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 | |