mbuf.h revision 22975
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 * $Id$ 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 *)((long)(x) & ~(MSIZE-1))) 67#define mtocl(x) (((u_long)(x) - (u_long)mbutl) >> MCLSHIFT) 68#define cltom(x) ((caddr_t)((u_long)mbutl + ((u_long)(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 caddr_t mh_data; /* location of data */ 75 int mh_len; /* amount of data in this mbuf */ 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 struct ifnet *rcvif; /* rcv interface */ 83 int len; /* total packet length */ 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 __P((caddr_t, u_int)); 91 u_int ext_size; /* size of buffer, for ext_free */ 92 void (*ext_ref) /* add a reference to the ext object */ 93 __P((caddr_t, u_int)); 94}; 95 96struct mbuf { 97 struct m_hdr m_hdr; 98 union { 99 struct { 100 struct pkthdr MH_pkthdr; /* M_PKTHDR set */ 101 union { 102 struct m_ext MH_ext; /* M_EXT set */ 103 char MH_databuf[MHLEN]; 104 } MH_dat; 105 } MH; 106 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ 107 } M_dat; 108}; 109#define m_next m_hdr.mh_next 110#define m_len m_hdr.mh_len 111#define m_data m_hdr.mh_data 112#define m_type m_hdr.mh_type 113#define m_flags m_hdr.mh_flags 114#define m_nextpkt m_hdr.mh_nextpkt 115#define m_act m_nextpkt 116#define m_pkthdr M_dat.MH.MH_pkthdr 117#define m_ext M_dat.MH.MH_dat.MH_ext 118#define m_pktdat M_dat.MH.MH_dat.MH_databuf 119#define m_dat M_dat.M_databuf 120 121/* mbuf flags */ 122#define M_EXT 0x0001 /* has associated external storage */ 123#define M_PKTHDR 0x0002 /* start of record */ 124#define M_EOR 0x0004 /* end of record */ 125#define M_PROTO1 0x0008 /* protocol-specific */ 126 127/* mbuf pkthdr flags, also in m_flags */ 128#define M_BCAST 0x0100 /* send/received as link-level broadcast */ 129#define M_MCAST 0x0200 /* send/received as link-level multicast */ 130 131/* flags copied when copying m_pkthdr */ 132#define M_COPYFLAGS (M_PKTHDR|M_EOR|M_PROTO1|M_BCAST|M_MCAST) 133 134/* mbuf types */ 135#define MT_FREE 0 /* should be on free list */ 136#define MT_DATA 1 /* dynamic (data) allocation */ 137#define MT_HEADER 2 /* packet header */ 138#define MT_SOCKET 3 /* socket structure */ 139#define MT_PCB 4 /* protocol control block */ 140#define MT_RTABLE 5 /* routing tables */ 141#define MT_HTABLE 6 /* IMP host tables */ 142#define MT_ATABLE 7 /* address resolution tables */ 143#define MT_SONAME 8 /* socket name */ 144#define MT_SOOPTS 10 /* socket options */ 145#define MT_FTABLE 11 /* fragment reassembly header */ 146#define MT_RIGHTS 12 /* access rights */ 147#define MT_IFADDR 13 /* interface address */ 148#define MT_CONTROL 14 /* extra-data protocol message */ 149#define MT_OOBDATA 15 /* expedited data */ 150 151/* flags to m_get/MGET */ 152#define M_DONTWAIT M_NOWAIT 153#define M_WAIT M_WAITOK 154 155/* Freelists: 156 * 157 * Normal mbuf clusters are normally treated as character arrays 158 * after allocation, but use the first word of the buffer as a free list 159 * pointer while on the free list. 160 */ 161union mcluster { 162 union mcluster *mcl_next; 163 char mcl_buf[MCLBYTES]; 164}; 165 166/* 167 * mbuf utility macros: 168 * 169 * MBUFLOCK(code) 170 * prevents a section of code from from being interrupted by network 171 * drivers. 172 */ 173#define MBUFLOCK(code) \ 174 { int ms = splimp(); \ 175 { code } \ 176 splx(ms); \ 177 } 178 179/* 180 * mbuf allocation/deallocation macros: 181 * 182 * MGET(struct mbuf *m, int how, int type) 183 * allocates an mbuf and initializes it to contain internal data. 184 * 185 * MGETHDR(struct mbuf *m, int how, int type) 186 * allocates an mbuf and initializes it to contain a packet header 187 * and internal data. 188 */ 189#define MGET(m, how, type) { \ 190 int _ms = splimp(); \ 191 if (mmbfree == 0) \ 192 (void)m_mballoc(1, (how)); \ 193 if (((m) = mmbfree) != 0) { \ 194 mmbfree = (m)->m_next; \ 195 mbstat.m_mtypes[MT_FREE]--; \ 196 (m)->m_type = (type); \ 197 mbstat.m_mtypes[type]++; \ 198 (m)->m_next = (struct mbuf *)NULL; \ 199 (m)->m_nextpkt = (struct mbuf *)NULL; \ 200 (m)->m_data = (m)->m_dat; \ 201 (m)->m_flags = 0; \ 202 splx(_ms); \ 203 } else { \ 204 splx(_ms); \ 205 (m) = m_retry((how), (type)); \ 206 } \ 207} 208 209#define MGETHDR(m, how, type) { \ 210 int _ms = splimp(); \ 211 if (mmbfree == 0) \ 212 (void)m_mballoc(1, (how)); \ 213 if (((m) = mmbfree) != 0) { \ 214 mmbfree = (m)->m_next; \ 215 mbstat.m_mtypes[MT_FREE]--; \ 216 (m)->m_type = (type); \ 217 mbstat.m_mtypes[type]++; \ 218 (m)->m_next = (struct mbuf *)NULL; \ 219 (m)->m_nextpkt = (struct mbuf *)NULL; \ 220 (m)->m_data = (m)->m_pktdat; \ 221 (m)->m_flags = M_PKTHDR; \ 222 splx(_ms); \ 223 } else { \ 224 splx(_ms); \ 225 (m) = m_retryhdr((how), (type)); \ 226 } \ 227} 228 229/* 230 * Mbuf cluster macros. 231 * MCLALLOC(caddr_t p, int how) allocates an mbuf cluster. 232 * MCLGET adds such clusters to a normal mbuf; 233 * the flag M_EXT is set upon success. 234 * MCLFREE releases a reference to a cluster allocated by MCLALLOC, 235 * freeing the cluster if the reference count has reached 0. 236 */ 237#define MCLALLOC(p, how) \ 238 MBUFLOCK( \ 239 if (mclfree == 0) \ 240 (void)m_clalloc(1, (how)); \ 241 if (((p) = (caddr_t)mclfree) != 0) { \ 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_free = NULL; \ 254 (m)->m_ext.ext_ref = NULL; \ 255 (m)->m_ext.ext_size = MCLBYTES; \ 256 } \ 257 } 258 259#define MCLFREE(p) \ 260 MBUFLOCK ( \ 261 if (--mclrefcnt[mtocl(p)] == 0) { \ 262 ((union mcluster *)(p))->mcl_next = mclfree; \ 263 mclfree = (union mcluster *)(p); \ 264 mbstat.m_clfree++; \ 265 } \ 266 ) 267 268/* 269 * MFREE(struct mbuf *m, struct mbuf *n) 270 * Free a single mbuf and associated external storage. 271 * Place the successor, if any, in n. 272 */ 273#define MFREE(m, n) \ 274 MBUFLOCK( \ 275 mbstat.m_mtypes[(m)->m_type]--; \ 276 if ((m)->m_flags & M_EXT) { \ 277 if ((m)->m_ext.ext_free) \ 278 (*((m)->m_ext.ext_free))((m)->m_ext.ext_buf, \ 279 (m)->m_ext.ext_size); \ 280 else { \ 281 char *p = (m)->m_ext.ext_buf; \ 282 if (--mclrefcnt[mtocl(p)] == 0) { \ 283 ((union mcluster *)(p))->mcl_next = mclfree; \ 284 mclfree = (union mcluster *)(p); \ 285 mbstat.m_clfree++; \ 286 } \ 287 } \ 288 } \ 289 (n) = (m)->m_next; \ 290 (m)->m_type = MT_FREE; \ 291 mbstat.m_mtypes[MT_FREE]++; \ 292 (m)->m_next = mmbfree; \ 293 mmbfree = (m); \ 294 ) 295 296/* 297 * Copy mbuf pkthdr from from to to. 298 * from must have M_PKTHDR set, and to must be empty. 299 */ 300#define M_COPY_PKTHDR(to, from) { \ 301 (to)->m_pkthdr = (from)->m_pkthdr; \ 302 (to)->m_flags = (from)->m_flags & M_COPYFLAGS; \ 303 (to)->m_data = (to)->m_pktdat; \ 304} 305 306/* 307 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place 308 * an object of the specified size at the end of the mbuf, longword aligned. 309 */ 310#define M_ALIGN(m, len) \ 311 { (m)->m_data += (MLEN - (len)) &~ (sizeof(long) - 1); } 312/* 313 * As above, for mbufs allocated with m_gethdr/MGETHDR 314 * or initialized by M_COPY_PKTHDR. 315 */ 316#define MH_ALIGN(m, len) \ 317 { (m)->m_data += (MHLEN - (len)) &~ (sizeof(long) - 1); } 318 319/* 320 * Compute the amount of space available 321 * before the current start of data in an mbuf. 322 */ 323#define M_LEADINGSPACE(m) \ 324 ((m)->m_flags & M_EXT ? /* (m)->m_data - (m)->m_ext.ext_buf */ 0 : \ 325 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 326 (m)->m_data - (m)->m_dat) 327 328/* 329 * Compute the amount of space available 330 * after the end of data in an mbuf. 331 */ 332#define M_TRAILINGSPACE(m) \ 333 ((m)->m_flags & M_EXT ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size - \ 334 ((m)->m_data + (m)->m_len) : \ 335 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 336 337/* 338 * Arrange to prepend space of size plen to mbuf m. 339 * If a new mbuf must be allocated, how specifies whether to wait. 340 * If how is M_DONTWAIT and allocation fails, the original mbuf chain 341 * is freed and m is set to NULL. 342 */ 343#define M_PREPEND(m, plen, how) { \ 344 if (M_LEADINGSPACE(m) >= (plen)) { \ 345 (m)->m_data -= (plen); \ 346 (m)->m_len += (plen); \ 347 } else \ 348 (m) = m_prepend((m), (plen), (how)); \ 349 if ((m) && (m)->m_flags & M_PKTHDR) \ 350 (m)->m_pkthdr.len += (plen); \ 351} 352 353/* change mbuf to new type */ 354#define MCHTYPE(m, t) { \ 355 MBUFLOCK(mbstat.m_mtypes[(m)->m_type]--; mbstat.m_mtypes[t]++;) \ 356 (m)->m_type = t;\ 357} 358 359/* length to m_copy to copy all */ 360#define M_COPYALL 1000000000 361 362/* compatibility with 4.3 */ 363#define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT) 364 365/* 366 * Mbuf statistics. 367 */ 368struct mbstat { 369 u_long m_mbufs; /* mbufs obtained from page pool */ 370 u_long m_clusters; /* clusters obtained from page pool */ 371 u_long m_spare; /* spare field */ 372 u_long m_clfree; /* free clusters */ 373 u_long m_drops; /* times failed to find space */ 374 u_long m_wait; /* times waited for space */ 375 u_long m_drain; /* times drained protocols for space */ 376 u_short m_mtypes[256]; /* type specific mbuf allocations */ 377}; 378 379#ifdef KERNEL 380extern struct mbuf *mbutl; /* virtual address of mclusters */ 381extern char *mclrefcnt; /* cluster reference counts */ 382extern struct mbstat mbstat; 383extern int nmbclusters; 384extern int nmbufs; 385extern struct mbuf *mmbfree; 386extern union mcluster *mclfree; 387extern int max_linkhdr; /* largest link-level header */ 388extern int max_protohdr; /* largest protocol header */ 389extern int max_hdr; /* largest link+protocol header */ 390extern int max_datalen; /* MHLEN - max_hdr */ 391extern int mbtypes[]; /* XXX */ 392 393struct mbuf *m_copym __P((struct mbuf *, int, int, int)); 394struct mbuf *m_copypacket __P((struct mbuf *, int)); 395struct mbuf *m_devget __P((char *, int, int, struct ifnet *, 396 void (*copy)(char *, caddr_t, u_int))); 397struct mbuf *m_free __P((struct mbuf *)); 398struct mbuf *m_get __P((int, int)); 399struct mbuf *m_getclr __P((int, int)); 400struct mbuf *m_gethdr __P((int, int)); 401struct mbuf *m_prepend __P((struct mbuf *,int,int)); 402struct mbuf *m_pullup __P((struct mbuf *, int)); 403struct mbuf *m_retry __P((int, int)); 404struct mbuf *m_retryhdr __P((int, int)); 405struct mbuf *m_split __P((struct mbuf *,int,int)); 406void m_adj __P((struct mbuf *, int)); 407void m_cat __P((struct mbuf *,struct mbuf *)); 408int m_mballoc __P((int, int)); 409int m_clalloc __P((int, int)); 410void m_copyback __P((struct mbuf *, int, int, caddr_t)); 411void m_copydata __P((struct mbuf *,int,int,caddr_t)); 412void m_freem __P((struct mbuf *)); 413 414#ifdef MBTYPES 415int mbtypes[] = { /* XXX */ 416 M_FREE, /* MT_FREE 0 should be on free list */ 417 M_MBUF, /* MT_DATA 1 dynamic (data) allocation */ 418 M_MBUF, /* MT_HEADER 2 packet header */ 419 M_SOCKET, /* MT_SOCKET 3 socket structure */ 420 M_PCB, /* MT_PCB 4 protocol control block */ 421 M_RTABLE, /* MT_RTABLE 5 routing tables */ 422 M_HTABLE, /* MT_HTABLE 6 IMP host tables */ 423 0, /* MT_ATABLE 7 address resolution tables */ 424 M_MBUF, /* MT_SONAME 8 socket name */ 425 0, /* 9 */ 426 M_SOOPTS, /* MT_SOOPTS 10 socket options */ 427 M_FTABLE, /* MT_FTABLE 11 fragment reassembly header */ 428 M_MBUF, /* MT_RIGHTS 12 access rights */ 429 M_IFADDR, /* MT_IFADDR 13 interface address */ 430 M_MBUF, /* MT_CONTROL 14 extra-data protocol message */ 431 M_MBUF, /* MT_OOBDATA 15 expedited data */ 432#ifdef DATAKIT 433 25, 26, 27, 28, 29, 30, 31, 32 /* datakit ugliness */ 434#endif 435}; 436#endif 437#endif 438 439#endif /* !_SYS_MBUF_H_ */ 440