1 /* 2 * Copyright (c) 2004 The DragonFly Project. All rights reserved. 3 * 4 * Copyright (c) 1982, 1986, 1988, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)mbuf.h 8.5 (Berkeley) 2/19/95 36 * $FreeBSD: src/sys/sys/mbuf.h,v 1.44.2.17 2003/04/15 06:15:02 silby Exp $ 37 * $DragonFly: src/sys/sys/mbuf.h,v 1.18 2004/09/25 15:20:33 joerg Exp $ 38 */ 39 40 #ifndef _SYS_MBUF_H_ 41 #define _SYS_MBUF_H_ 42 43 #include <sys/queue.h> 44 45 /* 46 * Mbufs are of a single size, MSIZE (machine/param.h), which 47 * includes overhead. An mbuf may add a single "mbuf cluster" of size 48 * MCLBYTES (also in machine/param.h), which has no additional overhead 49 * and is used instead of the internal data area; this is done when 50 * at least MINCLSIZE of data must be stored. 51 */ 52 #define MLEN (MSIZE - sizeof(struct m_hdr)) /* normal data len */ 53 #define MHLEN (MLEN - sizeof(struct pkthdr)) /* data len w/pkthdr */ 54 #define MINCLSIZE (MHLEN + 1) /* smallest amount to put in cluster */ 55 #define M_MAXCOMPRESS (MHLEN / 2) /* max amount to copy for compression */ 56 57 /* 58 * Macros for type conversion: 59 * mtod(m, t) -- Convert mbuf pointer to data pointer of correct type. 60 * mtocl(x) - convert pointer within cluster to cluster index # 61 * cltom(x) - convert cluster # to ptr to beginning of cluster 62 */ 63 #define mtod(m, t) ((t)((m)->m_data)) 64 65 /* 66 * Header present at the beginning of every mbuf. 67 */ 68 struct m_hdr { 69 struct mbuf *mh_next; /* next buffer in chain */ 70 struct mbuf *mh_nextpkt; /* next chain in queue/record */ 71 caddr_t mh_data; /* location of data */ 72 int mh_len; /* amount of data in this mbuf */ 73 short mh_type; /* type of data in this mbuf */ 74 short mh_flags; /* flags; see below */ 75 }; 76 77 /* 78 * Packet tag structure (see below for details). 79 */ 80 struct m_tag { 81 SLIST_ENTRY(m_tag) m_tag_link; /* List of packet tags */ 82 u_int16_t m_tag_id; /* Tag ID */ 83 u_int16_t m_tag_len; /* Length of data */ 84 u_int32_t m_tag_cookie; /* ABI/Module ID */ 85 }; 86 87 SLIST_HEAD(packet_tags, m_tag); 88 89 /* 90 * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set. 91 */ 92 struct pkthdr { 93 struct ifnet *rcvif; /* rcv interface */ 94 int len; /* total packet length */ 95 struct packet_tags tags; /* list of packet tags */ 96 97 /* variables for ip and tcp reassembly */ 98 void *header; /* pointer to packet header */ 99 100 /* variables for hardware checksum */ 101 int csum_flags; /* flags regarding checksum */ 102 int csum_data; /* data field used by csum routines */ 103 104 /* variables for PF processing */ 105 int pf_flags; /* flags for PF */ 106 uint16_t pf_tag; /* PF tag id */ 107 uint8_t pf_routed; /* PF routing counter */ 108 uint8_t pf_unused01; /* pad */ 109 }; 110 111 /* 112 * Description of external storage mapped into mbuf; valid only if M_EXT is set. 113 */ 114 struct m_ext { 115 caddr_t ext_buf; /* start of buffer */ 116 union { 117 void (*old)(caddr_t, u_int); 118 void (*new)(void *arg); 119 void *any; 120 } ext_nfree; 121 u_int ext_size; /* size of buffer, for ext_nfree */ 122 union { 123 void (*old)(caddr_t, u_int); 124 void (*new)(void *arg); 125 void *any; 126 } ext_nref; 127 void *ext_arg; 128 }; 129 130 /* 131 * The core of the mbuf object along with some shortcut defines for 132 * practical purposes. 133 */ 134 struct 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_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 * Code that uses m_act should be converted to use m_nextpkt 160 * instead; m_act is historical and deprecated. 161 */ 162 #define m_act m_nextpkt 163 164 /* 165 * mbuf flags. 166 */ 167 #define M_EXT 0x0001 /* has associated external storage */ 168 #define M_PKTHDR 0x0002 /* start of record */ 169 #define M_EOR 0x0004 /* end of record */ 170 #define M_PROTO1 0x0008 /* protocol-specific */ 171 #define M_PROTO2 0x0010 /* protocol-specific */ 172 #define M_PROTO3 0x0020 /* protocol-specific */ 173 #define M_PROTO4 0x0040 /* protocol-specific */ 174 #define M_PROTO5 0x0080 /* protocol-specific */ 175 176 /* 177 * mbuf pkthdr flags (also stored in m_flags). 178 */ 179 #define M_BCAST 0x0100 /* send/received as link-level broadcast */ 180 #define M_MCAST 0x0200 /* send/received as link-level multicast */ 181 #define M_FRAG 0x0400 /* packet is a fragment of a larger packet */ 182 #define M_FIRSTFRAG 0x0800 /* packet is first fragment */ 183 #define M_LASTFRAG 0x1000 /* packet is last fragment */ 184 #define M_EXT_OLD 0x2000 /* new ext function format */ 185 #define M_EXT_CLUSTER 0x4000 /* standard cluster else special */ 186 187 /* 188 * Flags copied when copying m_pkthdr. 189 */ 190 #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_PROTO1|M_PROTO1|M_PROTO2|M_PROTO3 | \ 191 M_PROTO4|M_PROTO5|M_BCAST|M_MCAST|M_FRAG | \ 192 M_FIRSTFRAG|M_LASTFRAG) 193 194 /* 195 * Flags indicating hw checksum support and sw checksum requirements. 196 */ 197 #define CSUM_IP 0x0001 /* will csum IP */ 198 #define CSUM_TCP 0x0002 /* will csum TCP */ 199 #define CSUM_UDP 0x0004 /* will csum UDP */ 200 #define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */ 201 #define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */ 202 203 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */ 204 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */ 205 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */ 206 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */ 207 208 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP) 209 #define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */ 210 211 /* 212 * Flags indicating PF processing status 213 */ 214 #define PF_MBUF_GENERATED 0x00000001 215 #define PF_MBUF_TAGGED 0x00000002 /* pf_tag field is valid */ 216 #define PF_MBUF_ROUTED 0x00000004 /* pf_routed field is valid */ 217 #define PF_MBUF_TRANSLATE_LOCALHOST \ 218 0x00000008 219 #define PF_MBUF_FRAGCACHE 0x00000010 220 221 /* 222 * mbuf types. 223 */ 224 #define MT_FREE 0 /* should be on free list */ 225 #define MT_DATA 1 /* dynamic (data) allocation */ 226 #define MT_HEADER 2 /* packet header */ 227 #if 0 228 #define MT_SOCKET 3 /* socket structure */ 229 #define MT_PCB 4 /* protocol control block */ 230 #define MT_RTABLE 5 /* routing tables */ 231 #define MT_HTABLE 6 /* IMP host tables */ 232 #define MT_ATABLE 7 /* address resolution tables */ 233 #endif 234 #define MT_SONAME 8 /* socket name */ 235 #if 0 236 #define MT_SOOPTS 10 /* socket options */ 237 #endif 238 #define MT_FTABLE 11 /* fragment reassembly header */ 239 #if 0 240 #define MT_RIGHTS 12 /* access rights */ 241 #define MT_IFADDR 13 /* interface address */ 242 #endif 243 #define MT_TAG 13 /* volatile metadata associated to pkts */ 244 #define MT_CONTROL 14 /* extra-data protocol message */ 245 #define MT_OOBDATA 15 /* expedited data */ 246 #define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */ 247 248 /* 249 * General mbuf allocator statistics structure. 250 */ 251 struct mbstat { 252 u_long m_mbufs; /* mbufs obtained from page pool */ 253 u_long m_clusters; /* clusters obtained from page pool */ 254 u_long m_spare; /* spare field */ 255 u_long m_clfree; /* free clusters */ 256 u_long m_drops; /* times failed to find space */ 257 u_long m_wait; /* times waited for space */ 258 u_long m_drain; /* times drained protocols for space */ 259 u_long m_mcfail; /* times m_copym failed */ 260 u_long m_mpfail; /* times m_pullup failed */ 261 u_long m_msize; /* length of an mbuf */ 262 u_long m_mclbytes; /* length of an mbuf cluster */ 263 u_long m_minclsize; /* min length of data to allocate a cluster */ 264 u_long m_mlen; /* length of data in an mbuf */ 265 u_long m_mhlen; /* length of data in a header mbuf */ 266 }; 267 268 /* 269 * Flags specifying how an allocation should be made. 270 */ 271 272 #define MB_DONTWAIT 0x4 273 #define MB_TRYWAIT 0x8 274 #define MB_WAIT MB_TRYWAIT 275 276 /* 277 * Mbuf to Malloc Flag Conversion. 278 */ 279 #define MBTOM(how) ((how) & MB_TRYWAIT ? M_WAITOK : M_NOWAIT) 280 281 /* 282 * These are identifying numbers passed to the m_mballoc_wait function, 283 * allowing us to determine whether the call came from an MGETHDR or 284 * an MGET. 285 */ 286 #define MGETHDR_C 1 287 #define MGET_C 2 288 289 /* 290 * Wake up the next instance (if any) of m_mballoc_wait() which is 291 * waiting for an mbuf to be freed. This should be called at splimp(). 292 * 293 * XXX: If there is another free mbuf, this routine will be called [again] 294 * from the m_mballoc_wait routine in order to wake another sleep instance. 295 */ 296 #define MMBWAKEUP() do { \ 297 if (m_mballoc_wid) { \ 298 m_mballoc_wid--; \ 299 wakeup_one(&m_mballoc_wid); \ 300 } \ 301 } while (0) 302 303 /* 304 * Same as above, but for mbuf cluster(s). 305 */ 306 #define MCLWAKEUP() do { \ 307 if (m_clalloc_wid) { \ 308 m_clalloc_wid--; \ 309 wakeup_one(&m_clalloc_wid); \ 310 } \ 311 } while (0) 312 313 /* 314 * mbuf utility macros: 315 * 316 * MBUFLOCK(code) 317 * prevents a section of code from from being interrupted by network 318 * drivers. 319 */ 320 #define MBUFLOCK(code) do { \ 321 int _ms = splimp(); \ 322 \ 323 { code } \ 324 splx(_ms); \ 325 } while (0) 326 327 /* 328 * mbuf allocation/deallocation macros (YYY deprecated, too big): 329 * 330 * MGET(struct mbuf *m, int how, int type) 331 * allocates an mbuf and initializes it to contain internal data. 332 * 333 * MGETHDR(struct mbuf *m, int how, int type) 334 * allocates an mbuf and initializes it to contain a packet header 335 * and internal data. 336 */ 337 #define MGET(m, how, type) do { \ 338 (m) = m_get((how), (type)); \ 339 } while (0) 340 341 #define MGETHDR(m, how, type) do { \ 342 (m) = m_gethdr((how), (type)); \ 343 } while (0) 344 345 /* 346 * MCLGET adds such clusters to a normal mbuf. The flag M_EXT is set upon 347 * success. 348 */ 349 #define MCLGET(m, how) do { \ 350 m_mclget((m), (how)); \ 351 } while (0) 352 353 /* 354 * NB: M_COPY_PKTHDR is deprecated; use either M_MOVE_PKTHDR 355 * or m_dup_pkthdr. 356 */ 357 /* 358 * Move mbuf pkthdr from "from" to "to". 359 * from should have M_PKTHDR set, and to must be empty. 360 * from no longer has a pkthdr after this operation. 361 */ 362 #define M_MOVE_PKTHDR(_to, _from) m_move_pkthdr((_to), (_from)) 363 364 /* 365 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place 366 * an object of the specified size at the end of the mbuf, longword aligned. 367 */ 368 #define M_ALIGN(m, len) do { \ 369 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \ 370 } while (0) 371 372 /* 373 * As above, for mbufs allocated with m_gethdr/MGETHDR 374 * or initialized by M_COPY_PKTHDR. 375 */ 376 #define MH_ALIGN(m, len) do { \ 377 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \ 378 } while (0) 379 380 /* 381 * Check if we can write to an mbuf. 382 */ 383 #define M_EXT_WRITABLE(m) (m_sharecount(m) == 1) 384 #define M_WRITABLE(m) (!((m)->m_flags & M_EXT) || M_EXT_WRITABLE(m)) 385 386 /* 387 * Check if the supplied mbuf has a packet header, or else panic. 388 */ 389 #define M_ASSERTPKTHDR(m) \ 390 KASSERT(m != NULL && m->m_flags & M_PKTHDR, \ 391 ("%s: invalid mbuf or no mbuf packet header!", __func__)) 392 393 /* 394 * Compute the amount of space available 395 * before the current start of data in an mbuf. 396 * 397 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 398 * of checking writability of the mbuf data area rests solely with the caller. 399 */ 400 #define M_LEADINGSPACE(m) \ 401 ((m)->m_flags & M_EXT ? \ 402 (M_EXT_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \ 403 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 404 (m)->m_data - (m)->m_dat) 405 406 /* 407 * Compute the amount of space available 408 * after the end of data in an mbuf. 409 * 410 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 411 * of checking writability of the mbuf data area rests solely with the caller. 412 */ 413 #define M_TRAILINGSPACE(m) \ 414 ((m)->m_flags & M_EXT ? \ 415 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \ 416 - ((m)->m_data + (m)->m_len) : 0) : \ 417 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 418 419 /* 420 * Arrange to prepend space of size plen to mbuf m. 421 * If a new mbuf must be allocated, how specifies whether to wait. 422 * If how is MB_DONTWAIT and allocation fails, the original mbuf chain 423 * is freed and m is set to NULL. 424 */ 425 #define M_PREPEND(m, plen, how) do { \ 426 struct mbuf **_mmp = &(m); \ 427 struct mbuf *_mm = *_mmp; \ 428 int _mplen = (plen); \ 429 int __mhow = (how); \ 430 \ 431 if (M_LEADINGSPACE(_mm) >= _mplen) { \ 432 _mm->m_data -= _mplen; \ 433 _mm->m_len += _mplen; \ 434 } else \ 435 _mm = m_prepend(_mm, _mplen, __mhow); \ 436 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \ 437 _mm->m_pkthdr.len += _mplen; \ 438 *_mmp = _mm; \ 439 } while (0) 440 441 /* Length to m_copy to copy all. */ 442 #define M_COPYALL 1000000000 443 444 /* Compatibility with 4.3 */ 445 #define m_copy(m, o, l) m_copym((m), (o), (l), MB_DONTWAIT) 446 447 #ifdef _KERNEL 448 extern u_int m_clalloc_wid; /* mbuf cluster wait count */ 449 extern u_int m_mballoc_wid; /* mbuf wait count */ 450 extern int max_linkhdr; /* largest link-level header */ 451 extern int max_protohdr; /* largest protocol header */ 452 extern int max_hdr; /* largest link+protocol header */ 453 extern int max_datalen; /* MHLEN - max_hdr */ 454 extern struct mbstat mbstat; 455 extern int mbuf_wait; /* mbuf sleep time */ 456 extern int nmbclusters; 457 extern int nmbufs; 458 459 struct uio; 460 461 void m_adj(struct mbuf *, int); 462 void m_cat(struct mbuf *, struct mbuf *); 463 void m_copyback(struct mbuf *, int, int, caddr_t); 464 void m_copydata(const struct mbuf *, int, int, caddr_t); 465 struct mbuf *m_copym(const struct mbuf *, int, int, int); 466 struct mbuf *m_copypacket(struct mbuf *, int); 467 struct mbuf *m_defrag(struct mbuf *, int); 468 struct mbuf *m_devget(char *, int, int, struct ifnet *, 469 void (*copy)(char *, caddr_t, u_int)); 470 struct mbuf *m_dup(struct mbuf *, int); 471 int m_dup_pkthdr(struct mbuf *, const struct mbuf *, int); 472 struct mbuf *m_free(struct mbuf *); 473 void m_freem(struct mbuf *); 474 struct mbuf *m_get(int, int); 475 struct mbuf *m_getcl(int how, short type, int flags); 476 struct mbuf *m_getclr(int, int); 477 struct mbuf *m_gethdr(int, int); 478 struct mbuf *m_getm(struct mbuf *, int, int, int); 479 void m_move_pkthdr(struct mbuf *, struct mbuf *); 480 struct mbuf *m_prepend(struct mbuf *, int, int); 481 void m_print(const struct mbuf *m); 482 struct mbuf *m_pulldown(struct mbuf *, int, int, int *); 483 struct mbuf *m_pullup(struct mbuf *, int); 484 struct mbuf *m_retry(int, int); 485 struct mbuf *m_retryhdr(int, int); 486 struct mbuf *m_split(struct mbuf *, int, int); 487 struct mbuf *m_uiomove(struct uio *, int, int); 488 void m_mclget(struct mbuf *m, int how); 489 int m_sharecount(struct mbuf *m); 490 void m_chtype(struct mbuf *m, int type); 491 492 493 /* 494 * Packets may have annotations attached by affixing a list 495 * of "packet tags" to the pkthdr structure. Packet tags are 496 * dynamically allocated semi-opaque data structures that have 497 * a fixed header (struct m_tag) that specifies the size of the 498 * memory block and a <cookie,type> pair that identifies it. 499 * The cookie is a 32-bit unique unsigned value used to identify 500 * a module or ABI. By convention this value is chose as the 501 * date+time that the module is created, expressed as the number of 502 * seconds since the epoch (e.g. using date -u +'%s'). The type value 503 * is an ABI/module-specific value that identifies a particular annotation 504 * and is private to the module. For compatibility with systems 505 * like openbsd that define packet tags w/o an ABI/module cookie, 506 * the value PACKET_ABI_COMPAT is used to implement m_tag_get and 507 * m_tag_find compatibility shim functions and several tag types are 508 * defined below. Users that do not require compatibility should use 509 * a private cookie value so that packet tag-related definitions 510 * can be maintained privately. 511 * 512 * Note that the packet tag returned by m_tag_allocate has the default 513 * memory alignment implemented by malloc. To reference private data 514 * one can use a construct like: 515 * 516 * struct m_tag *mtag = m_tag_allocate(...); 517 * struct foo *p = (struct foo *)(mtag+1); 518 * 519 * if the alignment of struct m_tag is sufficient for referencing members 520 * of struct foo. Otherwise it is necessary to embed struct m_tag within 521 * the private data structure to insure proper alignment; e.g. 522 * 523 * struct foo { 524 * struct m_tag tag; 525 * ... 526 * }; 527 * struct foo *p = (struct foo *) m_tag_allocate(...); 528 * struct m_tag *mtag = &p->tag; 529 */ 530 531 #define PACKET_TAG_NONE 0 /* Nadda */ 532 533 /* Packet tag for use with PACKET_ABI_COMPAT */ 534 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */ 535 /* struct tdb_indent */ 536 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */ 537 /* struct tdb_indent */ 538 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */ 539 /* struct tdb_indent, never added */ 540 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */ 541 /* struct tdb_indent, never added */ 542 #define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */ 543 /* struct tdb_indent, never added */ 544 #define PACKET_TAG_ENCAP 11 /* Encap. processing */ 545 /* struct ifnet *, the GIF interface */ 546 #define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */ 547 /* struct ipsec_history */ 548 #define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */ 549 /* struct ip6aux */ 550 551 /* 552 * As a temporary and low impact solution to replace the even uglier 553 * approach used so far in some parts of the network stack (which relies 554 * on global variables), packet tag-like annotations are stored in MT_TAG 555 * mbufs (or lookalikes) prepended to the actual mbuf chain. 556 * 557 * m_type = MT_TAG 558 * m_flags = m_tag_id 559 * m_next = next buffer in chain. 560 * 561 * BE VERY CAREFUL not to pass these blocks to the mbuf handling routines. 562 */ 563 #define _m_tag_id m_hdr.mh_flags 564 565 /* Packet tags used in the FreeBSD network stack */ 566 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */ 567 /* struct dn_pkt as fake mbuf */ 568 #define PACKET_TAG_DIVERT 17 /* divert info */ 569 /* uint16_t, encoded in m_data */ 570 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */ 571 /* struct sockaddr_in * as m_data */ 572 573 /* Packet tag routines */ 574 struct m_tag *m_tag_alloc(u_int32_t, int, int, int); 575 void m_tag_free(struct m_tag *); 576 void m_tag_prepend(struct mbuf *, struct m_tag *); 577 void m_tag_unlink(struct mbuf *, struct m_tag *); 578 void m_tag_delete(struct mbuf *, struct m_tag *); 579 void m_tag_delete_chain(struct mbuf *, struct m_tag *); 580 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *); 581 struct m_tag *m_tag_copy(struct m_tag *, int); 582 int m_tag_copy_chain(struct mbuf *, const struct mbuf *, int); 583 void m_tag_init(struct mbuf *); 584 struct m_tag *m_tag_first(struct mbuf *); 585 struct m_tag *m_tag_next(struct mbuf *, struct m_tag *); 586 587 /* these are for openbsd compatibility */ 588 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */ 589 590 static __inline struct m_tag * 591 m_tag_get(int type, int length, int wait) 592 { 593 return m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait); 594 } 595 596 static __inline struct m_tag * 597 m_tag_find(struct mbuf *m, int type, struct m_tag *start) 598 { 599 return m_tag_locate(m, MTAG_ABI_COMPAT, type, start); 600 } 601 #endif /* _KERNEL */ 602 603 #endif /* !_SYS_MBUF_H_ */ 604