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 #ifdef WITNESS 42 #include <sys/lock.h> 43 #endif 44 #endif 45 46 /* 47 * Mbufs are of a single size, MSIZE (sys/param.h), which 48 * includes overhead. An mbuf may add a single "mbuf cluster" of size 49 * MCLBYTES (also in sys/param.h), which has no additional overhead 50 * and is used instead of the internal data area; this is done when 51 * at least MINCLSIZE of data must be stored. Additionally, it is possible 52 * to allocate a separate buffer externally and attach it to the mbuf in 53 * a way similar to that of mbuf clusters. 54 */ 55 #define MLEN (MSIZE - sizeof(struct m_hdr)) /* normal data len */ 56 #define MHLEN (MLEN - sizeof(struct pkthdr)) /* data len w/pkthdr */ 57 #define MINCLSIZE (MHLEN + 1) /* smallest amount to put in cluster */ 58 #define M_MAXCOMPRESS (MHLEN / 2) /* max amount to copy for compression */ 59 60 #ifdef _KERNEL 61 /*- 62 * Macros for type conversion: 63 * mtod(m, t) -- Convert mbuf pointer to data pointer of correct type. 64 * dtom(x) -- Convert data pointer within mbuf to mbuf pointer (XXX). 65 */ 66 #define mtod(m, t) ((t)((m)->m_data)) 67 #define dtom(x) ((struct mbuf *)((intptr_t)(x) & ~(MSIZE-1))) 68 69 /* 70 * Argument structure passed to UMA routines during mbuf and packet 71 * allocations. 72 */ 73 struct mb_args { 74 int flags; /* Flags for mbuf being allocated */ 75 int how; /* How to allocate: M_WAITOK or M_DONTWAIT */ 76 short type; /* Type of mbuf being allocated */ 77 }; 78 #endif /* _KERNEL */ 79 80 /* 81 * Header present at the beginning of every mbuf. 82 */ 83 struct m_hdr { 84 struct mbuf *mh_next; /* next buffer in chain */ 85 struct mbuf *mh_nextpkt; /* next chain in queue/record */ 86 caddr_t mh_data; /* location of data */ 87 int mh_len; /* amount of data in this mbuf */ 88 int mh_flags; /* flags; see below */ 89 short mh_type; /* type of data in this mbuf */ 90 }; 91 92 /* 93 * Packet tag structure (see below for details). 94 */ 95 struct m_tag { 96 SLIST_ENTRY(m_tag) m_tag_link; /* List of packet tags */ 97 u_int16_t m_tag_id; /* Tag ID */ 98 u_int16_t m_tag_len; /* Length of data */ 99 u_int32_t m_tag_cookie; /* ABI/Module ID */ 100 void (*m_tag_free)(struct m_tag *); 101 }; 102 103 /* 104 * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set. 105 */ 106 struct pkthdr { 107 struct ifnet *rcvif; /* rcv interface */ 108 int len; /* total packet length */ 109 /* variables for ip and tcp reassembly */ 110 void *header; /* pointer to packet header */ 111 /* variables for hardware checksum */ 112 int csum_flags; /* flags regarding checksum */ 113 int csum_data; /* data field used by csum routines */ 114 SLIST_HEAD(packet_tags, m_tag) tags; /* list of packet tags */ 115 }; 116 117 /* 118 * Description of external storage mapped into mbuf; valid only if M_EXT is set. 119 */ 120 struct m_ext { 121 caddr_t ext_buf; /* start of buffer */ 122 void (*ext_free) /* free routine if not the usual */ 123 (void *, void *); 124 void *ext_args; /* optional argument pointer */ 125 u_int ext_size; /* size of buffer, for ext_free */ 126 u_int *ref_cnt; /* pointer to ref count info */ 127 int ext_type; /* type of external storage */ 128 }; 129 130 /* 131 * The core of the mbuf object along with some shortcut defines for 132 * practical purposes. 133 */ 134 struct mbuf { 135 struct m_hdr m_hdr; 136 union { 137 struct { 138 struct pkthdr MH_pkthdr; /* M_PKTHDR set */ 139 union { 140 struct m_ext MH_ext; /* M_EXT set */ 141 char MH_databuf[MHLEN]; 142 } MH_dat; 143 } MH; 144 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ 145 } M_dat; 146 }; 147 #define m_next m_hdr.mh_next 148 #define m_len m_hdr.mh_len 149 #define m_data m_hdr.mh_data 150 #define m_type m_hdr.mh_type 151 #define m_flags m_hdr.mh_flags 152 #define m_nextpkt m_hdr.mh_nextpkt 153 #define m_act m_nextpkt 154 #define m_pkthdr M_dat.MH.MH_pkthdr 155 #define m_ext M_dat.MH.MH_dat.MH_ext 156 #define m_pktdat M_dat.MH.MH_dat.MH_databuf 157 #define m_dat M_dat.M_databuf 158 159 /* 160 * mbuf flags. 161 */ 162 #define M_EXT 0x0001 /* has associated external storage */ 163 #define M_PKTHDR 0x0002 /* start of record */ 164 #define M_EOR 0x0004 /* end of record */ 165 #define M_RDONLY 0x0008 /* associated data is marked read-only */ 166 #define M_PROTO1 0x0010 /* protocol-specific */ 167 #define M_PROTO2 0x0020 /* protocol-specific */ 168 #define M_PROTO3 0x0040 /* protocol-specific */ 169 #define M_PROTO4 0x0080 /* protocol-specific */ 170 #define M_PROTO5 0x0100 /* protocol-specific */ 171 #define M_SKIP_FIREWALL 0x4000 /* skip firewall processing */ 172 #define M_FREELIST 0x8000 /* mbuf is on the free list */ 173 174 /* 175 * mbuf pkthdr flags (also stored in m_flags). 176 */ 177 #define M_BCAST 0x0200 /* send/received as link-level broadcast */ 178 #define M_MCAST 0x0400 /* send/received as link-level multicast */ 179 #define M_FRAG 0x0800 /* packet is a fragment of a larger packet */ 180 #define M_FIRSTFRAG 0x1000 /* packet is first fragment */ 181 #define M_LASTFRAG 0x2000 /* packet is last fragment */ 182 183 /* 184 * External buffer types: identify ext_buf type. 185 */ 186 #define EXT_CLUSTER 1 /* mbuf cluster */ 187 #define EXT_SFBUF 2 /* sendfile(2)'s sf_bufs */ 188 #define EXT_PACKET 3 /* came out of Packet zone */ 189 #define EXT_NET_DRV 100 /* custom ext_buf provided by net driver(s) */ 190 #define EXT_MOD_TYPE 200 /* custom module's ext_buf type */ 191 #define EXT_DISPOSABLE 300 /* can throw this buffer away w/page flipping */ 192 #define EXT_EXTREF 400 /* has externally maintained ref_cnt ptr */ 193 194 /* 195 * Flags copied when copying m_pkthdr. 196 */ 197 #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_RDONLY|M_PROTO1|M_PROTO1|M_PROTO2|\ 198 M_PROTO3|M_PROTO4|M_PROTO5|M_SKIP_FIREWALL|\ 199 M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG) 200 201 /* 202 * Flags indicating hw checksum support and sw checksum requirements. 203 */ 204 #define CSUM_IP 0x0001 /* will csum IP */ 205 #define CSUM_TCP 0x0002 /* will csum TCP */ 206 #define CSUM_UDP 0x0004 /* will csum UDP */ 207 #define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */ 208 #define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */ 209 210 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */ 211 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */ 212 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */ 213 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */ 214 215 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP) 216 #define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */ 217 218 /* 219 * mbuf types. 220 */ 221 #define MT_NOTMBUF 0 /* USED INTERNALLY ONLY! Object is not mbuf */ 222 #define MT_DATA 1 /* dynamic (data) allocation */ 223 #define MT_HEADER 2 /* packet header */ 224 #if 0 225 #define MT_SOCKET 3 /* socket structure */ 226 #define MT_PCB 4 /* protocol control block */ 227 #define MT_RTABLE 5 /* routing tables */ 228 #define MT_HTABLE 6 /* IMP host tables */ 229 #define MT_ATABLE 7 /* address resolution tables */ 230 #endif 231 #define MT_SONAME 8 /* socket name */ 232 #if 0 233 #define MT_SOOPTS 10 /* socket options */ 234 #endif 235 #define MT_FTABLE 11 /* fragment reassembly header */ 236 #if 0 237 #define MT_RIGHTS 12 /* access rights */ 238 #define MT_IFADDR 13 /* interface address */ 239 #endif 240 #define MT_CONTROL 14 /* extra-data protocol message */ 241 #define MT_OOBDATA 15 /* expedited data */ 242 #define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */ 243 244 /* 245 * General mbuf allocator statistics structure. 246 */ 247 struct mbstat { 248 u_long m_mbufs; /* XXX */ 249 u_long m_mclusts; /* XXX */ 250 251 u_long m_drain; /* times drained protocols for space */ 252 u_long m_mcfail; /* XXX: times m_copym failed */ 253 u_long m_mpfail; /* XXX: times m_pullup failed */ 254 u_long m_msize; /* length of an mbuf */ 255 u_long m_mclbytes; /* length of an mbuf cluster */ 256 u_long m_minclsize; /* min length of data to allocate a cluster */ 257 u_long m_mlen; /* length of data in an mbuf */ 258 u_long m_mhlen; /* length of data in a header mbuf */ 259 260 /* Number of mbtypes (gives # elems in mbtypes[] array: */ 261 short m_numtypes; 262 263 /* XXX: Sendfile stats should eventually move to their own struct */ 264 u_long sf_iocnt; /* times sendfile had to do disk I/O */ 265 u_long sf_allocfail; /* times sfbuf allocation failed */ 266 u_long sf_allocwait; /* times sfbuf allocation had to wait */ 267 }; 268 269 /* 270 * Flags specifying how an allocation should be made. 271 * 272 * The flag to use is as follows: 273 * - M_DONTWAIT or M_NOWAIT from an interrupt handler to not block allocation. 274 * - M_WAIT or M_WAITOK or M_TRYWAIT from wherever it is safe to block. 275 * 276 * M_DONTWAIT/M_NOWAIT means that we will not block the thread explicitly 277 * and if we cannot allocate immediately we may return NULL, 278 * whereas M_WAIT/M_WAITOK/M_TRYWAIT means that if we cannot allocate 279 * resources we will block until they are available, and thus never 280 * return NULL. 281 * 282 * XXX Eventually just phase this out to use M_WAITOK/M_NOWAIT. 283 */ 284 #define MBTOM(how) (how) 285 #define M_DONTWAIT M_NOWAIT 286 #define M_TRYWAIT M_WAITOK 287 #define M_WAIT M_WAITOK 288 289 #ifdef _KERNEL 290 /*- 291 * mbuf external reference count management macros. 292 * 293 * MEXT_IS_REF(m): true if (m) is not the only mbuf referencing 294 * the external buffer ext_buf. 295 * 296 * MEXT_REM_REF(m): remove reference to m_ext object. 297 * 298 * MEXT_ADD_REF(m): add reference to m_ext object already 299 * referred to by (m). 300 */ 301 #define MEXT_IS_REF(m) (*((m)->m_ext.ref_cnt) > 1) 302 303 #define MEXT_REM_REF(m) do { \ 304 KASSERT(*((m)->m_ext.ref_cnt) > 0, ("m_ext refcnt < 0")); \ 305 atomic_subtract_int((m)->m_ext.ref_cnt, 1); \ 306 } while(0) 307 308 #define MEXT_ADD_REF(m) atomic_add_int((m)->m_ext.ref_cnt, 1) 309 310 #ifdef WITNESS 311 #define MBUF_CHECKSLEEP(how) do { \ 312 if (how == M_WAITOK) \ 313 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, \ 314 "Sleeping in \"%s\"", __func__); \ 315 } while(0) 316 #else 317 #define MBUF_CHECKSLEEP(how) 318 #endif 319 320 /* 321 * Network buffer allocation API 322 * 323 * The rest of it is defined in kern/subr_mbuf.c 324 */ 325 326 extern uma_zone_t zone_mbuf; 327 extern uma_zone_t zone_clust; 328 extern uma_zone_t zone_pack; 329 330 static __inline struct mbuf *m_get(int how, short type); 331 static __inline struct mbuf *m_gethdr(int how, short type); 332 static __inline struct mbuf *m_getcl(int how, short type, int flags); 333 static __inline struct mbuf *m_getclr(int how, short type); /* XXX */ 334 static __inline struct mbuf *m_free(struct mbuf *m); 335 static __inline void m_clget(struct mbuf *m, int how); 336 static __inline void m_chtype(struct mbuf *m, short new_type); 337 void mb_free_ext(struct mbuf *); 338 339 static __inline 340 struct mbuf * 341 m_get(int how, short type) 342 { 343 struct mb_args args; 344 345 args.flags = 0; 346 args.how = how; 347 args.type = type; 348 return (uma_zalloc_arg(zone_mbuf, &args, how)); 349 } 350 351 /* XXX This should be depracated, very little use */ 352 static __inline 353 struct mbuf * 354 m_getclr(int how, short type) 355 { 356 struct mbuf *m; 357 struct mb_args args; 358 359 args.flags = 0; 360 args.how = how; 361 args.type = type; 362 m = uma_zalloc_arg(zone_mbuf, &args, how); 363 if (m != NULL) 364 bzero(m->m_data, MLEN); 365 return m; 366 } 367 368 static __inline 369 struct mbuf * 370 m_gethdr(int how, short type) 371 { 372 struct mb_args args; 373 374 args.flags = M_PKTHDR; 375 args.how = how; 376 args.type = type; 377 return (uma_zalloc_arg(zone_mbuf, &args, how)); 378 } 379 380 static __inline 381 struct mbuf * 382 m_getcl(int how, short type, int flags) 383 { 384 struct mb_args args; 385 386 args.flags = flags; 387 args.how = how; 388 args.type = type; 389 return (uma_zalloc_arg(zone_pack, &args, how)); 390 } 391 392 static __inline 393 struct mbuf * 394 m_free(struct mbuf *m) 395 { 396 struct mbuf *n = m->m_next; 397 398 #ifdef INVARIANTS 399 m->m_flags |= M_FREELIST; 400 #endif 401 if (m->m_flags & M_EXT) 402 mb_free_ext(m); 403 else 404 uma_zfree(zone_mbuf, m); 405 return n; 406 } 407 408 static __inline 409 void 410 m_clget(struct mbuf *m, int how) 411 { 412 413 m->m_ext.ext_buf = NULL; 414 uma_zalloc_arg(zone_clust, m, how); 415 } 416 417 static __inline 418 void 419 m_chtype(struct mbuf *m, short new_type) 420 { 421 m->m_type = new_type; 422 } 423 424 /* 425 * mbuf, cluster, and external object allocation macros 426 * (for compatibility purposes). 427 */ 428 /* NB: M_COPY_PKTHDR is deprecated. Use M_MOVE_PKTHDR or m_dup_pktdr. */ 429 #define M_MOVE_PKTHDR(to, from) m_move_pkthdr((to), (from)) 430 #define MGET(m, how, type) ((m) = m_get((how), (type))) 431 #define MGETHDR(m, how, type) ((m) = m_gethdr((how), (type))) 432 #define MCLGET(m, how) m_clget((m), (how)) 433 #define MEXTADD(m, buf, size, free, args, flags, type) \ 434 m_extadd((m), (caddr_t)(buf), (size), (free), (args), (flags), (type)) 435 436 /* 437 * Evaluate TRUE if it's safe to write to the mbuf m's data region (this 438 * can be both the local data payload, or an external buffer area, 439 * depending on whether M_EXT is set). 440 */ 441 #define M_WRITABLE(m) (!((m)->m_flags & M_RDONLY) && (!((m)->m_flags \ 442 & M_EXT) || !MEXT_IS_REF(m))) 443 444 /* Check if the supplied mbuf has a packet header, or else panic. */ 445 #define M_ASSERTPKTHDR(m) \ 446 KASSERT(m != NULL && m->m_flags & M_PKTHDR, \ 447 ("%s: no mbuf packet header!", __func__)) 448 449 /* Ensure that the supplied mbuf is a valid, non-free mbuf. */ 450 #define M_ASSERTVALID(m) \ 451 KASSERT((((struct mbuf *)m)->m_flags & M_FREELIST) == 0, \ 452 ("%s: attempted use of a free mbuf!", __func__)) 453 454 /* 455 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place 456 * an object of the specified size at the end of the mbuf, longword aligned. 457 */ 458 #define M_ALIGN(m, len) do { \ 459 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \ 460 } while (0) 461 462 /* 463 * As above, for mbufs allocated with m_gethdr/MGETHDR 464 * or initialized by M_COPY_PKTHDR. 465 */ 466 #define MH_ALIGN(m, len) do { \ 467 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \ 468 } while (0) 469 470 /* 471 * Compute the amount of space available 472 * before the current start of data in an mbuf. 473 * 474 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 475 * of checking writability of the mbuf data area rests solely with the caller. 476 */ 477 #define M_LEADINGSPACE(m) \ 478 ((m)->m_flags & M_EXT ? \ 479 (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \ 480 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 481 (m)->m_data - (m)->m_dat) 482 483 /* 484 * Compute the amount of space available 485 * after the end of data in an mbuf. 486 * 487 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 488 * of checking writability of the mbuf data area rests solely with the caller. 489 */ 490 #define M_TRAILINGSPACE(m) \ 491 ((m)->m_flags & M_EXT ? \ 492 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \ 493 - ((m)->m_data + (m)->m_len) : 0) : \ 494 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 495 496 /* 497 * Arrange to prepend space of size plen to mbuf m. 498 * If a new mbuf must be allocated, how specifies whether to wait. 499 * If the allocation fails, the original mbuf chain is freed and m is 500 * set to NULL. 501 */ 502 #define M_PREPEND(m, plen, how) do { \ 503 struct mbuf **_mmp = &(m); \ 504 struct mbuf *_mm = *_mmp; \ 505 int _mplen = (plen); \ 506 int __mhow = (how); \ 507 \ 508 MBUF_CHECKSLEEP(how); \ 509 if (M_LEADINGSPACE(_mm) >= _mplen) { \ 510 _mm->m_data -= _mplen; \ 511 _mm->m_len += _mplen; \ 512 } else \ 513 _mm = m_prepend(_mm, _mplen, __mhow); \ 514 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \ 515 _mm->m_pkthdr.len += _mplen; \ 516 *_mmp = _mm; \ 517 } while (0) 518 519 /* 520 * Change mbuf to new type. 521 * This is a relatively expensive operation and should be avoided. 522 */ 523 #define MCHTYPE(m, t) m_chtype((m), (t)) 524 525 /* Length to m_copy to copy all. */ 526 #define M_COPYALL 1000000000 527 528 /* Compatibility with 4.3. */ 529 #define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT) 530 531 extern int max_datalen; /* MHLEN - max_hdr */ 532 extern int max_hdr; /* Largest link + protocol header */ 533 extern int max_linkhdr; /* Largest link-level header */ 534 extern int max_protohdr; /* Largest protocol header */ 535 extern struct mbstat mbstat; /* General mbuf stats/infos */ 536 extern int nmbclusters; /* Maximum number of clusters */ 537 538 struct uio; 539 540 void m_adj(struct mbuf *, int); 541 int m_apply(struct mbuf *, int, int, 542 int (*)(void *, void *, u_int), void *); 543 void m_cat(struct mbuf *, struct mbuf *); 544 void m_extadd(struct mbuf *, caddr_t, u_int, 545 void (*)(void *, void *), void *, int, int); 546 void m_copyback(struct mbuf *, int, int, c_caddr_t); 547 void m_copydata(const struct mbuf *, int, int, caddr_t); 548 struct mbuf *m_copym(struct mbuf *, int, int, int); 549 struct mbuf *m_copypacket(struct mbuf *, int); 550 void m_copy_pkthdr(struct mbuf *, struct mbuf *); 551 struct mbuf *m_defrag(struct mbuf *, int); 552 struct mbuf *m_devget(char *, int, int, struct ifnet *, 553 void (*)(char *, caddr_t, u_int)); 554 struct mbuf *m_dup(struct mbuf *, int); 555 int m_dup_pkthdr(struct mbuf *, struct mbuf *, int); 556 u_int m_fixhdr(struct mbuf *); 557 struct mbuf *m_fragment(struct mbuf *, int, int); 558 void m_freem(struct mbuf *); 559 struct mbuf *m_getm(struct mbuf *, int, int, short); 560 struct mbuf *m_getptr(struct mbuf *, int, int *); 561 u_int m_length(struct mbuf *, struct mbuf **); 562 void m_move_pkthdr(struct mbuf *, struct mbuf *); 563 struct mbuf *m_prepend(struct mbuf *, int, int); 564 void m_print(const struct mbuf *); 565 struct mbuf *m_pulldown(struct mbuf *, int, int, int *); 566 struct mbuf *m_pullup(struct mbuf *, int); 567 struct mbuf *m_split(struct mbuf *, int, int); 568 struct mbuf *m_uiotombuf(struct uio *, int, int); 569 570 /*- 571 * Network packets may have annotations attached by affixing a list 572 * of "packet tags" to the pkthdr structure. Packet tags are 573 * dynamically allocated semi-opaque data structures that have 574 * a fixed header (struct m_tag) that specifies the size of the 575 * memory block and a <cookie,type> pair that identifies it. 576 * The cookie is a 32-bit unique unsigned value used to identify 577 * a module or ABI. By convention this value is chose as the 578 * date+time that the module is created, expressed as the number of 579 * seconds since the epoch (e.g., using date -u +'%s'). The type value 580 * is an ABI/module-specific value that identifies a particular annotation 581 * and is private to the module. For compatibility with systems 582 * like OpenBSD that define packet tags w/o an ABI/module cookie, 583 * the value PACKET_ABI_COMPAT is used to implement m_tag_get and 584 * m_tag_find compatibility shim functions and several tag types are 585 * defined below. Users that do not require compatibility should use 586 * a private cookie value so that packet tag-related definitions 587 * can be maintained privately. 588 * 589 * Note that the packet tag returned by m_tag_alloc has the default 590 * memory alignment implemented by malloc. To reference private data 591 * one can use a construct like: 592 * 593 * struct m_tag *mtag = m_tag_alloc(...); 594 * struct foo *p = (struct foo *)(mtag+1); 595 * 596 * if the alignment of struct m_tag is sufficient for referencing members 597 * of struct foo. Otherwise it is necessary to embed struct m_tag within 598 * the private data structure to insure proper alignment; e.g., 599 * 600 * struct foo { 601 * struct m_tag tag; 602 * ... 603 * }; 604 * struct foo *p = (struct foo *) m_tag_alloc(...); 605 * struct m_tag *mtag = &p->tag; 606 */ 607 608 /* 609 * Persistent tags stay with an mbuf until the mbuf is reclaimed. 610 * Otherwise tags are expected to ``vanish'' when they pass through 611 * a network interface. For most interfaces this happens normally 612 * as the tags are reclaimed when the mbuf is free'd. However in 613 * some special cases reclaiming must be done manually. An example 614 * is packets that pass through the loopback interface. Also, one 615 * must be careful to do this when ``turning around'' packets (e.g., 616 * icmp_reflect). 617 * 618 * To mark a tag persistent bit-or this flag in when defining the 619 * tag id. The tag will then be treated as described above. 620 */ 621 #define MTAG_PERSISTENT 0x800 622 623 #define PACKET_TAG_NONE 0 /* Nadda */ 624 625 /* Packet tags for use with PACKET_ABI_COMPAT. */ 626 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */ 627 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */ 628 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */ 629 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */ 630 #define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO 5 /* NIC notifies IPsec */ 631 #define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */ 632 #define PACKET_TAG_BRIDGE 7 /* Bridge processing done */ 633 #define PACKET_TAG_GIF 8 /* GIF processing done */ 634 #define PACKET_TAG_GRE 9 /* GRE processing done */ 635 #define PACKET_TAG_IN_PACKET_CHECKSUM 10 /* NIC checksumming done */ 636 #define PACKET_TAG_ENCAP 11 /* Encap. processing */ 637 #define PACKET_TAG_IPSEC_SOCKET 12 /* IPSEC socket ref */ 638 #define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */ 639 #define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */ 640 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */ 641 #define PACKET_TAG_DIVERT 17 /* divert info */ 642 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */ 643 #define PACKET_TAG_MACLABEL (19 | MTAG_PERSISTENT) /* MAC label */ 644 #define PACKET_TAG_PF_ROUTED 21 /* PF routed, avoid loops */ 645 #define PACKET_TAG_PF_FRAGCACHE 22 /* PF fragment cached */ 646 #define PACKET_TAG_PF_QID 23 /* PF ALTQ queue id */ 647 #define PACKET_TAG_PF_TAG 24 /* PF tagged */ 648 #define PACKET_TAG_RTSOCKFAM 25 /* rtsock sa family */ 649 #define PACKET_TAG_PF_TRANSLATE_LOCALHOST 26 /* PF translate localhost */ 650 651 /* Packet tag routines. */ 652 struct m_tag *m_tag_alloc(u_int32_t, int, int, int); 653 void m_tag_delete(struct mbuf *, struct m_tag *); 654 void m_tag_delete_chain(struct mbuf *, struct m_tag *); 655 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *); 656 struct m_tag *m_tag_copy(struct m_tag *, int); 657 int m_tag_copy_chain(struct mbuf *, struct mbuf *, int); 658 void m_tag_delete_nonpersistent(struct mbuf *); 659 660 /* 661 * Initialize the list of tags associated with an mbuf. 662 */ 663 static __inline void 664 m_tag_init(struct mbuf *m) 665 { 666 SLIST_INIT(&m->m_pkthdr.tags); 667 } 668 669 /* 670 * Set up the contents of a tag. Note that this does not 671 * fill in the free method; the caller is expected to do that. 672 * 673 * XXX probably should be called m_tag_init, but that was 674 * already taken. 675 */ 676 static __inline void 677 m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len) 678 { 679 t->m_tag_id = type; 680 t->m_tag_len = len; 681 t->m_tag_cookie = cookie; 682 } 683 684 /* 685 * Reclaim resources associated with a tag. 686 */ 687 static __inline void 688 m_tag_free(struct m_tag *t) 689 { 690 (*t->m_tag_free)(t); 691 } 692 693 /* 694 * Return the first tag associated with an mbuf. 695 */ 696 static __inline struct m_tag * 697 m_tag_first(struct mbuf *m) 698 { 699 return (SLIST_FIRST(&m->m_pkthdr.tags)); 700 } 701 702 /* 703 * Return the next tag in the list of tags associated with an mbuf. 704 */ 705 static __inline struct m_tag * 706 m_tag_next(struct mbuf *m, struct m_tag *t) 707 { 708 return (SLIST_NEXT(t, m_tag_link)); 709 } 710 711 /* 712 * Prepend a tag to the list of tags associated with an mbuf. 713 */ 714 static __inline void 715 m_tag_prepend(struct mbuf *m, struct m_tag *t) 716 { 717 SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link); 718 } 719 720 /* 721 * Unlink a tag from the list of tags associated with an mbuf. 722 */ 723 static __inline void 724 m_tag_unlink(struct mbuf *m, struct m_tag *t) 725 { 726 SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link); 727 } 728 729 /* These are for OpenBSD compatibility. */ 730 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */ 731 732 static __inline struct m_tag * 733 m_tag_get(int type, int length, int wait) 734 { 735 return (m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait)); 736 } 737 738 static __inline struct m_tag * 739 m_tag_find(struct mbuf *m, int type, struct m_tag *start) 740 { 741 return (SLIST_EMPTY(&m->m_pkthdr.tags) ? 742 NULL : m_tag_locate(m, MTAG_ABI_COMPAT, type, start)); 743 } 744 745 /* 746 * Obtain next_hop information associated with the mbuf, if any. 747 * If a tag is present devalidate it also. 748 */ 749 static __inline struct sockaddr_in * 750 m_claim_next(struct mbuf *m, int type) 751 { 752 struct m_tag *mtag = m_tag_find(m, type, NULL); 753 if (mtag) { 754 struct sockaddr_in *sin = *(struct sockaddr_in **)(mtag + 1); 755 mtag->m_tag_id = PACKET_TAG_NONE; 756 return (sin); 757 } 758 return (NULL); 759 } 760 #endif /* _KERNEL */ 761 762 #endif /* !_SYS_MBUF_H_ */ 763