1 /*- 2 * Copyright (c) 1982, 1986, 1988, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)mbuf.h 8.5 (Berkeley) 2/19/95 30 * $FreeBSD$ 31 */ 32 33 #ifndef _SYS_MBUF_H_ 34 #define _SYS_MBUF_H_ 35 36 /* XXX: These includes suck. Sorry! */ 37 #include <sys/queue.h> 38 #ifdef _KERNEL 39 #include <sys/systm.h> 40 #include <vm/uma.h> 41 #ifdef WITNESS 42 #include <sys/lock.h> 43 #endif 44 #endif 45 46 /* 47 * Mbufs are of a single size, MSIZE (sys/param.h), which 48 * includes overhead. An mbuf may add a single "mbuf cluster" of size 49 * MCLBYTES (also in sys/param.h), which has no additional overhead 50 * and is used instead of the internal data area; this is done when 51 * at least MINCLSIZE of data must be stored. Additionally, it is possible 52 * to allocate a separate buffer externally and attach it to the mbuf in 53 * a way similar to that of mbuf clusters. 54 */ 55 #define MLEN (MSIZE - sizeof(struct m_hdr)) /* normal data len */ 56 #define MHLEN (MLEN - sizeof(struct pkthdr)) /* data len w/pkthdr */ 57 #define MINCLSIZE (MHLEN + 1) /* smallest amount to put in cluster */ 58 #define M_MAXCOMPRESS (MHLEN / 2) /* max amount to copy for compression */ 59 60 #ifdef _KERNEL 61 /*- 62 * Macros for type conversion: 63 * mtod(m, t) -- Convert mbuf pointer to data pointer of correct type. 64 * dtom(x) -- Convert data pointer within mbuf to mbuf pointer (XXX). 65 */ 66 #define mtod(m, t) ((t)((m)->m_data)) 67 #define dtom(x) ((struct mbuf *)((intptr_t)(x) & ~(MSIZE-1))) 68 69 /* 70 * Argument structure passed to UMA routines during mbuf and packet 71 * allocations. 72 */ 73 struct mb_args { 74 int flags; /* Flags for mbuf being allocated */ 75 short type; /* Type of mbuf being allocated */ 76 }; 77 #endif /* _KERNEL */ 78 79 /* 80 * Header present at the beginning of every mbuf. 81 */ 82 struct 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 */ 94 struct 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 */ 105 struct 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 */ 119 struct 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 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 */ 133 struct 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 */ 181 182 /* 183 * External buffer types: identify ext_buf type. 184 */ 185 #define EXT_CLUSTER 1 /* mbuf cluster */ 186 #define EXT_SFBUF 2 /* sendfile(2)'s sf_bufs */ 187 #define EXT_PACKET 3 /* came out of Packet zone */ 188 #define EXT_NET_DRV 100 /* custom ext_buf provided by net driver(s) */ 189 #define EXT_MOD_TYPE 200 /* custom module's ext_buf type */ 190 #define EXT_DISPOSABLE 300 /* can throw this buffer away w/page flipping */ 191 #define EXT_EXTREF 400 /* has externally maintained ref_cnt ptr */ 192 193 /* 194 * Flags copied when copying m_pkthdr. 195 */ 196 #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_RDONLY|M_PROTO1|M_PROTO1|M_PROTO2|\ 197 M_PROTO3|M_PROTO4|M_PROTO5|M_SKIP_FIREWALL|\ 198 M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG) 199 200 /* 201 * Flags indicating hw checksum support and sw checksum requirements. 202 */ 203 #define CSUM_IP 0x0001 /* will csum IP */ 204 #define CSUM_TCP 0x0002 /* will csum TCP */ 205 #define CSUM_UDP 0x0004 /* will csum UDP */ 206 #define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */ 207 #define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */ 208 209 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */ 210 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */ 211 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */ 212 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */ 213 214 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP) 215 #define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */ 216 217 /* 218 * mbuf types. 219 */ 220 #define MT_NOTMBUF 0 /* USED INTERNALLY ONLY! Object is not mbuf */ 221 #define MT_DATA 1 /* dynamic (data) allocation */ 222 #define MT_HEADER 2 /* packet header */ 223 #if 0 224 #define MT_SOCKET 3 /* socket structure */ 225 #define MT_PCB 4 /* protocol control block */ 226 #define MT_RTABLE 5 /* routing tables */ 227 #define MT_HTABLE 6 /* IMP host tables */ 228 #define MT_ATABLE 7 /* address resolution tables */ 229 #endif 230 #define MT_SONAME 8 /* socket name */ 231 #if 0 232 #define MT_SOOPTS 10 /* socket options */ 233 #endif 234 #define MT_FTABLE 11 /* fragment reassembly header */ 235 #if 0 236 #define MT_RIGHTS 12 /* access rights */ 237 #define MT_IFADDR 13 /* interface address */ 238 #endif 239 #define MT_CONTROL 14 /* extra-data protocol message */ 240 #define MT_OOBDATA 15 /* expedited data */ 241 #define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */ 242 243 /* 244 * General mbuf allocator statistics structure. 245 */ 246 struct mbstat { 247 u_long m_mbufs; /* XXX */ 248 u_long m_mclusts; /* XXX */ 249 250 u_long m_drain; /* times drained protocols for space */ 251 u_long m_mcfail; /* XXX: times m_copym failed */ 252 u_long m_mpfail; /* XXX: times m_pullup failed */ 253 u_long m_msize; /* length of an mbuf */ 254 u_long m_mclbytes; /* length of an mbuf cluster */ 255 u_long m_minclsize; /* min length of data to allocate a cluster */ 256 u_long m_mlen; /* length of data in an mbuf */ 257 u_long m_mhlen; /* length of data in a header mbuf */ 258 259 /* Number of mbtypes (gives # elems in mbtypes[] array: */ 260 short m_numtypes; 261 262 /* XXX: Sendfile stats should eventually move to their own struct */ 263 u_long sf_iocnt; /* times sendfile had to do disk I/O */ 264 u_long sf_allocfail; /* times sfbuf allocation failed */ 265 u_long sf_allocwait; /* times sfbuf allocation had to wait */ 266 }; 267 268 /* 269 * Flags specifying how an allocation should be made. 270 * 271 * The flag to use is as follows: 272 * - M_DONTWAIT or M_NOWAIT from an interrupt handler to not block allocation. 273 * - M_WAIT or M_WAITOK or M_TRYWAIT from wherever it is safe to block. 274 * 275 * M_DONTWAIT/M_NOWAIT means that we will not block the thread explicitly 276 * and if we cannot allocate immediately we may return NULL, 277 * whereas M_WAIT/M_WAITOK/M_TRYWAIT means that if we cannot allocate 278 * resources we will block until they are available, and thus never 279 * return NULL. 280 * 281 * XXX Eventually just phase this out to use M_WAITOK/M_NOWAIT. 282 */ 283 #define MBTOM(how) (how) 284 #define M_DONTWAIT M_NOWAIT 285 #define M_TRYWAIT M_WAITOK 286 #define M_WAIT M_WAITOK 287 288 #ifdef _KERNEL 289 /*- 290 * mbuf external reference count management macros. 291 * 292 * MEXT_IS_REF(m): true if (m) is not the only mbuf referencing 293 * the external buffer ext_buf. 294 * 295 * MEXT_REM_REF(m): remove reference to m_ext object. 296 * 297 * MEXT_ADD_REF(m): add reference to m_ext object already 298 * referred to by (m). 299 */ 300 #define MEXT_IS_REF(m) (*((m)->m_ext.ref_cnt) > 1) 301 302 #define MEXT_REM_REF(m) do { \ 303 KASSERT(*((m)->m_ext.ref_cnt) > 0, ("m_ext refcnt < 0")); \ 304 atomic_subtract_int((m)->m_ext.ref_cnt, 1); \ 305 } while(0) 306 307 #define MEXT_ADD_REF(m) atomic_add_int((m)->m_ext.ref_cnt, 1) 308 309 #ifdef WITNESS 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 #else 316 #define MBUF_CHECKSLEEP(how) 317 #endif 318 319 /* 320 * Network buffer allocation API 321 * 322 * The rest of it is defined in kern/subr_mbuf.c 323 */ 324 325 extern uma_zone_t zone_mbuf; 326 extern uma_zone_t zone_clust; 327 extern uma_zone_t zone_pack; 328 329 static __inline struct mbuf *m_get(int how, short type); 330 static __inline struct mbuf *m_gethdr(int how, short type); 331 static __inline struct mbuf *m_getcl(int how, short type, int flags); 332 static __inline struct mbuf *m_getclr(int how, short type); /* XXX */ 333 static __inline struct mbuf *m_free(struct mbuf *m); 334 static __inline void m_clget(struct mbuf *m, int how); 335 static __inline void m_chtype(struct mbuf *m, short new_type); 336 void mb_free_ext(struct mbuf *); 337 338 static __inline 339 struct mbuf * 340 m_get(int how, short type) 341 { 342 struct mb_args args; 343 344 args.flags = 0; 345 args.type = type; 346 return (uma_zalloc_arg(zone_mbuf, &args, how)); 347 } 348 349 /* XXX This should be depracated, very little use */ 350 static __inline 351 struct mbuf * 352 m_getclr(int how, short type) 353 { 354 struct mbuf *m; 355 struct mb_args args; 356 357 args.flags = 0; 358 args.type = type; 359 m = uma_zalloc_arg(zone_mbuf, &args, how); 360 if (m != NULL) 361 bzero(m->m_data, MLEN); 362 return m; 363 } 364 365 static __inline 366 struct mbuf * 367 m_gethdr(int how, short type) 368 { 369 struct mb_args args; 370 371 args.flags = M_PKTHDR; 372 args.type = type; 373 return (uma_zalloc_arg(zone_mbuf, &args, how)); 374 } 375 376 static __inline 377 struct mbuf * 378 m_getcl(int how, short type, int flags) 379 { 380 struct mb_args args; 381 382 args.flags = flags; 383 args.type = type; 384 return (uma_zalloc_arg(zone_pack, &args, how)); 385 } 386 387 static __inline 388 struct mbuf * 389 m_free(struct mbuf *m) 390 { 391 struct mbuf *n = m->m_next; 392 393 #ifdef INVARIANTS 394 m->m_flags |= M_FREELIST; 395 #endif 396 if (m->m_flags & M_EXT) 397 mb_free_ext(m); 398 else 399 uma_zfree(zone_mbuf, m); 400 return n; 401 } 402 403 static __inline 404 void 405 m_clget(struct mbuf *m, int how) 406 { 407 408 m->m_ext.ext_buf = NULL; 409 uma_zalloc_arg(zone_clust, m, how); 410 } 411 412 static __inline 413 void 414 m_chtype(struct mbuf *m, short new_type) 415 { 416 m->m_type = new_type; 417 } 418 419 /* 420 * mbuf, cluster, and external object allocation macros 421 * (for compatibility purposes). 422 */ 423 /* NB: M_COPY_PKTHDR is deprecated. Use M_MOVE_PKTHDR or m_dup_pktdr. */ 424 #define M_MOVE_PKTHDR(to, from) m_move_pkthdr((to), (from)) 425 #define MGET(m, how, type) ((m) = m_get((how), (type))) 426 #define MGETHDR(m, how, type) ((m) = m_gethdr((how), (type))) 427 #define MCLGET(m, how) m_clget((m), (how)) 428 #define MEXTADD(m, buf, size, free, args, flags, type) \ 429 m_extadd((m), (caddr_t)(buf), (size), (free), (args), (flags), (type)) 430 431 /* 432 * Evaluate TRUE if it's safe to write to the mbuf m's data region (this 433 * can be both the local data payload, or an external buffer area, 434 * depending on whether M_EXT is set). 435 */ 436 #define M_WRITABLE(m) (!((m)->m_flags & M_RDONLY) && (!((m)->m_flags \ 437 & M_EXT) || !MEXT_IS_REF(m))) 438 439 /* Check if the supplied mbuf has a packet header, or else panic. */ 440 #define M_ASSERTPKTHDR(m) \ 441 KASSERT(m != NULL && m->m_flags & M_PKTHDR, \ 442 ("%s: no mbuf packet header!", __func__)) 443 444 /* Ensure that the supplied mbuf is a valid, non-free mbuf. */ 445 #define M_ASSERTVALID(m) \ 446 KASSERT((((struct mbuf *)m)->m_flags & M_FREELIST) == 0, \ 447 ("%s: attempted use of a free mbuf!", __func__)) 448 449 /* 450 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place 451 * an object of the specified size at the end of the mbuf, longword aligned. 452 */ 453 #define M_ALIGN(m, len) do { \ 454 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \ 455 } while (0) 456 457 /* 458 * As above, for mbufs allocated with m_gethdr/MGETHDR 459 * or initialized by M_COPY_PKTHDR. 460 */ 461 #define MH_ALIGN(m, len) do { \ 462 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \ 463 } while (0) 464 465 /* 466 * Compute the amount of space available 467 * before the current start of data in an mbuf. 468 * 469 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 470 * of checking writability of the mbuf data area rests solely with the caller. 471 */ 472 #define M_LEADINGSPACE(m) \ 473 ((m)->m_flags & M_EXT ? \ 474 (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \ 475 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 476 (m)->m_data - (m)->m_dat) 477 478 /* 479 * Compute the amount of space available 480 * after the end of data in an mbuf. 481 * 482 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 483 * of checking writability of the mbuf data area rests solely with the caller. 484 */ 485 #define M_TRAILINGSPACE(m) \ 486 ((m)->m_flags & M_EXT ? \ 487 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \ 488 - ((m)->m_data + (m)->m_len) : 0) : \ 489 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 490 491 /* 492 * Arrange to prepend space of size plen to mbuf m. 493 * If a new mbuf must be allocated, how specifies whether to wait. 494 * If the allocation fails, the original mbuf chain is freed and m is 495 * set to NULL. 496 */ 497 #define M_PREPEND(m, plen, how) do { \ 498 struct mbuf **_mmp = &(m); \ 499 struct mbuf *_mm = *_mmp; \ 500 int _mplen = (plen); \ 501 int __mhow = (how); \ 502 \ 503 MBUF_CHECKSLEEP(how); \ 504 if (M_LEADINGSPACE(_mm) >= _mplen) { \ 505 _mm->m_data -= _mplen; \ 506 _mm->m_len += _mplen; \ 507 } else \ 508 _mm = m_prepend(_mm, _mplen, __mhow); \ 509 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \ 510 _mm->m_pkthdr.len += _mplen; \ 511 *_mmp = _mm; \ 512 } while (0) 513 514 /* 515 * Change mbuf to new type. 516 * This is a relatively expensive operation and should be avoided. 517 */ 518 #define MCHTYPE(m, t) m_chtype((m), (t)) 519 520 /* Length to m_copy to copy all. */ 521 #define M_COPYALL 1000000000 522 523 /* Compatibility with 4.3. */ 524 #define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT) 525 526 extern int max_datalen; /* MHLEN - max_hdr */ 527 extern int max_hdr; /* Largest link + protocol header */ 528 extern int max_linkhdr; /* Largest link-level header */ 529 extern int max_protohdr; /* Largest protocol header */ 530 extern struct mbstat mbstat; /* General mbuf stats/infos */ 531 extern int nmbclusters; /* Maximum number of clusters */ 532 533 struct uio; 534 535 void m_adj(struct mbuf *, int); 536 int m_apply(struct mbuf *, int, int, 537 int (*)(void *, void *, u_int), void *); 538 void m_cat(struct mbuf *, struct mbuf *); 539 void m_extadd(struct mbuf *, caddr_t, u_int, 540 void (*)(void *, void *), void *, int, int); 541 void m_copyback(struct mbuf *, int, int, c_caddr_t); 542 void m_copydata(const struct mbuf *, int, int, caddr_t); 543 struct mbuf *m_copym(struct mbuf *, int, int, int); 544 struct mbuf *m_copypacket(struct mbuf *, int); 545 void m_copy_pkthdr(struct mbuf *, struct mbuf *); 546 struct mbuf *m_defrag(struct mbuf *, int); 547 struct mbuf *m_devget(char *, int, int, struct ifnet *, 548 void (*)(char *, caddr_t, u_int)); 549 struct mbuf *m_dup(struct mbuf *, int); 550 int m_dup_pkthdr(struct mbuf *, struct mbuf *, int); 551 u_int m_fixhdr(struct mbuf *); 552 struct mbuf *m_fragment(struct mbuf *, int, int); 553 void m_freem(struct mbuf *); 554 struct mbuf *m_getm(struct mbuf *, int, int, short); 555 struct mbuf *m_getptr(struct mbuf *, int, int *); 556 u_int m_length(struct mbuf *, struct mbuf **); 557 void m_move_pkthdr(struct mbuf *, struct mbuf *); 558 struct mbuf *m_prepend(struct mbuf *, int, int); 559 void m_print(const struct mbuf *); 560 struct mbuf *m_pulldown(struct mbuf *, int, int, int *); 561 struct mbuf *m_pullup(struct mbuf *, int); 562 struct mbuf *m_split(struct mbuf *, int, int); 563 struct mbuf *m_uiotombuf(struct uio *, int, int); 564 565 /*- 566 * Network packets may have annotations attached by affixing a list 567 * of "packet tags" to the pkthdr structure. Packet tags are 568 * dynamically allocated semi-opaque data structures that have 569 * a fixed header (struct m_tag) that specifies the size of the 570 * memory block and a <cookie,type> pair that identifies it. 571 * The cookie is a 32-bit unique unsigned value used to identify 572 * a module or ABI. By convention this value is chose as the 573 * date+time that the module is created, expressed as the number of 574 * seconds since the epoch (e.g., using date -u +'%s'). The type value 575 * is an ABI/module-specific value that identifies a particular annotation 576 * and is private to the module. For compatibility with systems 577 * like OpenBSD that define packet tags w/o an ABI/module cookie, 578 * the value PACKET_ABI_COMPAT is used to implement m_tag_get and 579 * m_tag_find compatibility shim functions and several tag types are 580 * defined below. Users that do not require compatibility should use 581 * a private cookie value so that packet tag-related definitions 582 * can be maintained privately. 583 * 584 * Note that the packet tag returned by m_tag_alloc has the default 585 * memory alignment implemented by malloc. To reference private data 586 * one can use a construct like: 587 * 588 * struct m_tag *mtag = m_tag_alloc(...); 589 * struct foo *p = (struct foo *)(mtag+1); 590 * 591 * if the alignment of struct m_tag is sufficient for referencing members 592 * of struct foo. Otherwise it is necessary to embed struct m_tag within 593 * the private data structure to insure proper alignment; e.g., 594 * 595 * struct foo { 596 * struct m_tag tag; 597 * ... 598 * }; 599 * struct foo *p = (struct foo *) m_tag_alloc(...); 600 * struct m_tag *mtag = &p->tag; 601 */ 602 603 /* 604 * Persistent tags stay with an mbuf until the mbuf is reclaimed. 605 * Otherwise tags are expected to ``vanish'' when they pass through 606 * a network interface. For most interfaces this happens normally 607 * as the tags are reclaimed when the mbuf is free'd. However in 608 * some special cases reclaiming must be done manually. An example 609 * is packets that pass through the loopback interface. Also, one 610 * must be careful to do this when ``turning around'' packets (e.g., 611 * icmp_reflect). 612 * 613 * To mark a tag persistent bit-or this flag in when defining the 614 * tag id. The tag will then be treated as described above. 615 */ 616 #define MTAG_PERSISTENT 0x800 617 618 #define PACKET_TAG_NONE 0 /* Nadda */ 619 620 /* Packet tags for use with PACKET_ABI_COMPAT. */ 621 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */ 622 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */ 623 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */ 624 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */ 625 #define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO 5 /* NIC notifies IPsec */ 626 #define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */ 627 #define PACKET_TAG_BRIDGE 7 /* Bridge processing done */ 628 #define PACKET_TAG_GIF 8 /* GIF processing done */ 629 #define PACKET_TAG_GRE 9 /* GRE processing done */ 630 #define PACKET_TAG_IN_PACKET_CHECKSUM 10 /* NIC checksumming done */ 631 #define PACKET_TAG_ENCAP 11 /* Encap. processing */ 632 #define PACKET_TAG_IPSEC_SOCKET 12 /* IPSEC socket ref */ 633 #define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */ 634 #define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */ 635 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */ 636 #define PACKET_TAG_DIVERT 17 /* divert info */ 637 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */ 638 #define PACKET_TAG_MACLABEL (19 | MTAG_PERSISTENT) /* MAC label */ 639 #define PACKET_TAG_PF_ROUTED 21 /* PF routed, avoid loops */ 640 #define PACKET_TAG_PF_FRAGCACHE 22 /* PF fragment cached */ 641 #define PACKET_TAG_PF_QID 23 /* PF ALTQ queue id */ 642 #define PACKET_TAG_PF_TAG 24 /* PF tagged */ 643 #define PACKET_TAG_RTSOCKFAM 25 /* rtsock sa family */ 644 #define PACKET_TAG_PF_TRANSLATE_LOCALHOST 26 /* PF translate localhost */ 645 646 /* Packet tag routines. */ 647 struct m_tag *m_tag_alloc(u_int32_t, int, int, int); 648 void m_tag_delete(struct mbuf *, struct m_tag *); 649 void m_tag_delete_chain(struct mbuf *, struct m_tag *); 650 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *); 651 struct m_tag *m_tag_copy(struct m_tag *, int); 652 int m_tag_copy_chain(struct mbuf *, struct mbuf *, int); 653 void m_tag_delete_nonpersistent(struct mbuf *); 654 655 /* 656 * Initialize the list of tags associated with an mbuf. 657 */ 658 static __inline void 659 m_tag_init(struct mbuf *m) 660 { 661 SLIST_INIT(&m->m_pkthdr.tags); 662 } 663 664 /* 665 * Set up the contents of a tag. Note that this does not 666 * fill in the free method; the caller is expected to do that. 667 * 668 * XXX probably should be called m_tag_init, but that was 669 * already taken. 670 */ 671 static __inline void 672 m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len) 673 { 674 t->m_tag_id = type; 675 t->m_tag_len = len; 676 t->m_tag_cookie = cookie; 677 } 678 679 /* 680 * Reclaim resources associated with a tag. 681 */ 682 static __inline void 683 m_tag_free(struct m_tag *t) 684 { 685 (*t->m_tag_free)(t); 686 } 687 688 /* 689 * Return the first tag associated with an mbuf. 690 */ 691 static __inline struct m_tag * 692 m_tag_first(struct mbuf *m) 693 { 694 return (SLIST_FIRST(&m->m_pkthdr.tags)); 695 } 696 697 /* 698 * Return the next tag in the list of tags associated with an mbuf. 699 */ 700 static __inline struct m_tag * 701 m_tag_next(struct mbuf *m, struct m_tag *t) 702 { 703 return (SLIST_NEXT(t, m_tag_link)); 704 } 705 706 /* 707 * Prepend a tag to the list of tags associated with an mbuf. 708 */ 709 static __inline void 710 m_tag_prepend(struct mbuf *m, struct m_tag *t) 711 { 712 SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link); 713 } 714 715 /* 716 * Unlink a tag from the list of tags associated with an mbuf. 717 */ 718 static __inline void 719 m_tag_unlink(struct mbuf *m, struct m_tag *t) 720 { 721 SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link); 722 } 723 724 /* These are for OpenBSD compatibility. */ 725 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */ 726 727 static __inline struct m_tag * 728 m_tag_get(int type, int length, int wait) 729 { 730 return (m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait)); 731 } 732 733 static __inline struct m_tag * 734 m_tag_find(struct mbuf *m, int type, struct m_tag *start) 735 { 736 return (SLIST_EMPTY(&m->m_pkthdr.tags) ? 737 NULL : m_tag_locate(m, MTAG_ABI_COMPAT, type, start)); 738 } 739 740 #endif /* _KERNEL */ 741 742 #endif /* !_SYS_MBUF_H_ */ 743