2 * Copyright (c) 2004 Jeffrey M. Hsu. All rights reserved.
3 * Copyright (c) 2004 The DragonFly Project. All rights reserved.
5 * This code is derived from software contributed to The DragonFly Project
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of The DragonFly Project nor the names of its
17 * contributors may be used to endorse or promote products derived
18 * from this software without specific, prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
30 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * Copyright (c) 1982, 1986, 1988, 1991, 1993
36 * The Regents of the University of California. All rights reserved.
38 * Redistribution and use in source and binary forms, with or without
39 * modification, are permitted provided that the following conditions
41 * 1. Redistributions of source code must retain the above copyright
42 * notice, this list of conditions and the following disclaimer.
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45 * documentation and/or other materials provided with the distribution.
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50 * 4. Neither the name of the University nor the names of its contributors
51 * may be used to endorse or promote products derived from this software
52 * without specific prior written permission.
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55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
66 * @(#)uipc_mbuf.c 8.2 (Berkeley) 1/4/94
67 * $FreeBSD: src/sys/kern/uipc_mbuf.c,v 1.51.2.24 2003/04/15 06:59:29 silby Exp $
68 * $DragonFly: src/sys/kern/uipc_mbuf.c,v 1.70 2008/11/20 14:21:01 sephe Exp $
71 #include "opt_param.h"
73 #include "opt_mbuf_stress_test.h"
74 #include <sys/param.h>
75 #include <sys/systm.h>
76 #include <sys/malloc.h>
78 #include <sys/kernel.h>
79 #include <sys/sysctl.h>
80 #include <sys/domain.h>
81 #include <sys/objcache.h>
83 #include <sys/protosw.h>
85 #include <sys/thread.h>
86 #include <sys/globaldata.h>
87 #include <sys/thread2.h>
89 #include <machine/atomic.h>
92 #include <vm/vm_kern.h>
93 #include <vm/vm_extern.h>
96 #include <machine/cpu.h>
100 * mbuf cluster meta-data
108 * mbuf tracking for debugging purposes
112 static MALLOC_DEFINE(M_MTRACK
, "mtrack", "mtrack");
115 RB_HEAD(mbuf_rb_tree
, mbtrack
);
116 RB_PROTOTYPE2(mbuf_rb_tree
, mbtrack
, rb_node
, mbtrack_cmp
, struct mbuf
*);
119 RB_ENTRY(mbtrack
) rb_node
;
125 mbtrack_cmp(struct mbtrack
*mb1
, struct mbtrack
*mb2
)
134 RB_GENERATE2(mbuf_rb_tree
, mbtrack
, rb_node
, mbtrack_cmp
, struct mbuf
*, m
);
136 struct mbuf_rb_tree mbuf_track_root
;
139 mbuftrack(struct mbuf
*m
)
144 mbt
= kmalloc(sizeof(*mbt
), M_MTRACK
, M_INTWAIT
|M_ZERO
);
146 if (mbuf_rb_tree_RB_INSERT(&mbuf_track_root
, mbt
))
147 panic("mbuftrack: mbuf %p already being tracked\n", m
);
152 mbufuntrack(struct mbuf
*m
)
157 mbt
= mbuf_rb_tree_RB_LOOKUP(&mbuf_track_root
, m
);
159 kprintf("mbufuntrack: mbuf %p was not tracked\n", m
);
161 mbuf_rb_tree_RB_REMOVE(&mbuf_track_root
, mbt
);
162 kfree(mbt
, M_MTRACK
);
168 mbuftrackid(struct mbuf
*m
, int trackid
)
177 mbt
= mbuf_rb_tree_RB_LOOKUP(&mbuf_track_root
, m
);
179 mbt
->trackid
= trackid
;
188 mbuftrack_callback(struct mbtrack
*mbt
, void *arg
)
190 struct sysctl_req
*req
= arg
;
194 ksnprintf(buf
, sizeof(buf
), "mbuf %p track %d\n", mbt
->m
, mbt
->trackid
);
196 error
= SYSCTL_OUT(req
, buf
, strlen(buf
));
203 mbuftrack_show(SYSCTL_HANDLER_ARGS
)
208 error
= mbuf_rb_tree_RB_SCAN(&mbuf_track_root
, NULL
,
209 mbuftrack_callback
, req
);
213 SYSCTL_PROC(_kern_ipc
, OID_AUTO
, showmbufs
, CTLFLAG_RD
|CTLTYPE_STRING
,
214 0, 0, mbuftrack_show
, "A", "Show all in-use mbufs");
219 #define mbufuntrack(m)
223 static void mbinit(void *);
224 SYSINIT(mbuf
, SI_BOOT2_MACHDEP
, SI_ORDER_FIRST
, mbinit
, NULL
)
226 static u_long mbtypes
[SMP_MAXCPU
][MT_NTYPES
];
228 static struct mbstat mbstat
[SMP_MAXCPU
];
237 #ifdef MBUF_STRESS_TEST
238 int m_defragrandomfailures
;
241 struct objcache
*mbuf_cache
, *mbufphdr_cache
;
242 struct objcache
*mclmeta_cache
;
243 struct objcache
*mbufcluster_cache
, *mbufphdrcluster_cache
;
248 SYSCTL_INT(_kern_ipc
, KIPC_MAX_LINKHDR
, max_linkhdr
, CTLFLAG_RW
,
249 &max_linkhdr
, 0, "");
250 SYSCTL_INT(_kern_ipc
, KIPC_MAX_PROTOHDR
, max_protohdr
, CTLFLAG_RW
,
251 &max_protohdr
, 0, "");
252 SYSCTL_INT(_kern_ipc
, KIPC_MAX_HDR
, max_hdr
, CTLFLAG_RW
, &max_hdr
, 0, "");
253 SYSCTL_INT(_kern_ipc
, KIPC_MAX_DATALEN
, max_datalen
, CTLFLAG_RW
,
254 &max_datalen
, 0, "");
255 SYSCTL_INT(_kern_ipc
, OID_AUTO
, mbuf_wait
, CTLFLAG_RW
,
257 static int do_mbstat(SYSCTL_HANDLER_ARGS
);
259 SYSCTL_PROC(_kern_ipc
, KIPC_MBSTAT
, mbstat
, CTLTYPE_STRUCT
|CTLFLAG_RD
,
260 0, 0, do_mbstat
, "S,mbstat", "");
262 static int do_mbtypes(SYSCTL_HANDLER_ARGS
);
264 SYSCTL_PROC(_kern_ipc
, OID_AUTO
, mbtypes
, CTLTYPE_ULONG
|CTLFLAG_RD
,
265 0, 0, do_mbtypes
, "LU", "");
268 do_mbstat(SYSCTL_HANDLER_ARGS
)
270 struct mbstat mbstat_total
;
271 struct mbstat
*mbstat_totalp
;
274 bzero(&mbstat_total
, sizeof(mbstat_total
));
275 mbstat_totalp
= &mbstat_total
;
277 for (i
= 0; i
< ncpus
; i
++)
279 mbstat_total
.m_mbufs
+= mbstat
[i
].m_mbufs
;
280 mbstat_total
.m_clusters
+= mbstat
[i
].m_clusters
;
281 mbstat_total
.m_spare
+= mbstat
[i
].m_spare
;
282 mbstat_total
.m_clfree
+= mbstat
[i
].m_clfree
;
283 mbstat_total
.m_drops
+= mbstat
[i
].m_drops
;
284 mbstat_total
.m_wait
+= mbstat
[i
].m_wait
;
285 mbstat_total
.m_drain
+= mbstat
[i
].m_drain
;
286 mbstat_total
.m_mcfail
+= mbstat
[i
].m_mcfail
;
287 mbstat_total
.m_mpfail
+= mbstat
[i
].m_mpfail
;
291 * The following fields are not cumulative fields so just
292 * get their values once.
294 mbstat_total
.m_msize
= mbstat
[0].m_msize
;
295 mbstat_total
.m_mclbytes
= mbstat
[0].m_mclbytes
;
296 mbstat_total
.m_minclsize
= mbstat
[0].m_minclsize
;
297 mbstat_total
.m_mlen
= mbstat
[0].m_mlen
;
298 mbstat_total
.m_mhlen
= mbstat
[0].m_mhlen
;
300 return(sysctl_handle_opaque(oidp
, mbstat_totalp
, sizeof(mbstat_total
), req
));
304 do_mbtypes(SYSCTL_HANDLER_ARGS
)
306 u_long totals
[MT_NTYPES
];
309 for (i
= 0; i
< MT_NTYPES
; i
++)
312 for (i
= 0; i
< ncpus
; i
++)
314 for (j
= 0; j
< MT_NTYPES
; j
++)
315 totals
[j
] += mbtypes
[i
][j
];
318 return(sysctl_handle_opaque(oidp
, totals
, sizeof(totals
), req
));
322 * These are read-only because we do not currently have any code
323 * to adjust the objcache limits after the fact. The variables
324 * may only be set as boot-time tunables.
326 SYSCTL_INT(_kern_ipc
, KIPC_NMBCLUSTERS
, nmbclusters
, CTLFLAG_RD
,
327 &nmbclusters
, 0, "Maximum number of mbuf clusters available");
328 SYSCTL_INT(_kern_ipc
, OID_AUTO
, nmbufs
, CTLFLAG_RD
, &nmbufs
, 0,
329 "Maximum number of mbufs available");
331 SYSCTL_INT(_kern_ipc
, OID_AUTO
, m_defragpackets
, CTLFLAG_RD
,
332 &m_defragpackets
, 0, "");
333 SYSCTL_INT(_kern_ipc
, OID_AUTO
, m_defragbytes
, CTLFLAG_RD
,
334 &m_defragbytes
, 0, "");
335 SYSCTL_INT(_kern_ipc
, OID_AUTO
, m_defraguseless
, CTLFLAG_RD
,
336 &m_defraguseless
, 0, "");
337 SYSCTL_INT(_kern_ipc
, OID_AUTO
, m_defragfailure
, CTLFLAG_RD
,
338 &m_defragfailure
, 0, "");
339 #ifdef MBUF_STRESS_TEST
340 SYSCTL_INT(_kern_ipc
, OID_AUTO
, m_defragrandomfailures
, CTLFLAG_RW
,
341 &m_defragrandomfailures
, 0, "");
344 static MALLOC_DEFINE(M_MBUF
, "mbuf", "mbuf");
345 static MALLOC_DEFINE(M_MBUFCL
, "mbufcl", "mbufcl");
346 static MALLOC_DEFINE(M_MCLMETA
, "mclmeta", "mclmeta");
348 static void m_reclaim (void);
349 static void m_mclref(void *arg
);
350 static void m_mclfree(void *arg
);
353 #define NMBCLUSTERS (512 + maxusers * 16)
356 #define NMBUFS (nmbclusters * 2)
360 * Perform sanity checks of tunables declared above.
363 tunable_mbinit(void *dummy
)
366 * This has to be done before VM init.
368 nmbclusters
= NMBCLUSTERS
;
369 TUNABLE_INT_FETCH("kern.ipc.nmbclusters", &nmbclusters
);
371 TUNABLE_INT_FETCH("kern.ipc.nmbufs", &nmbufs
);
373 if (nmbufs
< nmbclusters
* 2)
374 nmbufs
= nmbclusters
* 2;
376 SYSINIT(tunable_mbinit
, SI_BOOT1_TUNABLES
, SI_ORDER_ANY
,
377 tunable_mbinit
, NULL
);
379 /* "number of clusters of pages" */
385 * The mbuf object cache only guarantees that m_next and m_nextpkt are
386 * NULL and that m_data points to the beginning of the data area. In
387 * particular, m_len and m_pkthdr.len are uninitialized. It is the
388 * responsibility of the caller to initialize those fields before use.
391 static boolean_t __inline
392 mbuf_ctor(void *obj
, void *private, int ocflags
)
394 struct mbuf
*m
= obj
;
398 m
->m_data
= m
->m_dat
;
405 * Initialize the mbuf and the packet header fields.
408 mbufphdr_ctor(void *obj
, void *private, int ocflags
)
410 struct mbuf
*m
= obj
;
414 m
->m_data
= m
->m_pktdat
;
415 m
->m_flags
= M_PKTHDR
| M_PHCACHE
;
417 m
->m_pkthdr
.rcvif
= NULL
; /* eliminate XXX JH */
418 SLIST_INIT(&m
->m_pkthdr
.tags
);
419 m
->m_pkthdr
.csum_flags
= 0; /* eliminate XXX JH */
420 m
->m_pkthdr
.fw_flags
= 0; /* eliminate XXX JH */
426 * A mbcluster object consists of 2K (MCLBYTES) cluster and a refcount.
429 mclmeta_ctor(void *obj
, void *private, int ocflags
)
431 struct mbcluster
*cl
= obj
;
434 if (ocflags
& M_NOWAIT
)
435 buf
= kmalloc(MCLBYTES
, M_MBUFCL
, M_NOWAIT
| M_ZERO
);
437 buf
= kmalloc(MCLBYTES
, M_MBUFCL
, M_INTWAIT
| M_ZERO
);
446 mclmeta_dtor(void *obj
, void *private)
448 struct mbcluster
*mcl
= obj
;
450 KKASSERT(mcl
->mcl_refs
== 0);
451 kfree(mcl
->mcl_data
, M_MBUFCL
);
455 linkcluster(struct mbuf
*m
, struct mbcluster
*cl
)
458 * Add the cluster to the mbuf. The caller will detect that the
459 * mbuf now has an attached cluster.
461 m
->m_ext
.ext_arg
= cl
;
462 m
->m_ext
.ext_buf
= cl
->mcl_data
;
463 m
->m_ext
.ext_ref
= m_mclref
;
464 m
->m_ext
.ext_free
= m_mclfree
;
465 m
->m_ext
.ext_size
= MCLBYTES
;
466 atomic_add_int(&cl
->mcl_refs
, 1);
468 m
->m_data
= m
->m_ext
.ext_buf
;
469 m
->m_flags
|= M_EXT
| M_EXT_CLUSTER
;
473 mbufphdrcluster_ctor(void *obj
, void *private, int ocflags
)
475 struct mbuf
*m
= obj
;
476 struct mbcluster
*cl
;
478 mbufphdr_ctor(obj
, private, ocflags
);
479 cl
= objcache_get(mclmeta_cache
, ocflags
);
482 m
->m_flags
|= M_CLCACHE
;
488 mbufcluster_ctor(void *obj
, void *private, int ocflags
)
490 struct mbuf
*m
= obj
;
491 struct mbcluster
*cl
;
493 mbuf_ctor(obj
, private, ocflags
);
494 cl
= objcache_get(mclmeta_cache
, ocflags
);
497 m
->m_flags
|= M_CLCACHE
;
503 * Used for both the cluster and cluster PHDR caches.
505 * The mbuf may have lost its cluster due to sharing, deal
506 * with the situation by checking M_EXT.
509 mbufcluster_dtor(void *obj
, void *private)
511 struct mbuf
*m
= obj
;
512 struct mbcluster
*mcl
;
514 if (m
->m_flags
& M_EXT
) {
515 KKASSERT((m
->m_flags
& M_EXT_CLUSTER
) != 0);
516 mcl
= m
->m_ext
.ext_arg
;
517 KKASSERT(mcl
->mcl_refs
== 1);
519 objcache_put(mclmeta_cache
, mcl
);
523 struct objcache_malloc_args mbuf_malloc_args
= { MSIZE
, M_MBUF
};
524 struct objcache_malloc_args mclmeta_malloc_args
=
525 { sizeof(struct mbcluster
), M_MCLMETA
};
531 int mb_limit
, cl_limit
, mbcl_limit
;
536 * Initialize statistics
538 for (i
= 0; i
< ncpus
; i
++) {
539 atomic_set_long_nonlocked(&mbstat
[i
].m_msize
, MSIZE
);
540 atomic_set_long_nonlocked(&mbstat
[i
].m_mclbytes
, MCLBYTES
);
541 atomic_set_long_nonlocked(&mbstat
[i
].m_minclsize
, MINCLSIZE
);
542 atomic_set_long_nonlocked(&mbstat
[i
].m_mlen
, MLEN
);
543 atomic_set_long_nonlocked(&mbstat
[i
].m_mhlen
, MHLEN
);
547 * Create objtect caches and save cluster limits, which will
548 * be used to adjust backing kmalloc pools' limit later.
551 mb_limit
= cl_limit
= mbcl_limit
= 0;
554 mbuf_cache
= objcache_create("mbuf", &limit
, 0,
555 mbuf_ctor
, NULL
, NULL
,
556 objcache_malloc_alloc
, objcache_malloc_free
, &mbuf_malloc_args
);
557 if (limit
> mb_limit
)
561 mbufphdr_cache
= objcache_create("mbuf pkt hdr", &limit
, 64,
562 mbufphdr_ctor
, NULL
, NULL
,
563 objcache_malloc_alloc
, objcache_malloc_free
, &mbuf_malloc_args
);
564 if (limit
> mb_limit
)
567 cl_limit
= nmbclusters
;
568 mclmeta_cache
= objcache_create("cluster mbuf", &cl_limit
, 0,
569 mclmeta_ctor
, mclmeta_dtor
, NULL
,
570 objcache_malloc_alloc
, objcache_malloc_free
, &mclmeta_malloc_args
);
573 mbufcluster_cache
= objcache_create("mbuf + cluster", &limit
, 0,
574 mbufcluster_ctor
, mbufcluster_dtor
, NULL
,
575 objcache_malloc_alloc
, objcache_malloc_free
, &mbuf_malloc_args
);
576 if (limit
> mbcl_limit
)
580 mbufphdrcluster_cache
= objcache_create("mbuf pkt hdr + cluster",
581 &limit
, 64, mbufphdrcluster_ctor
, mbufcluster_dtor
, NULL
,
582 objcache_malloc_alloc
, objcache_malloc_free
, &mbuf_malloc_args
);
583 if (limit
> mbcl_limit
)
587 * Adjust backing kmalloc pools' limit
589 * NOTE: We raise the limit by another 1/8 to take the effect
590 * of loosememuse into account.
592 cl_limit
+= cl_limit
/ 8;
593 kmalloc_raise_limit(mclmeta_malloc_args
.mtype
,
594 mclmeta_malloc_args
.objsize
* cl_limit
);
595 kmalloc_raise_limit(M_MBUFCL
, MCLBYTES
* cl_limit
);
597 mb_limit
+= mbcl_limit
;
598 mb_limit
+= mb_limit
/ 4; /* save some space for non-pkthdr mbufs */
599 mb_limit
+= mb_limit
/ 8;
600 kmalloc_raise_limit(mbuf_malloc_args
.mtype
,
601 mbuf_malloc_args
.objsize
* mb_limit
);
605 * Return the number of references to this mbuf's data. 0 is returned
606 * if the mbuf is not M_EXT, a reference count is returned if it is
607 * M_EXT | M_EXT_CLUSTER, and 99 is returned if it is a special M_EXT.
610 m_sharecount(struct mbuf
*m
)
612 switch (m
->m_flags
& (M_EXT
| M_EXT_CLUSTER
)) {
617 case M_EXT
| M_EXT_CLUSTER
:
618 return (((struct mbcluster
*)m
->m_ext
.ext_arg
)->mcl_refs
);
621 return (0); /* to shut up compiler */
625 * change mbuf to new type
628 m_chtype(struct mbuf
*m
, int type
)
630 struct globaldata
*gd
= mycpu
;
632 atomic_add_long_nonlocked(&mbtypes
[gd
->gd_cpuid
][type
], 1);
633 atomic_subtract_long_nonlocked(&mbtypes
[gd
->gd_cpuid
][m
->m_type
], 1);
634 atomic_set_short_nonlocked(&m
->m_type
, type
);
644 SLIST_FOREACH(dp
, &domains
, dom_next
) {
645 for (pr
= dp
->dom_protosw
; pr
< dp
->dom_protoswNPROTOSW
; pr
++) {
651 atomic_add_long_nonlocked(&mbstat
[mycpu
->gd_cpuid
].m_drain
, 1);
655 updatestats(struct mbuf
*m
, int type
)
657 struct globaldata
*gd
= mycpu
;
662 atomic_add_long_nonlocked(&mbtypes
[gd
->gd_cpuid
][type
], 1);
663 atomic_add_long_nonlocked(&mbstat
[mycpu
->gd_cpuid
].m_mbufs
, 1);
671 m_get(int how
, int type
)
675 int ocf
= MBTOM(how
);
679 m
= objcache_get(mbuf_cache
, ocf
);
682 if ((how
& MB_TRYWAIT
) && ntries
++ == 0) {
683 struct objcache
*reclaimlist
[] = {
685 mbufcluster_cache
, mbufphdrcluster_cache
687 const int nreclaims
= __arysize(reclaimlist
);
689 if (!objcache_reclaimlist(reclaimlist
, nreclaims
, ocf
))
696 updatestats(m
, type
);
701 m_gethdr(int how
, int type
)
704 int ocf
= MBTOM(how
);
709 m
= objcache_get(mbufphdr_cache
, ocf
);
712 if ((how
& MB_TRYWAIT
) && ntries
++ == 0) {
713 struct objcache
*reclaimlist
[] = {
715 mbufcluster_cache
, mbufphdrcluster_cache
717 const int nreclaims
= __arysize(reclaimlist
);
719 if (!objcache_reclaimlist(reclaimlist
, nreclaims
, ocf
))
726 updatestats(m
, type
);
731 * Get a mbuf (not a mbuf cluster!) and zero it.
735 m_getclr(int how
, int type
)
739 m
= m_get(how
, type
);
741 bzero(m
->m_data
, MLEN
);
746 * Returns an mbuf with an attached cluster.
747 * Because many network drivers use this kind of buffers a lot, it is
748 * convenient to keep a small pool of free buffers of this kind.
749 * Even a small size such as 10 gives about 10% improvement in the
750 * forwarding rate in a bridge or router.
753 m_getcl(int how
, short type
, int flags
)
756 int ocflags
= MBTOM(how
);
761 if (flags
& M_PKTHDR
)
762 m
= objcache_get(mbufphdrcluster_cache
, ocflags
);
764 m
= objcache_get(mbufcluster_cache
, ocflags
);
767 if ((how
& MB_TRYWAIT
) && ntries
++ == 0) {
768 struct objcache
*reclaimlist
[1];
770 if (flags
& M_PKTHDR
)
771 reclaimlist
[0] = mbufcluster_cache
;
773 reclaimlist
[0] = mbufphdrcluster_cache
;
774 if (!objcache_reclaimlist(reclaimlist
, 1, ocflags
))
785 atomic_add_long_nonlocked(&mbtypes
[mycpu
->gd_cpuid
][type
], 1);
786 atomic_add_long_nonlocked(&mbstat
[mycpu
->gd_cpuid
].m_clusters
, 1);
791 * Allocate chain of requested length.
794 m_getc(int len
, int how
, int type
)
796 struct mbuf
*n
, *nfirst
= NULL
, **ntail
= &nfirst
;
800 n
= m_getl(len
, how
, type
, 0, &nsize
);
816 * Allocate len-worth of mbufs and/or mbuf clusters (whatever fits best)
817 * and return a pointer to the head of the allocated chain. If m0 is
818 * non-null, then we assume that it is a single mbuf or an mbuf chain to
819 * which we want len bytes worth of mbufs and/or clusters attached, and so
820 * if we succeed in allocating it, we will just return a pointer to m0.
822 * If we happen to fail at any point during the allocation, we will free
823 * up everything we have already allocated and return NULL.
825 * Deprecated. Use m_getc() and m_cat() instead.
828 m_getm(struct mbuf
*m0
, int len
, int type
, int how
)
832 nfirst
= m_getc(len
, how
, type
);
835 m_last(m0
)->m_next
= nfirst
;
843 * Adds a cluster to a normal mbuf, M_EXT is set on success.
844 * Deprecated. Use m_getcl() instead.
847 m_mclget(struct mbuf
*m
, int how
)
849 struct mbcluster
*mcl
;
851 KKASSERT((m
->m_flags
& M_EXT
) == 0);
852 mcl
= objcache_get(mclmeta_cache
, MBTOM(how
));
855 atomic_add_long_nonlocked(&mbstat
[mycpu
->gd_cpuid
].m_clusters
, 1);
860 * Updates to mbcluster must be MPSAFE. Only an entity which already has
861 * a reference to the cluster can ref it, so we are in no danger of
862 * racing an add with a subtract. But the operation must still be atomic
863 * since multiple entities may have a reference on the cluster.
865 * m_mclfree() is almost the same but it must contend with two entities
866 * freeing the cluster at the same time. If there is only one reference
867 * count we are the only entity referencing the cluster and no further
868 * locking is required. Otherwise we must protect against a race to 0
869 * with the serializer.
874 struct mbcluster
*mcl
= arg
;
876 atomic_add_int(&mcl
->mcl_refs
, 1);
880 * When dereferencing a cluster we have to deal with a N->0 race, where
881 * N entities free their references simultaniously. To do this we use
882 * atomic_fetchadd_int().
887 struct mbcluster
*mcl
= arg
;
889 if (atomic_fetchadd_int(&mcl
->mcl_refs
, -1) == 1)
890 objcache_put(mclmeta_cache
, mcl
);
893 extern void db_print_backtrace(void);
896 * Free a single mbuf and any associated external storage. The successor,
897 * if any, is returned.
899 * We do need to check non-first mbuf for m_aux, since some of existing
900 * code does not call M_PREPEND properly.
901 * (example: call to bpf_mtap from drivers)
904 m_free(struct mbuf
*m
)
907 struct globaldata
*gd
= mycpu
;
909 KASSERT(m
->m_type
!= MT_FREE
, ("freeing free mbuf %p", m
));
910 atomic_subtract_long_nonlocked(&mbtypes
[gd
->gd_cpuid
][m
->m_type
], 1);
915 * Make sure the mbuf is in constructed state before returning it
921 KKASSERT(m
->m_nextpkt
== NULL
);
923 if (m
->m_nextpkt
!= NULL
) {
925 static int afewtimes
= 10;
927 if (afewtimes
-- > 0) {
928 kprintf("mfree: m->m_nextpkt != NULL\n");
929 db_print_backtrace();
935 if (m
->m_flags
& M_PKTHDR
) {
936 m_tag_delete_chain(m
); /* eliminate XXX JH */
939 m
->m_flags
&= (M_EXT
| M_EXT_CLUSTER
| M_CLCACHE
| M_PHCACHE
);
942 * Clean the M_PKTHDR state so we can return the mbuf to its original
943 * cache. This is based on the PHCACHE flag which tells us whether
944 * the mbuf was originally allocated out of a packet-header cache
945 * or a non-packet-header cache.
947 if (m
->m_flags
& M_PHCACHE
) {
948 m
->m_flags
|= M_PKTHDR
;
949 m
->m_pkthdr
.rcvif
= NULL
; /* eliminate XXX JH */
950 m
->m_pkthdr
.csum_flags
= 0; /* eliminate XXX JH */
951 m
->m_pkthdr
.fw_flags
= 0; /* eliminate XXX JH */
952 SLIST_INIT(&m
->m_pkthdr
.tags
);
956 * Handle remaining flags combinations. M_CLCACHE tells us whether
957 * the mbuf was originally allocated from a cluster cache or not,
958 * and is totally separate from whether the mbuf is currently
959 * associated with a cluster.
962 switch(m
->m_flags
& (M_CLCACHE
| M_EXT
| M_EXT_CLUSTER
)) {
963 case M_CLCACHE
| M_EXT
| M_EXT_CLUSTER
:
965 * mbuf+cluster cache case. The mbuf was allocated from the
966 * combined mbuf_cluster cache and can be returned to the
967 * cache if the cluster hasn't been shared.
969 if (m_sharecount(m
) == 1) {
971 * The cluster has not been shared, we can just
972 * reset the data pointer and return the mbuf
973 * to the cluster cache. Note that the reference
974 * count is left intact (it is still associated with
977 m
->m_data
= m
->m_ext
.ext_buf
;
978 if (m
->m_flags
& M_PHCACHE
)
979 objcache_put(mbufphdrcluster_cache
, m
);
981 objcache_put(mbufcluster_cache
, m
);
982 atomic_subtract_long_nonlocked(&mbstat
[mycpu
->gd_cpuid
].m_clusters
, 1);
985 * Hell. Someone else has a ref on this cluster,
986 * we have to disconnect it which means we can't
987 * put it back into the mbufcluster_cache, we
988 * have to destroy the mbuf.
990 * Other mbuf references to the cluster will typically
991 * be M_EXT | M_EXT_CLUSTER but without M_CLCACHE.
993 * XXX we could try to connect another cluster to
996 m
->m_ext
.ext_free(m
->m_ext
.ext_arg
);
997 m
->m_flags
&= ~(M_EXT
| M_EXT_CLUSTER
);
998 if (m
->m_flags
& M_PHCACHE
)
999 objcache_dtor(mbufphdrcluster_cache
, m
);
1001 objcache_dtor(mbufcluster_cache
, m
);
1004 case M_EXT
| M_EXT_CLUSTER
:
1006 * Normal cluster associated with an mbuf that was allocated
1007 * from the normal mbuf pool rather then the cluster pool.
1008 * The cluster has to be independantly disassociated from the
1011 if (m_sharecount(m
) == 1)
1012 atomic_subtract_long_nonlocked(&mbstat
[mycpu
->gd_cpuid
].m_clusters
, 1);
1016 * Normal cluster association case, disconnect the cluster from
1017 * the mbuf. The cluster may or may not be custom.
1019 m
->m_ext
.ext_free(m
->m_ext
.ext_arg
);
1020 m
->m_flags
&= ~(M_EXT
| M_EXT_CLUSTER
);
1024 * return the mbuf to the mbuf cache.
1026 if (m
->m_flags
& M_PHCACHE
) {
1027 m
->m_data
= m
->m_pktdat
;
1028 objcache_put(mbufphdr_cache
, m
);
1030 m
->m_data
= m
->m_dat
;
1031 objcache_put(mbuf_cache
, m
);
1033 atomic_subtract_long_nonlocked(&mbstat
[mycpu
->gd_cpuid
].m_mbufs
, 1);
1037 panic("bad mbuf flags %p %08x\n", m
, m
->m_flags
);
1045 m_freem(struct mbuf
*m
)
1054 * mbuf utility routines
1058 * Lesser-used path for M_PREPEND: allocate new mbuf to prepend to chain and
1062 m_prepend(struct mbuf
*m
, int len
, int how
)
1066 if (m
->m_flags
& M_PKTHDR
)
1067 mn
= m_gethdr(how
, m
->m_type
);
1069 mn
= m_get(how
, m
->m_type
);
1074 if (m
->m_flags
& M_PKTHDR
)
1075 M_MOVE_PKTHDR(mn
, m
);
1085 * Make a copy of an mbuf chain starting "off0" bytes from the beginning,
1086 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf.
1087 * The wait parameter is a choice of MB_WAIT/MB_DONTWAIT from caller.
1088 * Note that the copy is read-only, because clusters are not copied,
1089 * only their reference counts are incremented.
1092 m_copym(const struct mbuf
*m
, int off0
, int len
, int wait
)
1094 struct mbuf
*n
, **np
;
1099 KASSERT(off
>= 0, ("m_copym, negative off %d", off
));
1100 KASSERT(len
>= 0, ("m_copym, negative len %d", len
));
1101 if (off
== 0 && m
->m_flags
& M_PKTHDR
)
1104 KASSERT(m
!= NULL
, ("m_copym, offset > size of mbuf chain"));
1114 KASSERT(len
== M_COPYALL
,
1115 ("m_copym, length > size of mbuf chain"));
1119 * Because we are sharing any cluster attachment below,
1120 * be sure to get an mbuf that does not have a cluster
1121 * associated with it.
1124 n
= m_gethdr(wait
, m
->m_type
);
1126 n
= m_get(wait
, m
->m_type
);
1131 if (!m_dup_pkthdr(n
, m
, wait
))
1133 if (len
== M_COPYALL
)
1134 n
->m_pkthdr
.len
-= off0
;
1136 n
->m_pkthdr
.len
= len
;
1139 n
->m_len
= min(len
, m
->m_len
- off
);
1140 if (m
->m_flags
& M_EXT
) {
1141 KKASSERT((n
->m_flags
& M_EXT
) == 0);
1142 n
->m_data
= m
->m_data
+ off
;
1143 m
->m_ext
.ext_ref(m
->m_ext
.ext_arg
);
1144 n
->m_ext
= m
->m_ext
;
1145 n
->m_flags
|= m
->m_flags
& (M_EXT
| M_EXT_CLUSTER
);
1147 bcopy(mtod(m
, caddr_t
)+off
, mtod(n
, caddr_t
),
1148 (unsigned)n
->m_len
);
1150 if (len
!= M_COPYALL
)
1157 atomic_add_long_nonlocked(&mbstat
[mycpu
->gd_cpuid
].m_mcfail
, 1);
1161 atomic_add_long_nonlocked(&mbstat
[mycpu
->gd_cpuid
].m_mcfail
, 1);
1166 * Copy an entire packet, including header (which must be present).
1167 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'.
1168 * Note that the copy is read-only, because clusters are not copied,
1169 * only their reference counts are incremented.
1170 * Preserve alignment of the first mbuf so if the creator has left
1171 * some room at the beginning (e.g. for inserting protocol headers)
1172 * the copies also have the room available.
1175 m_copypacket(struct mbuf
*m
, int how
)
1177 struct mbuf
*top
, *n
, *o
;
1179 n
= m_gethdr(how
, m
->m_type
);
1184 if (!m_dup_pkthdr(n
, m
, how
))
1186 n
->m_len
= m
->m_len
;
1187 if (m
->m_flags
& M_EXT
) {
1188 KKASSERT((n
->m_flags
& M_EXT
) == 0);
1189 n
->m_data
= m
->m_data
;
1190 m
->m_ext
.ext_ref(m
->m_ext
.ext_arg
);
1191 n
->m_ext
= m
->m_ext
;
1192 n
->m_flags
|= m
->m_flags
& (M_EXT
| M_EXT_CLUSTER
);
1194 n
->m_data
= n
->m_pktdat
+ (m
->m_data
- m
->m_pktdat
);
1195 bcopy(mtod(m
, char *), mtod(n
, char *), n
->m_len
);
1200 o
= m_get(how
, m
->m_type
);
1207 n
->m_len
= m
->m_len
;
1208 if (m
->m_flags
& M_EXT
) {
1209 KKASSERT((n
->m_flags
& M_EXT
) == 0);
1210 n
->m_data
= m
->m_data
;
1211 m
->m_ext
.ext_ref(m
->m_ext
.ext_arg
);
1212 n
->m_ext
= m
->m_ext
;
1213 n
->m_flags
|= m
->m_flags
& (M_EXT
| M_EXT_CLUSTER
);
1215 bcopy(mtod(m
, char *), mtod(n
, char *), n
->m_len
);
1223 atomic_add_long_nonlocked(&mbstat
[mycpu
->gd_cpuid
].m_mcfail
, 1);
1228 * Copy data from an mbuf chain starting "off" bytes from the beginning,
1229 * continuing for "len" bytes, into the indicated buffer.
1232 m_copydata(const struct mbuf
*m
, int off
, int len
, caddr_t cp
)
1236 KASSERT(off
>= 0, ("m_copydata, negative off %d", off
));
1237 KASSERT(len
>= 0, ("m_copydata, negative len %d", len
));
1239 KASSERT(m
!= NULL
, ("m_copydata, offset > size of mbuf chain"));
1246 KASSERT(m
!= NULL
, ("m_copydata, length > size of mbuf chain"));
1247 count
= min(m
->m_len
- off
, len
);
1248 bcopy(mtod(m
, caddr_t
) + off
, cp
, count
);
1257 * Copy a packet header mbuf chain into a completely new chain, including
1258 * copying any mbuf clusters. Use this instead of m_copypacket() when
1259 * you need a writable copy of an mbuf chain.
1262 m_dup(struct mbuf
*m
, int how
)
1264 struct mbuf
**p
, *top
= NULL
;
1265 int remain
, moff
, nsize
;
1270 KASSERT((m
->m_flags
& M_PKTHDR
) != 0, ("%s: !PKTHDR", __func__
));
1272 /* While there's more data, get a new mbuf, tack it on, and fill it */
1273 remain
= m
->m_pkthdr
.len
;
1276 while (remain
> 0 || top
== NULL
) { /* allow m->m_pkthdr.len == 0 */
1279 /* Get the next new mbuf */
1280 n
= m_getl(remain
, how
, m
->m_type
, top
== NULL
? M_PKTHDR
: 0,
1285 if (!m_dup_pkthdr(n
, m
, how
))
1288 /* Link it into the new chain */
1292 /* Copy data from original mbuf(s) into new mbuf */
1294 while (n
->m_len
< nsize
&& m
!= NULL
) {
1295 int chunk
= min(nsize
- n
->m_len
, m
->m_len
- moff
);
1297 bcopy(m
->m_data
+ moff
, n
->m_data
+ n
->m_len
, chunk
);
1301 if (moff
== m
->m_len
) {
1307 /* Check correct total mbuf length */
1308 KASSERT((remain
> 0 && m
!= NULL
) || (remain
== 0 && m
== NULL
),
1309 ("%s: bogus m_pkthdr.len", __func__
));
1316 atomic_add_long_nonlocked(&mbstat
[mycpu
->gd_cpuid
].m_mcfail
, 1);
1321 * Concatenate mbuf chain n to m.
1322 * Both chains must be of the same type (e.g. MT_DATA).
1323 * Any m_pkthdr is not updated.
1326 m_cat(struct mbuf
*m
, struct mbuf
*n
)
1330 if (m
->m_flags
& M_EXT
||
1331 m
->m_data
+ m
->m_len
+ n
->m_len
>= &m
->m_dat
[MLEN
]) {
1332 /* just join the two chains */
1336 /* splat the data from one into the other */
1337 bcopy(mtod(n
, caddr_t
), mtod(m
, caddr_t
) + m
->m_len
,
1339 m
->m_len
+= n
->m_len
;
1345 m_adj(struct mbuf
*mp
, int req_len
)
1351 if ((m
= mp
) == NULL
)
1357 while (m
!= NULL
&& len
> 0) {
1358 if (m
->m_len
<= len
) {
1369 if (mp
->m_flags
& M_PKTHDR
)
1370 m
->m_pkthdr
.len
-= (req_len
- len
);
1373 * Trim from tail. Scan the mbuf chain,
1374 * calculating its length and finding the last mbuf.
1375 * If the adjustment only affects this mbuf, then just
1376 * adjust and return. Otherwise, rescan and truncate
1377 * after the remaining size.
1383 if (m
->m_next
== (struct mbuf
*)0)
1387 if (m
->m_len
>= len
) {
1389 if (mp
->m_flags
& M_PKTHDR
)
1390 mp
->m_pkthdr
.len
-= len
;
1397 * Correct length for chain is "count".
1398 * Find the mbuf with last data, adjust its length,
1399 * and toss data from remaining mbufs on chain.
1402 if (m
->m_flags
& M_PKTHDR
)
1403 m
->m_pkthdr
.len
= count
;
1404 for (; m
; m
= m
->m_next
) {
1405 if (m
->m_len
>= count
) {
1412 (m
= m
->m_next
) ->m_len
= 0;
1417 * Rearrange an mbuf chain so that len bytes are contiguous
1418 * and in the data area of an mbuf (so that mtod will work for a structure
1419 * of size len). Returns the resulting mbuf chain on success, frees it and
1420 * returns null on failure. If there is room, it will add up to
1421 * max_protohdr-len extra bytes to the contiguous region in an attempt to
1422 * avoid being called next time.
1425 m_pullup(struct mbuf
*n
, int len
)
1432 * If first mbuf has no cluster, and has room for len bytes
1433 * without shifting current data, pullup into it,
1434 * otherwise allocate a new mbuf to prepend to the chain.
1436 if (!(n
->m_flags
& M_EXT
) &&
1437 n
->m_data
+ len
< &n
->m_dat
[MLEN
] &&
1439 if (n
->m_len
>= len
)
1447 if (n
->m_flags
& M_PKTHDR
)
1448 m
= m_gethdr(MB_DONTWAIT
, n
->m_type
);
1450 m
= m_get(MB_DONTWAIT
, n
->m_type
);
1454 if (n
->m_flags
& M_PKTHDR
)
1455 M_MOVE_PKTHDR(m
, n
);
1457 space
= &m
->m_dat
[MLEN
] - (m
->m_data
+ m
->m_len
);
1459 count
= min(min(max(len
, max_protohdr
), space
), n
->m_len
);
1460 bcopy(mtod(n
, caddr_t
), mtod(m
, caddr_t
) + m
->m_len
,
1470 } while (len
> 0 && n
);
1479 atomic_add_long_nonlocked(&mbstat
[mycpu
->gd_cpuid
].m_mcfail
, 1);
1484 * Partition an mbuf chain in two pieces, returning the tail --
1485 * all but the first len0 bytes. In case of failure, it returns NULL and
1486 * attempts to restore the chain to its original state.
1488 * Note that the resulting mbufs might be read-only, because the new
1489 * mbuf can end up sharing an mbuf cluster with the original mbuf if
1490 * the "breaking point" happens to lie within a cluster mbuf. Use the
1491 * M_WRITABLE() macro to check for this case.
1494 m_split(struct mbuf
*m0
, int len0
, int wait
)
1497 unsigned len
= len0
, remain
;
1499 for (m
= m0
; m
&& len
> m
->m_len
; m
= m
->m_next
)
1503 remain
= m
->m_len
- len
;
1504 if (m0
->m_flags
& M_PKTHDR
) {
1505 n
= m_gethdr(wait
, m0
->m_type
);
1508 n
->m_pkthdr
.rcvif
= m0
->m_pkthdr
.rcvif
;
1509 n
->m_pkthdr
.len
= m0
->m_pkthdr
.len
- len0
;
1510 m0
->m_pkthdr
.len
= len0
;
1511 if (m
->m_flags
& M_EXT
)
1513 if (remain
> MHLEN
) {
1514 /* m can't be the lead packet */
1516 n
->m_next
= m_split(m
, len
, wait
);
1517 if (n
->m_next
== NULL
) {
1525 MH_ALIGN(n
, remain
);
1526 } else if (remain
== 0) {
1531 n
= m_get(wait
, m
->m_type
);
1537 if (m
->m_flags
& M_EXT
) {
1538 KKASSERT((n
->m_flags
& M_EXT
) == 0);
1539 n
->m_data
= m
->m_data
+ len
;
1540 m
->m_ext
.ext_ref(m
->m_ext
.ext_arg
);
1541 n
->m_ext
= m
->m_ext
;
1542 n
->m_flags
|= m
->m_flags
& (M_EXT
| M_EXT_CLUSTER
);
1544 bcopy(mtod(m
, caddr_t
) + len
, mtod(n
, caddr_t
), remain
);
1548 n
->m_next
= m
->m_next
;
1554 * Routine to copy from device local memory into mbufs.
1555 * Note: "offset" is ill-defined and always called as 0, so ignore it.
1558 m_devget(char *buf
, int len
, int offset
, struct ifnet
*ifp
,
1559 void (*copy
)(volatile const void *from
, volatile void *to
, size_t length
))
1561 struct mbuf
*m
, *mfirst
= NULL
, **mtail
;
1570 m
= m_getl(len
, MB_DONTWAIT
, MT_DATA
, flags
, &nsize
);
1575 m
->m_len
= min(len
, nsize
);
1577 if (flags
& M_PKTHDR
) {
1578 if (len
+ max_linkhdr
<= nsize
)
1579 m
->m_data
+= max_linkhdr
;
1580 m
->m_pkthdr
.rcvif
= ifp
;
1581 m
->m_pkthdr
.len
= len
;
1585 copy(buf
, m
->m_data
, (unsigned)m
->m_len
);
1596 * Routine to pad mbuf to the specified length 'padto'.
1599 m_devpad(struct mbuf
*m
, int padto
)
1601 struct mbuf
*last
= NULL
;
1604 if (padto
<= m
->m_pkthdr
.len
)
1607 padlen
= padto
- m
->m_pkthdr
.len
;
1609 /* if there's only the packet-header and we can pad there, use it. */
1610 if (m
->m_pkthdr
.len
== m
->m_len
&& M_TRAILINGSPACE(m
) >= padlen
) {
1614 * Walk packet chain to find last mbuf. We will either
1615 * pad there, or append a new mbuf and pad it
1617 for (last
= m
; last
->m_next
!= NULL
; last
= last
->m_next
)
1620 /* `last' now points to last in chain. */
1621 if (M_TRAILINGSPACE(last
) < padlen
) {
1624 /* Allocate new empty mbuf, pad it. Compact later. */
1625 MGET(n
, MB_DONTWAIT
, MT_DATA
);
1633 KKASSERT(M_TRAILINGSPACE(last
) >= padlen
);
1634 KKASSERT(M_WRITABLE(last
));
1636 /* Now zero the pad area */
1637 bzero(mtod(last
, char *) + last
->m_len
, padlen
);
1638 last
->m_len
+= padlen
;
1639 m
->m_pkthdr
.len
+= padlen
;
1644 * Copy data from a buffer back into the indicated mbuf chain,
1645 * starting "off" bytes from the beginning, extending the mbuf
1646 * chain if necessary.
1649 m_copyback(struct mbuf
*m0
, int off
, int len
, caddr_t cp
)
1652 struct mbuf
*m
= m0
, *n
;
1657 while (off
> (mlen
= m
->m_len
)) {
1660 if (m
->m_next
== NULL
) {
1661 n
= m_getclr(MB_DONTWAIT
, m
->m_type
);
1664 n
->m_len
= min(MLEN
, len
+ off
);
1670 mlen
= min (m
->m_len
- off
, len
);
1671 bcopy(cp
, off
+ mtod(m
, caddr_t
), (unsigned)mlen
);
1679 if (m
->m_next
== NULL
) {
1680 n
= m_get(MB_DONTWAIT
, m
->m_type
);
1683 n
->m_len
= min(MLEN
, len
);
1688 out
: if (((m
= m0
)->m_flags
& M_PKTHDR
) && (m
->m_pkthdr
.len
< totlen
))
1689 m
->m_pkthdr
.len
= totlen
;
1693 m_print(const struct mbuf
*m
)
1696 const struct mbuf
*m2
;
1698 len
= m
->m_pkthdr
.len
;
1701 kprintf("%p %*D\n", m2
, m2
->m_len
, (u_char
*)m2
->m_data
, "-");
1709 * "Move" mbuf pkthdr from "from" to "to".
1710 * "from" must have M_PKTHDR set, and "to" must be empty.
1713 m_move_pkthdr(struct mbuf
*to
, struct mbuf
*from
)
1715 KASSERT((to
->m_flags
& M_PKTHDR
), ("m_move_pkthdr: not packet header"));
1717 to
->m_flags
|= from
->m_flags
& M_COPYFLAGS
;
1718 to
->m_pkthdr
= from
->m_pkthdr
; /* especially tags */
1719 SLIST_INIT(&from
->m_pkthdr
.tags
); /* purge tags from src */
1723 * Duplicate "from"'s mbuf pkthdr in "to".
1724 * "from" must have M_PKTHDR set, and "to" must be empty.
1725 * In particular, this does a deep copy of the packet tags.
1728 m_dup_pkthdr(struct mbuf
*to
, const struct mbuf
*from
, int how
)
1730 KASSERT((to
->m_flags
& M_PKTHDR
), ("m_dup_pkthdr: not packet header"));
1732 to
->m_flags
= (from
->m_flags
& M_COPYFLAGS
) |
1733 (to
->m_flags
& ~M_COPYFLAGS
);
1734 to
->m_pkthdr
= from
->m_pkthdr
;
1735 SLIST_INIT(&to
->m_pkthdr
.tags
);
1736 return (m_tag_copy_chain(to
, from
, how
));
1740 * Defragment a mbuf chain, returning the shortest possible
1741 * chain of mbufs and clusters. If allocation fails and
1742 * this cannot be completed, NULL will be returned, but
1743 * the passed in chain will be unchanged. Upon success,
1744 * the original chain will be freed, and the new chain
1747 * If a non-packet header is passed in, the original
1748 * mbuf (chain?) will be returned unharmed.
1750 * m_defrag_nofree doesn't free the passed in mbuf.
1753 m_defrag(struct mbuf
*m0
, int how
)
1757 if ((m_new
= m_defrag_nofree(m0
, how
)) == NULL
)
1765 m_defrag_nofree(struct mbuf
*m0
, int how
)
1767 struct mbuf
*m_new
= NULL
, *m_final
= NULL
;
1768 int progress
= 0, length
, nsize
;
1770 if (!(m0
->m_flags
& M_PKTHDR
))
1773 #ifdef MBUF_STRESS_TEST
1774 if (m_defragrandomfailures
) {
1775 int temp
= karc4random() & 0xff;
1781 m_final
= m_getl(m0
->m_pkthdr
.len
, how
, MT_DATA
, M_PKTHDR
, &nsize
);
1782 if (m_final
== NULL
)
1784 m_final
->m_len
= 0; /* in case m0->m_pkthdr.len is zero */
1786 if (m_dup_pkthdr(m_final
, m0
, how
) == 0)
1791 while (progress
< m0
->m_pkthdr
.len
) {
1792 length
= m0
->m_pkthdr
.len
- progress
;
1793 if (length
> MCLBYTES
)
1796 if (m_new
== NULL
) {
1797 m_new
= m_getl(length
, how
, MT_DATA
, 0, &nsize
);
1802 m_copydata(m0
, progress
, length
, mtod(m_new
, caddr_t
));
1804 m_new
->m_len
= length
;
1805 if (m_new
!= m_final
)
1806 m_cat(m_final
, m_new
);
1809 if (m0
->m_next
== NULL
)
1812 m_defragbytes
+= m_final
->m_pkthdr
.len
;
1823 * Move data from uio into mbufs.
1826 m_uiomove(struct uio
*uio
)
1828 struct mbuf
*m
; /* current working mbuf */
1829 struct mbuf
*head
= NULL
; /* result mbuf chain */
1830 struct mbuf
**mp
= &head
;
1831 int resid
= uio
->uio_resid
, nsize
, flags
= M_PKTHDR
, error
;
1834 m
= m_getl(resid
, MB_WAIT
, MT_DATA
, flags
, &nsize
);
1836 m
->m_pkthdr
.len
= 0;
1837 /* Leave room for protocol headers. */
1842 m
->m_len
= min(nsize
, resid
);
1843 error
= uiomove(mtod(m
, caddr_t
), m
->m_len
, uio
);
1850 head
->m_pkthdr
.len
+= m
->m_len
;
1852 } while (resid
> 0);
1862 m_last(struct mbuf
*m
)
1870 * Return the number of bytes in an mbuf chain.
1871 * If lastm is not NULL, also return the last mbuf.
1874 m_lengthm(struct mbuf
*m
, struct mbuf
**lastm
)
1877 struct mbuf
*prev
= m
;
1890 * Like m_lengthm(), except also keep track of mbuf usage.
1893 m_countm(struct mbuf
*m
, struct mbuf
**lastm
, u_int
*pmbcnt
)
1895 u_int len
= 0, mbcnt
= 0;
1896 struct mbuf
*prev
= m
;
1901 if (m
->m_flags
& M_EXT
)
1902 mbcnt
+= m
->m_ext
.ext_size
;