1 /* 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94 34 * $Id: uipc_usrreq.c,v 1.22 1997/03/23 03:36:33 bde Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/queue.h> 39 #include <sys/systm.h> 40 #include <sys/kernel.h> 41 #include <sys/domain.h> 42 #include <sys/fcntl.h> 43 #include <sys/file.h> 44 #include <sys/filedesc.h> 45 #include <sys/mbuf.h> 46 #include <sys/namei.h> 47 #include <sys/proc.h> 48 #include <sys/protosw.h> 49 #include <sys/socket.h> 50 #include <sys/socketvar.h> 51 #include <sys/stat.h> 52 #include <sys/sysctl.h> 53 #include <sys/un.h> 54 #include <sys/unpcb.h> 55 #include <sys/vnode.h> 56 57 /* 58 * Unix communications domain. 59 * 60 * TODO: 61 * SEQPACKET, RDM 62 * rethink name space problems 63 * need a proper out-of-band 64 */ 65 static struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; 66 static ino_t unp_ino; /* prototype for fake inode numbers */ 67 68 static int unp_attach __P((struct socket *)); 69 static void unp_detach __P((struct unpcb *)); 70 static int unp_bind __P((struct unpcb *,struct mbuf *, struct proc *)); 71 static int unp_connect __P((struct socket *,struct mbuf *, struct proc *)); 72 static void unp_disconnect __P((struct unpcb *)); 73 static void unp_shutdown __P((struct unpcb *)); 74 static void unp_drop __P((struct unpcb *, int)); 75 static void unp_gc __P((void)); 76 static void unp_scan __P((struct mbuf *, void (*)(struct file *))); 77 static void unp_mark __P((struct file *)); 78 static void unp_discard __P((struct file *)); 79 static int unp_internalize __P((struct mbuf *, struct proc *)); 80 81 static int 82 uipc_abort(struct socket *so) 83 { 84 struct unpcb *unp = sotounpcb(so); 85 86 if (unp == 0) 87 return EINVAL; 88 unp_drop(unp, ECONNABORTED); 89 return 0; 90 } 91 92 static int 93 uipc_accept(struct socket *so, struct mbuf *nam) 94 { 95 struct unpcb *unp = sotounpcb(so); 96 97 if (unp == 0) 98 return EINVAL; 99 100 /* 101 * Pass back name of connected socket, 102 * if it was bound and we are still connected 103 * (our peer may have closed already!). 104 */ 105 if (unp->unp_conn && unp->unp_conn->unp_addr) { 106 nam->m_len = unp->unp_conn->unp_addr->m_len; 107 bcopy(mtod(unp->unp_conn->unp_addr, caddr_t), 108 mtod(nam, caddr_t), (unsigned)nam->m_len); 109 } else { 110 nam->m_len = sizeof(sun_noname); 111 *(mtod(nam, struct sockaddr *)) = sun_noname; 112 } 113 return 0; 114 } 115 116 static int 117 uipc_attach(struct socket *so, int proto, struct proc *p) 118 { 119 struct unpcb *unp = sotounpcb(so); 120 121 if (unp != 0) 122 return EISCONN; 123 return unp_attach(so); 124 } 125 126 static int 127 uipc_bind(struct socket *so, struct mbuf *nam, struct proc *p) 128 { 129 struct unpcb *unp = sotounpcb(so); 130 131 if (unp == 0) 132 return EINVAL; 133 134 return unp_bind(unp, nam, p); 135 } 136 137 static int 138 uipc_connect(struct socket *so, struct mbuf *nam, struct proc *p) 139 { 140 struct unpcb *unp = sotounpcb(so); 141 142 if (unp == 0) 143 return EINVAL; 144 return unp_connect(so, nam, curproc); 145 } 146 147 static int 148 uipc_connect2(struct socket *so1, struct socket *so2) 149 { 150 struct unpcb *unp = sotounpcb(so1); 151 152 if (unp == 0) 153 return EINVAL; 154 155 return unp_connect2(so1, so2); 156 } 157 158 /* control is EOPNOTSUPP */ 159 160 static int 161 uipc_detach(struct socket *so) 162 { 163 struct unpcb *unp = sotounpcb(so); 164 165 if (unp == 0) 166 return EINVAL; 167 168 unp_detach(unp); 169 return 0; 170 } 171 172 static int 173 uipc_disconnect(struct socket *so) 174 { 175 struct unpcb *unp = sotounpcb(so); 176 177 if (unp == 0) 178 return EINVAL; 179 unp_disconnect(unp); 180 return 0; 181 } 182 183 static int 184 uipc_listen(struct socket *so, struct proc *p) 185 { 186 struct unpcb *unp = sotounpcb(so); 187 188 if (unp == 0 || unp->unp_vnode == 0) 189 return EINVAL; 190 return 0; 191 } 192 193 static int 194 uipc_peeraddr(struct socket *so, struct mbuf *nam) 195 { 196 struct unpcb *unp = sotounpcb(so); 197 198 if (unp == 0) 199 return EINVAL; 200 if (unp->unp_conn && unp->unp_conn->unp_addr) { 201 nam->m_len = unp->unp_conn->unp_addr->m_len; 202 bcopy(mtod(unp->unp_conn->unp_addr, caddr_t), 203 mtod(nam, caddr_t), (unsigned)nam->m_len); 204 } else 205 nam->m_len = 0; 206 return 0; 207 } 208 209 static int 210 uipc_rcvd(struct socket *so, int flags) 211 { 212 struct unpcb *unp = sotounpcb(so); 213 struct socket *so2; 214 215 if (unp == 0) 216 return EINVAL; 217 switch (so->so_type) { 218 case SOCK_DGRAM: 219 panic("uipc_rcvd DGRAM?"); 220 /*NOTREACHED*/ 221 222 case SOCK_STREAM: 223 #define rcv (&so->so_rcv) 224 #define snd (&so2->so_snd) 225 if (unp->unp_conn == 0) 226 break; 227 so2 = unp->unp_conn->unp_socket; 228 /* 229 * Adjust backpressure on sender 230 * and wakeup any waiting to write. 231 */ 232 snd->sb_mbmax += unp->unp_mbcnt - rcv->sb_mbcnt; 233 unp->unp_mbcnt = rcv->sb_mbcnt; 234 snd->sb_hiwat += unp->unp_cc - rcv->sb_cc; 235 unp->unp_cc = rcv->sb_cc; 236 sowwakeup(so2); 237 #undef snd 238 #undef rcv 239 break; 240 241 default: 242 panic("uipc_rcvd unknown socktype"); 243 } 244 return 0; 245 } 246 247 /* pru_rcvoob is EOPNOTSUPP */ 248 249 static int 250 uipc_send(struct socket *so, int flags, struct mbuf *m, struct mbuf *nam, 251 struct mbuf *control, struct proc *p) 252 { 253 int error = 0; 254 struct unpcb *unp = sotounpcb(so); 255 struct socket *so2; 256 257 if (unp == 0) { 258 error = EINVAL; 259 goto release; 260 } 261 if (flags & PRUS_OOB) { 262 error = EOPNOTSUPP; 263 goto release; 264 } 265 266 if (control && (error = unp_internalize(control, p))) 267 goto release; 268 269 switch (so->so_type) { 270 case SOCK_DGRAM: 271 { 272 struct sockaddr *from; 273 274 if (nam) { 275 if (unp->unp_conn) { 276 error = EISCONN; 277 break; 278 } 279 error = unp_connect(so, nam, p); 280 if (error) 281 break; 282 } else { 283 if (unp->unp_conn == 0) { 284 error = ENOTCONN; 285 break; 286 } 287 } 288 so2 = unp->unp_conn->unp_socket; 289 if (unp->unp_addr) 290 from = mtod(unp->unp_addr, struct sockaddr *); 291 else 292 from = &sun_noname; 293 if (sbappendaddr(&so2->so_rcv, from, m, control)) { 294 sorwakeup(so2); 295 m = 0; 296 control = 0; 297 } else 298 error = ENOBUFS; 299 if (nam) 300 unp_disconnect(unp); 301 break; 302 } 303 304 case SOCK_STREAM: 305 #define rcv (&so2->so_rcv) 306 #define snd (&so->so_snd) 307 /* Connect if not connected yet. */ 308 /* 309 * Note: A better implementation would complain 310 * if not equal to the peer's address. 311 */ 312 if ((so->so_state & SS_ISCONNECTED) == 0) { 313 if (nam) { 314 error = unp_connect(so, nam, p); 315 if (error) 316 break; /* XXX */ 317 } else { 318 error = ENOTCONN; 319 break; 320 } 321 } 322 323 if (so->so_state & SS_CANTSENDMORE) { 324 error = EPIPE; 325 break; 326 } 327 if (unp->unp_conn == 0) 328 panic("uipc_send connected but no connection?"); 329 so2 = unp->unp_conn->unp_socket; 330 /* 331 * Send to paired receive port, and then reduce 332 * send buffer hiwater marks to maintain backpressure. 333 * Wake up readers. 334 */ 335 if (control) { 336 if (sbappendcontrol(rcv, m, control)) 337 control = 0; 338 } else 339 sbappend(rcv, m); 340 snd->sb_mbmax -= 341 rcv->sb_mbcnt - unp->unp_conn->unp_mbcnt; 342 unp->unp_conn->unp_mbcnt = rcv->sb_mbcnt; 343 snd->sb_hiwat -= rcv->sb_cc - unp->unp_conn->unp_cc; 344 unp->unp_conn->unp_cc = rcv->sb_cc; 345 sorwakeup(so2); 346 m = 0; 347 #undef snd 348 #undef rcv 349 break; 350 351 default: 352 panic("uipc_send unknown socktype"); 353 } 354 355 /* 356 * SEND_EOF is equivalent to a SEND followed by 357 * a SHUTDOWN. 358 */ 359 if (flags & PRUS_EOF) { 360 socantsendmore(so); 361 unp_shutdown(unp); 362 } 363 364 release: 365 if (control) 366 m_freem(control); 367 if (m) 368 m_freem(m); 369 return error; 370 } 371 372 static int 373 uipc_sense(struct socket *so, struct stat *sb) 374 { 375 struct unpcb *unp = sotounpcb(so); 376 struct socket *so2; 377 378 if (unp == 0) 379 return EINVAL; 380 sb->st_blksize = so->so_snd.sb_hiwat; 381 if (so->so_type == SOCK_STREAM && unp->unp_conn != 0) { 382 so2 = unp->unp_conn->unp_socket; 383 sb->st_blksize += so2->so_rcv.sb_cc; 384 } 385 sb->st_dev = NODEV; 386 if (unp->unp_ino == 0) 387 unp->unp_ino = unp_ino++; 388 sb->st_ino = unp->unp_ino; 389 return (0); 390 } 391 392 static int 393 uipc_shutdown(struct socket *so) 394 { 395 struct unpcb *unp = sotounpcb(so); 396 397 if (unp == 0) 398 return EINVAL; 399 socantsendmore(so); 400 unp_shutdown(unp); 401 return 0; 402 } 403 404 static int 405 uipc_sockaddr(struct socket *so, struct mbuf *nam) 406 { 407 struct unpcb *unp = sotounpcb(so); 408 409 if (unp == 0) 410 return EINVAL; 411 if (unp->unp_addr) { 412 nam->m_len = unp->unp_addr->m_len; 413 bcopy(mtod(unp->unp_addr, caddr_t), 414 mtod(nam, caddr_t), (unsigned)nam->m_len); 415 } else 416 nam->m_len = 0; 417 return 0; 418 } 419 420 struct pr_usrreqs uipc_usrreqs = { 421 uipc_abort, uipc_accept, uipc_attach, uipc_bind, uipc_connect, 422 uipc_connect2, pru_control_notsupp, uipc_detach, uipc_disconnect, 423 uipc_listen, uipc_peeraddr, uipc_rcvd, pru_rcvoob_notsupp, 424 uipc_send, uipc_sense, uipc_shutdown, uipc_sockaddr, 425 sosend, soreceive, soselect 426 }; 427 428 /* 429 * Both send and receive buffers are allocated PIPSIZ bytes of buffering 430 * for stream sockets, although the total for sender and receiver is 431 * actually only PIPSIZ. 432 * Datagram sockets really use the sendspace as the maximum datagram size, 433 * and don't really want to reserve the sendspace. Their recvspace should 434 * be large enough for at least one max-size datagram plus address. 435 */ 436 #ifndef PIPSIZ 437 #define PIPSIZ 8192 438 #endif 439 static u_long unpst_sendspace = PIPSIZ; 440 static u_long unpst_recvspace = PIPSIZ; 441 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 442 static u_long unpdg_recvspace = 4*1024; 443 444 static int unp_rights; /* file descriptors in flight */ 445 446 SYSCTL_INT(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, 447 &unpst_sendspace, 0, ""); 448 SYSCTL_INT(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, 449 &unpst_recvspace, 0, ""); 450 SYSCTL_INT(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, 451 &unpdg_sendspace, 0, ""); 452 SYSCTL_INT(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, 453 &unpdg_recvspace, 0, ""); 454 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, ""); 455 456 static int 457 unp_attach(so) 458 struct socket *so; 459 { 460 register struct mbuf *m; 461 register struct unpcb *unp; 462 int error; 463 464 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 465 switch (so->so_type) { 466 467 case SOCK_STREAM: 468 error = soreserve(so, unpst_sendspace, unpst_recvspace); 469 break; 470 471 case SOCK_DGRAM: 472 error = soreserve(so, unpdg_sendspace, unpdg_recvspace); 473 break; 474 475 default: 476 panic("unp_attach"); 477 } 478 if (error) 479 return (error); 480 } 481 m = m_getclr(M_DONTWAIT, MT_PCB); 482 if (m == NULL) 483 return (ENOBUFS); 484 unp = mtod(m, struct unpcb *); 485 so->so_pcb = (caddr_t)unp; 486 unp->unp_socket = so; 487 return (0); 488 } 489 490 static void 491 unp_detach(unp) 492 register struct unpcb *unp; 493 { 494 495 if (unp->unp_vnode) { 496 unp->unp_vnode->v_socket = 0; 497 vrele(unp->unp_vnode); 498 unp->unp_vnode = 0; 499 } 500 if (unp->unp_conn) 501 unp_disconnect(unp); 502 while (unp->unp_refs) 503 unp_drop(unp->unp_refs, ECONNRESET); 504 soisdisconnected(unp->unp_socket); 505 unp->unp_socket->so_pcb = 0; 506 if (unp_rights) { 507 /* 508 * Normally the receive buffer is flushed later, 509 * in sofree, but if our receive buffer holds references 510 * to descriptors that are now garbage, we will dispose 511 * of those descriptor references after the garbage collector 512 * gets them (resulting in a "panic: closef: count < 0"). 513 */ 514 sorflush(unp->unp_socket); 515 unp_gc(); 516 } 517 m_freem(unp->unp_addr); 518 (void) m_free(dtom(unp)); 519 } 520 521 static int 522 unp_bind(unp, nam, p) 523 struct unpcb *unp; 524 struct mbuf *nam; 525 struct proc *p; 526 { 527 struct sockaddr_un *soun = mtod(nam, struct sockaddr_un *); 528 register struct vnode *vp; 529 struct vattr vattr; 530 int error; 531 struct nameidata nd; 532 533 NDINIT(&nd, CREATE, FOLLOW | LOCKPARENT, UIO_SYSSPACE, 534 soun->sun_path, p); 535 if (unp->unp_vnode != NULL) 536 return (EINVAL); 537 if (nam->m_len == MLEN) { 538 if (*(mtod(nam, caddr_t) + nam->m_len - 1) != 0) 539 return (EINVAL); 540 } else 541 *(mtod(nam, caddr_t) + nam->m_len) = 0; 542 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 543 error = namei(&nd); 544 if (error) 545 return (error); 546 vp = nd.ni_vp; 547 if (vp != NULL) { 548 VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd); 549 if (nd.ni_dvp == vp) 550 vrele(nd.ni_dvp); 551 else 552 vput(nd.ni_dvp); 553 vrele(vp); 554 return (EADDRINUSE); 555 } 556 VATTR_NULL(&vattr); 557 vattr.va_type = VSOCK; 558 vattr.va_mode = (ACCESSPERMS & ~p->p_fd->fd_cmask); 559 VOP_LEASE(nd.ni_dvp, p, p->p_ucred, LEASE_WRITE); 560 if (error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr)) 561 return (error); 562 vp = nd.ni_vp; 563 vp->v_socket = unp->unp_socket; 564 unp->unp_vnode = vp; 565 unp->unp_addr = m_copy(nam, 0, (int)M_COPYALL); 566 VOP_UNLOCK(vp, 0, p); 567 return (0); 568 } 569 570 static int 571 unp_connect(so, nam, p) 572 struct socket *so; 573 struct mbuf *nam; 574 struct proc *p; 575 { 576 register struct sockaddr_un *soun = mtod(nam, struct sockaddr_un *); 577 register struct vnode *vp; 578 register struct socket *so2, *so3; 579 struct unpcb *unp2, *unp3; 580 int error; 581 struct nameidata nd; 582 583 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, soun->sun_path, p); 584 if (nam->m_data + nam->m_len == &nam->m_dat[MLEN]) { /* XXX */ 585 if (*(mtod(nam, caddr_t) + nam->m_len - 1) != 0) 586 return (EMSGSIZE); 587 } else 588 *(mtod(nam, caddr_t) + nam->m_len) = 0; 589 error = namei(&nd); 590 if (error) 591 return (error); 592 vp = nd.ni_vp; 593 if (vp->v_type != VSOCK) { 594 error = ENOTSOCK; 595 goto bad; 596 } 597 error = VOP_ACCESS(vp, VWRITE, p->p_ucred, p); 598 if (error) 599 goto bad; 600 so2 = vp->v_socket; 601 if (so2 == 0) { 602 error = ECONNREFUSED; 603 goto bad; 604 } 605 if (so->so_type != so2->so_type) { 606 error = EPROTOTYPE; 607 goto bad; 608 } 609 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 610 if ((so2->so_options & SO_ACCEPTCONN) == 0 || 611 (so3 = sonewconn(so2, 0)) == 0) { 612 error = ECONNREFUSED; 613 goto bad; 614 } 615 unp2 = sotounpcb(so2); 616 unp3 = sotounpcb(so3); 617 if (unp2->unp_addr) 618 unp3->unp_addr = 619 m_copy(unp2->unp_addr, 0, (int)M_COPYALL); 620 so2 = so3; 621 } 622 error = unp_connect2(so, so2); 623 bad: 624 vput(vp); 625 return (error); 626 } 627 628 int 629 unp_connect2(so, so2) 630 register struct socket *so; 631 register struct socket *so2; 632 { 633 register struct unpcb *unp = sotounpcb(so); 634 register struct unpcb *unp2; 635 636 if (so2->so_type != so->so_type) 637 return (EPROTOTYPE); 638 unp2 = sotounpcb(so2); 639 unp->unp_conn = unp2; 640 switch (so->so_type) { 641 642 case SOCK_DGRAM: 643 unp->unp_nextref = unp2->unp_refs; 644 unp2->unp_refs = unp; 645 soisconnected(so); 646 break; 647 648 case SOCK_STREAM: 649 unp2->unp_conn = unp; 650 soisconnected(so); 651 soisconnected(so2); 652 break; 653 654 default: 655 panic("unp_connect2"); 656 } 657 return (0); 658 } 659 660 static void 661 unp_disconnect(unp) 662 struct unpcb *unp; 663 { 664 register struct unpcb *unp2 = unp->unp_conn; 665 666 if (unp2 == 0) 667 return; 668 unp->unp_conn = 0; 669 switch (unp->unp_socket->so_type) { 670 671 case SOCK_DGRAM: 672 if (unp2->unp_refs == unp) 673 unp2->unp_refs = unp->unp_nextref; 674 else { 675 unp2 = unp2->unp_refs; 676 for (;;) { 677 if (unp2 == 0) 678 panic("unp_disconnect"); 679 if (unp2->unp_nextref == unp) 680 break; 681 unp2 = unp2->unp_nextref; 682 } 683 unp2->unp_nextref = unp->unp_nextref; 684 } 685 unp->unp_nextref = 0; 686 unp->unp_socket->so_state &= ~SS_ISCONNECTED; 687 break; 688 689 case SOCK_STREAM: 690 soisdisconnected(unp->unp_socket); 691 unp2->unp_conn = 0; 692 soisdisconnected(unp2->unp_socket); 693 break; 694 } 695 } 696 697 #ifdef notdef 698 void 699 unp_abort(unp) 700 struct unpcb *unp; 701 { 702 703 unp_detach(unp); 704 } 705 #endif 706 707 static void 708 unp_shutdown(unp) 709 struct unpcb *unp; 710 { 711 struct socket *so; 712 713 if (unp->unp_socket->so_type == SOCK_STREAM && unp->unp_conn && 714 (so = unp->unp_conn->unp_socket)) 715 socantrcvmore(so); 716 } 717 718 static void 719 unp_drop(unp, errno) 720 struct unpcb *unp; 721 int errno; 722 { 723 struct socket *so = unp->unp_socket; 724 725 so->so_error = errno; 726 unp_disconnect(unp); 727 if (so->so_head) { 728 so->so_pcb = (caddr_t) 0; 729 m_freem(unp->unp_addr); 730 (void) m_free(dtom(unp)); 731 sofree(so); 732 } 733 } 734 735 #ifdef notdef 736 void 737 unp_drain() 738 { 739 740 } 741 #endif 742 743 int 744 unp_externalize(rights) 745 struct mbuf *rights; 746 { 747 struct proc *p = curproc; /* XXX */ 748 register int i; 749 register struct cmsghdr *cm = mtod(rights, struct cmsghdr *); 750 register struct file **rp = (struct file **)(cm + 1); 751 register struct file *fp; 752 int newfds = (cm->cmsg_len - sizeof(*cm)) / sizeof (int); 753 int f; 754 755 /* 756 * if the new FD's will not fit, then we free them all 757 */ 758 if (!fdavail(p, newfds)) { 759 for (i = 0; i < newfds; i++) { 760 fp = *rp; 761 unp_discard(fp); 762 *rp++ = 0; 763 } 764 return (EMSGSIZE); 765 } 766 /* 767 * now change each pointer to an fd in the global table to 768 * an integer that is the index to the local fd table entry 769 * that we set up to point to the global one we are transferring. 770 * XXX this assumes a pointer and int are the same size...! 771 */ 772 for (i = 0; i < newfds; i++) { 773 if (fdalloc(p, 0, &f)) 774 panic("unp_externalize"); 775 fp = *rp; 776 p->p_fd->fd_ofiles[f] = fp; 777 fp->f_msgcount--; 778 unp_rights--; 779 *(int *)rp++ = f; 780 } 781 return (0); 782 } 783 784 #ifndef MIN 785 #define MIN(a,b) (((a)<(b))?(a):(b)) 786 #endif 787 788 static int 789 unp_internalize(control, p) 790 struct mbuf *control; 791 struct proc *p; 792 { 793 struct filedesc *fdp = p->p_fd; 794 register struct cmsghdr *cm = mtod(control, struct cmsghdr *); 795 register struct file **rp; 796 register struct file *fp; 797 register int i, fd; 798 register struct cmsgcred *cmcred; 799 int oldfds; 800 801 if ((cm->cmsg_type != SCM_RIGHTS && cm->cmsg_type != SCM_CREDS) || 802 cm->cmsg_level != SOL_SOCKET || cm->cmsg_len != control->m_len) 803 return (EINVAL); 804 805 /* 806 * Fill in credential information. 807 */ 808 if (cm->cmsg_type == SCM_CREDS) { 809 cmcred = (struct cmsgcred *)(cm + 1); 810 cmcred->cmcred_pid = p->p_pid; 811 cmcred->cmcred_uid = p->p_cred->p_ruid; 812 cmcred->cmcred_gid = p->p_cred->p_rgid; 813 cmcred->cmcred_euid = p->p_ucred->cr_uid; 814 cmcred->cmcred_ngroups = MIN(p->p_ucred->cr_ngroups, 815 CMGROUP_MAX); 816 for (i = 0; i < cmcred->cmcred_ngroups; i++) 817 cmcred->cmcred_groups[i] = p->p_ucred->cr_groups[i]; 818 return(0); 819 } 820 821 oldfds = (cm->cmsg_len - sizeof (*cm)) / sizeof (int); 822 /* 823 * check that all the FDs passed in refer to legal OPEN files 824 * If not, reject the entire operation. 825 */ 826 rp = (struct file **)(cm + 1); 827 for (i = 0; i < oldfds; i++) { 828 fd = *(int *)rp++; 829 if ((unsigned)fd >= fdp->fd_nfiles || 830 fdp->fd_ofiles[fd] == NULL) 831 return (EBADF); 832 } 833 /* 834 * Now replace the integer FDs with pointers to 835 * the associated global file table entry.. 836 * XXX this assumes a pointer and an int are the same size! 837 */ 838 rp = (struct file **)(cm + 1); 839 for (i = 0; i < oldfds; i++) { 840 fp = fdp->fd_ofiles[*(int *)rp]; 841 *rp++ = fp; 842 fp->f_count++; 843 fp->f_msgcount++; 844 unp_rights++; 845 } 846 return (0); 847 } 848 849 static int unp_defer, unp_gcing; 850 851 static void 852 unp_gc() 853 { 854 register struct file *fp, *nextfp; 855 register struct socket *so; 856 struct file **extra_ref, **fpp; 857 int nunref, i; 858 859 if (unp_gcing) 860 return; 861 unp_gcing = 1; 862 unp_defer = 0; 863 /* 864 * before going through all this, set all FDs to 865 * be NOT defered and NOT externally accessible 866 */ 867 for (fp = filehead.lh_first; fp != 0; fp = fp->f_list.le_next) 868 fp->f_flag &= ~(FMARK|FDEFER); 869 do { 870 for (fp = filehead.lh_first; fp != 0; fp = fp->f_list.le_next) { 871 /* 872 * If the file is not open, skip it 873 */ 874 if (fp->f_count == 0) 875 continue; 876 /* 877 * If we already marked it as 'defer' in a 878 * previous pass, then try process it this time 879 * and un-mark it 880 */ 881 if (fp->f_flag & FDEFER) { 882 fp->f_flag &= ~FDEFER; 883 unp_defer--; 884 } else { 885 /* 886 * if it's not defered, then check if it's 887 * already marked.. if so skip it 888 */ 889 if (fp->f_flag & FMARK) 890 continue; 891 /* 892 * If all references are from messages 893 * in transit, then skip it. it's not 894 * externally accessible. 895 */ 896 if (fp->f_count == fp->f_msgcount) 897 continue; 898 /* 899 * If it got this far then it must be 900 * externally accessible. 901 */ 902 fp->f_flag |= FMARK; 903 } 904 /* 905 * either it was defered, or it is externally 906 * accessible and not already marked so. 907 * Now check if it is possibly one of OUR sockets. 908 */ 909 if (fp->f_type != DTYPE_SOCKET || 910 (so = (struct socket *)fp->f_data) == 0) 911 continue; 912 if (so->so_proto->pr_domain != &localdomain || 913 (so->so_proto->pr_flags&PR_RIGHTS) == 0) 914 continue; 915 #ifdef notdef 916 if (so->so_rcv.sb_flags & SB_LOCK) { 917 /* 918 * This is problematical; it's not clear 919 * we need to wait for the sockbuf to be 920 * unlocked (on a uniprocessor, at least), 921 * and it's also not clear what to do 922 * if sbwait returns an error due to receipt 923 * of a signal. If sbwait does return 924 * an error, we'll go into an infinite 925 * loop. Delete all of this for now. 926 */ 927 (void) sbwait(&so->so_rcv); 928 goto restart; 929 } 930 #endif 931 /* 932 * So, Ok, it's one of our sockets and it IS externally 933 * accessible (or was defered). Now we look 934 * to see if we hold any file descriptors in it's 935 * message buffers. Follow those links and mark them 936 * as accessible too. 937 */ 938 unp_scan(so->so_rcv.sb_mb, unp_mark); 939 } 940 } while (unp_defer); 941 /* 942 * We grab an extra reference to each of the file table entries 943 * that are not otherwise accessible and then free the rights 944 * that are stored in messages on them. 945 * 946 * The bug in the orginal code is a little tricky, so I'll describe 947 * what's wrong with it here. 948 * 949 * It is incorrect to simply unp_discard each entry for f_msgcount 950 * times -- consider the case of sockets A and B that contain 951 * references to each other. On a last close of some other socket, 952 * we trigger a gc since the number of outstanding rights (unp_rights) 953 * is non-zero. If during the sweep phase the gc code un_discards, 954 * we end up doing a (full) closef on the descriptor. A closef on A 955 * results in the following chain. Closef calls soo_close, which 956 * calls soclose. Soclose calls first (through the switch 957 * uipc_usrreq) unp_detach, which re-invokes unp_gc. Unp_gc simply 958 * returns because the previous instance had set unp_gcing, and 959 * we return all the way back to soclose, which marks the socket 960 * with SS_NOFDREF, and then calls sofree. Sofree calls sorflush 961 * to free up the rights that are queued in messages on the socket A, 962 * i.e., the reference on B. The sorflush calls via the dom_dispose 963 * switch unp_dispose, which unp_scans with unp_discard. This second 964 * instance of unp_discard just calls closef on B. 965 * 966 * Well, a similar chain occurs on B, resulting in a sorflush on B, 967 * which results in another closef on A. Unfortunately, A is already 968 * being closed, and the descriptor has already been marked with 969 * SS_NOFDREF, and soclose panics at this point. 970 * 971 * Here, we first take an extra reference to each inaccessible 972 * descriptor. Then, we call sorflush ourself, since we know 973 * it is a Unix domain socket anyhow. After we destroy all the 974 * rights carried in messages, we do a last closef to get rid 975 * of our extra reference. This is the last close, and the 976 * unp_detach etc will shut down the socket. 977 * 978 * 91/09/19, bsy@cs.cmu.edu 979 */ 980 extra_ref = malloc(nfiles * sizeof(struct file *), M_FILE, M_WAITOK); 981 for (nunref = 0, fp = filehead.lh_first, fpp = extra_ref; fp != 0; 982 fp = nextfp) { 983 nextfp = fp->f_list.le_next; 984 /* 985 * If it's not open, skip it 986 */ 987 if (fp->f_count == 0) 988 continue; 989 /* 990 * If all refs are from msgs, and it's not marked accessible 991 * then it must be referenced from some unreachable cycle 992 * of (shut-down) FDs, so include it in our 993 * list of FDs to remove 994 */ 995 if (fp->f_count == fp->f_msgcount && !(fp->f_flag & FMARK)) { 996 *fpp++ = fp; 997 nunref++; 998 fp->f_count++; 999 } 1000 } 1001 /* 1002 * for each FD on our hit list, do the following two things 1003 */ 1004 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) 1005 sorflush((struct socket *)(*fpp)->f_data); 1006 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) 1007 closef(*fpp, (struct proc *) NULL); 1008 free((caddr_t)extra_ref, M_FILE); 1009 unp_gcing = 0; 1010 } 1011 1012 void 1013 unp_dispose(m) 1014 struct mbuf *m; 1015 { 1016 1017 if (m) 1018 unp_scan(m, unp_discard); 1019 } 1020 1021 static void 1022 unp_scan(m0, op) 1023 register struct mbuf *m0; 1024 void (*op) __P((struct file *)); 1025 { 1026 register struct mbuf *m; 1027 register struct file **rp; 1028 register struct cmsghdr *cm; 1029 register int i; 1030 int qfds; 1031 1032 while (m0) { 1033 for (m = m0; m; m = m->m_next) 1034 if (m->m_type == MT_CONTROL && 1035 m->m_len >= sizeof(*cm)) { 1036 cm = mtod(m, struct cmsghdr *); 1037 if (cm->cmsg_level != SOL_SOCKET || 1038 cm->cmsg_type != SCM_RIGHTS) 1039 continue; 1040 qfds = (cm->cmsg_len - sizeof *cm) 1041 / sizeof (struct file *); 1042 rp = (struct file **)(cm + 1); 1043 for (i = 0; i < qfds; i++) 1044 (*op)(*rp++); 1045 break; /* XXX, but saves time */ 1046 } 1047 m0 = m0->m_act; 1048 } 1049 } 1050 1051 static void 1052 unp_mark(fp) 1053 struct file *fp; 1054 { 1055 1056 if (fp->f_flag & FMARK) 1057 return; 1058 unp_defer++; 1059 fp->f_flag |= (FMARK|FDEFER); 1060 } 1061 1062 static void 1063 unp_discard(fp) 1064 struct file *fp; 1065 { 1066 1067 fp->f_msgcount--; 1068 unp_rights--; 1069 (void) closef(fp, (struct proc *)NULL); 1070 } 1071