uipc_usrreq.c revision 65198
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 * $FreeBSD: head/sys/kern/uipc_usrreq.c 65198 2000-08-29 11:28:06Z green $ 35 */ 36 37#include <sys/param.h> 38#include <sys/systm.h> 39#include <sys/kernel.h> 40#include <sys/domain.h> 41#include <sys/fcntl.h> 42#include <sys/malloc.h> /* XXX must be before <sys/file.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/resourcevar.h> 52#include <sys/stat.h> 53#include <sys/sysctl.h> 54#include <sys/un.h> 55#include <sys/unpcb.h> 56#include <sys/vnode.h> 57 58#include <vm/vm_zone.h> 59 60static struct vm_zone *unp_zone; 61static unp_gen_t unp_gencnt; 62static u_int unp_count; 63 64static struct unp_head unp_shead, unp_dhead; 65 66/* 67 * Unix communications domain. 68 * 69 * TODO: 70 * SEQPACKET, RDM 71 * rethink name space problems 72 * need a proper out-of-band 73 * lock pushdown 74 */ 75static struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; 76static ino_t unp_ino; /* prototype for fake inode numbers */ 77 78static int unp_attach __P((struct socket *)); 79static void unp_detach __P((struct unpcb *)); 80static int unp_bind __P((struct unpcb *,struct sockaddr *, struct proc *)); 81static int unp_connect __P((struct socket *,struct sockaddr *, 82 struct proc *)); 83static void unp_disconnect __P((struct unpcb *)); 84static void unp_shutdown __P((struct unpcb *)); 85static void unp_drop __P((struct unpcb *, int)); 86static void unp_gc __P((void)); 87static void unp_scan __P((struct mbuf *, void (*)(struct file *))); 88static void unp_mark __P((struct file *)); 89static void unp_discard __P((struct file *)); 90static int unp_internalize __P((struct mbuf *, struct proc *)); 91 92static int 93uipc_abort(struct socket *so) 94{ 95 struct unpcb *unp = sotounpcb(so); 96 97 if (unp == 0) 98 return EINVAL; 99 unp_drop(unp, ECONNABORTED); 100 return 0; 101} 102 103static int 104uipc_accept(struct socket *so, struct sockaddr **nam) 105{ 106 struct unpcb *unp = sotounpcb(so); 107 108 if (unp == 0) 109 return EINVAL; 110 111 /* 112 * Pass back name of connected socket, 113 * if it was bound and we are still connected 114 * (our peer may have closed already!). 115 */ 116 if (unp->unp_conn && unp->unp_conn->unp_addr) { 117 *nam = dup_sockaddr((struct sockaddr *)unp->unp_conn->unp_addr, 118 1); 119 } else { 120 *nam = dup_sockaddr((struct sockaddr *)&sun_noname, 1); 121 } 122 return 0; 123} 124 125static int 126uipc_attach(struct socket *so, int proto, struct proc *p) 127{ 128 struct unpcb *unp = sotounpcb(so); 129 130 if (unp != 0) 131 return EISCONN; 132 return unp_attach(so); 133} 134 135static int 136uipc_bind(struct socket *so, struct sockaddr *nam, struct proc *p) 137{ 138 struct unpcb *unp = sotounpcb(so); 139 140 if (unp == 0) 141 return EINVAL; 142 143 return unp_bind(unp, nam, p); 144} 145 146static int 147uipc_connect(struct socket *so, struct sockaddr *nam, struct proc *p) 148{ 149 struct unpcb *unp = sotounpcb(so); 150 151 if (unp == 0) 152 return EINVAL; 153 return unp_connect(so, nam, curproc); 154} 155 156static int 157uipc_connect2(struct socket *so1, struct socket *so2) 158{ 159 struct unpcb *unp = sotounpcb(so1); 160 161 if (unp == 0) 162 return EINVAL; 163 164 return unp_connect2(so1, so2); 165} 166 167/* control is EOPNOTSUPP */ 168 169static int 170uipc_detach(struct socket *so) 171{ 172 struct unpcb *unp = sotounpcb(so); 173 174 if (unp == 0) 175 return EINVAL; 176 177 unp_detach(unp); 178 return 0; 179} 180 181static int 182uipc_disconnect(struct socket *so) 183{ 184 struct unpcb *unp = sotounpcb(so); 185 186 if (unp == 0) 187 return EINVAL; 188 unp_disconnect(unp); 189 return 0; 190} 191 192static int 193uipc_listen(struct socket *so, struct proc *p) 194{ 195 struct unpcb *unp = sotounpcb(so); 196 197 if (unp == 0 || unp->unp_vnode == 0) 198 return EINVAL; 199 return 0; 200} 201 202static int 203uipc_peeraddr(struct socket *so, struct sockaddr **nam) 204{ 205 struct unpcb *unp = sotounpcb(so); 206 207 if (unp == 0) 208 return EINVAL; 209 if (unp->unp_conn && unp->unp_conn->unp_addr) 210 *nam = dup_sockaddr((struct sockaddr *)unp->unp_conn->unp_addr, 211 1); 212 return 0; 213} 214 215static int 216uipc_rcvd(struct socket *so, int flags) 217{ 218 struct unpcb *unp = sotounpcb(so); 219 struct socket *so2; 220 u_long newhiwat; 221 222 if (unp == 0) 223 return EINVAL; 224 switch (so->so_type) { 225 case SOCK_DGRAM: 226 panic("uipc_rcvd DGRAM?"); 227 /*NOTREACHED*/ 228 229 case SOCK_STREAM: 230 if (unp->unp_conn == 0) 231 break; 232 so2 = unp->unp_conn->unp_socket; 233 /* 234 * Adjust backpressure on sender 235 * and wakeup any waiting to write. 236 */ 237 so2->so_snd.sb_mbmax += unp->unp_mbcnt - so->so_rcv.sb_mbcnt; 238 unp->unp_mbcnt = so->so_rcv.sb_mbcnt; 239 newhiwat = so2->so_snd.sb_hiwat + unp->unp_cc - 240 so->so_rcv.sb_cc; 241 (void)chgsbsize(so2->so_cred->cr_uid, &so2->so_snd.sb_hiwat, 242 newhiwat, RLIM_INFINITY); 243 unp->unp_cc = so->so_rcv.sb_cc; 244 sowwakeup(so2); 245 break; 246 247 default: 248 panic("uipc_rcvd unknown socktype"); 249 } 250 return 0; 251} 252 253/* pru_rcvoob is EOPNOTSUPP */ 254 255static int 256uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 257 struct mbuf *control, struct proc *p) 258{ 259 int error = 0; 260 struct unpcb *unp = sotounpcb(so); 261 struct socket *so2; 262 u_long newhiwat; 263 264 if (unp == 0) { 265 error = EINVAL; 266 goto release; 267 } 268 if (flags & PRUS_OOB) { 269 error = EOPNOTSUPP; 270 goto release; 271 } 272 273 if (control && (error = unp_internalize(control, p))) 274 goto release; 275 276 switch (so->so_type) { 277 case SOCK_DGRAM: 278 { 279 struct sockaddr *from; 280 281 if (nam) { 282 if (unp->unp_conn) { 283 error = EISCONN; 284 break; 285 } 286 error = unp_connect(so, nam, p); 287 if (error) 288 break; 289 } else { 290 if (unp->unp_conn == 0) { 291 error = ENOTCONN; 292 break; 293 } 294 } 295 so2 = unp->unp_conn->unp_socket; 296 if (unp->unp_addr) 297 from = (struct sockaddr *)unp->unp_addr; 298 else 299 from = &sun_noname; 300 if (sbappendaddr(&so2->so_rcv, from, m, control)) { 301 sorwakeup(so2); 302 m = 0; 303 control = 0; 304 } else 305 error = ENOBUFS; 306 if (nam) 307 unp_disconnect(unp); 308 break; 309 } 310 311 case SOCK_STREAM: 312 /* Connect if not connected yet. */ 313 /* 314 * Note: A better implementation would complain 315 * if not equal to the peer's address. 316 */ 317 if ((so->so_state & SS_ISCONNECTED) == 0) { 318 if (nam) { 319 error = unp_connect(so, nam, p); 320 if (error) 321 break; /* XXX */ 322 } else { 323 error = ENOTCONN; 324 break; 325 } 326 } 327 328 if (so->so_state & SS_CANTSENDMORE) { 329 error = EPIPE; 330 break; 331 } 332 if (unp->unp_conn == 0) 333 panic("uipc_send connected but no connection?"); 334 so2 = unp->unp_conn->unp_socket; 335 /* 336 * Send to paired receive port, and then reduce 337 * send buffer hiwater marks to maintain backpressure. 338 * Wake up readers. 339 */ 340 if (control) { 341 if (sbappendcontrol(&so2->so_rcv, m, control)) 342 control = 0; 343 } else 344 sbappend(&so2->so_rcv, m); 345 so->so_snd.sb_mbmax -= 346 so2->so_rcv.sb_mbcnt - unp->unp_conn->unp_mbcnt; 347 unp->unp_conn->unp_mbcnt = so2->so_rcv.sb_mbcnt; 348 newhiwat = so->so_snd.sb_hiwat - 349 (so2->so_rcv.sb_cc - unp->unp_conn->unp_cc); 350 (void)chgsbsize(so->so_cred->cr_uid, &so->so_snd.sb_hiwat, 351 newhiwat, RLIM_INFINITY); 352 unp->unp_conn->unp_cc = so2->so_rcv.sb_cc; 353 sorwakeup(so2); 354 m = 0; 355 break; 356 357 default: 358 panic("uipc_send unknown socktype"); 359 } 360 361 /* 362 * SEND_EOF is equivalent to a SEND followed by 363 * a SHUTDOWN. 364 */ 365 if (flags & PRUS_EOF) { 366 socantsendmore(so); 367 unp_shutdown(unp); 368 } 369 370 if (control && error != 0) 371 unp_dispose(control); 372 373release: 374 if (control) 375 m_freem(control); 376 if (m) 377 m_freem(m); 378 return error; 379} 380 381static int 382uipc_sense(struct socket *so, struct stat *sb) 383{ 384 struct unpcb *unp = sotounpcb(so); 385 struct socket *so2; 386 387 if (unp == 0) 388 return EINVAL; 389 sb->st_blksize = so->so_snd.sb_hiwat; 390 if (so->so_type == SOCK_STREAM && unp->unp_conn != 0) { 391 so2 = unp->unp_conn->unp_socket; 392 sb->st_blksize += so2->so_rcv.sb_cc; 393 } 394 sb->st_dev = NOUDEV; 395 if (unp->unp_ino == 0) 396 unp->unp_ino = unp_ino++; 397 sb->st_ino = unp->unp_ino; 398 return (0); 399} 400 401static int 402uipc_shutdown(struct socket *so) 403{ 404 struct unpcb *unp = sotounpcb(so); 405 406 if (unp == 0) 407 return EINVAL; 408 socantsendmore(so); 409 unp_shutdown(unp); 410 return 0; 411} 412 413static int 414uipc_sockaddr(struct socket *so, struct sockaddr **nam) 415{ 416 struct unpcb *unp = sotounpcb(so); 417 418 if (unp == 0) 419 return EINVAL; 420 if (unp->unp_addr) 421 *nam = dup_sockaddr((struct sockaddr *)unp->unp_addr, 1); 422 return 0; 423} 424 425struct pr_usrreqs uipc_usrreqs = { 426 uipc_abort, uipc_accept, uipc_attach, uipc_bind, uipc_connect, 427 uipc_connect2, pru_control_notsupp, uipc_detach, uipc_disconnect, 428 uipc_listen, uipc_peeraddr, uipc_rcvd, pru_rcvoob_notsupp, 429 uipc_send, uipc_sense, uipc_shutdown, uipc_sockaddr, 430 sosend, soreceive, sopoll 431}; 432 433/* 434 * Both send and receive buffers are allocated PIPSIZ bytes of buffering 435 * for stream sockets, although the total for sender and receiver is 436 * actually only PIPSIZ. 437 * Datagram sockets really use the sendspace as the maximum datagram size, 438 * and don't really want to reserve the sendspace. Their recvspace should 439 * be large enough for at least one max-size datagram plus address. 440 */ 441#ifndef PIPSIZ 442#define PIPSIZ 8192 443#endif 444static u_long unpst_sendspace = PIPSIZ; 445static u_long unpst_recvspace = PIPSIZ; 446static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 447static u_long unpdg_recvspace = 4*1024; 448 449static int unp_rights; /* file descriptors in flight */ 450 451SYSCTL_DECL(_net_local_stream); 452SYSCTL_INT(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, 453 &unpst_sendspace, 0, ""); 454SYSCTL_INT(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, 455 &unpst_recvspace, 0, ""); 456SYSCTL_DECL(_net_local_dgram); 457SYSCTL_INT(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, 458 &unpdg_sendspace, 0, ""); 459SYSCTL_INT(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, 460 &unpdg_recvspace, 0, ""); 461SYSCTL_DECL(_net_local); 462SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, ""); 463 464static int 465unp_attach(so) 466 struct socket *so; 467{ 468 register struct unpcb *unp; 469 int error; 470 471 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 472 switch (so->so_type) { 473 474 case SOCK_STREAM: 475 error = soreserve(so, unpst_sendspace, unpst_recvspace); 476 break; 477 478 case SOCK_DGRAM: 479 error = soreserve(so, unpdg_sendspace, unpdg_recvspace); 480 break; 481 482 default: 483 panic("unp_attach"); 484 } 485 if (error) 486 return (error); 487 } 488 unp = zalloc(unp_zone); 489 if (unp == NULL) 490 return (ENOBUFS); 491 bzero(unp, sizeof *unp); 492 unp->unp_gencnt = ++unp_gencnt; 493 unp_count++; 494 LIST_INIT(&unp->unp_refs); 495 unp->unp_socket = so; 496 unp->unp_rvnode = curproc->p_fd->fd_rdir; 497 LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead 498 : &unp_shead, unp, unp_link); 499 so->so_pcb = (caddr_t)unp; 500 return (0); 501} 502 503static void 504unp_detach(unp) 505 register struct unpcb *unp; 506{ 507 LIST_REMOVE(unp, unp_link); 508 unp->unp_gencnt = ++unp_gencnt; 509 --unp_count; 510 if (unp->unp_vnode) { 511 unp->unp_vnode->v_socket = 0; 512 vrele(unp->unp_vnode); 513 unp->unp_vnode = 0; 514 } 515 if (unp->unp_conn) 516 unp_disconnect(unp); 517 while (!LIST_EMPTY(&unp->unp_refs)) 518 unp_drop(LIST_FIRST(&unp->unp_refs), ECONNRESET); 519 soisdisconnected(unp->unp_socket); 520 unp->unp_socket->so_pcb = 0; 521 if (unp_rights) { 522 /* 523 * Normally the receive buffer is flushed later, 524 * in sofree, but if our receive buffer holds references 525 * to descriptors that are now garbage, we will dispose 526 * of those descriptor references after the garbage collector 527 * gets them (resulting in a "panic: closef: count < 0"). 528 */ 529 sorflush(unp->unp_socket); 530 unp_gc(); 531 } 532 if (unp->unp_addr) 533 FREE(unp->unp_addr, M_SONAME); 534 zfree(unp_zone, unp); 535} 536 537static int 538unp_bind(unp, nam, p) 539 struct unpcb *unp; 540 struct sockaddr *nam; 541 struct proc *p; 542{ 543 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 544 struct vnode *vp; 545 struct mount *mp; 546 struct vattr vattr; 547 int error, namelen; 548 struct nameidata nd; 549 char buf[SOCK_MAXADDRLEN]; 550 551 if (unp->unp_vnode != NULL) 552 return (EINVAL); 553#define offsetof(s, e) ((char *)&((s *)0)->e - (char *)((s *)0)) 554 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 555 if (namelen <= 0) 556 return EINVAL; 557 strncpy(buf, soun->sun_path, namelen); 558 buf[namelen] = 0; /* null-terminate the string */ 559restart: 560 NDINIT(&nd, CREATE, NOFOLLOW | LOCKPARENT, UIO_SYSSPACE, 561 buf, p); 562/* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 563 error = namei(&nd); 564 if (error) 565 return (error); 566 vp = nd.ni_vp; 567 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 568 NDFREE(&nd, NDF_ONLY_PNBUF); 569 if (nd.ni_dvp == vp) 570 vrele(nd.ni_dvp); 571 else 572 vput(nd.ni_dvp); 573 if (vp != NULL) { 574 vrele(vp); 575 return (EADDRINUSE); 576 } 577 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 578 return (error); 579 goto restart; 580 } 581 VATTR_NULL(&vattr); 582 vattr.va_type = VSOCK; 583 vattr.va_mode = (ACCESSPERMS & ~p->p_fd->fd_cmask); 584 VOP_LEASE(nd.ni_dvp, p, p->p_ucred, LEASE_WRITE); 585 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 586 NDFREE(&nd, NDF_ONLY_PNBUF); 587 vput(nd.ni_dvp); 588 if (error) 589 return (error); 590 vp = nd.ni_vp; 591 vp->v_socket = unp->unp_socket; 592 unp->unp_vnode = vp; 593 unp->unp_addr = (struct sockaddr_un *)dup_sockaddr(nam, 1); 594 VOP_UNLOCK(vp, 0, p); 595 vn_finished_write(mp); 596 return (0); 597} 598 599static int 600unp_connect(so, nam, p) 601 struct socket *so; 602 struct sockaddr *nam; 603 struct proc *p; 604{ 605 register struct sockaddr_un *soun = (struct sockaddr_un *)nam; 606 register struct vnode *vp; 607 register struct socket *so2, *so3; 608 struct unpcb *unp2, *unp3; 609 int error, len; 610 struct nameidata nd; 611 char buf[SOCK_MAXADDRLEN]; 612 613 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 614 if (len <= 0) 615 return EINVAL; 616 strncpy(buf, soun->sun_path, len); 617 buf[len] = 0; 618 619 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, buf, p); 620 error = namei(&nd); 621 if (error) 622 return (error); 623 vp = nd.ni_vp; 624 NDFREE(&nd, NDF_ONLY_PNBUF); 625 if (vp->v_type != VSOCK) { 626 error = ENOTSOCK; 627 goto bad; 628 } 629 error = VOP_ACCESS(vp, VWRITE, p->p_ucred, p); 630 if (error) 631 goto bad; 632 so2 = vp->v_socket; 633 if (so2 == 0) { 634 error = ECONNREFUSED; 635 goto bad; 636 } 637 if (so->so_type != so2->so_type) { 638 error = EPROTOTYPE; 639 goto bad; 640 } 641 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 642 if ((so2->so_options & SO_ACCEPTCONN) == 0 || 643 (so3 = sonewconn3(so2, 0, p)) == 0) { 644 error = ECONNREFUSED; 645 goto bad; 646 } 647 unp2 = sotounpcb(so2); 648 unp3 = sotounpcb(so3); 649 if (unp2->unp_addr) 650 unp3->unp_addr = (struct sockaddr_un *) 651 dup_sockaddr((struct sockaddr *) 652 unp2->unp_addr, 1); 653 so2 = so3; 654 } 655 error = unp_connect2(so, so2); 656bad: 657 vput(vp); 658 return (error); 659} 660 661int 662unp_connect2(so, so2) 663 register struct socket *so; 664 register struct socket *so2; 665{ 666 register struct unpcb *unp = sotounpcb(so); 667 register struct unpcb *unp2; 668 669 if (so2->so_type != so->so_type) 670 return (EPROTOTYPE); 671 unp2 = sotounpcb(so2); 672 unp->unp_conn = unp2; 673 switch (so->so_type) { 674 675 case SOCK_DGRAM: 676 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 677 soisconnected(so); 678 break; 679 680 case SOCK_STREAM: 681 unp2->unp_conn = unp; 682 soisconnected(so); 683 soisconnected(so2); 684 break; 685 686 default: 687 panic("unp_connect2"); 688 } 689 return (0); 690} 691 692static void 693unp_disconnect(unp) 694 struct unpcb *unp; 695{ 696 register struct unpcb *unp2 = unp->unp_conn; 697 698 if (unp2 == 0) 699 return; 700 unp->unp_conn = 0; 701 switch (unp->unp_socket->so_type) { 702 703 case SOCK_DGRAM: 704 LIST_REMOVE(unp, unp_reflink); 705 unp->unp_socket->so_state &= ~SS_ISCONNECTED; 706 break; 707 708 case SOCK_STREAM: 709 soisdisconnected(unp->unp_socket); 710 unp2->unp_conn = 0; 711 soisdisconnected(unp2->unp_socket); 712 break; 713 } 714} 715 716#ifdef notdef 717void 718unp_abort(unp) 719 struct unpcb *unp; 720{ 721 722 unp_detach(unp); 723} 724#endif 725 726static int 727prison_unpcb(struct proc *p, struct unpcb *unp) 728{ 729 if (!p->p_prison) 730 return (0); 731 if (p->p_fd->fd_rdir == unp->unp_rvnode) 732 return (0); 733 return (1); 734} 735 736static int 737unp_pcblist(SYSCTL_HANDLER_ARGS) 738{ 739 int error, i, n; 740 struct unpcb *unp, **unp_list; 741 unp_gen_t gencnt; 742 struct xunpgen xug; 743 struct unp_head *head; 744 745 head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead); 746 747 /* 748 * The process of preparing the PCB list is too time-consuming and 749 * resource-intensive to repeat twice on every request. 750 */ 751 if (req->oldptr == 0) { 752 n = unp_count; 753 req->oldidx = 2 * (sizeof xug) 754 + (n + n/8) * sizeof(struct xunpcb); 755 return 0; 756 } 757 758 if (req->newptr != 0) 759 return EPERM; 760 761 /* 762 * OK, now we're committed to doing something. 763 */ 764 gencnt = unp_gencnt; 765 n = unp_count; 766 767 xug.xug_len = sizeof xug; 768 xug.xug_count = n; 769 xug.xug_gen = gencnt; 770 xug.xug_sogen = so_gencnt; 771 error = SYSCTL_OUT(req, &xug, sizeof xug); 772 if (error) 773 return error; 774 775 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 776 if (unp_list == 0) 777 return ENOMEM; 778 779 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 780 unp = LIST_NEXT(unp, unp_link)) { 781 if (unp->unp_gencnt <= gencnt && !prison_unpcb(req->p, unp)) 782 unp_list[i++] = unp; 783 } 784 n = i; /* in case we lost some during malloc */ 785 786 error = 0; 787 for (i = 0; i < n; i++) { 788 unp = unp_list[i]; 789 if (unp->unp_gencnt <= gencnt) { 790 struct xunpcb xu; 791 xu.xu_len = sizeof xu; 792 xu.xu_unpp = unp; 793 /* 794 * XXX - need more locking here to protect against 795 * connect/disconnect races for SMP. 796 */ 797 if (unp->unp_addr) 798 bcopy(unp->unp_addr, &xu.xu_addr, 799 unp->unp_addr->sun_len); 800 if (unp->unp_conn && unp->unp_conn->unp_addr) 801 bcopy(unp->unp_conn->unp_addr, 802 &xu.xu_caddr, 803 unp->unp_conn->unp_addr->sun_len); 804 bcopy(unp, &xu.xu_unp, sizeof *unp); 805 sotoxsocket(unp->unp_socket, &xu.xu_socket); 806 error = SYSCTL_OUT(req, &xu, sizeof xu); 807 } 808 } 809 if (!error) { 810 /* 811 * Give the user an updated idea of our state. 812 * If the generation differs from what we told 813 * her before, she knows that something happened 814 * while we were processing this request, and it 815 * might be necessary to retry. 816 */ 817 xug.xug_gen = unp_gencnt; 818 xug.xug_sogen = so_gencnt; 819 xug.xug_count = unp_count; 820 error = SYSCTL_OUT(req, &xug, sizeof xug); 821 } 822 free(unp_list, M_TEMP); 823 return error; 824} 825 826SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD, 827 (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 828 "List of active local datagram sockets"); 829SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD, 830 (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 831 "List of active local stream sockets"); 832 833static void 834unp_shutdown(unp) 835 struct unpcb *unp; 836{ 837 struct socket *so; 838 839 if (unp->unp_socket->so_type == SOCK_STREAM && unp->unp_conn && 840 (so = unp->unp_conn->unp_socket)) 841 socantrcvmore(so); 842} 843 844static void 845unp_drop(unp, errno) 846 struct unpcb *unp; 847 int errno; 848{ 849 struct socket *so = unp->unp_socket; 850 851 so->so_error = errno; 852 unp_disconnect(unp); 853 if (so->so_head) { 854 LIST_REMOVE(unp, unp_link); 855 unp->unp_gencnt = ++unp_gencnt; 856 unp_count--; 857 so->so_pcb = (caddr_t) 0; 858 if (unp->unp_addr) 859 FREE(unp->unp_addr, M_SONAME); 860 zfree(unp_zone, unp); 861 sofree(so); 862 } 863} 864 865#ifdef notdef 866void 867unp_drain() 868{ 869 870} 871#endif 872 873int 874unp_externalize(rights) 875 struct mbuf *rights; 876{ 877 struct proc *p = curproc; /* XXX */ 878 register int i; 879 register struct cmsghdr *cm = mtod(rights, struct cmsghdr *); 880 register int *fdp; 881 register struct file **rp; 882 register struct file *fp; 883 int newfds = (cm->cmsg_len - (CMSG_DATA(cm) - (u_char *)cm)) 884 / sizeof (struct file *); 885 int f; 886 887 /* 888 * if the new FD's will not fit, then we free them all 889 */ 890 if (!fdavail(p, newfds)) { 891 rp = (struct file **)CMSG_DATA(cm); 892 for (i = 0; i < newfds; i++) { 893 fp = *rp; 894 /* 895 * zero the pointer before calling unp_discard, 896 * since it may end up in unp_gc().. 897 */ 898 *rp++ = 0; 899 unp_discard(fp); 900 } 901 return (EMSGSIZE); 902 } 903 /* 904 * now change each pointer to an fd in the global table to 905 * an integer that is the index to the local fd table entry 906 * that we set up to point to the global one we are transferring. 907 * If sizeof (struct file *) is bigger than or equal to sizeof int, 908 * then do it in forward order. In that case, an integer will 909 * always come in the same place or before its corresponding 910 * struct file pointer. 911 * If sizeof (struct file *) is smaller than sizeof int, then 912 * do it in reverse order. 913 */ 914 if (sizeof (struct file *) >= sizeof (int)) { 915 fdp = (int *)(cm + 1); 916 rp = (struct file **)CMSG_DATA(cm); 917 for (i = 0; i < newfds; i++) { 918 if (fdalloc(p, 0, &f)) 919 panic("unp_externalize"); 920 fp = *rp++; 921 p->p_fd->fd_ofiles[f] = fp; 922 fp->f_msgcount--; 923 unp_rights--; 924 *fdp++ = f; 925 } 926 } else { 927 fdp = (int *)(cm + 1) + newfds - 1; 928 rp = (struct file **)CMSG_DATA(cm) + newfds - 1; 929 for (i = 0; i < newfds; i++) { 930 if (fdalloc(p, 0, &f)) 931 panic("unp_externalize"); 932 fp = *rp--; 933 p->p_fd->fd_ofiles[f] = fp; 934 fp->f_msgcount--; 935 unp_rights--; 936 *fdp-- = f; 937 } 938 } 939 940 /* 941 * Adjust length, in case sizeof(struct file *) and sizeof(int) 942 * differs. 943 */ 944 cm->cmsg_len = CMSG_LEN(newfds * sizeof(int)); 945 rights->m_len = cm->cmsg_len; 946 return (0); 947} 948 949void 950unp_init(void) 951{ 952 unp_zone = zinit("unpcb", sizeof(struct unpcb), nmbclusters, 0, 0); 953 if (unp_zone == 0) 954 panic("unp_init"); 955 LIST_INIT(&unp_dhead); 956 LIST_INIT(&unp_shead); 957} 958 959#ifndef MIN 960#define MIN(a,b) (((a)<(b))?(a):(b)) 961#endif 962 963static int 964unp_internalize(control, p) 965 struct mbuf *control; 966 struct proc *p; 967{ 968 struct filedesc *fdescp = p->p_fd; 969 register struct cmsghdr *cm = mtod(control, struct cmsghdr *); 970 register struct file **rp; 971 register struct file *fp; 972 register int i, fd, *fdp; 973 register struct cmsgcred *cmcred; 974 int oldfds; 975 u_int newlen; 976 977 if ((cm->cmsg_type != SCM_RIGHTS && cm->cmsg_type != SCM_CREDS) || 978 cm->cmsg_level != SOL_SOCKET || cm->cmsg_len != control->m_len) 979 return (EINVAL); 980 981 /* 982 * Fill in credential information. 983 */ 984 if (cm->cmsg_type == SCM_CREDS) { 985 cmcred = (struct cmsgcred *)(cm + 1); 986 cmcred->cmcred_pid = p->p_pid; 987 cmcred->cmcred_uid = p->p_cred->p_ruid; 988 cmcred->cmcred_gid = p->p_cred->p_rgid; 989 cmcred->cmcred_euid = p->p_ucred->cr_uid; 990 cmcred->cmcred_ngroups = MIN(p->p_ucred->cr_ngroups, 991 CMGROUP_MAX); 992 for (i = 0; i < cmcred->cmcred_ngroups; i++) 993 cmcred->cmcred_groups[i] = p->p_ucred->cr_groups[i]; 994 return(0); 995 } 996 997 oldfds = (cm->cmsg_len - sizeof (*cm)) / sizeof (int); 998 /* 999 * check that all the FDs passed in refer to legal OPEN files 1000 * If not, reject the entire operation. 1001 */ 1002 fdp = (int *)(cm + 1); 1003 for (i = 0; i < oldfds; i++) { 1004 fd = *fdp++; 1005 if ((unsigned)fd >= fdescp->fd_nfiles || 1006 fdescp->fd_ofiles[fd] == NULL) 1007 return (EBADF); 1008 } 1009 /* 1010 * Now replace the integer FDs with pointers to 1011 * the associated global file table entry.. 1012 * Allocate a bigger buffer as necessary. But if an cluster is not 1013 * enough, return E2BIG. 1014 */ 1015 newlen = CMSG_LEN(oldfds * sizeof(struct file *)); 1016 if (newlen > MCLBYTES) 1017 return (E2BIG); 1018 if (newlen - control->m_len > M_TRAILINGSPACE(control)) { 1019 if (control->m_flags & M_EXT) 1020 return (E2BIG); 1021 MCLGET(control, M_WAIT); 1022 if ((control->m_flags & M_EXT) == 0) 1023 return (ENOBUFS); 1024 1025 /* copy the data to the cluster */ 1026 memcpy(mtod(control, char *), cm, cm->cmsg_len); 1027 cm = mtod(control, struct cmsghdr *); 1028 } 1029 1030 /* 1031 * Adjust length, in case sizeof(struct file *) and sizeof(int) 1032 * differs. 1033 */ 1034 control->m_len = cm->cmsg_len = newlen; 1035 1036 /* 1037 * Transform the file descriptors into struct file pointers. 1038 * If sizeof (struct file *) is bigger than or equal to sizeof int, 1039 * then do it in reverse order so that the int won't get until 1040 * we're done. 1041 * If sizeof (struct file *) is smaller than sizeof int, then 1042 * do it in forward order. 1043 */ 1044 if (sizeof (struct file *) >= sizeof (int)) { 1045 fdp = (int *)(cm + 1) + oldfds - 1; 1046 rp = (struct file **)CMSG_DATA(cm) + oldfds - 1; 1047 for (i = 0; i < oldfds; i++) { 1048 fp = fdescp->fd_ofiles[*fdp--]; 1049 *rp-- = fp; 1050 fp->f_count++; 1051 fp->f_msgcount++; 1052 unp_rights++; 1053 } 1054 } else { 1055 fdp = (int *)(cm + 1); 1056 rp = (struct file **)CMSG_DATA(cm); 1057 for (i = 0; i < oldfds; i++) { 1058 fp = fdescp->fd_ofiles[*fdp++]; 1059 *rp++ = fp; 1060 fp->f_count++; 1061 fp->f_msgcount++; 1062 unp_rights++; 1063 } 1064 } 1065 return (0); 1066} 1067 1068static int unp_defer, unp_gcing; 1069 1070static void 1071unp_gc() 1072{ 1073 register struct file *fp, *nextfp; 1074 register struct socket *so; 1075 struct file **extra_ref, **fpp; 1076 int nunref, i; 1077 1078 if (unp_gcing) 1079 return; 1080 unp_gcing = 1; 1081 unp_defer = 0; 1082 /* 1083 * before going through all this, set all FDs to 1084 * be NOT defered and NOT externally accessible 1085 */ 1086 LIST_FOREACH(fp, &filehead, f_list) 1087 fp->f_flag &= ~(FMARK|FDEFER); 1088 do { 1089 LIST_FOREACH(fp, &filehead, f_list) { 1090 /* 1091 * If the file is not open, skip it 1092 */ 1093 if (fp->f_count == 0) 1094 continue; 1095 /* 1096 * If we already marked it as 'defer' in a 1097 * previous pass, then try process it this time 1098 * and un-mark it 1099 */ 1100 if (fp->f_flag & FDEFER) { 1101 fp->f_flag &= ~FDEFER; 1102 unp_defer--; 1103 } else { 1104 /* 1105 * if it's not defered, then check if it's 1106 * already marked.. if so skip it 1107 */ 1108 if (fp->f_flag & FMARK) 1109 continue; 1110 /* 1111 * If all references are from messages 1112 * in transit, then skip it. it's not 1113 * externally accessible. 1114 */ 1115 if (fp->f_count == fp->f_msgcount) 1116 continue; 1117 /* 1118 * If it got this far then it must be 1119 * externally accessible. 1120 */ 1121 fp->f_flag |= FMARK; 1122 } 1123 /* 1124 * either it was defered, or it is externally 1125 * accessible and not already marked so. 1126 * Now check if it is possibly one of OUR sockets. 1127 */ 1128 if (fp->f_type != DTYPE_SOCKET || 1129 (so = (struct socket *)fp->f_data) == 0) 1130 continue; 1131 if (so->so_proto->pr_domain != &localdomain || 1132 (so->so_proto->pr_flags&PR_RIGHTS) == 0) 1133 continue; 1134#ifdef notdef 1135 if (so->so_rcv.sb_flags & SB_LOCK) { 1136 /* 1137 * This is problematical; it's not clear 1138 * we need to wait for the sockbuf to be 1139 * unlocked (on a uniprocessor, at least), 1140 * and it's also not clear what to do 1141 * if sbwait returns an error due to receipt 1142 * of a signal. If sbwait does return 1143 * an error, we'll go into an infinite 1144 * loop. Delete all of this for now. 1145 */ 1146 (void) sbwait(&so->so_rcv); 1147 goto restart; 1148 } 1149#endif 1150 /* 1151 * So, Ok, it's one of our sockets and it IS externally 1152 * accessible (or was defered). Now we look 1153 * to see if we hold any file descriptors in its 1154 * message buffers. Follow those links and mark them 1155 * as accessible too. 1156 */ 1157 unp_scan(so->so_rcv.sb_mb, unp_mark); 1158 } 1159 } while (unp_defer); 1160 /* 1161 * We grab an extra reference to each of the file table entries 1162 * that are not otherwise accessible and then free the rights 1163 * that are stored in messages on them. 1164 * 1165 * The bug in the orginal code is a little tricky, so I'll describe 1166 * what's wrong with it here. 1167 * 1168 * It is incorrect to simply unp_discard each entry for f_msgcount 1169 * times -- consider the case of sockets A and B that contain 1170 * references to each other. On a last close of some other socket, 1171 * we trigger a gc since the number of outstanding rights (unp_rights) 1172 * is non-zero. If during the sweep phase the gc code un_discards, 1173 * we end up doing a (full) closef on the descriptor. A closef on A 1174 * results in the following chain. Closef calls soo_close, which 1175 * calls soclose. Soclose calls first (through the switch 1176 * uipc_usrreq) unp_detach, which re-invokes unp_gc. Unp_gc simply 1177 * returns because the previous instance had set unp_gcing, and 1178 * we return all the way back to soclose, which marks the socket 1179 * with SS_NOFDREF, and then calls sofree. Sofree calls sorflush 1180 * to free up the rights that are queued in messages on the socket A, 1181 * i.e., the reference on B. The sorflush calls via the dom_dispose 1182 * switch unp_dispose, which unp_scans with unp_discard. This second 1183 * instance of unp_discard just calls closef on B. 1184 * 1185 * Well, a similar chain occurs on B, resulting in a sorflush on B, 1186 * which results in another closef on A. Unfortunately, A is already 1187 * being closed, and the descriptor has already been marked with 1188 * SS_NOFDREF, and soclose panics at this point. 1189 * 1190 * Here, we first take an extra reference to each inaccessible 1191 * descriptor. Then, we call sorflush ourself, since we know 1192 * it is a Unix domain socket anyhow. After we destroy all the 1193 * rights carried in messages, we do a last closef to get rid 1194 * of our extra reference. This is the last close, and the 1195 * unp_detach etc will shut down the socket. 1196 * 1197 * 91/09/19, bsy@cs.cmu.edu 1198 */ 1199 extra_ref = malloc(nfiles * sizeof(struct file *), M_FILE, M_WAITOK); 1200 for (nunref = 0, fp = LIST_FIRST(&filehead), fpp = extra_ref; fp != 0; 1201 fp = nextfp) { 1202 nextfp = LIST_NEXT(fp, f_list); 1203 /* 1204 * If it's not open, skip it 1205 */ 1206 if (fp->f_count == 0) 1207 continue; 1208 /* 1209 * If all refs are from msgs, and it's not marked accessible 1210 * then it must be referenced from some unreachable cycle 1211 * of (shut-down) FDs, so include it in our 1212 * list of FDs to remove 1213 */ 1214 if (fp->f_count == fp->f_msgcount && !(fp->f_flag & FMARK)) { 1215 *fpp++ = fp; 1216 nunref++; 1217 fp->f_count++; 1218 } 1219 } 1220 /* 1221 * for each FD on our hit list, do the following two things 1222 */ 1223 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) { 1224 struct file *tfp = *fpp; 1225 if (tfp->f_type == DTYPE_SOCKET && tfp->f_data != NULL) 1226 sorflush((struct socket *)(tfp->f_data)); 1227 } 1228 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) 1229 closef(*fpp, (struct proc *) NULL); 1230 free((caddr_t)extra_ref, M_FILE); 1231 unp_gcing = 0; 1232} 1233 1234void 1235unp_dispose(m) 1236 struct mbuf *m; 1237{ 1238 1239 if (m) 1240 unp_scan(m, unp_discard); 1241} 1242 1243static void 1244unp_scan(m0, op) 1245 register struct mbuf *m0; 1246 void (*op) __P((struct file *)); 1247{ 1248 register struct mbuf *m; 1249 register struct file **rp; 1250 register struct cmsghdr *cm; 1251 register int i; 1252 int qfds; 1253 1254 while (m0) { 1255 for (m = m0; m; m = m->m_next) 1256 if (m->m_type == MT_CONTROL && 1257 m->m_len >= sizeof(*cm)) { 1258 cm = mtod(m, struct cmsghdr *); 1259 if (cm->cmsg_level != SOL_SOCKET || 1260 cm->cmsg_type != SCM_RIGHTS) 1261 continue; 1262 qfds = (cm->cmsg_len - 1263 (CMSG_DATA(cm) - (u_char *)cm)) 1264 / sizeof (struct file *); 1265 rp = (struct file **)CMSG_DATA(cm); 1266 for (i = 0; i < qfds; i++) 1267 (*op)(*rp++); 1268 break; /* XXX, but saves time */ 1269 } 1270 m0 = m0->m_act; 1271 } 1272} 1273 1274static void 1275unp_mark(fp) 1276 struct file *fp; 1277{ 1278 1279 if (fp->f_flag & FMARK) 1280 return; 1281 unp_defer++; 1282 fp->f_flag |= (FMARK|FDEFER); 1283} 1284 1285static void 1286unp_discard(fp) 1287 struct file *fp; 1288{ 1289 1290 fp->f_msgcount--; 1291 unp_rights--; 1292 (void) closef(fp, (struct proc *)NULL); 1293} 1294