2 * Copyright (c) 2004 The DragonFly Project. All rights reserved.
4 * Copyright (c) 1982, 1986, 1988, 1993
5 * The Regents of the University of California. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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11 * notice, this list of conditions and the following disclaimer.
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13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by the University of
18 * California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
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32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * @(#)mbuf.h 8.5 (Berkeley) 2/19/95
36 * $FreeBSD: src/sys/sys/mbuf.h,v 1.44.2.17 2003/04/15 06:15:02 silby Exp $
37 * $DragonFly: src/sys/sys/mbuf.h,v 1.46 2008/03/10 10:47:57 sephe Exp $
43 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
46 #include <sys/types.h>
49 #include <sys/param.h>
52 #include <sys/queue.h>
54 #ifndef _NET_NETISR_H_
55 #include <net/netisr.h>
59 * Mbufs are of a single size, MSIZE (machine/param.h), which
60 * includes overhead. An mbuf may add a single "mbuf cluster" of size
61 * MCLBYTES (also in machine/param.h), which has no additional overhead
62 * and is used instead of the internal data area; this is done when
63 * at least MINCLSIZE of data must be stored.
65 #define MLEN (MSIZE - sizeof(struct m_hdr)) /* normal data len */
66 #define MHLEN (MLEN - sizeof(struct pkthdr)) /* data len w/pkthdr */
67 #define MINCLSIZE (MHLEN + 1) /* smallest amount to put in cluster */
68 #define M_MAXCOMPRESS (MHLEN / 2) /* max amount to copy for compression */
71 * Macros for type conversion:
72 * mtod(m, t) -- Convert mbuf pointer to data pointer of correct type.
73 * mtocl(x) - convert pointer within cluster to cluster index #
74 * cltom(x) - convert cluster # to ptr to beginning of cluster
76 #define mtod(m, t) ((t)((m)->m_data))
79 * Header present at the beginning of every mbuf.
82 struct mbuf *mh_next; /* next buffer in chain */
83 struct mbuf *mh_nextpkt; /* next chain in queue/record */
84 caddr_t mh_data; /* location of data */
85 int mh_len; /* amount of data in this mbuf */
86 int mh_flags; /* flags; see below */
87 short mh_type; /* type of data in this mbuf */
88 short mh_pad; /* padding */
89 struct netmsg_packet mh_netmsg; /* hardware->proto stack msg */
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 */
102 SLIST_HEAD(packet_tags, m_tag);
105 * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
107 * Be careful: The fields have been carefully ordered to avoid hidden padding.
108 * Keep this in mind, when adding or removing fields!
111 struct ifnet *rcvif; /* rcv interface */
112 int len; /* total packet length */
113 struct packet_tags tags; /* list of packet tags */
115 /* variables for ip and tcp reassembly */
116 void *header; /* pointer to packet header */
118 /* variables for hardware checksum */
119 int csum_flags; /* flags regarding checksum */
120 int csum_data; /* data field used by csum routines */
123 uint32_t fw_flags; /* flags for PF */
125 /* variables for PF processing */
126 uint16_t pf_tag; /* PF tag id */
127 uint8_t pf_routed; /* PF routing counter */
129 /* variables for ALTQ processing */
130 uint8_t ecn_af; /* address family for ECN */
131 uint32_t altq_qid; /* queue id */
133 uint16_t ether_vlantag; /* ethernet 802.1p+q vlan tag */
134 uint16_t pad; /* explicit padding */
138 * Description of external storage mapped into mbuf; valid only if M_EXT is set.
141 caddr_t ext_buf; /* start of buffer */
142 void (*ext_free)(void *);
143 u_int ext_size; /* size of buffer, for ext_free */
144 void (*ext_ref)(void *);
149 * The core of the mbuf object along with some shortcut defines for
150 * practical purposes.
156 struct pkthdr MH_pkthdr; /* M_PKTHDR set */
158 struct m_ext MH_ext; /* M_EXT set */
159 char MH_databuf[MHLEN];
162 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */
165 #define m_next m_hdr.mh_next
166 #define m_len m_hdr.mh_len
167 #define m_data m_hdr.mh_data
168 #define m_type m_hdr.mh_type
169 #define m_flags m_hdr.mh_flags
170 #define m_nextpkt m_hdr.mh_nextpkt
171 #define m_pkthdr M_dat.MH.MH_pkthdr
172 #define m_ext M_dat.MH.MH_dat.MH_ext
173 #define m_pktdat M_dat.MH.MH_dat.MH_databuf
174 #define m_dat M_dat.M_databuf
177 * Code that uses m_act should be converted to use m_nextpkt
178 * instead; m_act is historical and deprecated.
180 #define m_act m_nextpkt
185 #define M_EXT 0x0001 /* has associated external storage */
186 #define M_PKTHDR 0x0002 /* start of record */
187 #define M_EOR 0x0004 /* end of record */
188 #define M_PROTO1 0x0008 /* protocol-specific */
189 #define M_PROTO2 0x0010 /* protocol-specific */
190 #define M_PROTO3 0x0020 /* protocol-specific */
191 #define M_PROTO4 0x0040 /* protocol-specific */
192 #define M_PROTO5 0x0080 /* protocol-specific */
195 * mbuf pkthdr flags (also stored in m_flags).
197 #define M_BCAST 0x0100 /* send/received as link-level broadcast */
198 #define M_MCAST 0x0200 /* send/received as link-level multicast */
199 #define M_FRAG 0x0400 /* packet is a fragment of a larger packet */
200 #define M_FIRSTFRAG 0x0800 /* packet is first fragment */
201 #define M_LASTFRAG 0x1000 /* packet is last fragment */
202 #define M_CLCACHE 0x2000 /* mbuf allocated from the cluster cache */
203 #define M_EXT_CLUSTER 0x4000 /* standard cluster else special */
204 #define M_PHCACHE 0x8000 /* mbuf allocated from the pkt header cache */
205 #define M_NOTIFICATION 0x10000 /* notification event */
206 #define M_VLANTAG 0x20000 /* ether_vlantag is valid */
209 * Flags copied when copying m_pkthdr.
211 #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_PROTO1|M_PROTO1|M_PROTO2|M_PROTO3 | \
212 M_PROTO4|M_PROTO5|M_BCAST|M_MCAST|M_FRAG | \
213 M_FIRSTFRAG|M_LASTFRAG|M_VLANTAG)
216 * Flags indicating hw checksum support and sw checksum requirements.
218 #define CSUM_IP 0x0001 /* will csum IP */
219 #define CSUM_TCP 0x0002 /* will csum TCP */
220 #define CSUM_UDP 0x0004 /* will csum UDP */
221 #define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */
222 #define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */
224 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */
225 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */
226 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */
227 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */
228 #define CSUM_FRAG_NOT_CHECKED 0x1000 /* did _not_ csum fragment
229 * NB: This flag is only used
230 * by IP defragmenter.
233 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP)
234 #define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */
237 * Flags indicating PF processing status
239 #define FW_MBUF_GENERATED 0x00000001
240 #define PF_MBUF_TAGGED 0x00000002 /* pf_tag field is valid */
241 #define PF_MBUF_ROUTED 0x00000004 /* pf_routed field is valid */
242 #define PF_MBUF_TRANSLATE_LOCALHOST \
244 #define PF_MBUF_FRAGCACHE 0x00000010
245 #define ALTQ_MBUF_TAGGED 0x00000020 /* altq_qid is valid */
246 #define PF_MBUF_GENERATED FW_MBUF_GENERATED
247 #define IPFW_MBUF_GENERATED FW_MBUF_GENERATED
248 #define DUMMYNET_MBUF_TAGGED 0x00000080
253 #define MT_FREE 0 /* should be on free list */
254 #define MT_DATA 1 /* dynamic (data) allocation */
255 #define MT_HEADER 2 /* packet header */
256 #define MT_SONAME 3 /* socket name */
257 #define MT_TAG 4 /* volatile metadata associated to pkts */
258 #define MT_CONTROL 5 /* extra-data protocol message */
259 #define MT_OOBDATA 6 /* expedited data */
260 #define MT_NTYPES 7 /* number of mbuf types for mbtypes[] */
263 * General mbuf allocator statistics structure.
266 u_long m_mbufs; /* mbufs obtained from page pool */
267 u_long m_clusters; /* clusters obtained from page pool */
268 u_long m_spare; /* spare field */
269 u_long m_clfree; /* free clusters */
270 u_long m_drops; /* times failed to find space */
271 u_long m_wait; /* times waited for space */
272 u_long m_drain; /* times drained protocols for space */
273 u_long m_mcfail; /* times m_copym failed */
274 u_long m_mpfail; /* times m_pullup failed */
275 u_long m_msize; /* length of an mbuf */
276 u_long m_mclbytes; /* length of an mbuf cluster */
277 u_long m_minclsize; /* min length of data to allocate a cluster */
278 u_long m_mlen; /* length of data in an mbuf */
279 u_long m_mhlen; /* length of data in a header mbuf */
283 * Flags specifying how an allocation should be made.
286 #define MB_DONTWAIT 0x4
287 #define MB_TRYWAIT 0x8
288 #define MB_WAIT MB_TRYWAIT
291 * Mbuf to Malloc Flag Conversion.
293 #define MBTOM(how) ((how) & MB_TRYWAIT ? M_WAITOK : M_NOWAIT)
296 * These are identifying numbers passed to the m_mballoc_wait function,
297 * allowing us to determine whether the call came from an MGETHDR or
304 * mbuf allocation/deallocation macros (YYY deprecated, too big):
306 * MGET(struct mbuf *m, int how, int type)
307 * allocates an mbuf and initializes it to contain internal data.
309 * MGETHDR(struct mbuf *m, int how, int type)
310 * allocates an mbuf and initializes it to contain a packet header
313 #define MGET(m, how, type) do { \
314 (m) = m_get((how), (type)); \
317 #define MGETHDR(m, how, type) do { \
318 (m) = m_gethdr((how), (type)); \
322 * MCLGET adds such clusters to a normal mbuf. The flag M_EXT is set upon
324 * Deprecated. Use m_getcl() or m_getl() instead.
326 #define MCLGET(m, how) do { \
327 m_mclget((m), (how)); \
331 * NB: M_COPY_PKTHDR is deprecated; use either M_MOVE_PKTHDR
335 * Move mbuf pkthdr from "from" to "to".
336 * from should have M_PKTHDR set, and to must be empty.
337 * from no longer has a pkthdr after this operation.
339 #define M_MOVE_PKTHDR(_to, _from) m_move_pkthdr((_to), (_from))
342 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place
343 * an object of the specified size at the end of the mbuf, longword aligned.
345 #define M_ALIGN(m, len) do { \
346 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \
350 * As above, for mbufs allocated with m_gethdr/MGETHDR
351 * or initialized by M_COPY_PKTHDR.
353 #define MH_ALIGN(m, len) do { \
354 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \
358 * Check if we can write to an mbuf.
360 #define M_EXT_WRITABLE(m) (m_sharecount(m) == 1)
361 #define M_WRITABLE(m) (!((m)->m_flags & M_EXT) || M_EXT_WRITABLE(m))
364 * Check if the supplied mbuf has a packet header, or else panic.
366 #define M_ASSERTPKTHDR(m) \
367 KASSERT(m != NULL && m->m_flags & M_PKTHDR, \
368 ("%s: invalid mbuf or no mbuf packet header!", __func__))
371 * Compute the amount of space available before the current start of data.
372 * The M_EXT_WRITABLE() is a temporary, conservative safety measure: the burden
373 * of checking writability of the mbuf data area rests solely with the caller.
375 #define M_LEADINGSPACE(m) \
376 ((m)->m_flags & M_EXT ? \
377 (M_EXT_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \
378 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \
379 (m)->m_data - (m)->m_dat)
382 * Compute the amount of space available after the end of data in an mbuf.
383 * The M_WRITABLE() is a temporary, conservative safety measure: the burden
384 * of checking writability of the mbuf data area rests solely with the caller.
386 #define M_TRAILINGSPACE(m) \
387 ((m)->m_flags & M_EXT ? \
388 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \
389 - ((m)->m_data + (m)->m_len) : 0) : \
390 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
393 * Arrange to prepend space of size plen to mbuf m.
394 * If a new mbuf must be allocated, how specifies whether to wait.
395 * If how is MB_DONTWAIT and allocation fails, the original mbuf chain
396 * is freed and m is set to NULL.
398 #define M_PREPEND(m, plen, how) do { \
399 struct mbuf **_mmp = &(m); \
400 struct mbuf *_mm = *_mmp; \
401 int _mplen = (plen); \
402 int __mhow = (how); \
404 if (M_LEADINGSPACE(_mm) >= _mplen) { \
405 _mm->m_data -= _mplen; \
406 _mm->m_len += _mplen; \
408 _mm = m_prepend(_mm, _mplen, __mhow); \
409 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \
410 _mm->m_pkthdr.len += _mplen; \
414 /* Length to m_copy to copy all. */
415 #define M_COPYALL 1000000000
417 /* Compatibility with 4.3 */
418 #define m_copy(m, o, l) m_copym((m), (o), (l), MB_DONTWAIT)
421 extern u_int m_clalloc_wid; /* mbuf cluster wait count */
422 extern u_int m_mballoc_wid; /* mbuf wait count */
423 extern int max_linkhdr; /* largest link-level header */
424 extern int max_protohdr; /* largest protocol header */
425 extern int max_hdr; /* largest link+protocol header */
426 extern int max_datalen; /* MHLEN - max_hdr */
427 extern int mbuf_wait; /* mbuf sleep time */
428 extern int nmbclusters;
433 void m_adj(struct mbuf *, int);
434 void m_cat(struct mbuf *, struct mbuf *);
435 u_int m_countm(struct mbuf *m, struct mbuf **lastm, u_int *mbcnt);
436 void m_copyback(struct mbuf *, int, int, caddr_t);
437 void m_copydata(const struct mbuf *, int, int, caddr_t);
438 struct mbuf *m_copym(const struct mbuf *, int, int, int);
439 struct mbuf *m_copypacket(struct mbuf *, int);
440 struct mbuf *m_defrag(struct mbuf *, int);
441 struct mbuf *m_defrag_nofree(struct mbuf *, int);
442 struct mbuf *m_devget(char *, int, int, struct ifnet *,
443 void (*copy)(volatile const void *, volatile void *, size_t));
444 struct mbuf *m_dup(struct mbuf *, int);
445 int m_dup_pkthdr(struct mbuf *, const struct mbuf *, int);
446 struct mbuf *m_free(struct mbuf *);
447 void m_freem(struct mbuf *);
448 struct mbuf *m_get(int, int);
449 struct mbuf *m_getc(int len, int how, int type);
450 struct mbuf *m_getcl(int how, short type, int flags);
451 struct mbuf *m_getclr(int, int);
452 struct mbuf *m_gethdr(int, int);
453 struct mbuf *m_getm(struct mbuf *, int, int, int);
454 struct mbuf *m_last(struct mbuf *m);
455 u_int m_lengthm(struct mbuf *m, struct mbuf **lastm);
456 void m_move_pkthdr(struct mbuf *, struct mbuf *);
457 struct mbuf *m_prepend(struct mbuf *, int, int);
458 void m_print(const struct mbuf *m);
459 struct mbuf *m_pulldown(struct mbuf *, int, int, int *);
460 struct mbuf *m_pullup(struct mbuf *, int);
461 struct mbuf *m_split(struct mbuf *, int, int);
462 struct mbuf *m_uiomove(struct uio *);
463 void m_mclget(struct mbuf *m, int how);
464 int m_sharecount(struct mbuf *m);
465 void m_chtype(struct mbuf *m, int type);
468 void mbuftrackid(struct mbuf *, int);
470 #define mbuftrackid(m, id) /* empty */
474 * Allocate the right type of mbuf for the desired total length.
475 * The mbuf returned does not necessarily cover the entire requested length.
476 * This function follows mbuf chaining policy of allowing MINCLSIZE
477 * amount of chained mbufs.
479 static __inline struct mbuf *
480 m_getl(int len, int how, int type, int flags, int *psize)
485 if (len >= MINCLSIZE) {
486 m = m_getcl(how, type, flags);
488 } else if (flags & M_PKTHDR) {
489 m = m_gethdr(how, type);
492 m = m_get(how, type);
501 * Get a single mbuf that covers the requested number of bytes.
502 * This function does not create mbuf chains. It explicitly marks
503 * places in the code that abuse mbufs for contiguous data buffers.
505 static __inline struct mbuf *
506 m_getb(int len, int how, int type, int flags)
509 int mbufsize = (flags & M_PKTHDR) ? MHLEN : MLEN;
512 m = m_getcl(how, type, flags);
513 else if (flags & M_PKTHDR)
514 m = m_gethdr(how, type);
516 m = m_get(how, type);
521 * Packets may have annotations attached by affixing a list
522 * of "packet tags" to the pkthdr structure. Packet tags are
523 * dynamically allocated semi-opaque data structures that have
524 * a fixed header (struct m_tag) that specifies the size of the
525 * memory block and a <cookie,type> pair that identifies it.
526 * The cookie is a 32-bit unique unsigned value used to identify
527 * a module or ABI. By convention this value is chose as the
528 * date+time that the module is created, expressed as the number of
529 * seconds since the epoch (e.g. using date -u +'%s'). The type value
530 * is an ABI/module-specific value that identifies a particular annotation
531 * and is private to the module. For compatibility with systems
532 * like openbsd that define packet tags w/o an ABI/module cookie,
533 * the value PACKET_ABI_COMPAT is used to implement m_tag_get and
534 * m_tag_find compatibility shim functions and several tag types are
535 * defined below. Users that do not require compatibility should use
536 * a private cookie value so that packet tag-related definitions
537 * can be maintained privately.
539 * Note that the packet tag returned by m_tag_alloc has the default
540 * memory alignment implemented by kmalloc. To reference private data
541 * one can use a construct like:
543 * struct m_tag *mtag = m_tag_alloc(...);
544 * struct foo *p = m_tag_data(mtag);
546 * if the alignment of struct m_tag is sufficient for referencing members
547 * of struct foo. Otherwise it is necessary to embed struct m_tag within
548 * the private data structure to insure proper alignment; e.g.
554 * struct foo *p = (struct foo *)m_tag_alloc(...);
555 * struct m_tag *mtag = &p->tag;
558 #define PACKET_TAG_NONE 0 /* Nadda */
560 /* Packet tag for use with PACKET_ABI_COMPAT */
561 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */
562 /* struct tdb_indent */
563 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */
564 /* struct tdb_indent */
565 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */
566 /* struct tdb_indent, never added */
567 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */
568 /* struct tdb_indent, never added */
569 #define PACKET_TAG_IPSEC_PENDING_TDB 5 /* Reminder to do IPsec */
570 /* struct tdb_indent, never added */
571 #define PACKET_TAG_ENCAP 6 /* Encap. processing */
572 /* struct ifnet *, the GIF interface */
573 #define PACKET_TAG_IPSEC_HISTORY 7 /* IPSEC history */
574 /* struct ipsec_history */
575 #define PACKET_TAG_IPV6_INPUT 8 /* IPV6 input processing */
577 #define PACKET_TAG_IPFW_DIVERT 9 /* divert info */
579 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */
581 #define PACKET_TAG_CARP 28 /* CARP info */
584 * As a temporary and low impact solution to replace the even uglier
585 * approach used so far in some parts of the network stack (which relies
586 * on global variables), packet tag-like annotations are stored in MT_TAG
587 * mbufs (or lookalikes) prepended to the actual mbuf chain.
591 * m_next = next buffer in chain.
593 * BE VERY CAREFUL not to pass these blocks to the mbuf handling routines.
595 #define _m_tag_id m_hdr.mh_flags
597 /* Packet tags used in the FreeBSD network stack */
598 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */
599 /* struct sockaddr_in * as m_data */
601 /* Packet tag routines */
602 struct m_tag *m_tag_alloc(u_int32_t, int, int, int);
603 void m_tag_free(struct m_tag *);
604 void m_tag_prepend(struct mbuf *, struct m_tag *);
605 void m_tag_unlink(struct mbuf *, struct m_tag *);
606 void m_tag_delete(struct mbuf *, struct m_tag *);
607 void m_tag_delete_chain(struct mbuf *);
608 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *);
609 struct m_tag *m_tag_copy(struct m_tag *, int);
610 int m_tag_copy_chain(struct mbuf *, const struct mbuf *, int);
611 void m_tag_init(struct mbuf *);
612 struct m_tag *m_tag_first(struct mbuf *);
613 struct m_tag *m_tag_next(struct mbuf *, struct m_tag *);
615 /* these are for openbsd compatibility */
616 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */
618 static __inline void *
619 m_tag_data(struct m_tag *tag)
621 return ((void *)(tag + 1));
624 static __inline struct m_tag *
625 m_tag_get(int type, int length, int wait)
627 return m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait);
630 static __inline struct m_tag *
631 m_tag_find(struct mbuf *m, int type, struct m_tag *start)
633 return m_tag_locate(m, MTAG_ABI_COMPAT, type, start);
638 #endif /* _KERNEL || _KERNEL_STRUCTURES */
639 #endif /* !_SYS_MBUF_H_ */