FreeBSD/Linux Kernel Cross Reference
sys/kern/uipc_mbuf.c
1 /*-
2 * Copyright (c) 1982, 1986, 1988, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)uipc_mbuf.c 8.2 (Berkeley) 1/4/94
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD: releng/10.1/sys/kern/uipc_mbuf.c 258483 2013-11-22 19:27:17Z glebius $");
34
35 #include "opt_param.h"
36 #include "opt_mbuf_stress_test.h"
37 #include "opt_mbuf_profiling.h"
38
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/kernel.h>
42 #include <sys/limits.h>
43 #include <sys/lock.h>
44 #include <sys/malloc.h>
45 #include <sys/mbuf.h>
46 #include <sys/sysctl.h>
47 #include <sys/domain.h>
48 #include <sys/protosw.h>
49 #include <sys/uio.h>
50
51 int max_linkhdr;
52 int max_protohdr;
53 int max_hdr;
54 int max_datalen;
55 #ifdef MBUF_STRESS_TEST
56 int m_defragpackets;
57 int m_defragbytes;
58 int m_defraguseless;
59 int m_defragfailure;
60 int m_defragrandomfailures;
61 #endif
62
63 /*
64 * sysctl(8) exported objects
65 */
66 SYSCTL_INT(_kern_ipc, KIPC_MAX_LINKHDR, max_linkhdr, CTLFLAG_RD,
67 &max_linkhdr, 0, "Size of largest link layer header");
68 SYSCTL_INT(_kern_ipc, KIPC_MAX_PROTOHDR, max_protohdr, CTLFLAG_RD,
69 &max_protohdr, 0, "Size of largest protocol layer header");
70 SYSCTL_INT(_kern_ipc, KIPC_MAX_HDR, max_hdr, CTLFLAG_RD,
71 &max_hdr, 0, "Size of largest link plus protocol header");
72 SYSCTL_INT(_kern_ipc, KIPC_MAX_DATALEN, max_datalen, CTLFLAG_RD,
73 &max_datalen, 0, "Minimum space left in mbuf after max_hdr");
74 #ifdef MBUF_STRESS_TEST
75 SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragpackets, CTLFLAG_RD,
76 &m_defragpackets, 0, "");
77 SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragbytes, CTLFLAG_RD,
78 &m_defragbytes, 0, "");
79 SYSCTL_INT(_kern_ipc, OID_AUTO, m_defraguseless, CTLFLAG_RD,
80 &m_defraguseless, 0, "");
81 SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragfailure, CTLFLAG_RD,
82 &m_defragfailure, 0, "");
83 SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragrandomfailures, CTLFLAG_RW,
84 &m_defragrandomfailures, 0, "");
85 #endif
86
87 /*
88 * Ensure the correct size of various mbuf parameters. It could be off due
89 * to compiler-induced padding and alignment artifacts.
90 */
91 CTASSERT(sizeof(struct mbuf) == MSIZE);
92 CTASSERT(MSIZE - offsetof(struct mbuf, m_dat) == MLEN);
93 CTASSERT(MSIZE - offsetof(struct mbuf, m_pktdat) == MHLEN);
94
95 /*
96 * m_get2() allocates minimum mbuf that would fit "size" argument.
97 */
98 struct mbuf *
99 m_get2(int size, int how, short type, int flags)
100 {
101 struct mb_args args;
102 struct mbuf *m, *n;
103
104 args.flags = flags;
105 args.type = type;
106
107 if (size <= MHLEN || (size <= MLEN && (flags & M_PKTHDR) == 0))
108 return (uma_zalloc_arg(zone_mbuf, &args, how));
109 if (size <= MCLBYTES)
110 return (uma_zalloc_arg(zone_pack, &args, how));
111
112 if (size > MJUMPAGESIZE)
113 return (NULL);
114
115 m = uma_zalloc_arg(zone_mbuf, &args, how);
116 if (m == NULL)
117 return (NULL);
118
119 n = uma_zalloc_arg(zone_jumbop, m, how);
120 if (n == NULL) {
121 uma_zfree(zone_mbuf, m);
122 return (NULL);
123 }
124
125 return (m);
126 }
127
128 /*
129 * m_getjcl() returns an mbuf with a cluster of the specified size attached.
130 * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES.
131 */
132 struct mbuf *
133 m_getjcl(int how, short type, int flags, int size)
134 {
135 struct mb_args args;
136 struct mbuf *m, *n;
137 uma_zone_t zone;
138
139 if (size == MCLBYTES)
140 return m_getcl(how, type, flags);
141
142 args.flags = flags;
143 args.type = type;
144
145 m = uma_zalloc_arg(zone_mbuf, &args, how);
146 if (m == NULL)
147 return (NULL);
148
149 zone = m_getzone(size);
150 n = uma_zalloc_arg(zone, m, how);
151 if (n == NULL) {
152 uma_zfree(zone_mbuf, m);
153 return (NULL);
154 }
155 return (m);
156 }
157
158 /*
159 * Allocate a given length worth of mbufs and/or clusters (whatever fits
160 * best) and return a pointer to the top of the allocated chain. If an
161 * existing mbuf chain is provided, then we will append the new chain
162 * to the existing one but still return the top of the newly allocated
163 * chain.
164 */
165 struct mbuf *
166 m_getm2(struct mbuf *m, int len, int how, short type, int flags)
167 {
168 struct mbuf *mb, *nm = NULL, *mtail = NULL;
169
170 KASSERT(len >= 0, ("%s: len is < 0", __func__));
171
172 /* Validate flags. */
173 flags &= (M_PKTHDR | M_EOR);
174
175 /* Packet header mbuf must be first in chain. */
176 if ((flags & M_PKTHDR) && m != NULL)
177 flags &= ~M_PKTHDR;
178
179 /* Loop and append maximum sized mbufs to the chain tail. */
180 while (len > 0) {
181 if (len > MCLBYTES)
182 mb = m_getjcl(how, type, (flags & M_PKTHDR),
183 MJUMPAGESIZE);
184 else if (len >= MINCLSIZE)
185 mb = m_getcl(how, type, (flags & M_PKTHDR));
186 else if (flags & M_PKTHDR)
187 mb = m_gethdr(how, type);
188 else
189 mb = m_get(how, type);
190
191 /* Fail the whole operation if one mbuf can't be allocated. */
192 if (mb == NULL) {
193 if (nm != NULL)
194 m_freem(nm);
195 return (NULL);
196 }
197
198 /* Book keeping. */
199 len -= (mb->m_flags & M_EXT) ? mb->m_ext.ext_size :
200 ((mb->m_flags & M_PKTHDR) ? MHLEN : MLEN);
201 if (mtail != NULL)
202 mtail->m_next = mb;
203 else
204 nm = mb;
205 mtail = mb;
206 flags &= ~M_PKTHDR; /* Only valid on the first mbuf. */
207 }
208 if (flags & M_EOR)
209 mtail->m_flags |= M_EOR; /* Only valid on the last mbuf. */
210
211 /* If mbuf was supplied, append new chain to the end of it. */
212 if (m != NULL) {
213 for (mtail = m; mtail->m_next != NULL; mtail = mtail->m_next)
214 ;
215 mtail->m_next = nm;
216 mtail->m_flags &= ~M_EOR;
217 } else
218 m = nm;
219
220 return (m);
221 }
222
223 /*
224 * Free an entire chain of mbufs and associated external buffers, if
225 * applicable.
226 */
227 void
228 m_freem(struct mbuf *mb)
229 {
230
231 while (mb != NULL)
232 mb = m_free(mb);
233 }
234
235 /*-
236 * Configure a provided mbuf to refer to the provided external storage
237 * buffer and setup a reference count for said buffer. If the setting
238 * up of the reference count fails, the M_EXT bit will not be set. If
239 * successfull, the M_EXT bit is set in the mbuf's flags.
240 *
241 * Arguments:
242 * mb The existing mbuf to which to attach the provided buffer.
243 * buf The address of the provided external storage buffer.
244 * size The size of the provided buffer.
245 * freef A pointer to a routine that is responsible for freeing the
246 * provided external storage buffer.
247 * args A pointer to an argument structure (of any type) to be passed
248 * to the provided freef routine (may be NULL).
249 * flags Any other flags to be passed to the provided mbuf.
250 * type The type that the external storage buffer should be
251 * labeled with.
252 *
253 * Returns:
254 * Nothing.
255 */
256 int
257 m_extadd(struct mbuf *mb, caddr_t buf, u_int size,
258 int (*freef)(struct mbuf *, void *, void *), void *arg1, void *arg2,
259 int flags, int type, int wait)
260 {
261 KASSERT(type != EXT_CLUSTER, ("%s: EXT_CLUSTER not allowed", __func__));
262
263 if (type != EXT_EXTREF)
264 mb->m_ext.ref_cnt = uma_zalloc(zone_ext_refcnt, wait);
265
266 if (mb->m_ext.ref_cnt == NULL)
267 return (ENOMEM);
268
269 *(mb->m_ext.ref_cnt) = 1;
270 mb->m_flags |= (M_EXT | flags);
271 mb->m_ext.ext_buf = buf;
272 mb->m_data = mb->m_ext.ext_buf;
273 mb->m_ext.ext_size = size;
274 mb->m_ext.ext_free = freef;
275 mb->m_ext.ext_arg1 = arg1;
276 mb->m_ext.ext_arg2 = arg2;
277 mb->m_ext.ext_type = type;
278 mb->m_ext.ext_flags = 0;
279
280 return (0);
281 }
282
283 /*
284 * Non-directly-exported function to clean up after mbufs with M_EXT
285 * storage attached to them if the reference count hits 1.
286 */
287 void
288 mb_free_ext(struct mbuf *m)
289 {
290 int skipmbuf;
291
292 KASSERT((m->m_flags & M_EXT) == M_EXT, ("%s: M_EXT not set", __func__));
293 KASSERT(m->m_ext.ref_cnt != NULL, ("%s: ref_cnt not set", __func__));
294
295 /*
296 * check if the header is embedded in the cluster
297 */
298 skipmbuf = (m->m_flags & M_NOFREE);
299
300 /* Free attached storage if this mbuf is the only reference to it. */
301 if (*(m->m_ext.ref_cnt) == 1 ||
302 atomic_fetchadd_int(m->m_ext.ref_cnt, -1) == 1) {
303 switch (m->m_ext.ext_type) {
304 case EXT_PACKET: /* The packet zone is special. */
305 if (*(m->m_ext.ref_cnt) == 0)
306 *(m->m_ext.ref_cnt) = 1;
307 uma_zfree(zone_pack, m);
308 return; /* Job done. */
309 case EXT_CLUSTER:
310 uma_zfree(zone_clust, m->m_ext.ext_buf);
311 break;
312 case EXT_JUMBOP:
313 uma_zfree(zone_jumbop, m->m_ext.ext_buf);
314 break;
315 case EXT_JUMBO9:
316 uma_zfree(zone_jumbo9, m->m_ext.ext_buf);
317 break;
318 case EXT_JUMBO16:
319 uma_zfree(zone_jumbo16, m->m_ext.ext_buf);
320 break;
321 case EXT_SFBUF:
322 case EXT_NET_DRV:
323 case EXT_MOD_TYPE:
324 case EXT_DISPOSABLE:
325 *(m->m_ext.ref_cnt) = 0;
326 uma_zfree(zone_ext_refcnt, __DEVOLATILE(u_int *,
327 m->m_ext.ref_cnt));
328 /* FALLTHROUGH */
329 case EXT_EXTREF:
330 KASSERT(m->m_ext.ext_free != NULL,
331 ("%s: ext_free not set", __func__));
332 (void)(*(m->m_ext.ext_free))(m, m->m_ext.ext_arg1,
333 m->m_ext.ext_arg2);
334 break;
335 default:
336 KASSERT(m->m_ext.ext_type == 0,
337 ("%s: unknown ext_type", __func__));
338 }
339 }
340 if (skipmbuf)
341 return;
342
343 /*
344 * Free this mbuf back to the mbuf zone with all m_ext
345 * information purged.
346 */
347 m->m_ext.ext_buf = NULL;
348 m->m_ext.ext_free = NULL;
349 m->m_ext.ext_arg1 = NULL;
350 m->m_ext.ext_arg2 = NULL;
351 m->m_ext.ref_cnt = NULL;
352 m->m_ext.ext_size = 0;
353 m->m_ext.ext_type = 0;
354 m->m_ext.ext_flags = 0;
355 m->m_flags &= ~M_EXT;
356 uma_zfree(zone_mbuf, m);
357 }
358
359 /*
360 * Attach the cluster from *m to *n, set up m_ext in *n
361 * and bump the refcount of the cluster.
362 */
363 static void
364 mb_dupcl(struct mbuf *n, struct mbuf *m)
365 {
366 KASSERT((m->m_flags & M_EXT) == M_EXT, ("%s: M_EXT not set", __func__));
367 KASSERT(m->m_ext.ref_cnt != NULL, ("%s: ref_cnt not set", __func__));
368 KASSERT((n->m_flags & M_EXT) == 0, ("%s: M_EXT set", __func__));
369
370 if (*(m->m_ext.ref_cnt) == 1)
371 *(m->m_ext.ref_cnt) += 1;
372 else
373 atomic_add_int(m->m_ext.ref_cnt, 1);
374 n->m_ext.ext_buf = m->m_ext.ext_buf;
375 n->m_ext.ext_free = m->m_ext.ext_free;
376 n->m_ext.ext_arg1 = m->m_ext.ext_arg1;
377 n->m_ext.ext_arg2 = m->m_ext.ext_arg2;
378 n->m_ext.ext_size = m->m_ext.ext_size;
379 n->m_ext.ref_cnt = m->m_ext.ref_cnt;
380 n->m_ext.ext_type = m->m_ext.ext_type;
381 n->m_ext.ext_flags = m->m_ext.ext_flags;
382 n->m_flags |= M_EXT;
383 n->m_flags |= m->m_flags & M_RDONLY;
384 }
385
386 /*
387 * Clean up mbuf (chain) from any tags and packet headers.
388 * If "all" is set then the first mbuf in the chain will be
389 * cleaned too.
390 */
391 void
392 m_demote(struct mbuf *m0, int all)
393 {
394 struct mbuf *m;
395
396 for (m = all ? m0 : m0->m_next; m != NULL; m = m->m_next) {
397 if (m->m_flags & M_PKTHDR) {
398 m_tag_delete_chain(m, NULL);
399 m->m_flags &= ~M_PKTHDR;
400 bzero(&m->m_pkthdr, sizeof(struct pkthdr));
401 }
402 if (m != m0 && m->m_nextpkt != NULL) {
403 KASSERT(m->m_nextpkt == NULL,
404 ("%s: m_nextpkt not NULL", __func__));
405 m_freem(m->m_nextpkt);
406 m->m_nextpkt = NULL;
407 }
408 m->m_flags = m->m_flags & (M_EXT|M_RDONLY|M_NOFREE);
409 }
410 }
411
412 /*
413 * Sanity checks on mbuf (chain) for use in KASSERT() and general
414 * debugging.
415 * Returns 0 or panics when bad and 1 on all tests passed.
416 * Sanitize, 0 to run M_SANITY_ACTION, 1 to garble things so they
417 * blow up later.
418 */
419 int
420 m_sanity(struct mbuf *m0, int sanitize)
421 {
422 struct mbuf *m;
423 caddr_t a, b;
424 int pktlen = 0;
425
426 #ifdef INVARIANTS
427 #define M_SANITY_ACTION(s) panic("mbuf %p: " s, m)
428 #else
429 #define M_SANITY_ACTION(s) printf("mbuf %p: " s, m)
430 #endif
431
432 for (m = m0; m != NULL; m = m->m_next) {
433 /*
434 * Basic pointer checks. If any of these fails then some
435 * unrelated kernel memory before or after us is trashed.
436 * No way to recover from that.
437 */
438 a = ((m->m_flags & M_EXT) ? m->m_ext.ext_buf :
439 ((m->m_flags & M_PKTHDR) ? (caddr_t)(&m->m_pktdat) :
440 (caddr_t)(&m->m_dat)) );
441 b = (caddr_t)(a + (m->m_flags & M_EXT ? m->m_ext.ext_size :
442 ((m->m_flags & M_PKTHDR) ? MHLEN : MLEN)));
443 if ((caddr_t)m->m_data < a)
444 M_SANITY_ACTION("m_data outside mbuf data range left");
445 if ((caddr_t)m->m_data > b)
446 M_SANITY_ACTION("m_data outside mbuf data range right");
447 if ((caddr_t)m->m_data + m->m_len > b)
448 M_SANITY_ACTION("m_data + m_len exeeds mbuf space");
449
450 /* m->m_nextpkt may only be set on first mbuf in chain. */
451 if (m != m0 && m->m_nextpkt != NULL) {
452 if (sanitize) {
453 m_freem(m->m_nextpkt);
454 m->m_nextpkt = (struct mbuf *)0xDEADC0DE;
455 } else
456 M_SANITY_ACTION("m->m_nextpkt on in-chain mbuf");
457 }
458
459 /* packet length (not mbuf length!) calculation */
460 if (m0->m_flags & M_PKTHDR)
461 pktlen += m->m_len;
462
463 /* m_tags may only be attached to first mbuf in chain. */
464 if (m != m0 && m->m_flags & M_PKTHDR &&
465 !SLIST_EMPTY(&m->m_pkthdr.tags)) {
466 if (sanitize) {
467 m_tag_delete_chain(m, NULL);
468 /* put in 0xDEADC0DE perhaps? */
469 } else
470 M_SANITY_ACTION("m_tags on in-chain mbuf");
471 }
472
473 /* M_PKTHDR may only be set on first mbuf in chain */
474 if (m != m0 && m->m_flags & M_PKTHDR) {
475 if (sanitize) {
476 bzero(&m->m_pkthdr, sizeof(m->m_pkthdr));
477 m->m_flags &= ~M_PKTHDR;
478 /* put in 0xDEADCODE and leave hdr flag in */
479 } else
480 M_SANITY_ACTION("M_PKTHDR on in-chain mbuf");
481 }
482 }
483 m = m0;
484 if (pktlen && pktlen != m->m_pkthdr.len) {
485 if (sanitize)
486 m->m_pkthdr.len = 0;
487 else
488 M_SANITY_ACTION("m_pkthdr.len != mbuf chain length");
489 }
490 return 1;
491
492 #undef M_SANITY_ACTION
493 }
494
495
496 /*
497 * "Move" mbuf pkthdr from "from" to "to".
498 * "from" must have M_PKTHDR set, and "to" must be empty.
499 */
500 void
501 m_move_pkthdr(struct mbuf *to, struct mbuf *from)
502 {
503
504 #if 0
505 /* see below for why these are not enabled */
506 M_ASSERTPKTHDR(to);
507 /* Note: with MAC, this may not be a good assertion. */
508 KASSERT(SLIST_EMPTY(&to->m_pkthdr.tags),
509 ("m_move_pkthdr: to has tags"));
510 #endif
511 #ifdef MAC
512 /*
513 * XXXMAC: It could be this should also occur for non-MAC?
514 */
515 if (to->m_flags & M_PKTHDR)
516 m_tag_delete_chain(to, NULL);
517 #endif
518 to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT);
519 if ((to->m_flags & M_EXT) == 0)
520 to->m_data = to->m_pktdat;
521 to->m_pkthdr = from->m_pkthdr; /* especially tags */
522 SLIST_INIT(&from->m_pkthdr.tags); /* purge tags from src */
523 from->m_flags &= ~M_PKTHDR;
524 }
525
526 /*
527 * Duplicate "from"'s mbuf pkthdr in "to".
528 * "from" must have M_PKTHDR set, and "to" must be empty.
529 * In particular, this does a deep copy of the packet tags.
530 */
531 int
532 m_dup_pkthdr(struct mbuf *to, struct mbuf *from, int how)
533 {
534
535 #if 0
536 /*
537 * The mbuf allocator only initializes the pkthdr
538 * when the mbuf is allocated with m_gethdr(). Many users
539 * (e.g. m_copy*, m_prepend) use m_get() and then
540 * smash the pkthdr as needed causing these
541 * assertions to trip. For now just disable them.
542 */
543 M_ASSERTPKTHDR(to);
544 /* Note: with MAC, this may not be a good assertion. */
545 KASSERT(SLIST_EMPTY(&to->m_pkthdr.tags), ("m_dup_pkthdr: to has tags"));
546 #endif
547 MBUF_CHECKSLEEP(how);
548 #ifdef MAC
549 if (to->m_flags & M_PKTHDR)
550 m_tag_delete_chain(to, NULL);
551 #endif
552 to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT);
553 if ((to->m_flags & M_EXT) == 0)
554 to->m_data = to->m_pktdat;
555 to->m_pkthdr = from->m_pkthdr;
556 SLIST_INIT(&to->m_pkthdr.tags);
557 return (m_tag_copy_chain(to, from, MBTOM(how)));
558 }
559
560 /*
561 * Lesser-used path for M_PREPEND:
562 * allocate new mbuf to prepend to chain,
563 * copy junk along.
564 */
565 struct mbuf *
566 m_prepend(struct mbuf *m, int len, int how)
567 {
568 struct mbuf *mn;
569
570 if (m->m_flags & M_PKTHDR)
571 mn = m_gethdr(how, m->m_type);
572 else
573 mn = m_get(how, m->m_type);
574 if (mn == NULL) {
575 m_freem(m);
576 return (NULL);
577 }
578 if (m->m_flags & M_PKTHDR)
579 m_move_pkthdr(mn, m);
580 mn->m_next = m;
581 m = mn;
582 if(m->m_flags & M_PKTHDR) {
583 if (len < MHLEN)
584 MH_ALIGN(m, len);
585 } else {
586 if (len < MLEN)
587 M_ALIGN(m, len);
588 }
589 m->m_len = len;
590 return (m);
591 }
592
593 /*
594 * Make a copy of an mbuf chain starting "off0" bytes from the beginning,
595 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf.
596 * The wait parameter is a choice of M_WAITOK/M_NOWAIT from caller.
597 * Note that the copy is read-only, because clusters are not copied,
598 * only their reference counts are incremented.
599 */
600 struct mbuf *
601 m_copym(struct mbuf *m, int off0, int len, int wait)
602 {
603 struct mbuf *n, **np;
604 int off = off0;
605 struct mbuf *top;
606 int copyhdr = 0;
607
608 KASSERT(off >= 0, ("m_copym, negative off %d", off));
609 KASSERT(len >= 0, ("m_copym, negative len %d", len));
610 MBUF_CHECKSLEEP(wait);
611 if (off == 0 && m->m_flags & M_PKTHDR)
612 copyhdr = 1;
613 while (off > 0) {
614 KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain"));
615 if (off < m->m_len)
616 break;
617 off -= m->m_len;
618 m = m->m_next;
619 }
620 np = ⊤
621 top = 0;
622 while (len > 0) {
623 if (m == NULL) {
624 KASSERT(len == M_COPYALL,
625 ("m_copym, length > size of mbuf chain"));
626 break;
627 }
628 if (copyhdr)
629 n = m_gethdr(wait, m->m_type);
630 else
631 n = m_get(wait, m->m_type);
632 *np = n;
633 if (n == NULL)
634 goto nospace;
635 if (copyhdr) {
636 if (!m_dup_pkthdr(n, m, wait))
637 goto nospace;
638 if (len == M_COPYALL)
639 n->m_pkthdr.len -= off0;
640 else
641 n->m_pkthdr.len = len;
642 copyhdr = 0;
643 }
644 n->m_len = min(len, m->m_len - off);
645 if (m->m_flags & M_EXT) {
646 n->m_data = m->m_data + off;
647 mb_dupcl(n, m);
648 } else
649 bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
650 (u_int)n->m_len);
651 if (len != M_COPYALL)
652 len -= n->m_len;
653 off = 0;
654 m = m->m_next;
655 np = &n->m_next;
656 }
657
658 return (top);
659 nospace:
660 m_freem(top);
661 return (NULL);
662 }
663
664 /*
665 * Returns mbuf chain with new head for the prepending case.
666 * Copies from mbuf (chain) n from off for len to mbuf (chain) m
667 * either prepending or appending the data.
668 * The resulting mbuf (chain) m is fully writeable.
669 * m is destination (is made writeable)
670 * n is source, off is offset in source, len is len from offset
671 * dir, 0 append, 1 prepend
672 * how, wait or nowait
673 */
674
675 static int
676 m_bcopyxxx(void *s, void *t, u_int len)
677 {
678 bcopy(s, t, (size_t)len);
679 return 0;
680 }
681
682 struct mbuf *
683 m_copymdata(struct mbuf *m, struct mbuf *n, int off, int len,
684 int prep, int how)
685 {
686 struct mbuf *mm, *x, *z, *prev = NULL;
687 caddr_t p;
688 int i, nlen = 0;
689 caddr_t buf[MLEN];
690
691 KASSERT(m != NULL && n != NULL, ("m_copymdata, no target or source"));
692 KASSERT(off >= 0, ("m_copymdata, negative off %d", off));
693 KASSERT(len >= 0, ("m_copymdata, negative len %d", len));
694 KASSERT(prep == 0 || prep == 1, ("m_copymdata, unknown direction %d", prep));
695
696 mm = m;
697 if (!prep) {
698 while(mm->m_next) {
699 prev = mm;
700 mm = mm->m_next;
701 }
702 }
703 for (z = n; z != NULL; z = z->m_next)
704 nlen += z->m_len;
705 if (len == M_COPYALL)
706 len = nlen - off;
707 if (off + len > nlen || len < 1)
708 return NULL;
709
710 if (!M_WRITABLE(mm)) {
711 /* XXX: Use proper m_xxx function instead. */
712 x = m_getcl(how, MT_DATA, mm->m_flags);
713 if (x == NULL)
714 return NULL;
715 bcopy(mm->m_ext.ext_buf, x->m_ext.ext_buf, x->m_ext.ext_size);
716 p = x->m_ext.ext_buf + (mm->m_data - mm->m_ext.ext_buf);
717 x->m_data = p;
718 mm->m_next = NULL;
719 if (mm != m)
720 prev->m_next = x;
721 m_free(mm);
722 mm = x;
723 }
724
725 /*
726 * Append/prepend the data. Allocating mbufs as necessary.
727 */
728 /* Shortcut if enough free space in first/last mbuf. */
729 if (!prep && M_TRAILINGSPACE(mm) >= len) {
730 m_apply(n, off, len, m_bcopyxxx, mtod(mm, caddr_t) +
731 mm->m_len);
732 mm->m_len += len;
733 mm->m_pkthdr.len += len;
734 return m;
735 }
736 if (prep && M_LEADINGSPACE(mm) >= len) {
737 mm->m_data = mtod(mm, caddr_t) - len;
738 m_apply(n, off, len, m_bcopyxxx, mtod(mm, caddr_t));
739 mm->m_len += len;
740 mm->m_pkthdr.len += len;
741 return mm;
742 }
743
744 /* Expand first/last mbuf to cluster if possible. */
745 if (!prep && !(mm->m_flags & M_EXT) && len > M_TRAILINGSPACE(mm)) {
746 bcopy(mm->m_data, &buf, mm->m_len);
747 m_clget(mm, how);
748 if (!(mm->m_flags & M_EXT))
749 return NULL;
750 bcopy(&buf, mm->m_ext.ext_buf, mm->m_len);
751 mm->m_data = mm->m_ext.ext_buf;
752 }
753 if (prep && !(mm->m_flags & M_EXT) && len > M_LEADINGSPACE(mm)) {
754 bcopy(mm->m_data, &buf, mm->m_len);
755 m_clget(mm, how);
756 if (!(mm->m_flags & M_EXT))
757 return NULL;
758 bcopy(&buf, (caddr_t *)mm->m_ext.ext_buf +
759 mm->m_ext.ext_size - mm->m_len, mm->m_len);
760 mm->m_data = (caddr_t)mm->m_ext.ext_buf +
761 mm->m_ext.ext_size - mm->m_len;
762 }
763
764 /* Append/prepend as many mbuf (clusters) as necessary to fit len. */
765 if (!prep && len > M_TRAILINGSPACE(mm)) {
766 if (!m_getm(mm, len - M_TRAILINGSPACE(mm), how, MT_DATA))
767 return NULL;
768 }
769 if (prep && len > M_LEADINGSPACE(mm)) {
770 if (!(z = m_getm(NULL, len - M_LEADINGSPACE(mm), how, MT_DATA)))
771 return NULL;
772 i = 0;
773 for (x = z; x != NULL; x = x->m_next) {
774 i += x->m_flags & M_EXT ? x->m_ext.ext_size :
775 (x->m_flags & M_PKTHDR ? MHLEN : MLEN);
776 if (!x->m_next)
777 break;
778 }
779 z->m_data += i - len;
780 m_move_pkthdr(mm, z);
781 x->m_next = mm;
782 mm = z;
783 }
784
785 /* Seek to start position in source mbuf. Optimization for long chains. */
786 while (off > 0) {
787 if (off < n->m_len)
788 break;
789 off -= n->m_len;
790 n = n->m_next;
791 }
792
793 /* Copy data into target mbuf. */
794 z = mm;
795 while (len > 0) {
796 KASSERT(z != NULL, ("m_copymdata, falling off target edge"));
797 i = M_TRAILINGSPACE(z);
798 m_apply(n, off, i, m_bcopyxxx, mtod(z, caddr_t) + z->m_len);
799 z->m_len += i;
800 /* fixup pkthdr.len if necessary */
801 if ((prep ? mm : m)->m_flags & M_PKTHDR)
802 (prep ? mm : m)->m_pkthdr.len += i;
803 off += i;
804 len -= i;
805 z = z->m_next;
806 }
807 return (prep ? mm : m);
808 }
809
810 /*
811 * Copy an entire packet, including header (which must be present).
812 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'.
813 * Note that the copy is read-only, because clusters are not copied,
814 * only their reference counts are incremented.
815 * Preserve alignment of the first mbuf so if the creator has left
816 * some room at the beginning (e.g. for inserting protocol headers)
817 * the copies still have the room available.
818 */
819 struct mbuf *
820 m_copypacket(struct mbuf *m, int how)
821 {
822 struct mbuf *top, *n, *o;
823
824 MBUF_CHECKSLEEP(how);
825 n = m_get(how, m->m_type);
826 top = n;
827 if (n == NULL)
828 goto nospace;
829
830 if (!m_dup_pkthdr(n, m, how))
831 goto nospace;
832 n->m_len = m->m_len;
833 if (m->m_flags & M_EXT) {
834 n->m_data = m->m_data;
835 mb_dupcl(n, m);
836 } else {
837 n->m_data = n->m_pktdat + (m->m_data - m->m_pktdat );
838 bcopy(mtod(m, char *), mtod(n, char *), n->m_len);
839 }
840
841 m = m->m_next;
842 while (m) {
843 o = m_get(how, m->m_type);
844 if (o == NULL)
845 goto nospace;
846
847 n->m_next = o;
848 n = n->m_next;
849
850 n->m_len = m->m_len;
851 if (m->m_flags & M_EXT) {
852 n->m_data = m->m_data;
853 mb_dupcl(n, m);
854 } else {
855 bcopy(mtod(m, char *), mtod(n, char *), n->m_len);
856 }
857
858 m = m->m_next;
859 }
860 return top;
861 nospace:
862 m_freem(top);
863 return (NULL);
864 }
865
866 /*
867 * Copy data from an mbuf chain starting "off" bytes from the beginning,
868 * continuing for "len" bytes, into the indicated buffer.
869 */
870 void
871 m_copydata(const struct mbuf *m, int off, int len, caddr_t cp)
872 {
873 u_int count;
874
875 KASSERT(off >= 0, ("m_copydata, negative off %d", off));
876 KASSERT(len >= 0, ("m_copydata, negative len %d", len));
877 while (off > 0) {
878 KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain"));
879 if (off < m->m_len)
880 break;
881 off -= m->m_len;
882 m = m->m_next;
883 }
884 while (len > 0) {
885 KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain"));
886 count = min(m->m_len - off, len);
887 bcopy(mtod(m, caddr_t) + off, cp, count);
888 len -= count;
889 cp += count;
890 off = 0;
891 m = m->m_next;
892 }
893 }
894
895 /*
896 * Copy a packet header mbuf chain into a completely new chain, including
897 * copying any mbuf clusters. Use this instead of m_copypacket() when
898 * you need a writable copy of an mbuf chain.
899 */
900 struct mbuf *
901 m_dup(struct mbuf *m, int how)
902 {
903 struct mbuf **p, *top = NULL;
904 int remain, moff, nsize;
905
906 MBUF_CHECKSLEEP(how);
907 /* Sanity check */
908 if (m == NULL)
909 return (NULL);
910 M_ASSERTPKTHDR(m);
911
912 /* While there's more data, get a new mbuf, tack it on, and fill it */
913 remain = m->m_pkthdr.len;
914 moff = 0;
915 p = ⊤
916 while (remain > 0 || top == NULL) { /* allow m->m_pkthdr.len == 0 */
917 struct mbuf *n;
918
919 /* Get the next new mbuf */
920 if (remain >= MINCLSIZE) {
921 n = m_getcl(how, m->m_type, 0);
922 nsize = MCLBYTES;
923 } else {
924 n = m_get(how, m->m_type);
925 nsize = MLEN;
926 }
927 if (n == NULL)
928 goto nospace;
929
930 if (top == NULL) { /* First one, must be PKTHDR */
931 if (!m_dup_pkthdr(n, m, how)) {
932 m_free(n);
933 goto nospace;
934 }
935 if ((n->m_flags & M_EXT) == 0)
936 nsize = MHLEN;
937 }
938 n->m_len = 0;
939
940 /* Link it into the new chain */
941 *p = n;
942 p = &n->m_next;
943
944 /* Copy data from original mbuf(s) into new mbuf */
945 while (n->m_len < nsize && m != NULL) {
946 int chunk = min(nsize - n->m_len, m->m_len - moff);
947
948 bcopy(m->m_data + moff, n->m_data + n->m_len, chunk);
949 moff += chunk;
950 n->m_len += chunk;
951 remain -= chunk;
952 if (moff == m->m_len) {
953 m = m->m_next;
954 moff = 0;
955 }
956 }
957
958 /* Check correct total mbuf length */
959 KASSERT((remain > 0 && m != NULL) || (remain == 0 && m == NULL),
960 ("%s: bogus m_pkthdr.len", __func__));
961 }
962 return (top);
963
964 nospace:
965 m_freem(top);
966 return (NULL);
967 }
968
969 /*
970 * Concatenate mbuf chain n to m.
971 * Both chains must be of the same type (e.g. MT_DATA).
972 * Any m_pkthdr is not updated.
973 */
974 void
975 m_cat(struct mbuf *m, struct mbuf *n)
976 {
977 while (m->m_next)
978 m = m->m_next;
979 while (n) {
980 if (!M_WRITABLE(m) ||
981 M_TRAILINGSPACE(m) < n->m_len) {
982 /* just join the two chains */
983 m->m_next = n;
984 return;
985 }
986 /* splat the data from one into the other */
987 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len,
988 (u_int)n->m_len);
989 m->m_len += n->m_len;
990 n = m_free(n);
991 }
992 }
993
994 void
995 m_adj(struct mbuf *mp, int req_len)
996 {
997 int len = req_len;
998 struct mbuf *m;
999 int count;
1000
1001 if ((m = mp) == NULL)
1002 return;
1003 if (len >= 0) {
1004 /*
1005 * Trim from head.
1006 */
1007 while (m != NULL && len > 0) {
1008 if (m->m_len <= len) {
1009 len -= m->m_len;
1010 m->m_len = 0;
1011 m = m->m_next;
1012 } else {
1013 m->m_len -= len;
1014 m->m_data += len;
1015 len = 0;
1016 }
1017 }
1018 if (mp->m_flags & M_PKTHDR)
1019 mp->m_pkthdr.len -= (req_len - len);
1020 } else {
1021 /*
1022 * Trim from tail. Scan the mbuf chain,
1023 * calculating its length and finding the last mbuf.
1024 * If the adjustment only affects this mbuf, then just
1025 * adjust and return. Otherwise, rescan and truncate
1026 * after the remaining size.
1027 */
1028 len = -len;
1029 count = 0;
1030 for (;;) {
1031 count += m->m_len;
1032 if (m->m_next == (struct mbuf *)0)
1033 break;
1034 m = m->m_next;
1035 }
1036 if (m->m_len >= len) {
1037 m->m_len -= len;
1038 if (mp->m_flags & M_PKTHDR)
1039 mp->m_pkthdr.len -= len;
1040 return;
1041 }
1042 count -= len;
1043 if (count < 0)
1044 count = 0;
1045 /*
1046 * Correct length for chain is "count".
1047 * Find the mbuf with last data, adjust its length,
1048 * and toss data from remaining mbufs on chain.
1049 */
1050 m = mp;
1051 if (m->m_flags & M_PKTHDR)
1052 m->m_pkthdr.len = count;
1053 for (; m; m = m->m_next) {
1054 if (m->m_len >= count) {
1055 m->m_len = count;
1056 if (m->m_next != NULL) {
1057 m_freem(m->m_next);
1058 m->m_next = NULL;
1059 }
1060 break;
1061 }
1062 count -= m->m_len;
1063 }
1064 }
1065 }
1066
1067 /*
1068 * Rearange an mbuf chain so that len bytes are contiguous
1069 * and in the data area of an mbuf (so that mtod will work
1070 * for a structure of size len). Returns the resulting
1071 * mbuf chain on success, frees it and returns null on failure.
1072 * If there is room, it will add up to max_protohdr-len extra bytes to the
1073 * contiguous region in an attempt to avoid being called next time.
1074 */
1075 struct mbuf *
1076 m_pullup(struct mbuf *n, int len)
1077 {
1078 struct mbuf *m;
1079 int count;
1080 int space;
1081
1082 /*
1083 * If first mbuf has no cluster, and has room for len bytes
1084 * without shifting current data, pullup into it,
1085 * otherwise allocate a new mbuf to prepend to the chain.
1086 */
1087 if ((n->m_flags & M_EXT) == 0 &&
1088 n->m_data + len < &n->m_dat[MLEN] && n->m_next) {
1089 if (n->m_len >= len)
1090 return (n);
1091 m = n;
1092 n = n->m_next;
1093 len -= m->m_len;
1094 } else {
1095 if (len > MHLEN)
1096 goto bad;
1097 m = m_get(M_NOWAIT, n->m_type);
1098 if (m == NULL)
1099 goto bad;
1100 if (n->m_flags & M_PKTHDR)
1101 m_move_pkthdr(m, n);
1102 }
1103 space = &m->m_dat[MLEN] - (m->m_data + m->m_len);
1104 do {
1105 count = min(min(max(len, max_protohdr), space), n->m_len);
1106 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len,
1107 (u_int)count);
1108 len -= count;
1109 m->m_len += count;
1110 n->m_len -= count;
1111 space -= count;
1112 if (n->m_len)
1113 n->m_data += count;
1114 else
1115 n = m_free(n);
1116 } while (len > 0 && n);
1117 if (len > 0) {
1118 (void) m_free(m);
1119 goto bad;
1120 }
1121 m->m_next = n;
1122 return (m);
1123 bad:
1124 m_freem(n);
1125 return (NULL);
1126 }
1127
1128 /*
1129 * Like m_pullup(), except a new mbuf is always allocated, and we allow
1130 * the amount of empty space before the data in the new mbuf to be specified
1131 * (in the event that the caller expects to prepend later).
1132 */
1133 int MSFail;
1134
1135 struct mbuf *
1136 m_copyup(struct mbuf *n, int len, int dstoff)
1137 {
1138 struct mbuf *m;
1139 int count, space;
1140
1141 if (len > (MHLEN - dstoff))
1142 goto bad;
1143 m = m_get(M_NOWAIT, n->m_type);
1144 if (m == NULL)
1145 goto bad;
1146 if (n->m_flags & M_PKTHDR)
1147 m_move_pkthdr(m, n);
1148 m->m_data += dstoff;
1149 space = &m->m_dat[MLEN] - (m->m_data + m->m_len);
1150 do {
1151 count = min(min(max(len, max_protohdr), space), n->m_len);
1152 memcpy(mtod(m, caddr_t) + m->m_len, mtod(n, caddr_t),
1153 (unsigned)count);
1154 len -= count;
1155 m->m_len += count;
1156 n->m_len -= count;
1157 space -= count;
1158 if (n->m_len)
1159 n->m_data += count;
1160 else
1161 n = m_free(n);
1162 } while (len > 0 && n);
1163 if (len > 0) {
1164 (void) m_free(m);
1165 goto bad;
1166 }
1167 m->m_next = n;
1168 return (m);
1169 bad:
1170 m_freem(n);
1171 MSFail++;
1172 return (NULL);
1173 }
1174
1175 /*
1176 * Partition an mbuf chain in two pieces, returning the tail --
1177 * all but the first len0 bytes. In case of failure, it returns NULL and
1178 * attempts to restore the chain to its original state.
1179 *
1180 * Note that the resulting mbufs might be read-only, because the new
1181 * mbuf can end up sharing an mbuf cluster with the original mbuf if
1182 * the "breaking point" happens to lie within a cluster mbuf. Use the
1183 * M_WRITABLE() macro to check for this case.
1184 */
1185 struct mbuf *
1186 m_split(struct mbuf *m0, int len0, int wait)
1187 {
1188 struct mbuf *m, *n;
1189 u_int len = len0, remain;
1190
1191 MBUF_CHECKSLEEP(wait);
1192 for (m = m0; m && len > m->m_len; m = m->m_next)
1193 len -= m->m_len;
1194 if (m == NULL)
1195 return (NULL);
1196 remain = m->m_len - len;
1197 if (m0->m_flags & M_PKTHDR && remain == 0) {
1198 n = m_gethdr(wait, m0->m_type);
1199 if (n == NULL)
1200 return (NULL);
1201 n->m_next = m->m_next;
1202 m->m_next = NULL;
1203 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif;
1204 n->m_pkthdr.len = m0->m_pkthdr.len - len0;
1205 m0->m_pkthdr.len = len0;
1206 return (n);
1207 } else if (m0->m_flags & M_PKTHDR) {
1208 n = m_gethdr(wait, m0->m_type);
1209 if (n == NULL)
1210 return (NULL);
1211 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif;
1212 n->m_pkthdr.len = m0->m_pkthdr.len - len0;
1213 m0->m_pkthdr.len = len0;
1214 if (m->m_flags & M_EXT)
1215 goto extpacket;
1216 if (remain > MHLEN) {
1217 /* m can't be the lead packet */
1218 MH_ALIGN(n, 0);
1219 n->m_next = m_split(m, len, wait);
1220 if (n->m_next == NULL) {
1221 (void) m_free(n);
1222 return (NULL);
1223 } else {
1224 n->m_len = 0;
1225 return (n);
1226 }
1227 } else
1228 MH_ALIGN(n, remain);
1229 } else if (remain == 0) {
1230 n = m->m_next;
1231 m->m_next = NULL;
1232 return (n);
1233 } else {
1234 n = m_get(wait, m->m_type);
1235 if (n == NULL)
1236 return (NULL);
1237 M_ALIGN(n, remain);
1238 }
1239 extpacket:
1240 if (m->m_flags & M_EXT) {
1241 n->m_data = m->m_data + len;
1242 mb_dupcl(n, m);
1243 } else {
1244 bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain);
1245 }
1246 n->m_len = remain;
1247 m->m_len = len;
1248 n->m_next = m->m_next;
1249 m->m_next = NULL;
1250 return (n);
1251 }
1252 /*
1253 * Routine to copy from device local memory into mbufs.
1254 * Note that `off' argument is offset into first mbuf of target chain from
1255 * which to begin copying the data to.
1256 */
1257 struct mbuf *
1258 m_devget(char *buf, int totlen, int off, struct ifnet *ifp,
1259 void (*copy)(char *from, caddr_t to, u_int len))
1260 {
1261 struct mbuf *m;
1262 struct mbuf *top = NULL, **mp = ⊤
1263 int len;
1264
1265 if (off < 0 || off > MHLEN)
1266 return (NULL);
1267
1268 while (totlen > 0) {
1269 if (top == NULL) { /* First one, must be PKTHDR */
1270 if (totlen + off >= MINCLSIZE) {
1271 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
1272 len = MCLBYTES;
1273 } else {
1274 m = m_gethdr(M_NOWAIT, MT_DATA);
1275 len = MHLEN;
1276
1277 /* Place initial small packet/header at end of mbuf */
1278 if (m && totlen + off + max_linkhdr <= MLEN) {
1279 m->m_data += max_linkhdr;
1280 len -= max_linkhdr;
1281 }
1282 }
1283 if (m == NULL)
1284 return NULL;
1285 m->m_pkthdr.rcvif = ifp;
1286 m->m_pkthdr.len = totlen;
1287 } else {
1288 if (totlen + off >= MINCLSIZE) {
1289 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1290 len = MCLBYTES;
1291 } else {
1292 m = m_get(M_NOWAIT, MT_DATA);
1293 len = MLEN;
1294 }
1295 if (m == NULL) {
1296 m_freem(top);
1297 return NULL;
1298 }
1299 }
1300 if (off) {
1301 m->m_data += off;
1302 len -= off;
1303 off = 0;
1304 }
1305 m->m_len = len = min(totlen, len);
1306 if (copy)
1307 copy(buf, mtod(m, caddr_t), (u_int)len);
1308 else
1309 bcopy(buf, mtod(m, caddr_t), (u_int)len);
1310 buf += len;
1311 *mp = m;
1312 mp = &m->m_next;
1313 totlen -= len;
1314 }
1315 return (top);
1316 }
1317
1318 /*
1319 * Copy data from a buffer back into the indicated mbuf chain,
1320 * starting "off" bytes from the beginning, extending the mbuf
1321 * chain if necessary.
1322 */
1323 void
1324 m_copyback(struct mbuf *m0, int off, int len, c_caddr_t cp)
1325 {
1326 int mlen;
1327 struct mbuf *m = m0, *n;
1328 int totlen = 0;
1329
1330 if (m0 == NULL)
1331 return;
1332 while (off > (mlen = m->m_len)) {
1333 off -= mlen;
1334 totlen += mlen;
1335 if (m->m_next == NULL) {
1336 n = m_get(M_NOWAIT, m->m_type);
1337 if (n == NULL)
1338 goto out;
1339 bzero(mtod(n, caddr_t), MLEN);
1340 n->m_len = min(MLEN, len + off);
1341 m->m_next = n;
1342 }
1343 m = m->m_next;
1344 }
1345 while (len > 0) {
1346 if (m->m_next == NULL && (len > m->m_len - off)) {
1347 m->m_len += min(len - (m->m_len - off),
1348 M_TRAILINGSPACE(m));
1349 }
1350 mlen = min (m->m_len - off, len);
1351 bcopy(cp, off + mtod(m, caddr_t), (u_int)mlen);
1352 cp += mlen;
1353 len -= mlen;
1354 mlen += off;
1355 off = 0;
1356 totlen += mlen;
1357 if (len == 0)
1358 break;
1359 if (m->m_next == NULL) {
1360 n = m_get(M_NOWAIT, m->m_type);
1361 if (n == NULL)
1362 break;
1363 n->m_len = min(MLEN, len);
1364 m->m_next = n;
1365 }
1366 m = m->m_next;
1367 }
1368 out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen))
1369 m->m_pkthdr.len = totlen;
1370 }
1371
1372 /*
1373 * Append the specified data to the indicated mbuf chain,
1374 * Extend the mbuf chain if the new data does not fit in
1375 * existing space.
1376 *
1377 * Return 1 if able to complete the job; otherwise 0.
1378 */
1379 int
1380 m_append(struct mbuf *m0, int len, c_caddr_t cp)
1381 {
1382 struct mbuf *m, *n;
1383 int remainder, space;
1384
1385 for (m = m0; m->m_next != NULL; m = m->m_next)
1386 ;
1387 remainder = len;
1388 space = M_TRAILINGSPACE(m);
1389 if (space > 0) {
1390 /*
1391 * Copy into available space.
1392 */
1393 if (space > remainder)
1394 space = remainder;
1395 bcopy(cp, mtod(m, caddr_t) + m->m_len, space);
1396 m->m_len += space;
1397 cp += space, remainder -= space;
1398 }
1399 while (remainder > 0) {
1400 /*
1401 * Allocate a new mbuf; could check space
1402 * and allocate a cluster instead.
1403 */
1404 n = m_get(M_NOWAIT, m->m_type);
1405 if (n == NULL)
1406 break;
1407 n->m_len = min(MLEN, remainder);
1408 bcopy(cp, mtod(n, caddr_t), n->m_len);
1409 cp += n->m_len, remainder -= n->m_len;
1410 m->m_next = n;
1411 m = n;
1412 }
1413 if (m0->m_flags & M_PKTHDR)
1414 m0->m_pkthdr.len += len - remainder;
1415 return (remainder == 0);
1416 }
1417
1418 /*
1419 * Apply function f to the data in an mbuf chain starting "off" bytes from
1420 * the beginning, continuing for "len" bytes.
1421 */
1422 int
1423 m_apply(struct mbuf *m, int off, int len,
1424 int (*f)(void *, void *, u_int), void *arg)
1425 {
1426 u_int count;
1427 int rval;
1428
1429 KASSERT(off >= 0, ("m_apply, negative off %d", off));
1430 KASSERT(len >= 0, ("m_apply, negative len %d", len));
1431 while (off > 0) {
1432 KASSERT(m != NULL, ("m_apply, offset > size of mbuf chain"));
1433 if (off < m->m_len)
1434 break;
1435 off -= m->m_len;
1436 m = m->m_next;
1437 }
1438 while (len > 0) {
1439 KASSERT(m != NULL, ("m_apply, offset > size of mbuf chain"));
1440 count = min(m->m_len - off, len);
1441 rval = (*f)(arg, mtod(m, caddr_t) + off, count);
1442 if (rval)
1443 return (rval);
1444 len -= count;
1445 off = 0;
1446 m = m->m_next;
1447 }
1448 return (0);
1449 }
1450
1451 /*
1452 * Return a pointer to mbuf/offset of location in mbuf chain.
1453 */
1454 struct mbuf *
1455 m_getptr(struct mbuf *m, int loc, int *off)
1456 {
1457
1458 while (loc >= 0) {
1459 /* Normal end of search. */
1460 if (m->m_len > loc) {
1461 *off = loc;
1462 return (m);
1463 } else {
1464 loc -= m->m_len;
1465 if (m->m_next == NULL) {
1466 if (loc == 0) {
1467 /* Point at the end of valid data. */
1468 *off = m->m_len;
1469 return (m);
1470 }
1471 return (NULL);
1472 }
1473 m = m->m_next;
1474 }
1475 }
1476 return (NULL);
1477 }
1478
1479 void
1480 m_print(const struct mbuf *m, int maxlen)
1481 {
1482 int len;
1483 int pdata;
1484 const struct mbuf *m2;
1485
1486 if (m == NULL) {
1487 printf("mbuf: %p\n", m);
1488 return;
1489 }
1490
1491 if (m->m_flags & M_PKTHDR)
1492 len = m->m_pkthdr.len;
1493 else
1494 len = -1;
1495 m2 = m;
1496 while (m2 != NULL && (len == -1 || len)) {
1497 pdata = m2->m_len;
1498 if (maxlen != -1 && pdata > maxlen)
1499 pdata = maxlen;
1500 printf("mbuf: %p len: %d, next: %p, %b%s", m2, m2->m_len,
1501 m2->m_next, m2->m_flags, "\2\20freelist\17skipfw"
1502 "\11proto5\10proto4\7proto3\6proto2\5proto1\4rdonly"
1503 "\3eor\2pkthdr\1ext", pdata ? "" : "\n");
1504 if (pdata)
1505 printf(", %*D\n", pdata, (u_char *)m2->m_data, "-");
1506 if (len != -1)
1507 len -= m2->m_len;
1508 m2 = m2->m_next;
1509 }
1510 if (len > 0)
1511 printf("%d bytes unaccounted for.\n", len);
1512 return;
1513 }
1514
1515 u_int
1516 m_fixhdr(struct mbuf *m0)
1517 {
1518 u_int len;
1519
1520 len = m_length(m0, NULL);
1521 m0->m_pkthdr.len = len;
1522 return (len);
1523 }
1524
1525 u_int
1526 m_length(struct mbuf *m0, struct mbuf **last)
1527 {
1528 struct mbuf *m;
1529 u_int len;
1530
1531 len = 0;
1532 for (m = m0; m != NULL; m = m->m_next) {
1533 len += m->m_len;
1534 if (m->m_next == NULL)
1535 break;
1536 }
1537 if (last != NULL)
1538 *last = m;
1539 return (len);
1540 }
1541
1542 /*
1543 * Defragment a mbuf chain, returning the shortest possible
1544 * chain of mbufs and clusters. If allocation fails and
1545 * this cannot be completed, NULL will be returned, but
1546 * the passed in chain will be unchanged. Upon success,
1547 * the original chain will be freed, and the new chain
1548 * will be returned.
1549 *
1550 * If a non-packet header is passed in, the original
1551 * mbuf (chain?) will be returned unharmed.
1552 */
1553 struct mbuf *
1554 m_defrag(struct mbuf *m0, int how)
1555 {
1556 struct mbuf *m_new = NULL, *m_final = NULL;
1557 int progress = 0, length;
1558
1559 MBUF_CHECKSLEEP(how);
1560 if (!(m0->m_flags & M_PKTHDR))
1561 return (m0);
1562
1563 m_fixhdr(m0); /* Needed sanity check */
1564
1565 #ifdef MBUF_STRESS_TEST
1566 if (m_defragrandomfailures) {
1567 int temp = arc4random() & 0xff;
1568 if (temp == 0xba)
1569 goto nospace;
1570 }
1571 #endif
1572
1573 if (m0->m_pkthdr.len > MHLEN)
1574 m_final = m_getcl(how, MT_DATA, M_PKTHDR);
1575 else
1576 m_final = m_gethdr(how, MT_DATA);
1577
1578 if (m_final == NULL)
1579 goto nospace;
1580
1581 if (m_dup_pkthdr(m_final, m0, how) == 0)
1582 goto nospace;
1583
1584 m_new = m_final;
1585
1586 while (progress < m0->m_pkthdr.len) {
1587 length = m0->m_pkthdr.len - progress;
1588 if (length > MCLBYTES)
1589 length = MCLBYTES;
1590
1591 if (m_new == NULL) {
1592 if (length > MLEN)
1593 m_new = m_getcl(how, MT_DATA, 0);
1594 else
1595 m_new = m_get(how, MT_DATA);
1596 if (m_new == NULL)
1597 goto nospace;
1598 }
1599
1600 m_copydata(m0, progress, length, mtod(m_new, caddr_t));
1601 progress += length;
1602 m_new->m_len = length;
1603 if (m_new != m_final)
1604 m_cat(m_final, m_new);
1605 m_new = NULL;
1606 }
1607 #ifdef MBUF_STRESS_TEST
1608 if (m0->m_next == NULL)
1609 m_defraguseless++;
1610 #endif
1611 m_freem(m0);
1612 m0 = m_final;
1613 #ifdef MBUF_STRESS_TEST
1614 m_defragpackets++;
1615 m_defragbytes += m0->m_pkthdr.len;
1616 #endif
1617 return (m0);
1618 nospace:
1619 #ifdef MBUF_STRESS_TEST
1620 m_defragfailure++;
1621 #endif
1622 if (m_final)
1623 m_freem(m_final);
1624 return (NULL);
1625 }
1626
1627 /*
1628 * Defragment an mbuf chain, returning at most maxfrags separate
1629 * mbufs+clusters. If this is not possible NULL is returned and
1630 * the original mbuf chain is left in it's present (potentially
1631 * modified) state. We use two techniques: collapsing consecutive
1632 * mbufs and replacing consecutive mbufs by a cluster.
1633 *
1634 * NB: this should really be named m_defrag but that name is taken
1635 */
1636 struct mbuf *
1637 m_collapse(struct mbuf *m0, int how, int maxfrags)
1638 {
1639 struct mbuf *m, *n, *n2, **prev;
1640 u_int curfrags;
1641
1642 /*
1643 * Calculate the current number of frags.
1644 */
1645 curfrags = 0;
1646 for (m = m0; m != NULL; m = m->m_next)
1647 curfrags++;
1648 /*
1649 * First, try to collapse mbufs. Note that we always collapse
1650 * towards the front so we don't need to deal with moving the
1651 * pkthdr. This may be suboptimal if the first mbuf has much
1652 * less data than the following.
1653 */
1654 m = m0;
1655 again:
1656 for (;;) {
1657 n = m->m_next;
1658 if (n == NULL)
1659 break;
1660 if (M_WRITABLE(m) &&
1661 n->m_len < M_TRAILINGSPACE(m)) {
1662 bcopy(mtod(n, void *), mtod(m, char *) + m->m_len,
1663 n->m_len);
1664 m->m_len += n->m_len;
1665 m->m_next = n->m_next;
1666 m_free(n);
1667 if (--curfrags <= maxfrags)
1668 return m0;
1669 } else
1670 m = n;
1671 }
1672 KASSERT(maxfrags > 1,
1673 ("maxfrags %u, but normal collapse failed", maxfrags));
1674 /*
1675 * Collapse consecutive mbufs to a cluster.
1676 */
1677 prev = &m0->m_next; /* NB: not the first mbuf */
1678 while ((n = *prev) != NULL) {
1679 if ((n2 = n->m_next) != NULL &&
1680 n->m_len + n2->m_len < MCLBYTES) {
1681 m = m_getcl(how, MT_DATA, 0);
1682 if (m == NULL)
1683 goto bad;
1684 bcopy(mtod(n, void *), mtod(m, void *), n->m_len);
1685 bcopy(mtod(n2, void *), mtod(m, char *) + n->m_len,
1686 n2->m_len);
1687 m->m_len = n->m_len + n2->m_len;
1688 m->m_next = n2->m_next;
1689 *prev = m;
1690 m_free(n);
1691 m_free(n2);
1692 if (--curfrags <= maxfrags) /* +1 cl -2 mbufs */
1693 return m0;
1694 /*
1695 * Still not there, try the normal collapse
1696 * again before we allocate another cluster.
1697 */
1698 goto again;
1699 }
1700 prev = &n->m_next;
1701 }
1702 /*
1703 * No place where we can collapse to a cluster; punt.
1704 * This can occur if, for example, you request 2 frags
1705 * but the packet requires that both be clusters (we
1706 * never reallocate the first mbuf to avoid moving the
1707 * packet header).
1708 */
1709 bad:
1710 return NULL;
1711 }
1712
1713 #ifdef MBUF_STRESS_TEST
1714
1715 /*
1716 * Fragment an mbuf chain. There's no reason you'd ever want to do
1717 * this in normal usage, but it's great for stress testing various
1718 * mbuf consumers.
1719 *
1720 * If fragmentation is not possible, the original chain will be
1721 * returned.
1722 *
1723 * Possible length values:
1724 * 0 no fragmentation will occur
1725 * > 0 each fragment will be of the specified length
1726 * -1 each fragment will be the same random value in length
1727 * -2 each fragment's length will be entirely random
1728 * (Random values range from 1 to 256)
1729 */
1730 struct mbuf *
1731 m_fragment(struct mbuf *m0, int how, int length)
1732 {
1733 struct mbuf *m_new = NULL, *m_final = NULL;
1734 int progress = 0;
1735
1736 if (!(m0->m_flags & M_PKTHDR))
1737 return (m0);
1738
1739 if ((length == 0) || (length < -2))
1740 return (m0);
1741
1742 m_fixhdr(m0); /* Needed sanity check */
1743
1744 m_final = m_getcl(how, MT_DATA, M_PKTHDR);
1745
1746 if (m_final == NULL)
1747 goto nospace;
1748
1749 if (m_dup_pkthdr(m_final, m0, how) == 0)
1750 goto nospace;
1751
1752 m_new = m_final;
1753
1754 if (length == -1)
1755 length = 1 + (arc4random() & 255);
1756
1757 while (progress < m0->m_pkthdr.len) {
1758 int fraglen;
1759
1760 if (length > 0)
1761 fraglen = length;
1762 else
1763 fraglen = 1 + (arc4random() & 255);
1764 if (fraglen > m0->m_pkthdr.len - progress)
1765 fraglen = m0->m_pkthdr.len - progress;
1766
1767 if (fraglen > MCLBYTES)
1768 fraglen = MCLBYTES;
1769
1770 if (m_new == NULL) {
1771 m_new = m_getcl(how, MT_DATA, 0);
1772 if (m_new == NULL)
1773 goto nospace;
1774 }
1775
1776 m_copydata(m0, progress, fraglen, mtod(m_new, caddr_t));
1777 progress += fraglen;
1778 m_new->m_len = fraglen;
1779 if (m_new != m_final)
1780 m_cat(m_final, m_new);
1781 m_new = NULL;
1782 }
1783 m_freem(m0);
1784 m0 = m_final;
1785 return (m0);
1786 nospace:
1787 if (m_final)
1788 m_freem(m_final);
1789 /* Return the original chain on failure */
1790 return (m0);
1791 }
1792
1793 #endif
1794
1795 /*
1796 * Copy the contents of uio into a properly sized mbuf chain.
1797 */
1798 struct mbuf *
1799 m_uiotombuf(struct uio *uio, int how, int len, int align, int flags)
1800 {
1801 struct mbuf *m, *mb;
1802 int error, length;
1803 ssize_t total;
1804 int progress = 0;
1805
1806 /*
1807 * len can be zero or an arbitrary large value bound by
1808 * the total data supplied by the uio.
1809 */
1810 if (len > 0)
1811 total = min(uio->uio_resid, len);
1812 else
1813 total = uio->uio_resid;
1814
1815 /*
1816 * The smallest unit returned by m_getm2() is a single mbuf
1817 * with pkthdr. We can't align past it.
1818 */
1819 if (align >= MHLEN)
1820 return (NULL);
1821
1822 /*
1823 * Give us the full allocation or nothing.
1824 * If len is zero return the smallest empty mbuf.
1825 */
1826 m = m_getm2(NULL, max(total + align, 1), how, MT_DATA, flags);
1827 if (m == NULL)
1828 return (NULL);
1829 m->m_data += align;
1830
1831 /* Fill all mbufs with uio data and update header information. */
1832 for (mb = m; mb != NULL; mb = mb->m_next) {
1833 length = min(M_TRAILINGSPACE(mb), total - progress);
1834
1835 error = uiomove(mtod(mb, void *), length, uio);
1836 if (error) {
1837 m_freem(m);
1838 return (NULL);
1839 }
1840
1841 mb->m_len = length;
1842 progress += length;
1843 if (flags & M_PKTHDR)
1844 m->m_pkthdr.len += length;
1845 }
1846 KASSERT(progress == total, ("%s: progress != total", __func__));
1847
1848 return (m);
1849 }
1850
1851 /*
1852 * Copy an mbuf chain into a uio limited by len if set.
1853 */
1854 int
1855 m_mbuftouio(struct uio *uio, struct mbuf *m, int len)
1856 {
1857 int error, length, total;
1858 int progress = 0;
1859
1860 if (len > 0)
1861 total = min(uio->uio_resid, len);
1862 else
1863 total = uio->uio_resid;
1864
1865 /* Fill the uio with data from the mbufs. */
1866 for (; m != NULL; m = m->m_next) {
1867 length = min(m->m_len, total - progress);
1868
1869 error = uiomove(mtod(m, void *), length, uio);
1870 if (error)
1871 return (error);
1872
1873 progress += length;
1874 }
1875
1876 return (0);
1877 }
1878
1879 /*
1880 * Set the m_data pointer of a newly-allocated mbuf
1881 * to place an object of the specified size at the
1882 * end of the mbuf, longword aligned.
1883 */
1884 void
1885 m_align(struct mbuf *m, int len)
1886 {
1887 #ifdef INVARIANTS
1888 const char *msg = "%s: not a virgin mbuf";
1889 #endif
1890 int adjust;
1891
1892 if (m->m_flags & M_EXT) {
1893 KASSERT(m->m_data == m->m_ext.ext_buf, (msg, __func__));
1894 adjust = m->m_ext.ext_size - len;
1895 } else if (m->m_flags & M_PKTHDR) {
1896 KASSERT(m->m_data == m->m_pktdat, (msg, __func__));
1897 adjust = MHLEN - len;
1898 } else {
1899 KASSERT(m->m_data == m->m_dat, (msg, __func__));
1900 adjust = MLEN - len;
1901 }
1902
1903 m->m_data += adjust &~ (sizeof(long)-1);
1904 }
1905
1906 /*
1907 * Create a writable copy of the mbuf chain. While doing this
1908 * we compact the chain with a goal of producing a chain with
1909 * at most two mbufs. The second mbuf in this chain is likely
1910 * to be a cluster. The primary purpose of this work is to create
1911 * a writable packet for encryption, compression, etc. The
1912 * secondary goal is to linearize the data so the data can be
1913 * passed to crypto hardware in the most efficient manner possible.
1914 */
1915 struct mbuf *
1916 m_unshare(struct mbuf *m0, int how)
1917 {
1918 struct mbuf *m, *mprev;
1919 struct mbuf *n, *mfirst, *mlast;
1920 int len, off;
1921
1922 mprev = NULL;
1923 for (m = m0; m != NULL; m = mprev->m_next) {
1924 /*
1925 * Regular mbufs are ignored unless there's a cluster
1926 * in front of it that we can use to coalesce. We do
1927 * the latter mainly so later clusters can be coalesced
1928 * also w/o having to handle them specially (i.e. convert
1929 * mbuf+cluster -> cluster). This optimization is heavily
1930 * influenced by the assumption that we're running over
1931 * Ethernet where MCLBYTES is large enough that the max
1932 * packet size will permit lots of coalescing into a
1933 * single cluster. This in turn permits efficient
1934 * crypto operations, especially when using hardware.
1935 */
1936 if ((m->m_flags & M_EXT) == 0) {
1937 if (mprev && (mprev->m_flags & M_EXT) &&
1938 m->m_len <= M_TRAILINGSPACE(mprev)) {
1939 /* XXX: this ignores mbuf types */
1940 memcpy(mtod(mprev, caddr_t) + mprev->m_len,
1941 mtod(m, caddr_t), m->m_len);
1942 mprev->m_len += m->m_len;
1943 mprev->m_next = m->m_next; /* unlink from chain */
1944 m_free(m); /* reclaim mbuf */
1945 #if 0
1946 newipsecstat.ips_mbcoalesced++;
1947 #endif
1948 } else {
1949 mprev = m;
1950 }
1951 continue;
1952 }
1953 /*
1954 * Writable mbufs are left alone (for now).
1955 */
1956 if (M_WRITABLE(m)) {
1957 mprev = m;
1958 continue;
1959 }
1960
1961 /*
1962 * Not writable, replace with a copy or coalesce with
1963 * the previous mbuf if possible (since we have to copy
1964 * it anyway, we try to reduce the number of mbufs and
1965 * clusters so that future work is easier).
1966 */
1967 KASSERT(m->m_flags & M_EXT, ("m_flags 0x%x", m->m_flags));
1968 /* NB: we only coalesce into a cluster or larger */
1969 if (mprev != NULL && (mprev->m_flags & M_EXT) &&
1970 m->m_len <= M_TRAILINGSPACE(mprev)) {
1971 /* XXX: this ignores mbuf types */
1972 memcpy(mtod(mprev, caddr_t) + mprev->m_len,
1973 mtod(m, caddr_t), m->m_len);
1974 mprev->m_len += m->m_len;
1975 mprev->m_next = m->m_next; /* unlink from chain */
1976 m_free(m); /* reclaim mbuf */
1977 #if 0
1978 newipsecstat.ips_clcoalesced++;
1979 #endif
1980 continue;
1981 }
1982
1983 /*
1984 * Allocate new space to hold the copy and copy the data.
1985 * We deal with jumbo mbufs (i.e. m_len > MCLBYTES) by
1986 * splitting them into clusters. We could just malloc a
1987 * buffer and make it external but too many device drivers
1988 * don't know how to break up the non-contiguous memory when
1989 * doing DMA.
1990 */
1991 n = m_getcl(how, m->m_type, m->m_flags);
1992 if (n == NULL) {
1993 m_freem(m0);
1994 return (NULL);
1995 }
1996 len = m->m_len;
1997 off = 0;
1998 mfirst = n;
1999 mlast = NULL;
2000 for (;;) {
2001 int cc = min(len, MCLBYTES);
2002 memcpy(mtod(n, caddr_t), mtod(m, caddr_t) + off, cc);
2003 n->m_len = cc;
2004 if (mlast != NULL)
2005 mlast->m_next = n;
2006 mlast = n;
2007 #if 0
2008 newipsecstat.ips_clcopied++;
2009 #endif
2010
2011 len -= cc;
2012 if (len <= 0)
2013 break;
2014 off += cc;
2015
2016 n = m_getcl(how, m->m_type, m->m_flags);
2017 if (n == NULL) {
2018 m_freem(mfirst);
2019 m_freem(m0);
2020 return (NULL);
2021 }
2022 }
2023 n->m_next = m->m_next;
2024 if (mprev == NULL)
2025 m0 = mfirst; /* new head of chain */
2026 else
2027 mprev->m_next = mfirst; /* replace old mbuf */
2028 m_free(m); /* release old mbuf */
2029 mprev = mfirst;
2030 }
2031 return (m0);
2032 }
2033
2034 #ifdef MBUF_PROFILING
2035
2036 #define MP_BUCKETS 32 /* don't just change this as things may overflow.*/
2037 struct mbufprofile {
2038 uintmax_t wasted[MP_BUCKETS];
2039 uintmax_t used[MP_BUCKETS];
2040 uintmax_t segments[MP_BUCKETS];
2041 } mbprof;
2042
2043 #define MP_MAXDIGITS 21 /* strlen("16,000,000,000,000,000,000") == 21 */
2044 #define MP_NUMLINES 6
2045 #define MP_NUMSPERLINE 16
2046 #define MP_EXTRABYTES 64 /* > strlen("used:\nwasted:\nsegments:\n") */
2047 /* work out max space needed and add a bit of spare space too */
2048 #define MP_MAXLINE ((MP_MAXDIGITS+1) * MP_NUMSPERLINE)
2049 #define MP_BUFSIZE ((MP_MAXLINE * MP_NUMLINES) + 1 + MP_EXTRABYTES)
2050
2051 char mbprofbuf[MP_BUFSIZE];
2052
2053 void
2054 m_profile(struct mbuf *m)
2055 {
2056 int segments = 0;
2057 int used = 0;
2058 int wasted = 0;
2059
2060 while (m) {
2061 segments++;
2062 used += m->m_len;
2063 if (m->m_flags & M_EXT) {
2064 wasted += MHLEN - sizeof(m->m_ext) +
2065 m->m_ext.ext_size - m->m_len;
2066 } else {
2067 if (m->m_flags & M_PKTHDR)
2068 wasted += MHLEN - m->m_len;
2069 else
2070 wasted += MLEN - m->m_len;
2071 }
2072 m = m->m_next;
2073 }
2074 /* be paranoid.. it helps */
2075 if (segments > MP_BUCKETS - 1)
2076 segments = MP_BUCKETS - 1;
2077 if (used > 100000)
2078 used = 100000;
2079 if (wasted > 100000)
2080 wasted = 100000;
2081 /* store in the appropriate bucket */
2082 /* don't bother locking. if it's slightly off, so what? */
2083 mbprof.segments[segments]++;
2084 mbprof.used[fls(used)]++;
2085 mbprof.wasted[fls(wasted)]++;
2086 }
2087
2088 static void
2089 mbprof_textify(void)
2090 {
2091 int offset;
2092 char *c;
2093 uint64_t *p;
2094
2095
2096 p = &mbprof.wasted[0];
2097 c = mbprofbuf;
2098 offset = snprintf(c, MP_MAXLINE + 10,
2099 "wasted:\n"
2100 "%ju %ju %ju %ju %ju %ju %ju %ju "
2101 "%ju %ju %ju %ju %ju %ju %ju %ju\n",
2102 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
2103 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
2104 #ifdef BIG_ARRAY
2105 p = &mbprof.wasted[16];
2106 c += offset;
2107 offset = snprintf(c, MP_MAXLINE,
2108 "%ju %ju %ju %ju %ju %ju %ju %ju "
2109 "%ju %ju %ju %ju %ju %ju %ju %ju\n",
2110 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
2111 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
2112 #endif
2113 p = &mbprof.used[0];
2114 c += offset;
2115 offset = snprintf(c, MP_MAXLINE + 10,
2116 "used:\n"
2117 "%ju %ju %ju %ju %ju %ju %ju %ju "
2118 "%ju %ju %ju %ju %ju %ju %ju %ju\n",
2119 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
2120 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
2121 #ifdef BIG_ARRAY
2122 p = &mbprof.used[16];
2123 c += offset;
2124 offset = snprintf(c, MP_MAXLINE,
2125 "%ju %ju %ju %ju %ju %ju %ju %ju "
2126 "%ju %ju %ju %ju %ju %ju %ju %ju\n",
2127 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
2128 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
2129 #endif
2130 p = &mbprof.segments[0];
2131 c += offset;
2132 offset = snprintf(c, MP_MAXLINE + 10,
2133 "segments:\n"
2134 "%ju %ju %ju %ju %ju %ju %ju %ju "
2135 "%ju %ju %ju %ju %ju %ju %ju %ju\n",
2136 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
2137 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
2138 #ifdef BIG_ARRAY
2139 p = &mbprof.segments[16];
2140 c += offset;
2141 offset = snprintf(c, MP_MAXLINE,
2142 "%ju %ju %ju %ju %ju %ju %ju %ju "
2143 "%ju %ju %ju %ju %ju %ju %ju %jju",
2144 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
2145 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
2146 #endif
2147 }
2148
2149 static int
2150 mbprof_handler(SYSCTL_HANDLER_ARGS)
2151 {
2152 int error;
2153
2154 mbprof_textify();
2155 error = SYSCTL_OUT(req, mbprofbuf, strlen(mbprofbuf) + 1);
2156 return (error);
2157 }
2158
2159 static int
2160 mbprof_clr_handler(SYSCTL_HANDLER_ARGS)
2161 {
2162 int clear, error;
2163
2164 clear = 0;
2165 error = sysctl_handle_int(oidp, &clear, 0, req);
2166 if (error || !req->newptr)
2167 return (error);
2168
2169 if (clear) {
2170 bzero(&mbprof, sizeof(mbprof));
2171 }
2172
2173 return (error);
2174 }
2175
2176
2177 SYSCTL_PROC(_kern_ipc, OID_AUTO, mbufprofile, CTLTYPE_STRING|CTLFLAG_RD,
2178 NULL, 0, mbprof_handler, "A", "mbuf profiling statistics");
2179
2180 SYSCTL_PROC(_kern_ipc, OID_AUTO, mbufprofileclr, CTLTYPE_INT|CTLFLAG_RW,
2181 NULL, 0, mbprof_clr_handler, "I", "clear mbuf profiling statistics");
2182 #endif
2183
Cache object: d153ad02b11122facc7831e9fd25cbbd
|