1 /* $NetBSD: uipc_usrreq.c,v 1.78 2004/05/22 22:52:13 jonathan 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 1.78 2004/05/22 22:52:13 jonathan 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> 123 124 /* 125 * Unix communications domain. 126 * 127 * TODO: 128 * SEQPACKET, RDM 129 * rethink name space problems 130 * need a proper out-of-band 131 */ 132 const struct sockaddr_un sun_noname = { sizeof(sun_noname), AF_LOCAL }; 133 ino_t unp_ino; /* prototype for fake inode numbers */ 134 135 struct mbuf *unp_addsockcred(struct proc *, struct mbuf *); 136 137 int 138 unp_output(struct mbuf *m, struct mbuf *control, struct unpcb *unp, 139 struct proc *p) 140 { 141 struct socket *so2; 142 const struct sockaddr_un *sun; 143 144 so2 = unp->unp_conn->unp_socket; 145 if (unp->unp_addr) 146 sun = unp->unp_addr; 147 else 148 sun = &sun_noname; 149 if (unp->unp_conn->unp_flags & UNP_WANTCRED) 150 control = unp_addsockcred(p, control); 151 if (sbappendaddr(&so2->so_rcv, (struct sockaddr *)sun, m, 152 control) == 0) { 153 m_freem(control); 154 m_freem(m); 155 return (ENOBUFS); 156 } else { 157 sorwakeup(so2); 158 return (0); 159 } 160 } 161 162 void 163 unp_setsockaddr(struct unpcb *unp, struct mbuf *nam) 164 { 165 const struct sockaddr_un *sun; 166 167 if (unp->unp_addr) 168 sun = unp->unp_addr; 169 else 170 sun = &sun_noname; 171 nam->m_len = sun->sun_len; 172 if (nam->m_len > MLEN) 173 MEXTMALLOC(nam, nam->m_len, M_WAITOK); 174 memcpy(mtod(nam, caddr_t), sun, (size_t)nam->m_len); 175 } 176 177 void 178 unp_setpeeraddr(struct unpcb *unp, struct mbuf *nam) 179 { 180 const struct sockaddr_un *sun; 181 182 if (unp->unp_conn && unp->unp_conn->unp_addr) 183 sun = unp->unp_conn->unp_addr; 184 else 185 sun = &sun_noname; 186 nam->m_len = sun->sun_len; 187 if (nam->m_len > MLEN) 188 MEXTMALLOC(nam, nam->m_len, M_WAITOK); 189 memcpy(mtod(nam, caddr_t), sun, (size_t)nam->m_len); 190 } 191 192 /*ARGSUSED*/ 193 int 194 uipc_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam, 195 struct mbuf *control, struct proc *p) 196 { 197 struct unpcb *unp = sotounpcb(so); 198 struct socket *so2; 199 u_int newhiwat; 200 int error = 0; 201 202 if (req == PRU_CONTROL) 203 return (EOPNOTSUPP); 204 205 #ifdef DIAGNOSTIC 206 if (req != PRU_SEND && req != PRU_SENDOOB && control) 207 panic("uipc_usrreq: unexpected control mbuf"); 208 #endif 209 if (unp == 0 && req != PRU_ATTACH) { 210 error = EINVAL; 211 goto release; 212 } 213 214 switch (req) { 215 216 case PRU_ATTACH: 217 if (unp != 0) { 218 error = EISCONN; 219 break; 220 } 221 error = unp_attach(so); 222 break; 223 224 case PRU_DETACH: 225 unp_detach(unp); 226 break; 227 228 case PRU_BIND: 229 error = unp_bind(unp, nam, p); 230 break; 231 232 case PRU_LISTEN: 233 if (unp->unp_vnode == 0) 234 error = EINVAL; 235 break; 236 237 case PRU_CONNECT: 238 error = unp_connect(so, nam, p); 239 break; 240 241 case PRU_CONNECT2: 242 error = unp_connect2(so, (struct socket *)nam, PRU_CONNECT2); 243 break; 244 245 case PRU_DISCONNECT: 246 unp_disconnect(unp); 247 break; 248 249 case PRU_ACCEPT: 250 unp_setpeeraddr(unp, nam); 251 /* 252 * Mark the initiating STREAM socket as connected *ONLY* 253 * after it's been accepted. This prevents a client from 254 * overrunning a server and receiving ECONNREFUSED. 255 */ 256 if (unp->unp_conn != NULL && 257 (unp->unp_conn->unp_socket->so_state & SS_ISCONNECTING)) 258 soisconnected(unp->unp_conn->unp_socket); 259 break; 260 261 case PRU_SHUTDOWN: 262 socantsendmore(so); 263 unp_shutdown(unp); 264 break; 265 266 case PRU_RCVD: 267 switch (so->so_type) { 268 269 case SOCK_DGRAM: 270 panic("uipc 1"); 271 /*NOTREACHED*/ 272 273 case SOCK_STREAM: 274 #define rcv (&so->so_rcv) 275 #define snd (&so2->so_snd) 276 if (unp->unp_conn == 0) 277 break; 278 so2 = unp->unp_conn->unp_socket; 279 /* 280 * Adjust backpressure on sender 281 * and wakeup any waiting to write. 282 */ 283 snd->sb_mbmax += unp->unp_mbcnt - rcv->sb_mbcnt; 284 unp->unp_mbcnt = rcv->sb_mbcnt; 285 newhiwat = snd->sb_hiwat + unp->unp_cc - rcv->sb_cc; 286 (void)chgsbsize(so2->so_uid, 287 &snd->sb_hiwat, newhiwat, RLIM_INFINITY); 288 unp->unp_cc = rcv->sb_cc; 289 sowwakeup(so2); 290 #undef snd 291 #undef rcv 292 break; 293 294 default: 295 panic("uipc 2"); 296 } 297 break; 298 299 case PRU_SEND: 300 /* 301 * Note: unp_internalize() rejects any control message 302 * other than SCM_RIGHTS, and only allows one. This 303 * has the side-effect of preventing a caller from 304 * forging SCM_CREDS. 305 */ 306 if (control && (error = unp_internalize(control, p))) 307 break; 308 switch (so->so_type) { 309 310 case SOCK_DGRAM: { 311 if (nam) { 312 if ((so->so_state & SS_ISCONNECTED) != 0) { 313 error = EISCONN; 314 goto die; 315 } 316 error = unp_connect(so, nam, p); 317 if (error) { 318 die: 319 m_freem(control); 320 m_freem(m); 321 break; 322 } 323 } else { 324 if ((so->so_state & SS_ISCONNECTED) == 0) { 325 error = ENOTCONN; 326 goto die; 327 } 328 } 329 error = unp_output(m, control, unp, p); 330 if (nam) 331 unp_disconnect(unp); 332 break; 333 } 334 335 case SOCK_STREAM: 336 #define rcv (&so2->so_rcv) 337 #define snd (&so->so_snd) 338 if (unp->unp_conn == 0) 339 panic("uipc 3"); 340 so2 = unp->unp_conn->unp_socket; 341 if (unp->unp_conn->unp_flags & UNP_WANTCRED) { 342 /* 343 * Credentials are passed only once on 344 * SOCK_STREAM. 345 */ 346 unp->unp_conn->unp_flags &= ~UNP_WANTCRED; 347 control = unp_addsockcred(p, control); 348 } 349 /* 350 * Send to paired receive port, and then reduce 351 * send buffer hiwater marks to maintain backpressure. 352 * Wake up readers. 353 */ 354 if (control) { 355 if (sbappendcontrol(rcv, m, control) == 0) 356 m_freem(control); 357 } else 358 sbappend(rcv, m); 359 snd->sb_mbmax -= 360 rcv->sb_mbcnt - unp->unp_conn->unp_mbcnt; 361 unp->unp_conn->unp_mbcnt = rcv->sb_mbcnt; 362 newhiwat = snd->sb_hiwat - 363 (rcv->sb_cc - unp->unp_conn->unp_cc); 364 (void)chgsbsize(so->so_uid, 365 &snd->sb_hiwat, newhiwat, RLIM_INFINITY); 366 unp->unp_conn->unp_cc = rcv->sb_cc; 367 sorwakeup(so2); 368 #undef snd 369 #undef rcv 370 break; 371 372 default: 373 panic("uipc 4"); 374 } 375 break; 376 377 case PRU_ABORT: 378 unp_drop(unp, ECONNABORTED); 379 380 #ifdef DIAGNOSTIC 381 if (so->so_pcb == 0) 382 panic("uipc 5: drop killed pcb"); 383 #endif 384 unp_detach(unp); 385 break; 386 387 case PRU_SENSE: 388 ((struct stat *) m)->st_blksize = so->so_snd.sb_hiwat; 389 if (so->so_type == SOCK_STREAM && unp->unp_conn != 0) { 390 so2 = unp->unp_conn->unp_socket; 391 ((struct stat *) m)->st_blksize += so2->so_rcv.sb_cc; 392 } 393 ((struct stat *) m)->st_dev = NODEV; 394 if (unp->unp_ino == 0) 395 unp->unp_ino = unp_ino++; 396 ((struct stat *) m)->st_atimespec = 397 ((struct stat *) m)->st_mtimespec = 398 ((struct stat *) m)->st_ctimespec = unp->unp_ctime; 399 ((struct stat *) m)->st_ino = unp->unp_ino; 400 return (0); 401 402 case PRU_RCVOOB: 403 error = EOPNOTSUPP; 404 break; 405 406 case PRU_SENDOOB: 407 m_freem(control); 408 m_freem(m); 409 error = EOPNOTSUPP; 410 break; 411 412 case PRU_SOCKADDR: 413 unp_setsockaddr(unp, nam); 414 break; 415 416 case PRU_PEERADDR: 417 unp_setpeeraddr(unp, nam); 418 break; 419 420 default: 421 panic("piusrreq"); 422 } 423 424 release: 425 return (error); 426 } 427 428 /* 429 * Unix domain socket option processing. 430 */ 431 int 432 uipc_ctloutput(int op, struct socket *so, int level, int optname, 433 struct mbuf **mp) 434 { 435 struct unpcb *unp = sotounpcb(so); 436 struct mbuf *m = *mp; 437 int optval = 0, error = 0; 438 439 if (level != 0) { 440 error = EINVAL; 441 if (op == PRCO_SETOPT && m) 442 (void) m_free(m); 443 } else switch (op) { 444 445 case PRCO_SETOPT: 446 switch (optname) { 447 case LOCAL_CREDS: 448 case LOCAL_CONNWAIT: 449 if (m == NULL || m->m_len != sizeof(int)) 450 error = EINVAL; 451 else { 452 optval = *mtod(m, int *); 453 switch (optname) { 454 #define OPTSET(bit) \ 455 if (optval) \ 456 unp->unp_flags |= (bit); \ 457 else \ 458 unp->unp_flags &= ~(bit); 459 460 case LOCAL_CREDS: 461 OPTSET(UNP_WANTCRED); 462 break; 463 case LOCAL_CONNWAIT: 464 OPTSET(UNP_CONNWAIT); 465 break; 466 } 467 } 468 break; 469 #undef OPTSET 470 471 default: 472 error = ENOPROTOOPT; 473 break; 474 } 475 if (m) 476 (void) m_free(m); 477 break; 478 479 case PRCO_GETOPT: 480 switch (optname) { 481 case LOCAL_CREDS: 482 *mp = m = m_get(M_WAIT, MT_SOOPTS); 483 m->m_len = sizeof(int); 484 switch (optname) { 485 486 #define OPTBIT(bit) (unp->unp_flags & (bit) ? 1 : 0) 487 488 case LOCAL_CREDS: 489 optval = OPTBIT(UNP_WANTCRED); 490 break; 491 } 492 *mtod(m, int *) = optval; 493 break; 494 #undef OPTBIT 495 496 default: 497 error = ENOPROTOOPT; 498 break; 499 } 500 break; 501 } 502 return (error); 503 } 504 505 /* 506 * Both send and receive buffers are allocated PIPSIZ bytes of buffering 507 * for stream sockets, although the total for sender and receiver is 508 * actually only PIPSIZ. 509 * Datagram sockets really use the sendspace as the maximum datagram size, 510 * and don't really want to reserve the sendspace. Their recvspace should 511 * be large enough for at least one max-size datagram plus address. 512 */ 513 #define PIPSIZ 4096 514 u_long unpst_sendspace = PIPSIZ; 515 u_long unpst_recvspace = PIPSIZ; 516 u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 517 u_long unpdg_recvspace = 4*1024; 518 519 int unp_rights; /* file descriptors in flight */ 520 521 int 522 unp_attach(struct socket *so) 523 { 524 struct unpcb *unp; 525 struct timeval tv; 526 int error; 527 528 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 529 switch (so->so_type) { 530 531 case SOCK_STREAM: 532 error = soreserve(so, unpst_sendspace, unpst_recvspace); 533 break; 534 535 case SOCK_DGRAM: 536 error = soreserve(so, unpdg_sendspace, unpdg_recvspace); 537 break; 538 539 default: 540 panic("unp_attach"); 541 } 542 if (error) 543 return (error); 544 } 545 unp = malloc(sizeof(*unp), M_PCB, M_NOWAIT); 546 if (unp == NULL) 547 return (ENOBUFS); 548 memset((caddr_t)unp, 0, sizeof(*unp)); 549 unp->unp_socket = so; 550 so->so_pcb = unp; 551 microtime(&tv); 552 TIMEVAL_TO_TIMESPEC(&tv, &unp->unp_ctime); 553 return (0); 554 } 555 556 void 557 unp_detach(struct unpcb *unp) 558 { 559 560 if (unp->unp_vnode) { 561 unp->unp_vnode->v_socket = 0; 562 vrele(unp->unp_vnode); 563 unp->unp_vnode = 0; 564 } 565 if (unp->unp_conn) 566 unp_disconnect(unp); 567 while (unp->unp_refs) 568 unp_drop(unp->unp_refs, ECONNRESET); 569 soisdisconnected(unp->unp_socket); 570 unp->unp_socket->so_pcb = 0; 571 if (unp->unp_addr) 572 free(unp->unp_addr, M_SONAME); 573 if (unp_rights) { 574 /* 575 * Normally the receive buffer is flushed later, 576 * in sofree, but if our receive buffer holds references 577 * to descriptors that are now garbage, we will dispose 578 * of those descriptor references after the garbage collector 579 * gets them (resulting in a "panic: closef: count < 0"). 580 */ 581 sorflush(unp->unp_socket); 582 free(unp, M_PCB); 583 unp_gc(); 584 } else 585 free(unp, M_PCB); 586 } 587 588 int 589 unp_bind(struct unpcb *unp, struct mbuf *nam, struct proc *p) 590 { 591 struct sockaddr_un *sun; 592 struct vnode *vp; 593 struct mount *mp; 594 struct vattr vattr; 595 size_t addrlen; 596 int error; 597 struct nameidata nd; 598 599 if (unp->unp_vnode != 0) 600 return (EINVAL); 601 602 /* 603 * Allocate the new sockaddr. We have to allocate one 604 * extra byte so that we can ensure that the pathname 605 * is nul-terminated. 606 */ 607 addrlen = nam->m_len + 1; 608 sun = malloc(addrlen, M_SONAME, M_WAITOK); 609 m_copydata(nam, 0, nam->m_len, (caddr_t)sun); 610 *(((char *)sun) + nam->m_len) = '\0'; 611 612 restart: 613 NDINIT(&nd, CREATE, FOLLOW | LOCKPARENT, UIO_SYSSPACE, 614 sun->sun_path, p); 615 616 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 617 if ((error = namei(&nd)) != 0) 618 goto bad; 619 vp = nd.ni_vp; 620 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 621 VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd); 622 if (nd.ni_dvp == vp) 623 vrele(nd.ni_dvp); 624 else 625 vput(nd.ni_dvp); 626 vrele(vp); 627 if (vp != NULL) { 628 error = EADDRINUSE; 629 goto bad; 630 } 631 error = vn_start_write(NULL, &mp, 632 V_WAIT | V_SLEEPONLY | V_PCATCH); 633 if (error) 634 goto bad; 635 goto restart; 636 } 637 VATTR_NULL(&vattr); 638 vattr.va_type = VSOCK; 639 vattr.va_mode = ACCESSPERMS; 640 VOP_LEASE(nd.ni_dvp, p, p->p_ucred, LEASE_WRITE); 641 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 642 vn_finished_write(mp, 0); 643 if (error) 644 goto bad; 645 vp = nd.ni_vp; 646 vp->v_socket = unp->unp_socket; 647 unp->unp_vnode = vp; 648 unp->unp_addrlen = addrlen; 649 unp->unp_addr = sun; 650 VOP_UNLOCK(vp, 0); 651 return (0); 652 653 bad: 654 free(sun, M_SONAME); 655 return (error); 656 } 657 658 int 659 unp_connect(struct socket *so, struct mbuf *nam, struct proc *p) 660 { 661 struct sockaddr_un *sun; 662 struct vnode *vp; 663 struct socket *so2, *so3; 664 struct unpcb *unp2, *unp3; 665 size_t addrlen; 666 int error; 667 struct nameidata nd; 668 669 /* 670 * Allocate a temporary sockaddr. We have to allocate one extra 671 * byte so that we can ensure that the pathname is nul-terminated. 672 * When we establish the connection, we copy the other PCB's 673 * sockaddr to our own. 674 */ 675 addrlen = nam->m_len + 1; 676 sun = malloc(addrlen, M_SONAME, M_WAITOK); 677 m_copydata(nam, 0, nam->m_len, (caddr_t)sun); 678 *(((char *)sun) + nam->m_len) = '\0'; 679 680 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, sun->sun_path, p); 681 682 if ((error = namei(&nd)) != 0) 683 goto bad2; 684 vp = nd.ni_vp; 685 if (vp->v_type != VSOCK) { 686 error = ENOTSOCK; 687 goto bad; 688 } 689 if ((error = VOP_ACCESS(vp, VWRITE, p->p_ucred, p)) != 0) 690 goto bad; 691 so2 = vp->v_socket; 692 if (so2 == 0) { 693 error = ECONNREFUSED; 694 goto bad; 695 } 696 if (so->so_type != so2->so_type) { 697 error = EPROTOTYPE; 698 goto bad; 699 } 700 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 701 if ((so2->so_options & SO_ACCEPTCONN) == 0 || 702 (so3 = sonewconn(so2, 0)) == 0) { 703 error = ECONNREFUSED; 704 goto bad; 705 } 706 unp2 = sotounpcb(so2); 707 unp3 = sotounpcb(so3); 708 if (unp2->unp_addr) { 709 unp3->unp_addr = malloc(unp2->unp_addrlen, 710 M_SONAME, M_WAITOK); 711 memcpy(unp3->unp_addr, unp2->unp_addr, 712 unp2->unp_addrlen); 713 unp3->unp_addrlen = unp2->unp_addrlen; 714 } 715 unp3->unp_flags = unp2->unp_flags; 716 so2 = so3; 717 } 718 error = unp_connect2(so, so2, PRU_CONNECT); 719 bad: 720 vput(vp); 721 bad2: 722 free(sun, M_SONAME); 723 return (error); 724 } 725 726 int 727 unp_connect2(struct socket *so, struct socket *so2, int req) 728 { 729 struct unpcb *unp = sotounpcb(so); 730 struct unpcb *unp2; 731 732 if (so2->so_type != so->so_type) 733 return (EPROTOTYPE); 734 unp2 = sotounpcb(so2); 735 unp->unp_conn = unp2; 736 switch (so->so_type) { 737 738 case SOCK_DGRAM: 739 unp->unp_nextref = unp2->unp_refs; 740 unp2->unp_refs = unp; 741 soisconnected(so); 742 break; 743 744 case SOCK_STREAM: 745 unp2->unp_conn = unp; 746 if (req == PRU_CONNECT && 747 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 748 soisconnecting(so); 749 else 750 soisconnected(so); 751 soisconnected(so2); 752 break; 753 754 default: 755 panic("unp_connect2"); 756 } 757 return (0); 758 } 759 760 void 761 unp_disconnect(struct unpcb *unp) 762 { 763 struct unpcb *unp2 = unp->unp_conn; 764 765 if (unp2 == 0) 766 return; 767 unp->unp_conn = 0; 768 switch (unp->unp_socket->so_type) { 769 770 case SOCK_DGRAM: 771 if (unp2->unp_refs == unp) 772 unp2->unp_refs = unp->unp_nextref; 773 else { 774 unp2 = unp2->unp_refs; 775 for (;;) { 776 if (unp2 == 0) 777 panic("unp_disconnect"); 778 if (unp2->unp_nextref == unp) 779 break; 780 unp2 = unp2->unp_nextref; 781 } 782 unp2->unp_nextref = unp->unp_nextref; 783 } 784 unp->unp_nextref = 0; 785 unp->unp_socket->so_state &= ~SS_ISCONNECTED; 786 break; 787 788 case SOCK_STREAM: 789 soisdisconnected(unp->unp_socket); 790 unp2->unp_conn = 0; 791 soisdisconnected(unp2->unp_socket); 792 break; 793 } 794 } 795 796 #ifdef notdef 797 unp_abort(struct unpcb *unp) 798 { 799 unp_detach(unp); 800 } 801 #endif 802 803 void 804 unp_shutdown(struct unpcb *unp) 805 { 806 struct socket *so; 807 808 if (unp->unp_socket->so_type == SOCK_STREAM && unp->unp_conn && 809 (so = unp->unp_conn->unp_socket)) 810 socantrcvmore(so); 811 } 812 813 void 814 unp_drop(struct unpcb *unp, int errno) 815 { 816 struct socket *so = unp->unp_socket; 817 818 so->so_error = errno; 819 unp_disconnect(unp); 820 if (so->so_head) { 821 so->so_pcb = 0; 822 sofree(so); 823 if (unp->unp_addr) 824 free(unp->unp_addr, M_SONAME); 825 free(unp, M_PCB); 826 } 827 } 828 829 #ifdef notdef 830 unp_drain(void) 831 { 832 833 } 834 #endif 835 836 int 837 unp_externalize(struct mbuf *rights, struct proc *p) 838 { 839 struct cmsghdr *cm = mtod(rights, struct cmsghdr *); 840 int i, *fdp; 841 struct file **rp; 842 struct file *fp; 843 int nfds, error = 0; 844 845 nfds = (cm->cmsg_len - CMSG_ALIGN(sizeof(*cm))) / 846 sizeof(struct file *); 847 rp = (struct file **)CMSG_DATA(cm); 848 849 fdp = malloc(nfds * sizeof(int), M_TEMP, M_WAITOK); 850 851 /* Make sure the recipient should be able to see the descriptors.. */ 852 if (p->p_cwdi->cwdi_rdir != NULL) { 853 rp = (struct file **)CMSG_DATA(cm); 854 for (i = 0; i < nfds; i++) { 855 fp = *rp++; 856 /* 857 * If we are in a chroot'ed directory, and 858 * someone wants to pass us a directory, make 859 * sure it's inside the subtree we're allowed 860 * to access. 861 */ 862 if (fp->f_type == DTYPE_VNODE) { 863 struct vnode *vp = (struct vnode *)fp->f_data; 864 if ((vp->v_type == VDIR) && 865 !vn_isunder(vp, p->p_cwdi->cwdi_rdir, p)) { 866 error = EPERM; 867 break; 868 } 869 } 870 } 871 } 872 873 restart: 874 rp = (struct file **)CMSG_DATA(cm); 875 if (error != 0) { 876 for (i = 0; i < nfds; i++) { 877 fp = *rp; 878 /* 879 * zero the pointer before calling unp_discard, 880 * since it may end up in unp_gc().. 881 */ 882 *rp++ = 0; 883 unp_discard(fp); 884 } 885 goto out; 886 } 887 888 /* 889 * First loop -- allocate file descriptor table slots for the 890 * new descriptors. 891 */ 892 for (i = 0; i < nfds; i++) { 893 fp = *rp++; 894 if ((error = fdalloc(p, 0, &fdp[i])) != 0) { 895 /* 896 * Back out what we've done so far. 897 */ 898 for (--i; i >= 0; i--) 899 fdremove(p->p_fd, fdp[i]); 900 901 if (error == ENOSPC) { 902 fdexpand(p); 903 error = 0; 904 } else { 905 /* 906 * This is the error that has historically 907 * been returned, and some callers may 908 * expect it. 909 */ 910 error = EMSGSIZE; 911 } 912 goto restart; 913 } 914 915 /* 916 * Make the slot reference the descriptor so that 917 * fdalloc() works properly.. We finalize it all 918 * in the loop below. 919 */ 920 p->p_fd->fd_ofiles[fdp[i]] = fp; 921 } 922 923 /* 924 * Now that adding them has succeeded, update all of the 925 * descriptor passing state. 926 */ 927 rp = (struct file **)CMSG_DATA(cm); 928 for (i = 0; i < nfds; i++) { 929 fp = *rp++; 930 fp->f_msgcount--; 931 unp_rights--; 932 } 933 934 /* 935 * Copy temporary array to message and adjust length, in case of 936 * transition from large struct file pointers to ints. 937 */ 938 memcpy(CMSG_DATA(cm), fdp, nfds * sizeof(int)); 939 cm->cmsg_len = CMSG_LEN(nfds * sizeof(int)); 940 rights->m_len = CMSG_SPACE(nfds * sizeof(int)); 941 out: 942 free(fdp, M_TEMP); 943 return (error); 944 } 945 946 int 947 unp_internalize(struct mbuf *control, struct proc *p) 948 { 949 struct filedesc *fdescp = p->p_fd; 950 struct cmsghdr *newcm, *cm = mtod(control, struct cmsghdr *); 951 struct file **rp, **files; 952 struct file *fp; 953 int i, fd, *fdp; 954 int nfds; 955 u_int neededspace; 956 957 /* Sanity check the control message header */ 958 if (cm->cmsg_type != SCM_RIGHTS || cm->cmsg_level != SOL_SOCKET || 959 cm->cmsg_len != control->m_len) 960 return (EINVAL); 961 962 /* Verify that the file descriptors are valid */ 963 nfds = (cm->cmsg_len - CMSG_ALIGN(sizeof(*cm))) / sizeof(int); 964 fdp = (int *)CMSG_DATA(cm); 965 for (i = 0; i < nfds; i++) { 966 fd = *fdp++; 967 if ((fp = fd_getfile(fdescp, fd)) == NULL) 968 return (EBADF); 969 simple_unlock(&fp->f_slock); 970 } 971 972 /* Make sure we have room for the struct file pointers */ 973 neededspace = CMSG_SPACE(nfds * sizeof(struct file *)) - 974 control->m_len; 975 if (neededspace > M_TRAILINGSPACE(control)) { 976 977 /* allocate new space and copy header into it */ 978 newcm = malloc( 979 CMSG_SPACE(nfds * sizeof(struct file *)), 980 M_MBUF, M_WAITOK); 981 if (newcm == NULL) 982 return (E2BIG); 983 memcpy(newcm, cm, sizeof(struct cmsghdr)); 984 files = (struct file **)CMSG_DATA(newcm); 985 } else { 986 /* we can convert in-place */ 987 newcm = NULL; 988 files = (struct file **)CMSG_DATA(cm); 989 } 990 991 /* 992 * Transform the file descriptors into struct file pointers, in 993 * reverse order so that if pointers are bigger than ints, the 994 * int won't get until we're done. 995 */ 996 fdp = (int *)CMSG_DATA(cm) + nfds - 1; 997 rp = files + nfds - 1; 998 for (i = 0; i < nfds; i++) { 999 fp = fdescp->fd_ofiles[*fdp--]; 1000 simple_lock(&fp->f_slock); 1001 #ifdef DIAGNOSTIC 1002 if (fp->f_iflags & FIF_WANTCLOSE) 1003 panic("unp_internalize: file already closed"); 1004 #endif 1005 *rp-- = fp; 1006 fp->f_count++; 1007 fp->f_msgcount++; 1008 simple_unlock(&fp->f_slock); 1009 unp_rights++; 1010 } 1011 1012 if (newcm) { 1013 if (control->m_flags & M_EXT) 1014 MEXTREMOVE(control); 1015 MEXTADD(control, newcm, 1016 CMSG_SPACE(nfds * sizeof(struct file *)), 1017 M_MBUF, NULL, NULL); 1018 cm = newcm; 1019 } 1020 1021 /* adjust message & mbuf to note amount of space actually used. */ 1022 cm->cmsg_len = CMSG_LEN(nfds * sizeof(struct file *)); 1023 control->m_len = CMSG_SPACE(nfds * sizeof(struct file *)); 1024 1025 return (0); 1026 } 1027 1028 struct mbuf * 1029 unp_addsockcred(struct proc *p, struct mbuf *control) 1030 { 1031 struct cmsghdr *cmp; 1032 struct sockcred *sc; 1033 struct mbuf *m, *n; 1034 int len, space, i; 1035 1036 len = CMSG_LEN(SOCKCREDSIZE(p->p_ucred->cr_ngroups)); 1037 space = CMSG_SPACE(SOCKCREDSIZE(p->p_ucred->cr_ngroups)); 1038 1039 m = m_get(M_WAIT, MT_CONTROL); 1040 if (space > MLEN) { 1041 if (space > MCLBYTES) 1042 MEXTMALLOC(m, space, M_WAITOK); 1043 else 1044 m_clget(m, M_WAIT); 1045 if ((m->m_flags & M_EXT) == 0) { 1046 m_free(m); 1047 return (control); 1048 } 1049 } 1050 1051 m->m_len = space; 1052 m->m_next = NULL; 1053 cmp = mtod(m, struct cmsghdr *); 1054 sc = (struct sockcred *)CMSG_DATA(cmp); 1055 cmp->cmsg_len = len; 1056 cmp->cmsg_level = SOL_SOCKET; 1057 cmp->cmsg_type = SCM_CREDS; 1058 sc->sc_uid = p->p_cred->p_ruid; 1059 sc->sc_euid = p->p_ucred->cr_uid; 1060 sc->sc_gid = p->p_cred->p_rgid; 1061 sc->sc_egid = p->p_ucred->cr_gid; 1062 sc->sc_ngroups = p->p_ucred->cr_ngroups; 1063 for (i = 0; i < sc->sc_ngroups; i++) 1064 sc->sc_groups[i] = p->p_ucred->cr_groups[i]; 1065 1066 /* 1067 * If a control message already exists, append us to the end. 1068 */ 1069 if (control != NULL) { 1070 for (n = control; n->m_next != NULL; n = n->m_next) 1071 ; 1072 n->m_next = m; 1073 } else 1074 control = m; 1075 1076 return (control); 1077 } 1078 1079 int unp_defer, unp_gcing; 1080 extern struct domain unixdomain; 1081 1082 /* 1083 * Comment added long after the fact explaining what's going on here. 1084 * Do a mark-sweep GC of file descriptors on the system, to free up 1085 * any which are caught in flight to an about-to-be-closed socket. 1086 * 1087 * Traditional mark-sweep gc's start at the "root", and mark 1088 * everything reachable from the root (which, in our case would be the 1089 * process table). The mark bits are cleared during the sweep. 1090 * 1091 * XXX For some inexplicable reason (perhaps because the file 1092 * descriptor tables used to live in the u area which could be swapped 1093 * out and thus hard to reach), we do multiple scans over the set of 1094 * descriptors, using use *two* mark bits per object (DEFER and MARK). 1095 * Whenever we find a descriptor which references other descriptors, 1096 * the ones it references are marked with both bits, and we iterate 1097 * over the whole file table until there are no more DEFER bits set. 1098 * We also make an extra pass *before* the GC to clear the mark bits, 1099 * which could have been cleared at almost no cost during the previous 1100 * sweep. 1101 * 1102 * XXX MP: this needs to run with locks such that no other thread of 1103 * control can create or destroy references to file descriptors. it 1104 * may be necessary to defer the GC until later (when the locking 1105 * situation is more hospitable); it may be necessary to push this 1106 * into a separate thread. 1107 */ 1108 void 1109 unp_gc(void) 1110 { 1111 struct file *fp, *nextfp; 1112 struct socket *so, *so1; 1113 struct file **extra_ref, **fpp; 1114 int nunref, i; 1115 1116 if (unp_gcing) 1117 return; 1118 unp_gcing = 1; 1119 unp_defer = 0; 1120 1121 /* Clear mark bits */ 1122 LIST_FOREACH(fp, &filehead, f_list) 1123 fp->f_flag &= ~(FMARK|FDEFER); 1124 1125 /* 1126 * Iterate over the set of descriptors, marking ones believed 1127 * (based on refcount) to be referenced from a process, and 1128 * marking for rescan descriptors which are queued on a socket. 1129 */ 1130 do { 1131 LIST_FOREACH(fp, &filehead, f_list) { 1132 if (fp->f_flag & FDEFER) { 1133 fp->f_flag &= ~FDEFER; 1134 unp_defer--; 1135 #ifdef DIAGNOSTIC 1136 if (fp->f_count == 0) 1137 panic("unp_gc: deferred unreferenced socket"); 1138 #endif 1139 } else { 1140 if (fp->f_count == 0) 1141 continue; 1142 if (fp->f_flag & FMARK) 1143 continue; 1144 if (fp->f_count == fp->f_msgcount) 1145 continue; 1146 } 1147 fp->f_flag |= FMARK; 1148 1149 if (fp->f_type != DTYPE_SOCKET || 1150 (so = (struct socket *)fp->f_data) == 0) 1151 continue; 1152 if (so->so_proto->pr_domain != &unixdomain || 1153 (so->so_proto->pr_flags&PR_RIGHTS) == 0) 1154 continue; 1155 #ifdef notdef 1156 if (so->so_rcv.sb_flags & SB_LOCK) { 1157 /* 1158 * This is problematical; it's not clear 1159 * we need to wait for the sockbuf to be 1160 * unlocked (on a uniprocessor, at least), 1161 * and it's also not clear what to do 1162 * if sbwait returns an error due to receipt 1163 * of a signal. If sbwait does return 1164 * an error, we'll go into an infinite 1165 * loop. Delete all of this for now. 1166 */ 1167 (void) sbwait(&so->so_rcv); 1168 goto restart; 1169 } 1170 #endif 1171 unp_scan(so->so_rcv.sb_mb, unp_mark, 0); 1172 /* 1173 * mark descriptors referenced from sockets queued on the accept queue as well. 1174 */ 1175 if (so->so_options & SO_ACCEPTCONN) { 1176 TAILQ_FOREACH(so1, &so->so_q0, so_qe) { 1177 unp_scan(so1->so_rcv.sb_mb, unp_mark, 0); 1178 } 1179 TAILQ_FOREACH(so1, &so->so_q, so_qe) { 1180 unp_scan(so1->so_rcv.sb_mb, unp_mark, 0); 1181 } 1182 } 1183 1184 } 1185 } while (unp_defer); 1186 /* 1187 * Sweep pass. Find unmarked descriptors, and free them. 1188 * 1189 * We grab an extra reference to each of the file table entries 1190 * that are not otherwise accessible and then free the rights 1191 * that are stored in messages on them. 1192 * 1193 * The bug in the original code is a little tricky, so I'll describe 1194 * what's wrong with it here. 1195 * 1196 * It is incorrect to simply unp_discard each entry for f_msgcount 1197 * times -- consider the case of sockets A and B that contain 1198 * references to each other. On a last close of some other socket, 1199 * we trigger a gc since the number of outstanding rights (unp_rights) 1200 * is non-zero. If during the sweep phase the gc code un_discards, 1201 * we end up doing a (full) closef on the descriptor. A closef on A 1202 * results in the following chain. Closef calls soo_close, which 1203 * calls soclose. Soclose calls first (through the switch 1204 * uipc_usrreq) unp_detach, which re-invokes unp_gc. Unp_gc simply 1205 * returns because the previous instance had set unp_gcing, and 1206 * we return all the way back to soclose, which marks the socket 1207 * with SS_NOFDREF, and then calls sofree. Sofree calls sorflush 1208 * to free up the rights that are queued in messages on the socket A, 1209 * i.e., the reference on B. The sorflush calls via the dom_dispose 1210 * switch unp_dispose, which unp_scans with unp_discard. This second 1211 * instance of unp_discard just calls closef on B. 1212 * 1213 * Well, a similar chain occurs on B, resulting in a sorflush on B, 1214 * which results in another closef on A. Unfortunately, A is already 1215 * being closed, and the descriptor has already been marked with 1216 * SS_NOFDREF, and soclose panics at this point. 1217 * 1218 * Here, we first take an extra reference to each inaccessible 1219 * descriptor. Then, if the inaccessible descriptor is a 1220 * socket, we call sorflush in case it is a Unix domain 1221 * socket. After we destroy all the rights carried in 1222 * messages, we do a last closef to get rid of our extra 1223 * reference. This is the last close, and the unp_detach etc 1224 * will shut down the socket. 1225 * 1226 * 91/09/19, bsy@cs.cmu.edu 1227 */ 1228 extra_ref = malloc(nfiles * sizeof(struct file *), M_FILE, M_WAITOK); 1229 for (nunref = 0, fp = LIST_FIRST(&filehead), fpp = extra_ref; fp != 0; 1230 fp = nextfp) { 1231 nextfp = LIST_NEXT(fp, f_list); 1232 simple_lock(&fp->f_slock); 1233 if (fp->f_count != 0 && 1234 fp->f_count == fp->f_msgcount && !(fp->f_flag & FMARK)) { 1235 *fpp++ = fp; 1236 nunref++; 1237 fp->f_count++; 1238 } 1239 simple_unlock(&fp->f_slock); 1240 } 1241 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) { 1242 fp = *fpp; 1243 simple_lock(&fp->f_slock); 1244 FILE_USE(fp); 1245 if (fp->f_type == DTYPE_SOCKET) 1246 sorflush((struct socket *)fp->f_data); 1247 FILE_UNUSE(fp, NULL); 1248 } 1249 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) { 1250 fp = *fpp; 1251 simple_lock(&fp->f_slock); 1252 FILE_USE(fp); 1253 (void) closef(fp, (struct proc *)0); 1254 } 1255 free((caddr_t)extra_ref, M_FILE); 1256 unp_gcing = 0; 1257 } 1258 1259 void 1260 unp_dispose(struct mbuf *m) 1261 { 1262 1263 if (m) 1264 unp_scan(m, unp_discard, 1); 1265 } 1266 1267 void 1268 unp_scan(struct mbuf *m0, void (*op)(struct file *), int discard) 1269 { 1270 struct mbuf *m; 1271 struct file **rp; 1272 struct cmsghdr *cm; 1273 int i; 1274 int qfds; 1275 1276 while (m0) { 1277 for (m = m0; m; m = m->m_next) { 1278 if (m->m_type == MT_CONTROL && 1279 m->m_len >= sizeof(*cm)) { 1280 cm = mtod(m, struct cmsghdr *); 1281 if (cm->cmsg_level != SOL_SOCKET || 1282 cm->cmsg_type != SCM_RIGHTS) 1283 continue; 1284 qfds = (cm->cmsg_len - CMSG_ALIGN(sizeof(*cm))) 1285 / sizeof(struct file *); 1286 rp = (struct file **)CMSG_DATA(cm); 1287 for (i = 0; i < qfds; i++) { 1288 struct file *fp = *rp; 1289 if (discard) 1290 *rp = 0; 1291 (*op)(fp); 1292 rp++; 1293 } 1294 break; /* XXX, but saves time */ 1295 } 1296 } 1297 m0 = m0->m_nextpkt; 1298 } 1299 } 1300 1301 void 1302 unp_mark(struct file *fp) 1303 { 1304 if (fp == NULL) 1305 return; 1306 1307 if (fp->f_flag & FMARK) 1308 return; 1309 1310 /* If we're already deferred, don't screw up the defer count */ 1311 if (fp->f_flag & FDEFER) 1312 return; 1313 1314 /* 1315 * Minimize the number of deferrals... Sockets are the only 1316 * type of descriptor which can hold references to another 1317 * descriptor, so just mark other descriptors, and defer 1318 * unmarked sockets for the next pass. 1319 */ 1320 if (fp->f_type == DTYPE_SOCKET) { 1321 unp_defer++; 1322 if (fp->f_count == 0) 1323 panic("unp_mark: queued unref"); 1324 fp->f_flag |= FDEFER; 1325 } else { 1326 fp->f_flag |= FMARK; 1327 } 1328 return; 1329 } 1330 1331 void 1332 unp_discard(struct file *fp) 1333 { 1334 if (fp == NULL) 1335 return; 1336 simple_lock(&fp->f_slock); 1337 fp->f_usecount++; /* i.e. FILE_USE(fp) sans locking */ 1338 fp->f_msgcount--; 1339 simple_unlock(&fp->f_slock); 1340 unp_rights--; 1341 (void) closef(fp, (struct proc *)0); 1342 } 1343