mbuf.h revision 177566
1/*- 2 * Copyright (c) 1982, 1986, 1988, 1993 3 * The Regents of the University of California. 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 * @(#)mbuf.h 8.5 (Berkeley) 2/19/95 31 * $FreeBSD: head/sys/sys/mbuf.h 177566 2008-03-24 19:01:29Z sam $ 32 */ 33 34#ifndef _SYS_MBUF_H_ 35#define _SYS_MBUF_H_ 36 37/* XXX: These includes suck. Sorry! */ 38#include <sys/queue.h> 39#ifdef _KERNEL 40#include <sys/systm.h> 41#include <vm/uma.h> 42#ifdef WITNESS 43#include <sys/lock.h> 44#endif 45#endif 46 47/* 48 * Mbufs are of a single size, MSIZE (sys/param.h), which includes overhead. 49 * An mbuf may add a single "mbuf cluster" of size MCLBYTES (also in 50 * sys/param.h), which has no additional overhead and is used instead of the 51 * internal data area; this is done when at least MINCLSIZE of data must be 52 * stored. Additionally, it is possible to allocate a separate buffer 53 * externally and attach it to the mbuf in a way similar to that of mbuf 54 * clusters. 55 */ 56#define MLEN (MSIZE - sizeof(struct m_hdr)) /* normal data len */ 57#define MHLEN (MLEN - sizeof(struct pkthdr)) /* data len w/pkthdr */ 58#define MINCLSIZE (MHLEN + 1) /* smallest amount to put in cluster */ 59#define M_MAXCOMPRESS (MHLEN / 2) /* max amount to copy for compression */ 60 61#ifdef _KERNEL 62/*- 63 * Macros for type conversion: 64 * mtod(m, t) -- Convert mbuf pointer to data pointer of correct type. 65 * dtom(x) -- Convert data pointer within mbuf to mbuf pointer (XXX). 66 */ 67#define mtod(m, t) ((t)((m)->m_data)) 68#define dtom(x) ((struct mbuf *)((intptr_t)(x) & ~(MSIZE-1))) 69 70/* 71 * Argument structure passed to UMA routines during mbuf and packet 72 * allocations. 73 */ 74struct mb_args { 75 int flags; /* Flags for mbuf being allocated */ 76 short type; /* Type of mbuf being allocated */ 77}; 78#endif /* _KERNEL */ 79 80#if defined(__LP64__) 81#define M_HDR_PAD 6 82#else 83#define M_HDR_PAD 2 84#endif 85 86/* 87 * Header present at the beginning of every mbuf. 88 */ 89struct m_hdr { 90 struct mbuf *mh_next; /* next buffer in chain */ 91 struct mbuf *mh_nextpkt; /* next chain in queue/record */ 92 caddr_t mh_data; /* location of data */ 93 int mh_len; /* amount of data in this mbuf */ 94 int mh_flags; /* flags; see below */ 95 short mh_type; /* type of data in this mbuf */ 96 uint8_t pad[M_HDR_PAD];/* word align */ 97}; 98 99/* 100 * Packet tag structure (see below for details). 101 */ 102struct m_tag { 103 SLIST_ENTRY(m_tag) m_tag_link; /* List of packet tags */ 104 u_int16_t m_tag_id; /* Tag ID */ 105 u_int16_t m_tag_len; /* Length of data */ 106 u_int32_t m_tag_cookie; /* ABI/Module ID */ 107 void (*m_tag_free)(struct m_tag *); 108}; 109 110/* 111 * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set. 112 */ 113struct pkthdr { 114 struct ifnet *rcvif; /* rcv interface */ 115 /* variables for ip and tcp reassembly */ 116 void *header; /* pointer to packet header */ 117 int len; /* total packet length */ 118 /* variables for hardware checksum */ 119 int csum_flags; /* flags regarding checksum */ 120 int csum_data; /* data field used by csum routines */ 121 u_int16_t tso_segsz; /* TSO segment size */ 122 u_int16_t ether_vtag; /* Ethernet 802.1p+q vlan tag */ 123 SLIST_HEAD(packet_tags, m_tag) tags; /* list of packet tags */ 124}; 125 126/* 127 * Description of external storage mapped into mbuf; valid only if M_EXT is 128 * set. 129 */ 130struct m_ext { 131 caddr_t ext_buf; /* start of buffer */ 132 void (*ext_free) /* free routine if not the usual */ 133 (void *, void *); 134 void *ext_arg1; /* optional argument pointer */ 135 void *ext_arg2; /* optional argument pointer */ 136 u_int ext_size; /* size of buffer, for ext_free */ 137 volatile u_int *ref_cnt; /* pointer to ref count info */ 138 int ext_type; /* type of external storage */ 139}; 140 141/* 142 * The core of the mbuf object along with some shortcut defines for practical 143 * purposes. 144 */ 145struct mbuf { 146 struct m_hdr m_hdr; 147 union { 148 struct { 149 struct pkthdr MH_pkthdr; /* M_PKTHDR set */ 150 union { 151 struct m_ext MH_ext; /* M_EXT set */ 152 char MH_databuf[MHLEN]; 153 } MH_dat; 154 } MH; 155 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ 156 } M_dat; 157}; 158#define m_next m_hdr.mh_next 159#define m_len m_hdr.mh_len 160#define m_data m_hdr.mh_data 161#define m_type m_hdr.mh_type 162#define m_flags m_hdr.mh_flags 163#define m_nextpkt m_hdr.mh_nextpkt 164#define m_act m_nextpkt 165#define m_pkthdr M_dat.MH.MH_pkthdr 166#define m_ext M_dat.MH.MH_dat.MH_ext 167#define m_pktdat M_dat.MH.MH_dat.MH_databuf 168#define m_dat M_dat.M_databuf 169 170/* 171 * mbuf flags. 172 */ 173#define M_EXT 0x00000001 /* has associated external storage */ 174#define M_PKTHDR 0x00000002 /* start of record */ 175#define M_EOR 0x00000004 /* end of record */ 176#define M_RDONLY 0x00000008 /* associated data is marked read-only */ 177#define M_PROTO1 0x00000010 /* protocol-specific */ 178#define M_PROTO2 0x00000020 /* protocol-specific */ 179#define M_PROTO3 0x00000040 /* protocol-specific */ 180#define M_PROTO4 0x00000080 /* protocol-specific */ 181#define M_PROTO5 0x00000100 /* protocol-specific */ 182#define M_BCAST 0x00000200 /* send/received as link-level broadcast */ 183#define M_MCAST 0x00000400 /* send/received as link-level multicast */ 184#define M_FRAG 0x00000800 /* packet is a fragment of a larger packet */ 185#define M_FIRSTFRAG 0x00001000 /* packet is first fragment */ 186#define M_LASTFRAG 0x00002000 /* packet is last fragment */ 187#define M_SKIP_FIREWALL 0x00004000 /* skip firewall processing */ 188#define M_FREELIST 0x00008000 /* mbuf is on the free list */ 189#define M_VLANTAG 0x00010000 /* ether_vtag is valid */ 190#define M_PROMISC 0x00020000 /* packet was not for us */ 191#define M_NOFREE 0x00040000 /* do not free mbuf, embedded in cluster */ 192#define M_PROTO6 0x00080000 /* protocol-specific */ 193#define M_PROTO7 0x00100000 /* protocol-specific */ 194#define M_PROTO8 0x00200000 /* protocol-specific */ 195 196#define M_NOTIFICATION M_PROTO5 /* SCTP notification */ 197 198/* 199 * Flags to purge when crossing layers. 200 */ 201#define M_PROTOFLAGS \ 202 (M_PROTO1|M_PROTO2|M_PROTO3|M_PROTO4|M_PROTO5|M_PROTO6|M_PROTO7|M_PROTO8) 203 204/* 205 * Flags preserved when copying m_pkthdr. 206 */ 207#define M_COPYFLAGS \ 208 (M_PKTHDR|M_EOR|M_RDONLY|M_PROTOFLAGS|M_SKIP_FIREWALL|M_BCAST|M_MCAST|\ 209 M_FRAG|M_FIRSTFRAG|M_LASTFRAG|M_VLANTAG|M_PROMISC) 210 211/* 212 * External buffer types: identify ext_buf type. 213 */ 214#define EXT_CLUSTER 1 /* mbuf cluster */ 215#define EXT_SFBUF 2 /* sendfile(2)'s sf_bufs */ 216#define EXT_JUMBOP 3 /* jumbo cluster 4096 bytes */ 217#define EXT_JUMBO9 4 /* jumbo cluster 9216 bytes */ 218#define EXT_JUMBO16 5 /* jumbo cluster 16184 bytes */ 219#define EXT_PACKET 6 /* mbuf+cluster from packet zone */ 220#define EXT_MBUF 7 /* external mbuf reference (M_IOVEC) */ 221#define EXT_NET_DRV 100 /* custom ext_buf provided by net driver(s) */ 222#define EXT_MOD_TYPE 200 /* custom module's ext_buf type */ 223#define EXT_DISPOSABLE 300 /* can throw this buffer away w/page flipping */ 224#define EXT_EXTREF 400 /* has externally maintained ref_cnt ptr */ 225 226/* 227 * Flags indicating hw checksum support and sw checksum requirements. This 228 * field can be directly tested against if_data.ifi_hwassist. 229 */ 230#define CSUM_IP 0x0001 /* will csum IP */ 231#define CSUM_TCP 0x0002 /* will csum TCP */ 232#define CSUM_UDP 0x0004 /* will csum UDP */ 233#define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */ 234#define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */ 235#define CSUM_TSO 0x0020 /* will do TSO */ 236 237#define CSUM_IP_CHECKED 0x0100 /* did csum IP */ 238#define CSUM_IP_VALID 0x0200 /* ... the csum is valid */ 239#define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */ 240#define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */ 241 242#define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP) 243#define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */ 244 245/* 246 * mbuf types. 247 */ 248#define MT_NOTMBUF 0 /* USED INTERNALLY ONLY! Object is not mbuf */ 249#define MT_DATA 1 /* dynamic (data) allocation */ 250#define MT_HEADER MT_DATA /* packet header, use M_PKTHDR instead */ 251#define MT_SONAME 8 /* socket name */ 252#define MT_CONTROL 14 /* extra-data protocol message */ 253#define MT_OOBDATA 15 /* expedited data */ 254#define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */ 255 256#define MT_NOINIT 255 /* Not a type but a flag to allocate 257 a non-initialized mbuf */ 258 259#define MB_NOTAGS 0x1UL /* no tags attached to mbuf */ 260 261/* 262 * General mbuf allocator statistics structure. 263 * 264 * Many of these statistics are no longer used; we instead track many 265 * allocator statistics through UMA's built in statistics mechanism. 266 */ 267struct mbstat { 268 u_long m_mbufs; /* XXX */ 269 u_long m_mclusts; /* XXX */ 270 271 u_long m_drain; /* times drained protocols for space */ 272 u_long m_mcfail; /* XXX: times m_copym failed */ 273 u_long m_mpfail; /* XXX: times m_pullup failed */ 274 u_long m_msize; /* length of an mbuf */ 275 u_long m_mclbytes; /* length of an mbuf cluster */ 276 u_long m_minclsize; /* min length of data to allocate a cluster */ 277 u_long m_mlen; /* length of data in an mbuf */ 278 u_long m_mhlen; /* length of data in a header mbuf */ 279 280 /* Number of mbtypes (gives # elems in mbtypes[] array: */ 281 short m_numtypes; 282 283 /* XXX: Sendfile stats should eventually move to their own struct */ 284 u_long sf_iocnt; /* times sendfile had to do disk I/O */ 285 u_long sf_allocfail; /* times sfbuf allocation failed */ 286 u_long sf_allocwait; /* times sfbuf allocation had to wait */ 287}; 288 289/* 290 * Flags specifying how an allocation should be made. 291 * 292 * The flag to use is as follows: 293 * - M_DONTWAIT or M_NOWAIT from an interrupt handler to not block allocation. 294 * - M_WAIT or M_WAITOK or M_TRYWAIT from wherever it is safe to block. 295 * 296 * M_DONTWAIT/M_NOWAIT means that we will not block the thread explicitly and 297 * if we cannot allocate immediately we may return NULL, whereas 298 * M_WAIT/M_WAITOK/M_TRYWAIT means that if we cannot allocate resources we 299 * will block until they are available, and thus never return NULL. 300 * 301 * XXX Eventually just phase this out to use M_WAITOK/M_NOWAIT. 302 */ 303#define MBTOM(how) (how) 304#define M_DONTWAIT M_NOWAIT 305#define M_TRYWAIT M_WAITOK 306#define M_WAIT M_WAITOK 307 308/* 309 * String names of mbuf-related UMA(9) and malloc(9) types. Exposed to 310 * !_KERNEL so that monitoring tools can look up the zones with 311 * libmemstat(3). 312 */ 313#define MBUF_MEM_NAME "mbuf" 314#define MBUF_CLUSTER_MEM_NAME "mbuf_cluster" 315#define MBUF_PACKET_MEM_NAME "mbuf_packet" 316#define MBUF_JUMBOP_MEM_NAME "mbuf_jumbo_page" 317#define MBUF_JUMBO9_MEM_NAME "mbuf_jumbo_9k" 318#define MBUF_JUMBO16_MEM_NAME "mbuf_jumbo_16k" 319#define MBUF_TAG_MEM_NAME "mbuf_tag" 320#define MBUF_EXTREFCNT_MEM_NAME "mbuf_ext_refcnt" 321 322#ifdef _KERNEL 323 324#ifdef WITNESS 325#define MBUF_CHECKSLEEP(how) do { \ 326 if (how == M_WAITOK) \ 327 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, \ 328 "Sleeping in \"%s\"", __func__); \ 329} while (0) 330#else 331#define MBUF_CHECKSLEEP(how) 332#endif 333 334/* 335 * Network buffer allocation API 336 * 337 * The rest of it is defined in kern/kern_mbuf.c 338 */ 339 340extern uma_zone_t zone_mbuf; 341extern uma_zone_t zone_clust; 342extern uma_zone_t zone_pack; 343extern uma_zone_t zone_jumbop; 344extern uma_zone_t zone_jumbo9; 345extern uma_zone_t zone_jumbo16; 346extern uma_zone_t zone_ext_refcnt; 347 348static __inline struct mbuf *m_getcl(int how, short type, int flags); 349static __inline struct mbuf *m_get(int how, short type); 350static __inline struct mbuf *m_gethdr(int how, short type); 351static __inline struct mbuf *m_getjcl(int how, short type, int flags, 352 int size); 353static __inline struct mbuf *m_getclr(int how, short type); /* XXX */ 354static __inline struct mbuf *m_free(struct mbuf *m); 355static __inline void m_clget(struct mbuf *m, int how); 356static __inline void *m_cljget(struct mbuf *m, int how, int size); 357static __inline void m_chtype(struct mbuf *m, short new_type); 358void mb_free_ext(struct mbuf *); 359static __inline struct mbuf *m_last(struct mbuf *m); 360 361static __inline int 362m_gettype(int size) 363{ 364 int type; 365 366 switch (size) { 367 case MSIZE: 368 type = EXT_MBUF; 369 break; 370 case MCLBYTES: 371 type = EXT_CLUSTER; 372 break; 373#if MJUMPAGESIZE != MCLBYTES 374 case MJUMPAGESIZE: 375 type = EXT_JUMBOP; 376 break; 377#endif 378 case MJUM9BYTES: 379 type = EXT_JUMBO9; 380 break; 381 case MJUM16BYTES: 382 type = EXT_JUMBO16; 383 break; 384 default: 385 panic("%s: m_getjcl: invalid cluster size", __func__); 386 } 387 388 return (type); 389} 390 391static __inline uma_zone_t 392m_getzone(int size) 393{ 394 uma_zone_t zone; 395 396 switch (size) { 397 case MSIZE: 398 zone = zone_mbuf; 399 break; 400 case MCLBYTES: 401 zone = zone_clust; 402 break; 403#if MJUMPAGESIZE != MCLBYTES 404 case MJUMPAGESIZE: 405 zone = zone_jumbop; 406 break; 407#endif 408 case MJUM9BYTES: 409 zone = zone_jumbo9; 410 break; 411 case MJUM16BYTES: 412 zone = zone_jumbo16; 413 break; 414 default: 415 panic("%s: m_getjcl: invalid cluster type", __func__); 416 } 417 418 return (zone); 419} 420 421static __inline struct mbuf * 422m_get(int how, short type) 423{ 424 struct mb_args args; 425 426 args.flags = 0; 427 args.type = type; 428 return ((struct mbuf *)(uma_zalloc_arg(zone_mbuf, &args, how))); 429} 430 431/* 432 * XXX This should be deprecated, very little use. 433 */ 434static __inline struct mbuf * 435m_getclr(int how, short type) 436{ 437 struct mbuf *m; 438 struct mb_args args; 439 440 args.flags = 0; 441 args.type = type; 442 m = uma_zalloc_arg(zone_mbuf, &args, how); 443 if (m != NULL) 444 bzero(m->m_data, MLEN); 445 return (m); 446} 447 448static __inline struct mbuf * 449m_gethdr(int how, short type) 450{ 451 struct mb_args args; 452 453 args.flags = M_PKTHDR; 454 args.type = type; 455 return ((struct mbuf *)(uma_zalloc_arg(zone_mbuf, &args, how))); 456} 457 458static __inline struct mbuf * 459m_getcl(int how, short type, int flags) 460{ 461 struct mb_args args; 462 463 args.flags = flags; 464 args.type = type; 465 return ((struct mbuf *)(uma_zalloc_arg(zone_pack, &args, how))); 466} 467 468/* 469 * m_getjcl() returns an mbuf with a cluster of the specified size attached. 470 * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES. 471 * 472 * XXX: This is rather large, should be real function maybe. 473 */ 474static __inline struct mbuf * 475m_getjcl(int how, short type, int flags, int size) 476{ 477 struct mb_args args; 478 struct mbuf *m, *n; 479 uma_zone_t zone; 480 481 args.flags = flags; 482 args.type = type; 483 484 m = uma_zalloc_arg(zone_mbuf, &args, how); 485 if (m == NULL) 486 return (NULL); 487 488 zone = m_getzone(size); 489 n = uma_zalloc_arg(zone, m, how); 490 if (n == NULL) { 491 uma_zfree(zone_mbuf, m); 492 return (NULL); 493 } 494 return (m); 495} 496 497static __inline void 498m_free_fast(struct mbuf *m) 499{ 500#ifdef INVARIANTS 501 if (m->m_flags & M_PKTHDR) 502 KASSERT(SLIST_EMPTY(&m->m_pkthdr.tags), ("doing fast free of mbuf with tags")); 503#endif 504 505 uma_zfree_arg(zone_mbuf, m, (void *)MB_NOTAGS); 506} 507 508static __inline struct mbuf * 509m_free(struct mbuf *m) 510{ 511 struct mbuf *n = m->m_next; 512 513 if (m->m_flags & M_EXT) 514 mb_free_ext(m); 515 else if ((m->m_flags & M_NOFREE) == 0) 516 uma_zfree(zone_mbuf, m); 517 return (n); 518} 519 520static __inline void 521m_clget(struct mbuf *m, int how) 522{ 523 524 if (m->m_flags & M_EXT) 525 printf("%s: %p mbuf already has cluster\n", __func__, m); 526 m->m_ext.ext_buf = (char *)NULL; 527 uma_zalloc_arg(zone_clust, m, how); 528 /* 529 * On a cluster allocation failure, drain the packet zone and retry, 530 * we might be able to loosen a few clusters up on the drain. 531 */ 532 if ((how & M_NOWAIT) && (m->m_ext.ext_buf == NULL)) { 533 zone_drain(zone_pack); 534 uma_zalloc_arg(zone_clust, m, how); 535 } 536} 537 538/* 539 * m_cljget() is different from m_clget() as it can allocate clusters without 540 * attaching them to an mbuf. In that case the return value is the pointer 541 * to the cluster of the requested size. If an mbuf was specified, it gets 542 * the cluster attached to it and the return value can be safely ignored. 543 * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES. 544 */ 545static __inline void * 546m_cljget(struct mbuf *m, int how, int size) 547{ 548 uma_zone_t zone; 549 550 if (m && m->m_flags & M_EXT) 551 printf("%s: %p mbuf already has cluster\n", __func__, m); 552 if (m != NULL) 553 m->m_ext.ext_buf = NULL; 554 555 zone = m_getzone(size); 556 return (uma_zalloc_arg(zone, m, how)); 557} 558 559static __inline void 560m_cljset(struct mbuf *m, void *cl, int type) 561{ 562 uma_zone_t zone; 563 int size; 564 565 switch (type) { 566 case EXT_CLUSTER: 567 size = MCLBYTES; 568 zone = zone_clust; 569 break; 570#if MJUMPAGESIZE != MCLBYTES 571 case EXT_JUMBOP: 572 size = MJUMPAGESIZE; 573 zone = zone_jumbop; 574 break; 575#endif 576 case EXT_JUMBO9: 577 size = MJUM9BYTES; 578 zone = zone_jumbo9; 579 break; 580 case EXT_JUMBO16: 581 size = MJUM16BYTES; 582 zone = zone_jumbo16; 583 break; 584 default: 585 panic("unknown cluster type"); 586 break; 587 } 588 589 m->m_data = m->m_ext.ext_buf = cl; 590 m->m_ext.ext_free = m->m_ext.ext_arg1 = m->m_ext.ext_arg2 = NULL; 591 m->m_ext.ext_size = size; 592 m->m_ext.ext_type = type; 593 m->m_ext.ref_cnt = uma_find_refcnt(zone, cl); 594 m->m_flags |= M_EXT; 595 596} 597 598static __inline void 599m_chtype(struct mbuf *m, short new_type) 600{ 601 602 m->m_type = new_type; 603} 604 605static __inline struct mbuf * 606m_last(struct mbuf *m) 607{ 608 609 while (m->m_next) 610 m = m->m_next; 611 return (m); 612} 613 614/* 615 * mbuf, cluster, and external object allocation macros (for compatibility 616 * purposes). 617 */ 618#define M_MOVE_PKTHDR(to, from) m_move_pkthdr((to), (from)) 619#define MGET(m, how, type) ((m) = m_get((how), (type))) 620#define MGETHDR(m, how, type) ((m) = m_gethdr((how), (type))) 621#define MCLGET(m, how) m_clget((m), (how)) 622#define MEXTADD(m, buf, size, free, arg1, arg2, flags, type) \ 623 m_extadd((m), (caddr_t)(buf), (size), (free),(arg1),(arg2),(flags), (type)) 624#define m_getm(m, len, how, type) \ 625 m_getm2((m), (len), (how), (type), M_PKTHDR) 626 627/* 628 * Evaluate TRUE if it's safe to write to the mbuf m's data region (this can 629 * be both the local data payload, or an external buffer area, depending on 630 * whether M_EXT is set). 631 */ 632#define M_WRITABLE(m) (!((m)->m_flags & M_RDONLY) && \ 633 (!(((m)->m_flags & M_EXT)) || \ 634 (*((m)->m_ext.ref_cnt) == 1)) ) \ 635 636/* Check if the supplied mbuf has a packet header, or else panic. */ 637#define M_ASSERTPKTHDR(m) \ 638 KASSERT((m) != NULL && (m)->m_flags & M_PKTHDR, \ 639 ("%s: no mbuf packet header!", __func__)) 640 641/* 642 * Ensure that the supplied mbuf is a valid, non-free mbuf. 643 * 644 * XXX: Broken at the moment. Need some UMA magic to make it work again. 645 */ 646#define M_ASSERTVALID(m) \ 647 KASSERT((((struct mbuf *)m)->m_flags & 0) == 0, \ 648 ("%s: attempted use of a free mbuf!", __func__)) 649 650/* 651 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place an 652 * object of the specified size at the end of the mbuf, longword aligned. 653 */ 654#define M_ALIGN(m, len) do { \ 655 KASSERT(!((m)->m_flags & (M_PKTHDR|M_EXT)), \ 656 ("%s: M_ALIGN not normal mbuf", __func__)); \ 657 KASSERT((m)->m_data == (m)->m_dat, \ 658 ("%s: M_ALIGN not a virgin mbuf", __func__)); \ 659 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \ 660} while (0) 661 662/* 663 * As above, for mbufs allocated with m_gethdr/MGETHDR or initialized by 664 * M_DUP/MOVE_PKTHDR. 665 */ 666#define MH_ALIGN(m, len) do { \ 667 KASSERT((m)->m_flags & M_PKTHDR && !((m)->m_flags & M_EXT), \ 668 ("%s: MH_ALIGN not PKTHDR mbuf", __func__)); \ 669 KASSERT((m)->m_data == (m)->m_pktdat, \ 670 ("%s: MH_ALIGN not a virgin mbuf", __func__)); \ 671 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \ 672} while (0) 673 674/* 675 * Compute the amount of space available before the current start of data in 676 * an mbuf. 677 * 678 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 679 * of checking writability of the mbuf data area rests solely with the caller. 680 */ 681#define M_LEADINGSPACE(m) \ 682 ((m)->m_flags & M_EXT ? \ 683 (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \ 684 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 685 (m)->m_data - (m)->m_dat) 686 687/* 688 * Compute the amount of space available after the end of data in an mbuf. 689 * 690 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 691 * of checking writability of the mbuf data area rests solely with the caller. 692 */ 693#define M_TRAILINGSPACE(m) \ 694 ((m)->m_flags & M_EXT ? \ 695 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \ 696 - ((m)->m_data + (m)->m_len) : 0) : \ 697 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 698 699/* 700 * Arrange to prepend space of size plen to mbuf m. If a new mbuf must be 701 * allocated, how specifies whether to wait. If the allocation fails, the 702 * original mbuf chain is freed and m is set to NULL. 703 */ 704#define M_PREPEND(m, plen, how) do { \ 705 struct mbuf **_mmp = &(m); \ 706 struct mbuf *_mm = *_mmp; \ 707 int _mplen = (plen); \ 708 int __mhow = (how); \ 709 \ 710 MBUF_CHECKSLEEP(how); \ 711 if (M_LEADINGSPACE(_mm) >= _mplen) { \ 712 _mm->m_data -= _mplen; \ 713 _mm->m_len += _mplen; \ 714 } else \ 715 _mm = m_prepend(_mm, _mplen, __mhow); \ 716 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \ 717 _mm->m_pkthdr.len += _mplen; \ 718 *_mmp = _mm; \ 719} while (0) 720 721/* 722 * Change mbuf to new type. This is a relatively expensive operation and 723 * should be avoided. 724 */ 725#define MCHTYPE(m, t) m_chtype((m), (t)) 726 727/* Length to m_copy to copy all. */ 728#define M_COPYALL 1000000000 729 730/* Compatibility with 4.3. */ 731#define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT) 732 733extern int max_datalen; /* MHLEN - max_hdr */ 734extern int max_hdr; /* Largest link + protocol header */ 735extern int max_linkhdr; /* Largest link-level header */ 736extern int max_protohdr; /* Largest protocol header */ 737extern struct mbstat mbstat; /* General mbuf stats/infos */ 738extern int nmbclusters; /* Maximum number of clusters */ 739 740struct uio; 741 742void m_adj(struct mbuf *, int); 743void m_align(struct mbuf *, int); 744int m_apply(struct mbuf *, int, int, 745 int (*)(void *, void *, u_int), void *); 746int m_append(struct mbuf *, int, c_caddr_t); 747void m_cat(struct mbuf *, struct mbuf *); 748void m_extadd(struct mbuf *, caddr_t, u_int, 749 void (*)(void *, void *), void *, void *, int, int); 750struct mbuf *m_collapse(struct mbuf *, int, int); 751void m_copyback(struct mbuf *, int, int, c_caddr_t); 752void m_copydata(const struct mbuf *, int, int, caddr_t); 753struct mbuf *m_copym(struct mbuf *, int, int, int); 754struct mbuf *m_copymdata(struct mbuf *, struct mbuf *, 755 int, int, int, int); 756struct mbuf *m_copypacket(struct mbuf *, int); 757void m_copy_pkthdr(struct mbuf *, struct mbuf *); 758struct mbuf *m_copyup(struct mbuf *n, int len, int dstoff); 759struct mbuf *m_defrag(struct mbuf *, int); 760void m_demote(struct mbuf *, int); 761struct mbuf *m_devget(char *, int, int, struct ifnet *, 762 void (*)(char *, caddr_t, u_int)); 763struct mbuf *m_dup(struct mbuf *, int); 764int m_dup_pkthdr(struct mbuf *, struct mbuf *, int); 765u_int m_fixhdr(struct mbuf *); 766struct mbuf *m_fragment(struct mbuf *, int, int); 767void m_freem(struct mbuf *); 768struct mbuf *m_getm2(struct mbuf *, int, int, short, int); 769struct mbuf *m_getptr(struct mbuf *, int, int *); 770u_int m_length(struct mbuf *, struct mbuf **); 771void m_move_pkthdr(struct mbuf *, struct mbuf *); 772struct mbuf *m_prepend(struct mbuf *, int, int); 773void m_print(const struct mbuf *, int); 774struct mbuf *m_pulldown(struct mbuf *, int, int, int *); 775struct mbuf *m_pullup(struct mbuf *, int); 776int m_sanity(struct mbuf *, int); 777struct mbuf *m_split(struct mbuf *, int, int); 778struct mbuf *m_uiotombuf(struct uio *, int, int, int, int); 779struct mbuf *m_unshare(struct mbuf *, int how); 780 781/*- 782 * Network packets may have annotations attached by affixing a list of 783 * "packet tags" to the pkthdr structure. Packet tags are dynamically 784 * allocated semi-opaque data structures that have a fixed header 785 * (struct m_tag) that specifies the size of the memory block and a 786 * <cookie,type> pair that identifies it. The cookie is a 32-bit unique 787 * unsigned value used to identify a module or ABI. By convention this value 788 * is chosen as the date+time that the module is created, expressed as the 789 * number of seconds since the epoch (e.g., using date -u +'%s'). The type 790 * value is an ABI/module-specific value that identifies a particular 791 * annotation and is private to the module. For compatibility with systems 792 * like OpenBSD that define packet tags w/o an ABI/module cookie, the value 793 * PACKET_ABI_COMPAT is used to implement m_tag_get and m_tag_find 794 * compatibility shim functions and several tag types are defined below. 795 * Users that do not require compatibility should use a private cookie value 796 * so that packet tag-related definitions can be maintained privately. 797 * 798 * Note that the packet tag returned by m_tag_alloc has the default memory 799 * alignment implemented by malloc. To reference private data one can use a 800 * construct like: 801 * 802 * struct m_tag *mtag = m_tag_alloc(...); 803 * struct foo *p = (struct foo *)(mtag+1); 804 * 805 * if the alignment of struct m_tag is sufficient for referencing members of 806 * struct foo. Otherwise it is necessary to embed struct m_tag within the 807 * private data structure to insure proper alignment; e.g., 808 * 809 * struct foo { 810 * struct m_tag tag; 811 * ... 812 * }; 813 * struct foo *p = (struct foo *) m_tag_alloc(...); 814 * struct m_tag *mtag = &p->tag; 815 */ 816 817/* 818 * Persistent tags stay with an mbuf until the mbuf is reclaimed. Otherwise 819 * tags are expected to ``vanish'' when they pass through a network 820 * interface. For most interfaces this happens normally as the tags are 821 * reclaimed when the mbuf is free'd. However in some special cases 822 * reclaiming must be done manually. An example is packets that pass through 823 * the loopback interface. Also, one must be careful to do this when 824 * ``turning around'' packets (e.g., icmp_reflect). 825 * 826 * To mark a tag persistent bit-or this flag in when defining the tag id. 827 * The tag will then be treated as described above. 828 */ 829#define MTAG_PERSISTENT 0x800 830 831#define PACKET_TAG_NONE 0 /* Nadda */ 832 833/* Packet tags for use with PACKET_ABI_COMPAT. */ 834#define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */ 835#define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */ 836#define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */ 837#define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */ 838#define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO 5 /* NIC notifies IPsec */ 839#define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */ 840#define PACKET_TAG_BRIDGE 7 /* Bridge processing done */ 841#define PACKET_TAG_GIF 8 /* GIF processing done */ 842#define PACKET_TAG_GRE 9 /* GRE processing done */ 843#define PACKET_TAG_IN_PACKET_CHECKSUM 10 /* NIC checksumming done */ 844#define PACKET_TAG_ENCAP 11 /* Encap. processing */ 845#define PACKET_TAG_IPSEC_SOCKET 12 /* IPSEC socket ref */ 846#define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */ 847#define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */ 848#define PACKET_TAG_DUMMYNET 15 /* dummynet info */ 849#define PACKET_TAG_DIVERT 17 /* divert info */ 850#define PACKET_TAG_IPFORWARD 18 /* ipforward info */ 851#define PACKET_TAG_MACLABEL (19 | MTAG_PERSISTENT) /* MAC label */ 852#define PACKET_TAG_PF 21 /* PF + ALTQ information */ 853#define PACKET_TAG_RTSOCKFAM 25 /* rtsock sa family */ 854#define PACKET_TAG_IPOPTIONS 27 /* Saved IP options */ 855#define PACKET_TAG_CARP 28 /* CARP info */ 856 857/* Specific cookies and tags. */ 858 859/* Packet tag routines. */ 860struct m_tag *m_tag_alloc(u_int32_t, int, int, int); 861void m_tag_delete(struct mbuf *, struct m_tag *); 862void m_tag_delete_chain(struct mbuf *, struct m_tag *); 863void m_tag_free_default(struct m_tag *); 864struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *); 865struct m_tag *m_tag_copy(struct m_tag *, int); 866int m_tag_copy_chain(struct mbuf *, struct mbuf *, int); 867void m_tag_delete_nonpersistent(struct mbuf *); 868 869/* 870 * Initialize the list of tags associated with an mbuf. 871 */ 872static __inline void 873m_tag_init(struct mbuf *m) 874{ 875 876 SLIST_INIT(&m->m_pkthdr.tags); 877} 878 879/* 880 * Set up the contents of a tag. Note that this does not fill in the free 881 * method; the caller is expected to do that. 882 * 883 * XXX probably should be called m_tag_init, but that was already taken. 884 */ 885static __inline void 886m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len) 887{ 888 889 t->m_tag_id = type; 890 t->m_tag_len = len; 891 t->m_tag_cookie = cookie; 892} 893 894/* 895 * Reclaim resources associated with a tag. 896 */ 897static __inline void 898m_tag_free(struct m_tag *t) 899{ 900 901 (*t->m_tag_free)(t); 902} 903 904/* 905 * Return the first tag associated with an mbuf. 906 */ 907static __inline struct m_tag * 908m_tag_first(struct mbuf *m) 909{ 910 911 return (SLIST_FIRST(&m->m_pkthdr.tags)); 912} 913 914/* 915 * Return the next tag in the list of tags associated with an mbuf. 916 */ 917static __inline struct m_tag * 918m_tag_next(struct mbuf *m, struct m_tag *t) 919{ 920 921 return (SLIST_NEXT(t, m_tag_link)); 922} 923 924/* 925 * Prepend a tag to the list of tags associated with an mbuf. 926 */ 927static __inline void 928m_tag_prepend(struct mbuf *m, struct m_tag *t) 929{ 930 931 SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link); 932} 933 934/* 935 * Unlink a tag from the list of tags associated with an mbuf. 936 */ 937static __inline void 938m_tag_unlink(struct mbuf *m, struct m_tag *t) 939{ 940 941 SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link); 942} 943 944/* These are for OpenBSD compatibility. */ 945#define MTAG_ABI_COMPAT 0 /* compatibility ABI */ 946 947static __inline struct m_tag * 948m_tag_get(int type, int length, int wait) 949{ 950 return (m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait)); 951} 952 953static __inline struct m_tag * 954m_tag_find(struct mbuf *m, int type, struct m_tag *start) 955{ 956 return (SLIST_EMPTY(&m->m_pkthdr.tags) ? (struct m_tag *)NULL : 957 m_tag_locate(m, MTAG_ABI_COMPAT, type, start)); 958} 959 960#endif /* _KERNEL */ 961 962#endif /* !_SYS_MBUF_H_ */ 963