| 1 | /* $NetBSD: uipc_socket2.c,v 1.124 2016/10/02 19:26:46 christos Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 2008 The NetBSD Foundation, Inc. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions |
| 9 | * are met: |
| 10 | * 1. Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * 2. Redistributions in binary form must reproduce the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer in the |
| 14 | * documentation and/or other materials provided with the distribution. |
| 15 | * |
| 16 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
| 17 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 18 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 19 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
| 20 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 21 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 22 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 23 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 24 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 25 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 26 | * POSSIBILITY OF SUCH DAMAGE. |
| 27 | */ |
| 28 | |
| 29 | /* |
| 30 | * Copyright (c) 1982, 1986, 1988, 1990, 1993 |
| 31 | * The Regents of the University of California. All rights reserved. |
| 32 | * |
| 33 | * Redistribution and use in source and binary forms, with or without |
| 34 | * modification, are permitted provided that the following conditions |
| 35 | * are met: |
| 36 | * 1. Redistributions of source code must retain the above copyright |
| 37 | * notice, this list of conditions and the following disclaimer. |
| 38 | * 2. Redistributions in binary form must reproduce the above copyright |
| 39 | * notice, this list of conditions and the following disclaimer in the |
| 40 | * documentation and/or other materials provided with the distribution. |
| 41 | * 3. Neither the name of the University nor the names of its contributors |
| 42 | * may be used to endorse or promote products derived from this software |
| 43 | * without specific prior written permission. |
| 44 | * |
| 45 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 46 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 47 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 48 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 49 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 50 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 51 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 52 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 53 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 54 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 55 | * SUCH DAMAGE. |
| 56 | * |
| 57 | * @(#)uipc_socket2.c 8.2 (Berkeley) 2/14/95 |
| 58 | */ |
| 59 | |
| 60 | #include <sys/cdefs.h> |
| 61 | __KERNEL_RCSID(0, "$NetBSD: uipc_socket2.c,v 1.124 2016/10/02 19:26:46 christos Exp $" ); |
| 62 | |
| 63 | #ifdef _KERNEL_OPT |
| 64 | #include "opt_mbuftrace.h" |
| 65 | #include "opt_sb_max.h" |
| 66 | #endif |
| 67 | |
| 68 | #include <sys/param.h> |
| 69 | #include <sys/systm.h> |
| 70 | #include <sys/proc.h> |
| 71 | #include <sys/file.h> |
| 72 | #include <sys/buf.h> |
| 73 | #include <sys/mbuf.h> |
| 74 | #include <sys/protosw.h> |
| 75 | #include <sys/domain.h> |
| 76 | #include <sys/poll.h> |
| 77 | #include <sys/socket.h> |
| 78 | #include <sys/socketvar.h> |
| 79 | #include <sys/signalvar.h> |
| 80 | #include <sys/kauth.h> |
| 81 | #include <sys/pool.h> |
| 82 | #include <sys/uidinfo.h> |
| 83 | |
| 84 | /* |
| 85 | * Primitive routines for operating on sockets and socket buffers. |
| 86 | * |
| 87 | * Connection life-cycle: |
| 88 | * |
| 89 | * Normal sequence from the active (originating) side: |
| 90 | * |
| 91 | * - soisconnecting() is called during processing of connect() call, |
| 92 | * - resulting in an eventual call to soisconnected() if/when the |
| 93 | * connection is established. |
| 94 | * |
| 95 | * When the connection is torn down during processing of disconnect(): |
| 96 | * |
| 97 | * - soisdisconnecting() is called and, |
| 98 | * - soisdisconnected() is called when the connection to the peer |
| 99 | * is totally severed. |
| 100 | * |
| 101 | * The semantics of these routines are such that connectionless protocols |
| 102 | * can call soisconnected() and soisdisconnected() only, bypassing the |
| 103 | * in-progress calls when setting up a ``connection'' takes no time. |
| 104 | * |
| 105 | * From the passive side, a socket is created with two queues of sockets: |
| 106 | * |
| 107 | * - so_q0 (0) for partial connections (i.e. connections in progress) |
| 108 | * - so_q (1) for connections already made and awaiting user acceptance. |
| 109 | * |
| 110 | * As a protocol is preparing incoming connections, it creates a socket |
| 111 | * structure queued on so_q0 by calling sonewconn(). When the connection |
| 112 | * is established, soisconnected() is called, and transfers the |
| 113 | * socket structure to so_q, making it available to accept(). |
| 114 | * |
| 115 | * If a socket is closed with sockets on either so_q0 or so_q, these |
| 116 | * sockets are dropped. |
| 117 | * |
| 118 | * Locking rules and assumptions: |
| 119 | * |
| 120 | * o socket::so_lock can change on the fly. The low level routines used |
| 121 | * to lock sockets are aware of this. When so_lock is acquired, the |
| 122 | * routine locking must check to see if so_lock still points to the |
| 123 | * lock that was acquired. If so_lock has changed in the meantime, the |
| 124 | * now irrelevant lock that was acquired must be dropped and the lock |
| 125 | * operation retried. Although not proven here, this is completely safe |
| 126 | * on a multiprocessor system, even with relaxed memory ordering, given |
| 127 | * the next two rules: |
| 128 | * |
| 129 | * o In order to mutate so_lock, the lock pointed to by the current value |
| 130 | * of so_lock must be held: i.e., the socket must be held locked by the |
| 131 | * changing thread. The thread must issue membar_exit() to prevent |
| 132 | * memory accesses being reordered, and can set so_lock to the desired |
| 133 | * value. If the lock pointed to by the new value of so_lock is not |
| 134 | * held by the changing thread, the socket must then be considered |
| 135 | * unlocked. |
| 136 | * |
| 137 | * o If so_lock is mutated, and the previous lock referred to by so_lock |
| 138 | * could still be visible to other threads in the system (e.g. via file |
| 139 | * descriptor or protocol-internal reference), then the old lock must |
| 140 | * remain valid until the socket and/or protocol control block has been |
| 141 | * torn down. |
| 142 | * |
| 143 | * o If a socket has a non-NULL so_head value (i.e. is in the process of |
| 144 | * connecting), then locking the socket must also lock the socket pointed |
| 145 | * to by so_head: their lock pointers must match. |
| 146 | * |
| 147 | * o If a socket has connections in progress (so_q, so_q0 not empty) then |
| 148 | * locking the socket must also lock the sockets attached to both queues. |
| 149 | * Again, their lock pointers must match. |
| 150 | * |
| 151 | * o Beyond the initial lock assignment in socreate(), assigning locks to |
| 152 | * sockets is the responsibility of the individual protocols / protocol |
| 153 | * domains. |
| 154 | */ |
| 155 | |
| 156 | static pool_cache_t socket_cache; |
| 157 | u_long sb_max = SB_MAX;/* maximum socket buffer size */ |
| 158 | static u_long sb_max_adj; /* adjusted sb_max */ |
| 159 | |
| 160 | void |
| 161 | soisconnecting(struct socket *so) |
| 162 | { |
| 163 | |
| 164 | KASSERT(solocked(so)); |
| 165 | |
| 166 | so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING); |
| 167 | so->so_state |= SS_ISCONNECTING; |
| 168 | } |
| 169 | |
| 170 | void |
| 171 | soisconnected(struct socket *so) |
| 172 | { |
| 173 | struct socket *head; |
| 174 | |
| 175 | head = so->so_head; |
| 176 | |
| 177 | KASSERT(solocked(so)); |
| 178 | KASSERT(head == NULL || solocked2(so, head)); |
| 179 | |
| 180 | so->so_state &= ~(SS_ISCONNECTING | SS_ISDISCONNECTING); |
| 181 | so->so_state |= SS_ISCONNECTED; |
| 182 | if (head && so->so_onq == &head->so_q0) { |
| 183 | if ((so->so_options & SO_ACCEPTFILTER) == 0) { |
| 184 | /* |
| 185 | * Re-enqueue and wake up any waiters, e.g. |
| 186 | * processes blocking on accept(). |
| 187 | */ |
| 188 | soqremque(so, 0); |
| 189 | soqinsque(head, so, 1); |
| 190 | sorwakeup(head); |
| 191 | cv_broadcast(&head->so_cv); |
| 192 | } else { |
| 193 | so->so_upcall = |
| 194 | head->so_accf->so_accept_filter->accf_callback; |
| 195 | so->so_upcallarg = head->so_accf->so_accept_filter_arg; |
| 196 | so->so_rcv.sb_flags |= SB_UPCALL; |
| 197 | so->so_options &= ~SO_ACCEPTFILTER; |
| 198 | (*so->so_upcall)(so, so->so_upcallarg, |
| 199 | POLLIN|POLLRDNORM, M_DONTWAIT); |
| 200 | } |
| 201 | } else { |
| 202 | cv_broadcast(&so->so_cv); |
| 203 | sorwakeup(so); |
| 204 | sowwakeup(so); |
| 205 | } |
| 206 | } |
| 207 | |
| 208 | void |
| 209 | soisdisconnecting(struct socket *so) |
| 210 | { |
| 211 | |
| 212 | KASSERT(solocked(so)); |
| 213 | |
| 214 | so->so_state &= ~SS_ISCONNECTING; |
| 215 | so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE); |
| 216 | cv_broadcast(&so->so_cv); |
| 217 | sowwakeup(so); |
| 218 | sorwakeup(so); |
| 219 | } |
| 220 | |
| 221 | void |
| 222 | soisdisconnected(struct socket *so) |
| 223 | { |
| 224 | |
| 225 | KASSERT(solocked(so)); |
| 226 | |
| 227 | so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING); |
| 228 | so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE|SS_ISDISCONNECTED); |
| 229 | cv_broadcast(&so->so_cv); |
| 230 | sowwakeup(so); |
| 231 | sorwakeup(so); |
| 232 | } |
| 233 | |
| 234 | void |
| 235 | soinit2(void) |
| 236 | { |
| 237 | |
| 238 | socket_cache = pool_cache_init(sizeof(struct socket), 0, 0, 0, |
| 239 | "socket" , NULL, IPL_SOFTNET, NULL, NULL, NULL); |
| 240 | } |
| 241 | |
| 242 | /* |
| 243 | * sonewconn: accept a new connection. |
| 244 | * |
| 245 | * When an attempt at a new connection is noted on a socket which accepts |
| 246 | * connections, sonewconn(9) is called. If the connection is possible |
| 247 | * (subject to space constraints, etc) then we allocate a new structure, |
| 248 | * properly linked into the data structure of the original socket. |
| 249 | * |
| 250 | * => If 'soready' is true, then socket will become ready for accept() i.e. |
| 251 | * inserted into the so_q queue, SS_ISCONNECTED set and waiters awoken. |
| 252 | * => May be called from soft-interrupt context. |
| 253 | * => Listening socket should be locked. |
| 254 | * => Returns the new socket locked. |
| 255 | */ |
| 256 | struct socket * |
| 257 | sonewconn(struct socket *head, bool soready) |
| 258 | { |
| 259 | struct socket *so; |
| 260 | int soqueue, error; |
| 261 | |
| 262 | KASSERT(solocked(head)); |
| 263 | |
| 264 | if (head->so_qlen + head->so_q0len > 3 * head->so_qlimit / 2) { |
| 265 | /* |
| 266 | * Listen queue overflow. If there is an accept filter |
| 267 | * active, pass through the oldest cxn it's handling. |
| 268 | */ |
| 269 | if (head->so_accf == NULL) { |
| 270 | return NULL; |
| 271 | } else { |
| 272 | struct socket *so2, *next; |
| 273 | |
| 274 | /* Pass the oldest connection waiting in the |
| 275 | accept filter */ |
| 276 | for (so2 = TAILQ_FIRST(&head->so_q0); |
| 277 | so2 != NULL; so2 = next) { |
| 278 | next = TAILQ_NEXT(so2, so_qe); |
| 279 | if (so2->so_upcall == NULL) { |
| 280 | continue; |
| 281 | } |
| 282 | so2->so_upcall = NULL; |
| 283 | so2->so_upcallarg = NULL; |
| 284 | so2->so_options &= ~SO_ACCEPTFILTER; |
| 285 | so2->so_rcv.sb_flags &= ~SB_UPCALL; |
| 286 | soisconnected(so2); |
| 287 | break; |
| 288 | } |
| 289 | |
| 290 | /* If nothing was nudged out of the acept filter, bail |
| 291 | * out; otherwise proceed allocating the socket. */ |
| 292 | if (so2 == NULL) { |
| 293 | return NULL; |
| 294 | } |
| 295 | } |
| 296 | } |
| 297 | if ((head->so_options & SO_ACCEPTFILTER) != 0) { |
| 298 | soready = false; |
| 299 | } |
| 300 | soqueue = soready ? 1 : 0; |
| 301 | |
| 302 | if ((so = soget(false)) == NULL) { |
| 303 | return NULL; |
| 304 | } |
| 305 | so->so_type = head->so_type; |
| 306 | so->so_options = head->so_options & ~SO_ACCEPTCONN; |
| 307 | so->so_linger = head->so_linger; |
| 308 | so->so_state = head->so_state | SS_NOFDREF; |
| 309 | so->so_proto = head->so_proto; |
| 310 | so->so_timeo = head->so_timeo; |
| 311 | so->so_pgid = head->so_pgid; |
| 312 | so->so_send = head->so_send; |
| 313 | so->so_receive = head->so_receive; |
| 314 | so->so_uidinfo = head->so_uidinfo; |
| 315 | so->so_cpid = head->so_cpid; |
| 316 | |
| 317 | /* |
| 318 | * Share the lock with the listening-socket, it may get unshared |
| 319 | * once the connection is complete. |
| 320 | */ |
| 321 | mutex_obj_hold(head->so_lock); |
| 322 | so->so_lock = head->so_lock; |
| 323 | |
| 324 | /* |
| 325 | * Reserve the space for socket buffers. |
| 326 | */ |
| 327 | #ifdef MBUFTRACE |
| 328 | so->so_mowner = head->so_mowner; |
| 329 | so->so_rcv.sb_mowner = head->so_rcv.sb_mowner; |
| 330 | so->so_snd.sb_mowner = head->so_snd.sb_mowner; |
| 331 | #endif |
| 332 | if (soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat)) { |
| 333 | goto out; |
| 334 | } |
| 335 | so->so_snd.sb_lowat = head->so_snd.sb_lowat; |
| 336 | so->so_rcv.sb_lowat = head->so_rcv.sb_lowat; |
| 337 | so->so_rcv.sb_timeo = head->so_rcv.sb_timeo; |
| 338 | so->so_snd.sb_timeo = head->so_snd.sb_timeo; |
| 339 | so->so_rcv.sb_flags |= head->so_rcv.sb_flags & (SB_AUTOSIZE | SB_ASYNC); |
| 340 | so->so_snd.sb_flags |= head->so_snd.sb_flags & (SB_AUTOSIZE | SB_ASYNC); |
| 341 | |
| 342 | /* |
| 343 | * Finally, perform the protocol attach. Note: a new socket |
| 344 | * lock may be assigned at this point (if so, it will be held). |
| 345 | */ |
| 346 | error = (*so->so_proto->pr_usrreqs->pr_attach)(so, 0); |
| 347 | if (error) { |
| 348 | out: |
| 349 | KASSERT(solocked(so)); |
| 350 | KASSERT(so->so_accf == NULL); |
| 351 | soput(so); |
| 352 | |
| 353 | /* Note: the listening socket shall stay locked. */ |
| 354 | KASSERT(solocked(head)); |
| 355 | return NULL; |
| 356 | } |
| 357 | KASSERT(solocked2(head, so)); |
| 358 | |
| 359 | /* |
| 360 | * Insert into the queue. If ready, update the connection status |
| 361 | * and wake up any waiters, e.g. processes blocking on accept(). |
| 362 | */ |
| 363 | soqinsque(head, so, soqueue); |
| 364 | if (soready) { |
| 365 | so->so_state |= SS_ISCONNECTED; |
| 366 | sorwakeup(head); |
| 367 | cv_broadcast(&head->so_cv); |
| 368 | } |
| 369 | return so; |
| 370 | } |
| 371 | |
| 372 | struct socket * |
| 373 | soget(bool waitok) |
| 374 | { |
| 375 | struct socket *so; |
| 376 | |
| 377 | so = pool_cache_get(socket_cache, (waitok ? PR_WAITOK : PR_NOWAIT)); |
| 378 | if (__predict_false(so == NULL)) |
| 379 | return (NULL); |
| 380 | memset(so, 0, sizeof(*so)); |
| 381 | TAILQ_INIT(&so->so_q0); |
| 382 | TAILQ_INIT(&so->so_q); |
| 383 | cv_init(&so->so_cv, "socket" ); |
| 384 | cv_init(&so->so_rcv.sb_cv, "netio" ); |
| 385 | cv_init(&so->so_snd.sb_cv, "netio" ); |
| 386 | selinit(&so->so_rcv.sb_sel); |
| 387 | selinit(&so->so_snd.sb_sel); |
| 388 | so->so_rcv.sb_so = so; |
| 389 | so->so_snd.sb_so = so; |
| 390 | return so; |
| 391 | } |
| 392 | |
| 393 | void |
| 394 | soput(struct socket *so) |
| 395 | { |
| 396 | |
| 397 | KASSERT(!cv_has_waiters(&so->so_cv)); |
| 398 | KASSERT(!cv_has_waiters(&so->so_rcv.sb_cv)); |
| 399 | KASSERT(!cv_has_waiters(&so->so_snd.sb_cv)); |
| 400 | seldestroy(&so->so_rcv.sb_sel); |
| 401 | seldestroy(&so->so_snd.sb_sel); |
| 402 | mutex_obj_free(so->so_lock); |
| 403 | cv_destroy(&so->so_cv); |
| 404 | cv_destroy(&so->so_rcv.sb_cv); |
| 405 | cv_destroy(&so->so_snd.sb_cv); |
| 406 | pool_cache_put(socket_cache, so); |
| 407 | } |
| 408 | |
| 409 | /* |
| 410 | * soqinsque: insert socket of a new connection into the specified |
| 411 | * accept queue of the listening socket (head). |
| 412 | * |
| 413 | * q = 0: queue of partial connections |
| 414 | * q = 1: queue of incoming connections |
| 415 | */ |
| 416 | void |
| 417 | soqinsque(struct socket *head, struct socket *so, int q) |
| 418 | { |
| 419 | KASSERT(q == 0 || q == 1); |
| 420 | KASSERT(solocked2(head, so)); |
| 421 | KASSERT(so->so_onq == NULL); |
| 422 | KASSERT(so->so_head == NULL); |
| 423 | |
| 424 | so->so_head = head; |
| 425 | if (q == 0) { |
| 426 | head->so_q0len++; |
| 427 | so->so_onq = &head->so_q0; |
| 428 | } else { |
| 429 | head->so_qlen++; |
| 430 | so->so_onq = &head->so_q; |
| 431 | } |
| 432 | TAILQ_INSERT_TAIL(so->so_onq, so, so_qe); |
| 433 | } |
| 434 | |
| 435 | /* |
| 436 | * soqremque: remove socket from the specified queue. |
| 437 | * |
| 438 | * => Returns true if socket was removed from the specified queue. |
| 439 | * => False if socket was not removed (because it was in other queue). |
| 440 | */ |
| 441 | bool |
| 442 | soqremque(struct socket *so, int q) |
| 443 | { |
| 444 | struct socket *head = so->so_head; |
| 445 | |
| 446 | KASSERT(q == 0 || q == 1); |
| 447 | KASSERT(solocked(so)); |
| 448 | KASSERT(so->so_onq != NULL); |
| 449 | KASSERT(head != NULL); |
| 450 | |
| 451 | if (q == 0) { |
| 452 | if (so->so_onq != &head->so_q0) |
| 453 | return false; |
| 454 | head->so_q0len--; |
| 455 | } else { |
| 456 | if (so->so_onq != &head->so_q) |
| 457 | return false; |
| 458 | head->so_qlen--; |
| 459 | } |
| 460 | KASSERT(solocked2(so, head)); |
| 461 | TAILQ_REMOVE(so->so_onq, so, so_qe); |
| 462 | so->so_onq = NULL; |
| 463 | so->so_head = NULL; |
| 464 | return true; |
| 465 | } |
| 466 | |
| 467 | /* |
| 468 | * socantsendmore: indicates that no more data will be sent on the |
| 469 | * socket; it would normally be applied to a socket when the user |
| 470 | * informs the system that no more data is to be sent, by the protocol |
| 471 | * code (in case pr_shutdown()). |
| 472 | */ |
| 473 | void |
| 474 | socantsendmore(struct socket *so) |
| 475 | { |
| 476 | KASSERT(solocked(so)); |
| 477 | |
| 478 | so->so_state |= SS_CANTSENDMORE; |
| 479 | sowwakeup(so); |
| 480 | } |
| 481 | |
| 482 | /* |
| 483 | * socantrcvmore(): indicates that no more data will be received and |
| 484 | * will normally be applied to the socket by a protocol when it detects |
| 485 | * that the peer will send no more data. Data queued for reading in |
| 486 | * the socket may yet be read. |
| 487 | */ |
| 488 | void |
| 489 | socantrcvmore(struct socket *so) |
| 490 | { |
| 491 | KASSERT(solocked(so)); |
| 492 | |
| 493 | so->so_state |= SS_CANTRCVMORE; |
| 494 | sorwakeup(so); |
| 495 | } |
| 496 | |
| 497 | /* |
| 498 | * Wait for data to arrive at/drain from a socket buffer. |
| 499 | */ |
| 500 | int |
| 501 | sbwait(struct sockbuf *sb) |
| 502 | { |
| 503 | struct socket *so; |
| 504 | kmutex_t *lock; |
| 505 | int error; |
| 506 | |
| 507 | so = sb->sb_so; |
| 508 | |
| 509 | KASSERT(solocked(so)); |
| 510 | |
| 511 | sb->sb_flags |= SB_NOTIFY; |
| 512 | lock = so->so_lock; |
| 513 | if ((sb->sb_flags & SB_NOINTR) != 0) |
| 514 | error = cv_timedwait(&sb->sb_cv, lock, sb->sb_timeo); |
| 515 | else |
| 516 | error = cv_timedwait_sig(&sb->sb_cv, lock, sb->sb_timeo); |
| 517 | if (__predict_false(lock != so->so_lock)) |
| 518 | solockretry(so, lock); |
| 519 | return error; |
| 520 | } |
| 521 | |
| 522 | /* |
| 523 | * Wakeup processes waiting on a socket buffer. |
| 524 | * Do asynchronous notification via SIGIO |
| 525 | * if the socket buffer has the SB_ASYNC flag set. |
| 526 | */ |
| 527 | void |
| 528 | sowakeup(struct socket *so, struct sockbuf *sb, int code) |
| 529 | { |
| 530 | int band; |
| 531 | |
| 532 | KASSERT(solocked(so)); |
| 533 | KASSERT(sb->sb_so == so); |
| 534 | |
| 535 | if (code == POLL_IN) |
| 536 | band = POLLIN|POLLRDNORM; |
| 537 | else |
| 538 | band = POLLOUT|POLLWRNORM; |
| 539 | sb->sb_flags &= ~SB_NOTIFY; |
| 540 | selnotify(&sb->sb_sel, band, NOTE_SUBMIT); |
| 541 | cv_broadcast(&sb->sb_cv); |
| 542 | if (sb->sb_flags & SB_ASYNC) |
| 543 | fownsignal(so->so_pgid, SIGIO, code, band, so); |
| 544 | if (sb->sb_flags & SB_UPCALL) |
| 545 | (*so->so_upcall)(so, so->so_upcallarg, band, M_DONTWAIT); |
| 546 | } |
| 547 | |
| 548 | /* |
| 549 | * Reset a socket's lock pointer. Wake all threads waiting on the |
| 550 | * socket's condition variables so that they can restart their waits |
| 551 | * using the new lock. The existing lock must be held. |
| 552 | */ |
| 553 | void |
| 554 | solockreset(struct socket *so, kmutex_t *lock) |
| 555 | { |
| 556 | |
| 557 | KASSERT(solocked(so)); |
| 558 | |
| 559 | so->so_lock = lock; |
| 560 | cv_broadcast(&so->so_snd.sb_cv); |
| 561 | cv_broadcast(&so->so_rcv.sb_cv); |
| 562 | cv_broadcast(&so->so_cv); |
| 563 | } |
| 564 | |
| 565 | /* |
| 566 | * Socket buffer (struct sockbuf) utility routines. |
| 567 | * |
| 568 | * Each socket contains two socket buffers: one for sending data and |
| 569 | * one for receiving data. Each buffer contains a queue of mbufs, |
| 570 | * information about the number of mbufs and amount of data in the |
| 571 | * queue, and other fields allowing poll() statements and notification |
| 572 | * on data availability to be implemented. |
| 573 | * |
| 574 | * Data stored in a socket buffer is maintained as a list of records. |
| 575 | * Each record is a list of mbufs chained together with the m_next |
| 576 | * field. Records are chained together with the m_nextpkt field. The upper |
| 577 | * level routine soreceive() expects the following conventions to be |
| 578 | * observed when placing information in the receive buffer: |
| 579 | * |
| 580 | * 1. If the protocol requires each message be preceded by the sender's |
| 581 | * name, then a record containing that name must be present before |
| 582 | * any associated data (mbuf's must be of type MT_SONAME). |
| 583 | * 2. If the protocol supports the exchange of ``access rights'' (really |
| 584 | * just additional data associated with the message), and there are |
| 585 | * ``rights'' to be received, then a record containing this data |
| 586 | * should be present (mbuf's must be of type MT_CONTROL). |
| 587 | * 3. If a name or rights record exists, then it must be followed by |
| 588 | * a data record, perhaps of zero length. |
| 589 | * |
| 590 | * Before using a new socket structure it is first necessary to reserve |
| 591 | * buffer space to the socket, by calling sbreserve(). This should commit |
| 592 | * some of the available buffer space in the system buffer pool for the |
| 593 | * socket (currently, it does nothing but enforce limits). The space |
| 594 | * should be released by calling sbrelease() when the socket is destroyed. |
| 595 | */ |
| 596 | |
| 597 | int |
| 598 | sb_max_set(u_long new_sbmax) |
| 599 | { |
| 600 | int s; |
| 601 | |
| 602 | if (new_sbmax < (16 * 1024)) |
| 603 | return (EINVAL); |
| 604 | |
| 605 | s = splsoftnet(); |
| 606 | sb_max = new_sbmax; |
| 607 | sb_max_adj = (u_quad_t)new_sbmax * MCLBYTES / (MSIZE + MCLBYTES); |
| 608 | splx(s); |
| 609 | |
| 610 | return (0); |
| 611 | } |
| 612 | |
| 613 | int |
| 614 | soreserve(struct socket *so, u_long sndcc, u_long rcvcc) |
| 615 | { |
| 616 | KASSERT(so->so_pcb == NULL || solocked(so)); |
| 617 | |
| 618 | /* |
| 619 | * there's at least one application (a configure script of screen) |
| 620 | * which expects a fifo is writable even if it has "some" bytes |
| 621 | * in its buffer. |
| 622 | * so we want to make sure (hiwat - lowat) >= (some bytes). |
| 623 | * |
| 624 | * PIPE_BUF here is an arbitrary value chosen as (some bytes) above. |
| 625 | * we expect it's large enough for such applications. |
| 626 | */ |
| 627 | u_long lowat = MAX(sock_loan_thresh, MCLBYTES); |
| 628 | u_long hiwat = lowat + PIPE_BUF; |
| 629 | |
| 630 | if (sndcc < hiwat) |
| 631 | sndcc = hiwat; |
| 632 | if (sbreserve(&so->so_snd, sndcc, so) == 0) |
| 633 | goto bad; |
| 634 | if (sbreserve(&so->so_rcv, rcvcc, so) == 0) |
| 635 | goto bad2; |
| 636 | if (so->so_rcv.sb_lowat == 0) |
| 637 | so->so_rcv.sb_lowat = 1; |
| 638 | if (so->so_snd.sb_lowat == 0) |
| 639 | so->so_snd.sb_lowat = lowat; |
| 640 | if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat) |
| 641 | so->so_snd.sb_lowat = so->so_snd.sb_hiwat; |
| 642 | return (0); |
| 643 | bad2: |
| 644 | sbrelease(&so->so_snd, so); |
| 645 | bad: |
| 646 | return (ENOBUFS); |
| 647 | } |
| 648 | |
| 649 | /* |
| 650 | * Allot mbufs to a sockbuf. |
| 651 | * Attempt to scale mbmax so that mbcnt doesn't become limiting |
| 652 | * if buffering efficiency is near the normal case. |
| 653 | */ |
| 654 | int |
| 655 | sbreserve(struct sockbuf *sb, u_long cc, struct socket *so) |
| 656 | { |
| 657 | struct lwp *l = curlwp; /* XXX */ |
| 658 | rlim_t maxcc; |
| 659 | struct uidinfo *uidinfo; |
| 660 | |
| 661 | KASSERT(so->so_pcb == NULL || solocked(so)); |
| 662 | KASSERT(sb->sb_so == so); |
| 663 | KASSERT(sb_max_adj != 0); |
| 664 | |
| 665 | if (cc == 0 || cc > sb_max_adj) |
| 666 | return (0); |
| 667 | |
| 668 | maxcc = l->l_proc->p_rlimit[RLIMIT_SBSIZE].rlim_cur; |
| 669 | |
| 670 | uidinfo = so->so_uidinfo; |
| 671 | if (!chgsbsize(uidinfo, &sb->sb_hiwat, cc, maxcc)) |
| 672 | return 0; |
| 673 | sb->sb_mbmax = min(cc * 2, sb_max); |
| 674 | if (sb->sb_lowat > sb->sb_hiwat) |
| 675 | sb->sb_lowat = sb->sb_hiwat; |
| 676 | return (1); |
| 677 | } |
| 678 | |
| 679 | /* |
| 680 | * Free mbufs held by a socket, and reserved mbuf space. We do not assert |
| 681 | * that the socket is held locked here: see sorflush(). |
| 682 | */ |
| 683 | void |
| 684 | sbrelease(struct sockbuf *sb, struct socket *so) |
| 685 | { |
| 686 | |
| 687 | KASSERT(sb->sb_so == so); |
| 688 | |
| 689 | sbflush(sb); |
| 690 | (void)chgsbsize(so->so_uidinfo, &sb->sb_hiwat, 0, RLIM_INFINITY); |
| 691 | sb->sb_mbmax = 0; |
| 692 | } |
| 693 | |
| 694 | /* |
| 695 | * Routines to add and remove |
| 696 | * data from an mbuf queue. |
| 697 | * |
| 698 | * The routines sbappend() or sbappendrecord() are normally called to |
| 699 | * append new mbufs to a socket buffer, after checking that adequate |
| 700 | * space is available, comparing the function sbspace() with the amount |
| 701 | * of data to be added. sbappendrecord() differs from sbappend() in |
| 702 | * that data supplied is treated as the beginning of a new record. |
| 703 | * To place a sender's address, optional access rights, and data in a |
| 704 | * socket receive buffer, sbappendaddr() should be used. To place |
| 705 | * access rights and data in a socket receive buffer, sbappendrights() |
| 706 | * should be used. In either case, the new data begins a new record. |
| 707 | * Note that unlike sbappend() and sbappendrecord(), these routines check |
| 708 | * for the caller that there will be enough space to store the data. |
| 709 | * Each fails if there is not enough space, or if it cannot find mbufs |
| 710 | * to store additional information in. |
| 711 | * |
| 712 | * Reliable protocols may use the socket send buffer to hold data |
| 713 | * awaiting acknowledgement. Data is normally copied from a socket |
| 714 | * send buffer in a protocol with m_copy for output to a peer, |
| 715 | * and then removing the data from the socket buffer with sbdrop() |
| 716 | * or sbdroprecord() when the data is acknowledged by the peer. |
| 717 | */ |
| 718 | |
| 719 | #ifdef SOCKBUF_DEBUG |
| 720 | void |
| 721 | sblastrecordchk(struct sockbuf *sb, const char *where) |
| 722 | { |
| 723 | struct mbuf *m = sb->sb_mb; |
| 724 | |
| 725 | KASSERT(solocked(sb->sb_so)); |
| 726 | |
| 727 | while (m && m->m_nextpkt) |
| 728 | m = m->m_nextpkt; |
| 729 | |
| 730 | if (m != sb->sb_lastrecord) { |
| 731 | printf("sblastrecordchk: sb_mb %p sb_lastrecord %p last %p\n" , |
| 732 | sb->sb_mb, sb->sb_lastrecord, m); |
| 733 | printf("packet chain:\n" ); |
| 734 | for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt) |
| 735 | printf("\t%p\n" , m); |
| 736 | panic("sblastrecordchk from %s" , where); |
| 737 | } |
| 738 | } |
| 739 | |
| 740 | void |
| 741 | sblastmbufchk(struct sockbuf *sb, const char *where) |
| 742 | { |
| 743 | struct mbuf *m = sb->sb_mb; |
| 744 | struct mbuf *n; |
| 745 | |
| 746 | KASSERT(solocked(sb->sb_so)); |
| 747 | |
| 748 | while (m && m->m_nextpkt) |
| 749 | m = m->m_nextpkt; |
| 750 | |
| 751 | while (m && m->m_next) |
| 752 | m = m->m_next; |
| 753 | |
| 754 | if (m != sb->sb_mbtail) { |
| 755 | printf("sblastmbufchk: sb_mb %p sb_mbtail %p last %p\n" , |
| 756 | sb->sb_mb, sb->sb_mbtail, m); |
| 757 | printf("packet tree:\n" ); |
| 758 | for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt) { |
| 759 | printf("\t" ); |
| 760 | for (n = m; n != NULL; n = n->m_next) |
| 761 | printf("%p " , n); |
| 762 | printf("\n" ); |
| 763 | } |
| 764 | panic("sblastmbufchk from %s" , where); |
| 765 | } |
| 766 | } |
| 767 | #endif /* SOCKBUF_DEBUG */ |
| 768 | |
| 769 | /* |
| 770 | * Link a chain of records onto a socket buffer |
| 771 | */ |
| 772 | #define SBLINKRECORDCHAIN(sb, m0, mlast) \ |
| 773 | do { \ |
| 774 | if ((sb)->sb_lastrecord != NULL) \ |
| 775 | (sb)->sb_lastrecord->m_nextpkt = (m0); \ |
| 776 | else \ |
| 777 | (sb)->sb_mb = (m0); \ |
| 778 | (sb)->sb_lastrecord = (mlast); \ |
| 779 | } while (/*CONSTCOND*/0) |
| 780 | |
| 781 | |
| 782 | #define SBLINKRECORD(sb, m0) \ |
| 783 | SBLINKRECORDCHAIN(sb, m0, m0) |
| 784 | |
| 785 | /* |
| 786 | * Append mbuf chain m to the last record in the |
| 787 | * socket buffer sb. The additional space associated |
| 788 | * the mbuf chain is recorded in sb. Empty mbufs are |
| 789 | * discarded and mbufs are compacted where possible. |
| 790 | */ |
| 791 | void |
| 792 | sbappend(struct sockbuf *sb, struct mbuf *m) |
| 793 | { |
| 794 | struct mbuf *n; |
| 795 | |
| 796 | KASSERT(solocked(sb->sb_so)); |
| 797 | |
| 798 | if (m == NULL) |
| 799 | return; |
| 800 | |
| 801 | #ifdef MBUFTRACE |
| 802 | m_claimm(m, sb->sb_mowner); |
| 803 | #endif |
| 804 | |
| 805 | SBLASTRECORDCHK(sb, "sbappend 1" ); |
| 806 | |
| 807 | if ((n = sb->sb_lastrecord) != NULL) { |
| 808 | /* |
| 809 | * XXX Would like to simply use sb_mbtail here, but |
| 810 | * XXX I need to verify that I won't miss an EOR that |
| 811 | * XXX way. |
| 812 | */ |
| 813 | do { |
| 814 | if (n->m_flags & M_EOR) { |
| 815 | sbappendrecord(sb, m); /* XXXXXX!!!! */ |
| 816 | return; |
| 817 | } |
| 818 | } while (n->m_next && (n = n->m_next)); |
| 819 | } else { |
| 820 | /* |
| 821 | * If this is the first record in the socket buffer, it's |
| 822 | * also the last record. |
| 823 | */ |
| 824 | sb->sb_lastrecord = m; |
| 825 | } |
| 826 | sbcompress(sb, m, n); |
| 827 | SBLASTRECORDCHK(sb, "sbappend 2" ); |
| 828 | } |
| 829 | |
| 830 | /* |
| 831 | * This version of sbappend() should only be used when the caller |
| 832 | * absolutely knows that there will never be more than one record |
| 833 | * in the socket buffer, that is, a stream protocol (such as TCP). |
| 834 | */ |
| 835 | void |
| 836 | sbappendstream(struct sockbuf *sb, struct mbuf *m) |
| 837 | { |
| 838 | |
| 839 | KASSERT(solocked(sb->sb_so)); |
| 840 | KDASSERT(m->m_nextpkt == NULL); |
| 841 | KASSERT(sb->sb_mb == sb->sb_lastrecord); |
| 842 | |
| 843 | SBLASTMBUFCHK(sb, __func__); |
| 844 | |
| 845 | #ifdef MBUFTRACE |
| 846 | m_claimm(m, sb->sb_mowner); |
| 847 | #endif |
| 848 | |
| 849 | sbcompress(sb, m, sb->sb_mbtail); |
| 850 | |
| 851 | sb->sb_lastrecord = sb->sb_mb; |
| 852 | SBLASTRECORDCHK(sb, __func__); |
| 853 | } |
| 854 | |
| 855 | #ifdef SOCKBUF_DEBUG |
| 856 | void |
| 857 | sbcheck(struct sockbuf *sb) |
| 858 | { |
| 859 | struct mbuf *m, *m2; |
| 860 | u_long len, mbcnt; |
| 861 | |
| 862 | KASSERT(solocked(sb->sb_so)); |
| 863 | |
| 864 | len = 0; |
| 865 | mbcnt = 0; |
| 866 | for (m = sb->sb_mb; m; m = m->m_nextpkt) { |
| 867 | for (m2 = m; m2 != NULL; m2 = m2->m_next) { |
| 868 | len += m2->m_len; |
| 869 | mbcnt += MSIZE; |
| 870 | if (m2->m_flags & M_EXT) |
| 871 | mbcnt += m2->m_ext.ext_size; |
| 872 | if (m2->m_nextpkt != NULL) |
| 873 | panic("sbcheck nextpkt" ); |
| 874 | } |
| 875 | } |
| 876 | if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) { |
| 877 | printf("cc %lu != %lu || mbcnt %lu != %lu\n" , len, sb->sb_cc, |
| 878 | mbcnt, sb->sb_mbcnt); |
| 879 | panic("sbcheck" ); |
| 880 | } |
| 881 | } |
| 882 | #endif |
| 883 | |
| 884 | /* |
| 885 | * As above, except the mbuf chain |
| 886 | * begins a new record. |
| 887 | */ |
| 888 | void |
| 889 | sbappendrecord(struct sockbuf *sb, struct mbuf *m0) |
| 890 | { |
| 891 | struct mbuf *m; |
| 892 | |
| 893 | KASSERT(solocked(sb->sb_so)); |
| 894 | |
| 895 | if (m0 == NULL) |
| 896 | return; |
| 897 | |
| 898 | #ifdef MBUFTRACE |
| 899 | m_claimm(m0, sb->sb_mowner); |
| 900 | #endif |
| 901 | /* |
| 902 | * Put the first mbuf on the queue. |
| 903 | * Note this permits zero length records. |
| 904 | */ |
| 905 | sballoc(sb, m0); |
| 906 | SBLASTRECORDCHK(sb, "sbappendrecord 1" ); |
| 907 | SBLINKRECORD(sb, m0); |
| 908 | m = m0->m_next; |
| 909 | m0->m_next = 0; |
| 910 | if (m && (m0->m_flags & M_EOR)) { |
| 911 | m0->m_flags &= ~M_EOR; |
| 912 | m->m_flags |= M_EOR; |
| 913 | } |
| 914 | sbcompress(sb, m, m0); |
| 915 | SBLASTRECORDCHK(sb, "sbappendrecord 2" ); |
| 916 | } |
| 917 | |
| 918 | /* |
| 919 | * As above except that OOB data |
| 920 | * is inserted at the beginning of the sockbuf, |
| 921 | * but after any other OOB data. |
| 922 | */ |
| 923 | void |
| 924 | sbinsertoob(struct sockbuf *sb, struct mbuf *m0) |
| 925 | { |
| 926 | struct mbuf *m, **mp; |
| 927 | |
| 928 | KASSERT(solocked(sb->sb_so)); |
| 929 | |
| 930 | if (m0 == NULL) |
| 931 | return; |
| 932 | |
| 933 | SBLASTRECORDCHK(sb, "sbinsertoob 1" ); |
| 934 | |
| 935 | for (mp = &sb->sb_mb; (m = *mp) != NULL; mp = &((*mp)->m_nextpkt)) { |
| 936 | again: |
| 937 | switch (m->m_type) { |
| 938 | |
| 939 | case MT_OOBDATA: |
| 940 | continue; /* WANT next train */ |
| 941 | |
| 942 | case MT_CONTROL: |
| 943 | if ((m = m->m_next) != NULL) |
| 944 | goto again; /* inspect THIS train further */ |
| 945 | } |
| 946 | break; |
| 947 | } |
| 948 | /* |
| 949 | * Put the first mbuf on the queue. |
| 950 | * Note this permits zero length records. |
| 951 | */ |
| 952 | sballoc(sb, m0); |
| 953 | m0->m_nextpkt = *mp; |
| 954 | if (*mp == NULL) { |
| 955 | /* m0 is actually the new tail */ |
| 956 | sb->sb_lastrecord = m0; |
| 957 | } |
| 958 | *mp = m0; |
| 959 | m = m0->m_next; |
| 960 | m0->m_next = 0; |
| 961 | if (m && (m0->m_flags & M_EOR)) { |
| 962 | m0->m_flags &= ~M_EOR; |
| 963 | m->m_flags |= M_EOR; |
| 964 | } |
| 965 | sbcompress(sb, m, m0); |
| 966 | SBLASTRECORDCHK(sb, "sbinsertoob 2" ); |
| 967 | } |
| 968 | |
| 969 | /* |
| 970 | * Append address and data, and optionally, control (ancillary) data |
| 971 | * to the receive queue of a socket. If present, |
| 972 | * m0 must include a packet header with total length. |
| 973 | * Returns 0 if no space in sockbuf or insufficient mbufs. |
| 974 | */ |
| 975 | int |
| 976 | sbappendaddr(struct sockbuf *sb, const struct sockaddr *asa, struct mbuf *m0, |
| 977 | struct mbuf *control) |
| 978 | { |
| 979 | struct mbuf *m, *n, *nlast; |
| 980 | int space, len; |
| 981 | |
| 982 | KASSERT(solocked(sb->sb_so)); |
| 983 | |
| 984 | space = asa->sa_len; |
| 985 | |
| 986 | if (m0 != NULL) { |
| 987 | if ((m0->m_flags & M_PKTHDR) == 0) |
| 988 | panic("sbappendaddr" ); |
| 989 | space += m0->m_pkthdr.len; |
| 990 | #ifdef MBUFTRACE |
| 991 | m_claimm(m0, sb->sb_mowner); |
| 992 | #endif |
| 993 | } |
| 994 | for (n = control; n; n = n->m_next) { |
| 995 | space += n->m_len; |
| 996 | MCLAIM(n, sb->sb_mowner); |
| 997 | if (n->m_next == NULL) /* keep pointer to last control buf */ |
| 998 | break; |
| 999 | } |
| 1000 | if (space > sbspace(sb)) |
| 1001 | return (0); |
| 1002 | m = m_get(M_DONTWAIT, MT_SONAME); |
| 1003 | if (m == NULL) |
| 1004 | return (0); |
| 1005 | MCLAIM(m, sb->sb_mowner); |
| 1006 | /* |
| 1007 | * XXX avoid 'comparison always true' warning which isn't easily |
| 1008 | * avoided. |
| 1009 | */ |
| 1010 | len = asa->sa_len; |
| 1011 | if (len > MLEN) { |
| 1012 | MEXTMALLOC(m, asa->sa_len, M_NOWAIT); |
| 1013 | if ((m->m_flags & M_EXT) == 0) { |
| 1014 | m_free(m); |
| 1015 | return (0); |
| 1016 | } |
| 1017 | } |
| 1018 | m->m_len = asa->sa_len; |
| 1019 | memcpy(mtod(m, void *), asa, asa->sa_len); |
| 1020 | if (n) |
| 1021 | n->m_next = m0; /* concatenate data to control */ |
| 1022 | else |
| 1023 | control = m0; |
| 1024 | m->m_next = control; |
| 1025 | |
| 1026 | SBLASTRECORDCHK(sb, "sbappendaddr 1" ); |
| 1027 | |
| 1028 | for (n = m; n->m_next != NULL; n = n->m_next) |
| 1029 | sballoc(sb, n); |
| 1030 | sballoc(sb, n); |
| 1031 | nlast = n; |
| 1032 | SBLINKRECORD(sb, m); |
| 1033 | |
| 1034 | sb->sb_mbtail = nlast; |
| 1035 | SBLASTMBUFCHK(sb, "sbappendaddr" ); |
| 1036 | SBLASTRECORDCHK(sb, "sbappendaddr 2" ); |
| 1037 | |
| 1038 | return (1); |
| 1039 | } |
| 1040 | |
| 1041 | /* |
| 1042 | * Helper for sbappendchainaddr: prepend a struct sockaddr* to |
| 1043 | * an mbuf chain. |
| 1044 | */ |
| 1045 | static inline struct mbuf * |
| 1046 | m_prepend_sockaddr(struct sockbuf *sb, struct mbuf *m0, |
| 1047 | const struct sockaddr *asa) |
| 1048 | { |
| 1049 | struct mbuf *m; |
| 1050 | const int salen = asa->sa_len; |
| 1051 | |
| 1052 | KASSERT(solocked(sb->sb_so)); |
| 1053 | |
| 1054 | /* only the first in each chain need be a pkthdr */ |
| 1055 | m = m_gethdr(M_DONTWAIT, MT_SONAME); |
| 1056 | if (m == NULL) |
| 1057 | return NULL; |
| 1058 | MCLAIM(m, sb->sb_mowner); |
| 1059 | #ifdef notyet |
| 1060 | if (salen > MHLEN) { |
| 1061 | MEXTMALLOC(m, salen, M_NOWAIT); |
| 1062 | if ((m->m_flags & M_EXT) == 0) { |
| 1063 | m_free(m); |
| 1064 | return NULL; |
| 1065 | } |
| 1066 | } |
| 1067 | #else |
| 1068 | KASSERT(salen <= MHLEN); |
| 1069 | #endif |
| 1070 | m->m_len = salen; |
| 1071 | memcpy(mtod(m, void *), asa, salen); |
| 1072 | m->m_next = m0; |
| 1073 | m->m_pkthdr.len = salen + m0->m_pkthdr.len; |
| 1074 | |
| 1075 | return m; |
| 1076 | } |
| 1077 | |
| 1078 | int |
| 1079 | sbappendaddrchain(struct sockbuf *sb, const struct sockaddr *asa, |
| 1080 | struct mbuf *m0, int sbprio) |
| 1081 | { |
| 1082 | struct mbuf *m, *n, *n0, *nlast; |
| 1083 | int error; |
| 1084 | |
| 1085 | KASSERT(solocked(sb->sb_so)); |
| 1086 | |
| 1087 | /* |
| 1088 | * XXX sbprio reserved for encoding priority of this* request: |
| 1089 | * SB_PRIO_NONE --> honour normal sb limits |
| 1090 | * SB_PRIO_ONESHOT_OVERFLOW --> if socket has any space, |
| 1091 | * take whole chain. Intended for large requests |
| 1092 | * that should be delivered atomically (all, or none). |
| 1093 | * SB_PRIO_OVERDRAFT -- allow a small (2*MLEN) overflow |
| 1094 | * over normal socket limits, for messages indicating |
| 1095 | * buffer overflow in earlier normal/lower-priority messages |
| 1096 | * SB_PRIO_BESTEFFORT --> ignore limits entirely. |
| 1097 | * Intended for kernel-generated messages only. |
| 1098 | * Up to generator to avoid total mbuf resource exhaustion. |
| 1099 | */ |
| 1100 | (void)sbprio; |
| 1101 | |
| 1102 | if (m0 && (m0->m_flags & M_PKTHDR) == 0) |
| 1103 | panic("sbappendaddrchain" ); |
| 1104 | |
| 1105 | #ifdef notyet |
| 1106 | space = sbspace(sb); |
| 1107 | |
| 1108 | /* |
| 1109 | * Enforce SB_PRIO_* limits as described above. |
| 1110 | */ |
| 1111 | #endif |
| 1112 | |
| 1113 | n0 = NULL; |
| 1114 | nlast = NULL; |
| 1115 | for (m = m0; m; m = m->m_nextpkt) { |
| 1116 | struct mbuf *np; |
| 1117 | |
| 1118 | #ifdef MBUFTRACE |
| 1119 | m_claimm(m, sb->sb_mowner); |
| 1120 | #endif |
| 1121 | |
| 1122 | /* Prepend sockaddr to this record (m) of input chain m0 */ |
| 1123 | n = m_prepend_sockaddr(sb, m, asa); |
| 1124 | if (n == NULL) { |
| 1125 | error = ENOBUFS; |
| 1126 | goto bad; |
| 1127 | } |
| 1128 | |
| 1129 | /* Append record (asa+m) to end of new chain n0 */ |
| 1130 | if (n0 == NULL) { |
| 1131 | n0 = n; |
| 1132 | } else { |
| 1133 | nlast->m_nextpkt = n; |
| 1134 | } |
| 1135 | /* Keep track of last record on new chain */ |
| 1136 | nlast = n; |
| 1137 | |
| 1138 | for (np = n; np; np = np->m_next) |
| 1139 | sballoc(sb, np); |
| 1140 | } |
| 1141 | |
| 1142 | SBLASTRECORDCHK(sb, "sbappendaddrchain 1" ); |
| 1143 | |
| 1144 | /* Drop the entire chain of (asa+m) records onto the socket */ |
| 1145 | SBLINKRECORDCHAIN(sb, n0, nlast); |
| 1146 | |
| 1147 | SBLASTRECORDCHK(sb, "sbappendaddrchain 2" ); |
| 1148 | |
| 1149 | for (m = nlast; m->m_next; m = m->m_next) |
| 1150 | ; |
| 1151 | sb->sb_mbtail = m; |
| 1152 | SBLASTMBUFCHK(sb, "sbappendaddrchain" ); |
| 1153 | |
| 1154 | return (1); |
| 1155 | |
| 1156 | bad: |
| 1157 | /* |
| 1158 | * On error, free the prepended addreseses. For consistency |
| 1159 | * with sbappendaddr(), leave it to our caller to free |
| 1160 | * the input record chain passed to us as m0. |
| 1161 | */ |
| 1162 | while ((n = n0) != NULL) { |
| 1163 | struct mbuf *np; |
| 1164 | |
| 1165 | /* Undo the sballoc() of this record */ |
| 1166 | for (np = n; np; np = np->m_next) |
| 1167 | sbfree(sb, np); |
| 1168 | |
| 1169 | n0 = n->m_nextpkt; /* iterate at next prepended address */ |
| 1170 | np = m_free(n); /* free prepended address (not data) */ |
| 1171 | } |
| 1172 | return error; |
| 1173 | } |
| 1174 | |
| 1175 | |
| 1176 | int |
| 1177 | sbappendcontrol(struct sockbuf *sb, struct mbuf *m0, struct mbuf *control) |
| 1178 | { |
| 1179 | struct mbuf *m, *mlast, *n; |
| 1180 | int space; |
| 1181 | |
| 1182 | KASSERT(solocked(sb->sb_so)); |
| 1183 | |
| 1184 | space = 0; |
| 1185 | if (control == NULL) |
| 1186 | panic("sbappendcontrol" ); |
| 1187 | for (m = control; ; m = m->m_next) { |
| 1188 | space += m->m_len; |
| 1189 | MCLAIM(m, sb->sb_mowner); |
| 1190 | if (m->m_next == NULL) |
| 1191 | break; |
| 1192 | } |
| 1193 | n = m; /* save pointer to last control buffer */ |
| 1194 | for (m = m0; m; m = m->m_next) { |
| 1195 | MCLAIM(m, sb->sb_mowner); |
| 1196 | space += m->m_len; |
| 1197 | } |
| 1198 | if (space > sbspace(sb)) |
| 1199 | return (0); |
| 1200 | n->m_next = m0; /* concatenate data to control */ |
| 1201 | |
| 1202 | SBLASTRECORDCHK(sb, "sbappendcontrol 1" ); |
| 1203 | |
| 1204 | for (m = control; m->m_next != NULL; m = m->m_next) |
| 1205 | sballoc(sb, m); |
| 1206 | sballoc(sb, m); |
| 1207 | mlast = m; |
| 1208 | SBLINKRECORD(sb, control); |
| 1209 | |
| 1210 | sb->sb_mbtail = mlast; |
| 1211 | SBLASTMBUFCHK(sb, "sbappendcontrol" ); |
| 1212 | SBLASTRECORDCHK(sb, "sbappendcontrol 2" ); |
| 1213 | |
| 1214 | return (1); |
| 1215 | } |
| 1216 | |
| 1217 | /* |
| 1218 | * Compress mbuf chain m into the socket |
| 1219 | * buffer sb following mbuf n. If n |
| 1220 | * is null, the buffer is presumed empty. |
| 1221 | */ |
| 1222 | void |
| 1223 | sbcompress(struct sockbuf *sb, struct mbuf *m, struct mbuf *n) |
| 1224 | { |
| 1225 | int eor; |
| 1226 | struct mbuf *o; |
| 1227 | |
| 1228 | KASSERT(solocked(sb->sb_so)); |
| 1229 | |
| 1230 | eor = 0; |
| 1231 | while (m) { |
| 1232 | eor |= m->m_flags & M_EOR; |
| 1233 | if (m->m_len == 0 && |
| 1234 | (eor == 0 || |
| 1235 | (((o = m->m_next) || (o = n)) && |
| 1236 | o->m_type == m->m_type))) { |
| 1237 | if (sb->sb_lastrecord == m) |
| 1238 | sb->sb_lastrecord = m->m_next; |
| 1239 | m = m_free(m); |
| 1240 | continue; |
| 1241 | } |
| 1242 | if (n && (n->m_flags & M_EOR) == 0 && |
| 1243 | /* M_TRAILINGSPACE() checks buffer writeability */ |
| 1244 | m->m_len <= MCLBYTES / 4 && /* XXX Don't copy too much */ |
| 1245 | m->m_len <= M_TRAILINGSPACE(n) && |
| 1246 | n->m_type == m->m_type) { |
| 1247 | memcpy(mtod(n, char *) + n->m_len, mtod(m, void *), |
| 1248 | (unsigned)m->m_len); |
| 1249 | n->m_len += m->m_len; |
| 1250 | sb->sb_cc += m->m_len; |
| 1251 | m = m_free(m); |
| 1252 | continue; |
| 1253 | } |
| 1254 | if (n) |
| 1255 | n->m_next = m; |
| 1256 | else |
| 1257 | sb->sb_mb = m; |
| 1258 | sb->sb_mbtail = m; |
| 1259 | sballoc(sb, m); |
| 1260 | n = m; |
| 1261 | m->m_flags &= ~M_EOR; |
| 1262 | m = m->m_next; |
| 1263 | n->m_next = 0; |
| 1264 | } |
| 1265 | if (eor) { |
| 1266 | if (n) |
| 1267 | n->m_flags |= eor; |
| 1268 | else |
| 1269 | printf("semi-panic: sbcompress\n" ); |
| 1270 | } |
| 1271 | SBLASTMBUFCHK(sb, __func__); |
| 1272 | } |
| 1273 | |
| 1274 | /* |
| 1275 | * Free all mbufs in a sockbuf. |
| 1276 | * Check that all resources are reclaimed. |
| 1277 | */ |
| 1278 | void |
| 1279 | sbflush(struct sockbuf *sb) |
| 1280 | { |
| 1281 | |
| 1282 | KASSERT(solocked(sb->sb_so)); |
| 1283 | KASSERT((sb->sb_flags & SB_LOCK) == 0); |
| 1284 | |
| 1285 | while (sb->sb_mbcnt) |
| 1286 | sbdrop(sb, (int)sb->sb_cc); |
| 1287 | |
| 1288 | KASSERT(sb->sb_cc == 0); |
| 1289 | KASSERT(sb->sb_mb == NULL); |
| 1290 | KASSERT(sb->sb_mbtail == NULL); |
| 1291 | KASSERT(sb->sb_lastrecord == NULL); |
| 1292 | } |
| 1293 | |
| 1294 | /* |
| 1295 | * Drop data from (the front of) a sockbuf. |
| 1296 | */ |
| 1297 | void |
| 1298 | sbdrop(struct sockbuf *sb, int len) |
| 1299 | { |
| 1300 | struct mbuf *m, *next; |
| 1301 | |
| 1302 | KASSERT(solocked(sb->sb_so)); |
| 1303 | |
| 1304 | next = (m = sb->sb_mb) ? m->m_nextpkt : NULL; |
| 1305 | while (len > 0) { |
| 1306 | if (m == NULL) { |
| 1307 | if (next == NULL) |
| 1308 | panic("sbdrop(%p,%d): cc=%lu" , |
| 1309 | sb, len, sb->sb_cc); |
| 1310 | m = next; |
| 1311 | next = m->m_nextpkt; |
| 1312 | continue; |
| 1313 | } |
| 1314 | if (m->m_len > len) { |
| 1315 | m->m_len -= len; |
| 1316 | m->m_data += len; |
| 1317 | sb->sb_cc -= len; |
| 1318 | break; |
| 1319 | } |
| 1320 | len -= m->m_len; |
| 1321 | sbfree(sb, m); |
| 1322 | m = m_free(m); |
| 1323 | } |
| 1324 | while (m && m->m_len == 0) { |
| 1325 | sbfree(sb, m); |
| 1326 | m = m_free(m); |
| 1327 | } |
| 1328 | if (m) { |
| 1329 | sb->sb_mb = m; |
| 1330 | m->m_nextpkt = next; |
| 1331 | } else |
| 1332 | sb->sb_mb = next; |
| 1333 | /* |
| 1334 | * First part is an inline SB_EMPTY_FIXUP(). Second part |
| 1335 | * makes sure sb_lastrecord is up-to-date if we dropped |
| 1336 | * part of the last record. |
| 1337 | */ |
| 1338 | m = sb->sb_mb; |
| 1339 | if (m == NULL) { |
| 1340 | sb->sb_mbtail = NULL; |
| 1341 | sb->sb_lastrecord = NULL; |
| 1342 | } else if (m->m_nextpkt == NULL) |
| 1343 | sb->sb_lastrecord = m; |
| 1344 | } |
| 1345 | |
| 1346 | /* |
| 1347 | * Drop a record off the front of a sockbuf |
| 1348 | * and move the next record to the front. |
| 1349 | */ |
| 1350 | void |
| 1351 | sbdroprecord(struct sockbuf *sb) |
| 1352 | { |
| 1353 | struct mbuf *m, *mn; |
| 1354 | |
| 1355 | KASSERT(solocked(sb->sb_so)); |
| 1356 | |
| 1357 | m = sb->sb_mb; |
| 1358 | if (m) { |
| 1359 | sb->sb_mb = m->m_nextpkt; |
| 1360 | do { |
| 1361 | sbfree(sb, m); |
| 1362 | mn = m_free(m); |
| 1363 | } while ((m = mn) != NULL); |
| 1364 | } |
| 1365 | SB_EMPTY_FIXUP(sb); |
| 1366 | } |
| 1367 | |
| 1368 | /* |
| 1369 | * Create a "control" mbuf containing the specified data |
| 1370 | * with the specified type for presentation on a socket buffer. |
| 1371 | */ |
| 1372 | struct mbuf * |
| 1373 | sbcreatecontrol1(void **p, int size, int type, int level, int flags) |
| 1374 | { |
| 1375 | struct cmsghdr *cp; |
| 1376 | struct mbuf *m; |
| 1377 | int space = CMSG_SPACE(size); |
| 1378 | |
| 1379 | if ((flags & M_DONTWAIT) && space > MCLBYTES) { |
| 1380 | printf("%s: message too large %d\n" , __func__, space); |
| 1381 | return NULL; |
| 1382 | } |
| 1383 | |
| 1384 | if ((m = m_get(flags, MT_CONTROL)) == NULL) |
| 1385 | return NULL; |
| 1386 | if (space > MLEN) { |
| 1387 | if (space > MCLBYTES) |
| 1388 | MEXTMALLOC(m, space, M_WAITOK); |
| 1389 | else |
| 1390 | MCLGET(m, flags); |
| 1391 | if ((m->m_flags & M_EXT) == 0) { |
| 1392 | m_free(m); |
| 1393 | return NULL; |
| 1394 | } |
| 1395 | } |
| 1396 | cp = mtod(m, struct cmsghdr *); |
| 1397 | *p = CMSG_DATA(cp); |
| 1398 | m->m_len = space; |
| 1399 | cp->cmsg_len = CMSG_LEN(size); |
| 1400 | cp->cmsg_level = level; |
| 1401 | cp->cmsg_type = type; |
| 1402 | return m; |
| 1403 | } |
| 1404 | |
| 1405 | struct mbuf * |
| 1406 | sbcreatecontrol(void *p, int size, int type, int level) |
| 1407 | { |
| 1408 | struct mbuf *m; |
| 1409 | void *v; |
| 1410 | |
| 1411 | m = sbcreatecontrol1(&v, size, type, level, M_DONTWAIT); |
| 1412 | if (m == NULL) |
| 1413 | return NULL; |
| 1414 | memcpy(v, p, size); |
| 1415 | return m; |
| 1416 | } |
| 1417 | |
| 1418 | void |
| 1419 | solockretry(struct socket *so, kmutex_t *lock) |
| 1420 | { |
| 1421 | |
| 1422 | while (lock != so->so_lock) { |
| 1423 | mutex_exit(lock); |
| 1424 | lock = so->so_lock; |
| 1425 | mutex_enter(lock); |
| 1426 | } |
| 1427 | } |
| 1428 | |
| 1429 | bool |
| 1430 | solocked(struct socket *so) |
| 1431 | { |
| 1432 | |
| 1433 | return mutex_owned(so->so_lock); |
| 1434 | } |
| 1435 | |
| 1436 | bool |
| 1437 | solocked2(struct socket *so1, struct socket *so2) |
| 1438 | { |
| 1439 | kmutex_t *lock; |
| 1440 | |
| 1441 | lock = so1->so_lock; |
| 1442 | if (lock != so2->so_lock) |
| 1443 | return false; |
| 1444 | return mutex_owned(lock); |
| 1445 | } |
| 1446 | |
| 1447 | /* |
| 1448 | * sosetlock: assign a default lock to a new socket. |
| 1449 | */ |
| 1450 | void |
| 1451 | sosetlock(struct socket *so) |
| 1452 | { |
| 1453 | if (so->so_lock == NULL) { |
| 1454 | kmutex_t *lock = softnet_lock; |
| 1455 | |
| 1456 | so->so_lock = lock; |
| 1457 | mutex_obj_hold(lock); |
| 1458 | mutex_enter(lock); |
| 1459 | } |
| 1460 | KASSERT(solocked(so)); |
| 1461 | } |
| 1462 | |
| 1463 | /* |
| 1464 | * Set lock on sockbuf sb; sleep if lock is already held. |
| 1465 | * Unless SB_NOINTR is set on sockbuf, sleep is interruptible. |
| 1466 | * Returns error without lock if sleep is interrupted. |
| 1467 | */ |
| 1468 | int |
| 1469 | sblock(struct sockbuf *sb, int wf) |
| 1470 | { |
| 1471 | struct socket *so; |
| 1472 | kmutex_t *lock; |
| 1473 | int error; |
| 1474 | |
| 1475 | KASSERT(solocked(sb->sb_so)); |
| 1476 | |
| 1477 | for (;;) { |
| 1478 | if (__predict_true((sb->sb_flags & SB_LOCK) == 0)) { |
| 1479 | sb->sb_flags |= SB_LOCK; |
| 1480 | return 0; |
| 1481 | } |
| 1482 | if (wf != M_WAITOK) |
| 1483 | return EWOULDBLOCK; |
| 1484 | so = sb->sb_so; |
| 1485 | lock = so->so_lock; |
| 1486 | if ((sb->sb_flags & SB_NOINTR) != 0) { |
| 1487 | cv_wait(&so->so_cv, lock); |
| 1488 | error = 0; |
| 1489 | } else |
| 1490 | error = cv_wait_sig(&so->so_cv, lock); |
| 1491 | if (__predict_false(lock != so->so_lock)) |
| 1492 | solockretry(so, lock); |
| 1493 | if (error != 0) |
| 1494 | return error; |
| 1495 | } |
| 1496 | } |
| 1497 | |
| 1498 | void |
| 1499 | sbunlock(struct sockbuf *sb) |
| 1500 | { |
| 1501 | struct socket *so; |
| 1502 | |
| 1503 | so = sb->sb_so; |
| 1504 | |
| 1505 | KASSERT(solocked(so)); |
| 1506 | KASSERT((sb->sb_flags & SB_LOCK) != 0); |
| 1507 | |
| 1508 | sb->sb_flags &= ~SB_LOCK; |
| 1509 | cv_broadcast(&so->so_cv); |
| 1510 | } |
| 1511 | |
| 1512 | int |
| 1513 | sowait(struct socket *so, bool catch_p, int timo) |
| 1514 | { |
| 1515 | kmutex_t *lock; |
| 1516 | int error; |
| 1517 | |
| 1518 | KASSERT(solocked(so)); |
| 1519 | KASSERT(catch_p || timo != 0); |
| 1520 | |
| 1521 | lock = so->so_lock; |
| 1522 | if (catch_p) |
| 1523 | error = cv_timedwait_sig(&so->so_cv, lock, timo); |
| 1524 | else |
| 1525 | error = cv_timedwait(&so->so_cv, lock, timo); |
| 1526 | if (__predict_false(lock != so->so_lock)) |
| 1527 | solockretry(so, lock); |
| 1528 | return error; |
| 1529 | } |
| 1530 | |