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 * $FreeBSD$ 35 */ 36 37 #ifndef _SYS_MBUF_H_ 38 #define _SYS_MBUF_H_ 39 40 #ifdef _KERNEL 41 #include <sys/condvar.h> /* XXX */ 42 #include <sys/_lock.h> 43 #include <sys/_mutex.h> 44 #endif /* _KERNEL */ 45 46 /* 47 * Mbufs are of a single size, MSIZE (machine/param.h), which 48 * includes overhead. An mbuf may add a single "mbuf cluster" of size 49 * MCLBYTES (also in machine/param.h), which has no additional overhead 50 * and is used instead of the internal data area; this is done when 51 * at least MINCLSIZE of data must be stored. 52 */ 53 54 #define MLEN (MSIZE - sizeof(struct m_hdr)) /* normal data len */ 55 #define MHLEN (MLEN - sizeof(struct pkthdr)) /* data len w/pkthdr */ 56 57 #define MINCLSIZE (MHLEN + 1) /* smallest amount to put in cluster */ 58 #define M_MAXCOMPRESS (MHLEN / 2) /* max amount to copy for compression */ 59 60 /* 61 * Maximum number of allocatable counters for external buffers. This 62 * ensures enough VM address space for the allocation of counters 63 * in the extreme case where all possible external buffers are allocated. 64 * 65 * Note: When new types of external storage are allocated, EXT_COUNTERS 66 * must be tuned accordingly. Practically, this isn't a big deal 67 * as each counter is only a word long, so we can fit 68 * (PAGE_SIZE / length of word) counters in a single page. 69 * 70 * XXX: Must increase this if using any of if_ti, if_wb, if_sk drivers, 71 * or any other drivers which may manage their own buffers and 72 * eventually attach them to mbufs. 73 */ 74 #define EXT_COUNTERS (nmbclusters + nsfbufs) 75 76 #ifdef _KERNEL 77 /* 78 * Macros for type conversion 79 * mtod(m, t) - convert mbuf pointer to data pointer of correct type 80 * dtom(x) - convert data pointer within mbuf to mbuf pointer (XXX) 81 */ 82 #define mtod(m, t) ((t)((m)->m_data)) 83 #define dtom(x) ((struct mbuf *)((intptr_t)(x) & ~(MSIZE-1))) 84 #endif /* _KERNEL */ 85 86 /* header at beginning of each mbuf: */ 87 struct m_hdr { 88 struct mbuf *mh_next; /* next buffer in chain */ 89 struct mbuf *mh_nextpkt; /* next chain in queue/record */ 90 caddr_t mh_data; /* location of data */ 91 int mh_len; /* amount of data in this mbuf */ 92 short mh_type; /* type of data in this mbuf */ 93 short mh_flags; /* flags; see below */ 94 }; 95 96 /* record/packet header in first mbuf of chain; valid if M_PKTHDR set */ 97 struct pkthdr { 98 struct ifnet *rcvif; /* rcv interface */ 99 int len; /* total packet length */ 100 /* variables for ip and tcp reassembly */ 101 void *header; /* pointer to packet header */ 102 /* variables for hardware checksum */ 103 int csum_flags; /* flags regarding checksum */ 104 int csum_data; /* data field used by csum routines */ 105 struct mbuf *aux; /* extra data buffer; ipsec/others */ 106 }; 107 108 /* description of external storage mapped into mbuf, valid if M_EXT set */ 109 struct m_ext { 110 caddr_t ext_buf; /* start of buffer */ 111 void (*ext_free) /* free routine if not the usual */ 112 (caddr_t, void *); 113 void *ext_args; /* optional argument pointer */ 114 u_int ext_size; /* size of buffer, for ext_free */ 115 union mext_refcnt *ref_cnt; /* pointer to ref count info */ 116 int ext_type; /* type of external storage */ 117 }; 118 119 struct mbuf { 120 struct m_hdr m_hdr; 121 union { 122 struct { 123 struct pkthdr MH_pkthdr; /* M_PKTHDR set */ 124 union { 125 struct m_ext MH_ext; /* M_EXT set */ 126 char MH_databuf[MHLEN]; 127 } MH_dat; 128 } MH; 129 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ 130 } M_dat; 131 }; 132 #define m_next m_hdr.mh_next 133 #define m_len m_hdr.mh_len 134 #define m_data m_hdr.mh_data 135 #define m_type m_hdr.mh_type 136 #define m_flags m_hdr.mh_flags 137 #define m_nextpkt m_hdr.mh_nextpkt 138 #define m_act m_nextpkt 139 #define m_pkthdr M_dat.MH.MH_pkthdr 140 #define m_ext M_dat.MH.MH_dat.MH_ext 141 #define m_pktdat M_dat.MH.MH_dat.MH_databuf 142 #define m_dat M_dat.M_databuf 143 144 /* mbuf flags */ 145 #define M_EXT 0x0001 /* has associated external storage */ 146 #define M_PKTHDR 0x0002 /* start of record */ 147 #define M_EOR 0x0004 /* end of record */ 148 #define M_RDONLY 0x0008 /* associated data is marked read-only */ 149 #define M_PROTO1 0x0010 /* protocol-specific */ 150 #define M_PROTO2 0x0020 /* protocol-specific */ 151 #define M_PROTO3 0x0040 /* protocol-specific */ 152 #define M_PROTO4 0x0080 /* protocol-specific */ 153 #define M_PROTO5 0x0100 /* protocol-specific */ 154 155 /* mbuf pkthdr flags, also in m_flags */ 156 #define M_BCAST 0x0200 /* send/received as link-level broadcast */ 157 #define M_MCAST 0x0400 /* send/received as link-level multicast */ 158 #define M_FRAG 0x0800 /* packet is a fragment of a larger packet */ 159 #define M_FIRSTFRAG 0x1000 /* packet is first fragment */ 160 #define M_LASTFRAG 0x2000 /* packet is last fragment */ 161 162 /* external buffer types: identify ext_buf type */ 163 #define EXT_CLUSTER 1 /* mbuf cluster */ 164 #define EXT_SFBUF 2 /* sendfile(2)'s sf_bufs */ 165 #define EXT_NET_DRV 100 /* custom ext_buf provided by net driver(s) */ 166 #define EXT_MOD_TYPE 200 /* custom module's ext_buf type */ 167 168 /* flags copied when copying m_pkthdr */ 169 #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_PROTO1|M_PROTO1|M_PROTO2|M_PROTO3 | \ 170 M_PROTO4|M_PROTO5|M_BCAST|M_MCAST|M_FRAG|M_RDONLY) 171 172 /* flags indicating hw checksum support and sw checksum requirements */ 173 #define CSUM_IP 0x0001 /* will csum IP */ 174 #define CSUM_TCP 0x0002 /* will csum TCP */ 175 #define CSUM_UDP 0x0004 /* will csum UDP */ 176 #define CSUM_IP_FRAGS 0x0008 /* will csum IP fragments */ 177 #define CSUM_FRAGMENT 0x0010 /* will do IP fragmentation */ 178 179 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */ 180 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */ 181 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */ 182 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */ 183 184 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP) 185 #define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */ 186 187 /* mbuf types */ 188 #define MT_FREE 0 /* should be on free list */ 189 #define MT_DATA 1 /* dynamic (data) allocation */ 190 #define MT_HEADER 2 /* packet header */ 191 #if 0 192 #define MT_SOCKET 3 /* socket structure */ 193 #define MT_PCB 4 /* protocol control block */ 194 #define MT_RTABLE 5 /* routing tables */ 195 #define MT_HTABLE 6 /* IMP host tables */ 196 #define MT_ATABLE 7 /* address resolution tables */ 197 #endif 198 #define MT_SONAME 8 /* socket name */ 199 #if 0 200 #define MT_SOOPTS 10 /* socket options */ 201 #endif 202 #define MT_FTABLE 11 /* fragment reassembly header */ 203 #if 0 204 #define MT_RIGHTS 12 /* access rights */ 205 #define MT_IFADDR 13 /* interface address */ 206 #endif 207 #define MT_CONTROL 14 /* extra-data protocol message */ 208 #define MT_OOBDATA 15 /* expedited data */ 209 #define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */ 210 211 /* 212 * mbuf statistics 213 */ 214 struct mbstat { 215 u_long m_mbufs; /* # mbufs obtained from page pool */ 216 u_long m_clusters; /* # clusters obtained from page pool */ 217 u_long m_clfree; /* # clusters on freelist (cache) */ 218 u_long m_refcnt; /* # ref counters obtained from page pool */ 219 u_long m_refree; /* # ref counters on freelist (cache) */ 220 u_long m_spare; /* spare field */ 221 u_long m_drops; /* times failed to find space */ 222 u_long m_wait; /* times waited for space */ 223 u_long m_drain; /* times drained protocols for space */ 224 u_long m_mcfail; /* times m_copym failed */ 225 u_long m_mpfail; /* times m_pullup failed */ 226 u_long m_msize; /* length of an mbuf */ 227 u_long m_mclbytes; /* length of an mbuf cluster */ 228 u_long m_minclsize; /* min length of data to allocate a cluster */ 229 u_long m_mlen; /* length of data in an mbuf */ 230 u_long m_mhlen; /* length of data in a header mbuf */ 231 }; 232 233 /* flags to m_get/MGET */ 234 #define M_DONTWAIT 1 235 #define M_TRYWAIT 0 236 #define M_WAIT M_TRYWAIT /* XXX: Deprecated. */ 237 238 /* 239 * Normal mbuf clusters are normally treated as character arrays 240 * after allocation, but use the first word of the buffer as a free list 241 * pointer while on the free list. 242 */ 243 union mcluster { 244 union mcluster *mcl_next; 245 char mcl_buf[MCLBYTES]; 246 }; 247 248 /* 249 * The m_ext object reference counter structure. 250 */ 251 union mext_refcnt { 252 union mext_refcnt *next_ref; 253 u_int refcnt; 254 }; 255 256 #ifdef _KERNEL 257 /* 258 * The freelists for mbufs and mbuf clusters include condition variables 259 * that are used in cases of depletion/starvation. 260 * The counter freelist does not require a condition variable as we never 261 * expect to consume more than the reserved address space for counters. 262 * All are presently protected by the mbuf_mtx lock. 263 */ 264 struct mbffree_lst { 265 struct mbuf *m_head; 266 struct cv m_starved; 267 }; 268 269 struct mclfree_lst { 270 union mcluster *m_head; 271 struct cv m_starved; 272 }; 273 274 struct mcntfree_lst { 275 union mext_refcnt *m_head; 276 }; 277 278 /* 279 * Signal a single instance (if any) blocked on a m_starved cv (i.e. an 280 * instance waiting for an {mbuf, cluster} to be freed to the global 281 * cache lists). 282 * 283 * Must be called with mbuf_mtx held. 284 */ 285 #define MBWAKEUP(m_wid, m_cv) do { \ 286 if ((m_wid) > 0) \ 287 cv_signal((m_cv)); \ 288 } while (0) 289 290 /* 291 * mbuf external reference count management macros: 292 * 293 * MEXT_IS_REF(m): true if (m) is not the only mbuf referencing 294 * the external buffer ext_buf 295 * MEXT_REM_REF(m): remove reference to m_ext object 296 * MEXT_ADD_REF(m): add reference to m_ext object already 297 * referred to by (m) 298 * MEXT_INIT_REF(m): allocate and initialize an external 299 * object reference counter for (m) 300 */ 301 #define MEXT_IS_REF(m) ((m)->m_ext.ref_cnt->refcnt > 1) 302 303 #define MEXT_REM_REF(m) do { \ 304 KASSERT((m)->m_ext.ref_cnt->refcnt > 0, ("m_ext refcnt < 0")); \ 305 atomic_subtract_int(&((m)->m_ext.ref_cnt->refcnt), 1); \ 306 } while(0) 307 308 #define MEXT_ADD_REF(m) atomic_add_int(&((m)->m_ext.ref_cnt->refcnt), 1) 309 310 #define _MEXT_ALLOC_CNT(m_cnt, how) do { \ 311 union mext_refcnt *__mcnt; \ 312 \ 313 mtx_lock(&mbuf_mtx); \ 314 if (mcntfree.m_head == NULL) \ 315 m_alloc_ref(1, (how)); \ 316 __mcnt = mcntfree.m_head; \ 317 if (__mcnt != NULL) { \ 318 mcntfree.m_head = __mcnt->next_ref; \ 319 mbstat.m_refree--; \ 320 __mcnt->refcnt = 0; \ 321 } \ 322 mtx_unlock(&mbuf_mtx); \ 323 (m_cnt) = __mcnt; \ 324 } while (0) 325 326 #define _MEXT_DEALLOC_CNT(m_cnt) do { \ 327 union mext_refcnt *__mcnt = (m_cnt); \ 328 \ 329 mtx_lock(&mbuf_mtx); \ 330 __mcnt->next_ref = mcntfree.m_head; \ 331 mcntfree.m_head = __mcnt; \ 332 mbstat.m_refree++; \ 333 mtx_unlock(&mbuf_mtx); \ 334 } while (0) 335 336 #define MEXT_INIT_REF(m, how) do { \ 337 struct mbuf *__mmm = (m); \ 338 \ 339 _MEXT_ALLOC_CNT(__mmm->m_ext.ref_cnt, (how)); \ 340 if (__mmm->m_ext.ref_cnt != NULL) \ 341 MEXT_ADD_REF(__mmm); \ 342 } while (0) 343 344 /* 345 * mbuf allocation/deallocation macros: 346 * 347 * MGET(struct mbuf *m, int how, int type) 348 * allocates an mbuf and initializes it to contain internal data. 349 * 350 * MGETHDR(struct mbuf *m, int how, int type) 351 * allocates an mbuf and initializes it to contain a packet header 352 * and internal data. 353 */ 354 /* 355 * Lower-level macros for MGET(HDR)... Not to be used outside the 356 * subsystem ("non-exportable" macro names are prepended with "_"). 357 */ 358 #define _MGET_SETUP(m_set, m_set_type) do { \ 359 (m_set)->m_type = (m_set_type); \ 360 (m_set)->m_next = NULL; \ 361 (m_set)->m_nextpkt = NULL; \ 362 (m_set)->m_data = (m_set)->m_dat; \ 363 (m_set)->m_flags = 0; \ 364 } while (0) 365 366 #define _MGET(m_mget, m_get_how) do { \ 367 if (mmbfree.m_head == NULL) \ 368 m_mballoc(1, (m_get_how)); \ 369 (m_mget) = mmbfree.m_head; \ 370 if ((m_mget) != NULL) { \ 371 mmbfree.m_head = (m_mget)->m_next; \ 372 mbtypes[MT_FREE]--; \ 373 } else { \ 374 if ((m_get_how) == M_TRYWAIT) \ 375 (m_mget) = m_mballoc_wait(); \ 376 } \ 377 } while (0) 378 379 #define MGET(m, how, type) do { \ 380 struct mbuf *_mm; \ 381 int _mhow = (how); \ 382 int _mtype = (type); \ 383 \ 384 mtx_lock(&mbuf_mtx); \ 385 _MGET(_mm, _mhow); \ 386 if (_mm != NULL) { \ 387 mbtypes[_mtype]++; \ 388 mtx_unlock(&mbuf_mtx); \ 389 _MGET_SETUP(_mm, _mtype); \ 390 } else { \ 391 mbstat.m_drops++; \ 392 mtx_unlock(&mbuf_mtx); \ 393 } \ 394 (m) = _mm; \ 395 } while (0) 396 397 #define _MGETHDR_SETUP(m_set, m_set_type) do { \ 398 (m_set)->m_type = (m_set_type); \ 399 (m_set)->m_next = NULL; \ 400 (m_set)->m_nextpkt = NULL; \ 401 (m_set)->m_data = (m_set)->m_pktdat; \ 402 (m_set)->m_flags = M_PKTHDR; \ 403 (m_set)->m_pkthdr.rcvif = NULL; \ 404 (m_set)->m_pkthdr.csum_flags = 0; \ 405 (m_set)->m_pkthdr.aux = NULL; \ 406 } while (0) 407 408 #define MGETHDR(m, how, type) do { \ 409 struct mbuf *_mm; \ 410 int _mhow = (how); \ 411 int _mtype = (type); \ 412 \ 413 mtx_lock(&mbuf_mtx); \ 414 _MGET(_mm, _mhow); \ 415 if (_mm != NULL) { \ 416 mbtypes[_mtype]++; \ 417 mtx_unlock(&mbuf_mtx); \ 418 _MGETHDR_SETUP(_mm, _mtype); \ 419 } else { \ 420 mbstat.m_drops++; \ 421 mtx_unlock(&mbuf_mtx); \ 422 } \ 423 (m) = _mm; \ 424 } while (0) 425 426 /* 427 * mbuf external storage macros: 428 * 429 * MCLGET allocates and refers an mcluster to an mbuf 430 * MEXTADD sets up pre-allocated external storage and refers to mbuf 431 * MEXTFREE removes reference to external object and frees it if 432 * necessary 433 */ 434 #define _MCLALLOC(p, how) do { \ 435 caddr_t _mp; \ 436 int _mhow = (how); \ 437 \ 438 if (mclfree.m_head == NULL) \ 439 m_clalloc(1, _mhow); \ 440 _mp = (caddr_t)mclfree.m_head; \ 441 if (_mp != NULL) { \ 442 mbstat.m_clfree--; \ 443 mclfree.m_head = ((union mcluster *)_mp)->mcl_next; \ 444 } else { \ 445 if (_mhow == M_TRYWAIT) \ 446 _mp = m_clalloc_wait(); \ 447 } \ 448 (p) = _mp; \ 449 } while (0) 450 451 #define MCLGET(m, how) do { \ 452 struct mbuf *_mm = (m); \ 453 \ 454 mtx_lock(&mbuf_mtx); \ 455 _MCLALLOC(_mm->m_ext.ext_buf, (how)); \ 456 if (_mm->m_ext.ext_buf != NULL) { \ 457 mtx_unlock(&mbuf_mtx); \ 458 MEXT_INIT_REF(_mm, (how)); \ 459 if (_mm->m_ext.ref_cnt == NULL) { \ 460 _MCLFREE(_mm->m_ext.ext_buf); \ 461 _mm->m_ext.ext_buf = NULL; \ 462 } else { \ 463 _mm->m_data = _mm->m_ext.ext_buf; \ 464 _mm->m_flags |= M_EXT; \ 465 _mm->m_ext.ext_free = NULL; \ 466 _mm->m_ext.ext_args = NULL; \ 467 _mm->m_ext.ext_size = MCLBYTES; \ 468 _mm->m_ext.ext_type = EXT_CLUSTER; \ 469 } \ 470 } else { \ 471 mbstat.m_drops++; \ 472 mtx_unlock(&mbuf_mtx); \ 473 } \ 474 } while (0) 475 476 #define MEXTADD(m, buf, size, free, args, flags, type) do { \ 477 struct mbuf *_mm = (m); \ 478 \ 479 MEXT_INIT_REF(_mm, M_TRYWAIT); \ 480 if (_mm->m_ext.ref_cnt != NULL) { \ 481 _mm->m_flags |= (M_EXT | (flags)); \ 482 _mm->m_ext.ext_buf = (caddr_t)(buf); \ 483 _mm->m_data = _mm->m_ext.ext_buf; \ 484 _mm->m_ext.ext_size = (size); \ 485 _mm->m_ext.ext_free = (free); \ 486 _mm->m_ext.ext_args = (args); \ 487 _mm->m_ext.ext_type = (type); \ 488 } \ 489 } while (0) 490 491 #define _MCLFREE(p) do { \ 492 union mcluster *_mp = (union mcluster *)(p); \ 493 \ 494 mtx_lock(&mbuf_mtx); \ 495 _mp->mcl_next = mclfree.m_head; \ 496 mclfree.m_head = _mp; \ 497 mbstat.m_clfree++; \ 498 MBWAKEUP(m_clalloc_wid, &mclfree.m_starved); \ 499 mtx_unlock(&mbuf_mtx); \ 500 } while (0) 501 502 /* MEXTFREE: 503 * If the atomic_cmpset_int() returns 0, then we effectively do nothing 504 * in terms of "cleaning up" (freeing the ext buf and ref. counter) as 505 * this means that either there are still references, or another thread 506 * is taking care of the clean-up. 507 */ 508 #define MEXTFREE(m) do { \ 509 struct mbuf *_mmm = (m); \ 510 \ 511 MEXT_REM_REF(_mmm); \ 512 if (atomic_cmpset_int(&_mmm->m_ext.ref_cnt->refcnt, 0, 1)) { \ 513 if (_mmm->m_ext.ext_type != EXT_CLUSTER) { \ 514 (*(_mmm->m_ext.ext_free))(_mmm->m_ext.ext_buf, \ 515 _mmm->m_ext.ext_args); \ 516 } else \ 517 _MCLFREE(_mmm->m_ext.ext_buf); \ 518 _MEXT_DEALLOC_CNT(_mmm->m_ext.ref_cnt); \ 519 } \ 520 _mmm->m_flags &= ~M_EXT; \ 521 } while (0) 522 523 /* 524 * MFREE(struct mbuf *m, struct mbuf *n) 525 * Free a single mbuf and associated external storage. 526 * Place the successor, if any, in n. 527 */ 528 #define MFREE(m, n) do { \ 529 struct mbuf *_mm = (m); \ 530 \ 531 KASSERT(_mm->m_type != MT_FREE, ("freeing free mbuf")); \ 532 if (_mm->m_flags & M_EXT) \ 533 MEXTFREE(_mm); \ 534 mtx_lock(&mbuf_mtx); \ 535 mbtypes[_mm->m_type]--; \ 536 _mm->m_type = MT_FREE; \ 537 mbtypes[MT_FREE]++; \ 538 (n) = _mm->m_next; \ 539 _mm->m_next = mmbfree.m_head; \ 540 mmbfree.m_head = _mm; \ 541 MBWAKEUP(m_mballoc_wid, &mmbfree.m_starved); \ 542 mtx_unlock(&mbuf_mtx); \ 543 } while (0) 544 545 /* 546 * M_WRITABLE(m) 547 * Evaluate TRUE if it's safe to write to the mbuf m's data region (this 548 * can be both the local data payload, or an external buffer area, 549 * depending on whether M_EXT is set). 550 */ 551 #define M_WRITABLE(m) (!((m)->m_flags & M_RDONLY) && (!((m)->m_flags \ 552 & M_EXT) || !MEXT_IS_REF(m))) 553 554 /* 555 * Copy mbuf pkthdr from "from" to "to". 556 * from must have M_PKTHDR set, and to must be empty. 557 * aux pointer will be moved to `to'. 558 */ 559 #define M_COPY_PKTHDR(to, from) do { \ 560 struct mbuf *_mfrom = (from); \ 561 struct mbuf *_mto = (to); \ 562 \ 563 _mto->m_data = _mto->m_pktdat; \ 564 _mto->m_flags = _mfrom->m_flags & M_COPYFLAGS; \ 565 _mto->m_pkthdr = _mfrom->m_pkthdr; \ 566 _mfrom->m_pkthdr.aux = NULL; \ 567 } while (0) 568 569 /* 570 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place 571 * an object of the specified size at the end of the mbuf, longword aligned. 572 */ 573 #define M_ALIGN(m, len) do { \ 574 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \ 575 } while (0) 576 577 /* 578 * As above, for mbufs allocated with m_gethdr/MGETHDR 579 * or initialized by M_COPY_PKTHDR. 580 */ 581 #define MH_ALIGN(m, len) do { \ 582 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \ 583 } while (0) 584 585 /* 586 * Compute the amount of space available 587 * before the current start of data in an mbuf. 588 */ 589 #define M_LEADINGSPACE(m) \ 590 ((m)->m_flags & M_EXT ? \ 591 /* (m)->m_data - (m)->m_ext.ext_buf */ 0 : \ 592 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 593 (m)->m_data - (m)->m_dat) 594 595 /* 596 * Compute the amount of space available 597 * after the end of data in an mbuf. 598 */ 599 #define M_TRAILINGSPACE(m) \ 600 ((m)->m_flags & M_EXT ? (m)->m_ext.ext_buf + \ 601 (m)->m_ext.ext_size - ((m)->m_data + (m)->m_len) : \ 602 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 603 604 /* 605 * Arrange to prepend space of size plen to mbuf m. 606 * If a new mbuf must be allocated, how specifies whether to wait. 607 * If the allocation fails, the original mbuf chain is freed and m is 608 * set to NULL. 609 */ 610 #define M_PREPEND(m, plen, how) do { \ 611 struct mbuf **_mmp = &(m); \ 612 struct mbuf *_mm = *_mmp; \ 613 int _mplen = (plen); \ 614 int __mhow = (how); \ 615 \ 616 if (M_LEADINGSPACE(_mm) >= _mplen) { \ 617 _mm->m_data -= _mplen; \ 618 _mm->m_len += _mplen; \ 619 } else \ 620 _mm = m_prepend(_mm, _mplen, __mhow); \ 621 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \ 622 _mm->m_pkthdr.len += _mplen; \ 623 *_mmp = _mm; \ 624 } while (0) 625 626 /* 627 * change mbuf to new type 628 */ 629 #define MCHTYPE(m, t) do { \ 630 struct mbuf *_mm = (m); \ 631 int _mt = (t); \ 632 \ 633 mtx_lock(&mbuf_mtx); \ 634 mbtypes[_mm->m_type]--; \ 635 mbtypes[_mt]++; \ 636 mtx_unlock(&mbuf_mtx); \ 637 _mm->m_type = (_mt); \ 638 } while (0) 639 640 /* length to m_copy to copy all */ 641 #define M_COPYALL 1000000000 642 643 /* compatibility with 4.3 */ 644 #define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT) 645 646 /* 647 * pkthdr.aux type tags. 648 */ 649 struct mauxtag { 650 int af; 651 int type; 652 }; 653 654 extern u_long m_clalloc_wid; /* mbuf cluster wait count */ 655 extern u_long m_mballoc_wid; /* mbuf wait count */ 656 extern int max_datalen; /* MHLEN - max_hdr */ 657 extern int max_hdr; /* largest link+protocol header */ 658 extern int max_linkhdr; /* largest link-level header */ 659 extern int max_protohdr; /* largest protocol header */ 660 extern struct mbstat mbstat; 661 extern u_long mbtypes[MT_NTYPES]; /* per-type mbuf allocations */ 662 extern int mbuf_wait; /* mbuf sleep time */ 663 extern struct mtx mbuf_mtx; 664 extern struct mbuf *mbutl; /* virtual address of mclusters */ 665 extern struct mclfree_lst mclfree; 666 extern struct mcntfree_lst mcntfree; 667 extern struct mbffree_lst mmbfree; 668 extern int nmbclusters; 669 extern int nmbcnt; 670 extern int nmbufs; 671 extern int nsfbufs; 672 673 void m_adj(struct mbuf *, int); 674 int m_alloc_ref(u_int, int); 675 struct mbuf *m_aux_add(struct mbuf *, int, int); 676 void m_aux_delete(struct mbuf *, struct mbuf *); 677 struct mbuf *m_aux_find(struct mbuf *, int, int); 678 void m_cat(struct mbuf *, struct mbuf *); 679 int m_clalloc(int, int); 680 caddr_t m_clalloc_wait(void); 681 void m_copyback(struct mbuf *, int, int, caddr_t); 682 void m_copydata(struct mbuf *, int, int, caddr_t); 683 struct mbuf *m_copym(struct mbuf *, int, int, int); 684 struct mbuf *m_copypacket(struct mbuf *, int); 685 struct mbuf *m_devget(char *, int, int, struct ifnet *, 686 void (*copy)(char *, caddr_t, u_int)); 687 struct mbuf *m_dup(struct mbuf *, int); 688 struct mbuf *m_free(struct mbuf *); 689 void m_freem(struct mbuf *); 690 struct mbuf *m_get(int, int); 691 struct mbuf *m_getclr(int, int); 692 struct mbuf *m_gethdr(int, int); 693 struct mbuf *m_getm(struct mbuf *, int, int, int); 694 int m_mballoc(int, int); 695 struct mbuf *m_mballoc_wait(void); 696 struct mbuf *m_prepend(struct mbuf *, int, int); 697 void m_print(const struct mbuf *m); 698 struct mbuf *m_pulldown(struct mbuf *, int, int, int *); 699 struct mbuf *m_pullup(struct mbuf *, int); 700 struct mbuf *m_split(struct mbuf *, int, int); 701 #endif /* _KERNEL */ 702 703 #endif /* !_SYS_MBUF_H_ */ 704