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/8.0/sys/kern/uipc_mbuf.c 209964 2010-07-13 02:45:17Z cperciva $");
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 * Allocate a given length worth of mbufs and/or clusters (whatever fits
89 * best) and return a pointer to the top of the allocated chain. If an
90 * existing mbuf chain is provided, then we will append the new chain
91 * to the existing one but still return the top of the newly allocated
92 * chain.
93 */
94 struct mbuf *
95 m_getm2(struct mbuf *m, int len, int how, short type, int flags)
96 {
97 struct mbuf *mb, *nm = NULL, *mtail = NULL;
98
99 KASSERT(len >= 0, ("%s: len is < 0", __func__));
100
101 /* Validate flags. */
102 flags &= (M_PKTHDR | M_EOR);
103
104 /* Packet header mbuf must be first in chain. */
105 if ((flags & M_PKTHDR) && m != NULL)
106 flags &= ~M_PKTHDR;
107
108 /* Loop and append maximum sized mbufs to the chain tail. */
109 while (len > 0) {
110 if (len > MCLBYTES)
111 mb = m_getjcl(how, type, (flags & M_PKTHDR),
112 MJUMPAGESIZE);
113 else if (len >= MINCLSIZE)
114 mb = m_getcl(how, type, (flags & M_PKTHDR));
115 else if (flags & M_PKTHDR)
116 mb = m_gethdr(how, type);
117 else
118 mb = m_get(how, type);
119
120 /* Fail the whole operation if one mbuf can't be allocated. */
121 if (mb == NULL) {
122 if (nm != NULL)
123 m_freem(nm);
124 return (NULL);
125 }
126
127 /* Book keeping. */
128 len -= (mb->m_flags & M_EXT) ? mb->m_ext.ext_size :
129 ((mb->m_flags & M_PKTHDR) ? MHLEN : MLEN);
130 if (mtail != NULL)
131 mtail->m_next = mb;
132 else
133 nm = mb;
134 mtail = mb;
135 flags &= ~M_PKTHDR; /* Only valid on the first mbuf. */
136 }
137 if (flags & M_EOR)
138 mtail->m_flags |= M_EOR; /* Only valid on the last mbuf. */
139
140 /* If mbuf was supplied, append new chain to the end of it. */
141 if (m != NULL) {
142 for (mtail = m; mtail->m_next != NULL; mtail = mtail->m_next)
143 ;
144 mtail->m_next = nm;
145 mtail->m_flags &= ~M_EOR;
146 } else
147 m = nm;
148
149 return (m);
150 }
151
152 /*
153 * Free an entire chain of mbufs and associated external buffers, if
154 * applicable.
155 */
156 void
157 m_freem(struct mbuf *mb)
158 {
159
160 while (mb != NULL)
161 mb = m_free(mb);
162 }
163
164 /*-
165 * Configure a provided mbuf to refer to the provided external storage
166 * buffer and setup a reference count for said buffer. If the setting
167 * up of the reference count fails, the M_EXT bit will not be set. If
168 * successfull, the M_EXT bit is set in the mbuf's flags.
169 *
170 * Arguments:
171 * mb The existing mbuf to which to attach the provided buffer.
172 * buf The address of the provided external storage buffer.
173 * size The size of the provided buffer.
174 * freef A pointer to a routine that is responsible for freeing the
175 * provided external storage buffer.
176 * args A pointer to an argument structure (of any type) to be passed
177 * to the provided freef routine (may be NULL).
178 * flags Any other flags to be passed to the provided mbuf.
179 * type The type that the external storage buffer should be
180 * labeled with.
181 *
182 * Returns:
183 * Nothing.
184 */
185 void
186 m_extadd(struct mbuf *mb, caddr_t buf, u_int size,
187 void (*freef)(void *, void *), void *arg1, void *arg2, int flags, int type)
188 {
189 KASSERT(type != EXT_CLUSTER, ("%s: EXT_CLUSTER not allowed", __func__));
190
191 if (type != EXT_EXTREF)
192 mb->m_ext.ref_cnt = (u_int *)uma_zalloc(zone_ext_refcnt, M_NOWAIT);
193 if (mb->m_ext.ref_cnt != NULL) {
194 *(mb->m_ext.ref_cnt) = 1;
195 mb->m_flags |= (M_EXT | flags);
196 mb->m_ext.ext_buf = buf;
197 mb->m_data = mb->m_ext.ext_buf;
198 mb->m_ext.ext_size = size;
199 mb->m_ext.ext_free = freef;
200 mb->m_ext.ext_arg1 = arg1;
201 mb->m_ext.ext_arg2 = arg2;
202 mb->m_ext.ext_type = type;
203 }
204 }
205
206 /*
207 * Non-directly-exported function to clean up after mbufs with M_EXT
208 * storage attached to them if the reference count hits 1.
209 */
210 void
211 mb_free_ext(struct mbuf *m)
212 {
213 int skipmbuf;
214
215 KASSERT((m->m_flags & M_EXT) == M_EXT, ("%s: M_EXT not set", __func__));
216 KASSERT(m->m_ext.ref_cnt != NULL, ("%s: ref_cnt not set", __func__));
217
218
219 /*
220 * check if the header is embedded in the cluster
221 */
222 skipmbuf = (m->m_flags & M_NOFREE);
223
224 /* Free attached storage if this mbuf is the only reference to it. */
225 if (*(m->m_ext.ref_cnt) == 1 ||
226 atomic_fetchadd_int(m->m_ext.ref_cnt, -1) == 1) {
227 switch (m->m_ext.ext_type) {
228 case EXT_PACKET: /* The packet zone is special. */
229 if (*(m->m_ext.ref_cnt) == 0)
230 *(m->m_ext.ref_cnt) = 1;
231 uma_zfree(zone_pack, m);
232 return; /* Job done. */
233 case EXT_CLUSTER:
234 uma_zfree(zone_clust, m->m_ext.ext_buf);
235 break;
236 case EXT_JUMBOP:
237 uma_zfree(zone_jumbop, m->m_ext.ext_buf);
238 break;
239 case EXT_JUMBO9:
240 uma_zfree(zone_jumbo9, m->m_ext.ext_buf);
241 break;
242 case EXT_JUMBO16:
243 uma_zfree(zone_jumbo16, m->m_ext.ext_buf);
244 break;
245 case EXT_SFBUF:
246 case EXT_NET_DRV:
247 case EXT_MOD_TYPE:
248 case EXT_DISPOSABLE:
249 *(m->m_ext.ref_cnt) = 0;
250 uma_zfree(zone_ext_refcnt, __DEVOLATILE(u_int *,
251 m->m_ext.ref_cnt));
252 /* FALLTHROUGH */
253 case EXT_EXTREF:
254 KASSERT(m->m_ext.ext_free != NULL,
255 ("%s: ext_free not set", __func__));
256 (*(m->m_ext.ext_free))(m->m_ext.ext_arg1,
257 m->m_ext.ext_arg2);
258 break;
259 default:
260 KASSERT(m->m_ext.ext_type == 0,
261 ("%s: unknown ext_type", __func__));
262 }
263 }
264 if (skipmbuf)
265 return;
266
267 /*
268 * Free this mbuf back to the mbuf zone with all m_ext
269 * information purged.
270 */
271 m->m_ext.ext_buf = NULL;
272 m->m_ext.ext_free = NULL;
273 m->m_ext.ext_arg1 = NULL;
274 m->m_ext.ext_arg2 = NULL;
275 m->m_ext.ref_cnt = NULL;
276 m->m_ext.ext_size = 0;
277 m->m_ext.ext_type = 0;
278 m->m_flags &= ~M_EXT;
279 uma_zfree(zone_mbuf, m);
280 }
281
282 /*
283 * Attach the the cluster from *m to *n, set up m_ext in *n
284 * and bump the refcount of the cluster.
285 */
286 static void
287 mb_dupcl(struct mbuf *n, struct mbuf *m)
288 {
289 KASSERT((m->m_flags & M_EXT) == M_EXT, ("%s: M_EXT not set", __func__));
290 KASSERT(m->m_ext.ref_cnt != NULL, ("%s: ref_cnt not set", __func__));
291 KASSERT((n->m_flags & M_EXT) == 0, ("%s: M_EXT set", __func__));
292
293 if (*(m->m_ext.ref_cnt) == 1)
294 *(m->m_ext.ref_cnt) += 1;
295 else
296 atomic_add_int(m->m_ext.ref_cnt, 1);
297 n->m_ext.ext_buf = m->m_ext.ext_buf;
298 n->m_ext.ext_free = m->m_ext.ext_free;
299 n->m_ext.ext_arg1 = m->m_ext.ext_arg1;
300 n->m_ext.ext_arg2 = m->m_ext.ext_arg2;
301 n->m_ext.ext_size = m->m_ext.ext_size;
302 n->m_ext.ref_cnt = m->m_ext.ref_cnt;
303 n->m_ext.ext_type = m->m_ext.ext_type;
304 n->m_flags |= M_EXT;
305 n->m_flags |= m->m_flags & M_RDONLY;
306 }
307
308 /*
309 * Clean up mbuf (chain) from any tags and packet headers.
310 * If "all" is set then the first mbuf in the chain will be
311 * cleaned too.
312 */
313 void
314 m_demote(struct mbuf *m0, int all)
315 {
316 struct mbuf *m;
317
318 for (m = all ? m0 : m0->m_next; m != NULL; m = m->m_next) {
319 if (m->m_flags & M_PKTHDR) {
320 m_tag_delete_chain(m, NULL);
321 m->m_flags &= ~M_PKTHDR;
322 bzero(&m->m_pkthdr, sizeof(struct pkthdr));
323 }
324 if (m != m0 && m->m_nextpkt != NULL) {
325 KASSERT(m->m_nextpkt == NULL,
326 ("%s: m_nextpkt not NULL", __func__));
327 m_freem(m->m_nextpkt);
328 m->m_nextpkt = NULL;
329 }
330 m->m_flags = m->m_flags & (M_EXT|M_RDONLY|M_FREELIST|M_NOFREE);
331 }
332 }
333
334 /*
335 * Sanity checks on mbuf (chain) for use in KASSERT() and general
336 * debugging.
337 * Returns 0 or panics when bad and 1 on all tests passed.
338 * Sanitize, 0 to run M_SANITY_ACTION, 1 to garble things so they
339 * blow up later.
340 */
341 int
342 m_sanity(struct mbuf *m0, int sanitize)
343 {
344 struct mbuf *m;
345 caddr_t a, b;
346 int pktlen = 0;
347
348 #ifdef INVARIANTS
349 #define M_SANITY_ACTION(s) panic("mbuf %p: " s, m)
350 #else
351 #define M_SANITY_ACTION(s) printf("mbuf %p: " s, m)
352 #endif
353
354 for (m = m0; m != NULL; m = m->m_next) {
355 /*
356 * Basic pointer checks. If any of these fails then some
357 * unrelated kernel memory before or after us is trashed.
358 * No way to recover from that.
359 */
360 a = ((m->m_flags & M_EXT) ? m->m_ext.ext_buf :
361 ((m->m_flags & M_PKTHDR) ? (caddr_t)(&m->m_pktdat) :
362 (caddr_t)(&m->m_dat)) );
363 b = (caddr_t)(a + (m->m_flags & M_EXT ? m->m_ext.ext_size :
364 ((m->m_flags & M_PKTHDR) ? MHLEN : MLEN)));
365 if ((caddr_t)m->m_data < a)
366 M_SANITY_ACTION("m_data outside mbuf data range left");
367 if ((caddr_t)m->m_data > b)
368 M_SANITY_ACTION("m_data outside mbuf data range right");
369 if ((caddr_t)m->m_data + m->m_len > b)
370 M_SANITY_ACTION("m_data + m_len exeeds mbuf space");
371 if ((m->m_flags & M_PKTHDR) && m->m_pkthdr.header) {
372 if ((caddr_t)m->m_pkthdr.header < a ||
373 (caddr_t)m->m_pkthdr.header > b)
374 M_SANITY_ACTION("m_pkthdr.header outside mbuf data range");
375 }
376
377 /* m->m_nextpkt may only be set on first mbuf in chain. */
378 if (m != m0 && m->m_nextpkt != NULL) {
379 if (sanitize) {
380 m_freem(m->m_nextpkt);
381 m->m_nextpkt = (struct mbuf *)0xDEADC0DE;
382 } else
383 M_SANITY_ACTION("m->m_nextpkt on in-chain mbuf");
384 }
385
386 /* packet length (not mbuf length!) calculation */
387 if (m0->m_flags & M_PKTHDR)
388 pktlen += m->m_len;
389
390 /* m_tags may only be attached to first mbuf in chain. */
391 if (m != m0 && m->m_flags & M_PKTHDR &&
392 !SLIST_EMPTY(&m->m_pkthdr.tags)) {
393 if (sanitize) {
394 m_tag_delete_chain(m, NULL);
395 /* put in 0xDEADC0DE perhaps? */
396 } else
397 M_SANITY_ACTION("m_tags on in-chain mbuf");
398 }
399
400 /* M_PKTHDR may only be set on first mbuf in chain */
401 if (m != m0 && m->m_flags & M_PKTHDR) {
402 if (sanitize) {
403 bzero(&m->m_pkthdr, sizeof(m->m_pkthdr));
404 m->m_flags &= ~M_PKTHDR;
405 /* put in 0xDEADCODE and leave hdr flag in */
406 } else
407 M_SANITY_ACTION("M_PKTHDR on in-chain mbuf");
408 }
409 }
410 m = m0;
411 if (pktlen && pktlen != m->m_pkthdr.len) {
412 if (sanitize)
413 m->m_pkthdr.len = 0;
414 else
415 M_SANITY_ACTION("m_pkthdr.len != mbuf chain length");
416 }
417 return 1;
418
419 #undef M_SANITY_ACTION
420 }
421
422
423 /*
424 * "Move" mbuf pkthdr from "from" to "to".
425 * "from" must have M_PKTHDR set, and "to" must be empty.
426 */
427 void
428 m_move_pkthdr(struct mbuf *to, struct mbuf *from)
429 {
430
431 #if 0
432 /* see below for why these are not enabled */
433 M_ASSERTPKTHDR(to);
434 /* Note: with MAC, this may not be a good assertion. */
435 KASSERT(SLIST_EMPTY(&to->m_pkthdr.tags),
436 ("m_move_pkthdr: to has tags"));
437 #endif
438 #ifdef MAC
439 /*
440 * XXXMAC: It could be this should also occur for non-MAC?
441 */
442 if (to->m_flags & M_PKTHDR)
443 m_tag_delete_chain(to, NULL);
444 #endif
445 to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT);
446 if ((to->m_flags & M_EXT) == 0)
447 to->m_data = to->m_pktdat;
448 to->m_pkthdr = from->m_pkthdr; /* especially tags */
449 SLIST_INIT(&from->m_pkthdr.tags); /* purge tags from src */
450 from->m_flags &= ~M_PKTHDR;
451 }
452
453 /*
454 * Duplicate "from"'s mbuf pkthdr in "to".
455 * "from" must have M_PKTHDR set, and "to" must be empty.
456 * In particular, this does a deep copy of the packet tags.
457 */
458 int
459 m_dup_pkthdr(struct mbuf *to, struct mbuf *from, int how)
460 {
461
462 #if 0
463 /*
464 * The mbuf allocator only initializes the pkthdr
465 * when the mbuf is allocated with MGETHDR. Many users
466 * (e.g. m_copy*, m_prepend) use MGET and then
467 * smash the pkthdr as needed causing these
468 * assertions to trip. For now just disable them.
469 */
470 M_ASSERTPKTHDR(to);
471 /* Note: with MAC, this may not be a good assertion. */
472 KASSERT(SLIST_EMPTY(&to->m_pkthdr.tags), ("m_dup_pkthdr: to has tags"));
473 #endif
474 MBUF_CHECKSLEEP(how);
475 #ifdef MAC
476 if (to->m_flags & M_PKTHDR)
477 m_tag_delete_chain(to, NULL);
478 #endif
479 to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT);
480 if ((to->m_flags & M_EXT) == 0)
481 to->m_data = to->m_pktdat;
482 to->m_pkthdr = from->m_pkthdr;
483 SLIST_INIT(&to->m_pkthdr.tags);
484 return (m_tag_copy_chain(to, from, MBTOM(how)));
485 }
486
487 /*
488 * Lesser-used path for M_PREPEND:
489 * allocate new mbuf to prepend to chain,
490 * copy junk along.
491 */
492 struct mbuf *
493 m_prepend(struct mbuf *m, int len, int how)
494 {
495 struct mbuf *mn;
496
497 if (m->m_flags & M_PKTHDR)
498 MGETHDR(mn, how, m->m_type);
499 else
500 MGET(mn, how, m->m_type);
501 if (mn == NULL) {
502 m_freem(m);
503 return (NULL);
504 }
505 if (m->m_flags & M_PKTHDR)
506 M_MOVE_PKTHDR(mn, m);
507 mn->m_next = m;
508 m = mn;
509 if(m->m_flags & M_PKTHDR) {
510 if (len < MHLEN)
511 MH_ALIGN(m, len);
512 } else {
513 if (len < MLEN)
514 M_ALIGN(m, len);
515 }
516 m->m_len = len;
517 return (m);
518 }
519
520 /*
521 * Make a copy of an mbuf chain starting "off0" bytes from the beginning,
522 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf.
523 * The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller.
524 * Note that the copy is read-only, because clusters are not copied,
525 * only their reference counts are incremented.
526 */
527 struct mbuf *
528 m_copym(struct mbuf *m, int off0, int len, int wait)
529 {
530 struct mbuf *n, **np;
531 int off = off0;
532 struct mbuf *top;
533 int copyhdr = 0;
534
535 KASSERT(off >= 0, ("m_copym, negative off %d", off));
536 KASSERT(len >= 0, ("m_copym, negative len %d", len));
537 MBUF_CHECKSLEEP(wait);
538 if (off == 0 && m->m_flags & M_PKTHDR)
539 copyhdr = 1;
540 while (off > 0) {
541 KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain"));
542 if (off < m->m_len)
543 break;
544 off -= m->m_len;
545 m = m->m_next;
546 }
547 np = ⊤
548 top = 0;
549 while (len > 0) {
550 if (m == NULL) {
551 KASSERT(len == M_COPYALL,
552 ("m_copym, length > size of mbuf chain"));
553 break;
554 }
555 if (copyhdr)
556 MGETHDR(n, wait, m->m_type);
557 else
558 MGET(n, wait, m->m_type);
559 *np = n;
560 if (n == NULL)
561 goto nospace;
562 if (copyhdr) {
563 if (!m_dup_pkthdr(n, m, wait))
564 goto nospace;
565 if (len == M_COPYALL)
566 n->m_pkthdr.len -= off0;
567 else
568 n->m_pkthdr.len = len;
569 copyhdr = 0;
570 }
571 n->m_len = min(len, m->m_len - off);
572 if (m->m_flags & M_EXT) {
573 n->m_data = m->m_data + off;
574 mb_dupcl(n, m);
575 } else
576 bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
577 (u_int)n->m_len);
578 if (len != M_COPYALL)
579 len -= n->m_len;
580 off = 0;
581 m = m->m_next;
582 np = &n->m_next;
583 }
584 if (top == NULL)
585 mbstat.m_mcfail++; /* XXX: No consistency. */
586
587 return (top);
588 nospace:
589 m_freem(top);
590 mbstat.m_mcfail++; /* XXX: No consistency. */
591 return (NULL);
592 }
593
594 /*
595 * Returns mbuf chain with new head for the prepending case.
596 * Copies from mbuf (chain) n from off for len to mbuf (chain) m
597 * either prepending or appending the data.
598 * The resulting mbuf (chain) m is fully writeable.
599 * m is destination (is made writeable)
600 * n is source, off is offset in source, len is len from offset
601 * dir, 0 append, 1 prepend
602 * how, wait or nowait
603 */
604
605 static int
606 m_bcopyxxx(void *s, void *t, u_int len)
607 {
608 bcopy(s, t, (size_t)len);
609 return 0;
610 }
611
612 struct mbuf *
613 m_copymdata(struct mbuf *m, struct mbuf *n, int off, int len,
614 int prep, int how)
615 {
616 struct mbuf *mm, *x, *z, *prev = NULL;
617 caddr_t p;
618 int i, nlen = 0;
619 caddr_t buf[MLEN];
620
621 KASSERT(m != NULL && n != NULL, ("m_copymdata, no target or source"));
622 KASSERT(off >= 0, ("m_copymdata, negative off %d", off));
623 KASSERT(len >= 0, ("m_copymdata, negative len %d", len));
624 KASSERT(prep == 0 || prep == 1, ("m_copymdata, unknown direction %d", prep));
625
626 mm = m;
627 if (!prep) {
628 while(mm->m_next) {
629 prev = mm;
630 mm = mm->m_next;
631 }
632 }
633 for (z = n; z != NULL; z = z->m_next)
634 nlen += z->m_len;
635 if (len == M_COPYALL)
636 len = nlen - off;
637 if (off + len > nlen || len < 1)
638 return NULL;
639
640 if (!M_WRITABLE(mm)) {
641 /* XXX: Use proper m_xxx function instead. */
642 x = m_getcl(how, MT_DATA, mm->m_flags);
643 if (x == NULL)
644 return NULL;
645 bcopy(mm->m_ext.ext_buf, x->m_ext.ext_buf, x->m_ext.ext_size);
646 p = x->m_ext.ext_buf + (mm->m_data - mm->m_ext.ext_buf);
647 x->m_data = p;
648 mm->m_next = NULL;
649 if (mm != m)
650 prev->m_next = x;
651 m_free(mm);
652 mm = x;
653 }
654
655 /*
656 * Append/prepend the data. Allocating mbufs as necessary.
657 */
658 /* Shortcut if enough free space in first/last mbuf. */
659 if (!prep && M_TRAILINGSPACE(mm) >= len) {
660 m_apply(n, off, len, m_bcopyxxx, mtod(mm, caddr_t) +
661 mm->m_len);
662 mm->m_len += len;
663 mm->m_pkthdr.len += len;
664 return m;
665 }
666 if (prep && M_LEADINGSPACE(mm) >= len) {
667 mm->m_data = mtod(mm, caddr_t) - len;
668 m_apply(n, off, len, m_bcopyxxx, mtod(mm, caddr_t));
669 mm->m_len += len;
670 mm->m_pkthdr.len += len;
671 return mm;
672 }
673
674 /* Expand first/last mbuf to cluster if possible. */
675 if (!prep && !(mm->m_flags & M_EXT) && len > M_TRAILINGSPACE(mm)) {
676 bcopy(mm->m_data, &buf, mm->m_len);
677 m_clget(mm, how);
678 if (!(mm->m_flags & M_EXT))
679 return NULL;
680 bcopy(&buf, mm->m_ext.ext_buf, mm->m_len);
681 mm->m_data = mm->m_ext.ext_buf;
682 mm->m_pkthdr.header = NULL;
683 }
684 if (prep && !(mm->m_flags & M_EXT) && len > M_LEADINGSPACE(mm)) {
685 bcopy(mm->m_data, &buf, mm->m_len);
686 m_clget(mm, how);
687 if (!(mm->m_flags & M_EXT))
688 return NULL;
689 bcopy(&buf, (caddr_t *)mm->m_ext.ext_buf +
690 mm->m_ext.ext_size - mm->m_len, mm->m_len);
691 mm->m_data = (caddr_t)mm->m_ext.ext_buf +
692 mm->m_ext.ext_size - mm->m_len;
693 mm->m_pkthdr.header = NULL;
694 }
695
696 /* Append/prepend as many mbuf (clusters) as necessary to fit len. */
697 if (!prep && len > M_TRAILINGSPACE(mm)) {
698 if (!m_getm(mm, len - M_TRAILINGSPACE(mm), how, MT_DATA))
699 return NULL;
700 }
701 if (prep && len > M_LEADINGSPACE(mm)) {
702 if (!(z = m_getm(NULL, len - M_LEADINGSPACE(mm), how, MT_DATA)))
703 return NULL;
704 i = 0;
705 for (x = z; x != NULL; x = x->m_next) {
706 i += x->m_flags & M_EXT ? x->m_ext.ext_size :
707 (x->m_flags & M_PKTHDR ? MHLEN : MLEN);
708 if (!x->m_next)
709 break;
710 }
711 z->m_data += i - len;
712 m_move_pkthdr(mm, z);
713 x->m_next = mm;
714 mm = z;
715 }
716
717 /* Seek to start position in source mbuf. Optimization for long chains. */
718 while (off > 0) {
719 if (off < n->m_len)
720 break;
721 off -= n->m_len;
722 n = n->m_next;
723 }
724
725 /* Copy data into target mbuf. */
726 z = mm;
727 while (len > 0) {
728 KASSERT(z != NULL, ("m_copymdata, falling off target edge"));
729 i = M_TRAILINGSPACE(z);
730 m_apply(n, off, i, m_bcopyxxx, mtod(z, caddr_t) + z->m_len);
731 z->m_len += i;
732 /* fixup pkthdr.len if necessary */
733 if ((prep ? mm : m)->m_flags & M_PKTHDR)
734 (prep ? mm : m)->m_pkthdr.len += i;
735 off += i;
736 len -= i;
737 z = z->m_next;
738 }
739 return (prep ? mm : m);
740 }
741
742 /*
743 * Copy an entire packet, including header (which must be present).
744 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'.
745 * Note that the copy is read-only, because clusters are not copied,
746 * only their reference counts are incremented.
747 * Preserve alignment of the first mbuf so if the creator has left
748 * some room at the beginning (e.g. for inserting protocol headers)
749 * the copies still have the room available.
750 */
751 struct mbuf *
752 m_copypacket(struct mbuf *m, int how)
753 {
754 struct mbuf *top, *n, *o;
755
756 MBUF_CHECKSLEEP(how);
757 MGET(n, how, m->m_type);
758 top = n;
759 if (n == NULL)
760 goto nospace;
761
762 if (!m_dup_pkthdr(n, m, how))
763 goto nospace;
764 n->m_len = m->m_len;
765 if (m->m_flags & M_EXT) {
766 n->m_data = m->m_data;
767 mb_dupcl(n, m);
768 } else {
769 n->m_data = n->m_pktdat + (m->m_data - m->m_pktdat );
770 bcopy(mtod(m, char *), mtod(n, char *), n->m_len);
771 }
772
773 m = m->m_next;
774 while (m) {
775 MGET(o, how, m->m_type);
776 if (o == NULL)
777 goto nospace;
778
779 n->m_next = o;
780 n = n->m_next;
781
782 n->m_len = m->m_len;
783 if (m->m_flags & M_EXT) {
784 n->m_data = m->m_data;
785 mb_dupcl(n, m);
786 } else {
787 bcopy(mtod(m, char *), mtod(n, char *), n->m_len);
788 }
789
790 m = m->m_next;
791 }
792 return top;
793 nospace:
794 m_freem(top);
795 mbstat.m_mcfail++; /* XXX: No consistency. */
796 return (NULL);
797 }
798
799 /*
800 * Copy data from an mbuf chain starting "off" bytes from the beginning,
801 * continuing for "len" bytes, into the indicated buffer.
802 */
803 void
804 m_copydata(const struct mbuf *m, int off, int len, caddr_t cp)
805 {
806 u_int count;
807
808 KASSERT(off >= 0, ("m_copydata, negative off %d", off));
809 KASSERT(len >= 0, ("m_copydata, negative len %d", len));
810 while (off > 0) {
811 KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain"));
812 if (off < m->m_len)
813 break;
814 off -= m->m_len;
815 m = m->m_next;
816 }
817 while (len > 0) {
818 KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain"));
819 count = min(m->m_len - off, len);
820 bcopy(mtod(m, caddr_t) + off, cp, count);
821 len -= count;
822 cp += count;
823 off = 0;
824 m = m->m_next;
825 }
826 }
827
828 /*
829 * Copy a packet header mbuf chain into a completely new chain, including
830 * copying any mbuf clusters. Use this instead of m_copypacket() when
831 * you need a writable copy of an mbuf chain.
832 */
833 struct mbuf *
834 m_dup(struct mbuf *m, int how)
835 {
836 struct mbuf **p, *top = NULL;
837 int remain, moff, nsize;
838
839 MBUF_CHECKSLEEP(how);
840 /* Sanity check */
841 if (m == NULL)
842 return (NULL);
843 M_ASSERTPKTHDR(m);
844
845 /* While there's more data, get a new mbuf, tack it on, and fill it */
846 remain = m->m_pkthdr.len;
847 moff = 0;
848 p = ⊤
849 while (remain > 0 || top == NULL) { /* allow m->m_pkthdr.len == 0 */
850 struct mbuf *n;
851
852 /* Get the next new mbuf */
853 if (remain >= MINCLSIZE) {
854 n = m_getcl(how, m->m_type, 0);
855 nsize = MCLBYTES;
856 } else {
857 n = m_get(how, m->m_type);
858 nsize = MLEN;
859 }
860 if (n == NULL)
861 goto nospace;
862
863 if (top == NULL) { /* First one, must be PKTHDR */
864 if (!m_dup_pkthdr(n, m, how)) {
865 m_free(n);
866 goto nospace;
867 }
868 if ((n->m_flags & M_EXT) == 0)
869 nsize = MHLEN;
870 }
871 n->m_len = 0;
872
873 /* Link it into the new chain */
874 *p = n;
875 p = &n->m_next;
876
877 /* Copy data from original mbuf(s) into new mbuf */
878 while (n->m_len < nsize && m != NULL) {
879 int chunk = min(nsize - n->m_len, m->m_len - moff);
880
881 bcopy(m->m_data + moff, n->m_data + n->m_len, chunk);
882 moff += chunk;
883 n->m_len += chunk;
884 remain -= chunk;
885 if (moff == m->m_len) {
886 m = m->m_next;
887 moff = 0;
888 }
889 }
890
891 /* Check correct total mbuf length */
892 KASSERT((remain > 0 && m != NULL) || (remain == 0 && m == NULL),
893 ("%s: bogus m_pkthdr.len", __func__));
894 }
895 return (top);
896
897 nospace:
898 m_freem(top);
899 mbstat.m_mcfail++; /* XXX: No consistency. */
900 return (NULL);
901 }
902
903 /*
904 * Concatenate mbuf chain n to m.
905 * Both chains must be of the same type (e.g. MT_DATA).
906 * Any m_pkthdr is not updated.
907 */
908 void
909 m_cat(struct mbuf *m, struct mbuf *n)
910 {
911 while (m->m_next)
912 m = m->m_next;
913 while (n) {
914 if (m->m_flags & M_EXT ||
915 m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) {
916 /* just join the two chains */
917 m->m_next = n;
918 return;
919 }
920 /* splat the data from one into the other */
921 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len,
922 (u_int)n->m_len);
923 m->m_len += n->m_len;
924 n = m_free(n);
925 }
926 }
927
928 void
929 m_adj(struct mbuf *mp, int req_len)
930 {
931 int len = req_len;
932 struct mbuf *m;
933 int count;
934
935 if ((m = mp) == NULL)
936 return;
937 if (len >= 0) {
938 /*
939 * Trim from head.
940 */
941 while (m != NULL && len > 0) {
942 if (m->m_len <= len) {
943 len -= m->m_len;
944 m->m_len = 0;
945 m = m->m_next;
946 } else {
947 m->m_len -= len;
948 m->m_data += len;
949 len = 0;
950 }
951 }
952 m = mp;
953 if (mp->m_flags & M_PKTHDR)
954 m->m_pkthdr.len -= (req_len - len);
955 } else {
956 /*
957 * Trim from tail. Scan the mbuf chain,
958 * calculating its length and finding the last mbuf.
959 * If the adjustment only affects this mbuf, then just
960 * adjust and return. Otherwise, rescan and truncate
961 * after the remaining size.
962 */
963 len = -len;
964 count = 0;
965 for (;;) {
966 count += m->m_len;
967 if (m->m_next == (struct mbuf *)0)
968 break;
969 m = m->m_next;
970 }
971 if (m->m_len >= len) {
972 m->m_len -= len;
973 if (mp->m_flags & M_PKTHDR)
974 mp->m_pkthdr.len -= len;
975 return;
976 }
977 count -= len;
978 if (count < 0)
979 count = 0;
980 /*
981 * Correct length for chain is "count".
982 * Find the mbuf with last data, adjust its length,
983 * and toss data from remaining mbufs on chain.
984 */
985 m = mp;
986 if (m->m_flags & M_PKTHDR)
987 m->m_pkthdr.len = count;
988 for (; m; m = m->m_next) {
989 if (m->m_len >= count) {
990 m->m_len = count;
991 if (m->m_next != NULL) {
992 m_freem(m->m_next);
993 m->m_next = NULL;
994 }
995 break;
996 }
997 count -= m->m_len;
998 }
999 }
1000 }
1001
1002 /*
1003 * Rearange an mbuf chain so that len bytes are contiguous
1004 * and in the data area of an mbuf (so that mtod and dtom
1005 * will work for a structure of size len). Returns the resulting
1006 * mbuf chain on success, frees it and returns null on failure.
1007 * If there is room, it will add up to max_protohdr-len extra bytes to the
1008 * contiguous region in an attempt to avoid being called next time.
1009 */
1010 struct mbuf *
1011 m_pullup(struct mbuf *n, int len)
1012 {
1013 struct mbuf *m;
1014 int count;
1015 int space;
1016
1017 /*
1018 * If first mbuf has no cluster, and has room for len bytes
1019 * without shifting current data, pullup into it,
1020 * otherwise allocate a new mbuf to prepend to the chain.
1021 */
1022 if ((n->m_flags & M_EXT) == 0 &&
1023 n->m_data + len < &n->m_dat[MLEN] && n->m_next) {
1024 if (n->m_len >= len)
1025 return (n);
1026 m = n;
1027 n = n->m_next;
1028 len -= m->m_len;
1029 } else {
1030 if (len > MHLEN)
1031 goto bad;
1032 MGET(m, M_DONTWAIT, n->m_type);
1033 if (m == NULL)
1034 goto bad;
1035 m->m_len = 0;
1036 if (n->m_flags & M_PKTHDR)
1037 M_MOVE_PKTHDR(m, n);
1038 }
1039 space = &m->m_dat[MLEN] - (m->m_data + m->m_len);
1040 do {
1041 count = min(min(max(len, max_protohdr), space), n->m_len);
1042 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len,
1043 (u_int)count);
1044 len -= count;
1045 m->m_len += count;
1046 n->m_len -= count;
1047 space -= count;
1048 if (n->m_len)
1049 n->m_data += count;
1050 else
1051 n = m_free(n);
1052 } while (len > 0 && n);
1053 if (len > 0) {
1054 (void) m_free(m);
1055 goto bad;
1056 }
1057 m->m_next = n;
1058 return (m);
1059 bad:
1060 m_freem(n);
1061 mbstat.m_mpfail++; /* XXX: No consistency. */
1062 return (NULL);
1063 }
1064
1065 /*
1066 * Like m_pullup(), except a new mbuf is always allocated, and we allow
1067 * the amount of empty space before the data in the new mbuf to be specified
1068 * (in the event that the caller expects to prepend later).
1069 */
1070 int MSFail;
1071
1072 struct mbuf *
1073 m_copyup(struct mbuf *n, int len, int dstoff)
1074 {
1075 struct mbuf *m;
1076 int count, space;
1077
1078 if (len > (MHLEN - dstoff))
1079 goto bad;
1080 MGET(m, M_DONTWAIT, n->m_type);
1081 if (m == NULL)
1082 goto bad;
1083 m->m_len = 0;
1084 if (n->m_flags & M_PKTHDR)
1085 M_MOVE_PKTHDR(m, n);
1086 m->m_data += dstoff;
1087 space = &m->m_dat[MLEN] - (m->m_data + m->m_len);
1088 do {
1089 count = min(min(max(len, max_protohdr), space), n->m_len);
1090 memcpy(mtod(m, caddr_t) + m->m_len, mtod(n, caddr_t),
1091 (unsigned)count);
1092 len -= count;
1093 m->m_len += count;
1094 n->m_len -= count;
1095 space -= count;
1096 if (n->m_len)
1097 n->m_data += count;
1098 else
1099 n = m_free(n);
1100 } while (len > 0 && n);
1101 if (len > 0) {
1102 (void) m_free(m);
1103 goto bad;
1104 }
1105 m->m_next = n;
1106 return (m);
1107 bad:
1108 m_freem(n);
1109 MSFail++;
1110 return (NULL);
1111 }
1112
1113 /*
1114 * Partition an mbuf chain in two pieces, returning the tail --
1115 * all but the first len0 bytes. In case of failure, it returns NULL and
1116 * attempts to restore the chain to its original state.
1117 *
1118 * Note that the resulting mbufs might be read-only, because the new
1119 * mbuf can end up sharing an mbuf cluster with the original mbuf if
1120 * the "breaking point" happens to lie within a cluster mbuf. Use the
1121 * M_WRITABLE() macro to check for this case.
1122 */
1123 struct mbuf *
1124 m_split(struct mbuf *m0, int len0, int wait)
1125 {
1126 struct mbuf *m, *n;
1127 u_int len = len0, remain;
1128
1129 MBUF_CHECKSLEEP(wait);
1130 for (m = m0; m && len > m->m_len; m = m->m_next)
1131 len -= m->m_len;
1132 if (m == NULL)
1133 return (NULL);
1134 remain = m->m_len - len;
1135 if (m0->m_flags & M_PKTHDR) {
1136 MGETHDR(n, wait, m0->m_type);
1137 if (n == NULL)
1138 return (NULL);
1139 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif;
1140 n->m_pkthdr.len = m0->m_pkthdr.len - len0;
1141 m0->m_pkthdr.len = len0;
1142 if (m->m_flags & M_EXT)
1143 goto extpacket;
1144 if (remain > MHLEN) {
1145 /* m can't be the lead packet */
1146 MH_ALIGN(n, 0);
1147 n->m_next = m_split(m, len, wait);
1148 if (n->m_next == NULL) {
1149 (void) m_free(n);
1150 return (NULL);
1151 } else {
1152 n->m_len = 0;
1153 return (n);
1154 }
1155 } else
1156 MH_ALIGN(n, remain);
1157 } else if (remain == 0) {
1158 n = m->m_next;
1159 m->m_next = NULL;
1160 return (n);
1161 } else {
1162 MGET(n, wait, m->m_type);
1163 if (n == NULL)
1164 return (NULL);
1165 M_ALIGN(n, remain);
1166 }
1167 extpacket:
1168 if (m->m_flags & M_EXT) {
1169 n->m_data = m->m_data + len;
1170 mb_dupcl(n, m);
1171 } else {
1172 bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain);
1173 }
1174 n->m_len = remain;
1175 m->m_len = len;
1176 n->m_next = m->m_next;
1177 m->m_next = NULL;
1178 return (n);
1179 }
1180 /*
1181 * Routine to copy from device local memory into mbufs.
1182 * Note that `off' argument is offset into first mbuf of target chain from
1183 * which to begin copying the data to.
1184 */
1185 struct mbuf *
1186 m_devget(char *buf, int totlen, int off, struct ifnet *ifp,
1187 void (*copy)(char *from, caddr_t to, u_int len))
1188 {
1189 struct mbuf *m;
1190 struct mbuf *top = NULL, **mp = ⊤
1191 int len;
1192
1193 if (off < 0 || off > MHLEN)
1194 return (NULL);
1195
1196 while (totlen > 0) {
1197 if (top == NULL) { /* First one, must be PKTHDR */
1198 if (totlen + off >= MINCLSIZE) {
1199 m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
1200 len = MCLBYTES;
1201 } else {
1202 m = m_gethdr(M_DONTWAIT, MT_DATA);
1203 len = MHLEN;
1204
1205 /* Place initial small packet/header at end of mbuf */
1206 if (m && totlen + off + max_linkhdr <= MLEN) {
1207 m->m_data += max_linkhdr;
1208 len -= max_linkhdr;
1209 }
1210 }
1211 if (m == NULL)
1212 return NULL;
1213 m->m_pkthdr.rcvif = ifp;
1214 m->m_pkthdr.len = totlen;
1215 } else {
1216 if (totlen + off >= MINCLSIZE) {
1217 m = m_getcl(M_DONTWAIT, MT_DATA, 0);
1218 len = MCLBYTES;
1219 } else {
1220 m = m_get(M_DONTWAIT, MT_DATA);
1221 len = MLEN;
1222 }
1223 if (m == NULL) {
1224 m_freem(top);
1225 return NULL;
1226 }
1227 }
1228 if (off) {
1229 m->m_data += off;
1230 len -= off;
1231 off = 0;
1232 }
1233 m->m_len = len = min(totlen, len);
1234 if (copy)
1235 copy(buf, mtod(m, caddr_t), (u_int)len);
1236 else
1237 bcopy(buf, mtod(m, caddr_t), (u_int)len);
1238 buf += len;
1239 *mp = m;
1240 mp = &m->m_next;
1241 totlen -= len;
1242 }
1243 return (top);
1244 }
1245
1246 /*
1247 * Copy data from a buffer back into the indicated mbuf chain,
1248 * starting "off" bytes from the beginning, extending the mbuf
1249 * chain if necessary.
1250 */
1251 void
1252 m_copyback(struct mbuf *m0, int off, int len, c_caddr_t cp)
1253 {
1254 int mlen;
1255 struct mbuf *m = m0, *n;
1256 int totlen = 0;
1257
1258 if (m0 == NULL)
1259 return;
1260 while (off > (mlen = m->m_len)) {
1261 off -= mlen;
1262 totlen += mlen;
1263 if (m->m_next == NULL) {
1264 n = m_get(M_DONTWAIT, m->m_type);
1265 if (n == NULL)
1266 goto out;
1267 bzero(mtod(n, caddr_t), MLEN);
1268 n->m_len = min(MLEN, len + off);
1269 m->m_next = n;
1270 }
1271 m = m->m_next;
1272 }
1273 while (len > 0) {
1274 if (m->m_next == NULL && (len > m->m_len - off)) {
1275 m->m_len += min(len - (m->m_len - off),
1276 M_TRAILINGSPACE(m));
1277 }
1278 mlen = min (m->m_len - off, len);
1279 bcopy(cp, off + mtod(m, caddr_t), (u_int)mlen);
1280 cp += mlen;
1281 len -= mlen;
1282 mlen += off;
1283 off = 0;
1284 totlen += mlen;
1285 if (len == 0)
1286 break;
1287 if (m->m_next == NULL) {
1288 n = m_get(M_DONTWAIT, m->m_type);
1289 if (n == NULL)
1290 break;
1291 n->m_len = min(MLEN, len);
1292 m->m_next = n;
1293 }
1294 m = m->m_next;
1295 }
1296 out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen))
1297 m->m_pkthdr.len = totlen;
1298 }
1299
1300 /*
1301 * Append the specified data to the indicated mbuf chain,
1302 * Extend the mbuf chain if the new data does not fit in
1303 * existing space.
1304 *
1305 * Return 1 if able to complete the job; otherwise 0.
1306 */
1307 int
1308 m_append(struct mbuf *m0, int len, c_caddr_t cp)
1309 {
1310 struct mbuf *m, *n;
1311 int remainder, space;
1312
1313 for (m = m0; m->m_next != NULL; m = m->m_next)
1314 ;
1315 remainder = len;
1316 space = M_TRAILINGSPACE(m);
1317 if (space > 0) {
1318 /*
1319 * Copy into available space.
1320 */
1321 if (space > remainder)
1322 space = remainder;
1323 bcopy(cp, mtod(m, caddr_t) + m->m_len, space);
1324 m->m_len += space;
1325 cp += space, remainder -= space;
1326 }
1327 while (remainder > 0) {
1328 /*
1329 * Allocate a new mbuf; could check space
1330 * and allocate a cluster instead.
1331 */
1332 n = m_get(M_DONTWAIT, m->m_type);
1333 if (n == NULL)
1334 break;
1335 n->m_len = min(MLEN, remainder);
1336 bcopy(cp, mtod(n, caddr_t), n->m_len);
1337 cp += n->m_len, remainder -= n->m_len;
1338 m->m_next = n;
1339 m = n;
1340 }
1341 if (m0->m_flags & M_PKTHDR)
1342 m0->m_pkthdr.len += len - remainder;
1343 return (remainder == 0);
1344 }
1345
1346 /*
1347 * Apply function f to the data in an mbuf chain starting "off" bytes from
1348 * the beginning, continuing for "len" bytes.
1349 */
1350 int
1351 m_apply(struct mbuf *m, int off, int len,
1352 int (*f)(void *, void *, u_int), void *arg)
1353 {
1354 u_int count;
1355 int rval;
1356
1357 KASSERT(off >= 0, ("m_apply, negative off %d", off));
1358 KASSERT(len >= 0, ("m_apply, negative len %d", len));
1359 while (off > 0) {
1360 KASSERT(m != NULL, ("m_apply, offset > size of mbuf chain"));
1361 if (off < m->m_len)
1362 break;
1363 off -= m->m_len;
1364 m = m->m_next;
1365 }
1366 while (len > 0) {
1367 KASSERT(m != NULL, ("m_apply, offset > size of mbuf chain"));
1368 count = min(m->m_len - off, len);
1369 rval = (*f)(arg, mtod(m, caddr_t) + off, count);
1370 if (rval)
1371 return (rval);
1372 len -= count;
1373 off = 0;
1374 m = m->m_next;
1375 }
1376 return (0);
1377 }
1378
1379 /*
1380 * Return a pointer to mbuf/offset of location in mbuf chain.
1381 */
1382 struct mbuf *
1383 m_getptr(struct mbuf *m, int loc, int *off)
1384 {
1385
1386 while (loc >= 0) {
1387 /* Normal end of search. */
1388 if (m->m_len > loc) {
1389 *off = loc;
1390 return (m);
1391 } else {
1392 loc -= m->m_len;
1393 if (m->m_next == NULL) {
1394 if (loc == 0) {
1395 /* Point at the end of valid data. */
1396 *off = m->m_len;
1397 return (m);
1398 }
1399 return (NULL);
1400 }
1401 m = m->m_next;
1402 }
1403 }
1404 return (NULL);
1405 }
1406
1407 void
1408 m_print(const struct mbuf *m, int maxlen)
1409 {
1410 int len;
1411 int pdata;
1412 const struct mbuf *m2;
1413
1414 if (m->m_flags & M_PKTHDR)
1415 len = m->m_pkthdr.len;
1416 else
1417 len = -1;
1418 m2 = m;
1419 while (m2 != NULL && (len == -1 || len)) {
1420 pdata = m2->m_len;
1421 if (maxlen != -1 && pdata > maxlen)
1422 pdata = maxlen;
1423 printf("mbuf: %p len: %d, next: %p, %b%s", m2, m2->m_len,
1424 m2->m_next, m2->m_flags, "\2\20freelist\17skipfw"
1425 "\11proto5\10proto4\7proto3\6proto2\5proto1\4rdonly"
1426 "\3eor\2pkthdr\1ext", pdata ? "" : "\n");
1427 if (pdata)
1428 printf(", %*D\n", pdata, (u_char *)m2->m_data, "-");
1429 if (len != -1)
1430 len -= m2->m_len;
1431 m2 = m2->m_next;
1432 }
1433 if (len > 0)
1434 printf("%d bytes unaccounted for.\n", len);
1435 return;
1436 }
1437
1438 u_int
1439 m_fixhdr(struct mbuf *m0)
1440 {
1441 u_int len;
1442
1443 len = m_length(m0, NULL);
1444 m0->m_pkthdr.len = len;
1445 return (len);
1446 }
1447
1448 u_int
1449 m_length(struct mbuf *m0, struct mbuf **last)
1450 {
1451 struct mbuf *m;
1452 u_int len;
1453
1454 len = 0;
1455 for (m = m0; m != NULL; m = m->m_next) {
1456 len += m->m_len;
1457 if (m->m_next == NULL)
1458 break;
1459 }
1460 if (last != NULL)
1461 *last = m;
1462 return (len);
1463 }
1464
1465 /*
1466 * Defragment a mbuf chain, returning the shortest possible
1467 * chain of mbufs and clusters. If allocation fails and
1468 * this cannot be completed, NULL will be returned, but
1469 * the passed in chain will be unchanged. Upon success,
1470 * the original chain will be freed, and the new chain
1471 * will be returned.
1472 *
1473 * If a non-packet header is passed in, the original
1474 * mbuf (chain?) will be returned unharmed.
1475 */
1476 struct mbuf *
1477 m_defrag(struct mbuf *m0, int how)
1478 {
1479 struct mbuf *m_new = NULL, *m_final = NULL;
1480 int progress = 0, length;
1481
1482 MBUF_CHECKSLEEP(how);
1483 if (!(m0->m_flags & M_PKTHDR))
1484 return (m0);
1485
1486 m_fixhdr(m0); /* Needed sanity check */
1487
1488 #ifdef MBUF_STRESS_TEST
1489 if (m_defragrandomfailures) {
1490 int temp = arc4random() & 0xff;
1491 if (temp == 0xba)
1492 goto nospace;
1493 }
1494 #endif
1495
1496 if (m0->m_pkthdr.len > MHLEN)
1497 m_final = m_getcl(how, MT_DATA, M_PKTHDR);
1498 else
1499 m_final = m_gethdr(how, MT_DATA);
1500
1501 if (m_final == NULL)
1502 goto nospace;
1503
1504 if (m_dup_pkthdr(m_final, m0, how) == 0)
1505 goto nospace;
1506
1507 m_new = m_final;
1508
1509 while (progress < m0->m_pkthdr.len) {
1510 length = m0->m_pkthdr.len - progress;
1511 if (length > MCLBYTES)
1512 length = MCLBYTES;
1513
1514 if (m_new == NULL) {
1515 if (length > MLEN)
1516 m_new = m_getcl(how, MT_DATA, 0);
1517 else
1518 m_new = m_get(how, MT_DATA);
1519 if (m_new == NULL)
1520 goto nospace;
1521 }
1522
1523 m_copydata(m0, progress, length, mtod(m_new, caddr_t));
1524 progress += length;
1525 m_new->m_len = length;
1526 if (m_new != m_final)
1527 m_cat(m_final, m_new);
1528 m_new = NULL;
1529 }
1530 #ifdef MBUF_STRESS_TEST
1531 if (m0->m_next == NULL)
1532 m_defraguseless++;
1533 #endif
1534 m_freem(m0);
1535 m0 = m_final;
1536 #ifdef MBUF_STRESS_TEST
1537 m_defragpackets++;
1538 m_defragbytes += m0->m_pkthdr.len;
1539 #endif
1540 return (m0);
1541 nospace:
1542 #ifdef MBUF_STRESS_TEST
1543 m_defragfailure++;
1544 #endif
1545 if (m_final)
1546 m_freem(m_final);
1547 return (NULL);
1548 }
1549
1550 /*
1551 * Defragment an mbuf chain, returning at most maxfrags separate
1552 * mbufs+clusters. If this is not possible NULL is returned and
1553 * the original mbuf chain is left in it's present (potentially
1554 * modified) state. We use two techniques: collapsing consecutive
1555 * mbufs and replacing consecutive mbufs by a cluster.
1556 *
1557 * NB: this should really be named m_defrag but that name is taken
1558 */
1559 struct mbuf *
1560 m_collapse(struct mbuf *m0, int how, int maxfrags)
1561 {
1562 struct mbuf *m, *n, *n2, **prev;
1563 u_int curfrags;
1564
1565 /*
1566 * Calculate the current number of frags.
1567 */
1568 curfrags = 0;
1569 for (m = m0; m != NULL; m = m->m_next)
1570 curfrags++;
1571 /*
1572 * First, try to collapse mbufs. Note that we always collapse
1573 * towards the front so we don't need to deal with moving the
1574 * pkthdr. This may be suboptimal if the first mbuf has much
1575 * less data than the following.
1576 */
1577 m = m0;
1578 again:
1579 for (;;) {
1580 n = m->m_next;
1581 if (n == NULL)
1582 break;
1583 if ((m->m_flags & M_RDONLY) == 0 &&
1584 n->m_len < M_TRAILINGSPACE(m)) {
1585 bcopy(mtod(n, void *), mtod(m, char *) + m->m_len,
1586 n->m_len);
1587 m->m_len += n->m_len;
1588 m->m_next = n->m_next;
1589 m_free(n);
1590 if (--curfrags <= maxfrags)
1591 return m0;
1592 } else
1593 m = n;
1594 }
1595 KASSERT(maxfrags > 1,
1596 ("maxfrags %u, but normal collapse failed", maxfrags));
1597 /*
1598 * Collapse consecutive mbufs to a cluster.
1599 */
1600 prev = &m0->m_next; /* NB: not the first mbuf */
1601 while ((n = *prev) != NULL) {
1602 if ((n2 = n->m_next) != NULL &&
1603 n->m_len + n2->m_len < MCLBYTES) {
1604 m = m_getcl(how, MT_DATA, 0);
1605 if (m == NULL)
1606 goto bad;
1607 bcopy(mtod(n, void *), mtod(m, void *), n->m_len);
1608 bcopy(mtod(n2, void *), mtod(m, char *) + n->m_len,
1609 n2->m_len);
1610 m->m_len = n->m_len + n2->m_len;
1611 m->m_next = n2->m_next;
1612 *prev = m;
1613 m_free(n);
1614 m_free(n2);
1615 if (--curfrags <= maxfrags) /* +1 cl -2 mbufs */
1616 return m0;
1617 /*
1618 * Still not there, try the normal collapse
1619 * again before we allocate another cluster.
1620 */
1621 goto again;
1622 }
1623 prev = &n->m_next;
1624 }
1625 /*
1626 * No place where we can collapse to a cluster; punt.
1627 * This can occur if, for example, you request 2 frags
1628 * but the packet requires that both be clusters (we
1629 * never reallocate the first mbuf to avoid moving the
1630 * packet header).
1631 */
1632 bad:
1633 return NULL;
1634 }
1635
1636 #ifdef MBUF_STRESS_TEST
1637
1638 /*
1639 * Fragment an mbuf chain. There's no reason you'd ever want to do
1640 * this in normal usage, but it's great for stress testing various
1641 * mbuf consumers.
1642 *
1643 * If fragmentation is not possible, the original chain will be
1644 * returned.
1645 *
1646 * Possible length values:
1647 * 0 no fragmentation will occur
1648 * > 0 each fragment will be of the specified length
1649 * -1 each fragment will be the same random value in length
1650 * -2 each fragment's length will be entirely random
1651 * (Random values range from 1 to 256)
1652 */
1653 struct mbuf *
1654 m_fragment(struct mbuf *m0, int how, int length)
1655 {
1656 struct mbuf *m_new = NULL, *m_final = NULL;
1657 int progress = 0;
1658
1659 if (!(m0->m_flags & M_PKTHDR))
1660 return (m0);
1661
1662 if ((length == 0) || (length < -2))
1663 return (m0);
1664
1665 m_fixhdr(m0); /* Needed sanity check */
1666
1667 m_final = m_getcl(how, MT_DATA, M_PKTHDR);
1668
1669 if (m_final == NULL)
1670 goto nospace;
1671
1672 if (m_dup_pkthdr(m_final, m0, how) == 0)
1673 goto nospace;
1674
1675 m_new = m_final;
1676
1677 if (length == -1)
1678 length = 1 + (arc4random() & 255);
1679
1680 while (progress < m0->m_pkthdr.len) {
1681 int fraglen;
1682
1683 if (length > 0)
1684 fraglen = length;
1685 else
1686 fraglen = 1 + (arc4random() & 255);
1687 if (fraglen > m0->m_pkthdr.len - progress)
1688 fraglen = m0->m_pkthdr.len - progress;
1689
1690 if (fraglen > MCLBYTES)
1691 fraglen = MCLBYTES;
1692
1693 if (m_new == NULL) {
1694 m_new = m_getcl(how, MT_DATA, 0);
1695 if (m_new == NULL)
1696 goto nospace;
1697 }
1698
1699 m_copydata(m0, progress, fraglen, mtod(m_new, caddr_t));
1700 progress += fraglen;
1701 m_new->m_len = fraglen;
1702 if (m_new != m_final)
1703 m_cat(m_final, m_new);
1704 m_new = NULL;
1705 }
1706 m_freem(m0);
1707 m0 = m_final;
1708 return (m0);
1709 nospace:
1710 if (m_final)
1711 m_freem(m_final);
1712 /* Return the original chain on failure */
1713 return (m0);
1714 }
1715
1716 #endif
1717
1718 /*
1719 * Copy the contents of uio into a properly sized mbuf chain.
1720 */
1721 struct mbuf *
1722 m_uiotombuf(struct uio *uio, int how, int len, int align, int flags)
1723 {
1724 struct mbuf *m, *mb;
1725 int error, length, total;
1726 int progress = 0;
1727
1728 /*
1729 * len can be zero or an arbitrary large value bound by
1730 * the total data supplied by the uio.
1731 */
1732 if (len > 0)
1733 total = min(uio->uio_resid, len);
1734 else
1735 total = uio->uio_resid;
1736
1737 /*
1738 * The smallest unit returned by m_getm2() is a single mbuf
1739 * with pkthdr. We can't align past it.
1740 */
1741 if (align >= MHLEN)
1742 return (NULL);
1743
1744 /*
1745 * Give us the full allocation or nothing.
1746 * If len is zero return the smallest empty mbuf.
1747 */
1748 m = m_getm2(NULL, max(total + align, 1), how, MT_DATA, flags);
1749 if (m == NULL)
1750 return (NULL);
1751 m->m_data += align;
1752
1753 /* Fill all mbufs with uio data and update header information. */
1754 for (mb = m; mb != NULL; mb = mb->m_next) {
1755 length = min(M_TRAILINGSPACE(mb), total - progress);
1756
1757 error = uiomove(mtod(mb, void *), length, uio);
1758 if (error) {
1759 m_freem(m);
1760 return (NULL);
1761 }
1762
1763 mb->m_len = length;
1764 progress += length;
1765 if (flags & M_PKTHDR)
1766 m->m_pkthdr.len += length;
1767 }
1768 KASSERT(progress == total, ("%s: progress != total", __func__));
1769
1770 return (m);
1771 }
1772
1773 /*
1774 * Copy an mbuf chain into a uio limited by len if set.
1775 */
1776 int
1777 m_mbuftouio(struct uio *uio, struct mbuf *m, int len)
1778 {
1779 int error, length, total;
1780 int progress = 0;
1781
1782 if (len > 0)
1783 total = min(uio->uio_resid, len);
1784 else
1785 total = uio->uio_resid;
1786
1787 /* Fill the uio with data from the mbufs. */
1788 for (; m != NULL; m = m->m_next) {
1789 length = min(m->m_len, total - progress);
1790
1791 error = uiomove(mtod(m, void *), length, uio);
1792 if (error)
1793 return (error);
1794
1795 progress += length;
1796 }
1797
1798 return (0);
1799 }
1800
1801 /*
1802 * Set the m_data pointer of a newly-allocated mbuf
1803 * to place an object of the specified size at the
1804 * end of the mbuf, longword aligned.
1805 */
1806 void
1807 m_align(struct mbuf *m, int len)
1808 {
1809 int adjust;
1810
1811 if (m->m_flags & M_EXT)
1812 adjust = m->m_ext.ext_size - len;
1813 else if (m->m_flags & M_PKTHDR)
1814 adjust = MHLEN - len;
1815 else
1816 adjust = MLEN - len;
1817 m->m_data += adjust &~ (sizeof(long)-1);
1818 }
1819
1820 /*
1821 * Create a writable copy of the mbuf chain. While doing this
1822 * we compact the chain with a goal of producing a chain with
1823 * at most two mbufs. The second mbuf in this chain is likely
1824 * to be a cluster. The primary purpose of this work is to create
1825 * a writable packet for encryption, compression, etc. The
1826 * secondary goal is to linearize the data so the data can be
1827 * passed to crypto hardware in the most efficient manner possible.
1828 */
1829 struct mbuf *
1830 m_unshare(struct mbuf *m0, int how)
1831 {
1832 struct mbuf *m, *mprev;
1833 struct mbuf *n, *mfirst, *mlast;
1834 int len, off;
1835
1836 mprev = NULL;
1837 for (m = m0; m != NULL; m = mprev->m_next) {
1838 /*
1839 * Regular mbufs are ignored unless there's a cluster
1840 * in front of it that we can use to coalesce. We do
1841 * the latter mainly so later clusters can be coalesced
1842 * also w/o having to handle them specially (i.e. convert
1843 * mbuf+cluster -> cluster). This optimization is heavily
1844 * influenced by the assumption that we're running over
1845 * Ethernet where MCLBYTES is large enough that the max
1846 * packet size will permit lots of coalescing into a
1847 * single cluster. This in turn permits efficient
1848 * crypto operations, especially when using hardware.
1849 */
1850 if ((m->m_flags & M_EXT) == 0) {
1851 if (mprev && (mprev->m_flags & M_EXT) &&
1852 m->m_len <= M_TRAILINGSPACE(mprev)) {
1853 /* XXX: this ignores mbuf types */
1854 memcpy(mtod(mprev, caddr_t) + mprev->m_len,
1855 mtod(m, caddr_t), m->m_len);
1856 mprev->m_len += m->m_len;
1857 mprev->m_next = m->m_next; /* unlink from chain */
1858 m_free(m); /* reclaim mbuf */
1859 #if 0
1860 newipsecstat.ips_mbcoalesced++;
1861 #endif
1862 } else {
1863 mprev = m;
1864 }
1865 continue;
1866 }
1867 /*
1868 * Writable mbufs are left alone (for now).
1869 */
1870 if (M_WRITABLE(m)) {
1871 mprev = m;
1872 continue;
1873 }
1874
1875 /*
1876 * Not writable, replace with a copy or coalesce with
1877 * the previous mbuf if possible (since we have to copy
1878 * it anyway, we try to reduce the number of mbufs and
1879 * clusters so that future work is easier).
1880 */
1881 KASSERT(m->m_flags & M_EXT, ("m_flags 0x%x", m->m_flags));
1882 /* NB: we only coalesce into a cluster or larger */
1883 if (mprev != NULL && (mprev->m_flags & M_EXT) &&
1884 m->m_len <= M_TRAILINGSPACE(mprev)) {
1885 /* XXX: this ignores mbuf types */
1886 memcpy(mtod(mprev, caddr_t) + mprev->m_len,
1887 mtod(m, caddr_t), m->m_len);
1888 mprev->m_len += m->m_len;
1889 mprev->m_next = m->m_next; /* unlink from chain */
1890 m_free(m); /* reclaim mbuf */
1891 #if 0
1892 newipsecstat.ips_clcoalesced++;
1893 #endif
1894 continue;
1895 }
1896
1897 /*
1898 * Allocate new space to hold the copy...
1899 */
1900 /* XXX why can M_PKTHDR be set past the first mbuf? */
1901 if (mprev == NULL && (m->m_flags & M_PKTHDR)) {
1902 /*
1903 * NB: if a packet header is present we must
1904 * allocate the mbuf separately from any cluster
1905 * because M_MOVE_PKTHDR will smash the data
1906 * pointer and drop the M_EXT marker.
1907 */
1908 MGETHDR(n, how, m->m_type);
1909 if (n == NULL) {
1910 m_freem(m0);
1911 return (NULL);
1912 }
1913 M_MOVE_PKTHDR(n, m);
1914 MCLGET(n, how);
1915 if ((n->m_flags & M_EXT) == 0) {
1916 m_free(n);
1917 m_freem(m0);
1918 return (NULL);
1919 }
1920 } else {
1921 n = m_getcl(how, m->m_type, m->m_flags);
1922 if (n == NULL) {
1923 m_freem(m0);
1924 return (NULL);
1925 }
1926 }
1927 /*
1928 * ... and copy the data. We deal with jumbo mbufs
1929 * (i.e. m_len > MCLBYTES) by splitting them into
1930 * clusters. We could just malloc a buffer and make
1931 * it external but too many device drivers don't know
1932 * how to break up the non-contiguous memory when
1933 * doing DMA.
1934 */
1935 len = m->m_len;
1936 off = 0;
1937 mfirst = n;
1938 mlast = NULL;
1939 for (;;) {
1940 int cc = min(len, MCLBYTES);
1941 memcpy(mtod(n, caddr_t), mtod(m, caddr_t) + off, cc);
1942 n->m_len = cc;
1943 if (mlast != NULL)
1944 mlast->m_next = n;
1945 mlast = n;
1946 #if 0
1947 newipsecstat.ips_clcopied++;
1948 #endif
1949
1950 len -= cc;
1951 if (len <= 0)
1952 break;
1953 off += cc;
1954
1955 n = m_getcl(how, m->m_type, m->m_flags);
1956 if (n == NULL) {
1957 m_freem(mfirst);
1958 m_freem(m0);
1959 return (NULL);
1960 }
1961 }
1962 n->m_next = m->m_next;
1963 if (mprev == NULL)
1964 m0 = mfirst; /* new head of chain */
1965 else
1966 mprev->m_next = mfirst; /* replace old mbuf */
1967 m_free(m); /* release old mbuf */
1968 mprev = mfirst;
1969 }
1970 return (m0);
1971 }
1972
1973 #ifdef MBUF_PROFILING
1974
1975 #define MP_BUCKETS 32 /* don't just change this as things may overflow.*/
1976 struct mbufprofile {
1977 uintmax_t wasted[MP_BUCKETS];
1978 uintmax_t used[MP_BUCKETS];
1979 uintmax_t segments[MP_BUCKETS];
1980 } mbprof;
1981
1982 #define MP_MAXDIGITS 21 /* strlen("16,000,000,000,000,000,000") == 21 */
1983 #define MP_NUMLINES 6
1984 #define MP_NUMSPERLINE 16
1985 #define MP_EXTRABYTES 64 /* > strlen("used:\nwasted:\nsegments:\n") */
1986 /* work out max space needed and add a bit of spare space too */
1987 #define MP_MAXLINE ((MP_MAXDIGITS+1) * MP_NUMSPERLINE)
1988 #define MP_BUFSIZE ((MP_MAXLINE * MP_NUMLINES) + 1 + MP_EXTRABYTES)
1989
1990 char mbprofbuf[MP_BUFSIZE];
1991
1992 void
1993 m_profile(struct mbuf *m)
1994 {
1995 int segments = 0;
1996 int used = 0;
1997 int wasted = 0;
1998
1999 while (m) {
2000 segments++;
2001 used += m->m_len;
2002 if (m->m_flags & M_EXT) {
2003 wasted += MHLEN - sizeof(m->m_ext) +
2004 m->m_ext.ext_size - m->m_len;
2005 } else {
2006 if (m->m_flags & M_PKTHDR)
2007 wasted += MHLEN - m->m_len;
2008 else
2009 wasted += MLEN - m->m_len;
2010 }
2011 m = m->m_next;
2012 }
2013 /* be paranoid.. it helps */
2014 if (segments > MP_BUCKETS - 1)
2015 segments = MP_BUCKETS - 1;
2016 if (used > 100000)
2017 used = 100000;
2018 if (wasted > 100000)
2019 wasted = 100000;
2020 /* store in the appropriate bucket */
2021 /* don't bother locking. if it's slightly off, so what? */
2022 mbprof.segments[segments]++;
2023 mbprof.used[fls(used)]++;
2024 mbprof.wasted[fls(wasted)]++;
2025 }
2026
2027 static void
2028 mbprof_textify(void)
2029 {
2030 int offset;
2031 char *c;
2032 u_int64_t *p;
2033
2034
2035 p = &mbprof.wasted[0];
2036 c = mbprofbuf;
2037 offset = snprintf(c, MP_MAXLINE + 10,
2038 "wasted:\n"
2039 "%ju %ju %ju %ju %ju %ju %ju %ju "
2040 "%ju %ju %ju %ju %ju %ju %ju %ju\n",
2041 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
2042 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
2043 #ifdef BIG_ARRAY
2044 p = &mbprof.wasted[16];
2045 c += offset;
2046 offset = snprintf(c, MP_MAXLINE,
2047 "%ju %ju %ju %ju %ju %ju %ju %ju "
2048 "%ju %ju %ju %ju %ju %ju %ju %ju\n",
2049 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
2050 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
2051 #endif
2052 p = &mbprof.used[0];
2053 c += offset;
2054 offset = snprintf(c, MP_MAXLINE + 10,
2055 "used:\n"
2056 "%ju %ju %ju %ju %ju %ju %ju %ju "
2057 "%ju %ju %ju %ju %ju %ju %ju %ju\n",
2058 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
2059 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
2060 #ifdef BIG_ARRAY
2061 p = &mbprof.used[16];
2062 c += offset;
2063 offset = snprintf(c, MP_MAXLINE,
2064 "%ju %ju %ju %ju %ju %ju %ju %ju "
2065 "%ju %ju %ju %ju %ju %ju %ju %ju\n",
2066 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
2067 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
2068 #endif
2069 p = &mbprof.segments[0];
2070 c += offset;
2071 offset = snprintf(c, MP_MAXLINE + 10,
2072 "segments:\n"
2073 "%ju %ju %ju %ju %ju %ju %ju %ju "
2074 "%ju %ju %ju %ju %ju %ju %ju %ju\n",
2075 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
2076 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
2077 #ifdef BIG_ARRAY
2078 p = &mbprof.segments[16];
2079 c += offset;
2080 offset = snprintf(c, MP_MAXLINE,
2081 "%ju %ju %ju %ju %ju %ju %ju %ju "
2082 "%ju %ju %ju %ju %ju %ju %ju %jju",
2083 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
2084 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
2085 #endif
2086 }
2087
2088 static int
2089 mbprof_handler(SYSCTL_HANDLER_ARGS)
2090 {
2091 int error;
2092
2093 mbprof_textify();
2094 error = SYSCTL_OUT(req, mbprofbuf, strlen(mbprofbuf) + 1);
2095 return (error);
2096 }
2097
2098 static int
2099 mbprof_clr_handler(SYSCTL_HANDLER_ARGS)
2100 {
2101 int clear, error;
2102
2103 clear = 0;
2104 error = sysctl_handle_int(oidp, &clear, 0, req);
2105 if (error || !req->newptr)
2106 return (error);
2107
2108 if (clear) {
2109 bzero(&mbprof, sizeof(mbprof));
2110 }
2111
2112 return (error);
2113 }
2114
2115
2116 SYSCTL_PROC(_kern_ipc, OID_AUTO, mbufprofile, CTLTYPE_STRING|CTLFLAG_RD,
2117 NULL, 0, mbprof_handler, "A", "mbuf profiling statistics");
2118
2119 SYSCTL_PROC(_kern_ipc, OID_AUTO, mbufprofileclr, CTLTYPE_INT|CTLFLAG_RW,
2120 NULL, 0, mbprof_clr_handler, "I", "clear mbuf profiling statistics");
2121 #endif
2122
Cache object: b9f1265339c6d71ed1c25fe4ac093eeb
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