1 /*
2 * Copyright (c) 1982, 1986, 1988, 1990 Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * $Id: sockbufs.c,v 1.1 94/10/19 23:49:56 bill Exp $
34 */
35
36 #include "sys/param.h"
37 #include "sys/file.h"
38 #include "sys/errno.h"
39 #include "systm.h" /* selwait */
40 #include "proc.h"
41 #include "signalvar.h"
42 #include "buf.h"
43 #include "malloc.h"
44 #include "mbuf.h"
45 #include "protosw.h"
46 #include "socketvar.h"
47 #include "prototypes.h"
48
49 /*
50 * Primitive routines for operating on sockets and socket buffers
51 */
52
53 /* strings for sleep message: */
54 char netio[] = "netio";
55 char netcon[] = "netcon";
56 char netcls[] = "netcls";
57
58 u_long sb_max = SB_MAX; /* patchable */
59
60 /*
61 * Procedures to manipulate state flags of socket
62 * and do appropriate wakeups. Normal sequence from the
63 * active (originating) side is that soisconnecting() is
64 * called during processing of connect() call,
65 * resulting in an eventual call to soisconnected() if/when the
66 * connection is established. When the connection is torn down
67 * soisdisconnecting() is called during processing of disconnect() call,
68 * and soisdisconnected() is called when the connection to the peer
69 * is totally severed. The semantics of these routines are such that
70 * connectionless protocols can call soisconnected() and soisdisconnected()
71 * only, bypassing the in-progress calls when setting up a ``connection''
72 * takes no time.
73 *
74 * From the passive side, a socket is created with
75 * two queues of sockets: so_q0 for connections in progress
76 * and so_q for connections already made and awaiting user acceptance.
77 * As a protocol is preparing incoming connections, it creates a socket
78 * structure queued on so_q0 by calling sonewconn(). When the connection
79 * is established, soisconnected() is called, and transfers the
80 * socket structure to so_q, making it available to accept().
81 *
82 * If a socket is closed with sockets on either
83 * so_q0 or so_q, these sockets are dropped.
84 *
85 * If higher level protocols are implemented in
86 * the kernel, the wakeups done here will sometimes
87 * cause software-interrupt process scheduling.
88 */
89
soisconnecting(so)90 soisconnecting(so)
91 register struct socket *so;
92 {
93
94 so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
95 so->so_state |= SS_ISCONNECTING;
96 }
97
soisconnected(so)98 soisconnected(so)
99 register struct socket *so;
100 {
101 register struct socket *head = so->so_head;
102
103 so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
104 so->so_state |= SS_ISCONNECTED;
105 if (head && soqremque(so, 0)) {
106 soqinsque(head, so, 1);
107 sorwakeup(head);
108 wakeup((caddr_t)&head->so_timeo);
109 } else {
110 wakeup((caddr_t)&so->so_timeo);
111 sorwakeup(so);
112 sowwakeup(so);
113 }
114 }
115
soisdisconnecting(so)116 soisdisconnecting(so)
117 register struct socket *so;
118 {
119
120 so->so_state &= ~SS_ISCONNECTING;
121 so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE);
122 wakeup((caddr_t)&so->so_timeo);
123 sowwakeup(so);
124 sorwakeup(so);
125 }
126
soisdisconnected(so)127 soisdisconnected(so)
128 register struct socket *so;
129 {
130
131 so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
132 so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE);
133 wakeup((caddr_t)&so->so_timeo);
134 sowwakeup(so);
135 sorwakeup(so);
136 }
137
138 /*
139 * When an attempt at a new connection is noted on a socket
140 * which accepts connections, sonewconn is called. If the
141 * connection is possible (subject to space constraints, etc.)
142 * then we allocate a new structure, propoerly linked into the
143 * data structure of the original socket, and return this.
144 * Connstatus may be 0, or SO_ISCONFIRMING, or SO_ISCONNECTED.
145 *
146 * Currently, sonewconn() is defined as sonewconn1() in socketvar.h
147 * to catch calls that are missing the (new) second parameter.
148 */
149 struct socket *
sonewconn1(head,connstatus)150 sonewconn1(head, connstatus)
151 register struct socket *head;
152 int connstatus;
153 {
154 register struct socket *so;
155 int soqueue = connstatus ? 1 : 0;
156
157 if (head->so_qlen + head->so_q0len > 3 * head->so_qlimit / 2)
158 return ((struct socket *)0);
159 MALLOC(so, struct socket *, sizeof(*so), M_SOCKET, M_DONTWAIT);
160 if (so == NULL)
161 return ((struct socket *)0);
162 (void) memset((caddr_t)so, 0, sizeof(*so));
163 so->so_type = head->so_type;
164 so->so_options = head->so_options &~ SO_ACCEPTCONN;
165 so->so_linger = head->so_linger;
166 so->so_state = head->so_state | SS_NOFDREF;
167 so->so_proto = head->so_proto;
168 so->so_timeo = head->so_timeo;
169 so->so_pgid = head->so_pgid;
170 (void) soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat);
171 soqinsque(head, so, soqueue);
172 if ((*so->so_proto->pr_usrreq)(so, PRU_ATTACH,
173 (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0)) {
174 (void) soqremque(so, soqueue);
175 (void) free((caddr_t)so, M_SOCKET);
176 return ((struct socket *)0);
177 }
178 if (connstatus) {
179 sorwakeup(head);
180 wakeup((caddr_t)&head->so_timeo);
181 so->so_state |= connstatus;
182 }
183 return (so);
184 }
185
soqinsque(head,so,q)186 soqinsque(head, so, q)
187 register struct socket *head, *so;
188 int q;
189 {
190
191 register struct socket **prev;
192 so->so_head = head;
193 if (q == 0) {
194 head->so_q0len++;
195 so->so_q0 = 0;
196 for (prev = &(head->so_q0); *prev; )
197 prev = &((*prev)->so_q0);
198 } else {
199 head->so_qlen++;
200 so->so_q = 0;
201 for (prev = &(head->so_q); *prev; )
202 prev = &((*prev)->so_q);
203 }
204 *prev = so;
205 }
206
soqremque(so,q)207 soqremque(so, q)
208 register struct socket *so;
209 int q;
210 {
211 register struct socket *head, *prev, *next;
212
213 head = so->so_head;
214 prev = head;
215 for (;;) {
216 next = q ? prev->so_q : prev->so_q0;
217 if (next == so)
218 break;
219 if (next == 0)
220 return (0);
221 prev = next;
222 }
223 if (q == 0) {
224 prev->so_q0 = next->so_q0;
225 head->so_q0len--;
226 } else {
227 prev->so_q = next->so_q;
228 head->so_qlen--;
229 }
230 next->so_q0 = next->so_q = 0;
231 next->so_head = 0;
232 return (1);
233 }
234
235 /*
236 * Socantsendmore indicates that no more data will be sent on the
237 * socket; it would normally be applied to a socket when the user
238 * informs the system that no more data is to be sent, by the protocol
239 * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data
240 * will be received, and will normally be applied to the socket by a
241 * protocol when it detects that the peer will send no more data.
242 * Data queued for reading in the socket may yet be read.
243 */
244
245 socantsendmore(so)
246 struct socket *so;
247 {
248
249 so->so_state |= SS_CANTSENDMORE;
250 sowwakeup(so);
251 }
252
253 socantrcvmore(so)
254 struct socket *so;
255 {
256
257 so->so_state |= SS_CANTRCVMORE;
258 sorwakeup(so);
259 }
260
261 /*
262 * Socket select/wakeup routines.
263 */
264
265 /*
266 * Queue a process for a select on a socket buffer.
267 */
268 sbselqueue(sb, cp)
269 struct sockbuf *sb;
270 struct proc *cp;
271 {
272 struct proc *p;
273
274 if (sb->sb_sel && (p = pfind(sb->sb_sel)) && p->p_wchan == (caddr_t)&selwait)
275 sb->sb_flags |= SB_COLL;
276 else {
277 sb->sb_sel = cp->p_pid;
278 sb->sb_flags |= SB_SEL;
279 }
280 }
281
282 /*
283 * Wait for data to arrive at/drain from a socket buffer.
284 */
285 sbwait(sb)
286 struct sockbuf *sb;
287 {
288
289 sb->sb_flags |= SB_WAIT;
290 return (tsleep((caddr_t)&sb->sb_cc,
291 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, netio,
292 sb->sb_timeo));
293 }
294
295 /*
296 * Lock a sockbuf already known to be locked;
297 * return any error returned from sleep (EINTR).
298 */
sb_lock(sb)299 sb_lock(sb)
300 register struct sockbuf *sb;
301 {
302 int error;
303
304 while (sb->sb_flags & SB_LOCK) {
305 sb->sb_flags |= SB_WANT;
306 if (error = tsleep((caddr_t)&sb->sb_flags,
307 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK|PCATCH,
308 netio, 0))
309 return (error);
310 }
311 sb->sb_flags |= SB_LOCK;
312 return (0);
313 }
314
315 /*
316 * Wakeup processes waiting on a socket buffer.
317 * Do asynchronous notification via SIGIO
318 * if the socket has the SS_ASYNC flag set.
319 */
320 void
sowakeup(struct socket * so,struct sockbuf * sb)321 sowakeup(struct socket *so, struct sockbuf *sb)
322 {
323
324 if (sb->sb_sel) {
325 selwakeup(sb->sb_sel, sb->sb_flags & SB_COLL);
326 sb->sb_sel = 0;
327 sb->sb_flags &= ~(SB_SEL|SB_COLL);
328 }
329
330 if (sb->sb_flags & SB_WAIT) {
331 sb->sb_flags &= ~SB_WAIT;
332 wakeup((caddr_t)&sb->sb_cc);
333 }
334
335 if (so->so_state & SS_ASYNC) {
336 #ifdef nope
337 struct proc *p;
338 struct pgrp *pgrp;
339 pid_t pgid = so->so_pgid;
340
341 if (pgid < 0 && (pgrp = pgfind(-pgid)) != 0)
342 pgsignal(pgrp, SIGIO, 0);
343 else if (pgid > 0 && (p = pfind(pgid)) != 0)
344 psignal(p, SIGIO);
345 #else
346 signalpid(so->so_pgid);
347 #endif
348 }
349 }
350
351 /*
352 * Socket buffer (struct sockbuf) utility routines.
353 *
354 * Each socket contains two socket buffers: one for sending data and
355 * one for receiving data. Each buffer contains a queue of mbufs,
356 * information about the number of mbufs and amount of data in the
357 * queue, and other fields allowing select() statements and notification
358 * on data availability to be implemented.
359 *
360 * Data stored in a socket buffer is maintained as a list of records.
361 * Each record is a list of mbufs chained together with the m_next
362 * field. Records are chained together with the m_nextpkt field. The upper
363 * level routine soreceive() expects the following conventions to be
364 * observed when placing information in the receive buffer:
365 *
366 * 1. If the protocol requires each message be preceded by the sender's
367 * name, then a record containing that name must be present before
368 * any associated data (mbuf's must be of type MT_SONAME).
369 * 2. If the protocol supports the exchange of ``access rights'' (really
370 * just additional data associated with the message), and there are
371 * ``rights'' to be received, then a record containing this data
372 * should be present (mbuf's must be of type MT_RIGHTS).
373 * 3. If a name or rights record exists, then it must be followed by
374 * a data record, perhaps of zero length.
375 *
376 * Before using a new socket structure it is first necessary to reserve
377 * buffer space to the socket, by calling sbreserve(). This should commit
378 * some of the available buffer space in the system buffer pool for the
379 * socket (currently, it does nothing but enforce limits). The space
380 * should be released by calling sbrelease() when the socket is destroyed.
381 */
382
soreserve(so,sndcc,rcvcc)383 soreserve(so, sndcc, rcvcc)
384 register struct socket *so;
385 u_long sndcc, rcvcc;
386 {
387
388 if (sbreserve(&so->so_snd, sndcc) == 0)
389 goto bad;
390 if (sbreserve(&so->so_rcv, rcvcc) == 0)
391 goto bad2;
392 if (so->so_rcv.sb_lowat == 0)
393 so->so_rcv.sb_lowat = 1;
394 if (so->so_snd.sb_lowat == 0)
395 so->so_snd.sb_lowat = MCLBYTES;
396 if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat)
397 so->so_snd.sb_lowat = so->so_snd.sb_hiwat;
398 return (0);
399 bad2:
400 sbrelease(&so->so_snd);
401 bad:
402 return (ENOBUFS);
403 }
404
405 /*
406 * Allot mbufs to a sockbuf.
407 * Attempt to scale mbmax so that mbcnt doesn't become limiting
408 * if buffering efficiency is near the normal case.
409 */
410 sbreserve(sb, cc)
411 struct sockbuf *sb;
412 u_long cc;
413 {
414
415 if (cc > sb_max * MCLBYTES / (MSIZE + MCLBYTES))
416 return (0);
417 sb->sb_hiwat = cc;
418 sb->sb_mbmax = min(cc * 2, sb_max);
419 if (sb->sb_lowat > sb->sb_hiwat)
420 sb->sb_lowat = sb->sb_hiwat;
421 return (1);
422 }
423
424 /*
425 * Free mbufs held by a socket, and reserved mbuf space.
426 */
427 sbrelease(sb)
428 struct sockbuf *sb;
429 {
430
431 sbflush(sb);
432 sb->sb_hiwat = sb->sb_mbmax = 0;
433 }
434
435 /*
436 * Routines to add and remove
437 * data from an mbuf queue.
438 *
439 * The routines sbappend() or sbappendrecord() are normally called to
440 * append new mbufs to a socket buffer, after checking that adequate
441 * space is available, comparing the function sbspace() with the amount
442 * of data to be added. sbappendrecord() differs from sbappend() in
443 * that data supplied is treated as the beginning of a new record.
444 * To place a sender's address, optional access rights, and data in a
445 * socket receive buffer, sbappendaddr() should be used. To place
446 * access rights and data in a socket receive buffer, sbappendrights()
447 * should be used. In either case, the new data begins a new record.
448 * Note that unlike sbappend() and sbappendrecord(), these routines check
449 * for the caller that there will be enough space to store the data.
450 * Each fails if there is not enough space, or if it cannot find mbufs
451 * to store additional information in.
452 *
453 * Reliable protocols may use the socket send buffer to hold data
454 * awaiting acknowledgement. Data is normally copied from a socket
455 * send buffer in a protocol with m_copy for output to a peer,
456 * and then removing the data from the socket buffer with sbdrop()
457 * or sbdroprecord() when the data is acknowledged by the peer.
458 */
459
460 /*
461 * Append mbuf chain m to the last record in the
462 * socket buffer sb. The additional space associated
463 * the mbuf chain is recorded in sb. Empty mbufs are
464 * discarded and mbufs are compacted where possible.
465 */
466 sbappend(sb, m)
467 struct sockbuf *sb;
468 struct mbuf *m;
469 {
470 register struct mbuf *n;
471
472 if (m == 0)
473 return;
474 if (n = sb->sb_mb) {
475 while (n->m_nextpkt)
476 n = n->m_nextpkt;
477 do {
478 if (n->m_flags & M_EOR) {
479 sbappendrecord(sb, m); /* XXXXXX!!!! */
480 return;
481 }
482 } while (n->m_next && (n = n->m_next));
483 }
484 sbcompress(sb, m, n);
485 }
486
487 #ifdef SOCKBUF_DEBUG
sbcheck(sb)488 sbcheck(sb)
489 register struct sockbuf *sb;
490 {
491 register struct mbuf *m;
492 register int len = 0, mbcnt = 0;
493
494 for (m = sb->sb_mb; m; m = m->m_next) {
495 len += m->m_len;
496 mbcnt += MSIZE;
497 if (m->m_flags & M_EXT)
498 mbcnt += m->m_ext.ext_size;
499 if (m->m_nextpkt)
500 panic("sbcheck nextpkt");
501 }
502 if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) {
503 printf("cc %d != %d || mbcnt %d != %d\n", len, sb->sb_cc,
504 mbcnt, sb->sb_mbcnt);
505 panic("sbcheck");
506 }
507 }
508 #endif
509
510 /*
511 * As above, except the mbuf chain
512 * begins a new record.
513 */
sbappendrecord(sb,m0)514 sbappendrecord(sb, m0)
515 register struct sockbuf *sb;
516 register struct mbuf *m0;
517 {
518 register struct mbuf *m;
519
520 if (m0 == 0)
521 return;
522 if (m = sb->sb_mb)
523 while (m->m_nextpkt)
524 m = m->m_nextpkt;
525 /*
526 * Put the first mbuf on the queue.
527 * Note this permits zero length records.
528 */
529 sballoc(sb, m0);
530 if (m)
531 m->m_nextpkt = m0;
532 else
533 sb->sb_mb = m0;
534 m = m0->m_next;
535 m0->m_next = 0;
536 if (m && (m0->m_flags & M_EOR)) {
537 m0->m_flags &= ~M_EOR;
538 m->m_flags |= M_EOR;
539 }
540 sbcompress(sb, m, m0);
541 }
542
543 /*
544 * As above except that OOB data
545 * is inserted at the beginning of the sockbuf,
546 * but after any other OOB data.
547 */
sbinsertoob(sb,m0)548 sbinsertoob(sb, m0)
549 register struct sockbuf *sb;
550 register struct mbuf *m0;
551 {
552 register struct mbuf *m;
553 register struct mbuf **mp;
554
555 if (m0 == 0)
556 return;
557 for (mp = &sb->sb_mb; m = *mp; mp = &((*mp)->m_nextpkt)) {
558 again:
559 switch (m->m_type) {
560
561 case MT_OOBDATA:
562 continue; /* WANT next train */
563
564 case MT_CONTROL:
565 if (m = m->m_next)
566 goto again; /* inspect THIS train further */
567 }
568 break;
569 }
570 /*
571 * Put the first mbuf on the queue.
572 * Note this permits zero length records.
573 */
574 sballoc(sb, m0);
575 m0->m_nextpkt = *mp;
576 *mp = m0;
577 m = m0->m_next;
578 m0->m_next = 0;
579 if (m && (m0->m_flags & M_EOR)) {
580 m0->m_flags &= ~M_EOR;
581 m->m_flags |= M_EOR;
582 }
583 sbcompress(sb, m, m0);
584 }
585
586 /*
587 * Append address and data, and optionally, control (ancillary) data
588 * to the receive queue of a socket. If present,
589 * m0 must include a packet header with total length.
590 * Returns 0 if no space in sockbuf or insufficient mbufs.
591 */
sbappendaddr(sb,asa,m0,control)592 sbappendaddr(sb, asa, m0, control)
593 register struct sockbuf *sb;
594 struct sockaddr *asa;
595 struct mbuf *m0, *control;
596 {
597 register struct mbuf *m, *n;
598 int space = asa->sa_len;
599
600 if (m0 && (m0->m_flags & M_PKTHDR) == 0)
601 panic("sbappendaddr");
602 if (m0)
603 space += m0->m_pkthdr.len;
604 for (n = control; n; n = n->m_next) {
605 space += n->m_len;
606 if (n->m_next == 0) /* keep pointer to last control buf */
607 break;
608 }
609 if (space > sbspace(sb))
610 return (0);
611 if (asa->sa_len > MLEN)
612 return (0);
613 MGET(m, M_DONTWAIT, MT_SONAME);
614 if (m == 0)
615 return (0);
616 m->m_len = asa->sa_len;
617 (void) memcpy(mtod(m, caddr_t), (caddr_t)asa, asa->sa_len);
618 if (n)
619 n->m_next = m0; /* concatenate data to control */
620 else
621 control = m0;
622 m->m_next = control;
623 for (n = m; n; n = n->m_next)
624 sballoc(sb, n);
625 if (n = sb->sb_mb) {
626 while (n->m_nextpkt)
627 n = n->m_nextpkt;
628 n->m_nextpkt = m;
629 } else
630 sb->sb_mb = m;
631 return (1);
632 }
633
634 sbappendcontrol(sb, m0, control)
635 struct sockbuf *sb;
636 struct mbuf *control, *m0;
637 {
638 register struct mbuf *m, *n;
639 int space = 0;
640
641 if (control == 0)
642 panic("sbappendcontrol");
643 for (m = control; ; m = m->m_next) {
644 space += m->m_len;
645 if (m->m_next == 0)
646 break;
647 }
648 n = m; /* save pointer to last control buffer */
649 for (m = m0; m; m = m->m_next)
650 space += m->m_len;
651 if (space > sbspace(sb))
652 return (0);
653 n->m_next = m0; /* concatenate data to control */
654 for (m = control; m; m = m->m_next)
655 sballoc(sb, m);
656 if (n = sb->sb_mb) {
657 while (n->m_nextpkt)
658 n = n->m_nextpkt;
659 n->m_nextpkt = control;
660 } else
661 sb->sb_mb = control;
662 return (1);
663 }
664
665 /*
666 * Compress mbuf chain m into the socket
667 * buffer sb following mbuf n. If n
668 * is null, the buffer is presumed empty.
669 */
sbcompress(sb,m,n)670 sbcompress(sb, m, n)
671 register struct sockbuf *sb;
672 register struct mbuf *m, *n;
673 {
674 register int eor = 0;
675 register struct mbuf *o;
676
677 while (m) {
678 eor |= m->m_flags & M_EOR;
679 if (m->m_len == 0 &&
680 (eor == 0 ||
681 (((o = m->m_next) || (o = n)) &&
682 o->m_type == m->m_type))) {
683 m = m_free(m);
684 continue;
685 }
686 if (n && (n->m_flags & (M_EXT | M_EOR)) == 0 &&
687 (n->m_data + n->m_len + m->m_len) < &n->m_dat[MLEN] &&
688 n->m_type == m->m_type) {
689 (void) memcpy(mtod(n, caddr_t) + n->m_len, mtod(m, caddr_t),
690 (unsigned)m->m_len);
691 n->m_len += m->m_len;
692 sb->sb_cc += m->m_len;
693 m = m_free(m);
694 continue;
695 }
696 if (n)
697 n->m_next = m;
698 else
699 sb->sb_mb = m;
700 sballoc(sb, m);
701 n = m;
702 m->m_flags &= ~M_EOR;
703 m = m->m_next;
704 n->m_next = 0;
705 }
706 if (eor) {
707 if (n)
708 n->m_flags |= eor;
709 else
710 printf("semi-panic: sbcompress\n");
711 }
712 }
713
714 /*
715 * Free all mbufs in a sockbuf.
716 * Check that all resources are reclaimed.
717 */
sbflush(sb)718 sbflush(sb)
719 register struct sockbuf *sb;
720 {
721
722 if (sb->sb_flags & SB_LOCK)
723 panic("sbflush");
724 while (sb->sb_mbcnt)
725 sbdrop(sb, (int)sb->sb_cc);
726 if (sb->sb_cc || sb->sb_mb)
727 panic("sbflush 2");
728 }
729
730 /*
731 * Drop data from (the front of) a sockbuf.
732 */
sbdrop(sb,len)733 sbdrop(sb, len)
734 register struct sockbuf *sb;
735 register int len;
736 {
737 register struct mbuf *m, *mn;
738 struct mbuf *next;
739
740 next = (m = sb->sb_mb) ? m->m_nextpkt : 0;
741 while (len > 0) {
742 if (m == 0) {
743 if (next == 0)
744 panic("sbdrop");
745 m = next;
746 next = m->m_nextpkt;
747 continue;
748 }
749 if (m->m_len > len) {
750 m->m_len -= len;
751 m->m_data += len;
752 sb->sb_cc -= len;
753 break;
754 }
755 len -= m->m_len;
756 sbfree(sb, m);
757 MFREE(m, mn);
758 m = mn;
759 }
760 while (m && m->m_len == 0) {
761 sbfree(sb, m);
762 MFREE(m, mn);
763 m = mn;
764 }
765 if (m) {
766 sb->sb_mb = m;
767 m->m_nextpkt = next;
768 } else
769 sb->sb_mb = next;
770 }
771
772 /*
773 * Drop a record off the front of a sockbuf
774 * and move the next record to the front.
775 */
sbdroprecord(sb)776 sbdroprecord(sb)
777 register struct sockbuf *sb;
778 {
779 register struct mbuf *m, *mn;
780
781 m = sb->sb_mb;
782 if (m) {
783 sb->sb_mb = m->m_nextpkt;
784 do {
785 sbfree(sb, m);
786 MFREE(m, mn);
787 } while (m = mn);
788 }
789 }
790