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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 */
81 * Header present at the beginning of every mbuf.
84 struct mbuf *mh_next; /* next buffer in chain */
85 struct mbuf *mh_nextpkt; /* next chain in queue/record */
86 caddr_t mh_data; /* location of data */
87 int mh_len; /* amount of data in this mbuf */
88 int mh_flags; /* flags; see below */
89 short mh_type; /* type of data in this mbuf */
93 * Packet tag structure (see below for details).
96 SLIST_ENTRY(m_tag) m_tag_link; /* List of packet tags */
97 u_int16_t m_tag_id; /* Tag ID */
98 u_int16_t m_tag_len; /* Length of data */
99 u_int32_t m_tag_cookie; /* ABI/Module ID */
100 void (*m_tag_free)(struct m_tag *);
104 * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
107 struct ifnet *rcvif; /* rcv interface */
108 int len; /* total packet length */
109 /* variables for ip and tcp reassembly */
110 void *header; /* pointer to packet header */
111 /* variables for hardware checksum */
112 int csum_flags; /* flags regarding checksum */
113 int csum_data; /* data field used by csum routines */
114 u_int16_t tso_segsz; /* TSO segment size */
115 u_int16_t ether_vtag; /* Ethernet 802.1p+q vlan tag */
116 SLIST_HEAD(packet_tags, m_tag) tags; /* list of packet tags */
120 * Description of external storage mapped into mbuf; valid only if M_EXT is
124 caddr_t ext_buf; /* start of buffer */
125 void (*ext_free) /* free routine if not the usual */
127 void *ext_args; /* optional argument pointer */
128 u_int ext_size; /* size of buffer, for ext_free */
129 volatile u_int *ref_cnt; /* pointer to ref count info */
130 int ext_type; /* type of external storage */
134 * The core of the mbuf object along with some shortcut defines for practical
141 struct pkthdr MH_pkthdr; /* M_PKTHDR set */
143 struct m_ext MH_ext; /* M_EXT set */
144 char MH_databuf[MHLEN];
147 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */
150 #define m_next m_hdr.mh_next
151 #define m_len m_hdr.mh_len
152 #define m_data m_hdr.mh_data
153 #define m_type m_hdr.mh_type
154 #define m_flags m_hdr.mh_flags
155 #define m_nextpkt m_hdr.mh_nextpkt
156 #define m_act m_nextpkt
157 #define m_pkthdr M_dat.MH.MH_pkthdr
158 #define m_ext M_dat.MH.MH_dat.MH_ext
159 #define m_pktdat M_dat.MH.MH_dat.MH_databuf
160 #define m_dat M_dat.M_databuf
165 #define M_EXT 0x0001 /* has associated external storage */
166 #define M_PKTHDR 0x0002 /* start of record */
167 #define M_EOR 0x0004 /* end of record */
168 #define M_RDONLY 0x0008 /* associated data is marked read-only */
169 #define M_PROTO1 0x0010 /* protocol-specific */
170 #define M_PROTO2 0x0020 /* protocol-specific */
171 #define M_PROTO3 0x0040 /* protocol-specific */
172 #define M_PROTO4 0x0080 /* protocol-specific */
173 #define M_PROTO5 0x0100 /* protocol-specific */
174 #define M_NOTIFICATION 0x2000 /* SCTP notification */
175 #define M_SKIP_FIREWALL 0x4000 /* skip firewall processing */
176 #define M_FREELIST 0x8000 /* mbuf is on the free list */
179 * mbuf pkthdr flags (also stored in m_flags).
181 #define M_BCAST 0x0200 /* send/received as link-level broadcast */
182 #define M_MCAST 0x0400 /* send/received as link-level multicast */
183 #define M_FRAG 0x0800 /* packet is a fragment of a larger packet */
184 #define M_FIRSTFRAG 0x1000 /* packet is first fragment */
185 #define M_LASTFRAG 0x2000 /* packet is last fragment */
186 #define M_VLANTAG 0x10000 /* ether_vtag is valid */
187 #define M_PROMISC 0x20000 /* packet was not for us */
190 * External buffer types: identify ext_buf type.
192 #define EXT_CLUSTER 1 /* mbuf cluster */
193 #define EXT_SFBUF 2 /* sendfile(2)'s sf_bufs */
194 #define EXT_JUMBOP 3 /* jumbo cluster 4096 bytes */
195 #define EXT_JUMBO9 4 /* jumbo cluster 9216 bytes */
196 #define EXT_JUMBO16 5 /* jumbo cluster 16184 bytes */
197 #define EXT_PACKET 6 /* mbuf+cluster from packet zone */
198 #define EXT_MBUF 7 /* external mbuf reference (M_IOVEC) */
199 #define EXT_NET_DRV 100 /* custom ext_buf provided by net driver(s) */
200 #define EXT_MOD_TYPE 200 /* custom module's ext_buf type */
201 #define EXT_DISPOSABLE 300 /* can throw this buffer away w/page flipping */
202 #define EXT_EXTREF 400 /* has externally maintained ref_cnt ptr */
205 * Flags copied when copying m_pkthdr.
207 #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_RDONLY|M_PROTO1|M_PROTO1|M_PROTO2|\
208 M_PROTO3|M_PROTO4|M_PROTO5|M_SKIP_FIREWALL|\
209 M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG|\
213 * Flags to purge when crossing layers.
215 #define M_PROTOFLAGS (M_PROTO1|M_PROTO2|M_PROTO3|M_PROTO4|M_PROTO5)
218 * Flags indicating hw checksum support and sw checksum requirements. This
219 * field can be directly tested against if_data.ifi_hwassist.
221 #define CSUM_IP 0x0001 /* will csum IP */
222 #define CSUM_TCP 0x0002 /* will csum TCP */
223 #define CSUM_UDP 0x0004 /* will csum UDP */
224 #define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */
225 #define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */
226 #define CSUM_TSO 0x0020 /* will do TSO */
228 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */
229 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */
230 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */
231 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */
233 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP)
234 #define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */
239 #define MT_NOTMBUF 0 /* USED INTERNALLY ONLY! Object is not mbuf */
240 #define MT_DATA 1 /* dynamic (data) allocation */
241 #define MT_HEADER MT_DATA /* packet header, use M_PKTHDR instead */
242 #define MT_SONAME 8 /* socket name */
243 #define MT_CONTROL 14 /* extra-data protocol message */
244 #define MT_OOBDATA 15 /* expedited data */
245 #define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */
247 #define MT_NOINIT 255 /* Not a type but a flag to allocate
248 a non-initialized mbuf */
251 * General mbuf allocator statistics structure.
253 * Many of these statistics are no longer used; we instead track many
254 * allocator statistics through UMA's built in statistics mechanism.
257 u_long m_mbufs; /* XXX */
258 u_long m_mclusts; /* XXX */
260 u_long m_drain; /* times drained protocols for space */
261 u_long m_mcfail; /* XXX: times m_copym failed */
262 u_long m_mpfail; /* XXX: times m_pullup failed */
263 u_long m_msize; /* length of an mbuf */
264 u_long m_mclbytes; /* length of an mbuf cluster */
265 u_long m_minclsize; /* min length of data to allocate a cluster */
266 u_long m_mlen; /* length of data in an mbuf */
267 u_long m_mhlen; /* length of data in a header mbuf */
269 /* Number of mbtypes (gives # elems in mbtypes[] array: */
272 /* XXX: Sendfile stats should eventually move to their own struct */
273 u_long sf_iocnt; /* times sendfile had to do disk I/O */
274 u_long sf_allocfail; /* times sfbuf allocation failed */
275 u_long sf_allocwait; /* times sfbuf allocation had to wait */
279 * Flags specifying how an allocation should be made.
281 * The flag to use is as follows:
282 * - M_DONTWAIT or M_NOWAIT from an interrupt handler to not block allocation.
283 * - M_WAIT or M_WAITOK or M_TRYWAIT from wherever it is safe to block.
285 * M_DONTWAIT/M_NOWAIT means that we will not block the thread explicitly and
286 * if we cannot allocate immediately we may return NULL, whereas
287 * M_WAIT/M_WAITOK/M_TRYWAIT means that if we cannot allocate resources we
288 * will block until they are available, and thus never return NULL.
290 * XXX Eventually just phase this out to use M_WAITOK/M_NOWAIT.
292 #define MBTOM(how) (how)
293 #define M_DONTWAIT M_NOWAIT
294 #define M_TRYWAIT M_WAITOK
295 #define M_WAIT M_WAITOK
298 * String names of mbuf-related UMA(9) and malloc(9) types. Exposed to
299 * !_KERNEL so that monitoring tools can look up the zones with
302 #define MBUF_MEM_NAME "mbuf"
303 #define MBUF_CLUSTER_MEM_NAME "mbuf_cluster"
304 #define MBUF_PACKET_MEM_NAME "mbuf_packet"
305 #define MBUF_JUMBOP_MEM_NAME "mbuf_jumbo_pagesize"
306 #define MBUF_JUMBO9_MEM_NAME "mbuf_jumbo_9k"
307 #define MBUF_JUMBO16_MEM_NAME "mbuf_jumbo_16k"
308 #define MBUF_TAG_MEM_NAME "mbuf_tag"
309 #define MBUF_EXTREFCNT_MEM_NAME "mbuf_ext_refcnt"
314 #define MBUF_CHECKSLEEP(how) do { \
315 if (how == M_WAITOK) \
316 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, \
317 "Sleeping in \"%s\"", __func__); \
320 #define MBUF_CHECKSLEEP(how)
324 * Network buffer allocation API
326 * The rest of it is defined in kern/kern_mbuf.c
329 extern uma_zone_t zone_mbuf;
330 extern uma_zone_t zone_clust;
331 extern uma_zone_t zone_pack;
332 extern uma_zone_t zone_jumbop;
333 extern uma_zone_t zone_jumbo9;
334 extern uma_zone_t zone_jumbo16;
335 extern uma_zone_t zone_ext_refcnt;
337 static __inline struct mbuf *m_get(int how, short type);
338 static __inline struct mbuf *m_gethdr(int how, short type);
339 static __inline struct mbuf *m_getcl(int how, short type, int flags);
340 static __inline struct mbuf *m_getjcl(int how, short type, int flags,
342 static __inline struct mbuf *m_getclr(int how, short type); /* XXX */
343 static __inline struct mbuf *m_free(struct mbuf *m);
344 static __inline void m_clget(struct mbuf *m, int how);
345 static __inline void *m_cljget(struct mbuf *m, int how, int size);
346 static __inline void m_chtype(struct mbuf *m, short new_type);
347 void mb_free_ext(struct mbuf *);
361 #if MJUMPAGESIZE != MCLBYTES
373 panic("%s: m_getjcl: invalid cluster size", __func__);
379 static __inline uma_zone_t
391 #if MJUMPAGESIZE != MCLBYTES
403 panic("%s: m_getjcl: invalid cluster type", __func__);
409 static __inline struct mbuf *
410 m_get(int how, short type)
416 return ((struct mbuf *)(uma_zalloc_arg(zone_mbuf, &args, how)));
420 * XXX This should be deprecated, very little use.
422 static __inline struct mbuf *
423 m_getclr(int how, short type)
430 m = uma_zalloc_arg(zone_mbuf, &args, how);
432 bzero(m->m_data, MLEN);
436 static __inline struct mbuf *
437 m_gethdr(int how, short type)
441 args.flags = M_PKTHDR;
443 return ((struct mbuf *)(uma_zalloc_arg(zone_mbuf, &args, how)));
446 static __inline struct mbuf *
447 m_getcl(int how, short type, int flags)
453 return ((struct mbuf *)(uma_zalloc_arg(zone_pack, &args, how)));
457 * m_getjcl() returns an mbuf with a cluster of the specified size attached.
458 * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES.
460 * XXX: This is rather large, should be real function maybe.
462 static __inline struct mbuf *
463 m_getjcl(int how, short type, int flags, int size)
472 m = uma_zalloc_arg(zone_mbuf, &args, how);
476 zone = m_getzone(size);
477 n = uma_zalloc_arg(zone, m, how);
479 uma_zfree(zone_mbuf, m);
485 static __inline struct mbuf *
486 m_free(struct mbuf *m)
488 struct mbuf *n = m->m_next;
490 if (m->m_flags & M_EXT)
493 uma_zfree(zone_mbuf, m);
498 m_clget(struct mbuf *m, int how)
501 if (m->m_flags & M_EXT)
502 printf("%s: %p mbuf already has cluster\n", __func__, m);
503 m->m_ext.ext_buf = (char *)NULL;
504 uma_zalloc_arg(zone_clust, m, how);
506 * On a cluster allocation failure, drain the packet zone and retry,
507 * we might be able to loosen a few clusters up on the drain.
509 if ((how & M_NOWAIT) && (m->m_ext.ext_buf == NULL)) {
510 zone_drain(zone_pack);
511 uma_zalloc_arg(zone_clust, m, how);
516 * m_cljget() is different from m_clget() as it can allocate clusters without
517 * attaching them to an mbuf. In that case the return value is the pointer
518 * to the cluster of the requested size. If an mbuf was specified, it gets
519 * the cluster attached to it and the return value can be safely ignored.
520 * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES.
522 static __inline void *
523 m_cljget(struct mbuf *m, int how, int size)
527 if (m && m->m_flags & M_EXT)
528 printf("%s: %p mbuf already has cluster\n", __func__, m);
530 m->m_ext.ext_buf = NULL;
532 zone = m_getzone(size);
533 return (uma_zalloc_arg(zone, m, how));
537 m_cljset(struct mbuf *m, void *cl, int type)
547 #if MJUMPAGESIZE != MCLBYTES
562 panic("unknown cluster type");
566 m->m_data = m->m_ext.ext_buf = cl;
567 m->m_ext.ext_free = m->m_ext.ext_args = NULL;
568 m->m_ext.ext_size = size;
569 m->m_ext.ext_type = type;
570 m->m_ext.ref_cnt = uma_find_refcnt(zone, cl);
576 m_chtype(struct mbuf *m, short new_type)
579 m->m_type = new_type;
583 * mbuf, cluster, and external object allocation macros (for compatibility
586 #define M_MOVE_PKTHDR(to, from) m_move_pkthdr((to), (from))
587 #define MGET(m, how, type) ((m) = m_get((how), (type)))
588 #define MGETHDR(m, how, type) ((m) = m_gethdr((how), (type)))
589 #define MCLGET(m, how) m_clget((m), (how))
590 #define MEXTADD(m, buf, size, free, args, flags, type) \
591 m_extadd((m), (caddr_t)(buf), (size), (free), (args), (flags), (type))
592 #define m_getm(m, len, how, type) \
593 m_getm2((m), (len), (how), (type), M_PKTHDR)
596 * Evaluate TRUE if it's safe to write to the mbuf m's data region (this can
597 * be both the local data payload, or an external buffer area, depending on
598 * whether M_EXT is set).
600 #define M_WRITABLE(m) (!((m)->m_flags & M_RDONLY) && \
601 (!(((m)->m_flags & M_EXT)) || \
602 (*((m)->m_ext.ref_cnt) == 1)) ) \
604 /* Check if the supplied mbuf has a packet header, or else panic. */
605 #define M_ASSERTPKTHDR(m) \
606 KASSERT(m != NULL && m->m_flags & M_PKTHDR, \
607 ("%s: no mbuf packet header!", __func__))
610 * Ensure that the supplied mbuf is a valid, non-free mbuf.
612 * XXX: Broken at the moment. Need some UMA magic to make it work again.
614 #define M_ASSERTVALID(m) \
615 KASSERT((((struct mbuf *)m)->m_flags & 0) == 0, \
616 ("%s: attempted use of a free mbuf!", __func__))
619 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place an
620 * object of the specified size at the end of the mbuf, longword aligned.
622 #define M_ALIGN(m, len) do { \
623 KASSERT(!((m)->m_flags & (M_PKTHDR|M_EXT)), \
624 ("%s: M_ALIGN not normal mbuf", __func__)); \
625 KASSERT((m)->m_data == (m)->m_dat, \
626 ("%s: M_ALIGN not a virgin mbuf", __func__)); \
627 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \
631 * As above, for mbufs allocated with m_gethdr/MGETHDR or initialized by
634 #define MH_ALIGN(m, len) do { \
635 KASSERT((m)->m_flags & M_PKTHDR && !((m)->m_flags & M_EXT), \
636 ("%s: MH_ALIGN not PKTHDR mbuf", __func__)); \
637 KASSERT((m)->m_data == (m)->m_pktdat, \
638 ("%s: MH_ALIGN not a virgin mbuf", __func__)); \
639 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \
643 * Compute the amount of space available before the current start of data in
646 * The M_WRITABLE() is a temporary, conservative safety measure: the burden
647 * of checking writability of the mbuf data area rests solely with the caller.
649 #define M_LEADINGSPACE(m) \
650 ((m)->m_flags & M_EXT ? \
651 (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \
652 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \
653 (m)->m_data - (m)->m_dat)
656 * Compute the amount of space available after the end of data in an mbuf.
658 * The M_WRITABLE() is a temporary, conservative safety measure: the burden
659 * of checking writability of the mbuf data area rests solely with the caller.
661 #define M_TRAILINGSPACE(m) \
662 ((m)->m_flags & M_EXT ? \
663 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \
664 - ((m)->m_data + (m)->m_len) : 0) : \
665 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
668 * Arrange to prepend space of size plen to mbuf m. If a new mbuf must be
669 * allocated, how specifies whether to wait. If the allocation fails, the
670 * original mbuf chain is freed and m is set to NULL.
672 #define M_PREPEND(m, plen, how) do { \
673 struct mbuf **_mmp = &(m); \
674 struct mbuf *_mm = *_mmp; \
675 int _mplen = (plen); \
676 int __mhow = (how); \
678 MBUF_CHECKSLEEP(how); \
679 if (M_LEADINGSPACE(_mm) >= _mplen) { \
680 _mm->m_data -= _mplen; \
681 _mm->m_len += _mplen; \
683 _mm = m_prepend(_mm, _mplen, __mhow); \
684 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \
685 _mm->m_pkthdr.len += _mplen; \
690 * Change mbuf to new type. This is a relatively expensive operation and
693 #define MCHTYPE(m, t) m_chtype((m), (t))
695 /* Length to m_copy to copy all. */
696 #define M_COPYALL 1000000000
698 /* Compatibility with 4.3. */
699 #define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT)
701 extern int max_datalen; /* MHLEN - max_hdr */
702 extern int max_hdr; /* Largest link + protocol header */
703 extern int max_linkhdr; /* Largest link-level header */
704 extern int max_protohdr; /* Largest protocol header */
705 extern struct mbstat mbstat; /* General mbuf stats/infos */
706 extern int nmbclusters; /* Maximum number of clusters */
710 void m_adj(struct mbuf *, int);
711 void m_align(struct mbuf *, int);
712 int m_apply(struct mbuf *, int, int,
713 int (*)(void *, void *, u_int), void *);
714 int m_append(struct mbuf *, int, c_caddr_t);
715 void m_cat(struct mbuf *, struct mbuf *);
716 void m_extadd(struct mbuf *, caddr_t, u_int,
717 void (*)(void *, void *), void *, int, int);
718 void m_copyback(struct mbuf *, int, int, c_caddr_t);
719 void m_copydata(const struct mbuf *, int, int, caddr_t);
720 struct mbuf *m_copym(struct mbuf *, int, int, int);
721 struct mbuf *m_copymdata(struct mbuf *, struct mbuf *,
723 struct mbuf *m_copypacket(struct mbuf *, int);
724 void m_copy_pkthdr(struct mbuf *, struct mbuf *);
725 struct mbuf *m_copyup(struct mbuf *n, int len, int dstoff);
726 struct mbuf *m_defrag(struct mbuf *, int);
727 void m_demote(struct mbuf *, int);
728 struct mbuf *m_devget(char *, int, int, struct ifnet *,
729 void (*)(char *, caddr_t, u_int));
730 struct mbuf *m_dup(struct mbuf *, int);
731 int m_dup_pkthdr(struct mbuf *, struct mbuf *, int);
732 u_int m_fixhdr(struct mbuf *);
733 struct mbuf *m_fragment(struct mbuf *, int, int);
734 void m_freem(struct mbuf *);
735 struct mbuf *m_getm2(struct mbuf *, int, int, short, int);
736 struct mbuf *m_getptr(struct mbuf *, int, int *);
737 u_int m_length(struct mbuf *, struct mbuf **);
738 void m_move_pkthdr(struct mbuf *, struct mbuf *);
739 struct mbuf *m_prepend(struct mbuf *, int, int);
740 void m_print(const struct mbuf *, int);
741 struct mbuf *m_pulldown(struct mbuf *, int, int, int *);
742 struct mbuf *m_pullup(struct mbuf *, int);
743 int m_sanity(struct mbuf *, int);
744 struct mbuf *m_split(struct mbuf *, int, int);
745 struct mbuf *m_uiotombuf(struct uio *, int, int, int, int);
746 struct mbuf *m_unshare(struct mbuf *, int how);
749 * Network packets may have annotations attached by affixing a list of
750 * "packet tags" to the pkthdr structure. Packet tags are dynamically
751 * allocated semi-opaque data structures that have a fixed header
752 * (struct m_tag) that specifies the size of the memory block and a
753 * <cookie,type> pair that identifies it. The cookie is a 32-bit unique
754 * unsigned value used to identify a module or ABI. By convention this value
755 * is chosen as the date+time that the module is created, expressed as the
756 * number of seconds since the epoch (e.g., using date -u +'%s'). The type
757 * value is an ABI/module-specific value that identifies a particular
758 * annotation and is private to the module. For compatibility with systems
759 * like OpenBSD that define packet tags w/o an ABI/module cookie, the value
760 * PACKET_ABI_COMPAT is used to implement m_tag_get and m_tag_find
761 * compatibility shim functions and several tag types are defined below.
762 * Users that do not require compatibility should use a private cookie value
763 * so that packet tag-related definitions can be maintained privately.
765 * Note that the packet tag returned by m_tag_alloc has the default memory
766 * alignment implemented by malloc. To reference private data one can use a
769 * struct m_tag *mtag = m_tag_alloc(...);
770 * struct foo *p = (struct foo *)(mtag+1);
772 * if the alignment of struct m_tag is sufficient for referencing members of
773 * struct foo. Otherwise it is necessary to embed struct m_tag within the
774 * private data structure to insure proper alignment; e.g.,
780 * struct foo *p = (struct foo *) m_tag_alloc(...);
781 * struct m_tag *mtag = &p->tag;
785 * Persistent tags stay with an mbuf until the mbuf is reclaimed. Otherwise
786 * tags are expected to ``vanish'' when they pass through a network
787 * interface. For most interfaces this happens normally as the tags are
788 * reclaimed when the mbuf is free'd. However in some special cases
789 * reclaiming must be done manually. An example is packets that pass through
790 * the loopback interface. Also, one must be careful to do this when
791 * ``turning around'' packets (e.g., icmp_reflect).
793 * To mark a tag persistent bit-or this flag in when defining the tag id.
794 * The tag will then be treated as described above.
796 #define MTAG_PERSISTENT 0x800
798 #define PACKET_TAG_NONE 0 /* Nadda */
800 /* Packet tags for use with PACKET_ABI_COMPAT. */
801 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */
802 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */
803 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */
804 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */
805 #define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO 5 /* NIC notifies IPsec */
806 #define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */
807 #define PACKET_TAG_BRIDGE 7 /* Bridge processing done */
808 #define PACKET_TAG_GIF 8 /* GIF processing done */
809 #define PACKET_TAG_GRE 9 /* GRE processing done */
810 #define PACKET_TAG_IN_PACKET_CHECKSUM 10 /* NIC checksumming done */
811 #define PACKET_TAG_ENCAP 11 /* Encap. processing */
812 #define PACKET_TAG_IPSEC_SOCKET 12 /* IPSEC socket ref */
813 #define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */
814 #define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */
815 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */
816 #define PACKET_TAG_DIVERT 17 /* divert info */
817 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */
818 #define PACKET_TAG_MACLABEL (19 | MTAG_PERSISTENT) /* MAC label */
819 #define PACKET_TAG_PF_ROUTED 21 /* PF routed, avoid loops */
820 #define PACKET_TAG_PF_FRAGCACHE 22 /* PF fragment cached */
821 #define PACKET_TAG_PF_QID 23 /* PF ALTQ queue id */
822 #define PACKET_TAG_PF_TAG 24 /* PF tagged */
823 #define PACKET_TAG_RTSOCKFAM 25 /* rtsock sa family */
824 #define PACKET_TAG_PF_TRANSLATE_LOCALHOST 26 /* PF translate localhost */
825 #define PACKET_TAG_IPOPTIONS 27 /* Saved IP options */
826 #define PACKET_TAG_CARP 28 /* CARP info */
828 /* Specific cookies and tags. */
830 /* Packet tag routines. */
831 struct m_tag *m_tag_alloc(u_int32_t, int, int, int);
832 void m_tag_delete(struct mbuf *, struct m_tag *);
833 void m_tag_delete_chain(struct mbuf *, struct m_tag *);
834 void m_tag_free_default(struct m_tag *);
835 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *);
836 struct m_tag *m_tag_copy(struct m_tag *, int);
837 int m_tag_copy_chain(struct mbuf *, struct mbuf *, int);
838 void m_tag_delete_nonpersistent(struct mbuf *);
841 * Initialize the list of tags associated with an mbuf.
844 m_tag_init(struct mbuf *m)
847 SLIST_INIT(&m->m_pkthdr.tags);
851 * Set up the contents of a tag. Note that this does not fill in the free
852 * method; the caller is expected to do that.
854 * XXX probably should be called m_tag_init, but that was already taken.
857 m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len)
862 t->m_tag_cookie = cookie;
866 * Reclaim resources associated with a tag.
869 m_tag_free(struct m_tag *t)
876 * Return the first tag associated with an mbuf.
878 static __inline struct m_tag *
879 m_tag_first(struct mbuf *m)
882 return (SLIST_FIRST(&m->m_pkthdr.tags));
886 * Return the next tag in the list of tags associated with an mbuf.
888 static __inline struct m_tag *
889 m_tag_next(struct mbuf *m, struct m_tag *t)
892 return (SLIST_NEXT(t, m_tag_link));
896 * Prepend a tag to the list of tags associated with an mbuf.
899 m_tag_prepend(struct mbuf *m, struct m_tag *t)
902 SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link);
906 * Unlink a tag from the list of tags associated with an mbuf.
909 m_tag_unlink(struct mbuf *m, struct m_tag *t)
912 SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link);
915 /* These are for OpenBSD compatibility. */
916 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */
918 static __inline struct m_tag *
919 m_tag_get(int type, int length, int wait)
921 return (m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait));
924 static __inline struct m_tag *
925 m_tag_find(struct mbuf *m, int type, struct m_tag *start)
927 return (SLIST_EMPTY(&m->m_pkthdr.tags) ? (struct m_tag *)NULL :
928 m_tag_locate(m, MTAG_ABI_COMPAT, type, start));
933 #endif /* !_SYS_MBUF_H_ */