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 */
60void	(*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
68u_long	sb_max = SB_MAX;
69u_long sb_max_adj = BUF_MAX_ADJ(SB_MAX);
70
71static	u_long sb_efficiency = 8;	/* parameter for sbreserve() */
72
73#ifdef KERN_TLS
74static void	sbcompress_ktls_rx(struct sockbuf *sb, struct mbuf *m,
75    struct mbuf *n);
76#endif
77static struct mbuf	*sbcut_internal(struct sockbuf *sb, int len);
78static void	sbflush_internal(struct sockbuf *sb);
79
80/*
81 * Our own version of m_clrprotoflags(), that can preserve M_NOTREADY.
82 */
83static void
84sbm_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 */
106static void
107sbready_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 */
194int
195sbready(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 */
259void
260sballoc(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 */
287void
288sbfree(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 */
336void
337sballoc_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
351void
352sbfree_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 */
378void
379socantsendmore_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
389void
390socantsendmore(struct socket *so)
391{
392
393	SOCK_SENDBUF_LOCK(so);
394	socantsendmore_locked(so);
395	SOCK_SENDBUF_UNLOCK_ASSERT(so);
396}
397
398void
399socantrcvmore_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
413void
414socantrcvmore(struct socket *so)
415{
416
417	SOCK_RECVBUF_LOCK(so);
418	socantrcvmore_locked(so);
419	SOCK_RECVBUF_UNLOCK_ASSERT(so);
420}
421
422void
423soroverflow_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
437void
438soroverflow(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 */
449int
450sbwait(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 */
475static __always_inline void
476sowakeup(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 */
514static __always_inline bool
515sb_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
521void
522sorwakeup_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
531void
532sowwakeup_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 */
572int
573soreserve(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);
592bad2:
593	sbrelease_locked(so, SO_SND);
594bad:
595	SOCK_RECVBUF_UNLOCK(so);
596	SOCK_SENDBUF_UNLOCK(so);
597	return (ENOBUFS);
598}
599
600static int
601sysctl_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 */
620bool
621sbreserve_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
651bool
652sbreserve_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
658int
659sbsetopt(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 */
753static void
754sbrelease_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
764void
765sbrelease_locked(struct socket *so, sb_which which)
766{
767
768	SOCK_BUF_LOCK_ASSERT(so, which);
769
770	sbrelease_internal(so, which);
771}
772
773void
774sbrelease(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
782void
783sbdestroy(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
818void
819sblastrecordchk(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
838void
839sblastmbufchk(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 */
899void
900sbappend_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 */
951void
952sbappend(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 */
966static void
967sbappend_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 */
1016void
1017sbappendstream_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 */
1060void
1061sbappendstream(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
1070void
1071sbcheck(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;
1156fail:
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 */
1164void
1165sbappendrecord_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 */
1198void
1199sbappendrecord(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. */
1208static int
1209sbappendaddr_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 */
1267int
1268sbappendaddr_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 */
1293int
1294sbappendaddr_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 */
1311int
1312sbappendaddr(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
1323void
1324sbappendcontrol_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
1350void
1351sbappendcontrol(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 */
1380void
1381sbcompress(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 */
1448static void
1449sbcompress_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 */
1504static void
1505sbflush_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
1522void
1523sbflush_locked(struct sockbuf *sb)
1524{
1525
1526	SOCKBUF_LOCK_ASSERT(sb);
1527	sbflush_internal(sb);
1528}
1529
1530void
1531sbflush(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 */
1542static struct mbuf *
1543sbcut_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 */
1658void
1659sbdrop_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 */
1670struct mbuf *
1671sbcut_locked(struct sockbuf *sb, int len)
1672{
1673
1674	SOCKBUF_LOCK_ASSERT(sb);
1675	return (sbcut_internal(sb, len));
1676}
1677
1678void
1679sbdrop(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
1690struct mbuf *
1691sbsndptr_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
1711void
1712sbsndptr_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 */
1743struct mbuf *
1744sbsndmbuf(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 */
1774void
1775sbdroprecord_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 */
1796void
1797sbdroprecord(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 */
1809struct mbuf *
1810sbcreatecontrol(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 */
1855void
1856sbtoxsockbuf(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. */
1869static int dummy;
1870SYSCTL_INT(_kern, KERN_DUMMY, dummy, CTLFLAG_RW | CTLFLAG_SKIP, &dummy, 0, "");
1871SYSCTL_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");
1875SYSCTL_ULONG(_kern_ipc, KIPC_SOCKBUF_WASTE, sockbuf_waste_factor, CTLFLAG_RW,
1876    &sb_efficiency, 0, "Socket buffer size waste factor");
1877