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29 * @(#)mbuf.h 8.5 (Berkeley) 2/19/95
36 /* XXX: These includes suck. Sorry! */
37 #include <sys/queue.h>
39 #include <sys/systm.h>
47 * Mbufs are of a single size, MSIZE (sys/param.h), which
48 * includes overhead. An mbuf may add a single "mbuf cluster" of size
49 * MCLBYTES (also in sys/param.h), which has no additional overhead
50 * and is used instead of the internal data area; this is done when
51 * at least MINCLSIZE of data must be stored. Additionally, it is possible
52 * to allocate a separate buffer externally and attach it to the mbuf in
53 * a way similar to that of mbuf clusters.
55 #define MLEN (MSIZE - sizeof(struct m_hdr)) /* normal data len */
56 #define MHLEN (MLEN - sizeof(struct pkthdr)) /* data len w/pkthdr */
57 #define MINCLSIZE (MHLEN + 1) /* smallest amount to put in cluster */
58 #define M_MAXCOMPRESS (MHLEN / 2) /* max amount to copy for compression */
62 * Macros for type conversion:
63 * mtod(m, t) -- Convert mbuf pointer to data pointer of correct type.
64 * dtom(x) -- Convert data pointer within mbuf to mbuf pointer (XXX).
66 #define mtod(m, t) ((t)((m)->m_data))
67 #define dtom(x) ((struct mbuf *)((intptr_t)(x) & ~(MSIZE-1)))
70 * Argument structure passed to UMA routines during mbuf and packet
74 int flags; /* Flags for mbuf being allocated */
75 short type; /* Type of mbuf being allocated */
80 * Header present at the beginning of every mbuf.
83 struct mbuf *mh_next; /* next buffer in chain */
84 struct mbuf *mh_nextpkt; /* next chain in queue/record */
85 caddr_t mh_data; /* location of data */
86 int mh_len; /* amount of data in this mbuf */
87 int mh_flags; /* flags; see below */
88 short mh_type; /* type of data in this mbuf */
92 * Packet tag structure (see below for details).
95 SLIST_ENTRY(m_tag) m_tag_link; /* List of packet tags */
96 u_int16_t m_tag_id; /* Tag ID */
97 u_int16_t m_tag_len; /* Length of data */
98 u_int32_t m_tag_cookie; /* ABI/Module ID */
99 void (*m_tag_free)(struct m_tag *);
103 * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
106 struct ifnet *rcvif; /* rcv interface */
107 int len; /* total packet length */
108 /* variables for ip and tcp reassembly */
109 void *header; /* pointer to packet header */
110 /* variables for hardware checksum */
111 int csum_flags; /* flags regarding checksum */
112 int csum_data; /* data field used by csum routines */
113 SLIST_HEAD(packet_tags, m_tag) tags; /* list of packet tags */
117 * Description of external storage mapped into mbuf; valid only if M_EXT is set.
120 caddr_t ext_buf; /* start of buffer */
121 void (*ext_free) /* free routine if not the usual */
123 void *ext_args; /* optional argument pointer */
124 u_int ext_size; /* size of buffer, for ext_free */
125 volatile u_int *ref_cnt; /* pointer to ref count info */
126 int ext_type; /* type of external storage */
130 * The core of the mbuf object along with some shortcut defines for
131 * practical purposes.
137 struct pkthdr MH_pkthdr; /* M_PKTHDR set */
139 struct m_ext MH_ext; /* M_EXT set */
140 char MH_databuf[MHLEN];
143 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */
146 #define m_next m_hdr.mh_next
147 #define m_len m_hdr.mh_len
148 #define m_data m_hdr.mh_data
149 #define m_type m_hdr.mh_type
150 #define m_flags m_hdr.mh_flags
151 #define m_nextpkt m_hdr.mh_nextpkt
152 #define m_act m_nextpkt
153 #define m_pkthdr M_dat.MH.MH_pkthdr
154 #define m_ext M_dat.MH.MH_dat.MH_ext
155 #define m_pktdat M_dat.MH.MH_dat.MH_databuf
156 #define m_dat M_dat.M_databuf
161 #define M_EXT 0x0001 /* has associated external storage */
162 #define M_PKTHDR 0x0002 /* start of record */
163 #define M_EOR 0x0004 /* end of record */
164 #define M_RDONLY 0x0008 /* associated data is marked read-only */
165 #define M_PROTO1 0x0010 /* protocol-specific */
166 #define M_PROTO2 0x0020 /* protocol-specific */
167 #define M_PROTO3 0x0040 /* protocol-specific */
168 #define M_PROTO4 0x0080 /* protocol-specific */
169 #define M_PROTO5 0x0100 /* protocol-specific */
170 #define M_SKIP_FIREWALL 0x4000 /* skip firewall processing */
171 #define M_FREELIST 0x8000 /* mbuf is on the free list */
174 * mbuf pkthdr flags (also stored in m_flags).
176 #define M_BCAST 0x0200 /* send/received as link-level broadcast */
177 #define M_MCAST 0x0400 /* send/received as link-level multicast */
178 #define M_FRAG 0x0800 /* packet is a fragment of a larger packet */
179 #define M_FIRSTFRAG 0x1000 /* packet is first fragment */
180 #define M_LASTFRAG 0x2000 /* packet is last fragment */
181 #define M_VLANTAG 0x10000 /* packet has VLAN tag attached */
184 * External buffer types: identify ext_buf type.
186 #define EXT_CLUSTER 1 /* mbuf cluster */
187 #define EXT_SFBUF 2 /* sendfile(2)'s sf_bufs */
188 #define EXT_JUMBO4 3 /* jumbo cluster 4096 bytes */
189 #define EXT_JUMBO9 4 /* jumbo cluster 9216 bytes */
190 #define EXT_JUMBO16 5 /* jumbo cluster 16184 bytes */
191 #define EXT_PACKET 6 /* mbuf+cluster from packet zone */
192 #define EXT_NET_DRV 100 /* custom ext_buf provided by net driver(s) */
193 #define EXT_MOD_TYPE 200 /* custom module's ext_buf type */
194 #define EXT_DISPOSABLE 300 /* can throw this buffer away w/page flipping */
195 #define EXT_EXTREF 400 /* has externally maintained ref_cnt ptr */
198 * Flags copied when copying m_pkthdr.
200 #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_RDONLY|M_PROTO1|M_PROTO1|M_PROTO2|\
201 M_PROTO3|M_PROTO4|M_PROTO5|M_SKIP_FIREWALL|\
202 M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG|\
206 * Flags to purge when crossing layers.
208 #define M_PROTOFLAGS (M_PROTO1|M_PROTO2|M_PROTO3|M_PROTO4|M_PROTO5)
211 * Flags indicating hw checksum support and sw checksum requirements.
213 #define CSUM_IP 0x0001 /* will csum IP */
214 #define CSUM_TCP 0x0002 /* will csum TCP */
215 #define CSUM_UDP 0x0004 /* will csum UDP */
216 #define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */
217 #define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */
219 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */
220 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */
221 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */
222 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */
224 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP)
225 #define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */
230 #define MT_NOTMBUF 0 /* USED INTERNALLY ONLY! Object is not mbuf */
231 #define MT_DATA 1 /* dynamic (data) allocation */
232 #define MT_HEADER MT_DATA /* packet header, use M_PKTHDR instead */
234 #define MT_SOCKET 3 /* socket structure */
235 #define MT_PCB 4 /* protocol control block */
236 #define MT_RTABLE 5 /* routing tables */
237 #define MT_HTABLE 6 /* IMP host tables */
238 #define MT_ATABLE 7 /* address resolution tables */
240 #define MT_SONAME 8 /* socket name */
242 #define MT_SOOPTS 10 /* socket options */
244 #define MT_FTABLE 11 /* fragment reassembly header */
246 #define MT_RIGHTS 12 /* access rights */
247 #define MT_IFADDR 13 /* interface address */
249 #define MT_CONTROL 14 /* extra-data protocol message */
250 #define MT_OOBDATA 15 /* expedited data */
251 #define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */
253 #define MT_NOINIT 255 /* Not a type but a flag to allocate
254 a non-initialized mbuf */
257 * General mbuf allocator statistics structure.
260 u_long m_mbufs; /* XXX */
261 u_long m_mclusts; /* XXX */
263 u_long m_drain; /* times drained protocols for space */
264 u_long m_mcfail; /* XXX: times m_copym failed */
265 u_long m_mpfail; /* XXX: times m_pullup failed */
266 u_long m_msize; /* length of an mbuf */
267 u_long m_mclbytes; /* length of an mbuf cluster */
268 u_long m_minclsize; /* min length of data to allocate a cluster */
269 u_long m_mlen; /* length of data in an mbuf */
270 u_long m_mhlen; /* length of data in a header mbuf */
272 /* Number of mbtypes (gives # elems in mbtypes[] array: */
275 /* XXX: Sendfile stats should eventually move to their own struct */
276 u_long sf_iocnt; /* times sendfile had to do disk I/O */
277 u_long sf_allocfail; /* times sfbuf allocation failed */
278 u_long sf_allocwait; /* times sfbuf allocation had to wait */
282 * Flags specifying how an allocation should be made.
284 * The flag to use is as follows:
285 * - M_DONTWAIT or M_NOWAIT from an interrupt handler to not block allocation.
286 * - M_WAIT or M_WAITOK or M_TRYWAIT from wherever it is safe to block.
288 * M_DONTWAIT/M_NOWAIT means that we will not block the thread explicitly
289 * and if we cannot allocate immediately we may return NULL,
290 * whereas M_WAIT/M_WAITOK/M_TRYWAIT means that if we cannot allocate
291 * resources we will block until they are available, and thus never
294 * XXX Eventually just phase this out to use M_WAITOK/M_NOWAIT.
296 #define MBTOM(how) (how)
297 #define M_DONTWAIT M_NOWAIT
298 #define M_TRYWAIT M_WAITOK
299 #define M_WAIT M_WAITOK
302 * String names of mbuf-related UMA(9) and malloc(9) types. Exposed to
303 * !_KERNEL so that monitoring tools can look up the zones with
306 #define MBUF_MEM_NAME "mbuf"
307 #define MBUF_CLUSTER_MEM_NAME "mbuf_cluster"
308 #define MBUF_PACKET_MEM_NAME "mbuf_packet"
309 #define MBUF_JUMBO4_MEM_NAME "mbuf_jumbo_4k"
310 #define MBUF_JUMBO9_MEM_NAME "mbuf_jumbo_9k"
311 #define MBUF_JUMBO16_MEM_NAME "mbuf_jumbo_16k"
312 #define MBUF_TAG_MEM_NAME "mbuf_tag"
313 #define MBUF_EXTREFCNT_MEM_NAME "mbuf_ext_refcnt"
318 #define MBUF_CHECKSLEEP(how) do { \
319 if (how == M_WAITOK) \
320 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, \
321 "Sleeping in \"%s\"", __func__); \
324 #define MBUF_CHECKSLEEP(how)
328 * Network buffer allocation API
330 * The rest of it is defined in kern/kern_mbuf.c
333 extern uma_zone_t zone_mbuf;
334 extern uma_zone_t zone_clust;
335 extern uma_zone_t zone_pack;
336 extern uma_zone_t zone_jumbo4;
337 extern uma_zone_t zone_jumbo9;
338 extern uma_zone_t zone_jumbo16;
339 extern uma_zone_t zone_ext_refcnt;
340 extern uma_zone_t zone_mtag_vlan;
342 static __inline struct mbuf *m_get(int how, short type);
343 static __inline struct mbuf *m_gethdr(int how, short type);
344 static __inline struct mbuf *m_getcl(int how, short type, int flags);
345 static __inline struct mbuf *m_getjcl(int how, short type, int flags, int size);
346 static __inline struct mbuf *m_getclr(int how, short type); /* XXX */
347 static __inline struct mbuf *m_free(struct mbuf *m);
348 static __inline void m_clget(struct mbuf *m, int how);
349 static __inline void *m_cljget(struct mbuf *m, int how, int size);
350 static __inline void m_chtype(struct mbuf *m, short new_type);
351 void mb_free_ext(struct mbuf *);
355 m_get(int how, short type)
361 return (uma_zalloc_arg(zone_mbuf, &args, how));
364 /* XXX This should be depracated, very little use */
367 m_getclr(int how, short type)
374 m = uma_zalloc_arg(zone_mbuf, &args, how);
376 bzero(m->m_data, MLEN);
382 m_gethdr(int how, short type)
386 args.flags = M_PKTHDR;
388 return (uma_zalloc_arg(zone_mbuf, &args, how));
393 m_getcl(int how, short type, int flags)
399 return (uma_zalloc_arg(zone_pack, &args, how));
403 * m_getjcl() returns an mbuf with a cluster of the specified size attached.
404 * For size it takes MCLBYTES, MJUM4BYTES, MJUM9BYTES, MJUM16BYTES.
406 static __inline /* XXX: This is rather large, should be real function maybe. */
408 m_getjcl(int how, short type, int flags, int size)
417 m = uma_zalloc_arg(zone_mbuf, &args, how);
425 #if MJUM4BYTES != MCLBYTES
437 panic("%s: m_getjcl: invalid cluster type", __func__);
439 n = uma_zalloc_arg(zone, m, how);
441 uma_zfree(zone_mbuf, m);
449 m_free(struct mbuf *m)
451 struct mbuf *n = m->m_next;
453 if (m->m_flags & M_EXT)
456 uma_zfree(zone_mbuf, m);
462 m_clget(struct mbuf *m, int how)
464 if (m->m_flags & M_EXT)
465 printf("%s: %p mbuf already has cluster\n", __func__, m);
466 m->m_ext.ext_buf = NULL;
467 uma_zalloc_arg(zone_clust, m, how);
471 * m_cljget() is different from m_clget() as it can allocate clusters
472 * without attaching them to an mbuf. In that case the return value
473 * is the pointer to the cluster of the requested size. If an mbuf was
474 * specified, it gets the cluster attached to it and the return value
475 * can be safely ignored.
476 * For size it takes MCLBYTES, MJUM4BYTES, MJUM9BYTES, MJUM16BYTES.
480 m_cljget(struct mbuf *m, int how, int size)
484 if (m && m->m_flags & M_EXT)
485 printf("%s: %p mbuf already has cluster\n", __func__, m);
487 m->m_ext.ext_buf = NULL;
493 #if MJUM4BYTES != MCLBYTES
505 panic("%s: m_getjcl: invalid cluster type", __func__);
508 return (uma_zalloc_arg(zone, m, how));
513 m_chtype(struct mbuf *m, short new_type)
515 m->m_type = new_type;
519 * mbuf, cluster, and external object allocation macros
520 * (for compatibility purposes).
522 /* NB: M_COPY_PKTHDR is deprecated. Use M_MOVE_PKTHDR or m_dup_pktdr. */
523 #define M_MOVE_PKTHDR(to, from) m_move_pkthdr((to), (from))
524 #define MGET(m, how, type) ((m) = m_get((how), (type)))
525 #define MGETHDR(m, how, type) ((m) = m_gethdr((how), (type)))
526 #define MCLGET(m, how) m_clget((m), (how))
527 #define MEXTADD(m, buf, size, free, args, flags, type) \
528 m_extadd((m), (caddr_t)(buf), (size), (free), (args), (flags), (type))
531 * Evaluate TRUE if it's safe to write to the mbuf m's data region (this
532 * can be both the local data payload, or an external buffer area,
533 * depending on whether M_EXT is set).
535 #define M_WRITABLE(m) (!((m)->m_flags & M_RDONLY) && \
536 (!(((m)->m_flags & M_EXT)) || \
537 (*((m)->m_ext.ref_cnt) == 1)) ) \
539 /* Check if the supplied mbuf has a packet header, or else panic. */
540 #define M_ASSERTPKTHDR(m) \
541 KASSERT(m != NULL && m->m_flags & M_PKTHDR, \
542 ("%s: no mbuf packet header!", __func__))
544 /* Ensure that the supplied mbuf is a valid, non-free mbuf. */
545 /* XXX: Broken at the moment. Need some UMA magic to make it work again. */
546 #define M_ASSERTVALID(m) \
547 KASSERT((((struct mbuf *)m)->m_flags & 0) == 0, \
548 ("%s: attempted use of a free mbuf!", __func__))
551 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place
552 * an object of the specified size at the end of the mbuf, longword aligned.
554 #define M_ALIGN(m, len) do { \
555 KASSERT(!((m)->m_flags & (M_PKTHDR|M_EXT)), \
556 ("%s: M_ALIGN not normal mbuf", __func__)); \
557 KASSERT((m)->m_data == (m)->m_dat, \
558 ("%s: M_ALIGN not a virgin mbuf", __func__)); \
559 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \
563 * As above, for mbufs allocated with m_gethdr/MGETHDR
564 * or initialized by M_COPY_PKTHDR.
566 #define MH_ALIGN(m, len) do { \
567 KASSERT((m)->m_flags & M_PKTHDR && !((m)->m_flags & M_EXT), \
568 ("%s: MH_ALIGN not PKTHDR mbuf", __func__)); \
569 KASSERT((m)->m_data == (m)->m_pktdat, \
570 ("%s: MH_ALIGN not a virgin mbuf", __func__)); \
571 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \
575 * Compute the amount of space available
576 * before the current start of data in an mbuf.
578 * The M_WRITABLE() is a temporary, conservative safety measure: the burden
579 * of checking writability of the mbuf data area rests solely with the caller.
581 #define M_LEADINGSPACE(m) \
582 ((m)->m_flags & M_EXT ? \
583 (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \
584 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \
585 (m)->m_data - (m)->m_dat)
588 * Compute the amount of space available
589 * after the end of data in an mbuf.
591 * The M_WRITABLE() is a temporary, conservative safety measure: the burden
592 * of checking writability of the mbuf data area rests solely with the caller.
594 #define M_TRAILINGSPACE(m) \
595 ((m)->m_flags & M_EXT ? \
596 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \
597 - ((m)->m_data + (m)->m_len) : 0) : \
598 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
601 * Arrange to prepend space of size plen to mbuf m.
602 * If a new mbuf must be allocated, how specifies whether to wait.
603 * If the allocation fails, the original mbuf chain is freed and m is
606 #define M_PREPEND(m, plen, how) do { \
607 struct mbuf **_mmp = &(m); \
608 struct mbuf *_mm = *_mmp; \
609 int _mplen = (plen); \
610 int __mhow = (how); \
612 MBUF_CHECKSLEEP(how); \
613 if (M_LEADINGSPACE(_mm) >= _mplen) { \
614 _mm->m_data -= _mplen; \
615 _mm->m_len += _mplen; \
617 _mm = m_prepend(_mm, _mplen, __mhow); \
618 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \
619 _mm->m_pkthdr.len += _mplen; \
624 * Change mbuf to new type.
625 * This is a relatively expensive operation and should be avoided.
627 #define MCHTYPE(m, t) m_chtype((m), (t))
629 /* Length to m_copy to copy all. */
630 #define M_COPYALL 1000000000
632 /* Compatibility with 4.3. */
633 #define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT)
635 extern int max_datalen; /* MHLEN - max_hdr */
636 extern int max_hdr; /* Largest link + protocol header */
637 extern int max_linkhdr; /* Largest link-level header */
638 extern int max_protohdr; /* Largest protocol header */
639 extern struct mbstat mbstat; /* General mbuf stats/infos */
640 extern int nmbclusters; /* Maximum number of clusters */
644 void m_adj(struct mbuf *, int);
645 void m_align(struct mbuf *, int);
646 int m_apply(struct mbuf *, int, int,
647 int (*)(void *, void *, u_int), void *);
648 int m_append(struct mbuf *, int, c_caddr_t);
649 void m_cat(struct mbuf *, struct mbuf *);
650 void m_extadd(struct mbuf *, caddr_t, u_int,
651 void (*)(void *, void *), void *, int, int);
652 void m_copyback(struct mbuf *, int, int, c_caddr_t);
653 void m_copydata(const struct mbuf *, int, int, caddr_t);
654 struct mbuf *m_copym(struct mbuf *, int, int, int);
655 struct mbuf *m_copymdata(struct mbuf *, struct mbuf *,
657 struct mbuf *m_copypacket(struct mbuf *, int);
658 void m_copy_pkthdr(struct mbuf *, struct mbuf *);
659 struct mbuf *m_copyup(struct mbuf *n, int len, int dstoff);
660 struct mbuf *m_defrag(struct mbuf *, int);
661 void m_demote(struct mbuf *, int);
662 struct mbuf *m_devget(char *, int, int, struct ifnet *,
663 void (*)(char *, caddr_t, u_int));
664 struct mbuf *m_dup(struct mbuf *, int);
665 int m_dup_pkthdr(struct mbuf *, struct mbuf *, int);
666 u_int m_fixhdr(struct mbuf *);
667 struct mbuf *m_fragment(struct mbuf *, int, int);
668 void m_freem(struct mbuf *);
669 struct mbuf *m_getm(struct mbuf *, int, int, short);
670 struct mbuf *m_getptr(struct mbuf *, int, int *);
671 u_int m_length(struct mbuf *, struct mbuf **);
672 void m_move_pkthdr(struct mbuf *, struct mbuf *);
673 struct mbuf *m_prepend(struct mbuf *, int, int);
674 void m_print(const struct mbuf *, int);
675 struct mbuf *m_pulldown(struct mbuf *, int, int, int *);
676 struct mbuf *m_pullup(struct mbuf *, int);
677 int m_sanity(struct mbuf *, int);
678 struct mbuf *m_split(struct mbuf *, int, int);
679 struct mbuf *m_uiotombuf(struct uio *, int, int, int);
682 * Network packets may have annotations attached by affixing a list
683 * of "packet tags" to the pkthdr structure. Packet tags are
684 * dynamically allocated semi-opaque data structures that have
685 * a fixed header (struct m_tag) that specifies the size of the
686 * memory block and a <cookie,type> pair that identifies it.
687 * The cookie is a 32-bit unique unsigned value used to identify
688 * a module or ABI. By convention this value is chose as the
689 * date+time that the module is created, expressed as the number of
690 * seconds since the epoch (e.g., using date -u +'%s'). The type value
691 * is an ABI/module-specific value that identifies a particular annotation
692 * and is private to the module. For compatibility with systems
693 * like OpenBSD that define packet tags w/o an ABI/module cookie,
694 * the value PACKET_ABI_COMPAT is used to implement m_tag_get and
695 * m_tag_find compatibility shim functions and several tag types are
696 * defined below. Users that do not require compatibility should use
697 * a private cookie value so that packet tag-related definitions
698 * can be maintained privately.
700 * Note that the packet tag returned by m_tag_alloc has the default
701 * memory alignment implemented by malloc. To reference private data
702 * one can use a construct like:
704 * struct m_tag *mtag = m_tag_alloc(...);
705 * struct foo *p = (struct foo *)(mtag+1);
707 * if the alignment of struct m_tag is sufficient for referencing members
708 * of struct foo. Otherwise it is necessary to embed struct m_tag within
709 * the private data structure to insure proper alignment; e.g.,
715 * struct foo *p = (struct foo *) m_tag_alloc(...);
716 * struct m_tag *mtag = &p->tag;
720 * Persistent tags stay with an mbuf until the mbuf is reclaimed.
721 * Otherwise tags are expected to ``vanish'' when they pass through
722 * a network interface. For most interfaces this happens normally
723 * as the tags are reclaimed when the mbuf is free'd. However in
724 * some special cases reclaiming must be done manually. An example
725 * is packets that pass through the loopback interface. Also, one
726 * must be careful to do this when ``turning around'' packets (e.g.,
729 * To mark a tag persistent bit-or this flag in when defining the
730 * tag id. The tag will then be treated as described above.
732 #define MTAG_PERSISTENT 0x800
734 #define PACKET_TAG_NONE 0 /* Nadda */
736 /* Packet tags for use with PACKET_ABI_COMPAT. */
737 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */
738 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */
739 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */
740 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */
741 #define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO 5 /* NIC notifies IPsec */
742 #define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */
743 #define PACKET_TAG_BRIDGE 7 /* Bridge processing done */
744 #define PACKET_TAG_GIF 8 /* GIF processing done */
745 #define PACKET_TAG_GRE 9 /* GRE processing done */
746 #define PACKET_TAG_IN_PACKET_CHECKSUM 10 /* NIC checksumming done */
747 #define PACKET_TAG_ENCAP 11 /* Encap. processing */
748 #define PACKET_TAG_IPSEC_SOCKET 12 /* IPSEC socket ref */
749 #define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */
750 #define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */
751 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */
752 #define PACKET_TAG_DIVERT 17 /* divert info */
753 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */
754 #define PACKET_TAG_MACLABEL (19 | MTAG_PERSISTENT) /* MAC label */
755 #define PACKET_TAG_PF_ROUTED 21 /* PF routed, avoid loops */
756 #define PACKET_TAG_PF_FRAGCACHE 22 /* PF fragment cached */
757 #define PACKET_TAG_PF_QID 23 /* PF ALTQ queue id */
758 #define PACKET_TAG_PF_TAG 24 /* PF tagged */
759 #define PACKET_TAG_RTSOCKFAM 25 /* rtsock sa family */
760 #define PACKET_TAG_PF_TRANSLATE_LOCALHOST 26 /* PF translate localhost */
761 #define PACKET_TAG_IPOPTIONS 27 /* Saved IP options */
762 #define PACKET_TAG_CARP 28 /* CARP info */
764 /* Specific cookies and tags. */
765 #define MTAG_VLAN 1035328035
766 #define MTAG_VLAN_TAG 0 /* tag of VLAN interface */
768 /* Packet tag routines. */
769 struct m_tag *m_tag_alloc(u_int32_t, int, int, int);
770 void m_tag_delete(struct mbuf *, struct m_tag *);
771 void m_tag_delete_chain(struct mbuf *, struct m_tag *);
772 void m_tag_free_default(struct m_tag *);
773 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *);
774 struct m_tag *m_tag_copy(struct m_tag *, int);
775 int m_tag_copy_chain(struct mbuf *, struct mbuf *, int);
776 void m_tag_delete_nonpersistent(struct mbuf *);
779 * Initialize the list of tags associated with an mbuf.
782 m_tag_init(struct mbuf *m)
784 SLIST_INIT(&m->m_pkthdr.tags);
788 * Set up the contents of a tag. Note that this does not
789 * fill in the free method; the caller is expected to do that.
791 * XXX probably should be called m_tag_init, but that was
795 m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len)
799 t->m_tag_cookie = cookie;
803 * Reclaim resources associated with a tag.
806 m_tag_free(struct m_tag *t)
812 * Return the first tag associated with an mbuf.
814 static __inline struct m_tag *
815 m_tag_first(struct mbuf *m)
817 return (SLIST_FIRST(&m->m_pkthdr.tags));
821 * Return the next tag in the list of tags associated with an mbuf.
823 static __inline struct m_tag *
824 m_tag_next(struct mbuf *m, struct m_tag *t)
826 return (SLIST_NEXT(t, m_tag_link));
830 * Prepend a tag to the list of tags associated with an mbuf.
833 m_tag_prepend(struct mbuf *m, struct m_tag *t)
835 SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link);
839 * Unlink a tag from the list of tags associated with an mbuf.
842 m_tag_unlink(struct mbuf *m, struct m_tag *t)
844 SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link);
847 /* These are for OpenBSD compatibility. */
848 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */
850 static __inline struct m_tag *
851 m_tag_get(int type, int length, int wait)
853 return (m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait));
856 static __inline struct m_tag *
857 m_tag_find(struct mbuf *m, int type, struct m_tag *start)
859 return (SLIST_EMPTY(&m->m_pkthdr.tags) ?
860 NULL : m_tag_locate(m, MTAG_ABI_COMPAT, type, start));
865 #endif /* !_SYS_MBUF_H_ */