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 1.49 2008/08/05 15:11:32 nant 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 pf_tag; /* 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 pad; /* explicit padding */ 136 }; 137 138 /* 139 * Description of external storage mapped into mbuf; valid only if M_EXT is set. 140 */ 141 struct m_ext { 142 caddr_t ext_buf; /* start of buffer */ 143 void (*ext_free)(void *); 144 u_int ext_size; /* size of buffer, for ext_free */ 145 void (*ext_ref)(void *); 146 void *ext_arg; 147 }; 148 149 /* 150 * The core of the mbuf object along with some shortcut defines for 151 * practical purposes. 152 */ 153 struct mbuf { 154 struct m_hdr m_hdr; 155 union { 156 struct { 157 struct pkthdr MH_pkthdr; /* M_PKTHDR set */ 158 union { 159 struct m_ext MH_ext; /* M_EXT set */ 160 char MH_databuf[MHLEN]; 161 } MH_dat; 162 } MH; 163 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ 164 } M_dat; 165 }; 166 #define m_next m_hdr.mh_next 167 #define m_len m_hdr.mh_len 168 #define m_data m_hdr.mh_data 169 #define m_type m_hdr.mh_type 170 #define m_flags m_hdr.mh_flags 171 #define m_nextpkt m_hdr.mh_nextpkt 172 #define m_pkthdr M_dat.MH.MH_pkthdr 173 #define m_ext M_dat.MH.MH_dat.MH_ext 174 #define m_pktdat M_dat.MH.MH_dat.MH_databuf 175 #define m_dat M_dat.M_databuf 176 177 /* 178 * Code that uses m_act should be converted to use m_nextpkt 179 * instead; m_act is historical and deprecated. 180 */ 181 #define m_act m_nextpkt 182 183 /* 184 * mbuf flags. 185 */ 186 #define M_EXT 0x0001 /* has associated external storage */ 187 #define M_PKTHDR 0x0002 /* start of record */ 188 #define M_EOR 0x0004 /* end of record */ 189 #define M_PROTO1 0x0008 /* protocol-specific */ 190 #define M_PROTO2 0x0010 /* protocol-specific */ 191 #define M_PROTO3 0x0020 /* protocol-specific */ 192 #define M_PROTO4 0x0040 /* protocol-specific */ 193 #define M_PROTO5 0x0080 /* protocol-specific */ 194 195 /* 196 * mbuf pkthdr flags (also stored in m_flags). 197 */ 198 #define M_BCAST 0x0100 /* send/received as link-level broadcast */ 199 #define M_MCAST 0x0200 /* send/received as link-level multicast */ 200 #define M_FRAG 0x0400 /* packet is a fragment of a larger packet */ 201 #define M_FIRSTFRAG 0x0800 /* packet is first fragment */ 202 #define M_LASTFRAG 0x1000 /* packet is last fragment */ 203 #define M_CLCACHE 0x2000 /* mbuf allocated from the cluster cache */ 204 #define M_EXT_CLUSTER 0x4000 /* standard cluster else special */ 205 #define M_PHCACHE 0x8000 /* mbuf allocated from the pkt header cache */ 206 #define M_NOTIFICATION 0x10000 /* notification event */ 207 #define M_VLANTAG 0x20000 /* ether_vlantag is valid */ 208 #define M_MPLSLABELED 0x40000 /* packet is mpls labeled */ 209 210 /* 211 * Flags copied when copying m_pkthdr. 212 */ 213 #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_PROTO1|M_PROTO1|M_PROTO2|M_PROTO3 | \ 214 M_PROTO4|M_PROTO5|M_BCAST|M_MCAST|M_FRAG | \ 215 M_FIRSTFRAG|M_LASTFRAG|M_VLANTAG|M_MPLSLABELED) 216 217 /* 218 * Flags indicating hw checksum support and sw checksum requirements. 219 */ 220 #define CSUM_IP 0x0001 /* will csum IP */ 221 #define CSUM_TCP 0x0002 /* will csum TCP */ 222 #define CSUM_UDP 0x0004 /* will csum UDP */ 223 #define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */ 224 #define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */ 225 226 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */ 227 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */ 228 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */ 229 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */ 230 #define CSUM_FRAG_NOT_CHECKED 0x1000 /* did _not_ csum fragment 231 * NB: This flag is only used 232 * by IP defragmenter. 233 */ 234 235 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP) 236 #define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */ 237 238 /* 239 * Flags indicating PF processing status 240 */ 241 #define FW_MBUF_GENERATED 0x00000001 242 #define PF_MBUF_TAGGED 0x00000002 /* pf_tag field is valid */ 243 #define PF_MBUF_ROUTED 0x00000004 /* pf_routed field is valid */ 244 #define PF_MBUF_TRANSLATE_LOCALHOST \ 245 0x00000008 246 #define PF_MBUF_FRAGCACHE 0x00000010 247 #define ALTQ_MBUF_TAGGED 0x00000020 /* altq_qid is valid */ 248 #define PF_MBUF_GENERATED FW_MBUF_GENERATED 249 #define IPFW_MBUF_GENERATED FW_MBUF_GENERATED 250 #define DUMMYNET_MBUF_TAGGED 0x00000080 251 #define ALTQ_MBUF_STATE_HASHED 0x00000100 252 253 /* 254 * mbuf types. 255 */ 256 #define MT_FREE 0 /* should be on free list */ 257 #define MT_DATA 1 /* dynamic (data) allocation */ 258 #define MT_HEADER 2 /* packet header */ 259 #define MT_SONAME 3 /* socket name */ 260 #define MT_TAG 4 /* volatile metadata associated to pkts */ 261 #define MT_CONTROL 5 /* extra-data protocol message */ 262 #define MT_OOBDATA 6 /* expedited data */ 263 #define MT_NTYPES 7 /* number of mbuf types for mbtypes[] */ 264 265 struct mbuf_chain { 266 struct mbuf *mc_head; 267 struct mbuf *mc_tail; 268 }; 269 270 /* 271 * General mbuf allocator statistics structure. 272 */ 273 struct mbstat { 274 u_long m_mbufs; /* mbufs obtained from page pool */ 275 u_long m_clusters; /* clusters obtained from page pool */ 276 u_long m_spare; /* spare field */ 277 u_long m_clfree; /* free clusters */ 278 u_long m_drops; /* times failed to find space */ 279 u_long m_wait; /* times waited for space */ 280 u_long m_drain; /* times drained protocols for space */ 281 u_long m_mcfail; /* times m_copym failed */ 282 u_long m_mpfail; /* times m_pullup failed */ 283 u_long m_msize; /* length of an mbuf */ 284 u_long m_mclbytes; /* length of an mbuf cluster */ 285 u_long m_minclsize; /* min length of data to allocate a cluster */ 286 u_long m_mlen; /* length of data in an mbuf */ 287 u_long m_mhlen; /* length of data in a header mbuf */ 288 }; 289 290 /* 291 * Flags specifying how an allocation should be made. 292 */ 293 294 #define MB_DONTWAIT 0x4 295 #define MB_TRYWAIT 0x8 296 #define MB_WAIT MB_TRYWAIT 297 298 /* 299 * Mbuf to Malloc Flag Conversion. 300 */ 301 #define MBTOM(how) ((how) & MB_TRYWAIT ? M_WAITOK : M_NOWAIT) 302 303 /* 304 * These are identifying numbers passed to the m_mballoc_wait function, 305 * allowing us to determine whether the call came from an MGETHDR or 306 * an MGET. 307 */ 308 #define MGETHDR_C 1 309 #define MGET_C 2 310 311 /* 312 * mbuf allocation/deallocation macros (YYY deprecated, too big): 313 * 314 * MGET(struct mbuf *m, int how, int type) 315 * allocates an mbuf and initializes it to contain internal data. 316 * 317 * MGETHDR(struct mbuf *m, int how, int type) 318 * allocates an mbuf and initializes it to contain a packet header 319 * and internal data. 320 */ 321 #define MGET(m, how, type) do { \ 322 (m) = m_get((how), (type)); \ 323 } while (0) 324 325 #define MGETHDR(m, how, type) do { \ 326 (m) = m_gethdr((how), (type)); \ 327 } while (0) 328 329 /* 330 * MCLGET adds such clusters to a normal mbuf. The flag M_EXT is set upon 331 * success. 332 * Deprecated. Use m_getcl() or m_getl() instead. 333 */ 334 #define MCLGET(m, how) do { \ 335 m_mclget((m), (how)); \ 336 } while (0) 337 338 /* 339 * NB: M_COPY_PKTHDR is deprecated; use either M_MOVE_PKTHDR 340 * or m_dup_pkthdr. 341 */ 342 /* 343 * Move mbuf pkthdr from "from" to "to". 344 * from should have M_PKTHDR set, and to must be empty. 345 * from no longer has a pkthdr after this operation. 346 */ 347 #define M_MOVE_PKTHDR(_to, _from) m_move_pkthdr((_to), (_from)) 348 349 /* 350 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place 351 * an object of the specified size at the end of the mbuf, longword aligned. 352 */ 353 #define M_ALIGN(m, len) do { \ 354 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \ 355 } while (0) 356 357 /* 358 * As above, for mbufs allocated with m_gethdr/MGETHDR 359 * or initialized by M_COPY_PKTHDR. 360 */ 361 #define MH_ALIGN(m, len) do { \ 362 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \ 363 } while (0) 364 365 /* 366 * Check if we can write to an mbuf. 367 */ 368 #define M_EXT_WRITABLE(m) (m_sharecount(m) == 1) 369 #define M_WRITABLE(m) (!((m)->m_flags & M_EXT) || M_EXT_WRITABLE(m)) 370 371 /* 372 * Check if the supplied mbuf has a packet header, or else panic. 373 */ 374 #define M_ASSERTPKTHDR(m) \ 375 KASSERT(m != NULL && m->m_flags & M_PKTHDR, \ 376 ("%s: invalid mbuf or no mbuf packet header!", __func__)) 377 378 /* 379 * Compute the amount of space available before the current start of data. 380 * The M_EXT_WRITABLE() is a temporary, conservative safety measure: the burden 381 * of checking writability of the mbuf data area rests solely with the caller. 382 */ 383 #define M_LEADINGSPACE(m) \ 384 ((m)->m_flags & M_EXT ? \ 385 (M_EXT_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \ 386 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 387 (m)->m_data - (m)->m_dat) 388 389 /* 390 * Compute the amount of space available after the end of data in an mbuf. 391 * The M_WRITABLE() is a temporary, conservative safety measure: the burden 392 * of checking writability of the mbuf data area rests solely with the caller. 393 */ 394 #define M_TRAILINGSPACE(m) \ 395 ((m)->m_flags & M_EXT ? \ 396 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \ 397 - ((m)->m_data + (m)->m_len) : 0) : \ 398 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 399 400 /* 401 * Arrange to prepend space of size plen to mbuf m. 402 * If a new mbuf must be allocated, how specifies whether to wait. 403 * If how is MB_DONTWAIT and allocation fails, the original mbuf chain 404 * is freed and m is set to NULL. 405 */ 406 #define M_PREPEND(m, plen, how) do { \ 407 struct mbuf **_mmp = &(m); \ 408 struct mbuf *_mm = *_mmp; \ 409 int _mplen = (plen); \ 410 int __mhow = (how); \ 411 \ 412 if (M_LEADINGSPACE(_mm) >= _mplen) { \ 413 _mm->m_data -= _mplen; \ 414 _mm->m_len += _mplen; \ 415 } else \ 416 _mm = m_prepend(_mm, _mplen, __mhow); \ 417 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \ 418 _mm->m_pkthdr.len += _mplen; \ 419 *_mmp = _mm; \ 420 } while (0) 421 422 /* Length to m_copy to copy all. */ 423 #define M_COPYALL 1000000000 424 425 /* Compatibility with 4.3 */ 426 #define m_copy(m, o, l) m_copym((m), (o), (l), MB_DONTWAIT) 427 428 #ifdef _KERNEL 429 extern u_int m_clalloc_wid; /* mbuf cluster wait count */ 430 extern u_int m_mballoc_wid; /* mbuf wait count */ 431 extern int max_linkhdr; /* largest link-level header */ 432 extern int max_protohdr; /* largest protocol header */ 433 extern int max_hdr; /* largest link+protocol header */ 434 extern int max_datalen; /* MHLEN - max_hdr */ 435 extern int mbuf_wait; /* mbuf sleep time */ 436 extern int nmbclusters; 437 extern int nmbufs; 438 439 struct uio; 440 441 void m_adj(struct mbuf *, int); 442 void m_cat(struct mbuf *, struct mbuf *); 443 u_int m_countm(struct mbuf *m, struct mbuf **lastm, u_int *mbcnt); 444 void m_copyback(struct mbuf *, int, int, caddr_t); 445 void m_copydata(const struct mbuf *, int, int, caddr_t); 446 struct mbuf *m_copym(const struct mbuf *, int, int, int); 447 struct mbuf *m_copypacket(struct mbuf *, int); 448 struct mbuf *m_defrag(struct mbuf *, int); 449 struct mbuf *m_defrag_nofree(struct mbuf *, int); 450 struct mbuf *m_devget(char *, int, int, struct ifnet *, 451 void (*copy)(volatile const void *, volatile void *, size_t)); 452 struct mbuf *m_dup(struct mbuf *, int); 453 int m_dup_pkthdr(struct mbuf *, const struct mbuf *, int); 454 struct mbuf *m_free(struct mbuf *); 455 void m_freem(struct mbuf *); 456 struct mbuf *m_get(int, int); 457 struct mbuf *m_getc(int len, int how, int type); 458 struct mbuf *m_getcl(int how, short type, int flags); 459 struct mbuf *m_getclr(int, int); 460 struct mbuf *m_gethdr(int, int); 461 struct mbuf *m_getm(struct mbuf *, int, int, int); 462 struct mbuf *m_last(struct mbuf *m); 463 u_int m_lengthm(struct mbuf *m, struct mbuf **lastm); 464 void m_move_pkthdr(struct mbuf *, struct mbuf *); 465 struct mbuf *m_prepend(struct mbuf *, int, int); 466 void m_print(const struct mbuf *m); 467 struct mbuf *m_pulldown(struct mbuf *, int, int, int *); 468 struct mbuf *m_pullup(struct mbuf *, int); 469 struct mbuf *m_split(struct mbuf *, int, int); 470 struct mbuf *m_uiomove(struct uio *); 471 void m_mclget(struct mbuf *m, int how); 472 int m_sharecount(struct mbuf *m); 473 void m_chtype(struct mbuf *m, int type); 474 475 #ifdef MBUF_DEBUG 476 void mbuftrackid(struct mbuf *, int); 477 #else 478 #define mbuftrackid(m, id) /* empty */ 479 #endif 480 481 /* 482 * Allocate the right type of mbuf for the desired total length. 483 * The mbuf returned does not necessarily cover the entire requested length. 484 * This function follows mbuf chaining policy of allowing MINCLSIZE 485 * amount of chained mbufs. 486 */ 487 static __inline struct mbuf * 488 m_getl(int len, int how, int type, int flags, int *psize) 489 { 490 struct mbuf *m; 491 int size; 492 493 if (len >= MINCLSIZE) { 494 m = m_getcl(how, type, flags); 495 size = MCLBYTES; 496 } else if (flags & M_PKTHDR) { 497 m = m_gethdr(how, type); 498 size = MHLEN; 499 } else { 500 m = m_get(how, type); 501 size = MLEN; 502 } 503 if (psize != NULL) 504 *psize = size; 505 return (m); 506 } 507 508 /* 509 * Get a single mbuf that covers the requested number of bytes. 510 * This function does not create mbuf chains. It explicitly marks 511 * places in the code that abuse mbufs for contiguous data buffers. 512 */ 513 static __inline struct mbuf * 514 m_getb(int len, int how, int type, int flags) 515 { 516 struct mbuf *m; 517 int mbufsize = (flags & M_PKTHDR) ? MHLEN : MLEN; 518 519 if (len > mbufsize) 520 m = m_getcl(how, type, flags); 521 else if (flags & M_PKTHDR) 522 m = m_gethdr(how, type); 523 else 524 m = m_get(how, type); 525 return (m); 526 } 527 528 /* 529 * Packets may have annotations attached by affixing a list 530 * of "packet tags" to the pkthdr structure. Packet tags are 531 * dynamically allocated semi-opaque data structures that have 532 * a fixed header (struct m_tag) that specifies the size of the 533 * memory block and a <cookie,type> pair that identifies it. 534 * The cookie is a 32-bit unique unsigned value used to identify 535 * a module or ABI. By convention this value is chose as the 536 * date+time that the module is created, expressed as the number of 537 * seconds since the epoch (e.g. using date -u +'%s'). The type value 538 * is an ABI/module-specific value that identifies a particular annotation 539 * and is private to the module. For compatibility with systems 540 * like openbsd that define packet tags w/o an ABI/module cookie, 541 * the value PACKET_ABI_COMPAT is used to implement m_tag_get and 542 * m_tag_find compatibility shim functions and several tag types are 543 * defined below. Users that do not require compatibility should use 544 * a private cookie value so that packet tag-related definitions 545 * can be maintained privately. 546 * 547 * Note that the packet tag returned by m_tag_alloc has the default 548 * memory alignment implemented by kmalloc. To reference private data 549 * one can use a construct like: 550 * 551 * struct m_tag *mtag = m_tag_alloc(...); 552 * struct foo *p = m_tag_data(mtag); 553 * 554 * if the alignment of struct m_tag is sufficient for referencing members 555 * of struct foo. Otherwise it is necessary to embed struct m_tag within 556 * the private data structure to insure proper alignment; e.g. 557 * 558 * struct foo { 559 * struct m_tag tag; 560 * ... 561 * }; 562 * struct foo *p = (struct foo *)m_tag_alloc(...); 563 * struct m_tag *mtag = &p->tag; 564 */ 565 566 #define PACKET_TAG_NONE 0 /* Nadda */ 567 568 /* Packet tag for use with PACKET_ABI_COMPAT */ 569 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */ 570 /* struct tdb_indent */ 571 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */ 572 /* struct tdb_indent */ 573 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */ 574 /* struct tdb_indent, never added */ 575 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */ 576 /* struct tdb_indent, never added */ 577 #define PACKET_TAG_IPSEC_PENDING_TDB 5 /* Reminder to do IPsec */ 578 /* struct tdb_indent, never added */ 579 #define PACKET_TAG_ENCAP 6 /* Encap. processing */ 580 /* struct ifnet *, the GIF interface */ 581 #define PACKET_TAG_IPSEC_HISTORY 7 /* IPSEC history */ 582 /* struct ipsec_history */ 583 #define PACKET_TAG_IPV6_INPUT 8 /* IPV6 input processing */ 584 /* struct ip6aux */ 585 #define PACKET_TAG_IPFW_DIVERT 9 /* divert info */ 586 /* uint16_t */ 587 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */ 588 /* struct dn_pkt */ 589 #define PACKET_TAG_CARP 28 /* CARP info */ 590 591 /* 592 * As a temporary and low impact solution to replace the even uglier 593 * approach used so far in some parts of the network stack (which relies 594 * on global variables), packet tag-like annotations are stored in MT_TAG 595 * mbufs (or lookalikes) prepended to the actual mbuf chain. 596 * 597 * m_type = MT_TAG 598 * m_flags = m_tag_id 599 * m_next = next buffer in chain. 600 * 601 * BE VERY CAREFUL not to pass these blocks to the mbuf handling routines. 602 */ 603 #define _m_tag_id m_hdr.mh_flags 604 605 /* Packet tags used in the FreeBSD network stack */ 606 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */ 607 /* struct sockaddr_in * as m_data */ 608 609 /* Packet tag routines */ 610 struct m_tag *m_tag_alloc(u_int32_t, int, int, int); 611 void m_tag_free(struct m_tag *); 612 void m_tag_prepend(struct mbuf *, struct m_tag *); 613 void m_tag_unlink(struct mbuf *, struct m_tag *); 614 void m_tag_delete(struct mbuf *, struct m_tag *); 615 void m_tag_delete_chain(struct mbuf *); 616 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *); 617 struct m_tag *m_tag_copy(struct m_tag *, int); 618 int m_tag_copy_chain(struct mbuf *, const struct mbuf *, int); 619 void m_tag_init(struct mbuf *); 620 struct m_tag *m_tag_first(struct mbuf *); 621 struct m_tag *m_tag_next(struct mbuf *, struct m_tag *); 622 623 /* these are for openbsd compatibility */ 624 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */ 625 626 static __inline void * 627 m_tag_data(struct m_tag *tag) 628 { 629 return ((void *)(tag + 1)); 630 } 631 632 static __inline struct m_tag * 633 m_tag_get(int type, int length, int wait) 634 { 635 return m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait); 636 } 637 638 static __inline struct m_tag * 639 m_tag_find(struct mbuf *m, int type, struct m_tag *start) 640 { 641 return m_tag_locate(m, MTAG_ABI_COMPAT, type, start); 642 } 643 644 #endif /* _KERNEL */ 645 646 #endif /* _KERNEL || _KERNEL_STRUCTURES */ 647 #endif /* !_SYS_MBUF_H_ */ 648