2 * Copyright (c) 1982, 1986, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * @(#)mbuf.h 8.5 (Berkeley) 2/19/95
34 * $FreeBSD: src/sys/sys/mbuf.h,v 1.44.2.17 2003/04/15 06:15:02 silby Exp $
40 #include <sys/queue.h>
43 * Mbufs are of a single size, MSIZE (machine/param.h), which
44 * includes overhead. An mbuf may add a single "mbuf cluster" of size
45 * MCLBYTES (also in machine/param.h), which has no additional overhead
46 * and is used instead of the internal data area; this is done when
47 * at least MINCLSIZE of data must be stored.
49 #define MLEN (MSIZE - sizeof(struct m_hdr)) /* normal data len */
50 #define MHLEN (MLEN - sizeof(struct pkthdr)) /* data len w/pkthdr */
51 #define MINCLSIZE (MHLEN + 1) /* smallest amount to put in cluster */
52 #define M_MAXCOMPRESS (MHLEN / 2) /* max amount to copy for compression */
55 * Macros for type conversion:
56 * mtod(m, t) -- Convert mbuf pointer to data pointer of correct type.
57 * dtom(x) -- Convert data pointer within mbuf to mbuf pointer (XXX).
58 * mtocl(x) - convert pointer within cluster to cluster index #
59 * cltom(x) - convert cluster # to ptr to beginning of cluster
61 #define mtod(m, t) ((t)((m)->m_data))
62 #define dtom(x) ((struct mbuf *)((intptr_t)(x) & ~(MSIZE-1)))
63 #define mtocl(x) (((uintptr_t)(x) - (uintptr_t)mbutl) >> MCLSHIFT)
64 #define cltom(x) ((caddr_t)((uintptr_t)mbutl + \
65 ((uintptr_t)(x) << MCLSHIFT)))
68 * Header present at the beginning of every mbuf.
71 struct mbuf *mh_next; /* next buffer in chain */
72 struct mbuf *mh_nextpkt; /* next chain in queue/record */
73 caddr_t mh_data; /* location of data */
74 int mh_len; /* amount of data in this mbuf */
75 short mh_type; /* type of data in this mbuf */
76 short mh_flags; /* flags; see below */
80 * Packet tag structure (see below for details).
83 SLIST_ENTRY(m_tag) m_tag_link; /* List of packet tags */
84 u_int16_t m_tag_id; /* Tag ID */
85 u_int16_t m_tag_len; /* Length of data */
86 u_int32_t m_tag_cookie; /* ABI/Module ID */
90 * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
93 struct ifnet *rcvif; /* rcv interface */
94 int len; /* total packet length */
95 /* variables for ip and tcp reassembly */
96 void *header; /* pointer to packet header */
97 /* variables for hardware checksum */
98 int csum_flags; /* flags regarding checksum */
99 int csum_data; /* data field used by csum routines */
100 SLIST_HEAD(packet_tags, m_tag) tags; /* list of packet tags */
104 * Description of external storage mapped into mbuf; valid only if M_EXT is set.
107 caddr_t ext_buf; /* start of buffer */
108 void (*ext_free) /* free routine if not the usual */
110 u_int ext_size; /* size of buffer, for ext_free */
111 void (*ext_ref) /* add a reference to the ext object */
116 * The core of the mbuf object along with some shortcut defines for
117 * practical purposes.
123 struct pkthdr MH_pkthdr; /* M_PKTHDR set */
125 struct m_ext MH_ext; /* M_EXT set */
126 char MH_databuf[MHLEN];
129 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */
132 #define m_next m_hdr.mh_next
133 #define m_len m_hdr.mh_len
134 #define m_data m_hdr.mh_data
135 #define m_type m_hdr.mh_type
136 #define m_flags m_hdr.mh_flags
137 #define m_nextpkt m_hdr.mh_nextpkt
138 #define m_act m_nextpkt
139 #define m_pkthdr M_dat.MH.MH_pkthdr
140 #define m_ext M_dat.MH.MH_dat.MH_ext
141 #define m_pktdat M_dat.MH.MH_dat.MH_databuf
142 #define m_dat M_dat.M_databuf
147 #define M_EXT 0x0001 /* has associated external storage */
148 #define M_PKTHDR 0x0002 /* start of record */
149 #define M_EOR 0x0004 /* end of record */
150 #define M_PROTO1 0x0008 /* protocol-specific */
151 #define M_PROTO2 0x0010 /* protocol-specific */
152 #define M_PROTO3 0x0020 /* protocol-specific */
153 #define M_PROTO4 0x0040 /* protocol-specific */
154 #define M_PROTO5 0x0080 /* protocol-specific */
157 * mbuf pkthdr flags (also stored in m_flags).
159 #define M_BCAST 0x0100 /* send/received as link-level broadcast */
160 #define M_MCAST 0x0200 /* send/received as link-level multicast */
161 #define M_FRAG 0x0400 /* packet is a fragment of a larger packet */
162 #define M_FIRSTFRAG 0x0800 /* packet is first fragment */
163 #define M_LASTFRAG 0x1000 /* packet is last fragment */
166 * Flags copied when copying m_pkthdr.
168 #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_PROTO1|M_PROTO1|M_PROTO2|M_PROTO3 | \
169 M_PROTO4|M_PROTO5|M_BCAST|M_MCAST|M_FRAG | \
170 M_FIRSTFRAG|M_LASTFRAG)
173 * Flags indicating hw checksum support and sw checksum requirements.
175 #define CSUM_IP 0x0001 /* will csum IP */
176 #define CSUM_TCP 0x0002 /* will csum TCP */
177 #define CSUM_UDP 0x0004 /* will csum UDP */
178 #define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */
179 #define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */
181 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */
182 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */
183 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */
184 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */
186 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP)
187 #define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */
192 #define MT_FREE 0 /* should be on free list */
193 #define MT_DATA 1 /* dynamic (data) allocation */
194 #define MT_HEADER 2 /* packet header */
196 #define MT_SOCKET 3 /* socket structure */
197 #define MT_PCB 4 /* protocol control block */
198 #define MT_RTABLE 5 /* routing tables */
199 #define MT_HTABLE 6 /* IMP host tables */
200 #define MT_ATABLE 7 /* address resolution tables */
202 #define MT_SONAME 8 /* socket name */
204 #define MT_SOOPTS 10 /* socket options */
206 #define MT_FTABLE 11 /* fragment reassembly header */
208 #define MT_RIGHTS 12 /* access rights */
209 #define MT_IFADDR 13 /* interface address */
211 #define MT_TAG 13 /* volatile metadata associated to pkts */
212 #define MT_CONTROL 14 /* extra-data protocol message */
213 #define MT_OOBDATA 15 /* expedited data */
214 #define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */
217 * General mbuf allocator statistics structure.
220 u_long m_mbufs; /* mbufs obtained from page pool */
221 u_long m_clusters; /* clusters obtained from page pool */
222 u_long m_spare; /* spare field */
223 u_long m_clfree; /* free clusters */
224 u_long m_drops; /* times failed to find space */
225 u_long m_wait; /* times waited for space */
226 u_long m_drain; /* times drained protocols for space */
227 u_long m_mcfail; /* times m_copym failed */
228 u_long m_mpfail; /* times m_pullup failed */
229 u_long m_msize; /* length of an mbuf */
230 u_long m_mclbytes; /* length of an mbuf cluster */
231 u_long m_minclsize; /* min length of data to allocate a cluster */
232 u_long m_mlen; /* length of data in an mbuf */
233 u_long m_mhlen; /* length of data in a header mbuf */
237 * Flags specifying how an allocation should be made.
245 * Normal mbuf clusters are normally treated as character arrays
246 * after allocation, but use the first word of the buffer as a free list
247 * pointer while on the free list.
250 union mcluster *mcl_next;
251 char mcl_buf[MCLBYTES];
256 * These are identifying numbers passed to the m_mballoc_wait function,
257 * allowing us to determine whether the call came from an MGETHDR or
264 * Wake up the next instance (if any) of m_mballoc_wait() which is
265 * waiting for an mbuf to be freed. This should be called at splimp().
267 * XXX: If there is another free mbuf, this routine will be called [again]
268 * from the m_mballoc_wait routine in order to wake another sleep instance.
270 #define MMBWAKEUP() do { \
271 if (m_mballoc_wid) { \
273 wakeup_one(&m_mballoc_wid); \
278 * Same as above, but for mbuf cluster(s).
280 #define MCLWAKEUP() do { \
281 if (m_clalloc_wid) { \
283 wakeup_one(&m_clalloc_wid); \
288 * mbuf utility macros:
291 * prevents a section of code from from being interrupted by network
294 #define MBUFLOCK(code) do { \
295 int _ms = splimp(); \
302 * mbuf allocation/deallocation macros:
304 * MGET(struct mbuf *m, int how, int type)
305 * allocates an mbuf and initializes it to contain internal data.
307 * MGETHDR(struct mbuf *m, int how, int type)
308 * allocates an mbuf and initializes it to contain a packet header
311 #define MGET(m, how, type) do { \
314 int _mtype = (type); \
315 int _ms = splimp(); \
317 if (mmbfree == NULL) \
318 (void)m_mballoc(1, _mhow); \
321 mmbfree = _mm->m_next; \
322 mbtypes[MT_FREE]--; \
323 _mm->m_type = _mtype; \
325 _mm->m_next = NULL; \
326 _mm->m_nextpkt = NULL; \
327 _mm->m_data = _mm->m_dat; \
333 _mm = m_retry(_mhow, _mtype); \
334 if (_mm == NULL && _mhow == M_WAIT) \
335 (m) = m_mballoc_wait(MGET_C, _mtype); \
341 #define MGETHDR(m, how, type) do { \
344 int _mtype = (type); \
345 int _ms = splimp(); \
347 if (mmbfree == NULL) \
348 (void)m_mballoc(1, _mhow); \
351 mmbfree = _mm->m_next; \
352 mbtypes[MT_FREE]--; \
353 _mm->m_type = _mtype; \
355 _mm->m_next = NULL; \
356 _mm->m_nextpkt = NULL; \
357 _mm->m_data = _mm->m_pktdat; \
358 _mm->m_flags = M_PKTHDR; \
359 _mm->m_pkthdr.rcvif = NULL; \
360 SLIST_INIT(&_mm->m_pkthdr.tags); \
361 _mm->m_pkthdr.csum_flags = 0; \
366 _mm = m_retryhdr(_mhow, _mtype); \
367 if (_mm == NULL && _mhow == M_WAIT) \
368 (m) = m_mballoc_wait(MGETHDR_C, _mtype); \
375 * Mbuf cluster macros.
376 * MCLALLOC(caddr_t p, int how) allocates an mbuf cluster.
377 * MCLGET adds such clusters to a normal mbuf;
378 * the flag M_EXT is set upon success.
379 * MCLFREE releases a reference to a cluster allocated by MCLALLOC,
380 * freeing the cluster if the reference count has reached 0.
382 #define MCLALLOC(p, how) do { \
385 int _ms = splimp(); \
387 if (mclfree == NULL) \
388 (void)m_clalloc(1, _mhow); \
389 _mp = (caddr_t)mclfree; \
391 mclrefcnt[mtocl(_mp)]++; \
393 mclfree = ((union mcluster *)_mp)->mcl_next; \
398 if (_mhow == M_WAIT) \
399 (p) = m_clalloc_wait(); \
405 #define MCLGET(m, how) do { \
406 struct mbuf *_mm = (m); \
408 MCLALLOC(_mm->m_ext.ext_buf, (how)); \
409 if (_mm->m_ext.ext_buf != NULL) { \
410 _mm->m_data = _mm->m_ext.ext_buf; \
411 _mm->m_flags |= M_EXT; \
412 _mm->m_ext.ext_free = NULL; \
413 _mm->m_ext.ext_ref = NULL; \
414 _mm->m_ext.ext_size = MCLBYTES; \
418 #define MCLFREE1(p) do { \
419 union mcluster *_mp = (union mcluster *)(p); \
421 KASSERT(mclrefcnt[mtocl(_mp)] > 0, ("freeing free cluster")); \
422 if (--mclrefcnt[mtocl(_mp)] == 0) { \
423 _mp->mcl_next = mclfree; \
430 #define MCLFREE(p) MBUFLOCK( \
434 #define MEXTFREE1(m) do { \
435 struct mbuf *_mm = (m); \
437 if (_mm->m_ext.ext_free != NULL) \
438 (*_mm->m_ext.ext_free)(_mm->m_ext.ext_buf, \
439 _mm->m_ext.ext_size); \
441 MCLFREE1(_mm->m_ext.ext_buf); \
444 #define MEXTFREE(m) MBUFLOCK( \
449 * NB: M_COPY_PKTHDR is deprecated; use either M_MOVE_PKTHDR
453 * Move mbuf pkthdr from "from" to "to".
454 * from should have M_PKTHDR set, and to must be empty.
455 * from no longer has a pkthdr after this operation.
457 #define M_MOVE_PKTHDR(_to, _from) m_move_pkthdr((_to), (_from))
460 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place
461 * an object of the specified size at the end of the mbuf, longword aligned.
463 #define M_ALIGN(m, len) do { \
464 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \
468 * As above, for mbufs allocated with m_gethdr/MGETHDR
469 * or initialized by M_COPY_PKTHDR.
471 #define MH_ALIGN(m, len) do { \
472 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \
476 * Check if we can write to an mbuf.
478 #define M_EXT_WRITABLE(m) \
479 ((m)->m_ext.ext_free == NULL && mclrefcnt[mtocl((m)->m_ext.ext_buf)] == 1)
481 #define M_WRITABLE(m) (!((m)->m_flags & M_EXT) || \
485 * Compute the amount of space available
486 * before the current start of data in an mbuf.
488 * The M_WRITABLE() is a temporary, conservative safety measure: the burden
489 * of checking writability of the mbuf data area rests solely with the caller.
491 #define M_LEADINGSPACE(m) \
492 ((m)->m_flags & M_EXT ? \
493 (M_EXT_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \
494 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \
495 (m)->m_data - (m)->m_dat)
498 * Compute the amount of space available
499 * after the end of data in an mbuf.
501 * The M_WRITABLE() is a temporary, conservative safety measure: the burden
502 * of checking writability of the mbuf data area rests solely with the caller.
504 #define M_TRAILINGSPACE(m) \
505 ((m)->m_flags & M_EXT ? \
506 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \
507 - ((m)->m_data + (m)->m_len) : 0) : \
508 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
511 * Arrange to prepend space of size plen to mbuf m.
512 * If a new mbuf must be allocated, how specifies whether to wait.
513 * If how is M_DONTWAIT and allocation fails, the original mbuf chain
514 * is freed and m is set to NULL.
516 #define M_PREPEND(m, plen, how) do { \
517 struct mbuf **_mmp = &(m); \
518 struct mbuf *_mm = *_mmp; \
519 int _mplen = (plen); \
520 int __mhow = (how); \
522 if (M_LEADINGSPACE(_mm) >= _mplen) { \
523 _mm->m_data -= _mplen; \
524 _mm->m_len += _mplen; \
526 _mm = m_prepend(_mm, _mplen, __mhow); \
527 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \
528 _mm->m_pkthdr.len += _mplen; \
532 /* change mbuf to new type */
533 #define MCHTYPE(m, t) do { \
534 struct mbuf *_mm = (m); \
536 int _ms = splimp(); \
538 mbtypes[_mm->m_type]--; \
541 _mm->m_type = (_mt); \
544 /* Length to m_copy to copy all. */
545 #define M_COPYALL 1000000000
547 /* Compatibility with 4.3 */
548 #define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT)
551 extern u_int m_clalloc_wid; /* mbuf cluster wait count */
552 extern u_int m_mballoc_wid; /* mbuf wait count */
553 extern int max_linkhdr; /* largest link-level header */
554 extern int max_protohdr; /* largest protocol header */
555 extern int max_hdr; /* largest link+protocol header */
556 extern int max_datalen; /* MHLEN - max_hdr */
557 extern struct mbstat mbstat;
558 extern u_long mbtypes[MT_NTYPES]; /* per-type mbuf allocations */
559 extern int mbuf_wait; /* mbuf sleep time */
560 extern struct mbuf *mbutl; /* virtual address of mclusters */
561 extern char *mclrefcnt; /* cluster reference counts */
562 extern union mcluster *mclfree;
563 extern struct mbuf *mmbfree;
564 extern int nmbclusters;
568 void m_adj(struct mbuf *, int);
569 void m_cat(struct mbuf *, struct mbuf *);
570 int m_clalloc(int, int);
571 caddr_t m_clalloc_wait(void);
572 void m_copyback(struct mbuf *, int, int, caddr_t);
573 void m_copydata(struct mbuf *, int, int, caddr_t);
574 struct mbuf *m_copym(struct mbuf *, int, int, int);
575 struct mbuf *m_copypacket(struct mbuf *, int);
576 struct mbuf *m_defrag(struct mbuf *, int);
577 struct mbuf *m_devget(char *, int, int, struct ifnet *,
578 void (*copy)(char *, caddr_t, u_int));
579 struct mbuf *m_dup(struct mbuf *, int);
580 int m_dup_pkthdr(struct mbuf *, struct mbuf *, int);
581 struct mbuf *m_free(struct mbuf *);
582 void m_freem(struct mbuf *);
583 struct mbuf *m_get(int, int);
584 struct mbuf *m_getcl(int how, short type, int flags);
585 struct mbuf *m_getclr(int, int);
586 struct mbuf *m_gethdr(int, int);
587 struct mbuf *m_getm(struct mbuf *, int, int, int);
588 int m_mballoc(int, int);
589 struct mbuf *m_mballoc_wait(int, int);
590 void m_move_pkthdr(struct mbuf *, struct mbuf *);
591 struct mbuf *m_prepend(struct mbuf *, int, int);
592 void m_print(const struct mbuf *m);
593 struct mbuf *m_pulldown(struct mbuf *, int, int, int *);
594 struct mbuf *m_pullup(struct mbuf *, int);
595 struct mbuf *m_retry(int, int);
596 struct mbuf *m_retryhdr(int, int);
597 struct mbuf *m_split(struct mbuf *, int, int);
600 * Packets may have annotations attached by affixing a list
601 * of "packet tags" to the pkthdr structure. Packet tags are
602 * dynamically allocated semi-opaque data structures that have
603 * a fixed header (struct m_tag) that specifies the size of the
604 * memory block and a <cookie,type> pair that identifies it.
605 * The cookie is a 32-bit unique unsigned value used to identify
606 * a module or ABI. By convention this value is chose as the
607 * date+time that the module is created, expressed as the number of
608 * seconds since the epoch (e.g. using date -u +'%s'). The type value
609 * is an ABI/module-specific value that identifies a particular annotation
610 * and is private to the module. For compatibility with systems
611 * like openbsd that define packet tags w/o an ABI/module cookie,
612 * the value PACKET_ABI_COMPAT is used to implement m_tag_get and
613 * m_tag_find compatibility shim functions and several tag types are
614 * defined below. Users that do not require compatibility should use
615 * a private cookie value so that packet tag-related definitions
616 * can be maintained privately.
618 * Note that the packet tag returned by m_tag_allocate has the default
619 * memory alignment implemented by malloc. To reference private data
620 * one can use a construct like:
622 * struct m_tag *mtag = m_tag_allocate(...);
623 * struct foo *p = (struct foo *)(mtag+1);
625 * if the alignment of struct m_tag is sufficient for referencing members
626 * of struct foo. Otherwise it is necessary to embed struct m_tag within
627 * the private data structure to insure proper alignment; e.g.
633 * struct foo *p = (struct foo *) m_tag_allocate(...);
634 * struct m_tag *mtag = &p->tag;
637 #define PACKET_TAG_NONE 0 /* Nadda */
639 /* Packet tag for use with PACKET_ABI_COMPAT */
640 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */
641 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */
642 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */
643 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */
644 #define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO 5 /* NIC notifies IPsec */
645 #define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */
646 #define PACKET_TAG_BRIDGE 7 /* Bridge processing done */
647 #define PACKET_TAG_GIF 8 /* GIF processing done */
648 #define PACKET_TAG_GRE 9 /* GRE processing done */
649 #define PACKET_TAG_IN_PACKET_CHECKSUM 10 /* NIC checksumming done */
650 #define PACKET_TAG_ENCAP 11 /* Encap. processing */
651 #define PACKET_TAG_IPSEC_SOCKET 12 /* IPSEC socket ref */
652 #define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */
653 #define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */
656 * As a temporary and low impact solution to replace the even uglier
657 * approach used so far in some parts of the network stack (which relies
658 * on global variables), packet tag-like annotations are stored in MT_TAG
659 * mbufs (or lookalikes) prepended to the actual mbuf chain.
663 * m_next = next buffer in chain.
665 * BE VERY CAREFUL not to pass these blocks to the mbuf handling routines.
667 #define _m_tag_id m_hdr.mh_flags
669 /* Packet tags used in the FreeBSD network stack */
670 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */
671 #define PACKET_TAG_IPFW 16 /* ipfw classification */
672 #define PACKET_TAG_DIVERT 17 /* divert info */
673 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */
675 /* Packet tag routines */
676 struct m_tag *m_tag_alloc(u_int32_t, int, int, int);
677 void m_tag_free(struct m_tag *);
678 void m_tag_prepend(struct mbuf *, struct m_tag *);
679 void m_tag_unlink(struct mbuf *, struct m_tag *);
680 void m_tag_delete(struct mbuf *, struct m_tag *);
681 void m_tag_delete_chain(struct mbuf *, struct m_tag *);
682 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *);
683 struct m_tag *m_tag_copy(struct m_tag *, int);
684 int m_tag_copy_chain(struct mbuf *, struct mbuf *, int);
685 void m_tag_init(struct mbuf *);
686 struct m_tag *m_tag_first(struct mbuf *);
687 struct m_tag *m_tag_next(struct mbuf *, struct m_tag *);
689 /* these are for openbsd compatibility */
690 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */
692 static __inline struct m_tag *
693 m_tag_get(int type, int length, int wait)
695 return m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait);
698 static __inline struct m_tag *
699 m_tag_find(struct mbuf *m, int type, struct m_tag *start)
701 return m_tag_locate(m, MTAG_ABI_COMPAT, type, start);
705 #endif /* !_SYS_MBUF_H_ */