Annotation of sys/kern/uipc_socket2.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: uipc_socket2.c,v 1.42 2007/02/26 23:53:33 kurt Exp $ */
2: /* $NetBSD: uipc_socket2.c,v 1.11 1996/02/04 02:17:55 christos Exp $ */
3:
4: /*
5: * Copyright (c) 1982, 1986, 1988, 1990, 1993
6: * The Regents of the University of California. All rights reserved.
7: *
8: * Redistribution and use in source and binary forms, with or without
9: * modification, are permitted provided that the following conditions
10: * are met:
11: * 1. Redistributions of source code must retain the above copyright
12: * notice, this list of conditions and the following disclaimer.
13: * 2. Redistributions in binary form must reproduce the above copyright
14: * notice, this list of conditions and the following disclaimer in the
15: * documentation and/or other materials provided with the distribution.
16: * 3. Neither the name of the University nor the names of its contributors
17: * may be used to endorse or promote products derived from this software
18: * without specific prior written permission.
19: *
20: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30: * SUCH DAMAGE.
31: *
32: * @(#)uipc_socket2.c 8.1 (Berkeley) 6/10/93
33: */
34:
35: #include <sys/param.h>
36: #include <sys/systm.h>
37: #include <sys/proc.h>
38: #include <sys/file.h>
39: #include <sys/buf.h>
40: #include <sys/malloc.h>
41: #include <sys/mbuf.h>
42: #include <sys/protosw.h>
43: #include <sys/socket.h>
44: #include <sys/socketvar.h>
45: #include <sys/signalvar.h>
46: #include <sys/event.h>
47:
48: /*
49: * Primitive routines for operating on sockets and socket buffers
50: */
51:
52: /* strings for sleep message: */
53: const char netcon[] = "netcon";
54: const char netcls[] = "netcls";
55: const char netio[] = "netio";
56: const char netlck[] = "netlck";
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:
90: void
91: soisconnecting(struct socket *so)
92: {
93:
94: so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
95: so->so_state |= SS_ISCONNECTING;
96: }
97:
98: void
99: soisconnected(struct socket *so)
100: {
101: 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_one(&head->so_timeo);
109: } else {
110: wakeup(&so->so_timeo);
111: sorwakeup(so);
112: sowwakeup(so);
113: }
114: }
115:
116: void
117: soisdisconnecting(struct socket *so)
118: {
119:
120: so->so_state &= ~SS_ISCONNECTING;
121: so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE);
122: wakeup(&so->so_timeo);
123: sowwakeup(so);
124: sorwakeup(so);
125: }
126:
127: void
128: soisdisconnected(struct socket *so)
129: {
130:
131: so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
132: so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE|SS_ISDISCONNECTED);
133: wakeup(&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, properly linked into the
143: * data structure of the original socket, and return this.
144: * Connstatus may be 0, or SS_ISCONFIRMING, or SS_ISCONNECTED.
145: *
146: * Must be called at splsoftnet()
147: */
148: struct socket *
149: sonewconn(struct socket *head, int connstatus)
150: {
151: struct socket *so;
152: int soqueue = connstatus ? 1 : 0;
153: extern u_long unpst_sendspace, unpst_recvspace;
154: u_long snd_sb_hiwat, rcv_sb_hiwat;
155:
156: splassert(IPL_SOFTNET);
157:
158: if (mclpool.pr_nout > mclpool.pr_hardlimit * 95 / 100)
159: return ((struct socket *)0);
160: if (head->so_qlen + head->so_q0len > head->so_qlimit * 3)
161: return ((struct socket *)0);
162: so = pool_get(&socket_pool, PR_NOWAIT);
163: if (so == NULL)
164: return ((struct socket *)0);
165: bzero(so, sizeof(*so));
166: so->so_type = head->so_type;
167: so->so_options = head->so_options &~ SO_ACCEPTCONN;
168: so->so_linger = head->so_linger;
169: so->so_state = head->so_state | SS_NOFDREF;
170: so->so_proto = head->so_proto;
171: so->so_timeo = head->so_timeo;
172: so->so_pgid = head->so_pgid;
173: so->so_euid = head->so_euid;
174: so->so_ruid = head->so_ruid;
175: so->so_egid = head->so_egid;
176: so->so_rgid = head->so_rgid;
177: so->so_cpid = head->so_cpid;
178: so->so_siguid = head->so_siguid;
179: so->so_sigeuid = head->so_sigeuid;
180:
181: /*
182: * If we are tight on mbuf clusters, create the new socket
183: * with the minimum. Sorry, you lose.
184: */
185: snd_sb_hiwat = head->so_snd.sb_hiwat;
186: if (sbcheckreserve(snd_sb_hiwat, unpst_sendspace))
187: snd_sb_hiwat = unpst_sendspace; /* and udp? */
188: rcv_sb_hiwat = head->so_rcv.sb_hiwat;
189: if (sbcheckreserve(rcv_sb_hiwat, unpst_recvspace))
190: rcv_sb_hiwat = unpst_recvspace; /* and udp? */
191:
192: (void) soreserve(so, snd_sb_hiwat, rcv_sb_hiwat);
193: soqinsque(head, so, soqueue);
194: if ((*so->so_proto->pr_usrreq)(so, PRU_ATTACH,
195: (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0)) {
196: (void) soqremque(so, soqueue);
197: pool_put(&socket_pool, so);
198: return ((struct socket *)0);
199: }
200: if (connstatus) {
201: sorwakeup(head);
202: wakeup(&head->so_timeo);
203: so->so_state |= connstatus;
204: }
205: return (so);
206: }
207:
208: void
209: soqinsque(struct socket *head, struct socket *so, int q)
210: {
211:
212: #ifdef DIAGNOSTIC
213: if (so->so_onq != NULL)
214: panic("soqinsque");
215: #endif
216:
217: so->so_head = head;
218: if (q == 0) {
219: head->so_q0len++;
220: so->so_onq = &head->so_q0;
221: } else {
222: head->so_qlen++;
223: so->so_onq = &head->so_q;
224: }
225: TAILQ_INSERT_TAIL(so->so_onq, so, so_qe);
226: }
227:
228: int
229: soqremque(struct socket *so, int q)
230: {
231: struct socket *head;
232:
233: head = so->so_head;
234: if (q == 0) {
235: if (so->so_onq != &head->so_q0)
236: return (0);
237: head->so_q0len--;
238: } else {
239: if (so->so_onq != &head->so_q)
240: return (0);
241: head->so_qlen--;
242: }
243: TAILQ_REMOVE(so->so_onq, so, so_qe);
244: so->so_onq = NULL;
245: so->so_head = NULL;
246: return (1);
247: }
248:
249: /*
250: * Socantsendmore indicates that no more data will be sent on the
251: * socket; it would normally be applied to a socket when the user
252: * informs the system that no more data is to be sent, by the protocol
253: * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data
254: * will be received, and will normally be applied to the socket by a
255: * protocol when it detects that the peer will send no more data.
256: * Data queued for reading in the socket may yet be read.
257: */
258:
259: void
260: socantsendmore(struct socket *so)
261: {
262:
263: so->so_state |= SS_CANTSENDMORE;
264: sowwakeup(so);
265: }
266:
267: void
268: socantrcvmore(struct socket *so)
269: {
270:
271: so->so_state |= SS_CANTRCVMORE;
272: sorwakeup(so);
273: }
274:
275: /*
276: * Wait for data to arrive at/drain from a socket buffer.
277: */
278: int
279: sbwait(struct sockbuf *sb)
280: {
281:
282: sb->sb_flags |= SB_WAIT;
283: return (tsleep(&sb->sb_cc,
284: (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, netio,
285: sb->sb_timeo));
286: }
287:
288: /*
289: * Lock a sockbuf already known to be locked;
290: * return any error returned from sleep (EINTR).
291: */
292: int
293: sb_lock(struct sockbuf *sb)
294: {
295: int error;
296:
297: while (sb->sb_flags & SB_LOCK) {
298: sb->sb_flags |= SB_WANT;
299: error = tsleep(&sb->sb_flags,
300: (sb->sb_flags & SB_NOINTR) ?
301: PSOCK : PSOCK|PCATCH, netlck, 0);
302: if (error)
303: return (error);
304: }
305: sb->sb_flags |= SB_LOCK;
306: return (0);
307: }
308:
309: /*
310: * Wakeup processes waiting on a socket buffer.
311: * Do asynchronous notification via SIGIO
312: * if the socket has the SS_ASYNC flag set.
313: */
314: void
315: sowakeup(struct socket *so, struct sockbuf *sb)
316: {
317: selwakeup(&sb->sb_sel);
318: sb->sb_flags &= ~SB_SEL;
319: if (sb->sb_flags & SB_WAIT) {
320: sb->sb_flags &= ~SB_WAIT;
321: wakeup(&sb->sb_cc);
322: }
323: if (so->so_state & SS_ASYNC)
324: csignal(so->so_pgid, SIGIO, so->so_siguid, so->so_sigeuid);
325: KNOTE(&sb->sb_sel.si_note, 0);
326: }
327:
328: /*
329: * Socket buffer (struct sockbuf) utility routines.
330: *
331: * Each socket contains two socket buffers: one for sending data and
332: * one for receiving data. Each buffer contains a queue of mbufs,
333: * information about the number of mbufs and amount of data in the
334: * queue, and other fields allowing select() statements and notification
335: * on data availability to be implemented.
336: *
337: * Data stored in a socket buffer is maintained as a list of records.
338: * Each record is a list of mbufs chained together with the m_next
339: * field. Records are chained together with the m_nextpkt field. The upper
340: * level routine soreceive() expects the following conventions to be
341: * observed when placing information in the receive buffer:
342: *
343: * 1. If the protocol requires each message be preceded by the sender's
344: * name, then a record containing that name must be present before
345: * any associated data (mbuf's must be of type MT_SONAME).
346: * 2. If the protocol supports the exchange of ``access rights'' (really
347: * just additional data associated with the message), and there are
348: * ``rights'' to be received, then a record containing this data
349: * should be present (mbuf's must be of type MT_CONTROL).
350: * 3. If a name or rights record exists, then it must be followed by
351: * a data record, perhaps of zero length.
352: *
353: * Before using a new socket structure it is first necessary to reserve
354: * buffer space to the socket, by calling sbreserve(). This should commit
355: * some of the available buffer space in the system buffer pool for the
356: * socket (currently, it does nothing but enforce limits). The space
357: * should be released by calling sbrelease() when the socket is destroyed.
358: */
359:
360: int
361: soreserve(struct socket *so, u_long sndcc, u_long rcvcc)
362: {
363:
364: if (sbreserve(&so->so_snd, sndcc) == 0)
365: goto bad;
366: if (sbreserve(&so->so_rcv, rcvcc) == 0)
367: goto bad2;
368: if (so->so_rcv.sb_lowat == 0)
369: so->so_rcv.sb_lowat = 1;
370: if (so->so_snd.sb_lowat == 0)
371: so->so_snd.sb_lowat = MCLBYTES;
372: if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat)
373: so->so_snd.sb_lowat = so->so_snd.sb_hiwat;
374: return (0);
375: bad2:
376: sbrelease(&so->so_snd);
377: bad:
378: return (ENOBUFS);
379: }
380:
381: /*
382: * Allot mbufs to a sockbuf.
383: * Attempt to scale mbmax so that mbcnt doesn't become limiting
384: * if buffering efficiency is near the normal case.
385: */
386: int
387: sbreserve(struct sockbuf *sb, u_long cc)
388: {
389:
390: if (cc == 0 || cc > sb_max)
391: return (0);
392: sb->sb_hiwat = cc;
393: sb->sb_mbmax = min(cc * 2, sb_max + (sb_max / MCLBYTES) * MSIZE);
394: if (sb->sb_lowat > sb->sb_hiwat)
395: sb->sb_lowat = sb->sb_hiwat;
396: return (1);
397: }
398:
399: /*
400: * If over 50% of mbuf clusters in use, do not accept any
401: * greater than normal request.
402: */
403: int
404: sbcheckreserve(u_long cnt, u_long defcnt)
405: {
406: if (cnt > defcnt &&
407: mclpool.pr_nout> mclpool.pr_hardlimit / 2)
408: return (ENOBUFS);
409: return (0);
410: }
411:
412: /*
413: * Free mbufs held by a socket, and reserved mbuf space.
414: */
415: void
416: sbrelease(struct sockbuf *sb)
417: {
418:
419: sbflush(sb);
420: sb->sb_hiwat = sb->sb_mbmax = 0;
421: }
422:
423: /*
424: * Routines to add and remove
425: * data from an mbuf queue.
426: *
427: * The routines sbappend() or sbappendrecord() are normally called to
428: * append new mbufs to a socket buffer, after checking that adequate
429: * space is available, comparing the function sbspace() with the amount
430: * of data to be added. sbappendrecord() differs from sbappend() in
431: * that data supplied is treated as the beginning of a new record.
432: * To place a sender's address, optional access rights, and data in a
433: * socket receive buffer, sbappendaddr() should be used. To place
434: * access rights and data in a socket receive buffer, sbappendrights()
435: * should be used. In either case, the new data begins a new record.
436: * Note that unlike sbappend() and sbappendrecord(), these routines check
437: * for the caller that there will be enough space to store the data.
438: * Each fails if there is not enough space, or if it cannot find mbufs
439: * to store additional information in.
440: *
441: * Reliable protocols may use the socket send buffer to hold data
442: * awaiting acknowledgement. Data is normally copied from a socket
443: * send buffer in a protocol with m_copy for output to a peer,
444: * and then removing the data from the socket buffer with sbdrop()
445: * or sbdroprecord() when the data is acknowledged by the peer.
446: */
447:
448: #ifdef SOCKBUF_DEBUG
449: void
450: sblastrecordchk(struct sockbuf *sb, const char *where)
451: {
452: struct mbuf *m = sb->sb_mb;
453:
454: while (m && m->m_nextpkt)
455: m = m->m_nextpkt;
456:
457: if (m != sb->sb_lastrecord) {
458: printf("sblastrecordchk: sb_mb %p sb_lastrecord %p last %p\n",
459: sb->sb_mb, sb->sb_lastrecord, m);
460: printf("packet chain:\n");
461: for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt)
462: printf("\t%p\n", m);
463: panic("sblastrecordchk from %s", where);
464: }
465: }
466:
467: void
468: sblastmbufchk(struct sockbuf *sb, const char *where)
469: {
470: struct mbuf *m = sb->sb_mb;
471: struct mbuf *n;
472:
473: while (m && m->m_nextpkt)
474: m = m->m_nextpkt;
475:
476: while (m && m->m_next)
477: m = m->m_next;
478:
479: if (m != sb->sb_mbtail) {
480: printf("sblastmbufchk: sb_mb %p sb_mbtail %p last %p\n",
481: sb->sb_mb, sb->sb_mbtail, m);
482: printf("packet tree:\n");
483: for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt) {
484: printf("\t");
485: for (n = m; n != NULL; n = n->m_next)
486: printf("%p ", n);
487: printf("\n");
488: }
489: panic("sblastmbufchk from %s", where);
490: }
491: }
492: #endif /* SOCKBUF_DEBUG */
493:
494: #define SBLINKRECORD(sb, m0) \
495: do { \
496: if ((sb)->sb_lastrecord != NULL) \
497: (sb)->sb_lastrecord->m_nextpkt = (m0); \
498: else \
499: (sb)->sb_mb = (m0); \
500: (sb)->sb_lastrecord = (m0); \
501: } while (/*CONSTCOND*/0)
502:
503: /*
504: * Append mbuf chain m to the last record in the
505: * socket buffer sb. The additional space associated
506: * the mbuf chain is recorded in sb. Empty mbufs are
507: * discarded and mbufs are compacted where possible.
508: */
509: void
510: sbappend(struct sockbuf *sb, struct mbuf *m)
511: {
512: struct mbuf *n;
513:
514: if (m == NULL)
515: return;
516:
517: SBLASTRECORDCHK(sb, "sbappend 1");
518:
519: if ((n = sb->sb_lastrecord) != NULL) {
520: /*
521: * XXX Would like to simply use sb_mbtail here, but
522: * XXX I need to verify that I won't miss an EOR that
523: * XXX way.
524: */
525: do {
526: if (n->m_flags & M_EOR) {
527: sbappendrecord(sb, m); /* XXXXXX!!!! */
528: return;
529: }
530: } while (n->m_next && (n = n->m_next));
531: } else {
532: /*
533: * If this is the first record in the socket buffer, it's
534: * also the last record.
535: */
536: sb->sb_lastrecord = m;
537: }
538: sbcompress(sb, m, n);
539: SBLASTRECORDCHK(sb, "sbappend 2");
540: }
541:
542: /*
543: * This version of sbappend() should only be used when the caller
544: * absolutely knows that there will never be more than one record
545: * in the socket buffer, that is, a stream protocol (such as TCP).
546: */
547: void
548: sbappendstream(struct sockbuf *sb, struct mbuf *m)
549: {
550:
551: KDASSERT(m->m_nextpkt == NULL);
552: KASSERT(sb->sb_mb == sb->sb_lastrecord);
553:
554: SBLASTMBUFCHK(sb, __func__);
555:
556: sbcompress(sb, m, sb->sb_mbtail);
557:
558: sb->sb_lastrecord = sb->sb_mb;
559: SBLASTRECORDCHK(sb, __func__);
560: }
561:
562: #ifdef SOCKBUF_DEBUG
563: void
564: sbcheck(struct sockbuf *sb)
565: {
566: struct mbuf *m;
567: u_long len = 0, mbcnt = 0;
568:
569: for (m = sb->sb_mb; m; m = m->m_next) {
570: len += m->m_len;
571: mbcnt += MSIZE;
572: if (m->m_flags & M_EXT)
573: mbcnt += m->m_ext.ext_size;
574: if (m->m_nextpkt)
575: panic("sbcheck nextpkt");
576: }
577: if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) {
578: printf("cc %lu != %lu || mbcnt %lu != %lu\n", len, sb->sb_cc,
579: mbcnt, sb->sb_mbcnt);
580: panic("sbcheck");
581: }
582: }
583: #endif
584:
585: /*
586: * As above, except the mbuf chain
587: * begins a new record.
588: */
589: void
590: sbappendrecord(struct sockbuf *sb, struct mbuf *m0)
591: {
592: struct mbuf *m;
593:
594: if (m0 == NULL)
595: return;
596:
597: /*
598: * Put the first mbuf on the queue.
599: * Note this permits zero length records.
600: */
601: sballoc(sb, m0);
602: SBLASTRECORDCHK(sb, "sbappendrecord 1");
603: SBLINKRECORD(sb, m0);
604: m = m0->m_next;
605: m0->m_next = NULL;
606: if (m && (m0->m_flags & M_EOR)) {
607: m0->m_flags &= ~M_EOR;
608: m->m_flags |= M_EOR;
609: }
610: sbcompress(sb, m, m0);
611: SBLASTRECORDCHK(sb, "sbappendrecord 2");
612: }
613:
614: /*
615: * As above except that OOB data
616: * is inserted at the beginning of the sockbuf,
617: * but after any other OOB data.
618: */
619: void
620: sbinsertoob(struct sockbuf *sb, struct mbuf *m0)
621: {
622: struct mbuf *m, **mp;
623:
624: if (m0 == NULL)
625: return;
626:
627: SBLASTRECORDCHK(sb, "sbinsertoob 1");
628:
629: for (mp = &sb->sb_mb; (m = *mp) != NULL; mp = &((*mp)->m_nextpkt)) {
630: again:
631: switch (m->m_type) {
632:
633: case MT_OOBDATA:
634: continue; /* WANT next train */
635:
636: case MT_CONTROL:
637: if ((m = m->m_next) != NULL)
638: goto again; /* inspect THIS train further */
639: }
640: break;
641: }
642: /*
643: * Put the first mbuf on the queue.
644: * Note this permits zero length records.
645: */
646: sballoc(sb, m0);
647: m0->m_nextpkt = *mp;
648: if (*mp == NULL) {
649: /* m0 is actually the new tail */
650: sb->sb_lastrecord = m0;
651: }
652: *mp = m0;
653: m = m0->m_next;
654: m0->m_next = NULL;
655: if (m && (m0->m_flags & M_EOR)) {
656: m0->m_flags &= ~M_EOR;
657: m->m_flags |= M_EOR;
658: }
659: sbcompress(sb, m, m0);
660: SBLASTRECORDCHK(sb, "sbinsertoob 2");
661: }
662:
663: /*
664: * Append address and data, and optionally, control (ancillary) data
665: * to the receive queue of a socket. If present,
666: * m0 must include a packet header with total length.
667: * Returns 0 if no space in sockbuf or insufficient mbufs.
668: */
669: int
670: sbappendaddr(struct sockbuf *sb, struct sockaddr *asa, struct mbuf *m0,
671: struct mbuf *control)
672: {
673: struct mbuf *m, *n, *nlast;
674: int space = asa->sa_len;
675:
676: if (m0 && (m0->m_flags & M_PKTHDR) == 0)
677: panic("sbappendaddr");
678: if (m0)
679: space += m0->m_pkthdr.len;
680: for (n = control; n; n = n->m_next) {
681: space += n->m_len;
682: if (n->m_next == NULL) /* keep pointer to last control buf */
683: break;
684: }
685: if (space > sbspace(sb))
686: return (0);
687: if (asa->sa_len > MLEN)
688: return (0);
689: MGET(m, M_DONTWAIT, MT_SONAME);
690: if (m == NULL)
691: return (0);
692: m->m_len = asa->sa_len;
693: bcopy(asa, mtod(m, caddr_t), asa->sa_len);
694: if (n)
695: n->m_next = m0; /* concatenate data to control */
696: else
697: control = m0;
698: m->m_next = control;
699:
700: SBLASTRECORDCHK(sb, "sbappendaddr 1");
701:
702: for (n = m; n->m_next != NULL; n = n->m_next)
703: sballoc(sb, n);
704: sballoc(sb, n);
705: nlast = n;
706: SBLINKRECORD(sb, m);
707:
708: sb->sb_mbtail = nlast;
709: SBLASTMBUFCHK(sb, "sbappendaddr");
710:
711: SBLASTRECORDCHK(sb, "sbappendaddr 2");
712:
713: return (1);
714: }
715:
716: int
717: sbappendcontrol(struct sockbuf *sb, struct mbuf *m0, struct mbuf *control)
718: {
719: struct mbuf *m, *mlast, *n;
720: int space = 0;
721:
722: if (control == NULL)
723: panic("sbappendcontrol");
724: for (m = control; ; m = m->m_next) {
725: space += m->m_len;
726: if (m->m_next == NULL)
727: break;
728: }
729: n = m; /* save pointer to last control buffer */
730: for (m = m0; m; m = m->m_next)
731: space += m->m_len;
732: if (space > sbspace(sb))
733: return (0);
734: n->m_next = m0; /* concatenate data to control */
735:
736: SBLASTRECORDCHK(sb, "sbappendcontrol 1");
737:
738: for (m = control; m->m_next != NULL; m = m->m_next)
739: sballoc(sb, m);
740: sballoc(sb, m);
741: mlast = m;
742: SBLINKRECORD(sb, control);
743:
744: sb->sb_mbtail = mlast;
745: SBLASTMBUFCHK(sb, "sbappendcontrol");
746:
747: SBLASTRECORDCHK(sb, "sbappendcontrol 2");
748:
749: return (1);
750: }
751:
752: /*
753: * Compress mbuf chain m into the socket
754: * buffer sb following mbuf n. If n
755: * is null, the buffer is presumed empty.
756: */
757: void
758: sbcompress(struct sockbuf *sb, struct mbuf *m, struct mbuf *n)
759: {
760: int eor = 0;
761: struct mbuf *o;
762:
763: while (m) {
764: eor |= m->m_flags & M_EOR;
765: if (m->m_len == 0 &&
766: (eor == 0 ||
767: (((o = m->m_next) || (o = n)) &&
768: o->m_type == m->m_type))) {
769: if (sb->sb_lastrecord == m)
770: sb->sb_lastrecord = m->m_next;
771: m = m_free(m);
772: continue;
773: }
774: if (n && (n->m_flags & M_EOR) == 0 &&
775: /* M_TRAILINGSPACE() checks buffer writeability */
776: m->m_len <= MCLBYTES / 4 && /* XXX Don't copy too much */
777: m->m_len <= M_TRAILINGSPACE(n) &&
778: n->m_type == m->m_type) {
779: bcopy(mtod(m, caddr_t), mtod(n, caddr_t) + n->m_len,
780: (unsigned)m->m_len);
781: n->m_len += m->m_len;
782: sb->sb_cc += m->m_len;
783: if (m->m_type != MT_CONTROL && m->m_type != MT_SONAME)
784: sb->sb_datacc += m->m_len;
785: m = m_free(m);
786: continue;
787: }
788: if (n)
789: n->m_next = m;
790: else
791: sb->sb_mb = m;
792: sb->sb_mbtail = m;
793: sballoc(sb, m);
794: n = m;
795: m->m_flags &= ~M_EOR;
796: m = m->m_next;
797: n->m_next = NULL;
798: }
799: if (eor) {
800: if (n)
801: n->m_flags |= eor;
802: else
803: printf("semi-panic: sbcompress");
804: }
805: SBLASTMBUFCHK(sb, __func__);
806: }
807:
808: /*
809: * Free all mbufs in a sockbuf.
810: * Check that all resources are reclaimed.
811: */
812: void
813: sbflush(struct sockbuf *sb)
814: {
815:
816: KASSERT((sb->sb_flags & SB_LOCK) == 0);
817:
818: while (sb->sb_mbcnt)
819: sbdrop(sb, (int)sb->sb_cc);
820:
821: KASSERT(sb->sb_cc == 0);
822: KASSERT(sb->sb_datacc == 0);
823: KASSERT(sb->sb_mb == NULL);
824: KASSERT(sb->sb_mbtail == NULL);
825: KASSERT(sb->sb_lastrecord == NULL);
826: }
827:
828: /*
829: * Drop data from (the front of) a sockbuf.
830: */
831: void
832: sbdrop(struct sockbuf *sb, int len)
833: {
834: struct mbuf *m, *mn;
835: struct mbuf *next;
836:
837: next = (m = sb->sb_mb) ? m->m_nextpkt : 0;
838: while (len > 0) {
839: if (m == NULL) {
840: if (next == NULL)
841: panic("sbdrop");
842: m = next;
843: next = m->m_nextpkt;
844: continue;
845: }
846: if (m->m_len > len) {
847: m->m_len -= len;
848: m->m_data += len;
849: sb->sb_cc -= len;
850: if (m->m_type != MT_CONTROL && m->m_type != MT_SONAME)
851: sb->sb_datacc -= len;
852: break;
853: }
854: len -= m->m_len;
855: sbfree(sb, m);
856: MFREE(m, mn);
857: m = mn;
858: }
859: while (m && m->m_len == 0) {
860: sbfree(sb, m);
861: MFREE(m, mn);
862: m = mn;
863: }
864: if (m) {
865: sb->sb_mb = m;
866: m->m_nextpkt = next;
867: } else
868: sb->sb_mb = next;
869: /*
870: * First part is an inline SB_EMPTY_FIXUP(). Second part
871: * makes sure sb_lastrecord is up-to-date if we dropped
872: * part of the last record.
873: */
874: m = sb->sb_mb;
875: if (m == NULL) {
876: sb->sb_mbtail = NULL;
877: sb->sb_lastrecord = NULL;
878: } else if (m->m_nextpkt == NULL)
879: sb->sb_lastrecord = m;
880: }
881:
882: /*
883: * Drop a record off the front of a sockbuf
884: * and move the next record to the front.
885: */
886: void
887: sbdroprecord(struct sockbuf *sb)
888: {
889: struct mbuf *m, *mn;
890:
891: m = sb->sb_mb;
892: if (m) {
893: sb->sb_mb = m->m_nextpkt;
894: do {
895: sbfree(sb, m);
896: MFREE(m, mn);
897: } while ((m = mn) != NULL);
898: }
899: SB_EMPTY_FIXUP(sb);
900: }
901:
902: /*
903: * Create a "control" mbuf containing the specified data
904: * with the specified type for presentation on a socket buffer.
905: */
906: struct mbuf *
907: sbcreatecontrol(caddr_t p, int size, int type, int level)
908: {
909: struct cmsghdr *cp;
910: struct mbuf *m;
911:
912: if (CMSG_SPACE(size) > MCLBYTES) {
913: printf("sbcreatecontrol: message too large %d\n", size);
914: return NULL;
915: }
916:
917: if ((m = m_get(M_DONTWAIT, MT_CONTROL)) == NULL)
918: return ((struct mbuf *) NULL);
919: if (CMSG_SPACE(size) > MLEN) {
920: MCLGET(m, M_DONTWAIT);
921: if ((m->m_flags & M_EXT) == 0) {
922: m_free(m);
923: return NULL;
924: }
925: }
926: cp = mtod(m, struct cmsghdr *);
927: bcopy(p, CMSG_DATA(cp), size);
928: m->m_len = CMSG_SPACE(size);
929: cp->cmsg_len = CMSG_LEN(size);
930: cp->cmsg_level = level;
931: cp->cmsg_type = type;
932: return (m);
933: }
CVSweb
![[BACK]](/icons/back.gif){kind=icon}
Return to uipc_socket2.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / sys / kern