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 #define mtodoff(m, t, off) ((t)((m)->m_data + (off))) 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 short mh_pad; /* padding */ 90 struct netmsg_packet mh_netmsg; /* hardware->proto stack msg */ 91 }; 92 93 /* pf stuff */ 94 struct pkthdr_pf { 95 void *hdr; /* saved hdr pos in mbuf, for ECN */ 96 u_int rtableid; /* alternate routing table id */ 97 u_int32_t qid; /* queue id */ 98 u_int16_t tag; /* tag id */ 99 u_int8_t flags; 100 u_int8_t routed; 101 uint32_t state_hash; /* identifies 'connections' */ 102 uint8_t ecn_af; /* for altq_red */ 103 uint8_t unused01; 104 uint8_t unused02; 105 uint8_t unused03; 106 }; 107 108 /* 109 * Packet tag structure (see below for details). 110 */ 111 struct m_tag { 112 SLIST_ENTRY(m_tag) m_tag_link; /* List of packet tags */ 113 u_int16_t m_tag_id; /* Tag ID */ 114 u_int16_t m_tag_len; /* Length of data */ 115 u_int32_t m_tag_cookie; /* ABI/Module ID */ 116 }; 117 118 SLIST_HEAD(packet_tags, m_tag); 119 120 /* 121 * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set. 122 * 123 * Be careful: The fields have been carefully ordered to avoid hidden padding. 124 * Keep this in mind, when adding or removing fields! 125 */ 126 struct pkthdr { 127 struct ifnet *rcvif; /* rcv interface */ 128 int len; /* total packet length */ 129 struct packet_tags tags; /* list of packet tags */ 130 131 /* variables for ip and tcp reassembly */ 132 void *header; /* pointer to packet header */ 133 134 /* variables for hardware checksum */ 135 int csum_flags; /* flags regarding checksum */ 136 int csum_data; /* data field used by csum routines */ 137 138 /* firewall flags */ 139 uint32_t fw_flags; /* flags for PF */ 140 141 /* variables for PF processing */ 142 struct pkthdr_pf pf; /* structure for PF */ 143 144 uint16_t ether_vlantag; /* ethernet 802.1p+q vlan tag */ 145 uint16_t hash; /* packet hash */ 146 147 uint16_t wlan_seqno; /* IEEE 802.11 seq no. */ 148 }; 149 150 /* 151 * Description of external storage mapped into mbuf; valid only if M_EXT is set. 152 */ 153 struct m_ext { 154 caddr_t ext_buf; /* start of buffer */ 155 void (*ext_free)(void *); 156 u_int ext_size; /* size of buffer, for ext_free */ 157 void (*ext_ref)(void *); 158 void *ext_arg; 159 }; 160 161 /* 162 * The core of the mbuf object along with some shortcut defines for 163 * practical purposes. 164 */ 165 struct mbuf { 166 struct m_hdr m_hdr; 167 union { 168 struct { 169 struct pkthdr MH_pkthdr; /* M_PKTHDR set */ 170 union { 171 struct m_ext MH_ext; /* M_EXT set */ 172 char MH_databuf[MHLEN]; 173 } MH_dat; 174 } MH; 175 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ 176 } M_dat; 177 }; 178 #define m_next m_hdr.mh_next 179 #define m_len m_hdr.mh_len 180 #define m_data m_hdr.mh_data 181 #define m_type m_hdr.mh_type 182 #define m_flags m_hdr.mh_flags 183 #define m_nextpkt m_hdr.mh_nextpkt 184 #define m_pkthdr M_dat.MH.MH_pkthdr 185 #define m_ext M_dat.MH.MH_dat.MH_ext 186 #define m_pktdat M_dat.MH.MH_dat.MH_databuf 187 #define m_dat M_dat.M_databuf 188 189 /* 190 * Code that uses m_act should be converted to use m_nextpkt 191 * instead; m_act is historical and deprecated. 192 */ 193 #define m_act m_nextpkt 194 195 /* 196 * mbuf flags. 197 */ 198 #define M_EXT 0x0001 /* has associated external storage */ 199 #define M_PKTHDR 0x0002 /* start of record */ 200 #define M_EOR 0x0004 /* end of record */ 201 #define M_PROTO1 0x0008 /* protocol-specific */ 202 #define M_PROTO2 0x0010 /* protocol-specific */ 203 #define M_PROTO3 0x0020 /* protocol-specific */ 204 #define M_PROTO4 0x0040 /* protocol-specific */ 205 #define M_PROTO5 0x0080 /* protocol-specific */ 206 207 /* 208 * mbuf pkthdr flags (also stored in m_flags). 209 */ 210 #define M_BCAST 0x0100 /* send/received as link-level broadcast */ 211 #define M_MCAST 0x0200 /* send/received as link-level multicast */ 212 #define M_FRAG 0x0400 /* packet is a fragment of a larger packet */ 213 #define M_FIRSTFRAG 0x0800 /* packet is first fragment */ 214 #define M_LASTFRAG 0x1000 /* packet is last fragment */ 215 #define M_CLCACHE 0x2000 /* mbuf allocated from the cluster cache */ 216 #define M_EXT_CLUSTER 0x4000 /* standard cluster else special */ 217 #define M_PHCACHE 0x8000 /* mbuf allocated from the pkt header cache */ 218 #define M_NOTIFICATION 0x10000 /* notification event */ 219 #define M_VLANTAG 0x20000 /* ether_vlantag is valid */ 220 #define M_MPLSLABELED 0x40000 /* packet is mpls labeled */ 221 #define M_LENCHECKED 0x80000 /* packet proto lengths are checked */ 222 #define M_HASH 0x100000/* hash field in pkthdr is valid */ 223 #define M_PROTO6 0x200000/* protocol-specific */ 224 #define M_PROTO7 0x400000/* protocol-specific */ 225 #define M_PROTO8 0x800000/* protocol-specific */ 226 227 /* 228 * Flags copied when copying m_pkthdr. 229 */ 230 #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_PROTO1|M_PROTO2|M_PROTO3 | \ 231 M_PROTO4|M_PROTO5|M_PROTO6|M_PROTO7|M_PROTO8 | \ 232 M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG | \ 233 M_VLANTAG|M_MPLSLABELED | \ 234 M_LENCHECKED|M_HASH) 235 236 /* 237 * Flags indicating hw checksum support and sw checksum requirements. 238 */ 239 #define CSUM_IP 0x0001 /* will csum IP */ 240 #define CSUM_TCP 0x0002 /* will csum TCP */ 241 #define CSUM_UDP 0x0004 /* will csum UDP */ 242 #define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */ 243 #define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */ 244 245 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */ 246 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */ 247 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */ 248 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */ 249 #define CSUM_FRAG_NOT_CHECKED 0x1000 /* did _not_ csum fragment 250 * NB: This flag is only used 251 * by IP defragmenter. 252 */ 253 254 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP) 255 #define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */ 256 257 /* 258 * Flags indicating PF processing status 259 */ 260 #define FW_MBUF_GENERATED 0x00000001 261 #define PF_MBUF_STRUCTURE 0x00000002 /* m_pkthdr.pf valid */ 262 #define PF_MBUF_ROUTED 0x00000004 /* pf_routed field is valid */ 263 #define XX_MBUF_UNUSED08 0x00000008 264 #define XX_MBUF_UNUSED10 0x00000010 265 #define XX_MBUF_UNUSED20 0x00000020 266 #define IPFORWARD_MBUF_TAGGED 0x00000040 267 #define DUMMYNET_MBUF_TAGGED 0x00000080 268 #define XX_MBUF_UNUSED100 0x00000100 269 #define FW_MBUF_REDISPATCH 0x00000200 270 #define IPFW_MBUF_GENERATED FW_MBUF_GENERATED 271 /* 272 * mbuf types. 273 */ 274 #define MT_FREE 0 /* should be on free list */ 275 #define MT_DATA 1 /* dynamic (data) allocation */ 276 #define MT_HEADER 2 /* packet header */ 277 #define MT_SONAME 3 /* socket name */ 278 /* 4 was MT_TAG */ 279 #define MT_CONTROL 5 /* extra-data protocol message */ 280 #define MT_OOBDATA 6 /* expedited data */ 281 #define MT_NTYPES 7 /* number of mbuf types for mbtypes[] */ 282 283 struct mbuf_chain { 284 struct mbuf *mc_head; 285 struct mbuf *mc_tail; 286 }; 287 288 /* 289 * General mbuf allocator statistics structure. 290 */ 291 struct mbstat { 292 u_long m_mbufs; /* mbufs obtained from page pool */ 293 u_long m_clusters; /* clusters obtained from page pool */ 294 u_long m_spare; /* spare field */ 295 u_long m_clfree; /* free clusters */ 296 u_long m_drops; /* times failed to find space */ 297 u_long m_wait; /* times waited for space */ 298 u_long m_drain; /* times drained protocols for space */ 299 u_long m_mcfail; /* times m_copym failed */ 300 u_long m_mpfail; /* times m_pullup failed */ 301 u_long m_msize; /* length of an mbuf */ 302 u_long m_mclbytes; /* length of an mbuf cluster */ 303 u_long m_minclsize; /* min length of data to allocate a cluster */ 304 u_long m_mlen; /* length of data in an mbuf */ 305 u_long m_mhlen; /* length of data in a header mbuf */ 306 }; 307 308 /* 309 * Flags specifying how an allocation should be made. 310 */ 311 312 #define MB_DONTWAIT 0x4 313 #define MB_TRYWAIT 0x8 314 #define MB_WAIT MB_TRYWAIT 315 316 /* 317 * Mbuf to Malloc Flag Conversion. 318 */ 319 #define MBTOM(how) ((how) & MB_TRYWAIT ? M_WAITOK : M_NOWAIT) 320 321 /* 322 * These are identifying numbers passed to the m_mballoc_wait function, 323 * allowing us to determine whether the call came from an MGETHDR or 324 * an MGET. 325 */ 326 #define MGETHDR_C 1 327 #define MGET_C 2 328 329 /* 330 * mbuf allocation/deallocation macros (YYY deprecated, too big): 331 * 332 * MGET(struct mbuf *m, int how, int type) 333 * allocates an mbuf and initializes it to contain internal data. 334 * 335 * MGETHDR(struct mbuf *m, int how, int type) 336 * allocates an mbuf and initializes it to contain a packet header 337 * and internal data. 338 */ 339 #define MGET(m, how, type) do { \ 340 (m) = m_get((how), (type)); \ 341 } while (0) 342 343 #define MGETHDR(m, how, type) do { \ 344 (m) = m_gethdr((how), (type)); \ 345 } while (0) 346 347 /* 348 * MCLGET adds such clusters to a normal mbuf. The flag M_EXT is set upon 349 * success. 350 * Deprecated. Use m_getcl() or m_getl() instead. 351 */ 352 #define MCLGET(m, how) do { \ 353 m_mclget((m), (how)); \ 354 } while (0) 355 356 /* 357 * NB: M_COPY_PKTHDR is deprecated; use either M_MOVE_PKTHDR 358 * or m_dup_pkthdr. 359 */ 360 /* 361 * Move mbuf pkthdr from "from" to "to". 362 * from should have M_PKTHDR set, and to must be empty. 363 * from no longer has a pkthdr after this operation. 364 */ 365 #define M_MOVE_PKTHDR(_to, _from) m_move_pkthdr((_to), (_from)) 366 367 /* 368 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place 369 * an object of the specified size at the end of the mbuf, longword aligned. 370 */ 371 #define M_ALIGN(m, len) do { \ 372 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \ 373 } while (0) 374 375 /* 376 * As above, for mbufs allocated with m_gethdr/MGETHDR 377 * or initialized by M_COPY_PKTHDR. 378 */ 379 #define MH_ALIGN(m, len) do { \ 380 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \ 381 } while (0) 382 383 /* 384 * Check if we can write to an mbuf. 385 */ 386 #define M_EXT_WRITABLE(m) (m_sharecount(m) == 1) 387 #define M_WRITABLE(m) (!((m)->m_flags & M_EXT) || M_EXT_WRITABLE(m)) 388 389 /* 390 * Check if the supplied mbuf has a packet header, or else panic. 391 */ 392 #define M_ASSERTPKTHDR(m) \ 393 KASSERT(m != NULL && m->m_flags & M_PKTHDR, \ 394 ("%s: invalid mbuf or no mbuf packet header!", __func__)) 395 396 /* 397 * Compute the amount of space available before the current start of data. 398 * The M_EXT_WRITABLE() is a temporary, conservative safety measure: the burden 399 * of checking writability of the mbuf data area rests solely with the caller. 400 */ 401 #define M_LEADINGSPACE(m) \ 402 ((m)->m_flags & M_EXT ? \ 403 (M_EXT_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \ 404 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 405 (m)->m_data - (m)->m_dat) 406 407 /* 408 * Compute the amount of space available after the end of data in an mbuf. 409 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 410 * of checking writability of the mbuf data area rests solely with the caller. 411 */ 412 #define M_TRAILINGSPACE(m) \ 413 ((m)->m_flags & M_EXT ? \ 414 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \ 415 - ((m)->m_data + (m)->m_len) : 0) : \ 416 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 417 418 /* 419 * Arrange to prepend space of size plen to mbuf m. 420 * If a new mbuf must be allocated, how specifies whether to wait. 421 * If how is MB_DONTWAIT and allocation fails, the original mbuf chain 422 * is freed and m is set to NULL. 423 */ 424 #define M_PREPEND(m, plen, how) do { \ 425 struct mbuf **_mmp = &(m); \ 426 struct mbuf *_mm = *_mmp; \ 427 int _mplen = (plen); \ 428 int __mhow = (how); \ 429 \ 430 if (M_LEADINGSPACE(_mm) >= _mplen) { \ 431 _mm->m_data -= _mplen; \ 432 _mm->m_len += _mplen; \ 433 } else \ 434 _mm = m_prepend(_mm, _mplen, __mhow); \ 435 if (_mm != NULL && (_mm->m_flags & M_PKTHDR)) \ 436 _mm->m_pkthdr.len += _mplen; \ 437 *_mmp = _mm; \ 438 } while (0) 439 440 /* Length to m_copy to copy all. */ 441 #define M_COPYALL 1000000000 442 443 /* Compatibility with 4.3 */ 444 #define m_copy(m, o, l) m_copym((m), (o), (l), MB_DONTWAIT) 445 446 #ifdef _KERNEL 447 extern u_int m_clalloc_wid; /* mbuf cluster wait count */ 448 extern u_int m_mballoc_wid; /* mbuf wait count */ 449 extern int max_linkhdr; /* largest link-level header */ 450 extern int max_protohdr; /* largest protocol header */ 451 extern int max_hdr; /* largest link+protocol header */ 452 extern int max_datalen; /* MHLEN - max_hdr */ 453 extern int mbuf_wait; /* mbuf sleep time */ 454 extern int nmbclusters; 455 extern int nmbufs; 456 457 struct uio; 458 459 void m_adj(struct mbuf *, int); 460 void m_align(struct mbuf *, int); 461 int m_apply(struct mbuf *, int, int, 462 int (*)(void *, void *, u_int), void *); 463 int m_append(struct mbuf *, int, c_caddr_t); 464 void m_cat(struct mbuf *, struct mbuf *); 465 u_int m_countm(struct mbuf *m, struct mbuf **lastm, u_int *mbcnt); 466 void m_copyback(struct mbuf *, int, int, caddr_t); 467 void m_copydata(const struct mbuf *, int, int, caddr_t); 468 struct mbuf *m_copym(const struct mbuf *, int, int, int); 469 struct mbuf *m_copypacket(struct mbuf *, int); 470 struct mbuf *m_defrag(struct mbuf *, int); 471 struct mbuf *m_defrag_nofree(struct mbuf *, int); 472 struct mbuf *m_devget(char *, int, int, struct ifnet *, 473 void (*copy)(volatile const void *, volatile void *, size_t)); 474 struct mbuf *m_dup(struct mbuf *, int); 475 struct mbuf *m_dup_data(struct mbuf *, int); 476 int m_dup_pkthdr(struct mbuf *, const struct mbuf *, int); 477 struct mbuf *m_free(struct mbuf *); 478 void m_freem(struct mbuf *); 479 struct mbuf *m_get(int, int); 480 struct mbuf *m_getc(int len, int how, int type); 481 struct mbuf *m_getcl(int how, short type, int flags); 482 struct mbuf *m_getclr(int, int); 483 struct mbuf *m_gethdr(int, int); 484 struct mbuf *m_getm(struct mbuf *, int, int, int); 485 struct mbuf *m_getptr(struct mbuf *, int, int *); 486 struct mbuf *m_last(struct mbuf *m); 487 u_int m_lengthm(struct mbuf *m, struct mbuf **lastm); 488 void m_move_pkthdr(struct mbuf *, struct mbuf *); 489 struct mbuf *m_prepend(struct mbuf *, int, int); 490 void m_print(const struct mbuf *m); 491 struct mbuf *m_pulldown(struct mbuf *, int, int, int *); 492 struct mbuf *m_pullup(struct mbuf *, int); 493 struct mbuf *m_split(struct mbuf *, int, int); 494 struct mbuf *m_uiomove(struct uio *); 495 void m_mclget(struct mbuf *m, int how); 496 int m_sharecount(struct mbuf *m); 497 void m_chtype(struct mbuf *m, int type); 498 int m_devpad(struct mbuf *m, int padto); 499 500 #ifdef MBUF_DEBUG 501 void mbuftrackid(struct mbuf *, int); 502 #else 503 #define mbuftrackid(m, id) /* empty */ 504 #endif 505 506 /* 507 * Allocate the right type of mbuf for the desired total length. 508 * The mbuf returned does not necessarily cover the entire requested length. 509 * This function follows mbuf chaining policy of allowing MINCLSIZE 510 * amount of chained mbufs. 511 */ 512 static __inline struct mbuf * 513 m_getl(int len, int how, int type, int flags, int *psize) 514 { 515 struct mbuf *m; 516 int size; 517 518 if (len >= MINCLSIZE) { 519 m = m_getcl(how, type, flags); 520 size = MCLBYTES; 521 } else if (flags & M_PKTHDR) { 522 m = m_gethdr(how, type); 523 size = MHLEN; 524 } else { 525 m = m_get(how, type); 526 size = MLEN; 527 } 528 if (psize != NULL) 529 *psize = size; 530 return (m); 531 } 532 533 /* 534 * Get a single mbuf that covers the requested number of bytes. 535 * This function does not create mbuf chains. It explicitly marks 536 * places in the code that abuse mbufs for contiguous data buffers. 537 */ 538 static __inline struct mbuf * 539 m_getb(int len, int how, int type, int flags) 540 { 541 struct mbuf *m; 542 int mbufsize = (flags & M_PKTHDR) ? MHLEN : MLEN; 543 544 if (len > mbufsize) 545 m = m_getcl(how, type, flags); 546 else if (flags & M_PKTHDR) 547 m = m_gethdr(how, type); 548 else 549 m = m_get(how, type); 550 return (m); 551 } 552 553 /* 554 * Packets may have annotations attached by affixing a list 555 * of "packet tags" to the pkthdr structure. Packet tags are 556 * dynamically allocated semi-opaque data structures that have 557 * a fixed header (struct m_tag) that specifies the size of the 558 * memory block and a <cookie,type> pair that identifies it. 559 * The cookie is a 32-bit unique unsigned value used to identify 560 * a module or ABI. By convention this value is chose as the 561 * date+time that the module is created, expressed as the number of 562 * seconds since the epoch (e.g. using date -u +'%s'). The type value 563 * is an ABI/module-specific value that identifies a particular annotation 564 * and is private to the module. For compatibility with systems 565 * like openbsd that define packet tags w/o an ABI/module cookie, 566 * the value PACKET_ABI_COMPAT is used to implement m_tag_get and 567 * m_tag_find compatibility shim functions and several tag types are 568 * defined below. Users that do not require compatibility should use 569 * a private cookie value so that packet tag-related definitions 570 * can be maintained privately. 571 * 572 * Note that the packet tag returned by m_tag_alloc has the default 573 * memory alignment implemented by kmalloc. To reference private data 574 * one can use a construct like: 575 * 576 * struct m_tag *mtag = m_tag_alloc(...); 577 * struct foo *p = m_tag_data(mtag); 578 * 579 * if the alignment of struct m_tag is sufficient for referencing members 580 * of struct foo. Otherwise it is necessary to embed struct m_tag within 581 * the private data structure to insure proper alignment; e.g. 582 * 583 * struct foo { 584 * struct m_tag tag; 585 * ... 586 * }; 587 * struct foo *p = (struct foo *)m_tag_alloc(...); 588 * struct m_tag *mtag = &p->tag; 589 */ 590 591 #define PACKET_TAG_NONE 0 /* Nadda */ 592 593 /* Packet tag for use with PACKET_ABI_COMPAT */ 594 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */ 595 /* struct tdb_indent */ 596 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */ 597 /* struct tdb_indent */ 598 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */ 599 /* struct tdb_indent, never added */ 600 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */ 601 /* struct tdb_indent, never added */ 602 #define PACKET_TAG_IPSEC_PENDING_TDB 5 /* Reminder to do IPsec */ 603 /* struct tdb_indent, never added */ 604 #define PACKET_TAG_ENCAP 6 /* Encap. processing */ 605 /* struct ifnet *, the GIF interface */ 606 #define PACKET_TAG_IPSEC_HISTORY 7 /* IPSEC history */ 607 /* struct ipsec_history */ 608 #define PACKET_TAG_IPV6_INPUT 8 /* IPV6 input processing */ 609 /* struct ip6aux */ 610 #define PACKET_TAG_IPFW_DIVERT 9 /* divert info */ 611 /* struct divert_info */ 612 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */ 613 /* struct dn_pkt */ 614 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */ 615 /* struct sockaddr_in */ 616 #define PACKET_TAG_IPSRCRT 27 /* IP srcrt opts */ 617 /* struct ip_srcrt_opt */ 618 #define PACKET_TAG_CARP 28 /* CARP info */ 619 /* struct pf_mtag */ 620 #define PACKET_TAG_PF 29 /* PF info */ 621 622 /* Packet tag routines */ 623 struct m_tag *m_tag_alloc(u_int32_t, int, int, int); 624 void m_tag_free(struct m_tag *); 625 void m_tag_prepend(struct mbuf *, struct m_tag *); 626 void m_tag_unlink(struct mbuf *, struct m_tag *); 627 void m_tag_delete(struct mbuf *, struct m_tag *); 628 void m_tag_delete_chain(struct mbuf *); 629 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *); 630 struct m_tag *m_tag_copy(struct m_tag *, int); 631 int m_tag_copy_chain(struct mbuf *, const struct mbuf *, int); 632 void m_tag_init(struct mbuf *); 633 struct m_tag *m_tag_first(struct mbuf *); 634 struct m_tag *m_tag_next(struct mbuf *, struct m_tag *); 635 636 /* these are for openbsd compatibility */ 637 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */ 638 639 static __inline void * 640 m_tag_data(struct m_tag *tag) 641 { 642 return ((void *)(tag + 1)); 643 } 644 645 static __inline struct m_tag * 646 m_tag_get(int type, int length, int wait) 647 { 648 return m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait); 649 } 650 651 static __inline struct m_tag * 652 m_tag_find(struct mbuf *m, int type, struct m_tag *start) 653 { 654 return m_tag_locate(m, MTAG_ABI_COMPAT, type, start); 655 } 656 657 #endif /* _KERNEL */ 658 659 #endif /* _KERNEL || _KERNEL_STRUCTURES */ 660 #endif /* !_SYS_MBUF_H_ */ 661