mbuf.h revision 172463
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 172463 2007-10-06 21:42:39Z kmacy $ 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_args; /* optional argument pointer */ 135 u_int ext_size; /* size of buffer, for ext_free */ 136 volatile u_int *ref_cnt; /* pointer to ref count info */ 137 int ext_type; /* type of external storage */ 138}; 139 140/* 141 * The core of the mbuf object along with some shortcut defines for practical 142 * purposes. 143 */ 144struct mbuf { 145 struct m_hdr m_hdr; 146 union { 147 struct { 148 struct pkthdr MH_pkthdr; /* M_PKTHDR set */ 149 union { 150 struct m_ext MH_ext; /* M_EXT set */ 151 char MH_databuf[MHLEN]; 152 } MH_dat; 153 } MH; 154 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ 155 } M_dat; 156}; 157#define m_next m_hdr.mh_next 158#define m_len m_hdr.mh_len 159#define m_data m_hdr.mh_data 160#define m_type m_hdr.mh_type 161#define m_flags m_hdr.mh_flags 162#define m_nextpkt m_hdr.mh_nextpkt 163#define m_act m_nextpkt 164#define m_pkthdr M_dat.MH.MH_pkthdr 165#define m_ext M_dat.MH.MH_dat.MH_ext 166#define m_pktdat M_dat.MH.MH_dat.MH_databuf 167#define m_dat M_dat.M_databuf 168 169/* 170 * mbuf flags. 171 */ 172#define M_EXT 0x0001 /* has associated external storage */ 173#define M_PKTHDR 0x0002 /* start of record */ 174#define M_EOR 0x0004 /* end of record */ 175#define M_RDONLY 0x0008 /* associated data is marked read-only */ 176#define M_PROTO1 0x0010 /* protocol-specific */ 177#define M_PROTO2 0x0020 /* protocol-specific */ 178#define M_PROTO3 0x0040 /* protocol-specific */ 179#define M_PROTO4 0x0080 /* protocol-specific */ 180#define M_PROTO5 0x0100 /* protocol-specific */ 181#define M_NOTIFICATION M_PROTO5/* SCTP notification */ 182#define M_SKIP_FIREWALL 0x4000 /* skip firewall processing */ 183#define M_FREELIST 0x8000 /* mbuf is on the free list */ 184 185/* 186 * mbuf pkthdr flags (also stored in m_flags). 187 */ 188#define M_BCAST 0x0200 /* send/received as link-level broadcast */ 189#define M_MCAST 0x0400 /* send/received as link-level multicast */ 190#define M_FRAG 0x0800 /* packet is a fragment of a larger packet */ 191#define M_FIRSTFRAG 0x1000 /* packet is first fragment */ 192#define M_LASTFRAG 0x2000 /* packet is last fragment */ 193#define M_VLANTAG 0x10000 /* ether_vtag is valid */ 194#define M_PROMISC 0x20000 /* packet was not for us */ 195#define M_NOFREE 0x40000 /* do not free mbuf - it is embedded in the cluster */ 196 197/* 198 * External buffer types: identify ext_buf type. 199 */ 200#define EXT_CLUSTER 1 /* mbuf cluster */ 201#define EXT_SFBUF 2 /* sendfile(2)'s sf_bufs */ 202#define EXT_JUMBOP 3 /* jumbo cluster 4096 bytes */ 203#define EXT_JUMBO9 4 /* jumbo cluster 9216 bytes */ 204#define EXT_JUMBO16 5 /* jumbo cluster 16184 bytes */ 205#define EXT_PACKET 6 /* mbuf+cluster from packet zone */ 206#define EXT_MBUF 7 /* external mbuf reference (M_IOVEC) */ 207#define EXT_NET_DRV 100 /* custom ext_buf provided by net driver(s) */ 208#define EXT_MOD_TYPE 200 /* custom module's ext_buf type */ 209#define EXT_DISPOSABLE 300 /* can throw this buffer away w/page flipping */ 210#define EXT_EXTREF 400 /* has externally maintained ref_cnt ptr */ 211 212/* 213 * Flags copied when copying m_pkthdr. 214 */ 215#define M_COPYFLAGS (M_PKTHDR|M_EOR|M_RDONLY|M_PROTO1|M_PROTO1|M_PROTO2|\ 216 M_PROTO3|M_PROTO4|M_PROTO5|M_SKIP_FIREWALL|\ 217 M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG|\ 218 M_VLANTAG|M_PROMISC) 219 220/* 221 * Flags to purge when crossing layers. 222 */ 223#define M_PROTOFLAGS (M_PROTO1|M_PROTO2|M_PROTO3|M_PROTO4|M_PROTO5) 224 225/* 226 * Flags indicating hw checksum support and sw checksum requirements. This 227 * field can be directly tested against if_data.ifi_hwassist. 228 */ 229#define CSUM_IP 0x0001 /* will csum IP */ 230#define CSUM_TCP 0x0002 /* will csum TCP */ 231#define CSUM_UDP 0x0004 /* will csum UDP */ 232#define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */ 233#define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */ 234#define CSUM_TSO 0x0020 /* will do TSO */ 235 236#define CSUM_IP_CHECKED 0x0100 /* did csum IP */ 237#define CSUM_IP_VALID 0x0200 /* ... the csum is valid */ 238#define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */ 239#define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */ 240 241#define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP) 242#define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */ 243 244/* 245 * mbuf types. 246 */ 247#define MT_NOTMBUF 0 /* USED INTERNALLY ONLY! Object is not mbuf */ 248#define MT_DATA 1 /* dynamic (data) allocation */ 249#define MT_HEADER MT_DATA /* packet header, use M_PKTHDR instead */ 250#define MT_SONAME 8 /* socket name */ 251#define MT_CONTROL 14 /* extra-data protocol message */ 252#define MT_OOBDATA 15 /* expedited data */ 253#define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */ 254 255#define MT_NOINIT 255 /* Not a type but a flag to allocate 256 a non-initialized mbuf */ 257 258#define MB_NOTAGS 0x1UL /* no tags attached to mbuf */ 259 260/* 261 * General mbuf allocator statistics structure. 262 * 263 * Many of these statistics are no longer used; we instead track many 264 * allocator statistics through UMA's built in statistics mechanism. 265 */ 266struct mbstat { 267 u_long m_mbufs; /* XXX */ 268 u_long m_mclusts; /* XXX */ 269 270 u_long m_drain; /* times drained protocols for space */ 271 u_long m_mcfail; /* XXX: times m_copym failed */ 272 u_long m_mpfail; /* XXX: times m_pullup failed */ 273 u_long m_msize; /* length of an mbuf */ 274 u_long m_mclbytes; /* length of an mbuf cluster */ 275 u_long m_minclsize; /* min length of data to allocate a cluster */ 276 u_long m_mlen; /* length of data in an mbuf */ 277 u_long m_mhlen; /* length of data in a header mbuf */ 278 279 /* Number of mbtypes (gives # elems in mbtypes[] array: */ 280 short m_numtypes; 281 282 /* XXX: Sendfile stats should eventually move to their own struct */ 283 u_long sf_iocnt; /* times sendfile had to do disk I/O */ 284 u_long sf_allocfail; /* times sfbuf allocation failed */ 285 u_long sf_allocwait; /* times sfbuf allocation had to wait */ 286}; 287 288/* 289 * Flags specifying how an allocation should be made. 290 * 291 * The flag to use is as follows: 292 * - M_DONTWAIT or M_NOWAIT from an interrupt handler to not block allocation. 293 * - M_WAIT or M_WAITOK or M_TRYWAIT from wherever it is safe to block. 294 * 295 * M_DONTWAIT/M_NOWAIT means that we will not block the thread explicitly and 296 * if we cannot allocate immediately we may return NULL, whereas 297 * M_WAIT/M_WAITOK/M_TRYWAIT means that if we cannot allocate resources we 298 * will block until they are available, and thus never return NULL. 299 * 300 * XXX Eventually just phase this out to use M_WAITOK/M_NOWAIT. 301 */ 302#define MBTOM(how) (how) 303#define M_DONTWAIT M_NOWAIT 304#define M_TRYWAIT M_WAITOK 305#define M_WAIT M_WAITOK 306 307/* 308 * String names of mbuf-related UMA(9) and malloc(9) types. Exposed to 309 * !_KERNEL so that monitoring tools can look up the zones with 310 * libmemstat(3). 311 */ 312#define MBUF_MEM_NAME "mbuf" 313#define MBUF_CLUSTER_MEM_NAME "mbuf_cluster" 314#define MBUF_PACKET_MEM_NAME "mbuf_packet" 315#define MBUF_JUMBOP_MEM_NAME "mbuf_jumbo_pagesize" 316#define MBUF_JUMBO9_MEM_NAME "mbuf_jumbo_9k" 317#define MBUF_JUMBO16_MEM_NAME "mbuf_jumbo_16k" 318#define MBUF_TAG_MEM_NAME "mbuf_tag" 319#define MBUF_EXTREFCNT_MEM_NAME "mbuf_ext_refcnt" 320 321#ifdef _KERNEL 322 323#ifdef WITNESS 324#define MBUF_CHECKSLEEP(how) do { \ 325 if (how == M_WAITOK) \ 326 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, \ 327 "Sleeping in \"%s\"", __func__); \ 328} while (0) 329#else 330#define MBUF_CHECKSLEEP(how) 331#endif 332 333/* 334 * Network buffer allocation API 335 * 336 * The rest of it is defined in kern/kern_mbuf.c 337 */ 338 339extern uma_zone_t zone_mbuf; 340extern uma_zone_t zone_clust; 341extern uma_zone_t zone_pack; 342extern uma_zone_t zone_jumbop; 343extern uma_zone_t zone_jumbo9; 344extern uma_zone_t zone_jumbo16; 345extern uma_zone_t zone_ext_refcnt; 346 347static __inline struct mbuf *m_getcl(int how, short type, int flags); 348static __inline struct mbuf *m_get(int how, short type); 349static __inline struct mbuf *m_gethdr(int how, short type); 350static __inline struct mbuf *m_getjcl(int how, short type, int flags, 351 int size); 352static __inline struct mbuf *m_getclr(int how, short type); /* XXX */ 353static __inline struct mbuf *m_free(struct mbuf *m); 354static __inline void m_clget(struct mbuf *m, int how); 355static __inline void *m_cljget(struct mbuf *m, int how, int size); 356static __inline void m_chtype(struct mbuf *m, short new_type); 357void mb_free_ext(struct mbuf *); 358static __inline struct mbuf *m_last(struct mbuf *m); 359 360static __inline int 361m_gettype(int size) 362{ 363 int type; 364 365 switch (size) { 366 case MSIZE: 367 type = EXT_MBUF; 368 break; 369 case MCLBYTES: 370 type = EXT_CLUSTER; 371 break; 372#if MJUMPAGESIZE != MCLBYTES 373 case MJUMPAGESIZE: 374 type = EXT_JUMBOP; 375 break; 376#endif 377 case MJUM9BYTES: 378 type = EXT_JUMBO9; 379 break; 380 case MJUM16BYTES: 381 type = EXT_JUMBO16; 382 break; 383 default: 384 panic("%s: m_getjcl: invalid cluster size", __func__); 385 } 386 387 return (type); 388} 389 390static __inline uma_zone_t 391m_getzone(int size) 392{ 393 uma_zone_t zone; 394 395 switch (size) { 396 case MSIZE: 397 zone = zone_mbuf; 398 break; 399 case MCLBYTES: 400 zone = zone_clust; 401 break; 402#if MJUMPAGESIZE != MCLBYTES 403 case MJUMPAGESIZE: 404 zone = zone_jumbop; 405 break; 406#endif 407 case MJUM9BYTES: 408 zone = zone_jumbo9; 409 break; 410 case MJUM16BYTES: 411 zone = zone_jumbo16; 412 break; 413 default: 414 panic("%s: m_getjcl: invalid cluster type", __func__); 415 } 416 417 return (zone); 418} 419 420static __inline struct mbuf * 421m_get(int how, short type) 422{ 423 struct mb_args args; 424 425 args.flags = 0; 426 args.type = type; 427 return ((struct mbuf *)(uma_zalloc_arg(zone_mbuf, &args, how))); 428} 429 430/* 431 * XXX This should be deprecated, very little use. 432 */ 433static __inline struct mbuf * 434m_getclr(int how, short type) 435{ 436 struct mbuf *m; 437 struct mb_args args; 438 439 args.flags = 0; 440 args.type = type; 441 m = uma_zalloc_arg(zone_mbuf, &args, how); 442 if (m != NULL) 443 bzero(m->m_data, MLEN); 444 return (m); 445} 446 447static __inline struct mbuf * 448m_gethdr(int how, short type) 449{ 450 struct mb_args args; 451 452 args.flags = M_PKTHDR; 453 args.type = type; 454 return ((struct mbuf *)(uma_zalloc_arg(zone_mbuf, &args, how))); 455} 456 457static __inline struct mbuf * 458m_getcl(int how, short type, int flags) 459{ 460 struct mb_args args; 461 462 args.flags = flags; 463 args.type = type; 464 return ((struct mbuf *)(uma_zalloc_arg(zone_pack, &args, how))); 465} 466 467/* 468 * m_getjcl() returns an mbuf with a cluster of the specified size attached. 469 * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES. 470 * 471 * XXX: This is rather large, should be real function maybe. 472 */ 473static __inline struct mbuf * 474m_getjcl(int how, short type, int flags, int size) 475{ 476 struct mb_args args; 477 struct mbuf *m, *n; 478 uma_zone_t zone; 479 480 args.flags = flags; 481 args.type = type; 482 483 m = uma_zalloc_arg(zone_mbuf, &args, how); 484 if (m == NULL) 485 return (NULL); 486 487 zone = m_getzone(size); 488 n = uma_zalloc_arg(zone, m, how); 489 if (n == NULL) { 490 uma_zfree(zone_mbuf, m); 491 return (NULL); 492 } 493 return (m); 494} 495 496static __inline void 497m_free_fast(struct mbuf *m) 498{ 499 KASSERT(SLIST_EMPTY(&m->m_pkthdr.tags), ("doing fast free of mbuf with tags")); 500 501 uma_zfree_arg(zone_mbuf, m, (void *)MB_NOTAGS); 502} 503 504static __inline struct mbuf * 505m_free(struct mbuf *m) 506{ 507 struct mbuf *n = m->m_next; 508 509 if (m->m_flags & M_EXT) 510 mb_free_ext(m); 511 else if ((m->m_flags & M_NOFREE) == 0) 512 uma_zfree(zone_mbuf, m); 513 return (n); 514} 515 516static __inline void 517m_clget(struct mbuf *m, int how) 518{ 519 520 if (m->m_flags & M_EXT) 521 printf("%s: %p mbuf already has cluster\n", __func__, m); 522 m->m_ext.ext_buf = (char *)NULL; 523 uma_zalloc_arg(zone_clust, m, how); 524 /* 525 * On a cluster allocation failure, drain the packet zone and retry, 526 * we might be able to loosen a few clusters up on the drain. 527 */ 528 if ((how & M_NOWAIT) && (m->m_ext.ext_buf == NULL)) { 529 zone_drain(zone_pack); 530 uma_zalloc_arg(zone_clust, m, how); 531 } 532} 533 534/* 535 * m_cljget() is different from m_clget() as it can allocate clusters without 536 * attaching them to an mbuf. In that case the return value is the pointer 537 * to the cluster of the requested size. If an mbuf was specified, it gets 538 * the cluster attached to it and the return value can be safely ignored. 539 * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES. 540 */ 541static __inline void * 542m_cljget(struct mbuf *m, int how, int size) 543{ 544 uma_zone_t zone; 545 546 if (m && m->m_flags & M_EXT) 547 printf("%s: %p mbuf already has cluster\n", __func__, m); 548 if (m != NULL) 549 m->m_ext.ext_buf = NULL; 550 551 zone = m_getzone(size); 552 return (uma_zalloc_arg(zone, m, how)); 553} 554 555static __inline void 556m_cljset(struct mbuf *m, void *cl, int type) 557{ 558 uma_zone_t zone; 559 int size; 560 561 switch (type) { 562 case EXT_CLUSTER: 563 size = MCLBYTES; 564 zone = zone_clust; 565 break; 566#if MJUMPAGESIZE != MCLBYTES 567 case EXT_JUMBOP: 568 size = MJUMPAGESIZE; 569 zone = zone_jumbop; 570 break; 571#endif 572 case EXT_JUMBO9: 573 size = MJUM9BYTES; 574 zone = zone_jumbo9; 575 break; 576 case EXT_JUMBO16: 577 size = MJUM16BYTES; 578 zone = zone_jumbo16; 579 break; 580 default: 581 panic("unknown cluster type"); 582 break; 583 } 584 585 m->m_data = m->m_ext.ext_buf = cl; 586 m->m_ext.ext_free = m->m_ext.ext_args = NULL; 587 m->m_ext.ext_size = size; 588 m->m_ext.ext_type = type; 589 m->m_ext.ref_cnt = uma_find_refcnt(zone, cl); 590 m->m_flags |= M_EXT; 591 592} 593 594static __inline void 595m_chtype(struct mbuf *m, short new_type) 596{ 597 598 m->m_type = new_type; 599} 600 601static __inline struct mbuf * 602m_last(struct mbuf *m) 603{ 604 605 while (m->m_next) 606 m = m->m_next; 607 return (m); 608} 609 610/* 611 * mbuf, cluster, and external object allocation macros (for compatibility 612 * purposes). 613 */ 614#define M_MOVE_PKTHDR(to, from) m_move_pkthdr((to), (from)) 615#define MGET(m, how, type) ((m) = m_get((how), (type))) 616#define MGETHDR(m, how, type) ((m) = m_gethdr((how), (type))) 617#define MCLGET(m, how) m_clget((m), (how)) 618#define MEXTADD(m, buf, size, free, args, flags, type) \ 619 m_extadd((m), (caddr_t)(buf), (size), (free), (args), (flags), (type)) 620#define m_getm(m, len, how, type) \ 621 m_getm2((m), (len), (how), (type), M_PKTHDR) 622 623/* 624 * Evaluate TRUE if it's safe to write to the mbuf m's data region (this can 625 * be both the local data payload, or an external buffer area, depending on 626 * whether M_EXT is set). 627 */ 628#define M_WRITABLE(m) (!((m)->m_flags & M_RDONLY) && \ 629 (!(((m)->m_flags & M_EXT)) || \ 630 (*((m)->m_ext.ref_cnt) == 1)) ) \ 631 632/* Check if the supplied mbuf has a packet header, or else panic. */ 633#define M_ASSERTPKTHDR(m) \ 634 KASSERT(m != NULL && m->m_flags & M_PKTHDR, \ 635 ("%s: no mbuf packet header!", __func__)) 636 637/* 638 * Ensure that the supplied mbuf is a valid, non-free mbuf. 639 * 640 * XXX: Broken at the moment. Need some UMA magic to make it work again. 641 */ 642#define M_ASSERTVALID(m) \ 643 KASSERT((((struct mbuf *)m)->m_flags & 0) == 0, \ 644 ("%s: attempted use of a free mbuf!", __func__)) 645 646/* 647 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place an 648 * object of the specified size at the end of the mbuf, longword aligned. 649 */ 650#define M_ALIGN(m, len) do { \ 651 KASSERT(!((m)->m_flags & (M_PKTHDR|M_EXT)), \ 652 ("%s: M_ALIGN not normal mbuf", __func__)); \ 653 KASSERT((m)->m_data == (m)->m_dat, \ 654 ("%s: M_ALIGN not a virgin mbuf", __func__)); \ 655 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \ 656} while (0) 657 658/* 659 * As above, for mbufs allocated with m_gethdr/MGETHDR or initialized by 660 * M_DUP/MOVE_PKTHDR. 661 */ 662#define MH_ALIGN(m, len) do { \ 663 KASSERT((m)->m_flags & M_PKTHDR && !((m)->m_flags & M_EXT), \ 664 ("%s: MH_ALIGN not PKTHDR mbuf", __func__)); \ 665 KASSERT((m)->m_data == (m)->m_pktdat, \ 666 ("%s: MH_ALIGN not a virgin mbuf", __func__)); \ 667 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \ 668} while (0) 669 670/* 671 * Compute the amount of space available before the current start of data in 672 * an mbuf. 673 * 674 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 675 * of checking writability of the mbuf data area rests solely with the caller. 676 */ 677#define M_LEADINGSPACE(m) \ 678 ((m)->m_flags & M_EXT ? \ 679 (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \ 680 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 681 (m)->m_data - (m)->m_dat) 682 683/* 684 * Compute the amount of space available after the end of data in an mbuf. 685 * 686 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 687 * of checking writability of the mbuf data area rests solely with the caller. 688 */ 689#define M_TRAILINGSPACE(m) \ 690 ((m)->m_flags & M_EXT ? \ 691 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \ 692 - ((m)->m_data + (m)->m_len) : 0) : \ 693 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 694 695/* 696 * Arrange to prepend space of size plen to mbuf m. If a new mbuf must be 697 * allocated, how specifies whether to wait. If the allocation fails, the 698 * original mbuf chain is freed and m is set to NULL. 699 */ 700#define M_PREPEND(m, plen, how) do { \ 701 struct mbuf **_mmp = &(m); \ 702 struct mbuf *_mm = *_mmp; \ 703 int _mplen = (plen); \ 704 int __mhow = (how); \ 705 \ 706 MBUF_CHECKSLEEP(how); \ 707 if (M_LEADINGSPACE(_mm) >= _mplen) { \ 708 _mm->m_data -= _mplen; \ 709 _mm->m_len += _mplen; \ 710 } else \ 711 _mm = m_prepend(_mm, _mplen, __mhow); \ 712 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \ 713 _mm->m_pkthdr.len += _mplen; \ 714 *_mmp = _mm; \ 715} while (0) 716 717/* 718 * Change mbuf to new type. This is a relatively expensive operation and 719 * should be avoided. 720 */ 721#define MCHTYPE(m, t) m_chtype((m), (t)) 722 723/* Length to m_copy to copy all. */ 724#define M_COPYALL 1000000000 725 726/* Compatibility with 4.3. */ 727#define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT) 728 729extern int max_datalen; /* MHLEN - max_hdr */ 730extern int max_hdr; /* Largest link + protocol header */ 731extern int max_linkhdr; /* Largest link-level header */ 732extern int max_protohdr; /* Largest protocol header */ 733extern struct mbstat mbstat; /* General mbuf stats/infos */ 734extern int nmbclusters; /* Maximum number of clusters */ 735 736struct uio; 737 738void m_adj(struct mbuf *, int); 739void m_align(struct mbuf *, int); 740int m_apply(struct mbuf *, int, int, 741 int (*)(void *, void *, u_int), void *); 742int m_append(struct mbuf *, int, c_caddr_t); 743void m_cat(struct mbuf *, struct mbuf *); 744void m_extadd(struct mbuf *, caddr_t, u_int, 745 void (*)(void *, void *), void *, int, int); 746void m_copyback(struct mbuf *, int, int, c_caddr_t); 747void m_copydata(const struct mbuf *, int, int, caddr_t); 748struct mbuf *m_copym(struct mbuf *, int, int, int); 749struct mbuf *m_copymdata(struct mbuf *, struct mbuf *, 750 int, int, int, int); 751struct mbuf *m_copypacket(struct mbuf *, int); 752void m_copy_pkthdr(struct mbuf *, struct mbuf *); 753struct mbuf *m_copyup(struct mbuf *n, int len, int dstoff); 754struct mbuf *m_defrag(struct mbuf *, int); 755void m_demote(struct mbuf *, int); 756struct mbuf *m_devget(char *, int, int, struct ifnet *, 757 void (*)(char *, caddr_t, u_int)); 758struct mbuf *m_dup(struct mbuf *, int); 759int m_dup_pkthdr(struct mbuf *, struct mbuf *, int); 760u_int m_fixhdr(struct mbuf *); 761struct mbuf *m_fragment(struct mbuf *, int, int); 762void m_freem(struct mbuf *); 763struct mbuf *m_getm2(struct mbuf *, int, int, short, int); 764struct mbuf *m_getptr(struct mbuf *, int, int *); 765u_int m_length(struct mbuf *, struct mbuf **); 766void m_move_pkthdr(struct mbuf *, struct mbuf *); 767struct mbuf *m_prepend(struct mbuf *, int, int); 768void m_print(const struct mbuf *, int); 769struct mbuf *m_pulldown(struct mbuf *, int, int, int *); 770struct mbuf *m_pullup(struct mbuf *, int); 771int m_sanity(struct mbuf *, int); 772struct mbuf *m_split(struct mbuf *, int, int); 773struct mbuf *m_uiotombuf(struct uio *, int, int, int, int); 774struct mbuf *m_unshare(struct mbuf *, int how); 775 776/*- 777 * Network packets may have annotations attached by affixing a list of 778 * "packet tags" to the pkthdr structure. Packet tags are dynamically 779 * allocated semi-opaque data structures that have a fixed header 780 * (struct m_tag) that specifies the size of the memory block and a 781 * <cookie,type> pair that identifies it. The cookie is a 32-bit unique 782 * unsigned value used to identify a module or ABI. By convention this value 783 * is chosen as the date+time that the module is created, expressed as the 784 * number of seconds since the epoch (e.g., using date -u +'%s'). The type 785 * value is an ABI/module-specific value that identifies a particular 786 * annotation and is private to the module. For compatibility with systems 787 * like OpenBSD that define packet tags w/o an ABI/module cookie, the value 788 * PACKET_ABI_COMPAT is used to implement m_tag_get and m_tag_find 789 * compatibility shim functions and several tag types are defined below. 790 * Users that do not require compatibility should use a private cookie value 791 * so that packet tag-related definitions can be maintained privately. 792 * 793 * Note that the packet tag returned by m_tag_alloc has the default memory 794 * alignment implemented by malloc. To reference private data one can use a 795 * construct like: 796 * 797 * struct m_tag *mtag = m_tag_alloc(...); 798 * struct foo *p = (struct foo *)(mtag+1); 799 * 800 * if the alignment of struct m_tag is sufficient for referencing members of 801 * struct foo. Otherwise it is necessary to embed struct m_tag within the 802 * private data structure to insure proper alignment; e.g., 803 * 804 * struct foo { 805 * struct m_tag tag; 806 * ... 807 * }; 808 * struct foo *p = (struct foo *) m_tag_alloc(...); 809 * struct m_tag *mtag = &p->tag; 810 */ 811 812/* 813 * Persistent tags stay with an mbuf until the mbuf is reclaimed. Otherwise 814 * tags are expected to ``vanish'' when they pass through a network 815 * interface. For most interfaces this happens normally as the tags are 816 * reclaimed when the mbuf is free'd. However in some special cases 817 * reclaiming must be done manually. An example is packets that pass through 818 * the loopback interface. Also, one must be careful to do this when 819 * ``turning around'' packets (e.g., icmp_reflect). 820 * 821 * To mark a tag persistent bit-or this flag in when defining the tag id. 822 * The tag will then be treated as described above. 823 */ 824#define MTAG_PERSISTENT 0x800 825 826#define PACKET_TAG_NONE 0 /* Nadda */ 827 828/* Packet tags for use with PACKET_ABI_COMPAT. */ 829#define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */ 830#define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */ 831#define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */ 832#define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */ 833#define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO 5 /* NIC notifies IPsec */ 834#define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */ 835#define PACKET_TAG_BRIDGE 7 /* Bridge processing done */ 836#define PACKET_TAG_GIF 8 /* GIF processing done */ 837#define PACKET_TAG_GRE 9 /* GRE processing done */ 838#define PACKET_TAG_IN_PACKET_CHECKSUM 10 /* NIC checksumming done */ 839#define PACKET_TAG_ENCAP 11 /* Encap. processing */ 840#define PACKET_TAG_IPSEC_SOCKET 12 /* IPSEC socket ref */ 841#define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */ 842#define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */ 843#define PACKET_TAG_DUMMYNET 15 /* dummynet info */ 844#define PACKET_TAG_DIVERT 17 /* divert info */ 845#define PACKET_TAG_IPFORWARD 18 /* ipforward info */ 846#define PACKET_TAG_MACLABEL (19 | MTAG_PERSISTENT) /* MAC label */ 847#define PACKET_TAG_PF 21 /* PF + ALTQ information */ 848#define PACKET_TAG_RTSOCKFAM 25 /* rtsock sa family */ 849#define PACKET_TAG_IPOPTIONS 27 /* Saved IP options */ 850#define PACKET_TAG_CARP 28 /* CARP info */ 851 852/* Specific cookies and tags. */ 853 854/* Packet tag routines. */ 855struct m_tag *m_tag_alloc(u_int32_t, int, int, int); 856void m_tag_delete(struct mbuf *, struct m_tag *); 857void m_tag_delete_chain(struct mbuf *, struct m_tag *); 858void m_tag_free_default(struct m_tag *); 859struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *); 860struct m_tag *m_tag_copy(struct m_tag *, int); 861int m_tag_copy_chain(struct mbuf *, struct mbuf *, int); 862void m_tag_delete_nonpersistent(struct mbuf *); 863 864/* 865 * Initialize the list of tags associated with an mbuf. 866 */ 867static __inline void 868m_tag_init(struct mbuf *m) 869{ 870 871 SLIST_INIT(&m->m_pkthdr.tags); 872} 873 874/* 875 * Set up the contents of a tag. Note that this does not fill in the free 876 * method; the caller is expected to do that. 877 * 878 * XXX probably should be called m_tag_init, but that was already taken. 879 */ 880static __inline void 881m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len) 882{ 883 884 t->m_tag_id = type; 885 t->m_tag_len = len; 886 t->m_tag_cookie = cookie; 887} 888 889/* 890 * Reclaim resources associated with a tag. 891 */ 892static __inline void 893m_tag_free(struct m_tag *t) 894{ 895 896 (*t->m_tag_free)(t); 897} 898 899/* 900 * Return the first tag associated with an mbuf. 901 */ 902static __inline struct m_tag * 903m_tag_first(struct mbuf *m) 904{ 905 906 return (SLIST_FIRST(&m->m_pkthdr.tags)); 907} 908 909/* 910 * Return the next tag in the list of tags associated with an mbuf. 911 */ 912static __inline struct m_tag * 913m_tag_next(struct mbuf *m, struct m_tag *t) 914{ 915 916 return (SLIST_NEXT(t, m_tag_link)); 917} 918 919/* 920 * Prepend a tag to the list of tags associated with an mbuf. 921 */ 922static __inline void 923m_tag_prepend(struct mbuf *m, struct m_tag *t) 924{ 925 926 SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link); 927} 928 929/* 930 * Unlink a tag from the list of tags associated with an mbuf. 931 */ 932static __inline void 933m_tag_unlink(struct mbuf *m, struct m_tag *t) 934{ 935 936 SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link); 937} 938 939/* These are for OpenBSD compatibility. */ 940#define MTAG_ABI_COMPAT 0 /* compatibility ABI */ 941 942static __inline struct m_tag * 943m_tag_get(int type, int length, int wait) 944{ 945 return (m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait)); 946} 947 948static __inline struct m_tag * 949m_tag_find(struct mbuf *m, int type, struct m_tag *start) 950{ 951 return (SLIST_EMPTY(&m->m_pkthdr.tags) ? (struct m_tag *)NULL : 952 m_tag_locate(m, MTAG_ABI_COMPAT, type, start)); 953} 954 955#endif /* _KERNEL */ 956 957#endif /* !_SYS_MBUF_H_ */ 958