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
--- 16 unchanged lines hidden (view full) ---
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: head/sys/kern/uipc_sockbuf.c 160875 2006-08-01 10:30:26Z rwatson $");
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/mbuf.h>
--- 17 unchanged lines hidden (view full) ---
59 */
60
61u_long sb_max = SB_MAX;
62static u_long sb_max_adj =
63 SB_MAX * MCLBYTES / (MSIZE + MCLBYTES); /* adjusted sb_max */
64
65static u_long sb_efficiency = 8; /* parameter for sbreserve() */
66
67static void sbdrop_internal(register struct sockbuf *sb, register int len);
68static void sbflush_internal(register struct sockbuf *sb);
69static void sbrelease_internal(struct sockbuf *sb, struct socket *so);
70
71/*
72 * Socantsendmore indicates that no more data will be sent on the
73 * socket; it would normally be applied to a socket when the user
74 * informs the system that no more data is to be sent, by the protocol
75 * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data
76 * will be received, and will normally be applied to the socket by a
77 * protocol when it detects that the peer will send no more data.
78 * Data queued for reading in the socket may yet be read.
79 */
80void
81socantsendmore_locked(so)
82 struct socket *so;
83{
84
85 SOCKBUF_LOCK_ASSERT(&so->so_snd);
86
87 so->so_snd.sb_state |= SBS_CANTSENDMORE;
88 sowwakeup_locked(so);
89 mtx_assert(SOCKBUF_MTX(&so->so_snd), MA_NOTOWNED);
90}
91
92void
93socantsendmore(so)
94 struct socket *so;
95{
96
97 SOCKBUF_LOCK(&so->so_snd);
98 socantsendmore_locked(so);
99 mtx_assert(SOCKBUF_MTX(&so->so_snd), MA_NOTOWNED);
100}
101
102void
103socantrcvmore_locked(so)
104 struct socket *so;
105{
106
107 SOCKBUF_LOCK_ASSERT(&so->so_rcv);
108
109 so->so_rcv.sb_state |= SBS_CANTRCVMORE;
110 sorwakeup_locked(so);
111 mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED);
112}
113
114void
115socantrcvmore(so)
116 struct socket *so;
117{
118
119 SOCKBUF_LOCK(&so->so_rcv);
120 socantrcvmore_locked(so);
121 mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED);
122}
123
124/*
125 * Wait for data to arrive at/drain from a socket buffer.
126 */
127int
128sbwait(sb)
129 struct sockbuf *sb;
130{
131
132 SOCKBUF_LOCK_ASSERT(sb);
133
134 sb->sb_flags |= SB_WAIT;
135 return (msleep(&sb->sb_cc, &sb->sb_mtx,
136 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, "sbwait",
137 sb->sb_timeo));
138}
139
140/*
141 * Lock a sockbuf already known to be locked;
142 * return any error returned from sleep (EINTR).
143 */
144int
145sb_lock(sb)
146 register struct sockbuf *sb;
147{
148 int error;
149
150 SOCKBUF_LOCK_ASSERT(sb);
151
152 while (sb->sb_flags & SB_LOCK) {
153 sb->sb_flags |= SB_WANT;
154 error = msleep(&sb->sb_flags, &sb->sb_mtx,
155 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK|PCATCH,
156 "sblock", 0);
157 if (error)
158 return (error);
159 }
160 sb->sb_flags |= SB_LOCK;
161 return (0);
162}
163
164/*
165 * Wakeup processes waiting on a socket buffer. Do asynchronous
166 * notification via SIGIO if the socket has the SS_ASYNC flag set.
167 *
168 * Called with the socket buffer lock held; will release the lock by the end
169 * of the function. This allows the caller to acquire the socket buffer lock
170 * while testing for the need for various sorts of wakeup and hold it through
171 * to the point where it's no longer required. We currently hold the lock
172 * through calls out to other subsystems (with the exception of kqueue), and
173 * then release it to avoid lock order issues. It's not clear that's
174 * correct.
175 */
176void
177sowakeup(so, sb)
178 register struct socket *so;
179 register struct sockbuf *sb;
180{
181
182 SOCKBUF_LOCK_ASSERT(sb);
183
184 selwakeuppri(&sb->sb_sel, PSOCK);
185 sb->sb_flags &= ~SB_SEL;
186 if (sb->sb_flags & SB_WAIT) {
187 sb->sb_flags &= ~SB_WAIT;
--- 8 unchanged lines hidden (view full) ---
196 if (sb->sb_flags & SB_AIO)
197 aio_swake(so, sb);
198 mtx_assert(SOCKBUF_MTX(sb), MA_NOTOWNED);
199}
200
201/*
202 * Socket buffer (struct sockbuf) utility routines.
203 *
204 * Each socket contains two socket buffers: one for sending data and
205 * one for receiving data. Each buffer contains a queue of mbufs,
206 * information about the number of mbufs and amount of data in the
207 * queue, and other fields allowing select() statements and notification
208 * on data availability to be implemented.
209 *
210 * Data stored in a socket buffer is maintained as a list of records.
211 * Each record is a list of mbufs chained together with the m_next
212 * field. Records are chained together with the m_nextpkt field. The upper
213 * level routine soreceive() expects the following conventions to be
214 * observed when placing information in the receive buffer:
215 *
216 * 1. If the protocol requires each message be preceded by the sender's
217 * name, then a record containing that name must be present before
218 * any associated data (mbuf's must be of type MT_SONAME).
219 * 2. If the protocol supports the exchange of ``access rights'' (really
220 * just additional data associated with the message), and there are
221 * ``rights'' to be received, then a record containing this data
222 * should be present (mbuf's must be of type MT_RIGHTS).
223 * 3. If a name or rights record exists, then it must be followed by
224 * a data record, perhaps of zero length.
225 *
226 * Before using a new socket structure it is first necessary to reserve
227 * buffer space to the socket, by calling sbreserve(). This should commit
228 * some of the available buffer space in the system buffer pool for the
229 * socket (currently, it does nothing but enforce limits). The space
230 * should be released by calling sbrelease() when the socket is destroyed.
231 */
232
233int
234soreserve(so, sndcc, rcvcc)
235 register struct socket *so;
236 u_long sndcc, rcvcc;
237{
238 struct thread *td = curthread;
239
240 SOCKBUF_LOCK(&so->so_snd);
241 SOCKBUF_LOCK(&so->so_rcv);
242 if (sbreserve_locked(&so->so_snd, sndcc, so, td) == 0)
243 goto bad;
244 if (sbreserve_locked(&so->so_rcv, rcvcc, so, td) == 0)
--- 31 unchanged lines hidden (view full) ---
276 sb_max = old_sb_max;
277 return (EINVAL);
278 }
279 sb_max_adj = (u_quad_t)sb_max * MCLBYTES / (MSIZE + MCLBYTES);
280 return (0);
281}
282
283/*
284 * Allot mbufs to a sockbuf.
285 * Attempt to scale mbmax so that mbcnt doesn't become limiting
286 * if buffering efficiency is near the normal case.
287 */
288int
289sbreserve_locked(sb, cc, so, td)
290 struct sockbuf *sb;
291 u_long cc;
292 struct socket *so;
293 struct thread *td;
294{
295 rlim_t sbsize_limit;
296
297 SOCKBUF_LOCK_ASSERT(sb);
298
299 /*
300 * td will only be NULL when we're in an interrupt
301 * (e.g. in tcp_input())
302 */
303 if (cc > sb_max_adj)
304 return (0);
305 if (td != NULL) {
306 PROC_LOCK(td->td_proc);
307 sbsize_limit = lim_cur(td->td_proc, RLIMIT_SBSIZE);
308 PROC_UNLOCK(td->td_proc);
309 } else
310 sbsize_limit = RLIM_INFINITY;
311 if (!chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, cc,
312 sbsize_limit))
313 return (0);
314 sb->sb_mbmax = min(cc * sb_efficiency, sb_max);
315 if (sb->sb_lowat > sb->sb_hiwat)
316 sb->sb_lowat = sb->sb_hiwat;
317 return (1);
318}
319
320int
321sbreserve(sb, cc, so, td)
322 struct sockbuf *sb;
323 u_long cc;
324 struct socket *so;
325 struct thread *td;
326{
327 int error;
328
329 SOCKBUF_LOCK(sb);
330 error = sbreserve_locked(sb, cc, so, td);
331 SOCKBUF_UNLOCK(sb);
332 return (error);
333}
334
335/*
336 * Free mbufs held by a socket, and reserved mbuf space.
337 */
338static void
339sbrelease_internal(sb, so)
340 struct sockbuf *sb;
341 struct socket *so;
342{
343
344 sbflush_internal(sb);
345 (void)chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, 0,
346 RLIM_INFINITY);
347 sb->sb_mbmax = 0;
348}
349
350void
351sbrelease_locked(sb, so)
352 struct sockbuf *sb;
353 struct socket *so;
354{
355
356 SOCKBUF_LOCK_ASSERT(sb);
357
358 sbrelease_internal(sb, so);
359}
360
361void
362sbrelease(sb, so)
363 struct sockbuf *sb;
364 struct socket *so;
365{
366
367 SOCKBUF_LOCK(sb);
368 sbrelease_locked(sb, so);
369 SOCKBUF_UNLOCK(sb);
370}
371
372void
373sbdestroy(sb, so)
374 struct sockbuf *sb;
375 struct socket *so;
376{
377
378 sbrelease_internal(sb, so);
379}
380
381
382/*
383 * Routines to add and remove
384 * data from an mbuf queue.
385 *
386 * The routines sbappend() or sbappendrecord() are normally called to
387 * append new mbufs to a socket buffer, after checking that adequate
388 * space is available, comparing the function sbspace() with the amount
389 * of data to be added. sbappendrecord() differs from sbappend() in
390 * that data supplied is treated as the beginning of a new record.
391 * To place a sender's address, optional access rights, and data in a
392 * socket receive buffer, sbappendaddr() should be used. To place
393 * access rights and data in a socket receive buffer, sbappendrights()
394 * should be used. In either case, the new data begins a new record.
395 * Note that unlike sbappend() and sbappendrecord(), these routines check
396 * for the caller that there will be enough space to store the data.
397 * Each fails if there is not enough space, or if it cannot find mbufs
398 * to store additional information in.
399 *
400 * Reliable protocols may use the socket send buffer to hold data
401 * awaiting acknowledgement. Data is normally copied from a socket
402 * send buffer in a protocol with m_copy for output to a peer,
403 * and then removing the data from the socket buffer with sbdrop()
404 * or sbdroprecord() when the data is acknowledged by the peer.
405 */
406
407#ifdef SOCKBUF_DEBUG
408void
409sblastrecordchk(struct sockbuf *sb, const char *file, int line)
410{
411 struct mbuf *m = sb->sb_mb;
412
413 SOCKBUF_LOCK_ASSERT(sb);
414
--- 44 unchanged lines hidden (view full) ---
459 if ((sb)->sb_lastrecord != NULL) \
460 (sb)->sb_lastrecord->m_nextpkt = (m0); \
461 else \
462 (sb)->sb_mb = (m0); \
463 (sb)->sb_lastrecord = (m0); \
464} while (/*CONSTCOND*/0)
465
466/*
467 * Append mbuf chain m to the last record in the
468 * socket buffer sb. The additional space associated
469 * the mbuf chain is recorded in sb. Empty mbufs are
470 * discarded and mbufs are compacted where possible.
471 */
472void
473sbappend_locked(sb, m)
474 struct sockbuf *sb;
475 struct mbuf *m;
476{
477 register struct mbuf *n;
478
479 SOCKBUF_LOCK_ASSERT(sb);
480
481 if (m == 0)
482 return;
483
484 SBLASTRECORDCHK(sb);
485 n = sb->sb_mb;
--- 27 unchanged lines hidden (view full) ---
513 sb->sb_lastrecord = m;
514 }
515 }
516 sbcompress(sb, m, n);
517 SBLASTRECORDCHK(sb);
518}
519
520/*
521 * Append mbuf chain m to the last record in the
522 * socket buffer sb. The additional space associated
523 * the mbuf chain is recorded in sb. Empty mbufs are
524 * discarded and mbufs are compacted where possible.
525 */
526void
527sbappend(sb, m)
528 struct sockbuf *sb;
529 struct mbuf *m;
530{
531
532 SOCKBUF_LOCK(sb);
533 sbappend_locked(sb, m);
534 SOCKBUF_UNLOCK(sb);
535}
536
537/*
538 * This version of sbappend() should only be used when the caller
539 * absolutely knows that there will never be more than one record
540 * in the socket buffer, that is, a stream protocol (such as TCP).
541 */
542void
543sbappendstream_locked(struct sockbuf *sb, struct mbuf *m)
544{
545 SOCKBUF_LOCK_ASSERT(sb);
546
547 KASSERT(m->m_nextpkt == NULL,("sbappendstream 0"));
548 KASSERT(sb->sb_mb == sb->sb_lastrecord,("sbappendstream 1"));
549
550 SBLASTMBUFCHK(sb);
551
552 sbcompress(sb, m, sb->sb_mbtail);
553
554 sb->sb_lastrecord = sb->sb_mb;
555 SBLASTRECORDCHK(sb);
556}
557
558/*
559 * This version of sbappend() should only be used when the caller
560 * absolutely knows that there will never be more than one record
561 * in the socket buffer, that is, a stream protocol (such as TCP).
562 */
563void
564sbappendstream(struct sockbuf *sb, struct mbuf *m)
565{
566
567 SOCKBUF_LOCK(sb);
568 sbappendstream_locked(sb, m);
569 SOCKBUF_UNLOCK(sb);
570}
571
572#ifdef SOCKBUF_DEBUG
573void
574sbcheck(sb)
575 struct sockbuf *sb;
576{
577 struct mbuf *m;
578 struct mbuf *n = 0;
579 u_long len = 0, mbcnt = 0;
580
581 SOCKBUF_LOCK_ASSERT(sb);
582
583 for (m = sb->sb_mb; m; m = n) {
--- 9 unchanged lines hidden (view full) ---
593 printf("cc %ld != %u || mbcnt %ld != %u\n", len, sb->sb_cc,
594 mbcnt, sb->sb_mbcnt);
595 panic("sbcheck");
596 }
597}
598#endif
599
600/*
601 * As above, except the mbuf chain
602 * begins a new record.
603 */
604void
605sbappendrecord_locked(sb, m0)
606 register struct sockbuf *sb;
607 register struct mbuf *m0;
608{
609 register struct mbuf *m;
610
611 SOCKBUF_LOCK_ASSERT(sb);
612
613 if (m0 == 0)
614 return;
615 m = sb->sb_mb;
616 if (m)
617 while (m->m_nextpkt)
618 m = m->m_nextpkt;
619 /*
620 * Put the first mbuf on the queue.
621 * Note this permits zero length records.
622 */
623 sballoc(sb, m0);
624 SBLASTRECORDCHK(sb);
625 SBLINKRECORD(sb, m0);
626 if (m)
627 m->m_nextpkt = m0;
628 else
629 sb->sb_mb = m0;
630 m = m0->m_next;
631 m0->m_next = 0;
632 if (m && (m0->m_flags & M_EOR)) {
633 m0->m_flags &= ~M_EOR;
634 m->m_flags |= M_EOR;
635 }
636 sbcompress(sb, m, m0);
637}
638
639/*
640 * As above, except the mbuf chain
641 * begins a new record.
642 */
643void
644sbappendrecord(sb, m0)
645 register struct sockbuf *sb;
646 register struct mbuf *m0;
647{
648
649 SOCKBUF_LOCK(sb);
650 sbappendrecord_locked(sb, m0);
651 SOCKBUF_UNLOCK(sb);
652}
653
654/*
655 * Append address and data, and optionally, control (ancillary) data
656 * to the receive queue of a socket. If present,
657 * m0 must include a packet header with total length.
658 * Returns 0 if no space in sockbuf or insufficient mbufs.
659 */
660int
661sbappendaddr_locked(sb, asa, m0, control)
662 struct sockbuf *sb;
663 const struct sockaddr *asa;
664 struct mbuf *m0, *control;
665{
666 struct mbuf *m, *n, *nlast;
667 int space = asa->sa_len;
668
669 SOCKBUF_LOCK_ASSERT(sb);
670
671 if (m0 && (m0->m_flags & M_PKTHDR) == 0)
672 panic("sbappendaddr_locked");
--- 26 unchanged lines hidden (view full) ---
699 sb->sb_mbtail = nlast;
700 SBLASTMBUFCHK(sb);
701
702 SBLASTRECORDCHK(sb);
703 return (1);
704}
705
706/*
707 * Append address and data, and optionally, control (ancillary) data
708 * to the receive queue of a socket. If present,
709 * m0 must include a packet header with total length.
710 * Returns 0 if no space in sockbuf or insufficient mbufs.
711 */
712int
713sbappendaddr(sb, asa, m0, control)
714 struct sockbuf *sb;
715 const struct sockaddr *asa;
716 struct mbuf *m0, *control;
717{
718 int retval;
719
720 SOCKBUF_LOCK(sb);
721 retval = sbappendaddr_locked(sb, asa, m0, control);
722 SOCKBUF_UNLOCK(sb);
723 return (retval);
724}
725
726int
727sbappendcontrol_locked(sb, m0, control)
728 struct sockbuf *sb;
729 struct mbuf *control, *m0;
730{
731 struct mbuf *m, *n, *mlast;
732 int space;
733
734 SOCKBUF_LOCK_ASSERT(sb);
735
736 if (control == 0)
737 panic("sbappendcontrol_locked");
--- 14 unchanged lines hidden (view full) ---
752 sb->sb_mbtail = mlast;
753 SBLASTMBUFCHK(sb);
754
755 SBLASTRECORDCHK(sb);
756 return (1);
757}
758
759int
760sbappendcontrol(sb, m0, control)
761 struct sockbuf *sb;
762 struct mbuf *control, *m0;
763{
764 int retval;
765
766 SOCKBUF_LOCK(sb);
767 retval = sbappendcontrol_locked(sb, m0, control);
768 SOCKBUF_UNLOCK(sb);
769 return (retval);
770}
--- 14 unchanged lines hidden (view full) ---
785 * will occur.
786 *
787 * (3) The mbuf may be appended to the end of the existing mbuf chain.
788 *
789 * If any of the new mbufs is marked as M_EOR, mark the last mbuf appended as
790 * end-of-record.
791 */
792void
793sbcompress(sb, m, n)
794 register struct sockbuf *sb;
795 register struct mbuf *m, *n;
796{
797 register int eor = 0;
798 register struct mbuf *o;
799
800 SOCKBUF_LOCK_ASSERT(sb);
801
802 while (m) {
803 eor |= m->m_flags & M_EOR;
804 if (m->m_len == 0 &&
805 (eor == 0 ||
806 (((o = m->m_next) || (o = n)) &&
--- 32 unchanged lines hidden (view full) ---
839 if (eor) {
840 KASSERT(n != NULL, ("sbcompress: eor && n == NULL"));
841 n->m_flags |= eor;
842 }
843 SBLASTMBUFCHK(sb);
844}
845
846/*
847 * Free all mbufs in a sockbuf.
848 * Check that all resources are reclaimed.
849 */
850static void
851sbflush_internal(sb)
852 register struct sockbuf *sb;
853{
854
855 if (sb->sb_flags & SB_LOCK)
856 panic("sbflush_locked: locked");
857 while (sb->sb_mbcnt) {
858 /*
859 * Don't call sbdrop(sb, 0) if the leading mbuf is non-empty:
860 * we would loop forever. Panic instead.
861 */
862 if (!sb->sb_cc && (sb->sb_mb == NULL || sb->sb_mb->m_len))
863 break;
864 sbdrop_internal(sb, (int)sb->sb_cc);
865 }
866 if (sb->sb_cc || sb->sb_mb || sb->sb_mbcnt)
867 panic("sbflush_locked: cc %u || mb %p || mbcnt %u", sb->sb_cc, (void *)sb->sb_mb, sb->sb_mbcnt);
868}
869
870void
871sbflush_locked(sb)
872 register struct sockbuf *sb;
873{
874
875 SOCKBUF_LOCK_ASSERT(sb);
876 sbflush_internal(sb);
877}
878
879void
880sbflush(sb)
881 register struct sockbuf *sb;
882{
883
884 SOCKBUF_LOCK(sb);
885 sbflush_locked(sb);
886 SOCKBUF_UNLOCK(sb);
887}
888
889/*
890 * Drop data from (the front of) a sockbuf.
891 */
892static void
893sbdrop_internal(sb, len)
894 register struct sockbuf *sb;
895 register int len;
896{
897 register struct mbuf *m;
898 struct mbuf *next;
899
900 next = (m = sb->sb_mb) ? m->m_nextpkt : 0;
901 while (len > 0) {
902 if (m == 0) {
903 if (next == 0)
904 panic("sbdrop");
905 m = next;
--- 17 unchanged lines hidden (view full) ---
923 m = m_free(m);
924 }
925 if (m) {
926 sb->sb_mb = m;
927 m->m_nextpkt = next;
928 } else
929 sb->sb_mb = next;
930 /*
931 * First part is an inline SB_EMPTY_FIXUP(). Second part
932 * makes sure sb_lastrecord is up-to-date if we dropped
933 * part of the last record.
934 */
935 m = sb->sb_mb;
936 if (m == NULL) {
937 sb->sb_mbtail = NULL;
938 sb->sb_lastrecord = NULL;
939 } else if (m->m_nextpkt == NULL) {
940 sb->sb_lastrecord = m;
941 }
942}
943
944/*
945 * Drop data from (the front of) a sockbuf.
946 */
947void
948sbdrop_locked(sb, len)
949 register struct sockbuf *sb;
950 register int len;
951{
952
953 SOCKBUF_LOCK_ASSERT(sb);
954
955 sbdrop_internal(sb, len);
956}
957
958void
959sbdrop(sb, len)
960 register struct sockbuf *sb;
961 register int len;
962{
963
964 SOCKBUF_LOCK(sb);
965 sbdrop_locked(sb, len);
966 SOCKBUF_UNLOCK(sb);
967}
968
969/*
970 * Drop a record off the front of a sockbuf
971 * and move the next record to the front.
972 */
973void
974sbdroprecord_locked(sb)
975 register struct sockbuf *sb;
976{
977 register struct mbuf *m;
978
979 SOCKBUF_LOCK_ASSERT(sb);
980
981 m = sb->sb_mb;
982 if (m) {
983 sb->sb_mb = m->m_nextpkt;
984 do {
985 sbfree(sb, m);
986 m = m_free(m);
987 } while (m);
988 }
989 SB_EMPTY_FIXUP(sb);
990}
991
992/*
993 * Drop a record off the front of a sockbuf
994 * and move the next record to the front.
995 */
996void
997sbdroprecord(sb)
998 register struct sockbuf *sb;
999{
1000
1001 SOCKBUF_LOCK(sb);
1002 sbdroprecord_locked(sb);
1003 SOCKBUF_UNLOCK(sb);
1004}
1005
1006/* This takes the place of kern.maxsockbuf, which moved to kern.ipc. */
1007static int dummy;
1008SYSCTL_INT(_kern, KERN_DUMMY, dummy, CTLFLAG_RW, &dummy, 0, "");
1009SYSCTL_OID(_kern_ipc, KIPC_MAXSOCKBUF, maxsockbuf, CTLTYPE_ULONG|CTLFLAG_RW,
1010 &sb_max, 0, sysctl_handle_sb_max, "LU", "Maximum socket buffer size");
1011SYSCTL_ULONG(_kern_ipc, KIPC_SOCKBUF_WASTE, sockbuf_waste_factor, CTLFLAG_RW,
1012 &sb_efficiency, 0, "");
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
--- 16 unchanged lines hidden (view full) ---
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: head/sys/kern/uipc_sockbuf.c 160875 2006-08-01 10:30:26Z rwatson $");
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/mbuf.h>
--- 17 unchanged lines hidden (view full) ---
59 */
60
61u_long sb_max = SB_MAX;
62static u_long sb_max_adj =
63 SB_MAX * MCLBYTES / (MSIZE + MCLBYTES); /* adjusted sb_max */
64
65static u_long sb_efficiency = 8; /* parameter for sbreserve() */
66
67static void sbdrop_internal(register struct sockbuf *sb, register int len);
68static void sbflush_internal(register struct sockbuf *sb);
69static void sbrelease_internal(struct sockbuf *sb, struct socket *so);
70
71/*
72 * Socantsendmore indicates that no more data will be sent on the
73 * socket; it would normally be applied to a socket when the user
74 * informs the system that no more data is to be sent, by the protocol
75 * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data
76 * will be received, and will normally be applied to the socket by a
77 * protocol when it detects that the peer will send no more data.
78 * Data queued for reading in the socket may yet be read.
79 */
80void
81socantsendmore_locked(so)
82 struct socket *so;
83{
84
85 SOCKBUF_LOCK_ASSERT(&so->so_snd);
86
87 so->so_snd.sb_state |= SBS_CANTSENDMORE;
88 sowwakeup_locked(so);
89 mtx_assert(SOCKBUF_MTX(&so->so_snd), MA_NOTOWNED);
90}
91
92void
93socantsendmore(so)
94 struct socket *so;
95{
96
97 SOCKBUF_LOCK(&so->so_snd);
98 socantsendmore_locked(so);
99 mtx_assert(SOCKBUF_MTX(&so->so_snd), MA_NOTOWNED);
100}
101
102void
103socantrcvmore_locked(so)
104 struct socket *so;
105{
106
107 SOCKBUF_LOCK_ASSERT(&so->so_rcv);
108
109 so->so_rcv.sb_state |= SBS_CANTRCVMORE;
110 sorwakeup_locked(so);
111 mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED);
112}
113
114void
115socantrcvmore(so)
116 struct socket *so;
117{
118
119 SOCKBUF_LOCK(&so->so_rcv);
120 socantrcvmore_locked(so);
121 mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED);
122}
123
124/*
125 * Wait for data to arrive at/drain from a socket buffer.
126 */
127int
128sbwait(sb)
129 struct sockbuf *sb;
130{
131
132 SOCKBUF_LOCK_ASSERT(sb);
133
134 sb->sb_flags |= SB_WAIT;
135 return (msleep(&sb->sb_cc, &sb->sb_mtx,
136 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, "sbwait",
137 sb->sb_timeo));
138}
139
140/*
141 * Lock a sockbuf already known to be locked;
142 * return any error returned from sleep (EINTR).
143 */
144int
145sb_lock(sb)
146 register struct sockbuf *sb;
147{
148 int error;
149
150 SOCKBUF_LOCK_ASSERT(sb);
151
152 while (sb->sb_flags & SB_LOCK) {
153 sb->sb_flags |= SB_WANT;
154 error = msleep(&sb->sb_flags, &sb->sb_mtx,
155 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK|PCATCH,
156 "sblock", 0);
157 if (error)
158 return (error);
159 }
160 sb->sb_flags |= SB_LOCK;
161 return (0);
162}
163
164/*
165 * Wakeup processes waiting on a socket buffer. Do asynchronous
166 * notification via SIGIO if the socket has the SS_ASYNC flag set.
167 *
168 * Called with the socket buffer lock held; will release the lock by the end
169 * of the function. This allows the caller to acquire the socket buffer lock
170 * while testing for the need for various sorts of wakeup and hold it through
171 * to the point where it's no longer required. We currently hold the lock
172 * through calls out to other subsystems (with the exception of kqueue), and
173 * then release it to avoid lock order issues. It's not clear that's
174 * correct.
175 */
176void
177sowakeup(so, sb)
178 register struct socket *so;
179 register struct sockbuf *sb;
180{
181
182 SOCKBUF_LOCK_ASSERT(sb);
183
184 selwakeuppri(&sb->sb_sel, PSOCK);
185 sb->sb_flags &= ~SB_SEL;
186 if (sb->sb_flags & SB_WAIT) {
187 sb->sb_flags &= ~SB_WAIT;
--- 8 unchanged lines hidden (view full) ---
196 if (sb->sb_flags & SB_AIO)
197 aio_swake(so, sb);
198 mtx_assert(SOCKBUF_MTX(sb), MA_NOTOWNED);
199}
200
201/*
202 * Socket buffer (struct sockbuf) utility routines.
203 *
204 * Each socket contains two socket buffers: one for sending data and
205 * one for receiving data. Each buffer contains a queue of mbufs,
206 * information about the number of mbufs and amount of data in the
207 * queue, and other fields allowing select() statements and notification
208 * on data availability to be implemented.
209 *
210 * Data stored in a socket buffer is maintained as a list of records.
211 * Each record is a list of mbufs chained together with the m_next
212 * field. Records are chained together with the m_nextpkt field. The upper
213 * level routine soreceive() expects the following conventions to be
214 * observed when placing information in the receive buffer:
215 *
216 * 1. If the protocol requires each message be preceded by the sender's
217 * name, then a record containing that name must be present before
218 * any associated data (mbuf's must be of type MT_SONAME).
219 * 2. If the protocol supports the exchange of ``access rights'' (really
220 * just additional data associated with the message), and there are
221 * ``rights'' to be received, then a record containing this data
222 * should be present (mbuf's must be of type MT_RIGHTS).
223 * 3. If a name or rights record exists, then it must be followed by
224 * a data record, perhaps of zero length.
225 *
226 * Before using a new socket structure it is first necessary to reserve
227 * buffer space to the socket, by calling sbreserve(). This should commit
228 * some of the available buffer space in the system buffer pool for the
229 * socket (currently, it does nothing but enforce limits). The space
230 * should be released by calling sbrelease() when the socket is destroyed.
231 */
232
233int
234soreserve(so, sndcc, rcvcc)
235 register struct socket *so;
236 u_long sndcc, rcvcc;
237{
238 struct thread *td = curthread;
239
240 SOCKBUF_LOCK(&so->so_snd);
241 SOCKBUF_LOCK(&so->so_rcv);
242 if (sbreserve_locked(&so->so_snd, sndcc, so, td) == 0)
243 goto bad;
244 if (sbreserve_locked(&so->so_rcv, rcvcc, so, td) == 0)
--- 31 unchanged lines hidden (view full) ---
276 sb_max = old_sb_max;
277 return (EINVAL);
278 }
279 sb_max_adj = (u_quad_t)sb_max * MCLBYTES / (MSIZE + MCLBYTES);
280 return (0);
281}
282
283/*
284 * Allot mbufs to a sockbuf.
285 * Attempt to scale mbmax so that mbcnt doesn't become limiting
286 * if buffering efficiency is near the normal case.
287 */
288int
289sbreserve_locked(sb, cc, so, td)
290 struct sockbuf *sb;
291 u_long cc;
292 struct socket *so;
293 struct thread *td;
294{
295 rlim_t sbsize_limit;
296
297 SOCKBUF_LOCK_ASSERT(sb);
298
299 /*
300 * td will only be NULL when we're in an interrupt
301 * (e.g. in tcp_input())
302 */
303 if (cc > sb_max_adj)
304 return (0);
305 if (td != NULL) {
306 PROC_LOCK(td->td_proc);
307 sbsize_limit = lim_cur(td->td_proc, RLIMIT_SBSIZE);
308 PROC_UNLOCK(td->td_proc);
309 } else
310 sbsize_limit = RLIM_INFINITY;
311 if (!chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, cc,
312 sbsize_limit))
313 return (0);
314 sb->sb_mbmax = min(cc * sb_efficiency, sb_max);
315 if (sb->sb_lowat > sb->sb_hiwat)
316 sb->sb_lowat = sb->sb_hiwat;
317 return (1);
318}
319
320int
321sbreserve(sb, cc, so, td)
322 struct sockbuf *sb;
323 u_long cc;
324 struct socket *so;
325 struct thread *td;
326{
327 int error;
328
329 SOCKBUF_LOCK(sb);
330 error = sbreserve_locked(sb, cc, so, td);
331 SOCKBUF_UNLOCK(sb);
332 return (error);
333}
334
335/*
336 * Free mbufs held by a socket, and reserved mbuf space.
337 */
338static void
339sbrelease_internal(sb, so)
340 struct sockbuf *sb;
341 struct socket *so;
342{
343
344 sbflush_internal(sb);
345 (void)chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, 0,
346 RLIM_INFINITY);
347 sb->sb_mbmax = 0;
348}
349
350void
351sbrelease_locked(sb, so)
352 struct sockbuf *sb;
353 struct socket *so;
354{
355
356 SOCKBUF_LOCK_ASSERT(sb);
357
358 sbrelease_internal(sb, so);
359}
360
361void
362sbrelease(sb, so)
363 struct sockbuf *sb;
364 struct socket *so;
365{
366
367 SOCKBUF_LOCK(sb);
368 sbrelease_locked(sb, so);
369 SOCKBUF_UNLOCK(sb);
370}
371
372void
373sbdestroy(sb, so)
374 struct sockbuf *sb;
375 struct socket *so;
376{
377
378 sbrelease_internal(sb, so);
379}
380
381
382/*
383 * Routines to add and remove
384 * data from an mbuf queue.
385 *
386 * The routines sbappend() or sbappendrecord() are normally called to
387 * append new mbufs to a socket buffer, after checking that adequate
388 * space is available, comparing the function sbspace() with the amount
389 * of data to be added. sbappendrecord() differs from sbappend() in
390 * that data supplied is treated as the beginning of a new record.
391 * To place a sender's address, optional access rights, and data in a
392 * socket receive buffer, sbappendaddr() should be used. To place
393 * access rights and data in a socket receive buffer, sbappendrights()
394 * should be used. In either case, the new data begins a new record.
395 * Note that unlike sbappend() and sbappendrecord(), these routines check
396 * for the caller that there will be enough space to store the data.
397 * Each fails if there is not enough space, or if it cannot find mbufs
398 * to store additional information in.
399 *
400 * Reliable protocols may use the socket send buffer to hold data
401 * awaiting acknowledgement. Data is normally copied from a socket
402 * send buffer in a protocol with m_copy for output to a peer,
403 * and then removing the data from the socket buffer with sbdrop()
404 * or sbdroprecord() when the data is acknowledged by the peer.
405 */
406
407#ifdef SOCKBUF_DEBUG
408void
409sblastrecordchk(struct sockbuf *sb, const char *file, int line)
410{
411 struct mbuf *m = sb->sb_mb;
412
413 SOCKBUF_LOCK_ASSERT(sb);
414
--- 44 unchanged lines hidden (view full) ---
459 if ((sb)->sb_lastrecord != NULL) \
460 (sb)->sb_lastrecord->m_nextpkt = (m0); \
461 else \
462 (sb)->sb_mb = (m0); \
463 (sb)->sb_lastrecord = (m0); \
464} while (/*CONSTCOND*/0)
465
466/*
467 * Append mbuf chain m to the last record in the
468 * socket buffer sb. The additional space associated
469 * the mbuf chain is recorded in sb. Empty mbufs are
470 * discarded and mbufs are compacted where possible.
471 */
472void
473sbappend_locked(sb, m)
474 struct sockbuf *sb;
475 struct mbuf *m;
476{
477 register struct mbuf *n;
478
479 SOCKBUF_LOCK_ASSERT(sb);
480
481 if (m == 0)
482 return;
483
484 SBLASTRECORDCHK(sb);
485 n = sb->sb_mb;
--- 27 unchanged lines hidden (view full) ---
513 sb->sb_lastrecord = m;
514 }
515 }
516 sbcompress(sb, m, n);
517 SBLASTRECORDCHK(sb);
518}
519
520/*
521 * Append mbuf chain m to the last record in the
522 * socket buffer sb. The additional space associated
523 * the mbuf chain is recorded in sb. Empty mbufs are
524 * discarded and mbufs are compacted where possible.
525 */
526void
527sbappend(sb, m)
528 struct sockbuf *sb;
529 struct mbuf *m;
530{
531
532 SOCKBUF_LOCK(sb);
533 sbappend_locked(sb, m);
534 SOCKBUF_UNLOCK(sb);
535}
536
537/*
538 * This version of sbappend() should only be used when the caller
539 * absolutely knows that there will never be more than one record
540 * in the socket buffer, that is, a stream protocol (such as TCP).
541 */
542void
543sbappendstream_locked(struct sockbuf *sb, struct mbuf *m)
544{
545 SOCKBUF_LOCK_ASSERT(sb);
546
547 KASSERT(m->m_nextpkt == NULL,("sbappendstream 0"));
548 KASSERT(sb->sb_mb == sb->sb_lastrecord,("sbappendstream 1"));
549
550 SBLASTMBUFCHK(sb);
551
552 sbcompress(sb, m, sb->sb_mbtail);
553
554 sb->sb_lastrecord = sb->sb_mb;
555 SBLASTRECORDCHK(sb);
556}
557
558/*
559 * This version of sbappend() should only be used when the caller
560 * absolutely knows that there will never be more than one record
561 * in the socket buffer, that is, a stream protocol (such as TCP).
562 */
563void
564sbappendstream(struct sockbuf *sb, struct mbuf *m)
565{
566
567 SOCKBUF_LOCK(sb);
568 sbappendstream_locked(sb, m);
569 SOCKBUF_UNLOCK(sb);
570}
571
572#ifdef SOCKBUF_DEBUG
573void
574sbcheck(sb)
575 struct sockbuf *sb;
576{
577 struct mbuf *m;
578 struct mbuf *n = 0;
579 u_long len = 0, mbcnt = 0;
580
581 SOCKBUF_LOCK_ASSERT(sb);
582
583 for (m = sb->sb_mb; m; m = n) {
--- 9 unchanged lines hidden (view full) ---
593 printf("cc %ld != %u || mbcnt %ld != %u\n", len, sb->sb_cc,
594 mbcnt, sb->sb_mbcnt);
595 panic("sbcheck");
596 }
597}
598#endif
599
600/*
601 * As above, except the mbuf chain
602 * begins a new record.
603 */
604void
605sbappendrecord_locked(sb, m0)
606 register struct sockbuf *sb;
607 register struct mbuf *m0;
608{
609 register struct mbuf *m;
610
611 SOCKBUF_LOCK_ASSERT(sb);
612
613 if (m0 == 0)
614 return;
615 m = sb->sb_mb;
616 if (m)
617 while (m->m_nextpkt)
618 m = m->m_nextpkt;
619 /*
620 * Put the first mbuf on the queue.
621 * Note this permits zero length records.
622 */
623 sballoc(sb, m0);
624 SBLASTRECORDCHK(sb);
625 SBLINKRECORD(sb, m0);
626 if (m)
627 m->m_nextpkt = m0;
628 else
629 sb->sb_mb = m0;
630 m = m0->m_next;
631 m0->m_next = 0;
632 if (m && (m0->m_flags & M_EOR)) {
633 m0->m_flags &= ~M_EOR;
634 m->m_flags |= M_EOR;
635 }
636 sbcompress(sb, m, m0);
637}
638
639/*
640 * As above, except the mbuf chain
641 * begins a new record.
642 */
643void
644sbappendrecord(sb, m0)
645 register struct sockbuf *sb;
646 register struct mbuf *m0;
647{
648
649 SOCKBUF_LOCK(sb);
650 sbappendrecord_locked(sb, m0);
651 SOCKBUF_UNLOCK(sb);
652}
653
654/*
655 * Append address and data, and optionally, control (ancillary) data
656 * to the receive queue of a socket. If present,
657 * m0 must include a packet header with total length.
658 * Returns 0 if no space in sockbuf or insufficient mbufs.
659 */
660int
661sbappendaddr_locked(sb, asa, m0, control)
662 struct sockbuf *sb;
663 const struct sockaddr *asa;
664 struct mbuf *m0, *control;
665{
666 struct mbuf *m, *n, *nlast;
667 int space = asa->sa_len;
668
669 SOCKBUF_LOCK_ASSERT(sb);
670
671 if (m0 && (m0->m_flags & M_PKTHDR) == 0)
672 panic("sbappendaddr_locked");
--- 26 unchanged lines hidden (view full) ---
699 sb->sb_mbtail = nlast;
700 SBLASTMBUFCHK(sb);
701
702 SBLASTRECORDCHK(sb);
703 return (1);
704}
705
706/*
707 * Append address and data, and optionally, control (ancillary) data
708 * to the receive queue of a socket. If present,
709 * m0 must include a packet header with total length.
710 * Returns 0 if no space in sockbuf or insufficient mbufs.
711 */
712int
713sbappendaddr(sb, asa, m0, control)
714 struct sockbuf *sb;
715 const struct sockaddr *asa;
716 struct mbuf *m0, *control;
717{
718 int retval;
719
720 SOCKBUF_LOCK(sb);
721 retval = sbappendaddr_locked(sb, asa, m0, control);
722 SOCKBUF_UNLOCK(sb);
723 return (retval);
724}
725
726int
727sbappendcontrol_locked(sb, m0, control)
728 struct sockbuf *sb;
729 struct mbuf *control, *m0;
730{
731 struct mbuf *m, *n, *mlast;
732 int space;
733
734 SOCKBUF_LOCK_ASSERT(sb);
735
736 if (control == 0)
737 panic("sbappendcontrol_locked");
--- 14 unchanged lines hidden (view full) ---
752 sb->sb_mbtail = mlast;
753 SBLASTMBUFCHK(sb);
754
755 SBLASTRECORDCHK(sb);
756 return (1);
757}
758
759int
760sbappendcontrol(sb, m0, control)
761 struct sockbuf *sb;
762 struct mbuf *control, *m0;
763{
764 int retval;
765
766 SOCKBUF_LOCK(sb);
767 retval = sbappendcontrol_locked(sb, m0, control);
768 SOCKBUF_UNLOCK(sb);
769 return (retval);
770}
--- 14 unchanged lines hidden (view full) ---
785 * will occur.
786 *
787 * (3) The mbuf may be appended to the end of the existing mbuf chain.
788 *
789 * If any of the new mbufs is marked as M_EOR, mark the last mbuf appended as
790 * end-of-record.
791 */
792void
793sbcompress(sb, m, n)
794 register struct sockbuf *sb;
795 register struct mbuf *m, *n;
796{
797 register int eor = 0;
798 register struct mbuf *o;
799
800 SOCKBUF_LOCK_ASSERT(sb);
801
802 while (m) {
803 eor |= m->m_flags & M_EOR;
804 if (m->m_len == 0 &&
805 (eor == 0 ||
806 (((o = m->m_next) || (o = n)) &&
--- 32 unchanged lines hidden (view full) ---
839 if (eor) {
840 KASSERT(n != NULL, ("sbcompress: eor && n == NULL"));
841 n->m_flags |= eor;
842 }
843 SBLASTMBUFCHK(sb);
844}
845
846/*
847 * Free all mbufs in a sockbuf.
848 * Check that all resources are reclaimed.
849 */
850static void
851sbflush_internal(sb)
852 register struct sockbuf *sb;
853{
854
855 if (sb->sb_flags & SB_LOCK)
856 panic("sbflush_locked: locked");
857 while (sb->sb_mbcnt) {
858 /*
859 * Don't call sbdrop(sb, 0) if the leading mbuf is non-empty:
860 * we would loop forever. Panic instead.
861 */
862 if (!sb->sb_cc && (sb->sb_mb == NULL || sb->sb_mb->m_len))
863 break;
864 sbdrop_internal(sb, (int)sb->sb_cc);
865 }
866 if (sb->sb_cc || sb->sb_mb || sb->sb_mbcnt)
867 panic("sbflush_locked: cc %u || mb %p || mbcnt %u", sb->sb_cc, (void *)sb->sb_mb, sb->sb_mbcnt);
868}
869
870void
871sbflush_locked(sb)
872 register struct sockbuf *sb;
873{
874
875 SOCKBUF_LOCK_ASSERT(sb);
876 sbflush_internal(sb);
877}
878
879void
880sbflush(sb)
881 register struct sockbuf *sb;
882{
883
884 SOCKBUF_LOCK(sb);
885 sbflush_locked(sb);
886 SOCKBUF_UNLOCK(sb);
887}
888
889/*
890 * Drop data from (the front of) a sockbuf.
891 */
892static void
893sbdrop_internal(sb, len)
894 register struct sockbuf *sb;
895 register int len;
896{
897 register struct mbuf *m;
898 struct mbuf *next;
899
900 next = (m = sb->sb_mb) ? m->m_nextpkt : 0;
901 while (len > 0) {
902 if (m == 0) {
903 if (next == 0)
904 panic("sbdrop");
905 m = next;
--- 17 unchanged lines hidden (view full) ---
923 m = m_free(m);
924 }
925 if (m) {
926 sb->sb_mb = m;
927 m->m_nextpkt = next;
928 } else
929 sb->sb_mb = next;
930 /*
931 * First part is an inline SB_EMPTY_FIXUP(). Second part
932 * makes sure sb_lastrecord is up-to-date if we dropped
933 * part of the last record.
934 */
935 m = sb->sb_mb;
936 if (m == NULL) {
937 sb->sb_mbtail = NULL;
938 sb->sb_lastrecord = NULL;
939 } else if (m->m_nextpkt == NULL) {
940 sb->sb_lastrecord = m;
941 }
942}
943
944/*
945 * Drop data from (the front of) a sockbuf.
946 */
947void
948sbdrop_locked(sb, len)
949 register struct sockbuf *sb;
950 register int len;
951{
952
953 SOCKBUF_LOCK_ASSERT(sb);
954
955 sbdrop_internal(sb, len);
956}
957
958void
959sbdrop(sb, len)
960 register struct sockbuf *sb;
961 register int len;
962{
963
964 SOCKBUF_LOCK(sb);
965 sbdrop_locked(sb, len);
966 SOCKBUF_UNLOCK(sb);
967}
968
969/*
970 * Drop a record off the front of a sockbuf
971 * and move the next record to the front.
972 */
973void
974sbdroprecord_locked(sb)
975 register struct sockbuf *sb;
976{
977 register struct mbuf *m;
978
979 SOCKBUF_LOCK_ASSERT(sb);
980
981 m = sb->sb_mb;
982 if (m) {
983 sb->sb_mb = m->m_nextpkt;
984 do {
985 sbfree(sb, m);
986 m = m_free(m);
987 } while (m);
988 }
989 SB_EMPTY_FIXUP(sb);
990}
991
992/*
993 * Drop a record off the front of a sockbuf
994 * and move the next record to the front.
995 */
996void
997sbdroprecord(sb)
998 register struct sockbuf *sb;
999{
1000
1001 SOCKBUF_LOCK(sb);
1002 sbdroprecord_locked(sb);
1003 SOCKBUF_UNLOCK(sb);
1004}
1005
1006/* This takes the place of kern.maxsockbuf, which moved to kern.ipc. */
1007static int dummy;
1008SYSCTL_INT(_kern, KERN_DUMMY, dummy, CTLFLAG_RW, &dummy, 0, "");
1009SYSCTL_OID(_kern_ipc, KIPC_MAXSOCKBUF, maxsockbuf, CTLTYPE_ULONG|CTLFLAG_RW,
1010 &sb_max, 0, sysctl_handle_sb_max, "LU", "Maximum socket buffer size");
1011SYSCTL_ULONG(_kern_ipc, KIPC_SOCKBUF_WASTE, sockbuf_waste_factor, CTLFLAG_RW,
1012 &sb_efficiency, 0, "");