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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)mbuf.h 8.5 (Berkeley) 2/19/95 30 * $FreeBSD$ 31 */ 32 33 #ifndef _SYS_MBUF_H_ 34 #define _SYS_MBUF_H_ 35 36 /* XXX: These includes suck. Sorry! */ 37 #include <sys/queue.h> 38 #ifdef _KERNEL 39 #include <sys/systm.h> 40 #include <vm/uma.h> 41 #endif 42 43 /* 44 * Mbufs are of a single size, MSIZE (sys/param.h), which 45 * includes overhead. An mbuf may add a single "mbuf cluster" of size 46 * MCLBYTES (also in sys/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 66 /* 67 * Argument structure passed to UMA routines during mbuf and packet 68 * allocations. 69 */ 70 struct mb_args { 71 int flags; /* Flags for mbuf being allocated */ 72 int how; /* How to allocate: M_WAITOK or M_DONTWAIT */ 73 short type; /* Type of mbuf being allocated */ 74 }; 75 #endif /* _KERNEL */ 76 77 /* 78 * Header present at the beginning of every mbuf. 79 */ 80 struct m_hdr { 81 struct mbuf *mh_next; /* next buffer in chain */ 82 struct mbuf *mh_nextpkt; /* next chain in queue/record */ 83 caddr_t mh_data; /* location of data */ 84 int mh_len; /* amount of data in this mbuf */ 85 int mh_flags; /* flags; see below */ 86 short mh_type; /* type of data in this mbuf */ 87 }; 88 89 /* 90 * Packet tag structure (see below for details). 91 */ 92 struct m_tag { 93 SLIST_ENTRY(m_tag) m_tag_link; /* List of packet tags */ 94 u_int16_t m_tag_id; /* Tag ID */ 95 u_int16_t m_tag_len; /* Length of data */ 96 u_int32_t m_tag_cookie; /* ABI/Module ID */ 97 void (*m_tag_free)(struct m_tag *); 98 }; 99 100 /* 101 * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set. 102 */ 103 struct pkthdr { 104 struct ifnet *rcvif; /* rcv interface */ 105 int len; /* total packet length */ 106 /* variables for ip and tcp reassembly */ 107 void *header; /* pointer to packet header */ 108 /* variables for hardware checksum */ 109 int csum_flags; /* flags regarding checksum */ 110 int csum_data; /* data field used by csum routines */ 111 SLIST_HEAD(packet_tags, m_tag) tags; /* list of packet tags */ 112 }; 113 114 /* 115 * Description of external storage mapped into mbuf; valid only if M_EXT is set. 116 */ 117 struct m_ext { 118 caddr_t ext_buf; /* start of buffer */ 119 void (*ext_free) /* free routine if not the usual */ 120 (void *, void *); 121 void *ext_args; /* optional argument pointer */ 122 u_int ext_size; /* size of buffer, for ext_free */ 123 u_int *ref_cnt; /* pointer to ref count info */ 124 int ext_type; /* type of external storage */ 125 }; 126 127 /* 128 * The core of the mbuf object along with some shortcut defines for 129 * practical purposes. 130 */ 131 struct mbuf { 132 struct m_hdr m_hdr; 133 union { 134 struct { 135 struct pkthdr MH_pkthdr; /* M_PKTHDR set */ 136 union { 137 struct m_ext MH_ext; /* M_EXT set */ 138 char MH_databuf[MHLEN]; 139 } MH_dat; 140 } MH; 141 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ 142 } M_dat; 143 }; 144 #define m_next m_hdr.mh_next 145 #define m_len m_hdr.mh_len 146 #define m_data m_hdr.mh_data 147 #define m_type m_hdr.mh_type 148 #define m_flags m_hdr.mh_flags 149 #define m_nextpkt m_hdr.mh_nextpkt 150 #define m_act m_nextpkt 151 #define m_pkthdr M_dat.MH.MH_pkthdr 152 #define m_ext M_dat.MH.MH_dat.MH_ext 153 #define m_pktdat M_dat.MH.MH_dat.MH_databuf 154 #define m_dat M_dat.M_databuf 155 156 /* 157 * mbuf flags. 158 */ 159 #define M_EXT 0x0001 /* has associated external storage */ 160 #define M_PKTHDR 0x0002 /* start of record */ 161 #define M_EOR 0x0004 /* end of record */ 162 #define M_RDONLY 0x0008 /* associated data is marked read-only */ 163 #define M_PROTO1 0x0010 /* protocol-specific */ 164 #define M_PROTO2 0x0020 /* protocol-specific */ 165 #define M_PROTO3 0x0040 /* protocol-specific */ 166 #define M_PROTO4 0x0080 /* protocol-specific */ 167 #define M_PROTO5 0x0100 /* protocol-specific */ 168 #define M_PROTO6 0x4000 /* protocol-specific (avoid M_BCAST conflict) */ 169 #define M_FREELIST 0x8000 /* mbuf is on the free list */ 170 171 /* 172 * mbuf pkthdr flags (also stored in m_flags). 173 */ 174 #define M_BCAST 0x0200 /* send/received as link-level broadcast */ 175 #define M_MCAST 0x0400 /* send/received as link-level multicast */ 176 #define M_FRAG 0x0800 /* packet is a fragment of a larger packet */ 177 #define M_FIRSTFRAG 0x1000 /* packet is first fragment */ 178 #define M_LASTFRAG 0x2000 /* packet is last fragment */ 179 180 /* 181 * External buffer types: identify ext_buf type. 182 */ 183 #define EXT_CLUSTER 1 /* mbuf cluster */ 184 #define EXT_SFBUF 2 /* sendfile(2)'s sf_bufs */ 185 #define EXT_PACKET 3 /* came out of Packet zone */ 186 #define EXT_NET_DRV 100 /* custom ext_buf provided by net driver(s) */ 187 #define EXT_MOD_TYPE 200 /* custom module's ext_buf type */ 188 #define EXT_DISPOSABLE 300 /* can throw this buffer away w/page flipping */ 189 #define EXT_EXTREF 400 /* has externally maintained ref_cnt ptr */ 190 191 /* 192 * Flags copied when copying m_pkthdr. 193 */ 194 #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_RDONLY|M_PROTO1|M_PROTO1|M_PROTO2|\ 195 M_PROTO3|M_PROTO4|M_PROTO5|M_PROTO6|\ 196 M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG) 197 198 /* 199 * Flags indicating hw checksum support and sw checksum requirements. 200 */ 201 #define CSUM_IP 0x0001 /* will csum IP */ 202 #define CSUM_TCP 0x0002 /* will csum TCP */ 203 #define CSUM_UDP 0x0004 /* will csum UDP */ 204 #define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */ 205 #define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */ 206 207 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */ 208 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */ 209 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */ 210 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */ 211 212 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP) 213 #define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */ 214 215 /* 216 * mbuf types. 217 */ 218 #define MT_NOTMBUF 0 /* USED INTERNALLY ONLY! Object is not mbuf */ 219 #define MT_DATA 1 /* dynamic (data) allocation */ 220 #define MT_HEADER 2 /* packet header */ 221 #if 0 222 #define MT_SOCKET 3 /* socket structure */ 223 #define MT_PCB 4 /* protocol control block */ 224 #define MT_RTABLE 5 /* routing tables */ 225 #define MT_HTABLE 6 /* IMP host tables */ 226 #define MT_ATABLE 7 /* address resolution tables */ 227 #endif 228 #define MT_SONAME 8 /* socket name */ 229 #if 0 230 #define MT_SOOPTS 10 /* socket options */ 231 #endif 232 #define MT_FTABLE 11 /* fragment reassembly header */ 233 #if 0 234 #define MT_RIGHTS 12 /* access rights */ 235 #define MT_IFADDR 13 /* interface address */ 236 #endif 237 #define MT_CONTROL 14 /* extra-data protocol message */ 238 #define MT_OOBDATA 15 /* expedited data */ 239 #define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */ 240 241 /* 242 * General mbuf allocator statistics structure. 243 */ 244 struct mbstat { 245 u_long m_mbufs; /* XXX */ 246 u_long m_mclusts; /* XXX */ 247 248 u_long m_drain; /* times drained protocols for space */ 249 u_long m_mcfail; /* XXX: times m_copym failed */ 250 u_long m_mpfail; /* XXX: times m_pullup failed */ 251 u_long m_msize; /* length of an mbuf */ 252 u_long m_mclbytes; /* length of an mbuf cluster */ 253 u_long m_minclsize; /* min length of data to allocate a cluster */ 254 u_long m_mlen; /* length of data in an mbuf */ 255 u_long m_mhlen; /* length of data in a header mbuf */ 256 257 /* Number of mbtypes (gives # elems in mbtypes[] array: */ 258 short m_numtypes; 259 260 /* XXX: Sendfile stats should eventually move to their own struct */ 261 u_long sf_iocnt; /* times sendfile had to do disk I/O */ 262 u_long sf_allocfail; /* times sfbuf allocation failed */ 263 u_long sf_allocwait; /* times sfbuf allocation had to wait */ 264 }; 265 266 /* 267 * Flags specifying how an allocation should be made. 268 * 269 * The flag to use is as follows: 270 * - M_DONTWAIT or M_NOWAIT from an interrupt handler to not block allocation. 271 * - M_WAIT or M_WAITOK or M_TRYWAIT from wherever it is safe to block. 272 * 273 * M_DONTWAIT/M_NOWAIT means that we will not block the thread explicitly 274 * and if we cannot allocate immediately we may return NULL, 275 * whereas M_WAIT/M_WAITOK/M_TRYWAIT means that if we cannot allocate 276 * resources we will block until they are available, and thus never 277 * return NULL. 278 * 279 * XXX Eventually just phase this out to use M_WAITOK/M_NOWAIT. 280 */ 281 #define MBTOM(how) (how) 282 #define M_DONTWAIT M_NOWAIT 283 #define M_TRYWAIT M_WAITOK 284 #define M_WAIT M_WAITOK 285 286 #ifdef _KERNEL 287 /*- 288 * mbuf external reference count management macros. 289 * 290 * MEXT_IS_REF(m): true if (m) is not the only mbuf referencing 291 * the external buffer ext_buf. 292 * 293 * MEXT_REM_REF(m): remove reference to m_ext object. 294 * 295 * MEXT_ADD_REF(m): add reference to m_ext object already 296 * referred to by (m). 297 */ 298 #define MEXT_IS_REF(m) (*((m)->m_ext.ref_cnt) > 1) 299 300 #define MEXT_REM_REF(m) do { \ 301 KASSERT(*((m)->m_ext.ref_cnt) > 0, ("m_ext refcnt < 0")); \ 302 atomic_subtract_int((m)->m_ext.ref_cnt, 1); \ 303 } while(0) 304 305 #define MEXT_ADD_REF(m) atomic_add_int((m)->m_ext.ref_cnt, 1) 306 307 /* 308 * Network buffer allocation API 309 * 310 * The rest of it is defined in kern/subr_mbuf.c 311 */ 312 313 extern uma_zone_t zone_mbuf; 314 extern uma_zone_t zone_clust; 315 extern uma_zone_t zone_pack; 316 317 static __inline struct mbuf *m_get(int how, short type); 318 static __inline struct mbuf *m_gethdr(int how, short type); 319 static __inline struct mbuf *m_getcl(int how, short type, int flags); 320 static __inline struct mbuf *m_getclr(int how, short type); /* XXX */ 321 static __inline struct mbuf *m_free(struct mbuf *m); 322 static __inline void m_clget(struct mbuf *m, int how); 323 static __inline void m_chtype(struct mbuf *m, short new_type); 324 void mb_free_ext(struct mbuf *); 325 326 static __inline 327 struct mbuf * 328 m_get(int how, short type) 329 { 330 struct mb_args args; 331 332 args.flags = 0; 333 args.how = how; 334 args.type = type; 335 return (uma_zalloc_arg(zone_mbuf, &args, how)); 336 } 337 338 /* XXX This should be depracated, very little use */ 339 static __inline 340 struct mbuf * 341 m_getclr(int how, short type) 342 { 343 struct mbuf *m; 344 struct mb_args args; 345 346 args.flags = 0; 347 args.how = how; 348 args.type = type; 349 m = uma_zalloc_arg(zone_mbuf, &args, how); 350 if (m != NULL) 351 bzero(m->m_data, MLEN); 352 return m; 353 } 354 355 static __inline 356 struct mbuf * 357 m_gethdr(int how, short type) 358 { 359 struct mb_args args; 360 361 args.flags = M_PKTHDR; 362 args.how = how; 363 args.type = type; 364 return (uma_zalloc_arg(zone_mbuf, &args, how)); 365 } 366 367 static __inline 368 struct mbuf * 369 m_getcl(int how, short type, int flags) 370 { 371 struct mb_args args; 372 373 args.flags = flags; 374 args.how = how; 375 args.type = type; 376 return (uma_zalloc_arg(zone_pack, &args, how)); 377 } 378 379 static __inline 380 struct mbuf * 381 m_free(struct mbuf *m) 382 { 383 struct mbuf *n = m->m_next; 384 385 #ifdef INVARIANTS 386 m->m_flags |= M_FREELIST; 387 #endif 388 if (m->m_flags & M_EXT) 389 mb_free_ext(m); 390 else 391 uma_zfree(zone_mbuf, m); 392 return n; 393 } 394 395 static __inline 396 void 397 m_clget(struct mbuf *m, int how) 398 { 399 m->m_ext.ext_buf = NULL; 400 uma_zalloc_arg(zone_clust, m, how); 401 } 402 403 static __inline 404 void 405 m_chtype(struct mbuf *m, short new_type) 406 { 407 m->m_type = new_type; 408 } 409 410 /* 411 * mbuf, cluster, and external object allocation macros 412 * (for compatibility purposes). 413 */ 414 /* NB: M_COPY_PKTHDR is deprecated. Use M_MOVE_PKTHDR or m_dup_pktdr. */ 415 #define M_MOVE_PKTHDR(to, from) m_move_pkthdr((to), (from)) 416 #define MGET(m, how, type) ((m) = m_get((how), (type))) 417 #define MGETHDR(m, how, type) ((m) = m_gethdr((how), (type))) 418 #define MCLGET(m, how) m_clget((m), (how)) 419 #define MEXTADD(m, buf, size, free, args, flags, type) \ 420 m_extadd((m), (caddr_t)(buf), (size), (free), (args), (flags), (type)) 421 422 /* 423 * Evaluate TRUE if it's safe to write to the mbuf m's data region (this 424 * can be both the local data payload, or an external buffer area, 425 * depending on whether M_EXT is set). 426 */ 427 #define M_WRITABLE(m) (!((m)->m_flags & M_RDONLY) && (!((m)->m_flags \ 428 & M_EXT) || !MEXT_IS_REF(m))) 429 430 /* Check if the supplied mbuf has a packet header, or else panic. */ 431 #define M_ASSERTPKTHDR(m) \ 432 KASSERT(m != NULL && m->m_flags & M_PKTHDR, \ 433 ("%s: no mbuf packet header!", __func__)) 434 435 /* Ensure that the supplied mbuf is a valid, non-free mbuf. */ 436 #define M_ASSERTVALID(m) \ 437 KASSERT((((struct mbuf *)m)->m_flags & M_FREELIST) == 0, \ 438 ("%s: attempted use of a free mbuf!", __func__)) 439 440 /* 441 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place 442 * an object of the specified size at the end of the mbuf, longword aligned. 443 */ 444 #define M_ALIGN(m, len) do { \ 445 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \ 446 } while (0) 447 448 /* 449 * As above, for mbufs allocated with m_gethdr/MGETHDR 450 * or initialized by M_COPY_PKTHDR. 451 */ 452 #define MH_ALIGN(m, len) do { \ 453 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \ 454 } while (0) 455 456 /* 457 * Compute the amount of space available 458 * before the current start of data in an mbuf. 459 * 460 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 461 * of checking writability of the mbuf data area rests solely with the caller. 462 */ 463 #define M_LEADINGSPACE(m) \ 464 ((m)->m_flags & M_EXT ? \ 465 (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \ 466 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 467 (m)->m_data - (m)->m_dat) 468 469 /* 470 * Compute the amount of space available 471 * after the end of data in an mbuf. 472 * 473 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 474 * of checking writability of the mbuf data area rests solely with the caller. 475 */ 476 #define M_TRAILINGSPACE(m) \ 477 ((m)->m_flags & M_EXT ? \ 478 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \ 479 - ((m)->m_data + (m)->m_len) : 0) : \ 480 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 481 482 /* 483 * Arrange to prepend space of size plen to mbuf m. 484 * If a new mbuf must be allocated, how specifies whether to wait. 485 * If the allocation fails, the original mbuf chain is freed and m is 486 * set to NULL. 487 */ 488 #define M_PREPEND(m, plen, how) do { \ 489 struct mbuf **_mmp = &(m); \ 490 struct mbuf *_mm = *_mmp; \ 491 int _mplen = (plen); \ 492 int __mhow = (how); \ 493 \ 494 if (M_LEADINGSPACE(_mm) >= _mplen) { \ 495 _mm->m_data -= _mplen; \ 496 _mm->m_len += _mplen; \ 497 } else \ 498 _mm = m_prepend(_mm, _mplen, __mhow); \ 499 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \ 500 _mm->m_pkthdr.len += _mplen; \ 501 *_mmp = _mm; \ 502 } while (0) 503 504 /* 505 * Change mbuf to new type. 506 * This is a relatively expensive operation and should be avoided. 507 */ 508 #define MCHTYPE(m, t) m_chtype((m), (t)) 509 510 /* Length to m_copy to copy all. */ 511 #define M_COPYALL 1000000000 512 513 /* Compatibility with 4.3. */ 514 #define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT) 515 516 extern int max_datalen; /* MHLEN - max_hdr */ 517 extern int max_hdr; /* Largest link + protocol header */ 518 extern int max_linkhdr; /* Largest link-level header */ 519 extern int max_protohdr; /* Largest protocol header */ 520 extern struct mbstat mbstat; /* General mbuf stats/infos */ 521 extern int nmbclusters; /* Maximum number of clusters */ 522 523 struct uio; 524 525 void m_adj(struct mbuf *, int); 526 int m_apply(struct mbuf *, int, int, 527 int (*)(void *, void *, u_int), void *); 528 void m_cat(struct mbuf *, struct mbuf *); 529 void m_extadd(struct mbuf *, caddr_t, u_int, 530 void (*)(void *, void *), void *, int, int); 531 void m_copyback(struct mbuf *, int, int, c_caddr_t); 532 void m_copydata(const struct mbuf *, int, int, caddr_t); 533 struct mbuf *m_copym(struct mbuf *, int, int, int); 534 struct mbuf *m_copypacket(struct mbuf *, int); 535 void m_copy_pkthdr(struct mbuf *, struct mbuf *); 536 struct mbuf *m_defrag(struct mbuf *, int); 537 struct mbuf *m_devget(char *, int, int, struct ifnet *, 538 void (*)(char *, caddr_t, u_int)); 539 struct mbuf *m_dup(struct mbuf *, int); 540 int m_dup_pkthdr(struct mbuf *, struct mbuf *, int); 541 u_int m_fixhdr(struct mbuf *); 542 struct mbuf *m_fragment(struct mbuf *, int, int); 543 void m_freem(struct mbuf *); 544 struct mbuf *m_getm(struct mbuf *, int, int, short); 545 struct mbuf *m_getptr(struct mbuf *, int, int *); 546 u_int m_length(struct mbuf *, struct mbuf **); 547 void m_move_pkthdr(struct mbuf *, struct mbuf *); 548 struct mbuf *m_prepend(struct mbuf *, int, int); 549 void m_print(const struct mbuf *); 550 struct mbuf *m_pulldown(struct mbuf *, int, int, int *); 551 struct mbuf *m_pullup(struct mbuf *, int); 552 struct mbuf *m_split(struct mbuf *, int, int); 553 struct mbuf *m_uiotombuf(struct uio *, int, int); 554 555 /*- 556 * Network packets may have annotations attached by affixing a list 557 * of "packet tags" to the pkthdr structure. Packet tags are 558 * dynamically allocated semi-opaque data structures that have 559 * a fixed header (struct m_tag) that specifies the size of the 560 * memory block and a <cookie,type> pair that identifies it. 561 * The cookie is a 32-bit unique unsigned value used to identify 562 * a module or ABI. By convention this value is chose as the 563 * date+time that the module is created, expressed as the number of 564 * seconds since the epoch (e.g., using date -u +'%s'). The type value 565 * is an ABI/module-specific value that identifies a particular annotation 566 * and is private to the module. For compatibility with systems 567 * like OpenBSD that define packet tags w/o an ABI/module cookie, 568 * the value PACKET_ABI_COMPAT is used to implement m_tag_get and 569 * m_tag_find compatibility shim functions and several tag types are 570 * defined below. Users that do not require compatibility should use 571 * a private cookie value so that packet tag-related definitions 572 * can be maintained privately. 573 * 574 * Note that the packet tag returned by m_tag_alloc has the default 575 * memory alignment implemented by malloc. To reference private data 576 * one can use a construct like: 577 * 578 * struct m_tag *mtag = m_tag_alloc(...); 579 * struct foo *p = (struct foo *)(mtag+1); 580 * 581 * if the alignment of struct m_tag is sufficient for referencing members 582 * of struct foo. Otherwise it is necessary to embed struct m_tag within 583 * the private data structure to insure proper alignment; e.g., 584 * 585 * struct foo { 586 * struct m_tag tag; 587 * ... 588 * }; 589 * struct foo *p = (struct foo *) m_tag_alloc(...); 590 * struct m_tag *mtag = &p->tag; 591 */ 592 593 /* 594 * Persistent tags stay with an mbuf until the mbuf is reclaimed. 595 * Otherwise tags are expected to ``vanish'' when they pass through 596 * a network interface. For most interfaces this happens normally 597 * as the tags are reclaimed when the mbuf is free'd. However in 598 * some special cases reclaiming must be done manually. An example 599 * is packets that pass through the loopback interface. Also, one 600 * must be careful to do this when ``turning around'' packets (e.g., 601 * icmp_reflect). 602 * 603 * To mark a tag persistent bit-or this flag in when defining the 604 * tag id. The tag will then be treated as described above. 605 */ 606 #define MTAG_PERSISTENT 0x800 607 608 #define PACKET_TAG_NONE 0 /* Nadda */ 609 610 /* Packet tags for use with PACKET_ABI_COMPAT. */ 611 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */ 612 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */ 613 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */ 614 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */ 615 #define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO 5 /* NIC notifies IPsec */ 616 #define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */ 617 #define PACKET_TAG_BRIDGE 7 /* Bridge processing done */ 618 #define PACKET_TAG_GIF 8 /* GIF processing done */ 619 #define PACKET_TAG_GRE 9 /* GRE processing done */ 620 #define PACKET_TAG_IN_PACKET_CHECKSUM 10 /* NIC checksumming done */ 621 #define PACKET_TAG_ENCAP 11 /* Encap. processing */ 622 #define PACKET_TAG_IPSEC_SOCKET 12 /* IPSEC socket ref */ 623 #define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */ 624 #define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */ 625 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */ 626 #define PACKET_TAG_DIVERT 17 /* divert info */ 627 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */ 628 #define PACKET_TAG_MACLABEL (19 | MTAG_PERSISTENT) /* MAC label */ 629 #define PACKET_TAG_PF_GENERATED (20 | MTAG_PERSISTENT) /* PF, pass always */ 630 #define PACKET_TAG_PF_ROUTED 21 /* PF routed, avoid loops */ 631 #define PACKET_TAG_PF_FRAGCACHE 22 /* PF fragment cached */ 632 #define PACKET_TAG_PF_QID 23 /* PF ALTQ queue id */ 633 #define PACKET_TAG_PF_TAG 24 /* PF tagged */ 634 #define PACKET_TAG_RTSOCKFAM 25 /* rtsock sa family */ 635 #define PACKET_TAG_PF_TRANSLATE_LOCALHOST 26 /* PF translate localhost */ 636 637 /* Packet tag routines. */ 638 struct m_tag *m_tag_alloc(u_int32_t, int, int, int); 639 void m_tag_delete(struct mbuf *, struct m_tag *); 640 void m_tag_delete_chain(struct mbuf *, struct m_tag *); 641 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *); 642 struct m_tag *m_tag_copy(struct m_tag *, int); 643 int m_tag_copy_chain(struct mbuf *, struct mbuf *, int); 644 void m_tag_delete_nonpersistent(struct mbuf *); 645 646 /* 647 * Initialize the list of tags associated with an mbuf. 648 */ 649 static __inline void 650 m_tag_init(struct mbuf *m) 651 { 652 SLIST_INIT(&m->m_pkthdr.tags); 653 } 654 655 /* 656 * Set up the contents of a tag. Note that this does not 657 * fill in the free method; the caller is expected to do that. 658 * 659 * XXX probably should be called m_tag_init, but that was 660 * already taken. 661 */ 662 static __inline void 663 m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len) 664 { 665 t->m_tag_id = type; 666 t->m_tag_len = len; 667 t->m_tag_cookie = cookie; 668 } 669 670 /* 671 * Reclaim resources associated with a tag. 672 */ 673 static __inline void 674 m_tag_free(struct m_tag *t) 675 { 676 (*t->m_tag_free)(t); 677 } 678 679 /* 680 * Return the first tag associated with an mbuf. 681 */ 682 static __inline struct m_tag * 683 m_tag_first(struct mbuf *m) 684 { 685 return (SLIST_FIRST(&m->m_pkthdr.tags)); 686 } 687 688 /* 689 * Return the next tag in the list of tags associated with an mbuf. 690 */ 691 static __inline struct m_tag * 692 m_tag_next(struct mbuf *m, struct m_tag *t) 693 { 694 return (SLIST_NEXT(t, m_tag_link)); 695 } 696 697 /* 698 * Prepend a tag to the list of tags associated with an mbuf. 699 */ 700 static __inline void 701 m_tag_prepend(struct mbuf *m, struct m_tag *t) 702 { 703 SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link); 704 } 705 706 /* 707 * Unlink a tag from the list of tags associated with an mbuf. 708 */ 709 static __inline void 710 m_tag_unlink(struct mbuf *m, struct m_tag *t) 711 { 712 SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link); 713 } 714 715 /* These are for OpenBSD compatibility. */ 716 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */ 717 718 static __inline struct m_tag * 719 m_tag_get(int type, int length, int wait) 720 { 721 return (m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait)); 722 } 723 724 static __inline struct m_tag * 725 m_tag_find(struct mbuf *m, int type, struct m_tag *start) 726 { 727 return (SLIST_EMPTY(&m->m_pkthdr.tags) ? 728 NULL : m_tag_locate(m, MTAG_ABI_COMPAT, type, start)); 729 } 730 731 /* 732 * Obtain next_hop information associated with the mbuf, if any. 733 * If a tag is present devalidate it also. 734 */ 735 static __inline struct sockaddr_in * 736 m_claim_next(struct mbuf *m, int type) 737 { 738 struct m_tag *mtag = m_tag_find(m, type, NULL); 739 if (mtag) { 740 struct sockaddr_in *sin = *(struct sockaddr_in **)(mtag + 1); 741 mtag->m_tag_id = PACKET_TAG_NONE; 742 return (sin); 743 } 744 return (NULL); 745 } 746 #endif /* _KERNEL */ 747 748 #endif /* !_SYS_MBUF_H_ */ 749