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