1 /*-
2 * Copyright (c) 1982, 1986, 1988, 1990, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)uipc_socket2.c 8.1 (Berkeley) 6/10/93
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD: releng/11.2/sys/kern/uipc_sockbuf.c 331722 2018-03-29 02:50:57Z eadler $");
34
35 #include "opt_param.h"
36
37 #include <sys/param.h>
38 #include <sys/aio.h> /* for aio_swake proto */
39 #include <sys/kernel.h>
40 #include <sys/lock.h>
41 #include <sys/malloc.h>
42 #include <sys/mbuf.h>
43 #include <sys/mutex.h>
44 #include <sys/proc.h>
45 #include <sys/protosw.h>
46 #include <sys/resourcevar.h>
47 #include <sys/signalvar.h>
48 #include <sys/socket.h>
49 #include <sys/socketvar.h>
50 #include <sys/sx.h>
51 #include <sys/sysctl.h>
52
53 /*
54 * Function pointer set by the AIO routines so that the socket buffer code
55 * can call back into the AIO module if it is loaded.
56 */
57 void (*aio_swake)(struct socket *, struct sockbuf *);
58
59 /*
60 * Primitive routines for operating on socket buffers
61 */
62
63 u_long sb_max = SB_MAX;
64 u_long sb_max_adj =
65 (quad_t)SB_MAX * MCLBYTES / (MSIZE + MCLBYTES); /* adjusted sb_max */
66
67 static u_long sb_efficiency = 8; /* parameter for sbreserve() */
68
69 static struct mbuf *sbcut_internal(struct sockbuf *sb, int len);
70 static void sbflush_internal(struct sockbuf *sb);
71
72 /*
73 * Our own version of m_clrprotoflags(), that can preserve M_NOTREADY.
74 */
75 static void
76 sbm_clrprotoflags(struct mbuf *m, int flags)
77 {
78 int mask;
79
80 mask = ~M_PROTOFLAGS;
81 if (flags & PRUS_NOTREADY)
82 mask |= M_NOTREADY;
83 while (m) {
84 m->m_flags &= mask;
85 m = m->m_next;
86 }
87 }
88
89 /*
90 * Mark ready "count" mbufs starting with "m".
91 */
92 int
93 sbready(struct sockbuf *sb, struct mbuf *m, int count)
94 {
95 u_int blocker;
96
97 SOCKBUF_LOCK_ASSERT(sb);
98 KASSERT(sb->sb_fnrdy != NULL, ("%s: sb %p NULL fnrdy", __func__, sb));
99
100 blocker = (sb->sb_fnrdy == m) ? M_BLOCKED : 0;
101
102 for (int i = 0; i < count; i++, m = m->m_next) {
103 KASSERT(m->m_flags & M_NOTREADY,
104 ("%s: m %p !M_NOTREADY", __func__, m));
105 m->m_flags &= ~(M_NOTREADY | blocker);
106 if (blocker)
107 sb->sb_acc += m->m_len;
108 }
109
110 if (!blocker)
111 return (EINPROGRESS);
112
113 /* This one was blocking all the queue. */
114 for (; m && (m->m_flags & M_NOTREADY) == 0; m = m->m_next) {
115 KASSERT(m->m_flags & M_BLOCKED,
116 ("%s: m %p !M_BLOCKED", __func__, m));
117 m->m_flags &= ~M_BLOCKED;
118 sb->sb_acc += m->m_len;
119 }
120
121 sb->sb_fnrdy = m;
122
123 return (0);
124 }
125
126 /*
127 * Adjust sockbuf state reflecting allocation of m.
128 */
129 void
130 sballoc(struct sockbuf *sb, struct mbuf *m)
131 {
132
133 SOCKBUF_LOCK_ASSERT(sb);
134
135 sb->sb_ccc += m->m_len;
136
137 if (sb->sb_fnrdy == NULL) {
138 if (m->m_flags & M_NOTREADY)
139 sb->sb_fnrdy = m;
140 else
141 sb->sb_acc += m->m_len;
142 } else
143 m->m_flags |= M_BLOCKED;
144
145 if (m->m_type != MT_DATA && m->m_type != MT_OOBDATA)
146 sb->sb_ctl += m->m_len;
147
148 sb->sb_mbcnt += MSIZE;
149 sb->sb_mcnt += 1;
150
151 if (m->m_flags & M_EXT) {
152 sb->sb_mbcnt += m->m_ext.ext_size;
153 sb->sb_ccnt += 1;
154 }
155 }
156
157 /*
158 * Adjust sockbuf state reflecting freeing of m.
159 */
160 void
161 sbfree(struct sockbuf *sb, struct mbuf *m)
162 {
163
164 #if 0 /* XXX: not yet: soclose() call path comes here w/o lock. */
165 SOCKBUF_LOCK_ASSERT(sb);
166 #endif
167
168 sb->sb_ccc -= m->m_len;
169
170 if (!(m->m_flags & M_NOTAVAIL))
171 sb->sb_acc -= m->m_len;
172
173 if (m == sb->sb_fnrdy) {
174 struct mbuf *n;
175
176 KASSERT(m->m_flags & M_NOTREADY,
177 ("%s: m %p !M_NOTREADY", __func__, m));
178
179 n = m->m_next;
180 while (n != NULL && !(n->m_flags & M_NOTREADY)) {
181 n->m_flags &= ~M_BLOCKED;
182 sb->sb_acc += n->m_len;
183 n = n->m_next;
184 }
185 sb->sb_fnrdy = n;
186 }
187
188 if (m->m_type != MT_DATA && m->m_type != MT_OOBDATA)
189 sb->sb_ctl -= m->m_len;
190
191 sb->sb_mbcnt -= MSIZE;
192 sb->sb_mcnt -= 1;
193 if (m->m_flags & M_EXT) {
194 sb->sb_mbcnt -= m->m_ext.ext_size;
195 sb->sb_ccnt -= 1;
196 }
197
198 if (sb->sb_sndptr == m) {
199 sb->sb_sndptr = NULL;
200 sb->sb_sndptroff = 0;
201 }
202 if (sb->sb_sndptroff != 0)
203 sb->sb_sndptroff -= m->m_len;
204 }
205
206 /*
207 * Socantsendmore indicates that no more data will be sent on the socket; it
208 * would normally be applied to a socket when the user informs the system
209 * that no more data is to be sent, by the protocol code (in case
210 * PRU_SHUTDOWN). Socantrcvmore indicates that no more data will be
211 * received, and will normally be applied to the socket by a protocol when it
212 * detects that the peer will send no more data. Data queued for reading in
213 * the socket may yet be read.
214 */
215 void
216 socantsendmore_locked(struct socket *so)
217 {
218
219 SOCKBUF_LOCK_ASSERT(&so->so_snd);
220
221 so->so_snd.sb_state |= SBS_CANTSENDMORE;
222 sowwakeup_locked(so);
223 mtx_assert(SOCKBUF_MTX(&so->so_snd), MA_NOTOWNED);
224 }
225
226 void
227 socantsendmore(struct socket *so)
228 {
229
230 SOCKBUF_LOCK(&so->so_snd);
231 socantsendmore_locked(so);
232 mtx_assert(SOCKBUF_MTX(&so->so_snd), MA_NOTOWNED);
233 }
234
235 void
236 socantrcvmore_locked(struct socket *so)
237 {
238
239 SOCKBUF_LOCK_ASSERT(&so->so_rcv);
240
241 so->so_rcv.sb_state |= SBS_CANTRCVMORE;
242 sorwakeup_locked(so);
243 mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED);
244 }
245
246 void
247 socantrcvmore(struct socket *so)
248 {
249
250 SOCKBUF_LOCK(&so->so_rcv);
251 socantrcvmore_locked(so);
252 mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED);
253 }
254
255 /*
256 * Wait for data to arrive at/drain from a socket buffer.
257 */
258 int
259 sbwait(struct sockbuf *sb)
260 {
261
262 SOCKBUF_LOCK_ASSERT(sb);
263
264 sb->sb_flags |= SB_WAIT;
265 return (msleep_sbt(&sb->sb_acc, &sb->sb_mtx,
266 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, "sbwait",
267 sb->sb_timeo, 0, 0));
268 }
269
270 int
271 sblock(struct sockbuf *sb, int flags)
272 {
273
274 KASSERT((flags & SBL_VALID) == flags,
275 ("sblock: flags invalid (0x%x)", flags));
276
277 if (flags & SBL_WAIT) {
278 if ((sb->sb_flags & SB_NOINTR) ||
279 (flags & SBL_NOINTR)) {
280 sx_xlock(&sb->sb_sx);
281 return (0);
282 }
283 return (sx_xlock_sig(&sb->sb_sx));
284 } else {
285 if (sx_try_xlock(&sb->sb_sx) == 0)
286 return (EWOULDBLOCK);
287 return (0);
288 }
289 }
290
291 void
292 sbunlock(struct sockbuf *sb)
293 {
294
295 sx_xunlock(&sb->sb_sx);
296 }
297
298 /*
299 * Wakeup processes waiting on a socket buffer. Do asynchronous notification
300 * via SIGIO if the socket has the SS_ASYNC flag set.
301 *
302 * Called with the socket buffer lock held; will release the lock by the end
303 * of the function. This allows the caller to acquire the socket buffer lock
304 * while testing for the need for various sorts of wakeup and hold it through
305 * to the point where it's no longer required. We currently hold the lock
306 * through calls out to other subsystems (with the exception of kqueue), and
307 * then release it to avoid lock order issues. It's not clear that's
308 * correct.
309 */
310 void
311 sowakeup(struct socket *so, struct sockbuf *sb)
312 {
313 int ret;
314
315 SOCKBUF_LOCK_ASSERT(sb);
316
317 selwakeuppri(&sb->sb_sel, PSOCK);
318 if (!SEL_WAITING(&sb->sb_sel))
319 sb->sb_flags &= ~SB_SEL;
320 if (sb->sb_flags & SB_WAIT) {
321 sb->sb_flags &= ~SB_WAIT;
322 wakeup(&sb->sb_acc);
323 }
324 KNOTE_LOCKED(&sb->sb_sel.si_note, 0);
325 if (sb->sb_upcall != NULL) {
326 ret = sb->sb_upcall(so, sb->sb_upcallarg, M_NOWAIT);
327 if (ret == SU_ISCONNECTED) {
328 KASSERT(sb == &so->so_rcv,
329 ("SO_SND upcall returned SU_ISCONNECTED"));
330 soupcall_clear(so, SO_RCV);
331 }
332 } else
333 ret = SU_OK;
334 if (sb->sb_flags & SB_AIO)
335 sowakeup_aio(so, sb);
336 SOCKBUF_UNLOCK(sb);
337 if (ret == SU_ISCONNECTED)
338 soisconnected(so);
339 if ((so->so_state & SS_ASYNC) && so->so_sigio != NULL)
340 pgsigio(&so->so_sigio, SIGIO, 0);
341 mtx_assert(SOCKBUF_MTX(sb), MA_NOTOWNED);
342 }
343
344 /*
345 * Socket buffer (struct sockbuf) utility routines.
346 *
347 * Each socket contains two socket buffers: one for sending data and one for
348 * receiving data. Each buffer contains a queue of mbufs, information about
349 * the number of mbufs and amount of data in the queue, and other fields
350 * allowing select() statements and notification on data availability to be
351 * implemented.
352 *
353 * Data stored in a socket buffer is maintained as a list of records. Each
354 * record is a list of mbufs chained together with the m_next field. Records
355 * are chained together with the m_nextpkt field. The upper level routine
356 * soreceive() expects the following conventions to be observed when placing
357 * information in the receive buffer:
358 *
359 * 1. If the protocol requires each message be preceded by the sender's name,
360 * then a record containing that name must be present before any
361 * associated data (mbuf's must be of type MT_SONAME).
362 * 2. If the protocol supports the exchange of ``access rights'' (really just
363 * additional data associated with the message), and there are ``rights''
364 * to be received, then a record containing this data should be present
365 * (mbuf's must be of type MT_RIGHTS).
366 * 3. If a name or rights record exists, then it must be followed by a data
367 * record, perhaps of zero length.
368 *
369 * Before using a new socket structure it is first necessary to reserve
370 * buffer space to the socket, by calling sbreserve(). This should commit
371 * some of the available buffer space in the system buffer pool for the
372 * socket (currently, it does nothing but enforce limits). The space should
373 * be released by calling sbrelease() when the socket is destroyed.
374 */
375 int
376 soreserve(struct socket *so, u_long sndcc, u_long rcvcc)
377 {
378 struct thread *td = curthread;
379
380 SOCKBUF_LOCK(&so->so_snd);
381 SOCKBUF_LOCK(&so->so_rcv);
382 if (sbreserve_locked(&so->so_snd, sndcc, so, td) == 0)
383 goto bad;
384 if (sbreserve_locked(&so->so_rcv, rcvcc, so, td) == 0)
385 goto bad2;
386 if (so->so_rcv.sb_lowat == 0)
387 so->so_rcv.sb_lowat = 1;
388 if (so->so_snd.sb_lowat == 0)
389 so->so_snd.sb_lowat = MCLBYTES;
390 if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat)
391 so->so_snd.sb_lowat = so->so_snd.sb_hiwat;
392 SOCKBUF_UNLOCK(&so->so_rcv);
393 SOCKBUF_UNLOCK(&so->so_snd);
394 return (0);
395 bad2:
396 sbrelease_locked(&so->so_snd, so);
397 bad:
398 SOCKBUF_UNLOCK(&so->so_rcv);
399 SOCKBUF_UNLOCK(&so->so_snd);
400 return (ENOBUFS);
401 }
402
403 static int
404 sysctl_handle_sb_max(SYSCTL_HANDLER_ARGS)
405 {
406 int error = 0;
407 u_long tmp_sb_max = sb_max;
408
409 error = sysctl_handle_long(oidp, &tmp_sb_max, arg2, req);
410 if (error || !req->newptr)
411 return (error);
412 if (tmp_sb_max < MSIZE + MCLBYTES)
413 return (EINVAL);
414 sb_max = tmp_sb_max;
415 sb_max_adj = (u_quad_t)sb_max * MCLBYTES / (MSIZE + MCLBYTES);
416 return (0);
417 }
418
419 /*
420 * Allot mbufs to a sockbuf. Attempt to scale mbmax so that mbcnt doesn't
421 * become limiting if buffering efficiency is near the normal case.
422 */
423 int
424 sbreserve_locked(struct sockbuf *sb, u_long cc, struct socket *so,
425 struct thread *td)
426 {
427 rlim_t sbsize_limit;
428
429 SOCKBUF_LOCK_ASSERT(sb);
430
431 /*
432 * When a thread is passed, we take into account the thread's socket
433 * buffer size limit. The caller will generally pass curthread, but
434 * in the TCP input path, NULL will be passed to indicate that no
435 * appropriate thread resource limits are available. In that case,
436 * we don't apply a process limit.
437 */
438 if (cc > sb_max_adj)
439 return (0);
440 if (td != NULL) {
441 sbsize_limit = lim_cur(td, RLIMIT_SBSIZE);
442 } else
443 sbsize_limit = RLIM_INFINITY;
444 if (!chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, cc,
445 sbsize_limit))
446 return (0);
447 sb->sb_mbmax = min(cc * sb_efficiency, sb_max);
448 if (sb->sb_lowat > sb->sb_hiwat)
449 sb->sb_lowat = sb->sb_hiwat;
450 return (1);
451 }
452
453 int
454 sbreserve(struct sockbuf *sb, u_long cc, struct socket *so,
455 struct thread *td)
456 {
457 int error;
458
459 SOCKBUF_LOCK(sb);
460 error = sbreserve_locked(sb, cc, so, td);
461 SOCKBUF_UNLOCK(sb);
462 return (error);
463 }
464
465 /*
466 * Free mbufs held by a socket, and reserved mbuf space.
467 */
468 void
469 sbrelease_internal(struct sockbuf *sb, struct socket *so)
470 {
471
472 sbflush_internal(sb);
473 (void)chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, 0,
474 RLIM_INFINITY);
475 sb->sb_mbmax = 0;
476 }
477
478 void
479 sbrelease_locked(struct sockbuf *sb, struct socket *so)
480 {
481
482 SOCKBUF_LOCK_ASSERT(sb);
483
484 sbrelease_internal(sb, so);
485 }
486
487 void
488 sbrelease(struct sockbuf *sb, struct socket *so)
489 {
490
491 SOCKBUF_LOCK(sb);
492 sbrelease_locked(sb, so);
493 SOCKBUF_UNLOCK(sb);
494 }
495
496 void
497 sbdestroy(struct sockbuf *sb, struct socket *so)
498 {
499
500 sbrelease_internal(sb, so);
501 }
502
503 /*
504 * Routines to add and remove data from an mbuf queue.
505 *
506 * The routines sbappend() or sbappendrecord() are normally called to append
507 * new mbufs to a socket buffer, after checking that adequate space is
508 * available, comparing the function sbspace() with the amount of data to be
509 * added. sbappendrecord() differs from sbappend() in that data supplied is
510 * treated as the beginning of a new record. To place a sender's address,
511 * optional access rights, and data in a socket receive buffer,
512 * sbappendaddr() should be used. To place access rights and data in a
513 * socket receive buffer, sbappendrights() should be used. In either case,
514 * the new data begins a new record. Note that unlike sbappend() and
515 * sbappendrecord(), these routines check for the caller that there will be
516 * enough space to store the data. Each fails if there is not enough space,
517 * or if it cannot find mbufs to store additional information in.
518 *
519 * Reliable protocols may use the socket send buffer to hold data awaiting
520 * acknowledgement. Data is normally copied from a socket send buffer in a
521 * protocol with m_copy for output to a peer, and then removing the data from
522 * the socket buffer with sbdrop() or sbdroprecord() when the data is
523 * acknowledged by the peer.
524 */
525 #ifdef SOCKBUF_DEBUG
526 void
527 sblastrecordchk(struct sockbuf *sb, const char *file, int line)
528 {
529 struct mbuf *m = sb->sb_mb;
530
531 SOCKBUF_LOCK_ASSERT(sb);
532
533 while (m && m->m_nextpkt)
534 m = m->m_nextpkt;
535
536 if (m != sb->sb_lastrecord) {
537 printf("%s: sb_mb %p sb_lastrecord %p last %p\n",
538 __func__, sb->sb_mb, sb->sb_lastrecord, m);
539 printf("packet chain:\n");
540 for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt)
541 printf("\t%p\n", m);
542 panic("%s from %s:%u", __func__, file, line);
543 }
544 }
545
546 void
547 sblastmbufchk(struct sockbuf *sb, const char *file, int line)
548 {
549 struct mbuf *m = sb->sb_mb;
550 struct mbuf *n;
551
552 SOCKBUF_LOCK_ASSERT(sb);
553
554 while (m && m->m_nextpkt)
555 m = m->m_nextpkt;
556
557 while (m && m->m_next)
558 m = m->m_next;
559
560 if (m != sb->sb_mbtail) {
561 printf("%s: sb_mb %p sb_mbtail %p last %p\n",
562 __func__, sb->sb_mb, sb->sb_mbtail, m);
563 printf("packet tree:\n");
564 for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt) {
565 printf("\t");
566 for (n = m; n != NULL; n = n->m_next)
567 printf("%p ", n);
568 printf("\n");
569 }
570 panic("%s from %s:%u", __func__, file, line);
571 }
572 }
573 #endif /* SOCKBUF_DEBUG */
574
575 #define SBLINKRECORD(sb, m0) do { \
576 SOCKBUF_LOCK_ASSERT(sb); \
577 if ((sb)->sb_lastrecord != NULL) \
578 (sb)->sb_lastrecord->m_nextpkt = (m0); \
579 else \
580 (sb)->sb_mb = (m0); \
581 (sb)->sb_lastrecord = (m0); \
582 } while (/*CONSTCOND*/0)
583
584 /*
585 * Append mbuf chain m to the last record in the socket buffer sb. The
586 * additional space associated the mbuf chain is recorded in sb. Empty mbufs
587 * are discarded and mbufs are compacted where possible.
588 */
589 void
590 sbappend_locked(struct sockbuf *sb, struct mbuf *m, int flags)
591 {
592 struct mbuf *n;
593
594 SOCKBUF_LOCK_ASSERT(sb);
595
596 if (m == NULL)
597 return;
598 sbm_clrprotoflags(m, flags);
599 SBLASTRECORDCHK(sb);
600 n = sb->sb_mb;
601 if (n) {
602 while (n->m_nextpkt)
603 n = n->m_nextpkt;
604 do {
605 if (n->m_flags & M_EOR) {
606 sbappendrecord_locked(sb, m); /* XXXXXX!!!! */
607 return;
608 }
609 } while (n->m_next && (n = n->m_next));
610 } else {
611 /*
612 * XXX Would like to simply use sb_mbtail here, but
613 * XXX I need to verify that I won't miss an EOR that
614 * XXX way.
615 */
616 if ((n = sb->sb_lastrecord) != NULL) {
617 do {
618 if (n->m_flags & M_EOR) {
619 sbappendrecord_locked(sb, m); /* XXXXXX!!!! */
620 return;
621 }
622 } while (n->m_next && (n = n->m_next));
623 } else {
624 /*
625 * If this is the first record in the socket buffer,
626 * it's also the last record.
627 */
628 sb->sb_lastrecord = m;
629 }
630 }
631 sbcompress(sb, m, n);
632 SBLASTRECORDCHK(sb);
633 }
634
635 /*
636 * Append mbuf chain m to the last record in the socket buffer sb. The
637 * additional space associated the mbuf chain is recorded in sb. Empty mbufs
638 * are discarded and mbufs are compacted where possible.
639 */
640 void
641 sbappend(struct sockbuf *sb, struct mbuf *m, int flags)
642 {
643
644 SOCKBUF_LOCK(sb);
645 sbappend_locked(sb, m, flags);
646 SOCKBUF_UNLOCK(sb);
647 }
648
649 /*
650 * This version of sbappend() should only be used when the caller absolutely
651 * knows that there will never be more than one record in the socket buffer,
652 * that is, a stream protocol (such as TCP).
653 */
654 void
655 sbappendstream_locked(struct sockbuf *sb, struct mbuf *m, int flags)
656 {
657 SOCKBUF_LOCK_ASSERT(sb);
658
659 KASSERT(m->m_nextpkt == NULL,("sbappendstream 0"));
660 KASSERT(sb->sb_mb == sb->sb_lastrecord,("sbappendstream 1"));
661
662 SBLASTMBUFCHK(sb);
663
664 /* Remove all packet headers and mbuf tags to get a pure data chain. */
665 m_demote(m, 1, flags & PRUS_NOTREADY ? M_NOTREADY : 0);
666
667 sbcompress(sb, m, sb->sb_mbtail);
668
669 sb->sb_lastrecord = sb->sb_mb;
670 SBLASTRECORDCHK(sb);
671 }
672
673 /*
674 * This version of sbappend() should only be used when the caller absolutely
675 * knows that there will never be more than one record in the socket buffer,
676 * that is, a stream protocol (such as TCP).
677 */
678 void
679 sbappendstream(struct sockbuf *sb, struct mbuf *m, int flags)
680 {
681
682 SOCKBUF_LOCK(sb);
683 sbappendstream_locked(sb, m, flags);
684 SOCKBUF_UNLOCK(sb);
685 }
686
687 #ifdef SOCKBUF_DEBUG
688 void
689 sbcheck(struct sockbuf *sb, const char *file, int line)
690 {
691 struct mbuf *m, *n, *fnrdy;
692 u_long acc, ccc, mbcnt;
693
694 SOCKBUF_LOCK_ASSERT(sb);
695
696 acc = ccc = mbcnt = 0;
697 fnrdy = NULL;
698
699 for (m = sb->sb_mb; m; m = n) {
700 n = m->m_nextpkt;
701 for (; m; m = m->m_next) {
702 if (m->m_len == 0) {
703 printf("sb %p empty mbuf %p\n", sb, m);
704 goto fail;
705 }
706 if ((m->m_flags & M_NOTREADY) && fnrdy == NULL) {
707 if (m != sb->sb_fnrdy) {
708 printf("sb %p: fnrdy %p != m %p\n",
709 sb, sb->sb_fnrdy, m);
710 goto fail;
711 }
712 fnrdy = m;
713 }
714 if (fnrdy) {
715 if (!(m->m_flags & M_NOTAVAIL)) {
716 printf("sb %p: fnrdy %p, m %p is avail\n",
717 sb, sb->sb_fnrdy, m);
718 goto fail;
719 }
720 } else
721 acc += m->m_len;
722 ccc += m->m_len;
723 mbcnt += MSIZE;
724 if (m->m_flags & M_EXT) /*XXX*/ /* pretty sure this is bogus */
725 mbcnt += m->m_ext.ext_size;
726 }
727 }
728 if (acc != sb->sb_acc || ccc != sb->sb_ccc || mbcnt != sb->sb_mbcnt) {
729 printf("acc %ld/%u ccc %ld/%u mbcnt %ld/%u\n",
730 acc, sb->sb_acc, ccc, sb->sb_ccc, mbcnt, sb->sb_mbcnt);
731 goto fail;
732 }
733 return;
734 fail:
735 panic("%s from %s:%u", __func__, file, line);
736 }
737 #endif
738
739 /*
740 * As above, except the mbuf chain begins a new record.
741 */
742 void
743 sbappendrecord_locked(struct sockbuf *sb, struct mbuf *m0)
744 {
745 struct mbuf *m;
746
747 SOCKBUF_LOCK_ASSERT(sb);
748
749 if (m0 == NULL)
750 return;
751 m_clrprotoflags(m0);
752 /*
753 * Put the first mbuf on the queue. Note this permits zero length
754 * records.
755 */
756 sballoc(sb, m0);
757 SBLASTRECORDCHK(sb);
758 SBLINKRECORD(sb, m0);
759 sb->sb_mbtail = m0;
760 m = m0->m_next;
761 m0->m_next = 0;
762 if (m && (m0->m_flags & M_EOR)) {
763 m0->m_flags &= ~M_EOR;
764 m->m_flags |= M_EOR;
765 }
766 /* always call sbcompress() so it can do SBLASTMBUFCHK() */
767 sbcompress(sb, m, m0);
768 }
769
770 /*
771 * As above, except the mbuf chain begins a new record.
772 */
773 void
774 sbappendrecord(struct sockbuf *sb, struct mbuf *m0)
775 {
776
777 SOCKBUF_LOCK(sb);
778 sbappendrecord_locked(sb, m0);
779 SOCKBUF_UNLOCK(sb);
780 }
781
782 /* Helper routine that appends data, control, and address to a sockbuf. */
783 static int
784 sbappendaddr_locked_internal(struct sockbuf *sb, const struct sockaddr *asa,
785 struct mbuf *m0, struct mbuf *control, struct mbuf *ctrl_last)
786 {
787 struct mbuf *m, *n, *nlast;
788 #if MSIZE <= 256
789 if (asa->sa_len > MLEN)
790 return (0);
791 #endif
792 m = m_get(M_NOWAIT, MT_SONAME);
793 if (m == NULL)
794 return (0);
795 m->m_len = asa->sa_len;
796 bcopy(asa, mtod(m, caddr_t), asa->sa_len);
797 if (m0) {
798 m_clrprotoflags(m0);
799 m_tag_delete_chain(m0, NULL);
800 /*
801 * Clear some persistent info from pkthdr.
802 * We don't use m_demote(), because some netgraph consumers
803 * expect M_PKTHDR presence.
804 */
805 m0->m_pkthdr.rcvif = NULL;
806 m0->m_pkthdr.flowid = 0;
807 m0->m_pkthdr.csum_flags = 0;
808 m0->m_pkthdr.fibnum = 0;
809 m0->m_pkthdr.rsstype = 0;
810 }
811 if (ctrl_last)
812 ctrl_last->m_next = m0; /* concatenate data to control */
813 else
814 control = m0;
815 m->m_next = control;
816 for (n = m; n->m_next != NULL; n = n->m_next)
817 sballoc(sb, n);
818 sballoc(sb, n);
819 nlast = n;
820 SBLINKRECORD(sb, m);
821
822 sb->sb_mbtail = nlast;
823 SBLASTMBUFCHK(sb);
824
825 SBLASTRECORDCHK(sb);
826 return (1);
827 }
828
829 /*
830 * Append address and data, and optionally, control (ancillary) data to the
831 * receive queue of a socket. If present, m0 must include a packet header
832 * with total length. Returns 0 if no space in sockbuf or insufficient
833 * mbufs.
834 */
835 int
836 sbappendaddr_locked(struct sockbuf *sb, const struct sockaddr *asa,
837 struct mbuf *m0, struct mbuf *control)
838 {
839 struct mbuf *ctrl_last;
840 int space = asa->sa_len;
841
842 SOCKBUF_LOCK_ASSERT(sb);
843
844 if (m0 && (m0->m_flags & M_PKTHDR) == 0)
845 panic("sbappendaddr_locked");
846 if (m0)
847 space += m0->m_pkthdr.len;
848 space += m_length(control, &ctrl_last);
849
850 if (space > sbspace(sb))
851 return (0);
852 return (sbappendaddr_locked_internal(sb, asa, m0, control, ctrl_last));
853 }
854
855 /*
856 * Append address and data, and optionally, control (ancillary) data to the
857 * receive queue of a socket. If present, m0 must include a packet header
858 * with total length. Returns 0 if insufficient mbufs. Does not validate space
859 * on the receiving sockbuf.
860 */
861 int
862 sbappendaddr_nospacecheck_locked(struct sockbuf *sb, const struct sockaddr *asa,
863 struct mbuf *m0, struct mbuf *control)
864 {
865 struct mbuf *ctrl_last;
866
867 SOCKBUF_LOCK_ASSERT(sb);
868
869 ctrl_last = (control == NULL) ? NULL : m_last(control);
870 return (sbappendaddr_locked_internal(sb, asa, m0, control, ctrl_last));
871 }
872
873 /*
874 * Append address and data, and optionally, control (ancillary) data to the
875 * receive queue of a socket. If present, m0 must include a packet header
876 * with total length. Returns 0 if no space in sockbuf or insufficient
877 * mbufs.
878 */
879 int
880 sbappendaddr(struct sockbuf *sb, const struct sockaddr *asa,
881 struct mbuf *m0, struct mbuf *control)
882 {
883 int retval;
884
885 SOCKBUF_LOCK(sb);
886 retval = sbappendaddr_locked(sb, asa, m0, control);
887 SOCKBUF_UNLOCK(sb);
888 return (retval);
889 }
890
891 int
892 sbappendcontrol_locked(struct sockbuf *sb, struct mbuf *m0,
893 struct mbuf *control)
894 {
895 struct mbuf *m, *n, *mlast;
896 int space;
897
898 SOCKBUF_LOCK_ASSERT(sb);
899
900 if (control == NULL)
901 panic("sbappendcontrol_locked");
902 space = m_length(control, &n) + m_length(m0, NULL);
903
904 if (space > sbspace(sb))
905 return (0);
906 m_clrprotoflags(m0);
907 n->m_next = m0; /* concatenate data to control */
908
909 SBLASTRECORDCHK(sb);
910
911 for (m = control; m->m_next; m = m->m_next)
912 sballoc(sb, m);
913 sballoc(sb, m);
914 mlast = m;
915 SBLINKRECORD(sb, control);
916
917 sb->sb_mbtail = mlast;
918 SBLASTMBUFCHK(sb);
919
920 SBLASTRECORDCHK(sb);
921 return (1);
922 }
923
924 int
925 sbappendcontrol(struct sockbuf *sb, struct mbuf *m0, struct mbuf *control)
926 {
927 int retval;
928
929 SOCKBUF_LOCK(sb);
930 retval = sbappendcontrol_locked(sb, m0, control);
931 SOCKBUF_UNLOCK(sb);
932 return (retval);
933 }
934
935 /*
936 * Append the data in mbuf chain (m) into the socket buffer sb following mbuf
937 * (n). If (n) is NULL, the buffer is presumed empty.
938 *
939 * When the data is compressed, mbufs in the chain may be handled in one of
940 * three ways:
941 *
942 * (1) The mbuf may simply be dropped, if it contributes nothing (no data, no
943 * record boundary, and no change in data type).
944 *
945 * (2) The mbuf may be coalesced -- i.e., data in the mbuf may be copied into
946 * an mbuf already in the socket buffer. This can occur if an
947 * appropriate mbuf exists, there is room, both mbufs are not marked as
948 * not ready, and no merging of data types will occur.
949 *
950 * (3) The mbuf may be appended to the end of the existing mbuf chain.
951 *
952 * If any of the new mbufs is marked as M_EOR, mark the last mbuf appended as
953 * end-of-record.
954 */
955 void
956 sbcompress(struct sockbuf *sb, struct mbuf *m, struct mbuf *n)
957 {
958 int eor = 0;
959 struct mbuf *o;
960
961 SOCKBUF_LOCK_ASSERT(sb);
962
963 while (m) {
964 eor |= m->m_flags & M_EOR;
965 if (m->m_len == 0 &&
966 (eor == 0 ||
967 (((o = m->m_next) || (o = n)) &&
968 o->m_type == m->m_type))) {
969 if (sb->sb_lastrecord == m)
970 sb->sb_lastrecord = m->m_next;
971 m = m_free(m);
972 continue;
973 }
974 if (n && (n->m_flags & M_EOR) == 0 &&
975 M_WRITABLE(n) &&
976 ((sb->sb_flags & SB_NOCOALESCE) == 0) &&
977 !(m->m_flags & M_NOTREADY) &&
978 !(n->m_flags & M_NOTREADY) &&
979 m->m_len <= MCLBYTES / 4 && /* XXX: Don't copy too much */
980 m->m_len <= M_TRAILINGSPACE(n) &&
981 n->m_type == m->m_type) {
982 bcopy(mtod(m, caddr_t), mtod(n, caddr_t) + n->m_len,
983 (unsigned)m->m_len);
984 n->m_len += m->m_len;
985 sb->sb_ccc += m->m_len;
986 if (sb->sb_fnrdy == NULL)
987 sb->sb_acc += m->m_len;
988 if (m->m_type != MT_DATA && m->m_type != MT_OOBDATA)
989 /* XXX: Probably don't need.*/
990 sb->sb_ctl += m->m_len;
991 m = m_free(m);
992 continue;
993 }
994 if (n)
995 n->m_next = m;
996 else
997 sb->sb_mb = m;
998 sb->sb_mbtail = m;
999 sballoc(sb, m);
1000 n = m;
1001 m->m_flags &= ~M_EOR;
1002 m = m->m_next;
1003 n->m_next = 0;
1004 }
1005 if (eor) {
1006 KASSERT(n != NULL, ("sbcompress: eor && n == NULL"));
1007 n->m_flags |= eor;
1008 }
1009 SBLASTMBUFCHK(sb);
1010 }
1011
1012 /*
1013 * Free all mbufs in a sockbuf. Check that all resources are reclaimed.
1014 */
1015 static void
1016 sbflush_internal(struct sockbuf *sb)
1017 {
1018
1019 while (sb->sb_mbcnt) {
1020 /*
1021 * Don't call sbcut(sb, 0) if the leading mbuf is non-empty:
1022 * we would loop forever. Panic instead.
1023 */
1024 if (sb->sb_ccc == 0 && (sb->sb_mb == NULL || sb->sb_mb->m_len))
1025 break;
1026 m_freem(sbcut_internal(sb, (int)sb->sb_ccc));
1027 }
1028 KASSERT(sb->sb_ccc == 0 && sb->sb_mb == 0 && sb->sb_mbcnt == 0,
1029 ("%s: ccc %u mb %p mbcnt %u", __func__,
1030 sb->sb_ccc, (void *)sb->sb_mb, sb->sb_mbcnt));
1031 }
1032
1033 void
1034 sbflush_locked(struct sockbuf *sb)
1035 {
1036
1037 SOCKBUF_LOCK_ASSERT(sb);
1038 sbflush_internal(sb);
1039 }
1040
1041 void
1042 sbflush(struct sockbuf *sb)
1043 {
1044
1045 SOCKBUF_LOCK(sb);
1046 sbflush_locked(sb);
1047 SOCKBUF_UNLOCK(sb);
1048 }
1049
1050 /*
1051 * Cut data from (the front of) a sockbuf.
1052 */
1053 static struct mbuf *
1054 sbcut_internal(struct sockbuf *sb, int len)
1055 {
1056 struct mbuf *m, *next, *mfree;
1057
1058 next = (m = sb->sb_mb) ? m->m_nextpkt : 0;
1059 mfree = NULL;
1060
1061 while (len > 0) {
1062 if (m == NULL) {
1063 KASSERT(next, ("%s: no next, len %d", __func__, len));
1064 m = next;
1065 next = m->m_nextpkt;
1066 }
1067 if (m->m_len > len) {
1068 KASSERT(!(m->m_flags & M_NOTAVAIL),
1069 ("%s: m %p M_NOTAVAIL", __func__, m));
1070 m->m_len -= len;
1071 m->m_data += len;
1072 sb->sb_ccc -= len;
1073 sb->sb_acc -= len;
1074 if (sb->sb_sndptroff != 0)
1075 sb->sb_sndptroff -= len;
1076 if (m->m_type != MT_DATA && m->m_type != MT_OOBDATA)
1077 sb->sb_ctl -= len;
1078 break;
1079 }
1080 len -= m->m_len;
1081 sbfree(sb, m);
1082 /*
1083 * Do not put M_NOTREADY buffers to the free list, they
1084 * are referenced from outside.
1085 */
1086 if (m->m_flags & M_NOTREADY)
1087 m = m->m_next;
1088 else {
1089 struct mbuf *n;
1090
1091 n = m->m_next;
1092 m->m_next = mfree;
1093 mfree = m;
1094 m = n;
1095 }
1096 }
1097 /*
1098 * Free any zero-length mbufs from the buffer.
1099 * For SOCK_DGRAM sockets such mbufs represent empty records.
1100 * XXX: For SOCK_STREAM sockets such mbufs can appear in the buffer,
1101 * when sosend_generic() needs to send only control data.
1102 */
1103 while (m && m->m_len == 0) {
1104 struct mbuf *n;
1105
1106 sbfree(sb, m);
1107 n = m->m_next;
1108 m->m_next = mfree;
1109 mfree = m;
1110 m = n;
1111 }
1112 if (m) {
1113 sb->sb_mb = m;
1114 m->m_nextpkt = next;
1115 } else
1116 sb->sb_mb = next;
1117 /*
1118 * First part is an inline SB_EMPTY_FIXUP(). Second part makes sure
1119 * sb_lastrecord is up-to-date if we dropped part of the last record.
1120 */
1121 m = sb->sb_mb;
1122 if (m == NULL) {
1123 sb->sb_mbtail = NULL;
1124 sb->sb_lastrecord = NULL;
1125 } else if (m->m_nextpkt == NULL) {
1126 sb->sb_lastrecord = m;
1127 }
1128
1129 return (mfree);
1130 }
1131
1132 /*
1133 * Drop data from (the front of) a sockbuf.
1134 */
1135 void
1136 sbdrop_locked(struct sockbuf *sb, int len)
1137 {
1138
1139 SOCKBUF_LOCK_ASSERT(sb);
1140 m_freem(sbcut_internal(sb, len));
1141 }
1142
1143 /*
1144 * Drop data from (the front of) a sockbuf,
1145 * and return it to caller.
1146 */
1147 struct mbuf *
1148 sbcut_locked(struct sockbuf *sb, int len)
1149 {
1150
1151 SOCKBUF_LOCK_ASSERT(sb);
1152 return (sbcut_internal(sb, len));
1153 }
1154
1155 void
1156 sbdrop(struct sockbuf *sb, int len)
1157 {
1158 struct mbuf *mfree;
1159
1160 SOCKBUF_LOCK(sb);
1161 mfree = sbcut_internal(sb, len);
1162 SOCKBUF_UNLOCK(sb);
1163
1164 m_freem(mfree);
1165 }
1166
1167 /*
1168 * Maintain a pointer and offset pair into the socket buffer mbuf chain to
1169 * avoid traversal of the entire socket buffer for larger offsets.
1170 */
1171 struct mbuf *
1172 sbsndptr(struct sockbuf *sb, u_int off, u_int len, u_int *moff)
1173 {
1174 struct mbuf *m, *ret;
1175
1176 KASSERT(sb->sb_mb != NULL, ("%s: sb_mb is NULL", __func__));
1177 KASSERT(off + len <= sb->sb_acc, ("%s: beyond sb", __func__));
1178 KASSERT(sb->sb_sndptroff <= sb->sb_acc, ("%s: sndptroff broken", __func__));
1179
1180 /*
1181 * Is off below stored offset? Happens on retransmits.
1182 * Just return, we can't help here.
1183 */
1184 if (sb->sb_sndptroff > off) {
1185 *moff = off;
1186 return (sb->sb_mb);
1187 }
1188
1189 /* Return closest mbuf in chain for current offset. */
1190 *moff = off - sb->sb_sndptroff;
1191 m = ret = sb->sb_sndptr ? sb->sb_sndptr : sb->sb_mb;
1192 if (*moff == m->m_len) {
1193 *moff = 0;
1194 sb->sb_sndptroff += m->m_len;
1195 m = ret = m->m_next;
1196 KASSERT(ret->m_len > 0,
1197 ("mbuf %p in sockbuf %p chain has no valid data", ret, sb));
1198 }
1199
1200 /* Advance by len to be as close as possible for the next transmit. */
1201 for (off = off - sb->sb_sndptroff + len - 1;
1202 off > 0 && m != NULL && off >= m->m_len;
1203 m = m->m_next) {
1204 sb->sb_sndptroff += m->m_len;
1205 off -= m->m_len;
1206 }
1207 if (off > 0 && m == NULL)
1208 panic("%s: sockbuf %p and mbuf %p clashing", __func__, sb, ret);
1209 sb->sb_sndptr = m;
1210
1211 return (ret);
1212 }
1213
1214 /*
1215 * Return the first mbuf and the mbuf data offset for the provided
1216 * send offset without changing the "sb_sndptroff" field.
1217 */
1218 struct mbuf *
1219 sbsndmbuf(struct sockbuf *sb, u_int off, u_int *moff)
1220 {
1221 struct mbuf *m;
1222
1223 KASSERT(sb->sb_mb != NULL, ("%s: sb_mb is NULL", __func__));
1224
1225 /*
1226 * If the "off" is below the stored offset, which happens on
1227 * retransmits, just use "sb_mb":
1228 */
1229 if (sb->sb_sndptr == NULL || sb->sb_sndptroff > off) {
1230 m = sb->sb_mb;
1231 } else {
1232 m = sb->sb_sndptr;
1233 off -= sb->sb_sndptroff;
1234 }
1235 while (off > 0 && m != NULL) {
1236 if (off < m->m_len)
1237 break;
1238 off -= m->m_len;
1239 m = m->m_next;
1240 }
1241 *moff = off;
1242 return (m);
1243 }
1244
1245 /*
1246 * Drop a record off the front of a sockbuf and move the next record to the
1247 * front.
1248 */
1249 void
1250 sbdroprecord_locked(struct sockbuf *sb)
1251 {
1252 struct mbuf *m;
1253
1254 SOCKBUF_LOCK_ASSERT(sb);
1255
1256 m = sb->sb_mb;
1257 if (m) {
1258 sb->sb_mb = m->m_nextpkt;
1259 do {
1260 sbfree(sb, m);
1261 m = m_free(m);
1262 } while (m);
1263 }
1264 SB_EMPTY_FIXUP(sb);
1265 }
1266
1267 /*
1268 * Drop a record off the front of a sockbuf and move the next record to the
1269 * front.
1270 */
1271 void
1272 sbdroprecord(struct sockbuf *sb)
1273 {
1274
1275 SOCKBUF_LOCK(sb);
1276 sbdroprecord_locked(sb);
1277 SOCKBUF_UNLOCK(sb);
1278 }
1279
1280 /*
1281 * Create a "control" mbuf containing the specified data with the specified
1282 * type for presentation on a socket buffer.
1283 */
1284 struct mbuf *
1285 sbcreatecontrol(caddr_t p, int size, int type, int level)
1286 {
1287 struct cmsghdr *cp;
1288 struct mbuf *m;
1289
1290 if (CMSG_SPACE((u_int)size) > MCLBYTES)
1291 return ((struct mbuf *) NULL);
1292 if (CMSG_SPACE((u_int)size) > MLEN)
1293 m = m_getcl(M_NOWAIT, MT_CONTROL, 0);
1294 else
1295 m = m_get(M_NOWAIT, MT_CONTROL);
1296 if (m == NULL)
1297 return ((struct mbuf *) NULL);
1298 cp = mtod(m, struct cmsghdr *);
1299 m->m_len = 0;
1300 KASSERT(CMSG_SPACE((u_int)size) <= M_TRAILINGSPACE(m),
1301 ("sbcreatecontrol: short mbuf"));
1302 /*
1303 * Don't leave the padding between the msg header and the
1304 * cmsg data and the padding after the cmsg data un-initialized.
1305 */
1306 bzero(cp, CMSG_SPACE((u_int)size));
1307 if (p != NULL)
1308 (void)memcpy(CMSG_DATA(cp), p, size);
1309 m->m_len = CMSG_SPACE(size);
1310 cp->cmsg_len = CMSG_LEN(size);
1311 cp->cmsg_level = level;
1312 cp->cmsg_type = type;
1313 return (m);
1314 }
1315
1316 /*
1317 * This does the same for socket buffers that sotoxsocket does for sockets:
1318 * generate an user-format data structure describing the socket buffer. Note
1319 * that the xsockbuf structure, since it is always embedded in a socket, does
1320 * not include a self pointer nor a length. We make this entry point public
1321 * in case some other mechanism needs it.
1322 */
1323 void
1324 sbtoxsockbuf(struct sockbuf *sb, struct xsockbuf *xsb)
1325 {
1326
1327 xsb->sb_cc = sb->sb_ccc;
1328 xsb->sb_hiwat = sb->sb_hiwat;
1329 xsb->sb_mbcnt = sb->sb_mbcnt;
1330 xsb->sb_mcnt = sb->sb_mcnt;
1331 xsb->sb_ccnt = sb->sb_ccnt;
1332 xsb->sb_mbmax = sb->sb_mbmax;
1333 xsb->sb_lowat = sb->sb_lowat;
1334 xsb->sb_flags = sb->sb_flags;
1335 xsb->sb_timeo = sb->sb_timeo;
1336 }
1337
1338 /* This takes the place of kern.maxsockbuf, which moved to kern.ipc. */
1339 static int dummy;
1340 SYSCTL_INT(_kern, KERN_DUMMY, dummy, CTLFLAG_RW, &dummy, 0, "");
1341 SYSCTL_OID(_kern_ipc, KIPC_MAXSOCKBUF, maxsockbuf, CTLTYPE_ULONG|CTLFLAG_RW,
1342 &sb_max, 0, sysctl_handle_sb_max, "LU", "Maximum socket buffer size");
1343 SYSCTL_ULONG(_kern_ipc, KIPC_SOCKBUF_WASTE, sockbuf_waste_factor, CTLFLAG_RW,
1344 &sb_efficiency, 0, "Socket buffer size waste factor");
Cache object: 7e2cdcbcc26a0d3244ad4acc9227165e
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