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 * mtodoff(m, t, off) -- Convert mbuf pointer at the specified offset to data 74 * pointer of correct type. 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 #ifdef MBUF_DEBUG 91 const char *mh_lastfunc; 92 #endif 93 struct netmsg_packet mh_netmsg; /* hardware->proto stack msg */ 94 }; 95 96 /* pf stuff */ 97 struct pkthdr_pf { 98 void *hdr; /* saved hdr pos in mbuf, for ECN */ 99 void *statekey; /* pf stackside statekey */ 100 u_int rtableid; /* alternate routing table id */ 101 u_int32_t qid; /* queue id */ 102 u_int16_t tag; /* tag id */ 103 u_int8_t flags; 104 u_int8_t routed; 105 uint32_t state_hash; /* identifies 'connections' */ 106 uint8_t ecn_af; /* for altq_red */ 107 uint8_t unused01; 108 uint8_t unused02; 109 uint8_t unused03; 110 }; 111 112 /* pkthdr_pf.flags */ 113 #define PF_TAG_GENERATED 0x01 114 #define PF_TAG_FRAGCACHE 0x02 115 #define PF_TAG_TRANSLATE_LOCALHOST 0x04 116 #define PF_TAG_DIVERTED 0x08 117 #define PF_TAG_DIVERTED_PACKET 0x10 118 #define PF_TAG_REROUTE 0x20 119 120 121 /* 122 * Packet tag structure (see below for details). 123 */ 124 struct m_tag { 125 SLIST_ENTRY(m_tag) m_tag_link; /* List of packet tags */ 126 u_int16_t m_tag_id; /* Tag ID */ 127 u_int16_t m_tag_len; /* Length of data */ 128 u_int32_t m_tag_cookie; /* ABI/Module ID */ 129 }; 130 131 SLIST_HEAD(packet_tags, m_tag); 132 133 /* 134 * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set. 135 * 136 * Be careful: The fields have been carefully ordered to avoid hidden padding. 137 * Keep this in mind, when adding or removing fields! 138 */ 139 struct pkthdr { 140 struct ifnet *rcvif; /* rcv interface */ 141 int len; /* total packet length */ 142 struct packet_tags tags; /* list of packet tags */ 143 144 /* variables for ip and tcp reassembly */ 145 void *header; /* pointer to packet header */ 146 147 /* variables for hardware checksum */ 148 int csum_flags; /* flags regarding checksum */ 149 int csum_data; /* data field used by csum routines */ 150 151 /* firewall flags */ 152 uint32_t fw_flags; /* flags for PF */ 153 154 /* variables for PF processing */ 155 struct pkthdr_pf pf; /* structure for PF */ 156 157 uint16_t ether_vlantag; /* ethernet 802.1p+q vlan tag */ 158 uint16_t hash; /* packet hash */ 159 160 uint16_t wlan_seqno; /* IEEE 802.11 seq no. */ 161 }; 162 163 /* 164 * Description of external storage mapped into mbuf; valid only if M_EXT is set. 165 */ 166 struct m_ext { 167 caddr_t ext_buf; /* start of buffer */ 168 void (*ext_free)(void *); 169 u_int ext_size; /* size of buffer, for ext_free */ 170 void (*ext_ref)(void *); 171 void *ext_arg; 172 }; 173 174 /* 175 * The core of the mbuf object along with some shortcut defines for 176 * practical purposes. 177 */ 178 struct mbuf { 179 struct m_hdr m_hdr; 180 union { 181 struct { 182 struct pkthdr MH_pkthdr; /* M_PKTHDR set */ 183 union { 184 struct m_ext MH_ext; /* M_EXT set */ 185 char MH_databuf[MHLEN]; 186 } MH_dat; 187 } MH; 188 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ 189 } M_dat; 190 }; 191 #define m_next m_hdr.mh_next 192 #define m_len m_hdr.mh_len 193 #define m_data m_hdr.mh_data 194 #define m_type m_hdr.mh_type 195 #define m_flags m_hdr.mh_flags 196 #define m_nextpkt m_hdr.mh_nextpkt 197 #define m_pkthdr M_dat.MH.MH_pkthdr 198 #define m_ext M_dat.MH.MH_dat.MH_ext 199 #define m_pktdat M_dat.MH.MH_dat.MH_databuf 200 #define m_dat M_dat.M_databuf 201 202 /* 203 * Code that uses m_act should be converted to use m_nextpkt 204 * instead; m_act is historical and deprecated. 205 */ 206 #define m_act m_nextpkt 207 208 /* 209 * mbuf flags. 210 */ 211 #define M_EXT 0x0001 /* has associated external storage */ 212 #define M_PKTHDR 0x0002 /* start of record */ 213 #define M_EOR 0x0004 /* end of record */ 214 #define M_PROTO1 0x0008 /* protocol-specific */ 215 #define M_PROTO2 0x0010 /* protocol-specific */ 216 #define M_PROTO3 0x0020 /* protocol-specific */ 217 #define M_PROTO4 0x0040 /* protocol-specific */ 218 #define M_PROTO5 0x0080 /* protocol-specific */ 219 220 /* 221 * mbuf pkthdr flags (also stored in m_flags). 222 */ 223 #define M_BCAST 0x0100 /* send/received as link-level broadcast */ 224 #define M_MCAST 0x0200 /* send/received as link-level multicast */ 225 #define M_FRAG 0x0400 /* packet is a fragment of a larger packet */ 226 #define M_FIRSTFRAG 0x0800 /* packet is first fragment */ 227 #define M_LASTFRAG 0x1000 /* packet is last fragment */ 228 #define M_CLCACHE 0x2000 /* mbuf allocated from the cluster cache */ 229 #define M_EXT_CLUSTER 0x4000 /* standard cluster else special */ 230 #define M_PHCACHE 0x8000 /* mbuf allocated from the pkt header cache */ 231 #define M_NOTIFICATION 0x10000 /* notification event */ 232 #define M_VLANTAG 0x20000 /* ether_vlantag is valid */ 233 #define M_MPLSLABELED 0x40000 /* packet is mpls labeled */ 234 #define M_LENCHECKED 0x80000 /* packet proto lengths are checked */ 235 #define M_HASH 0x100000/* hash field in pkthdr is valid */ 236 #define M_PROTO6 0x200000/* protocol-specific */ 237 #define M_PROTO7 0x400000/* protocol-specific */ 238 #define M_PROTO8 0x800000/* protocol-specific */ 239 240 /* 241 * Flags copied when copying m_pkthdr. 242 */ 243 #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_PROTO1|M_PROTO2|M_PROTO3 | \ 244 M_PROTO4|M_PROTO5|M_PROTO6|M_PROTO7|M_PROTO8 | \ 245 M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG | \ 246 M_VLANTAG|M_MPLSLABELED | \ 247 M_LENCHECKED|M_HASH) 248 249 /* 250 * Flags indicating hw checksum support and sw checksum requirements. 251 */ 252 #define CSUM_IP 0x0001 /* will csum IP */ 253 #define CSUM_TCP 0x0002 /* will csum TCP */ 254 #define CSUM_UDP 0x0004 /* will csum UDP */ 255 #define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */ 256 #define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */ 257 258 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */ 259 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */ 260 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */ 261 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */ 262 #define CSUM_FRAG_NOT_CHECKED 0x1000 /* did _not_ csum fragment 263 * NB: This flag is only used 264 * by IP defragmenter. 265 */ 266 267 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP) 268 #define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */ 269 270 /* 271 * Flags indicating PF processing status 272 */ 273 #define FW_MBUF_GENERATED 0x00000001 274 #define PF_MBUF_STRUCTURE 0x00000002 /* m_pkthdr.pf valid */ 275 #define PF_MBUF_ROUTED 0x00000004 /* pf_routed field is valid */ 276 #define PF_MBUF_TAGGED 0x00000008 277 #define XX_MBUF_UNUSED10 0x00000010 278 #define XX_MBUF_UNUSED20 0x00000020 279 #define IPFORWARD_MBUF_TAGGED 0x00000040 280 #define DUMMYNET_MBUF_TAGGED 0x00000080 281 #define XX_MBUF_UNUSED100 0x00000100 282 #define FW_MBUF_REDISPATCH 0x00000200 283 #define IPFW_MBUF_GENERATED FW_MBUF_GENERATED 284 /* 285 * mbuf types. 286 */ 287 #define MT_FREE 0 /* should be on free list */ 288 #define MT_DATA 1 /* dynamic (data) allocation */ 289 #define MT_HEADER 2 /* packet header */ 290 #define MT_SONAME 3 /* socket name */ 291 /* 4 was MT_TAG */ 292 #define MT_CONTROL 5 /* extra-data protocol message */ 293 #define MT_OOBDATA 6 /* expedited data */ 294 #define MT_NTYPES 7 /* number of mbuf types for mbtypes[] */ 295 296 struct mbuf_chain { 297 struct mbuf *mc_head; 298 struct mbuf *mc_tail; 299 }; 300 301 /* 302 * General mbuf allocator statistics structure. 303 */ 304 struct mbstat { 305 u_long m_mbufs; /* mbufs obtained from page pool */ 306 u_long m_clusters; /* clusters obtained from page pool */ 307 u_long m_spare; /* spare field */ 308 u_long m_clfree; /* free clusters */ 309 u_long m_drops; /* times failed to find space */ 310 u_long m_wait; /* times waited for space */ 311 u_long m_drain; /* times drained protocols for space */ 312 u_long m_mcfail; /* times m_copym failed */ 313 u_long m_mpfail; /* times m_pullup failed */ 314 u_long m_msize; /* length of an mbuf */ 315 u_long m_mclbytes; /* length of an mbuf cluster */ 316 u_long m_minclsize; /* min length of data to allocate a cluster */ 317 u_long m_mlen; /* length of data in an mbuf */ 318 u_long m_mhlen; /* length of data in a header mbuf */ 319 }; 320 321 /* 322 * Flags specifying how an allocation should be made. 323 */ 324 325 #define MB_DONTWAIT 0x4 326 #define MB_TRYWAIT 0x8 327 #define MB_WAIT MB_TRYWAIT 328 329 /* 330 * Mbuf to Malloc Flag Conversion. 331 */ 332 #define MBTOM(how) ((how) & MB_TRYWAIT ? M_WAITOK : M_NOWAIT) 333 334 /* 335 * These are identifying numbers passed to the m_mballoc_wait function, 336 * allowing us to determine whether the call came from an MGETHDR or 337 * an MGET. 338 */ 339 #define MGETHDR_C 1 340 #define MGET_C 2 341 342 /* 343 * mbuf allocation/deallocation macros (YYY deprecated, too big): 344 * 345 * MGET(struct mbuf *m, int how, int type) 346 * allocates an mbuf and initializes it to contain internal data. 347 * 348 * MGETHDR(struct mbuf *m, int how, int type) 349 * allocates an mbuf and initializes it to contain a packet header 350 * and internal data. 351 */ 352 #define MGET(m, how, type) do { \ 353 (m) = m_get((how), (type)); \ 354 } while (0) 355 356 #define MGETHDR(m, how, type) do { \ 357 (m) = m_gethdr((how), (type)); \ 358 } while (0) 359 360 /* 361 * MCLGET adds such clusters to a normal mbuf. The flag M_EXT is set upon 362 * success. 363 * Deprecated. Use m_getcl() or m_getl() instead. 364 */ 365 #define MCLGET(m, how) do { \ 366 m_mclget((m), (how)); \ 367 } while (0) 368 369 /* 370 * NB: M_COPY_PKTHDR is deprecated; use either M_MOVE_PKTHDR 371 * or m_dup_pkthdr. 372 */ 373 /* 374 * Move mbuf pkthdr from "from" to "to". 375 * from should have M_PKTHDR set, and to must be empty. 376 * from no longer has a pkthdr after this operation. 377 */ 378 #define M_MOVE_PKTHDR(_to, _from) m_move_pkthdr((_to), (_from)) 379 380 /* 381 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place 382 * an object of the specified size at the end of the mbuf, longword aligned. 383 */ 384 #define M_ALIGN(m, len) do { \ 385 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \ 386 } while (0) 387 388 /* 389 * As above, for mbufs allocated with m_gethdr/MGETHDR 390 * or initialized by M_COPY_PKTHDR. 391 */ 392 #define MH_ALIGN(m, len) do { \ 393 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \ 394 } while (0) 395 396 /* 397 * Check if we can write to an mbuf. 398 */ 399 #define M_EXT_WRITABLE(m) (m_sharecount(m) == 1) 400 #define M_WRITABLE(m) (!((m)->m_flags & M_EXT) || M_EXT_WRITABLE(m)) 401 402 /* 403 * Check if the supplied mbuf has a packet header, or else panic. 404 */ 405 #define M_ASSERTPKTHDR(m) \ 406 KASSERT(m != NULL && m->m_flags & M_PKTHDR, \ 407 ("%s: invalid mbuf or no mbuf packet header!", __func__)) 408 409 /* 410 * Compute the amount of space available before the current start of data. 411 * The M_EXT_WRITABLE() is a temporary, conservative safety measure: the burden 412 * of checking writability of the mbuf data area rests solely with the caller. 413 */ 414 #define M_LEADINGSPACE(m) \ 415 ((m)->m_flags & M_EXT ? \ 416 (M_EXT_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \ 417 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 418 (m)->m_data - (m)->m_dat) 419 420 /* 421 * Compute the amount of space available after the end of data in an mbuf. 422 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 423 * of checking writability of the mbuf data area rests solely with the caller. 424 */ 425 #define M_TRAILINGSPACE(m) \ 426 ((m)->m_flags & M_EXT ? \ 427 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \ 428 - ((m)->m_data + (m)->m_len) : 0) : \ 429 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 430 431 /* 432 * Arrange to prepend space of size plen to mbuf m. 433 * If a new mbuf must be allocated, how specifies whether to wait. 434 * If how is MB_DONTWAIT and allocation fails, the original mbuf chain 435 * is freed and m is set to NULL. 436 */ 437 #define M_PREPEND(m, plen, how) do { \ 438 struct mbuf **_mmp = &(m); \ 439 struct mbuf *_mm = *_mmp; \ 440 int _mplen = (plen); \ 441 int __mhow = (how); \ 442 \ 443 if (M_LEADINGSPACE(_mm) >= _mplen) { \ 444 _mm->m_data -= _mplen; \ 445 _mm->m_len += _mplen; \ 446 } else \ 447 _mm = m_prepend(_mm, _mplen, __mhow); \ 448 if (_mm != NULL && (_mm->m_flags & M_PKTHDR)) \ 449 _mm->m_pkthdr.len += _mplen; \ 450 *_mmp = _mm; \ 451 } while (0) 452 453 /* Length to m_copy to copy all. */ 454 #define M_COPYALL 1000000000 455 456 /* Compatibility with 4.3 */ 457 #define m_copy(m, o, l) m_copym((m), (o), (l), MB_DONTWAIT) 458 459 #ifdef _KERNEL 460 extern u_int m_clalloc_wid; /* mbuf cluster wait count */ 461 extern u_int m_mballoc_wid; /* mbuf wait count */ 462 extern int max_linkhdr; /* largest link-level header */ 463 extern int max_protohdr; /* largest protocol header */ 464 extern int max_hdr; /* largest link+protocol header */ 465 extern int max_datalen; /* MHLEN - max_hdr */ 466 extern int mbuf_wait; /* mbuf sleep time */ 467 extern int nmbclusters; 468 extern int nmbufs; 469 470 struct uio; 471 472 void m_adj(struct mbuf *, int); 473 void m_align(struct mbuf *, int); 474 int m_apply(struct mbuf *, int, int, 475 int (*)(void *, void *, u_int), void *); 476 int m_append(struct mbuf *, int, c_caddr_t); 477 void m_cat(struct mbuf *, struct mbuf *); 478 u_int m_countm(struct mbuf *m, struct mbuf **lastm, u_int *mbcnt); 479 void m_copyback(struct mbuf *, int, int, caddr_t); 480 void m_copydata(const struct mbuf *, int, int, caddr_t); 481 struct mbuf *m_copym(const struct mbuf *, int, int, int); 482 struct mbuf *m_copypacket(struct mbuf *, int); 483 struct mbuf *m_defrag(struct mbuf *, int); 484 struct mbuf *m_defrag_nofree(struct mbuf *, int); 485 struct mbuf *m_devget(char *, int, int, struct ifnet *, 486 void (*copy)(volatile const void *, volatile void *, size_t)); 487 struct mbuf *m_dup(struct mbuf *, int); 488 struct mbuf *m_dup_data(struct mbuf *, int); 489 int m_dup_pkthdr(struct mbuf *, const struct mbuf *, int); 490 #ifdef MBUF_DEBUG 491 struct mbuf *_m_free(struct mbuf *, const char *name); 492 void _m_freem(struct mbuf *, const char *name); 493 #else 494 struct mbuf *m_free(struct mbuf *); 495 void m_freem(struct mbuf *); 496 #endif 497 struct mbuf *m_get(int, int); 498 struct mbuf *m_getc(int len, int how, int type); 499 struct mbuf *m_getcl(int how, short type, int flags); 500 struct mbuf *m_getclr(int, int); 501 struct mbuf *m_gethdr(int, int); 502 struct mbuf *m_getm(struct mbuf *, int, int, int); 503 struct mbuf *m_getptr(struct mbuf *, int, int *); 504 struct mbuf *m_last(struct mbuf *m); 505 u_int m_lengthm(struct mbuf *m, struct mbuf **lastm); 506 void m_move_pkthdr(struct mbuf *, struct mbuf *); 507 struct mbuf *m_prepend(struct mbuf *, int, int); 508 void m_print(const struct mbuf *m); 509 struct mbuf *m_pulldown(struct mbuf *, int, int, int *); 510 struct mbuf *m_pullup(struct mbuf *, int); 511 struct mbuf *m_split(struct mbuf *, int, int); 512 struct mbuf *m_uiomove(struct uio *); 513 void m_mclget(struct mbuf *m, int how); 514 int m_sharecount(struct mbuf *m); 515 void m_chtype(struct mbuf *m, int type); 516 int m_devpad(struct mbuf *m, int padto); 517 518 #ifdef MBUF_DEBUG 519 520 void mbuftrackid(struct mbuf *, int); 521 522 #define m_free(m) _m_free(m, __func__) 523 #define m_freem(m) _m_freem(m, __func__) 524 525 #else 526 527 #define mbuftrackid(m, id) /* empty */ 528 529 #endif 530 531 /* 532 * Allocate the right type of mbuf for the desired total length. 533 * The mbuf returned does not necessarily cover the entire requested length. 534 * This function follows mbuf chaining policy of allowing MINCLSIZE 535 * amount of chained mbufs. 536 */ 537 static __inline struct mbuf * 538 m_getl(int len, int how, int type, int flags, int *psize) 539 { 540 struct mbuf *m; 541 int size; 542 543 if (len >= MINCLSIZE) { 544 m = m_getcl(how, type, flags); 545 size = MCLBYTES; 546 } else if (flags & M_PKTHDR) { 547 m = m_gethdr(how, type); 548 size = MHLEN; 549 } else { 550 m = m_get(how, type); 551 size = MLEN; 552 } 553 if (psize != NULL) 554 *psize = size; 555 return (m); 556 } 557 558 /* 559 * Get a single mbuf that covers the requested number of bytes. 560 * This function does not create mbuf chains. It explicitly marks 561 * places in the code that abuse mbufs for contiguous data buffers. 562 */ 563 static __inline struct mbuf * 564 m_getb(int len, int how, int type, int flags) 565 { 566 struct mbuf *m; 567 int mbufsize = (flags & M_PKTHDR) ? MHLEN : MLEN; 568 569 if (len > mbufsize) 570 m = m_getcl(how, type, flags); 571 else if (flags & M_PKTHDR) 572 m = m_gethdr(how, type); 573 else 574 m = m_get(how, type); 575 return (m); 576 } 577 578 /* 579 * Packets may have annotations attached by affixing a list 580 * of "packet tags" to the pkthdr structure. Packet tags are 581 * dynamically allocated semi-opaque data structures that have 582 * a fixed header (struct m_tag) that specifies the size of the 583 * memory block and a <cookie,type> pair that identifies it. 584 * The cookie is a 32-bit unique unsigned value used to identify 585 * a module or ABI. By convention this value is chose as the 586 * date+time that the module is created, expressed as the number of 587 * seconds since the epoch (e.g. using date -u +'%s'). The type value 588 * is an ABI/module-specific value that identifies a particular annotation 589 * and is private to the module. For compatibility with systems 590 * like openbsd that define packet tags w/o an ABI/module cookie, 591 * the value PACKET_ABI_COMPAT is used to implement m_tag_get and 592 * m_tag_find compatibility shim functions and several tag types are 593 * defined below. Users that do not require compatibility should use 594 * a private cookie value so that packet tag-related definitions 595 * can be maintained privately. 596 * 597 * Note that the packet tag returned by m_tag_alloc has the default 598 * memory alignment implemented by kmalloc. To reference private data 599 * one can use a construct like: 600 * 601 * struct m_tag *mtag = m_tag_alloc(...); 602 * struct foo *p = m_tag_data(mtag); 603 * 604 * if the alignment of struct m_tag is sufficient for referencing members 605 * of struct foo. Otherwise it is necessary to embed struct m_tag within 606 * the private data structure to insure proper alignment; e.g. 607 * 608 * struct foo { 609 * struct m_tag tag; 610 * ... 611 * }; 612 * struct foo *p = (struct foo *)m_tag_alloc(...); 613 * struct m_tag *mtag = &p->tag; 614 */ 615 616 #define PACKET_TAG_NONE 0 /* Nadda */ 617 618 /* Packet tag for use with PACKET_ABI_COMPAT */ 619 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */ 620 /* struct tdb_indent */ 621 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */ 622 /* struct tdb_indent */ 623 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */ 624 /* struct tdb_indent, never added */ 625 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */ 626 /* struct tdb_indent, never added */ 627 #define PACKET_TAG_IPSEC_PENDING_TDB 5 /* Reminder to do IPsec */ 628 /* struct tdb_indent, never added */ 629 #define PACKET_TAG_ENCAP 6 /* Encap. processing */ 630 /* struct ifnet *, the GIF interface */ 631 #define PACKET_TAG_IPSEC_HISTORY 7 /* IPSEC history */ 632 /* struct ipsec_history */ 633 #define PACKET_TAG_IPV6_INPUT 8 /* IPV6 input processing */ 634 /* struct ip6aux */ 635 #define PACKET_TAG_IPFW_DIVERT 9 /* divert info */ 636 /* struct divert_info */ 637 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */ 638 /* struct dn_pkt */ 639 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */ 640 /* struct sockaddr_in */ 641 #define PACKET_TAG_IPSRCRT 27 /* IP srcrt opts */ 642 /* struct ip_srcrt_opt */ 643 #define PACKET_TAG_CARP 28 /* CARP info */ 644 /* struct pf_mtag */ 645 #define PACKET_TAG_PF 29 /* PF info */ 646 647 #define PACKET_TAG_PF_DIVERT 0x0200 /* pf(4) diverted packet */ 648 649 650 /* Packet tag routines */ 651 struct m_tag *m_tag_alloc(u_int32_t, int, int, int); 652 void m_tag_free(struct m_tag *); 653 void m_tag_prepend(struct mbuf *, struct m_tag *); 654 void m_tag_unlink(struct mbuf *, struct m_tag *); 655 void m_tag_delete(struct mbuf *, struct m_tag *); 656 void m_tag_delete_chain(struct mbuf *); 657 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *); 658 struct m_tag *m_tag_copy(struct m_tag *, int); 659 int m_tag_copy_chain(struct mbuf *, const struct mbuf *, int); 660 void m_tag_init(struct mbuf *); 661 struct m_tag *m_tag_first(struct mbuf *); 662 struct m_tag *m_tag_next(struct mbuf *, struct m_tag *); 663 664 /* these are for openbsd compatibility */ 665 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */ 666 667 static __inline void * 668 m_tag_data(struct m_tag *tag) 669 { 670 return ((void *)(tag + 1)); 671 } 672 673 static __inline struct m_tag * 674 m_tag_get(int type, int length, int wait) 675 { 676 return m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait); 677 } 678 679 static __inline struct m_tag * 680 m_tag_find(struct mbuf *m, int type, struct m_tag *start) 681 { 682 return m_tag_locate(m, MTAG_ABI_COMPAT, type, start); 683 } 684 685 #endif /* _KERNEL */ 686 687 #endif /* _KERNEL || _KERNEL_STRUCTURES */ 688 #endif /* !_SYS_MBUF_H_ */ 689