mbuf.h revision 132488
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 132488 2004-07-21 07:12:24Z alfred $ 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 int how; /* How to allocate: M_WAITOK or M_DONTWAIT */ 76 short type; /* Type of mbuf being allocated */ 77}; 78#endif /* _KERNEL */ 79 80/* 81 * Header present at the beginning of every mbuf. 82 */ 83struct m_hdr { 84 struct mbuf *mh_next; /* next buffer in chain */ 85 struct mbuf *mh_nextpkt; /* next chain in queue/record */ 86 caddr_t mh_data; /* location of data */ 87 int mh_len; /* amount of data in this mbuf */ 88 int mh_flags; /* flags; see below */ 89 short mh_type; /* type of data in this mbuf */ 90}; 91 92/* 93 * Packet tag structure (see below for details). 94 */ 95struct m_tag { 96 SLIST_ENTRY(m_tag) m_tag_link; /* List of packet tags */ 97 u_int16_t m_tag_id; /* Tag ID */ 98 u_int16_t m_tag_len; /* Length of data */ 99 u_int32_t m_tag_cookie; /* ABI/Module ID */ 100 void (*m_tag_free)(struct m_tag *); 101}; 102 103/* 104 * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set. 105 */ 106struct pkthdr { 107 struct ifnet *rcvif; /* rcv interface */ 108 int len; /* total packet length */ 109 /* variables for ip and tcp reassembly */ 110 void *header; /* pointer to packet header */ 111 /* variables for hardware checksum */ 112 int csum_flags; /* flags regarding checksum */ 113 int csum_data; /* data field used by csum routines */ 114 SLIST_HEAD(packet_tags, m_tag) tags; /* list of packet tags */ 115}; 116 117/* 118 * Description of external storage mapped into mbuf; valid only if M_EXT is set. 119 */ 120struct m_ext { 121 caddr_t ext_buf; /* start of buffer */ 122 void (*ext_free) /* free routine if not the usual */ 123 (void *, void *); 124 void *ext_args; /* optional argument pointer */ 125 u_int ext_size; /* size of buffer, for ext_free */ 126 u_int *ref_cnt; /* pointer to ref count info */ 127 int ext_type; /* type of external storage */ 128}; 129 130/* 131 * The core of the mbuf object along with some shortcut defines for 132 * practical purposes. 133 */ 134struct mbuf { 135 struct m_hdr m_hdr; 136 union { 137 struct { 138 struct pkthdr MH_pkthdr; /* M_PKTHDR set */ 139 union { 140 struct m_ext MH_ext; /* M_EXT set */ 141 char MH_databuf[MHLEN]; 142 } MH_dat; 143 } MH; 144 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ 145 } M_dat; 146}; 147#define m_next m_hdr.mh_next 148#define m_len m_hdr.mh_len 149#define m_data m_hdr.mh_data 150#define m_type m_hdr.mh_type 151#define m_flags m_hdr.mh_flags 152#define m_nextpkt m_hdr.mh_nextpkt 153#define m_act m_nextpkt 154#define m_pkthdr M_dat.MH.MH_pkthdr 155#define m_ext M_dat.MH.MH_dat.MH_ext 156#define m_pktdat M_dat.MH.MH_dat.MH_databuf 157#define m_dat M_dat.M_databuf 158 159/* 160 * mbuf flags. 161 */ 162#define M_EXT 0x0001 /* has associated external storage */ 163#define M_PKTHDR 0x0002 /* start of record */ 164#define M_EOR 0x0004 /* end of record */ 165#define M_RDONLY 0x0008 /* associated data is marked read-only */ 166#define M_PROTO1 0x0010 /* protocol-specific */ 167#define M_PROTO2 0x0020 /* protocol-specific */ 168#define M_PROTO3 0x0040 /* protocol-specific */ 169#define M_PROTO4 0x0080 /* protocol-specific */ 170#define M_PROTO5 0x0100 /* protocol-specific */ 171#define M_SKIP_FIREWALL 0x4000 /* skip firewall processing */ 172#define M_FREELIST 0x8000 /* mbuf is on the free list */ 173 174/* 175 * mbuf pkthdr flags (also stored in m_flags). 176 */ 177#define M_BCAST 0x0200 /* send/received as link-level broadcast */ 178#define M_MCAST 0x0400 /* send/received as link-level multicast */ 179#define M_FRAG 0x0800 /* packet is a fragment of a larger packet */ 180#define M_FIRSTFRAG 0x1000 /* packet is first fragment */ 181#define M_LASTFRAG 0x2000 /* packet is last fragment */ 182 183/* 184 * External buffer types: identify ext_buf type. 185 */ 186#define EXT_CLUSTER 1 /* mbuf cluster */ 187#define EXT_SFBUF 2 /* sendfile(2)'s sf_bufs */ 188#define EXT_PACKET 3 /* came out of Packet zone */ 189#define EXT_NET_DRV 100 /* custom ext_buf provided by net driver(s) */ 190#define EXT_MOD_TYPE 200 /* custom module's ext_buf type */ 191#define EXT_DISPOSABLE 300 /* can throw this buffer away w/page flipping */ 192#define EXT_EXTREF 400 /* has externally maintained ref_cnt ptr */ 193 194/* 195 * Flags copied when copying m_pkthdr. 196 */ 197#define M_COPYFLAGS (M_PKTHDR|M_EOR|M_RDONLY|M_PROTO1|M_PROTO1|M_PROTO2|\ 198 M_PROTO3|M_PROTO4|M_PROTO5|M_SKIP_FIREWALL|\ 199 M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG) 200 201/* 202 * Flags indicating hw checksum support and sw checksum requirements. 203 */ 204#define CSUM_IP 0x0001 /* will csum IP */ 205#define CSUM_TCP 0x0002 /* will csum TCP */ 206#define CSUM_UDP 0x0004 /* will csum UDP */ 207#define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */ 208#define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */ 209 210#define CSUM_IP_CHECKED 0x0100 /* did csum IP */ 211#define CSUM_IP_VALID 0x0200 /* ... the csum is valid */ 212#define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */ 213#define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */ 214 215#define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP) 216#define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */ 217 218/* 219 * mbuf types. 220 */ 221#define MT_NOTMBUF 0 /* USED INTERNALLY ONLY! Object is not mbuf */ 222#define MT_DATA 1 /* dynamic (data) allocation */ 223#define MT_HEADER 2 /* packet header */ 224#if 0 225#define MT_SOCKET 3 /* socket structure */ 226#define MT_PCB 4 /* protocol control block */ 227#define MT_RTABLE 5 /* routing tables */ 228#define MT_HTABLE 6 /* IMP host tables */ 229#define MT_ATABLE 7 /* address resolution tables */ 230#endif 231#define MT_SONAME 8 /* socket name */ 232#if 0 233#define MT_SOOPTS 10 /* socket options */ 234#endif 235#define MT_FTABLE 11 /* fragment reassembly header */ 236#if 0 237#define MT_RIGHTS 12 /* access rights */ 238#define MT_IFADDR 13 /* interface address */ 239#endif 240#define MT_CONTROL 14 /* extra-data protocol message */ 241#define MT_OOBDATA 15 /* expedited data */ 242#define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */ 243 244/* 245 * General mbuf allocator statistics structure. 246 */ 247struct mbstat { 248 u_long m_mbufs; /* XXX */ 249 u_long m_mclusts; /* XXX */ 250 251 u_long m_drain; /* times drained protocols for space */ 252 u_long m_mcfail; /* XXX: times m_copym failed */ 253 u_long m_mpfail; /* XXX: times m_pullup failed */ 254 u_long m_msize; /* length of an mbuf */ 255 u_long m_mclbytes; /* length of an mbuf cluster */ 256 u_long m_minclsize; /* min length of data to allocate a cluster */ 257 u_long m_mlen; /* length of data in an mbuf */ 258 u_long m_mhlen; /* length of data in a header mbuf */ 259 260 /* Number of mbtypes (gives # elems in mbtypes[] array: */ 261 short m_numtypes; 262 263 /* XXX: Sendfile stats should eventually move to their own struct */ 264 u_long sf_iocnt; /* times sendfile had to do disk I/O */ 265 u_long sf_allocfail; /* times sfbuf allocation failed */ 266 u_long sf_allocwait; /* times sfbuf allocation had to wait */ 267}; 268 269/* 270 * Flags specifying how an allocation should be made. 271 * 272 * The flag to use is as follows: 273 * - M_DONTWAIT or M_NOWAIT from an interrupt handler to not block allocation. 274 * - M_WAIT or M_WAITOK or M_TRYWAIT from wherever it is safe to block. 275 * 276 * M_DONTWAIT/M_NOWAIT means that we will not block the thread explicitly 277 * and if we cannot allocate immediately we may return NULL, 278 * whereas M_WAIT/M_WAITOK/M_TRYWAIT means that if we cannot allocate 279 * resources we will block until they are available, and thus never 280 * return NULL. 281 * 282 * XXX Eventually just phase this out to use M_WAITOK/M_NOWAIT. 283 */ 284#define MBTOM(how) (how) 285#define M_DONTWAIT M_NOWAIT 286#define M_TRYWAIT M_WAITOK 287#define M_WAIT M_WAITOK 288 289#ifdef _KERNEL 290/*- 291 * mbuf external reference count management macros. 292 * 293 * MEXT_IS_REF(m): true if (m) is not the only mbuf referencing 294 * the external buffer ext_buf. 295 * 296 * MEXT_REM_REF(m): remove reference to m_ext object. 297 * 298 * MEXT_ADD_REF(m): add reference to m_ext object already 299 * referred to by (m). 300 */ 301#define MEXT_IS_REF(m) (*((m)->m_ext.ref_cnt) > 1) 302 303#define MEXT_REM_REF(m) do { \ 304 KASSERT(*((m)->m_ext.ref_cnt) > 0, ("m_ext refcnt < 0")); \ 305 atomic_subtract_int((m)->m_ext.ref_cnt, 1); \ 306} while(0) 307 308#define MEXT_ADD_REF(m) atomic_add_int((m)->m_ext.ref_cnt, 1) 309 310#define MBUF_CHECKSLEEP(how) do { \ 311 if (how == M_WAITOK) \ 312 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, \ 313 "Sleeping in \"%s\"", __func__); \ 314} while(0) 315 316/* 317 * Network buffer allocation API 318 * 319 * The rest of it is defined in kern/subr_mbuf.c 320 */ 321 322extern uma_zone_t zone_mbuf; 323extern uma_zone_t zone_clust; 324extern uma_zone_t zone_pack; 325 326static __inline struct mbuf *m_get(int how, short type); 327static __inline struct mbuf *m_gethdr(int how, short type); 328static __inline struct mbuf *m_getcl(int how, short type, int flags); 329static __inline struct mbuf *m_getclr(int how, short type); /* XXX */ 330static __inline struct mbuf *m_free(struct mbuf *m); 331static __inline void m_clget(struct mbuf *m, int how); 332static __inline void m_chtype(struct mbuf *m, short new_type); 333void mb_free_ext(struct mbuf *); 334 335static __inline 336struct mbuf * 337m_get(int how, short type) 338{ 339 struct mb_args args; 340 341 MBUF_CHECKSLEEP(how); 342 args.flags = 0; 343 args.how = how; 344 args.type = type; 345 return (uma_zalloc_arg(zone_mbuf, &args, how)); 346} 347 348/* XXX This should be depracated, very little use */ 349static __inline 350struct mbuf * 351m_getclr(int how, short type) 352{ 353 struct mbuf *m; 354 struct mb_args args; 355 356 MBUF_CHECKSLEEP(how); 357 args.flags = 0; 358 args.how = how; 359 args.type = type; 360 m = uma_zalloc_arg(zone_mbuf, &args, how); 361 if (m != NULL) 362 bzero(m->m_data, MLEN); 363 return m; 364} 365 366static __inline 367struct mbuf * 368m_gethdr(int how, short type) 369{ 370 struct mb_args args; 371 372 MBUF_CHECKSLEEP(how); 373 args.flags = M_PKTHDR; 374 args.how = how; 375 args.type = type; 376 return (uma_zalloc_arg(zone_mbuf, &args, how)); 377} 378 379static __inline 380struct mbuf * 381m_getcl(int how, short type, int flags) 382{ 383 struct mb_args args; 384 385 MBUF_CHECKSLEEP(how); 386 args.flags = flags; 387 args.how = how; 388 args.type = type; 389 return (uma_zalloc_arg(zone_pack, &args, how)); 390} 391 392static __inline 393struct mbuf * 394m_free(struct mbuf *m) 395{ 396 struct mbuf *n = m->m_next; 397 398#ifdef INVARIANTS 399 m->m_flags |= M_FREELIST; 400#endif 401 if (m->m_flags & M_EXT) 402 mb_free_ext(m); 403 else 404 uma_zfree(zone_mbuf, m); 405 return n; 406} 407 408static __inline 409void 410m_clget(struct mbuf *m, int how) 411{ 412 413 MBUF_CHECKSLEEP(how); 414 m->m_ext.ext_buf = NULL; 415 uma_zalloc_arg(zone_clust, m, how); 416} 417 418static __inline 419void 420m_chtype(struct mbuf *m, short new_type) 421{ 422 m->m_type = new_type; 423} 424 425/* 426 * mbuf, cluster, and external object allocation macros 427 * (for compatibility purposes). 428 */ 429/* NB: M_COPY_PKTHDR is deprecated. Use M_MOVE_PKTHDR or m_dup_pktdr. */ 430#define M_MOVE_PKTHDR(to, from) m_move_pkthdr((to), (from)) 431#define MGET(m, how, type) ((m) = m_get((how), (type))) 432#define MGETHDR(m, how, type) ((m) = m_gethdr((how), (type))) 433#define MCLGET(m, how) m_clget((m), (how)) 434#define MEXTADD(m, buf, size, free, args, flags, type) \ 435 m_extadd((m), (caddr_t)(buf), (size), (free), (args), (flags), (type)) 436 437/* 438 * Evaluate TRUE if it's safe to write to the mbuf m's data region (this 439 * can be both the local data payload, or an external buffer area, 440 * depending on whether M_EXT is set). 441 */ 442#define M_WRITABLE(m) (!((m)->m_flags & M_RDONLY) && (!((m)->m_flags \ 443 & M_EXT) || !MEXT_IS_REF(m))) 444 445/* Check if the supplied mbuf has a packet header, or else panic. */ 446#define M_ASSERTPKTHDR(m) \ 447 KASSERT(m != NULL && m->m_flags & M_PKTHDR, \ 448 ("%s: no mbuf packet header!", __func__)) 449 450/* Ensure that the supplied mbuf is a valid, non-free mbuf. */ 451#define M_ASSERTVALID(m) \ 452 KASSERT((((struct mbuf *)m)->m_flags & M_FREELIST) == 0, \ 453 ("%s: attempted use of a free mbuf!", __func__)) 454 455/* 456 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place 457 * an object of the specified size at the end of the mbuf, longword aligned. 458 */ 459#define M_ALIGN(m, len) do { \ 460 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \ 461} while (0) 462 463/* 464 * As above, for mbufs allocated with m_gethdr/MGETHDR 465 * or initialized by M_COPY_PKTHDR. 466 */ 467#define MH_ALIGN(m, len) do { \ 468 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \ 469} while (0) 470 471/* 472 * Compute the amount of space available 473 * before the current start of data in an mbuf. 474 * 475 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 476 * of checking writability of the mbuf data area rests solely with the caller. 477 */ 478#define M_LEADINGSPACE(m) \ 479 ((m)->m_flags & M_EXT ? \ 480 (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \ 481 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 482 (m)->m_data - (m)->m_dat) 483 484/* 485 * Compute the amount of space available 486 * after the end of data in an mbuf. 487 * 488 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 489 * of checking writability of the mbuf data area rests solely with the caller. 490 */ 491#define M_TRAILINGSPACE(m) \ 492 ((m)->m_flags & M_EXT ? \ 493 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \ 494 - ((m)->m_data + (m)->m_len) : 0) : \ 495 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 496 497/* 498 * Arrange to prepend space of size plen to mbuf m. 499 * If a new mbuf must be allocated, how specifies whether to wait. 500 * If the allocation fails, the original mbuf chain is freed and m is 501 * set to NULL. 502 */ 503#define M_PREPEND(m, plen, how) do { \ 504 struct mbuf **_mmp = &(m); \ 505 struct mbuf *_mm = *_mmp; \ 506 int _mplen = (plen); \ 507 int __mhow = (how); \ 508 \ 509 MBUF_CHECKSLEEP(how); \ 510 if (M_LEADINGSPACE(_mm) >= _mplen) { \ 511 _mm->m_data -= _mplen; \ 512 _mm->m_len += _mplen; \ 513 } else \ 514 _mm = m_prepend(_mm, _mplen, __mhow); \ 515 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \ 516 _mm->m_pkthdr.len += _mplen; \ 517 *_mmp = _mm; \ 518} while (0) 519 520/* 521 * Change mbuf to new type. 522 * This is a relatively expensive operation and should be avoided. 523 */ 524#define MCHTYPE(m, t) m_chtype((m), (t)) 525 526/* Length to m_copy to copy all. */ 527#define M_COPYALL 1000000000 528 529/* Compatibility with 4.3. */ 530#define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT) 531 532extern int max_datalen; /* MHLEN - max_hdr */ 533extern int max_hdr; /* Largest link + protocol header */ 534extern int max_linkhdr; /* Largest link-level header */ 535extern int max_protohdr; /* Largest protocol header */ 536extern struct mbstat mbstat; /* General mbuf stats/infos */ 537extern int nmbclusters; /* Maximum number of clusters */ 538 539struct uio; 540 541void m_adj(struct mbuf *, int); 542int m_apply(struct mbuf *, int, int, 543 int (*)(void *, void *, u_int), void *); 544void m_cat(struct mbuf *, struct mbuf *); 545void m_extadd(struct mbuf *, caddr_t, u_int, 546 void (*)(void *, void *), void *, int, int); 547void m_copyback(struct mbuf *, int, int, c_caddr_t); 548void m_copydata(const struct mbuf *, int, int, caddr_t); 549struct mbuf *m_copym(struct mbuf *, int, int, int); 550struct mbuf *m_copypacket(struct mbuf *, int); 551void m_copy_pkthdr(struct mbuf *, struct mbuf *); 552struct mbuf *m_defrag(struct mbuf *, int); 553struct mbuf *m_devget(char *, int, int, struct ifnet *, 554 void (*)(char *, caddr_t, u_int)); 555struct mbuf *m_dup(struct mbuf *, int); 556int m_dup_pkthdr(struct mbuf *, struct mbuf *, int); 557u_int m_fixhdr(struct mbuf *); 558struct mbuf *m_fragment(struct mbuf *, int, int); 559void m_freem(struct mbuf *); 560struct mbuf *m_getm(struct mbuf *, int, int, short); 561struct mbuf *m_getptr(struct mbuf *, int, int *); 562u_int m_length(struct mbuf *, struct mbuf **); 563void m_move_pkthdr(struct mbuf *, struct mbuf *); 564struct mbuf *m_prepend(struct mbuf *, int, int); 565void m_print(const struct mbuf *); 566struct mbuf *m_pulldown(struct mbuf *, int, int, int *); 567struct mbuf *m_pullup(struct mbuf *, int); 568struct mbuf *m_split(struct mbuf *, int, int); 569struct mbuf *m_uiotombuf(struct uio *, int, int); 570 571/*- 572 * Network packets may have annotations attached by affixing a list 573 * of "packet tags" to the pkthdr structure. Packet tags are 574 * dynamically allocated semi-opaque data structures that have 575 * a fixed header (struct m_tag) that specifies the size of the 576 * memory block and a <cookie,type> pair that identifies it. 577 * The cookie is a 32-bit unique unsigned value used to identify 578 * a module or ABI. By convention this value is chose as the 579 * date+time that the module is created, expressed as the number of 580 * seconds since the epoch (e.g., using date -u +'%s'). The type value 581 * is an ABI/module-specific value that identifies a particular annotation 582 * and is private to the module. For compatibility with systems 583 * like OpenBSD that define packet tags w/o an ABI/module cookie, 584 * the value PACKET_ABI_COMPAT is used to implement m_tag_get and 585 * m_tag_find compatibility shim functions and several tag types are 586 * defined below. Users that do not require compatibility should use 587 * a private cookie value so that packet tag-related definitions 588 * can be maintained privately. 589 * 590 * Note that the packet tag returned by m_tag_alloc has the default 591 * memory alignment implemented by malloc. To reference private data 592 * one can use a construct like: 593 * 594 * struct m_tag *mtag = m_tag_alloc(...); 595 * struct foo *p = (struct foo *)(mtag+1); 596 * 597 * if the alignment of struct m_tag is sufficient for referencing members 598 * of struct foo. Otherwise it is necessary to embed struct m_tag within 599 * the private data structure to insure proper alignment; e.g., 600 * 601 * struct foo { 602 * struct m_tag tag; 603 * ... 604 * }; 605 * struct foo *p = (struct foo *) m_tag_alloc(...); 606 * struct m_tag *mtag = &p->tag; 607 */ 608 609/* 610 * Persistent tags stay with an mbuf until the mbuf is reclaimed. 611 * Otherwise tags are expected to ``vanish'' when they pass through 612 * a network interface. For most interfaces this happens normally 613 * as the tags are reclaimed when the mbuf is free'd. However in 614 * some special cases reclaiming must be done manually. An example 615 * is packets that pass through the loopback interface. Also, one 616 * must be careful to do this when ``turning around'' packets (e.g., 617 * icmp_reflect). 618 * 619 * To mark a tag persistent bit-or this flag in when defining the 620 * tag id. The tag will then be treated as described above. 621 */ 622#define MTAG_PERSISTENT 0x800 623 624#define PACKET_TAG_NONE 0 /* Nadda */ 625 626/* Packet tags for use with PACKET_ABI_COMPAT. */ 627#define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */ 628#define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */ 629#define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */ 630#define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */ 631#define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO 5 /* NIC notifies IPsec */ 632#define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */ 633#define PACKET_TAG_BRIDGE 7 /* Bridge processing done */ 634#define PACKET_TAG_GIF 8 /* GIF processing done */ 635#define PACKET_TAG_GRE 9 /* GRE processing done */ 636#define PACKET_TAG_IN_PACKET_CHECKSUM 10 /* NIC checksumming done */ 637#define PACKET_TAG_ENCAP 11 /* Encap. processing */ 638#define PACKET_TAG_IPSEC_SOCKET 12 /* IPSEC socket ref */ 639#define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */ 640#define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */ 641#define PACKET_TAG_DUMMYNET 15 /* dummynet info */ 642#define PACKET_TAG_DIVERT 17 /* divert info */ 643#define PACKET_TAG_IPFORWARD 18 /* ipforward info */ 644#define PACKET_TAG_MACLABEL (19 | MTAG_PERSISTENT) /* MAC label */ 645#define PACKET_TAG_PF_ROUTED 21 /* PF routed, avoid loops */ 646#define PACKET_TAG_PF_FRAGCACHE 22 /* PF fragment cached */ 647#define PACKET_TAG_PF_QID 23 /* PF ALTQ queue id */ 648#define PACKET_TAG_PF_TAG 24 /* PF tagged */ 649#define PACKET_TAG_RTSOCKFAM 25 /* rtsock sa family */ 650#define PACKET_TAG_PF_TRANSLATE_LOCALHOST 26 /* PF translate localhost */ 651 652/* Packet tag routines. */ 653struct m_tag *m_tag_alloc(u_int32_t, int, int, int); 654void m_tag_delete(struct mbuf *, struct m_tag *); 655void m_tag_delete_chain(struct mbuf *, struct m_tag *); 656struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *); 657struct m_tag *m_tag_copy(struct m_tag *, int); 658int m_tag_copy_chain(struct mbuf *, struct mbuf *, int); 659void m_tag_delete_nonpersistent(struct mbuf *); 660 661/* 662 * Initialize the list of tags associated with an mbuf. 663 */ 664static __inline void 665m_tag_init(struct mbuf *m) 666{ 667 SLIST_INIT(&m->m_pkthdr.tags); 668} 669 670/* 671 * Set up the contents of a tag. Note that this does not 672 * fill in the free method; the caller is expected to do that. 673 * 674 * XXX probably should be called m_tag_init, but that was 675 * already taken. 676 */ 677static __inline void 678m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len) 679{ 680 t->m_tag_id = type; 681 t->m_tag_len = len; 682 t->m_tag_cookie = cookie; 683} 684 685/* 686 * Reclaim resources associated with a tag. 687 */ 688static __inline void 689m_tag_free(struct m_tag *t) 690{ 691 (*t->m_tag_free)(t); 692} 693 694/* 695 * Return the first tag associated with an mbuf. 696 */ 697static __inline struct m_tag * 698m_tag_first(struct mbuf *m) 699{ 700 return (SLIST_FIRST(&m->m_pkthdr.tags)); 701} 702 703/* 704 * Return the next tag in the list of tags associated with an mbuf. 705 */ 706static __inline struct m_tag * 707m_tag_next(struct mbuf *m, struct m_tag *t) 708{ 709 return (SLIST_NEXT(t, m_tag_link)); 710} 711 712/* 713 * Prepend a tag to the list of tags associated with an mbuf. 714 */ 715static __inline void 716m_tag_prepend(struct mbuf *m, struct m_tag *t) 717{ 718 SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link); 719} 720 721/* 722 * Unlink a tag from the list of tags associated with an mbuf. 723 */ 724static __inline void 725m_tag_unlink(struct mbuf *m, struct m_tag *t) 726{ 727 SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link); 728} 729 730/* These are for OpenBSD compatibility. */ 731#define MTAG_ABI_COMPAT 0 /* compatibility ABI */ 732 733static __inline struct m_tag * 734m_tag_get(int type, int length, int wait) 735{ 736 return (m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait)); 737} 738 739static __inline struct m_tag * 740m_tag_find(struct mbuf *m, int type, struct m_tag *start) 741{ 742 return (SLIST_EMPTY(&m->m_pkthdr.tags) ? 743 NULL : m_tag_locate(m, MTAG_ABI_COMPAT, type, start)); 744} 745 746/* 747 * Obtain next_hop information associated with the mbuf, if any. 748 * If a tag is present devalidate it also. 749 */ 750static __inline struct sockaddr_in * 751m_claim_next(struct mbuf *m, int type) 752{ 753 struct m_tag *mtag = m_tag_find(m, type, NULL); 754 if (mtag) { 755 struct sockaddr_in *sin = *(struct sockaddr_in **)(mtag + 1); 756 mtag->m_tag_id = PACKET_TAG_NONE; 757 return (sin); 758 } 759 return (NULL); 760} 761#endif /* _KERNEL */ 762 763#endif /* !_SYS_MBUF_H_ */ 764