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 * $FreeBSD$ 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 void (*m_tag_free)(struct m_tag *); 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 }; 102 103 /* 104 * Description of external storage mapped into mbuf; valid only if M_EXT is set. 105 */ 106 struct m_ext { 107 caddr_t ext_buf; /* start of buffer */ 108 void (*ext_free) /* free routine if not the usual */ 109 (void *, void *); 110 void *ext_args; /* optional argument pointer */ 111 u_int ext_size; /* size of buffer, for ext_free */ 112 u_int *ref_cnt; /* pointer to ref count info */ 113 int ext_type; /* type of external storage */ 114 }; 115 116 /* 117 * The core of the mbuf object along with some shortcut defines for 118 * practical purposes. 119 */ 120 struct mbuf { 121 struct m_hdr m_hdr; 122 union { 123 struct { 124 struct pkthdr MH_pkthdr; /* M_PKTHDR set */ 125 union { 126 struct m_ext MH_ext; /* M_EXT set */ 127 char MH_databuf[MHLEN]; 128 } MH_dat; 129 } MH; 130 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ 131 } M_dat; 132 }; 133 #define m_next m_hdr.mh_next 134 #define m_len m_hdr.mh_len 135 #define m_data m_hdr.mh_data 136 #define m_type m_hdr.mh_type 137 #define m_flags m_hdr.mh_flags 138 #define m_nextpkt m_hdr.mh_nextpkt 139 #define m_act m_nextpkt 140 #define m_pkthdr M_dat.MH.MH_pkthdr 141 #define m_ext M_dat.MH.MH_dat.MH_ext 142 #define m_pktdat M_dat.MH.MH_dat.MH_databuf 143 #define m_dat M_dat.M_databuf 144 145 /* 146 * mbuf flags. 147 */ 148 #define M_EXT 0x0001 /* has associated external storage */ 149 #define M_PKTHDR 0x0002 /* start of record */ 150 #define M_EOR 0x0004 /* end of record */ 151 #define M_RDONLY 0x0008 /* associated data is marked read-only */ 152 #define M_PROTO1 0x0010 /* protocol-specific */ 153 #define M_PROTO2 0x0020 /* protocol-specific */ 154 #define M_PROTO3 0x0040 /* protocol-specific */ 155 #define M_PROTO4 0x0080 /* protocol-specific */ 156 #define M_PROTO5 0x0100 /* protocol-specific */ 157 #define M_PROTO6 0x4000 /* protocol-specific (avoid M_BCAST conflict) */ 158 #define M_FREELIST 0x8000 /* mbuf is on the free list */ 159 160 /* 161 * mbuf pkthdr flags (also stored in m_flags). 162 */ 163 #define M_BCAST 0x0200 /* send/received as link-level broadcast */ 164 #define M_MCAST 0x0400 /* send/received as link-level multicast */ 165 #define M_FRAG 0x0800 /* packet is a fragment of a larger packet */ 166 #define M_FIRSTFRAG 0x1000 /* packet is first fragment */ 167 #define M_LASTFRAG 0x2000 /* packet is last fragment */ 168 169 /* 170 * External buffer types: identify ext_buf type. 171 */ 172 #define EXT_CLUSTER 1 /* mbuf cluster */ 173 #define EXT_SFBUF 2 /* sendfile(2)'s sf_bufs */ 174 #define EXT_NET_DRV 100 /* custom ext_buf provided by net driver(s) */ 175 #define EXT_MOD_TYPE 200 /* custom module's ext_buf type */ 176 #define EXT_DISPOSABLE 300 /* can throw this buffer away w/page flipping */ 177 #define EXT_EXTREF 400 /* has externally maintained ref_cnt ptr*/ 178 179 /* 180 * Flags copied when copying m_pkthdr. 181 */ 182 #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_RDONLY|M_PROTO1|M_PROTO1|M_PROTO2|\ 183 M_PROTO3|M_PROTO4|M_PROTO5|M_PROTO6|\ 184 M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG) 185 186 /* 187 * Flags indicating hw checksum support and sw checksum requirements. 188 */ 189 #define CSUM_IP 0x0001 /* will csum IP */ 190 #define CSUM_TCP 0x0002 /* will csum TCP */ 191 #define CSUM_UDP 0x0004 /* will csum UDP */ 192 #define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */ 193 #define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */ 194 195 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */ 196 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */ 197 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */ 198 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */ 199 200 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP) 201 #define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */ 202 203 /* 204 * mbuf types. 205 */ 206 #define MT_NOTMBUF 0 /* USED INTERNALLY ONLY! Object is not mbuf */ 207 #define MT_DATA 1 /* dynamic (data) allocation */ 208 #define MT_HEADER 2 /* packet header */ 209 #if 0 210 #define MT_SOCKET 3 /* socket structure */ 211 #define MT_PCB 4 /* protocol control block */ 212 #define MT_RTABLE 5 /* routing tables */ 213 #define MT_HTABLE 6 /* IMP host tables */ 214 #define MT_ATABLE 7 /* address resolution tables */ 215 #endif 216 #define MT_SONAME 8 /* socket name */ 217 #if 0 218 #define MT_SOOPTS 10 /* socket options */ 219 #endif 220 #define MT_FTABLE 11 /* fragment reassembly header */ 221 #if 0 222 #define MT_RIGHTS 12 /* access rights */ 223 #define MT_IFADDR 13 /* interface address */ 224 #endif 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 /* 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) 429 430 extern int max_datalen; /* MHLEN - max_hdr */ 431 extern int max_hdr; /* Largest link + protocol header */ 432 extern int max_linkhdr; /* Largest link-level header */ 433 extern int max_protohdr; /* Largest protocol header */ 434 extern struct mbstat mbstat; /* General mbuf stats/infos */ 435 extern int nmbclusters; /* Maximum number of clusters */ 436 extern int nmbcnt; /* Scale kmem_map for counter space */ 437 extern int nmbufs; /* Maximum number of mbufs */ 438 439 struct uio; 440 441 void _mext_free(struct mbuf *); 442 void m_adj(struct mbuf *, int); 443 int m_apply(struct mbuf *, int, int, 444 int (*)(void *, void *, unsigned int), void *); 445 void m_cat(struct mbuf *, struct mbuf *); 446 void m_chtype(struct mbuf *, short); 447 void m_clget(struct mbuf *, int); 448 void m_extadd(struct mbuf *, caddr_t, u_int, 449 void (*)(void *, void *), void *, int, int); 450 void m_copyback(struct mbuf *, int, int, caddr_t); 451 void m_copydata(const struct mbuf *, int, int, caddr_t); 452 struct mbuf *m_copym(struct mbuf *, int, int, int); 453 struct mbuf *m_copypacket(struct mbuf *, int); 454 void m_copy_pkthdr(struct mbuf *, struct mbuf *); 455 struct mbuf *m_defrag(struct mbuf *, int); 456 struct mbuf *m_devget(char *, int, int, struct ifnet *, 457 void (*)(char *, caddr_t, u_int)); 458 struct mbuf *m_dup(struct mbuf *, int); 459 int m_dup_pkthdr(struct mbuf *, struct mbuf *, int); 460 u_int m_fixhdr(struct mbuf *); 461 struct mbuf *m_fragment(struct mbuf *, int, int); 462 struct mbuf *m_free(struct mbuf *); 463 void m_freem(struct mbuf *); 464 struct mbuf *m_get(int, short); 465 struct mbuf *m_get_clrd(int, short); 466 struct mbuf *m_getcl(int, short, int); 467 struct mbuf *m_gethdr(int, short); 468 struct mbuf *m_gethdr_clrd(int, short); 469 struct mbuf *m_getm(struct mbuf *, int, int, short); 470 struct mbuf *m_getptr(struct mbuf *, int, int *); 471 u_int m_length(struct mbuf *, struct mbuf **); 472 void m_move_pkthdr(struct mbuf *, struct mbuf *); 473 struct mbuf *m_prepend(struct mbuf *, int, int); 474 void m_print(const struct mbuf *); 475 struct mbuf *m_pulldown(struct mbuf *, int, int, int *); 476 struct mbuf *m_pullup(struct mbuf *, int); 477 struct mbuf *m_split(struct mbuf *, int, int); 478 struct mbuf * 479 m_uiotombuf(struct uio *uio, int how, int len); 480 481 /* 482 * Packets may have annotations attached by affixing a list 483 * of "packet tags" to the pkthdr structure. Packet tags are 484 * dynamically allocated semi-opaque data structures that have 485 * a fixed header (struct m_tag) that specifies the size of the 486 * memory block and a <cookie,type> pair that identifies it. 487 * The cookie is a 32-bit unique unsigned value used to identify 488 * a module or ABI. By convention this value is chose as the 489 * date+time that the module is created, expressed as the number of 490 * seconds since the epoch (e.g., using date -u +'%s'). The type value 491 * is an ABI/module-specific value that identifies a particular annotation 492 * and is private to the module. For compatibility with systems 493 * like OpenBSD that define packet tags w/o an ABI/module cookie, 494 * the value PACKET_ABI_COMPAT is used to implement m_tag_get and 495 * m_tag_find compatibility shim functions and several tag types are 496 * defined below. Users that do not require compatibility should use 497 * a private cookie value so that packet tag-related definitions 498 * can be maintained privately. 499 * 500 * Note that the packet tag returned by m_tag_allocate has the default 501 * memory alignment implemented by malloc. To reference private data 502 * one can use a construct like: 503 * 504 * struct m_tag *mtag = m_tag_allocate(...); 505 * struct foo *p = (struct foo *)(mtag+1); 506 * 507 * if the alignment of struct m_tag is sufficient for referencing members 508 * of struct foo. Otherwise it is necessary to embed struct m_tag within 509 * the private data structure to insure proper alignment; e.g., 510 * 511 * struct foo { 512 * struct m_tag tag; 513 * ... 514 * }; 515 * struct foo *p = (struct foo *) m_tag_allocate(...); 516 * struct m_tag *mtag = &p->tag; 517 */ 518 519 /* 520 * Persistent tags stay with an mbuf until the mbuf is reclaimed. 521 * Otherwise tags are expected to ``vanish'' when they pass through 522 * a network interface. For most interfaces this happens normally 523 * as the tags are reclaimed when the mbuf is free'd. However in 524 * some special cases reclaiming must be done manually. An example 525 * is packets that pass through the loopback interface. Also, one 526 * must be careful to do this when ``turning around'' packets (e.g., 527 * icmp_reflect). 528 * 529 * To mark a tag persistent bit-or this flag in when defining the 530 * tag id. The tag will then be treated as described above. 531 */ 532 #define MTAG_PERSISTENT 0x800 533 534 #define PACKET_TAG_NONE 0 /* Nadda */ 535 536 /* Packet tag for use with PACKET_ABI_COMPAT. */ 537 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */ 538 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */ 539 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */ 540 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */ 541 #define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO 5 /* NIC notifies IPsec */ 542 #define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */ 543 #define PACKET_TAG_BRIDGE 7 /* Bridge processing done */ 544 #define PACKET_TAG_GIF 8 /* GIF processing done */ 545 #define PACKET_TAG_GRE 9 /* GRE processing done */ 546 #define PACKET_TAG_IN_PACKET_CHECKSUM 10 /* NIC checksumming done */ 547 #define PACKET_TAG_ENCAP 11 /* Encap. processing */ 548 #define PACKET_TAG_IPSEC_SOCKET 12 /* IPSEC socket ref */ 549 #define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */ 550 #define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */ 551 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */ 552 #define PACKET_TAG_DIVERT 17 /* divert info */ 553 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */ 554 #define PACKET_TAG_MACLABEL (19 | MTAG_PERSISTENT) /* MAC label */ 555 #define PACKET_TAG_PF_GENERATED (20 | MTAG_PERSISTENT) /* PF, pass always */ 556 #define PACKET_TAG_PF_ROUTED 21 /* PF routed, avoid loops */ 557 #define PACKET_TAG_PF_FRAGCACHE 22 /* PF fragment cached */ 558 #define PACKET_TAG_PF_QID 23 /* PF ALTQ queue id */ 559 #define PACKET_TAG_PF_TAG 24 /* PF tagged */ 560 561 /* Packet tag routines. */ 562 struct m_tag *m_tag_alloc(u_int32_t, int, int, int); 563 void m_tag_delete(struct mbuf *, struct m_tag *); 564 void m_tag_delete_chain(struct mbuf *, struct m_tag *); 565 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *); 566 struct m_tag *m_tag_copy(struct m_tag *, int); 567 int m_tag_copy_chain(struct mbuf *, struct mbuf *, int); 568 void m_tag_delete_nonpersistent(struct mbuf *); 569 570 /* 571 * Initialize the list of tags associated with an mbuf. 572 */ 573 static __inline void 574 m_tag_init(struct mbuf *m) 575 { 576 SLIST_INIT(&m->m_pkthdr.tags); 577 } 578 579 /* 580 * Setup the contents of a tag. Note that this does not 581 * fillin the free method; the caller is expected to do that. 582 * 583 * XXX probably should be called m_tag_init; but that was 584 * already taken. 585 */ 586 static __inline void 587 m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len) 588 { 589 t->m_tag_id = type; 590 t->m_tag_len = len; 591 t->m_tag_cookie = cookie; 592 } 593 594 /* 595 * Reclaim resources associated with a tag. 596 */ 597 static __inline void 598 m_tag_free(struct m_tag *t) 599 { 600 (*t->m_tag_free)(t); 601 } 602 603 /* 604 * Return the first tag associated with an mbuf. 605 */ 606 static __inline struct m_tag * 607 m_tag_first(struct mbuf *m) 608 { 609 return SLIST_FIRST(&m->m_pkthdr.tags); 610 } 611 612 /* 613 * Return the next tag in the list of tags associated with an mbuf. 614 */ 615 static __inline struct m_tag * 616 m_tag_next(struct mbuf *m, struct m_tag *t) 617 { 618 return SLIST_NEXT(t, m_tag_link); 619 } 620 621 /* 622 * Prepend a tag to the list of tags associated with an mbuf. 623 */ 624 static __inline void 625 m_tag_prepend(struct mbuf *m, struct m_tag *t) 626 { 627 SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link); 628 } 629 630 /* 631 * Unlink a tag from the list of tags associated with an mbuf. 632 */ 633 static __inline void 634 m_tag_unlink(struct mbuf *m, struct m_tag *t) 635 { 636 SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link); 637 } 638 639 /* These are for OpenBSD compatibility. */ 640 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */ 641 642 static __inline struct m_tag * 643 m_tag_get(int type, int length, int wait) 644 { 645 return m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait); 646 } 647 648 static __inline struct m_tag * 649 m_tag_find(struct mbuf *m, int type, struct m_tag *start) 650 { 651 return SLIST_EMPTY(&m->m_pkthdr.tags) ? 652 NULL : m_tag_locate(m, MTAG_ABI_COMPAT, type, start); 653 } 654 #endif /* _KERNEL */ 655 656 #endif /* !_SYS_MBUF_H_ */ 657