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 * 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 u_int16_t fibnum; /* this packet should use this fib */
133 u_int16_t pad2; /* align to 32 bits */
134 SLIST_HEAD(packet_tags, m_tag) tags; /* list of packet tags */
136 #define ether_vtag PH_vt.vt_vtag
139 * Description of external storage mapped into mbuf; valid only if M_EXT is
143 caddr_t ext_buf; /* start of buffer */
144 void (*ext_free) /* free routine if not the usual */
146 void *ext_arg1; /* optional argument pointer */
147 void *ext_arg2; /* optional argument pointer */
148 u_int ext_size; /* size of buffer, for ext_free */
149 volatile u_int *ref_cnt; /* pointer to ref count info */
150 int ext_type; /* type of external storage */
154 * The core of the mbuf object along with some shortcut defines for practical
161 struct pkthdr MH_pkthdr; /* M_PKTHDR set */
163 struct m_ext MH_ext; /* M_EXT set */
164 char MH_databuf[MHLEN];
167 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */
170 #define m_next m_hdr.mh_next
171 #define m_len m_hdr.mh_len
172 #define m_data m_hdr.mh_data
173 #define m_type m_hdr.mh_type
174 #define m_flags m_hdr.mh_flags
175 #define m_nextpkt m_hdr.mh_nextpkt
176 #define m_act m_nextpkt
177 #define m_pkthdr M_dat.MH.MH_pkthdr
178 #define m_ext M_dat.MH.MH_dat.MH_ext
179 #define m_pktdat M_dat.MH.MH_dat.MH_databuf
180 #define m_dat M_dat.M_databuf
185 #define M_EXT 0x00000001 /* has associated external storage */
186 #define M_PKTHDR 0x00000002 /* start of record */
187 #define M_EOR 0x00000004 /* end of record */
188 #define M_RDONLY 0x00000008 /* associated data is marked read-only */
189 #define M_PROTO1 0x00000010 /* protocol-specific */
190 #define M_PROTO2 0x00000020 /* protocol-specific */
191 #define M_PROTO3 0x00000040 /* protocol-specific */
192 #define M_PROTO4 0x00000080 /* protocol-specific */
193 #define M_PROTO5 0x00000100 /* protocol-specific */
194 #define M_BCAST 0x00000200 /* send/received as link-level broadcast */
195 #define M_MCAST 0x00000400 /* send/received as link-level multicast */
196 #define M_FRAG 0x00000800 /* packet is a fragment of a larger packet */
197 #define M_FIRSTFRAG 0x00001000 /* packet is first fragment */
198 #define M_LASTFRAG 0x00002000 /* packet is last fragment */
199 #define M_SKIP_FIREWALL 0x00004000 /* skip firewall processing */
200 /* 0x00008000 free */
201 #define M_VLANTAG 0x00010000 /* ether_vtag is valid */
202 #define M_PROMISC 0x00020000 /* packet was not for us */
203 #define M_NOFREE 0x00040000 /* do not free mbuf, embedded in cluster */
204 #define M_PROTO6 0x00080000 /* protocol-specific */
205 #define M_PROTO7 0x00100000 /* protocol-specific */
206 #define M_PROTO8 0x00200000 /* protocol-specific */
207 #define M_FLOWID 0x00400000 /* deprecated: flowid is valid */
208 #define M_HASHTYPEBITS 0x0F000000 /* mask of bits holding flowid hash type */
210 #define M_NOTIFICATION M_PROTO5 /* SCTP notification */
213 * Flags to purge when crossing layers.
215 #define M_PROTOFLAGS \
216 (M_PROTO1|M_PROTO2|M_PROTO3|M_PROTO4|M_PROTO5|M_PROTO6|M_PROTO7|M_PROTO8)
219 * Network interface cards are able to hash protocol fields (such as IPv4
220 * addresses and TCP port numbers) classify packets into flows. These flows
221 * can then be used to maintain ordering while delivering packets to the OS
222 * via parallel input queues, as well as to provide a stateless affinity
223 * model. NIC drivers can pass up the hash via m->m_pkthdr.flowid, and set
224 * m_flag fields to indicate how the hash should be interpreted by the
227 * Most NICs support RSS, which provides ordering and explicit affinity, and
228 * use the hash m_flag bits to indicate what header fields were covered by
229 * the hash. M_HASHTYPE_OPAQUE can be set by non-RSS cards or configurations
230 * that provide an opaque flow identifier, allowing for ordering and
231 * distribution without explicit affinity.
233 #define M_HASHTYPE_SHIFT 24
234 #define M_HASHTYPE_NONE 0x0
235 #define M_HASHTYPE_RSS_IPV4 0x1 /* IPv4 2-tuple */
236 #define M_HASHTYPE_RSS_TCP_IPV4 0x2 /* TCPv4 4-tuple */
237 #define M_HASHTYPE_RSS_IPV6 0x3 /* IPv6 2-tuple */
238 #define M_HASHTYPE_RSS_TCP_IPV6 0x4 /* TCPv6 4-tuple */
239 #define M_HASHTYPE_RSS_IPV6_EX 0x5 /* IPv6 2-tuple + ext hdrs */
240 #define M_HASHTYPE_RSS_TCP_IPV6_EX 0x6 /* TCPv6 4-tiple + ext hdrs */
241 #define M_HASHTYPE_OPAQUE 0xf /* ordering, not affinity */
243 #define M_HASHTYPE_CLEAR(m) (m)->m_flags &= ~(M_HASHTYPEBITS)
244 #define M_HASHTYPE_GET(m) (((m)->m_flags & M_HASHTYPEBITS) >> \
246 #define M_HASHTYPE_SET(m, v) do { \
247 (m)->m_flags &= ~M_HASHTYPEBITS; \
248 (m)->m_flags |= ((v) << M_HASHTYPE_SHIFT); \
250 #define M_HASHTYPE_TEST(m, v) (M_HASHTYPE_GET(m) == (v))
253 * Flags preserved when copying m_pkthdr.
255 #define M_COPYFLAGS \
256 (M_PKTHDR|M_EOR|M_RDONLY|M_PROTOFLAGS|M_SKIP_FIREWALL|M_BCAST|M_MCAST|\
257 M_FRAG|M_FIRSTFRAG|M_LASTFRAG|M_VLANTAG|M_PROMISC|M_HASHTYPEBITS)
260 * External buffer types: identify ext_buf type.
262 #define EXT_CLUSTER 1 /* mbuf cluster */
263 #define EXT_SFBUF 2 /* sendfile(2)'s sf_bufs */
264 #define EXT_JUMBOP 3 /* jumbo cluster 4096 bytes */
265 #define EXT_JUMBO9 4 /* jumbo cluster 9216 bytes */
266 #define EXT_JUMBO16 5 /* jumbo cluster 16184 bytes */
267 #define EXT_PACKET 6 /* mbuf+cluster from packet zone */
268 #define EXT_MBUF 7 /* external mbuf reference (M_IOVEC) */
269 #define EXT_NET_DRV 100 /* custom ext_buf provided by net driver(s) */
270 #define EXT_MOD_TYPE 200 /* custom module's ext_buf type */
271 #define EXT_DISPOSABLE 300 /* can throw this buffer away w/page flipping */
272 #define EXT_EXTREF 400 /* has externally maintained ref_cnt ptr */
275 * Flags indicating hw checksum support and sw checksum requirements. This
276 * field can be directly tested against if_data.ifi_hwassist.
278 #define CSUM_IP 0x0001 /* will csum IP */
279 #define CSUM_TCP 0x0002 /* will csum TCP */
280 #define CSUM_UDP 0x0004 /* will csum UDP */
281 #define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */
282 #define CSUM_TSO 0x0020 /* will do TSO */
283 #define CSUM_SCTP 0x0040 /* will csum SCTP */
284 #define CSUM_SCTP_IPV6 0x0080 /* will csum IPv6/SCTP */
286 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */
287 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */
288 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */
289 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */
290 #define CSUM_SCTP_VALID 0x1000 /* SCTP checksum is valid */
291 #define CSUM_UDP_IPV6 0x2000 /* will csum IPv6/UDP */
292 #define CSUM_TCP_IPV6 0x4000 /* will csum IPv6/TCP */
293 /* CSUM_TSO_IPV6 0x8000 will do IPv6/TSO */
295 /* CSUM_FRAGMENT_IPV6 0x10000 will do IPv6 fragementation */
297 #define CSUM_DELAY_DATA_IPV6 (CSUM_TCP_IPV6 | CSUM_UDP_IPV6)
298 #define CSUM_DATA_VALID_IPV6 CSUM_DATA_VALID
300 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP)
301 #define CSUM_DELAY_IP (CSUM_IP) /* Only v4, no v6 IP hdr csum */
306 #define MT_NOTMBUF 0 /* USED INTERNALLY ONLY! Object is not mbuf */
307 #define MT_DATA 1 /* dynamic (data) allocation */
308 #define MT_HEADER MT_DATA /* packet header, use M_PKTHDR instead */
309 #define MT_SONAME 8 /* socket name */
310 #define MT_CONTROL 14 /* extra-data protocol message */
311 #define MT_OOBDATA 15 /* expedited data */
312 #define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */
314 #define MT_NOINIT 255 /* Not a type but a flag to allocate
315 a non-initialized mbuf */
317 #define MB_NOTAGS 0x1UL /* no tags attached to mbuf */
320 * General mbuf allocator statistics structure.
322 * Many of these statistics are no longer used; we instead track many
323 * allocator statistics through UMA's built in statistics mechanism.
326 u_long m_mbufs; /* XXX */
327 u_long m_mclusts; /* XXX */
329 u_long m_drain; /* times drained protocols for space */
330 u_long m_mcfail; /* XXX: times m_copym failed */
331 u_long m_mpfail; /* XXX: times m_pullup failed */
332 u_long m_msize; /* length of an mbuf */
333 u_long m_mclbytes; /* length of an mbuf cluster */
334 u_long m_minclsize; /* min length of data to allocate a cluster */
335 u_long m_mlen; /* length of data in an mbuf */
336 u_long m_mhlen; /* length of data in a header mbuf */
338 /* Number of mbtypes (gives # elems in mbtypes[] array) */
341 /* XXX: Sendfile stats should eventually move to their own struct */
342 u_long sf_iocnt; /* times sendfile had to do disk I/O */
343 u_long sf_allocfail; /* times sfbuf allocation failed */
344 u_long sf_allocwait; /* times sfbuf allocation had to wait */
348 * Compatibility with historic mbuf allocator.
350 #define MBTOM(how) (how)
351 #define M_DONTWAIT M_NOWAIT
352 #define M_TRYWAIT M_WAITOK
353 #define M_WAIT M_WAITOK
356 * String names of mbuf-related UMA(9) and malloc(9) types. Exposed to
357 * !_KERNEL so that monitoring tools can look up the zones with
360 #define MBUF_MEM_NAME "mbuf"
361 #define MBUF_CLUSTER_MEM_NAME "mbuf_cluster"
362 #define MBUF_PACKET_MEM_NAME "mbuf_packet"
363 #define MBUF_JUMBOP_MEM_NAME "mbuf_jumbo_page"
364 #define MBUF_JUMBO9_MEM_NAME "mbuf_jumbo_9k"
365 #define MBUF_JUMBO16_MEM_NAME "mbuf_jumbo_16k"
366 #define MBUF_TAG_MEM_NAME "mbuf_tag"
367 #define MBUF_EXTREFCNT_MEM_NAME "mbuf_ext_refcnt"
372 #define MBUF_CHECKSLEEP(how) do { \
373 if (how == M_WAITOK) \
374 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, \
375 "Sleeping in \"%s\"", __func__); \
378 #define MBUF_CHECKSLEEP(how)
382 * Network buffer allocation API
384 * The rest of it is defined in kern/kern_mbuf.c
386 extern uma_zone_t zone_mbuf;
387 extern uma_zone_t zone_clust;
388 extern uma_zone_t zone_pack;
389 extern uma_zone_t zone_jumbop;
390 extern uma_zone_t zone_jumbo9;
391 extern uma_zone_t zone_jumbo16;
392 extern uma_zone_t zone_ext_refcnt;
394 void mb_free_ext(struct mbuf *);
395 int m_pkthdr_init(struct mbuf *, int);
409 #if MJUMPAGESIZE != MCLBYTES
421 panic("%s: invalid cluster size", __func__);
427 static __inline uma_zone_t
436 #if MJUMPAGESIZE != MCLBYTES
448 panic("%s: invalid cluster size", __func__);
455 * Initialize an mbuf with linear storage.
457 * Inline because the consumer text overhead will be roughly the same to
458 * initialize or call a function with this many parameters and M_PKTHDR
459 * should go away with constant propagation for !MGETHDR.
462 m_init(struct mbuf *m, uma_zone_t zone, int size, int how, short type,
469 m->m_data = m->m_dat;
473 if (flags & M_PKTHDR) {
474 if ((error = m_pkthdr_init(m, how)) != 0)
481 static __inline struct mbuf *
482 m_get(int how, short type)
488 return (uma_zalloc_arg(zone_mbuf, &args, how));
492 * XXX This should be deprecated, very little use.
494 static __inline struct mbuf *
495 m_getclr(int how, short type)
502 m = uma_zalloc_arg(zone_mbuf, &args, how);
504 bzero(m->m_data, MLEN);
508 static __inline struct mbuf *
509 m_gethdr(int how, short type)
513 args.flags = M_PKTHDR;
515 return (uma_zalloc_arg(zone_mbuf, &args, how));
518 static __inline struct mbuf *
519 m_getcl(int how, short type, int flags)
525 return (uma_zalloc_arg(zone_pack, &args, how));
529 m_free_fast(struct mbuf *m)
532 if (m->m_flags & M_PKTHDR)
533 KASSERT(SLIST_EMPTY(&m->m_pkthdr.tags), ("doing fast free of mbuf with tags"));
536 uma_zfree_arg(zone_mbuf, m, (void *)MB_NOTAGS);
539 static __inline struct mbuf *
540 m_free(struct mbuf *m)
542 struct mbuf *n = m->m_next;
544 if (m->m_flags & M_EXT)
546 else if ((m->m_flags & M_NOFREE) == 0)
547 uma_zfree(zone_mbuf, m);
552 m_clget(struct mbuf *m, int how)
555 if (m->m_flags & M_EXT)
556 printf("%s: %p mbuf already has cluster\n", __func__, m);
557 m->m_ext.ext_buf = (char *)NULL;
558 uma_zalloc_arg(zone_clust, m, how);
560 * On a cluster allocation failure, drain the packet zone and retry,
561 * we might be able to loosen a few clusters up on the drain.
563 if ((how & M_NOWAIT) && (m->m_ext.ext_buf == NULL)) {
564 zone_drain(zone_pack);
565 uma_zalloc_arg(zone_clust, m, how);
570 * m_cljget() is different from m_clget() as it can allocate clusters without
571 * attaching them to an mbuf. In that case the return value is the pointer
572 * to the cluster of the requested size. If an mbuf was specified, it gets
573 * the cluster attached to it and the return value can be safely ignored.
574 * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES.
576 static __inline void *
577 m_cljget(struct mbuf *m, int how, int size)
581 if (m && m->m_flags & M_EXT)
582 printf("%s: %p mbuf already has cluster\n", __func__, m);
584 m->m_ext.ext_buf = NULL;
586 zone = m_getzone(size);
587 return (uma_zalloc_arg(zone, m, how));
591 m_cljset(struct mbuf *m, void *cl, int type)
601 #if MJUMPAGESIZE != MCLBYTES
616 panic("%s: unknown cluster type", __func__);
620 m->m_data = m->m_ext.ext_buf = cl;
621 m->m_ext.ext_free = m->m_ext.ext_arg1 = m->m_ext.ext_arg2 = NULL;
622 m->m_ext.ext_size = size;
623 m->m_ext.ext_type = type;
624 m->m_ext.ref_cnt = uma_find_refcnt(zone, cl);
630 m_chtype(struct mbuf *m, short new_type)
633 m->m_type = new_type;
636 static __inline struct mbuf *
637 m_last(struct mbuf *m)
646 * mbuf, cluster, and external object allocation macros (for compatibility
649 #define M_MOVE_PKTHDR(to, from) m_move_pkthdr((to), (from))
650 #define MGET(m, how, type) ((m) = m_get((how), (type)))
651 #define MGETHDR(m, how, type) ((m) = m_gethdr((how), (type)))
652 #define MCLGET(m, how) m_clget((m), (how))
653 #define MEXTADD(m, buf, size, free, arg1, arg2, flags, type) \
654 (void )m_extadd((m), (caddr_t)(buf), (size), (free), (arg1), (arg2),\
655 (flags), (type), M_NOWAIT)
656 #define m_getm(m, len, how, type) \
657 m_getm2((m), (len), (how), (type), M_PKTHDR)
660 * Evaluate TRUE if it's safe to write to the mbuf m's data region (this can
661 * be both the local data payload, or an external buffer area, depending on
662 * whether M_EXT is set).
664 #define M_WRITABLE(m) (!((m)->m_flags & M_RDONLY) && \
665 (!(((m)->m_flags & M_EXT)) || \
666 (*((m)->m_ext.ref_cnt) == 1)) ) \
668 /* Check if the supplied mbuf has a packet header, or else panic. */
669 #define M_ASSERTPKTHDR(m) \
670 KASSERT((m) != NULL && (m)->m_flags & M_PKTHDR, \
671 ("%s: no mbuf packet header!", __func__))
674 * Ensure that the supplied mbuf is a valid, non-free mbuf.
676 * XXX: Broken at the moment. Need some UMA magic to make it work again.
678 #define M_ASSERTVALID(m) \
679 KASSERT((((struct mbuf *)m)->m_flags & 0) == 0, \
680 ("%s: attempted use of a free mbuf!", __func__))
683 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place an
684 * object of the specified size at the end of the mbuf, longword aligned.
686 #define M_ALIGN(m, len) do { \
687 KASSERT(!((m)->m_flags & (M_PKTHDR|M_EXT)), \
688 ("%s: M_ALIGN not normal mbuf", __func__)); \
689 KASSERT((m)->m_data == (m)->m_dat, \
690 ("%s: M_ALIGN not a virgin mbuf", __func__)); \
691 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \
695 * As above, for mbufs allocated with m_gethdr/MGETHDR or initialized by
698 #define MH_ALIGN(m, len) do { \
699 KASSERT((m)->m_flags & M_PKTHDR && !((m)->m_flags & M_EXT), \
700 ("%s: MH_ALIGN not PKTHDR mbuf", __func__)); \
701 KASSERT((m)->m_data == (m)->m_pktdat, \
702 ("%s: MH_ALIGN not a virgin mbuf", __func__)); \
703 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \
707 * As above, for mbuf with external storage.
709 #define MEXT_ALIGN(m, len) do { \
710 KASSERT((m)->m_flags & M_EXT, \
711 ("%s: MEXT_ALIGN not an M_EXT mbuf", __func__)); \
712 KASSERT((m)->m_data == (m)->m_ext.ext_buf, \
713 ("%s: MEXT_ALIGN not a virgin mbuf", __func__)); \
714 (m)->m_data += ((m)->m_ext.ext_size - (len)) & \
715 ~(sizeof(long) - 1); \
719 * Compute the amount of space available before the current start of data in
722 * The M_WRITABLE() is a temporary, conservative safety measure: the burden
723 * of checking writability of the mbuf data area rests solely with the caller.
725 #define M_LEADINGSPACE(m) \
726 ((m)->m_flags & M_EXT ? \
727 (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \
728 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \
729 (m)->m_data - (m)->m_dat)
732 * Compute the amount of space available after the end of data in an mbuf.
734 * The M_WRITABLE() is a temporary, conservative safety measure: the burden
735 * of checking writability of the mbuf data area rests solely with the caller.
737 #define M_TRAILINGSPACE(m) \
738 ((m)->m_flags & M_EXT ? \
739 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \
740 - ((m)->m_data + (m)->m_len) : 0) : \
741 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
744 * Arrange to prepend space of size plen to mbuf m. If a new mbuf must be
745 * allocated, how specifies whether to wait. If the allocation fails, the
746 * original mbuf chain is freed and m is set to NULL.
748 #define M_PREPEND(m, plen, how) do { \
749 struct mbuf **_mmp = &(m); \
750 struct mbuf *_mm = *_mmp; \
751 int _mplen = (plen); \
752 int __mhow = (how); \
754 MBUF_CHECKSLEEP(how); \
755 if (M_LEADINGSPACE(_mm) >= _mplen) { \
756 _mm->m_data -= _mplen; \
757 _mm->m_len += _mplen; \
759 _mm = m_prepend(_mm, _mplen, __mhow); \
760 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \
761 _mm->m_pkthdr.len += _mplen; \
766 * Change mbuf to new type. This is a relatively expensive operation and
769 #define MCHTYPE(m, t) m_chtype((m), (t))
771 /* Length to m_copy to copy all. */
772 #define M_COPYALL 1000000000
774 /* Compatibility with 4.3. */
775 #define m_copy(m, o, l) m_copym((m), (o), (l), M_NOWAIT)
777 extern int max_datalen; /* MHLEN - max_hdr */
778 extern int max_hdr; /* Largest link + protocol header */
779 extern int max_linkhdr; /* Largest link-level header */
780 extern int max_protohdr; /* Largest protocol header */
781 extern struct mbstat mbstat; /* General mbuf stats/infos */
782 extern int nmbclusters; /* Maximum number of clusters */
786 void m_adj(struct mbuf *, int);
787 void m_align(struct mbuf *, int);
788 int m_apply(struct mbuf *, int, int,
789 int (*)(void *, void *, u_int), void *);
790 int m_append(struct mbuf *, int, c_caddr_t);
791 void m_cat(struct mbuf *, struct mbuf *);
792 int m_extadd(struct mbuf *, caddr_t, u_int,
793 void (*)(void *, void *), void *, void *, int, int, int);
794 struct mbuf *m_collapse(struct mbuf *, int, int);
795 void m_copyback(struct mbuf *, int, int, c_caddr_t);
796 void m_copydata(const struct mbuf *, int, int, caddr_t);
797 struct mbuf *m_copym(struct mbuf *, int, int, int);
798 struct mbuf *m_copymdata(struct mbuf *, struct mbuf *,
800 struct mbuf *m_copypacket(struct mbuf *, int);
801 void m_copy_pkthdr(struct mbuf *, struct mbuf *);
802 struct mbuf *m_copyup(struct mbuf *, int, int);
803 struct mbuf *m_defrag(struct mbuf *, int);
804 void m_demote(struct mbuf *, int);
805 struct mbuf *m_devget(char *, int, int, struct ifnet *,
806 void (*)(char *, caddr_t, u_int));
807 struct mbuf *m_dup(struct mbuf *, int);
808 int m_dup_pkthdr(struct mbuf *, struct mbuf *, int);
809 u_int m_fixhdr(struct mbuf *);
810 struct mbuf *m_fragment(struct mbuf *, int, int);
811 void m_freem(struct mbuf *);
812 struct mbuf *m_get2(int, int, short, int);
813 struct mbuf *m_getjcl(int, short, int, int);
814 struct mbuf *m_getm2(struct mbuf *, int, int, short, int);
815 struct mbuf *m_getptr(struct mbuf *, int, int *);
816 u_int m_length(struct mbuf *, struct mbuf **);
817 int m_mbuftouio(struct uio *, struct mbuf *, int);
818 void m_move_pkthdr(struct mbuf *, struct mbuf *);
819 struct mbuf *m_prepend(struct mbuf *, int, int);
820 void m_print(const struct mbuf *, int);
821 struct mbuf *m_pulldown(struct mbuf *, int, int, int *);
822 struct mbuf *m_pullup(struct mbuf *, int);
823 int m_sanity(struct mbuf *, int);
824 struct mbuf *m_split(struct mbuf *, int, int);
825 struct mbuf *m_uiotombuf(struct uio *, int, int, int, int);
826 struct mbuf *m_unshare(struct mbuf *, int);
829 * Network packets may have annotations attached by affixing a list of
830 * "packet tags" to the pkthdr structure. Packet tags are dynamically
831 * allocated semi-opaque data structures that have a fixed header
832 * (struct m_tag) that specifies the size of the memory block and a
833 * <cookie,type> pair that identifies it. The cookie is a 32-bit unique
834 * unsigned value used to identify a module or ABI. By convention this value
835 * is chosen as the date+time that the module is created, expressed as the
836 * number of seconds since the epoch (e.g., using date -u +'%s'). The type
837 * value is an ABI/module-specific value that identifies a particular
838 * annotation and is private to the module. For compatibility with systems
839 * like OpenBSD that define packet tags w/o an ABI/module cookie, the value
840 * PACKET_ABI_COMPAT is used to implement m_tag_get and m_tag_find
841 * compatibility shim functions and several tag types are defined below.
842 * Users that do not require compatibility should use a private cookie value
843 * so that packet tag-related definitions can be maintained privately.
845 * Note that the packet tag returned by m_tag_alloc has the default memory
846 * alignment implemented by malloc. To reference private data one can use a
849 * struct m_tag *mtag = m_tag_alloc(...);
850 * struct foo *p = (struct foo *)(mtag+1);
852 * if the alignment of struct m_tag is sufficient for referencing members of
853 * struct foo. Otherwise it is necessary to embed struct m_tag within the
854 * private data structure to insure proper alignment; e.g.,
860 * struct foo *p = (struct foo *) m_tag_alloc(...);
861 * struct m_tag *mtag = &p->tag;
865 * Persistent tags stay with an mbuf until the mbuf is reclaimed. Otherwise
866 * tags are expected to ``vanish'' when they pass through a network
867 * interface. For most interfaces this happens normally as the tags are
868 * reclaimed when the mbuf is free'd. However in some special cases
869 * reclaiming must be done manually. An example is packets that pass through
870 * the loopback interface. Also, one must be careful to do this when
871 * ``turning around'' packets (e.g., icmp_reflect).
873 * To mark a tag persistent bit-or this flag in when defining the tag id.
874 * The tag will then be treated as described above.
876 #define MTAG_PERSISTENT 0x800
878 #define PACKET_TAG_NONE 0 /* Nadda */
880 /* Packet tags for use with PACKET_ABI_COMPAT. */
881 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */
882 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */
883 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */
884 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */
885 #define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO 5 /* NIC notifies IPsec */
886 #define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */
887 #define PACKET_TAG_BRIDGE 7 /* Bridge processing done */
888 #define PACKET_TAG_GIF 8 /* GIF processing done */
889 #define PACKET_TAG_GRE 9 /* GRE processing done */
890 #define PACKET_TAG_IN_PACKET_CHECKSUM 10 /* NIC checksumming done */
891 #define PACKET_TAG_ENCAP 11 /* Encap. processing */
892 #define PACKET_TAG_IPSEC_SOCKET 12 /* IPSEC socket ref */
893 #define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */
894 #define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */
895 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */
896 #define PACKET_TAG_DIVERT 17 /* divert info */
897 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */
898 #define PACKET_TAG_MACLABEL (19 | MTAG_PERSISTENT) /* MAC label */
899 #define PACKET_TAG_PF (21 | MTAG_PERSISTENT) /* PF/ALTQ information */
900 #define PACKET_TAG_RTSOCKFAM 25 /* rtsock sa family */
901 #define PACKET_TAG_IPOPTIONS 27 /* Saved IP options */
902 #define PACKET_TAG_CARP 28 /* CARP info */
903 #define PACKET_TAG_IPSEC_NAT_T_PORTS 29 /* two uint16_t */
904 #define PACKET_TAG_ND_OUTGOING 30 /* ND outgoing */
906 /* Specific cookies and tags. */
908 /* Packet tag routines. */
909 struct m_tag *m_tag_alloc(u_int32_t, int, int, int);
910 void m_tag_delete(struct mbuf *, struct m_tag *);
911 void m_tag_delete_chain(struct mbuf *, struct m_tag *);
912 void m_tag_free_default(struct m_tag *);
913 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *);
914 struct m_tag *m_tag_copy(struct m_tag *, int);
915 int m_tag_copy_chain(struct mbuf *, struct mbuf *, int);
916 void m_tag_delete_nonpersistent(struct mbuf *);
919 * Initialize the list of tags associated with an mbuf.
922 m_tag_init(struct mbuf *m)
925 SLIST_INIT(&m->m_pkthdr.tags);
929 * Set up the contents of a tag. Note that this does not fill in the free
930 * method; the caller is expected to do that.
932 * XXX probably should be called m_tag_init, but that was already taken.
935 m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len)
940 t->m_tag_cookie = cookie;
944 * Reclaim resources associated with a tag.
947 m_tag_free(struct m_tag *t)
954 * Return the first tag associated with an mbuf.
956 static __inline struct m_tag *
957 m_tag_first(struct mbuf *m)
960 return (SLIST_FIRST(&m->m_pkthdr.tags));
964 * Return the next tag in the list of tags associated with an mbuf.
966 static __inline struct m_tag *
967 m_tag_next(struct mbuf *m, struct m_tag *t)
970 return (SLIST_NEXT(t, m_tag_link));
974 * Prepend a tag to the list of tags associated with an mbuf.
977 m_tag_prepend(struct mbuf *m, struct m_tag *t)
980 SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link);
984 * Unlink a tag from the list of tags associated with an mbuf.
987 m_tag_unlink(struct mbuf *m, struct m_tag *t)
990 SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link);
993 /* These are for OpenBSD compatibility. */
994 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */
996 static __inline struct m_tag *
997 m_tag_get(int type, int length, int wait)
999 return (m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait));
1002 static __inline struct m_tag *
1003 m_tag_find(struct mbuf *m, int type, struct m_tag *start)
1005 return (SLIST_EMPTY(&m->m_pkthdr.tags) ? (struct m_tag *)NULL :
1006 m_tag_locate(m, MTAG_ABI_COMPAT, type, start));
1010 rt_m_getfib(struct mbuf *m)
1012 KASSERT(m->m_flags & M_PKTHDR , ("Attempt to get FIB from non header mbuf."));
1013 return (m->m_pkthdr.fibnum);
1016 #define M_GETFIB(_m) rt_m_getfib(_m)
1018 #define M_SETFIB(_m, _fib) do { \
1019 KASSERT((_m)->m_flags & M_PKTHDR, ("Attempt to set FIB on non header mbuf.")); \
1020 ((_m)->m_pkthdr.fibnum) = (_fib); \
1023 #endif /* _KERNEL */
1025 #ifdef MBUF_PROFILING
1026 void m_profile(struct mbuf *m);
1027 #define M_PROFILE(m) m_profile(m)
1029 #define M_PROFILE(m)
1033 #endif /* !_SYS_MBUF_H_ */