1 /* $NetBSD: uipc_usrreq.c,v 1.93 2006/09/03 21:15:29 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1998, 2000, 2004 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 9 * NASA Ames Research Center. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * Copyright (c) 1982, 1986, 1989, 1991, 1993 42 * The Regents of the University of California. All rights reserved. 43 * 44 * Redistribution and use in source and binary forms, with or without 45 * modification, are permitted provided that the following conditions 46 * are met: 47 * 1. Redistributions of source code must retain the above copyright 48 * notice, this list of conditions and the following disclaimer. 49 * 2. Redistributions in binary form must reproduce the above copyright 50 * notice, this list of conditions and the following disclaimer in the 51 * documentation and/or other materials provided with the distribution. 52 * 3. Neither the name of the University nor the names of its contributors 53 * may be used to endorse or promote products derived from this software 54 * without specific prior written permission. 55 * 56 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 57 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 58 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 59 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 60 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 61 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 62 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 63 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 64 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 65 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 66 * SUCH DAMAGE. 67 * 68 * @(#)uipc_usrreq.c 8.9 (Berkeley) 5/14/95 69 */ 70 71 /* 72 * Copyright (c) 1997 Christopher G. Demetriou. All rights reserved. 73 * 74 * Redistribution and use in source and binary forms, with or without 75 * modification, are permitted provided that the following conditions 76 * are met: 77 * 1. Redistributions of source code must retain the above copyright 78 * notice, this list of conditions and the following disclaimer. 79 * 2. Redistributions in binary form must reproduce the above copyright 80 * notice, this list of conditions and the following disclaimer in the 81 * documentation and/or other materials provided with the distribution. 82 * 3. All advertising materials mentioning features or use of this software 83 * must display the following acknowledgement: 84 * This product includes software developed by the University of 85 * California, Berkeley and its contributors. 86 * 4. Neither the name of the University nor the names of its contributors 87 * may be used to endorse or promote products derived from this software 88 * without specific prior written permission. 89 * 90 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 91 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 92 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 93 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 94 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 95 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 96 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 97 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 98 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 99 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 100 * SUCH DAMAGE. 101 * 102 * @(#)uipc_usrreq.c 8.9 (Berkeley) 5/14/95 103 */ 104 105 #include <sys/cdefs.h> 106 __KERNEL_RCSID(0, "$NetBSD: uipc_usrreq.c,v 1.93 2006/09/03 21:15:29 christos Exp $"); 107 108 #include <sys/param.h> 109 #include <sys/systm.h> 110 #include <sys/proc.h> 111 #include <sys/filedesc.h> 112 #include <sys/domain.h> 113 #include <sys/protosw.h> 114 #include <sys/socket.h> 115 #include <sys/socketvar.h> 116 #include <sys/unpcb.h> 117 #include <sys/un.h> 118 #include <sys/namei.h> 119 #include <sys/vnode.h> 120 #include <sys/file.h> 121 #include <sys/stat.h> 122 #include <sys/mbuf.h> 123 #include <sys/kauth.h> 124 125 /* 126 * Unix communications domain. 127 * 128 * TODO: 129 * SEQPACKET, RDM 130 * rethink name space problems 131 * need a proper out-of-band 132 */ 133 const struct sockaddr_un sun_noname = { 134 .sun_len = sizeof(sun_noname), 135 .sun_family = AF_LOCAL, 136 }; 137 ino_t unp_ino; /* prototype for fake inode numbers */ 138 139 struct mbuf *unp_addsockcred(struct lwp *, struct mbuf *); 140 141 int 142 unp_output(struct mbuf *m, struct mbuf *control, struct unpcb *unp, 143 struct lwp *l) 144 { 145 struct socket *so2; 146 const struct sockaddr_un *sun; 147 148 so2 = unp->unp_conn->unp_socket; 149 if (unp->unp_addr) 150 sun = unp->unp_addr; 151 else 152 sun = &sun_noname; 153 if (unp->unp_conn->unp_flags & UNP_WANTCRED) 154 control = unp_addsockcred(l, control); 155 if (sbappendaddr(&so2->so_rcv, (const struct sockaddr *)sun, m, 156 control) == 0) { 157 m_freem(control); 158 m_freem(m); 159 so2->so_rcv.sb_overflowed++; 160 return (ENOBUFS); 161 } else { 162 sorwakeup(so2); 163 return (0); 164 } 165 } 166 167 void 168 unp_setsockaddr(struct unpcb *unp, struct mbuf *nam) 169 { 170 const struct sockaddr_un *sun; 171 172 if (unp->unp_addr) 173 sun = unp->unp_addr; 174 else 175 sun = &sun_noname; 176 nam->m_len = sun->sun_len; 177 if (nam->m_len > MLEN) 178 MEXTMALLOC(nam, nam->m_len, M_WAITOK); 179 memcpy(mtod(nam, caddr_t), sun, (size_t)nam->m_len); 180 } 181 182 void 183 unp_setpeeraddr(struct unpcb *unp, struct mbuf *nam) 184 { 185 const struct sockaddr_un *sun; 186 187 if (unp->unp_conn && unp->unp_conn->unp_addr) 188 sun = unp->unp_conn->unp_addr; 189 else 190 sun = &sun_noname; 191 nam->m_len = sun->sun_len; 192 if (nam->m_len > MLEN) 193 MEXTMALLOC(nam, nam->m_len, M_WAITOK); 194 memcpy(mtod(nam, caddr_t), sun, (size_t)nam->m_len); 195 } 196 197 /*ARGSUSED*/ 198 int 199 uipc_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam, 200 struct mbuf *control, struct lwp *l) 201 { 202 struct unpcb *unp = sotounpcb(so); 203 struct socket *so2; 204 struct proc *p; 205 u_int newhiwat; 206 int error = 0; 207 208 if (req == PRU_CONTROL) 209 return (EOPNOTSUPP); 210 211 #ifdef DIAGNOSTIC 212 if (req != PRU_SEND && req != PRU_SENDOOB && control) 213 panic("uipc_usrreq: unexpected control mbuf"); 214 #endif 215 p = l ? l->l_proc : NULL; 216 if (unp == 0 && req != PRU_ATTACH) { 217 error = EINVAL; 218 goto release; 219 } 220 221 switch (req) { 222 223 case PRU_ATTACH: 224 if (unp != 0) { 225 error = EISCONN; 226 break; 227 } 228 error = unp_attach(so); 229 break; 230 231 case PRU_DETACH: 232 unp_detach(unp); 233 break; 234 235 case PRU_BIND: 236 KASSERT(l != NULL); 237 error = unp_bind(unp, nam, l); 238 break; 239 240 case PRU_LISTEN: 241 if (unp->unp_vnode == 0) 242 error = EINVAL; 243 break; 244 245 case PRU_CONNECT: 246 KASSERT(l != NULL); 247 error = unp_connect(so, nam, l); 248 break; 249 250 case PRU_CONNECT2: 251 error = unp_connect2(so, (struct socket *)nam, PRU_CONNECT2); 252 break; 253 254 case PRU_DISCONNECT: 255 unp_disconnect(unp); 256 break; 257 258 case PRU_ACCEPT: 259 unp_setpeeraddr(unp, nam); 260 /* 261 * Mark the initiating STREAM socket as connected *ONLY* 262 * after it's been accepted. This prevents a client from 263 * overrunning a server and receiving ECONNREFUSED. 264 */ 265 if (unp->unp_conn != NULL && 266 (unp->unp_conn->unp_socket->so_state & SS_ISCONNECTING)) 267 soisconnected(unp->unp_conn->unp_socket); 268 break; 269 270 case PRU_SHUTDOWN: 271 socantsendmore(so); 272 unp_shutdown(unp); 273 break; 274 275 case PRU_RCVD: 276 switch (so->so_type) { 277 278 case SOCK_DGRAM: 279 panic("uipc 1"); 280 /*NOTREACHED*/ 281 282 case SOCK_STREAM: 283 #define rcv (&so->so_rcv) 284 #define snd (&so2->so_snd) 285 if (unp->unp_conn == 0) 286 break; 287 so2 = unp->unp_conn->unp_socket; 288 /* 289 * Adjust backpressure on sender 290 * and wakeup any waiting to write. 291 */ 292 snd->sb_mbmax += unp->unp_mbcnt - rcv->sb_mbcnt; 293 unp->unp_mbcnt = rcv->sb_mbcnt; 294 newhiwat = snd->sb_hiwat + unp->unp_cc - rcv->sb_cc; 295 (void)chgsbsize(so2->so_uidinfo, 296 &snd->sb_hiwat, newhiwat, RLIM_INFINITY); 297 unp->unp_cc = rcv->sb_cc; 298 sowwakeup(so2); 299 #undef snd 300 #undef rcv 301 break; 302 303 default: 304 panic("uipc 2"); 305 } 306 break; 307 308 case PRU_SEND: 309 /* 310 * Note: unp_internalize() rejects any control message 311 * other than SCM_RIGHTS, and only allows one. This 312 * has the side-effect of preventing a caller from 313 * forging SCM_CREDS. 314 */ 315 if (control) { 316 KASSERT(l != NULL); 317 if ((error = unp_internalize(control, l)) != 0) 318 goto die; 319 } 320 switch (so->so_type) { 321 322 case SOCK_DGRAM: { 323 if (nam) { 324 if ((so->so_state & SS_ISCONNECTED) != 0) { 325 error = EISCONN; 326 goto die; 327 } 328 KASSERT(l != NULL); 329 error = unp_connect(so, nam, l); 330 if (error) { 331 die: 332 m_freem(control); 333 m_freem(m); 334 break; 335 } 336 } else { 337 if ((so->so_state & SS_ISCONNECTED) == 0) { 338 error = ENOTCONN; 339 goto die; 340 } 341 } 342 KASSERT(p != NULL); 343 error = unp_output(m, control, unp, l); 344 if (nam) 345 unp_disconnect(unp); 346 break; 347 } 348 349 case SOCK_STREAM: 350 #define rcv (&so2->so_rcv) 351 #define snd (&so->so_snd) 352 if (unp->unp_conn == NULL) { 353 error = ENOTCONN; 354 break; 355 } 356 so2 = unp->unp_conn->unp_socket; 357 if (unp->unp_conn->unp_flags & UNP_WANTCRED) { 358 /* 359 * Credentials are passed only once on 360 * SOCK_STREAM. 361 */ 362 unp->unp_conn->unp_flags &= ~UNP_WANTCRED; 363 control = unp_addsockcred(l, control); 364 } 365 /* 366 * Send to paired receive port, and then reduce 367 * send buffer hiwater marks to maintain backpressure. 368 * Wake up readers. 369 */ 370 if (control) { 371 if (sbappendcontrol(rcv, m, control) == 0) 372 m_freem(control); 373 } else 374 sbappend(rcv, m); 375 snd->sb_mbmax -= 376 rcv->sb_mbcnt - unp->unp_conn->unp_mbcnt; 377 unp->unp_conn->unp_mbcnt = rcv->sb_mbcnt; 378 newhiwat = snd->sb_hiwat - 379 (rcv->sb_cc - unp->unp_conn->unp_cc); 380 (void)chgsbsize(so->so_uidinfo, 381 &snd->sb_hiwat, newhiwat, RLIM_INFINITY); 382 unp->unp_conn->unp_cc = rcv->sb_cc; 383 sorwakeup(so2); 384 #undef snd 385 #undef rcv 386 break; 387 388 default: 389 panic("uipc 4"); 390 } 391 break; 392 393 case PRU_ABORT: 394 unp_drop(unp, ECONNABORTED); 395 396 KASSERT(so->so_head == NULL); 397 #ifdef DIAGNOSTIC 398 if (so->so_pcb == 0) 399 panic("uipc 5: drop killed pcb"); 400 #endif 401 unp_detach(unp); 402 break; 403 404 case PRU_SENSE: 405 ((struct stat *) m)->st_blksize = so->so_snd.sb_hiwat; 406 if (so->so_type == SOCK_STREAM && unp->unp_conn != 0) { 407 so2 = unp->unp_conn->unp_socket; 408 ((struct stat *) m)->st_blksize += so2->so_rcv.sb_cc; 409 } 410 ((struct stat *) m)->st_dev = NODEV; 411 if (unp->unp_ino == 0) 412 unp->unp_ino = unp_ino++; 413 ((struct stat *) m)->st_atimespec = 414 ((struct stat *) m)->st_mtimespec = 415 ((struct stat *) m)->st_ctimespec = unp->unp_ctime; 416 ((struct stat *) m)->st_ino = unp->unp_ino; 417 return (0); 418 419 case PRU_RCVOOB: 420 error = EOPNOTSUPP; 421 break; 422 423 case PRU_SENDOOB: 424 m_freem(control); 425 m_freem(m); 426 error = EOPNOTSUPP; 427 break; 428 429 case PRU_SOCKADDR: 430 unp_setsockaddr(unp, nam); 431 break; 432 433 case PRU_PEERADDR: 434 unp_setpeeraddr(unp, nam); 435 break; 436 437 default: 438 panic("piusrreq"); 439 } 440 441 release: 442 return (error); 443 } 444 445 /* 446 * Unix domain socket option processing. 447 */ 448 int 449 uipc_ctloutput(int op, struct socket *so, int level, int optname, 450 struct mbuf **mp) 451 { 452 struct unpcb *unp = sotounpcb(so); 453 struct mbuf *m = *mp; 454 int optval = 0, error = 0; 455 456 if (level != 0) { 457 error = EINVAL; 458 if (op == PRCO_SETOPT && m) 459 (void) m_free(m); 460 } else switch (op) { 461 462 case PRCO_SETOPT: 463 switch (optname) { 464 case LOCAL_CREDS: 465 case LOCAL_CONNWAIT: 466 if (m == NULL || m->m_len != sizeof(int)) 467 error = EINVAL; 468 else { 469 optval = *mtod(m, int *); 470 switch (optname) { 471 #define OPTSET(bit) \ 472 if (optval) \ 473 unp->unp_flags |= (bit); \ 474 else \ 475 unp->unp_flags &= ~(bit); 476 477 case LOCAL_CREDS: 478 OPTSET(UNP_WANTCRED); 479 break; 480 case LOCAL_CONNWAIT: 481 OPTSET(UNP_CONNWAIT); 482 break; 483 } 484 } 485 break; 486 #undef OPTSET 487 488 default: 489 error = ENOPROTOOPT; 490 break; 491 } 492 if (m) 493 (void) m_free(m); 494 break; 495 496 case PRCO_GETOPT: 497 switch (optname) { 498 case LOCAL_CREDS: 499 *mp = m = m_get(M_WAIT, MT_SOOPTS); 500 m->m_len = sizeof(int); 501 switch (optname) { 502 503 #define OPTBIT(bit) (unp->unp_flags & (bit) ? 1 : 0) 504 505 case LOCAL_CREDS: 506 optval = OPTBIT(UNP_WANTCRED); 507 break; 508 } 509 *mtod(m, int *) = optval; 510 break; 511 #undef OPTBIT 512 513 default: 514 error = ENOPROTOOPT; 515 break; 516 } 517 break; 518 } 519 return (error); 520 } 521 522 /* 523 * Both send and receive buffers are allocated PIPSIZ bytes of buffering 524 * for stream sockets, although the total for sender and receiver is 525 * actually only PIPSIZ. 526 * Datagram sockets really use the sendspace as the maximum datagram size, 527 * and don't really want to reserve the sendspace. Their recvspace should 528 * be large enough for at least one max-size datagram plus address. 529 */ 530 #define PIPSIZ 4096 531 u_long unpst_sendspace = PIPSIZ; 532 u_long unpst_recvspace = PIPSIZ; 533 u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 534 u_long unpdg_recvspace = 4*1024; 535 536 int unp_rights; /* file descriptors in flight */ 537 538 int 539 unp_attach(struct socket *so) 540 { 541 struct unpcb *unp; 542 int error; 543 544 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 545 switch (so->so_type) { 546 547 case SOCK_STREAM: 548 error = soreserve(so, unpst_sendspace, unpst_recvspace); 549 break; 550 551 case SOCK_DGRAM: 552 error = soreserve(so, unpdg_sendspace, unpdg_recvspace); 553 break; 554 555 default: 556 panic("unp_attach"); 557 } 558 if (error) 559 return (error); 560 } 561 unp = malloc(sizeof(*unp), M_PCB, M_NOWAIT); 562 if (unp == NULL) 563 return (ENOBUFS); 564 memset((caddr_t)unp, 0, sizeof(*unp)); 565 unp->unp_socket = so; 566 so->so_pcb = unp; 567 nanotime(&unp->unp_ctime); 568 return (0); 569 } 570 571 void 572 unp_detach(struct unpcb *unp) 573 { 574 575 if (unp->unp_vnode) { 576 unp->unp_vnode->v_socket = 0; 577 vrele(unp->unp_vnode); 578 unp->unp_vnode = 0; 579 } 580 if (unp->unp_conn) 581 unp_disconnect(unp); 582 while (unp->unp_refs) 583 unp_drop(unp->unp_refs, ECONNRESET); 584 soisdisconnected(unp->unp_socket); 585 unp->unp_socket->so_pcb = 0; 586 if (unp->unp_addr) 587 free(unp->unp_addr, M_SONAME); 588 if (unp_rights) { 589 /* 590 * Normally the receive buffer is flushed later, 591 * in sofree, but if our receive buffer holds references 592 * to descriptors that are now garbage, we will dispose 593 * of those descriptor references after the garbage collector 594 * gets them (resulting in a "panic: closef: count < 0"). 595 */ 596 sorflush(unp->unp_socket); 597 free(unp, M_PCB); 598 unp_gc(); 599 } else 600 free(unp, M_PCB); 601 } 602 603 int 604 unp_bind(struct unpcb *unp, struct mbuf *nam, struct lwp *l) 605 { 606 struct sockaddr_un *sun; 607 struct vnode *vp; 608 struct mount *mp; 609 struct vattr vattr; 610 size_t addrlen; 611 struct proc *p; 612 int error; 613 struct nameidata nd; 614 615 if (unp->unp_vnode != 0) 616 return (EINVAL); 617 618 p = l->l_proc; 619 /* 620 * Allocate the new sockaddr. We have to allocate one 621 * extra byte so that we can ensure that the pathname 622 * is nul-terminated. 623 */ 624 addrlen = nam->m_len + 1; 625 sun = malloc(addrlen, M_SONAME, M_WAITOK); 626 m_copydata(nam, 0, nam->m_len, (caddr_t)sun); 627 *(((char *)sun) + nam->m_len) = '\0'; 628 629 restart: 630 NDINIT(&nd, CREATE, FOLLOW | LOCKPARENT, UIO_SYSSPACE, 631 sun->sun_path, l); 632 633 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 634 if ((error = namei(&nd)) != 0) 635 goto bad; 636 vp = nd.ni_vp; 637 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 638 VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd); 639 if (nd.ni_dvp == vp) 640 vrele(nd.ni_dvp); 641 else 642 vput(nd.ni_dvp); 643 vrele(vp); 644 if (vp != NULL) { 645 error = EADDRINUSE; 646 goto bad; 647 } 648 error = vn_start_write(NULL, &mp, 649 V_WAIT | V_SLEEPONLY | V_PCATCH); 650 if (error) 651 goto bad; 652 goto restart; 653 } 654 VATTR_NULL(&vattr); 655 vattr.va_type = VSOCK; 656 vattr.va_mode = ACCESSPERMS & ~(p->p_cwdi->cwdi_cmask); 657 VOP_LEASE(nd.ni_dvp, l, l->l_cred, LEASE_WRITE); 658 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 659 vn_finished_write(mp, 0); 660 if (error) 661 goto bad; 662 vp = nd.ni_vp; 663 vp->v_socket = unp->unp_socket; 664 unp->unp_vnode = vp; 665 unp->unp_addrlen = addrlen; 666 unp->unp_addr = sun; 667 VOP_UNLOCK(vp, 0); 668 return (0); 669 670 bad: 671 free(sun, M_SONAME); 672 return (error); 673 } 674 675 int 676 unp_connect(struct socket *so, struct mbuf *nam, struct lwp *l) 677 { 678 struct sockaddr_un *sun; 679 struct vnode *vp; 680 struct socket *so2, *so3; 681 struct unpcb *unp2, *unp3; 682 size_t addrlen; 683 int error; 684 struct nameidata nd; 685 686 /* 687 * Allocate a temporary sockaddr. We have to allocate one extra 688 * byte so that we can ensure that the pathname is nul-terminated. 689 * When we establish the connection, we copy the other PCB's 690 * sockaddr to our own. 691 */ 692 addrlen = nam->m_len + 1; 693 sun = malloc(addrlen, M_SONAME, M_WAITOK); 694 m_copydata(nam, 0, nam->m_len, (caddr_t)sun); 695 *(((char *)sun) + nam->m_len) = '\0'; 696 697 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, sun->sun_path, l); 698 699 if ((error = namei(&nd)) != 0) 700 goto bad2; 701 vp = nd.ni_vp; 702 if (vp->v_type != VSOCK) { 703 error = ENOTSOCK; 704 goto bad; 705 } 706 if ((error = VOP_ACCESS(vp, VWRITE, l->l_cred, l)) != 0) 707 goto bad; 708 so2 = vp->v_socket; 709 if (so2 == 0) { 710 error = ECONNREFUSED; 711 goto bad; 712 } 713 if (so->so_type != so2->so_type) { 714 error = EPROTOTYPE; 715 goto bad; 716 } 717 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 718 if ((so2->so_options & SO_ACCEPTCONN) == 0 || 719 (so3 = sonewconn(so2, 0)) == 0) { 720 error = ECONNREFUSED; 721 goto bad; 722 } 723 unp2 = sotounpcb(so2); 724 unp3 = sotounpcb(so3); 725 if (unp2->unp_addr) { 726 unp3->unp_addr = malloc(unp2->unp_addrlen, 727 M_SONAME, M_WAITOK); 728 memcpy(unp3->unp_addr, unp2->unp_addr, 729 unp2->unp_addrlen); 730 unp3->unp_addrlen = unp2->unp_addrlen; 731 } 732 unp3->unp_flags = unp2->unp_flags; 733 so2 = so3; 734 } 735 error = unp_connect2(so, so2, PRU_CONNECT); 736 bad: 737 vput(vp); 738 bad2: 739 free(sun, M_SONAME); 740 return (error); 741 } 742 743 int 744 unp_connect2(struct socket *so, struct socket *so2, int req) 745 { 746 struct unpcb *unp = sotounpcb(so); 747 struct unpcb *unp2; 748 749 if (so2->so_type != so->so_type) 750 return (EPROTOTYPE); 751 unp2 = sotounpcb(so2); 752 unp->unp_conn = unp2; 753 switch (so->so_type) { 754 755 case SOCK_DGRAM: 756 unp->unp_nextref = unp2->unp_refs; 757 unp2->unp_refs = unp; 758 soisconnected(so); 759 break; 760 761 case SOCK_STREAM: 762 unp2->unp_conn = unp; 763 if (req == PRU_CONNECT && 764 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 765 soisconnecting(so); 766 else 767 soisconnected(so); 768 soisconnected(so2); 769 break; 770 771 default: 772 panic("unp_connect2"); 773 } 774 return (0); 775 } 776 777 void 778 unp_disconnect(struct unpcb *unp) 779 { 780 struct unpcb *unp2 = unp->unp_conn; 781 782 if (unp2 == 0) 783 return; 784 unp->unp_conn = 0; 785 switch (unp->unp_socket->so_type) { 786 787 case SOCK_DGRAM: 788 if (unp2->unp_refs == unp) 789 unp2->unp_refs = unp->unp_nextref; 790 else { 791 unp2 = unp2->unp_refs; 792 for (;;) { 793 if (unp2 == 0) 794 panic("unp_disconnect"); 795 if (unp2->unp_nextref == unp) 796 break; 797 unp2 = unp2->unp_nextref; 798 } 799 unp2->unp_nextref = unp->unp_nextref; 800 } 801 unp->unp_nextref = 0; 802 unp->unp_socket->so_state &= ~SS_ISCONNECTED; 803 break; 804 805 case SOCK_STREAM: 806 soisdisconnected(unp->unp_socket); 807 unp2->unp_conn = 0; 808 soisdisconnected(unp2->unp_socket); 809 break; 810 } 811 } 812 813 #ifdef notdef 814 unp_abort(struct unpcb *unp) 815 { 816 unp_detach(unp); 817 } 818 #endif 819 820 void 821 unp_shutdown(struct unpcb *unp) 822 { 823 struct socket *so; 824 825 if (unp->unp_socket->so_type == SOCK_STREAM && unp->unp_conn && 826 (so = unp->unp_conn->unp_socket)) 827 socantrcvmore(so); 828 } 829 830 void 831 unp_drop(struct unpcb *unp, int errno) 832 { 833 struct socket *so = unp->unp_socket; 834 835 so->so_error = errno; 836 unp_disconnect(unp); 837 if (so->so_head) { 838 so->so_pcb = 0; 839 sofree(so); 840 if (unp->unp_addr) 841 free(unp->unp_addr, M_SONAME); 842 free(unp, M_PCB); 843 } 844 } 845 846 #ifdef notdef 847 unp_drain(void) 848 { 849 850 } 851 #endif 852 853 int 854 unp_externalize(struct mbuf *rights, struct lwp *l) 855 { 856 struct cmsghdr *cm = mtod(rights, struct cmsghdr *); 857 struct proc *p = l->l_proc; 858 int i, *fdp; 859 struct file **rp; 860 struct file *fp; 861 int nfds, error = 0; 862 863 nfds = (cm->cmsg_len - CMSG_ALIGN(sizeof(*cm))) / 864 sizeof(struct file *); 865 rp = (struct file **)CMSG_DATA(cm); 866 867 fdp = malloc(nfds * sizeof(int), M_TEMP, M_WAITOK); 868 869 /* Make sure the recipient should be able to see the descriptors.. */ 870 if (p->p_cwdi->cwdi_rdir != NULL) { 871 rp = (struct file **)CMSG_DATA(cm); 872 for (i = 0; i < nfds; i++) { 873 fp = *rp++; 874 /* 875 * If we are in a chroot'ed directory, and 876 * someone wants to pass us a directory, make 877 * sure it's inside the subtree we're allowed 878 * to access. 879 */ 880 if (fp->f_type == DTYPE_VNODE) { 881 struct vnode *vp = (struct vnode *)fp->f_data; 882 if ((vp->v_type == VDIR) && 883 !vn_isunder(vp, p->p_cwdi->cwdi_rdir, l)) { 884 error = EPERM; 885 break; 886 } 887 } 888 } 889 } 890 891 restart: 892 rp = (struct file **)CMSG_DATA(cm); 893 if (error != 0) { 894 for (i = 0; i < nfds; i++) { 895 fp = *rp; 896 /* 897 * zero the pointer before calling unp_discard, 898 * since it may end up in unp_gc().. 899 */ 900 *rp++ = 0; 901 unp_discard(fp); 902 } 903 goto out; 904 } 905 906 /* 907 * First loop -- allocate file descriptor table slots for the 908 * new descriptors. 909 */ 910 for (i = 0; i < nfds; i++) { 911 fp = *rp++; 912 if ((error = fdalloc(p, 0, &fdp[i])) != 0) { 913 /* 914 * Back out what we've done so far. 915 */ 916 for (--i; i >= 0; i--) 917 fdremove(p->p_fd, fdp[i]); 918 919 if (error == ENOSPC) { 920 fdexpand(p); 921 error = 0; 922 } else { 923 /* 924 * This is the error that has historically 925 * been returned, and some callers may 926 * expect it. 927 */ 928 error = EMSGSIZE; 929 } 930 goto restart; 931 } 932 933 /* 934 * Make the slot reference the descriptor so that 935 * fdalloc() works properly.. We finalize it all 936 * in the loop below. 937 */ 938 p->p_fd->fd_ofiles[fdp[i]] = fp; 939 } 940 941 /* 942 * Now that adding them has succeeded, update all of the 943 * descriptor passing state. 944 */ 945 rp = (struct file **)CMSG_DATA(cm); 946 for (i = 0; i < nfds; i++) { 947 fp = *rp++; 948 fp->f_msgcount--; 949 unp_rights--; 950 } 951 952 /* 953 * Copy temporary array to message and adjust length, in case of 954 * transition from large struct file pointers to ints. 955 */ 956 memcpy(CMSG_DATA(cm), fdp, nfds * sizeof(int)); 957 cm->cmsg_len = CMSG_LEN(nfds * sizeof(int)); 958 rights->m_len = CMSG_SPACE(nfds * sizeof(int)); 959 out: 960 free(fdp, M_TEMP); 961 return (error); 962 } 963 964 int 965 unp_internalize(struct mbuf *control, struct lwp *l) 966 { 967 struct proc *p = l->l_proc; 968 struct filedesc *fdescp = p->p_fd; 969 struct cmsghdr *newcm, *cm = mtod(control, struct cmsghdr *); 970 struct file **rp, **files; 971 struct file *fp; 972 int i, fd, *fdp; 973 int nfds; 974 u_int neededspace; 975 976 /* Sanity check the control message header */ 977 if (cm->cmsg_type != SCM_RIGHTS || cm->cmsg_level != SOL_SOCKET || 978 cm->cmsg_len != control->m_len) 979 return (EINVAL); 980 981 /* Verify that the file descriptors are valid */ 982 nfds = (cm->cmsg_len - CMSG_ALIGN(sizeof(*cm))) / sizeof(int); 983 fdp = (int *)CMSG_DATA(cm); 984 for (i = 0; i < nfds; i++) { 985 fd = *fdp++; 986 if ((fp = fd_getfile(fdescp, fd)) == NULL) 987 return (EBADF); 988 simple_unlock(&fp->f_slock); 989 } 990 991 /* Make sure we have room for the struct file pointers */ 992 neededspace = CMSG_SPACE(nfds * sizeof(struct file *)) - 993 control->m_len; 994 if (neededspace > M_TRAILINGSPACE(control)) { 995 996 /* allocate new space and copy header into it */ 997 newcm = malloc( 998 CMSG_SPACE(nfds * sizeof(struct file *)), 999 M_MBUF, M_WAITOK); 1000 if (newcm == NULL) 1001 return (E2BIG); 1002 memcpy(newcm, cm, sizeof(struct cmsghdr)); 1003 files = (struct file **)CMSG_DATA(newcm); 1004 } else { 1005 /* we can convert in-place */ 1006 newcm = NULL; 1007 files = (struct file **)CMSG_DATA(cm); 1008 } 1009 1010 /* 1011 * Transform the file descriptors into struct file pointers, in 1012 * reverse order so that if pointers are bigger than ints, the 1013 * int won't get until we're done. 1014 */ 1015 fdp = (int *)CMSG_DATA(cm) + nfds - 1; 1016 rp = files + nfds - 1; 1017 for (i = 0; i < nfds; i++) { 1018 fp = fdescp->fd_ofiles[*fdp--]; 1019 simple_lock(&fp->f_slock); 1020 #ifdef DIAGNOSTIC 1021 if (fp->f_iflags & FIF_WANTCLOSE) 1022 panic("unp_internalize: file already closed"); 1023 #endif 1024 *rp-- = fp; 1025 fp->f_count++; 1026 fp->f_msgcount++; 1027 simple_unlock(&fp->f_slock); 1028 unp_rights++; 1029 } 1030 1031 if (newcm) { 1032 if (control->m_flags & M_EXT) 1033 MEXTREMOVE(control); 1034 MEXTADD(control, newcm, 1035 CMSG_SPACE(nfds * sizeof(struct file *)), 1036 M_MBUF, NULL, NULL); 1037 cm = newcm; 1038 } 1039 1040 /* adjust message & mbuf to note amount of space actually used. */ 1041 cm->cmsg_len = CMSG_LEN(nfds * sizeof(struct file *)); 1042 control->m_len = CMSG_SPACE(nfds * sizeof(struct file *)); 1043 1044 return (0); 1045 } 1046 1047 struct mbuf * 1048 unp_addsockcred(struct lwp *l, struct mbuf *control) 1049 { 1050 struct cmsghdr *cmp; 1051 struct sockcred *sc; 1052 struct mbuf *m, *n; 1053 int len, space, i; 1054 1055 len = CMSG_LEN(SOCKCREDSIZE(kauth_cred_ngroups(l->l_cred))); 1056 space = CMSG_SPACE(SOCKCREDSIZE(kauth_cred_ngroups(l->l_cred))); 1057 1058 m = m_get(M_WAIT, MT_CONTROL); 1059 if (space > MLEN) { 1060 if (space > MCLBYTES) 1061 MEXTMALLOC(m, space, M_WAITOK); 1062 else 1063 m_clget(m, M_WAIT); 1064 if ((m->m_flags & M_EXT) == 0) { 1065 m_free(m); 1066 return (control); 1067 } 1068 } 1069 1070 m->m_len = space; 1071 m->m_next = NULL; 1072 cmp = mtod(m, struct cmsghdr *); 1073 sc = (struct sockcred *)CMSG_DATA(cmp); 1074 cmp->cmsg_len = len; 1075 cmp->cmsg_level = SOL_SOCKET; 1076 cmp->cmsg_type = SCM_CREDS; 1077 sc->sc_uid = kauth_cred_getuid(l->l_cred); 1078 sc->sc_euid = kauth_cred_geteuid(l->l_cred); 1079 sc->sc_gid = kauth_cred_getgid(l->l_cred); 1080 sc->sc_egid = kauth_cred_getegid(l->l_cred); 1081 sc->sc_ngroups = kauth_cred_ngroups(l->l_cred); 1082 for (i = 0; i < sc->sc_ngroups; i++) 1083 sc->sc_groups[i] = kauth_cred_group(l->l_cred, i); 1084 1085 /* 1086 * If a control message already exists, append us to the end. 1087 */ 1088 if (control != NULL) { 1089 for (n = control; n->m_next != NULL; n = n->m_next) 1090 ; 1091 n->m_next = m; 1092 } else 1093 control = m; 1094 1095 return (control); 1096 } 1097 1098 int unp_defer, unp_gcing; 1099 extern struct domain unixdomain; 1100 1101 /* 1102 * Comment added long after the fact explaining what's going on here. 1103 * Do a mark-sweep GC of file descriptors on the system, to free up 1104 * any which are caught in flight to an about-to-be-closed socket. 1105 * 1106 * Traditional mark-sweep gc's start at the "root", and mark 1107 * everything reachable from the root (which, in our case would be the 1108 * process table). The mark bits are cleared during the sweep. 1109 * 1110 * XXX For some inexplicable reason (perhaps because the file 1111 * descriptor tables used to live in the u area which could be swapped 1112 * out and thus hard to reach), we do multiple scans over the set of 1113 * descriptors, using use *two* mark bits per object (DEFER and MARK). 1114 * Whenever we find a descriptor which references other descriptors, 1115 * the ones it references are marked with both bits, and we iterate 1116 * over the whole file table until there are no more DEFER bits set. 1117 * We also make an extra pass *before* the GC to clear the mark bits, 1118 * which could have been cleared at almost no cost during the previous 1119 * sweep. 1120 * 1121 * XXX MP: this needs to run with locks such that no other thread of 1122 * control can create or destroy references to file descriptors. it 1123 * may be necessary to defer the GC until later (when the locking 1124 * situation is more hospitable); it may be necessary to push this 1125 * into a separate thread. 1126 */ 1127 void 1128 unp_gc(void) 1129 { 1130 struct file *fp, *nextfp; 1131 struct socket *so, *so1; 1132 struct file **extra_ref, **fpp; 1133 int nunref, i; 1134 1135 if (unp_gcing) 1136 return; 1137 unp_gcing = 1; 1138 unp_defer = 0; 1139 1140 /* Clear mark bits */ 1141 LIST_FOREACH(fp, &filehead, f_list) 1142 fp->f_flag &= ~(FMARK|FDEFER); 1143 1144 /* 1145 * Iterate over the set of descriptors, marking ones believed 1146 * (based on refcount) to be referenced from a process, and 1147 * marking for rescan descriptors which are queued on a socket. 1148 */ 1149 do { 1150 LIST_FOREACH(fp, &filehead, f_list) { 1151 if (fp->f_flag & FDEFER) { 1152 fp->f_flag &= ~FDEFER; 1153 unp_defer--; 1154 #ifdef DIAGNOSTIC 1155 if (fp->f_count == 0) 1156 panic("unp_gc: deferred unreferenced socket"); 1157 #endif 1158 } else { 1159 if (fp->f_count == 0) 1160 continue; 1161 if (fp->f_flag & FMARK) 1162 continue; 1163 if (fp->f_count == fp->f_msgcount) 1164 continue; 1165 } 1166 fp->f_flag |= FMARK; 1167 1168 if (fp->f_type != DTYPE_SOCKET || 1169 (so = (struct socket *)fp->f_data) == 0) 1170 continue; 1171 if (so->so_proto->pr_domain != &unixdomain || 1172 (so->so_proto->pr_flags&PR_RIGHTS) == 0) 1173 continue; 1174 #ifdef notdef 1175 if (so->so_rcv.sb_flags & SB_LOCK) { 1176 /* 1177 * This is problematical; it's not clear 1178 * we need to wait for the sockbuf to be 1179 * unlocked (on a uniprocessor, at least), 1180 * and it's also not clear what to do 1181 * if sbwait returns an error due to receipt 1182 * of a signal. If sbwait does return 1183 * an error, we'll go into an infinite 1184 * loop. Delete all of this for now. 1185 */ 1186 (void) sbwait(&so->so_rcv); 1187 goto restart; 1188 } 1189 #endif 1190 unp_scan(so->so_rcv.sb_mb, unp_mark, 0); 1191 /* 1192 * mark descriptors referenced from sockets queued on the accept queue as well. 1193 */ 1194 if (so->so_options & SO_ACCEPTCONN) { 1195 TAILQ_FOREACH(so1, &so->so_q0, so_qe) { 1196 unp_scan(so1->so_rcv.sb_mb, unp_mark, 0); 1197 } 1198 TAILQ_FOREACH(so1, &so->so_q, so_qe) { 1199 unp_scan(so1->so_rcv.sb_mb, unp_mark, 0); 1200 } 1201 } 1202 1203 } 1204 } while (unp_defer); 1205 /* 1206 * Sweep pass. Find unmarked descriptors, and free them. 1207 * 1208 * We grab an extra reference to each of the file table entries 1209 * that are not otherwise accessible and then free the rights 1210 * that are stored in messages on them. 1211 * 1212 * The bug in the original code is a little tricky, so I'll describe 1213 * what's wrong with it here. 1214 * 1215 * It is incorrect to simply unp_discard each entry for f_msgcount 1216 * times -- consider the case of sockets A and B that contain 1217 * references to each other. On a last close of some other socket, 1218 * we trigger a gc since the number of outstanding rights (unp_rights) 1219 * is non-zero. If during the sweep phase the gc code un_discards, 1220 * we end up doing a (full) closef on the descriptor. A closef on A 1221 * results in the following chain. Closef calls soo_close, which 1222 * calls soclose. Soclose calls first (through the switch 1223 * uipc_usrreq) unp_detach, which re-invokes unp_gc. Unp_gc simply 1224 * returns because the previous instance had set unp_gcing, and 1225 * we return all the way back to soclose, which marks the socket 1226 * with SS_NOFDREF, and then calls sofree. Sofree calls sorflush 1227 * to free up the rights that are queued in messages on the socket A, 1228 * i.e., the reference on B. The sorflush calls via the dom_dispose 1229 * switch unp_dispose, which unp_scans with unp_discard. This second 1230 * instance of unp_discard just calls closef on B. 1231 * 1232 * Well, a similar chain occurs on B, resulting in a sorflush on B, 1233 * which results in another closef on A. Unfortunately, A is already 1234 * being closed, and the descriptor has already been marked with 1235 * SS_NOFDREF, and soclose panics at this point. 1236 * 1237 * Here, we first take an extra reference to each inaccessible 1238 * descriptor. Then, if the inaccessible descriptor is a 1239 * socket, we call sorflush in case it is a Unix domain 1240 * socket. After we destroy all the rights carried in 1241 * messages, we do a last closef to get rid of our extra 1242 * reference. This is the last close, and the unp_detach etc 1243 * will shut down the socket. 1244 * 1245 * 91/09/19, bsy@cs.cmu.edu 1246 */ 1247 extra_ref = malloc(nfiles * sizeof(struct file *), M_FILE, M_WAITOK); 1248 for (nunref = 0, fp = LIST_FIRST(&filehead), fpp = extra_ref; fp != 0; 1249 fp = nextfp) { 1250 nextfp = LIST_NEXT(fp, f_list); 1251 simple_lock(&fp->f_slock); 1252 if (fp->f_count != 0 && 1253 fp->f_count == fp->f_msgcount && !(fp->f_flag & FMARK)) { 1254 *fpp++ = fp; 1255 nunref++; 1256 fp->f_count++; 1257 } 1258 simple_unlock(&fp->f_slock); 1259 } 1260 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) { 1261 fp = *fpp; 1262 simple_lock(&fp->f_slock); 1263 FILE_USE(fp); 1264 if (fp->f_type == DTYPE_SOCKET) 1265 sorflush((struct socket *)fp->f_data); 1266 FILE_UNUSE(fp, NULL); 1267 } 1268 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) { 1269 fp = *fpp; 1270 simple_lock(&fp->f_slock); 1271 FILE_USE(fp); 1272 (void) closef(fp, (struct lwp *)0); 1273 } 1274 free((caddr_t)extra_ref, M_FILE); 1275 unp_gcing = 0; 1276 } 1277 1278 void 1279 unp_dispose(struct mbuf *m) 1280 { 1281 1282 if (m) 1283 unp_scan(m, unp_discard, 1); 1284 } 1285 1286 void 1287 unp_scan(struct mbuf *m0, void (*op)(struct file *), int discard) 1288 { 1289 struct mbuf *m; 1290 struct file **rp; 1291 struct cmsghdr *cm; 1292 int i; 1293 int qfds; 1294 1295 while (m0) { 1296 for (m = m0; m; m = m->m_next) { 1297 if (m->m_type == MT_CONTROL && 1298 m->m_len >= sizeof(*cm)) { 1299 cm = mtod(m, struct cmsghdr *); 1300 if (cm->cmsg_level != SOL_SOCKET || 1301 cm->cmsg_type != SCM_RIGHTS) 1302 continue; 1303 qfds = (cm->cmsg_len - CMSG_ALIGN(sizeof(*cm))) 1304 / sizeof(struct file *); 1305 rp = (struct file **)CMSG_DATA(cm); 1306 for (i = 0; i < qfds; i++) { 1307 struct file *fp = *rp; 1308 if (discard) 1309 *rp = 0; 1310 (*op)(fp); 1311 rp++; 1312 } 1313 break; /* XXX, but saves time */ 1314 } 1315 } 1316 m0 = m0->m_nextpkt; 1317 } 1318 } 1319 1320 void 1321 unp_mark(struct file *fp) 1322 { 1323 if (fp == NULL) 1324 return; 1325 1326 if (fp->f_flag & FMARK) 1327 return; 1328 1329 /* If we're already deferred, don't screw up the defer count */ 1330 if (fp->f_flag & FDEFER) 1331 return; 1332 1333 /* 1334 * Minimize the number of deferrals... Sockets are the only 1335 * type of descriptor which can hold references to another 1336 * descriptor, so just mark other descriptors, and defer 1337 * unmarked sockets for the next pass. 1338 */ 1339 if (fp->f_type == DTYPE_SOCKET) { 1340 unp_defer++; 1341 if (fp->f_count == 0) 1342 panic("unp_mark: queued unref"); 1343 fp->f_flag |= FDEFER; 1344 } else { 1345 fp->f_flag |= FMARK; 1346 } 1347 return; 1348 } 1349 1350 void 1351 unp_discard(struct file *fp) 1352 { 1353 if (fp == NULL) 1354 return; 1355 simple_lock(&fp->f_slock); 1356 fp->f_usecount++; /* i.e. FILE_USE(fp) sans locking */ 1357 fp->f_msgcount--; 1358 simple_unlock(&fp->f_slock); 1359 unp_rights--; 1360 (void) closef(fp, (struct lwp *)0); 1361 } 1362