1 /* $NetBSD: uipc_socket2.c,v 1.81 2006/11/01 10:17:59 yamt Exp $ */
2
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 * @(#)uipc_socket2.c 8.2 (Berkeley) 2/14/95
32 */
33
34 #include <sys/cdefs.h>
35 __KERNEL_RCSID(0, "$NetBSD: uipc_socket2.c,v 1.81 2006/11/01 10:17:59 yamt Exp $");
36
37 #include "opt_mbuftrace.h"
38 #include "opt_sb_max.h"
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/proc.h>
43 #include <sys/file.h>
44 #include <sys/buf.h>
45 #include <sys/malloc.h>
46 #include <sys/mbuf.h>
47 #include <sys/protosw.h>
48 #include <sys/poll.h>
49 #include <sys/socket.h>
50 #include <sys/socketvar.h>
51 #include <sys/signalvar.h>
52 #include <sys/kauth.h>
53
54 /*
55 * Primitive routines for operating on sockets and socket buffers
56 */
57
58 /* strings for sleep message: */
59 const char netcon[] = "netcon";
60 const char netcls[] = "netcls";
61 const char netio[] = "netio";
62 const char netlck[] = "netlck";
63
64 u_long sb_max = SB_MAX; /* maximum socket buffer size */
65 static u_long sb_max_adj; /* adjusted sb_max */
66
67 /*
68 * Procedures to manipulate state flags of socket
69 * and do appropriate wakeups. Normal sequence from the
70 * active (originating) side is that soisconnecting() is
71 * called during processing of connect() call,
72 * resulting in an eventual call to soisconnected() if/when the
73 * connection is established. When the connection is torn down
74 * soisdisconnecting() is called during processing of disconnect() call,
75 * and soisdisconnected() is called when the connection to the peer
76 * is totally severed. The semantics of these routines are such that
77 * connectionless protocols can call soisconnected() and soisdisconnected()
78 * only, bypassing the in-progress calls when setting up a ``connection''
79 * takes no time.
80 *
81 * From the passive side, a socket is created with
82 * two queues of sockets: so_q0 for connections in progress
83 * and so_q for connections already made and awaiting user acceptance.
84 * As a protocol is preparing incoming connections, it creates a socket
85 * structure queued on so_q0 by calling sonewconn(). When the connection
86 * is established, soisconnected() is called, and transfers the
87 * socket structure to so_q, making it available to accept().
88 *
89 * If a socket is closed with sockets on either
90 * so_q0 or so_q, these sockets are dropped.
91 *
92 * If higher level protocols are implemented in
93 * the kernel, the wakeups done here will sometimes
94 * cause software-interrupt process scheduling.
95 */
96
97 void
98 soisconnecting(struct socket *so)
99 {
100
101 so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
102 so->so_state |= SS_ISCONNECTING;
103 }
104
105 void
106 soisconnected(struct socket *so)
107 {
108 struct socket *head;
109
110 head = so->so_head;
111 so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
112 so->so_state |= SS_ISCONNECTED;
113 if (head && soqremque(so, 0)) {
114 soqinsque(head, so, 1);
115 sorwakeup(head);
116 wakeup((caddr_t)&head->so_timeo);
117 } else {
118 wakeup((caddr_t)&so->so_timeo);
119 sorwakeup(so);
120 sowwakeup(so);
121 }
122 }
123
124 void
125 soisdisconnecting(struct socket *so)
126 {
127
128 so->so_state &= ~SS_ISCONNECTING;
129 so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE);
130 wakeup((caddr_t)&so->so_timeo);
131 sowwakeup(so);
132 sorwakeup(so);
133 }
134
135 void
136 soisdisconnected(struct socket *so)
137 {
138
139 so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
140 so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE|SS_ISDISCONNECTED);
141 wakeup((caddr_t)&so->so_timeo);
142 sowwakeup(so);
143 sorwakeup(so);
144 }
145
146 /*
147 * When an attempt at a new connection is noted on a socket
148 * which accepts connections, sonewconn is called. If the
149 * connection is possible (subject to space constraints, etc.)
150 * then we allocate a new structure, propoerly linked into the
151 * data structure of the original socket, and return this.
152 * Connstatus may be 0, SS_ISCONFIRMING, or SS_ISCONNECTED.
153 */
154 struct socket *
155 sonewconn(struct socket *head, int connstatus)
156 {
157 struct socket *so;
158 int soqueue;
159
160 soqueue = connstatus ? 1 : 0;
161 if (head->so_qlen + head->so_q0len > 3 * head->so_qlimit / 2)
162 return ((struct socket *)0);
163 so = pool_get(&socket_pool, PR_NOWAIT);
164 if (so == NULL)
165 return (NULL);
166 memset((caddr_t)so, 0, sizeof(*so));
167 so->so_type = head->so_type;
168 so->so_options = head->so_options &~ SO_ACCEPTCONN;
169 so->so_linger = head->so_linger;
170 so->so_state = head->so_state | SS_NOFDREF;
171 so->so_proto = head->so_proto;
172 so->so_timeo = head->so_timeo;
173 so->so_pgid = head->so_pgid;
174 so->so_send = head->so_send;
175 so->so_receive = head->so_receive;
176 so->so_uidinfo = head->so_uidinfo;
177 #ifdef MBUFTRACE
178 so->so_mowner = head->so_mowner;
179 so->so_rcv.sb_mowner = head->so_rcv.sb_mowner;
180 so->so_snd.sb_mowner = head->so_snd.sb_mowner;
181 #endif
182 (void) soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat);
183 soqinsque(head, so, soqueue);
184 if ((*so->so_proto->pr_usrreq)(so, PRU_ATTACH,
185 (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0,
186 (struct lwp *)0)) {
187 (void) soqremque(so, soqueue);
188 pool_put(&socket_pool, so);
189 return (NULL);
190 }
191 if (connstatus) {
192 sorwakeup(head);
193 wakeup((caddr_t)&head->so_timeo);
194 so->so_state |= connstatus;
195 }
196 return (so);
197 }
198
199 void
200 soqinsque(struct socket *head, struct socket *so, int q)
201 {
202
203 #ifdef DIAGNOSTIC
204 if (so->so_onq != NULL)
205 panic("soqinsque");
206 #endif
207
208 so->so_head = head;
209 if (q == 0) {
210 head->so_q0len++;
211 so->so_onq = &head->so_q0;
212 } else {
213 head->so_qlen++;
214 so->so_onq = &head->so_q;
215 }
216 TAILQ_INSERT_TAIL(so->so_onq, so, so_qe);
217 }
218
219 int
220 soqremque(struct socket *so, int q)
221 {
222 struct socket *head;
223
224 head = so->so_head;
225 if (q == 0) {
226 if (so->so_onq != &head->so_q0)
227 return (0);
228 head->so_q0len--;
229 } else {
230 if (so->so_onq != &head->so_q)
231 return (0);
232 head->so_qlen--;
233 }
234 TAILQ_REMOVE(so->so_onq, so, so_qe);
235 so->so_onq = NULL;
236 so->so_head = NULL;
237 return (1);
238 }
239
240 /*
241 * Socantsendmore indicates that no more data will be sent on the
242 * socket; it would normally be applied to a socket when the user
243 * informs the system that no more data is to be sent, by the protocol
244 * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data
245 * will be received, and will normally be applied to the socket by a
246 * protocol when it detects that the peer will send no more data.
247 * Data queued for reading in the socket may yet be read.
248 */
249
250 void
251 socantsendmore(struct socket *so)
252 {
253
254 so->so_state |= SS_CANTSENDMORE;
255 sowwakeup(so);
256 }
257
258 void
259 socantrcvmore(struct socket *so)
260 {
261
262 so->so_state |= SS_CANTRCVMORE;
263 sorwakeup(so);
264 }
265
266 /*
267 * Wait for data to arrive at/drain from a socket buffer.
268 */
269 int
270 sbwait(struct sockbuf *sb)
271 {
272
273 sb->sb_flags |= SB_WAIT;
274 return (tsleep((caddr_t)&sb->sb_cc,
275 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, netio,
276 sb->sb_timeo));
277 }
278
279 /*
280 * Lock a sockbuf already known to be locked;
281 * return any error returned from sleep (EINTR).
282 */
283 int
284 sb_lock(struct sockbuf *sb)
285 {
286 int error;
287
288 while (sb->sb_flags & SB_LOCK) {
289 sb->sb_flags |= SB_WANT;
290 error = tsleep((caddr_t)&sb->sb_flags,
291 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK|PCATCH,
292 netlck, 0);
293 if (error)
294 return (error);
295 }
296 sb->sb_flags |= SB_LOCK;
297 return (0);
298 }
299
300 /*
301 * Wakeup processes waiting on a socket buffer.
302 * Do asynchronous notification via SIGIO
303 * if the socket buffer has the SB_ASYNC flag set.
304 */
305 void
306 sowakeup(struct socket *so, struct sockbuf *sb, int code)
307 {
308 selnotify(&sb->sb_sel, 0);
309 sb->sb_flags &= ~SB_SEL;
310 if (sb->sb_flags & SB_WAIT) {
311 sb->sb_flags &= ~SB_WAIT;
312 wakeup((caddr_t)&sb->sb_cc);
313 }
314 if (sb->sb_flags & SB_ASYNC) {
315 int band;
316 if (code == POLL_IN)
317 band = POLLIN|POLLRDNORM;
318 else
319 band = POLLOUT|POLLWRNORM;
320 fownsignal(so->so_pgid, SIGIO, code, band, so);
321 }
322 if (sb->sb_flags & SB_UPCALL)
323 (*so->so_upcall)(so, so->so_upcallarg, M_DONTWAIT);
324 }
325
326 /*
327 * Socket buffer (struct sockbuf) utility routines.
328 *
329 * Each socket contains two socket buffers: one for sending data and
330 * one for receiving data. Each buffer contains a queue of mbufs,
331 * information about the number of mbufs and amount of data in the
332 * queue, and other fields allowing poll() statements and notification
333 * on data availability to be implemented.
334 *
335 * Data stored in a socket buffer is maintained as a list of records.
336 * Each record is a list of mbufs chained together with the m_next
337 * field. Records are chained together with the m_nextpkt field. The upper
338 * level routine soreceive() expects the following conventions to be
339 * observed when placing information in the receive buffer:
340 *
341 * 1. If the protocol requires each message be preceded by the sender's
342 * name, then a record containing that name must be present before
343 * any associated data (mbuf's must be of type MT_SONAME).
344 * 2. If the protocol supports the exchange of ``access rights'' (really
345 * just additional data associated with the message), and there are
346 * ``rights'' to be received, then a record containing this data
347 * should be present (mbuf's must be of type MT_CONTROL).
348 * 3. If a name or rights record exists, then it must be followed by
349 * a data record, perhaps of zero length.
350 *
351 * Before using a new socket structure it is first necessary to reserve
352 * buffer space to the socket, by calling sbreserve(). This should commit
353 * some of the available buffer space in the system buffer pool for the
354 * socket (currently, it does nothing but enforce limits). The space
355 * should be released by calling sbrelease() when the socket is destroyed.
356 */
357
358 int
359 sb_max_set(u_long new_sbmax)
360 {
361 int s;
362
363 if (new_sbmax < (16 * 1024))
364 return (EINVAL);
365
366 s = splsoftnet();
367 sb_max = new_sbmax;
368 sb_max_adj = (u_quad_t)new_sbmax * MCLBYTES / (MSIZE + MCLBYTES);
369 splx(s);
370
371 return (0);
372 }
373
374 int
375 soreserve(struct socket *so, u_long sndcc, u_long rcvcc)
376 {
377 /*
378 * there's at least one application (a configure script of screen)
379 * which expects a fifo is writable even if it has "some" bytes
380 * in its buffer.
381 * so we want to make sure (hiwat - lowat) >= (some bytes).
382 *
383 * PIPE_BUF here is an arbitrary value chosen as (some bytes) above.
384 * we expect it's large enough for such applications.
385 */
386 u_long lowat = MAX(sock_loan_thresh, MCLBYTES);
387 u_long hiwat = lowat + PIPE_BUF;
388
389 if (sndcc < hiwat)
390 sndcc = hiwat;
391 if (sbreserve(&so->so_snd, sndcc, so) == 0)
392 goto bad;
393 if (sbreserve(&so->so_rcv, rcvcc, so) == 0)
394 goto bad2;
395 if (so->so_rcv.sb_lowat == 0)
396 so->so_rcv.sb_lowat = 1;
397 if (so->so_snd.sb_lowat == 0)
398 so->so_snd.sb_lowat = lowat;
399 if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat)
400 so->so_snd.sb_lowat = so->so_snd.sb_hiwat;
401 return (0);
402 bad2:
403 sbrelease(&so->so_snd, so);
404 bad:
405 return (ENOBUFS);
406 }
407
408 /*
409 * Allot mbufs to a sockbuf.
410 * Attempt to scale mbmax so that mbcnt doesn't become limiting
411 * if buffering efficiency is near the normal case.
412 */
413 int
414 sbreserve(struct sockbuf *sb, u_long cc, struct socket *so)
415 {
416 struct lwp *l = curlwp; /* XXX */
417 rlim_t maxcc;
418 struct uidinfo *uidinfo;
419
420 KDASSERT(sb_max_adj != 0);
421 if (cc == 0 || cc > sb_max_adj)
422 return (0);
423 if (so) {
424 if (l && kauth_cred_geteuid(l->l_cred) == so->so_uidinfo->ui_uid)
425 maxcc = l->l_proc->p_rlimit[RLIMIT_SBSIZE].rlim_cur;
426 else
427 maxcc = RLIM_INFINITY;
428 uidinfo = so->so_uidinfo;
429 } else {
430 uidinfo = uid_find(0); /* XXX: nothing better */
431 maxcc = RLIM_INFINITY;
432 }
433 if (!chgsbsize(uidinfo, &sb->sb_hiwat, cc, maxcc))
434 return 0;
435 sb->sb_mbmax = min(cc * 2, sb_max);
436 if (sb->sb_lowat > sb->sb_hiwat)
437 sb->sb_lowat = sb->sb_hiwat;
438 return (1);
439 }
440
441 /*
442 * Free mbufs held by a socket, and reserved mbuf space.
443 */
444 void
445 sbrelease(struct sockbuf *sb, struct socket *so)
446 {
447
448 sbflush(sb);
449 (void)chgsbsize(so->so_uidinfo, &sb->sb_hiwat, 0,
450 RLIM_INFINITY);
451 sb->sb_mbmax = 0;
452 }
453
454 /*
455 * Routines to add and remove
456 * data from an mbuf queue.
457 *
458 * The routines sbappend() or sbappendrecord() are normally called to
459 * append new mbufs to a socket buffer, after checking that adequate
460 * space is available, comparing the function sbspace() with the amount
461 * of data to be added. sbappendrecord() differs from sbappend() in
462 * that data supplied is treated as the beginning of a new record.
463 * To place a sender's address, optional access rights, and data in a
464 * socket receive buffer, sbappendaddr() should be used. To place
465 * access rights and data in a socket receive buffer, sbappendrights()
466 * should be used. In either case, the new data begins a new record.
467 * Note that unlike sbappend() and sbappendrecord(), these routines check
468 * for the caller that there will be enough space to store the data.
469 * Each fails if there is not enough space, or if it cannot find mbufs
470 * to store additional information in.
471 *
472 * Reliable protocols may use the socket send buffer to hold data
473 * awaiting acknowledgement. Data is normally copied from a socket
474 * send buffer in a protocol with m_copy for output to a peer,
475 * and then removing the data from the socket buffer with sbdrop()
476 * or sbdroprecord() when the data is acknowledged by the peer.
477 */
478
479 #ifdef SOCKBUF_DEBUG
480 void
481 sblastrecordchk(struct sockbuf *sb, const char *where)
482 {
483 struct mbuf *m = sb->sb_mb;
484
485 while (m && m->m_nextpkt)
486 m = m->m_nextpkt;
487
488 if (m != sb->sb_lastrecord) {
489 printf("sblastrecordchk: sb_mb %p sb_lastrecord %p last %p\n",
490 sb->sb_mb, sb->sb_lastrecord, m);
491 printf("packet chain:\n");
492 for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt)
493 printf("\t%p\n", m);
494 panic("sblastrecordchk from %s", where);
495 }
496 }
497
498 void
499 sblastmbufchk(struct sockbuf *sb, const char *where)
500 {
501 struct mbuf *m = sb->sb_mb;
502 struct mbuf *n;
503
504 while (m && m->m_nextpkt)
505 m = m->m_nextpkt;
506
507 while (m && m->m_next)
508 m = m->m_next;
509
510 if (m != sb->sb_mbtail) {
511 printf("sblastmbufchk: sb_mb %p sb_mbtail %p last %p\n",
512 sb->sb_mb, sb->sb_mbtail, m);
513 printf("packet tree:\n");
514 for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt) {
515 printf("\t");
516 for (n = m; n != NULL; n = n->m_next)
517 printf("%p ", n);
518 printf("\n");
519 }
520 panic("sblastmbufchk from %s", where);
521 }
522 }
523 #endif /* SOCKBUF_DEBUG */
524
525 /*
526 * Link a chain of records onto a socket buffer
527 */
528 #define SBLINKRECORDCHAIN(sb, m0, mlast) \
529 do { \
530 if ((sb)->sb_lastrecord != NULL) \
531 (sb)->sb_lastrecord->m_nextpkt = (m0); \
532 else \
533 (sb)->sb_mb = (m0); \
534 (sb)->sb_lastrecord = (mlast); \
535 } while (/*CONSTCOND*/0)
536
537
538 #define SBLINKRECORD(sb, m0) \
539 SBLINKRECORDCHAIN(sb, m0, m0)
540
541 /*
542 * Append mbuf chain m to the last record in the
543 * socket buffer sb. The additional space associated
544 * the mbuf chain is recorded in sb. Empty mbufs are
545 * discarded and mbufs are compacted where possible.
546 */
547 void
548 sbappend(struct sockbuf *sb, struct mbuf *m)
549 {
550 struct mbuf *n;
551
552 if (m == 0)
553 return;
554
555 #ifdef MBUFTRACE
556 m_claimm(m, sb->sb_mowner);
557 #endif
558
559 SBLASTRECORDCHK(sb, "sbappend 1");
560
561 if ((n = sb->sb_lastrecord) != NULL) {
562 /*
563 * XXX Would like to simply use sb_mbtail here, but
564 * XXX I need to verify that I won't miss an EOR that
565 * XXX way.
566 */
567 do {
568 if (n->m_flags & M_EOR) {
569 sbappendrecord(sb, m); /* XXXXXX!!!! */
570 return;
571 }
572 } while (n->m_next && (n = n->m_next));
573 } else {
574 /*
575 * If this is the first record in the socket buffer, it's
576 * also the last record.
577 */
578 sb->sb_lastrecord = m;
579 }
580 sbcompress(sb, m, n);
581 SBLASTRECORDCHK(sb, "sbappend 2");
582 }
583
584 /*
585 * This version of sbappend() should only be used when the caller
586 * absolutely knows that there will never be more than one record
587 * in the socket buffer, that is, a stream protocol (such as TCP).
588 */
589 void
590 sbappendstream(struct sockbuf *sb, struct mbuf *m)
591 {
592
593 KDASSERT(m->m_nextpkt == NULL);
594 KASSERT(sb->sb_mb == sb->sb_lastrecord);
595
596 SBLASTMBUFCHK(sb, __func__);
597
598 #ifdef MBUFTRACE
599 m_claimm(m, sb->sb_mowner);
600 #endif
601
602 sbcompress(sb, m, sb->sb_mbtail);
603
604 sb->sb_lastrecord = sb->sb_mb;
605 SBLASTRECORDCHK(sb, __func__);
606 }
607
608 #ifdef SOCKBUF_DEBUG
609 void
610 sbcheck(struct sockbuf *sb)
611 {
612 struct mbuf *m;
613 u_long len, mbcnt;
614
615 len = 0;
616 mbcnt = 0;
617 for (m = sb->sb_mb; m; m = m->m_next) {
618 len += m->m_len;
619 mbcnt += MSIZE;
620 if (m->m_flags & M_EXT)
621 mbcnt += m->m_ext.ext_size;
622 if (m->m_nextpkt)
623 panic("sbcheck nextpkt");
624 }
625 if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) {
626 printf("cc %lu != %lu || mbcnt %lu != %lu\n", len, sb->sb_cc,
627 mbcnt, sb->sb_mbcnt);
628 panic("sbcheck");
629 }
630 }
631 #endif
632
633 /*
634 * As above, except the mbuf chain
635 * begins a new record.
636 */
637 void
638 sbappendrecord(struct sockbuf *sb, struct mbuf *m0)
639 {
640 struct mbuf *m;
641
642 if (m0 == 0)
643 return;
644
645 #ifdef MBUFTRACE
646 m_claimm(m0, sb->sb_mowner);
647 #endif
648 /*
649 * Put the first mbuf on the queue.
650 * Note this permits zero length records.
651 */
652 sballoc(sb, m0);
653 SBLASTRECORDCHK(sb, "sbappendrecord 1");
654 SBLINKRECORD(sb, m0);
655 m = m0->m_next;
656 m0->m_next = 0;
657 if (m && (m0->m_flags & M_EOR)) {
658 m0->m_flags &= ~M_EOR;
659 m->m_flags |= M_EOR;
660 }
661 sbcompress(sb, m, m0);
662 SBLASTRECORDCHK(sb, "sbappendrecord 2");
663 }
664
665 /*
666 * As above except that OOB data
667 * is inserted at the beginning of the sockbuf,
668 * but after any other OOB data.
669 */
670 void
671 sbinsertoob(struct sockbuf *sb, struct mbuf *m0)
672 {
673 struct mbuf *m, **mp;
674
675 if (m0 == 0)
676 return;
677
678 SBLASTRECORDCHK(sb, "sbinsertoob 1");
679
680 for (mp = &sb->sb_mb; (m = *mp) != NULL; mp = &((*mp)->m_nextpkt)) {
681 again:
682 switch (m->m_type) {
683
684 case MT_OOBDATA:
685 continue; /* WANT next train */
686
687 case MT_CONTROL:
688 if ((m = m->m_next) != NULL)
689 goto again; /* inspect THIS train further */
690 }
691 break;
692 }
693 /*
694 * Put the first mbuf on the queue.
695 * Note this permits zero length records.
696 */
697 sballoc(sb, m0);
698 m0->m_nextpkt = *mp;
699 if (*mp == NULL) {
700 /* m0 is actually the new tail */
701 sb->sb_lastrecord = m0;
702 }
703 *mp = m0;
704 m = m0->m_next;
705 m0->m_next = 0;
706 if (m && (m0->m_flags & M_EOR)) {
707 m0->m_flags &= ~M_EOR;
708 m->m_flags |= M_EOR;
709 }
710 sbcompress(sb, m, m0);
711 SBLASTRECORDCHK(sb, "sbinsertoob 2");
712 }
713
714 /*
715 * Append address and data, and optionally, control (ancillary) data
716 * to the receive queue of a socket. If present,
717 * m0 must include a packet header with total length.
718 * Returns 0 if no space in sockbuf or insufficient mbufs.
719 */
720 int
721 sbappendaddr(struct sockbuf *sb, const struct sockaddr *asa, struct mbuf *m0,
722 struct mbuf *control)
723 {
724 struct mbuf *m, *n, *nlast;
725 int space, len;
726
727 space = asa->sa_len;
728
729 if (m0 != NULL) {
730 if ((m0->m_flags & M_PKTHDR) == 0)
731 panic("sbappendaddr");
732 space += m0->m_pkthdr.len;
733 #ifdef MBUFTRACE
734 m_claimm(m0, sb->sb_mowner);
735 #endif
736 }
737 for (n = control; n; n = n->m_next) {
738 space += n->m_len;
739 MCLAIM(n, sb->sb_mowner);
740 if (n->m_next == 0) /* keep pointer to last control buf */
741 break;
742 }
743 if (space > sbspace(sb))
744 return (0);
745 MGET(m, M_DONTWAIT, MT_SONAME);
746 if (m == 0)
747 return (0);
748 MCLAIM(m, sb->sb_mowner);
749 /*
750 * XXX avoid 'comparison always true' warning which isn't easily
751 * avoided.
752 */
753 len = asa->sa_len;
754 if (len > MLEN) {
755 MEXTMALLOC(m, asa->sa_len, M_NOWAIT);
756 if ((m->m_flags & M_EXT) == 0) {
757 m_free(m);
758 return (0);
759 }
760 }
761 m->m_len = asa->sa_len;
762 memcpy(mtod(m, caddr_t), asa, asa->sa_len);
763 if (n)
764 n->m_next = m0; /* concatenate data to control */
765 else
766 control = m0;
767 m->m_next = control;
768
769 SBLASTRECORDCHK(sb, "sbappendaddr 1");
770
771 for (n = m; n->m_next != NULL; n = n->m_next)
772 sballoc(sb, n);
773 sballoc(sb, n);
774 nlast = n;
775 SBLINKRECORD(sb, m);
776
777 sb->sb_mbtail = nlast;
778 SBLASTMBUFCHK(sb, "sbappendaddr");
779
780 SBLASTRECORDCHK(sb, "sbappendaddr 2");
781
782 return (1);
783 }
784
785 /*
786 * Helper for sbappendchainaddr: prepend a struct sockaddr* to
787 * an mbuf chain.
788 */
789 static inline struct mbuf *
790 m_prepend_sockaddr(struct sockbuf *sb, struct mbuf *m0,
791 const struct sockaddr *asa)
792 {
793 struct mbuf *m;
794 const int salen = asa->sa_len;
795
796 /* only the first in each chain need be a pkthdr */
797 MGETHDR(m, M_DONTWAIT, MT_SONAME);
798 if (m == 0)
799 return (0);
800 MCLAIM(m, sb->sb_mowner);
801 #ifdef notyet
802 if (salen > MHLEN) {
803 MEXTMALLOC(m, salen, M_NOWAIT);
804 if ((m->m_flags & M_EXT) == 0) {
805 m_free(m);
806 return (0);
807 }
808 }
809 #else
810 KASSERT(salen <= MHLEN);
811 #endif
812 m->m_len = salen;
813 memcpy(mtod(m, caddr_t), asa, salen);
814 m->m_next = m0;
815 m->m_pkthdr.len = salen + m0->m_pkthdr.len;
816
817 return m;
818 }
819
820 int
821 sbappendaddrchain(struct sockbuf *sb, const struct sockaddr *asa,
822 struct mbuf *m0, int sbprio)
823 {
824 int space;
825 struct mbuf *m, *n, *n0, *nlast;
826 int error;
827
828 /*
829 * XXX sbprio reserved for encoding priority of this* request:
830 * SB_PRIO_NONE --> honour normal sb limits
831 * SB_PRIO_ONESHOT_OVERFLOW --> if socket has any space,
832 * take whole chain. Intended for large requests
833 * that should be delivered atomically (all, or none).
834 * SB_PRIO_OVERDRAFT -- allow a small (2*MLEN) overflow
835 * over normal socket limits, for messages indicating
836 * buffer overflow in earlier normal/lower-priority messages
837 * SB_PRIO_BESTEFFORT --> ignore limits entirely.
838 * Intended for kernel-generated messages only.
839 * Up to generator to avoid total mbuf resource exhaustion.
840 */
841 (void)sbprio;
842
843 if (m0 && (m0->m_flags & M_PKTHDR) == 0)
844 panic("sbappendaddrchain");
845
846 space = sbspace(sb);
847
848 #ifdef notyet
849 /*
850 * Enforce SB_PRIO_* limits as described above.
851 */
852 #endif
853
854 n0 = NULL;
855 nlast = NULL;
856 for (m = m0; m; m = m->m_nextpkt) {
857 struct mbuf *np;
858
859 #ifdef MBUFTRACE
860 m_claimm(m, sb->sb_mowner);
861 #endif
862
863 /* Prepend sockaddr to this record (m) of input chain m0 */
864 n = m_prepend_sockaddr(sb, m, asa);
865 if (n == NULL) {
866 error = ENOBUFS;
867 goto bad;
868 }
869
870 /* Append record (asa+m) to end of new chain n0 */
871 if (n0 == NULL) {
872 n0 = n;
873 } else {
874 nlast->m_nextpkt = n;
875 }
876 /* Keep track of last record on new chain */
877 nlast = n;
878
879 for (np = n; np; np = np->m_next)
880 sballoc(sb, np);
881 }
882
883 SBLASTRECORDCHK(sb, "sbappendaddrchain 1");
884
885 /* Drop the entire chain of (asa+m) records onto the socket */
886 SBLINKRECORDCHAIN(sb, n0, nlast);
887
888 SBLASTRECORDCHK(sb, "sbappendaddrchain 2");
889
890 for (m = nlast; m->m_next; m = m->m_next)
891 ;
892 sb->sb_mbtail = m;
893 SBLASTMBUFCHK(sb, "sbappendaddrchain");
894
895 return (1);
896
897 bad:
898 /*
899 * On error, free the prepended addreseses. For consistency
900 * with sbappendaddr(), leave it to our caller to free
901 * the input record chain passed to us as m0.
902 */
903 while ((n = n0) != NULL) {
904 struct mbuf *np;
905
906 /* Undo the sballoc() of this record */
907 for (np = n; np; np = np->m_next)
908 sbfree(sb, np);
909
910 n0 = n->m_nextpkt; /* iterate at next prepended address */
911 MFREE(n, np); /* free prepended address (not data) */
912 }
913 return 0;
914 }
915
916
917 int
918 sbappendcontrol(struct sockbuf *sb, struct mbuf *m0, struct mbuf *control)
919 {
920 struct mbuf *m, *mlast, *n;
921 int space;
922
923 space = 0;
924 if (control == 0)
925 panic("sbappendcontrol");
926 for (m = control; ; m = m->m_next) {
927 space += m->m_len;
928 MCLAIM(m, sb->sb_mowner);
929 if (m->m_next == 0)
930 break;
931 }
932 n = m; /* save pointer to last control buffer */
933 for (m = m0; m; m = m->m_next) {
934 MCLAIM(m, sb->sb_mowner);
935 space += m->m_len;
936 }
937 if (space > sbspace(sb))
938 return (0);
939 n->m_next = m0; /* concatenate data to control */
940
941 SBLASTRECORDCHK(sb, "sbappendcontrol 1");
942
943 for (m = control; m->m_next != NULL; m = m->m_next)
944 sballoc(sb, m);
945 sballoc(sb, m);
946 mlast = m;
947 SBLINKRECORD(sb, control);
948
949 sb->sb_mbtail = mlast;
950 SBLASTMBUFCHK(sb, "sbappendcontrol");
951
952 SBLASTRECORDCHK(sb, "sbappendcontrol 2");
953
954 return (1);
955 }
956
957 /*
958 * Compress mbuf chain m into the socket
959 * buffer sb following mbuf n. If n
960 * is null, the buffer is presumed empty.
961 */
962 void
963 sbcompress(struct sockbuf *sb, struct mbuf *m, struct mbuf *n)
964 {
965 int eor;
966 struct mbuf *o;
967
968 eor = 0;
969 while (m) {
970 eor |= m->m_flags & M_EOR;
971 if (m->m_len == 0 &&
972 (eor == 0 ||
973 (((o = m->m_next) || (o = n)) &&
974 o->m_type == m->m_type))) {
975 if (sb->sb_lastrecord == m)
976 sb->sb_lastrecord = m->m_next;
977 m = m_free(m);
978 continue;
979 }
980 if (n && (n->m_flags & M_EOR) == 0 &&
981 /* M_TRAILINGSPACE() checks buffer writeability */
982 m->m_len <= MCLBYTES / 4 && /* XXX Don't copy too much */
983 m->m_len <= M_TRAILINGSPACE(n) &&
984 n->m_type == m->m_type) {
985 memcpy(mtod(n, caddr_t) + n->m_len, mtod(m, caddr_t),
986 (unsigned)m->m_len);
987 n->m_len += m->m_len;
988 sb->sb_cc += m->m_len;
989 m = m_free(m);
990 continue;
991 }
992 if (n)
993 n->m_next = m;
994 else
995 sb->sb_mb = m;
996 sb->sb_mbtail = m;
997 sballoc(sb, m);
998 n = m;
999 m->m_flags &= ~M_EOR;
1000 m = m->m_next;
1001 n->m_next = 0;
1002 }
1003 if (eor) {
1004 if (n)
1005 n->m_flags |= eor;
1006 else
1007 printf("semi-panic: sbcompress\n");
1008 }
1009 SBLASTMBUFCHK(sb, __func__);
1010 }
1011
1012 /*
1013 * Free all mbufs in a sockbuf.
1014 * Check that all resources are reclaimed.
1015 */
1016 void
1017 sbflush(struct sockbuf *sb)
1018 {
1019
1020 KASSERT((sb->sb_flags & SB_LOCK) == 0);
1021
1022 while (sb->sb_mbcnt)
1023 sbdrop(sb, (int)sb->sb_cc);
1024
1025 KASSERT(sb->sb_cc == 0);
1026 KASSERT(sb->sb_mb == NULL);
1027 KASSERT(sb->sb_mbtail == NULL);
1028 KASSERT(sb->sb_lastrecord == NULL);
1029 }
1030
1031 /*
1032 * Drop data from (the front of) a sockbuf.
1033 */
1034 void
1035 sbdrop(struct sockbuf *sb, int len)
1036 {
1037 struct mbuf *m, *mn, *next;
1038
1039 next = (m = sb->sb_mb) ? m->m_nextpkt : 0;
1040 while (len > 0) {
1041 if (m == 0) {
1042 if (next == 0)
1043 panic("sbdrop");
1044 m = next;
1045 next = m->m_nextpkt;
1046 continue;
1047 }
1048 if (m->m_len > len) {
1049 m->m_len -= len;
1050 m->m_data += len;
1051 sb->sb_cc -= len;
1052 break;
1053 }
1054 len -= m->m_len;
1055 sbfree(sb, m);
1056 MFREE(m, mn);
1057 m = mn;
1058 }
1059 while (m && m->m_len == 0) {
1060 sbfree(sb, m);
1061 MFREE(m, mn);
1062 m = mn;
1063 }
1064 if (m) {
1065 sb->sb_mb = m;
1066 m->m_nextpkt = next;
1067 } else
1068 sb->sb_mb = next;
1069 /*
1070 * First part is an inline SB_EMPTY_FIXUP(). Second part
1071 * makes sure sb_lastrecord is up-to-date if we dropped
1072 * part of the last record.
1073 */
1074 m = sb->sb_mb;
1075 if (m == NULL) {
1076 sb->sb_mbtail = NULL;
1077 sb->sb_lastrecord = NULL;
1078 } else if (m->m_nextpkt == NULL)
1079 sb->sb_lastrecord = m;
1080 }
1081
1082 /*
1083 * Drop a record off the front of a sockbuf
1084 * and move the next record to the front.
1085 */
1086 void
1087 sbdroprecord(struct sockbuf *sb)
1088 {
1089 struct mbuf *m, *mn;
1090
1091 m = sb->sb_mb;
1092 if (m) {
1093 sb->sb_mb = m->m_nextpkt;
1094 do {
1095 sbfree(sb, m);
1096 MFREE(m, mn);
1097 } while ((m = mn) != NULL);
1098 }
1099 SB_EMPTY_FIXUP(sb);
1100 }
1101
1102 /*
1103 * Create a "control" mbuf containing the specified data
1104 * with the specified type for presentation on a socket buffer.
1105 */
1106 struct mbuf *
1107 sbcreatecontrol(caddr_t p, int size, int type, int level)
1108 {
1109 struct cmsghdr *cp;
1110 struct mbuf *m;
1111
1112 if (CMSG_SPACE(size) > MCLBYTES) {
1113 printf("sbcreatecontrol: message too large %d\n", size);
1114 return NULL;
1115 }
1116
1117 if ((m = m_get(M_DONTWAIT, MT_CONTROL)) == NULL)
1118 return ((struct mbuf *) NULL);
1119 if (CMSG_SPACE(size) > MLEN) {
1120 MCLGET(m, M_DONTWAIT);
1121 if ((m->m_flags & M_EXT) == 0) {
1122 m_free(m);
1123 return NULL;
1124 }
1125 }
1126 cp = mtod(m, struct cmsghdr *);
1127 memcpy(CMSG_DATA(cp), p, size);
1128 m->m_len = CMSG_SPACE(size);
1129 cp->cmsg_len = CMSG_LEN(size);
1130 cp->cmsg_level = level;
1131 cp->cmsg_type = type;
1132 return (m);
1133 }
Cache object: 5ebbb7b4246f45b242e59bafe4159c94
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