?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
No empty .Rs/.Re
[netbsd-mini2440.git] / sys / kern / uipc_mbuf.c
blobb420892451eec117dc82f117299e9e79ef737e71
1 /* $NetBSD: uipc_mbuf.c,v 1.131 2009/03/15 17:14:40 cegger Exp $ */
2
3 /*-
4 * Copyright (c) 1999, 2001 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9 * NASA Ames Research Center.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 /*
34 * Copyright (c) 1982, 1986, 1988, 1991, 1993
35 * The Regents of the University of California. All rights reserved.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 * notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 * notice, this list of conditions and the following disclaimer in the
44 * documentation and/or other materials provided with the distribution.
45 * 3. Neither the name of the University nor the names of its contributors
46 * may be used to endorse or promote products derived from this software
47 * without specific prior written permission.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59 * SUCH DAMAGE.
60 *
61 * @(#)uipc_mbuf.c 8.4 (Berkeley) 2/14/95
62 */
63
64 #include <sys/cdefs.h>
65 __KERNEL_RCSID(0, "$NetBSD: uipc_mbuf.c,v 1.131 2009/03/15 17:14:40 cegger Exp $");
66
67 #include "opt_mbuftrace.h"
68 #include "opt_ddb.h"
69
70 #include <sys/param.h>
71 #include <sys/systm.h>
72 #include <sys/atomic.h>
73 #include <sys/cpu.h>
74 #include <sys/proc.h>
75 #include <sys/malloc.h>
76 #define MBTYPES
77 #include <sys/mbuf.h>
78 #include <sys/kernel.h>
79 #include <sys/syslog.h>
80 #include <sys/domain.h>
81 #include <sys/protosw.h>
82 #include <sys/percpu.h>
83 #include <sys/pool.h>
84 #include <sys/socket.h>
85 #include <sys/sysctl.h>
86
87 #include <net/if.h>
88
89 #include <uvm/uvm.h>
90
91 pool_cache_t mb_cache; /* mbuf cache */
92 pool_cache_t mcl_cache; /* mbuf cluster cache */
93
94 struct mbstat mbstat;
95 int max_linkhdr;
96 int max_protohdr;
97 int max_hdr;
98 int max_datalen;
99
100 static int mb_ctor(void *, void *, int);
101
102 static void *mclpool_alloc(struct pool *, int);
103 static void mclpool_release(struct pool *, void *);
104
105 static void sysctl_kern_mbuf_setup(void);
106
107 static struct sysctllog *mbuf_sysctllog;
108
109 static struct pool_allocator mclpool_allocator = {
110 .pa_alloc = mclpool_alloc,
111 .pa_free = mclpool_release,
112 };
113
114 static struct mbuf *m_copym0(struct mbuf *, int, int, int, int);
115 static struct mbuf *m_split0(struct mbuf *, int, int, int);
116 static int m_copyback0(struct mbuf **, int, int, const void *, int, int);
117
118 /* flags for m_copyback0 */
119 #define M_COPYBACK0_COPYBACK 0x0001 /* copyback from cp */
120 #define M_COPYBACK0_PRESERVE 0x0002 /* preserve original data */
121 #define M_COPYBACK0_COW 0x0004 /* do copy-on-write */
122 #define M_COPYBACK0_EXTEND 0x0008 /* extend chain */
123
124 static const char mclpool_warnmsg[] =
125 "WARNING: mclpool limit reached; increase NMBCLUSTERS";
126
127 MALLOC_DEFINE(M_MBUF, "mbuf", "mbuf");
128
129 static percpu_t *mbstat_percpu;
130
131 #ifdef MBUFTRACE
132 struct mownerhead mowners = LIST_HEAD_INITIALIZER(mowners);
133 struct mowner unknown_mowners[] = {
134 MOWNER_INIT("unknown", "free"),
135 MOWNER_INIT("unknown", "data"),
136 MOWNER_INIT("unknown", "header"),
137 MOWNER_INIT("unknown", "soname"),
138 MOWNER_INIT("unknown", "soopts"),
139 MOWNER_INIT("unknown", "ftable"),
140 MOWNER_INIT("unknown", "control"),
141 MOWNER_INIT("unknown", "oobdata"),
142 };
143 struct mowner revoked_mowner = MOWNER_INIT("revoked", "");
144 #endif
145
146 #define MEXT_ISEMBEDDED(m) ((m)->m_ext_ref == (m))
147
148 #define MCLADDREFERENCE(o, n) \
149 do { \
150 KASSERT(((o)->m_flags & M_EXT) != 0); \
151 KASSERT(((n)->m_flags & M_EXT) == 0); \
152 KASSERT((o)->m_ext.ext_refcnt >= 1); \
153 (n)->m_flags |= ((o)->m_flags & M_EXTCOPYFLAGS); \
154 atomic_inc_uint(&(o)->m_ext.ext_refcnt); \
155 (n)->m_ext_ref = (o)->m_ext_ref; \
156 mowner_ref((n), (n)->m_flags); \
157 MCLREFDEBUGN((n), __FILE__, __LINE__); \
158 } while (/* CONSTCOND */ 0)
159
160 /*
161 * Initialize the mbuf allocator.
162 */
163 void
164 mbinit(void)
165 {
166
167 CTASSERT(sizeof(struct _m_ext) <= MHLEN);
168 CTASSERT(sizeof(struct mbuf) == MSIZE);
169
170 sysctl_kern_mbuf_setup();
171
172 mclpool_allocator.pa_backingmap = mb_map;
173
174 mb_cache = pool_cache_init(msize, 0, 0, 0, "mbpl",
175 NULL, IPL_VM, mb_ctor, NULL, NULL);
176 KASSERT(mb_cache != NULL);
177
178 mcl_cache = pool_cache_init(mclbytes, 0, 0, 0, "mclpl",
179 &mclpool_allocator, IPL_VM, NULL, NULL, NULL);
180 KASSERT(mcl_cache != NULL);
181
182 pool_cache_set_drain_hook(mb_cache, m_reclaim, NULL);
183 pool_cache_set_drain_hook(mcl_cache, m_reclaim, NULL);
184
185 /*
186 * Set the hard limit on the mclpool to the number of
187 * mbuf clusters the kernel is to support. Log the limit
188 * reached message max once a minute.
189 */
190 pool_cache_sethardlimit(mcl_cache, nmbclusters, mclpool_warnmsg, 60);
191
192 mbstat_percpu = percpu_alloc(sizeof(struct mbstat_cpu));
193
194 /*
195 * Set a low water mark for both mbufs and clusters. This should
196 * help ensure that they can be allocated in a memory starvation
197 * situation. This is important for e.g. diskless systems which
198 * must allocate mbufs in order for the pagedaemon to clean pages.
199 */
200 pool_cache_setlowat(mb_cache, mblowat);
201 pool_cache_setlowat(mcl_cache, mcllowat);
202
203 #ifdef MBUFTRACE
204 {
205 /*
206 * Attach the unknown mowners.
207 */
208 int i;
209 MOWNER_ATTACH(&revoked_mowner);
210 for (i = sizeof(unknown_mowners)/sizeof(unknown_mowners[0]);
211 i-- > 0; )
212 MOWNER_ATTACH(&unknown_mowners[i]);
213 }
214 #endif
215 }
216
217 /*
218 * sysctl helper routine for the kern.mbuf subtree. nmbclusters may
219 * or may not be writable, and mblowat and mcllowat need range
220 * checking and pool tweaking after being reset.
221 */
222 static int
223 sysctl_kern_mbuf(SYSCTLFN_ARGS)
224 {
225 int error, newval;
226 struct sysctlnode node;
227
228 node = *rnode;
229 node.sysctl_data = &newval;
230 switch (rnode->sysctl_num) {
231 case MBUF_NMBCLUSTERS:
232 if (mb_map != NULL) {
233 node.sysctl_flags &= ~CTLFLAG_READWRITE;
234 node.sysctl_flags |= CTLFLAG_READONLY;
235 }
236 /* FALLTHROUGH */
237 case MBUF_MBLOWAT:
238 case MBUF_MCLLOWAT:
239 newval = *(int*)rnode->sysctl_data;
240 break;
241 default:
242 return (EOPNOTSUPP);
243 }
244
245 error = sysctl_lookup(SYSCTLFN_CALL(&node));
246 if (error || newp == NULL)
247 return (error);
248 if (newval < 0)
249 return (EINVAL);
250
251 switch (node.sysctl_num) {
252 case MBUF_NMBCLUSTERS:
253 if (newval < nmbclusters)
254 return (EINVAL);
255 nmbclusters = newval;
256 pool_cache_sethardlimit(mcl_cache, nmbclusters,
257 mclpool_warnmsg, 60);
258 break;
259 case MBUF_MBLOWAT:
260 mblowat = newval;
261 pool_cache_setlowat(mb_cache, mblowat);
262 break;
263 case MBUF_MCLLOWAT:
264 mcllowat = newval;
265 pool_cache_setlowat(mcl_cache, mcllowat);
266 break;
267 }
268
269 return (0);
270 }
271
272 #ifdef MBUFTRACE
273 static void
274 mowner_conver_to_user_cb(void *v1, void *v2, struct cpu_info *ci)
275 {
276 struct mowner_counter *mc = v1;
277 struct mowner_user *mo_user = v2;
278 int i;
279
280 for (i = 0; i < MOWNER_COUNTER_NCOUNTERS; i++) {
281 mo_user->mo_counter[i] += mc->mc_counter[i];
282 }
283 }
284
285 static void
286 mowner_convert_to_user(struct mowner *mo, struct mowner_user *mo_user)
287 {
288
289 memset(mo_user, 0, sizeof(*mo_user));
290 CTASSERT(sizeof(mo_user->mo_name) == sizeof(mo->mo_name));
291 CTASSERT(sizeof(mo_user->mo_descr) == sizeof(mo->mo_descr));
292 memcpy(mo_user->mo_name, mo->mo_name, sizeof(mo->mo_name));
293 memcpy(mo_user->mo_descr, mo->mo_descr, sizeof(mo->mo_descr));
294 percpu_foreach(mo->mo_counters, mowner_conver_to_user_cb, mo_user);
295 }
296
297 static int
298 sysctl_kern_mbuf_mowners(SYSCTLFN_ARGS)
299 {
300 struct mowner *mo;
301 size_t len = 0;
302 int error = 0;
303
304 if (namelen != 0)
305 return (EINVAL);
306 if (newp != NULL)
307 return (EPERM);
308
309 LIST_FOREACH(mo, &mowners, mo_link) {
310 struct mowner_user mo_user;
311
312 mowner_convert_to_user(mo, &mo_user);
313
314 if (oldp != NULL) {
315 if (*oldlenp - len < sizeof(mo_user)) {
316 error = ENOMEM;
317 break;
318 }
319 error = copyout(&mo_user, (char *)oldp + len,
320 sizeof(mo_user));
321 if (error)
322 break;
323 }
324 len += sizeof(mo_user);
325 }
326
327 if (error == 0)
328 *oldlenp = len;
329
330 return (error);
331 }
332 #endif /* MBUFTRACE */
333
334 static void
335 mbstat_conver_to_user_cb(void *v1, void *v2, struct cpu_info *ci)
336 {
337 struct mbstat_cpu *mbsc = v1;
338 struct mbstat *mbs = v2;
339 int i;
340
341 for (i = 0; i < __arraycount(mbs->m_mtypes); i++) {
342 mbs->m_mtypes[i] += mbsc->m_mtypes[i];
343 }
344 }
345
346 static void
347 mbstat_convert_to_user(struct mbstat *mbs)
348 {
349
350 memset(mbs, 0, sizeof(*mbs));
351 mbs->m_drain = mbstat.m_drain;
352 percpu_foreach(mbstat_percpu, mbstat_conver_to_user_cb, mbs);
353 }
354
355 static int
356 sysctl_kern_mbuf_stats(SYSCTLFN_ARGS)
357 {
358 struct sysctlnode node;
359 struct mbstat mbs;
360
361 mbstat_convert_to_user(&mbs);
362 node = *rnode;
363 node.sysctl_data = &mbs;
364 node.sysctl_size = sizeof(mbs);
365 return sysctl_lookup(SYSCTLFN_CALL(&node));
366 }
367
368 static void
369 sysctl_kern_mbuf_setup(void)
370 {
371
372 KASSERT(mbuf_sysctllog == NULL);
373 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL,
374 CTLFLAG_PERMANENT,
375 CTLTYPE_NODE, "kern", NULL,
376 NULL, 0, NULL, 0,
377 CTL_KERN, CTL_EOL);
378 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL,
379 CTLFLAG_PERMANENT,
380 CTLTYPE_NODE, "mbuf",
381 SYSCTL_DESCR("mbuf control variables"),
382 NULL, 0, NULL, 0,
383 CTL_KERN, KERN_MBUF, CTL_EOL);
384
385 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL,
386 CTLFLAG_PERMANENT|CTLFLAG_IMMEDIATE,
387 CTLTYPE_INT, "msize",
388 SYSCTL_DESCR("mbuf base size"),
389 NULL, msize, NULL, 0,
390 CTL_KERN, KERN_MBUF, MBUF_MSIZE, CTL_EOL);
391 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL,
392 CTLFLAG_PERMANENT|CTLFLAG_IMMEDIATE,
393 CTLTYPE_INT, "mclbytes",
394 SYSCTL_DESCR("mbuf cluster size"),
395 NULL, mclbytes, NULL, 0,
396 CTL_KERN, KERN_MBUF, MBUF_MCLBYTES, CTL_EOL);
397 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL,
398 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
399 CTLTYPE_INT, "nmbclusters",
400 SYSCTL_DESCR("Limit on the number of mbuf clusters"),
401 sysctl_kern_mbuf, 0, &nmbclusters, 0,
402 CTL_KERN, KERN_MBUF, MBUF_NMBCLUSTERS, CTL_EOL);
403 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL,
404 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
405 CTLTYPE_INT, "mblowat",
406 SYSCTL_DESCR("mbuf low water mark"),
407 sysctl_kern_mbuf, 0, &mblowat, 0,
408 CTL_KERN, KERN_MBUF, MBUF_MBLOWAT, CTL_EOL);
409 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL,
410 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
411 CTLTYPE_INT, "mcllowat",
412 SYSCTL_DESCR("mbuf cluster low water mark"),
413 sysctl_kern_mbuf, 0, &mcllowat, 0,
414 CTL_KERN, KERN_MBUF, MBUF_MCLLOWAT, CTL_EOL);
415 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL,
416 CTLFLAG_PERMANENT,
417 CTLTYPE_STRUCT, "stats",
418 SYSCTL_DESCR("mbuf allocation statistics"),
419 sysctl_kern_mbuf_stats, 0, NULL, 0,
420 CTL_KERN, KERN_MBUF, MBUF_STATS, CTL_EOL);
421 #ifdef MBUFTRACE
422 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL,
423 CTLFLAG_PERMANENT,
424 CTLTYPE_STRUCT, "mowners",
425 SYSCTL_DESCR("Information about mbuf owners"),
426 sysctl_kern_mbuf_mowners, 0, NULL, 0,
427 CTL_KERN, KERN_MBUF, MBUF_MOWNERS, CTL_EOL);
428 #endif /* MBUFTRACE */
429 }
430
431 static void *
432 mclpool_alloc(struct pool *pp, int flags)
433 {
434 bool waitok = (flags & PR_WAITOK) ? true : false;
435
436 return ((void *)uvm_km_alloc_poolpage(mb_map, waitok));
437 }
438
439 static void
440 mclpool_release(struct pool *pp, void *v)
441 {
442
443 uvm_km_free_poolpage(mb_map, (vaddr_t)v);
444 }
445
446 /*ARGSUSED*/
447 static int
448 mb_ctor(void *arg, void *object, int flags)
449 {
450 struct mbuf *m = object;
451
452 #ifdef POOL_VTOPHYS
453 m->m_paddr = POOL_VTOPHYS(m);
454 #else
455 m->m_paddr = M_PADDR_INVALID;
456 #endif
457 return (0);
458 }
459
460 void
461 m_reclaim(void *arg, int flags)
462 {
463 struct domain *dp;
464 const struct protosw *pr;
465 struct ifnet *ifp;
466 int s;
467
468 KERNEL_LOCK(1, NULL);
469 s = splvm();
470 DOMAIN_FOREACH(dp) {
471 for (pr = dp->dom_protosw;
472 pr < dp->dom_protoswNPROTOSW; pr++)
473 if (pr->pr_drain)
474 (*pr->pr_drain)();
475 }
476 IFNET_FOREACH(ifp) {
477 if (ifp->if_drain)
478 (*ifp->if_drain)(ifp);
479 }
480 splx(s);
481 mbstat.m_drain++;
482 KERNEL_UNLOCK_ONE(NULL);
483 }
484
485 /*
486 * Space allocation routines.
487 * These are also available as macros
488 * for critical paths.
489 */
490 struct mbuf *
491 m_get(int nowait, int type)
492 {
493 struct mbuf *m;
494
495 m = pool_cache_get(mb_cache,
496 nowait == M_WAIT ? PR_WAITOK|PR_LIMITFAIL : 0);
497 if (m == NULL)
498 return NULL;
499
500 mbstat_type_add(type, 1);
501 mowner_init(m, type);
502 m->m_ext_ref = m;
503 m->m_type = type;
504 m->m_next = NULL;
505 m->m_nextpkt = NULL;
506 m->m_data = m->m_dat;
507 m->m_flags = 0;
508
509 return m;
510 }
511
512 struct mbuf *
513 m_gethdr(int nowait, int type)
514 {
515 struct mbuf *m;
516
517 m = m_get(nowait, type);
518 if (m == NULL)
519 return NULL;
520
521 m->m_data = m->m_pktdat;
522 m->m_flags = M_PKTHDR;
523 m->m_pkthdr.rcvif = NULL;
524 m->m_pkthdr.csum_flags = 0;
525 m->m_pkthdr.csum_data = 0;
526 SLIST_INIT(&m->m_pkthdr.tags);
527
528 return m;
529 }
530
531 struct mbuf *
532 m_getclr(int nowait, int type)
533 {
534 struct mbuf *m;
535
536 MGET(m, nowait, type);
537 if (m == 0)
538 return (NULL);
539 memset(mtod(m, void *), 0, MLEN);
540 return (m);
541 }
542
543 void
544 m_clget(struct mbuf *m, int nowait)
545 {
546
547 MCLGET(m, nowait);
548 }
549
550 struct mbuf *
551 m_free(struct mbuf *m)
552 {
553 struct mbuf *n;
554
555 MFREE(m, n);
556 return (n);
557 }
558
559 void
560 m_freem(struct mbuf *m)
561 {
562 struct mbuf *n;
563
564 if (m == NULL)
565 return;
566 do {
567 MFREE(m, n);
568 m = n;
569 } while (m);
570 }
571
572 #ifdef MBUFTRACE
573 /*
574 * Walk a chain of mbufs, claiming ownership of each mbuf in the chain.
575 */
576 void
577 m_claimm(struct mbuf *m, struct mowner *mo)
578 {
579
580 for (; m != NULL; m = m->m_next)
581 MCLAIM(m, mo);
582 }
583 #endif
584
585 /*
586 * Mbuffer utility routines.
587 */
588
589 /*
590 * Lesser-used path for M_PREPEND:
591 * allocate new mbuf to prepend to chain,
592 * copy junk along.
593 */
594 struct mbuf *
595 m_prepend(struct mbuf *m, int len, int how)
596 {
597 struct mbuf *mn;
598
599 MGET(mn, how, m->m_type);
600 if (mn == (struct mbuf *)NULL) {
601 m_freem(m);
602 return ((struct mbuf *)NULL);
603 }
604 if (m->m_flags & M_PKTHDR) {
605 M_MOVE_PKTHDR(mn, m);
606 } else {
607 MCLAIM(mn, m->m_owner);
608 }
609 mn->m_next = m;
610 m = mn;
611 if (len < MHLEN)
612 MH_ALIGN(m, len);
613 m->m_len = len;
614 return (m);
615 }
616
617 /*
618 * Make a copy of an mbuf chain starting "off0" bytes from the beginning,
619 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf.
620 * The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller.
621 */
622 int MCFail;
623
624 struct mbuf *
625 m_copym(struct mbuf *m, int off0, int len, int wait)
626 {
627
628 return m_copym0(m, off0, len, wait, 0); /* shallow copy on M_EXT */
629 }
630
631 struct mbuf *
632 m_dup(struct mbuf *m, int off0, int len, int wait)
633 {
634
635 return m_copym0(m, off0, len, wait, 1); /* deep copy */
636 }
637
638 static struct mbuf *
639 m_copym0(struct mbuf *m, int off0, int len, int wait, int deep)
640 {
641 struct mbuf *n, **np;
642 int off = off0;
643 struct mbuf *top;
644 int copyhdr = 0;
645
646 if (off < 0 || len < 0)
647 panic("m_copym: off %d, len %d", off, len);
648 if (off == 0 && m->m_flags & M_PKTHDR)
649 copyhdr = 1;
650 while (off > 0) {
651 if (m == 0)
652 panic("m_copym: m == 0, off %d", off);
653 if (off < m->m_len)
654 break;
655 off -= m->m_len;
656 m = m->m_next;
657 }
658 np = &top;
659 top = 0;
660 while (len > 0) {
661 if (m == 0) {
662 if (len != M_COPYALL)
663 panic("m_copym: m == 0, len %d [!COPYALL]",
664 len);
665 break;
666 }
667 MGET(n, wait, m->m_type);
668 *np = n;
669 if (n == 0)
670 goto nospace;
671 MCLAIM(n, m->m_owner);
672 if (copyhdr) {
673 M_COPY_PKTHDR(n, m);
674 if (len == M_COPYALL)
675 n->m_pkthdr.len -= off0;
676 else
677 n->m_pkthdr.len = len;
678 copyhdr = 0;
679 }
680 n->m_len = min(len, m->m_len - off);
681 if (m->m_flags & M_EXT) {
682 if (!deep) {
683 n->m_data = m->m_data + off;
684 MCLADDREFERENCE(m, n);
685 } else {
686 /*
687 * we are unsure about the way m was allocated.
688 * copy into multiple MCLBYTES cluster mbufs.
689 */
690 MCLGET(n, wait);
691 n->m_len = 0;
692 n->m_len = M_TRAILINGSPACE(n);
693 n->m_len = min(n->m_len, len);
694 n->m_len = min(n->m_len, m->m_len - off);
695 memcpy(mtod(n, void *), mtod(m, char *) + off,
696 (unsigned)n->m_len);
697 }
698 } else
699 memcpy(mtod(n, void *), mtod(m, char *) + off,
700 (unsigned)n->m_len);
701 if (len != M_COPYALL)
702 len -= n->m_len;
703 off += n->m_len;
704 #ifdef DIAGNOSTIC
705 if (off > m->m_len)
706 panic("m_copym0 overrun");
707 #endif
708 if (off == m->m_len) {
709 m = m->m_next;
710 off = 0;
711 }
712 np = &n->m_next;
713 }
714 if (top == 0)
715 MCFail++;
716 return (top);
717 nospace:
718 m_freem(top);
719 MCFail++;
720 return (NULL);
721 }
722
723 /*
724 * Copy an entire packet, including header (which must be present).
725 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'.
726 */
727 struct mbuf *
728 m_copypacket(struct mbuf *m, int how)
729 {
730 struct mbuf *top, *n, *o;
731
732 MGET(n, how, m->m_type);
733 top = n;
734 if (!n)
735 goto nospace;
736
737 MCLAIM(n, m->m_owner);
738 M_COPY_PKTHDR(n, m);
739 n->m_len = m->m_len;
740 if (m->m_flags & M_EXT) {
741 n->m_data = m->m_data;
742 MCLADDREFERENCE(m, n);
743 } else {
744 memcpy(mtod(n, char *), mtod(m, char *), n->m_len);
745 }
746
747 m = m->m_next;
748 while (m) {
749 MGET(o, how, m->m_type);
750 if (!o)
751 goto nospace;
752
753 MCLAIM(o, m->m_owner);
754 n->m_next = o;
755 n = n->m_next;
756
757 n->m_len = m->m_len;
758 if (m->m_flags & M_EXT) {
759 n->m_data = m->m_data;
760 MCLADDREFERENCE(m, n);
761 } else {
762 memcpy(mtod(n, char *), mtod(m, char *), n->m_len);
763 }
764
765 m = m->m_next;
766 }
767 return top;
768 nospace:
769 m_freem(top);
770 MCFail++;
771 return NULL;
772 }
773
774 /*
775 * Copy data from an mbuf chain starting "off" bytes from the beginning,
776 * continuing for "len" bytes, into the indicated buffer.
777 */
778 void
779 m_copydata(struct mbuf *m, int off, int len, void *vp)
780 {
781 unsigned count;
782 void * cp = vp;
783
784 if (off < 0 || len < 0)
785 panic("m_copydata: off %d, len %d", off, len);
786 while (off > 0) {
787 if (m == NULL)
788 panic("m_copydata: m == NULL, off %d", off);
789 if (off < m->m_len)
790 break;
791 off -= m->m_len;
792 m = m->m_next;
793 }
794 while (len > 0) {
795 if (m == NULL)
796 panic("m_copydata: m == NULL, len %d", len);
797 count = min(m->m_len - off, len);
798 memcpy(cp, mtod(m, char *) + off, count);
799 len -= count;
800 cp = (char *)cp + count;
801 off = 0;
802 m = m->m_next;
803 }
804 }
805
806 /*
807 * Concatenate mbuf chain n to m.
808 * n might be copied into m (when n->m_len is small), therefore data portion of
809 * n could be copied into an mbuf of different mbuf type.
810 * Any m_pkthdr is not updated.
811 */
812 void
813 m_cat(struct mbuf *m, struct mbuf *n)
814 {
815
816 while (m->m_next)
817 m = m->m_next;
818 while (n) {
819 if (M_READONLY(m) || n->m_len > M_TRAILINGSPACE(m)) {
820 /* just join the two chains */
821 m->m_next = n;
822 return;
823 }
824 /* splat the data from one into the other */
825 memcpy(mtod(m, char *) + m->m_len, mtod(n, void *),
826 (u_int)n->m_len);
827 m->m_len += n->m_len;
828 n = m_free(n);
829 }
830 }
831
832 void
833 m_adj(struct mbuf *mp, int req_len)
834 {
835 int len = req_len;
836 struct mbuf *m;
837 int count;
838
839 if ((m = mp) == NULL)
840 return;
841 if (len >= 0) {
842 /*
843 * Trim from head.
844 */
845 while (m != NULL && len > 0) {
846 if (m->m_len <= len) {
847 len -= m->m_len;
848 m->m_len = 0;
849 m = m->m_next;
850 } else {
851 m->m_len -= len;
852 m->m_data += len;
853 len = 0;
854 }
855 }
856 m = mp;
857 if (mp->m_flags & M_PKTHDR)
858 m->m_pkthdr.len -= (req_len - len);
859 } else {
860 /*
861 * Trim from tail. Scan the mbuf chain,
862 * calculating its length and finding the last mbuf.
863 * If the adjustment only affects this mbuf, then just
864 * adjust and return. Otherwise, rescan and truncate
865 * after the remaining size.
866 */
867 len = -len;
868 count = 0;
869 for (;;) {
870 count += m->m_len;
871 if (m->m_next == (struct mbuf *)0)
872 break;
873 m = m->m_next;
874 }
875 if (m->m_len >= len) {
876 m->m_len -= len;
877 if (mp->m_flags & M_PKTHDR)
878 mp->m_pkthdr.len -= len;
879 return;
880 }
881 count -= len;
882 if (count < 0)
883 count = 0;
884 /*
885 * Correct length for chain is "count".
886 * Find the mbuf with last data, adjust its length,
887 * and toss data from remaining mbufs on chain.
888 */
889 m = mp;
890 if (m->m_flags & M_PKTHDR)
891 m->m_pkthdr.len = count;
892 for (; m; m = m->m_next) {
893 if (m->m_len >= count) {
894 m->m_len = count;
895 break;
896 }
897 count -= m->m_len;
898 }
899 if (m)
900 while (m->m_next)
901 (m = m->m_next)->m_len = 0;
902 }
903 }
904
905 /*
906 * Rearrange an mbuf chain so that len bytes are contiguous
907 * and in the data area of an mbuf (so that mtod and dtom
908 * will work for a structure of size len). Returns the resulting
909 * mbuf chain on success, frees it and returns null on failure.
910 * If there is room, it will add up to max_protohdr-len extra bytes to the
911 * contiguous region in an attempt to avoid being called next time.
912 */
913 int MPFail;
914
915 struct mbuf *
916 m_pullup(struct mbuf *n, int len)
917 {
918 struct mbuf *m;
919 int count;
920 int space;
921
922 /*
923 * If first mbuf has no cluster, and has room for len bytes
924 * without shifting current data, pullup into it,
925 * otherwise allocate a new mbuf to prepend to the chain.
926 */
927 if ((n->m_flags & M_EXT) == 0 &&
928 n->m_data + len < &n->m_dat[MLEN] && n->m_next) {
929 if (n->m_len >= len)
930 return (n);
931 m = n;
932 n = n->m_next;
933 len -= m->m_len;
934 } else {
935 if (len > MHLEN)
936 goto bad;
937 MGET(m, M_DONTWAIT, n->m_type);
938 if (m == 0)
939 goto bad;
940 MCLAIM(m, n->m_owner);
941 m->m_len = 0;
942 if (n->m_flags & M_PKTHDR) {
943 M_MOVE_PKTHDR(m, n);
944 }
945 }
946 space = &m->m_dat[MLEN] - (m->m_data + m->m_len);
947 do {
948 count = min(min(max(len, max_protohdr), space), n->m_len);
949 memcpy(mtod(m, char *) + m->m_len, mtod(n, void *),
950 (unsigned)count);
951 len -= count;
952 m->m_len += count;
953 n->m_len -= count;
954 space -= count;
955 if (n->m_len)
956 n->m_data += count;
957 else
958 n = m_free(n);
959 } while (len > 0 && n);
960 if (len > 0) {
961 (void) m_free(m);
962 goto bad;
963 }
964 m->m_next = n;
965 return (m);
966 bad:
967 m_freem(n);
968 MPFail++;
969 return (NULL);
970 }
971
972 /*
973 * Like m_pullup(), except a new mbuf is always allocated, and we allow
974 * the amount of empty space before the data in the new mbuf to be specified
975 * (in the event that the caller expects to prepend later).
976 */
977 int MSFail;
978
979 struct mbuf *
980 m_copyup(struct mbuf *n, int len, int dstoff)
981 {
982 struct mbuf *m;
983 int count, space;
984
985 if (len > (MHLEN - dstoff))
986 goto bad;
987 MGET(m, M_DONTWAIT, n->m_type);
988 if (m == NULL)
989 goto bad;
990 MCLAIM(m, n->m_owner);
991 m->m_len = 0;
992 if (n->m_flags & M_PKTHDR) {
993 M_MOVE_PKTHDR(m, n);
994 }
995 m->m_data += dstoff;
996 space = &m->m_dat[MLEN] - (m->m_data + m->m_len);
997 do {
998 count = min(min(max(len, max_protohdr), space), n->m_len);
999 memcpy(mtod(m, char *) + m->m_len, mtod(n, void *),
1000 (unsigned)count);
1001 len -= count;
1002 m->m_len += count;
1003 n->m_len -= count;
1004 space -= count;
1005 if (n->m_len)
1006 n->m_data += count;
1007 else
1008 n = m_free(n);
1009 } while (len > 0 && n);
1010 if (len > 0) {
1011 (void) m_free(m);
1012 goto bad;
1013 }
1014 m->m_next = n;
1015 return (m);
1016 bad:
1017 m_freem(n);
1018 MSFail++;
1019 return (NULL);
1020 }
1021
1022 /*
1023 * Partition an mbuf chain in two pieces, returning the tail --
1024 * all but the first len0 bytes. In case of failure, it returns NULL and
1025 * attempts to restore the chain to its original state.
1026 */
1027 struct mbuf *
1028 m_split(struct mbuf *m0, int len0, int wait)
1029 {
1030
1031 return m_split0(m0, len0, wait, 1);
1032 }
1033
1034 static struct mbuf *
1035 m_split0(struct mbuf *m0, int len0, int wait, int copyhdr)
1036 {
1037 struct mbuf *m, *n;
1038 unsigned len = len0, remain, len_save;
1039
1040 for (m = m0; m && len > m->m_len; m = m->m_next)
1041 len -= m->m_len;
1042 if (m == 0)
1043 return (NULL);
1044 remain = m->m_len - len;
1045 if (copyhdr && (m0->m_flags & M_PKTHDR)) {
1046 MGETHDR(n, wait, m0->m_type);
1047 if (n == 0)
1048 return (NULL);
1049 MCLAIM(n, m0->m_owner);
1050 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif;
1051 n->m_pkthdr.len = m0->m_pkthdr.len - len0;
1052 len_save = m0->m_pkthdr.len;
1053 m0->m_pkthdr.len = len0;
1054 if (m->m_flags & M_EXT)
1055 goto extpacket;
1056 if (remain > MHLEN) {
1057 /* m can't be the lead packet */
1058 MH_ALIGN(n, 0);
1059 n->m_len = 0;
1060 n->m_next = m_split(m, len, wait);
1061 if (n->m_next == 0) {
1062 (void) m_free(n);
1063 m0->m_pkthdr.len = len_save;
1064 return (NULL);
1065 } else
1066 return (n);
1067 } else
1068 MH_ALIGN(n, remain);
1069 } else if (remain == 0) {
1070 n = m->m_next;
1071 m->m_next = 0;
1072 return (n);
1073 } else {
1074 MGET(n, wait, m->m_type);
1075 if (n == 0)
1076 return (NULL);
1077 MCLAIM(n, m->m_owner);
1078 M_ALIGN(n, remain);
1079 }
1080 extpacket:
1081 if (m->m_flags & M_EXT) {
1082 n->m_data = m->m_data + len;
1083 MCLADDREFERENCE(m, n);
1084 } else {
1085 memcpy(mtod(n, void *), mtod(m, char *) + len, remain);
1086 }
1087 n->m_len = remain;
1088 m->m_len = len;
1089 n->m_next = m->m_next;
1090 m->m_next = 0;
1091 return (n);
1092 }
1093 /*
1094 * Routine to copy from device local memory into mbufs.
1095 */
1096 struct mbuf *
1097 m_devget(char *buf, int totlen, int off0, struct ifnet *ifp,
1098 void (*copy)(const void *from, void *to, size_t len))
1099 {
1100 struct mbuf *m;
1101 struct mbuf *top = 0, **mp = &top;
1102 int off = off0, len;
1103 char *cp;
1104 char *epkt;
1105
1106 cp = buf;
1107 epkt = cp + totlen;
1108 if (off) {
1109 /*
1110 * If 'off' is non-zero, packet is trailer-encapsulated,
1111 * so we have to skip the type and length fields.
1112 */
1113 cp += off + 2 * sizeof(uint16_t);
1114 totlen -= 2 * sizeof(uint16_t);
1115 }
1116 MGETHDR(m, M_DONTWAIT, MT_DATA);
1117 if (m == 0)
1118 return (NULL);
1119 m->m_pkthdr.rcvif = ifp;
1120 m->m_pkthdr.len = totlen;
1121 m->m_len = MHLEN;
1122
1123 while (totlen > 0) {
1124 if (top) {
1125 MGET(m, M_DONTWAIT, MT_DATA);
1126 if (m == 0) {
1127 m_freem(top);
1128 return (NULL);
1129 }
1130 m->m_len = MLEN;
1131 }
1132 len = min(totlen, epkt - cp);
1133 if (len >= MINCLSIZE) {
1134 MCLGET(m, M_DONTWAIT);
1135 if ((m->m_flags & M_EXT) == 0) {
1136 m_free(m);
1137 m_freem(top);
1138 return (NULL);
1139 }
1140 m->m_len = len = min(len, MCLBYTES);
1141 } else {
1142 /*
1143 * Place initial small packet/header at end of mbuf.
1144 */
1145 if (len < m->m_len) {
1146 if (top == 0 && len + max_linkhdr <= m->m_len)
1147 m->m_data += max_linkhdr;
1148 m->m_len = len;
1149 } else
1150 len = m->m_len;
1151 }
1152 if (copy)
1153 copy(cp, mtod(m, void *), (size_t)len);
1154 else
1155 memcpy(mtod(m, void *), cp, (size_t)len);
1156 cp += len;
1157 *mp = m;
1158 mp = &m->m_next;
1159 totlen -= len;
1160 if (cp == epkt)
1161 cp = buf;
1162 }
1163 return (top);
1164 }
1165
1166 /*
1167 * Copy data from a buffer back into the indicated mbuf chain,
1168 * starting "off" bytes from the beginning, extending the mbuf
1169 * chain if necessary.
1170 */
1171 void
1172 m_copyback(struct mbuf *m0, int off, int len, const void *cp)
1173 {
1174 #if defined(DEBUG)
1175 struct mbuf *origm = m0;
1176 int error;
1177 #endif /* defined(DEBUG) */
1178
1179 if (m0 == NULL)
1180 return;
1181
1182 #if defined(DEBUG)
1183 error =
1184 #endif /* defined(DEBUG) */
1185 m_copyback0(&m0, off, len, cp,
1186 M_COPYBACK0_COPYBACK|M_COPYBACK0_EXTEND, M_DONTWAIT);
1187
1188 #if defined(DEBUG)
1189 if (error != 0 || (m0 != NULL && origm != m0))
1190 panic("m_copyback");
1191 #endif /* defined(DEBUG) */
1192 }
1193
1194 struct mbuf *
1195 m_copyback_cow(struct mbuf *m0, int off, int len, const void *cp, int how)
1196 {
1197 int error;
1198
1199 /* don't support chain expansion */
1200 KDASSERT(off + len <= m_length(m0));
1201
1202 error = m_copyback0(&m0, off, len, cp,
1203 M_COPYBACK0_COPYBACK|M_COPYBACK0_COW, how);
1204 if (error) {
1205 /*
1206 * no way to recover from partial success.
1207 * just free the chain.
1208 */
1209 m_freem(m0);
1210 return NULL;
1211 }
1212 return m0;
1213 }
1214
1215 /*
1216 * m_makewritable: ensure the specified range writable.
1217 */
1218 int
1219 m_makewritable(struct mbuf **mp, int off, int len, int how)
1220 {
1221 int error;
1222 #if defined(DEBUG)
1223 struct mbuf *n;
1224 int origlen, reslen;
1225
1226 origlen = m_length(*mp);
1227 #endif /* defined(DEBUG) */
1228
1229 #if 0 /* M_COPYALL is large enough */
1230 if (len == M_COPYALL)
1231 len = m_length(*mp) - off; /* XXX */
1232 #endif
1233
1234 error = m_copyback0(mp, off, len, NULL,
1235 M_COPYBACK0_PRESERVE|M_COPYBACK0_COW, how);
1236
1237 #if defined(DEBUG)
1238 reslen = 0;
1239 for (n = *mp; n; n = n->m_next)
1240 reslen += n->m_len;
1241 if (origlen != reslen)
1242 panic("m_makewritable: length changed");
1243 if (((*mp)->m_flags & M_PKTHDR) != 0 && reslen != (*mp)->m_pkthdr.len)
1244 panic("m_makewritable: inconsist");
1245 #endif /* defined(DEBUG) */
1246
1247 return error;
1248 }
1249
1250 int
1251 m_copyback0(struct mbuf **mp0, int off, int len, const void *vp, int flags,
1252 int how)
1253 {
1254 int mlen;
1255 struct mbuf *m, *n;
1256 struct mbuf **mp;
1257 int totlen = 0;
1258 const char *cp = vp;
1259
1260 KASSERT(mp0 != NULL);
1261 KASSERT(*mp0 != NULL);
1262 KASSERT((flags & M_COPYBACK0_PRESERVE) == 0 || cp == NULL);
1263 KASSERT((flags & M_COPYBACK0_COPYBACK) == 0 || cp != NULL);
1264
1265 /*
1266 * we don't bother to update "totlen" in the case of M_COPYBACK0_COW,
1267 * assuming that M_COPYBACK0_EXTEND and M_COPYBACK0_COW are exclusive.
1268 */
1269
1270 KASSERT((~flags & (M_COPYBACK0_EXTEND|M_COPYBACK0_COW)) != 0);
1271
1272 mp = mp0;
1273 m = *mp;
1274 while (off > (mlen = m->m_len)) {
1275 off -= mlen;
1276 totlen += mlen;
1277 if (m->m_next == NULL) {
1278 int tspace;
1279 extend:
1280 if ((flags & M_COPYBACK0_EXTEND) == 0)
1281 goto out;
1282
1283 /*
1284 * try to make some space at the end of "m".
1285 */
1286
1287 mlen = m->m_len;
1288 if (off + len >= MINCLSIZE &&
1289 (m->m_flags & M_EXT) == 0 && m->m_len == 0) {
1290 MCLGET(m, how);
1291 }
1292 tspace = M_TRAILINGSPACE(m);
1293 if (tspace > 0) {
1294 tspace = min(tspace, off + len);
1295 KASSERT(tspace > 0);
1296 memset(mtod(m, char *) + m->m_len, 0,
1297 min(off, tspace));
1298 m->m_len += tspace;
1299 off += mlen;
1300 totlen -= mlen;
1301 continue;
1302 }
1303
1304 /*
1305 * need to allocate an mbuf.
1306 */
1307
1308 if (off + len >= MINCLSIZE) {
1309 n = m_getcl(how, m->m_type, 0);
1310 } else {
1311 n = m_get(how, m->m_type);
1312 }
1313 if (n == NULL) {
1314 goto out;
1315 }
1316 n->m_len = 0;
1317 n->m_len = min(M_TRAILINGSPACE(n), off + len);
1318 memset(mtod(n, char *), 0, min(n->m_len, off));
1319 m->m_next = n;
1320 }
1321 mp = &m->m_next;
1322 m = m->m_next;
1323 }
1324 while (len > 0) {
1325 mlen = m->m_len - off;
1326 if (mlen != 0 && M_READONLY(m)) {
1327 char *datap;
1328 int eatlen;
1329
1330 /*
1331 * this mbuf is read-only.
1332 * allocate a new writable mbuf and try again.
1333 */
1334
1335 #if defined(DIAGNOSTIC)
1336 if ((flags & M_COPYBACK0_COW) == 0)
1337 panic("m_copyback0: read-only");
1338 #endif /* defined(DIAGNOSTIC) */
1339
1340 /*
1341 * if we're going to write into the middle of
1342 * a mbuf, split it first.
1343 */
1344 if (off > 0 && len < mlen) {
1345 n = m_split0(m, off, how, 0);
1346 if (n == NULL)
1347 goto enobufs;
1348 m->m_next = n;
1349 mp = &m->m_next;
1350 m = n;
1351 off = 0;
1352 continue;
1353 }
1354
1355 /*
1356 * XXX TODO coalesce into the trailingspace of
1357 * the previous mbuf when possible.
1358 */
1359
1360 /*
1361 * allocate a new mbuf. copy packet header if needed.
1362 */
1363 MGET(n, how, m->m_type);
1364 if (n == NULL)
1365 goto enobufs;
1366 MCLAIM(n, m->m_owner);
1367 if (off == 0 && (m->m_flags & M_PKTHDR) != 0) {
1368 M_MOVE_PKTHDR(n, m);
1369 n->m_len = MHLEN;
1370 } else {
1371 if (len >= MINCLSIZE)
1372 MCLGET(n, M_DONTWAIT);
1373 n->m_len =
1374 (n->m_flags & M_EXT) ? MCLBYTES : MLEN;
1375 }
1376 if (n->m_len > len)
1377 n->m_len = len;
1378
1379 /*
1380 * free the region which has been overwritten.
1381 * copying data from old mbufs if requested.
1382 */
1383 if (flags & M_COPYBACK0_PRESERVE)
1384 datap = mtod(n, char *);
1385 else
1386 datap = NULL;
1387 eatlen = n->m_len;
1388 KDASSERT(off == 0 || eatlen >= mlen);
1389 if (off > 0) {
1390 KDASSERT(len >= mlen);
1391 m->m_len = off;
1392 m->m_next = n;
1393 if (datap) {
1394 m_copydata(m, off, mlen, datap);
1395 datap += mlen;
1396 }
1397 eatlen -= mlen;
1398 mp = &m->m_next;
1399 m = m->m_next;
1400 }
1401 while (m != NULL && M_READONLY(m) &&
1402 n->m_type == m->m_type && eatlen > 0) {
1403 mlen = min(eatlen, m->m_len);
1404 if (datap) {
1405 m_copydata(m, 0, mlen, datap);
1406 datap += mlen;
1407 }
1408 m->m_data += mlen;
1409 m->m_len -= mlen;
1410 eatlen -= mlen;
1411 if (m->m_len == 0)
1412 *mp = m = m_free(m);
1413 }
1414 if (eatlen > 0)
1415 n->m_len -= eatlen;
1416 n->m_next = m;
1417 *mp = m = n;
1418 continue;
1419 }
1420 mlen = min(mlen, len);
1421 if (flags & M_COPYBACK0_COPYBACK) {
1422 memcpy(mtod(m, char *) + off, cp, (unsigned)mlen);
1423 cp += mlen;
1424 }
1425 len -= mlen;
1426 mlen += off;
1427 off = 0;
1428 totlen += mlen;
1429 if (len == 0)
1430 break;
1431 if (m->m_next == NULL) {
1432 goto extend;
1433 }
1434 mp = &m->m_next;
1435 m = m->m_next;
1436 }
1437 out: if (((m = *mp0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) {
1438 KASSERT((flags & M_COPYBACK0_EXTEND) != 0);
1439 m->m_pkthdr.len = totlen;
1440 }
1441
1442 return 0;
1443
1444 enobufs:
1445 return ENOBUFS;
1446 }
1447
1448 void
1449 m_move_pkthdr(struct mbuf *to, struct mbuf *from)
1450 {
1451
1452 KASSERT((to->m_flags & M_EXT) == 0);
1453 KASSERT((to->m_flags & M_PKTHDR) == 0 || m_tag_first(to) == NULL);
1454 KASSERT((from->m_flags & M_PKTHDR) != 0);
1455
1456 to->m_pkthdr = from->m_pkthdr;
1457 to->m_flags = from->m_flags & M_COPYFLAGS;
1458 to->m_data = to->m_pktdat;
1459
1460 from->m_flags &= ~M_PKTHDR;
1461 }
1462
1463 /*
1464 * Apply function f to the data in an mbuf chain starting "off" bytes from the
1465 * beginning, continuing for "len" bytes.
1466 */
1467 int
1468 m_apply(struct mbuf *m, int off, int len,
1469 int (*f)(void *, void *, unsigned int), void *arg)
1470 {
1471 unsigned int count;
1472 int rval;
1473
1474 KASSERT(len >= 0);
1475 KASSERT(off >= 0);
1476
1477 while (off > 0) {
1478 KASSERT(m != NULL);
1479 if (off < m->m_len)
1480 break;
1481 off -= m->m_len;
1482 m = m->m_next;
1483 }
1484 while (len > 0) {
1485 KASSERT(m != NULL);
1486 count = min(m->m_len - off, len);
1487
1488 rval = (*f)(arg, mtod(m, char *) + off, count);
1489 if (rval)
1490 return (rval);
1491
1492 len -= count;
1493 off = 0;
1494 m = m->m_next;
1495 }
1496
1497 return (0);
1498 }
1499
1500 /*
1501 * Return a pointer to mbuf/offset of location in mbuf chain.
1502 */
1503 struct mbuf *
1504 m_getptr(struct mbuf *m, int loc, int *off)
1505 {
1506
1507 while (loc >= 0) {
1508 /* Normal end of search */
1509 if (m->m_len > loc) {
1510 *off = loc;
1511 return (m);
1512 } else {
1513 loc -= m->m_len;
1514
1515 if (m->m_next == NULL) {
1516 if (loc == 0) {
1517 /* Point at the end of valid data */
1518 *off = m->m_len;
1519 return (m);
1520 } else
1521 return (NULL);
1522 } else
1523 m = m->m_next;
1524 }
1525 }
1526
1527 return (NULL);
1528 }
1529
1530 /*
1531 * m_ext_free: release a reference to the mbuf external storage.
1532 *
1533 * => free the mbuf m itsself as well.
1534 */
1535
1536 void
1537 m_ext_free(struct mbuf *m)
1538 {
1539 bool embedded = MEXT_ISEMBEDDED(m);
1540 bool dofree = true;
1541 u_int refcnt;
1542
1543 KASSERT((m->m_flags & M_EXT) != 0);
1544 KASSERT(MEXT_ISEMBEDDED(m->m_ext_ref));
1545 KASSERT((m->m_ext_ref->m_flags & M_EXT) != 0);
1546 KASSERT((m->m_flags & M_EXT_CLUSTER) ==
1547 (m->m_ext_ref->m_flags & M_EXT_CLUSTER));
1548
1549 if (__predict_true(m->m_ext.ext_refcnt == 1)) {
1550 refcnt = m->m_ext.ext_refcnt = 0;
1551 } else {
1552 refcnt = atomic_dec_uint_nv(&m->m_ext.ext_refcnt);
1553 }
1554 if (refcnt > 0) {
1555 if (embedded) {
1556 /*
1557 * other mbuf's m_ext_ref still points to us.
1558 */
1559 dofree = false;
1560 } else {
1561 m->m_ext_ref = m;
1562 }
1563 } else {
1564 /*
1565 * dropping the last reference
1566 */
1567 if (!embedded) {
1568 m->m_ext.ext_refcnt++; /* XXX */
1569 m_ext_free(m->m_ext_ref);
1570 m->m_ext_ref = m;
1571 } else if ((m->m_flags & M_EXT_CLUSTER) != 0) {
1572 pool_cache_put_paddr((struct pool_cache *)
1573 m->m_ext.ext_arg,
1574 m->m_ext.ext_buf, m->m_ext.ext_paddr);
1575 } else if (m->m_ext.ext_free) {
1576 (*m->m_ext.ext_free)(m,
1577 m->m_ext.ext_buf, m->m_ext.ext_size,
1578 m->m_ext.ext_arg);
1579 /*
1580 * 'm' is already freed by the ext_free callback.
1581 */
1582 dofree = false;
1583 } else {
1584 free(m->m_ext.ext_buf, m->m_ext.ext_type);
1585 }
1586 }
1587 if (dofree) {
1588 pool_cache_put(mb_cache, m);
1589 }
1590 }
1591
1592 #if defined(DDB)
1593 void
1594 m_print(const struct mbuf *m, const char *modif, void (*pr)(const char *, ...))
1595 {
1596 char ch;
1597 bool opt_c = false;
1598 char buf[512];
1599
1600 while ((ch = *(modif++)) != '\0') {
1601 switch (ch) {
1602 case 'c':
1603 opt_c = true;
1604 break;
1605 }
1606 }
1607
1608 nextchain:
1609 (*pr)("MBUF %p\n", m);
1610 snprintb(buf, sizeof(buf), M_FLAGS_BITS, (u_int)m->m_flags);
1611 (*pr)(" data=%p, len=%d, type=%d, flags=0x%s\n",
1612 m->m_data, m->m_len, m->m_type, buf);
1613 (*pr)(" owner=%p, next=%p, nextpkt=%p\n", m->m_owner, m->m_next,
1614 m->m_nextpkt);
1615 (*pr)(" leadingspace=%u, trailingspace=%u, readonly=%u\n",
1616 (int)M_LEADINGSPACE(m), (int)M_TRAILINGSPACE(m),
1617 (int)M_READONLY(m));
1618 if ((m->m_flags & M_PKTHDR) != 0) {
1619 snprintb(buf, sizeof(buf), M_CSUM_BITS, m->m_pkthdr.csum_flags);
1620 (*pr)(" pktlen=%d, rcvif=%p, csum_flags=0x%s, csum_data=0x%"
1621 PRIx32 ", segsz=%u\n",
1622 m->m_pkthdr.len, m->m_pkthdr.rcvif,
1623 buf, m->m_pkthdr.csum_data, m->m_pkthdr.segsz);
1624 }
1625 if ((m->m_flags & M_EXT)) {
1626 (*pr)(" ext_refcnt=%u, ext_buf=%p, ext_size=%zd, "
1627 "ext_free=%p, ext_arg=%p\n",
1628 m->m_ext.ext_refcnt,
1629 m->m_ext.ext_buf, m->m_ext.ext_size,
1630 m->m_ext.ext_free, m->m_ext.ext_arg);
1631 }
1632 if ((~m->m_flags & (M_EXT|M_EXT_PAGES)) == 0) {
1633 vaddr_t sva = (vaddr_t)m->m_ext.ext_buf;
1634 vaddr_t eva = sva + m->m_ext.ext_size;
1635 int n = (round_page(eva) - trunc_page(sva)) >> PAGE_SHIFT;
1636 int i;
1637
1638 (*pr)(" pages:");
1639 for (i = 0; i < n; i ++) {
1640 (*pr)(" %p", m->m_ext.ext_pgs[i]);
1641 }
1642 (*pr)("\n");
1643 }
1644
1645 if (opt_c) {
1646 m = m->m_next;
1647 if (m != NULL) {
1648 goto nextchain;
1649 }
1650 }
1651 }
1652 #endif /* defined(DDB) */
1653
1654 void
1655 mbstat_type_add(int type, int diff)
1656 {
1657 struct mbstat_cpu *mb;
1658 int s;
1659
1660 s = splvm();
1661 mb = percpu_getref(mbstat_percpu);
1662 mb->m_mtypes[type] += diff;
1663 percpu_putref(mbstat_percpu);
1664 splx(s);
1665 }
1666
1667 #if defined(MBUFTRACE)
1668 void
1669 mowner_attach(struct mowner *mo)
1670 {
1671
1672 KASSERT(mo->mo_counters == NULL);
1673 mo->mo_counters = percpu_alloc(sizeof(struct mowner_counter));
1674
1675 /* XXX lock */
1676 LIST_INSERT_HEAD(&mowners, mo, mo_link);
1677 }
1678
1679 void
1680 mowner_detach(struct mowner *mo)
1681 {
1682
1683 KASSERT(mo->mo_counters != NULL);
1684
1685 /* XXX lock */
1686 LIST_REMOVE(mo, mo_link);
1687
1688 percpu_free(mo->mo_counters, sizeof(struct mowner_counter));
1689 mo->mo_counters = NULL;
1690 }
1691
1692 void
1693 mowner_init(struct mbuf *m, int type)
1694 {
1695 struct mowner_counter *mc;
1696 struct mowner *mo;
1697 int s;
1698
1699 m->m_owner = mo = &unknown_mowners[type];
1700 s = splvm();
1701 mc = percpu_getref(mo->mo_counters);
1702 mc->mc_counter[MOWNER_COUNTER_CLAIMS]++;
1703 percpu_putref(mo->mo_counters);
1704 splx(s);
1705 }
1706
1707 void
1708 mowner_ref(struct mbuf *m, int flags)
1709 {
1710 struct mowner *mo = m->m_owner;
1711 struct mowner_counter *mc;
1712 int s;
1713
1714 s = splvm();
1715 mc = percpu_getref(mo->mo_counters);
1716 if ((flags & M_EXT) != 0)
1717 mc->mc_counter[MOWNER_COUNTER_EXT_CLAIMS]++;
1718 if ((flags & M_CLUSTER) != 0)
1719 mc->mc_counter[MOWNER_COUNTER_CLUSTER_CLAIMS]++;
1720 percpu_putref(mo->mo_counters);
1721 splx(s);
1722 }
1723
1724 void
1725 mowner_revoke(struct mbuf *m, bool all, int flags)
1726 {
1727 struct mowner *mo = m->m_owner;
1728 struct mowner_counter *mc;
1729 int s;
1730
1731 s = splvm();
1732 mc = percpu_getref(mo->mo_counters);
1733 if ((flags & M_EXT) != 0)
1734 mc->mc_counter[MOWNER_COUNTER_EXT_RELEASES]++;
1735 if ((flags & M_CLUSTER) != 0)
1736 mc->mc_counter[MOWNER_COUNTER_CLUSTER_RELEASES]++;
1737 if (all)
1738 mc->mc_counter[MOWNER_COUNTER_RELEASES]++;
1739 percpu_putref(mo->mo_counters);
1740 splx(s);
1741 if (all)
1742 m->m_owner = &revoked_mowner;
1743 }
1744
1745 static void
1746 mowner_claim(struct mbuf *m, struct mowner *mo)
1747 {
1748 struct mowner_counter *mc;
1749 int flags = m->m_flags;
1750 int s;
1751
1752 s = splvm();
1753 mc = percpu_getref(mo->mo_counters);
1754 mc->mc_counter[MOWNER_COUNTER_CLAIMS]++;
1755 if ((flags & M_EXT) != 0)
1756 mc->mc_counter[MOWNER_COUNTER_EXT_CLAIMS]++;
1757 if ((flags & M_CLUSTER) != 0)
1758 mc->mc_counter[MOWNER_COUNTER_CLUSTER_CLAIMS]++;
1759 percpu_putref(mo->mo_counters);
1760 splx(s);
1761 m->m_owner = mo;
1762 }
1763
1764 void
1765 m_claim(struct mbuf *m, struct mowner *mo)
1766 {
1767
1768 if (m->m_owner == mo || mo == NULL)
1769 return;
1770
1771 mowner_revoke(m, true, m->m_flags);
1772 mowner_claim(m, mo);
1773 }
1774 #endif /* defined(MBUFTRACE) */
NetBSD on the FriendlyARM MINI2440