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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 * MLEN is data length in a normal mbuf.
57 * MHLEN is data length in an mbuf with pktheader.
58 * MINCLSIZE is a smallest amount of data that should be put into cluster.
60 #define MLEN ((int)(MSIZE - sizeof(struct m_hdr)))
61 #define MHLEN ((int)(MLEN - sizeof(struct pkthdr)))
62 #define MINCLSIZE (MHLEN + 1)
66 * Macro for type conversion: convert mbuf pointer to data pointer of correct
69 * mtod(m, t) -- Convert mbuf pointer to data pointer of correct type.
71 #define mtod(m, t) ((t)((m)->m_data))
74 * Argument structure passed to UMA routines during mbuf and packet
78 int flags; /* Flags for mbuf being allocated */
79 short type; /* Type of mbuf being allocated */
90 * Header present at the beginning of every mbuf.
93 struct mbuf *mh_next; /* next buffer in chain */
94 struct mbuf *mh_nextpkt; /* next chain in queue/record */
95 caddr_t mh_data; /* location of data */
96 int mh_len; /* amount of data in this mbuf */
97 int mh_flags; /* flags; see below */
98 short mh_type; /* type of data in this mbuf */
99 uint8_t pad[M_HDR_PAD];/* word align */
103 * Packet tag structure (see below for details).
106 SLIST_ENTRY(m_tag) m_tag_link; /* List of packet tags */
107 u_int16_t m_tag_id; /* Tag ID */
108 u_int16_t m_tag_len; /* Length of data */
109 u_int32_t m_tag_cookie; /* ABI/Module ID */
110 void (*m_tag_free)(struct m_tag *);
114 * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
117 struct ifnet *rcvif; /* rcv interface */
118 /* variables for ip and tcp reassembly */
119 void *header; /* pointer to packet header */
120 int len; /* total packet length */
121 uint32_t flowid; /* packet's 4-tuple system
124 /* variables for hardware checksum */
125 int csum_flags; /* flags regarding checksum */
126 int csum_data; /* data field used by csum routines */
127 u_int16_t tso_segsz; /* TSO segment size */
129 u_int16_t vt_vtag; /* Ethernet 802.1p+q vlan tag */
130 u_int16_t vt_nrecs; /* # of IGMPv3 records in this chain */
132 SLIST_HEAD(packet_tags, m_tag) tags; /* list of packet tags */
134 #define ether_vtag PH_vt.vt_vtag
137 * Description of external storage mapped into mbuf; valid only if M_EXT is
141 caddr_t ext_buf; /* start of buffer */
142 void (*ext_free) /* free routine if not the usual */
144 void *ext_arg1; /* optional argument pointer */
145 void *ext_arg2; /* optional argument pointer */
146 u_int ext_size; /* size of buffer, for ext_free */
147 volatile u_int *ref_cnt; /* pointer to ref count info */
148 int ext_type; /* type of external storage */
152 * The core of the mbuf object along with some shortcut defines for practical
159 struct pkthdr MH_pkthdr; /* M_PKTHDR set */
161 struct m_ext MH_ext; /* M_EXT set */
162 char MH_databuf[MHLEN];
165 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */
168 #define m_next m_hdr.mh_next
169 #define m_len m_hdr.mh_len
170 #define m_data m_hdr.mh_data
171 #define m_type m_hdr.mh_type
172 #define m_flags m_hdr.mh_flags
173 #define m_nextpkt m_hdr.mh_nextpkt
174 #define m_act m_nextpkt
175 #define m_pkthdr M_dat.MH.MH_pkthdr
176 #define m_ext M_dat.MH.MH_dat.MH_ext
177 #define m_pktdat M_dat.MH.MH_dat.MH_databuf
178 #define m_dat M_dat.M_databuf
183 #define M_EXT 0x00000001 /* has associated external storage */
184 #define M_PKTHDR 0x00000002 /* start of record */
185 #define M_EOR 0x00000004 /* end of record */
186 #define M_RDONLY 0x00000008 /* associated data is marked read-only */
187 #define M_PROTO1 0x00000010 /* protocol-specific */
188 #define M_PROTO2 0x00000020 /* protocol-specific */
189 #define M_PROTO3 0x00000040 /* protocol-specific */
190 #define M_PROTO4 0x00000080 /* protocol-specific */
191 #define M_PROTO5 0x00000100 /* protocol-specific */
192 #define M_BCAST 0x00000200 /* send/received as link-level broadcast */
193 #define M_MCAST 0x00000400 /* send/received as link-level multicast */
194 #define M_FRAG 0x00000800 /* packet is a fragment of a larger packet */
195 #define M_FIRSTFRAG 0x00001000 /* packet is first fragment */
196 #define M_LASTFRAG 0x00002000 /* packet is last fragment */
197 #define M_SKIP_FIREWALL 0x00004000 /* skip firewall processing */
198 /* 0x00008000 free */
199 #define M_VLANTAG 0x00010000 /* ether_vtag is valid */
200 #define M_PROMISC 0x00020000 /* packet was not for us */
201 #define M_NOFREE 0x00040000 /* do not free mbuf, embedded in cluster */
202 #define M_PROTO6 0x00080000 /* protocol-specific */
203 #define M_PROTO7 0x00100000 /* protocol-specific */
204 #define M_PROTO8 0x00200000 /* protocol-specific */
205 #define M_FLOWID 0x00400000 /* deprecated: flowid is valid */
206 #define M_HASHTYPEBITS 0x0F000000 /* mask of bits holding flowid hash type */
209 * For RELENG_{6,7} steal these flags for limited multiple routing table
210 * support. In RELENG_8 and beyond, use just one flag and a tag.
212 #define M_FIB 0xF0000000 /* steal some bits to store fib number. */
214 #define M_NOTIFICATION M_PROTO5 /* SCTP notification */
217 * Flags to purge when crossing layers.
219 #define M_PROTOFLAGS \
220 (M_PROTO1|M_PROTO2|M_PROTO3|M_PROTO4|M_PROTO5|M_PROTO6|M_PROTO7|M_PROTO8)
223 * Network interface cards are able to hash protocol fields (such as IPv4
224 * addresses and TCP port numbers) classify packets into flows. These flows
225 * can then be used to maintain ordering while delivering packets to the OS
226 * via parallel input queues, as well as to provide a stateless affinity
227 * model. NIC drivers can pass up the hash via m->m_pkthdr.flowid, and set
228 * m_flag fields to indicate how the hash should be interpreted by the
231 * Most NICs support RSS, which provides ordering and explicit affinity, and
232 * use the hash m_flag bits to indicate what header fields were covered by
233 * the hash. M_HASHTYPE_OPAQUE can be set by non-RSS cards or configurations
234 * that provide an opaque flow identifier, allowing for ordering and
235 * distribution without explicit affinity.
237 #define M_HASHTYPE_SHIFT 24
238 #define M_HASHTYPE_NONE 0x0
239 #define M_HASHTYPE_RSS_IPV4 0x1 /* IPv4 2-tuple */
240 #define M_HASHTYPE_RSS_TCP_IPV4 0x2 /* TCPv4 4-tuple */
241 #define M_HASHTYPE_RSS_IPV6 0x3 /* IPv6 2-tuple */
242 #define M_HASHTYPE_RSS_TCP_IPV6 0x4 /* TCPv6 4-tuple */
243 #define M_HASHTYPE_RSS_IPV6_EX 0x5 /* IPv6 2-tuple + ext hdrs */
244 #define M_HASHTYPE_RSS_TCP_IPV6_EX 0x6 /* TCPv6 4-tiple + ext hdrs */
245 #define M_HASHTYPE_OPAQUE 0xf /* ordering, not affinity */
247 #define M_HASHTYPE_CLEAR(m) (m)->m_flags &= ~(M_HASHTYPEBITS)
248 #define M_HASHTYPE_GET(m) (((m)->m_flags & M_HASHTYPEBITS) >> \
250 #define M_HASHTYPE_SET(m, v) do { \
251 (m)->m_flags &= ~M_HASHTYPEBITS; \
252 (m)->m_flags |= ((v) << M_HASHTYPE_SHIFT); \
254 #define M_HASHTYPE_TEST(m, v) (M_HASHTYPE_GET(m) == (v))
257 * Flags preserved when copying m_pkthdr.
259 #define M_COPYFLAGS \
260 (M_PKTHDR|M_EOR|M_RDONLY|M_PROTOFLAGS|M_SKIP_FIREWALL|M_BCAST|M_MCAST|\
261 M_FRAG|M_FIRSTFRAG|M_LASTFRAG|M_VLANTAG|M_PROMISC|M_FIB|M_HASHTYPEBITS)
264 * External buffer types: identify ext_buf type.
266 #define EXT_CLUSTER 1 /* mbuf cluster */
267 #define EXT_SFBUF 2 /* sendfile(2)'s sf_bufs */
268 #define EXT_JUMBOP 3 /* jumbo cluster 4096 bytes */
269 #define EXT_JUMBO9 4 /* jumbo cluster 9216 bytes */
270 #define EXT_JUMBO16 5 /* jumbo cluster 16184 bytes */
271 #define EXT_PACKET 6 /* mbuf+cluster from packet zone */
272 #define EXT_MBUF 7 /* external mbuf reference (M_IOVEC) */
273 #define EXT_NET_DRV 100 /* custom ext_buf provided by net driver(s) */
274 #define EXT_MOD_TYPE 200 /* custom module's ext_buf type */
275 #define EXT_DISPOSABLE 300 /* can throw this buffer away w/page flipping */
276 #define EXT_EXTREF 400 /* has externally maintained ref_cnt ptr */
279 * Flags indicating hw checksum support and sw checksum requirements. This
280 * field can be directly tested against if_data.ifi_hwassist.
282 #define CSUM_IP 0x0001 /* will csum IP */
283 #define CSUM_TCP 0x0002 /* will csum TCP */
284 #define CSUM_UDP 0x0004 /* will csum UDP */
285 #define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */
286 #define CSUM_TSO 0x0020 /* will do TSO */
287 #define CSUM_SCTP 0x0040 /* will csum SCTP */
288 #define CSUM_SCTP_IPV6 0x0080 /* will csum IPv6/SCTP */
290 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */
291 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */
292 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */
293 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */
294 #define CSUM_SCTP_VALID 0x1000 /* SCTP checksum is valid */
295 #define CSUM_UDP_IPV6 0x2000 /* will csum IPv6/UDP */
296 #define CSUM_TCP_IPV6 0x4000 /* will csum IPv6/TCP */
297 /* CSUM_TSO_IPV6 0x8000 will do IPv6/TSO */
299 /* CSUM_FRAGMENT_IPV6 0x10000 will do IPv6 fragementation */
301 #define CSUM_DELAY_DATA_IPV6 (CSUM_TCP_IPV6 | CSUM_UDP_IPV6)
302 #define CSUM_DATA_VALID_IPV6 CSUM_DATA_VALID
304 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP)
305 #define CSUM_DELAY_IP (CSUM_IP) /* Only v4, no v6 IP hdr csum */
310 #define MT_NOTMBUF 0 /* USED INTERNALLY ONLY! Object is not mbuf */
311 #define MT_DATA 1 /* dynamic (data) allocation */
312 #define MT_HEADER MT_DATA /* packet header, use M_PKTHDR instead */
313 #define MT_SONAME 8 /* socket name */
314 #define MT_CONTROL 14 /* extra-data protocol message */
315 #define MT_OOBDATA 15 /* expedited data */
316 #define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */
318 #define MT_NOINIT 255 /* Not a type but a flag to allocate
319 a non-initialized mbuf */
321 #define MB_NOTAGS 0x1UL /* no tags attached to mbuf */
324 * General mbuf allocator statistics structure.
326 * Many of these statistics are no longer used; we instead track many
327 * allocator statistics through UMA's built in statistics mechanism.
330 u_long m_mbufs; /* XXX */
331 u_long m_mclusts; /* XXX */
333 u_long m_drain; /* times drained protocols for space */
334 u_long m_mcfail; /* XXX: times m_copym failed */
335 u_long m_mpfail; /* XXX: times m_pullup failed */
336 u_long m_msize; /* length of an mbuf */
337 u_long m_mclbytes; /* length of an mbuf cluster */
338 u_long m_minclsize; /* min length of data to allocate a cluster */
339 u_long m_mlen; /* length of data in an mbuf */
340 u_long m_mhlen; /* length of data in a header mbuf */
342 /* Number of mbtypes (gives # elems in mbtypes[] array) */
345 /* XXX: Sendfile stats should eventually move to their own struct */
346 u_long sf_iocnt; /* times sendfile had to do disk I/O */
347 u_long sf_allocfail; /* times sfbuf allocation failed */
348 u_long sf_allocwait; /* times sfbuf allocation had to wait */
352 * Compatibility with historic mbuf allocator.
354 #define MBTOM(how) (how)
355 #define M_DONTWAIT M_NOWAIT
356 #define M_TRYWAIT M_WAITOK
357 #define M_WAIT M_WAITOK
360 * String names of mbuf-related UMA(9) and malloc(9) types. Exposed to
361 * !_KERNEL so that monitoring tools can look up the zones with
364 #define MBUF_MEM_NAME "mbuf"
365 #define MBUF_CLUSTER_MEM_NAME "mbuf_cluster"
366 #define MBUF_PACKET_MEM_NAME "mbuf_packet"
367 #define MBUF_JUMBOP_MEM_NAME "mbuf_jumbo_page"
368 #define MBUF_JUMBO9_MEM_NAME "mbuf_jumbo_9k"
369 #define MBUF_JUMBO16_MEM_NAME "mbuf_jumbo_16k"
370 #define MBUF_TAG_MEM_NAME "mbuf_tag"
371 #define MBUF_EXTREFCNT_MEM_NAME "mbuf_ext_refcnt"
376 #define MBUF_CHECKSLEEP(how) do { \
377 if (how == M_WAITOK) \
378 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, \
379 "Sleeping in \"%s\"", __func__); \
382 #define MBUF_CHECKSLEEP(how)
386 * Network buffer allocation API
388 * The rest of it is defined in kern/kern_mbuf.c
390 extern uma_zone_t zone_mbuf;
391 extern uma_zone_t zone_clust;
392 extern uma_zone_t zone_pack;
393 extern uma_zone_t zone_jumbop;
394 extern uma_zone_t zone_jumbo9;
395 extern uma_zone_t zone_jumbo16;
396 extern uma_zone_t zone_ext_refcnt;
398 void mb_free_ext(struct mbuf *);
399 int m_pkthdr_init(struct mbuf *, int);
413 #if MJUMPAGESIZE != MCLBYTES
425 panic("%s: invalid cluster size", __func__);
431 static __inline uma_zone_t
440 #if MJUMPAGESIZE != MCLBYTES
452 panic("%s: invalid cluster size", __func__);
459 * Initialize an mbuf with linear storage.
461 * Inline because the consumer text overhead will be roughly the same to
462 * initialize or call a function with this many parameters and M_PKTHDR
463 * should go away with constant propagation for !MGETHDR.
466 m_init(struct mbuf *m, uma_zone_t zone, int size, int how, short type,
473 m->m_data = m->m_dat;
477 if (flags & M_PKTHDR) {
478 if ((error = m_pkthdr_init(m, how)) != 0)
485 static __inline struct mbuf *
486 m_get(int how, short type)
492 return (uma_zalloc_arg(zone_mbuf, &args, how));
496 * XXX This should be deprecated, very little use.
498 static __inline struct mbuf *
499 m_getclr(int how, short type)
506 m = uma_zalloc_arg(zone_mbuf, &args, how);
508 bzero(m->m_data, MLEN);
512 static __inline struct mbuf *
513 m_gethdr(int how, short type)
517 args.flags = M_PKTHDR;
519 return (uma_zalloc_arg(zone_mbuf, &args, how));
522 static __inline struct mbuf *
523 m_getcl(int how, short type, int flags)
529 return (uma_zalloc_arg(zone_pack, &args, how));
533 m_free_fast(struct mbuf *m)
536 if (m->m_flags & M_PKTHDR)
537 KASSERT(SLIST_EMPTY(&m->m_pkthdr.tags), ("doing fast free of mbuf with tags"));
540 uma_zfree_arg(zone_mbuf, m, (void *)MB_NOTAGS);
543 static __inline struct mbuf *
544 m_free(struct mbuf *m)
546 struct mbuf *n = m->m_next;
548 if (m->m_flags & M_EXT)
550 else if ((m->m_flags & M_NOFREE) == 0)
551 uma_zfree(zone_mbuf, m);
556 m_clget(struct mbuf *m, int how)
559 if (m->m_flags & M_EXT)
560 printf("%s: %p mbuf already has cluster\n", __func__, m);
561 m->m_ext.ext_buf = (char *)NULL;
562 uma_zalloc_arg(zone_clust, m, how);
564 * On a cluster allocation failure, drain the packet zone and retry,
565 * we might be able to loosen a few clusters up on the drain.
567 if ((how & M_NOWAIT) && (m->m_ext.ext_buf == NULL)) {
568 zone_drain(zone_pack);
569 uma_zalloc_arg(zone_clust, m, how);
574 * m_cljget() is different from m_clget() as it can allocate clusters without
575 * attaching them to an mbuf. In that case the return value is the pointer
576 * to the cluster of the requested size. If an mbuf was specified, it gets
577 * the cluster attached to it and the return value can be safely ignored.
578 * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES.
580 static __inline void *
581 m_cljget(struct mbuf *m, int how, int size)
585 if (m && m->m_flags & M_EXT)
586 printf("%s: %p mbuf already has cluster\n", __func__, m);
588 m->m_ext.ext_buf = NULL;
590 zone = m_getzone(size);
591 return (uma_zalloc_arg(zone, m, how));
595 m_cljset(struct mbuf *m, void *cl, int type)
605 #if MJUMPAGESIZE != MCLBYTES
620 panic("%s: unknown cluster type", __func__);
624 m->m_data = m->m_ext.ext_buf = cl;
625 m->m_ext.ext_free = m->m_ext.ext_arg1 = m->m_ext.ext_arg2 = NULL;
626 m->m_ext.ext_size = size;
627 m->m_ext.ext_type = type;
628 m->m_ext.ref_cnt = uma_find_refcnt(zone, cl);
634 m_chtype(struct mbuf *m, short new_type)
637 m->m_type = new_type;
640 static __inline struct mbuf *
641 m_last(struct mbuf *m)
650 * mbuf, cluster, and external object allocation macros (for compatibility
653 #define M_MOVE_PKTHDR(to, from) m_move_pkthdr((to), (from))
654 #define MGET(m, how, type) ((m) = m_get((how), (type)))
655 #define MGETHDR(m, how, type) ((m) = m_gethdr((how), (type)))
656 #define MCLGET(m, how) m_clget((m), (how))
657 #define MEXTADD(m, buf, size, free, arg1, arg2, flags, type) \
658 (void )m_extadd((m), (caddr_t)(buf), (size), (free), (arg1), (arg2),\
659 (flags), (type), M_NOWAIT)
660 #define m_getm(m, len, how, type) \
661 m_getm2((m), (len), (how), (type), M_PKTHDR)
664 * Evaluate TRUE if it's safe to write to the mbuf m's data region (this can
665 * be both the local data payload, or an external buffer area, depending on
666 * whether M_EXT is set).
668 #define M_WRITABLE(m) (!((m)->m_flags & M_RDONLY) && \
669 (!(((m)->m_flags & M_EXT)) || \
670 (*((m)->m_ext.ref_cnt) == 1)) ) \
672 /* Check if the supplied mbuf has a packet header, or else panic. */
673 #define M_ASSERTPKTHDR(m) \
674 KASSERT((m) != NULL && (m)->m_flags & M_PKTHDR, \
675 ("%s: no mbuf packet header!", __func__))
678 * Ensure that the supplied mbuf is a valid, non-free mbuf.
680 * XXX: Broken at the moment. Need some UMA magic to make it work again.
682 #define M_ASSERTVALID(m) \
683 KASSERT((((struct mbuf *)m)->m_flags & 0) == 0, \
684 ("%s: attempted use of a free mbuf!", __func__))
687 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place an
688 * object of the specified size at the end of the mbuf, longword aligned.
690 #define M_ALIGN(m, len) do { \
691 KASSERT(!((m)->m_flags & (M_PKTHDR|M_EXT)), \
692 ("%s: M_ALIGN not normal mbuf", __func__)); \
693 KASSERT((m)->m_data == (m)->m_dat, \
694 ("%s: M_ALIGN not a virgin mbuf", __func__)); \
695 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \
699 * As above, for mbufs allocated with m_gethdr/MGETHDR or initialized by
702 #define MH_ALIGN(m, len) do { \
703 KASSERT((m)->m_flags & M_PKTHDR && !((m)->m_flags & M_EXT), \
704 ("%s: MH_ALIGN not PKTHDR mbuf", __func__)); \
705 KASSERT((m)->m_data == (m)->m_pktdat, \
706 ("%s: MH_ALIGN not a virgin mbuf", __func__)); \
707 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \
711 * As above, for mbuf with external storage.
713 #define MEXT_ALIGN(m, len) do { \
714 KASSERT((m)->m_flags & M_EXT, \
715 ("%s: MEXT_ALIGN not an M_EXT mbuf", __func__)); \
716 KASSERT((m)->m_data == (m)->m_ext.ext_buf, \
717 ("%s: MEXT_ALIGN not a virgin mbuf", __func__)); \
718 (m)->m_data += ((m)->m_ext.ext_size - (len)) & \
719 ~(sizeof(long) - 1); \
723 * Compute the amount of space available before the current start of data in
726 * The M_WRITABLE() is a temporary, conservative safety measure: the burden
727 * of checking writability of the mbuf data area rests solely with the caller.
729 #define M_LEADINGSPACE(m) \
730 ((m)->m_flags & M_EXT ? \
731 (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \
732 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \
733 (m)->m_data - (m)->m_dat)
736 * Compute the amount of space available after the end of data in an mbuf.
738 * The M_WRITABLE() is a temporary, conservative safety measure: the burden
739 * of checking writability of the mbuf data area rests solely with the caller.
741 #define M_TRAILINGSPACE(m) \
742 ((m)->m_flags & M_EXT ? \
743 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \
744 - ((m)->m_data + (m)->m_len) : 0) : \
745 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
748 * Arrange to prepend space of size plen to mbuf m. If a new mbuf must be
749 * allocated, how specifies whether to wait. If the allocation fails, the
750 * original mbuf chain is freed and m is set to NULL.
752 #define M_PREPEND(m, plen, how) do { \
753 struct mbuf **_mmp = &(m); \
754 struct mbuf *_mm = *_mmp; \
755 int _mplen = (plen); \
756 int __mhow = (how); \
758 MBUF_CHECKSLEEP(how); \
759 if (M_LEADINGSPACE(_mm) >= _mplen) { \
760 _mm->m_data -= _mplen; \
761 _mm->m_len += _mplen; \
763 _mm = m_prepend(_mm, _mplen, __mhow); \
764 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \
765 _mm->m_pkthdr.len += _mplen; \
770 * Change mbuf to new type. This is a relatively expensive operation and
773 #define MCHTYPE(m, t) m_chtype((m), (t))
775 /* Length to m_copy to copy all. */
776 #define M_COPYALL 1000000000
778 /* Compatibility with 4.3. */
779 #define m_copy(m, o, l) m_copym((m), (o), (l), M_NOWAIT)
781 extern int max_datalen; /* MHLEN - max_hdr */
782 extern int max_hdr; /* Largest link + protocol header */
783 extern int max_linkhdr; /* Largest link-level header */
784 extern int max_protohdr; /* Largest protocol header */
785 extern struct mbstat mbstat; /* General mbuf stats/infos */
786 extern int nmbclusters; /* Maximum number of clusters */
790 void m_adj(struct mbuf *, int);
791 void m_align(struct mbuf *, int);
792 int m_apply(struct mbuf *, int, int,
793 int (*)(void *, void *, u_int), void *);
794 int m_append(struct mbuf *, int, c_caddr_t);
795 void m_cat(struct mbuf *, struct mbuf *);
796 int m_extadd(struct mbuf *, caddr_t, u_int,
797 void (*)(void *, void *), void *, void *, int, int, int);
798 struct mbuf *m_collapse(struct mbuf *, int, int);
799 void m_copyback(struct mbuf *, int, int, c_caddr_t);
800 void m_copydata(const struct mbuf *, int, int, caddr_t);
801 struct mbuf *m_copym(struct mbuf *, int, int, int);
802 struct mbuf *m_copymdata(struct mbuf *, struct mbuf *,
804 struct mbuf *m_copypacket(struct mbuf *, int);
805 void m_copy_pkthdr(struct mbuf *, struct mbuf *);
806 struct mbuf *m_copyup(struct mbuf *, int, int);
807 struct mbuf *m_defrag(struct mbuf *, int);
808 void m_demote(struct mbuf *, int);
809 struct mbuf *m_devget(char *, int, int, struct ifnet *,
810 void (*)(char *, caddr_t, u_int));
811 struct mbuf *m_dup(struct mbuf *, int);
812 int m_dup_pkthdr(struct mbuf *, struct mbuf *, int);
813 u_int m_fixhdr(struct mbuf *);
814 struct mbuf *m_fragment(struct mbuf *, int, int);
815 void m_freem(struct mbuf *);
816 struct mbuf *m_get2(int, int, short, int);
817 struct mbuf *m_getjcl(int, short, int, int);
818 struct mbuf *m_getm2(struct mbuf *, int, int, short, int);
819 struct mbuf *m_getptr(struct mbuf *, int, int *);
820 u_int m_length(struct mbuf *, struct mbuf **);
821 int m_mbuftouio(struct uio *, struct mbuf *, int);
822 void m_move_pkthdr(struct mbuf *, struct mbuf *);
823 struct mbuf *m_prepend(struct mbuf *, int, int);
824 void m_print(const struct mbuf *, int);
825 struct mbuf *m_pulldown(struct mbuf *, int, int, int *);
826 struct mbuf *m_pullup(struct mbuf *, int);
827 int m_sanity(struct mbuf *, int);
828 struct mbuf *m_split(struct mbuf *, int, int);
829 struct mbuf *m_uiotombuf(struct uio *, int, int, int, int);
830 struct mbuf *m_unshare(struct mbuf *, int);
833 * Network packets may have annotations attached by affixing a list of
834 * "packet tags" to the pkthdr structure. Packet tags are dynamically
835 * allocated semi-opaque data structures that have a fixed header
836 * (struct m_tag) that specifies the size of the memory block and a
837 * <cookie,type> pair that identifies it. The cookie is a 32-bit unique
838 * unsigned value used to identify a module or ABI. By convention this value
839 * is chosen as the date+time that the module is created, expressed as the
840 * number of seconds since the epoch (e.g., using date -u +'%s'). The type
841 * value is an ABI/module-specific value that identifies a particular
842 * annotation and is private to the module. For compatibility with systems
843 * like OpenBSD that define packet tags w/o an ABI/module cookie, the value
844 * PACKET_ABI_COMPAT is used to implement m_tag_get and m_tag_find
845 * compatibility shim functions and several tag types are defined below.
846 * Users that do not require compatibility should use a private cookie value
847 * so that packet tag-related definitions can be maintained privately.
849 * Note that the packet tag returned by m_tag_alloc has the default memory
850 * alignment implemented by malloc. To reference private data one can use a
853 * struct m_tag *mtag = m_tag_alloc(...);
854 * struct foo *p = (struct foo *)(mtag+1);
856 * if the alignment of struct m_tag is sufficient for referencing members of
857 * struct foo. Otherwise it is necessary to embed struct m_tag within the
858 * private data structure to insure proper alignment; e.g.,
864 * struct foo *p = (struct foo *) m_tag_alloc(...);
865 * struct m_tag *mtag = &p->tag;
869 * Persistent tags stay with an mbuf until the mbuf is reclaimed. Otherwise
870 * tags are expected to ``vanish'' when they pass through a network
871 * interface. For most interfaces this happens normally as the tags are
872 * reclaimed when the mbuf is free'd. However in some special cases
873 * reclaiming must be done manually. An example is packets that pass through
874 * the loopback interface. Also, one must be careful to do this when
875 * ``turning around'' packets (e.g., icmp_reflect).
877 * To mark a tag persistent bit-or this flag in when defining the tag id.
878 * The tag will then be treated as described above.
880 #define MTAG_PERSISTENT 0x800
882 #define PACKET_TAG_NONE 0 /* Nadda */
884 /* Packet tags for use with PACKET_ABI_COMPAT. */
885 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */
886 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */
887 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */
888 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */
889 #define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO 5 /* NIC notifies IPsec */
890 #define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */
891 #define PACKET_TAG_BRIDGE 7 /* Bridge processing done */
892 #define PACKET_TAG_GIF 8 /* GIF processing done */
893 #define PACKET_TAG_GRE 9 /* GRE processing done */
894 #define PACKET_TAG_IN_PACKET_CHECKSUM 10 /* NIC checksumming done */
895 #define PACKET_TAG_ENCAP 11 /* Encap. processing */
896 #define PACKET_TAG_IPSEC_SOCKET 12 /* IPSEC socket ref */
897 #define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */
898 #define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */
899 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */
900 #define PACKET_TAG_DIVERT 17 /* divert info */
901 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */
902 #define PACKET_TAG_MACLABEL (19 | MTAG_PERSISTENT) /* MAC label */
903 #define PACKET_TAG_PF (21 | MTAG_PERSISTENT) /* PF/ALTQ information */
904 #define PACKET_TAG_RTSOCKFAM 25 /* rtsock sa family */
905 #define PACKET_TAG_IPOPTIONS 27 /* Saved IP options */
906 #define PACKET_TAG_CARP 28 /* CARP info */
907 #define PACKET_TAG_IPSEC_NAT_T_PORTS 29 /* two uint16_t */
908 #define PACKET_TAG_ND_OUTGOING 30 /* ND outgoing */
910 /* Specific cookies and tags. */
912 /* Packet tag routines. */
913 struct m_tag *m_tag_alloc(u_int32_t, int, int, int);
914 void m_tag_delete(struct mbuf *, struct m_tag *);
915 void m_tag_delete_chain(struct mbuf *, struct m_tag *);
916 void m_tag_free_default(struct m_tag *);
917 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *);
918 struct m_tag *m_tag_copy(struct m_tag *, int);
919 int m_tag_copy_chain(struct mbuf *, struct mbuf *, int);
920 void m_tag_delete_nonpersistent(struct mbuf *);
923 * Initialize the list of tags associated with an mbuf.
926 m_tag_init(struct mbuf *m)
929 SLIST_INIT(&m->m_pkthdr.tags);
933 * Set up the contents of a tag. Note that this does not fill in the free
934 * method; the caller is expected to do that.
936 * XXX probably should be called m_tag_init, but that was already taken.
939 m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len)
944 t->m_tag_cookie = cookie;
948 * Reclaim resources associated with a tag.
951 m_tag_free(struct m_tag *t)
958 * Return the first tag associated with an mbuf.
960 static __inline struct m_tag *
961 m_tag_first(struct mbuf *m)
964 return (SLIST_FIRST(&m->m_pkthdr.tags));
968 * Return the next tag in the list of tags associated with an mbuf.
970 static __inline struct m_tag *
971 m_tag_next(struct mbuf *m, struct m_tag *t)
974 return (SLIST_NEXT(t, m_tag_link));
978 * Prepend a tag to the list of tags associated with an mbuf.
981 m_tag_prepend(struct mbuf *m, struct m_tag *t)
984 SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link);
988 * Unlink a tag from the list of tags associated with an mbuf.
991 m_tag_unlink(struct mbuf *m, struct m_tag *t)
994 SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link);
997 /* These are for OpenBSD compatibility. */
998 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */
1000 static __inline struct m_tag *
1001 m_tag_get(int type, int length, int wait)
1003 return (m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait));
1006 static __inline struct m_tag *
1007 m_tag_find(struct mbuf *m, int type, struct m_tag *start)
1009 return (SLIST_EMPTY(&m->m_pkthdr.tags) ? (struct m_tag *)NULL :
1010 m_tag_locate(m, MTAG_ABI_COMPAT, type, start));
1013 /* XXX temporary FIB methods probably eventually use tags.*/
1014 #define M_FIBSHIFT 28
1015 #define M_FIBMASK 0x0F
1017 /* get the fib from an mbuf and if it is not set, return the default */
1018 #define M_GETFIB(_m) \
1019 ((((_m)->m_flags & M_FIB) >> M_FIBSHIFT) & M_FIBMASK)
1021 #define M_SETFIB(_m, _fib) do { \
1022 _m->m_flags &= ~M_FIB; \
1023 _m->m_flags |= (((_fib) << M_FIBSHIFT) & M_FIB); \
1026 #endif /* _KERNEL */
1028 #ifdef MBUF_PROFILING
1029 void m_profile(struct mbuf *m);
1030 #define M_PROFILE(m) m_profile(m)
1032 #define M_PROFILE(m)
1036 #endif /* !_SYS_MBUF_H_ */