mbuf.h revision 155051
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: head/sys/sys/mbuf.h 155051 2006-01-30 13:45:15Z glebius $ 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 */ 73struct mb_args { 74 int flags; /* Flags for mbuf being allocated */ 75 short type; /* Type of mbuf being allocated */ 76}; 77#endif /* _KERNEL */ 78 79/* 80 * Header present at the beginning of every mbuf. 81 */ 82struct m_hdr { 83 struct mbuf *mh_next; /* next buffer in chain */ 84 struct mbuf *mh_nextpkt; /* next chain in queue/record */ 85 caddr_t mh_data; /* location of data */ 86 int mh_len; /* amount of data in this mbuf */ 87 int mh_flags; /* flags; see below */ 88 short mh_type; /* type of data in this mbuf */ 89}; 90 91/* 92 * Packet tag structure (see below for details). 93 */ 94struct m_tag { 95 SLIST_ENTRY(m_tag) m_tag_link; /* List of packet tags */ 96 u_int16_t m_tag_id; /* Tag ID */ 97 u_int16_t m_tag_len; /* Length of data */ 98 u_int32_t m_tag_cookie; /* ABI/Module ID */ 99 void (*m_tag_free)(struct m_tag *); 100}; 101 102/* 103 * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set. 104 */ 105struct pkthdr { 106 struct ifnet *rcvif; /* rcv interface */ 107 int len; /* total packet length */ 108 /* variables for ip and tcp reassembly */ 109 void *header; /* pointer to packet header */ 110 /* variables for hardware checksum */ 111 int csum_flags; /* flags regarding checksum */ 112 int csum_data; /* data field used by csum routines */ 113 SLIST_HEAD(packet_tags, m_tag) tags; /* list of packet tags */ 114}; 115 116/* 117 * Description of external storage mapped into mbuf; valid only if M_EXT is set. 118 */ 119struct m_ext { 120 caddr_t ext_buf; /* start of buffer */ 121 void (*ext_free) /* free routine if not the usual */ 122 (void *, void *); 123 void *ext_args; /* optional argument pointer */ 124 u_int ext_size; /* size of buffer, for ext_free */ 125 volatile u_int *ref_cnt; /* pointer to ref count info */ 126 int ext_type; /* type of external storage */ 127}; 128 129/* 130 * The core of the mbuf object along with some shortcut defines for 131 * practical purposes. 132 */ 133struct mbuf { 134 struct m_hdr m_hdr; 135 union { 136 struct { 137 struct pkthdr MH_pkthdr; /* M_PKTHDR set */ 138 union { 139 struct m_ext MH_ext; /* M_EXT set */ 140 char MH_databuf[MHLEN]; 141 } MH_dat; 142 } MH; 143 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ 144 } M_dat; 145}; 146#define m_next m_hdr.mh_next 147#define m_len m_hdr.mh_len 148#define m_data m_hdr.mh_data 149#define m_type m_hdr.mh_type 150#define m_flags m_hdr.mh_flags 151#define m_nextpkt m_hdr.mh_nextpkt 152#define m_act m_nextpkt 153#define m_pkthdr M_dat.MH.MH_pkthdr 154#define m_ext M_dat.MH.MH_dat.MH_ext 155#define m_pktdat M_dat.MH.MH_dat.MH_databuf 156#define m_dat M_dat.M_databuf 157 158/* 159 * mbuf flags. 160 */ 161#define M_EXT 0x0001 /* has associated external storage */ 162#define M_PKTHDR 0x0002 /* start of record */ 163#define M_EOR 0x0004 /* end of record */ 164#define M_RDONLY 0x0008 /* associated data is marked read-only */ 165#define M_PROTO1 0x0010 /* protocol-specific */ 166#define M_PROTO2 0x0020 /* protocol-specific */ 167#define M_PROTO3 0x0040 /* protocol-specific */ 168#define M_PROTO4 0x0080 /* protocol-specific */ 169#define M_PROTO5 0x0100 /* protocol-specific */ 170#define M_SKIP_FIREWALL 0x4000 /* skip firewall processing */ 171#define M_FREELIST 0x8000 /* mbuf is on the free list */ 172 173/* 174 * mbuf pkthdr flags (also stored in m_flags). 175 */ 176#define M_BCAST 0x0200 /* send/received as link-level broadcast */ 177#define M_MCAST 0x0400 /* send/received as link-level multicast */ 178#define M_FRAG 0x0800 /* packet is a fragment of a larger packet */ 179#define M_FIRSTFRAG 0x1000 /* packet is first fragment */ 180#define M_LASTFRAG 0x2000 /* packet is last fragment */ 181#define M_VLANTAG 0x10000 /* packet has VLAN tag attached */ 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_JUMBO4 3 /* jumbo cluster 4096 bytes */ 189#define EXT_JUMBO9 4 /* jumbo cluster 9216 bytes */ 190#define EXT_JUMBO16 5 /* jumbo cluster 16184 bytes */ 191#define EXT_PACKET 6 /* mbuf+cluster from packet zone */ 192#define EXT_NET_DRV 100 /* custom ext_buf provided by net driver(s) */ 193#define EXT_MOD_TYPE 200 /* custom module's ext_buf type */ 194#define EXT_DISPOSABLE 300 /* can throw this buffer away w/page flipping */ 195#define EXT_EXTREF 400 /* has externally maintained ref_cnt ptr */ 196 197/* 198 * Flags copied when copying m_pkthdr. 199 */ 200#define M_COPYFLAGS (M_PKTHDR|M_EOR|M_RDONLY|M_PROTO1|M_PROTO1|M_PROTO2|\ 201 M_PROTO3|M_PROTO4|M_PROTO5|M_SKIP_FIREWALL|\ 202 M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG|\ 203 M_VLANTAG) 204 205/* 206 * Flags to purge when crossing layers. 207 */ 208#define M_PROTOFLAGS (M_PROTO1|M_PROTO2|M_PROTO3|M_PROTO4|M_PROTO5) 209 210/* 211 * Flags indicating hw checksum support and sw checksum requirements. 212 */ 213#define CSUM_IP 0x0001 /* will csum IP */ 214#define CSUM_TCP 0x0002 /* will csum TCP */ 215#define CSUM_UDP 0x0004 /* will csum UDP */ 216#define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */ 217#define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */ 218 219#define CSUM_IP_CHECKED 0x0100 /* did csum IP */ 220#define CSUM_IP_VALID 0x0200 /* ... the csum is valid */ 221#define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */ 222#define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */ 223 224#define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP) 225#define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */ 226 227/* 228 * mbuf types. 229 */ 230#define MT_NOTMBUF 0 /* USED INTERNALLY ONLY! Object is not mbuf */ 231#define MT_DATA 1 /* dynamic (data) allocation */ 232#define MT_HEADER MT_DATA /* packet header, use M_PKTHDR instead */ 233#if 0 234#define MT_SOCKET 3 /* socket structure */ 235#define MT_PCB 4 /* protocol control block */ 236#define MT_RTABLE 5 /* routing tables */ 237#define MT_HTABLE 6 /* IMP host tables */ 238#define MT_ATABLE 7 /* address resolution tables */ 239#endif 240#define MT_SONAME 8 /* socket name */ 241#if 0 242#define MT_SOOPTS 10 /* socket options */ 243#endif 244#define MT_FTABLE 11 /* fragment reassembly header */ 245#if 0 246#define MT_RIGHTS 12 /* access rights */ 247#define MT_IFADDR 13 /* interface address */ 248#endif 249#define MT_CONTROL 14 /* extra-data protocol message */ 250#define MT_OOBDATA 15 /* expedited data */ 251#define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */ 252 253#define MT_NOINIT 255 /* Not a type but a flag to allocate 254 a non-initialized mbuf */ 255 256/* 257 * General mbuf allocator statistics structure. 258 */ 259struct mbstat { 260 u_long m_mbufs; /* XXX */ 261 u_long m_mclusts; /* XXX */ 262 263 u_long m_drain; /* times drained protocols for space */ 264 u_long m_mcfail; /* XXX: times m_copym failed */ 265 u_long m_mpfail; /* XXX: times m_pullup failed */ 266 u_long m_msize; /* length of an mbuf */ 267 u_long m_mclbytes; /* length of an mbuf cluster */ 268 u_long m_minclsize; /* min length of data to allocate a cluster */ 269 u_long m_mlen; /* length of data in an mbuf */ 270 u_long m_mhlen; /* length of data in a header mbuf */ 271 272 /* Number of mbtypes (gives # elems in mbtypes[] array: */ 273 short m_numtypes; 274 275 /* XXX: Sendfile stats should eventually move to their own struct */ 276 u_long sf_iocnt; /* times sendfile had to do disk I/O */ 277 u_long sf_allocfail; /* times sfbuf allocation failed */ 278 u_long sf_allocwait; /* times sfbuf allocation had to wait */ 279}; 280 281/* 282 * Flags specifying how an allocation should be made. 283 * 284 * The flag to use is as follows: 285 * - M_DONTWAIT or M_NOWAIT from an interrupt handler to not block allocation. 286 * - M_WAIT or M_WAITOK or M_TRYWAIT from wherever it is safe to block. 287 * 288 * M_DONTWAIT/M_NOWAIT means that we will not block the thread explicitly 289 * and if we cannot allocate immediately we may return NULL, 290 * whereas M_WAIT/M_WAITOK/M_TRYWAIT means that if we cannot allocate 291 * resources we will block until they are available, and thus never 292 * return NULL. 293 * 294 * XXX Eventually just phase this out to use M_WAITOK/M_NOWAIT. 295 */ 296#define MBTOM(how) (how) 297#define M_DONTWAIT M_NOWAIT 298#define M_TRYWAIT M_WAITOK 299#define M_WAIT M_WAITOK 300 301/* 302 * String names of mbuf-related UMA(9) and malloc(9) types. Exposed to 303 * !_KERNEL so that monitoring tools can look up the zones with 304 * libmemstat(3). 305 */ 306#define MBUF_MEM_NAME "mbuf" 307#define MBUF_CLUSTER_MEM_NAME "mbuf_cluster" 308#define MBUF_PACKET_MEM_NAME "mbuf_packet" 309#define MBUF_JUMBO4_MEM_NAME "mbuf_jumbo_4k" 310#define MBUF_JUMBO9_MEM_NAME "mbuf_jumbo_9k" 311#define MBUF_JUMBO16_MEM_NAME "mbuf_jumbo_16k" 312#define MBUF_TAG_MEM_NAME "mbuf_tag" 313#define MBUF_EXTREFCNT_MEM_NAME "mbuf_ext_refcnt" 314 315#ifdef _KERNEL 316 317#ifdef WITNESS 318#define MBUF_CHECKSLEEP(how) do { \ 319 if (how == M_WAITOK) \ 320 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, \ 321 "Sleeping in \"%s\"", __func__); \ 322} while (0) 323#else 324#define MBUF_CHECKSLEEP(how) 325#endif 326 327/* 328 * Network buffer allocation API 329 * 330 * The rest of it is defined in kern/kern_mbuf.c 331 */ 332 333extern uma_zone_t zone_mbuf; 334extern uma_zone_t zone_clust; 335extern uma_zone_t zone_pack; 336extern uma_zone_t zone_jumbo4; 337extern uma_zone_t zone_jumbo9; 338extern uma_zone_t zone_jumbo16; 339extern uma_zone_t zone_ext_refcnt; 340extern uma_zone_t zone_mtag_vlan; 341 342static __inline struct mbuf *m_get(int how, short type); 343static __inline struct mbuf *m_gethdr(int how, short type); 344static __inline struct mbuf *m_getcl(int how, short type, int flags); 345static __inline struct mbuf *m_getjcl(int how, short type, int flags, int size); 346static __inline struct mbuf *m_getclr(int how, short type); /* XXX */ 347static __inline struct mbuf *m_free(struct mbuf *m); 348static __inline void m_clget(struct mbuf *m, int how); 349static __inline void *m_cljget(struct mbuf *m, int how, int size); 350static __inline void m_chtype(struct mbuf *m, short new_type); 351void mb_free_ext(struct mbuf *); 352 353static __inline 354struct mbuf * 355m_get(int how, short type) 356{ 357 struct mb_args args; 358 359 args.flags = 0; 360 args.type = type; 361 return (uma_zalloc_arg(zone_mbuf, &args, how)); 362} 363 364/* XXX This should be depracated, very little use */ 365static __inline 366struct mbuf * 367m_getclr(int how, short type) 368{ 369 struct mbuf *m; 370 struct mb_args args; 371 372 args.flags = 0; 373 args.type = type; 374 m = uma_zalloc_arg(zone_mbuf, &args, how); 375 if (m != NULL) 376 bzero(m->m_data, MLEN); 377 return m; 378} 379 380static __inline 381struct mbuf * 382m_gethdr(int how, short type) 383{ 384 struct mb_args args; 385 386 args.flags = M_PKTHDR; 387 args.type = type; 388 return (uma_zalloc_arg(zone_mbuf, &args, how)); 389} 390 391static __inline 392struct mbuf * 393m_getcl(int how, short type, int flags) 394{ 395 struct mb_args args; 396 397 args.flags = flags; 398 args.type = type; 399 return (uma_zalloc_arg(zone_pack, &args, how)); 400} 401 402/* 403 * m_getjcl() returns an mbuf with a cluster of the specified size attached. 404 * For size it takes MCLBYTES, MJUM4BYTES, MJUM9BYTES, MJUM16BYTES. 405 */ 406static __inline /* XXX: This is rather large, should be real function maybe. */ 407struct mbuf * 408m_getjcl(int how, short type, int flags, int size) 409{ 410 struct mb_args args; 411 struct mbuf *m, *n; 412 uma_zone_t zone; 413 414 args.flags = flags; 415 args.type = type; 416 417 m = uma_zalloc_arg(zone_mbuf, &args, how); 418 if (m == NULL) 419 return NULL; 420 421 switch (size) { 422 case MCLBYTES: 423 zone = zone_clust; 424 break; 425#if MJUM4BYTES != MCLBYTES 426 case MJUM4BYTES: 427 zone = zone_jumbo4; 428 break; 429#endif 430 case MJUM9BYTES: 431 zone = zone_jumbo9; 432 break; 433 case MJUM16BYTES: 434 zone = zone_jumbo16; 435 break; 436 default: 437 panic("%s: m_getjcl: invalid cluster type", __func__); 438 } 439 n = uma_zalloc_arg(zone, m, how); 440 if (n == NULL) { 441 uma_zfree(zone_mbuf, m); 442 return NULL; 443 } 444 return m; 445} 446 447static __inline 448struct mbuf * 449m_free(struct mbuf *m) 450{ 451 struct mbuf *n = m->m_next; 452 453 if (m->m_flags & M_EXT) 454 mb_free_ext(m); 455 else 456 uma_zfree(zone_mbuf, m); 457 return n; 458} 459 460static __inline 461void 462m_clget(struct mbuf *m, int how) 463{ 464 if (m->m_flags & M_EXT) 465 printf("%s: %p mbuf already has cluster\n", __func__, m); 466 m->m_ext.ext_buf = NULL; 467 uma_zalloc_arg(zone_clust, m, how); 468} 469 470/* 471 * m_cljget() is different from m_clget() as it can allocate clusters 472 * without attaching them to an mbuf. In that case the return value 473 * is the pointer to the cluster of the requested size. If an mbuf was 474 * specified, it gets the cluster attached to it and the return value 475 * can be safely ignored. 476 * For size it takes MCLBYTES, MJUM4BYTES, MJUM9BYTES, MJUM16BYTES. 477 */ 478static __inline 479void * 480m_cljget(struct mbuf *m, int how, int size) 481{ 482 uma_zone_t zone; 483 484 if (m && m->m_flags & M_EXT) 485 printf("%s: %p mbuf already has cluster\n", __func__, m); 486 if (m != NULL) 487 m->m_ext.ext_buf = NULL; 488 489 switch (size) { 490 case MCLBYTES: 491 zone = zone_clust; 492 break; 493#if MJUM4BYTES != MCLBYTES 494 case MJUM4BYTES: 495 zone = zone_jumbo4; 496 break; 497#endif 498 case MJUM9BYTES: 499 zone = zone_jumbo9; 500 break; 501 case MJUM16BYTES: 502 zone = zone_jumbo16; 503 break; 504 default: 505 panic("%s: m_getjcl: invalid cluster type", __func__); 506 } 507 508 return (uma_zalloc_arg(zone, m, how)); 509} 510 511static __inline 512void 513m_chtype(struct mbuf *m, short new_type) 514{ 515 m->m_type = new_type; 516} 517 518/* 519 * mbuf, cluster, and external object allocation macros 520 * (for compatibility purposes). 521 */ 522/* NB: M_COPY_PKTHDR is deprecated. Use M_MOVE_PKTHDR or m_dup_pktdr. */ 523#define M_MOVE_PKTHDR(to, from) m_move_pkthdr((to), (from)) 524#define MGET(m, how, type) ((m) = m_get((how), (type))) 525#define MGETHDR(m, how, type) ((m) = m_gethdr((how), (type))) 526#define MCLGET(m, how) m_clget((m), (how)) 527#define MEXTADD(m, buf, size, free, args, flags, type) \ 528 m_extadd((m), (caddr_t)(buf), (size), (free), (args), (flags), (type)) 529 530/* 531 * Evaluate TRUE if it's safe to write to the mbuf m's data region (this 532 * can be both the local data payload, or an external buffer area, 533 * depending on whether M_EXT is set). 534 */ 535#define M_WRITABLE(m) (!((m)->m_flags & M_RDONLY) && \ 536 (!(((m)->m_flags & M_EXT)) || \ 537 (*((m)->m_ext.ref_cnt) == 1)) ) \ 538 539/* Check if the supplied mbuf has a packet header, or else panic. */ 540#define M_ASSERTPKTHDR(m) \ 541 KASSERT(m != NULL && m->m_flags & M_PKTHDR, \ 542 ("%s: no mbuf packet header!", __func__)) 543 544/* Ensure that the supplied mbuf is a valid, non-free mbuf. */ 545/* XXX: Broken at the moment. Need some UMA magic to make it work again. */ 546#define M_ASSERTVALID(m) \ 547 KASSERT((((struct mbuf *)m)->m_flags & 0) == 0, \ 548 ("%s: attempted use of a free mbuf!", __func__)) 549 550/* 551 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place 552 * an object of the specified size at the end of the mbuf, longword aligned. 553 */ 554#define M_ALIGN(m, len) do { \ 555 KASSERT(!((m)->m_flags & (M_PKTHDR|M_EXT)), \ 556 ("%s: M_ALIGN not normal mbuf", __func__)); \ 557 KASSERT((m)->m_data == (m)->m_dat, \ 558 ("%s: M_ALIGN not a virgin mbuf", __func__)); \ 559 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \ 560} while (0) 561 562/* 563 * As above, for mbufs allocated with m_gethdr/MGETHDR 564 * or initialized by M_COPY_PKTHDR. 565 */ 566#define MH_ALIGN(m, len) do { \ 567 KASSERT((m)->m_flags & M_PKTHDR && !((m)->m_flags & M_EXT), \ 568 ("%s: MH_ALIGN not PKTHDR mbuf", __func__)); \ 569 KASSERT((m)->m_data == (m)->m_pktdat, \ 570 ("%s: MH_ALIGN not a virgin mbuf", __func__)); \ 571 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \ 572} while (0) 573 574/* 575 * Compute the amount of space available 576 * before the current start of data in an mbuf. 577 * 578 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 579 * of checking writability of the mbuf data area rests solely with the caller. 580 */ 581#define M_LEADINGSPACE(m) \ 582 ((m)->m_flags & M_EXT ? \ 583 (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \ 584 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 585 (m)->m_data - (m)->m_dat) 586 587/* 588 * Compute the amount of space available 589 * after the end of data in an mbuf. 590 * 591 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 592 * of checking writability of the mbuf data area rests solely with the caller. 593 */ 594#define M_TRAILINGSPACE(m) \ 595 ((m)->m_flags & M_EXT ? \ 596 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \ 597 - ((m)->m_data + (m)->m_len) : 0) : \ 598 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 599 600/* 601 * Arrange to prepend space of size plen to mbuf m. 602 * If a new mbuf must be allocated, how specifies whether to wait. 603 * If the allocation fails, the original mbuf chain is freed and m is 604 * set to NULL. 605 */ 606#define M_PREPEND(m, plen, how) do { \ 607 struct mbuf **_mmp = &(m); \ 608 struct mbuf *_mm = *_mmp; \ 609 int _mplen = (plen); \ 610 int __mhow = (how); \ 611 \ 612 MBUF_CHECKSLEEP(how); \ 613 if (M_LEADINGSPACE(_mm) >= _mplen) { \ 614 _mm->m_data -= _mplen; \ 615 _mm->m_len += _mplen; \ 616 } else \ 617 _mm = m_prepend(_mm, _mplen, __mhow); \ 618 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \ 619 _mm->m_pkthdr.len += _mplen; \ 620 *_mmp = _mm; \ 621} while (0) 622 623/* 624 * Change mbuf to new type. 625 * This is a relatively expensive operation and should be avoided. 626 */ 627#define MCHTYPE(m, t) m_chtype((m), (t)) 628 629/* Length to m_copy to copy all. */ 630#define M_COPYALL 1000000000 631 632/* Compatibility with 4.3. */ 633#define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT) 634 635extern int max_datalen; /* MHLEN - max_hdr */ 636extern int max_hdr; /* Largest link + protocol header */ 637extern int max_linkhdr; /* Largest link-level header */ 638extern int max_protohdr; /* Largest protocol header */ 639extern struct mbstat mbstat; /* General mbuf stats/infos */ 640extern int nmbclusters; /* Maximum number of clusters */ 641 642struct uio; 643 644void m_adj(struct mbuf *, int); 645void m_align(struct mbuf *, int); 646int m_apply(struct mbuf *, int, int, 647 int (*)(void *, void *, u_int), void *); 648int m_append(struct mbuf *, int, c_caddr_t); 649void m_cat(struct mbuf *, struct mbuf *); 650void m_extadd(struct mbuf *, caddr_t, u_int, 651 void (*)(void *, void *), void *, int, int); 652void m_copyback(struct mbuf *, int, int, c_caddr_t); 653void m_copydata(const struct mbuf *, int, int, caddr_t); 654struct mbuf *m_copym(struct mbuf *, int, int, int); 655struct mbuf *m_copymdata(struct mbuf *, struct mbuf *, 656 int, int, int, int); 657struct mbuf *m_copypacket(struct mbuf *, int); 658void m_copy_pkthdr(struct mbuf *, struct mbuf *); 659struct mbuf *m_copyup(struct mbuf *n, int len, int dstoff); 660struct mbuf *m_defrag(struct mbuf *, int); 661void m_demote(struct mbuf *, int); 662struct mbuf *m_devget(char *, int, int, struct ifnet *, 663 void (*)(char *, caddr_t, u_int)); 664struct mbuf *m_dup(struct mbuf *, int); 665int m_dup_pkthdr(struct mbuf *, struct mbuf *, int); 666u_int m_fixhdr(struct mbuf *); 667struct mbuf *m_fragment(struct mbuf *, int, int); 668void m_freem(struct mbuf *); 669struct mbuf *m_getm(struct mbuf *, int, int, short); 670struct mbuf *m_getptr(struct mbuf *, int, int *); 671u_int m_length(struct mbuf *, struct mbuf **); 672void m_move_pkthdr(struct mbuf *, struct mbuf *); 673struct mbuf *m_prepend(struct mbuf *, int, int); 674void m_print(const struct mbuf *, int); 675struct mbuf *m_pulldown(struct mbuf *, int, int, int *); 676struct mbuf *m_pullup(struct mbuf *, int); 677int m_sanity(struct mbuf *, int); 678struct mbuf *m_split(struct mbuf *, int, int); 679struct mbuf *m_uiotombuf(struct uio *, int, int, int); 680 681/*- 682 * Network packets may have annotations attached by affixing a list 683 * of "packet tags" to the pkthdr structure. Packet tags are 684 * dynamically allocated semi-opaque data structures that have 685 * a fixed header (struct m_tag) that specifies the size of the 686 * memory block and a <cookie,type> pair that identifies it. 687 * The cookie is a 32-bit unique unsigned value used to identify 688 * a module or ABI. By convention this value is chose as the 689 * date+time that the module is created, expressed as the number of 690 * seconds since the epoch (e.g., using date -u +'%s'). The type value 691 * is an ABI/module-specific value that identifies a particular annotation 692 * and is private to the module. For compatibility with systems 693 * like OpenBSD that define packet tags w/o an ABI/module cookie, 694 * the value PACKET_ABI_COMPAT is used to implement m_tag_get and 695 * m_tag_find compatibility shim functions and several tag types are 696 * defined below. Users that do not require compatibility should use 697 * a private cookie value so that packet tag-related definitions 698 * can be maintained privately. 699 * 700 * Note that the packet tag returned by m_tag_alloc has the default 701 * memory alignment implemented by malloc. To reference private data 702 * one can use a construct like: 703 * 704 * struct m_tag *mtag = m_tag_alloc(...); 705 * struct foo *p = (struct foo *)(mtag+1); 706 * 707 * if the alignment of struct m_tag is sufficient for referencing members 708 * of struct foo. Otherwise it is necessary to embed struct m_tag within 709 * the private data structure to insure proper alignment; e.g., 710 * 711 * struct foo { 712 * struct m_tag tag; 713 * ... 714 * }; 715 * struct foo *p = (struct foo *) m_tag_alloc(...); 716 * struct m_tag *mtag = &p->tag; 717 */ 718 719/* 720 * Persistent tags stay with an mbuf until the mbuf is reclaimed. 721 * Otherwise tags are expected to ``vanish'' when they pass through 722 * a network interface. For most interfaces this happens normally 723 * as the tags are reclaimed when the mbuf is free'd. However in 724 * some special cases reclaiming must be done manually. An example 725 * is packets that pass through the loopback interface. Also, one 726 * must be careful to do this when ``turning around'' packets (e.g., 727 * icmp_reflect). 728 * 729 * To mark a tag persistent bit-or this flag in when defining the 730 * tag id. The tag will then be treated as described above. 731 */ 732#define MTAG_PERSISTENT 0x800 733 734#define PACKET_TAG_NONE 0 /* Nadda */ 735 736/* Packet tags for use with PACKET_ABI_COMPAT. */ 737#define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */ 738#define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */ 739#define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */ 740#define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */ 741#define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO 5 /* NIC notifies IPsec */ 742#define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */ 743#define PACKET_TAG_BRIDGE 7 /* Bridge processing done */ 744#define PACKET_TAG_GIF 8 /* GIF processing done */ 745#define PACKET_TAG_GRE 9 /* GRE processing done */ 746#define PACKET_TAG_IN_PACKET_CHECKSUM 10 /* NIC checksumming done */ 747#define PACKET_TAG_ENCAP 11 /* Encap. processing */ 748#define PACKET_TAG_IPSEC_SOCKET 12 /* IPSEC socket ref */ 749#define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */ 750#define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */ 751#define PACKET_TAG_DUMMYNET 15 /* dummynet info */ 752#define PACKET_TAG_DIVERT 17 /* divert info */ 753#define PACKET_TAG_IPFORWARD 18 /* ipforward info */ 754#define PACKET_TAG_MACLABEL (19 | MTAG_PERSISTENT) /* MAC label */ 755#define PACKET_TAG_PF_ROUTED 21 /* PF routed, avoid loops */ 756#define PACKET_TAG_PF_FRAGCACHE 22 /* PF fragment cached */ 757#define PACKET_TAG_PF_QID 23 /* PF ALTQ queue id */ 758#define PACKET_TAG_PF_TAG 24 /* PF tagged */ 759#define PACKET_TAG_RTSOCKFAM 25 /* rtsock sa family */ 760#define PACKET_TAG_PF_TRANSLATE_LOCALHOST 26 /* PF translate localhost */ 761#define PACKET_TAG_IPOPTIONS 27 /* Saved IP options */ 762#define PACKET_TAG_CARP 28 /* CARP info */ 763 764/* Specific cookies and tags. */ 765#define MTAG_VLAN 1035328035 766#define MTAG_VLAN_TAG 0 /* tag of VLAN interface */ 767 768/* Packet tag routines. */ 769struct m_tag *m_tag_alloc(u_int32_t, int, int, int); 770void m_tag_delete(struct mbuf *, struct m_tag *); 771void m_tag_delete_chain(struct mbuf *, struct m_tag *); 772void m_tag_free_default(struct m_tag *); 773struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *); 774struct m_tag *m_tag_copy(struct m_tag *, int); 775int m_tag_copy_chain(struct mbuf *, struct mbuf *, int); 776void m_tag_delete_nonpersistent(struct mbuf *); 777 778/* 779 * Initialize the list of tags associated with an mbuf. 780 */ 781static __inline void 782m_tag_init(struct mbuf *m) 783{ 784 SLIST_INIT(&m->m_pkthdr.tags); 785} 786 787/* 788 * Set up the contents of a tag. Note that this does not 789 * fill in the free method; the caller is expected to do that. 790 * 791 * XXX probably should be called m_tag_init, but that was 792 * already taken. 793 */ 794static __inline void 795m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len) 796{ 797 t->m_tag_id = type; 798 t->m_tag_len = len; 799 t->m_tag_cookie = cookie; 800} 801 802/* 803 * Reclaim resources associated with a tag. 804 */ 805static __inline void 806m_tag_free(struct m_tag *t) 807{ 808 (*t->m_tag_free)(t); 809} 810 811/* 812 * Return the first tag associated with an mbuf. 813 */ 814static __inline struct m_tag * 815m_tag_first(struct mbuf *m) 816{ 817 return (SLIST_FIRST(&m->m_pkthdr.tags)); 818} 819 820/* 821 * Return the next tag in the list of tags associated with an mbuf. 822 */ 823static __inline struct m_tag * 824m_tag_next(struct mbuf *m, struct m_tag *t) 825{ 826 return (SLIST_NEXT(t, m_tag_link)); 827} 828 829/* 830 * Prepend a tag to the list of tags associated with an mbuf. 831 */ 832static __inline void 833m_tag_prepend(struct mbuf *m, struct m_tag *t) 834{ 835 SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link); 836} 837 838/* 839 * Unlink a tag from the list of tags associated with an mbuf. 840 */ 841static __inline void 842m_tag_unlink(struct mbuf *m, struct m_tag *t) 843{ 844 SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link); 845} 846 847/* These are for OpenBSD compatibility. */ 848#define MTAG_ABI_COMPAT 0 /* compatibility ABI */ 849 850static __inline struct m_tag * 851m_tag_get(int type, int length, int wait) 852{ 853 return (m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait)); 854} 855 856static __inline struct m_tag * 857m_tag_find(struct mbuf *m, int type, struct m_tag *start) 858{ 859 return (SLIST_EMPTY(&m->m_pkthdr.tags) ? 860 NULL : m_tag_locate(m, MTAG_ABI_COMPAT, type, start)); 861} 862 863#endif /* _KERNEL */ 864 865#endif /* !_SYS_MBUF_H_ */ 866