uipc_mbuf.c revision 1.126 1 /* $NetBSD: uipc_mbuf.c,v 1.126 2008/04/09 05:11:20 thorpej 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 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the NetBSD
22 * Foundation, Inc. and its contributors.
23 * 4. Neither the name of The NetBSD Foundation nor the names of its
24 * contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40 /*
41 * Copyright (c) 1982, 1986, 1988, 1991, 1993
42 * The Regents of the University of California. All rights reserved.
43 *
44 * Redistribution and use in source and binary forms, with or without
45 * modification, are permitted provided that the following conditions
46 * are met:
47 * 1. Redistributions of source code must retain the above copyright
48 * notice, this list of conditions and the following disclaimer.
49 * 2. Redistributions in binary form must reproduce the above copyright
50 * notice, this list of conditions and the following disclaimer in the
51 * documentation and/or other materials provided with the distribution.
52 * 3. Neither the name of the University nor the names of its contributors
53 * may be used to endorse or promote products derived from this software
54 * without specific prior written permission.
55 *
56 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
57 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
58 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
59 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
60 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
61 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
62 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
63 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
64 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
65 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
66 * SUCH DAMAGE.
67 *
68 * @(#)uipc_mbuf.c 8.4 (Berkeley) 2/14/95
69 */
70
71 #include <sys/cdefs.h>
72 __KERNEL_RCSID(0, "$NetBSD: uipc_mbuf.c,v 1.126 2008/04/09 05:11:20 thorpej Exp $");
73
74 #include "opt_mbuftrace.h"
75 #include "opt_ddb.h"
76
77 #include <sys/param.h>
78 #include <sys/systm.h>
79 #include <sys/atomic.h>
80 #include <sys/cpu.h>
81 #include <sys/proc.h>
82 #include <sys/malloc.h>
83 #define MBTYPES
84 #include <sys/mbuf.h>
85 #include <sys/kernel.h>
86 #include <sys/syslog.h>
87 #include <sys/domain.h>
88 #include <sys/protosw.h>
89 #include <sys/percpu.h>
90 #include <sys/pool.h>
91 #include <sys/socket.h>
92 #include <sys/sysctl.h>
93
94 #include <net/if.h>
95
96 #include <uvm/uvm.h>
97
98 pool_cache_t mb_cache; /* mbuf cache */
99 pool_cache_t mcl_cache; /* mbuf cluster cache */
100
101 struct mbstat mbstat;
102 int max_linkhdr;
103 int max_protohdr;
104 int max_hdr;
105 int max_datalen;
106
107 static int mb_ctor(void *, void *, int);
108
109 static void *mclpool_alloc(struct pool *, int);
110 static void mclpool_release(struct pool *, void *);
111
112 static struct pool_allocator mclpool_allocator = {
113 .pa_alloc = mclpool_alloc,
114 .pa_free = mclpool_release,
115 };
116
117 static struct mbuf *m_copym0(struct mbuf *, int, int, int, int);
118 static struct mbuf *m_split0(struct mbuf *, int, int, int);
119 static int m_copyback0(struct mbuf **, int, int, const void *, int, int);
120
121 /* flags for m_copyback0 */
122 #define M_COPYBACK0_COPYBACK 0x0001 /* copyback from cp */
123 #define M_COPYBACK0_PRESERVE 0x0002 /* preserve original data */
124 #define M_COPYBACK0_COW 0x0004 /* do copy-on-write */
125 #define M_COPYBACK0_EXTEND 0x0008 /* extend chain */
126
127 static const char mclpool_warnmsg[] =
128 "WARNING: mclpool limit reached; increase NMBCLUSTERS";
129
130 MALLOC_DEFINE(M_MBUF, "mbuf", "mbuf");
131
132 static percpu_t *mbstat_percpu;
133
134 #ifdef MBUFTRACE
135 struct mownerhead mowners = LIST_HEAD_INITIALIZER(mowners);
136 struct mowner unknown_mowners[] = {
137 MOWNER_INIT("unknown", "free"),
138 MOWNER_INIT("unknown", "data"),
139 MOWNER_INIT("unknown", "header"),
140 MOWNER_INIT("unknown", "soname"),
141 MOWNER_INIT("unknown", "soopts"),
142 MOWNER_INIT("unknown", "ftable"),
143 MOWNER_INIT("unknown", "control"),
144 MOWNER_INIT("unknown", "oobdata"),
145 };
146 struct mowner revoked_mowner = MOWNER_INIT("revoked", "");
147 #endif
148
149 #define MEXT_ISEMBEDDED(m) ((m)->m_ext_ref == (m))
150
151 #define MCLADDREFERENCE(o, n) \
152 do { \
153 KASSERT(((o)->m_flags & M_EXT) != 0); \
154 KASSERT(((n)->m_flags & M_EXT) == 0); \
155 KASSERT((o)->m_ext.ext_refcnt >= 1); \
156 (n)->m_flags |= ((o)->m_flags & M_EXTCOPYFLAGS); \
157 atomic_inc_uint(&(o)->m_ext.ext_refcnt); \
158 (n)->m_ext_ref = (o)->m_ext_ref; \
159 mowner_ref((n), (n)->m_flags); \
160 MCLREFDEBUGN((n), __FILE__, __LINE__); \
161 } while (/* CONSTCOND */ 0)
162
163 /*
164 * Initialize the mbuf allocator.
165 */
166 void
167 mbinit(void)
168 {
169
170 KASSERT(sizeof(struct _m_ext) <= MHLEN);
171 KASSERT(sizeof(struct mbuf) == MSIZE);
172
173 mclpool_allocator.pa_backingmap = mb_map;
174
175 mb_cache = pool_cache_init(msize, 0, 0, 0, "mbpl",
176 NULL, IPL_VM, mb_ctor, NULL, NULL);
177 KASSERT(mb_cache != NULL);
178
179 mcl_cache = pool_cache_init(mclbytes, 0, 0, 0, "mclpl",
180 &mclpool_allocator, IPL_VM, NULL, NULL, NULL);
181 KASSERT(mcl_cache != NULL);
182
183 pool_cache_set_drain_hook(mb_cache, m_reclaim, NULL);
184 pool_cache_set_drain_hook(mcl_cache, m_reclaim, NULL);
185
186 /*
187 * Set the hard limit on the mclpool to the number of
188 * mbuf clusters the kernel is to support. Log the limit
189 * reached message max once a minute.
190 */
191 pool_cache_sethardlimit(mcl_cache, nmbclusters, mclpool_warnmsg, 60);
192
193 mbstat_percpu = percpu_alloc(sizeof(struct mbstat_cpu));
194
195 /*
196 * Set a low water mark for both mbufs and clusters. This should
197 * help ensure that they can be allocated in a memory starvation
198 * situation. This is important for e.g. diskless systems which
199 * must allocate mbufs in order for the pagedaemon to clean pages.
200 */
201 pool_cache_setlowat(mb_cache, mblowat);
202 pool_cache_setlowat(mcl_cache, mcllowat);
203
204 #ifdef MBUFTRACE
205 {
206 /*
207 * Attach the unknown mowners.
208 */
209 int i;
210 MOWNER_ATTACH(&revoked_mowner);
211 for (i = sizeof(unknown_mowners)/sizeof(unknown_mowners[0]);
212 i-- > 0; )
213 MOWNER_ATTACH(&unknown_mowners[i]);
214 }
215 #endif
216 }
217
218 /*
219 * sysctl helper routine for the kern.mbuf subtree. nmbclusters may
220 * or may not be writable, and mblowat and mcllowat need range
221 * checking and pool tweaking after being reset.
222 */
223 static int
224 sysctl_kern_mbuf(SYSCTLFN_ARGS)
225 {
226 int error, newval;
227 struct sysctlnode node;
228
229 node = *rnode;
230 node.sysctl_data = &newval;
231 switch (rnode->sysctl_num) {
232 case MBUF_NMBCLUSTERS:
233 if (mb_map != NULL) {
234 node.sysctl_flags &= ~CTLFLAG_READWRITE;
235 node.sysctl_flags |= CTLFLAG_READONLY;
236 }
237 /* FALLTHROUGH */
238 case MBUF_MBLOWAT:
239 case MBUF_MCLLOWAT:
240 newval = *(int*)rnode->sysctl_data;
241 break;
242 default:
243 return (EOPNOTSUPP);
244 }
245
246 error = sysctl_lookup(SYSCTLFN_CALL(&node));
247 if (error || newp == NULL)
248 return (error);
249 if (newval < 0)
250 return (EINVAL);
251
252 switch (node.sysctl_num) {
253 case MBUF_NMBCLUSTERS:
254 if (newval < nmbclusters)
255 return (EINVAL);
256 nmbclusters = newval;
257 pool_cache_sethardlimit(mcl_cache, nmbclusters,
258 mclpool_warnmsg, 60);
259 break;
260 case MBUF_MBLOWAT:
261 mblowat = newval;
262 pool_cache_setlowat(mb_cache, mblowat);
263 break;
264 case MBUF_MCLLOWAT:
265 mcllowat = newval;
266 pool_cache_setlowat(mcl_cache, mcllowat);
267 break;
268 }
269
270 return (0);
271 }
272
273 #ifdef MBUFTRACE
274 static void
275 mowner_conver_to_user_cb(void *v1, void *v2, struct cpu_info *ci)
276 {
277 struct mowner_counter *mc = v1;
278 struct mowner_user *mo_user = v2;
279 int i;
280
281 for (i = 0; i < MOWNER_COUNTER_NCOUNTERS; i++) {
282 mo_user->mo_counter[i] += mc->mc_counter[i];
283 }
284 }
285
286 static void
287 mowner_convert_to_user(struct mowner *mo, struct mowner_user *mo_user)
288 {
289
290 memset(mo_user, 0, sizeof(*mo_user));
291 KASSERT(sizeof(mo_user->mo_name) == sizeof(mo->mo_name));
292 KASSERT(sizeof(mo_user->mo_descr) == sizeof(mo->mo_descr));
293 memcpy(mo_user->mo_name, mo->mo_name, sizeof(mo->mo_name));
294 memcpy(mo_user->mo_descr, mo->mo_descr, sizeof(mo->mo_descr));
295 percpu_foreach(mo->mo_counters, mowner_conver_to_user_cb, mo_user);
296 }
297
298 static int
299 sysctl_kern_mbuf_mowners(SYSCTLFN_ARGS)
300 {
301 struct mowner *mo;
302 size_t len = 0;
303 int error = 0;
304
305 if (namelen != 0)
306 return (EINVAL);
307 if (newp != NULL)
308 return (EPERM);
309
310 LIST_FOREACH(mo, &mowners, mo_link) {
311 struct mowner_user mo_user;
312
313 mowner_convert_to_user(mo, &mo_user);
314
315 if (oldp != NULL) {
316 if (*oldlenp - len < sizeof(mo_user)) {
317 error = ENOMEM;
318 break;
319 }
320 error = copyout(&mo_user, (char *)oldp + len,
321 sizeof(mo_user));
322 if (error)
323 break;
324 }
325 len += sizeof(mo_user);
326 }
327
328 if (error == 0)
329 *oldlenp = len;
330
331 return (error);
332 }
333 #endif /* MBUFTRACE */
334
335 static void
336 mbstat_conver_to_user_cb(void *v1, void *v2, struct cpu_info *ci)
337 {
338 struct mbstat_cpu *mbsc = v1;
339 struct mbstat *mbs = v2;
340 int i;
341
342 for (i = 0; i < __arraycount(mbs->m_mtypes); i++) {
343 mbs->m_mtypes[i] += mbsc->m_mtypes[i];
344 }
345 }
346
347 static void
348 mbstat_convert_to_user(struct mbstat *mbs)
349 {
350
351 memset(mbs, 0, sizeof(*mbs));
352 mbs->m_drain = mbstat.m_drain;
353 percpu_foreach(mbstat_percpu, mbstat_conver_to_user_cb, mbs);
354 }
355
356 static int
357 sysctl_kern_mbuf_stats(SYSCTLFN_ARGS)
358 {
359 struct sysctlnode node;
360 struct mbstat mbs;
361
362 mbstat_convert_to_user(&mbs);
363 node = *rnode;
364 node.sysctl_data = &mbs;
365 node.sysctl_size = sizeof(mbs);
366 return sysctl_lookup(SYSCTLFN_CALL(&node));
367 }
368
369 SYSCTL_SETUP(sysctl_kern_mbuf_setup, "sysctl kern.mbuf subtree setup")
370 {
371
372 sysctl_createv(clog, 0, NULL, NULL,
373 CTLFLAG_PERMANENT,
374 CTLTYPE_NODE, "kern", NULL,
375 NULL, 0, NULL, 0,
376 CTL_KERN, CTL_EOL);
377 sysctl_createv(clog, 0, NULL, NULL,
378 CTLFLAG_PERMANENT,
379 CTLTYPE_NODE, "mbuf",
380 SYSCTL_DESCR("mbuf control variables"),
381 NULL, 0, NULL, 0,
382 CTL_KERN, KERN_MBUF, CTL_EOL);
383
384 sysctl_createv(clog, 0, NULL, NULL,
385 CTLFLAG_PERMANENT|CTLFLAG_IMMEDIATE,
386 CTLTYPE_INT, "msize",
387 SYSCTL_DESCR("mbuf base size"),
388 NULL, msize, NULL, 0,
389 CTL_KERN, KERN_MBUF, MBUF_MSIZE, CTL_EOL);
390 sysctl_createv(clog, 0, NULL, NULL,
391 CTLFLAG_PERMANENT|CTLFLAG_IMMEDIATE,
392 CTLTYPE_INT, "mclbytes",
393 SYSCTL_DESCR("mbuf cluster size"),
394 NULL, mclbytes, NULL, 0,
395 CTL_KERN, KERN_MBUF, MBUF_MCLBYTES, CTL_EOL);
396 sysctl_createv(clog, 0, NULL, NULL,
397 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
398 CTLTYPE_INT, "nmbclusters",
399 SYSCTL_DESCR("Limit on the number of mbuf clusters"),
400 sysctl_kern_mbuf, 0, &nmbclusters, 0,
401 CTL_KERN, KERN_MBUF, MBUF_NMBCLUSTERS, CTL_EOL);
402 sysctl_createv(clog, 0, NULL, NULL,
403 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
404 CTLTYPE_INT, "mblowat",
405 SYSCTL_DESCR("mbuf low water mark"),
406 sysctl_kern_mbuf, 0, &mblowat, 0,
407 CTL_KERN, KERN_MBUF, MBUF_MBLOWAT, CTL_EOL);
408 sysctl_createv(clog, 0, NULL, NULL,
409 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
410 CTLTYPE_INT, "mcllowat",
411 SYSCTL_DESCR("mbuf cluster low water mark"),
412 sysctl_kern_mbuf, 0, &mcllowat, 0,
413 CTL_KERN, KERN_MBUF, MBUF_MCLLOWAT, CTL_EOL);
414 sysctl_createv(clog, 0, NULL, NULL,
415 CTLFLAG_PERMANENT,
416 CTLTYPE_STRUCT, "stats",
417 SYSCTL_DESCR("mbuf allocation statistics"),
418 sysctl_kern_mbuf_stats, 0, NULL, 0,
419 CTL_KERN, KERN_MBUF, MBUF_STATS, CTL_EOL);
420 #ifdef MBUFTRACE
421 sysctl_createv(clog, 0, NULL, NULL,
422 CTLFLAG_PERMANENT,
423 CTLTYPE_STRUCT, "mowners",
424 SYSCTL_DESCR("Information about mbuf owners"),
425 sysctl_kern_mbuf_mowners, 0, NULL, 0,
426 CTL_KERN, KERN_MBUF, MBUF_MOWNERS, CTL_EOL);
427 #endif /* MBUFTRACE */
428 }
429
430 static void *
431 mclpool_alloc(struct pool *pp, int flags)
432 {
433 bool waitok = (flags & PR_WAITOK) ? true : false;
434
435 return ((void *)uvm_km_alloc_poolpage(mb_map, waitok));
436 }
437
438 static void
439 mclpool_release(struct pool *pp, void *v)
440 {
441
442 uvm_km_free_poolpage(mb_map, (vaddr_t)v);
443 }
444
445 /*ARGSUSED*/
446 static int
447 mb_ctor(void *arg, void *object, int flags)
448 {
449 struct mbuf *m = object;
450
451 #ifdef POOL_VTOPHYS
452 m->m_paddr = POOL_VTOPHYS(m);
453 #else
454 m->m_paddr = M_PADDR_INVALID;
455 #endif
456 return (0);
457 }
458
459 void
460 m_reclaim(void *arg, int flags)
461 {
462 struct domain *dp;
463 const struct protosw *pr;
464 struct ifnet *ifp;
465 int s;
466
467 KERNEL_LOCK(1, NULL);
468 s = splvm();
469 DOMAIN_FOREACH(dp) {
470 for (pr = dp->dom_protosw;
471 pr < dp->dom_protoswNPROTOSW; pr++)
472 if (pr->pr_drain)
473 (*pr->pr_drain)();
474 }
475 IFNET_FOREACH(ifp) {
476 if (ifp->if_drain)
477 (*ifp->if_drain)(ifp);
478 }
479 splx(s);
480 mbstat.m_drain++;
481 KERNEL_UNLOCK_ONE(NULL);
482 }
483
484 /*
485 * Space allocation routines.
486 * These are also available as macros
487 * for critical paths.
488 */
489 struct mbuf *
490 m_get(int nowait, int type)
491 {
492 struct mbuf *m;
493
494 m = pool_cache_get(mb_cache,
495 nowait == M_WAIT ? PR_WAITOK|PR_LIMITFAIL : 0);
496 if (m == NULL)
497 return NULL;
498
499 mbstat_type_add(type, 1);
500 mowner_init(m, type);
501 m->m_ext_ref = m;
502 m->m_type = type;
503 m->m_next = NULL;
504 m->m_nextpkt = NULL;
505 m->m_data = m->m_dat;
506 m->m_flags = 0;
507
508 return m;
509 }
510
511 struct mbuf *
512 m_gethdr(int nowait, int type)
513 {
514 struct mbuf *m;
515
516 m = m_get(nowait, type);
517 if (m == NULL)
518 return NULL;
519
520 m->m_data = m->m_pktdat;
521 m->m_flags = M_PKTHDR;
522 m->m_pkthdr.rcvif = NULL;
523 m->m_pkthdr.csum_flags = 0;
524 m->m_pkthdr.csum_data = 0;
525 SLIST_INIT(&m->m_pkthdr.tags);
526
527 return m;
528 }
529
530 struct mbuf *
531 m_getclr(int nowait, int type)
532 {
533 struct mbuf *m;
534
535 MGET(m, nowait, type);
536 if (m == 0)
537 return (NULL);
538 memset(mtod(m, void *), 0, MLEN);
539 return (m);
540 }
541
542 void
543 m_clget(struct mbuf *m, int nowait)
544 {
545
546 MCLGET(m, nowait);
547 }
548
549 struct mbuf *
550 m_free(struct mbuf *m)
551 {
552 struct mbuf *n;
553
554 MFREE(m, n);
555 return (n);
556 }
557
558 void
559 m_freem(struct mbuf *m)
560 {
561 struct mbuf *n;
562
563 if (m == NULL)
564 return;
565 do {
566 MFREE(m, n);
567 m = n;
568 } while (m);
569 }
570
571 #ifdef MBUFTRACE
572 /*
573 * Walk a chain of mbufs, claiming ownership of each mbuf in the chain.
574 */
575 void
576 m_claimm(struct mbuf *m, struct mowner *mo)
577 {
578
579 for (; m != NULL; m = m->m_next)
580 MCLAIM(m, mo);
581 }
582 #endif
583
584 /*
585 * Mbuffer utility routines.
586 */
587
588 /*
589 * Lesser-used path for M_PREPEND:
590 * allocate new mbuf to prepend to chain,
591 * copy junk along.
592 */
593 struct mbuf *
594 m_prepend(struct mbuf *m, int len, int how)
595 {
596 struct mbuf *mn;
597
598 MGET(mn, how, m->m_type);
599 if (mn == (struct mbuf *)NULL) {
600 m_freem(m);
601 return ((struct mbuf *)NULL);
602 }
603 if (m->m_flags & M_PKTHDR) {
604 M_MOVE_PKTHDR(mn, m);
605 } else {
606 MCLAIM(mn, m->m_owner);
607 }
608 mn->m_next = m;
609 m = mn;
610 if (len < MHLEN)
611 MH_ALIGN(m, len);
612 m->m_len = len;
613 return (m);
614 }
615
616 /*
617 * Make a copy of an mbuf chain starting "off0" bytes from the beginning,
618 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf.
619 * The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller.
620 */
621 int MCFail;
622
623 struct mbuf *
624 m_copym(struct mbuf *m, int off0, int len, int wait)
625 {
626
627 return m_copym0(m, off0, len, wait, 0); /* shallow copy on M_EXT */
628 }
629
630 struct mbuf *
631 m_dup(struct mbuf *m, int off0, int len, int wait)
632 {
633
634 return m_copym0(m, off0, len, wait, 1); /* deep copy */
635 }
636
637 static struct mbuf *
638 m_copym0(struct mbuf *m, int off0, int len, int wait, int deep)
639 {
640 struct mbuf *n, **np;
641 int off = off0;
642 struct mbuf *top;
643 int copyhdr = 0;
644
645 if (off < 0 || len < 0)
646 panic("m_copym: off %d, len %d", off, len);
647 if (off == 0 && m->m_flags & M_PKTHDR)
648 copyhdr = 1;
649 while (off > 0) {
650 if (m == 0)
651 panic("m_copym: m == 0, off %d", off);
652 if (off < m->m_len)
653 break;
654 off -= m->m_len;
655 m = m->m_next;
656 }
657 np = ⊤
658 top = 0;
659 while (len > 0) {
660 if (m == 0) {
661 if (len != M_COPYALL)
662 panic("m_copym: m == 0, len %d [!COPYALL]",
663 len);
664 break;
665 }
666 MGET(n, wait, m->m_type);
667 *np = n;
668 if (n == 0)
669 goto nospace;
670 MCLAIM(n, m->m_owner);
671 if (copyhdr) {
672 M_COPY_PKTHDR(n, m);
673 if (len == M_COPYALL)
674 n->m_pkthdr.len -= off0;
675 else
676 n->m_pkthdr.len = len;
677 copyhdr = 0;
678 }
679 n->m_len = min(len, m->m_len - off);
680 if (m->m_flags & M_EXT) {
681 if (!deep) {
682 n->m_data = m->m_data + off;
683 MCLADDREFERENCE(m, n);
684 } else {
685 /*
686 * we are unsure about the way m was allocated.
687 * copy into multiple MCLBYTES cluster mbufs.
688 */
689 MCLGET(n, wait);
690 n->m_len = 0;
691 n->m_len = M_TRAILINGSPACE(n);
692 n->m_len = min(n->m_len, len);
693 n->m_len = min(n->m_len, m->m_len - off);
694 memcpy(mtod(n, void *), mtod(m, char *) + off,
695 (unsigned)n->m_len);
696 }
697 } else
698 memcpy(mtod(n, void *), mtod(m, char *) + off,
699 (unsigned)n->m_len);
700 if (len != M_COPYALL)
701 len -= n->m_len;
702 off += n->m_len;
703 #ifdef DIAGNOSTIC
704 if (off > m->m_len)
705 panic("m_copym0 overrun");
706 #endif
707 if (off == m->m_len) {
708 m = m->m_next;
709 off = 0;
710 }
711 np = &n->m_next;
712 }
713 if (top == 0)
714 MCFail++;
715 return (top);
716 nospace:
717 m_freem(top);
718 MCFail++;
719 return (NULL);
720 }
721
722 /*
723 * Copy an entire packet, including header (which must be present).
724 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'.
725 */
726 struct mbuf *
727 m_copypacket(struct mbuf *m, int how)
728 {
729 struct mbuf *top, *n, *o;
730
731 MGET(n, how, m->m_type);
732 top = n;
733 if (!n)
734 goto nospace;
735
736 MCLAIM(n, m->m_owner);
737 M_COPY_PKTHDR(n, m);
738 n->m_len = m->m_len;
739 if (m->m_flags & M_EXT) {
740 n->m_data = m->m_data;
741 MCLADDREFERENCE(m, n);
742 } else {
743 memcpy(mtod(n, char *), mtod(m, char *), n->m_len);
744 }
745
746 m = m->m_next;
747 while (m) {
748 MGET(o, how, m->m_type);
749 if (!o)
750 goto nospace;
751
752 MCLAIM(o, m->m_owner);
753 n->m_next = o;
754 n = n->m_next;
755
756 n->m_len = m->m_len;
757 if (m->m_flags & M_EXT) {
758 n->m_data = m->m_data;
759 MCLADDREFERENCE(m, n);
760 } else {
761 memcpy(mtod(n, char *), mtod(m, char *), n->m_len);
762 }
763
764 m = m->m_next;
765 }
766 return top;
767 nospace:
768 m_freem(top);
769 MCFail++;
770 return NULL;
771 }
772
773 /*
774 * Copy data from an mbuf chain starting "off" bytes from the beginning,
775 * continuing for "len" bytes, into the indicated buffer.
776 */
777 void
778 m_copydata(struct mbuf *m, int off, int len, void *vp)
779 {
780 unsigned count;
781 void * cp = vp;
782
783 if (off < 0 || len < 0)
784 panic("m_copydata: off %d, len %d", off, len);
785 while (off > 0) {
786 if (m == NULL)
787 panic("m_copydata: m == NULL, off %d", off);
788 if (off < m->m_len)
789 break;
790 off -= m->m_len;
791 m = m->m_next;
792 }
793 while (len > 0) {
794 if (m == NULL)
795 panic("m_copydata: m == NULL, len %d", len);
796 count = min(m->m_len - off, len);
797 memcpy(cp, mtod(m, char *) + off, count);
798 len -= count;
799 cp = (char *)cp + count;
800 off = 0;
801 m = m->m_next;
802 }
803 }
804
805 /*
806 * Concatenate mbuf chain n to m.
807 * n might be copied into m (when n->m_len is small), therefore data portion of
808 * n could be copied into an mbuf of different mbuf type.
809 * Any m_pkthdr is not updated.
810 */
811 void
812 m_cat(struct mbuf *m, struct mbuf *n)
813 {
814
815 while (m->m_next)
816 m = m->m_next;
817 while (n) {
818 if (M_READONLY(m) || n->m_len > M_TRAILINGSPACE(m)) {
819 /* just join the two chains */
820 m->m_next = n;
821 return;
822 }
823 /* splat the data from one into the other */
824 memcpy(mtod(m, char *) + m->m_len, mtod(n, void *),
825 (u_int)n->m_len);
826 m->m_len += n->m_len;
827 n = m_free(n);
828 }
829 }
830
831 void
832 m_adj(struct mbuf *mp, int req_len)
833 {
834 int len = req_len;
835 struct mbuf *m;
836 int count;
837
838 if ((m = mp) == NULL)
839 return;
840 if (len >= 0) {
841 /*
842 * Trim from head.
843 */
844 while (m != NULL && len > 0) {
845 if (m->m_len <= len) {
846 len -= m->m_len;
847 m->m_len = 0;
848 m = m->m_next;
849 } else {
850 m->m_len -= len;
851 m->m_data += len;
852 len = 0;
853 }
854 }
855 m = mp;
856 if (mp->m_flags & M_PKTHDR)
857 m->m_pkthdr.len -= (req_len - len);
858 } else {
859 /*
860 * Trim from tail. Scan the mbuf chain,
861 * calculating its length and finding the last mbuf.
862 * If the adjustment only affects this mbuf, then just
863 * adjust and return. Otherwise, rescan and truncate
864 * after the remaining size.
865 */
866 len = -len;
867 count = 0;
868 for (;;) {
869 count += m->m_len;
870 if (m->m_next == (struct mbuf *)0)
871 break;
872 m = m->m_next;
873 }
874 if (m->m_len >= len) {
875 m->m_len -= len;
876 if (mp->m_flags & M_PKTHDR)
877 mp->m_pkthdr.len -= len;
878 return;
879 }
880 count -= len;
881 if (count < 0)
882 count = 0;
883 /*
884 * Correct length for chain is "count".
885 * Find the mbuf with last data, adjust its length,
886 * and toss data from remaining mbufs on chain.
887 */
888 m = mp;
889 if (m->m_flags & M_PKTHDR)
890 m->m_pkthdr.len = count;
891 for (; m; m = m->m_next) {
892 if (m->m_len >= count) {
893 m->m_len = count;
894 break;
895 }
896 count -= m->m_len;
897 }
898 if (m)
899 while (m->m_next)
900 (m = m->m_next)->m_len = 0;
901 }
902 }
903
904 /*
905 * Rearrange an mbuf chain so that len bytes are contiguous
906 * and in the data area of an mbuf (so that mtod and dtom
907 * will work for a structure of size len). Returns the resulting
908 * mbuf chain on success, frees it and returns null on failure.
909 * If there is room, it will add up to max_protohdr-len extra bytes to the
910 * contiguous region in an attempt to avoid being called next time.
911 */
912 int MPFail;
913
914 struct mbuf *
915 m_pullup(struct mbuf *n, int len)
916 {
917 struct mbuf *m;
918 int count;
919 int space;
920
921 /*
922 * If first mbuf has no cluster, and has room for len bytes
923 * without shifting current data, pullup into it,
924 * otherwise allocate a new mbuf to prepend to the chain.
925 */
926 if ((n->m_flags & M_EXT) == 0 &&
927 n->m_data + len < &n->m_dat[MLEN] && n->m_next) {
928 if (n->m_len >= len)
929 return (n);
930 m = n;
931 n = n->m_next;
932 len -= m->m_len;
933 } else {
934 if (len > MHLEN)
935 goto bad;
936 MGET(m, M_DONTWAIT, n->m_type);
937 if (m == 0)
938 goto bad;
939 MCLAIM(m, n->m_owner);
940 m->m_len = 0;
941 if (n->m_flags & M_PKTHDR) {
942 M_MOVE_PKTHDR(m, n);
943 }
944 }
945 space = &m->m_dat[MLEN] - (m->m_data + m->m_len);
946 do {
947 count = min(min(max(len, max_protohdr), space), n->m_len);
948 memcpy(mtod(m, char *) + m->m_len, mtod(n, void *),
949 (unsigned)count);
950 len -= count;
951 m->m_len += count;
952 n->m_len -= count;
953 space -= count;
954 if (n->m_len)
955 n->m_data += count;
956 else
957 n = m_free(n);
958 } while (len > 0 && n);
959 if (len > 0) {
960 (void) m_free(m);
961 goto bad;
962 }
963 m->m_next = n;
964 return (m);
965 bad:
966 m_freem(n);
967 MPFail++;
968 return (NULL);
969 }
970
971 /*
972 * Like m_pullup(), except a new mbuf is always allocated, and we allow
973 * the amount of empty space before the data in the new mbuf to be specified
974 * (in the event that the caller expects to prepend later).
975 */
976 int MSFail;
977
978 struct mbuf *
979 m_copyup(struct mbuf *n, int len, int dstoff)
980 {
981 struct mbuf *m;
982 int count, space;
983
984 if (len > (MHLEN - dstoff))
985 goto bad;
986 MGET(m, M_DONTWAIT, n->m_type);
987 if (m == NULL)
988 goto bad;
989 MCLAIM(m, n->m_owner);
990 m->m_len = 0;
991 if (n->m_flags & M_PKTHDR) {
992 M_MOVE_PKTHDR(m, n);
993 }
994 m->m_data += dstoff;
995 space = &m->m_dat[MLEN] - (m->m_data + m->m_len);
996 do {
997 count = min(min(max(len, max_protohdr), space), n->m_len);
998 memcpy(mtod(m, char *) + m->m_len, mtod(n, void *),
999 (unsigned)count);
1000 len -= count;
1001 m->m_len += count;
1002 n->m_len -= count;
1003 space -= count;
1004 if (n->m_len)
1005 n->m_data += count;
1006 else
1007 n = m_free(n);
1008 } while (len > 0 && n);
1009 if (len > 0) {
1010 (void) m_free(m);
1011 goto bad;
1012 }
1013 m->m_next = n;
1014 return (m);
1015 bad:
1016 m_freem(n);
1017 MSFail++;
1018 return (NULL);
1019 }
1020
1021 /*
1022 * Partition an mbuf chain in two pieces, returning the tail --
1023 * all but the first len0 bytes. In case of failure, it returns NULL and
1024 * attempts to restore the chain to its original state.
1025 */
1026 struct mbuf *
1027 m_split(struct mbuf *m0, int len0, int wait)
1028 {
1029
1030 return m_split0(m0, len0, wait, 1);
1031 }
1032
1033 static struct mbuf *
1034 m_split0(struct mbuf *m0, int len0, int wait, int copyhdr)
1035 {
1036 struct mbuf *m, *n;
1037 unsigned len = len0, remain, len_save;
1038
1039 for (m = m0; m && len > m->m_len; m = m->m_next)
1040 len -= m->m_len;
1041 if (m == 0)
1042 return (NULL);
1043 remain = m->m_len - len;
1044 if (copyhdr && (m0->m_flags & M_PKTHDR)) {
1045 MGETHDR(n, wait, m0->m_type);
1046 if (n == 0)
1047 return (NULL);
1048 MCLAIM(n, m0->m_owner);
1049 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif;
1050 n->m_pkthdr.len = m0->m_pkthdr.len - len0;
1051 len_save = m0->m_pkthdr.len;
1052 m0->m_pkthdr.len = len0;
1053 if (m->m_flags & M_EXT)
1054 goto extpacket;
1055 if (remain > MHLEN) {
1056 /* m can't be the lead packet */
1057 MH_ALIGN(n, 0);
1058 n->m_next = m_split(m, len, wait);
1059 if (n->m_next == 0) {
1060 (void) m_free(n);
1061 m0->m_pkthdr.len = len_save;
1062 return (NULL);
1063 } else
1064 return (n);
1065 } else
1066 MH_ALIGN(n, remain);
1067 } else if (remain == 0) {
1068 n = m->m_next;
1069 m->m_next = 0;
1070 return (n);
1071 } else {
1072 MGET(n, wait, m->m_type);
1073 if (n == 0)
1074 return (NULL);
1075 MCLAIM(n, m->m_owner);
1076 M_ALIGN(n, remain);
1077 }
1078 extpacket:
1079 if (m->m_flags & M_EXT) {
1080 n->m_data = m->m_data + len;
1081 MCLADDREFERENCE(m, n);
1082 } else {
1083 memcpy(mtod(n, void *), mtod(m, char *) + len, remain);
1084 }
1085 n->m_len = remain;
1086 m->m_len = len;
1087 n->m_next = m->m_next;
1088 m->m_next = 0;
1089 return (n);
1090 }
1091 /*
1092 * Routine to copy from device local memory into mbufs.
1093 */
1094 struct mbuf *
1095 m_devget(char *buf, int totlen, int off0, struct ifnet *ifp,
1096 void (*copy)(const void *from, void *to, size_t len))
1097 {
1098 struct mbuf *m;
1099 struct mbuf *top = 0, **mp = ⊤
1100 int off = off0, len;
1101 char *cp;
1102 char *epkt;
1103
1104 cp = buf;
1105 epkt = cp + totlen;
1106 if (off) {
1107 /*
1108 * If 'off' is non-zero, packet is trailer-encapsulated,
1109 * so we have to skip the type and length fields.
1110 */
1111 cp += off + 2 * sizeof(uint16_t);
1112 totlen -= 2 * sizeof(uint16_t);
1113 }
1114 MGETHDR(m, M_DONTWAIT, MT_DATA);
1115 if (m == 0)
1116 return (NULL);
1117 m->m_pkthdr.rcvif = ifp;
1118 m->m_pkthdr.len = totlen;
1119 m->m_len = MHLEN;
1120
1121 while (totlen > 0) {
1122 if (top) {
1123 MGET(m, M_DONTWAIT, MT_DATA);
1124 if (m == 0) {
1125 m_freem(top);
1126 return (NULL);
1127 }
1128 m->m_len = MLEN;
1129 }
1130 len = min(totlen, epkt - cp);
1131 if (len >= MINCLSIZE) {
1132 MCLGET(m, M_DONTWAIT);
1133 if ((m->m_flags & M_EXT) == 0) {
1134 m_free(m);
1135 m_freem(top);
1136 return (NULL);
1137 }
1138 m->m_len = len = min(len, MCLBYTES);
1139 } else {
1140 /*
1141 * Place initial small packet/header at end of mbuf.
1142 */
1143 if (len < m->m_len) {
1144 if (top == 0 && len + max_linkhdr <= m->m_len)
1145 m->m_data += max_linkhdr;
1146 m->m_len = len;
1147 } else
1148 len = m->m_len;
1149 }
1150 if (copy)
1151 copy(cp, mtod(m, void *), (size_t)len);
1152 else
1153 memcpy(mtod(m, void *), cp, (size_t)len);
1154 cp += len;
1155 *mp = m;
1156 mp = &m->m_next;
1157 totlen -= len;
1158 if (cp == epkt)
1159 cp = buf;
1160 }
1161 return (top);
1162 }
1163
1164 /*
1165 * Copy data from a buffer back into the indicated mbuf chain,
1166 * starting "off" bytes from the beginning, extending the mbuf
1167 * chain if necessary.
1168 */
1169 void
1170 m_copyback(struct mbuf *m0, int off, int len, const void *cp)
1171 {
1172 #if defined(DEBUG)
1173 struct mbuf *origm = m0;
1174 int error;
1175 #endif /* defined(DEBUG) */
1176
1177 if (m0 == NULL)
1178 return;
1179
1180 #if defined(DEBUG)
1181 error =
1182 #endif /* defined(DEBUG) */
1183 m_copyback0(&m0, off, len, cp,
1184 M_COPYBACK0_COPYBACK|M_COPYBACK0_EXTEND, M_DONTWAIT);
1185
1186 #if defined(DEBUG)
1187 if (error != 0 || (m0 != NULL && origm != m0))
1188 panic("m_copyback");
1189 #endif /* defined(DEBUG) */
1190 }
1191
1192 struct mbuf *
1193 m_copyback_cow(struct mbuf *m0, int off, int len, const void *cp, int how)
1194 {
1195 int error;
1196
1197 /* don't support chain expansion */
1198 KDASSERT(off + len <= m_length(m0));
1199
1200 error = m_copyback0(&m0, off, len, cp,
1201 M_COPYBACK0_COPYBACK|M_COPYBACK0_COW, how);
1202 if (error) {
1203 /*
1204 * no way to recover from partial success.
1205 * just free the chain.
1206 */
1207 m_freem(m0);
1208 return NULL;
1209 }
1210 return m0;
1211 }
1212
1213 /*
1214 * m_makewritable: ensure the specified range writable.
1215 */
1216 int
1217 m_makewritable(struct mbuf **mp, int off, int len, int how)
1218 {
1219 int error;
1220 #if defined(DEBUG)
1221 struct mbuf *n;
1222 int origlen, reslen;
1223
1224 origlen = m_length(*mp);
1225 #endif /* defined(DEBUG) */
1226
1227 #if 0 /* M_COPYALL is large enough */
1228 if (len == M_COPYALL)
1229 len = m_length(*mp) - off; /* XXX */
1230 #endif
1231
1232 error = m_copyback0(mp, off, len, NULL,
1233 M_COPYBACK0_PRESERVE|M_COPYBACK0_COW, how);
1234
1235 #if defined(DEBUG)
1236 reslen = 0;
1237 for (n = *mp; n; n = n->m_next)
1238 reslen += n->m_len;
1239 if (origlen != reslen)
1240 panic("m_makewritable: length changed");
1241 if (((*mp)->m_flags & M_PKTHDR) != 0 && reslen != (*mp)->m_pkthdr.len)
1242 panic("m_makewritable: inconsist");
1243 #endif /* defined(DEBUG) */
1244
1245 return error;
1246 }
1247
1248 int
1249 m_copyback0(struct mbuf **mp0, int off, int len, const void *vp, int flags,
1250 int how)
1251 {
1252 int mlen;
1253 struct mbuf *m, *n;
1254 struct mbuf **mp;
1255 int totlen = 0;
1256 const char *cp = vp;
1257
1258 KASSERT(mp0 != NULL);
1259 KASSERT(*mp0 != NULL);
1260 KASSERT((flags & M_COPYBACK0_PRESERVE) == 0 || cp == NULL);
1261 KASSERT((flags & M_COPYBACK0_COPYBACK) == 0 || cp != NULL);
1262
1263 /*
1264 * we don't bother to update "totlen" in the case of M_COPYBACK0_COW,
1265 * assuming that M_COPYBACK0_EXTEND and M_COPYBACK0_COW are exclusive.
1266 */
1267
1268 KASSERT((~flags & (M_COPYBACK0_EXTEND|M_COPYBACK0_COW)) != 0);
1269
1270 mp = mp0;
1271 m = *mp;
1272 while (off > (mlen = m->m_len)) {
1273 off -= mlen;
1274 totlen += mlen;
1275 if (m->m_next == NULL) {
1276 int tspace;
1277 extend:
1278 if ((flags & M_COPYBACK0_EXTEND) == 0)
1279 goto out;
1280
1281 /*
1282 * try to make some space at the end of "m".
1283 */
1284
1285 mlen = m->m_len;
1286 if (off + len >= MINCLSIZE &&
1287 (m->m_flags & M_EXT) == 0 && m->m_len == 0) {
1288 MCLGET(m, how);
1289 }
1290 tspace = M_TRAILINGSPACE(m);
1291 if (tspace > 0) {
1292 tspace = min(tspace, off + len);
1293 KASSERT(tspace > 0);
1294 memset(mtod(m, char *) + m->m_len, 0,
1295 min(off, tspace));
1296 m->m_len += tspace;
1297 off += mlen;
1298 totlen -= mlen;
1299 continue;
1300 }
1301
1302 /*
1303 * need to allocate an mbuf.
1304 */
1305
1306 if (off + len >= MINCLSIZE) {
1307 n = m_getcl(how, m->m_type, 0);
1308 } else {
1309 n = m_get(how, m->m_type);
1310 }
1311 if (n == NULL) {
1312 goto out;
1313 }
1314 n->m_len = 0;
1315 n->m_len = min(M_TRAILINGSPACE(n), off + len);
1316 memset(mtod(n, char *), 0, min(n->m_len, off));
1317 m->m_next = n;
1318 }
1319 mp = &m->m_next;
1320 m = m->m_next;
1321 }
1322 while (len > 0) {
1323 mlen = m->m_len - off;
1324 if (mlen != 0 && M_READONLY(m)) {
1325 char *datap;
1326 int eatlen;
1327
1328 /*
1329 * this mbuf is read-only.
1330 * allocate a new writable mbuf and try again.
1331 */
1332
1333 #if defined(DIAGNOSTIC)
1334 if ((flags & M_COPYBACK0_COW) == 0)
1335 panic("m_copyback0: read-only");
1336 #endif /* defined(DIAGNOSTIC) */
1337
1338 /*
1339 * if we're going to write into the middle of
1340 * a mbuf, split it first.
1341 */
1342 if (off > 0 && len < mlen) {
1343 n = m_split0(m, off, how, 0);
1344 if (n == NULL)
1345 goto enobufs;
1346 m->m_next = n;
1347 mp = &m->m_next;
1348 m = n;
1349 off = 0;
1350 continue;
1351 }
1352
1353 /*
1354 * XXX TODO coalesce into the trailingspace of
1355 * the previous mbuf when possible.
1356 */
1357
1358 /*
1359 * allocate a new mbuf. copy packet header if needed.
1360 */
1361 MGET(n, how, m->m_type);
1362 if (n == NULL)
1363 goto enobufs;
1364 MCLAIM(n, m->m_owner);
1365 if (off == 0 && (m->m_flags & M_PKTHDR) != 0) {
1366 M_MOVE_PKTHDR(n, m);
1367 n->m_len = MHLEN;
1368 } else {
1369 if (len >= MINCLSIZE)
1370 MCLGET(n, M_DONTWAIT);
1371 n->m_len =
1372 (n->m_flags & M_EXT) ? MCLBYTES : MLEN;
1373 }
1374 if (n->m_len > len)
1375 n->m_len = len;
1376
1377 /*
1378 * free the region which has been overwritten.
1379 * copying data from old mbufs if requested.
1380 */
1381 if (flags & M_COPYBACK0_PRESERVE)
1382 datap = mtod(n, char *);
1383 else
1384 datap = NULL;
1385 eatlen = n->m_len;
1386 KDASSERT(off == 0 || eatlen >= mlen);
1387 if (off > 0) {
1388 KDASSERT(len >= mlen);
1389 m->m_len = off;
1390 m->m_next = n;
1391 if (datap) {
1392 m_copydata(m, off, mlen, datap);
1393 datap += mlen;
1394 }
1395 eatlen -= mlen;
1396 mp = &m->m_next;
1397 m = m->m_next;
1398 }
1399 while (m != NULL && M_READONLY(m) &&
1400 n->m_type == m->m_type && eatlen > 0) {
1401 mlen = min(eatlen, m->m_len);
1402 if (datap) {
1403 m_copydata(m, 0, mlen, datap);
1404 datap += mlen;
1405 }
1406 m->m_data += mlen;
1407 m->m_len -= mlen;
1408 eatlen -= mlen;
1409 if (m->m_len == 0)
1410 *mp = m = m_free(m);
1411 }
1412 if (eatlen > 0)
1413 n->m_len -= eatlen;
1414 n->m_next = m;
1415 *mp = m = n;
1416 continue;
1417 }
1418 mlen = min(mlen, len);
1419 if (flags & M_COPYBACK0_COPYBACK) {
1420 memcpy(mtod(m, char *) + off, cp, (unsigned)mlen);
1421 cp += mlen;
1422 }
1423 len -= mlen;
1424 mlen += off;
1425 off = 0;
1426 totlen += mlen;
1427 if (len == 0)
1428 break;
1429 if (m->m_next == NULL) {
1430 goto extend;
1431 }
1432 mp = &m->m_next;
1433 m = m->m_next;
1434 }
1435 out: if (((m = *mp0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) {
1436 KASSERT((flags & M_COPYBACK0_EXTEND) != 0);
1437 m->m_pkthdr.len = totlen;
1438 }
1439
1440 return 0;
1441
1442 enobufs:
1443 return ENOBUFS;
1444 }
1445
1446 void
1447 m_move_pkthdr(struct mbuf *to, struct mbuf *from)
1448 {
1449
1450 KASSERT((to->m_flags & M_EXT) == 0);
1451 KASSERT((to->m_flags & M_PKTHDR) == 0 || m_tag_first(to) == NULL);
1452 KASSERT((from->m_flags & M_PKTHDR) != 0);
1453
1454 to->m_pkthdr = from->m_pkthdr;
1455 to->m_flags = from->m_flags & M_COPYFLAGS;
1456 to->m_data = to->m_pktdat;
1457
1458 from->m_flags &= ~M_PKTHDR;
1459 }
1460
1461 /*
1462 * Apply function f to the data in an mbuf chain starting "off" bytes from the
1463 * beginning, continuing for "len" bytes.
1464 */
1465 int
1466 m_apply(struct mbuf *m, int off, int len,
1467 int (*f)(void *, void *, unsigned int), void *arg)
1468 {
1469 unsigned int count;
1470 int rval;
1471
1472 KASSERT(len >= 0);
1473 KASSERT(off >= 0);
1474
1475 while (off > 0) {
1476 KASSERT(m != NULL);
1477 if (off < m->m_len)
1478 break;
1479 off -= m->m_len;
1480 m = m->m_next;
1481 }
1482 while (len > 0) {
1483 KASSERT(m != NULL);
1484 count = min(m->m_len - off, len);
1485
1486 rval = (*f)(arg, mtod(m, char *) + off, count);
1487 if (rval)
1488 return (rval);
1489
1490 len -= count;
1491 off = 0;
1492 m = m->m_next;
1493 }
1494
1495 return (0);
1496 }
1497
1498 /*
1499 * Return a pointer to mbuf/offset of location in mbuf chain.
1500 */
1501 struct mbuf *
1502 m_getptr(struct mbuf *m, int loc, int *off)
1503 {
1504
1505 while (loc >= 0) {
1506 /* Normal end of search */
1507 if (m->m_len > loc) {
1508 *off = loc;
1509 return (m);
1510 } else {
1511 loc -= m->m_len;
1512
1513 if (m->m_next == NULL) {
1514 if (loc == 0) {
1515 /* Point at the end of valid data */
1516 *off = m->m_len;
1517 return (m);
1518 } else
1519 return (NULL);
1520 } else
1521 m = m->m_next;
1522 }
1523 }
1524
1525 return (NULL);
1526 }
1527
1528 /*
1529 * m_ext_free: release a reference to the mbuf external storage.
1530 *
1531 * => free the mbuf m itsself as well.
1532 */
1533
1534 void
1535 m_ext_free(struct mbuf *m)
1536 {
1537 bool embedded = MEXT_ISEMBEDDED(m);
1538 bool dofree = true;
1539 u_int refcnt;
1540
1541 KASSERT((m->m_flags & M_EXT) != 0);
1542 KASSERT(MEXT_ISEMBEDDED(m->m_ext_ref));
1543 KASSERT((m->m_ext_ref->m_flags & M_EXT) != 0);
1544 KASSERT((m->m_flags & M_EXT_CLUSTER) ==
1545 (m->m_ext_ref->m_flags & M_EXT_CLUSTER));
1546
1547 if (__predict_true(m->m_ext.ext_refcnt == 1)) {
1548 refcnt = m->m_ext.ext_refcnt = 0;
1549 } else {
1550 refcnt = atomic_dec_uint_nv(&m->m_ext.ext_refcnt);
1551 }
1552 if (refcnt > 0) {
1553 if (embedded) {
1554 /*
1555 * other mbuf's m_ext_ref still points to us.
1556 */
1557 dofree = false;
1558 } else {
1559 m->m_ext_ref = m;
1560 }
1561 } else {
1562 /*
1563 * dropping the last reference
1564 */
1565 if (!embedded) {
1566 m->m_ext.ext_refcnt++; /* XXX */
1567 m_ext_free(m->m_ext_ref);
1568 m->m_ext_ref = m;
1569 } else if ((m->m_flags & M_EXT_CLUSTER) != 0) {
1570 pool_cache_put_paddr((struct pool_cache *)
1571 m->m_ext.ext_arg,
1572 m->m_ext.ext_buf, m->m_ext.ext_paddr);
1573 } else if (m->m_ext.ext_free) {
1574 (*m->m_ext.ext_free)(m,
1575 m->m_ext.ext_buf, m->m_ext.ext_size,
1576 m->m_ext.ext_arg);
1577 /*
1578 * 'm' is already freed by the ext_free callback.
1579 */
1580 dofree = false;
1581 } else {
1582 free(m->m_ext.ext_buf, m->m_ext.ext_type);
1583 }
1584 }
1585 if (dofree) {
1586 pool_cache_put(mb_cache, m);
1587 }
1588 }
1589
1590 #if defined(DDB)
1591 void
1592 m_print(const struct mbuf *m, const char *modif, void (*pr)(const char *, ...))
1593 {
1594 char ch;
1595 bool opt_c = false;
1596 char buf[512];
1597
1598 while ((ch = *(modif++)) != '\0') {
1599 switch (ch) {
1600 case 'c':
1601 opt_c = true;
1602 break;
1603 }
1604 }
1605
1606 nextchain:
1607 (*pr)("MBUF %p\n", m);
1608 bitmask_snprintf((u_int)m->m_flags, M_FLAGS_BITS, buf, sizeof(buf));
1609 (*pr)(" data=%p, len=%d, type=%d, flags=0x%s\n",
1610 m->m_data, m->m_len, m->m_type, buf);
1611 (*pr)(" owner=%p, next=%p, nextpkt=%p\n", m->m_owner, m->m_next,
1612 m->m_nextpkt);
1613 (*pr)(" leadingspace=%u, trailingspace=%u, readonly=%u\n",
1614 (int)M_LEADINGSPACE(m), (int)M_TRAILINGSPACE(m),
1615 (int)M_READONLY(m));
1616 if ((m->m_flags & M_PKTHDR) != 0) {
1617 bitmask_snprintf(m->m_pkthdr.csum_flags, M_CSUM_BITS, buf,
1618 sizeof(buf));
1619 (*pr)(" pktlen=%d, rcvif=%p, csum_flags=0x%s, csum_data=0x%"
1620 PRIx32 ", segsz=%u\n",
1621 m->m_pkthdr.len, m->m_pkthdr.rcvif,
1622 buf, m->m_pkthdr.csum_data, m->m_pkthdr.segsz);
1623 }
1624 if ((m->m_flags & M_EXT)) {
1625 (*pr)(" ext_refcnt=%u, ext_buf=%p, ext_size=%zd, "
1626 "ext_free=%p, ext_arg=%p\n",
1627 m->m_ext.ext_refcnt,
1628 m->m_ext.ext_buf, m->m_ext.ext_size,
1629 m->m_ext.ext_free, m->m_ext.ext_arg);
1630 }
1631 if ((~m->m_flags & (M_EXT|M_EXT_PAGES)) == 0) {
1632 vaddr_t sva = (vaddr_t)m->m_ext.ext_buf;
1633 vaddr_t eva = sva + m->m_ext.ext_size;
1634 int n = (round_page(eva) - trunc_page(sva)) >> PAGE_SHIFT;
1635 int i;
1636
1637 (*pr)(" pages:");
1638 for (i = 0; i < n; i ++) {
1639 (*pr)(" %p", m->m_ext.ext_pgs[i]);
1640 }
1641 (*pr)("\n");
1642 }
1643
1644 if (opt_c) {
1645 m = m->m_next;
1646 if (m != NULL) {
1647 goto nextchain;
1648 }
1649 }
1650 }
1651 #endif /* defined(DDB) */
1652
1653 void
1654 mbstat_type_add(int type, int diff)
1655 {
1656 struct mbstat_cpu *mb;
1657 int s;
1658
1659 s = splvm();
1660 mb = percpu_getref(mbstat_percpu);
1661 mb->m_mtypes[type] += diff;
1662 percpu_putref(mbstat_percpu);
1663 splx(s);
1664 }
1665
1666 #if defined(MBUFTRACE)
1667 void
1668 mowner_attach(struct mowner *mo)
1669 {
1670
1671 KASSERT(mo->mo_counters == NULL);
1672 mo->mo_counters = percpu_alloc(sizeof(struct mowner_counter));
1673
1674 /* XXX lock */
1675 LIST_INSERT_HEAD(&mowners, mo, mo_link);
1676 }
1677
1678 void
1679 mowner_detach(struct mowner *mo)
1680 {
1681
1682 KASSERT(mo->mo_counters != NULL);
1683
1684 /* XXX lock */
1685 LIST_REMOVE(mo, mo_link);
1686
1687 percpu_free(mo->mo_counters, sizeof(struct mowner_counter));
1688 mo->mo_counters = NULL;
1689 }
1690
1691 void
1692 mowner_init(struct mbuf *m, int type)
1693 {
1694 struct mowner_counter *mc;
1695 struct mowner *mo;
1696 int s;
1697
1698 m->m_owner = mo = &unknown_mowners[type];
1699 s = splvm();
1700 mc = percpu_getref(mo->mo_counters);
1701 mc->mc_counter[MOWNER_COUNTER_CLAIMS]++;
1702 percpu_putref(mo->mo_counters);
1703 splx(s);
1704 }
1705
1706 void
1707 mowner_ref(struct mbuf *m, int flags)
1708 {
1709 struct mowner *mo = m->m_owner;
1710 struct mowner_counter *mc;
1711 int s;
1712
1713 s = splvm();
1714 mc = percpu_getref(mo->mo_counters);
1715 if ((flags & M_EXT) != 0)
1716 mc->mc_counter[MOWNER_COUNTER_EXT_CLAIMS]++;
1717 if ((flags & M_CLUSTER) != 0)
1718 mc->mc_counter[MOWNER_COUNTER_CLUSTER_CLAIMS]++;
1719 percpu_putref(mo->mo_counters);
1720 splx(s);
1721 }
1722
1723 void
1724 mowner_revoke(struct mbuf *m, bool all, int flags)
1725 {
1726 struct mowner *mo = m->m_owner;
1727 struct mowner_counter *mc;
1728 int s;
1729
1730 s = splvm();
1731 mc = percpu_getref(mo->mo_counters);
1732 if ((flags & M_EXT) != 0)
1733 mc->mc_counter[MOWNER_COUNTER_EXT_RELEASES]++;
1734 if ((flags & M_CLUSTER) != 0)
1735 mc->mc_counter[MOWNER_COUNTER_CLUSTER_RELEASES]++;
1736 if (all)
1737 mc->mc_counter[MOWNER_COUNTER_RELEASES]++;
1738 percpu_putref(mo->mo_counters);
1739 splx(s);
1740 if (all)
1741 m->m_owner = &revoked_mowner;
1742 }
1743
1744 static void
1745 mowner_claim(struct mbuf *m, struct mowner *mo)
1746 {
1747 struct mowner_counter *mc;
1748 int flags = m->m_flags;
1749 int s;
1750
1751 s = splvm();
1752 mc = percpu_getref(mo->mo_counters);
1753 mc->mc_counter[MOWNER_COUNTER_CLAIMS]++;
1754 if ((flags & M_EXT) != 0)
1755 mc->mc_counter[MOWNER_COUNTER_EXT_CLAIMS]++;
1756 if ((flags & M_CLUSTER) != 0)
1757 mc->mc_counter[MOWNER_COUNTER_CLUSTER_CLAIMS]++;
1758 percpu_putref(mo->mo_counters);
1759 splx(s);
1760 m->m_owner = mo;
1761 }
1762
1763 void
1764 m_claim(struct mbuf *m, struct mowner *mo)
1765 {
1766
1767 if (m->m_owner == mo || mo == NULL)
1768 return;
1769
1770 mowner_revoke(m, true, m->m_flags);
1771 mowner_claim(m, mo);
1772 }
1773 #endif /* defined(MBUFTRACE) */
1774