mbuf.h revision 123929
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: head/sys/sys/mbuf.h 123929 2003-12-28 08:57:09Z silby $ 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 */ 69struct 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 */ 81struct 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 */ 91struct 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 */ 105struct 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 */ 119struct 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 */ 232struct 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 */ 249struct 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 /* XXX: Sendfile stats should eventually move to their own struct */ 265 u_long sf_iocnt; /* times sendfile had to do disk I/O */ 266 u_long sf_allocfail; /* times sfbuf allocation failed */ 267 u_long sf_allocwait; /* times sfbuf allocation had to wait */ 268}; 269 270/* 271 * Flags specifying how an allocation should be made. 272 * M_DONTWAIT means "don't block if nothing is available" whereas 273 * M_TRYWAIT means "block for mbuf_wait ticks at most if nothing is 274 * available." 275 */ 276#define M_DONTWAIT 0x4 /* don't conflict with M_NOWAIT */ 277#define M_TRYWAIT 0x8 /* or M_WAITOK */ 278#define M_WAIT M_TRYWAIT /* XXX: deprecated */ 279#define MBTOM(how) ((how) & M_TRYWAIT ? M_WAITOK : M_NOWAIT) 280 281#ifdef _KERNEL 282/*- 283 * mbuf external reference count management macros. 284 * 285 * MEXT_IS_REF(m): true if (m) is not the only mbuf referencing 286 * the external buffer ext_buf. 287 * 288 * MEXT_REM_REF(m): remove reference to m_ext object. 289 * 290 * MEXT_ADD_REF(m): add reference to m_ext object already 291 * referred to by (m). 292 */ 293#define MEXT_IS_REF(m) (*((m)->m_ext.ref_cnt) > 1) 294 295#define MEXT_REM_REF(m) do { \ 296 KASSERT(*((m)->m_ext.ref_cnt) > 0, ("m_ext refcnt < 0")); \ 297 atomic_subtract_int((m)->m_ext.ref_cnt, 1); \ 298} while(0) 299 300#define MEXT_ADD_REF(m) atomic_add_int((m)->m_ext.ref_cnt, 1) 301 302/* 303 * mbuf, cluster, and external object allocation macros 304 * (for compatibility purposes). 305 */ 306/* NB: M_COPY_PKTHDR is deprecated. Use M_MOVE_PKTHDR or m_dup_pktdr. */ 307#define M_MOVE_PKTHDR(to, from) m_move_pkthdr((to), (from)) 308#define m_getclr(how, type) m_get_clrd((how), (type)) 309#define MGET(m, how, type) ((m) = m_get((how), (type))) 310#define MGETHDR(m, how, type) ((m) = m_gethdr((how), (type))) 311#define MCLGET(m, how) m_clget((m), (how)) 312#define MEXTADD(m, buf, size, free, args, flags, type) \ 313 m_extadd((m), (caddr_t)(buf), (size), (free), (args), (flags), (type)) 314 315/* 316 * MEXTFREE(m): disassociate (and possibly free) an external object from (m). 317 * 318 * If the atomic_cmpset_int() returns 0, then we effectively do nothing 319 * in terms of "cleaning up" (freeing the ext buf and ref. counter) as 320 * this means that either there are still references, or another thread 321 * is taking care of the clean-up. 322 */ 323#define MEXTFREE(m) do { \ 324 struct mbuf *_mb = (m); \ 325 \ 326 MEXT_REM_REF(_mb); \ 327 if (atomic_cmpset_int(_mb->m_ext.ref_cnt, 0, 1)) \ 328 _mext_free(_mb); \ 329 _mb->m_flags &= ~M_EXT; \ 330} while (0) 331 332/* 333 * Evaluate TRUE if it's safe to write to the mbuf m's data region (this 334 * can be both the local data payload, or an external buffer area, 335 * depending on whether M_EXT is set). 336 */ 337#define M_WRITABLE(m) (!((m)->m_flags & M_RDONLY) && (!((m)->m_flags \ 338 & M_EXT) || !MEXT_IS_REF(m))) 339 340/* 341 * Check if the supplied mbuf has a packet header, or else panic. 342 */ 343#define M_ASSERTPKTHDR(m) \ 344 KASSERT(m != NULL && m->m_flags & M_PKTHDR, \ 345 ("%s: no mbuf packet header!", __func__)) 346 347/* 348 * Ensure that the supplied mbuf is a valid, non-free mbuf. 349 */ 350#define M_ASSERTVALID(m) \ 351 KASSERT((((struct mbuf *)m)->m_flags & M_FREELIST) == 0, \ 352 ("%s: attempted use of a free mbuf!", __func__)) 353 354/* 355 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place 356 * an object of the specified size at the end of the mbuf, longword aligned. 357 */ 358#define M_ALIGN(m, len) do { \ 359 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \ 360} while (0) 361 362/* 363 * As above, for mbufs allocated with m_gethdr/MGETHDR 364 * or initialized by M_COPY_PKTHDR. 365 */ 366#define MH_ALIGN(m, len) do { \ 367 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \ 368} while (0) 369 370/* 371 * Compute the amount of space available 372 * before the current start of data in an mbuf. 373 * 374 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 375 * of checking writability of the mbuf data area rests solely with the caller. 376 */ 377#define M_LEADINGSPACE(m) \ 378 ((m)->m_flags & M_EXT ? \ 379 (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \ 380 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 381 (m)->m_data - (m)->m_dat) 382 383/* 384 * Compute the amount of space available 385 * after the end of data in an mbuf. 386 * 387 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 388 * of checking writability of the mbuf data area rests solely with the caller. 389 */ 390#define M_TRAILINGSPACE(m) \ 391 ((m)->m_flags & M_EXT ? \ 392 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \ 393 - ((m)->m_data + (m)->m_len) : 0) : \ 394 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 395 396/* 397 * Arrange to prepend space of size plen to mbuf m. 398 * If a new mbuf must be allocated, how specifies whether to wait. 399 * If the allocation fails, the original mbuf chain is freed and m is 400 * set to NULL. 401 */ 402#define M_PREPEND(m, plen, how) do { \ 403 struct mbuf **_mmp = &(m); \ 404 struct mbuf *_mm = *_mmp; \ 405 int _mplen = (plen); \ 406 int __mhow = (how); \ 407 \ 408 if (M_LEADINGSPACE(_mm) >= _mplen) { \ 409 _mm->m_data -= _mplen; \ 410 _mm->m_len += _mplen; \ 411 } else \ 412 _mm = m_prepend(_mm, _mplen, __mhow); \ 413 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \ 414 _mm->m_pkthdr.len += _mplen; \ 415 *_mmp = _mm; \ 416} while (0) 417 418/* 419 * Change mbuf to new type. 420 * This is a relatively expensive operation and should be avoided. 421 */ 422#define MCHTYPE(m, t) m_chtype((m), (t)) 423 424/* Length to m_copy to copy all. */ 425#define M_COPYALL 1000000000 426 427/* Compatibility with 4.3. */ 428#define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT) 429 430extern int max_datalen; /* MHLEN - max_hdr */ 431extern int max_hdr; /* Largest link + protocol header */ 432extern int max_linkhdr; /* Largest link-level header */ 433extern int max_protohdr; /* Largest protocol header */ 434extern struct mbstat mbstat; /* General mbuf stats/infos */ 435extern int nmbclusters; /* Maximum number of clusters */ 436extern int nmbcnt; /* Scale kmem_map for counter space */ 437extern int nmbufs; /* Maximum number of mbufs */ 438extern int nsfbufs; /* Number of sendfile(2) bufs alloced */ 439extern int nsfbufspeak; /* Peak of nsfbufsused */ 440extern int nsfbufsused; /* Number of sendfile(2) bufs in use */ 441 442void _mext_free(struct mbuf *); 443void m_adj(struct mbuf *, int); 444int m_apply(struct mbuf *, int, int, 445 int (*)(void *, void *, unsigned int), void *); 446void m_cat(struct mbuf *, struct mbuf *); 447void m_chtype(struct mbuf *, short); 448void m_clget(struct mbuf *, int); 449void m_extadd(struct mbuf *, caddr_t, u_int, 450 void (*)(void *, void *), void *, int, int); 451void m_copyback(struct mbuf *, int, int, caddr_t); 452void m_copydata(const struct mbuf *, int, int, caddr_t); 453struct mbuf *m_copym(struct mbuf *, int, int, int); 454struct mbuf *m_copypacket(struct mbuf *, int); 455void m_copy_pkthdr(struct mbuf *, struct mbuf *); 456struct mbuf *m_defrag(struct mbuf *, int); 457struct mbuf *m_devget(char *, int, int, struct ifnet *, 458 void (*)(char *, caddr_t, u_int)); 459struct mbuf *m_dup(struct mbuf *, int); 460int m_dup_pkthdr(struct mbuf *, struct mbuf *, int); 461u_int m_fixhdr(struct mbuf *); 462struct mbuf *m_fragment(struct mbuf *, int, int); 463struct mbuf *m_free(struct mbuf *); 464void m_freem(struct mbuf *); 465struct mbuf *m_get(int, short); 466struct mbuf *m_get_clrd(int, short); 467struct mbuf *m_getcl(int, short, int); 468struct mbuf *m_gethdr(int, short); 469struct mbuf *m_gethdr_clrd(int, short); 470struct mbuf *m_getm(struct mbuf *, int, int, short); 471struct mbuf *m_getptr(struct mbuf *, int, int *); 472u_int m_length(struct mbuf *, struct mbuf **); 473void m_move_pkthdr(struct mbuf *, struct mbuf *); 474struct mbuf *m_prepend(struct mbuf *, int, int); 475void m_print(const struct mbuf *); 476struct mbuf *m_pulldown(struct mbuf *, int, int, int *); 477struct mbuf *m_pullup(struct mbuf *, int); 478struct mbuf *m_split(struct mbuf *, int, int); 479 480/* 481 * Packets may have annotations attached by affixing a list 482 * of "packet tags" to the pkthdr structure. Packet tags are 483 * dynamically allocated semi-opaque data structures that have 484 * a fixed header (struct m_tag) that specifies the size of the 485 * memory block and a <cookie,type> pair that identifies it. 486 * The cookie is a 32-bit unique unsigned value used to identify 487 * a module or ABI. By convention this value is chose as the 488 * date+time that the module is created, expressed as the number of 489 * seconds since the epoch (e.g., using date -u +'%s'). The type value 490 * is an ABI/module-specific value that identifies a particular annotation 491 * and is private to the module. For compatibility with systems 492 * like OpenBSD that define packet tags w/o an ABI/module cookie, 493 * the value PACKET_ABI_COMPAT is used to implement m_tag_get and 494 * m_tag_find compatibility shim functions and several tag types are 495 * defined below. Users that do not require compatibility should use 496 * a private cookie value so that packet tag-related definitions 497 * can be maintained privately. 498 * 499 * Note that the packet tag returned by m_tag_allocate has the default 500 * memory alignment implemented by malloc. To reference private data 501 * one can use a construct like: 502 * 503 * struct m_tag *mtag = m_tag_allocate(...); 504 * struct foo *p = (struct foo *)(mtag+1); 505 * 506 * if the alignment of struct m_tag is sufficient for referencing members 507 * of struct foo. Otherwise it is necessary to embed struct m_tag within 508 * the private data structure to insure proper alignment; e.g., 509 * 510 * struct foo { 511 * struct m_tag tag; 512 * ... 513 * }; 514 * struct foo *p = (struct foo *) m_tag_allocate(...); 515 * struct m_tag *mtag = &p->tag; 516 */ 517 518/* 519 * Persistent tags stay with an mbuf until the mbuf is reclaimed. 520 * Otherwise tags are expected to ``vanish'' when they pass through 521 * a network interface. For most interfaces this happens normally 522 * as the tags are reclaimed when the mbuf is free'd. However in 523 * some special cases reclaiming must be done manually. An example 524 * is packets that pass through the loopback interface. Also, one 525 * must be careful to do this when ``turning around'' packets (e.g., 526 * icmp_reflect). 527 * 528 * To mark a tag persistent bit-or this flag in when defining the 529 * tag id. The tag will then be treated as described above. 530 */ 531#define MTAG_PERSISTENT 0x800 532 533#define PACKET_TAG_NONE 0 /* Nadda */ 534 535/* Packet tag for use with PACKET_ABI_COMPAT. */ 536#define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */ 537#define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */ 538#define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */ 539#define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */ 540#define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO 5 /* NIC notifies IPsec */ 541#define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */ 542#define PACKET_TAG_BRIDGE 7 /* Bridge processing done */ 543#define PACKET_TAG_GIF 8 /* GIF processing done */ 544#define PACKET_TAG_GRE 9 /* GRE processing done */ 545#define PACKET_TAG_IN_PACKET_CHECKSUM 10 /* NIC checksumming done */ 546#define PACKET_TAG_ENCAP 11 /* Encap. processing */ 547#define PACKET_TAG_IPSEC_SOCKET 12 /* IPSEC socket ref */ 548#define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */ 549#define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */ 550 551/* 552 * As a temporary and low impact solution to replace the even uglier 553 * approach used so far in some parts of the network stack (which relies 554 * on global variables), packet tag-like annotations are stored in MT_TAG 555 * mbufs (or lookalikes) prepended to the actual mbuf chain. 556 * 557 * m_type = MT_TAG 558 * m_flags = m_tag_id 559 * m_next = next buffer in chain. 560 * 561 * BE VERY CAREFUL not to pass these blocks to the mbuf handling routines. 562 */ 563#define _m_tag_id m_hdr.mh_flags 564 565/* Packet tags used in the FreeBSD network stack. */ 566#define PACKET_TAG_DUMMYNET 15 /* dummynet info */ 567#define PACKET_TAG_IPFW 16 /* ipfw classification */ 568#define PACKET_TAG_DIVERT 17 /* divert info */ 569#define PACKET_TAG_IPFORWARD 18 /* ipforward info */ 570#define PACKET_TAG_MACLABEL (19 | MTAG_PERSISTENT) /* MAC label */ 571#define PACKET_TAG_IPFASTFWD_OURS 20 /* IP fastforward dropback */ 572 573/* Packet tag routines. */ 574struct m_tag *m_tag_alloc(u_int32_t, int, int, int); 575void m_tag_free(struct m_tag *); 576void m_tag_prepend(struct mbuf *, struct m_tag *); 577void m_tag_unlink(struct mbuf *, struct m_tag *); 578void m_tag_delete(struct mbuf *, struct m_tag *); 579void m_tag_delete_chain(struct mbuf *, struct m_tag *); 580struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *); 581struct m_tag *m_tag_copy(struct m_tag *, int); 582int m_tag_copy_chain(struct mbuf *, struct mbuf *, int); 583void m_tag_init(struct mbuf *); 584struct m_tag *m_tag_first(struct mbuf *); 585struct m_tag *m_tag_next(struct mbuf *, struct m_tag *); 586void m_tag_delete_nonpersistent(struct mbuf *); 587 588/* These are for OpenBSD compatibility. */ 589#define MTAG_ABI_COMPAT 0 /* compatibility ABI */ 590 591static __inline struct m_tag * 592m_tag_get(int type, int length, int wait) 593{ 594 return m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait); 595} 596 597static __inline struct m_tag * 598m_tag_find(struct mbuf *m, int type, struct m_tag *start) 599{ 600 return m_tag_locate(m, MTAG_ABI_COMPAT, type, start); 601} 602#endif /* _KERNEL */ 603 604#endif /* !_SYS_MBUF_H_ */ 605