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/5.2/sys/sys/mbuf.h 122971 2003-11-24 03:57:03Z sam $
35 */
36
37 #ifndef _SYS_MBUF_H_
38 #define _SYS_MBUF_H_
39
40 #include <sys/queue.h>
41
42 /*
43 * Mbufs are of a single size, MSIZE (sys/param.h), which
44 * includes overhead. An mbuf may add a single "mbuf cluster" of size
45 * MCLBYTES (also in sys/param.h), which has no additional overhead
46 * and is used instead of the internal data area; this is done when
47 * at least MINCLSIZE of data must be stored. Additionally, it is possible
48 * to allocate a separate buffer externally and attach it to the mbuf in
49 * a way similar to that of mbuf clusters.
50 */
51 #define MLEN (MSIZE - sizeof(struct m_hdr)) /* normal data len */
52 #define MHLEN (MLEN - sizeof(struct pkthdr)) /* data len w/pkthdr */
53 #define MINCLSIZE (MHLEN + 1) /* smallest amount to put in cluster */
54 #define M_MAXCOMPRESS (MHLEN / 2) /* max amount to copy for compression */
55
56 #ifdef _KERNEL
57 /*-
58 * Macros for type conversion:
59 * mtod(m, t) -- Convert mbuf pointer to data pointer of correct type.
60 * dtom(x) -- Convert data pointer within mbuf to mbuf pointer (XXX).
61 */
62 #define mtod(m, t) ((t)((m)->m_data))
63 #define dtom(x) ((struct mbuf *)((intptr_t)(x) & ~(MSIZE-1)))
64 #endif /* _KERNEL */
65
66 /*
67 * Header present at the beginning of every mbuf.
68 */
69 struct m_hdr {
70 struct mbuf *mh_next; /* next buffer in chain */
71 struct mbuf *mh_nextpkt; /* next chain in queue/record */
72 caddr_t mh_data; /* location of data */
73 int mh_len; /* amount of data in this mbuf */
74 int mh_flags; /* flags; see below */
75 short mh_type; /* type of data in this mbuf */
76 };
77
78 /*
79 * Packet tag structure (see below for details).
80 */
81 struct m_tag {
82 SLIST_ENTRY(m_tag) m_tag_link; /* List of packet tags */
83 u_int16_t m_tag_id; /* Tag ID */
84 u_int16_t m_tag_len; /* Length of data */
85 u_int32_t m_tag_cookie; /* ABI/Module ID */
86 };
87
88 /*
89 * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
90 */
91 struct pkthdr {
92 struct ifnet *rcvif; /* rcv interface */
93 int len; /* total packet length */
94 /* variables for ip and tcp reassembly */
95 void *header; /* pointer to packet header */
96 /* variables for hardware checksum */
97 int csum_flags; /* flags regarding checksum */
98 int csum_data; /* data field used by csum routines */
99 SLIST_HEAD(packet_tags, m_tag) tags; /* list of packet tags */
100 };
101
102 /*
103 * Description of external storage mapped into mbuf; valid only if M_EXT is set.
104 */
105 struct m_ext {
106 caddr_t ext_buf; /* start of buffer */
107 void (*ext_free) /* free routine if not the usual */
108 (void *, void *);
109 void *ext_args; /* optional argument pointer */
110 u_int ext_size; /* size of buffer, for ext_free */
111 u_int *ref_cnt; /* pointer to ref count info */
112 int ext_type; /* type of external storage */
113 };
114
115 /*
116 * The core of the mbuf object along with some shortcut defines for
117 * practical purposes.
118 */
119 struct mbuf {
120 struct m_hdr m_hdr;
121 union {
122 struct {
123 struct pkthdr MH_pkthdr; /* M_PKTHDR set */
124 union {
125 struct m_ext MH_ext; /* M_EXT set */
126 char MH_databuf[MHLEN];
127 } MH_dat;
128 } MH;
129 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */
130 } M_dat;
131 };
132 #define m_next m_hdr.mh_next
133 #define m_len m_hdr.mh_len
134 #define m_data m_hdr.mh_data
135 #define m_type m_hdr.mh_type
136 #define m_flags m_hdr.mh_flags
137 #define m_nextpkt m_hdr.mh_nextpkt
138 #define m_act m_nextpkt
139 #define m_pkthdr M_dat.MH.MH_pkthdr
140 #define m_ext M_dat.MH.MH_dat.MH_ext
141 #define m_pktdat M_dat.MH.MH_dat.MH_databuf
142 #define m_dat M_dat.M_databuf
143
144 /*
145 * mbuf flags.
146 */
147 #define M_EXT 0x0001 /* has associated external storage */
148 #define M_PKTHDR 0x0002 /* start of record */
149 #define M_EOR 0x0004 /* end of record */
150 #define M_RDONLY 0x0008 /* associated data is marked read-only */
151 #define M_PROTO1 0x0010 /* protocol-specific */
152 #define M_PROTO2 0x0020 /* protocol-specific */
153 #define M_PROTO3 0x0040 /* protocol-specific */
154 #define M_PROTO4 0x0080 /* protocol-specific */
155 #define M_PROTO5 0x0100 /* protocol-specific */
156 #define M_PROTO6 0x4000 /* protocol-specific (avoid M_BCAST conflict) */
157 #define M_FREELIST 0x8000 /* mbuf is on the free list */
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 #define EXT_EXTREF 400 /* has externally maintained ref_cnt ptr*/
177
178 /*
179 * Flags copied when copying m_pkthdr.
180 */
181 #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_RDONLY|M_PROTO1|M_PROTO1|M_PROTO2|\
182 M_PROTO3|M_PROTO4|M_PROTO5|M_PROTO6|\
183 M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG)
184
185 /*
186 * Flags indicating hw checksum support and sw checksum requirements.
187 */
188 #define CSUM_IP 0x0001 /* will csum IP */
189 #define CSUM_TCP 0x0002 /* will csum TCP */
190 #define CSUM_UDP 0x0004 /* will csum UDP */
191 #define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */
192 #define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */
193
194 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */
195 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */
196 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */
197 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */
198
199 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP)
200 #define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */
201
202 /*
203 * mbuf types.
204 */
205 #define MT_NOTMBUF 0 /* USED INTERNALLY ONLY! Object is not mbuf */
206 #define MT_DATA 1 /* dynamic (data) allocation */
207 #define MT_HEADER 2 /* packet header */
208 #if 0
209 #define MT_SOCKET 3 /* socket structure */
210 #define MT_PCB 4 /* protocol control block */
211 #define MT_RTABLE 5 /* routing tables */
212 #define MT_HTABLE 6 /* IMP host tables */
213 #define MT_ATABLE 7 /* address resolution tables */
214 #endif
215 #define MT_SONAME 8 /* socket name */
216 #if 0
217 #define MT_SOOPTS 10 /* socket options */
218 #endif
219 #define MT_FTABLE 11 /* fragment reassembly header */
220 #if 0
221 #define MT_RIGHTS 12 /* access rights */
222 #define MT_IFADDR 13 /* interface address */
223 #endif
224 #define MT_TAG 13 /* volatile metadata associated to pkts */
225 #define MT_CONTROL 14 /* extra-data protocol message */
226 #define MT_OOBDATA 15 /* expedited data */
227 #define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */
228
229 /*
230 * Mbuf and cluster allocation statistics PCPU structure.
231 */
232 struct mbpstat {
233 u_long mb_mbfree;
234 u_long mb_mbbucks;
235 u_long mb_clfree;
236 u_long mb_clbucks;
237 long mb_mbtypes[MT_NTYPES];
238 short mb_active;
239 };
240
241 /*
242 * General mbuf allocator statistics structure.
243 * XXX: Modifications of these are not protected by any mutex locks nor by
244 * any atomic() manipulations. As a result, we may occasionally lose
245 * a count or two. Luckily, not all of these fields are modified at all
246 * and remain static, and those that are manipulated are only manipulated
247 * in failure situations, which do not occur (hopefully) very often.
248 */
249 struct mbstat {
250 u_long m_drops; /* times failed to allocate */
251 u_long m_wait; /* times succesfully returned from wait */
252 u_long m_drain; /* times drained protocols for space */
253 u_long m_mcfail; /* XXX: times m_copym failed */
254 u_long m_mpfail; /* XXX: times m_pullup failed */
255 u_long m_msize; /* length of an mbuf */
256 u_long m_mclbytes; /* length of an mbuf cluster */
257 u_long m_minclsize; /* min length of data to allocate a cluster */
258 u_long m_mlen; /* length of data in an mbuf */
259 u_long m_mhlen; /* length of data in a header mbuf */
260 u_int m_mbperbuck; /* number of mbufs per "bucket" */
261 u_int m_clperbuck; /* number of clusters per "bucket" */
262 /* Number of mbtypes (gives # elems in mbpstat's mb_mbtypes[] array: */
263 short m_numtypes;
264 };
265
266 /*
267 * Flags specifying how an allocation should be made.
268 * M_DONTWAIT means "don't block if nothing is available" whereas
269 * M_TRYWAIT means "block for mbuf_wait ticks at most if nothing is
270 * available."
271 */
272 #define M_DONTWAIT 0x4 /* don't conflict with M_NOWAIT */
273 #define M_TRYWAIT 0x8 /* or M_WAITOK */
274 #define M_WAIT M_TRYWAIT /* XXX: deprecated */
275 #define MBTOM(how) ((how) & M_TRYWAIT ? M_WAITOK : M_NOWAIT)
276
277 #ifdef _KERNEL
278 /*-
279 * mbuf external reference count management macros.
280 *
281 * MEXT_IS_REF(m): true if (m) is not the only mbuf referencing
282 * the external buffer ext_buf.
283 *
284 * MEXT_REM_REF(m): remove reference to m_ext object.
285 *
286 * MEXT_ADD_REF(m): add reference to m_ext object already
287 * referred to by (m).
288 */
289 #define MEXT_IS_REF(m) (*((m)->m_ext.ref_cnt) > 1)
290
291 #define MEXT_REM_REF(m) do { \
292 KASSERT(*((m)->m_ext.ref_cnt) > 0, ("m_ext refcnt < 0")); \
293 atomic_subtract_int((m)->m_ext.ref_cnt, 1); \
294 } while(0)
295
296 #define MEXT_ADD_REF(m) atomic_add_int((m)->m_ext.ref_cnt, 1)
297
298 /*
299 * mbuf, cluster, and external object allocation macros
300 * (for compatibility purposes).
301 */
302 /* NB: M_COPY_PKTHDR is deprecated. Use M_MOVE_PKTHDR or m_dup_pktdr. */
303 #define M_MOVE_PKTHDR(to, from) m_move_pkthdr((to), (from))
304 #define m_getclr(how, type) m_get_clrd((how), (type))
305 #define MGET(m, how, type) ((m) = m_get((how), (type)))
306 #define MGETHDR(m, how, type) ((m) = m_gethdr((how), (type)))
307 #define MCLGET(m, how) m_clget((m), (how))
308 #define MEXTADD(m, buf, size, free, args, flags, type) \
309 m_extadd((m), (caddr_t)(buf), (size), (free), (args), (flags), (type))
310
311 /*
312 * MEXTFREE(m): disassociate (and possibly free) an external object from (m).
313 *
314 * If the atomic_cmpset_int() returns 0, then we effectively do nothing
315 * in terms of "cleaning up" (freeing the ext buf and ref. counter) as
316 * this means that either there are still references, or another thread
317 * is taking care of the clean-up.
318 */
319 #define MEXTFREE(m) do { \
320 struct mbuf *_mb = (m); \
321 \
322 MEXT_REM_REF(_mb); \
323 if (atomic_cmpset_int(_mb->m_ext.ref_cnt, 0, 1)) \
324 _mext_free(_mb); \
325 _mb->m_flags &= ~M_EXT; \
326 } while (0)
327
328 /*
329 * Evaluate TRUE if it's safe to write to the mbuf m's data region (this
330 * can be both the local data payload, or an external buffer area,
331 * depending on whether M_EXT is set).
332 */
333 #define M_WRITABLE(m) (!((m)->m_flags & M_RDONLY) && (!((m)->m_flags \
334 & M_EXT) || !MEXT_IS_REF(m)))
335
336 /*
337 * Check if the supplied mbuf has a packet header, or else panic.
338 */
339 #define M_ASSERTPKTHDR(m) \
340 KASSERT(m != NULL && m->m_flags & M_PKTHDR, \
341 ("%s: no mbuf packet header!", __func__))
342
343 /*
344 * Ensure that the supplied mbuf is a valid, non-free mbuf.
345 */
346 #define M_ASSERTVALID(m) \
347 KASSERT((((struct mbuf *)m)->m_flags & M_FREELIST) == 0, \
348 ("%s: attempted use of a free mbuf!", __func__))
349
350 /*
351 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place
352 * an object of the specified size at the end of the mbuf, longword aligned.
353 */
354 #define M_ALIGN(m, len) do { \
355 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \
356 } while (0)
357
358 /*
359 * As above, for mbufs allocated with m_gethdr/MGETHDR
360 * or initialized by M_COPY_PKTHDR.
361 */
362 #define MH_ALIGN(m, len) do { \
363 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \
364 } while (0)
365
366 /*
367 * Compute the amount of space available
368 * before the current start of data in an mbuf.
369 *
370 * The M_WRITABLE() is a temporary, conservative safety measure: the burden
371 * of checking writability of the mbuf data area rests solely with the caller.
372 */
373 #define M_LEADINGSPACE(m) \
374 ((m)->m_flags & M_EXT ? \
375 (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \
376 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \
377 (m)->m_data - (m)->m_dat)
378
379 /*
380 * Compute the amount of space available
381 * after the end of data in an mbuf.
382 *
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.
385 */
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))
391
392 /*
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 the allocation fails, the original mbuf chain is freed and m is
396 * set to NULL.
397 */
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); \
403 \
404 if (M_LEADINGSPACE(_mm) >= _mplen) { \
405 _mm->m_data -= _mplen; \
406 _mm->m_len += _mplen; \
407 } else \
408 _mm = m_prepend(_mm, _mplen, __mhow); \
409 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \
410 _mm->m_pkthdr.len += _mplen; \
411 *_mmp = _mm; \
412 } while (0)
413
414 /*
415 * Change mbuf to new type.
416 * This is a relatively expensive operation and should be avoided.
417 */
418 #define MCHTYPE(m, t) m_chtype((m), (t))
419
420 /* Length to m_copy to copy all. */
421 #define M_COPYALL 1000000000
422
423 /* Compatibility with 4.3. */
424 #define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT)
425
426 extern int max_datalen; /* MHLEN - max_hdr */
427 extern int max_hdr; /* Largest link + protocol header */
428 extern int max_linkhdr; /* Largest link-level header */
429 extern int max_protohdr; /* Largest protocol header */
430 extern struct mbstat mbstat; /* General mbuf stats/infos */
431 extern int nmbclusters; /* Maximum number of clusters */
432 extern int nmbcnt; /* Scale kmem_map for counter space */
433 extern int nmbufs; /* Maximum number of mbufs */
434 extern int nsfbufs; /* Number of sendfile(2) bufs */
435
436 void _mext_free(struct mbuf *);
437 void m_adj(struct mbuf *, int);
438 void m_cat(struct mbuf *, struct mbuf *);
439 void m_chtype(struct mbuf *, short);
440 void m_clget(struct mbuf *, int);
441 void m_extadd(struct mbuf *, caddr_t, u_int,
442 void (*)(void *, void *), void *, int, int);
443 void m_copyback(struct mbuf *, int, int, caddr_t);
444 void m_copydata(const struct mbuf *, int, int, caddr_t);
445 struct mbuf *m_copym(struct mbuf *, int, int, int);
446 struct mbuf *m_copypacket(struct mbuf *, int);
447 void m_copy_pkthdr(struct mbuf *, struct mbuf *);
448 struct mbuf *m_defrag(struct mbuf *, int);
449 struct mbuf *m_devget(char *, int, int, struct ifnet *,
450 void (*)(char *, caddr_t, u_int));
451 struct mbuf *m_dup(struct mbuf *, int);
452 int m_dup_pkthdr(struct mbuf *, struct mbuf *, int);
453 u_int m_fixhdr(struct mbuf *);
454 struct mbuf *m_fragment(struct mbuf *, int, int);
455 struct mbuf *m_free(struct mbuf *);
456 void m_freem(struct mbuf *);
457 struct mbuf *m_get(int, short);
458 struct mbuf *m_get_clrd(int, short);
459 struct mbuf *m_getcl(int, short, int);
460 struct mbuf *m_gethdr(int, short);
461 struct mbuf *m_gethdr_clrd(int, short);
462 struct mbuf *m_getm(struct mbuf *, int, int, short);
463 u_int m_length(struct mbuf *, struct mbuf **);
464 void m_move_pkthdr(struct mbuf *, struct mbuf *);
465 struct mbuf *m_prepend(struct mbuf *, int, int);
466 void m_print(const struct mbuf *);
467 struct mbuf *m_pulldown(struct mbuf *, int, int, int *);
468 struct mbuf *m_pullup(struct mbuf *, int);
469 struct mbuf *m_split(struct mbuf *, int, int);
470
471 /*
472 * Packets may have annotations attached by affixing a list
473 * of "packet tags" to the pkthdr structure. Packet tags are
474 * dynamically allocated semi-opaque data structures that have
475 * a fixed header (struct m_tag) that specifies the size of the
476 * memory block and a <cookie,type> pair that identifies it.
477 * The cookie is a 32-bit unique unsigned value used to identify
478 * a module or ABI. By convention this value is chose as the
479 * date+time that the module is created, expressed as the number of
480 * seconds since the epoch (e.g., using date -u +'%s'). The type value
481 * is an ABI/module-specific value that identifies a particular annotation
482 * and is private to the module. For compatibility with systems
483 * like OpenBSD that define packet tags w/o an ABI/module cookie,
484 * the value PACKET_ABI_COMPAT is used to implement m_tag_get and
485 * m_tag_find compatibility shim functions and several tag types are
486 * defined below. Users that do not require compatibility should use
487 * a private cookie value so that packet tag-related definitions
488 * can be maintained privately.
489 *
490 * Note that the packet tag returned by m_tag_allocate has the default
491 * memory alignment implemented by malloc. To reference private data
492 * one can use a construct like:
493 *
494 * struct m_tag *mtag = m_tag_allocate(...);
495 * struct foo *p = (struct foo *)(mtag+1);
496 *
497 * if the alignment of struct m_tag is sufficient for referencing members
498 * of struct foo. Otherwise it is necessary to embed struct m_tag within
499 * the private data structure to insure proper alignment; e.g.,
500 *
501 * struct foo {
502 * struct m_tag tag;
503 * ...
504 * };
505 * struct foo *p = (struct foo *) m_tag_allocate(...);
506 * struct m_tag *mtag = &p->tag;
507 */
508
509 /*
510 * Persistent tags stay with an mbuf until the mbuf is reclaimed.
511 * Otherwise tags are expected to ``vanish'' when they pass through
512 * a network interface. For most interfaces this happens normally
513 * as the tags are reclaimed when the mbuf is free'd. However in
514 * some special cases reclaiming must be done manually. An example
515 * is packets that pass through the loopback interface. Also, one
516 * must be careful to do this when ``turning around'' packets (e.g.,
517 * icmp_reflect).
518 *
519 * To mark a tag persistent bit-or this flag in when defining the
520 * tag id. The tag will then be treated as described above.
521 */
522 #define MTAG_PERSISTENT 0x800
523
524 #define PACKET_TAG_NONE 0 /* Nadda */
525
526 /* Packet tag for use with PACKET_ABI_COMPAT. */
527 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */
528 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */
529 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */
530 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */
531 #define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO 5 /* NIC notifies IPsec */
532 #define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */
533 #define PACKET_TAG_BRIDGE 7 /* Bridge processing done */
534 #define PACKET_TAG_GIF 8 /* GIF processing done */
535 #define PACKET_TAG_GRE 9 /* GRE processing done */
536 #define PACKET_TAG_IN_PACKET_CHECKSUM 10 /* NIC checksumming done */
537 #define PACKET_TAG_ENCAP 11 /* Encap. processing */
538 #define PACKET_TAG_IPSEC_SOCKET 12 /* IPSEC socket ref */
539 #define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */
540 #define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */
541
542 /*
543 * As a temporary and low impact solution to replace the even uglier
544 * approach used so far in some parts of the network stack (which relies
545 * on global variables), packet tag-like annotations are stored in MT_TAG
546 * mbufs (or lookalikes) prepended to the actual mbuf chain.
547 *
548 * m_type = MT_TAG
549 * m_flags = m_tag_id
550 * m_next = next buffer in chain.
551 *
552 * BE VERY CAREFUL not to pass these blocks to the mbuf handling routines.
553 */
554 #define _m_tag_id m_hdr.mh_flags
555
556 /* Packet tags used in the FreeBSD network stack. */
557 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */
558 #define PACKET_TAG_IPFW 16 /* ipfw classification */
559 #define PACKET_TAG_DIVERT 17 /* divert info */
560 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */
561 #define PACKET_TAG_MACLABEL (19 | MTAG_PERSISTENT) /* MAC label */
562 #define PACKET_TAG_IPFASTFWD_OURS 20 /* IP fastforward dropback */
563
564 /* Packet tag routines. */
565 struct m_tag *m_tag_alloc(u_int32_t, int, int, int);
566 void m_tag_free(struct m_tag *);
567 void m_tag_prepend(struct mbuf *, struct m_tag *);
568 void m_tag_unlink(struct mbuf *, struct m_tag *);
569 void m_tag_delete(struct mbuf *, struct m_tag *);
570 void m_tag_delete_chain(struct mbuf *, struct m_tag *);
571 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *);
572 struct m_tag *m_tag_copy(struct m_tag *, int);
573 int m_tag_copy_chain(struct mbuf *, struct mbuf *, int);
574 void m_tag_init(struct mbuf *);
575 struct m_tag *m_tag_first(struct mbuf *);
576 struct m_tag *m_tag_next(struct mbuf *, struct m_tag *);
577 void m_tag_delete_nonpersistent(struct mbuf *);
578
579 /* These are for OpenBSD compatibility. */
580 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */
581
582 static __inline struct m_tag *
583 m_tag_get(int type, int length, int wait)
584 {
585 return m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait);
586 }
587
588 static __inline struct m_tag *
589 m_tag_find(struct mbuf *m, int type, struct m_tag *start)
590 {
591 return m_tag_locate(m, MTAG_ABI_COMPAT, type, start);
592 }
593 #endif /* _KERNEL */
594
595 #endif /* !_SYS_MBUF_H_ */
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