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 1.54 2008/10/19 08:39:55 sephe Exp $ 38 */ 39 40 #ifndef _SYS_MBUF_H_ 41 #define _SYS_MBUF_H_ 42 43 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES) 44 45 #ifndef _SYS_TYPES_H_ 46 #include <sys/types.h> 47 #endif 48 #ifndef _SYS_PARAM_H_ 49 #include <sys/param.h> 50 #endif 51 #ifndef _SYS_QUEUE_H_ 52 #include <sys/queue.h> 53 #endif 54 #ifndef _NET_NETISR_H_ 55 #include <net/netisr.h> 56 #endif 57 58 /* 59 * Mbufs are of a single size, MSIZE (machine/param.h), which 60 * includes overhead. An mbuf may add a single "mbuf cluster" of size 61 * MCLBYTES (also in machine/param.h), which has no additional overhead 62 * and is used instead of the internal data area; this is done when 63 * at least MINCLSIZE of data must be stored. 64 */ 65 #define MLEN (MSIZE - sizeof(struct m_hdr)) /* normal data len */ 66 #define MHLEN (MLEN - sizeof(struct pkthdr)) /* data len w/pkthdr */ 67 #define MINCLSIZE (MHLEN + 1) /* smallest amount to put in cluster */ 68 #define M_MAXCOMPRESS (MHLEN / 2) /* max amount to copy for compression */ 69 70 /* 71 * Macros for type conversion: 72 * mtod(m, t) -- Convert mbuf pointer to data pointer of correct type. 73 * mtocl(x) - convert pointer within cluster to cluster index # 74 * cltom(x) - convert cluster # to ptr to beginning of cluster 75 */ 76 #define mtod(m, t) ((t)((m)->m_data)) 77 78 /* 79 * Header present at the beginning of every mbuf. 80 */ 81 struct m_hdr { 82 struct mbuf *mh_next; /* next buffer in chain */ 83 struct mbuf *mh_nextpkt; /* next chain in queue/record */ 84 caddr_t mh_data; /* location of data */ 85 int mh_len; /* amount of data in this mbuf */ 86 int mh_flags; /* flags; see below */ 87 short mh_type; /* type of data in this mbuf */ 88 short mh_pad; /* padding */ 89 struct netmsg_packet mh_netmsg; /* hardware->proto stack msg */ 90 }; 91 92 /* 93 * Packet tag structure (see below for details). 94 */ 95 struct 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 }; 101 102 SLIST_HEAD(packet_tags, m_tag); 103 104 /* 105 * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set. 106 * 107 * Be careful: The fields have been carefully ordered to avoid hidden padding. 108 * Keep this in mind, when adding or removing fields! 109 */ 110 struct pkthdr { 111 struct ifnet *rcvif; /* rcv interface */ 112 int len; /* total packet length */ 113 struct packet_tags tags; /* list of packet tags */ 114 115 /* variables for ip and tcp reassembly */ 116 void *header; /* pointer to packet header */ 117 118 /* variables for hardware checksum */ 119 int csum_flags; /* flags regarding checksum */ 120 int csum_data; /* data field used by csum routines */ 121 122 /* firewall flags */ 123 uint32_t fw_flags; /* flags for PF */ 124 125 /* variables for PF processing */ 126 uint16_t unused01; /* was PF tag id */ 127 uint8_t pf_routed; /* PF routing counter */ 128 129 /* variables for ALTQ processing */ 130 uint8_t ecn_af; /* address family for ECN */ 131 uint32_t altq_qid; /* queue id */ 132 uint32_t altq_state_hash; /* identifies 'connections' */ 133 134 uint16_t ether_vlantag; /* ethernet 802.1p+q vlan tag */ 135 uint16_t hash; /* packet hash */ 136 137 uint16_t wlan_seqno; /* IEEE 802.11 seq no. */ 138 }; 139 140 /* 141 * Description of external storage mapped into mbuf; valid only if M_EXT is set. 142 */ 143 struct m_ext { 144 caddr_t ext_buf; /* start of buffer */ 145 void (*ext_free)(void *); 146 u_int ext_size; /* size of buffer, for ext_free */ 147 void (*ext_ref)(void *); 148 void *ext_arg; 149 }; 150 151 /* 152 * The core of the mbuf object along with some shortcut defines for 153 * practical purposes. 154 */ 155 struct mbuf { 156 struct m_hdr m_hdr; 157 union { 158 struct { 159 struct pkthdr MH_pkthdr; /* M_PKTHDR set */ 160 union { 161 struct m_ext MH_ext; /* M_EXT set */ 162 char MH_databuf[MHLEN]; 163 } MH_dat; 164 } MH; 165 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ 166 } M_dat; 167 }; 168 #define m_next m_hdr.mh_next 169 #define m_len m_hdr.mh_len 170 #define m_data m_hdr.mh_data 171 #define m_type m_hdr.mh_type 172 #define m_flags m_hdr.mh_flags 173 #define m_nextpkt m_hdr.mh_nextpkt 174 #define m_pkthdr M_dat.MH.MH_pkthdr 175 #define m_ext M_dat.MH.MH_dat.MH_ext 176 #define m_pktdat M_dat.MH.MH_dat.MH_databuf 177 #define m_dat M_dat.M_databuf 178 179 /* 180 * Code that uses m_act should be converted to use m_nextpkt 181 * instead; m_act is historical and deprecated. 182 */ 183 #define m_act m_nextpkt 184 185 /* 186 * mbuf flags. 187 */ 188 #define M_EXT 0x0001 /* has associated external storage */ 189 #define M_PKTHDR 0x0002 /* start of record */ 190 #define M_EOR 0x0004 /* end of record */ 191 #define M_PROTO1 0x0008 /* protocol-specific */ 192 #define M_PROTO2 0x0010 /* protocol-specific */ 193 #define M_PROTO3 0x0020 /* protocol-specific */ 194 #define M_PROTO4 0x0040 /* protocol-specific */ 195 #define M_PROTO5 0x0080 /* protocol-specific */ 196 197 /* 198 * mbuf pkthdr flags (also stored in m_flags). 199 */ 200 #define M_BCAST 0x0100 /* send/received as link-level broadcast */ 201 #define M_MCAST 0x0200 /* send/received as link-level multicast */ 202 #define M_FRAG 0x0400 /* packet is a fragment of a larger packet */ 203 #define M_FIRSTFRAG 0x0800 /* packet is first fragment */ 204 #define M_LASTFRAG 0x1000 /* packet is last fragment */ 205 #define M_CLCACHE 0x2000 /* mbuf allocated from the cluster cache */ 206 #define M_EXT_CLUSTER 0x4000 /* standard cluster else special */ 207 #define M_PHCACHE 0x8000 /* mbuf allocated from the pkt header cache */ 208 #define M_NOTIFICATION 0x10000 /* notification event */ 209 #define M_VLANTAG 0x20000 /* ether_vlantag is valid */ 210 #define M_MPLSLABELED 0x40000 /* packet is mpls labeled */ 211 #define M_LENCHECKED 0x80000 /* packet proto lengths are checked */ 212 #define M_HASH 0x100000/* hash field in pkthdr is valid */ 213 #define M_PROTO6 0x200000/* protocol-specific */ 214 #define M_PROTO7 0x400000/* protocol-specific */ 215 #define M_PROTO8 0x800000/* protocol-specific */ 216 217 /* 218 * Flags copied when copying m_pkthdr. 219 */ 220 #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_PROTO1|M_PROTO2|M_PROTO3 | \ 221 M_PROTO4|M_PROTO5|M_PROTO6|M_PROTO7|M_PROTO8 | \ 222 M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG | \ 223 M_VLANTAG|M_MPLSLABELED | \ 224 M_LENCHECKED|M_HASH) 225 226 /* 227 * Flags indicating hw checksum support and sw checksum requirements. 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 */ 234 235 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */ 236 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */ 237 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */ 238 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */ 239 #define CSUM_FRAG_NOT_CHECKED 0x1000 /* did _not_ csum fragment 240 * NB: This flag is only used 241 * by IP defragmenter. 242 */ 243 244 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP) 245 #define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */ 246 247 /* 248 * Flags indicating PF processing status 249 */ 250 #define FW_MBUF_GENERATED 0x00000001 251 #define XX_MBUF_UNUSED02 0x00000002 252 #define PF_MBUF_ROUTED 0x00000004 /* pf_routed field is valid */ 253 #define PF_MBUF_TRANSLATE_LOCALHOST \ 254 0x00000008 255 #define PF_MBUF_FRAGCACHE 0x00000010 256 #define XX_MBUF_UNUSED20 0x00000020 257 #define IPFORWARD_MBUF_TAGGED 0x00000040 258 #define DUMMYNET_MBUF_TAGGED 0x00000080 259 #define ALTQ_MBUF_STATE_HASHED 0x00000100 260 #define FW_MBUF_REDISPATCH 0x00000200 261 #define PF_MBUF_GENERATED FW_MBUF_GENERATED 262 #define IPFW_MBUF_GENERATED FW_MBUF_GENERATED 263 264 /* 265 * The PF code uses a different symbol name for the m_tag. This is 266 * NOT a pkthdr flag. 267 */ 268 #define PF_MBUF_TAGGED PACKET_TAG_PF 269 270 /* 271 * mbuf types. 272 */ 273 #define MT_FREE 0 /* should be on free list */ 274 #define MT_DATA 1 /* dynamic (data) allocation */ 275 #define MT_HEADER 2 /* packet header */ 276 #define MT_SONAME 3 /* socket name */ 277 /* 4 was MT_TAG */ 278 #define MT_CONTROL 5 /* extra-data protocol message */ 279 #define MT_OOBDATA 6 /* expedited data */ 280 #define MT_NTYPES 7 /* number of mbuf types for mbtypes[] */ 281 282 struct mbuf_chain { 283 struct mbuf *mc_head; 284 struct mbuf *mc_tail; 285 }; 286 287 /* 288 * General mbuf allocator statistics structure. 289 */ 290 struct mbstat { 291 u_long m_mbufs; /* mbufs obtained from page pool */ 292 u_long m_clusters; /* clusters obtained from page pool */ 293 u_long m_spare; /* spare field */ 294 u_long m_clfree; /* free clusters */ 295 u_long m_drops; /* times failed to find space */ 296 u_long m_wait; /* times waited for space */ 297 u_long m_drain; /* times drained protocols for space */ 298 u_long m_mcfail; /* times m_copym failed */ 299 u_long m_mpfail; /* times m_pullup failed */ 300 u_long m_msize; /* length of an mbuf */ 301 u_long m_mclbytes; /* length of an mbuf cluster */ 302 u_long m_minclsize; /* min length of data to allocate a cluster */ 303 u_long m_mlen; /* length of data in an mbuf */ 304 u_long m_mhlen; /* length of data in a header mbuf */ 305 }; 306 307 /* 308 * Flags specifying how an allocation should be made. 309 */ 310 311 #define MB_DONTWAIT 0x4 312 #define MB_TRYWAIT 0x8 313 #define MB_WAIT MB_TRYWAIT 314 315 /* 316 * Mbuf to Malloc Flag Conversion. 317 */ 318 #define MBTOM(how) ((how) & MB_TRYWAIT ? M_WAITOK : M_NOWAIT) 319 320 /* 321 * These are identifying numbers passed to the m_mballoc_wait function, 322 * allowing us to determine whether the call came from an MGETHDR or 323 * an MGET. 324 */ 325 #define MGETHDR_C 1 326 #define MGET_C 2 327 328 /* 329 * mbuf allocation/deallocation macros (YYY deprecated, too big): 330 * 331 * MGET(struct mbuf *m, int how, int type) 332 * allocates an mbuf and initializes it to contain internal data. 333 * 334 * MGETHDR(struct mbuf *m, int how, int type) 335 * allocates an mbuf and initializes it to contain a packet header 336 * and internal data. 337 */ 338 #define MGET(m, how, type) do { \ 339 (m) = m_get((how), (type)); \ 340 } while (0) 341 342 #define MGETHDR(m, how, type) do { \ 343 (m) = m_gethdr((how), (type)); \ 344 } while (0) 345 346 /* 347 * MCLGET adds such clusters to a normal mbuf. The flag M_EXT is set upon 348 * success. 349 * Deprecated. Use m_getcl() or m_getl() instead. 350 */ 351 #define MCLGET(m, how) do { \ 352 m_mclget((m), (how)); \ 353 } while (0) 354 355 /* 356 * NB: M_COPY_PKTHDR is deprecated; use either M_MOVE_PKTHDR 357 * or m_dup_pkthdr. 358 */ 359 /* 360 * Move mbuf pkthdr from "from" to "to". 361 * from should have M_PKTHDR set, and to must be empty. 362 * from no longer has a pkthdr after this operation. 363 */ 364 #define M_MOVE_PKTHDR(_to, _from) m_move_pkthdr((_to), (_from)) 365 366 /* 367 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place 368 * an object of the specified size at the end of the mbuf, longword aligned. 369 */ 370 #define M_ALIGN(m, len) do { \ 371 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \ 372 } while (0) 373 374 /* 375 * As above, for mbufs allocated with m_gethdr/MGETHDR 376 * or initialized by M_COPY_PKTHDR. 377 */ 378 #define MH_ALIGN(m, len) do { \ 379 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \ 380 } while (0) 381 382 /* 383 * Check if we can write to an mbuf. 384 */ 385 #define M_EXT_WRITABLE(m) (m_sharecount(m) == 1) 386 #define M_WRITABLE(m) (!((m)->m_flags & M_EXT) || M_EXT_WRITABLE(m)) 387 388 /* 389 * Check if the supplied mbuf has a packet header, or else panic. 390 */ 391 #define M_ASSERTPKTHDR(m) \ 392 KASSERT(m != NULL && m->m_flags & M_PKTHDR, \ 393 ("%s: invalid mbuf or no mbuf packet header!", __func__)) 394 395 /* 396 * Compute the amount of space available before the current start of data. 397 * The M_EXT_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 after the end of data in an mbuf. 408 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 409 * of checking writability of the mbuf data area rests solely with the caller. 410 */ 411 #define M_TRAILINGSPACE(m) \ 412 ((m)->m_flags & M_EXT ? \ 413 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \ 414 - ((m)->m_data + (m)->m_len) : 0) : \ 415 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 416 417 /* 418 * Arrange to prepend space of size plen to mbuf m. 419 * If a new mbuf must be allocated, how specifies whether to wait. 420 * If how is MB_DONTWAIT and allocation fails, the original mbuf chain 421 * is freed and m is set to NULL. 422 */ 423 #define M_PREPEND(m, plen, how) do { \ 424 struct mbuf **_mmp = &(m); \ 425 struct mbuf *_mm = *_mmp; \ 426 int _mplen = (plen); \ 427 int __mhow = (how); \ 428 \ 429 if (M_LEADINGSPACE(_mm) >= _mplen) { \ 430 _mm->m_data -= _mplen; \ 431 _mm->m_len += _mplen; \ 432 } else \ 433 _mm = m_prepend(_mm, _mplen, __mhow); \ 434 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \ 435 _mm->m_pkthdr.len += _mplen; \ 436 *_mmp = _mm; \ 437 } while (0) 438 439 /* Length to m_copy to copy all. */ 440 #define M_COPYALL 1000000000 441 442 /* Compatibility with 4.3 */ 443 #define m_copy(m, o, l) m_copym((m), (o), (l), MB_DONTWAIT) 444 445 #ifdef _KERNEL 446 extern u_int m_clalloc_wid; /* mbuf cluster wait count */ 447 extern u_int m_mballoc_wid; /* mbuf wait count */ 448 extern int max_linkhdr; /* largest link-level header */ 449 extern int max_protohdr; /* largest protocol header */ 450 extern int max_hdr; /* largest link+protocol header */ 451 extern int max_datalen; /* MHLEN - max_hdr */ 452 extern int mbuf_wait; /* mbuf sleep time */ 453 extern int nmbclusters; 454 extern int nmbufs; 455 456 struct uio; 457 458 void m_adj(struct mbuf *, int); 459 void m_align(struct mbuf *, int); 460 int m_apply(struct mbuf *, int, int, 461 int (*)(void *, void *, u_int), void *); 462 int m_append(struct mbuf *, int, c_caddr_t); 463 void m_cat(struct mbuf *, struct mbuf *); 464 u_int m_countm(struct mbuf *m, struct mbuf **lastm, u_int *mbcnt); 465 void m_copyback(struct mbuf *, int, int, caddr_t); 466 void m_copydata(const struct mbuf *, int, int, caddr_t); 467 struct mbuf *m_copym(const struct mbuf *, int, int, int); 468 struct mbuf *m_copypacket(struct mbuf *, int); 469 struct mbuf *m_defrag(struct mbuf *, int); 470 struct mbuf *m_defrag_nofree(struct mbuf *, int); 471 struct mbuf *m_devget(char *, int, int, struct ifnet *, 472 void (*copy)(volatile const void *, volatile void *, size_t)); 473 struct mbuf *m_dup(struct mbuf *, int); 474 int m_dup_pkthdr(struct mbuf *, const struct mbuf *, int); 475 struct mbuf *m_free(struct mbuf *); 476 void m_freem(struct mbuf *); 477 struct mbuf *m_get(int, int); 478 struct mbuf *m_getc(int len, int how, int type); 479 struct mbuf *m_getcl(int how, short type, int flags); 480 struct mbuf *m_getclr(int, int); 481 struct mbuf *m_gethdr(int, int); 482 struct mbuf *m_getm(struct mbuf *, int, int, int); 483 struct mbuf *m_getptr(struct mbuf *, int, int *); 484 struct mbuf *m_last(struct mbuf *m); 485 u_int m_lengthm(struct mbuf *m, struct mbuf **lastm); 486 void m_move_pkthdr(struct mbuf *, struct mbuf *); 487 struct mbuf *m_prepend(struct mbuf *, int, int); 488 void m_print(const struct mbuf *m); 489 struct mbuf *m_pulldown(struct mbuf *, int, int, int *); 490 struct mbuf *m_pullup(struct mbuf *, int); 491 struct mbuf *m_split(struct mbuf *, int, int); 492 struct mbuf *m_uiomove(struct uio *); 493 void m_mclget(struct mbuf *m, int how); 494 int m_sharecount(struct mbuf *m); 495 void m_chtype(struct mbuf *m, int type); 496 int m_devpad(struct mbuf *m, int padto); 497 498 #ifdef MBUF_DEBUG 499 void mbuftrackid(struct mbuf *, int); 500 #else 501 #define mbuftrackid(m, id) /* empty */ 502 #endif 503 504 /* 505 * Allocate the right type of mbuf for the desired total length. 506 * The mbuf returned does not necessarily cover the entire requested length. 507 * This function follows mbuf chaining policy of allowing MINCLSIZE 508 * amount of chained mbufs. 509 */ 510 static __inline struct mbuf * 511 m_getl(int len, int how, int type, int flags, int *psize) 512 { 513 struct mbuf *m; 514 int size; 515 516 if (len >= MINCLSIZE) { 517 m = m_getcl(how, type, flags); 518 size = MCLBYTES; 519 } else if (flags & M_PKTHDR) { 520 m = m_gethdr(how, type); 521 size = MHLEN; 522 } else { 523 m = m_get(how, type); 524 size = MLEN; 525 } 526 if (psize != NULL) 527 *psize = size; 528 return (m); 529 } 530 531 /* 532 * Get a single mbuf that covers the requested number of bytes. 533 * This function does not create mbuf chains. It explicitly marks 534 * places in the code that abuse mbufs for contiguous data buffers. 535 */ 536 static __inline struct mbuf * 537 m_getb(int len, int how, int type, int flags) 538 { 539 struct mbuf *m; 540 int mbufsize = (flags & M_PKTHDR) ? MHLEN : MLEN; 541 542 if (len > mbufsize) 543 m = m_getcl(how, type, flags); 544 else if (flags & M_PKTHDR) 545 m = m_gethdr(how, type); 546 else 547 m = m_get(how, type); 548 return (m); 549 } 550 551 /* 552 * Packets may have annotations attached by affixing a list 553 * of "packet tags" to the pkthdr structure. Packet tags are 554 * dynamically allocated semi-opaque data structures that have 555 * a fixed header (struct m_tag) that specifies the size of the 556 * memory block and a <cookie,type> pair that identifies it. 557 * The cookie is a 32-bit unique unsigned value used to identify 558 * a module or ABI. By convention this value is chose as the 559 * date+time that the module is created, expressed as the number of 560 * seconds since the epoch (e.g. using date -u +'%s'). The type value 561 * is an ABI/module-specific value that identifies a particular annotation 562 * and is private to the module. For compatibility with systems 563 * like openbsd that define packet tags w/o an ABI/module cookie, 564 * the value PACKET_ABI_COMPAT is used to implement m_tag_get and 565 * m_tag_find compatibility shim functions and several tag types are 566 * defined below. Users that do not require compatibility should use 567 * a private cookie value so that packet tag-related definitions 568 * can be maintained privately. 569 * 570 * Note that the packet tag returned by m_tag_alloc has the default 571 * memory alignment implemented by kmalloc. To reference private data 572 * one can use a construct like: 573 * 574 * struct m_tag *mtag = m_tag_alloc(...); 575 * struct foo *p = m_tag_data(mtag); 576 * 577 * if the alignment of struct m_tag is sufficient for referencing members 578 * of struct foo. Otherwise it is necessary to embed struct m_tag within 579 * the private data structure to insure proper alignment; e.g. 580 * 581 * struct foo { 582 * struct m_tag tag; 583 * ... 584 * }; 585 * struct foo *p = (struct foo *)m_tag_alloc(...); 586 * struct m_tag *mtag = &p->tag; 587 */ 588 589 #define PACKET_TAG_NONE 0 /* Nadda */ 590 591 /* Packet tag for use with PACKET_ABI_COMPAT */ 592 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */ 593 /* struct tdb_indent */ 594 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */ 595 /* struct tdb_indent */ 596 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */ 597 /* struct tdb_indent, never added */ 598 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */ 599 /* struct tdb_indent, never added */ 600 #define PACKET_TAG_IPSEC_PENDING_TDB 5 /* Reminder to do IPsec */ 601 /* struct tdb_indent, never added */ 602 #define PACKET_TAG_ENCAP 6 /* Encap. processing */ 603 /* struct ifnet *, the GIF interface */ 604 #define PACKET_TAG_IPSEC_HISTORY 7 /* IPSEC history */ 605 /* struct ipsec_history */ 606 #define PACKET_TAG_IPV6_INPUT 8 /* IPV6 input processing */ 607 /* struct ip6aux */ 608 #define PACKET_TAG_IPFW_DIVERT 9 /* divert info */ 609 /* struct divert_info */ 610 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */ 611 /* struct dn_pkt */ 612 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */ 613 /* struct sockaddr_in */ 614 #define PACKET_TAG_IPSRCRT 27 /* IP srcrt opts */ 615 /* struct ip_srcrt_opt */ 616 #define PACKET_TAG_CARP 28 /* CARP info */ 617 /* struct pf_mtag */ 618 #define PACKET_TAG_PF 29 /* PF info */ 619 620 /* Packet tag routines */ 621 struct m_tag *m_tag_alloc(u_int32_t, int, int, int); 622 void m_tag_free(struct m_tag *); 623 void m_tag_prepend(struct mbuf *, struct m_tag *); 624 void m_tag_unlink(struct mbuf *, struct m_tag *); 625 void m_tag_delete(struct mbuf *, struct m_tag *); 626 void m_tag_delete_chain(struct mbuf *); 627 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *); 628 struct m_tag *m_tag_copy(struct m_tag *, int); 629 int m_tag_copy_chain(struct mbuf *, const struct mbuf *, int); 630 void m_tag_init(struct mbuf *); 631 struct m_tag *m_tag_first(struct mbuf *); 632 struct m_tag *m_tag_next(struct mbuf *, struct m_tag *); 633 634 /* these are for openbsd compatibility */ 635 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */ 636 637 static __inline void * 638 m_tag_data(struct m_tag *tag) 639 { 640 return ((void *)(tag + 1)); 641 } 642 643 static __inline struct m_tag * 644 m_tag_get(int type, int length, int wait) 645 { 646 return m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait); 647 } 648 649 static __inline struct m_tag * 650 m_tag_find(struct mbuf *m, int type, struct m_tag *start) 651 { 652 return m_tag_locate(m, MTAG_ABI_COMPAT, type, start); 653 } 654 655 #endif /* _KERNEL */ 656 657 #endif /* _KERNEL || _KERNEL_STRUCTURES */ 658 #endif /* !_SYS_MBUF_H_ */ 659