2 * Copyright (c) 1982, 1986, 1988, 1993
3 * The Regents of the University of California.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * @(#)mbuf.h 8.5 (Berkeley) 2/19/95
37 /* XXX: These includes suck. Sorry! */
38 #include <sys/queue.h>
40 #include <sys/systm.h>
48 * Mbufs are of a single size, MSIZE (sys/param.h), which includes overhead.
49 * An mbuf may add a single "mbuf cluster" of size MCLBYTES (also in
50 * sys/param.h), which has no additional overhead and is used instead of the
51 * internal data area; this is done when at least MINCLSIZE of data must be
52 * stored. Additionally, it is possible to allocate a separate buffer
53 * externally and attach it to the mbuf in a way similar to that of mbuf
56 #define MLEN (MSIZE - sizeof(struct m_hdr)) /* normal data len */
57 #define MHLEN (MLEN - sizeof(struct pkthdr)) /* data len w/pkthdr */
58 #define MINCLSIZE (MHLEN + 1) /* smallest amount to put in cluster */
59 #define M_MAXCOMPRESS (MHLEN / 2) /* max amount to copy for compression */
63 * Macros for type conversion:
64 * mtod(m, t) -- Convert mbuf pointer to data pointer of correct type.
65 * dtom(x) -- Convert data pointer within mbuf to mbuf pointer (XXX).
67 #define mtod(m, t) ((t)((m)->m_data))
68 #define dtom(x) ((struct mbuf *)((intptr_t)(x) & ~(MSIZE-1)))
71 * Argument structure passed to UMA routines during mbuf and packet
75 int flags; /* Flags for mbuf being allocated */
76 short type; /* Type of mbuf being allocated */
87 * Header present at the beginning of every mbuf.
90 struct mbuf *mh_next; /* next buffer in chain */
91 struct mbuf *mh_nextpkt; /* next chain in queue/record */
92 caddr_t mh_data; /* location of data */
93 int mh_len; /* amount of data in this mbuf */
94 int mh_flags; /* flags; see below */
95 short mh_type; /* type of data in this mbuf */
96 uint8_t pad[M_HDR_PAD];/* word align */
100 * Packet tag structure (see below for details).
103 SLIST_ENTRY(m_tag) m_tag_link; /* List of packet tags */
104 u_int16_t m_tag_id; /* Tag ID */
105 u_int16_t m_tag_len; /* Length of data */
106 u_int32_t m_tag_cookie; /* ABI/Module ID */
107 void (*m_tag_free)(struct m_tag *);
111 * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
114 struct ifnet *rcvif; /* rcv interface */
115 /* variables for ip and tcp reassembly */
116 void *header; /* pointer to packet header */
117 int len; /* total packet length */
118 /* variables for hardware checksum */
119 int csum_flags; /* flags regarding checksum */
120 int csum_data; /* data field used by csum routines */
121 u_int16_t tso_segsz; /* TSO segment size */
122 u_int16_t ether_vtag; /* Ethernet 802.1p+q vlan tag */
123 SLIST_HEAD(packet_tags, m_tag) tags; /* list of packet tags */
127 * Description of external storage mapped into mbuf; valid only if M_EXT is
131 caddr_t ext_buf; /* start of buffer */
132 void (*ext_free) /* free routine if not the usual */
134 void *ext_args; /* optional argument pointer */
135 u_int ext_size; /* size of buffer, for ext_free */
136 volatile u_int *ref_cnt; /* pointer to ref count info */
137 int ext_type; /* type of external storage */
141 * The core of the mbuf object along with some shortcut defines for practical
148 struct pkthdr MH_pkthdr; /* M_PKTHDR set */
150 struct m_ext MH_ext; /* M_EXT set */
151 char MH_databuf[MHLEN];
154 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */
157 #define m_next m_hdr.mh_next
158 #define m_len m_hdr.mh_len
159 #define m_data m_hdr.mh_data
160 #define m_type m_hdr.mh_type
161 #define m_flags m_hdr.mh_flags
162 #define m_nextpkt m_hdr.mh_nextpkt
163 #define m_act m_nextpkt
164 #define m_pkthdr M_dat.MH.MH_pkthdr
165 #define m_ext M_dat.MH.MH_dat.MH_ext
166 #define m_pktdat M_dat.MH.MH_dat.MH_databuf
167 #define m_dat M_dat.M_databuf
172 #define M_EXT 0x0001 /* has associated external storage */
173 #define M_PKTHDR 0x0002 /* start of record */
174 #define M_EOR 0x0004 /* end of record */
175 #define M_RDONLY 0x0008 /* associated data is marked read-only */
176 #define M_PROTO1 0x0010 /* protocol-specific */
177 #define M_PROTO2 0x0020 /* protocol-specific */
178 #define M_PROTO3 0x0040 /* protocol-specific */
179 #define M_PROTO4 0x0080 /* protocol-specific */
180 #define M_PROTO5 0x0100 /* protocol-specific */
181 #define M_NOTIFICATION 0x2000 /* SCTP notification */
182 #define M_SKIP_FIREWALL 0x4000 /* skip firewall processing */
183 #define M_FREELIST 0x8000 /* mbuf is on the free list */
186 * mbuf pkthdr flags (also stored in m_flags).
188 #define M_BCAST 0x0200 /* send/received as link-level broadcast */
189 #define M_MCAST 0x0400 /* send/received as link-level multicast */
190 #define M_FRAG 0x0800 /* packet is a fragment of a larger packet */
191 #define M_FIRSTFRAG 0x1000 /* packet is first fragment */
192 #define M_LASTFRAG 0x2000 /* packet is last fragment */
193 #define M_VLANTAG 0x10000 /* ether_vtag is valid */
194 #define M_PROMISC 0x20000 /* packet was not for us */
197 * External buffer types: identify ext_buf type.
199 #define EXT_CLUSTER 1 /* mbuf cluster */
200 #define EXT_SFBUF 2 /* sendfile(2)'s sf_bufs */
201 #define EXT_JUMBOP 3 /* jumbo cluster 4096 bytes */
202 #define EXT_JUMBO9 4 /* jumbo cluster 9216 bytes */
203 #define EXT_JUMBO16 5 /* jumbo cluster 16184 bytes */
204 #define EXT_PACKET 6 /* mbuf+cluster from packet zone */
205 #define EXT_MBUF 7 /* external mbuf reference (M_IOVEC) */
206 #define EXT_NET_DRV 100 /* custom ext_buf provided by net driver(s) */
207 #define EXT_MOD_TYPE 200 /* custom module's ext_buf type */
208 #define EXT_DISPOSABLE 300 /* can throw this buffer away w/page flipping */
209 #define EXT_EXTREF 400 /* has externally maintained ref_cnt ptr */
212 * Flags copied when copying m_pkthdr.
214 #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_RDONLY|M_PROTO1|M_PROTO1|M_PROTO2|\
215 M_PROTO3|M_PROTO4|M_PROTO5|M_SKIP_FIREWALL|\
216 M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG|\
220 * Flags to purge when crossing layers.
222 #define M_PROTOFLAGS (M_PROTO1|M_PROTO2|M_PROTO3|M_PROTO4|M_PROTO5)
225 * Flags indicating hw checksum support and sw checksum requirements. This
226 * field can be directly tested against if_data.ifi_hwassist.
228 #define CSUM_IP 0x0001 /* will csum IP */
229 #define CSUM_TCP 0x0002 /* will csum TCP */
230 #define CSUM_UDP 0x0004 /* will csum UDP */
231 #define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */
232 #define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */
233 #define CSUM_TSO 0x0020 /* will do TSO */
235 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */
236 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */
237 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */
238 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */
240 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP)
241 #define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */
246 #define MT_NOTMBUF 0 /* USED INTERNALLY ONLY! Object is not mbuf */
247 #define MT_DATA 1 /* dynamic (data) allocation */
248 #define MT_HEADER MT_DATA /* packet header, use M_PKTHDR instead */
249 #define MT_SONAME 8 /* socket name */
250 #define MT_CONTROL 14 /* extra-data protocol message */
251 #define MT_OOBDATA 15 /* expedited data */
252 #define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */
254 #define MT_NOINIT 255 /* Not a type but a flag to allocate
255 a non-initialized mbuf */
258 * General mbuf allocator statistics structure.
260 * Many of these statistics are no longer used; we instead track many
261 * allocator statistics through UMA's built in statistics mechanism.
264 u_long m_mbufs; /* XXX */
265 u_long m_mclusts; /* XXX */
267 u_long m_drain; /* times drained protocols for space */
268 u_long m_mcfail; /* XXX: times m_copym failed */
269 u_long m_mpfail; /* XXX: times m_pullup failed */
270 u_long m_msize; /* length of an mbuf */
271 u_long m_mclbytes; /* length of an mbuf cluster */
272 u_long m_minclsize; /* min length of data to allocate a cluster */
273 u_long m_mlen; /* length of data in an mbuf */
274 u_long m_mhlen; /* length of data in a header mbuf */
276 /* Number of mbtypes (gives # elems in mbtypes[] array: */
279 /* XXX: Sendfile stats should eventually move to their own struct */
280 u_long sf_iocnt; /* times sendfile had to do disk I/O */
281 u_long sf_allocfail; /* times sfbuf allocation failed */
282 u_long sf_allocwait; /* times sfbuf allocation had to wait */
286 * Flags specifying how an allocation should be made.
288 * The flag to use is as follows:
289 * - M_DONTWAIT or M_NOWAIT from an interrupt handler to not block allocation.
290 * - M_WAIT or M_WAITOK or M_TRYWAIT from wherever it is safe to block.
292 * M_DONTWAIT/M_NOWAIT means that we will not block the thread explicitly and
293 * if we cannot allocate immediately we may return NULL, whereas
294 * M_WAIT/M_WAITOK/M_TRYWAIT means that if we cannot allocate resources we
295 * will block until they are available, and thus never return NULL.
297 * XXX Eventually just phase this out to use M_WAITOK/M_NOWAIT.
299 #define MBTOM(how) (how)
300 #define M_DONTWAIT M_NOWAIT
301 #define M_TRYWAIT M_WAITOK
302 #define M_WAIT M_WAITOK
305 * String names of mbuf-related UMA(9) and malloc(9) types. Exposed to
306 * !_KERNEL so that monitoring tools can look up the zones with
309 #define MBUF_MEM_NAME "mbuf"
310 #define MBUF_CLUSTER_MEM_NAME "mbuf_cluster"
311 #define MBUF_PACKET_MEM_NAME "mbuf_packet"
312 #define MBUF_JUMBOP_MEM_NAME "mbuf_jumbo_pagesize"
313 #define MBUF_JUMBO9_MEM_NAME "mbuf_jumbo_9k"
314 #define MBUF_JUMBO16_MEM_NAME "mbuf_jumbo_16k"
315 #define MBUF_TAG_MEM_NAME "mbuf_tag"
316 #define MBUF_EXTREFCNT_MEM_NAME "mbuf_ext_refcnt"
321 #define MBUF_CHECKSLEEP(how) do { \
322 if (how == M_WAITOK) \
323 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, \
324 "Sleeping in \"%s\"", __func__); \
327 #define MBUF_CHECKSLEEP(how)
331 * Network buffer allocation API
333 * The rest of it is defined in kern/kern_mbuf.c
336 extern uma_zone_t zone_mbuf;
337 extern uma_zone_t zone_clust;
338 extern uma_zone_t zone_pack;
339 extern uma_zone_t zone_jumbop;
340 extern uma_zone_t zone_jumbo9;
341 extern uma_zone_t zone_jumbo16;
342 extern uma_zone_t zone_ext_refcnt;
344 static __inline struct mbuf *m_getcl(int how, short type, int flags);
345 static __inline struct mbuf *m_get(int how, short type);
346 static __inline struct mbuf *m_gethdr(int how, short type);
347 static __inline struct mbuf *m_getjcl(int how, short type, int flags,
349 static __inline struct mbuf *m_getclr(int how, short type); /* XXX */
350 static __inline struct mbuf *m_free(struct mbuf *m);
351 static __inline void m_clget(struct mbuf *m, int how);
352 static __inline void *m_cljget(struct mbuf *m, int how, int size);
353 static __inline void m_chtype(struct mbuf *m, short new_type);
354 void mb_free_ext(struct mbuf *);
355 static __inline struct mbuf *m_last(struct mbuf *m);
369 #if MJUMPAGESIZE != MCLBYTES
381 panic("%s: m_getjcl: invalid cluster size", __func__);
387 static __inline uma_zone_t
399 #if MJUMPAGESIZE != MCLBYTES
411 panic("%s: m_getjcl: invalid cluster type", __func__);
417 static __inline struct mbuf *
418 m_get(int how, short type)
424 return ((struct mbuf *)(uma_zalloc_arg(zone_mbuf, &args, how)));
428 * XXX This should be deprecated, very little use.
430 static __inline struct mbuf *
431 m_getclr(int how, short type)
438 m = uma_zalloc_arg(zone_mbuf, &args, how);
440 bzero(m->m_data, MLEN);
444 static __inline struct mbuf *
445 m_gethdr(int how, short type)
449 args.flags = M_PKTHDR;
451 return ((struct mbuf *)(uma_zalloc_arg(zone_mbuf, &args, how)));
454 static __inline struct mbuf *
455 m_getcl(int how, short type, int flags)
461 return ((struct mbuf *)(uma_zalloc_arg(zone_pack, &args, how)));
465 * m_getjcl() returns an mbuf with a cluster of the specified size attached.
466 * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES.
468 * XXX: This is rather large, should be real function maybe.
470 static __inline struct mbuf *
471 m_getjcl(int how, short type, int flags, int size)
480 m = uma_zalloc_arg(zone_mbuf, &args, how);
484 zone = m_getzone(size);
485 n = uma_zalloc_arg(zone, m, how);
487 uma_zfree(zone_mbuf, m);
493 static __inline struct mbuf *
494 m_free(struct mbuf *m)
496 struct mbuf *n = m->m_next;
498 if (m->m_flags & M_EXT)
501 uma_zfree(zone_mbuf, m);
506 m_clget(struct mbuf *m, int how)
509 if (m->m_flags & M_EXT)
510 printf("%s: %p mbuf already has cluster\n", __func__, m);
511 m->m_ext.ext_buf = (char *)NULL;
512 uma_zalloc_arg(zone_clust, m, how);
514 * On a cluster allocation failure, drain the packet zone and retry,
515 * we might be able to loosen a few clusters up on the drain.
517 if ((how & M_NOWAIT) && (m->m_ext.ext_buf == NULL)) {
518 zone_drain(zone_pack);
519 uma_zalloc_arg(zone_clust, m, how);
524 * m_cljget() is different from m_clget() as it can allocate clusters without
525 * attaching them to an mbuf. In that case the return value is the pointer
526 * to the cluster of the requested size. If an mbuf was specified, it gets
527 * the cluster attached to it and the return value can be safely ignored.
528 * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES.
530 static __inline void *
531 m_cljget(struct mbuf *m, int how, int size)
535 if (m && m->m_flags & M_EXT)
536 printf("%s: %p mbuf already has cluster\n", __func__, m);
538 m->m_ext.ext_buf = NULL;
540 zone = m_getzone(size);
541 return (uma_zalloc_arg(zone, m, how));
545 m_cljset(struct mbuf *m, void *cl, int type)
555 #if MJUMPAGESIZE != MCLBYTES
570 panic("unknown cluster type");
574 m->m_data = m->m_ext.ext_buf = cl;
575 m->m_ext.ext_free = m->m_ext.ext_args = NULL;
576 m->m_ext.ext_size = size;
577 m->m_ext.ext_type = type;
578 m->m_ext.ref_cnt = uma_find_refcnt(zone, cl);
584 m_chtype(struct mbuf *m, short new_type)
587 m->m_type = new_type;
590 static __inline struct mbuf *
591 m_last(struct mbuf *m)
600 * mbuf, cluster, and external object allocation macros (for compatibility
603 #define M_MOVE_PKTHDR(to, from) m_move_pkthdr((to), (from))
604 #define MGET(m, how, type) ((m) = m_get((how), (type)))
605 #define MGETHDR(m, how, type) ((m) = m_gethdr((how), (type)))
606 #define MCLGET(m, how) m_clget((m), (how))
607 #define MEXTADD(m, buf, size, free, args, flags, type) \
608 m_extadd((m), (caddr_t)(buf), (size), (free), (args), (flags), (type))
609 #define m_getm(m, len, how, type) \
610 m_getm2((m), (len), (how), (type), M_PKTHDR)
613 * Evaluate TRUE if it's safe to write to the mbuf m's data region (this can
614 * be both the local data payload, or an external buffer area, depending on
615 * whether M_EXT is set).
617 #define M_WRITABLE(m) (!((m)->m_flags & M_RDONLY) && \
618 (!(((m)->m_flags & M_EXT)) || \
619 (*((m)->m_ext.ref_cnt) == 1)) ) \
621 /* Check if the supplied mbuf has a packet header, or else panic. */
622 #define M_ASSERTPKTHDR(m) \
623 KASSERT(m != NULL && m->m_flags & M_PKTHDR, \
624 ("%s: no mbuf packet header!", __func__))
627 * Ensure that the supplied mbuf is a valid, non-free mbuf.
629 * XXX: Broken at the moment. Need some UMA magic to make it work again.
631 #define M_ASSERTVALID(m) \
632 KASSERT((((struct mbuf *)m)->m_flags & 0) == 0, \
633 ("%s: attempted use of a free mbuf!", __func__))
636 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place an
637 * object of the specified size at the end of the mbuf, longword aligned.
639 #define M_ALIGN(m, len) do { \
640 KASSERT(!((m)->m_flags & (M_PKTHDR|M_EXT)), \
641 ("%s: M_ALIGN not normal mbuf", __func__)); \
642 KASSERT((m)->m_data == (m)->m_dat, \
643 ("%s: M_ALIGN not a virgin mbuf", __func__)); \
644 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \
648 * As above, for mbufs allocated with m_gethdr/MGETHDR or initialized by
651 #define MH_ALIGN(m, len) do { \
652 KASSERT((m)->m_flags & M_PKTHDR && !((m)->m_flags & M_EXT), \
653 ("%s: MH_ALIGN not PKTHDR mbuf", __func__)); \
654 KASSERT((m)->m_data == (m)->m_pktdat, \
655 ("%s: MH_ALIGN not a virgin mbuf", __func__)); \
656 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \
660 * Compute the amount of space available before the current start of data in
663 * The M_WRITABLE() is a temporary, conservative safety measure: the burden
664 * of checking writability of the mbuf data area rests solely with the caller.
666 #define M_LEADINGSPACE(m) \
667 ((m)->m_flags & M_EXT ? \
668 (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \
669 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \
670 (m)->m_data - (m)->m_dat)
673 * Compute the amount of space available after the end of data in an mbuf.
675 * The M_WRITABLE() is a temporary, conservative safety measure: the burden
676 * of checking writability of the mbuf data area rests solely with the caller.
678 #define M_TRAILINGSPACE(m) \
679 ((m)->m_flags & M_EXT ? \
680 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \
681 - ((m)->m_data + (m)->m_len) : 0) : \
682 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
685 * Arrange to prepend space of size plen to mbuf m. If a new mbuf must be
686 * allocated, how specifies whether to wait. If the allocation fails, the
687 * original mbuf chain is freed and m is set to NULL.
689 #define M_PREPEND(m, plen, how) do { \
690 struct mbuf **_mmp = &(m); \
691 struct mbuf *_mm = *_mmp; \
692 int _mplen = (plen); \
693 int __mhow = (how); \
695 MBUF_CHECKSLEEP(how); \
696 if (M_LEADINGSPACE(_mm) >= _mplen) { \
697 _mm->m_data -= _mplen; \
698 _mm->m_len += _mplen; \
700 _mm = m_prepend(_mm, _mplen, __mhow); \
701 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \
702 _mm->m_pkthdr.len += _mplen; \
707 * Change mbuf to new type. This is a relatively expensive operation and
710 #define MCHTYPE(m, t) m_chtype((m), (t))
712 /* Length to m_copy to copy all. */
713 #define M_COPYALL 1000000000
715 /* Compatibility with 4.3. */
716 #define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT)
718 extern int max_datalen; /* MHLEN - max_hdr */
719 extern int max_hdr; /* Largest link + protocol header */
720 extern int max_linkhdr; /* Largest link-level header */
721 extern int max_protohdr; /* Largest protocol header */
722 extern struct mbstat mbstat; /* General mbuf stats/infos */
723 extern int nmbclusters; /* Maximum number of clusters */
727 void m_adj(struct mbuf *, int);
728 void m_align(struct mbuf *, int);
729 int m_apply(struct mbuf *, int, int,
730 int (*)(void *, void *, u_int), void *);
731 int m_append(struct mbuf *, int, c_caddr_t);
732 void m_cat(struct mbuf *, struct mbuf *);
733 void m_extadd(struct mbuf *, caddr_t, u_int,
734 void (*)(void *, void *), void *, int, int);
735 void m_copyback(struct mbuf *, int, int, c_caddr_t);
736 void m_copydata(const struct mbuf *, int, int, caddr_t);
737 struct mbuf *m_copym(struct mbuf *, int, int, int);
738 struct mbuf *m_copymdata(struct mbuf *, struct mbuf *,
740 struct mbuf *m_copypacket(struct mbuf *, int);
741 void m_copy_pkthdr(struct mbuf *, struct mbuf *);
742 struct mbuf *m_copyup(struct mbuf *n, int len, int dstoff);
743 struct mbuf *m_defrag(struct mbuf *, int);
744 void m_demote(struct mbuf *, int);
745 struct mbuf *m_devget(char *, int, int, struct ifnet *,
746 void (*)(char *, caddr_t, u_int));
747 struct mbuf *m_dup(struct mbuf *, int);
748 int m_dup_pkthdr(struct mbuf *, struct mbuf *, int);
749 u_int m_fixhdr(struct mbuf *);
750 struct mbuf *m_fragment(struct mbuf *, int, int);
751 void m_freem(struct mbuf *);
752 struct mbuf *m_getm2(struct mbuf *, int, int, short, int);
753 struct mbuf *m_getptr(struct mbuf *, int, int *);
754 u_int m_length(struct mbuf *, struct mbuf **);
755 void m_move_pkthdr(struct mbuf *, struct mbuf *);
756 struct mbuf *m_prepend(struct mbuf *, int, int);
757 void m_print(const struct mbuf *, int);
758 struct mbuf *m_pulldown(struct mbuf *, int, int, int *);
759 struct mbuf *m_pullup(struct mbuf *, int);
760 int m_sanity(struct mbuf *, int);
761 struct mbuf *m_split(struct mbuf *, int, int);
762 struct mbuf *m_uiotombuf(struct uio *, int, int, int, int);
763 struct mbuf *m_unshare(struct mbuf *, int how);
766 * Network packets may have annotations attached by affixing a list of
767 * "packet tags" to the pkthdr structure. Packet tags are dynamically
768 * allocated semi-opaque data structures that have a fixed header
769 * (struct m_tag) that specifies the size of the memory block and a
770 * <cookie,type> pair that identifies it. The cookie is a 32-bit unique
771 * unsigned value used to identify a module or ABI. By convention this value
772 * is chosen as the date+time that the module is created, expressed as the
773 * number of seconds since the epoch (e.g., using date -u +'%s'). The type
774 * value is an ABI/module-specific value that identifies a particular
775 * annotation and is private to the module. For compatibility with systems
776 * like OpenBSD that define packet tags w/o an ABI/module cookie, the value
777 * PACKET_ABI_COMPAT is used to implement m_tag_get and m_tag_find
778 * compatibility shim functions and several tag types are defined below.
779 * Users that do not require compatibility should use a private cookie value
780 * so that packet tag-related definitions can be maintained privately.
782 * Note that the packet tag returned by m_tag_alloc has the default memory
783 * alignment implemented by malloc. To reference private data one can use a
786 * struct m_tag *mtag = m_tag_alloc(...);
787 * struct foo *p = (struct foo *)(mtag+1);
789 * if the alignment of struct m_tag is sufficient for referencing members of
790 * struct foo. Otherwise it is necessary to embed struct m_tag within the
791 * private data structure to insure proper alignment; e.g.,
797 * struct foo *p = (struct foo *) m_tag_alloc(...);
798 * struct m_tag *mtag = &p->tag;
802 * Persistent tags stay with an mbuf until the mbuf is reclaimed. Otherwise
803 * tags are expected to ``vanish'' when they pass through a network
804 * interface. For most interfaces this happens normally as the tags are
805 * reclaimed when the mbuf is free'd. However in some special cases
806 * reclaiming must be done manually. An example is packets that pass through
807 * the loopback interface. Also, one must be careful to do this when
808 * ``turning around'' packets (e.g., icmp_reflect).
810 * To mark a tag persistent bit-or this flag in when defining the tag id.
811 * The tag will then be treated as described above.
813 #define MTAG_PERSISTENT 0x800
815 #define PACKET_TAG_NONE 0 /* Nadda */
817 /* Packet tags for use with PACKET_ABI_COMPAT. */
818 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */
819 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */
820 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */
821 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */
822 #define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO 5 /* NIC notifies IPsec */
823 #define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */
824 #define PACKET_TAG_BRIDGE 7 /* Bridge processing done */
825 #define PACKET_TAG_GIF 8 /* GIF processing done */
826 #define PACKET_TAG_GRE 9 /* GRE processing done */
827 #define PACKET_TAG_IN_PACKET_CHECKSUM 10 /* NIC checksumming done */
828 #define PACKET_TAG_ENCAP 11 /* Encap. processing */
829 #define PACKET_TAG_IPSEC_SOCKET 12 /* IPSEC socket ref */
830 #define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */
831 #define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */
832 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */
833 #define PACKET_TAG_DIVERT 17 /* divert info */
834 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */
835 #define PACKET_TAG_MACLABEL (19 | MTAG_PERSISTENT) /* MAC label */
836 #define PACKET_TAG_PF 21 /* PF + ALTQ information */
837 #define PACKET_TAG_RTSOCKFAM 25 /* rtsock sa family */
838 #define PACKET_TAG_IPOPTIONS 27 /* Saved IP options */
839 #define PACKET_TAG_CARP 28 /* CARP info */
841 /* Specific cookies and tags. */
843 /* Packet tag routines. */
844 struct m_tag *m_tag_alloc(u_int32_t, int, int, int);
845 void m_tag_delete(struct mbuf *, struct m_tag *);
846 void m_tag_delete_chain(struct mbuf *, struct m_tag *);
847 void m_tag_free_default(struct m_tag *);
848 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *);
849 struct m_tag *m_tag_copy(struct m_tag *, int);
850 int m_tag_copy_chain(struct mbuf *, struct mbuf *, int);
851 void m_tag_delete_nonpersistent(struct mbuf *);
854 * Initialize the list of tags associated with an mbuf.
857 m_tag_init(struct mbuf *m)
860 SLIST_INIT(&m->m_pkthdr.tags);
864 * Set up the contents of a tag. Note that this does not fill in the free
865 * method; the caller is expected to do that.
867 * XXX probably should be called m_tag_init, but that was already taken.
870 m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len)
875 t->m_tag_cookie = cookie;
879 * Reclaim resources associated with a tag.
882 m_tag_free(struct m_tag *t)
889 * Return the first tag associated with an mbuf.
891 static __inline struct m_tag *
892 m_tag_first(struct mbuf *m)
895 return (SLIST_FIRST(&m->m_pkthdr.tags));
899 * Return the next tag in the list of tags associated with an mbuf.
901 static __inline struct m_tag *
902 m_tag_next(struct mbuf *m, struct m_tag *t)
905 return (SLIST_NEXT(t, m_tag_link));
909 * Prepend a tag to the list of tags associated with an mbuf.
912 m_tag_prepend(struct mbuf *m, struct m_tag *t)
915 SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link);
919 * Unlink a tag from the list of tags associated with an mbuf.
922 m_tag_unlink(struct mbuf *m, struct m_tag *t)
925 SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link);
928 /* These are for OpenBSD compatibility. */
929 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */
931 static __inline struct m_tag *
932 m_tag_get(int type, int length, int wait)
934 return (m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait));
937 static __inline struct m_tag *
938 m_tag_find(struct mbuf *m, int type, struct m_tag *start)
940 return (SLIST_EMPTY(&m->m_pkthdr.tags) ? (struct m_tag *)NULL :
941 m_tag_locate(m, MTAG_ABI_COMPAT, type, start));
946 #endif /* !_SYS_MBUF_H_ */