| 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. Neither the name of the University nor the names of its contributors |
| 14 | * may be used to endorse or promote products derived from this software |
| 15 | * without specific prior written permission. |
| 16 | * |
| 17 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 27 | * SUCH DAMAGE. |
| 28 | * |
| 29 | * From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94 |
| 30 | * $FreeBSD: src/sys/kern/uipc_usrreq.c,v 1.54.2.10 2003/03/04 17:28:09 nectar Exp $ |
| 31 | */ |
| 32 | |
| 33 | #include <sys/param.h> |
| 34 | #include <sys/systm.h> |
| 35 | #include <sys/kernel.h> |
| 36 | #include <sys/domain.h> |
| 37 | #include <sys/fcntl.h> |
| 38 | #include <sys/malloc.h> /* XXX must be before <sys/file.h> */ |
| 39 | #include <sys/proc.h> |
| 40 | #include <sys/file.h> |
| 41 | #include <sys/filedesc.h> |
| 42 | #include <sys/mbuf.h> |
| 43 | #include <sys/nlookup.h> |
| 44 | #include <sys/protosw.h> |
| 45 | #include <sys/socket.h> |
| 46 | #include <sys/socketvar.h> |
| 47 | #include <sys/resourcevar.h> |
| 48 | #include <sys/stat.h> |
| 49 | #include <sys/mount.h> |
| 50 | #include <sys/sysctl.h> |
| 51 | #include <sys/un.h> |
| 52 | #include <sys/unpcb.h> |
| 53 | #include <sys/vnode.h> |
| 54 | |
| 55 | #include <sys/file2.h> |
| 56 | #include <sys/spinlock2.h> |
| 57 | #include <sys/socketvar2.h> |
| 58 | #include <sys/msgport2.h> |
| 59 | |
| 60 | #define UNP_DETACHED UNP_PRIVATE1 |
| 61 | #define UNP_CONNECTING UNP_PRIVATE2 |
| 62 | #define UNP_DROPPED UNP_PRIVATE3 |
| 63 | |
| 64 | #define UNP_ISATTACHED(unp) \ |
| 65 | ((unp) != NULL && ((unp)->unp_flags & UNP_DETACHED) == 0) |
| 66 | |
| 67 | #ifdef INVARIANTS |
| 68 | #define UNP_ASSERT_TOKEN_HELD(unp) \ |
| 69 | ASSERT_LWKT_TOKEN_HELD(lwkt_token_pool_lookup((unp))) |
| 70 | #else /* !INVARIANTS */ |
| 71 | #define UNP_ASSERT_TOKEN_HELD(unp) |
| 72 | #endif /* INVARIANTS */ |
| 73 | |
| 74 | typedef struct unp_defdiscard { |
| 75 | struct unp_defdiscard *next; |
| 76 | struct file *fp; |
| 77 | } *unp_defdiscard_t; |
| 78 | |
| 79 | static MALLOC_DEFINE(M_UNPCB, "unpcb", "unpcb struct"); |
| 80 | static unp_gen_t unp_gencnt; |
| 81 | static u_int unp_count; |
| 82 | |
| 83 | static struct unp_head unp_shead, unp_dhead; |
| 84 | |
| 85 | static struct lwkt_token unp_token = LWKT_TOKEN_INITIALIZER(unp_token); |
| 86 | static int unp_defdiscard_nest; |
| 87 | static unp_defdiscard_t unp_defdiscard_base; |
| 88 | |
| 89 | /* |
| 90 | * Unix communications domain. |
| 91 | * |
| 92 | * TODO: |
| 93 | * RDM |
| 94 | * rethink name space problems |
| 95 | * need a proper out-of-band |
| 96 | * lock pushdown |
| 97 | */ |
| 98 | static struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; |
| 99 | static ino_t unp_ino = 1; /* prototype for fake inode numbers */ |
| 100 | static struct spinlock unp_ino_spin = SPINLOCK_INITIALIZER(&unp_ino_spin, "unp_ino_spin"); |
| 101 | |
| 102 | static int unp_attach (struct socket *, struct pru_attach_info *); |
| 103 | static void unp_detach (struct unpcb *); |
| 104 | static int unp_bind (struct unpcb *,struct sockaddr *, struct thread *); |
| 105 | static int unp_connect (struct socket *,struct sockaddr *, |
| 106 | struct thread *); |
| 107 | static void unp_disconnect(struct unpcb *, int); |
| 108 | static void unp_shutdown (struct unpcb *); |
| 109 | static void unp_gc (void); |
| 110 | static int unp_gc_clearmarks(struct file *, void *); |
| 111 | static int unp_gc_checkmarks(struct file *, void *); |
| 112 | static int unp_gc_checkrefs(struct file *, void *); |
| 113 | static int unp_revoke_gc_check(struct file *, void *); |
| 114 | static void unp_scan (struct mbuf *, void (*)(struct file *, void *), |
| 115 | void *data); |
| 116 | static void unp_mark (struct file *, void *data); |
| 117 | static void unp_discard (struct file *, void *); |
| 118 | static int unp_internalize (struct mbuf *, struct thread *); |
| 119 | static int unp_listen (struct unpcb *, struct thread *); |
| 120 | static void unp_fp_externalize(struct lwp *lp, struct file *fp, int fd); |
| 121 | static int unp_find_lockref(struct sockaddr *nam, struct thread *td, |
| 122 | short type, struct unpcb **unp_ret); |
| 123 | static int unp_connect_pair(struct unpcb *unp, struct unpcb *unp2); |
| 124 | static void unp_drop(struct unpcb *unp, int error); |
| 125 | |
| 126 | /* |
| 127 | * SMP Considerations: |
| 128 | * |
| 129 | * Since unp_token will be automaticly released upon execution of |
| 130 | * blocking code, we need to reference unp_conn before any possible |
| 131 | * blocking code to prevent it from being ripped behind our back. |
| 132 | * |
| 133 | * Any adjustment to unp->unp_conn requires both the global unp_token |
| 134 | * AND the per-unp token (lwkt_token_pool_lookup(unp)) to be held. |
| 135 | * |
| 136 | * Any access to so_pcb to obtain unp requires the pool token for |
| 137 | * unp to be held. |
| 138 | */ |
| 139 | |
| 140 | /* NOTE: unp_token MUST be held */ |
| 141 | static __inline void |
| 142 | unp_reference(struct unpcb *unp) |
| 143 | { |
| 144 | atomic_add_int(&unp->unp_refcnt, 1); |
| 145 | } |
| 146 | |
| 147 | /* NOTE: unp_token MUST be held */ |
| 148 | static __inline void |
| 149 | unp_free(struct unpcb *unp) |
| 150 | { |
| 151 | KKASSERT(unp->unp_refcnt > 0); |
| 152 | if (atomic_fetchadd_int(&unp->unp_refcnt, -1) == 1) |
| 153 | unp_detach(unp); |
| 154 | } |
| 155 | |
| 156 | static __inline struct unpcb * |
| 157 | unp_getsocktoken(struct socket *so) |
| 158 | { |
| 159 | struct unpcb *unp; |
| 160 | |
| 161 | /* |
| 162 | * The unp pointer is invalid until we verify that it is |
| 163 | * good by re-checking so_pcb AFTER obtaining the token. |
| 164 | */ |
| 165 | while ((unp = so->so_pcb) != NULL) { |
| 166 | lwkt_getpooltoken(unp); |
| 167 | if (unp == so->so_pcb) |
| 168 | break; |
| 169 | lwkt_relpooltoken(unp); |
| 170 | } |
| 171 | return unp; |
| 172 | } |
| 173 | |
| 174 | static __inline void |
| 175 | unp_reltoken(struct unpcb *unp) |
| 176 | { |
| 177 | if (unp != NULL) |
| 178 | lwkt_relpooltoken(unp); |
| 179 | } |
| 180 | |
| 181 | static __inline void |
| 182 | unp_setflags(struct unpcb *unp, int flags) |
| 183 | { |
| 184 | atomic_set_int(&unp->unp_flags, flags); |
| 185 | } |
| 186 | |
| 187 | static __inline void |
| 188 | unp_clrflags(struct unpcb *unp, int flags) |
| 189 | { |
| 190 | atomic_clear_int(&unp->unp_flags, flags); |
| 191 | } |
| 192 | |
| 193 | /* |
| 194 | * NOTE: (so) is referenced from soabort*() and netmsg_pru_abort() |
| 195 | * will sofree() it when we return. |
| 196 | */ |
| 197 | static void |
| 198 | uipc_abort(netmsg_t msg) |
| 199 | { |
| 200 | struct unpcb *unp; |
| 201 | int error; |
| 202 | |
| 203 | lwkt_gettoken(&unp_token); |
| 204 | unp = unp_getsocktoken(msg->base.nm_so); |
| 205 | |
| 206 | if (UNP_ISATTACHED(unp)) { |
| 207 | unp_setflags(unp, UNP_DETACHED); |
| 208 | unp_drop(unp, ECONNABORTED); |
| 209 | unp_free(unp); |
| 210 | error = 0; |
| 211 | } else { |
| 212 | error = EINVAL; |
| 213 | } |
| 214 | |
| 215 | unp_reltoken(unp); |
| 216 | lwkt_reltoken(&unp_token); |
| 217 | |
| 218 | lwkt_replymsg(&msg->lmsg, error); |
| 219 | } |
| 220 | |
| 221 | static void |
| 222 | uipc_accept(netmsg_t msg) |
| 223 | { |
| 224 | struct unpcb *unp; |
| 225 | int error; |
| 226 | |
| 227 | lwkt_gettoken(&unp_token); |
| 228 | unp = msg->base.nm_so->so_pcb; |
| 229 | if (!UNP_ISATTACHED(unp)) { |
| 230 | error = EINVAL; |
| 231 | } else { |
| 232 | struct unpcb *unp2 = unp->unp_conn; |
| 233 | |
| 234 | /* |
| 235 | * Pass back name of connected socket, |
| 236 | * if it was bound and we are still connected |
| 237 | * (our peer may have closed already!). |
| 238 | */ |
| 239 | if (unp2 && unp2->unp_addr) { |
| 240 | unp_reference(unp2); |
| 241 | *msg->accept.nm_nam = dup_sockaddr( |
| 242 | (struct sockaddr *)unp2->unp_addr); |
| 243 | unp_free(unp2); |
| 244 | } else { |
| 245 | *msg->accept.nm_nam = dup_sockaddr(&sun_noname); |
| 246 | } |
| 247 | error = 0; |
| 248 | } |
| 249 | lwkt_reltoken(&unp_token); |
| 250 | lwkt_replymsg(&msg->lmsg, error); |
| 251 | } |
| 252 | |
| 253 | static void |
| 254 | uipc_attach(netmsg_t msg) |
| 255 | { |
| 256 | struct unpcb *unp; |
| 257 | int error; |
| 258 | |
| 259 | lwkt_gettoken(&unp_token); |
| 260 | unp = msg->base.nm_so->so_pcb; |
| 261 | KASSERT(unp == NULL, ("double unp attach")); |
| 262 | error = unp_attach(msg->base.nm_so, msg->attach.nm_ai); |
| 263 | lwkt_reltoken(&unp_token); |
| 264 | lwkt_replymsg(&msg->lmsg, error); |
| 265 | } |
| 266 | |
| 267 | static void |
| 268 | uipc_bind(netmsg_t msg) |
| 269 | { |
| 270 | struct unpcb *unp; |
| 271 | int error; |
| 272 | |
| 273 | lwkt_gettoken(&unp_token); |
| 274 | unp = msg->base.nm_so->so_pcb; |
| 275 | if (UNP_ISATTACHED(unp)) |
| 276 | error = unp_bind(unp, msg->bind.nm_nam, msg->bind.nm_td); |
| 277 | else |
| 278 | error = EINVAL; |
| 279 | lwkt_reltoken(&unp_token); |
| 280 | lwkt_replymsg(&msg->lmsg, error); |
| 281 | } |
| 282 | |
| 283 | static void |
| 284 | uipc_connect(netmsg_t msg) |
| 285 | { |
| 286 | int error; |
| 287 | |
| 288 | error = unp_connect(msg->base.nm_so, msg->connect.nm_nam, |
| 289 | msg->connect.nm_td); |
| 290 | lwkt_replymsg(&msg->lmsg, error); |
| 291 | } |
| 292 | |
| 293 | static void |
| 294 | uipc_connect2(netmsg_t msg) |
| 295 | { |
| 296 | int error; |
| 297 | |
| 298 | error = unp_connect2(msg->connect2.nm_so1, msg->connect2.nm_so2); |
| 299 | lwkt_replymsg(&msg->lmsg, error); |
| 300 | } |
| 301 | |
| 302 | /* control is EOPNOTSUPP */ |
| 303 | |
| 304 | static void |
| 305 | uipc_detach(netmsg_t msg) |
| 306 | { |
| 307 | struct unpcb *unp; |
| 308 | int error; |
| 309 | |
| 310 | lwkt_gettoken(&unp_token); |
| 311 | unp = unp_getsocktoken(msg->base.nm_so); |
| 312 | |
| 313 | if (UNP_ISATTACHED(unp)) { |
| 314 | unp_setflags(unp, UNP_DETACHED); |
| 315 | unp_drop(unp, 0); |
| 316 | unp_free(unp); |
| 317 | error = 0; |
| 318 | } else { |
| 319 | error = EINVAL; |
| 320 | } |
| 321 | |
| 322 | unp_reltoken(unp); |
| 323 | lwkt_reltoken(&unp_token); |
| 324 | |
| 325 | lwkt_replymsg(&msg->lmsg, error); |
| 326 | } |
| 327 | |
| 328 | static void |
| 329 | uipc_disconnect(netmsg_t msg) |
| 330 | { |
| 331 | struct unpcb *unp; |
| 332 | int error; |
| 333 | |
| 334 | lwkt_gettoken(&unp_token); |
| 335 | unp = unp_getsocktoken(msg->base.nm_so); |
| 336 | |
| 337 | if (UNP_ISATTACHED(unp)) { |
| 338 | unp_disconnect(unp, 0); |
| 339 | error = 0; |
| 340 | } else { |
| 341 | error = EINVAL; |
| 342 | } |
| 343 | |
| 344 | unp_reltoken(unp); |
| 345 | lwkt_reltoken(&unp_token); |
| 346 | |
| 347 | lwkt_replymsg(&msg->lmsg, error); |
| 348 | } |
| 349 | |
| 350 | static void |
| 351 | uipc_listen(netmsg_t msg) |
| 352 | { |
| 353 | struct unpcb *unp; |
| 354 | int error; |
| 355 | |
| 356 | lwkt_gettoken(&unp_token); |
| 357 | unp = msg->base.nm_so->so_pcb; |
| 358 | if (!UNP_ISATTACHED(unp) || unp->unp_vnode == NULL) |
| 359 | error = EINVAL; |
| 360 | else |
| 361 | error = unp_listen(unp, msg->listen.nm_td); |
| 362 | lwkt_reltoken(&unp_token); |
| 363 | lwkt_replymsg(&msg->lmsg, error); |
| 364 | } |
| 365 | |
| 366 | static void |
| 367 | uipc_peeraddr(netmsg_t msg) |
| 368 | { |
| 369 | struct unpcb *unp; |
| 370 | int error; |
| 371 | |
| 372 | lwkt_gettoken(&unp_token); |
| 373 | unp = msg->base.nm_so->so_pcb; |
| 374 | if (!UNP_ISATTACHED(unp)) { |
| 375 | error = EINVAL; |
| 376 | } else if (unp->unp_conn && unp->unp_conn->unp_addr) { |
| 377 | struct unpcb *unp2 = unp->unp_conn; |
| 378 | |
| 379 | unp_reference(unp2); |
| 380 | *msg->peeraddr.nm_nam = dup_sockaddr( |
| 381 | (struct sockaddr *)unp2->unp_addr); |
| 382 | unp_free(unp2); |
| 383 | error = 0; |
| 384 | } else { |
| 385 | /* |
| 386 | * XXX: It seems that this test always fails even when |
| 387 | * connection is established. So, this else clause is |
| 388 | * added as workaround to return PF_LOCAL sockaddr. |
| 389 | */ |
| 390 | *msg->peeraddr.nm_nam = dup_sockaddr(&sun_noname); |
| 391 | error = 0; |
| 392 | } |
| 393 | lwkt_reltoken(&unp_token); |
| 394 | lwkt_replymsg(&msg->lmsg, error); |
| 395 | } |
| 396 | |
| 397 | static void |
| 398 | uipc_rcvd(netmsg_t msg) |
| 399 | { |
| 400 | struct unpcb *unp, *unp2; |
| 401 | struct socket *so; |
| 402 | struct socket *so2; |
| 403 | int error; |
| 404 | |
| 405 | /* |
| 406 | * so_pcb is only modified with both the global and the unp |
| 407 | * pool token held. |
| 408 | */ |
| 409 | so = msg->base.nm_so; |
| 410 | unp = unp_getsocktoken(so); |
| 411 | |
| 412 | if (!UNP_ISATTACHED(unp)) { |
| 413 | error = EINVAL; |
| 414 | goto done; |
| 415 | } |
| 416 | |
| 417 | switch (so->so_type) { |
| 418 | case SOCK_DGRAM: |
| 419 | panic("uipc_rcvd DGRAM?"); |
| 420 | /*NOTREACHED*/ |
| 421 | case SOCK_STREAM: |
| 422 | case SOCK_SEQPACKET: |
| 423 | if (unp->unp_conn == NULL) |
| 424 | break; |
| 425 | unp2 = unp->unp_conn; /* protected by pool token */ |
| 426 | |
| 427 | /* |
| 428 | * Because we are transfering mbufs directly to the |
| 429 | * peer socket we have to use SSB_STOP on the sender |
| 430 | * to prevent it from building up infinite mbufs. |
| 431 | * |
| 432 | * As in several places in this module w ehave to ref unp2 |
| 433 | * to ensure that it does not get ripped out from under us |
| 434 | * if we block on the so2 token or in sowwakeup(). |
| 435 | */ |
| 436 | so2 = unp2->unp_socket; |
| 437 | unp_reference(unp2); |
| 438 | lwkt_gettoken(&so2->so_rcv.ssb_token); |
| 439 | if (so->so_rcv.ssb_cc < so2->so_snd.ssb_hiwat && |
| 440 | so->so_rcv.ssb_mbcnt < so2->so_snd.ssb_mbmax |
| 441 | ) { |
| 442 | atomic_clear_int(&so2->so_snd.ssb_flags, SSB_STOP); |
| 443 | |
| 444 | sowwakeup(so2); |
| 445 | } |
| 446 | lwkt_reltoken(&so2->so_rcv.ssb_token); |
| 447 | unp_free(unp2); |
| 448 | break; |
| 449 | default: |
| 450 | panic("uipc_rcvd unknown socktype"); |
| 451 | /*NOTREACHED*/ |
| 452 | } |
| 453 | error = 0; |
| 454 | done: |
| 455 | unp_reltoken(unp); |
| 456 | lwkt_replymsg(&msg->lmsg, error); |
| 457 | } |
| 458 | |
| 459 | /* pru_rcvoob is EOPNOTSUPP */ |
| 460 | |
| 461 | static void |
| 462 | uipc_send(netmsg_t msg) |
| 463 | { |
| 464 | struct unpcb *unp, *unp2; |
| 465 | struct socket *so; |
| 466 | struct socket *so2; |
| 467 | struct mbuf *control; |
| 468 | struct mbuf *m; |
| 469 | int error = 0; |
| 470 | |
| 471 | so = msg->base.nm_so; |
| 472 | control = msg->send.nm_control; |
| 473 | m = msg->send.nm_m; |
| 474 | |
| 475 | /* |
| 476 | * so_pcb is only modified with both the global and the unp |
| 477 | * pool token held. |
| 478 | */ |
| 479 | so = msg->base.nm_so; |
| 480 | unp = unp_getsocktoken(so); |
| 481 | |
| 482 | if (!UNP_ISATTACHED(unp)) { |
| 483 | error = EINVAL; |
| 484 | goto release; |
| 485 | } |
| 486 | |
| 487 | if (msg->send.nm_flags & PRUS_OOB) { |
| 488 | error = EOPNOTSUPP; |
| 489 | goto release; |
| 490 | } |
| 491 | |
| 492 | wakeup_start_delayed(); |
| 493 | |
| 494 | if (control && (error = unp_internalize(control, msg->send.nm_td))) |
| 495 | goto release; |
| 496 | |
| 497 | switch (so->so_type) { |
| 498 | case SOCK_DGRAM: |
| 499 | { |
| 500 | struct sockaddr *from; |
| 501 | |
| 502 | if (msg->send.nm_addr) { |
| 503 | if (unp->unp_conn) { |
| 504 | error = EISCONN; |
| 505 | break; |
| 506 | } |
| 507 | error = unp_find_lockref(msg->send.nm_addr, |
| 508 | msg->send.nm_td, so->so_type, &unp2); |
| 509 | if (error) |
| 510 | break; |
| 511 | /* |
| 512 | * NOTE: |
| 513 | * unp2 is locked and referenced. |
| 514 | * |
| 515 | * We could unlock unp2 now, since it was checked |
| 516 | * and referenced. |
| 517 | */ |
| 518 | unp_reltoken(unp2); |
| 519 | } else { |
| 520 | if (unp->unp_conn == NULL) { |
| 521 | error = ENOTCONN; |
| 522 | break; |
| 523 | } |
| 524 | /* XXX racy. */ |
| 525 | unp2 = unp->unp_conn; |
| 526 | unp_reference(unp2); |
| 527 | } |
| 528 | /* NOTE: unp2 is referenced. */ |
| 529 | so2 = unp2->unp_socket; |
| 530 | |
| 531 | if (unp->unp_addr) |
| 532 | from = (struct sockaddr *)unp->unp_addr; |
| 533 | else |
| 534 | from = &sun_noname; |
| 535 | |
| 536 | lwkt_gettoken(&so2->so_rcv.ssb_token); |
| 537 | if (ssb_appendaddr(&so2->so_rcv, from, m, control)) { |
| 538 | sorwakeup(so2); |
| 539 | m = NULL; |
| 540 | control = NULL; |
| 541 | } else { |
| 542 | error = ENOBUFS; |
| 543 | } |
| 544 | lwkt_reltoken(&so2->so_rcv.ssb_token); |
| 545 | |
| 546 | unp_free(unp2); |
| 547 | break; |
| 548 | } |
| 549 | |
| 550 | case SOCK_STREAM: |
| 551 | case SOCK_SEQPACKET: |
| 552 | /* Connect if not connected yet. */ |
| 553 | /* |
| 554 | * Note: A better implementation would complain |
| 555 | * if not equal to the peer's address. |
| 556 | */ |
| 557 | if (!(so->so_state & SS_ISCONNECTED)) { |
| 558 | if (msg->send.nm_addr) { |
| 559 | error = unp_connect(so, |
| 560 | msg->send.nm_addr, |
| 561 | msg->send.nm_td); |
| 562 | if (error) |
| 563 | break; /* XXX */ |
| 564 | } else { |
| 565 | error = ENOTCONN; |
| 566 | break; |
| 567 | } |
| 568 | } |
| 569 | |
| 570 | if (so->so_state & SS_CANTSENDMORE) { |
| 571 | error = EPIPE; |
| 572 | break; |
| 573 | } |
| 574 | if (unp->unp_conn == NULL) |
| 575 | panic("uipc_send connected but no connection?"); |
| 576 | unp2 = unp->unp_conn; |
| 577 | so2 = unp2->unp_socket; |
| 578 | |
| 579 | unp_reference(unp2); |
| 580 | |
| 581 | /* |
| 582 | * Send to paired receive port, and then reduce |
| 583 | * send buffer hiwater marks to maintain backpressure. |
| 584 | * Wake up readers. |
| 585 | */ |
| 586 | lwkt_gettoken(&so2->so_rcv.ssb_token); |
| 587 | if (control) { |
| 588 | if (ssb_appendcontrol(&so2->so_rcv, m, control)) { |
| 589 | control = NULL; |
| 590 | m = NULL; |
| 591 | } |
| 592 | } else if (so->so_type == SOCK_SEQPACKET) { |
| 593 | sbappendrecord(&so2->so_rcv.sb, m); |
| 594 | m = NULL; |
| 595 | } else { |
| 596 | sbappend(&so2->so_rcv.sb, m); |
| 597 | m = NULL; |
| 598 | } |
| 599 | |
| 600 | /* |
| 601 | * Because we are transfering mbufs directly to the |
| 602 | * peer socket we have to use SSB_STOP on the sender |
| 603 | * to prevent it from building up infinite mbufs. |
| 604 | */ |
| 605 | if (so2->so_rcv.ssb_cc >= so->so_snd.ssb_hiwat || |
| 606 | so2->so_rcv.ssb_mbcnt >= so->so_snd.ssb_mbmax |
| 607 | ) { |
| 608 | atomic_set_int(&so->so_snd.ssb_flags, SSB_STOP); |
| 609 | } |
| 610 | lwkt_reltoken(&so2->so_rcv.ssb_token); |
| 611 | sorwakeup(so2); |
| 612 | |
| 613 | unp_free(unp2); |
| 614 | break; |
| 615 | |
| 616 | default: |
| 617 | panic("uipc_send unknown socktype"); |
| 618 | } |
| 619 | |
| 620 | /* |
| 621 | * SEND_EOF is equivalent to a SEND followed by a SHUTDOWN. |
| 622 | */ |
| 623 | if (msg->send.nm_flags & PRUS_EOF) { |
| 624 | socantsendmore(so); |
| 625 | unp_shutdown(unp); |
| 626 | } |
| 627 | |
| 628 | if (control && error != 0) |
| 629 | unp_dispose(control); |
| 630 | release: |
| 631 | unp_reltoken(unp); |
| 632 | wakeup_end_delayed(); |
| 633 | |
| 634 | if (control) |
| 635 | m_freem(control); |
| 636 | if (m) |
| 637 | m_freem(m); |
| 638 | lwkt_replymsg(&msg->lmsg, error); |
| 639 | } |
| 640 | |
| 641 | /* |
| 642 | * MPSAFE |
| 643 | */ |
| 644 | static void |
| 645 | uipc_sense(netmsg_t msg) |
| 646 | { |
| 647 | struct unpcb *unp; |
| 648 | struct socket *so; |
| 649 | struct stat *sb; |
| 650 | int error; |
| 651 | |
| 652 | so = msg->base.nm_so; |
| 653 | sb = msg->sense.nm_stat; |
| 654 | |
| 655 | /* |
| 656 | * so_pcb is only modified with both the global and the unp |
| 657 | * pool token held. |
| 658 | */ |
| 659 | unp = unp_getsocktoken(so); |
| 660 | |
| 661 | if (!UNP_ISATTACHED(unp)) { |
| 662 | error = EINVAL; |
| 663 | goto done; |
| 664 | } |
| 665 | |
| 666 | sb->st_blksize = so->so_snd.ssb_hiwat; |
| 667 | sb->st_dev = NOUDEV; |
| 668 | if (unp->unp_ino == 0) { /* make up a non-zero inode number */ |
| 669 | spin_lock(&unp_ino_spin); |
| 670 | unp->unp_ino = unp_ino++; |
| 671 | spin_unlock(&unp_ino_spin); |
| 672 | } |
| 673 | sb->st_ino = unp->unp_ino; |
| 674 | error = 0; |
| 675 | done: |
| 676 | unp_reltoken(unp); |
| 677 | lwkt_replymsg(&msg->lmsg, error); |
| 678 | } |
| 679 | |
| 680 | static void |
| 681 | uipc_shutdown(netmsg_t msg) |
| 682 | { |
| 683 | struct socket *so; |
| 684 | struct unpcb *unp; |
| 685 | int error; |
| 686 | |
| 687 | /* |
| 688 | * so_pcb is only modified with both the global and the unp |
| 689 | * pool token held. |
| 690 | */ |
| 691 | so = msg->base.nm_so; |
| 692 | unp = unp_getsocktoken(so); |
| 693 | |
| 694 | if (UNP_ISATTACHED(unp)) { |
| 695 | socantsendmore(so); |
| 696 | unp_shutdown(unp); |
| 697 | error = 0; |
| 698 | } else { |
| 699 | error = EINVAL; |
| 700 | } |
| 701 | |
| 702 | unp_reltoken(unp); |
| 703 | lwkt_replymsg(&msg->lmsg, error); |
| 704 | } |
| 705 | |
| 706 | static void |
| 707 | uipc_sockaddr(netmsg_t msg) |
| 708 | { |
| 709 | struct socket *so; |
| 710 | struct unpcb *unp; |
| 711 | int error; |
| 712 | |
| 713 | /* |
| 714 | * so_pcb is only modified with both the global and the unp |
| 715 | * pool token held. |
| 716 | */ |
| 717 | so = msg->base.nm_so; |
| 718 | unp = unp_getsocktoken(so); |
| 719 | |
| 720 | if (UNP_ISATTACHED(unp)) { |
| 721 | if (unp->unp_addr) { |
| 722 | *msg->sockaddr.nm_nam = |
| 723 | dup_sockaddr((struct sockaddr *)unp->unp_addr); |
| 724 | } |
| 725 | error = 0; |
| 726 | } else { |
| 727 | error = EINVAL; |
| 728 | } |
| 729 | |
| 730 | unp_reltoken(unp); |
| 731 | lwkt_replymsg(&msg->lmsg, error); |
| 732 | } |
| 733 | |
| 734 | struct pr_usrreqs uipc_usrreqs = { |
| 735 | .pru_abort = uipc_abort, |
| 736 | .pru_accept = uipc_accept, |
| 737 | .pru_attach = uipc_attach, |
| 738 | .pru_bind = uipc_bind, |
| 739 | .pru_connect = uipc_connect, |
| 740 | .pru_connect2 = uipc_connect2, |
| 741 | .pru_control = pr_generic_notsupp, |
| 742 | .pru_detach = uipc_detach, |
| 743 | .pru_disconnect = uipc_disconnect, |
| 744 | .pru_listen = uipc_listen, |
| 745 | .pru_peeraddr = uipc_peeraddr, |
| 746 | .pru_rcvd = uipc_rcvd, |
| 747 | .pru_rcvoob = pr_generic_notsupp, |
| 748 | .pru_send = uipc_send, |
| 749 | .pru_sense = uipc_sense, |
| 750 | .pru_shutdown = uipc_shutdown, |
| 751 | .pru_sockaddr = uipc_sockaddr, |
| 752 | .pru_sosend = sosend, |
| 753 | .pru_soreceive = soreceive |
| 754 | }; |
| 755 | |
| 756 | void |
| 757 | uipc_ctloutput(netmsg_t msg) |
| 758 | { |
| 759 | struct socket *so; |
| 760 | struct sockopt *sopt; |
| 761 | struct unpcb *unp; |
| 762 | int error = 0; |
| 763 | |
| 764 | lwkt_gettoken(&unp_token); |
| 765 | so = msg->base.nm_so; |
| 766 | sopt = msg->ctloutput.nm_sopt; |
| 767 | unp = so->so_pcb; |
| 768 | |
| 769 | switch (sopt->sopt_dir) { |
| 770 | case SOPT_GET: |
| 771 | switch (sopt->sopt_name) { |
| 772 | case LOCAL_PEERCRED: |
| 773 | if (unp->unp_flags & UNP_HAVEPC) |
| 774 | soopt_from_kbuf(sopt, &unp->unp_peercred, |
| 775 | sizeof(unp->unp_peercred)); |
| 776 | else { |
| 777 | if (so->so_type == SOCK_STREAM) |
| 778 | error = ENOTCONN; |
| 779 | else if (so->so_type == SOCK_SEQPACKET) |
| 780 | error = ENOTCONN; |
| 781 | else |
| 782 | error = EINVAL; |
| 783 | } |
| 784 | break; |
| 785 | default: |
| 786 | error = EOPNOTSUPP; |
| 787 | break; |
| 788 | } |
| 789 | break; |
| 790 | case SOPT_SET: |
| 791 | default: |
| 792 | error = EOPNOTSUPP; |
| 793 | break; |
| 794 | } |
| 795 | lwkt_reltoken(&unp_token); |
| 796 | lwkt_replymsg(&msg->lmsg, error); |
| 797 | } |
| 798 | |
| 799 | /* |
| 800 | * Both send and receive buffers are allocated PIPSIZ bytes of buffering |
| 801 | * for stream sockets, although the total for sender and receiver is |
| 802 | * actually only PIPSIZ. |
| 803 | * |
| 804 | * Datagram sockets really use the sendspace as the maximum datagram size, |
| 805 | * and don't really want to reserve the sendspace. Their recvspace should |
| 806 | * be large enough for at least one max-size datagram plus address. |
| 807 | * |
| 808 | * We want the local send/recv space to be significant larger then lo0's |
| 809 | * mtu of 16384. |
| 810 | */ |
| 811 | #ifndef PIPSIZ |
| 812 | #define PIPSIZ 57344 |
| 813 | #endif |
| 814 | static u_long unpst_sendspace = PIPSIZ; |
| 815 | static u_long unpst_recvspace = PIPSIZ; |
| 816 | static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ |
| 817 | static u_long unpdg_recvspace = 4*1024; |
| 818 | |
| 819 | static int unp_rights; /* file descriptors in flight */ |
| 820 | static struct spinlock unp_spin = SPINLOCK_INITIALIZER(&unp_spin, "unp_spin"); |
| 821 | |
| 822 | SYSCTL_DECL(_net_local_seqpacket); |
| 823 | SYSCTL_DECL(_net_local_stream); |
| 824 | SYSCTL_INT(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, |
| 825 | &unpst_sendspace, 0, "Size of stream socket send buffer"); |
| 826 | SYSCTL_INT(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, |
| 827 | &unpst_recvspace, 0, "Size of stream socket receive buffer"); |
| 828 | |
| 829 | SYSCTL_DECL(_net_local_dgram); |
| 830 | SYSCTL_INT(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, |
| 831 | &unpdg_sendspace, 0, "Max datagram socket size"); |
| 832 | SYSCTL_INT(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, |
| 833 | &unpdg_recvspace, 0, "Size of datagram socket receive buffer"); |
| 834 | |
| 835 | SYSCTL_DECL(_net_local); |
| 836 | SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, |
| 837 | "File descriptors in flight"); |
| 838 | |
| 839 | static int |
| 840 | unp_attach(struct socket *so, struct pru_attach_info *ai) |
| 841 | { |
| 842 | struct unpcb *unp; |
| 843 | int error; |
| 844 | |
| 845 | lwkt_gettoken(&unp_token); |
| 846 | |
| 847 | if (so->so_snd.ssb_hiwat == 0 || so->so_rcv.ssb_hiwat == 0) { |
| 848 | switch (so->so_type) { |
| 849 | case SOCK_STREAM: |
| 850 | case SOCK_SEQPACKET: |
| 851 | error = soreserve(so, unpst_sendspace, unpst_recvspace, |
| 852 | ai->sb_rlimit); |
| 853 | break; |
| 854 | |
| 855 | case SOCK_DGRAM: |
| 856 | error = soreserve(so, unpdg_sendspace, unpdg_recvspace, |
| 857 | ai->sb_rlimit); |
| 858 | break; |
| 859 | |
| 860 | default: |
| 861 | panic("unp_attach"); |
| 862 | } |
| 863 | if (error) |
| 864 | goto failed; |
| 865 | } |
| 866 | |
| 867 | /* |
| 868 | * In order to support sendfile we have to set either SSB_STOPSUPP |
| 869 | * or SSB_PREALLOC. Unix domain sockets use the SSB_STOP flow |
| 870 | * control mechanism. |
| 871 | */ |
| 872 | if (so->so_type == SOCK_STREAM) { |
| 873 | atomic_set_int(&so->so_rcv.ssb_flags, SSB_STOPSUPP); |
| 874 | atomic_set_int(&so->so_snd.ssb_flags, SSB_STOPSUPP); |
| 875 | } |
| 876 | |
| 877 | unp = kmalloc(sizeof(*unp), M_UNPCB, M_WAITOK | M_ZERO | M_NULLOK); |
| 878 | if (unp == NULL) { |
| 879 | error = ENOBUFS; |
| 880 | goto failed; |
| 881 | } |
| 882 | unp->unp_refcnt = 1; |
| 883 | unp->unp_gencnt = ++unp_gencnt; |
| 884 | unp_count++; |
| 885 | LIST_INIT(&unp->unp_refs); |
| 886 | unp->unp_socket = so; |
| 887 | unp->unp_rvnode = ai->fd_rdir; /* jail cruft XXX JH */ |
| 888 | LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead |
| 889 | : &unp_shead, unp, unp_link); |
| 890 | so->so_pcb = (caddr_t)unp; |
| 891 | soreference(so); |
| 892 | error = 0; |
| 893 | failed: |
| 894 | lwkt_reltoken(&unp_token); |
| 895 | return error; |
| 896 | } |
| 897 | |
| 898 | static void |
| 899 | unp_detach(struct unpcb *unp) |
| 900 | { |
| 901 | struct socket *so; |
| 902 | |
| 903 | lwkt_gettoken(&unp_token); |
| 904 | lwkt_getpooltoken(unp); |
| 905 | |
| 906 | LIST_REMOVE(unp, unp_link); /* both tokens required */ |
| 907 | unp->unp_gencnt = ++unp_gencnt; |
| 908 | --unp_count; |
| 909 | if (unp->unp_vnode) { |
| 910 | unp->unp_vnode->v_socket = NULL; |
| 911 | vrele(unp->unp_vnode); |
| 912 | unp->unp_vnode = NULL; |
| 913 | } |
| 914 | soisdisconnected(unp->unp_socket); |
| 915 | so = unp->unp_socket; |
| 916 | soreference(so); /* for delayed sorflush */ |
| 917 | KKASSERT(so->so_pcb == unp); |
| 918 | so->so_pcb = NULL; /* both tokens required */ |
| 919 | unp->unp_socket = NULL; |
| 920 | sofree(so); /* remove pcb ref */ |
| 921 | |
| 922 | if (unp_rights) { |
| 923 | /* |
| 924 | * Normally the receive buffer is flushed later, |
| 925 | * in sofree, but if our receive buffer holds references |
| 926 | * to descriptors that are now garbage, we will dispose |
| 927 | * of those descriptor references after the garbage collector |
| 928 | * gets them (resulting in a "panic: closef: count < 0"). |
| 929 | */ |
| 930 | sorflush(so); |
| 931 | unp_gc(); |
| 932 | } |
| 933 | sofree(so); |
| 934 | lwkt_relpooltoken(unp); |
| 935 | lwkt_reltoken(&unp_token); |
| 936 | |
| 937 | KASSERT(unp->unp_conn == NULL, ("unp is still connected")); |
| 938 | KASSERT(LIST_EMPTY(&unp->unp_refs), ("unp still has references")); |
| 939 | |
| 940 | if (unp->unp_addr) |
| 941 | kfree(unp->unp_addr, M_SONAME); |
| 942 | kfree(unp, M_UNPCB); |
| 943 | } |
| 944 | |
| 945 | static int |
| 946 | unp_bind(struct unpcb *unp, struct sockaddr *nam, struct thread *td) |
| 947 | { |
| 948 | struct proc *p = td->td_proc; |
| 949 | struct sockaddr_un *soun = (struct sockaddr_un *)nam; |
| 950 | struct vnode *vp; |
| 951 | struct vattr vattr; |
| 952 | int error, namelen; |
| 953 | struct nlookupdata nd; |
| 954 | char buf[SOCK_MAXADDRLEN]; |
| 955 | |
| 956 | lwkt_gettoken(&unp_token); |
| 957 | if (unp->unp_vnode != NULL) { |
| 958 | error = EINVAL; |
| 959 | goto failed; |
| 960 | } |
| 961 | namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); |
| 962 | if (namelen <= 0) { |
| 963 | error = EINVAL; |
| 964 | goto failed; |
| 965 | } |
| 966 | strncpy(buf, soun->sun_path, namelen); |
| 967 | buf[namelen] = 0; /* null-terminate the string */ |
| 968 | error = nlookup_init(&nd, buf, UIO_SYSSPACE, |
| 969 | NLC_LOCKVP | NLC_CREATE | NLC_REFDVP); |
| 970 | if (error == 0) |
| 971 | error = nlookup(&nd); |
| 972 | if (error == 0 && nd.nl_nch.ncp->nc_vp != NULL) |
| 973 | error = EADDRINUSE; |
| 974 | if (error) |
| 975 | goto done; |
| 976 | |
| 977 | VATTR_NULL(&vattr); |
| 978 | vattr.va_type = VSOCK; |
| 979 | vattr.va_mode = (ACCESSPERMS & ~p->p_fd->fd_cmask); |
| 980 | error = VOP_NCREATE(&nd.nl_nch, nd.nl_dvp, &vp, nd.nl_cred, &vattr); |
| 981 | if (error == 0) { |
| 982 | if (unp->unp_vnode == NULL) { |
| 983 | vp->v_socket = unp->unp_socket; |
| 984 | unp->unp_vnode = vp; |
| 985 | unp->unp_addr = (struct sockaddr_un *)dup_sockaddr(nam); |
| 986 | vn_unlock(vp); |
| 987 | } else { |
| 988 | vput(vp); /* late race */ |
| 989 | error = EINVAL; |
| 990 | } |
| 991 | } |
| 992 | done: |
| 993 | nlookup_done(&nd); |
| 994 | failed: |
| 995 | lwkt_reltoken(&unp_token); |
| 996 | return (error); |
| 997 | } |
| 998 | |
| 999 | static int |
| 1000 | unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) |
| 1001 | { |
| 1002 | struct unpcb *unp, *unp2; |
| 1003 | int error, flags = 0; |
| 1004 | |
| 1005 | lwkt_gettoken(&unp_token); |
| 1006 | |
| 1007 | unp = unp_getsocktoken(so); |
| 1008 | if (!UNP_ISATTACHED(unp)) { |
| 1009 | error = EINVAL; |
| 1010 | goto failed; |
| 1011 | } |
| 1012 | |
| 1013 | if ((unp->unp_flags & UNP_CONNECTING) || unp->unp_conn != NULL) { |
| 1014 | error = EISCONN; |
| 1015 | goto failed; |
| 1016 | } |
| 1017 | |
| 1018 | flags = UNP_CONNECTING; |
| 1019 | unp_setflags(unp, flags); |
| 1020 | |
| 1021 | error = unp_find_lockref(nam, td, so->so_type, &unp2); |
| 1022 | if (error) |
| 1023 | goto failed; |
| 1024 | /* |
| 1025 | * NOTE: |
| 1026 | * unp2 is locked and referenced. |
| 1027 | */ |
| 1028 | |
| 1029 | if (so->so_proto->pr_flags & PR_CONNREQUIRED) { |
| 1030 | struct socket *so2, *so3; |
| 1031 | struct unpcb *unp3; |
| 1032 | |
| 1033 | so2 = unp2->unp_socket; |
| 1034 | if (!(so2->so_options & SO_ACCEPTCONN) || |
| 1035 | (so3 = sonewconn_faddr(so2, 0, NULL, |
| 1036 | TRUE /* keep ref */)) == NULL) { |
| 1037 | error = ECONNREFUSED; |
| 1038 | goto done; |
| 1039 | } |
| 1040 | /* so3 has a socket reference. */ |
| 1041 | |
| 1042 | unp3 = unp_getsocktoken(so3); |
| 1043 | if (!UNP_ISATTACHED(unp3)) { |
| 1044 | unp_reltoken(unp3); |
| 1045 | /* |
| 1046 | * Already aborted; we only need to drop the |
| 1047 | * socket reference held by sonewconn_faddr(). |
| 1048 | */ |
| 1049 | sofree(so3); |
| 1050 | error = ECONNREFUSED; |
| 1051 | goto done; |
| 1052 | } |
| 1053 | unp_reference(unp3); |
| 1054 | /* |
| 1055 | * NOTE: |
| 1056 | * unp3 is locked and referenced. |
| 1057 | */ |
| 1058 | |
| 1059 | /* |
| 1060 | * Release so3 socket reference held by sonewconn_faddr(). |
| 1061 | * Since we have referenced unp3, neither unp3 nor so3 will |
| 1062 | * be destroyed here. |
| 1063 | */ |
| 1064 | sofree(so3); |
| 1065 | |
| 1066 | if (unp2->unp_addr != NULL) { |
| 1067 | unp3->unp_addr = (struct sockaddr_un *) |
| 1068 | dup_sockaddr((struct sockaddr *)unp2->unp_addr); |
| 1069 | } |
| 1070 | |
| 1071 | /* |
| 1072 | * unp_peercred management: |
| 1073 | * |
| 1074 | * The connecter's (client's) credentials are copied |
| 1075 | * from its process structure at the time of connect() |
| 1076 | * (which is now). |
| 1077 | */ |
| 1078 | cru2x(td->td_proc->p_ucred, &unp3->unp_peercred); |
| 1079 | unp_setflags(unp3, UNP_HAVEPC); |
| 1080 | /* |
| 1081 | * The receiver's (server's) credentials are copied |
| 1082 | * from the unp_peercred member of socket on which the |
| 1083 | * former called listen(); unp_listen() cached that |
| 1084 | * process's credentials at that time so we can use |
| 1085 | * them now. |
| 1086 | */ |
| 1087 | KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED, |
| 1088 | ("unp_connect: listener without cached peercred")); |
| 1089 | memcpy(&unp->unp_peercred, &unp2->unp_peercred, |
| 1090 | sizeof(unp->unp_peercred)); |
| 1091 | unp_setflags(unp, UNP_HAVEPC); |
| 1092 | |
| 1093 | error = unp_connect_pair(unp, unp3); |
| 1094 | if (error) { |
| 1095 | /* XXX we need a better name */ |
| 1096 | soabort_oncpu(so3); |
| 1097 | } |
| 1098 | |
| 1099 | /* Done with unp3 */ |
| 1100 | unp_free(unp3); |
| 1101 | unp_reltoken(unp3); |
| 1102 | } else { |
| 1103 | error = unp_connect_pair(unp, unp2); |
| 1104 | } |
| 1105 | done: |
| 1106 | unp_free(unp2); |
| 1107 | unp_reltoken(unp2); |
| 1108 | failed: |
| 1109 | if (flags) |
| 1110 | unp_clrflags(unp, flags); |
| 1111 | unp_reltoken(unp); |
| 1112 | |
| 1113 | lwkt_reltoken(&unp_token); |
| 1114 | return (error); |
| 1115 | } |
| 1116 | |
| 1117 | /* |
| 1118 | * Connect two unix domain sockets together. |
| 1119 | * |
| 1120 | * NOTE: Semantics for any change to unp_conn requires that the per-unp |
| 1121 | * pool token also be held. |
| 1122 | */ |
| 1123 | int |
| 1124 | unp_connect2(struct socket *so, struct socket *so2) |
| 1125 | { |
| 1126 | struct unpcb *unp, *unp2; |
| 1127 | int error; |
| 1128 | |
| 1129 | lwkt_gettoken(&unp_token); |
| 1130 | if (so2->so_type != so->so_type) { |
| 1131 | lwkt_reltoken(&unp_token); |
| 1132 | return (EPROTOTYPE); |
| 1133 | } |
| 1134 | unp = unp_getsocktoken(so); |
| 1135 | unp2 = unp_getsocktoken(so2); |
| 1136 | |
| 1137 | if (!UNP_ISATTACHED(unp)) { |
| 1138 | error = EINVAL; |
| 1139 | goto done; |
| 1140 | } |
| 1141 | if (!UNP_ISATTACHED(unp2)) { |
| 1142 | error = ECONNREFUSED; |
| 1143 | goto done; |
| 1144 | } |
| 1145 | |
| 1146 | if (unp->unp_conn != NULL) { |
| 1147 | error = EISCONN; |
| 1148 | goto done; |
| 1149 | } |
| 1150 | if ((so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET) && |
| 1151 | unp2->unp_conn != NULL) { |
| 1152 | error = EISCONN; |
| 1153 | goto done; |
| 1154 | } |
| 1155 | |
| 1156 | error = unp_connect_pair(unp, unp2); |
| 1157 | done: |
| 1158 | unp_reltoken(unp2); |
| 1159 | unp_reltoken(unp); |
| 1160 | lwkt_reltoken(&unp_token); |
| 1161 | return (error); |
| 1162 | } |
| 1163 | |
| 1164 | /* |
| 1165 | * Disconnect a unix domain socket pair. |
| 1166 | * |
| 1167 | * NOTE: Semantics for any change to unp_conn requires that the per-unp |
| 1168 | * pool token also be held. |
| 1169 | */ |
| 1170 | static void |
| 1171 | unp_disconnect(struct unpcb *unp, int error) |
| 1172 | { |
| 1173 | struct socket *so = unp->unp_socket; |
| 1174 | struct unpcb *unp2; |
| 1175 | |
| 1176 | ASSERT_LWKT_TOKEN_HELD(&unp_token); |
| 1177 | UNP_ASSERT_TOKEN_HELD(unp); |
| 1178 | |
| 1179 | if (error) |
| 1180 | so->so_error = error; |
| 1181 | |
| 1182 | while ((unp2 = unp->unp_conn) != NULL) { |
| 1183 | lwkt_getpooltoken(unp2); |
| 1184 | if (unp2 == unp->unp_conn) |
| 1185 | break; |
| 1186 | lwkt_relpooltoken(unp2); |
| 1187 | } |
| 1188 | if (unp2 == NULL) |
| 1189 | return; |
| 1190 | /* unp2 is locked. */ |
| 1191 | |
| 1192 | KASSERT((unp2->unp_flags & UNP_DROPPED) == 0, ("unp2 was dropped")); |
| 1193 | |
| 1194 | unp->unp_conn = NULL; |
| 1195 | |
| 1196 | switch (so->so_type) { |
| 1197 | case SOCK_DGRAM: |
| 1198 | LIST_REMOVE(unp, unp_reflink); |
| 1199 | soclrstate(so, SS_ISCONNECTED); |
| 1200 | break; |
| 1201 | |
| 1202 | case SOCK_STREAM: |
| 1203 | case SOCK_SEQPACKET: |
| 1204 | /* |
| 1205 | * Keep a reference before clearing the unp_conn |
| 1206 | * to avoid racing uipc_detach()/uipc_abort() in |
| 1207 | * other thread. |
| 1208 | */ |
| 1209 | unp_reference(unp2); |
| 1210 | KASSERT(unp2->unp_conn == unp, ("unp_conn mismatch")); |
| 1211 | unp2->unp_conn = NULL; |
| 1212 | |
| 1213 | soisdisconnected(so); |
| 1214 | soisdisconnected(unp2->unp_socket); |
| 1215 | |
| 1216 | unp_free(unp2); |
| 1217 | break; |
| 1218 | } |
| 1219 | |
| 1220 | lwkt_relpooltoken(unp2); |
| 1221 | } |
| 1222 | |
| 1223 | #ifdef notdef |
| 1224 | void |
| 1225 | unp_abort(struct unpcb *unp) |
| 1226 | { |
| 1227 | lwkt_gettoken(&unp_token); |
| 1228 | unp_free(unp); |
| 1229 | lwkt_reltoken(&unp_token); |
| 1230 | } |
| 1231 | #endif |
| 1232 | |
| 1233 | static int |
| 1234 | prison_unpcb(struct thread *td, struct unpcb *unp) |
| 1235 | { |
| 1236 | struct proc *p; |
| 1237 | |
| 1238 | if (td == NULL) |
| 1239 | return (0); |
| 1240 | if ((p = td->td_proc) == NULL) |
| 1241 | return (0); |
| 1242 | if (!p->p_ucred->cr_prison) |
| 1243 | return (0); |
| 1244 | if (p->p_fd->fd_rdir == unp->unp_rvnode) |
| 1245 | return (0); |
| 1246 | return (1); |
| 1247 | } |
| 1248 | |
| 1249 | static int |
| 1250 | unp_pcblist(SYSCTL_HANDLER_ARGS) |
| 1251 | { |
| 1252 | int error, i, n; |
| 1253 | struct unpcb *unp, **unp_list; |
| 1254 | unp_gen_t gencnt; |
| 1255 | struct unp_head *head; |
| 1256 | |
| 1257 | head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead); |
| 1258 | |
| 1259 | KKASSERT(curproc != NULL); |
| 1260 | |
| 1261 | /* |
| 1262 | * The process of preparing the PCB list is too time-consuming and |
| 1263 | * resource-intensive to repeat twice on every request. |
| 1264 | */ |
| 1265 | if (req->oldptr == NULL) { |
| 1266 | n = unp_count; |
| 1267 | req->oldidx = (n + n/8) * sizeof(struct xunpcb); |
| 1268 | return 0; |
| 1269 | } |
| 1270 | |
| 1271 | if (req->newptr != NULL) |
| 1272 | return EPERM; |
| 1273 | |
| 1274 | lwkt_gettoken(&unp_token); |
| 1275 | |
| 1276 | /* |
| 1277 | * OK, now we're committed to doing something. |
| 1278 | */ |
| 1279 | gencnt = unp_gencnt; |
| 1280 | n = unp_count; |
| 1281 | |
| 1282 | unp_list = kmalloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); |
| 1283 | |
| 1284 | for (unp = LIST_FIRST(head), i = 0; unp && i < n; |
| 1285 | unp = LIST_NEXT(unp, unp_link)) { |
| 1286 | if (unp->unp_gencnt <= gencnt && !prison_unpcb(req->td, unp)) |
| 1287 | unp_list[i++] = unp; |
| 1288 | } |
| 1289 | n = i; /* in case we lost some during malloc */ |
| 1290 | |
| 1291 | error = 0; |
| 1292 | for (i = 0; i < n; i++) { |
| 1293 | unp = unp_list[i]; |
| 1294 | if (unp->unp_gencnt <= gencnt) { |
| 1295 | struct xunpcb xu; |
| 1296 | xu.xu_len = sizeof xu; |
| 1297 | xu.xu_unpp = unp; |
| 1298 | /* |
| 1299 | * XXX - need more locking here to protect against |
| 1300 | * connect/disconnect races for SMP. |
| 1301 | */ |
| 1302 | if (unp->unp_addr) |
| 1303 | bcopy(unp->unp_addr, &xu.xu_addr, |
| 1304 | unp->unp_addr->sun_len); |
| 1305 | if (unp->unp_conn && unp->unp_conn->unp_addr) |
| 1306 | bcopy(unp->unp_conn->unp_addr, |
| 1307 | &xu.xu_caddr, |
| 1308 | unp->unp_conn->unp_addr->sun_len); |
| 1309 | bcopy(unp, &xu.xu_unp, sizeof *unp); |
| 1310 | sotoxsocket(unp->unp_socket, &xu.xu_socket); |
| 1311 | error = SYSCTL_OUT(req, &xu, sizeof xu); |
| 1312 | } |
| 1313 | } |
| 1314 | lwkt_reltoken(&unp_token); |
| 1315 | kfree(unp_list, M_TEMP); |
| 1316 | |
| 1317 | return error; |
| 1318 | } |
| 1319 | |
| 1320 | SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD, |
| 1321 | (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", |
| 1322 | "List of active local datagram sockets"); |
| 1323 | SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD, |
| 1324 | (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", |
| 1325 | "List of active local stream sockets"); |
| 1326 | SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, CTLFLAG_RD, |
| 1327 | (caddr_t)(long)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb", |
| 1328 | "List of active local seqpacket stream sockets"); |
| 1329 | |
| 1330 | static void |
| 1331 | unp_shutdown(struct unpcb *unp) |
| 1332 | { |
| 1333 | struct socket *so; |
| 1334 | |
| 1335 | if ((unp->unp_socket->so_type == SOCK_STREAM || |
| 1336 | unp->unp_socket->so_type == SOCK_SEQPACKET) && |
| 1337 | unp->unp_conn != NULL && (so = unp->unp_conn->unp_socket)) { |
| 1338 | socantrcvmore(so); |
| 1339 | } |
| 1340 | } |
| 1341 | |
| 1342 | #ifdef notdef |
| 1343 | void |
| 1344 | unp_drain(void) |
| 1345 | { |
| 1346 | lwkt_gettoken(&unp_token); |
| 1347 | lwkt_reltoken(&unp_token); |
| 1348 | } |
| 1349 | #endif |
| 1350 | |
| 1351 | int |
| 1352 | unp_externalize(struct mbuf *rights) |
| 1353 | { |
| 1354 | struct thread *td = curthread; |
| 1355 | struct proc *p = td->td_proc; /* XXX */ |
| 1356 | struct lwp *lp = td->td_lwp; |
| 1357 | struct cmsghdr *cm = mtod(rights, struct cmsghdr *); |
| 1358 | int *fdp; |
| 1359 | int i; |
| 1360 | struct file **rp; |
| 1361 | struct file *fp; |
| 1362 | int newfds = (cm->cmsg_len - (CMSG_DATA(cm) - (u_char *)cm)) |
| 1363 | / sizeof (struct file *); |
| 1364 | int f; |
| 1365 | |
| 1366 | lwkt_gettoken(&unp_token); |
| 1367 | |
| 1368 | /* |
| 1369 | * if the new FD's will not fit, then we free them all |
| 1370 | */ |
| 1371 | if (!fdavail(p, newfds)) { |
| 1372 | rp = (struct file **)CMSG_DATA(cm); |
| 1373 | for (i = 0; i < newfds; i++) { |
| 1374 | fp = *rp; |
| 1375 | /* |
| 1376 | * zero the pointer before calling unp_discard, |
| 1377 | * since it may end up in unp_gc().. |
| 1378 | */ |
| 1379 | *rp++ = NULL; |
| 1380 | unp_discard(fp, NULL); |
| 1381 | } |
| 1382 | lwkt_reltoken(&unp_token); |
| 1383 | return (EMSGSIZE); |
| 1384 | } |
| 1385 | |
| 1386 | /* |
| 1387 | * now change each pointer to an fd in the global table to |
| 1388 | * an integer that is the index to the local fd table entry |
| 1389 | * that we set up to point to the global one we are transferring. |
| 1390 | * If sizeof (struct file *) is bigger than or equal to sizeof int, |
| 1391 | * then do it in forward order. In that case, an integer will |
| 1392 | * always come in the same place or before its corresponding |
| 1393 | * struct file pointer. |
| 1394 | * If sizeof (struct file *) is smaller than sizeof int, then |
| 1395 | * do it in reverse order. |
| 1396 | */ |
| 1397 | if (sizeof (struct file *) >= sizeof (int)) { |
| 1398 | fdp = (int *)CMSG_DATA(cm); |
| 1399 | rp = (struct file **)CMSG_DATA(cm); |
| 1400 | for (i = 0; i < newfds; i++) { |
| 1401 | if (fdalloc(p, 0, &f)) |
| 1402 | panic("unp_externalize"); |
| 1403 | fp = *rp++; |
| 1404 | unp_fp_externalize(lp, fp, f); |
| 1405 | *fdp++ = f; |
| 1406 | } |
| 1407 | } else { |
| 1408 | fdp = (int *)CMSG_DATA(cm) + newfds - 1; |
| 1409 | rp = (struct file **)CMSG_DATA(cm) + newfds - 1; |
| 1410 | for (i = 0; i < newfds; i++) { |
| 1411 | if (fdalloc(p, 0, &f)) |
| 1412 | panic("unp_externalize"); |
| 1413 | fp = *rp--; |
| 1414 | unp_fp_externalize(lp, fp, f); |
| 1415 | *fdp-- = f; |
| 1416 | } |
| 1417 | } |
| 1418 | |
| 1419 | /* |
| 1420 | * Adjust length, in case sizeof(struct file *) and sizeof(int) |
| 1421 | * differs. |
| 1422 | */ |
| 1423 | cm->cmsg_len = CMSG_LEN(newfds * sizeof(int)); |
| 1424 | rights->m_len = cm->cmsg_len; |
| 1425 | |
| 1426 | lwkt_reltoken(&unp_token); |
| 1427 | return (0); |
| 1428 | } |
| 1429 | |
| 1430 | static void |
| 1431 | unp_fp_externalize(struct lwp *lp, struct file *fp, int fd) |
| 1432 | { |
| 1433 | struct file *fx; |
| 1434 | int error; |
| 1435 | |
| 1436 | lwkt_gettoken(&unp_token); |
| 1437 | |
| 1438 | if (lp) { |
| 1439 | KKASSERT(fd >= 0); |
| 1440 | if (fp->f_flag & FREVOKED) { |
| 1441 | kprintf("Warning: revoked fp exiting unix socket\n"); |
| 1442 | fx = NULL; |
| 1443 | error = falloc(lp, &fx, NULL); |
| 1444 | if (error == 0) |
| 1445 | fsetfd(lp->lwp_proc->p_fd, fx, fd); |
| 1446 | else |
| 1447 | fsetfd(lp->lwp_proc->p_fd, NULL, fd); |
| 1448 | fdrop(fx); |
| 1449 | } else { |
| 1450 | fsetfd(lp->lwp_proc->p_fd, fp, fd); |
| 1451 | } |
| 1452 | } |
| 1453 | spin_lock(&unp_spin); |
| 1454 | fp->f_msgcount--; |
| 1455 | unp_rights--; |
| 1456 | spin_unlock(&unp_spin); |
| 1457 | fdrop(fp); |
| 1458 | |
| 1459 | lwkt_reltoken(&unp_token); |
| 1460 | } |
| 1461 | |
| 1462 | |
| 1463 | void |
| 1464 | unp_init(void) |
| 1465 | { |
| 1466 | LIST_INIT(&unp_dhead); |
| 1467 | LIST_INIT(&unp_shead); |
| 1468 | spin_init(&unp_spin, "unpinit"); |
| 1469 | } |
| 1470 | |
| 1471 | static int |
| 1472 | unp_internalize(struct mbuf *control, struct thread *td) |
| 1473 | { |
| 1474 | struct proc *p = td->td_proc; |
| 1475 | struct filedesc *fdescp; |
| 1476 | struct cmsghdr *cm = mtod(control, struct cmsghdr *); |
| 1477 | struct file **rp; |
| 1478 | struct file *fp; |
| 1479 | int i, fd, *fdp; |
| 1480 | struct cmsgcred *cmcred; |
| 1481 | int oldfds; |
| 1482 | u_int newlen; |
| 1483 | int error; |
| 1484 | |
| 1485 | KKASSERT(p); |
| 1486 | lwkt_gettoken(&unp_token); |
| 1487 | |
| 1488 | fdescp = p->p_fd; |
| 1489 | if ((cm->cmsg_type != SCM_RIGHTS && cm->cmsg_type != SCM_CREDS) || |
| 1490 | cm->cmsg_level != SOL_SOCKET || |
| 1491 | CMSG_ALIGN(cm->cmsg_len) != control->m_len) { |
| 1492 | error = EINVAL; |
| 1493 | goto done; |
| 1494 | } |
| 1495 | |
| 1496 | /* |
| 1497 | * Fill in credential information. |
| 1498 | */ |
| 1499 | if (cm->cmsg_type == SCM_CREDS) { |
| 1500 | cmcred = (struct cmsgcred *)CMSG_DATA(cm); |
| 1501 | cmcred->cmcred_pid = p->p_pid; |
| 1502 | cmcred->cmcred_uid = p->p_ucred->cr_ruid; |
| 1503 | cmcred->cmcred_gid = p->p_ucred->cr_rgid; |
| 1504 | cmcred->cmcred_euid = p->p_ucred->cr_uid; |
| 1505 | cmcred->cmcred_ngroups = MIN(p->p_ucred->cr_ngroups, |
| 1506 | CMGROUP_MAX); |
| 1507 | for (i = 0; i < cmcred->cmcred_ngroups; i++) |
| 1508 | cmcred->cmcred_groups[i] = p->p_ucred->cr_groups[i]; |
| 1509 | error = 0; |
| 1510 | goto done; |
| 1511 | } |
| 1512 | |
| 1513 | /* |
| 1514 | * cmsghdr may not be aligned, do not allow calculation(s) to |
| 1515 | * go negative. |
| 1516 | */ |
| 1517 | if (cm->cmsg_len < CMSG_LEN(0)) { |
| 1518 | error = EINVAL; |
| 1519 | goto done; |
| 1520 | } |
| 1521 | |
| 1522 | oldfds = (cm->cmsg_len - CMSG_LEN(0)) / sizeof (int); |
| 1523 | |
| 1524 | /* |
| 1525 | * check that all the FDs passed in refer to legal OPEN files |
| 1526 | * If not, reject the entire operation. |
| 1527 | */ |
| 1528 | fdp = (int *)CMSG_DATA(cm); |
| 1529 | for (i = 0; i < oldfds; i++) { |
| 1530 | fd = *fdp++; |
| 1531 | if ((unsigned)fd >= fdescp->fd_nfiles || |
| 1532 | fdescp->fd_files[fd].fp == NULL) { |
| 1533 | error = EBADF; |
| 1534 | goto done; |
| 1535 | } |
| 1536 | if (fdescp->fd_files[fd].fp->f_type == DTYPE_KQUEUE) { |
| 1537 | error = EOPNOTSUPP; |
| 1538 | goto done; |
| 1539 | } |
| 1540 | } |
| 1541 | /* |
| 1542 | * Now replace the integer FDs with pointers to |
| 1543 | * the associated global file table entry.. |
| 1544 | * Allocate a bigger buffer as necessary. But if an cluster is not |
| 1545 | * enough, return E2BIG. |
| 1546 | */ |
| 1547 | newlen = CMSG_LEN(oldfds * sizeof(struct file *)); |
| 1548 | if (newlen > MCLBYTES) { |
| 1549 | error = E2BIG; |
| 1550 | goto done; |
| 1551 | } |
| 1552 | if (newlen - control->m_len > M_TRAILINGSPACE(control)) { |
| 1553 | if (control->m_flags & M_EXT) { |
| 1554 | error = E2BIG; |
| 1555 | goto done; |
| 1556 | } |
| 1557 | MCLGET(control, M_WAITOK); |
| 1558 | if (!(control->m_flags & M_EXT)) { |
| 1559 | error = ENOBUFS; |
| 1560 | goto done; |
| 1561 | } |
| 1562 | |
| 1563 | /* copy the data to the cluster */ |
| 1564 | memcpy(mtod(control, char *), cm, cm->cmsg_len); |
| 1565 | cm = mtod(control, struct cmsghdr *); |
| 1566 | } |
| 1567 | |
| 1568 | /* |
| 1569 | * Adjust length, in case sizeof(struct file *) and sizeof(int) |
| 1570 | * differs. |
| 1571 | */ |
| 1572 | cm->cmsg_len = newlen; |
| 1573 | control->m_len = CMSG_ALIGN(newlen); |
| 1574 | |
| 1575 | /* |
| 1576 | * Transform the file descriptors into struct file pointers. |
| 1577 | * If sizeof (struct file *) is bigger than or equal to sizeof int, |
| 1578 | * then do it in reverse order so that the int won't get until |
| 1579 | * we're done. |
| 1580 | * If sizeof (struct file *) is smaller than sizeof int, then |
| 1581 | * do it in forward order. |
| 1582 | */ |
| 1583 | if (sizeof (struct file *) >= sizeof (int)) { |
| 1584 | fdp = (int *)CMSG_DATA(cm) + oldfds - 1; |
| 1585 | rp = (struct file **)CMSG_DATA(cm) + oldfds - 1; |
| 1586 | for (i = 0; i < oldfds; i++) { |
| 1587 | fp = fdescp->fd_files[*fdp--].fp; |
| 1588 | *rp-- = fp; |
| 1589 | fhold(fp); |
| 1590 | spin_lock(&unp_spin); |
| 1591 | fp->f_msgcount++; |
| 1592 | unp_rights++; |
| 1593 | spin_unlock(&unp_spin); |
| 1594 | } |
| 1595 | } else { |
| 1596 | fdp = (int *)CMSG_DATA(cm); |
| 1597 | rp = (struct file **)CMSG_DATA(cm); |
| 1598 | for (i = 0; i < oldfds; i++) { |
| 1599 | fp = fdescp->fd_files[*fdp++].fp; |
| 1600 | *rp++ = fp; |
| 1601 | fhold(fp); |
| 1602 | spin_lock(&unp_spin); |
| 1603 | fp->f_msgcount++; |
| 1604 | unp_rights++; |
| 1605 | spin_unlock(&unp_spin); |
| 1606 | } |
| 1607 | } |
| 1608 | error = 0; |
| 1609 | done: |
| 1610 | lwkt_reltoken(&unp_token); |
| 1611 | return error; |
| 1612 | } |
| 1613 | |
| 1614 | /* |
| 1615 | * Garbage collect in-transit file descriptors that get lost due to |
| 1616 | * loops (i.e. when a socket is sent to another process over itself, |
| 1617 | * and more complex situations). |
| 1618 | * |
| 1619 | * NOT MPSAFE - TODO socket flush code and maybe closef. Rest is MPSAFE. |
| 1620 | */ |
| 1621 | |
| 1622 | struct unp_gc_info { |
| 1623 | struct file **extra_ref; |
| 1624 | struct file *locked_fp; |
| 1625 | int defer; |
| 1626 | int index; |
| 1627 | int maxindex; |
| 1628 | }; |
| 1629 | |
| 1630 | static void |
| 1631 | unp_gc(void) |
| 1632 | { |
| 1633 | struct unp_gc_info info; |
| 1634 | static boolean_t unp_gcing; |
| 1635 | struct file **fpp; |
| 1636 | int i; |
| 1637 | |
| 1638 | /* |
| 1639 | * Only one gc can be in-progress at any given moment |
| 1640 | */ |
| 1641 | spin_lock(&unp_spin); |
| 1642 | if (unp_gcing) { |
| 1643 | spin_unlock(&unp_spin); |
| 1644 | return; |
| 1645 | } |
| 1646 | unp_gcing = TRUE; |
| 1647 | spin_unlock(&unp_spin); |
| 1648 | |
| 1649 | lwkt_gettoken(&unp_token); |
| 1650 | |
| 1651 | /* |
| 1652 | * Before going through all this, set all FDs to be NOT defered |
| 1653 | * and NOT externally accessible (not marked). During the scan |
| 1654 | * a fd can be marked externally accessible but we may or may not |
| 1655 | * be able to immediately process it (controlled by FDEFER). |
| 1656 | * |
| 1657 | * If we loop sleep a bit. The complexity of the topology can cause |
| 1658 | * multiple loops. Also failure to acquire the socket's so_rcv |
| 1659 | * token can cause us to loop. |
| 1660 | */ |
| 1661 | allfiles_scan_exclusive(unp_gc_clearmarks, NULL); |
| 1662 | do { |
| 1663 | info.defer = 0; |
| 1664 | allfiles_scan_exclusive(unp_gc_checkmarks, &info); |
| 1665 | if (info.defer) |
| 1666 | tsleep(&info, 0, "gcagain", 1); |
| 1667 | } while (info.defer); |
| 1668 | |
| 1669 | /* |
| 1670 | * We grab an extra reference to each of the file table entries |
| 1671 | * that are not otherwise accessible and then free the rights |
| 1672 | * that are stored in messages on them. |
| 1673 | * |
| 1674 | * The bug in the orginal code is a little tricky, so I'll describe |
| 1675 | * what's wrong with it here. |
| 1676 | * |
| 1677 | * It is incorrect to simply unp_discard each entry for f_msgcount |
| 1678 | * times -- consider the case of sockets A and B that contain |
| 1679 | * references to each other. On a last close of some other socket, |
| 1680 | * we trigger a gc since the number of outstanding rights (unp_rights) |
| 1681 | * is non-zero. If during the sweep phase the gc code un_discards, |
| 1682 | * we end up doing a (full) closef on the descriptor. A closef on A |
| 1683 | * results in the following chain. Closef calls soo_close, which |
| 1684 | * calls soclose. Soclose calls first (through the switch |
| 1685 | * uipc_usrreq) unp_detach, which re-invokes unp_gc. Unp_gc simply |
| 1686 | * returns because the previous instance had set unp_gcing, and |
| 1687 | * we return all the way back to soclose, which marks the socket |
| 1688 | * with SS_NOFDREF, and then calls sofree. Sofree calls sorflush |
| 1689 | * to free up the rights that are queued in messages on the socket A, |
| 1690 | * i.e., the reference on B. The sorflush calls via the dom_dispose |
| 1691 | * switch unp_dispose, which unp_scans with unp_discard. This second |
| 1692 | * instance of unp_discard just calls closef on B. |
| 1693 | * |
| 1694 | * Well, a similar chain occurs on B, resulting in a sorflush on B, |
| 1695 | * which results in another closef on A. Unfortunately, A is already |
| 1696 | * being closed, and the descriptor has already been marked with |
| 1697 | * SS_NOFDREF, and soclose panics at this point. |
| 1698 | * |
| 1699 | * Here, we first take an extra reference to each inaccessible |
| 1700 | * descriptor. Then, we call sorflush ourself, since we know |
| 1701 | * it is a Unix domain socket anyhow. After we destroy all the |
| 1702 | * rights carried in messages, we do a last closef to get rid |
| 1703 | * of our extra reference. This is the last close, and the |
| 1704 | * unp_detach etc will shut down the socket. |
| 1705 | * |
| 1706 | * 91/09/19, bsy@cs.cmu.edu |
| 1707 | */ |
| 1708 | info.extra_ref = kmalloc(256 * sizeof(struct file *), M_FILE, M_WAITOK); |
| 1709 | info.maxindex = 256; |
| 1710 | |
| 1711 | do { |
| 1712 | /* |
| 1713 | * Look for matches |
| 1714 | */ |
| 1715 | info.index = 0; |
| 1716 | allfiles_scan_exclusive(unp_gc_checkrefs, &info); |
| 1717 | |
| 1718 | /* |
| 1719 | * For each FD on our hit list, do the following two things |
| 1720 | */ |
| 1721 | for (i = info.index, fpp = info.extra_ref; --i >= 0; ++fpp) { |
| 1722 | struct file *tfp = *fpp; |
| 1723 | if (tfp->f_type == DTYPE_SOCKET && tfp->f_data != NULL) |
| 1724 | sorflush((struct socket *)(tfp->f_data)); |
| 1725 | } |
| 1726 | for (i = info.index, fpp = info.extra_ref; --i >= 0; ++fpp) |
| 1727 | closef(*fpp, NULL); |
| 1728 | } while (info.index == info.maxindex); |
| 1729 | |
| 1730 | lwkt_reltoken(&unp_token); |
| 1731 | |
| 1732 | kfree((caddr_t)info.extra_ref, M_FILE); |
| 1733 | unp_gcing = FALSE; |
| 1734 | } |
| 1735 | |
| 1736 | /* |
| 1737 | * MPSAFE - NOTE: filehead list and file pointer spinlocked on entry |
| 1738 | */ |
| 1739 | static int |
| 1740 | unp_gc_checkrefs(struct file *fp, void *data) |
| 1741 | { |
| 1742 | struct unp_gc_info *info = data; |
| 1743 | |
| 1744 | if (fp->f_count == 0) |
| 1745 | return(0); |
| 1746 | if (info->index == info->maxindex) |
| 1747 | return(-1); |
| 1748 | |
| 1749 | /* |
| 1750 | * If all refs are from msgs, and it's not marked accessible |
| 1751 | * then it must be referenced from some unreachable cycle |
| 1752 | * of (shut-down) FDs, so include it in our |
| 1753 | * list of FDs to remove |
| 1754 | */ |
| 1755 | if (fp->f_count == fp->f_msgcount && !(fp->f_flag & FMARK)) { |
| 1756 | info->extra_ref[info->index++] = fp; |
| 1757 | fhold(fp); |
| 1758 | } |
| 1759 | return(0); |
| 1760 | } |
| 1761 | |
| 1762 | /* |
| 1763 | * MPSAFE - NOTE: filehead list and file pointer spinlocked on entry |
| 1764 | */ |
| 1765 | static int |
| 1766 | unp_gc_clearmarks(struct file *fp, void *data __unused) |
| 1767 | { |
| 1768 | atomic_clear_int(&fp->f_flag, FMARK | FDEFER); |
| 1769 | return(0); |
| 1770 | } |
| 1771 | |
| 1772 | /* |
| 1773 | * MPSAFE - NOTE: filehead list and file pointer spinlocked on entry |
| 1774 | */ |
| 1775 | static int |
| 1776 | unp_gc_checkmarks(struct file *fp, void *data) |
| 1777 | { |
| 1778 | struct unp_gc_info *info = data; |
| 1779 | struct socket *so; |
| 1780 | |
| 1781 | /* |
| 1782 | * If the file is not open, skip it. Make sure it isn't marked |
| 1783 | * defered or we could loop forever, in case we somehow race |
| 1784 | * something. |
| 1785 | */ |
| 1786 | if (fp->f_count == 0) { |
| 1787 | if (fp->f_flag & FDEFER) |
| 1788 | atomic_clear_int(&fp->f_flag, FDEFER); |
| 1789 | return(0); |
| 1790 | } |
| 1791 | /* |
| 1792 | * If we already marked it as 'defer' in a |
| 1793 | * previous pass, then try process it this time |
| 1794 | * and un-mark it |
| 1795 | */ |
| 1796 | if (fp->f_flag & FDEFER) { |
| 1797 | atomic_clear_int(&fp->f_flag, FDEFER); |
| 1798 | } else { |
| 1799 | /* |
| 1800 | * if it's not defered, then check if it's |
| 1801 | * already marked.. if so skip it |
| 1802 | */ |
| 1803 | if (fp->f_flag & FMARK) |
| 1804 | return(0); |
| 1805 | /* |
| 1806 | * If all references are from messages |
| 1807 | * in transit, then skip it. it's not |
| 1808 | * externally accessible. |
| 1809 | */ |
| 1810 | if (fp->f_count == fp->f_msgcount) |
| 1811 | return(0); |
| 1812 | /* |
| 1813 | * If it got this far then it must be |
| 1814 | * externally accessible. |
| 1815 | */ |
| 1816 | atomic_set_int(&fp->f_flag, FMARK); |
| 1817 | } |
| 1818 | |
| 1819 | /* |
| 1820 | * either it was defered, or it is externally |
| 1821 | * accessible and not already marked so. |
| 1822 | * Now check if it is possibly one of OUR sockets. |
| 1823 | */ |
| 1824 | if (fp->f_type != DTYPE_SOCKET || |
| 1825 | (so = (struct socket *)fp->f_data) == NULL) { |
| 1826 | return(0); |
| 1827 | } |
| 1828 | if (so->so_proto->pr_domain != &localdomain || |
| 1829 | !(so->so_proto->pr_flags & PR_RIGHTS)) { |
| 1830 | return(0); |
| 1831 | } |
| 1832 | |
| 1833 | /* |
| 1834 | * So, Ok, it's one of our sockets and it IS externally accessible |
| 1835 | * (or was defered). Now we look to see if we hold any file |
| 1836 | * descriptors in its message buffers. Follow those links and mark |
| 1837 | * them as accessible too. |
| 1838 | * |
| 1839 | * We are holding multiple spinlocks here, if we cannot get the |
| 1840 | * token non-blocking defer until the next loop. |
| 1841 | */ |
| 1842 | info->locked_fp = fp; |
| 1843 | if (lwkt_trytoken(&so->so_rcv.ssb_token)) { |
| 1844 | unp_scan(so->so_rcv.ssb_mb, unp_mark, info); |
| 1845 | lwkt_reltoken(&so->so_rcv.ssb_token); |
| 1846 | } else { |
| 1847 | atomic_set_int(&fp->f_flag, FDEFER); |
| 1848 | ++info->defer; |
| 1849 | } |
| 1850 | return (0); |
| 1851 | } |
| 1852 | |
| 1853 | /* |
| 1854 | * Scan all unix domain sockets and replace any revoked file pointers |
| 1855 | * found with the dummy file pointer fx. We don't worry about races |
| 1856 | * against file pointers being read out as those are handled in the |
| 1857 | * externalize code. |
| 1858 | */ |
| 1859 | |
| 1860 | #define REVOKE_GC_MAXFILES 32 |
| 1861 | |
| 1862 | struct unp_revoke_gc_info { |
| 1863 | struct file *fx; |
| 1864 | struct file *fary[REVOKE_GC_MAXFILES]; |
| 1865 | int fcount; |
| 1866 | }; |
| 1867 | |
| 1868 | void |
| 1869 | unp_revoke_gc(struct file *fx) |
| 1870 | { |
| 1871 | struct unp_revoke_gc_info info; |
| 1872 | int i; |
| 1873 | |
| 1874 | lwkt_gettoken(&unp_token); |
| 1875 | info.fx = fx; |
| 1876 | do { |
| 1877 | info.fcount = 0; |
| 1878 | allfiles_scan_exclusive(unp_revoke_gc_check, &info); |
| 1879 | for (i = 0; i < info.fcount; ++i) |
| 1880 | unp_fp_externalize(NULL, info.fary[i], -1); |
| 1881 | } while (info.fcount == REVOKE_GC_MAXFILES); |
| 1882 | lwkt_reltoken(&unp_token); |
| 1883 | } |
| 1884 | |
| 1885 | /* |
| 1886 | * Check for and replace revoked descriptors. |
| 1887 | * |
| 1888 | * WARNING: This routine is not allowed to block. |
| 1889 | */ |
| 1890 | static int |
| 1891 | unp_revoke_gc_check(struct file *fps, void *vinfo) |
| 1892 | { |
| 1893 | struct unp_revoke_gc_info *info = vinfo; |
| 1894 | struct file *fp; |
| 1895 | struct socket *so; |
| 1896 | struct mbuf *m0; |
| 1897 | struct mbuf *m; |
| 1898 | struct file **rp; |
| 1899 | struct cmsghdr *cm; |
| 1900 | int i; |
| 1901 | int qfds; |
| 1902 | |
| 1903 | /* |
| 1904 | * Is this a unix domain socket with rights-passing abilities? |
| 1905 | */ |
| 1906 | if (fps->f_type != DTYPE_SOCKET) |
| 1907 | return (0); |
| 1908 | if ((so = (struct socket *)fps->f_data) == NULL) |
| 1909 | return(0); |
| 1910 | if (so->so_proto->pr_domain != &localdomain) |
| 1911 | return(0); |
| 1912 | if ((so->so_proto->pr_flags & PR_RIGHTS) == 0) |
| 1913 | return(0); |
| 1914 | |
| 1915 | /* |
| 1916 | * Scan the mbufs for control messages and replace any revoked |
| 1917 | * descriptors we find. |
| 1918 | */ |
| 1919 | lwkt_gettoken(&so->so_rcv.ssb_token); |
| 1920 | m0 = so->so_rcv.ssb_mb; |
| 1921 | while (m0) { |
| 1922 | for (m = m0; m; m = m->m_next) { |
| 1923 | if (m->m_type != MT_CONTROL) |
| 1924 | continue; |
| 1925 | if (m->m_len < sizeof(*cm)) |
| 1926 | continue; |
| 1927 | cm = mtod(m, struct cmsghdr *); |
| 1928 | if (cm->cmsg_level != SOL_SOCKET || |
| 1929 | cm->cmsg_type != SCM_RIGHTS) { |
| 1930 | continue; |
| 1931 | } |
| 1932 | qfds = (cm->cmsg_len - CMSG_LEN(0)) / sizeof(void *); |
| 1933 | rp = (struct file **)CMSG_DATA(cm); |
| 1934 | for (i = 0; i < qfds; i++) { |
| 1935 | fp = rp[i]; |
| 1936 | if (fp->f_flag & FREVOKED) { |
| 1937 | kprintf("Warning: Removing revoked fp from unix domain socket queue\n"); |
| 1938 | fhold(info->fx); |
| 1939 | info->fx->f_msgcount++; |
| 1940 | unp_rights++; |
| 1941 | rp[i] = info->fx; |
| 1942 | info->fary[info->fcount++] = fp; |
| 1943 | } |
| 1944 | if (info->fcount == REVOKE_GC_MAXFILES) |
| 1945 | break; |
| 1946 | } |
| 1947 | if (info->fcount == REVOKE_GC_MAXFILES) |
| 1948 | break; |
| 1949 | } |
| 1950 | m0 = m0->m_nextpkt; |
| 1951 | if (info->fcount == REVOKE_GC_MAXFILES) |
| 1952 | break; |
| 1953 | } |
| 1954 | lwkt_reltoken(&so->so_rcv.ssb_token); |
| 1955 | |
| 1956 | /* |
| 1957 | * Stop the scan if we filled up our array. |
| 1958 | */ |
| 1959 | if (info->fcount == REVOKE_GC_MAXFILES) |
| 1960 | return(-1); |
| 1961 | return(0); |
| 1962 | } |
| 1963 | |
| 1964 | /* |
| 1965 | * Dispose of the fp's stored in a mbuf. |
| 1966 | * |
| 1967 | * The dds loop can cause additional fps to be entered onto the |
| 1968 | * list while it is running, flattening out the operation and avoiding |
| 1969 | * a deep kernel stack recursion. |
| 1970 | */ |
| 1971 | void |
| 1972 | unp_dispose(struct mbuf *m) |
| 1973 | { |
| 1974 | unp_defdiscard_t dds; |
| 1975 | |
| 1976 | lwkt_gettoken(&unp_token); |
| 1977 | ++unp_defdiscard_nest; |
| 1978 | if (m) { |
| 1979 | unp_scan(m, unp_discard, NULL); |
| 1980 | } |
| 1981 | if (unp_defdiscard_nest == 1) { |
| 1982 | while ((dds = unp_defdiscard_base) != NULL) { |
| 1983 | unp_defdiscard_base = dds->next; |
| 1984 | closef(dds->fp, NULL); |
| 1985 | kfree(dds, M_UNPCB); |
| 1986 | } |
| 1987 | } |
| 1988 | --unp_defdiscard_nest; |
| 1989 | lwkt_reltoken(&unp_token); |
| 1990 | } |
| 1991 | |
| 1992 | static int |
| 1993 | unp_listen(struct unpcb *unp, struct thread *td) |
| 1994 | { |
| 1995 | struct proc *p = td->td_proc; |
| 1996 | |
| 1997 | KKASSERT(p); |
| 1998 | lwkt_gettoken(&unp_token); |
| 1999 | cru2x(p->p_ucred, &unp->unp_peercred); |
| 2000 | unp_setflags(unp, UNP_HAVEPCCACHED); |
| 2001 | lwkt_reltoken(&unp_token); |
| 2002 | return (0); |
| 2003 | } |
| 2004 | |
| 2005 | static void |
| 2006 | unp_scan(struct mbuf *m0, void (*op)(struct file *, void *), void *data) |
| 2007 | { |
| 2008 | struct mbuf *m; |
| 2009 | struct file **rp; |
| 2010 | struct cmsghdr *cm; |
| 2011 | int i; |
| 2012 | int qfds; |
| 2013 | |
| 2014 | while (m0) { |
| 2015 | for (m = m0; m; m = m->m_next) { |
| 2016 | if (m->m_type == MT_CONTROL && |
| 2017 | m->m_len >= sizeof(*cm)) { |
| 2018 | cm = mtod(m, struct cmsghdr *); |
| 2019 | if (cm->cmsg_level != SOL_SOCKET || |
| 2020 | cm->cmsg_type != SCM_RIGHTS) |
| 2021 | continue; |
| 2022 | qfds = (cm->cmsg_len - CMSG_LEN(0)) / |
| 2023 | sizeof(void *); |
| 2024 | rp = (struct file **)CMSG_DATA(cm); |
| 2025 | for (i = 0; i < qfds; i++) |
| 2026 | (*op)(*rp++, data); |
| 2027 | break; /* XXX, but saves time */ |
| 2028 | } |
| 2029 | } |
| 2030 | m0 = m0->m_nextpkt; |
| 2031 | } |
| 2032 | } |
| 2033 | |
| 2034 | /* |
| 2035 | * Mark visibility. info->defer is recalculated on every pass. |
| 2036 | */ |
| 2037 | static void |
| 2038 | unp_mark(struct file *fp, void *data) |
| 2039 | { |
| 2040 | struct unp_gc_info *info = data; |
| 2041 | |
| 2042 | if ((fp->f_flag & FMARK) == 0) { |
| 2043 | ++info->defer; |
| 2044 | atomic_set_int(&fp->f_flag, FMARK | FDEFER); |
| 2045 | } else if (fp->f_flag & FDEFER) { |
| 2046 | ++info->defer; |
| 2047 | } |
| 2048 | } |
| 2049 | |
| 2050 | /* |
| 2051 | * Discard a fp previously held in a unix domain socket mbuf. To |
| 2052 | * avoid blowing out the kernel stack due to contrived chain-reactions |
| 2053 | * we may have to defer the operation to a higher procedural level. |
| 2054 | * |
| 2055 | * Caller holds unp_token |
| 2056 | */ |
| 2057 | static void |
| 2058 | unp_discard(struct file *fp, void *data __unused) |
| 2059 | { |
| 2060 | unp_defdiscard_t dds; |
| 2061 | |
| 2062 | spin_lock(&unp_spin); |
| 2063 | fp->f_msgcount--; |
| 2064 | unp_rights--; |
| 2065 | spin_unlock(&unp_spin); |
| 2066 | |
| 2067 | if (unp_defdiscard_nest) { |
| 2068 | dds = kmalloc(sizeof(*dds), M_UNPCB, M_WAITOK|M_ZERO); |
| 2069 | dds->fp = fp; |
| 2070 | dds->next = unp_defdiscard_base; |
| 2071 | unp_defdiscard_base = dds; |
| 2072 | } else { |
| 2073 | closef(fp, NULL); |
| 2074 | } |
| 2075 | } |
| 2076 | |
| 2077 | static int |
| 2078 | unp_find_lockref(struct sockaddr *nam, struct thread *td, short type, |
| 2079 | struct unpcb **unp_ret) |
| 2080 | { |
| 2081 | struct proc *p = td->td_proc; |
| 2082 | struct sockaddr_un *soun = (struct sockaddr_un *)nam; |
| 2083 | struct vnode *vp = NULL; |
| 2084 | struct socket *so; |
| 2085 | struct unpcb *unp; |
| 2086 | int error, len; |
| 2087 | struct nlookupdata nd; |
| 2088 | char buf[SOCK_MAXADDRLEN]; |
| 2089 | |
| 2090 | *unp_ret = NULL; |
| 2091 | |
| 2092 | len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); |
| 2093 | if (len <= 0) { |
| 2094 | error = EINVAL; |
| 2095 | goto failed; |
| 2096 | } |
| 2097 | strncpy(buf, soun->sun_path, len); |
| 2098 | buf[len] = 0; |
| 2099 | |
| 2100 | error = nlookup_init(&nd, buf, UIO_SYSSPACE, NLC_FOLLOW); |
| 2101 | if (error == 0) |
| 2102 | error = nlookup(&nd); |
| 2103 | if (error == 0) |
| 2104 | error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp); |
| 2105 | nlookup_done(&nd); |
| 2106 | if (error) { |
| 2107 | vp = NULL; |
| 2108 | goto failed; |
| 2109 | } |
| 2110 | |
| 2111 | if (vp->v_type != VSOCK) { |
| 2112 | error = ENOTSOCK; |
| 2113 | goto failed; |
| 2114 | } |
| 2115 | error = VOP_EACCESS(vp, VWRITE, p->p_ucred); |
| 2116 | if (error) |
| 2117 | goto failed; |
| 2118 | so = vp->v_socket; |
| 2119 | if (so == NULL) { |
| 2120 | error = ECONNREFUSED; |
| 2121 | goto failed; |
| 2122 | } |
| 2123 | if (so->so_type != type) { |
| 2124 | error = EPROTOTYPE; |
| 2125 | goto failed; |
| 2126 | } |
| 2127 | |
| 2128 | /* Lock this unp. */ |
| 2129 | unp = unp_getsocktoken(so); |
| 2130 | if (!UNP_ISATTACHED(unp)) { |
| 2131 | unp_reltoken(unp); |
| 2132 | error = ECONNREFUSED; |
| 2133 | goto failed; |
| 2134 | } |
| 2135 | /* And keep this unp referenced. */ |
| 2136 | unp_reference(unp); |
| 2137 | |
| 2138 | /* Done! */ |
| 2139 | *unp_ret = unp; |
| 2140 | error = 0; |
| 2141 | failed: |
| 2142 | if (vp != NULL) |
| 2143 | vput(vp); |
| 2144 | return error; |
| 2145 | } |
| 2146 | |
| 2147 | static int |
| 2148 | unp_connect_pair(struct unpcb *unp, struct unpcb *unp2) |
| 2149 | { |
| 2150 | struct socket *so = unp->unp_socket; |
| 2151 | struct socket *so2 = unp2->unp_socket; |
| 2152 | |
| 2153 | ASSERT_LWKT_TOKEN_HELD(&unp_token); |
| 2154 | UNP_ASSERT_TOKEN_HELD(unp); |
| 2155 | UNP_ASSERT_TOKEN_HELD(unp2); |
| 2156 | |
| 2157 | KASSERT(so->so_type == so2->so_type, |
| 2158 | ("socket type mismatch, so %d, so2 %d", so->so_type, so2->so_type)); |
| 2159 | |
| 2160 | if (!UNP_ISATTACHED(unp)) |
| 2161 | return EINVAL; |
| 2162 | if (!UNP_ISATTACHED(unp2)) |
| 2163 | return ECONNREFUSED; |
| 2164 | |
| 2165 | KASSERT(unp->unp_conn == NULL, ("unp is already connected")); |
| 2166 | unp->unp_conn = unp2; |
| 2167 | |
| 2168 | switch (so->so_type) { |
| 2169 | case SOCK_DGRAM: |
| 2170 | LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); |
| 2171 | soisconnected(so); |
| 2172 | break; |
| 2173 | |
| 2174 | case SOCK_STREAM: |
| 2175 | case SOCK_SEQPACKET: |
| 2176 | KASSERT(unp2->unp_conn == NULL, ("unp2 is already connected")); |
| 2177 | unp2->unp_conn = unp; |
| 2178 | soisconnected(so); |
| 2179 | soisconnected(so2); |
| 2180 | break; |
| 2181 | |
| 2182 | default: |
| 2183 | panic("unp_connect_pair: unknown socket type %d", so->so_type); |
| 2184 | } |
| 2185 | return 0; |
| 2186 | } |
| 2187 | |
| 2188 | static void |
| 2189 | unp_drop(struct unpcb *unp, int error) |
| 2190 | { |
| 2191 | struct unpcb *unp2; |
| 2192 | |
| 2193 | ASSERT_LWKT_TOKEN_HELD(&unp_token); |
| 2194 | UNP_ASSERT_TOKEN_HELD(unp); |
| 2195 | KASSERT(unp->unp_flags & UNP_DETACHED, ("unp is not detached")); |
| 2196 | |
| 2197 | unp_disconnect(unp, error); |
| 2198 | |
| 2199 | while ((unp2 = LIST_FIRST(&unp->unp_refs)) != NULL) { |
| 2200 | lwkt_getpooltoken(unp2); |
| 2201 | unp_disconnect(unp2, ECONNRESET); |
| 2202 | lwkt_relpooltoken(unp2); |
| 2203 | } |
| 2204 | unp_setflags(unp, UNP_DROPPED); |
| 2205 | } |