram size and back-pressure for SOCK_SEQPACKET, which 970 * can lead to undesired return of EMSGSIZE on send instead 971 * of more desirable blocking. 972 */ 973 mbcnt_delta = so2->so_rcv.sb_mbcnt - unp2->unp_mbcnt; 974 unp2->unp_mbcnt = so2->so_rcv.sb_mbcnt; 975 sbcc = so2->so_rcv.sb_cc; 976 sorwakeup_locked(so2); 977 978 SOCKBUF_LOCK(&so->so_snd); 979 if ((int)so->so_snd.sb_hiwat >= (int)(sbcc - unp2->unp_cc)) 980 newhiwat = so->so_snd.sb_hiwat - (sbcc - unp2->unp_cc); 981 else 982 newhiwat = 0; 983 (void)chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat, 984 newhiwat, RLIM_INFINITY); 985 so->so_snd.sb_mbmax -= mbcnt_delta; 986 SOCKBUF_UNLOCK(&so->so_snd); 987 unp2->unp_cc = sbcc; 988 UNP_PCB_UNLOCK(unp2); 989 m = NULL; 990 break; 991 992 default: 993 panic("uipc_send unknown socktype"); 994 } 995 996 /* 997 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown. 998 */ 999 if (flags & PRUS_EOF) { 1000 UNP_PCB_LOCK(unp); 1001 socantsendmore(so); 1002 unp_shutdown(unp); 1003 UNP_PCB_UNLOCK(unp); 1004 } 1005 1006 if ((nam != NULL) || (flags & PRUS_EOF)) 1007 UNP_LINK_WUNLOCK(); 1008 else 1009 UNP_LINK_RUNLOCK(); 1010 1011 if (control != NULL && error != 0) 1012 unp_dispose(control); 1013 1014release: 1015 if (control != NULL) 1016 m_freem(control); 1017 if (m != NULL) 1018 m_freem(m); 1019 return (error); 1020} 1021 1022static int 1023uipc_sense(struct socket *so, struct stat *sb) 1024{ 1025 struct unpcb *unp, *unp2; 1026 struct socket *so2; 1027 1028 unp = sotounpcb(so); 1029 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 1030 1031 sb->st_blksize = so->so_snd.sb_hiwat; 1032 UNP_LINK_RLOCK(); 1033 UNP_PCB_LOCK(unp); 1034 unp2 = unp->unp_conn; 1035 if ((so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET) && 1036 unp2 != NULL) { 1037 so2 = unp2->unp_socket; 1038 sb->st_blksize += so2->so_rcv.sb_cc; 1039 } 1040 sb->st_dev = NODEV; 1041 if (unp->unp_ino == 0) 1042 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino; 1043 sb->st_ino = unp->unp_ino; 1044 UNP_PCB_UNLOCK(unp); 1045 UNP_LINK_RUNLOCK(); 1046 return (0); 1047} 1048 1049static int 1050uipc_shutdown(struct socket *so) 1051{ 1052 struct unpcb *unp; 1053 1054 unp = sotounpcb(so); 1055 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 1056 1057 UNP_LINK_WLOCK(); 1058 UNP_PCB_LOCK(unp); 1059 socantsendmore(so); 1060 unp_shutdown(unp); 1061 UNP_PCB_UNLOCK(unp); 1062 UNP_LINK_WUNLOCK(); 1063 return (0); 1064} 1065 1066static int 1067uipc_sockaddr(struct socket *so, struct sockaddr **nam) 1068{ 1069 struct unpcb *unp; 1070 const struct sockaddr *sa; 1071 1072 unp = sotounpcb(so); 1073 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 1074 1075 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1076 UNP_PCB_LOCK(unp); 1077 if (unp->unp_addr != NULL) 1078 sa = (struct sockaddr *) unp->unp_addr; 1079 else 1080 sa = &sun_noname; 1081 bcopy(sa, *nam, sa->sa_len); 1082 UNP_PCB_UNLOCK(unp); 1083 return (0); 1084} 1085 1086static struct pr_usrreqs uipc_usrreqs_dgram = { 1087 .pru_abort = uipc_abort, 1088 .pru_accept = uipc_accept, 1089 .pru_attach = uipc_attach, 1090 .pru_bind = uipc_bind, 1091 .pru_connect = uipc_connect, 1092 .pru_connect2 = uipc_connect2, 1093 .pru_detach = uipc_detach, 1094 .pru_disconnect = uipc_disconnect, 1095 .pru_listen = uipc_listen, 1096 .pru_peeraddr = uipc_peeraddr, 1097 .pru_rcvd = uipc_rcvd, 1098 .pru_send = uipc_send, 1099 .pru_sense = uipc_sense, 1100 .pru_shutdown = uipc_shutdown, 1101 .pru_sockaddr = uipc_sockaddr, 1102 .pru_soreceive = soreceive_dgram, 1103 .pru_close = uipc_close, 1104}; 1105 1106static struct pr_usrreqs uipc_usrreqs_seqpacket = { 1107 .pru_abort = uipc_abort, 1108 .pru_accept = uipc_accept, 1109 .pru_attach = uipc_attach, 1110 .pru_bind = uipc_bind, 1111 .pru_connect = uipc_connect, 1112 .pru_connect2 = uipc_connect2, 1113 .pru_detach = uipc_detach, 1114 .pru_disconnect = uipc_disconnect, 1115 .pru_listen = uipc_listen, 1116 .pru_peeraddr = uipc_peeraddr, 1117 .pru_rcvd = uipc_rcvd, 1118 .pru_send = uipc_send, 1119 .pru_sense = uipc_sense, 1120 .pru_shutdown = uipc_shutdown, 1121 .pru_sockaddr = uipc_sockaddr, 1122 .pru_soreceive = soreceive_generic, /* XXX: or...? */ 1123 .pru_close = uipc_close, 1124}; 1125 1126static struct pr_usrreqs uipc_usrreqs_stream = { 1127 .pru_abort = uipc_abort, 1128 .pru_accept = uipc_accept, 1129 .pru_attach = uipc_attach, 1130 .pru_bind = uipc_bind, 1131 .pru_connect = uipc_connect, 1132 .pru_connect2 = uipc_connect2, 1133 .pru_detach = uipc_detach, 1134 .pru_disconnect = uipc_disconnect, 1135 .pru_listen = uipc_listen, 1136 .pru_peeraddr = uipc_peeraddr, 1137 .pru_rcvd = uipc_rcvd, 1138 .pru_send = uipc_send, 1139 .pru_sense = uipc_sense, 1140 .pru_shutdown = uipc_shutdown, 1141 .pru_sockaddr = uipc_sockaddr, 1142 .pru_soreceive = soreceive_generic, 1143 .pru_close = uipc_close, 1144}; 1145 1146static int 1147uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1148{ 1149 struct unpcb *unp; 1150 struct xucred xu; 1151 int error, optval; 1152 1153 if (sopt->sopt_level != 0) 1154 return (EINVAL); 1155 1156 unp = sotounpcb(so); 1157 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1158 error = 0; 1159 switch (sopt->sopt_dir) { 1160 case SOPT_GET: 1161 switch (sopt->sopt_name) { 1162 case LOCAL_PEERCRED: 1163 UNP_PCB_LOCK(unp); 1164 if (unp->unp_flags & UNP_HAVEPC) 1165 xu = unp->unp_peercred; 1166 else { 1167 if (so->so_type == SOCK_STREAM) 1168 error = ENOTCONN; 1169 else 1170 error = EINVAL; 1171 } 1172 UNP_PCB_UNLOCK(unp); 1173 if (error == 0) 1174 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1175 break; 1176 1177 case LOCAL_CREDS: 1178 /* Unlocked read. */ 1179 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0; 1180 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1181 break; 1182 1183 case LOCAL_CONNWAIT: 1184 /* Unlocked read. */ 1185 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1186 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1187 break; 1188 1189 default: 1190 error = EOPNOTSUPP; 1191 break; 1192 } 1193 break; 1194 1195 case SOPT_SET: 1196 switch (sopt->sopt_name) { 1197 case LOCAL_CREDS: 1198 case LOCAL_CONNWAIT: 1199 error = sooptcopyin(sopt, &optval, sizeof(optval), 1200 sizeof(optval)); 1201 if (error) 1202 break; 1203 1204#define OPTSET(bit) do { \ 1205 UNP_PCB_LOCK(unp); \ 1206 if (optval) \ 1207 unp->unp_flags |= bit; \ 1208 else \ 1209 unp->unp_flags &= ~bit; \ 1210 UNP_PCB_UNLOCK(unp); \ 1211} while (0) 1212 1213 switch (sopt->sopt_name) { 1214 case LOCAL_CREDS: 1215 OPTSET(UNP_WANTCRED); 1216 break; 1217 1218 case LOCAL_CONNWAIT: 1219 OPTSET(UNP_CONNWAIT); 1220 break; 1221 1222 default: 1223 break; 1224 } 1225 break; 1226#undef OPTSET 1227 default: 1228 error = ENOPROTOOPT; 1229 break; 1230 } 1231 break; 1232 1233 default: 1234 error = EOPNOTSUPP; 1235 break; 1236 } 1237 return (error); 1238} 1239 1240static int 1241unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1242{ 1243 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 1244 struct vnode *vp; 1245 struct socket *so2, *so3; 1246 struct unpcb *unp, *unp2, *unp3; 1247 int error, len, vfslocked; 1248 struct nameidata nd; 1249 char buf[SOCK_MAXADDRLEN]; 1250 struct sockaddr *sa; 1251 1252 UNP_LINK_WLOCK_ASSERT(); 1253 1254 unp = sotounpcb(so); 1255 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1256 1257 if (nam->sa_len > sizeof(struct sockaddr_un)) 1258 return (EINVAL); 1259 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1260 if (len <= 0) 1261 return (EINVAL); 1262 bcopy(soun->sun_path, buf, len); 1263 buf[len] = 0; 1264 1265 UNP_PCB_LOCK(unp); 1266 if (unp->unp_flags & UNP_CONNECTING) { 1267 UNP_PCB_UNLOCK(unp); 1268 return (EALREADY); 1269 } 1270 UNP_LINK_WUNLOCK(); 1271 unp->unp_flags |= UNP_CONNECTING; 1272 UNP_PCB_UNLOCK(unp); 1273 1274 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1275 NDINIT(&nd, LOOKUP, MPSAFE | FOLLOW | LOCKSHARED | LOCKLEAF, 1276 UIO_SYSSPACE, buf, td); 1277 error = namei(&nd); 1278 if (error) 1279 vp = NULL; 1280 else 1281 vp = nd.ni_vp; 1282 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1283 vfslocked = NDHASGIANT(&nd); 1284 NDFREE(&nd, NDF_ONLY_PNBUF); 1285 if (error) 1286 goto bad; 1287 1288 if (vp->v_type != VSOCK) { 1289 error = ENOTSOCK; 1290 goto bad; 1291 } 1292#ifdef MAC 1293 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1294 if (error) 1295 goto bad; 1296#endif 1297 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1298 if (error) 1299 goto bad; 1300 VFS_UNLOCK_GIANT(vfslocked); 1301 1302 unp = sotounpcb(so); 1303 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1304 1305 /* 1306 * Lock linkage lock for two reasons: make sure v_socket is stable, 1307 * and to protect simultaneous locking of multiple pcbs. 1308 */ 1309 UNP_LINK_WLOCK(); 1310 so2 = vp->v_socket; 1311 if (so2 == NULL) { 1312 error = ECONNREFUSED; 1313 goto bad2; 1314 } 1315 if (so->so_type != so2->so_type) { 1316 error = EPROTOTYPE; 1317 goto bad2; 1318 } 1319 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 1320 if (so2->so_options & SO_ACCEPTCONN) { 1321 CURVNET_SET(so2->so_vnet); 1322 so3 = sonewconn(so2, 0); 1323 CURVNET_RESTORE(); 1324 } else 1325 so3 = NULL; 1326 if (so3 == NULL) { 1327 error = ECONNREFUSED; 1328 goto bad2; 1329 } 1330 unp = sotounpcb(so); 1331 unp2 = sotounpcb(so2); 1332 unp3 = sotounpcb(so3); 1333 UNP_PCB_LOCK(unp); 1334 UNP_PCB_LOCK(unp2); 1335 UNP_PCB_LOCK(unp3); 1336 if (unp2->unp_addr != NULL) { 1337 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1338 unp3->unp_addr = (struct sockaddr_un *) sa; 1339 sa = NULL; 1340 } 1341 1342 /* 1343 * The connecter's (client's) credentials are copied from its 1344 * process structure at the time of connect() (which is now). 1345 */ 1346 cru2x(td->td_ucred, &unp3->unp_peercred); 1347 unp3->unp_flags |= UNP_HAVEPC; 1348 1349 /* 1350 * The receiver's (server's) credentials are copied from the 1351 * unp_peercred member of socket on which the former called 1352 * listen(); uipc_listen() cached that process's credentials 1353 * at that time so we can use them now. 1354 */ 1355 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED, 1356 ("unp_connect: listener without cached peercred")); 1357 memcpy(&unp->unp_peercred, &unp2->unp_peercred, 1358 sizeof(unp->unp_peercred)); 1359 unp->unp_flags |= UNP_HAVEPC; 1360 if (unp2->unp_flags & UNP_WANTCRED) 1361 unp3->unp_flags |= UNP_WANTCRED; 1362 UNP_PCB_UNLOCK(unp3); 1363 UNP_PCB_UNLOCK(unp2); 1364 UNP_PCB_UNLOCK(unp); 1365#ifdef MAC 1366 mac_socketpeer_set_from_socket(so, so3); 1367 mac_socketpeer_set_from_socket(so3, so); 1368#endif 1369 1370 so2 = so3; 1371 } 1372 unp = sotounpcb(so); 1373 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1374 unp2 = sotounpcb(so2); 1375 KASSERT(unp2 != NULL, ("unp_connect: unp2 == NULL")); 1376 UNP_PCB_LOCK(unp); 1377 UNP_PCB_LOCK(unp2); 1378 error = unp_connect2(so, so2, PRU_CONNECT); 1379 UNP_PCB_UNLOCK(unp2); 1380 UNP_PCB_UNLOCK(unp); 1381bad2: 1382 UNP_LINK_WUNLOCK(); 1383 if (vfslocked) 1384 /* 1385 * Giant has been previously acquired. This means filesystem 1386 * isn't MPSAFE. Do it once again. 1387 */ 1388 mtx_lock(&Giant); 1389bad: 1390 if (vp != NULL) 1391 vput(vp); 1392 VFS_UNLOCK_GIANT(vfslocked); 1393 free(sa, M_SONAME); 1394 UNP_LINK_WLOCK(); 1395 UNP_PCB_LOCK(unp); 1396 unp->unp_flags &= ~UNP_CONNECTING; 1397 UNP_PCB_UNLOCK(unp); 1398 return (error); 1399} 1400 1401static int 1402unp_connect2(struct socket *so, struct socket *so2, int req) 1403{ 1404 struct unpcb *unp; 1405 struct unpcb *unp2; 1406 1407 unp = sotounpcb(so); 1408 KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); 1409 unp2 = sotounpcb(so2); 1410 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 1411 1412 UNP_LINK_WLOCK_ASSERT(); 1413 UNP_PCB_LOCK_ASSERT(unp); 1414 UNP_PCB_LOCK_ASSERT(unp2); 1415 1416 if (so2->so_type != so->so_type) 1417 return (EPROTOTYPE); 1418 unp->unp_conn = unp2; 1419 1420 switch (so->so_type) { 1421 case SOCK_DGRAM: 1422 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1423 soisconnected(so); 1424 break; 1425 1426 case SOCK_STREAM: 1427 case SOCK_SEQPACKET: 1428 unp2->unp_conn = unp; 1429 if (req == PRU_CONNECT && 1430 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1431 soisconnecting(so); 1432 else 1433 soisconnected(so); 1434 soisconnected(so2); 1435 break; 1436 1437 default: 1438 panic("unp_connect2"); 1439 } 1440 return (0); 1441} 1442 1443static void 1444unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1445{ 1446 struct socket *so; 1447 1448 KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL")); 1449 1450 UNP_LINK_WLOCK_ASSERT(); 1451 UNP_PCB_LOCK_ASSERT(unp); 1452 UNP_PCB_LOCK_ASSERT(unp2); 1453 1454 unp->unp_conn = NULL; 1455 switch (unp->unp_socket->so_type) { 1456 case SOCK_DGRAM: 1457 LIST_REMOVE(unp, unp_reflink); 1458 so = unp->unp_socket; 1459 SOCK_LOCK(so); 1460 so->so_state &= ~SS_ISCONNECTED; 1461 SOCK_UNLOCK(so); 1462 break; 1463 1464 case SOCK_STREAM: 1465 case SOCK_SEQPACKET: 1466 soisdisconnected(unp->unp_socket); 1467 unp2->unp_conn = NULL; 1468 soisdisconnected(unp2->unp_socket); 1469 break; 1470 } 1471} 1472 1473/* 1474 * unp_pcblist() walks the global list of struct unpcb's to generate a 1475 * pointer list, bumping the refcount on each unpcb. It then copies them out 1476 * sequentially, validating the generation number on each to see if it has 1477 * been detached. All of this is necessary because copyout() may sleep on 1478 * disk I/O. 1479 */ 1480static int 1481unp_pcblist(SYSCTL_HANDLER_ARGS) 1482{ 1483 int error, i, n; 1484 int freeunp; 1485 struct unpcb *unp, **unp_list; 1486 unp_gen_t gencnt; 1487 struct xunpgen *xug; 1488 struct unp_head *head; 1489 struct xunpcb *xu; 1490 1491 switch ((intptr_t)arg1) { 1492 case SOCK_STREAM: 1493 head = &unp_shead; 1494 break; 1495 1496 case SOCK_DGRAM: 1497 head = &unp_dhead; 1498 break; 1499 1500 case SOCK_SEQPACKET: 1501 head = &unp_sphead; 1502 break; 1503 1504 default: 1505 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1); 1506 } 1507 1508 /* 1509 * The process of preparing the PCB list is too time-consuming and 1510 * resource-intensive to repeat twice on every request. 1511 */ 1512 if (req->oldptr == NULL) { 1513 n = unp_count; 1514 req->oldidx = 2 * (sizeof *xug) 1515 + (n + n/8) * sizeof(struct xunpcb); 1516 return (0); 1517 } 1518 1519 if (req->newptr != NULL) 1520 return (EPERM); 1521 1522 /* 1523 * OK, now we're committed to doing something. 1524 */ 1525 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK); 1526 UNP_LIST_LOCK(); 1527 gencnt = unp_gencnt; 1528 n = unp_count; 1529 UNP_LIST_UNLOCK(); 1530 1531 xug->xug_len = sizeof *xug; 1532 xug->xug_count = n; 1533 xug->xug_gen = gencnt; 1534 xug->xug_sogen = so_gencnt; 1535 error = SYSCTL_OUT(req, xug, sizeof *xug); 1536 if (error) { 1537 free(xug, M_TEMP); 1538 return (error); 1539 } 1540 1541 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1542 1543 UNP_LIST_LOCK(); 1544 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1545 unp = LIST_NEXT(unp, unp_link)) { 1546 UNP_PCB_LOCK(unp); 1547 if (unp->unp_gencnt <= gencnt) { 1548 if (cr_cansee(req->td->td_ucred, 1549 unp->unp_socket->so_cred)) { 1550 UNP_PCB_UNLOCK(unp); 1551 continue; 1552 } 1553 unp_list[i++] = unp; 1554 unp->unp_refcount++; 1555 } 1556 UNP_PCB_UNLOCK(unp); 1557 } 1558 UNP_LIST_UNLOCK(); 1559 n = i; /* In case we lost some during malloc. */ 1560 1561 error = 0; 1562 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1563 for (i = 0; i < n; i++) { 1564 unp = unp_list[i]; 1565 UNP_PCB_LOCK(unp); 1566 unp->unp_refcount--; 1567 if (unp->unp_refcount != 0 && unp->unp_gencnt <= gencnt) { 1568 xu->xu_len = sizeof *xu; 1569 xu->xu_unpp = unp; 1570 /* 1571 * XXX - need more locking here to protect against 1572 * connect/disconnect races for SMP. 1573 */ 1574 if (unp->unp_addr != NULL) 1575 bcopy(unp->unp_addr, &xu->xu_addr, 1576 unp->unp_addr->sun_len); 1577 if (unp->unp_conn != NULL && 1578 unp->unp_conn->unp_addr != NULL) 1579 bcopy(unp->unp_conn->unp_addr, 1580 &xu->xu_caddr, 1581 unp->unp_conn->unp_addr->sun_len); 1582 bcopy(unp, &xu->xu_unp, sizeof *unp); 1583 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1584 UNP_PCB_UNLOCK(unp); 1585 error = SYSCTL_OUT(req, xu, sizeof *xu); 1586 } else { 1587 freeunp = (unp->unp_refcount == 0); 1588 UNP_PCB_UNLOCK(unp); 1589 if (freeunp) { 1590 UNP_PCB_LOCK_DESTROY(unp); 1591 uma_zfree(unp_zone, unp); 1592 } 1593 } 1594 } 1595 free(xu, M_TEMP); 1596 if (!error) { 1597 /* 1598 * Give the user an updated idea of our state. If the 1599 * generation differs from what we told her before, she knows 1600 * that something happened while we were processing this 1601 * request, and it might be necessary to retry. 1602 */ 1603 xug->xug_gen = unp_gencnt; 1604 xug->xug_sogen = so_gencnt; 1605 xug->xug_count = unp_count; 1606 error = SYSCTL_OUT(req, xug, sizeof *xug); 1607 } 1608 free(unp_list, M_TEMP); 1609 free(xug, M_TEMP); 1610 return (error); 1611} 1612 1613SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 1614 (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1615 "List of active local datagram sockets"); 1616SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 1617 (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1618 "List of active local stream sockets"); 1619SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, 1620 CTLTYPE_OPAQUE | CTLFLAG_RD, 1621 (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb", 1622 "List of active local seqpacket sockets"); 1623 1624static void 1625unp_shutdown(struct unpcb *unp) 1626{ 1627 struct unpcb *unp2; 1628 struct socket *so; 1629 1630 UNP_LINK_WLOCK_ASSERT(); 1631 UNP_PCB_LOCK_ASSERT(unp); 1632 1633 unp2 = unp->unp_conn; 1634 if ((unp->unp_socket->so_type == SOCK_STREAM || 1635 (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) { 1636 so = unp2->unp_socket; 1637 if (so != NULL) 1638 socantrcvmore(so); 1639 } 1640} 1641 1642static void 1643unp_drop(struct unpcb *unp, int errno) 1644{ 1645 struct socket *so = unp->unp_socket; 1646 struct unpcb *unp2; 1647 1648 UNP_LINK_WLOCK_ASSERT(); 1649 UNP_PCB_LOCK_ASSERT(unp); 1650 1651 so->so_error = errno; 1652 unp2 = unp->unp_conn; 1653 if (unp2 == NULL) 1654 return; 1655 UNP_PCB_LOCK(unp2); 1656 unp_disconnect(unp, unp2); 1657 UNP_PCB_UNLOCK(unp2); 1658} 1659 1660static void 1661unp_freerights(struct file **rp, int fdcount) 1662{ 1663 int i; 1664 struct file *fp; 1665 1666 for (i = 0; i < fdcount; i++) { 1667 fp = *rp; 1668 *rp++ = NULL; 1669 unp_discard(fp); 1670 } 1671} 1672 1673static int 1674unp_externalize(struct mbuf *control, struct mbuf **controlp) 1675{ 1676 struct thread *td = curthread; /* XXX */ 1677 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1678 int i; 1679 int *fdp; 1680 struct file **rp; 1681 struct file *fp; 1682 void *data; 1683 socklen_t clen = control->m_len, datalen; 1684 int error, newfds; 1685 int f; 1686 u_int newlen; 1687 1688 UNP_LINK_UNLOCK_ASSERT(); 1689 1690 error = 0; 1691 if (controlp != NULL) /* controlp == NULL => free control messages */ 1692 *controlp = NULL; 1693 while (cm != NULL) { 1694 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 1695 error = EINVAL; 1696 break; 1697 } 1698 data = CMSG_DATA(cm); 1699 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1700 if (cm->cmsg_level == SOL_SOCKET 1701 && cm->cmsg_type == SCM_RIGHTS) { 1702 newfds = datalen / sizeof(struct file *); 1703 rp = data; 1704 1705 /* If we're not outputting the descriptors free them. */ 1706 if (error || controlp == NULL) { 1707 unp_freerights(rp, newfds); 1708 goto next; 1709 } 1710 FILEDESC_XLOCK(td->td_proc->p_fd); 1711 /* if the new FD's will not fit free them. */ 1712 if (!fdavail(td, newfds)) { 1713 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1714 error = EMSGSIZE; 1715 unp_freerights(rp, newfds); 1716 goto next; 1717 } 1718 1719 /* 1720 * Now change each pointer to an fd in the global 1721 * table to an integer that is the index to the local 1722 * fd table entry that we set up to point to the 1723 * global one we are transferring. 1724 */ 1725 newlen = newfds * sizeof(int); 1726 *controlp = sbcreatecontrol(NULL, newlen, 1727 SCM_RIGHTS, SOL_SOCKET); 1728 if (*controlp == NULL) { 1729 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1730 error = E2BIG; 1731 unp_freerights(rp, newfds); 1732 goto next; 1733 } 1734 1735 fdp = (int *) 1736 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1737 for (i = 0; i < newfds; i++) { 1738 if (fdalloc(td, 0, &f)) 1739 panic("unp_externalize fdalloc failed"); 1740 fp = *rp++; 1741 td->td_proc->p_fd->fd_ofiles[f] = fp; 1742 unp_externalize_fp(fp); 1743 *fdp++ = f; 1744 } 1745 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1746 } else { 1747 /* We can just copy anything else across. */ 1748 if (error || controlp == NULL) 1749 goto next; 1750 *controlp = sbcreatecontrol(NULL, datalen, 1751 cm->cmsg_type, cm->cmsg_level); 1752 if (*controlp == NULL) { 1753 error = ENOBUFS; 1754 goto next; 1755 } 1756 bcopy(data, 1757 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 1758 datalen); 1759 } 1760 controlp = &(*controlp)->m_next; 1761 1762next: 1763 if (CMSG_SPACE(datalen) < clen) { 1764 clen -= CMSG_SPACE(datalen); 1765 cm = (struct cmsghdr *) 1766 ((caddr_t)cm + CMSG_SPACE(datalen)); 1767 } else { 1768 clen = 0; 1769 cm = NULL; 1770 } 1771 } 1772 1773 m_freem(control); 1774 return (error); 1775} 1776 1777static void 1778unp_zone_change(void *tag) 1779{ 1780 1781 uma_zone_set_max(unp_zone, maxsockets); 1782} 1783 1784static void 1785unp_init(void) 1786{ 1787 1788#ifdef VIMAGE 1789 if (!IS_DEFAULT_VNET(curvnet)) 1790 return; 1791#endif 1792 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, 1793 NULL, NULL, UMA_ALIGN_PTR, 0); 1794 if (unp_zone == NULL) 1795 panic("unp_init"); 1796 uma_zone_set_max(unp_zone, maxsockets); 1797 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 1798 NULL, EVENTHANDLER_PRI_ANY); 1799 LIST_INIT(&unp_dhead); 1800 LIST_INIT(&unp_shead); 1801 LIST_INIT(&unp_sphead); 1802 SLIST_INIT(&unp_defers); 1803 TASK_INIT(&unp_gc_task, 0, unp_gc, NULL); 1804 TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL); 1805 UNP_LINK_LOCK_INIT(); 1806 UNP_LIST_LOCK_INIT(); 1807 UNP_DEFERRED_LOCK_INIT(); 1808} 1809 1810static int 1811unp_internalize(struct mbuf **controlp, struct thread *td) 1812{ 1813 struct mbuf *control = *controlp; 1814 struct proc *p = td->td_proc; 1815 struct filedesc *fdescp = p->p_fd; 1816 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1817 struct cmsgcred *cmcred; 1818 struct file **rp; 1819 struct file *fp; 1820 struct timeval *tv; 1821 int i, fd, *fdp; 1822 void *data; 1823 socklen_t clen = control->m_len, datalen; 1824 int error, oldfds; 1825 u_int newlen; 1826 1827 UNP_LINK_UNLOCK_ASSERT(); 1828 1829 error = 0; 1830 *controlp = NULL; 1831 while (cm != NULL) { 1832 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 1833 || cm->cmsg_len > clen) { 1834 error = EINVAL; 1835 goto out; 1836 } 1837 data = CMSG_DATA(cm); 1838 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1839 1840 switch (cm->cmsg_type) { 1841 /* 1842 * Fill in credential information. 1843 */ 1844 case SCM_CREDS: 1845 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 1846 SCM_CREDS, SOL_SOCKET); 1847 if (*controlp == NULL) { 1848 error = ENOBUFS; 1849 goto out; 1850 } 1851 cmcred = (struct cmsgcred *) 1852 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1853 cmcred->cmcred_pid = p->p_pid; 1854 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 1855 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 1856 cmcred->cmcred_euid = td->td_ucred->cr_uid; 1857 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 1858 CMGROUP_MAX); 1859 for (i = 0; i < cmcred->cmcred_ngroups; i++) 1860 cmcred->cmcred_groups[i] = 1861 td->td_ucred->cr_groups[i]; 1862 break; 1863 1864 case SCM_RIGHTS: 1865 oldfds = datalen / sizeof (int); 1866 /* 1867 * Check that all the FDs passed in refer to legal 1868 * files. If not, reject the entire operation. 1869 */ 1870 fdp = data; 1871 FILEDESC_SLOCK(fdescp); 1872 for (i = 0; i < oldfds; i++) { 1873 fd = *fdp++; 1874 if ((unsigned)fd >= fdescp->fd_nfiles || 1875 fdescp->fd_ofiles[fd] == NULL) { 1876 FILEDESC_SUNLOCK(fdescp); 1877 error = EBADF; 1878 goto out; 1879 } 1880 fp = fdescp->fd_ofiles[fd]; 1881 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 1882 FILEDESC_SUNLOCK(fdescp); 1883 error = EOPNOTSUPP; 1884 goto out; 1885 } 1886 1887 } 1888 1889 /* 1890 * Now replace the integer FDs with pointers to the 1891 * associated global file table entry.. 1892 */ 1893 newlen = oldfds * sizeof(struct file *); 1894 *controlp = sbcreatecontrol(NULL, newlen, 1895 SCM_RIGHTS, SOL_SOCKET); 1896 if (*controlp == NULL) { 1897 FILEDESC_SUNLOCK(fdescp); 1898 error = E2BIG; 1899 goto out; 1900 } 1901 fdp = data; 1902 rp = (struct file **) 1903 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1904 for (i = 0; i < oldfds; i++) { 1905 fp = fdescp->fd_ofiles[*fdp++]; 1906 *rp++ = fp; 1907 unp_internalize_fp(fp); 1908 } 1909 FILEDESC_SUNLOCK(fdescp); 1910 break; 1911 1912 case SCM_TIMESTAMP: 1913 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 1914 SCM_TIMESTAMP, SOL_SOCKET); 1915 if (*controlp == NULL) { 1916 error = ENOBUFS; 1917 goto out; 1918 } 1919 tv = (struct timeval *) 1920 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1921 microtime(tv); 1922 break; 1923 1924 default: 1925 error = EINVAL; 1926 goto out; 1927 } 1928 1929 controlp = &(*controlp)->m_next; 1930 if (CMSG_SPACE(datalen) < clen) { 1931 clen -= CMSG_SPACE(datalen); 1932 cm = (struct cmsghdr *) 1933 ((caddr_t)cm + CMSG_SPACE(datalen)); 1934 } else { 1935 clen = 0; 1936 cm = NULL; 1937 } 1938 } 1939 1940out: 1941 m_freem(control); 1942 return (error); 1943} 1944 1945static struct mbuf * 1946unp_addsockcred(struct thread *td, struct mbuf *control) 1947{ 1948 struct mbuf *m, *n, *n_prev; 1949 struct sockcred *sc; 1950 const struct cmsghdr *cm; 1951 int ngroups; 1952 int i; 1953 1954 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 1955 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET); 1956 if (m == NULL) 1957 return (control); 1958 1959 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *)); 1960 sc->sc_uid = td->td_ucred->cr_ruid; 1961 sc->sc_euid = td->td_ucred->cr_uid; 1962 sc->sc_gid = td->td_ucred->cr_rgid; 1963 sc->sc_egid = td->td_ucred->cr_gid; 1964 sc->sc_ngroups = ngroups; 1965 for (i = 0; i < sc->sc_ngroups; i++) 1966 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 1967 1968 /* 1969 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 1970 * created SCM_CREDS control message (struct sockcred) has another 1971 * format. 1972 */ 1973 if (control != NULL) 1974 for (n = control, n_prev = NULL; n != NULL;) { 1975 cm = mtod(n, struct cmsghdr *); 1976 if (cm->cmsg_level == SOL_SOCKET && 1977 cm->cmsg_type == SCM_CREDS) { 1978 if (n_prev == NULL) 1979 control = n->m_next; 1980 else 1981 n_prev->m_next = n->m_next; 1982 n = m_free(n); 1983 } else { 1984 n_prev = n; 1985 n = n->m_next; 1986 } 1987 } 1988 1989 /* Prepend it to the head. */ 1990 m->m_next = control; 1991 return (m); 1992} 1993 1994static struct unpcb * 1995fptounp(struct file *fp) 1996{ 1997 struct socket *so; 1998 1999 if (fp->f_type != DTYPE_SOCKET) 2000 return (NULL); 2001 if ((so = fp->f_data) == NULL) 2002 return (NULL); 2003 if (so->so_proto->pr_domain != &localdomain) 2004 return (NULL); 2005 return sotounpcb(so); 2006} 2007 2008static void 2009unp_discard(struct file *fp) 2010{ 2011 struct unp_defer *dr; 2012 2013 if (unp_externalize_fp(fp)) { 2014 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK); 2015 dr->ud_fp = fp; 2016 UNP_DEFERRED_LOCK(); 2017 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link); 2018 UNP_DEFERRED_UNLOCK(); 2019 atomic_add_int(&unp_defers_count, 1); 2020 taskqueue_enqueue(taskqueue_thread, &unp_defer_task); 2021 } else 2022 (void) closef(fp, (struct thread *)NULL); 2023} 2024 2025static void 2026unp_process_defers(void *arg __unused, int pending) 2027{ 2028 struct unp_defer *dr; 2029 SLIST_HEAD(, unp_defer) drl; 2030 int count; 2031 2032 SLIST_INIT(&drl); 2033 for (;;) { 2034 UNP_DEFERRED_LOCK(); 2035 if (SLIST_FIRST(&unp_defers) == NULL) { 2036 UNP_DEFERRED_UNLOCK(); 2037 break; 2038 } 2039 SLIST_SWAP(&unp_defers, &drl, unp_defer); 2040 UNP_DEFERRED_UNLOCK(); 2041 count = 0; 2042 while ((dr = SLIST_FIRST(&drl)) != NULL) { 2043 SLIST_REMOVE_HEAD(&drl, ud_link); 2044 closef(dr->ud_fp, NULL); 2045 free(dr, M_TEMP); 2046 count++; 2047 } 2048 atomic_add_int(&unp_defers_count, -count); 2049 } 2050} 2051 2052static void 2053unp_internalize_fp(struct file *fp) 2054{ 2055 struct unpcb *unp; 2056 2057 UNP_LINK_WLOCK(); 2058 if ((unp = fptounp(fp)) != NULL) { 2059 unp->unp_file = fp; 2060 unp->unp_msgcount++; 2061 } 2062 fhold(fp); 2063 unp_rights++; 2064 UNP_LINK_WUNLOCK(); 2065} 2066 2067static int 2068unp_externalize_fp(struct file *fp) 2069{ 2070 struct unpcb *unp; 2071 int ret; 2072 2073 UNP_LINK_WLOCK(); 2074 if ((unp = fptounp(fp)) != NULL) { 2075 unp->unp_msgcount--; 2076 ret = 1; 2077 } else 2078 ret = 0; 2079 unp_rights--; 2080 UNP_LINK_WUNLOCK(); 2081 return (ret); 2082} 2083 2084/* 2085 * unp_defer indicates whether additional work has been defered for a future 2086 * pass through unp_gc(). It is thread local and does not require explicit 2087 * synchronization. 2088 */ 2089static int unp_marked; 2090static int unp_unreachable; 2091 2092static void 2093unp_accessable(struct file *fp) 2094{ 2095 struct unpcb *unp; 2096 2097 if ((unp = fptounp(fp)) == NULL) 2098 return; 2099 if (unp->unp_gcflag & UNPGC_REF) 2100 return; 2101 unp->unp_gcflag &= ~UNPGC_DEAD; 2102 unp->unp_gcflag |= UNPGC_REF; 2103 unp_marked++; 2104} 2105 2106static void 2107unp_gc_process(struct unpcb *unp) 2108{ 2109 struct socket *soa; 2110 struct socket *so; 2111 struct file *fp; 2112 2113 /* Already processed. */ 2114 if (unp->unp_gcflag & UNPGC_SCANNED) 2115 return; 2116 fp = unp->unp_file; 2117 2118 /* 2119 * Check for a socket potentially in a cycle. It must be in a 2120 * queue as indicated by msgcount, and this must equal the file 2121 * reference count. Note that when msgcount is 0 the file is NULL. 2122 */ 2123 if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp && 2124 unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) { 2125 unp->unp_gcflag |= UNPGC_DEAD; 2126 unp_unreachable++; 2127 return; 2128 } 2129 2130 /* 2131 * Mark all sockets we reference with RIGHTS. 2132 */ 2133 so = unp->unp_socket; 2134 SOCKBUF_LOCK(&so->so_rcv); 2135 unp_scan(so->so_rcv.sb_mb, unp_accessable); 2136 SOCKBUF_UNLOCK(&so->so_rcv); 2137 2138 /* 2139 * Mark all sockets in our accept queue. 2140 */ 2141 ACCEPT_LOCK(); 2142 TAILQ_FOREACH(soa, &so->so_comp, so_list) { 2143 SOCKBUF_LOCK(&soa->so_rcv); 2144 unp_scan(soa->so_rcv.sb_mb, unp_accessable); 2145 SOCKBUF_UNLOCK(&soa->so_rcv); 2146 } 2147 ACCEPT_UNLOCK(); 2148 unp->unp_gcflag |= UNPGC_SCANNED; 2149} 2150 2151static int unp_recycled; 2152SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 2153 "Number of unreachable sockets claimed by the garbage collector."); 2154 2155static int unp_taskcount; 2156SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 2157 "Number of times the garbage collector has run."); 2158 2159static void 2160unp_gc(__unused void *arg, int pending) 2161{ 2162 struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead, 2163 NULL }; 2164 struct unp_head **head; 2165 struct file *f, **unref; 2166 struct unpcb *unp; 2167 int i, total; 2168 2169 unp_taskcount++; 2170 UNP_LIST_LOCK(); 2171 /* 2172 * First clear all gc flags from previous runs. 2173 */ 2174 for (head = heads; *head != NULL; head++) 2175 LIST_FOREACH(unp, *head, unp_link) 2176 unp->unp_gcflag = 0; 2177 2178 /* 2179 * Scan marking all reachable sockets with UNPGC_REF. Once a socket 2180 * is reachable all of the sockets it references are reachable. 2181 * Stop the scan once we do a complete loop without discovering 2182 * a new reachable socket. 2183 */ 2184 do { 2185 unp_unreachable = 0; 2186 unp_marked = 0; 2187 for (head = heads; *head != NULL; head++) 2188 LIST_FOREACH(unp, *head, unp_link) 2189 unp_gc_process(unp); 2190 } while (unp_marked); 2191 UNP_LIST_UNLOCK(); 2192 if (unp_unreachable == 0) 2193 return; 2194 2195 /* 2196 * Allocate space for a local list of dead unpcbs. 2197 */ 2198 unref = malloc(unp_unreachable * sizeof(struct file *), 2199 M_TEMP, M_WAITOK); 2200 2201 /* 2202 * Iterate looking for sockets which have been specifically marked 2203 * as as unreachable and store them locally. 2204 */ 2205 UNP_LINK_RLOCK(); 2206 UNP_LIST_LOCK(); 2207 for (total = 0, head = heads; *head != NULL; head++) 2208 LIST_FOREACH(unp, *head, unp_link) 2209 if ((unp->unp_gcflag & UNPGC_DEAD) != 0) { 2210 f = unp->unp_file; 2211 if (unp->unp_msgcount == 0 || f == NULL || 2212 f->f_count != unp->unp_msgcount) 2213 continue; 2214 unref[total++] = f; 2215 fhold(f); 2216 KASSERT(total <= unp_unreachable, 2217 ("unp_gc: incorrect unreachable count.")); 2218 } 2219 UNP_LIST_UNLOCK(); 2220 UNP_LINK_RUNLOCK(); 2221 2222 /* 2223 * Now flush all sockets, free'ing rights. This will free the 2224 * struct files associated with these sockets but leave each socket 2225 * with one remaining ref. 2226 */ 2227 for (i = 0; i < total; i++) { 2228 struct socket *so; 2229 2230 so = unref[i]->f_data; 2231 CURVNET_SET(so->so_vnet); 2232 sorflush(so); 2233 CURVNET_RESTORE(); 2234 } 2235 2236 /* 2237 * And finally release the sockets so they can be reclaimed. 2238 */ 2239 for (i = 0; i < total; i++) 2240 fdrop(unref[i], NULL); 2241 unp_recycled += total; 2242 free(unref, M_TEMP); 2243} 2244 2245static void 2246unp_dispose(struct mbuf *m) 2247{ 2248 2249 if (m) 2250 unp_scan(m, unp_discard); 2251} 2252 2253static void 2254unp_scan(struct mbuf *m0, void (*op)(struct file *)) 2255{ 2256 struct mbuf *m; 2257 struct file **rp; 2258 struct cmsghdr *cm; 2259 void *data; 2260 int i; 2261 socklen_t clen, datalen; 2262 int qfds; 2263 2264 while (m0 != NULL) { 2265 for (m = m0; m; m = m->m_next) { 2266 if (m->m_type != MT_CONTROL) 2267 continue; 2268 2269 cm = mtod(m, struct cmsghdr *); 2270 clen = m->m_len; 2271 2272 while (cm != NULL) { 2273 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2274 break; 2275 2276 data = CMSG_DATA(cm); 2277 datalen = (caddr_t)cm + cm->cmsg_len 2278 - (caddr_t)data; 2279 2280 if (cm->cmsg_level == SOL_SOCKET && 2281 cm->cmsg_type == SCM_RIGHTS) { 2282 qfds = datalen / sizeof (struct file *); 2283 rp = data; 2284 for (i = 0; i < qfds; i++) 2285 (*op)(*rp++); 2286 } 2287 2288 if (CMSG_SPACE(datalen) < clen) { 2289 clen -= CMSG_SPACE(datalen); 2290 cm = (struct cmsghdr *) 2291 ((caddr_t)cm + CMSG_SPACE(datalen)); 2292 } else { 2293 clen = 0; 2294 cm = NULL; 2295 } 2296 } 2297 } 2298 m0 = m0->m_act; 2299 } 2300} 2301 2302/* 2303 * A helper function called by VFS before socket-type vnode reclamation. 2304 * For an active vnode it clears unp_vnode pointer and decrements unp_vnode 2305 * use count. 2306 */ 2307void 2308vfs_unp_reclaim(struct vnode *vp) 2309{ 2310 struct socket *so; 2311 struct unpcb *unp; 2312 int active; 2313 2314 ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim"); 2315 KASSERT(vp->v_type == VSOCK, 2316 ("vfs_unp_reclaim: vp->v_type != VSOCK")); 2317 2318 active = 0; 2319 UNP_LINK_WLOCK(); 2320 so = vp->v_socket; 2321 if (so == NULL) 2322 goto done; 2323 unp = sotounpcb(so); 2324 if (unp == NULL) 2325 goto done; 2326 UNP_PCB_LOCK(unp); 2327 if (unp->unp_vnode != NULL) { 2328 KASSERT(unp->unp_vnode == vp, 2329 ("vfs_unp_reclaim: vp != unp->unp_vnode")); 2330 vp->v_socket = NULL; 2331 unp->unp_vnode = NULL; 2332 active = 1; 2333 } 2334 UNP_PCB_UNLOCK(unp); 2335done: 2336 UNP_LINK_WUNLOCK(); 2337 if (active) 2338 vunref(vp); 2339} 2340 2341#ifdef DDB 2342static void 2343db_print_indent(int indent) 2344{ 2345 int i; 2346 2347 for (i = 0; i < indent; i++) 2348 db_printf(" "); 2349} 2350 2351static void 2352db_print_unpflags(int unp_flags) 2353{ 2354 int comma; 2355 2356 comma = 0; 2357 if (unp_flags & UNP_HAVEPC) { 2358 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2359 comma = 1; 2360 } 2361 if (unp_flags & UNP_HAVEPCCACHED) { 2362 db_printf("%sUNP_HAVEPCCACHED", comma ? ", " : ""); 2363 comma = 1; 2364 } 2365 if (unp_flags & UNP_WANTCRED) { 2366 db_printf("%sUNP_WANTCRED", comma ? ", " : ""); 2367 comma = 1; 2368 } 2369 if (unp_flags & UNP_CONNWAIT) { 2370 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2371 comma = 1; 2372 } 2373 if (unp_flags & UNP_CONNECTING) { 2374 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2375 comma = 1; 2376 } 2377 if (unp_flags & UNP_BINDING) { 2378 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2379 comma = 1; 2380 } 2381} 2382 2383static void 2384db_print_xucred(int indent, struct xucred *xu) 2385{ 2386 int comma, i; 2387 2388 db_print_indent(indent); 2389 db_printf("cr_version: %u cr_uid: %u cr_ngroups: %d\n", 2390 xu->cr_version, xu->cr_uid, xu->cr_ngroups); 2391 db_print_indent(indent); 2392 db_printf("cr_groups: "); 2393 comma = 0; 2394 for (i = 0; i < xu->cr_ngroups; i++) { 2395 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2396 comma = 1; 2397 } 2398 db_printf("\n"); 2399} 2400 2401static void 2402db_print_unprefs(int indent, struct unp_head *uh) 2403{ 2404 struct unpcb *unp; 2405 int counter; 2406 2407 counter = 0; 2408 LIST_FOREACH(unp, uh, unp_reflink) { 2409 if (counter % 4 == 0) 2410 db_print_indent(indent); 2411 db_printf("%p ", unp); 2412 if (counter % 4 == 3) 2413 db_printf("\n"); 2414 counter++; 2415 } 2416 if (counter != 0 && counter % 4 != 0) 2417 db_printf("\n"); 2418} 2419 2420DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2421{ 2422 struct unpcb *unp; 2423 2424 if (!have_addr) { 2425 db_printf("usage: show unpcb <addr>\n"); 2426 return; 2427 } 2428 unp = (struct unpcb *)addr; 2429 2430 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2431 unp->unp_vnode); 2432 2433 db_printf("unp_ino: %d unp_conn: %p\n", unp->unp_ino, 2434 unp->unp_conn); 2435 2436 db_printf("unp_refs:\n"); 2437 db_print_unprefs(2, &unp->unp_refs); 2438 2439 /* XXXRW: Would be nice to print the full address, if any. */ 2440 db_printf("unp_addr: %p\n", unp->unp_addr); 2441 2442 db_printf("unp_cc: %d unp_mbcnt: %d unp_gencnt: %llu\n", 2443 unp->unp_cc, unp->unp_mbcnt, 2444 (unsigned long long)unp->unp_gencnt); 2445 2446 db_printf("unp_flags: %x (", unp->unp_flags); 2447 db_print_unpflags(unp->unp_flags); 2448 db_printf(")\n"); 2449 2450 db_printf("unp_peercred:\n"); 2451 db_print_xucred(2, &unp->unp_peercred); 2452 2453 db_printf("unp_refcount: %u\n", unp->unp_refcount); 2454} 2455#endif 2456