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