1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1988, 1990, 1993
5 * The Regents of the University of California. 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 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #include "opt_kern_tls.h"
34 #include "opt_param.h"
35
36 #include <sys/param.h>
37 #include <sys/aio.h> /* for aio_swake proto */
38 #include <sys/kernel.h>
39 #include <sys/ktls.h>
40 #include <sys/lock.h>
41 #include <sys/malloc.h>
42 #include <sys/mbuf.h>
43 #include <sys/msan.h>
44 #include <sys/mutex.h>
45 #include <sys/proc.h>
46 #include <sys/protosw.h>
47 #include <sys/resourcevar.h>
48 #include <sys/signalvar.h>
49 #include <sys/socket.h>
50 #include <sys/socketvar.h>
51 #include <sys/sx.h>
52 #include <sys/sysctl.h>
53
54 #include <netinet/in.h>
55
56 /*
57 * Function pointer set by the AIO routines so that the socket buffer code
58 * can call back into the AIO module if it is loaded.
59 */
60 void (*aio_swake)(struct socket *, struct sockbuf *);
61
62 /*
63 * Primitive routines for operating on socket buffers
64 */
65
66 #define BUF_MAX_ADJ(_sz) (((u_quad_t)(_sz)) * MCLBYTES / (MSIZE + MCLBYTES))
67
68 u_long sb_max = SB_MAX;
69 u_long sb_max_adj = BUF_MAX_ADJ(SB_MAX);
70
71 static u_long sb_efficiency = 8; /* parameter for sbreserve() */
72
73 #ifdef KERN_TLS
74 static void sbcompress_ktls_rx(struct sockbuf *sb, struct mbuf *m,
75 struct mbuf *n);
76 #endif
77 static struct mbuf *sbcut_internal(struct sockbuf *sb, int len);
78 static void sbflush_internal(struct sockbuf *sb);
79
80 /*
81 * Our own version of m_clrprotoflags(), that can preserve M_NOTREADY.
82 */
83 static void
sbm_clrprotoflags(struct mbuf * m,int flags)84 sbm_clrprotoflags(struct mbuf *m, int flags)
85 {
86 int mask;
87
88 mask = ~M_PROTOFLAGS;
89 if (flags & PRUS_NOTREADY)
90 mask |= M_NOTREADY;
91 while (m) {
92 m->m_flags &= mask;
93 m = m->m_next;
94 }
95 }
96
97 /*
98 * Compress M_NOTREADY mbufs after they have been readied by sbready().
99 *
100 * sbcompress() skips M_NOTREADY mbufs since the data is not available to
101 * be copied at the time of sbcompress(). This function combines small
102 * mbufs similar to sbcompress() once mbufs are ready. 'm0' is the first
103 * mbuf sbready() marked ready, and 'end' is the first mbuf still not
104 * ready.
105 */
106 static void
sbready_compress(struct sockbuf * sb,struct mbuf * m0,struct mbuf * end)107 sbready_compress(struct sockbuf *sb, struct mbuf *m0, struct mbuf *end)
108 {
109 struct mbuf *m, *n;
110 int ext_size;
111
112 SOCKBUF_LOCK_ASSERT(sb);
113
114 if ((sb->sb_flags & SB_NOCOALESCE) != 0)
115 return;
116
117 for (m = m0; m != end; m = m->m_next) {
118 MPASS((m->m_flags & M_NOTREADY) == 0);
119 /*
120 * NB: In sbcompress(), 'n' is the last mbuf in the
121 * socket buffer and 'm' is the new mbuf being copied
122 * into the trailing space of 'n'. Here, the roles
123 * are reversed and 'n' is the next mbuf after 'm'
124 * that is being copied into the trailing space of
125 * 'm'.
126 */
127 n = m->m_next;
128 #ifdef KERN_TLS
129 /* Try to coalesce adjacent ktls mbuf hdr/trailers. */
130 if ((n != NULL) && (n != end) && (m->m_flags & M_EOR) == 0 &&
131 (m->m_flags & M_EXTPG) &&
132 (n->m_flags & M_EXTPG) &&
133 !mbuf_has_tls_session(m) &&
134 !mbuf_has_tls_session(n)) {
135 int hdr_len, trail_len;
136
137 hdr_len = n->m_epg_hdrlen;
138 trail_len = m->m_epg_trllen;
139 if (trail_len != 0 && hdr_len != 0 &&
140 trail_len + hdr_len <= MBUF_PEXT_TRAIL_LEN) {
141 /* copy n's header to m's trailer */
142 memcpy(&m->m_epg_trail[trail_len],
143 n->m_epg_hdr, hdr_len);
144 m->m_epg_trllen += hdr_len;
145 m->m_len += hdr_len;
146 n->m_epg_hdrlen = 0;
147 n->m_len -= hdr_len;
148 }
149 }
150 #endif
151
152 /* Compress small unmapped mbufs into plain mbufs. */
153 if ((m->m_flags & M_EXTPG) && m->m_len <= MLEN &&
154 !mbuf_has_tls_session(m)) {
155 ext_size = m->m_ext.ext_size;
156 if (mb_unmapped_compress(m) == 0)
157 sb->sb_mbcnt -= ext_size;
158 }
159
160 while ((n != NULL) && (n != end) && (m->m_flags & M_EOR) == 0 &&
161 M_WRITABLE(m) &&
162 (m->m_flags & M_EXTPG) == 0 &&
163 !mbuf_has_tls_session(n) &&
164 !mbuf_has_tls_session(m) &&
165 n->m_len <= MCLBYTES / 4 && /* XXX: Don't copy too much */
166 n->m_len <= M_TRAILINGSPACE(m) &&
167 m->m_type == n->m_type) {
168 KASSERT(sb->sb_lastrecord != n,
169 ("%s: merging start of record (%p) into previous mbuf (%p)",
170 __func__, n, m));
171 m_copydata(n, 0, n->m_len, mtodo(m, m->m_len));
172 m->m_len += n->m_len;
173 m->m_next = n->m_next;
174 m->m_flags |= n->m_flags & M_EOR;
175 if (sb->sb_mbtail == n)
176 sb->sb_mbtail = m;
177
178 sb->sb_mbcnt -= MSIZE;
179 if (n->m_flags & M_EXT)
180 sb->sb_mbcnt -= n->m_ext.ext_size;
181 m_free(n);
182 n = m->m_next;
183 }
184 }
185 SBLASTRECORDCHK(sb);
186 SBLASTMBUFCHK(sb);
187 }
188
189 /*
190 * Mark ready "count" units of I/O starting with "m". Most mbufs
191 * count as a single unit of I/O except for M_EXTPG mbufs which
192 * are backed by multiple pages.
193 */
194 int
sbready(struct sockbuf * sb,struct mbuf * m0,int count)195 sbready(struct sockbuf *sb, struct mbuf *m0, int count)
196 {
197 struct mbuf *m;
198 u_int blocker;
199
200 SOCKBUF_LOCK_ASSERT(sb);
201 KASSERT(sb->sb_fnrdy != NULL, ("%s: sb %p NULL fnrdy", __func__, sb));
202 KASSERT(count > 0, ("%s: invalid count %d", __func__, count));
203
204 m = m0;
205 blocker = (sb->sb_fnrdy == m) ? M_BLOCKED : 0;
206
207 while (count > 0) {
208 KASSERT(m->m_flags & M_NOTREADY,
209 ("%s: m %p !M_NOTREADY", __func__, m));
210 if ((m->m_flags & M_EXTPG) != 0 && m->m_epg_npgs != 0) {
211 if (count < m->m_epg_nrdy) {
212 m->m_epg_nrdy -= count;
213 count = 0;
214 break;
215 }
216 count -= m->m_epg_nrdy;
217 m->m_epg_nrdy = 0;
218 } else
219 count--;
220
221 m->m_flags &= ~(M_NOTREADY | blocker);
222 if (blocker)
223 sb->sb_acc += m->m_len;
224 m = m->m_next;
225 }
226
227 /*
228 * If the first mbuf is still not fully ready because only
229 * some of its backing pages were readied, no further progress
230 * can be made.
231 */
232 if (m0 == m) {
233 MPASS(m->m_flags & M_NOTREADY);
234 return (EINPROGRESS);
235 }
236
237 if (!blocker) {
238 sbready_compress(sb, m0, m);
239 return (EINPROGRESS);
240 }
241
242 /* This one was blocking all the queue. */
243 for (; m && (m->m_flags & M_NOTREADY) == 0; m = m->m_next) {
244 KASSERT(m->m_flags & M_BLOCKED,
245 ("%s: m %p !M_BLOCKED", __func__, m));
246 m->m_flags &= ~M_BLOCKED;
247 sb->sb_acc += m->m_len;
248 }
249
250 sb->sb_fnrdy = m;
251 sbready_compress(sb, m0, m);
252
253 return (0);
254 }
255
256 /*
257 * Adjust sockbuf state reflecting allocation of m.
258 */
259 void
sballoc(struct sockbuf * sb,struct mbuf * m)260 sballoc(struct sockbuf *sb, struct mbuf *m)
261 {
262
263 SOCKBUF_LOCK_ASSERT(sb);
264
265 sb->sb_ccc += m->m_len;
266
267 if (sb->sb_fnrdy == NULL) {
268 if (m->m_flags & M_NOTREADY)
269 sb->sb_fnrdy = m;
270 else
271 sb->sb_acc += m->m_len;
272 } else
273 m->m_flags |= M_BLOCKED;
274
275 if (m->m_type != MT_DATA && m->m_type != MT_OOBDATA)
276 sb->sb_ctl += m->m_len;
277
278 sb->sb_mbcnt += MSIZE;
279
280 if (m->m_flags & M_EXT)
281 sb->sb_mbcnt += m->m_ext.ext_size;
282 }
283
284 /*
285 * Adjust sockbuf state reflecting freeing of m.
286 */
287 void
sbfree(struct sockbuf * sb,struct mbuf * m)288 sbfree(struct sockbuf *sb, struct mbuf *m)
289 {
290
291 #if 0 /* XXX: not yet: soclose() call path comes here w/o lock. */
292 SOCKBUF_LOCK_ASSERT(sb);
293 #endif
294
295 sb->sb_ccc -= m->m_len;
296
297 if (!(m->m_flags & M_NOTAVAIL))
298 sb->sb_acc -= m->m_len;
299
300 if (m == sb->sb_fnrdy) {
301 struct mbuf *n;
302
303 KASSERT(m->m_flags & M_NOTREADY,
304 ("%s: m %p !M_NOTREADY", __func__, m));
305
306 n = m->m_next;
307 while (n != NULL && !(n->m_flags & M_NOTREADY)) {
308 n->m_flags &= ~M_BLOCKED;
309 sb->sb_acc += n->m_len;
310 n = n->m_next;
311 }
312 sb->sb_fnrdy = n;
313 }
314
315 if (m->m_type != MT_DATA && m->m_type != MT_OOBDATA)
316 sb->sb_ctl -= m->m_len;
317
318 sb->sb_mbcnt -= MSIZE;
319 if (m->m_flags & M_EXT)
320 sb->sb_mbcnt -= m->m_ext.ext_size;
321
322 if (sb->sb_sndptr == m) {
323 sb->sb_sndptr = NULL;
324 sb->sb_sndptroff = 0;
325 }
326 if (sb->sb_sndptroff != 0)
327 sb->sb_sndptroff -= m->m_len;
328 }
329
330 #ifdef KERN_TLS
331 /*
332 * Similar to sballoc/sbfree but does not adjust state associated with
333 * the sb_mb chain such as sb_fnrdy or sb_sndptr*. Also assumes mbufs
334 * are not ready.
335 */
336 void
sballoc_ktls_rx(struct sockbuf * sb,struct mbuf * m)337 sballoc_ktls_rx(struct sockbuf *sb, struct mbuf *m)
338 {
339
340 SOCKBUF_LOCK_ASSERT(sb);
341
342 sb->sb_ccc += m->m_len;
343 sb->sb_tlscc += m->m_len;
344
345 sb->sb_mbcnt += MSIZE;
346
347 if (m->m_flags & M_EXT)
348 sb->sb_mbcnt += m->m_ext.ext_size;
349 }
350
351 void
sbfree_ktls_rx(struct sockbuf * sb,struct mbuf * m)352 sbfree_ktls_rx(struct sockbuf *sb, struct mbuf *m)
353 {
354
355 #if 0 /* XXX: not yet: soclose() call path comes here w/o lock. */
356 SOCKBUF_LOCK_ASSERT(sb);
357 #endif
358
359 sb->sb_ccc -= m->m_len;
360 sb->sb_tlscc -= m->m_len;
361
362 sb->sb_mbcnt -= MSIZE;
363
364 if (m->m_flags & M_EXT)
365 sb->sb_mbcnt -= m->m_ext.ext_size;
366 }
367 #endif
368
369 /*
370 * Socantsendmore indicates that no more data will be sent on the socket; it
371 * would normally be applied to a socket when the user informs the system
372 * that no more data is to be sent, by the protocol code (in case
373 * PRU_SHUTDOWN). Socantrcvmore indicates that no more data will be
374 * received, and will normally be applied to the socket by a protocol when it
375 * detects that the peer will send no more data. Data queued for reading in
376 * the socket may yet be read.
377 */
378 void
socantsendmore_locked(struct socket * so)379 socantsendmore_locked(struct socket *so)
380 {
381
382 SOCK_SENDBUF_LOCK_ASSERT(so);
383
384 so->so_snd.sb_state |= SBS_CANTSENDMORE;
385 sowwakeup_locked(so);
386 SOCK_SENDBUF_UNLOCK_ASSERT(so);
387 }
388
389 void
socantsendmore(struct socket * so)390 socantsendmore(struct socket *so)
391 {
392
393 SOCK_SENDBUF_LOCK(so);
394 socantsendmore_locked(so);
395 SOCK_SENDBUF_UNLOCK_ASSERT(so);
396 }
397
398 void
socantrcvmore_locked(struct socket * so)399 socantrcvmore_locked(struct socket *so)
400 {
401
402 SOCK_RECVBUF_LOCK_ASSERT(so);
403
404 so->so_rcv.sb_state |= SBS_CANTRCVMORE;
405 #ifdef KERN_TLS
406 if (so->so_rcv.sb_flags & SB_TLS_RX)
407 ktls_check_rx(&so->so_rcv);
408 #endif
409 sorwakeup_locked(so);
410 SOCK_RECVBUF_UNLOCK_ASSERT(so);
411 }
412
413 void
socantrcvmore(struct socket * so)414 socantrcvmore(struct socket *so)
415 {
416
417 SOCK_RECVBUF_LOCK(so);
418 socantrcvmore_locked(so);
419 SOCK_RECVBUF_UNLOCK_ASSERT(so);
420 }
421
422 void
soroverflow_locked(struct socket * so)423 soroverflow_locked(struct socket *so)
424 {
425
426 SOCK_RECVBUF_LOCK_ASSERT(so);
427
428 if (so->so_options & SO_RERROR) {
429 so->so_rerror = ENOBUFS;
430 sorwakeup_locked(so);
431 } else
432 SOCK_RECVBUF_UNLOCK(so);
433
434 SOCK_RECVBUF_UNLOCK_ASSERT(so);
435 }
436
437 void
soroverflow(struct socket * so)438 soroverflow(struct socket *so)
439 {
440
441 SOCK_RECVBUF_LOCK(so);
442 soroverflow_locked(so);
443 SOCK_RECVBUF_UNLOCK_ASSERT(so);
444 }
445
446 /*
447 * Wait for data to arrive at/drain from a socket buffer.
448 */
449 int
sbwait(struct socket * so,sb_which which)450 sbwait(struct socket *so, sb_which which)
451 {
452 struct sockbuf *sb;
453
454 SOCK_BUF_LOCK_ASSERT(so, which);
455
456 sb = sobuf(so, which);
457 sb->sb_flags |= SB_WAIT;
458 return (msleep_sbt(&sb->sb_acc, soeventmtx(so, which),
459 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, "sbwait",
460 sb->sb_timeo, 0, 0));
461 }
462
463 /*
464 * Wakeup processes waiting on a socket buffer. Do asynchronous notification
465 * via SIGIO if the socket has the SS_ASYNC flag set.
466 *
467 * Called with the socket buffer lock held; will release the lock by the end
468 * of the function. This allows the caller to acquire the socket buffer lock
469 * while testing for the need for various sorts of wakeup and hold it through
470 * to the point where it's no longer required. We currently hold the lock
471 * through calls out to other subsystems (with the exception of kqueue), and
472 * then release it to avoid lock order issues. It's not clear that's
473 * correct.
474 */
475 static __always_inline void
sowakeup(struct socket * so,const sb_which which)476 sowakeup(struct socket *so, const sb_which which)
477 {
478 struct sockbuf *sb;
479 int ret;
480
481 SOCK_BUF_LOCK_ASSERT(so, which);
482
483 sb = sobuf(so, which);
484 selwakeuppri(sb->sb_sel, PSOCK);
485 if (!SEL_WAITING(sb->sb_sel))
486 sb->sb_flags &= ~SB_SEL;
487 if (sb->sb_flags & SB_WAIT) {
488 sb->sb_flags &= ~SB_WAIT;
489 wakeup(&sb->sb_acc);
490 }
491 KNOTE_LOCKED(&sb->sb_sel->si_note, 0);
492 if (sb->sb_upcall != NULL) {
493 ret = sb->sb_upcall(so, sb->sb_upcallarg, M_NOWAIT);
494 if (ret == SU_ISCONNECTED) {
495 KASSERT(sb == &so->so_rcv,
496 ("SO_SND upcall returned SU_ISCONNECTED"));
497 soupcall_clear(so, SO_RCV);
498 }
499 } else
500 ret = SU_OK;
501 if (sb->sb_flags & SB_AIO)
502 sowakeup_aio(so, which);
503 SOCK_BUF_UNLOCK(so, which);
504 if (ret == SU_ISCONNECTED)
505 soisconnected(so);
506 if ((so->so_state & SS_ASYNC) && so->so_sigio != NULL)
507 pgsigio(&so->so_sigio, SIGIO, 0);
508 SOCK_BUF_UNLOCK_ASSERT(so, which);
509 }
510
511 /*
512 * Do we need to notify the other side when I/O is possible?
513 */
514 static __always_inline bool
sb_notify(const struct sockbuf * sb)515 sb_notify(const struct sockbuf *sb)
516 {
517 return ((sb->sb_flags & (SB_WAIT | SB_SEL | SB_ASYNC |
518 SB_UPCALL | SB_AIO | SB_KNOTE)) != 0);
519 }
520
521 void
sorwakeup_locked(struct socket * so)522 sorwakeup_locked(struct socket *so)
523 {
524 SOCK_RECVBUF_LOCK_ASSERT(so);
525 if (sb_notify(&so->so_rcv))
526 sowakeup(so, SO_RCV);
527 else
528 SOCK_RECVBUF_UNLOCK(so);
529 }
530
531 void
sowwakeup_locked(struct socket * so)532 sowwakeup_locked(struct socket *so)
533 {
534 SOCK_SENDBUF_LOCK_ASSERT(so);
535 if (sb_notify(&so->so_snd))
536 sowakeup(so, SO_SND);
537 else
538 SOCK_SENDBUF_UNLOCK(so);
539 }
540
541 /*
542 * Socket buffer (struct sockbuf) utility routines.
543 *
544 * Each socket contains two socket buffers: one for sending data and one for
545 * receiving data. Each buffer contains a queue of mbufs, information about
546 * the number of mbufs and amount of data in the queue, and other fields
547 * allowing select() statements and notification on data availability to be
548 * implemented.
549 *
550 * Data stored in a socket buffer is maintained as a list of records. Each
551 * record is a list of mbufs chained together with the m_next field. Records
552 * are chained together with the m_nextpkt field. The upper level routine
553 * soreceive() expects the following conventions to be observed when placing
554 * information in the receive buffer:
555 *
556 * 1. If the protocol requires each message be preceded by the sender's name,
557 * then a record containing that name must be present before any
558 * associated data (mbuf's must be of type MT_SONAME).
559 * 2. If the protocol supports the exchange of ``access rights'' (really just
560 * additional data associated with the message), and there are ``rights''
561 * to be received, then a record containing this data should be present
562 * (mbuf's must be of type MT_RIGHTS).
563 * 3. If a name or rights record exists, then it must be followed by a data
564 * record, perhaps of zero length.
565 *
566 * Before using a new socket structure it is first necessary to reserve
567 * buffer space to the socket, by calling sbreserve(). This should commit
568 * some of the available buffer space in the system buffer pool for the
569 * socket (currently, it does nothing but enforce limits). The space should
570 * be released by calling sbrelease() when the socket is destroyed.
571 */
572 int
soreserve(struct socket * so,u_long sndcc,u_long rcvcc)573 soreserve(struct socket *so, u_long sndcc, u_long rcvcc)
574 {
575 struct thread *td = curthread;
576
577 SOCK_SENDBUF_LOCK(so);
578 SOCK_RECVBUF_LOCK(so);
579 if (sbreserve_locked(so, SO_SND, sndcc, td) == 0)
580 goto bad;
581 if (sbreserve_locked(so, SO_RCV, rcvcc, td) == 0)
582 goto bad2;
583 if (so->so_rcv.sb_lowat == 0)
584 so->so_rcv.sb_lowat = 1;
585 if (so->so_snd.sb_lowat == 0)
586 so->so_snd.sb_lowat = MCLBYTES;
587 if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat)
588 so->so_snd.sb_lowat = so->so_snd.sb_hiwat;
589 SOCK_RECVBUF_UNLOCK(so);
590 SOCK_SENDBUF_UNLOCK(so);
591 return (0);
592 bad2:
593 sbrelease_locked(so, SO_SND);
594 bad:
595 SOCK_RECVBUF_UNLOCK(so);
596 SOCK_SENDBUF_UNLOCK(so);
597 return (ENOBUFS);
598 }
599
600 static int
sysctl_handle_sb_max(SYSCTL_HANDLER_ARGS)601 sysctl_handle_sb_max(SYSCTL_HANDLER_ARGS)
602 {
603 int error = 0;
604 u_long tmp_sb_max = sb_max;
605
606 error = sysctl_handle_long(oidp, &tmp_sb_max, arg2, req);
607 if (error || !req->newptr)
608 return (error);
609 if (tmp_sb_max < MSIZE + MCLBYTES)
610 return (EINVAL);
611 sb_max = tmp_sb_max;
612 sb_max_adj = BUF_MAX_ADJ(sb_max);
613 return (0);
614 }
615
616 /*
617 * Allot mbufs to a sockbuf. Attempt to scale mbmax so that mbcnt doesn't
618 * become limiting if buffering efficiency is near the normal case.
619 */
620 bool
sbreserve_locked_limit(struct socket * so,sb_which which,u_long cc,u_long buf_max,struct thread * td)621 sbreserve_locked_limit(struct socket *so, sb_which which, u_long cc,
622 u_long buf_max, struct thread *td)
623 {
624 struct sockbuf *sb = sobuf(so, which);
625 rlim_t sbsize_limit;
626
627 SOCK_BUF_LOCK_ASSERT(so, which);
628
629 /*
630 * When a thread is passed, we take into account the thread's socket
631 * buffer size limit. The caller will generally pass curthread, but
632 * in the TCP input path, NULL will be passed to indicate that no
633 * appropriate thread resource limits are available. In that case,
634 * we don't apply a process limit.
635 */
636 if (cc > BUF_MAX_ADJ(buf_max))
637 return (false);
638 if (td != NULL) {
639 sbsize_limit = lim_cur(td, RLIMIT_SBSIZE);
640 } else
641 sbsize_limit = RLIM_INFINITY;
642 if (!chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, cc,
643 sbsize_limit))
644 return (false);
645 sb->sb_mbmax = min(cc * sb_efficiency, buf_max);
646 if (sb->sb_lowat > sb->sb_hiwat)
647 sb->sb_lowat = sb->sb_hiwat;
648 return (true);
649 }
650
651 bool
sbreserve_locked(struct socket * so,sb_which which,u_long cc,struct thread * td)652 sbreserve_locked(struct socket *so, sb_which which, u_long cc,
653 struct thread *td)
654 {
655 return (sbreserve_locked_limit(so, which, cc, sb_max, td));
656 }
657
658 int
sbsetopt(struct socket * so,struct sockopt * sopt)659 sbsetopt(struct socket *so, struct sockopt *sopt)
660 {
661 struct sockbuf *sb;
662 sb_which wh;
663 short *flags;
664 u_int cc, *hiwat, *lowat;
665 int error, optval;
666
667 error = sooptcopyin(sopt, &optval, sizeof optval, sizeof optval);
668 if (error != 0)
669 return (error);
670
671 /*
672 * Values < 1 make no sense for any of these options,
673 * so disallow them.
674 */
675 if (optval < 1)
676 return (EINVAL);
677 cc = optval;
678
679 sb = NULL;
680 SOCK_LOCK(so);
681 if (SOLISTENING(so)) {
682 switch (sopt->sopt_name) {
683 case SO_SNDLOWAT:
684 case SO_SNDBUF:
685 lowat = &so->sol_sbsnd_lowat;
686 hiwat = &so->sol_sbsnd_hiwat;
687 flags = &so->sol_sbsnd_flags;
688 break;
689 case SO_RCVLOWAT:
690 case SO_RCVBUF:
691 lowat = &so->sol_sbrcv_lowat;
692 hiwat = &so->sol_sbrcv_hiwat;
693 flags = &so->sol_sbrcv_flags;
694 break;
695 }
696 } else {
697 switch (sopt->sopt_name) {
698 case SO_SNDLOWAT:
699 case SO_SNDBUF:
700 sb = &so->so_snd;
701 wh = SO_SND;
702 break;
703 case SO_RCVLOWAT:
704 case SO_RCVBUF:
705 sb = &so->so_rcv;
706 wh = SO_RCV;
707 break;
708 }
709 flags = &sb->sb_flags;
710 hiwat = &sb->sb_hiwat;
711 lowat = &sb->sb_lowat;
712 SOCK_BUF_LOCK(so, wh);
713 }
714
715 error = 0;
716 switch (sopt->sopt_name) {
717 case SO_SNDBUF:
718 case SO_RCVBUF:
719 if (SOLISTENING(so)) {
720 if (cc > sb_max_adj) {
721 error = ENOBUFS;
722 break;
723 }
724 *hiwat = cc;
725 if (*lowat > *hiwat)
726 *lowat = *hiwat;
727 } else {
728 if (!sbreserve_locked(so, wh, cc, curthread))
729 error = ENOBUFS;
730 }
731 if (error == 0)
732 *flags &= ~SB_AUTOSIZE;
733 break;
734 case SO_SNDLOWAT:
735 case SO_RCVLOWAT:
736 /*
737 * Make sure the low-water is never greater than the
738 * high-water.
739 */
740 *lowat = (cc > *hiwat) ? *hiwat : cc;
741 break;
742 }
743
744 if (!SOLISTENING(so))
745 SOCK_BUF_UNLOCK(so, wh);
746 SOCK_UNLOCK(so);
747 return (error);
748 }
749
750 /*
751 * Free mbufs held by a socket, and reserved mbuf space.
752 */
753 static void
sbrelease_internal(struct socket * so,sb_which which)754 sbrelease_internal(struct socket *so, sb_which which)
755 {
756 struct sockbuf *sb = sobuf(so, which);
757
758 sbflush_internal(sb);
759 (void)chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, 0,
760 RLIM_INFINITY);
761 sb->sb_mbmax = 0;
762 }
763
764 void
sbrelease_locked(struct socket * so,sb_which which)765 sbrelease_locked(struct socket *so, sb_which which)
766 {
767
768 SOCK_BUF_LOCK_ASSERT(so, which);
769
770 sbrelease_internal(so, which);
771 }
772
773 void
sbrelease(struct socket * so,sb_which which)774 sbrelease(struct socket *so, sb_which which)
775 {
776
777 SOCK_BUF_LOCK(so, which);
778 sbrelease_locked(so, which);
779 SOCK_BUF_UNLOCK(so, which);
780 }
781
782 void
sbdestroy(struct socket * so,sb_which which)783 sbdestroy(struct socket *so, sb_which which)
784 {
785 #ifdef KERN_TLS
786 struct sockbuf *sb = sobuf(so, which);
787
788 if (sb->sb_tls_info != NULL)
789 ktls_free(sb->sb_tls_info);
790 sb->sb_tls_info = NULL;
791 #endif
792 sbrelease_internal(so, which);
793 }
794
795 /*
796 * Routines to add and remove data from an mbuf queue.
797 *
798 * The routines sbappend() or sbappendrecord() are normally called to append
799 * new mbufs to a socket buffer, after checking that adequate space is
800 * available, comparing the function sbspace() with the amount of data to be
801 * added. sbappendrecord() differs from sbappend() in that data supplied is
802 * treated as the beginning of a new record. To place a sender's address,
803 * optional access rights, and data in a socket receive buffer,
804 * sbappendaddr() should be used. To place access rights and data in a
805 * socket receive buffer, sbappendrights() should be used. In either case,
806 * the new data begins a new record. Note that unlike sbappend() and
807 * sbappendrecord(), these routines check for the caller that there will be
808 * enough space to store the data. Each fails if there is not enough space,
809 * or if it cannot find mbufs to store additional information in.
810 *
811 * Reliable protocols may use the socket send buffer to hold data awaiting
812 * acknowledgement. Data is normally copied from a socket send buffer in a
813 * protocol with m_copy for output to a peer, and then removing the data from
814 * the socket buffer with sbdrop() or sbdroprecord() when the data is
815 * acknowledged by the peer.
816 */
817 #ifdef SOCKBUF_DEBUG
818 void
sblastrecordchk(struct sockbuf * sb,const char * file,int line)819 sblastrecordchk(struct sockbuf *sb, const char *file, int line)
820 {
821 struct mbuf *m = sb->sb_mb;
822
823 SOCKBUF_LOCK_ASSERT(sb);
824
825 while (m && m->m_nextpkt)
826 m = m->m_nextpkt;
827
828 if (m != sb->sb_lastrecord) {
829 printf("%s: sb_mb %p sb_lastrecord %p last %p\n",
830 __func__, sb->sb_mb, sb->sb_lastrecord, m);
831 printf("packet chain:\n");
832 for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt)
833 printf("\t%p\n", m);
834 panic("%s from %s:%u", __func__, file, line);
835 }
836 }
837
838 void
sblastmbufchk(struct sockbuf * sb,const char * file,int line)839 sblastmbufchk(struct sockbuf *sb, const char *file, int line)
840 {
841 struct mbuf *m = sb->sb_mb;
842 struct mbuf *n;
843
844 SOCKBUF_LOCK_ASSERT(sb);
845
846 while (m && m->m_nextpkt)
847 m = m->m_nextpkt;
848
849 while (m && m->m_next)
850 m = m->m_next;
851
852 if (m != sb->sb_mbtail) {
853 printf("%s: sb_mb %p sb_mbtail %p last %p\n",
854 __func__, sb->sb_mb, sb->sb_mbtail, m);
855 printf("packet tree:\n");
856 for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt) {
857 printf("\t");
858 for (n = m; n != NULL; n = n->m_next)
859 printf("%p ", n);
860 printf("\n");
861 }
862 panic("%s from %s:%u", __func__, file, line);
863 }
864
865 #ifdef KERN_TLS
866 m = sb->sb_mtls;
867 while (m && m->m_next)
868 m = m->m_next;
869
870 if (m != sb->sb_mtlstail) {
871 printf("%s: sb_mtls %p sb_mtlstail %p last %p\n",
872 __func__, sb->sb_mtls, sb->sb_mtlstail, m);
873 printf("TLS packet tree:\n");
874 printf("\t");
875 for (m = sb->sb_mtls; m != NULL; m = m->m_next) {
876 printf("%p ", m);
877 }
878 printf("\n");
879 panic("%s from %s:%u", __func__, file, line);
880 }
881 #endif
882 }
883 #endif /* SOCKBUF_DEBUG */
884
885 #define SBLINKRECORD(sb, m0) do { \
886 SOCKBUF_LOCK_ASSERT(sb); \
887 if ((sb)->sb_lastrecord != NULL) \
888 (sb)->sb_lastrecord->m_nextpkt = (m0); \
889 else \
890 (sb)->sb_mb = (m0); \
891 (sb)->sb_lastrecord = (m0); \
892 } while (/*CONSTCOND*/0)
893
894 /*
895 * Append mbuf chain m to the last record in the socket buffer sb. The
896 * additional space associated the mbuf chain is recorded in sb. Empty mbufs
897 * are discarded and mbufs are compacted where possible.
898 */
899 void
sbappend_locked(struct sockbuf * sb,struct mbuf * m,int flags)900 sbappend_locked(struct sockbuf *sb, struct mbuf *m, int flags)
901 {
902 struct mbuf *n;
903
904 SOCKBUF_LOCK_ASSERT(sb);
905
906 if (m == NULL)
907 return;
908 kmsan_check_mbuf(m, "sbappend");
909 sbm_clrprotoflags(m, flags);
910 SBLASTRECORDCHK(sb);
911 n = sb->sb_mb;
912 if (n) {
913 while (n->m_nextpkt)
914 n = n->m_nextpkt;
915 do {
916 if (n->m_flags & M_EOR) {
917 sbappendrecord_locked(sb, m); /* XXXXXX!!!! */
918 return;
919 }
920 } while (n->m_next && (n = n->m_next));
921 } else {
922 /*
923 * XXX Would like to simply use sb_mbtail here, but
924 * XXX I need to verify that I won't miss an EOR that
925 * XXX way.
926 */
927 if ((n = sb->sb_lastrecord) != NULL) {
928 do {
929 if (n->m_flags & M_EOR) {
930 sbappendrecord_locked(sb, m); /* XXXXXX!!!! */
931 return;
932 }
933 } while (n->m_next && (n = n->m_next));
934 } else {
935 /*
936 * If this is the first record in the socket buffer,
937 * it's also the last record.
938 */
939 sb->sb_lastrecord = m;
940 }
941 }
942 sbcompress(sb, m, n);
943 SBLASTRECORDCHK(sb);
944 }
945
946 /*
947 * Append mbuf chain m to the last record in the socket buffer sb. The
948 * additional space associated the mbuf chain is recorded in sb. Empty mbufs
949 * are discarded and mbufs are compacted where possible.
950 */
951 void
sbappend(struct sockbuf * sb,struct mbuf * m,int flags)952 sbappend(struct sockbuf *sb, struct mbuf *m, int flags)
953 {
954
955 SOCKBUF_LOCK(sb);
956 sbappend_locked(sb, m, flags);
957 SOCKBUF_UNLOCK(sb);
958 }
959
960 #ifdef KERN_TLS
961 /*
962 * Append an mbuf containing encrypted TLS data. The data
963 * is marked M_NOTREADY until it has been decrypted and
964 * stored as a TLS record.
965 */
966 static void
sbappend_ktls_rx(struct sockbuf * sb,struct mbuf * m)967 sbappend_ktls_rx(struct sockbuf *sb, struct mbuf *m)
968 {
969 struct ifnet *ifp;
970 struct mbuf *n;
971 int flags;
972
973 ifp = NULL;
974 flags = M_NOTREADY;
975
976 SBLASTMBUFCHK(sb);
977
978 /* Mbuf chain must start with a packet header. */
979 MPASS((m->m_flags & M_PKTHDR) != 0);
980
981 /* Remove all packet headers and mbuf tags to get a pure data chain. */
982 for (n = m; n != NULL; n = n->m_next) {
983 if (n->m_flags & M_PKTHDR) {
984 ifp = m->m_pkthdr.leaf_rcvif;
985 if ((n->m_pkthdr.csum_flags & CSUM_TLS_MASK) ==
986 CSUM_TLS_DECRYPTED) {
987 /* Mark all mbufs in this packet decrypted. */
988 flags = M_NOTREADY | M_DECRYPTED;
989 } else {
990 flags = M_NOTREADY;
991 }
992 m_demote_pkthdr(n);
993 }
994
995 n->m_flags &= M_DEMOTEFLAGS;
996 n->m_flags |= flags;
997
998 MPASS((n->m_flags & M_NOTREADY) != 0);
999 }
1000
1001 sbcompress_ktls_rx(sb, m, sb->sb_mtlstail);
1002 ktls_check_rx(sb);
1003
1004 /* Check for incoming packet route changes: */
1005 if (ifp != NULL && sb->sb_tls_info->rx_ifp != NULL &&
1006 sb->sb_tls_info->rx_ifp != ifp)
1007 ktls_input_ifp_mismatch(sb, ifp);
1008 }
1009 #endif
1010
1011 /*
1012 * This version of sbappend() should only be used when the caller absolutely
1013 * knows that there will never be more than one record in the socket buffer,
1014 * that is, a stream protocol (such as TCP).
1015 */
1016 void
sbappendstream_locked(struct sockbuf * sb,struct mbuf * m,int flags)1017 sbappendstream_locked(struct sockbuf *sb, struct mbuf *m, int flags)
1018 {
1019 SOCKBUF_LOCK_ASSERT(sb);
1020
1021 KASSERT(m->m_nextpkt == NULL,("sbappendstream 0"));
1022
1023 kmsan_check_mbuf(m, "sbappend");
1024
1025 #ifdef KERN_TLS
1026 /*
1027 * Decrypted TLS records are appended as records via
1028 * sbappendrecord(). TCP passes encrypted TLS records to this
1029 * function which must be scheduled for decryption.
1030 */
1031 if (sb->sb_flags & SB_TLS_RX) {
1032 sbappend_ktls_rx(sb, m);
1033 return;
1034 }
1035 #endif
1036
1037 KASSERT(sb->sb_mb == sb->sb_lastrecord,("sbappendstream 1"));
1038
1039 SBLASTMBUFCHK(sb);
1040
1041 #ifdef KERN_TLS
1042 if (sb->sb_tls_info != NULL)
1043 ktls_seq(sb, m);
1044 #endif
1045
1046 /* Remove all packet headers and mbuf tags to get a pure data chain. */
1047 m_demote(m, 1, flags & PRUS_NOTREADY ? M_NOTREADY : 0);
1048
1049 sbcompress(sb, m, sb->sb_mbtail);
1050
1051 sb->sb_lastrecord = sb->sb_mb;
1052 SBLASTRECORDCHK(sb);
1053 }
1054
1055 /*
1056 * This version of sbappend() should only be used when the caller absolutely
1057 * knows that there will never be more than one record in the socket buffer,
1058 * that is, a stream protocol (such as TCP).
1059 */
1060 void
sbappendstream(struct sockbuf * sb,struct mbuf * m,int flags)1061 sbappendstream(struct sockbuf *sb, struct mbuf *m, int flags)
1062 {
1063
1064 SOCKBUF_LOCK(sb);
1065 sbappendstream_locked(sb, m, flags);
1066 SOCKBUF_UNLOCK(sb);
1067 }
1068
1069 #ifdef SOCKBUF_DEBUG
1070 void
sbcheck(struct sockbuf * sb,const char * file,int line)1071 sbcheck(struct sockbuf *sb, const char *file, int line)
1072 {
1073 struct mbuf *m, *n, *fnrdy;
1074 u_long acc, ccc, mbcnt;
1075 #ifdef KERN_TLS
1076 u_long tlscc;
1077 #endif
1078
1079 SOCKBUF_LOCK_ASSERT(sb);
1080
1081 acc = ccc = mbcnt = 0;
1082 fnrdy = NULL;
1083
1084 for (m = sb->sb_mb; m; m = n) {
1085 n = m->m_nextpkt;
1086 for (; m; m = m->m_next) {
1087 if (m->m_len == 0) {
1088 printf("sb %p empty mbuf %p\n", sb, m);
1089 goto fail;
1090 }
1091 if ((m->m_flags & M_NOTREADY) && fnrdy == NULL) {
1092 if (m != sb->sb_fnrdy) {
1093 printf("sb %p: fnrdy %p != m %p\n",
1094 sb, sb->sb_fnrdy, m);
1095 goto fail;
1096 }
1097 fnrdy = m;
1098 }
1099 if (fnrdy) {
1100 if (!(m->m_flags & M_NOTAVAIL)) {
1101 printf("sb %p: fnrdy %p, m %p is avail\n",
1102 sb, sb->sb_fnrdy, m);
1103 goto fail;
1104 }
1105 } else
1106 acc += m->m_len;
1107 ccc += m->m_len;
1108 mbcnt += MSIZE;
1109 if (m->m_flags & M_EXT) /*XXX*/ /* pretty sure this is bogus */
1110 mbcnt += m->m_ext.ext_size;
1111 }
1112 }
1113 #ifdef KERN_TLS
1114 /*
1115 * Account for mbufs "detached" by ktls_detach_record() while
1116 * they are decrypted by ktls_decrypt(). tlsdcc gives a count
1117 * of the detached bytes that are included in ccc. The mbufs
1118 * and clusters are not included in the socket buffer
1119 * accounting.
1120 */
1121 ccc += sb->sb_tlsdcc;
1122
1123 tlscc = 0;
1124 for (m = sb->sb_mtls; m; m = m->m_next) {
1125 if (m->m_nextpkt != NULL) {
1126 printf("sb %p TLS mbuf %p with nextpkt\n", sb, m);
1127 goto fail;
1128 }
1129 if ((m->m_flags & M_NOTREADY) == 0) {
1130 printf("sb %p TLS mbuf %p ready\n", sb, m);
1131 goto fail;
1132 }
1133 tlscc += m->m_len;
1134 ccc += m->m_len;
1135 mbcnt += MSIZE;
1136 if (m->m_flags & M_EXT) /*XXX*/ /* pretty sure this is bogus */
1137 mbcnt += m->m_ext.ext_size;
1138 }
1139
1140 if (sb->sb_tlscc != tlscc) {
1141 printf("tlscc %ld/%u dcc %u\n", tlscc, sb->sb_tlscc,
1142 sb->sb_tlsdcc);
1143 goto fail;
1144 }
1145 #endif
1146 if (acc != sb->sb_acc || ccc != sb->sb_ccc || mbcnt != sb->sb_mbcnt) {
1147 printf("acc %ld/%u ccc %ld/%u mbcnt %ld/%u\n",
1148 acc, sb->sb_acc, ccc, sb->sb_ccc, mbcnt, sb->sb_mbcnt);
1149 #ifdef KERN_TLS
1150 printf("tlscc %ld/%u dcc %u\n", tlscc, sb->sb_tlscc,
1151 sb->sb_tlsdcc);
1152 #endif
1153 goto fail;
1154 }
1155 return;
1156 fail:
1157 panic("%s from %s:%u", __func__, file, line);
1158 }
1159 #endif
1160
1161 /*
1162 * As above, except the mbuf chain begins a new record.
1163 */
1164 void
sbappendrecord_locked(struct sockbuf * sb,struct mbuf * m0)1165 sbappendrecord_locked(struct sockbuf *sb, struct mbuf *m0)
1166 {
1167 struct mbuf *m;
1168
1169 SOCKBUF_LOCK_ASSERT(sb);
1170
1171 if (m0 == NULL)
1172 return;
1173
1174 kmsan_check_mbuf(m0, "sbappend");
1175 m_clrprotoflags(m0);
1176
1177 /*
1178 * Put the first mbuf on the queue. Note this permits zero length
1179 * records.
1180 */
1181 sballoc(sb, m0);
1182 SBLASTRECORDCHK(sb);
1183 SBLINKRECORD(sb, m0);
1184 sb->sb_mbtail = m0;
1185 m = m0->m_next;
1186 m0->m_next = 0;
1187 if (m && (m0->m_flags & M_EOR)) {
1188 m0->m_flags &= ~M_EOR;
1189 m->m_flags |= M_EOR;
1190 }
1191 /* always call sbcompress() so it can do SBLASTMBUFCHK() */
1192 sbcompress(sb, m, m0);
1193 }
1194
1195 /*
1196 * As above, except the mbuf chain begins a new record.
1197 */
1198 void
sbappendrecord(struct sockbuf * sb,struct mbuf * m0)1199 sbappendrecord(struct sockbuf *sb, struct mbuf *m0)
1200 {
1201
1202 SOCKBUF_LOCK(sb);
1203 sbappendrecord_locked(sb, m0);
1204 SOCKBUF_UNLOCK(sb);
1205 }
1206
1207 /* Helper routine that appends data, control, and address to a sockbuf. */
1208 static int
sbappendaddr_locked_internal(struct sockbuf * sb,const struct sockaddr * asa,struct mbuf * m0,struct mbuf * control,struct mbuf * ctrl_last)1209 sbappendaddr_locked_internal(struct sockbuf *sb, const struct sockaddr *asa,
1210 struct mbuf *m0, struct mbuf *control, struct mbuf *ctrl_last)
1211 {
1212 struct mbuf *m, *n, *nlast;
1213
1214 if (m0 != NULL)
1215 kmsan_check_mbuf(m0, "sbappend");
1216 if (control != NULL)
1217 kmsan_check_mbuf(control, "sbappend");
1218
1219 #if MSIZE <= 256
1220 if (asa->sa_len > MLEN)
1221 return (0);
1222 #endif
1223 m = m_get(M_NOWAIT, MT_SONAME);
1224 if (m == NULL)
1225 return (0);
1226 m->m_len = asa->sa_len;
1227 bcopy(asa, mtod(m, caddr_t), asa->sa_len);
1228 if (m0) {
1229 M_ASSERT_NO_SND_TAG(m0);
1230 m_clrprotoflags(m0);
1231 m_tag_delete_chain(m0, NULL);
1232 /*
1233 * Clear some persistent info from pkthdr.
1234 * We don't use m_demote(), because some netgraph consumers
1235 * expect M_PKTHDR presence.
1236 */
1237 m0->m_pkthdr.rcvif = NULL;
1238 m0->m_pkthdr.flowid = 0;
1239 m0->m_pkthdr.csum_flags = 0;
1240 m0->m_pkthdr.fibnum = 0;
1241 m0->m_pkthdr.rsstype = 0;
1242 }
1243 if (ctrl_last)
1244 ctrl_last->m_next = m0; /* concatenate data to control */
1245 else
1246 control = m0;
1247 m->m_next = control;
1248 for (n = m; n->m_next != NULL; n = n->m_next)
1249 sballoc(sb, n);
1250 sballoc(sb, n);
1251 nlast = n;
1252 SBLINKRECORD(sb, m);
1253
1254 sb->sb_mbtail = nlast;
1255 SBLASTMBUFCHK(sb);
1256
1257 SBLASTRECORDCHK(sb);
1258 return (1);
1259 }
1260
1261 /*
1262 * Append address and data, and optionally, control (ancillary) data to the
1263 * receive queue of a socket. If present, m0 must include a packet header
1264 * with total length. Returns 0 if no space in sockbuf or insufficient
1265 * mbufs.
1266 */
1267 int
sbappendaddr_locked(struct sockbuf * sb,const struct sockaddr * asa,struct mbuf * m0,struct mbuf * control)1268 sbappendaddr_locked(struct sockbuf *sb, const struct sockaddr *asa,
1269 struct mbuf *m0, struct mbuf *control)
1270 {
1271 struct mbuf *ctrl_last;
1272 int space = asa->sa_len;
1273
1274 SOCKBUF_LOCK_ASSERT(sb);
1275
1276 if (m0 && (m0->m_flags & M_PKTHDR) == 0)
1277 panic("sbappendaddr_locked");
1278 if (m0)
1279 space += m0->m_pkthdr.len;
1280 space += m_length(control, &ctrl_last);
1281
1282 if (space > sbspace(sb))
1283 return (0);
1284 return (sbappendaddr_locked_internal(sb, asa, m0, control, ctrl_last));
1285 }
1286
1287 /*
1288 * Append address and data, and optionally, control (ancillary) data to the
1289 * receive queue of a socket. If present, m0 must include a packet header
1290 * with total length. Returns 0 if insufficient mbufs. Does not validate space
1291 * on the receiving sockbuf.
1292 */
1293 int
sbappendaddr_nospacecheck_locked(struct sockbuf * sb,const struct sockaddr * asa,struct mbuf * m0,struct mbuf * control)1294 sbappendaddr_nospacecheck_locked(struct sockbuf *sb, const struct sockaddr *asa,
1295 struct mbuf *m0, struct mbuf *control)
1296 {
1297 struct mbuf *ctrl_last;
1298
1299 SOCKBUF_LOCK_ASSERT(sb);
1300
1301 ctrl_last = (control == NULL) ? NULL : m_last(control);
1302 return (sbappendaddr_locked_internal(sb, asa, m0, control, ctrl_last));
1303 }
1304
1305 /*
1306 * Append address and data, and optionally, control (ancillary) data to the
1307 * receive queue of a socket. If present, m0 must include a packet header
1308 * with total length. Returns 0 if no space in sockbuf or insufficient
1309 * mbufs.
1310 */
1311 int
sbappendaddr(struct sockbuf * sb,const struct sockaddr * asa,struct mbuf * m0,struct mbuf * control)1312 sbappendaddr(struct sockbuf *sb, const struct sockaddr *asa,
1313 struct mbuf *m0, struct mbuf *control)
1314 {
1315 int retval;
1316
1317 SOCKBUF_LOCK(sb);
1318 retval = sbappendaddr_locked(sb, asa, m0, control);
1319 SOCKBUF_UNLOCK(sb);
1320 return (retval);
1321 }
1322
1323 void
sbappendcontrol_locked(struct sockbuf * sb,struct mbuf * m0,struct mbuf * control,int flags)1324 sbappendcontrol_locked(struct sockbuf *sb, struct mbuf *m0,
1325 struct mbuf *control, int flags)
1326 {
1327 struct mbuf *m, *mlast;
1328
1329 if (m0 != NULL)
1330 kmsan_check_mbuf(m0, "sbappend");
1331 kmsan_check_mbuf(control, "sbappend");
1332
1333 sbm_clrprotoflags(m0, flags);
1334 m_last(control)->m_next = m0;
1335
1336 SBLASTRECORDCHK(sb);
1337
1338 for (m = control; m->m_next; m = m->m_next)
1339 sballoc(sb, m);
1340 sballoc(sb, m);
1341 mlast = m;
1342 SBLINKRECORD(sb, control);
1343
1344 sb->sb_mbtail = mlast;
1345 SBLASTMBUFCHK(sb);
1346
1347 SBLASTRECORDCHK(sb);
1348 }
1349
1350 void
sbappendcontrol(struct sockbuf * sb,struct mbuf * m0,struct mbuf * control,int flags)1351 sbappendcontrol(struct sockbuf *sb, struct mbuf *m0, struct mbuf *control,
1352 int flags)
1353 {
1354
1355 SOCKBUF_LOCK(sb);
1356 sbappendcontrol_locked(sb, m0, control, flags);
1357 SOCKBUF_UNLOCK(sb);
1358 }
1359
1360 /*
1361 * Append the data in mbuf chain (m) into the socket buffer sb following mbuf
1362 * (n). If (n) is NULL, the buffer is presumed empty.
1363 *
1364 * When the data is compressed, mbufs in the chain may be handled in one of
1365 * three ways:
1366 *
1367 * (1) The mbuf may simply be dropped, if it contributes nothing (no data, no
1368 * record boundary, and no change in data type).
1369 *
1370 * (2) The mbuf may be coalesced -- i.e., data in the mbuf may be copied into
1371 * an mbuf already in the socket buffer. This can occur if an
1372 * appropriate mbuf exists, there is room, both mbufs are not marked as
1373 * not ready, and no merging of data types will occur.
1374 *
1375 * (3) The mbuf may be appended to the end of the existing mbuf chain.
1376 *
1377 * If any of the new mbufs is marked as M_EOR, mark the last mbuf appended as
1378 * end-of-record.
1379 */
1380 void
sbcompress(struct sockbuf * sb,struct mbuf * m,struct mbuf * n)1381 sbcompress(struct sockbuf *sb, struct mbuf *m, struct mbuf *n)
1382 {
1383 int eor = 0;
1384 struct mbuf *o;
1385
1386 SOCKBUF_LOCK_ASSERT(sb);
1387
1388 while (m) {
1389 eor |= m->m_flags & M_EOR;
1390 if (m->m_len == 0 &&
1391 (eor == 0 ||
1392 (((o = m->m_next) || (o = n)) &&
1393 o->m_type == m->m_type))) {
1394 if (sb->sb_lastrecord == m)
1395 sb->sb_lastrecord = m->m_next;
1396 m = m_free(m);
1397 continue;
1398 }
1399 if (n && (n->m_flags & M_EOR) == 0 &&
1400 M_WRITABLE(n) &&
1401 ((sb->sb_flags & SB_NOCOALESCE) == 0) &&
1402 !(m->m_flags & M_NOTREADY) &&
1403 !(n->m_flags & (M_NOTREADY | M_EXTPG)) &&
1404 !mbuf_has_tls_session(m) &&
1405 !mbuf_has_tls_session(n) &&
1406 m->m_len <= MCLBYTES / 4 && /* XXX: Don't copy too much */
1407 m->m_len <= M_TRAILINGSPACE(n) &&
1408 n->m_type == m->m_type) {
1409 m_copydata(m, 0, m->m_len, mtodo(n, n->m_len));
1410 n->m_len += m->m_len;
1411 sb->sb_ccc += m->m_len;
1412 if (sb->sb_fnrdy == NULL)
1413 sb->sb_acc += m->m_len;
1414 if (m->m_type != MT_DATA && m->m_type != MT_OOBDATA)
1415 /* XXX: Probably don't need.*/
1416 sb->sb_ctl += m->m_len;
1417 m = m_free(m);
1418 continue;
1419 }
1420 if (m->m_len <= MLEN && (m->m_flags & M_EXTPG) &&
1421 (m->m_flags & M_NOTREADY) == 0 &&
1422 !mbuf_has_tls_session(m))
1423 (void)mb_unmapped_compress(m);
1424 if (n)
1425 n->m_next = m;
1426 else
1427 sb->sb_mb = m;
1428 sb->sb_mbtail = m;
1429 sballoc(sb, m);
1430 n = m;
1431 m->m_flags &= ~M_EOR;
1432 m = m->m_next;
1433 n->m_next = 0;
1434 }
1435 if (eor) {
1436 KASSERT(n != NULL, ("sbcompress: eor && n == NULL"));
1437 n->m_flags |= eor;
1438 }
1439 SBLASTMBUFCHK(sb);
1440 }
1441
1442 #ifdef KERN_TLS
1443 /*
1444 * A version of sbcompress() for encrypted TLS RX mbufs. These mbufs
1445 * are appended to the 'sb_mtls' chain instead of 'sb_mb' and are also
1446 * a bit simpler (no EOR markers, always MT_DATA, etc.).
1447 */
1448 static void
sbcompress_ktls_rx(struct sockbuf * sb,struct mbuf * m,struct mbuf * n)1449 sbcompress_ktls_rx(struct sockbuf *sb, struct mbuf *m, struct mbuf *n)
1450 {
1451
1452 SOCKBUF_LOCK_ASSERT(sb);
1453
1454 while (m) {
1455 KASSERT((m->m_flags & M_EOR) == 0,
1456 ("TLS RX mbuf %p with EOR", m));
1457 KASSERT(m->m_type == MT_DATA,
1458 ("TLS RX mbuf %p is not MT_DATA", m));
1459 KASSERT((m->m_flags & M_NOTREADY) != 0,
1460 ("TLS RX mbuf %p ready", m));
1461 KASSERT((m->m_flags & M_EXTPG) == 0,
1462 ("TLS RX mbuf %p unmapped", m));
1463
1464 if (m->m_len == 0) {
1465 m = m_free(m);
1466 continue;
1467 }
1468
1469 /*
1470 * Even though both 'n' and 'm' are NOTREADY, it's ok
1471 * to coalesce the data.
1472 */
1473 if (n &&
1474 M_WRITABLE(n) &&
1475 ((sb->sb_flags & SB_NOCOALESCE) == 0) &&
1476 !((m->m_flags ^ n->m_flags) & M_DECRYPTED) &&
1477 !(n->m_flags & M_EXTPG) &&
1478 m->m_len <= MCLBYTES / 4 && /* XXX: Don't copy too much */
1479 m->m_len <= M_TRAILINGSPACE(n)) {
1480 m_copydata(m, 0, m->m_len, mtodo(n, n->m_len));
1481 n->m_len += m->m_len;
1482 sb->sb_ccc += m->m_len;
1483 sb->sb_tlscc += m->m_len;
1484 m = m_free(m);
1485 continue;
1486 }
1487 if (n)
1488 n->m_next = m;
1489 else
1490 sb->sb_mtls = m;
1491 sb->sb_mtlstail = m;
1492 sballoc_ktls_rx(sb, m);
1493 n = m;
1494 m = m->m_next;
1495 n->m_next = NULL;
1496 }
1497 SBLASTMBUFCHK(sb);
1498 }
1499 #endif
1500
1501 /*
1502 * Free all mbufs in a sockbuf. Check that all resources are reclaimed.
1503 */
1504 static void
sbflush_internal(struct sockbuf * sb)1505 sbflush_internal(struct sockbuf *sb)
1506 {
1507
1508 while (sb->sb_mbcnt || sb->sb_tlsdcc) {
1509 /*
1510 * Don't call sbcut(sb, 0) if the leading mbuf is non-empty:
1511 * we would loop forever. Panic instead.
1512 */
1513 if (sb->sb_ccc == 0 && (sb->sb_mb == NULL || sb->sb_mb->m_len))
1514 break;
1515 m_freem(sbcut_internal(sb, (int)sb->sb_ccc));
1516 }
1517 KASSERT(sb->sb_ccc == 0 && sb->sb_mb == 0 && sb->sb_mbcnt == 0,
1518 ("%s: ccc %u mb %p mbcnt %u", __func__,
1519 sb->sb_ccc, (void *)sb->sb_mb, sb->sb_mbcnt));
1520 }
1521
1522 void
sbflush_locked(struct sockbuf * sb)1523 sbflush_locked(struct sockbuf *sb)
1524 {
1525
1526 SOCKBUF_LOCK_ASSERT(sb);
1527 sbflush_internal(sb);
1528 }
1529
1530 void
sbflush(struct sockbuf * sb)1531 sbflush(struct sockbuf *sb)
1532 {
1533
1534 SOCKBUF_LOCK(sb);
1535 sbflush_locked(sb);
1536 SOCKBUF_UNLOCK(sb);
1537 }
1538
1539 /*
1540 * Cut data from (the front of) a sockbuf.
1541 */
1542 static struct mbuf *
sbcut_internal(struct sockbuf * sb,int len)1543 sbcut_internal(struct sockbuf *sb, int len)
1544 {
1545 struct mbuf *m, *next, *mfree;
1546 bool is_tls;
1547
1548 KASSERT(len >= 0, ("%s: len is %d but it is supposed to be >= 0",
1549 __func__, len));
1550 KASSERT(len <= sb->sb_ccc, ("%s: len: %d is > ccc: %u",
1551 __func__, len, sb->sb_ccc));
1552
1553 next = (m = sb->sb_mb) ? m->m_nextpkt : 0;
1554 is_tls = false;
1555 mfree = NULL;
1556
1557 while (len > 0) {
1558 if (m == NULL) {
1559 #ifdef KERN_TLS
1560 if (next == NULL && !is_tls) {
1561 if (sb->sb_tlsdcc != 0) {
1562 MPASS(len >= sb->sb_tlsdcc);
1563 len -= sb->sb_tlsdcc;
1564 sb->sb_ccc -= sb->sb_tlsdcc;
1565 sb->sb_tlsdcc = 0;
1566 if (len == 0)
1567 break;
1568 }
1569 next = sb->sb_mtls;
1570 is_tls = true;
1571 }
1572 #endif
1573 KASSERT(next, ("%s: no next, len %d", __func__, len));
1574 m = next;
1575 next = m->m_nextpkt;
1576 }
1577 if (m->m_len > len) {
1578 KASSERT(!(m->m_flags & M_NOTAVAIL),
1579 ("%s: m %p M_NOTAVAIL", __func__, m));
1580 m->m_len -= len;
1581 m->m_data += len;
1582 sb->sb_ccc -= len;
1583 sb->sb_acc -= len;
1584 if (sb->sb_sndptroff != 0)
1585 sb->sb_sndptroff -= len;
1586 if (m->m_type != MT_DATA && m->m_type != MT_OOBDATA)
1587 sb->sb_ctl -= len;
1588 break;
1589 }
1590 len -= m->m_len;
1591 #ifdef KERN_TLS
1592 if (is_tls)
1593 sbfree_ktls_rx(sb, m);
1594 else
1595 #endif
1596 sbfree(sb, m);
1597 /*
1598 * Do not put M_NOTREADY buffers to the free list, they
1599 * are referenced from outside.
1600 */
1601 if (m->m_flags & M_NOTREADY && !is_tls)
1602 m = m->m_next;
1603 else {
1604 struct mbuf *n;
1605
1606 n = m->m_next;
1607 m->m_next = mfree;
1608 mfree = m;
1609 m = n;
1610 }
1611 }
1612 /*
1613 * Free any zero-length mbufs from the buffer.
1614 * For SOCK_DGRAM sockets such mbufs represent empty records.
1615 * XXX: For SOCK_STREAM sockets such mbufs can appear in the buffer,
1616 * when sosend_generic() needs to send only control data.
1617 */
1618 while (m && m->m_len == 0) {
1619 struct mbuf *n;
1620
1621 sbfree(sb, m);
1622 n = m->m_next;
1623 m->m_next = mfree;
1624 mfree = m;
1625 m = n;
1626 }
1627 #ifdef KERN_TLS
1628 if (is_tls) {
1629 sb->sb_mb = NULL;
1630 sb->sb_mtls = m;
1631 if (m == NULL)
1632 sb->sb_mtlstail = NULL;
1633 } else
1634 #endif
1635 if (m) {
1636 sb->sb_mb = m;
1637 m->m_nextpkt = next;
1638 } else
1639 sb->sb_mb = next;
1640 /*
1641 * First part is an inline SB_EMPTY_FIXUP(). Second part makes sure
1642 * sb_lastrecord is up-to-date if we dropped part of the last record.
1643 */
1644 m = sb->sb_mb;
1645 if (m == NULL) {
1646 sb->sb_mbtail = NULL;
1647 sb->sb_lastrecord = NULL;
1648 } else if (m->m_nextpkt == NULL) {
1649 sb->sb_lastrecord = m;
1650 }
1651
1652 return (mfree);
1653 }
1654
1655 /*
1656 * Drop data from (the front of) a sockbuf.
1657 */
1658 void
sbdrop_locked(struct sockbuf * sb,int len)1659 sbdrop_locked(struct sockbuf *sb, int len)
1660 {
1661
1662 SOCKBUF_LOCK_ASSERT(sb);
1663 m_freem(sbcut_internal(sb, len));
1664 }
1665
1666 /*
1667 * Drop data from (the front of) a sockbuf,
1668 * and return it to caller.
1669 */
1670 struct mbuf *
sbcut_locked(struct sockbuf * sb,int len)1671 sbcut_locked(struct sockbuf *sb, int len)
1672 {
1673
1674 SOCKBUF_LOCK_ASSERT(sb);
1675 return (sbcut_internal(sb, len));
1676 }
1677
1678 void
sbdrop(struct sockbuf * sb,int len)1679 sbdrop(struct sockbuf *sb, int len)
1680 {
1681 struct mbuf *mfree;
1682
1683 SOCKBUF_LOCK(sb);
1684 mfree = sbcut_internal(sb, len);
1685 SOCKBUF_UNLOCK(sb);
1686
1687 m_freem(mfree);
1688 }
1689
1690 struct mbuf *
sbsndptr_noadv(struct sockbuf * sb,uint32_t off,uint32_t * moff)1691 sbsndptr_noadv(struct sockbuf *sb, uint32_t off, uint32_t *moff)
1692 {
1693 struct mbuf *m;
1694
1695 KASSERT(sb->sb_mb != NULL, ("%s: sb_mb is NULL", __func__));
1696 if (sb->sb_sndptr == NULL || sb->sb_sndptroff > off) {
1697 *moff = off;
1698 if (sb->sb_sndptr == NULL) {
1699 sb->sb_sndptr = sb->sb_mb;
1700 sb->sb_sndptroff = 0;
1701 }
1702 return (sb->sb_mb);
1703 } else {
1704 m = sb->sb_sndptr;
1705 off -= sb->sb_sndptroff;
1706 }
1707 *moff = off;
1708 return (m);
1709 }
1710
1711 void
sbsndptr_adv(struct sockbuf * sb,struct mbuf * mb,uint32_t len)1712 sbsndptr_adv(struct sockbuf *sb, struct mbuf *mb, uint32_t len)
1713 {
1714 /*
1715 * A small copy was done, advance forward the sb_sbsndptr to cover
1716 * it.
1717 */
1718 struct mbuf *m;
1719
1720 if (mb != sb->sb_sndptr) {
1721 /* Did not copyout at the same mbuf */
1722 return;
1723 }
1724 m = mb;
1725 while (m && (len > 0)) {
1726 if (len >= m->m_len) {
1727 len -= m->m_len;
1728 if (m->m_next) {
1729 sb->sb_sndptroff += m->m_len;
1730 sb->sb_sndptr = m->m_next;
1731 }
1732 m = m->m_next;
1733 } else {
1734 len = 0;
1735 }
1736 }
1737 }
1738
1739 /*
1740 * Return the first mbuf and the mbuf data offset for the provided
1741 * send offset without changing the "sb_sndptroff" field.
1742 */
1743 struct mbuf *
sbsndmbuf(struct sockbuf * sb,u_int off,u_int * moff)1744 sbsndmbuf(struct sockbuf *sb, u_int off, u_int *moff)
1745 {
1746 struct mbuf *m;
1747
1748 KASSERT(sb->sb_mb != NULL, ("%s: sb_mb is NULL", __func__));
1749
1750 /*
1751 * If the "off" is below the stored offset, which happens on
1752 * retransmits, just use "sb_mb":
1753 */
1754 if (sb->sb_sndptr == NULL || sb->sb_sndptroff > off) {
1755 m = sb->sb_mb;
1756 } else {
1757 m = sb->sb_sndptr;
1758 off -= sb->sb_sndptroff;
1759 }
1760 while (off > 0 && m != NULL) {
1761 if (off < m->m_len)
1762 break;
1763 off -= m->m_len;
1764 m = m->m_next;
1765 }
1766 *moff = off;
1767 return (m);
1768 }
1769
1770 /*
1771 * Drop a record off the front of a sockbuf and move the next record to the
1772 * front.
1773 */
1774 void
sbdroprecord_locked(struct sockbuf * sb)1775 sbdroprecord_locked(struct sockbuf *sb)
1776 {
1777 struct mbuf *m;
1778
1779 SOCKBUF_LOCK_ASSERT(sb);
1780
1781 m = sb->sb_mb;
1782 if (m) {
1783 sb->sb_mb = m->m_nextpkt;
1784 do {
1785 sbfree(sb, m);
1786 m = m_free(m);
1787 } while (m);
1788 }
1789 SB_EMPTY_FIXUP(sb);
1790 }
1791
1792 /*
1793 * Drop a record off the front of a sockbuf and move the next record to the
1794 * front.
1795 */
1796 void
sbdroprecord(struct sockbuf * sb)1797 sbdroprecord(struct sockbuf *sb)
1798 {
1799
1800 SOCKBUF_LOCK(sb);
1801 sbdroprecord_locked(sb);
1802 SOCKBUF_UNLOCK(sb);
1803 }
1804
1805 /*
1806 * Create a "control" mbuf containing the specified data with the specified
1807 * type for presentation on a socket buffer.
1808 */
1809 struct mbuf *
sbcreatecontrol(const void * p,u_int size,int type,int level,int wait)1810 sbcreatecontrol(const void *p, u_int size, int type, int level, int wait)
1811 {
1812 struct cmsghdr *cp;
1813 struct mbuf *m;
1814
1815 MBUF_CHECKSLEEP(wait);
1816
1817 if (wait == M_NOWAIT) {
1818 if (CMSG_SPACE(size) > MCLBYTES)
1819 return (NULL);
1820 } else
1821 KASSERT(CMSG_SPACE(size) <= MCLBYTES,
1822 ("%s: passed CMSG_SPACE(%u) > MCLBYTES", __func__, size));
1823
1824 if (CMSG_SPACE(size) > MLEN)
1825 m = m_getcl(wait, MT_CONTROL, 0);
1826 else
1827 m = m_get(wait, MT_CONTROL);
1828 if (m == NULL)
1829 return (NULL);
1830
1831 KASSERT(CMSG_SPACE(size) <= M_TRAILINGSPACE(m),
1832 ("sbcreatecontrol: short mbuf"));
1833 /*
1834 * Don't leave the padding between the msg header and the
1835 * cmsg data and the padding after the cmsg data un-initialized.
1836 */
1837 cp = mtod(m, struct cmsghdr *);
1838 bzero(cp, CMSG_SPACE(size));
1839 if (p != NULL)
1840 (void)memcpy(CMSG_DATA(cp), p, size);
1841 m->m_len = CMSG_SPACE(size);
1842 cp->cmsg_len = CMSG_LEN(size);
1843 cp->cmsg_level = level;
1844 cp->cmsg_type = type;
1845 return (m);
1846 }
1847
1848 /*
1849 * This does the same for socket buffers that sotoxsocket does for sockets:
1850 * generate an user-format data structure describing the socket buffer. Note
1851 * that the xsockbuf structure, since it is always embedded in a socket, does
1852 * not include a self pointer nor a length. We make this entry point public
1853 * in case some other mechanism needs it.
1854 */
1855 void
sbtoxsockbuf(struct sockbuf * sb,struct xsockbuf * xsb)1856 sbtoxsockbuf(struct sockbuf *sb, struct xsockbuf *xsb)
1857 {
1858
1859 xsb->sb_cc = sb->sb_ccc;
1860 xsb->sb_hiwat = sb->sb_hiwat;
1861 xsb->sb_mbcnt = sb->sb_mbcnt;
1862 xsb->sb_mbmax = sb->sb_mbmax;
1863 xsb->sb_lowat = sb->sb_lowat;
1864 xsb->sb_flags = sb->sb_flags;
1865 xsb->sb_timeo = sb->sb_timeo;
1866 }
1867
1868 /* This takes the place of kern.maxsockbuf, which moved to kern.ipc. */
1869 static int dummy;
1870 SYSCTL_INT(_kern, KERN_DUMMY, dummy, CTLFLAG_RW | CTLFLAG_SKIP, &dummy, 0, "");
1871 SYSCTL_OID(_kern_ipc, KIPC_MAXSOCKBUF, maxsockbuf,
1872 CTLTYPE_ULONG | CTLFLAG_RW | CTLFLAG_MPSAFE, &sb_max, 0,
1873 sysctl_handle_sb_max, "LU",
1874 "Maximum socket buffer size");
1875 SYSCTL_ULONG(_kern_ipc, KIPC_SOCKBUF_WASTE, sockbuf_waste_factor, CTLFLAG_RW,
1876 &sb_efficiency, 0, "Socket buffer size waste factor");
1877