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 /* 41 * Mbufs are of a single size, MSIZE (machine/param.h), which 42 * includes overhead. An mbuf may add a single "mbuf cluster" of size 43 * MCLBYTES (also in machine/param.h), which has no additional overhead 44 * and is used instead of the internal data area; this is done when 45 * at least MINCLSIZE of data must be stored. 46 */ 47 48 #define MLEN (MSIZE - sizeof(struct m_hdr)) /* normal data len */ 49 #define MHLEN (MLEN - sizeof(struct pkthdr)) /* data len w/pkthdr */ 50 51 #define MINCLSIZE (MHLEN + 1) /* smallest amount to put in cluster */ 52 #define M_MAXCOMPRESS (MHLEN / 2) /* max amount to copy for compression */ 53 54 /* 55 * Macros for type conversion 56 * mtod(m, t) - convert mbuf pointer to data pointer of correct type 57 * dtom(x) - convert data pointer within mbuf to mbuf pointer (XXX) 58 * mtocl(x) - convert pointer within cluster to cluster index # 59 * cltom(x) - convert cluster # to ptr to beginning of cluster 60 */ 61 #define mtod(m, t) ((t)((m)->m_data)) 62 #define dtom(x) ((struct mbuf *)((intptr_t)(x) & ~(MSIZE-1))) 63 #define mtocl(x) (((uintptr_t)(x) - (uintptr_t)mbutl) >> MCLSHIFT) 64 #define cltom(x) ((caddr_t)((uintptr_t)mbutl + \ 65 ((uintptr_t)(x) << MCLSHIFT))) 66 67 /* header at beginning of each mbuf: */ 68 struct m_hdr { 69 struct mbuf *mh_next; /* next buffer in chain */ 70 struct mbuf *mh_nextpkt; /* next chain in queue/record */ 71 caddr_t mh_data; /* location of data */ 72 int mh_len; /* amount of data in this mbuf */ 73 short mh_type; /* type of data in this mbuf */ 74 short mh_flags; /* flags; see below */ 75 }; 76 77 /* record/packet header in first mbuf of chain; valid if M_PKTHDR set */ 78 struct pkthdr { 79 struct ifnet *rcvif; /* rcv interface */ 80 int len; /* total packet length */ 81 /* variables for ip and tcp reassembly */ 82 caddr_t header; /* pointer to packet header */ 83 }; 84 85 /* description of external storage mapped into mbuf, valid if M_EXT set */ 86 struct m_ext { 87 caddr_t ext_buf; /* start of buffer */ 88 void (*ext_free) /* free routine if not the usual */ 89 __P((caddr_t, u_int)); 90 u_int ext_size; /* size of buffer, for ext_free */ 91 void (*ext_ref) /* add a reference to the ext object */ 92 __P((caddr_t, u_int)); 93 }; 94 95 struct mbuf { 96 struct m_hdr m_hdr; 97 union { 98 struct { 99 struct pkthdr MH_pkthdr; /* M_PKTHDR set */ 100 union { 101 struct m_ext MH_ext; /* M_EXT set */ 102 char MH_databuf[MHLEN]; 103 } MH_dat; 104 } MH; 105 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ 106 } M_dat; 107 }; 108 #define m_next m_hdr.mh_next 109 #define m_len m_hdr.mh_len 110 #define m_data m_hdr.mh_data 111 #define m_type m_hdr.mh_type 112 #define m_flags m_hdr.mh_flags 113 #define m_nextpkt m_hdr.mh_nextpkt 114 #define m_act m_nextpkt 115 #define m_pkthdr M_dat.MH.MH_pkthdr 116 #define m_ext M_dat.MH.MH_dat.MH_ext 117 #define m_pktdat M_dat.MH.MH_dat.MH_databuf 118 #define m_dat M_dat.M_databuf 119 120 /* mbuf flags */ 121 #define M_EXT 0x0001 /* has associated external storage */ 122 #define M_PKTHDR 0x0002 /* start of record */ 123 #define M_EOR 0x0004 /* end of record */ 124 #define M_PROTO1 0x0008 /* protocol-specific */ 125 #define M_PROTO2 0x0010 /* protocol-specific */ 126 #define M_PROTO3 0x0020 /* protocol-specific */ 127 #define M_PROTO4 0x0040 /* protocol-specific */ 128 #define M_PROTO5 0x0080 /* protocol-specific */ 129 130 /* mbuf pkthdr flags, also in m_flags */ 131 #define M_BCAST 0x0100 /* send/received as link-level broadcast */ 132 #define M_MCAST 0x0200 /* send/received as link-level multicast */ 133 #define M_FRAG 0x0400 /* packet is a fragment of a larger packet */ 134 135 /* flags copied when copying m_pkthdr */ 136 #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_PROTO1|M_PROTO1|M_PROTO2|M_PROTO3 | \ 137 M_PROTO4|M_PROTO5|M_BCAST|M_MCAST|M_FRAG) 138 139 /* mbuf types */ 140 #define MT_FREE 0 /* should be on free list */ 141 #define MT_DATA 1 /* dynamic (data) allocation */ 142 #define MT_HEADER 2 /* packet header */ 143 #if 0 144 #define MT_SOCKET 3 /* socket structure */ 145 #define MT_PCB 4 /* protocol control block */ 146 #define MT_RTABLE 5 /* routing tables */ 147 #define MT_HTABLE 6 /* IMP host tables */ 148 #define MT_ATABLE 7 /* address resolution tables */ 149 #endif 150 #define MT_SONAME 8 /* socket name */ 151 #if 0 152 #define MT_SOOPTS 10 /* socket options */ 153 #endif 154 #define MT_FTABLE 11 /* fragment reassembly header */ 155 #if 0 156 #define MT_RIGHTS 12 /* access rights */ 157 #define MT_IFADDR 13 /* interface address */ 158 #endif 159 #define MT_CONTROL 14 /* extra-data protocol message */ 160 #define MT_OOBDATA 15 /* expedited data */ 161 162 /* 163 * mbuf statistics 164 */ 165 struct mbstat { 166 u_long m_mbufs; /* mbufs obtained from page pool */ 167 u_long m_clusters; /* clusters obtained from page pool */ 168 u_long m_spare; /* spare field */ 169 u_long m_clfree; /* free clusters */ 170 u_long m_drops; /* times failed to find space */ 171 u_long m_wait; /* times waited for space */ 172 u_long m_drain; /* times drained protocols for space */ 173 u_short m_mtypes[256]; /* type specific mbuf allocations */ 174 u_long m_mcfail; /* times m_copym failed */ 175 u_long m_mpfail; /* times m_pullup failed */ 176 u_long m_msize; /* length of an mbuf */ 177 u_long m_mclbytes; /* length of an mbuf cluster */ 178 u_long m_minclsize; /* min length of data to allocate a cluster */ 179 u_long m_mlen; /* length of data in an mbuf */ 180 u_long m_mhlen; /* length of data in a header mbuf */ 181 }; 182 183 /* flags to m_get/MGET */ 184 #define M_DONTWAIT 1 185 #define M_WAIT 0 186 187 /* Freelists: 188 * 189 * Normal mbuf clusters are normally treated as character arrays 190 * after allocation, but use the first word of the buffer as a free list 191 * pointer while on the free list. 192 */ 193 union mcluster { 194 union mcluster *mcl_next; 195 char mcl_buf[MCLBYTES]; 196 }; 197 198 199 /* 200 * These are identifying numbers passed to the m_mballoc_wait function, 201 * allowing us to determine whether the call came from an MGETHDR or 202 * an MGET. 203 */ 204 #define MGETHDR_C 1 205 #define MGET_C 2 206 207 /* 208 * Wake up the next instance (if any) of m_mballoc_wait() which is 209 * waiting for an mbuf to be freed. This should be called at splimp(). 210 * 211 * XXX: If there is another free mbuf, this routine will be called [again] 212 * from the m_mballoc_wait routine in order to wake another sleep instance. 213 */ 214 #define MMBWAKEUP() do { \ 215 if (m_mballoc_wid) { \ 216 m_mballoc_wid--; \ 217 wakeup_one(&m_mballoc_wid); \ 218 } \ 219 } while (0) 220 221 /* 222 * Same as above, but for mbuf cluster(s). 223 */ 224 #define MCLWAKEUP() do { \ 225 if (m_clalloc_wid) { \ 226 m_clalloc_wid--; \ 227 wakeup_one(&m_clalloc_wid); \ 228 } \ 229 } while (0) 230 231 /* 232 * mbuf utility macros: 233 * 234 * MBUFLOCK(code) 235 * prevents a section of code from from being interrupted by network 236 * drivers. 237 */ 238 #define MBUFLOCK(code) do { \ 239 int _ms = splimp(); \ 240 \ 241 { code } \ 242 splx(_ms); \ 243 } while (0) 244 245 /* 246 * mbuf allocation/deallocation macros: 247 * 248 * MGET(struct mbuf *m, int how, int type) 249 * allocates an mbuf and initializes it to contain internal data. 250 * 251 * MGETHDR(struct mbuf *m, int how, int type) 252 * allocates an mbuf and initializes it to contain a packet header 253 * and internal data. 254 * 255 * Warning: MGETHDR() does *not* initialize m->m_pkthdr.rcvif. 256 */ 257 #define MGET(m, how, type) do { \ 258 struct mbuf *_mm; \ 259 int _mhow = (how); \ 260 int _mtype = (type); \ 261 int _ms = splimp(); \ 262 \ 263 if (mmbfree == NULL) \ 264 (void)m_mballoc(1, _mhow); \ 265 _mm = mmbfree; \ 266 if (_mm != NULL) { \ 267 mmbfree = _mm->m_next; \ 268 mbstat.m_mtypes[MT_FREE]--; \ 269 _mm->m_type = _mtype; \ 270 mbstat.m_mtypes[_mtype]++; \ 271 _mm->m_next = NULL; \ 272 _mm->m_nextpkt = NULL; \ 273 _mm->m_data = _mm->m_dat; \ 274 _mm->m_flags = 0; \ 275 (m) = _mm; \ 276 splx(_ms); \ 277 } else { \ 278 splx(_ms); \ 279 _mm = m_retry(_mhow, _mtype); \ 280 if (_mm == NULL && _mhow == M_WAIT) \ 281 (m) = m_mballoc_wait(MGET_C, _mtype); \ 282 else \ 283 (m) = _mm; \ 284 } \ 285 } while (0) 286 287 #define MGETHDR(m, how, type) do { \ 288 struct mbuf *_mm; \ 289 int _mhow = (how); \ 290 int _mtype = (type); \ 291 int _ms = splimp(); \ 292 \ 293 if (mmbfree == NULL) \ 294 (void)m_mballoc(1, _mhow); \ 295 _mm = mmbfree; \ 296 if (_mm != NULL) { \ 297 mmbfree = _mm->m_next; \ 298 mbstat.m_mtypes[MT_FREE]--; \ 299 _mm->m_type = _mtype; \ 300 mbstat.m_mtypes[_mtype]++; \ 301 _mm->m_next = NULL; \ 302 _mm->m_nextpkt = NULL; \ 303 _mm->m_data = _mm->m_pktdat; \ 304 _mm->m_flags = M_PKTHDR; \ 305 (m) = _mm; \ 306 splx(_ms); \ 307 } else { \ 308 splx(_ms); \ 309 _mm = m_retryhdr(_mhow, _mtype); \ 310 if (_mm == NULL && _mhow == M_WAIT) \ 311 (m) = m_mballoc_wait(MGETHDR_C, _mtype); \ 312 else \ 313 (m) = _mm; \ 314 } \ 315 } while (0) 316 317 /* 318 * Mbuf cluster macros. 319 * MCLALLOC(caddr_t p, int how) allocates an mbuf cluster. 320 * MCLGET adds such clusters to a normal mbuf; 321 * the flag M_EXT is set upon success. 322 * MCLFREE releases a reference to a cluster allocated by MCLALLOC, 323 * freeing the cluster if the reference count has reached 0. 324 */ 325 #define MCLALLOC(p, how) do { \ 326 caddr_t _mp; \ 327 int _mhow = (how); \ 328 int _ms = splimp(); \ 329 \ 330 if (mclfree == NULL) \ 331 (void)m_clalloc(1, _mhow); \ 332 _mp = (caddr_t)mclfree; \ 333 if (_mp != NULL) { \ 334 mclrefcnt[mtocl(_mp)]++; \ 335 mbstat.m_clfree--; \ 336 mclfree = ((union mcluster *)_mp)->mcl_next; \ 337 (p) = _mp; \ 338 splx(_ms); \ 339 } else { \ 340 splx(_ms); \ 341 if (_mhow == M_WAIT) \ 342 (p) = m_clalloc_wait(); \ 343 else \ 344 (p) = NULL; \ 345 } \ 346 } while (0) 347 348 #define MCLGET(m, how) do { \ 349 struct mbuf *_mm = (m); \ 350 \ 351 MCLALLOC(_mm->m_ext.ext_buf, (how)); \ 352 if (_mm->m_ext.ext_buf != NULL) { \ 353 _mm->m_data = _mm->m_ext.ext_buf; \ 354 _mm->m_flags |= M_EXT; \ 355 _mm->m_ext.ext_free = NULL; \ 356 _mm->m_ext.ext_ref = NULL; \ 357 _mm->m_ext.ext_size = MCLBYTES; \ 358 } \ 359 } while (0) 360 361 #define MCLFREE1(p) do { \ 362 union mcluster *_mp = (union mcluster *)(p); \ 363 \ 364 if (--mclrefcnt[mtocl(_mp)] == 0) { \ 365 _mp->mcl_next = mclfree; \ 366 mclfree = _mp; \ 367 mbstat.m_clfree++; \ 368 MCLWAKEUP(); \ 369 } \ 370 } while (0) 371 372 #define MCLFREE(p) MBUFLOCK( \ 373 MCLFREE1(p); \ 374 ) 375 376 #define MEXTFREE1(m) do { \ 377 struct mbuf *_mm = (m); \ 378 \ 379 if (_mm->m_ext.ext_free != NULL) \ 380 (*_mm->m_ext.ext_free)(_mm->m_ext.ext_buf, \ 381 _mm->m_ext.ext_size); \ 382 else \ 383 MCLFREE1(_mm->m_ext.ext_buf); \ 384 } while (0) 385 386 #define MEXTFREE(m) MBUFLOCK( \ 387 MEXTFREE1(m); \ 388 ) 389 390 /* 391 * MFREE(struct mbuf *m, struct mbuf *n) 392 * Free a single mbuf and associated external storage. 393 * Place the successor, if any, in n. 394 */ 395 #define MFREE(m, n) MBUFLOCK( \ 396 struct mbuf *_mm = (m); \ 397 \ 398 mbstat.m_mtypes[_mm->m_type]--; \ 399 if (_mm->m_flags & M_EXT) \ 400 MEXTFREE1(m); \ 401 (n) = _mm->m_next; \ 402 _mm->m_type = MT_FREE; \ 403 mbstat.m_mtypes[MT_FREE]++; \ 404 _mm->m_next = mmbfree; \ 405 mmbfree = _mm; \ 406 MMBWAKEUP(); \ 407 ) 408 409 /* 410 * Copy mbuf pkthdr from "from" to "to". 411 * from must have M_PKTHDR set, and to must be empty. 412 */ 413 #define M_COPY_PKTHDR(to, from) do { \ 414 struct mbuf *_mfrom = (from); \ 415 struct mbuf *_mto = (to); \ 416 \ 417 _mto->m_data = _mto->m_pktdat; \ 418 _mto->m_flags = _mfrom->m_flags & M_COPYFLAGS; \ 419 _mto->m_pkthdr = _mfrom->m_pkthdr; \ 420 } while (0) 421 422 /* 423 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place 424 * an object of the specified size at the end of the mbuf, longword aligned. 425 */ 426 #define M_ALIGN(m, len) do { \ 427 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \ 428 } while (0) 429 430 /* 431 * As above, for mbufs allocated with m_gethdr/MGETHDR 432 * or initialized by M_COPY_PKTHDR. 433 */ 434 #define MH_ALIGN(m, len) do { \ 435 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \ 436 } while (0) 437 438 /* 439 * Compute the amount of space available 440 * before the current start of data in an mbuf. 441 */ 442 #define M_LEADINGSPACE(m) \ 443 ((m)->m_flags & M_EXT ? \ 444 /* (m)->m_data - (m)->m_ext.ext_buf */ 0 : \ 445 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 446 (m)->m_data - (m)->m_dat) 447 448 /* 449 * Compute the amount of space available 450 * after the end of data in an mbuf. 451 */ 452 #define M_TRAILINGSPACE(m) \ 453 ((m)->m_flags & M_EXT ? (m)->m_ext.ext_buf + \ 454 (m)->m_ext.ext_size - ((m)->m_data + (m)->m_len) : \ 455 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 456 457 /* 458 * Arrange to prepend space of size plen to mbuf m. 459 * If a new mbuf must be allocated, how specifies whether to wait. 460 * If how is M_DONTWAIT and allocation fails, the original mbuf chain 461 * is freed and m is set to NULL. 462 */ 463 #define M_PREPEND(m, plen, how) do { \ 464 struct mbuf **_mmp = &(m); \ 465 struct mbuf *_mm = *_mmp; \ 466 int _mplen = (plen); \ 467 int __mhow = (how); \ 468 \ 469 if (_mm == NULL) { \ 470 MGET(_mm, __mhow, MT_DATA); \ 471 if (_mm == NULL) \ 472 break; \ 473 } \ 474 if (M_LEADINGSPACE(_mm) >= _mplen) { \ 475 _mm->m_data -= _mplen; \ 476 _mm->m_len += _mplen; \ 477 } else \ 478 _mm = m_prepend(_mm, _mplen, __mhow); \ 479 if (_mm->m_flags & M_PKTHDR) \ 480 _mm->m_pkthdr.len += _mplen; \ 481 *_mmp = _mm; \ 482 } while (0) 483 484 /* change mbuf to new type */ 485 #define MCHTYPE(m, t) do { \ 486 struct mbuf *_mm = (m); \ 487 int _mt = (t); \ 488 int _ms = splimp(); \ 489 \ 490 mbstat.m_mtypes[_mm->m_type]--; \ 491 mbstat.m_mtypes[_mt]++; \ 492 splx(_ms); \ 493 _mm->m_type = (_mt); \ 494 } while (0) 495 496 /* length to m_copy to copy all */ 497 #define M_COPYALL 1000000000 498 499 /* compatibility with 4.3 */ 500 #define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT) 501 502 #ifdef _KERNEL 503 extern u_int m_clalloc_wid; /* mbuf cluster wait count */ 504 extern u_int m_mballoc_wid; /* mbuf wait count */ 505 extern int max_linkhdr; /* largest link-level header */ 506 extern int max_protohdr; /* largest protocol header */ 507 extern int max_hdr; /* largest link+protocol header */ 508 extern int max_datalen; /* MHLEN - max_hdr */ 509 extern struct mbstat mbstat; 510 extern int mbuf_wait; /* mbuf sleep time */ 511 extern struct mbuf *mbutl; /* virtual address of mclusters */ 512 extern char *mclrefcnt; /* cluster reference counts */ 513 extern union mcluster *mclfree; 514 extern struct mbuf *mmbfree; 515 extern int nmbclusters; 516 extern int nmbufs; 517 extern int nsfbufs; 518 519 void m_adj __P((struct mbuf *, int)); 520 void m_cat __P((struct mbuf *,struct mbuf *)); 521 int m_clalloc __P((int, int)); 522 caddr_t m_clalloc_wait __P((void)); 523 void m_copyback __P((struct mbuf *, int, int, caddr_t)); 524 void m_copydata __P((struct mbuf *,int,int,caddr_t)); 525 struct mbuf *m_copym __P((struct mbuf *, int, int, int)); 526 struct mbuf *m_copypacket __P((struct mbuf *, int)); 527 struct mbuf *m_devget __P((char *, int, int, struct ifnet *, 528 void (*copy)(char *, caddr_t, u_int))); 529 struct mbuf *m_dup __P((struct mbuf *, int)); 530 struct mbuf *m_free __P((struct mbuf *)); 531 void m_freem __P((struct mbuf *)); 532 struct mbuf *m_get __P((int, int)); 533 struct mbuf *m_getclr __P((int, int)); 534 struct mbuf *m_gethdr __P((int, int)); 535 int m_mballoc __P((int, int)); 536 struct mbuf *m_mballoc_wait __P((int, int)); 537 struct mbuf *m_prepend __P((struct mbuf *,int,int)); 538 void m_print __P((const struct mbuf *m)); 539 struct mbuf *m_pullup __P((struct mbuf *, int)); 540 struct mbuf *m_retry __P((int, int)); 541 struct mbuf *m_retryhdr __P((int, int)); 542 struct mbuf *m_split __P((struct mbuf *,int,int)); 543 #endif /* _KERNEL */ 544 545 #endif /* !_SYS_MBUF_H_ */ 546