FreeBSD/Linux Kernel Cross Reference
sys/sys/mbuf.h
1 /*-
2 * Copyright (c) 1982, 1986, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)mbuf.h 8.5 (Berkeley) 2/19/95
34 * $FreeBSD: releng/5.0/sys/sys/mbuf.h 105530 2002-10-20 16:55:52Z phk $
35 */
36
37 #ifndef _SYS_MBUF_H_
38 #define _SYS_MBUF_H_
39
40 #include <sys/_label.h>
41 #include <sys/queue.h>
42
43 /*
44 * Mbufs are of a single size, MSIZE (machine/param.h), which
45 * includes overhead. An mbuf may add a single "mbuf cluster" of size
46 * MCLBYTES (also in machine/param.h), which has no additional overhead
47 * and is used instead of the internal data area; this is done when
48 * at least MINCLSIZE of data must be stored. Additionally, it is possible
49 * to allocate a separate buffer externally and attach it to the mbuf in
50 * a way similar to that of mbuf clusters.
51 */
52 #define MLEN (MSIZE - sizeof(struct m_hdr)) /* normal data len */
53 #define MHLEN (MLEN - sizeof(struct pkthdr)) /* data len w/pkthdr */
54 #define MINCLSIZE (MHLEN + 1) /* smallest amount to put in cluster */
55 #define M_MAXCOMPRESS (MHLEN / 2) /* max amount to copy for compression */
56
57 #ifdef _KERNEL
58 /*-
59 * Macros for type conversion:
60 * mtod(m, t) -- Convert mbuf pointer to data pointer of correct type.
61 * dtom(x) -- Convert data pointer within mbuf to mbuf pointer (XXX).
62 */
63 #define mtod(m, t) ((t)((m)->m_data))
64 #define dtom(x) ((struct mbuf *)((intptr_t)(x) & ~(MSIZE-1)))
65 #endif /* _KERNEL */
66
67 /*
68 * Header present at the beginning of every mbuf.
69 */
70 struct m_hdr {
71 struct mbuf *mh_next; /* next buffer in chain */
72 struct mbuf *mh_nextpkt; /* next chain in queue/record */
73 caddr_t mh_data; /* location of data */
74 int mh_len; /* amount of data in this mbuf */
75 int mh_flags; /* flags; see below */
76 short mh_type; /* type of data in this mbuf */
77 };
78
79 /*
80 * Packet tag structure (see below for details).
81 */
82 struct m_tag {
83 SLIST_ENTRY(m_tag) m_tag_link; /* List of packet tags */
84 u_int16_t m_tag_id; /* Tag ID */
85 u_int16_t m_tag_len; /* Length of data */
86 u_int32_t m_tag_cookie; /* ABI/Module ID */
87 };
88
89 /*
90 * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
91 */
92 struct pkthdr {
93 struct ifnet *rcvif; /* rcv interface */
94 int len; /* total packet length */
95 /* variables for ip and tcp reassembly */
96 void *header; /* pointer to packet header */
97 /* variables for hardware checksum */
98 int csum_flags; /* flags regarding checksum */
99 int csum_data; /* data field used by csum routines */
100 SLIST_HEAD(packet_tags, m_tag) tags; /* list of packet tags */
101 struct label label; /* MAC label of data in packet */
102 };
103
104 /*
105 * Description of external storage mapped into mbuf; valid only if M_EXT is set.
106 */
107 struct m_ext {
108 caddr_t ext_buf; /* start of buffer */
109 void (*ext_free) /* free routine if not the usual */
110 (void *, void *);
111 void *ext_args; /* optional argument pointer */
112 u_int ext_size; /* size of buffer, for ext_free */
113 u_int *ref_cnt; /* pointer to ref count info */
114 int ext_type; /* type of external storage */
115 };
116
117 /*
118 * The core of the mbuf object along with some shortcut defines for
119 * practical purposes.
120 */
121 struct mbuf {
122 struct m_hdr m_hdr;
123 union {
124 struct {
125 struct pkthdr MH_pkthdr; /* M_PKTHDR set */
126 union {
127 struct m_ext MH_ext; /* M_EXT set */
128 char MH_databuf[MHLEN];
129 } MH_dat;
130 } MH;
131 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */
132 } M_dat;
133 };
134 #define m_next m_hdr.mh_next
135 #define m_len m_hdr.mh_len
136 #define m_data m_hdr.mh_data
137 #define m_type m_hdr.mh_type
138 #define m_flags m_hdr.mh_flags
139 #define m_nextpkt m_hdr.mh_nextpkt
140 #define m_act m_nextpkt
141 #define m_pkthdr M_dat.MH.MH_pkthdr
142 #define m_ext M_dat.MH.MH_dat.MH_ext
143 #define m_pktdat M_dat.MH.MH_dat.MH_databuf
144 #define m_dat M_dat.M_databuf
145
146 /*
147 * mbuf flags.
148 */
149 #define M_EXT 0x0001 /* has associated external storage */
150 #define M_PKTHDR 0x0002 /* start of record */
151 #define M_EOR 0x0004 /* end of record */
152 #define M_RDONLY 0x0008 /* associated data is marked read-only */
153 #define M_PROTO1 0x0010 /* protocol-specific */
154 #define M_PROTO2 0x0020 /* protocol-specific */
155 #define M_PROTO3 0x0040 /* protocol-specific */
156 #define M_PROTO4 0x0080 /* protocol-specific */
157 #define M_PROTO5 0x0100 /* protocol-specific */
158
159 /*
160 * mbuf pkthdr flags (also stored in m_flags).
161 */
162 #define M_BCAST 0x0200 /* send/received as link-level broadcast */
163 #define M_MCAST 0x0400 /* send/received as link-level multicast */
164 #define M_FRAG 0x0800 /* packet is a fragment of a larger packet */
165 #define M_FIRSTFRAG 0x1000 /* packet is first fragment */
166 #define M_LASTFRAG 0x2000 /* packet is last fragment */
167
168 /*
169 * External buffer types: identify ext_buf type.
170 */
171 #define EXT_CLUSTER 1 /* mbuf cluster */
172 #define EXT_SFBUF 2 /* sendfile(2)'s sf_bufs */
173 #define EXT_NET_DRV 100 /* custom ext_buf provided by net driver(s) */
174 #define EXT_MOD_TYPE 200 /* custom module's ext_buf type */
175 #define EXT_DISPOSABLE 300 /* can throw this buffer away w/page flipping */
176
177 /*
178 * Flags copied when copying m_pkthdr.
179 */
180 #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_PROTO1|M_PROTO1|M_PROTO2|M_PROTO3 | \
181 M_PROTO4|M_PROTO5|M_BCAST|M_MCAST|M_FRAG|M_RDONLY)
182
183 /*
184 * Flags indicating hw checksum support and sw checksum requirements.
185 */
186 #define CSUM_IP 0x0001 /* will csum IP */
187 #define CSUM_TCP 0x0002 /* will csum TCP */
188 #define CSUM_UDP 0x0004 /* will csum UDP */
189 #define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */
190 #define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */
191
192 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */
193 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */
194 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */
195 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */
196
197 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP)
198 #define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */
199
200 /*
201 * mbuf types.
202 */
203 #define MT_NOTMBUF 0 /* USED INTERNALLY ONLY! Object is not mbuf */
204 #define MT_DATA 1 /* dynamic (data) allocation */
205 #define MT_HEADER 2 /* packet header */
206 #if 0
207 #define MT_SOCKET 3 /* socket structure */
208 #define MT_PCB 4 /* protocol control block */
209 #define MT_RTABLE 5 /* routing tables */
210 #define MT_HTABLE 6 /* IMP host tables */
211 #define MT_ATABLE 7 /* address resolution tables */
212 #endif
213 #define MT_SONAME 8 /* socket name */
214 #if 0
215 #define MT_SOOPTS 10 /* socket options */
216 #endif
217 #define MT_FTABLE 11 /* fragment reassembly header */
218 #if 0
219 #define MT_RIGHTS 12 /* access rights */
220 #define MT_IFADDR 13 /* interface address */
221 #endif
222 #define MT_TAG 13 /* volatile metadata associated to pkts */
223 #define MT_CONTROL 14 /* extra-data protocol message */
224 #define MT_OOBDATA 15 /* expedited data */
225 #define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */
226
227 /*
228 * Mbuf and cluster allocation statistics PCPU structure.
229 */
230 struct mbpstat {
231 u_long mb_mbfree;
232 u_long mb_mbpgs;
233 u_long mb_clfree;
234 u_long mb_clpgs;
235 long mb_mbtypes[MT_NTYPES];
236 short mb_active;
237 };
238
239 /*
240 * General mbuf allocator statistics structure.
241 * XXX: Modifications of these are not protected by any mutex locks nor by
242 * any atomic() manipulations. As a result, we may occasionally lose
243 * a count or two. Luckily, not all of these fields are modified at all
244 * and remain static, and those that are manipulated are only manipulated
245 * in failure situations, which do not occur (hopefully) very often.
246 */
247 struct mbstat {
248 u_long m_drops; /* times failed to allocate */
249 u_long m_wait; /* times succesfully returned from wait */
250 u_long m_drain; /* times drained protocols for space */
251 u_long m_mcfail; /* XXX: times m_copym failed */
252 u_long m_mpfail; /* XXX: times m_pullup failed */
253 u_long m_msize; /* length of an mbuf */
254 u_long m_mclbytes; /* length of an mbuf cluster */
255 u_long m_minclsize; /* min length of data to allocate a cluster */
256 u_long m_mlen; /* length of data in an mbuf */
257 u_long m_mhlen; /* length of data in a header mbuf */
258 /* Number of mbtypes (gives # elems in mbpstat's mb_mbtypes[] array: */
259 short m_numtypes;
260 };
261
262 /*
263 * Flags specifying how an allocation should be made.
264 * M_DONTWAIT means "don't block if nothing is available" whereas
265 * M_TRYWAIT means "block for mbuf_wait ticks at most if nothing is
266 * available."
267 */
268 #define M_DONTWAIT 1
269 #define M_TRYWAIT 0
270 #define M_WAIT M_TRYWAIT /* XXX: Deprecated. */
271
272 #ifdef _KERNEL
273 /*-
274 * mbuf external reference count management macros.
275 *
276 * MEXT_IS_REF(m): true if (m) is not the only mbuf referencing
277 * the external buffer ext_buf.
278 *
279 * MEXT_REM_REF(m): remove reference to m_ext object.
280 *
281 * MEXT_ADD_REF(m): add reference to m_ext object already
282 * referred to by (m).
283 */
284 #define MEXT_IS_REF(m) (*((m)->m_ext.ref_cnt) > 1)
285
286 #define MEXT_REM_REF(m) do { \
287 KASSERT(*((m)->m_ext.ref_cnt) > 0, ("m_ext refcnt < 0")); \
288 atomic_subtract_int((m)->m_ext.ref_cnt, 1); \
289 } while(0)
290
291 #define MEXT_ADD_REF(m) atomic_add_int((m)->m_ext.ref_cnt, 1)
292
293 /*
294 * mbuf, cluster, and external object allocation macros
295 * (for compatibility purposes).
296 */
297 #define M_COPY_PKTHDR(to, from) m_copy_pkthdr((to), (from))
298 #define m_getclr(how, type) m_get_clrd((how), (type))
299 #define MGET(m, how, type) ((m) = m_get((how), (type)))
300 #define MGETHDR(m, how, type) ((m) = m_gethdr((how), (type)))
301 #define MCLGET(m, how) m_clget((m), (how))
302 #define MEXTADD(m, buf, size, free, args, flags, type) \
303 m_extadd((m), (caddr_t)(buf), (size), (free), (args), (flags), (type))
304
305 /*
306 * MEXTFREE(m): disassociate (and possibly free) an external object from (m).
307 *
308 * If the atomic_cmpset_int() returns 0, then we effectively do nothing
309 * in terms of "cleaning up" (freeing the ext buf and ref. counter) as
310 * this means that either there are still references, or another thread
311 * is taking care of the clean-up.
312 */
313 #define MEXTFREE(m) do { \
314 struct mbuf *_mb = (m); \
315 \
316 MEXT_REM_REF(_mb); \
317 if (atomic_cmpset_int(_mb->m_ext.ref_cnt, 0, 1)) \
318 _mext_free(_mb); \
319 _mb->m_flags &= ~M_EXT; \
320 } while (0)
321
322 /*
323 * Evaluate TRUE if it's safe to write to the mbuf m's data region (this
324 * can be both the local data payload, or an external buffer area,
325 * depending on whether M_EXT is set).
326 */
327 #define M_WRITABLE(m) (!((m)->m_flags & M_RDONLY) && (!((m)->m_flags \
328 & M_EXT) || !MEXT_IS_REF(m)))
329
330 /*
331 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place
332 * an object of the specified size at the end of the mbuf, longword aligned.
333 */
334 #define M_ALIGN(m, len) do { \
335 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \
336 } while (0)
337
338 /*
339 * As above, for mbufs allocated with m_gethdr/MGETHDR
340 * or initialized by M_COPY_PKTHDR.
341 */
342 #define MH_ALIGN(m, len) do { \
343 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \
344 } while (0)
345
346 /*
347 * Compute the amount of space available
348 * before the current start of data in an mbuf.
349 *
350 * The M_WRITABLE() is a temporary, conservative safety measure: the burden
351 * of checking writability of the mbuf data area rests solely with the caller.
352 */
353 #define M_LEADINGSPACE(m) \
354 ((m)->m_flags & M_EXT ? \
355 (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \
356 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \
357 (m)->m_data - (m)->m_dat)
358
359 /*
360 * Compute the amount of space available
361 * after the end of data in an mbuf.
362 *
363 * The M_WRITABLE() is a temporary, conservative safety measure: the burden
364 * of checking writability of the mbuf data area rests solely with the caller.
365 */
366 #define M_TRAILINGSPACE(m) \
367 ((m)->m_flags & M_EXT ? \
368 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \
369 - ((m)->m_data + (m)->m_len) : 0) : \
370 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
371
372 /*
373 * Arrange to prepend space of size plen to mbuf m.
374 * If a new mbuf must be allocated, how specifies whether to wait.
375 * If the allocation fails, the original mbuf chain is freed and m is
376 * set to NULL.
377 */
378 #define M_PREPEND(m, plen, how) do { \
379 struct mbuf **_mmp = &(m); \
380 struct mbuf *_mm = *_mmp; \
381 int _mplen = (plen); \
382 int __mhow = (how); \
383 \
384 if (M_LEADINGSPACE(_mm) >= _mplen) { \
385 _mm->m_data -= _mplen; \
386 _mm->m_len += _mplen; \
387 } else \
388 _mm = m_prepend(_mm, _mplen, __mhow); \
389 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \
390 _mm->m_pkthdr.len += _mplen; \
391 *_mmp = _mm; \
392 } while (0)
393
394 /*
395 * Change mbuf to new type.
396 * This is a relatively expensive operation and should be avoided.
397 */
398 #define MCHTYPE(m, t) m_chtype((m), (t))
399
400 /* Length to m_copy to copy all. */
401 #define M_COPYALL 1000000000
402
403 /* Compatibility with 4.3. */
404 #define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT)
405
406 extern int max_datalen; /* MHLEN - max_hdr */
407 extern int max_hdr; /* Largest link + protocol header */
408 extern int max_linkhdr; /* Largest link-level header */
409 extern int max_protohdr; /* Largest protocol header */
410 extern struct mbstat mbstat; /* General mbuf stats/infos */
411 extern int nmbclusters; /* Maximum number of clusters */
412 extern int nmbcnt; /* Scale kmem_map for counter space */
413 extern int nmbufs; /* Maximum number of mbufs */
414 extern int nsfbufs; /* Number of sendfile(2) bufs */
415
416 void _mext_free(struct mbuf *);
417 void m_adj(struct mbuf *, int);
418 void m_cat(struct mbuf *, struct mbuf *);
419 void m_chtype(struct mbuf *, short);
420 void m_clget(struct mbuf *, int);
421 void m_extadd(struct mbuf *, caddr_t, u_int,
422 void (*)(void *, void *), void *, int, int);
423 void m_copyback(struct mbuf *, int, int, caddr_t);
424 void m_copydata(const struct mbuf *, int, int, caddr_t);
425 struct mbuf *m_copym(struct mbuf *, int, int, int);
426 struct mbuf *m_copypacket(struct mbuf *, int);
427 void m_copy_pkthdr(struct mbuf *, struct mbuf *);
428 struct mbuf *m_devget(char *, int, int, struct ifnet *,
429 void (*)(char *, caddr_t, u_int));
430 struct mbuf *m_dup(struct mbuf *, int);
431 u_int m_fixhdr(struct mbuf *);
432 struct mbuf *m_free(struct mbuf *);
433 void m_freem(struct mbuf *);
434 struct mbuf *m_get(int, short);
435 struct mbuf *m_get_clrd(int, short);
436 struct mbuf *m_getcl(int, short, int);
437 struct mbuf *m_gethdr(int, short);
438 struct mbuf *m_gethdr_clrd(int, short);
439 struct mbuf *m_getm(struct mbuf *, int, int, short);
440 u_int m_length(struct mbuf *, struct mbuf **);
441 struct mbuf *m_prepend(struct mbuf *, int, int);
442 void m_print(const struct mbuf *);
443 struct mbuf *m_pulldown(struct mbuf *, int, int, int *);
444 struct mbuf *m_pullup(struct mbuf *, int);
445 struct mbuf *m_split(struct mbuf *, int, int);
446
447 /*
448 * Packets may have annotations attached by affixing a list
449 * of "packet tags" to the pkthdr structure. Packet tags are
450 * dynamically allocated semi-opaque data structures that have
451 * a fixed header (struct m_tag) that specifies the size of the
452 * memory block and a <cookie,type> pair that identifies it.
453 * The cookie is a 32-bit unique unsigned value used to identify
454 * a module or ABI. By convention this value is chose as the
455 * date+time that the module is created, expressed as the number of
456 * seconds since the epoch (e.g. using date -u +'%s'). The type value
457 * is an ABI/module-specific value that identifies a particular annotation
458 * and is private to the module. For compatibility with systems
459 * like openbsd that define packet tags w/o an ABI/module cookie,
460 * the value PACKET_ABI_COMPAT is used to implement m_tag_get and
461 * m_tag_find compatibility shim functions and several tag types are
462 * defined below. Users that do not require compatibility should use
463 * a private cookie value so that packet tag-related definitions
464 * can be maintained privately.
465 *
466 * Note that the packet tag returned by m_tag_allocate has the default
467 * memory alignment implemented by malloc. To reference private data
468 * one can use a construct like:
469 *
470 * struct m_tag *mtag = m_tag_allocate(...);
471 * struct foo *p = (struct foo *)(mtag+1);
472 *
473 * if the alignment of struct m_tag is sufficient for referencing members
474 * of struct foo. Otherwise it is necessary to embed struct m_tag within
475 * the private data structure to insure proper alignment; e.g.
476 *
477 * struct foo {
478 * struct m_tag tag;
479 * ...
480 * };
481 * struct foo *p = (struct foo *) m_tag_allocate(...);
482 * struct m_tag *mtag = &p->tag;
483 */
484
485 #define PACKET_TAG_NONE 0 /* Nadda */
486
487 /* Packet tag for use with PACKET_ABI_COMPAT */
488 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */
489 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */
490 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */
491 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */
492 #define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO 5 /* NIC notifies IPsec */
493 #define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */
494 #define PACKET_TAG_BRIDGE 7 /* Bridge processing done */
495 #define PACKET_TAG_GIF 8 /* GIF processing done */
496 #define PACKET_TAG_GRE 9 /* GRE processing done */
497 #define PACKET_TAG_IN_PACKET_CHECKSUM 10 /* NIC checksumming done */
498 #define PACKET_TAG_ENCAP 11 /* Encap. processing */
499 #define PACKET_TAG_IPSEC_SOCKET 12 /* IPSEC socket ref */
500 #define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */
501 #define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */
502
503 /*
504 * As a temporary and low impact solution to replace the even uglier
505 * approach used so far in some parts of the network stack (which relies
506 * on global variables), packet tag-like annotations are stored in MT_TAG
507 * mbufs (or lookalikes) prepended to the actual mbuf chain.
508 *
509 * m_type = MT_TAG
510 * m_flags = m_tag_id
511 * m_next = next buffer in chain.
512 *
513 * BE VERY CAREFUL not to pass these blocks to the mbuf handling routines.
514 */
515 #define _m_tag_id m_hdr.mh_flags
516
517 /* Packet tags used in the FreeBSD network stack */
518 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */
519 #define PACKET_TAG_IPFW 16 /* ipfw classification */
520 #define PACKET_TAG_DIVERT 17 /* divert info */
521 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */
522
523 /* Packet tag routines */
524 struct m_tag *m_tag_alloc(u_int32_t, int, int, int);
525 void m_tag_free(struct m_tag *);
526 void m_tag_prepend(struct mbuf *, struct m_tag *);
527 void m_tag_unlink(struct mbuf *, struct m_tag *);
528 void m_tag_delete(struct mbuf *, struct m_tag *);
529 void m_tag_delete_chain(struct mbuf *, struct m_tag *);
530 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *);
531 struct m_tag *m_tag_copy(struct m_tag *);
532 int m_tag_copy_chain(struct mbuf *, struct mbuf *);
533 void m_tag_init(struct mbuf *);
534 struct m_tag *m_tag_first(struct mbuf *);
535 struct m_tag *m_tag_next(struct mbuf *, struct m_tag *);
536
537 /* these are for openbsd compatibility */
538 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */
539
540 static __inline struct m_tag *
541 m_tag_get(int type, int length, int wait)
542 {
543 return m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait);
544 }
545
546 static __inline struct m_tag *
547 m_tag_find(struct mbuf *m, int type, struct m_tag *start)
548 {
549 return m_tag_locate(m, MTAG_ABI_COMPAT, type, start);
550 }
551 #endif /* _KERNEL */
552
553 #endif /* !_SYS_MBUF_H_ */
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