mbuf.h revision 2197
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 8.3 (Berkeley) 1/21/94 34 * $Id: mbuf.h,v 1.4 1994/08/21 04:41:51 paul Exp $ 35 */ 36 37#ifndef _SYS_MBUF_H_ 38#define _SYS_MBUF_H_ 39 40#ifndef M_WAITOK 41#include <sys/malloc.h> 42#endif 43 44/* 45 * Mbufs are of a single size, MSIZE (machine/machparam.h), which 46 * includes overhead. An mbuf may add a single "mbuf cluster" of size 47 * MCLBYTES (also in machine/machparam.h), which has no additional overhead 48 * and is used instead of the internal data area; this is done when 49 * at least MINCLSIZE of data must be stored. 50 */ 51 52#define MLEN (MSIZE - sizeof(struct m_hdr)) /* normal data len */ 53#define MHLEN (MLEN - sizeof(struct pkthdr)) /* data len w/pkthdr */ 54 55#define MINCLSIZE (MHLEN + MLEN) /* smallest amount to put in cluster */ 56#define M_MAXCOMPRESS (MHLEN / 2) /* max amount to copy for compression */ 57 58/* 59 * Macros for type conversion 60 * mtod(m,t) - convert mbuf pointer to data pointer of correct type 61 * dtom(x) - convert data pointer within mbuf to mbuf pointer (XXX) 62 * mtocl(x) - convert pointer within cluster to cluster index # 63 * cltom(x) - convert cluster # to ptr to beginning of cluster 64 */ 65#define mtod(m,t) ((t)((m)->m_data)) 66#define dtom(x) ((struct mbuf *)((int)(x) & ~(MSIZE-1))) 67#define mtocl(x) (((u_int)(x) - (u_int)mbutl) >> MCLSHIFT) 68#define cltom(x) ((caddr_t)((u_int)mbutl + ((u_int)(x) << MCLSHIFT))) 69 70/* header at beginning of each mbuf: */ 71struct m_hdr { 72 struct mbuf *mh_next; /* next buffer in chain */ 73 struct mbuf *mh_nextpkt; /* next chain in queue/record */ 74 int mh_len; /* amount of data in this mbuf */ 75 caddr_t mh_data; /* location of data */ 76 short mh_type; /* type of data in this mbuf */ 77 short mh_flags; /* flags; see below */ 78}; 79 80/* record/packet header in first mbuf of chain; valid if M_PKTHDR set */ 81struct pkthdr { 82 int len; /* total packet length */ 83 struct ifnet *rcvif; /* rcv interface */ 84}; 85 86/* description of external storage mapped into mbuf, valid if M_EXT set */ 87struct m_ext { 88 caddr_t ext_buf; /* start of buffer */ 89 void (*ext_free)(); /* free routine if not the usual */ 90 u_int ext_size; /* size of buffer, for ext_free */ 91}; 92 93struct mbuf { 94 struct m_hdr m_hdr; 95 union { 96 struct { 97 struct pkthdr MH_pkthdr; /* M_PKTHDR set */ 98 union { 99 struct m_ext MH_ext; /* M_EXT set */ 100 char MH_databuf[MHLEN]; 101 } MH_dat; 102 } MH; 103 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ 104 } M_dat; 105}; 106#define m_next m_hdr.mh_next 107#define m_len m_hdr.mh_len 108#define m_data m_hdr.mh_data 109#define m_type m_hdr.mh_type 110#define m_flags m_hdr.mh_flags 111#define m_nextpkt m_hdr.mh_nextpkt 112#define m_act m_nextpkt 113#define m_pkthdr M_dat.MH.MH_pkthdr 114#define m_ext M_dat.MH.MH_dat.MH_ext 115#define m_pktdat M_dat.MH.MH_dat.MH_databuf 116#define m_dat M_dat.M_databuf 117 118/* mbuf flags */ 119#define M_EXT 0x0001 /* has associated external storage */ 120#define M_PKTHDR 0x0002 /* start of record */ 121#define M_EOR 0x0004 /* end of record */ 122 123/* mbuf pkthdr flags, also in m_flags */ 124#define M_BCAST 0x0100 /* send/received as link-level broadcast */ 125#define M_MCAST 0x0200 /* send/received as link-level multicast */ 126 127/* flags copied when copying m_pkthdr */ 128#define M_COPYFLAGS (M_PKTHDR|M_EOR|M_BCAST|M_MCAST) 129 130/* mbuf types */ 131#define MT_FREE 0 /* should be on free list */ 132#define MT_DATA 1 /* dynamic (data) allocation */ 133#define MT_HEADER 2 /* packet header */ 134#define MT_SOCKET 3 /* socket structure */ 135#define MT_PCB 4 /* protocol control block */ 136#define MT_RTABLE 5 /* routing tables */ 137#define MT_HTABLE 6 /* IMP host tables */ 138#define MT_ATABLE 7 /* address resolution tables */ 139#define MT_SONAME 8 /* socket name */ 140#define MT_SOOPTS 10 /* socket options */ 141#define MT_FTABLE 11 /* fragment reassembly header */ 142#define MT_RIGHTS 12 /* access rights */ 143#define MT_IFADDR 13 /* interface address */ 144#define MT_CONTROL 14 /* extra-data protocol message */ 145#define MT_OOBDATA 15 /* expedited data */ 146 147/* flags to m_get/MGET */ 148#define M_DONTWAIT M_NOWAIT 149#define M_WAIT M_WAITOK 150 151/* 152 * mbuf utility macros: 153 * 154 * MBUFLOCK(code) 155 * prevents a section of code from from being interrupted by network 156 * drivers. 157 */ 158#define MBUFLOCK(code) \ 159 { int ms = splimp(); \ 160 { code } \ 161 splx(ms); \ 162 } 163 164/* 165 * mbuf allocation/deallocation macros: 166 * 167 * MGET(struct mbuf *m, int how, int type) 168 * allocates an mbuf and initializes it to contain internal data. 169 * 170 * MGETHDR(struct mbuf *m, int how, int type) 171 * allocates an mbuf and initializes it to contain a packet header 172 * and internal data. 173 */ 174struct mbuf *mbuffree; 175int mbuffreecnt; 176#define MGET(m, how, type) { \ 177 int s = splimp(); \ 178 if (mbuffree == 0) { \ 179 splx(s); \ 180 MALLOC((m), struct mbuf *, MSIZE, mbtypes[type], (how)); \ 181 } else { \ 182 --mbuffreecnt; \ 183 (m) = mbuffree; \ 184 mbuffree = (m)->m_next; \ 185 splx(s); \ 186 } \ 187 if (m) { \ 188 (m)->m_type = (type); \ 189 MBUFLOCK(mbstat.m_mtypes[type]++;) \ 190 (m)->m_next = (struct mbuf *)NULL; \ 191 (m)->m_nextpkt = (struct mbuf *)NULL; \ 192 (m)->m_data = (m)->m_dat; \ 193 (m)->m_flags = 0; \ 194 } else \ 195 (m) = m_retry((how), (type)); \ 196} 197 198#define MGETHDR(m, how, type) { \ 199 int s = splimp(); \ 200 if (mbuffree == 0) { \ 201 splx(s); \ 202 MALLOC((m), struct mbuf *, MSIZE, mbtypes[type], (how)); \ 203 } else { \ 204 --mbuffreecnt; \ 205 (m) = mbuffree; \ 206 mbuffree = (m)->m_next; \ 207 splx(s); \ 208 } \ 209 if (m) { \ 210 (m)->m_type = (type); \ 211 MBUFLOCK(mbstat.m_mtypes[type]++;) \ 212 (m)->m_next = (struct mbuf *)NULL; \ 213 (m)->m_nextpkt = (struct mbuf *)NULL; \ 214 (m)->m_data = (m)->m_pktdat; \ 215 (m)->m_flags = M_PKTHDR; \ 216 } else \ 217 (m) = m_retryhdr((how), (type)); \ 218} 219 220/* 221 * Mbuf cluster macros. 222 * MCLALLOC(caddr_t p, int how) allocates an mbuf cluster. 223 * MCLGET adds such clusters to a normal mbuf; 224 * the flag M_EXT is set upon success. 225 * MCLFREE releases a reference to a cluster allocated by MCLALLOC, 226 * freeing the cluster if the reference count has reached 0. 227 * 228 * Normal mbuf clusters are normally treated as character arrays 229 * after allocation, but use the first word of the buffer as a free list 230 * pointer while on the free list. 231 */ 232union mcluster { 233 union mcluster *mcl_next; 234 char mcl_buf[MCLBYTES]; 235}; 236 237#define MCLALLOC(p, how) \ 238 MBUFLOCK( \ 239 if (mclfree == 0) \ 240 (void)m_clalloc(1, (how)); \ 241 if ((p) = (caddr_t)mclfree) { \ 242 ++mclrefcnt[mtocl(p)]; \ 243 mbstat.m_clfree--; \ 244 mclfree = ((union mcluster *)(p))->mcl_next; \ 245 } \ 246 ) 247 248#define MCLGET(m, how) \ 249 { MCLALLOC((m)->m_ext.ext_buf, (how)); \ 250 if ((m)->m_ext.ext_buf != NULL) { \ 251 (m)->m_data = (m)->m_ext.ext_buf; \ 252 (m)->m_flags |= M_EXT; \ 253 (m)->m_ext.ext_size = MCLBYTES; \ 254 } \ 255 } 256 257#define MCLFREE(p) \ 258 MBUFLOCK ( \ 259 if (--mclrefcnt[mtocl(p)] == 0) { \ 260 ((union mcluster *)(p))->mcl_next = mclfree; \ 261 mclfree = (union mcluster *)(p); \ 262 mbstat.m_clfree++; \ 263 } \ 264 ) 265 266/* 267 * MFREE(struct mbuf *m, struct mbuf *n) 268 * Free a single mbuf and associated external storage. 269 * Place the successor, if any, in n. 270 */ 271#ifdef notyet 272#define MFREE(m, n) \ 273 { MBUFLOCK(mbstat.m_mtypes[(m)->m_type]--;) \ 274 if ((m)->m_flags & M_EXT) { \ 275 if ((m)->m_ext.ext_free) \ 276 (*((m)->m_ext.ext_free))((m)->m_ext.ext_buf, \ 277 (m)->m_ext.ext_size); \ 278 else \ 279 MCLFREE((m)->m_ext.ext_buf); \ 280 } \ 281 (n) = (m)->m_next; \ 282 FREE((m), mbtypes[(m)->m_type]); \ 283 } 284#else /* notyet */ 285#define MFREE(m, nn) \ 286 { MBUFLOCK(mbstat.m_mtypes[(m)->m_type]--;) \ 287 if ((m)->m_flags & M_EXT) { \ 288 MCLFREE((m)->m_ext.ext_buf); \ 289 } \ 290 (nn) = (m)->m_next; \ 291 if (mbuffreecnt < 256) { \ 292 int s = splimp(); \ 293 ++mbuffreecnt; \ 294 (m)->m_next = mbuffree; \ 295 mbuffree = (m); \ 296 splx(s); \ 297 } else { \ 298 FREE((m), mbtypes[(m)->m_type]); \ 299 } \ 300 } 301#endif 302 303/* 304 * Copy mbuf pkthdr from from to to. 305 * from must have M_PKTHDR set, and to must be empty. 306 */ 307#define M_COPY_PKTHDR(to, from) { \ 308 (to)->m_pkthdr = (from)->m_pkthdr; \ 309 (to)->m_flags = (from)->m_flags & M_COPYFLAGS; \ 310 (to)->m_data = (to)->m_pktdat; \ 311} 312 313/* 314 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place 315 * an object of the specified size at the end of the mbuf, longword aligned. 316 */ 317#define M_ALIGN(m, len) \ 318 { (m)->m_data += (MLEN - (len)) &~ (sizeof(long) - 1); } 319/* 320 * As above, for mbufs allocated with m_gethdr/MGETHDR 321 * or initialized by M_COPY_PKTHDR. 322 */ 323#define MH_ALIGN(m, len) \ 324 { (m)->m_data += (MHLEN - (len)) &~ (sizeof(long) - 1); } 325 326/* 327 * Compute the amount of space available 328 * before the current start of data in an mbuf. 329 */ 330#define M_LEADINGSPACE(m) \ 331 ((m)->m_flags & M_EXT ? /* (m)->m_data - (m)->m_ext.ext_buf */ 0 : \ 332 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 333 (m)->m_data - (m)->m_dat) 334 335/* 336 * Compute the amount of space available 337 * after the end of data in an mbuf. 338 */ 339#define M_TRAILINGSPACE(m) \ 340 ((m)->m_flags & M_EXT ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size - \ 341 ((m)->m_data + (m)->m_len) : \ 342 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 343 344/* 345 * Arrange to prepend space of size plen to mbuf m. 346 * If a new mbuf must be allocated, how specifies whether to wait. 347 * If how is M_DONTWAIT and allocation fails, the original mbuf chain 348 * is freed and m is set to NULL. 349 */ 350#define M_PREPEND(m, plen, how) { \ 351 if (M_LEADINGSPACE(m) >= (plen)) { \ 352 (m)->m_data -= (plen); \ 353 (m)->m_len += (plen); \ 354 } else \ 355 (m) = m_prepend((m), (plen), (how)); \ 356 if ((m) && (m)->m_flags & M_PKTHDR) \ 357 (m)->m_pkthdr.len += (plen); \ 358} 359 360/* change mbuf to new type */ 361#define MCHTYPE(m, t) { \ 362 MBUFLOCK(mbstat.m_mtypes[(m)->m_type]--; mbstat.m_mtypes[t]++;) \ 363 (m)->m_type = t;\ 364} 365 366/* length to m_copy to copy all */ 367#define M_COPYALL 1000000000 368 369/* compatiblity with 4.3 */ 370#define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT) 371 372/* 373 * Mbuf statistics. 374 */ 375struct mbstat { 376 u_long m_mbufs; /* mbufs obtained from page pool */ 377 u_long m_clusters; /* clusters obtained from page pool */ 378 u_long m_spare; /* spare field */ 379 u_long m_clfree; /* free clusters */ 380 u_long m_drops; /* times failed to find space */ 381 u_long m_wait; /* times waited for space */ 382 u_long m_drain; /* times drained protocols for space */ 383 u_short m_mtypes[256]; /* type specific mbuf allocations */ 384}; 385 386#ifdef KERNEL 387extern struct mbuf *mbutl; /* virtual address of mclusters */ 388extern char *mclrefcnt; /* cluster reference counts */ 389struct mbstat mbstat; 390extern int nmbclusters; 391union mcluster *mclfree; 392int max_linkhdr; /* largest link-level header */ 393int max_protohdr; /* largest protocol header */ 394int max_hdr; /* largest link+protocol header */ 395int max_datalen; /* MHLEN - max_hdr */ 396extern int mbtypes[]; /* XXX */ 397 398struct mbuf *m_copym __P((struct mbuf *, int, int, int)); 399struct mbuf *m_free __P((struct mbuf *)); 400struct mbuf *m_get __P((int, int)); 401struct mbuf *m_getclr __P((int, int)); 402struct mbuf *m_gethdr __P((int, int)); 403struct mbuf *m_prepend __P((struct mbuf *, int, int)); 404struct mbuf *m_pullup __P((struct mbuf *, int)); 405struct mbuf *m_retry __P((int, int)); 406struct mbuf *m_retryhdr __P((int, int)); 407int m_clalloc __P((int, int)); 408void m_copyback __P((struct mbuf *, int, int, caddr_t)); 409void m_freem __P((struct mbuf *)); 410 411#ifdef MBTYPES 412int mbtypes[] = { /* XXX */ 413 M_FREE, /* MT_FREE 0 should be on free list */ 414 M_MBUF, /* MT_DATA 1 dynamic (data) allocation */ 415 M_MBUF, /* MT_HEADER 2 packet header */ 416 M_SOCKET, /* MT_SOCKET 3 socket structure */ 417 M_PCB, /* MT_PCB 4 protocol control block */ 418 M_RTABLE, /* MT_RTABLE 5 routing tables */ 419 M_HTABLE, /* MT_HTABLE 6 IMP host tables */ 420 0, /* MT_ATABLE 7 address resolution tables */ 421 M_MBUF, /* MT_SONAME 8 socket name */ 422 0, /* 9 */ 423 M_SOOPTS, /* MT_SOOPTS 10 socket options */ 424 M_FTABLE, /* MT_FTABLE 11 fragment reassembly header */ 425 M_MBUF, /* MT_RIGHTS 12 access rights */ 426 M_IFADDR, /* MT_IFADDR 13 interface address */ 427 M_MBUF, /* MT_CONTROL 14 extra-data protocol message */ 428 M_MBUF, /* MT_OOBDATA 15 expedited data */ 429#ifdef DATAKIT 430 25, 26, 27, 28, 29, 30, 31, 32 /* datakit ugliness */ 431#endif 432}; 433#endif 434#endif 435 436#endif 437