mbuf.h revision 67146
1/* 2 * Copyright (c) 1982, 1986, 1988, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)mbuf.h 8.5 (Berkeley) 2/19/95 34 * $FreeBSD: head/sys/sys/mbuf.h 67146 2000-10-15 06:27:01Z bmilekic $ 35 */ 36 37#ifndef _SYS_MBUF_H_ 38#define _SYS_MBUF_H_ 39 40#include <machine/mutex.h> /* XXX */ 41 42/* 43 * Mbufs are of a single size, MSIZE (machine/param.h), which 44 * includes overhead. An mbuf may add a single "mbuf cluster" of size 45 * MCLBYTES (also in machine/param.h), which has no additional overhead 46 * and is used instead of the internal data area; this is done when 47 * at least MINCLSIZE of data must be stored. 48 */ 49 50#define MLEN (MSIZE - sizeof(struct m_hdr)) /* normal data len */ 51#define MHLEN (MLEN - sizeof(struct pkthdr)) /* data len w/pkthdr */ 52 53#define MINCLSIZE (MHLEN + 1) /* smallest amount to put in cluster */ 54#define M_MAXCOMPRESS (MHLEN / 2) /* max amount to copy for compression */ 55 56/* 57 * Maximum number of allocatable counters for external buffers. This 58 * ensures enough VM address space for the allocation of counters 59 * in the extreme case where all possible external buffers are allocated. 60 * 61 * Note: When new types of external storage are allocated, EXT_COUNTERS 62 * must be tuned accordingly. Practically, this isn't a big deal 63 * as each counter is only a word long, so we can fit 64 * (PAGE_SIZE / length of word) counters in a single page. 65 * 66 * XXX: Must increase this if using any of if_ti, if_wb, if_sk drivers, 67 * or any other drivers which may manage their own buffers and 68 * eventually attach them to mbufs. 69 */ 70#define EXT_COUNTERS (nmbclusters + nsfbufs) 71 72/* 73 * Macros for type conversion 74 * mtod(m, t) - convert mbuf pointer to data pointer of correct type 75 * dtom(x) - convert data pointer within mbuf to mbuf pointer (XXX) 76 */ 77#define mtod(m, t) ((t)((m)->m_data)) 78#define dtom(x) ((struct mbuf *)((intptr_t)(x) & ~(MSIZE-1))) 79 80/* header at beginning of each mbuf: */ 81struct 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 short mh_type; /* type of data in this mbuf */ 87 short mh_flags; /* flags; see below */ 88}; 89 90/* record/packet header in first mbuf of chain; valid if M_PKTHDR set */ 91struct pkthdr { 92 struct ifnet *rcvif; /* rcv interface */ 93 int len; /* total packet length */ 94 /* variables for ip and tcp reassembly */ 95 void *header; /* pointer to packet header */ 96 /* variables for hardware checksum */ 97 int csum_flags; /* flags regarding checksum */ 98 int csum_data; /* data field used by csum routines */ 99 struct mbuf *aux; /* extra data buffer; ipsec/others */ 100}; 101 102/* description of external storage mapped into mbuf, valid if M_EXT set */ 103struct m_ext { 104 caddr_t ext_buf; /* start of buffer */ 105 void (*ext_free) /* free routine if not the usual */ 106 __P((caddr_t, void *)); 107 void *ext_args; /* optional argument pointer */ 108 u_int ext_size; /* size of buffer, for ext_free */ 109 union mext_refcnt *ref_cnt; /* pointer to ref count info */ 110}; 111 112struct mbuf { 113 struct m_hdr m_hdr; 114 union { 115 struct { 116 struct pkthdr MH_pkthdr; /* M_PKTHDR set */ 117 union { 118 struct m_ext MH_ext; /* M_EXT set */ 119 char MH_databuf[MHLEN]; 120 } MH_dat; 121 } MH; 122 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ 123 } M_dat; 124}; 125#define m_next m_hdr.mh_next 126#define m_len m_hdr.mh_len 127#define m_data m_hdr.mh_data 128#define m_type m_hdr.mh_type 129#define m_flags m_hdr.mh_flags 130#define m_nextpkt m_hdr.mh_nextpkt 131#define m_act m_nextpkt 132#define m_pkthdr M_dat.MH.MH_pkthdr 133#define m_ext M_dat.MH.MH_dat.MH_ext 134#define m_pktdat M_dat.MH.MH_dat.MH_databuf 135#define m_dat M_dat.M_databuf 136 137/* mbuf flags */ 138#define M_EXT 0x0001 /* has associated external storage */ 139#define M_PKTHDR 0x0002 /* start of record */ 140#define M_EOR 0x0004 /* end of record */ 141#define M_PROTO1 0x0008 /* protocol-specific */ 142#define M_PROTO2 0x0010 /* protocol-specific */ 143#define M_PROTO3 0x0020 /* protocol-specific */ 144#define M_PROTO4 0x0040 /* protocol-specific */ 145#define M_PROTO5 0x0080 /* protocol-specific */ 146 147/* mbuf pkthdr flags, also in m_flags */ 148#define M_BCAST 0x0100 /* send/received as link-level broadcast */ 149#define M_MCAST 0x0200 /* send/received as link-level multicast */ 150#define M_FRAG 0x0400 /* packet is a fragment of a larger packet */ 151#define M_FIRSTFRAG 0x0800 /* packet is first fragment */ 152#define M_LASTFRAG 0x1000 /* packet is last fragment */ 153 154/* flags copied when copying m_pkthdr */ 155#define M_COPYFLAGS (M_PKTHDR|M_EOR|M_PROTO1|M_PROTO1|M_PROTO2|M_PROTO3 | \ 156 M_PROTO4|M_PROTO5|M_BCAST|M_MCAST|M_FRAG) 157 158/* flags indicating hw checksum support and sw checksum requirements */ 159#define CSUM_IP 0x0001 /* will csum IP */ 160#define CSUM_TCP 0x0002 /* will csum TCP */ 161#define CSUM_UDP 0x0004 /* will csum UDP */ 162#define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */ 163#define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */ 164 165#define CSUM_IP_CHECKED 0x0100 /* did csum IP */ 166#define CSUM_IP_VALID 0x0200 /* ... the csum is valid */ 167#define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */ 168#define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */ 169 170#define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP) 171#define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */ 172 173/* mbuf types */ 174#define MT_FREE 0 /* should be on free list */ 175#define MT_DATA 1 /* dynamic (data) allocation */ 176#define MT_HEADER 2 /* packet header */ 177#if 0 178#define MT_SOCKET 3 /* socket structure */ 179#define MT_PCB 4 /* protocol control block */ 180#define MT_RTABLE 5 /* routing tables */ 181#define MT_HTABLE 6 /* IMP host tables */ 182#define MT_ATABLE 7 /* address resolution tables */ 183#endif 184#define MT_SONAME 8 /* socket name */ 185#if 0 186#define MT_SOOPTS 10 /* socket options */ 187#endif 188#define MT_FTABLE 11 /* fragment reassembly header */ 189#if 0 190#define MT_RIGHTS 12 /* access rights */ 191#define MT_IFADDR 13 /* interface address */ 192#endif 193#define MT_CONTROL 14 /* extra-data protocol message */ 194#define MT_OOBDATA 15 /* expedited data */ 195 196#define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */ 197 198/* 199 * mbuf statistics 200 */ 201struct mbstat { 202 u_long m_mbufs; /* # mbufs obtained from page pool */ 203 u_long m_clusters; /* # clusters obtained from page pool */ 204 u_long m_clfree; /* # clusters on freelist (cache) */ 205 u_long m_refcnt; /* # ref counters obtained from page pool */ 206 u_long m_refree; /* # ref counters on freelist (cache) */ 207 u_long m_spare; /* spare field */ 208 u_long m_drops; /* times failed to find space */ 209 u_long m_wait; /* times waited for space */ 210 u_long m_drain; /* times drained protocols for space */ 211 u_long m_mcfail; /* times m_copym failed */ 212 u_long m_mpfail; /* times m_pullup failed */ 213 u_long m_msize; /* length of an mbuf */ 214 u_long m_mclbytes; /* length of an mbuf cluster */ 215 u_long m_minclsize; /* min length of data to allocate a cluster */ 216 u_long m_mlen; /* length of data in an mbuf */ 217 u_long m_mhlen; /* length of data in a header mbuf */ 218}; 219 220/* flags to m_get/MGET */ 221#define M_DONTWAIT 1 222#define M_WAIT 0 223 224/* 225 * Normal mbuf clusters are normally treated as character arrays 226 * after allocation, but use the first word of the buffer as a free list 227 * pointer while on the free list. 228 */ 229union mcluster { 230 union mcluster *mcl_next; 231 char mcl_buf[MCLBYTES]; 232}; 233 234/* 235 * The m_ext object reference counter structure. 236 */ 237union mext_refcnt { 238 union mext_refcnt *next_ref; 239 u_long refcnt; 240}; 241 242/* 243 * free list header definitions: mbffree_lst, mclfree_lst, mcntfree_lst 244 */ 245struct mbffree_lst { 246 struct mbuf *m_head; 247 struct mtx m_mtx; 248}; 249 250struct mclfree_lst { 251 union mcluster *m_head; 252 struct mtx m_mtx; 253}; 254 255struct mcntfree_lst { 256 union mext_refcnt *m_head; 257 struct mtx m_mtx; 258}; 259 260/* 261 * Wake up the next instance (if any) of a sleeping allocation - which is 262 * waiting for a {cluster, mbuf} to be freed. 263 * 264 * Must be called with the appropriate mutex held. 265 */ 266#define MBWAKEUP(m_wid) do { \ 267 if ((m_wid)) { \ 268 m_wid--; \ 269 wakeup_one(&(m_wid)); \ 270 } \ 271} while (0) 272 273/* 274 * mbuf external reference count management macros: 275 * 276 * MEXT_IS_REF(m): true if (m) is not the only mbuf referencing 277 * the external buffer ext_buf 278 * MEXT_REM_REF(m): remove reference to m_ext object 279 * MEXT_ADD_REF(m): add reference to m_ext object already 280 * referred to by (m) 281 * MEXT_INIT_REF(m): allocate and initialize an external 282 * object reference counter for (m) 283 */ 284#define MEXT_IS_REF(m) ((m)->m_ext.ref_cnt->refcnt > 1) 285 286#define MEXT_REM_REF(m) do { \ 287 KASSERT((m)->m_ext.ref_cnt->refcnt > 0, ("m_ext refcnt < 0")); \ 288 atomic_subtract_long(&((m)->m_ext.ref_cnt->refcnt), 1); \ 289} while(0) 290 291#define MEXT_ADD_REF(m) atomic_add_long(&((m)->m_ext.ref_cnt->refcnt), 1) 292 293#define _MEXT_ALLOC_CNT(m_cnt, how) do { \ 294 union mext_refcnt *__mcnt; \ 295 \ 296 mtx_enter(&mcntfree.m_mtx, MTX_DEF); \ 297 if (mcntfree.m_head == NULL) \ 298 m_alloc_ref(1, (how)); \ 299 __mcnt = mcntfree.m_head; \ 300 if (__mcnt != NULL) { \ 301 mcntfree.m_head = __mcnt->next_ref; \ 302 mbstat.m_refree--; \ 303 __mcnt->refcnt = 0; \ 304 } \ 305 mtx_exit(&mcntfree.m_mtx, MTX_DEF); \ 306 (m_cnt) = __mcnt; \ 307} while (0) 308 309#define _MEXT_DEALLOC_CNT(m_cnt) do { \ 310 union mext_refcnt *__mcnt = (m_cnt); \ 311 \ 312 mtx_enter(&mcntfree.m_mtx, MTX_DEF); \ 313 __mcnt->next_ref = mcntfree.m_head; \ 314 mcntfree.m_head = __mcnt; \ 315 mbstat.m_refree++; \ 316 mtx_exit(&mcntfree.m_mtx, MTX_DEF); \ 317} while (0) 318 319#define MEXT_INIT_REF(m, how) do { \ 320 struct mbuf *__mmm = (m); \ 321 \ 322 _MEXT_ALLOC_CNT(__mmm->m_ext.ref_cnt, (how)); \ 323 if (__mmm != NULL) \ 324 MEXT_ADD_REF(__mmm); \ 325} while (0) 326 327/* 328 * mbuf allocation/deallocation macros: 329 * 330 * MGET(struct mbuf *m, int how, int type) 331 * allocates an mbuf and initializes it to contain internal data. 332 * 333 * MGETHDR(struct mbuf *m, int how, int type) 334 * allocates an mbuf and initializes it to contain a packet header 335 * and internal data. 336 */ 337/* 338 * Lower-level macros for MGET(HDR)... Not to be used outside the 339 * subsystem ("non-exportable" macro names are prepended with "_"). 340 */ 341#define _MGET_SETUP(m_set, m_set_type) do { \ 342 (m_set)->m_type = (m_set_type); \ 343 (m_set)->m_next = NULL; \ 344 (m_set)->m_nextpkt = NULL; \ 345 (m_set)->m_data = (m_set)->m_dat; \ 346 (m_set)->m_flags = 0; \ 347} while (0) 348 349#define _MGET(m_mget, m_get_how) do { \ 350 if (mmbfree.m_head == NULL) \ 351 m_mballoc(1, (m_get_how)); \ 352 (m_mget) = mmbfree.m_head; \ 353 if ((m_mget) != NULL) { \ 354 mmbfree.m_head = (m_mget)->m_next; \ 355 mbtypes[MT_FREE]--; \ 356 } else { \ 357 if ((m_get_how) == M_WAIT) \ 358 (m_mget) = m_mballoc_wait(); \ 359 } \ 360} while (0) 361 362#define MGET(m, how, type) do { \ 363 struct mbuf *_mm; \ 364 int _mhow = (how); \ 365 int _mtype = (type); \ 366 \ 367 mtx_enter(&mmbfree.m_mtx, MTX_DEF); \ 368 _MGET(_mm, _mhow); \ 369 if (_mm != NULL) { \ 370 mbtypes[_mtype]++; \ 371 mtx_exit(&mmbfree.m_mtx, MTX_DEF); \ 372 _MGET_SETUP(_mm, _mtype); \ 373 } else \ 374 mtx_exit(&mmbfree.m_mtx, MTX_DEF); \ 375 (m) = _mm; \ 376} while (0) 377 378#define _MGETHDR_SETUP(m_set, m_set_type) do { \ 379 (m_set)->m_type = (m_set_type); \ 380 (m_set)->m_next = NULL; \ 381 (m_set)->m_nextpkt = NULL; \ 382 (m_set)->m_data = (m_set)->m_pktdat; \ 383 (m_set)->m_flags = M_PKTHDR; \ 384 (m_set)->m_pkthdr.rcvif = NULL; \ 385 (m_set)->m_pkthdr.csum_flags = 0; \ 386 (m_set)->m_pkthdr.aux = NULL; \ 387} while (0) 388 389#define MGETHDR(m, how, type) do { \ 390 struct mbuf *_mm; \ 391 int _mhow = (how); \ 392 int _mtype = (type); \ 393 \ 394 mtx_enter(&mmbfree.m_mtx, MTX_DEF); \ 395 _MGET(_mm, _mhow); \ 396 if (_mm != NULL) { \ 397 mbtypes[_mtype]++; \ 398 mtx_exit(&mmbfree.m_mtx, MTX_DEF); \ 399 _MGETHDR_SETUP(_mm, _mtype); \ 400 } else \ 401 mtx_exit(&mmbfree.m_mtx, MTX_DEF); \ 402 (m) = _mm; \ 403} while (0) 404 405/* 406 * mbuf external storage macros: 407 * 408 * MCLGET allocates and refers an mcluster to an mbuf 409 * MEXTADD sets up pre-allocated external storage and refers to mbuf 410 * MEXTFREE removes reference to external object and frees it if 411 * necessary 412 */ 413#define _MCLALLOC(p, how) do { \ 414 caddr_t _mp; \ 415 int _mhow = (how); \ 416 \ 417 if (mclfree.m_head == NULL) \ 418 m_clalloc(1, _mhow); \ 419 _mp = (caddr_t)mclfree.m_head; \ 420 if (_mp != NULL) { \ 421 mbstat.m_clfree--; \ 422 mclfree.m_head = ((union mcluster *)_mp)->mcl_next; \ 423 } else { \ 424 if (_mhow == M_WAIT) \ 425 _mp = m_clalloc_wait(); \ 426 } \ 427 (p) = _mp; \ 428} while (0) 429 430#define MCLGET(m, how) do { \ 431 struct mbuf *_mm = (m); \ 432 \ 433 mtx_enter(&mclfree.m_mtx, MTX_DEF); \ 434 _MCLALLOC(_mm->m_ext.ext_buf, (how)); \ 435 mtx_exit(&mclfree.m_mtx, MTX_DEF); \ 436 if (_mm->m_ext.ext_buf != NULL) { \ 437 MEXT_INIT_REF(_mm, (how)); \ 438 if (_mm->m_ext.ref_cnt == NULL) { \ 439 _MCLFREE(_mm->m_ext.ext_buf); \ 440 _mm->m_ext.ext_buf = NULL; \ 441 } else { \ 442 _mm->m_data = _mm->m_ext.ext_buf; \ 443 _mm->m_flags |= M_EXT; \ 444 _mm->m_ext.ext_free = NULL; \ 445 _mm->m_ext.ext_args = NULL; \ 446 _mm->m_ext.ext_size = MCLBYTES; \ 447 } \ 448 } \ 449} while (0) 450 451#define MEXTADD(m, buf, size, free, args) do { \ 452 struct mbuf *_mm = (m); \ 453 \ 454 MEXT_INIT_REF(_mm, M_WAIT); \ 455 if (_mm->m_ext.ref_cnt != NULL) { \ 456 _mm->m_flags |= M_EXT; \ 457 _mm->m_ext.ext_buf = (caddr_t)(buf); \ 458 _mm->m_data = _mm->m_ext.ext_buf; \ 459 _mm->m_ext.ext_size = (size); \ 460 _mm->m_ext.ext_free = (free); \ 461 _mm->m_ext.ext_args = (args); \ 462 } \ 463} while (0) 464 465#define _MCLFREE(p) do { \ 466 union mcluster *_mp = (union mcluster *)(p); \ 467 \ 468 mtx_enter(&mclfree.m_mtx, MTX_DEF); \ 469 _mp->mcl_next = mclfree.m_head; \ 470 mclfree.m_head = _mp; \ 471 mbstat.m_clfree++; \ 472 MBWAKEUP(m_clalloc_wid); \ 473 mtx_exit(&mclfree.m_mtx, MTX_DEF); \ 474} while (0) 475 476#define MEXTFREE(m) do { \ 477 struct mbuf *_mmm = (m); \ 478 \ 479 if (MEXT_IS_REF(_mmm)) \ 480 MEXT_REM_REF(_mmm); \ 481 else if (_mmm->m_ext.ext_free != NULL) { \ 482 (*(_mmm->m_ext.ext_free))(_mmm->m_ext.ext_buf, \ 483 _mmm->m_ext.ext_args); \ 484 _MEXT_DEALLOC_CNT(_mmm->m_ext.ref_cnt); \ 485 } else { \ 486 _MCLFREE(_mmm->m_ext.ext_buf); \ 487 _MEXT_DEALLOC_CNT(_mmm->m_ext.ref_cnt); \ 488 } \ 489 _mmm->m_flags &= ~M_EXT; \ 490} while (0) 491 492/* 493 * MFREE(struct mbuf *m, struct mbuf *n) 494 * Free a single mbuf and associated external storage. 495 * Place the successor, if any, in n. 496 */ 497#define MFREE(m, n) do { \ 498 struct mbuf *_mm = (m); \ 499 \ 500 KASSERT(_mm->m_type != MT_FREE, ("freeing free mbuf")); \ 501 if (_mm->m_flags & M_EXT) \ 502 MEXTFREE(_mm); \ 503 mtx_enter(&mmbfree.m_mtx, MTX_DEF); \ 504 mbtypes[_mm->m_type]--; \ 505 _mm->m_type = MT_FREE; \ 506 mbtypes[MT_FREE]++; \ 507 (n) = _mm->m_next; \ 508 _mm->m_next = mmbfree.m_head; \ 509 mmbfree.m_head = _mm; \ 510 MBWAKEUP(m_mballoc_wid); \ 511 mtx_exit(&mmbfree.m_mtx, MTX_DEF); \ 512} while (0) 513 514/* 515 * Copy mbuf pkthdr from "from" to "to". 516 * from must have M_PKTHDR set, and to must be empty. 517 * aux pointer will be moved to `to'. 518 */ 519#define M_COPY_PKTHDR(to, from) do { \ 520 struct mbuf *_mfrom = (from); \ 521 struct mbuf *_mto = (to); \ 522 \ 523 _mto->m_data = _mto->m_pktdat; \ 524 _mto->m_flags = _mfrom->m_flags & M_COPYFLAGS; \ 525 _mto->m_pkthdr = _mfrom->m_pkthdr; \ 526 _mfrom->m_pkthdr.aux = (struct mbuf *)NULL; \ 527} while (0) 528 529/* 530 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place 531 * an object of the specified size at the end of the mbuf, longword aligned. 532 */ 533#define M_ALIGN(m, len) do { \ 534 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \ 535} while (0) 536 537/* 538 * As above, for mbufs allocated with m_gethdr/MGETHDR 539 * or initialized by M_COPY_PKTHDR. 540 */ 541#define MH_ALIGN(m, len) do { \ 542 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \ 543} while (0) 544 545/* 546 * Compute the amount of space available 547 * before the current start of data in an mbuf. 548 */ 549#define M_LEADINGSPACE(m) \ 550 ((m)->m_flags & M_EXT ? \ 551 /* (m)->m_data - (m)->m_ext.ext_buf */ 0 : \ 552 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 553 (m)->m_data - (m)->m_dat) 554 555/* 556 * Compute the amount of space available 557 * after the end of data in an mbuf. 558 */ 559#define M_TRAILINGSPACE(m) \ 560 ((m)->m_flags & M_EXT ? (m)->m_ext.ext_buf + \ 561 (m)->m_ext.ext_size - ((m)->m_data + (m)->m_len) : \ 562 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 563 564/* 565 * Arrange to prepend space of size plen to mbuf m. 566 * If a new mbuf must be allocated, how specifies whether to wait. 567 * If how is M_DONTWAIT and allocation fails, the original mbuf chain 568 * is freed and m is set to NULL. 569 */ 570#define M_PREPEND(m, plen, how) do { \ 571 struct mbuf **_mmp = &(m); \ 572 struct mbuf *_mm = *_mmp; \ 573 int _mplen = (plen); \ 574 int __mhow = (how); \ 575 \ 576 if (M_LEADINGSPACE(_mm) >= _mplen) { \ 577 _mm->m_data -= _mplen; \ 578 _mm->m_len += _mplen; \ 579 } else \ 580 _mm = m_prepend(_mm, _mplen, __mhow); \ 581 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \ 582 _mm->m_pkthdr.len += _mplen; \ 583 *_mmp = _mm; \ 584} while (0) 585 586/* 587 * change mbuf to new type 588 */ 589#define MCHTYPE(m, t) do { \ 590 struct mbuf *_mm = (m); \ 591 int _mt = (t); \ 592 \ 593 atomic_subtract_long(&mbtypes[_mm->m_type], 1); \ 594 atomic_add_long(&mbtypes[_mt], 1); \ 595 _mm->m_type = (_mt); \ 596} while (0) 597 598/* length to m_copy to copy all */ 599#define M_COPYALL 1000000000 600 601/* compatibility with 4.3 */ 602#define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT) 603 604/* 605 * pkthdr.aux type tags. 606 */ 607struct mauxtag { 608 int af; 609 int type; 610}; 611 612#ifdef _KERNEL 613extern u_long m_clalloc_wid; /* mbuf cluster wait count */ 614extern u_long m_mballoc_wid; /* mbuf wait count */ 615extern int max_linkhdr; /* largest link-level header */ 616extern int max_protohdr; /* largest protocol header */ 617extern int max_hdr; /* largest link+protocol header */ 618extern int max_datalen; /* MHLEN - max_hdr */ 619extern struct mbstat mbstat; 620extern u_long mbtypes[MT_NTYPES]; /* per-type mbuf allocations */ 621extern int mbuf_wait; /* mbuf sleep time */ 622extern struct mbuf *mbutl; /* virtual address of mclusters */ 623extern struct mclfree_lst mclfree; 624extern struct mbffree_lst mmbfree; 625extern struct mcntfree_lst mcntfree; 626extern int nmbclusters; 627extern int nmbufs; 628extern int nsfbufs; 629 630void m_adj __P((struct mbuf *, int)); 631int m_alloc_ref __P((u_int, int)); 632void m_cat __P((struct mbuf *,struct mbuf *)); 633int m_clalloc __P((int, int)); 634caddr_t m_clalloc_wait __P((void)); 635void m_copyback __P((struct mbuf *, int, int, caddr_t)); 636void m_copydata __P((struct mbuf *,int,int,caddr_t)); 637struct mbuf *m_copym __P((struct mbuf *, int, int, int)); 638struct mbuf *m_copypacket __P((struct mbuf *, int)); 639struct mbuf *m_devget __P((char *, int, int, struct ifnet *, 640 void (*copy)(char *, caddr_t, u_int))); 641struct mbuf *m_dup __P((struct mbuf *, int)); 642struct mbuf *m_free __P((struct mbuf *)); 643void m_freem __P((struct mbuf *)); 644struct mbuf *m_get __P((int, int)); 645struct mbuf *m_getclr __P((int, int)); 646struct mbuf *m_gethdr __P((int, int)); 647int m_mballoc __P((int, int)); 648struct mbuf *m_mballoc_wait __P((void)); 649struct mbuf *m_prepend __P((struct mbuf *,int,int)); 650struct mbuf *m_pulldown __P((struct mbuf *, int, int, int *)); 651void m_print __P((const struct mbuf *m)); 652struct mbuf *m_pullup __P((struct mbuf *, int)); 653struct mbuf *m_split __P((struct mbuf *,int,int)); 654struct mbuf *m_aux_add __P((struct mbuf *, int, int)); 655struct mbuf *m_aux_find __P((struct mbuf *, int, int)); 656void m_aux_delete __P((struct mbuf *, struct mbuf *)); 657#endif /* _KERNEL */ 658 659#endif /* !_SYS_MBUF_H_ */ 660