mbuf.h revision 15689
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: mbuf.h,v 1.14 1996/03/11 02:14:16 hsu 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 *)((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}; 93 94struct mbuf { 95 struct m_hdr m_hdr; 96 union { 97 struct { 98 struct pkthdr MH_pkthdr; /* M_PKTHDR set */ 99 union { 100 struct m_ext MH_ext; /* M_EXT set */ 101 char MH_databuf[MHLEN]; 102 } MH_dat; 103 } MH; 104 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ 105 } M_dat; 106}; 107#define m_next m_hdr.mh_next 108#define m_len m_hdr.mh_len 109#define m_data m_hdr.mh_data 110#define m_type m_hdr.mh_type 111#define m_flags m_hdr.mh_flags 112#define m_nextpkt m_hdr.mh_nextpkt 113#define m_act m_nextpkt 114#define m_pkthdr M_dat.MH.MH_pkthdr 115#define m_ext M_dat.MH.MH_dat.MH_ext 116#define m_pktdat M_dat.MH.MH_dat.MH_databuf 117#define m_dat M_dat.M_databuf 118 119/* mbuf flags */ 120#define M_EXT 0x0001 /* has associated external storage */ 121#define M_PKTHDR 0x0002 /* start of record */ 122#define M_EOR 0x0004 /* end of record */ 123 124/* mbuf pkthdr flags, also in m_flags */ 125#define M_BCAST 0x0100 /* send/received as link-level broadcast */ 126#define M_MCAST 0x0200 /* send/received as link-level multicast */ 127 128/* flags copied when copying m_pkthdr */ 129#define M_COPYFLAGS (M_PKTHDR|M_EOR|M_BCAST|M_MCAST) 130 131/* mbuf types */ 132#define MT_FREE 0 /* should be on free list */ 133#define MT_DATA 1 /* dynamic (data) allocation */ 134#define MT_HEADER 2 /* packet header */ 135#define MT_SOCKET 3 /* socket structure */ 136#define MT_PCB 4 /* protocol control block */ 137#define MT_RTABLE 5 /* routing tables */ 138#define MT_HTABLE 6 /* IMP host tables */ 139#define MT_ATABLE 7 /* address resolution tables */ 140#define MT_SONAME 8 /* socket name */ 141#define MT_SOOPTS 10 /* socket options */ 142#define MT_FTABLE 11 /* fragment reassembly header */ 143#define MT_RIGHTS 12 /* access rights */ 144#define MT_IFADDR 13 /* interface address */ 145#define MT_CONTROL 14 /* extra-data protocol message */ 146#define MT_OOBDATA 15 /* expedited data */ 147 148/* flags to m_get/MGET */ 149#define M_DONTWAIT M_NOWAIT 150#define M_WAIT M_WAITOK 151 152/* Freelists: 153 * 154 * Normal mbuf clusters are normally treated as character arrays 155 * after allocation, but use the first word of the buffer as a free list 156 * pointer while on the free list. 157 */ 158union mcluster { 159 union mcluster *mcl_next; 160 char mcl_buf[MCLBYTES]; 161}; 162 163/* 164 * mbuf utility macros: 165 * 166 * MBUFLOCK(code) 167 * prevents a section of code from from being interrupted by network 168 * drivers. 169 */ 170#define MBUFLOCK(code) \ 171 { int ms = splimp(); \ 172 { code } \ 173 splx(ms); \ 174 } 175 176/* 177 * mbuf allocation/deallocation macros: 178 * 179 * MGET(struct mbuf *m, int how, int type) 180 * allocates an mbuf and initializes it to contain internal data. 181 * 182 * MGETHDR(struct mbuf *m, int how, int type) 183 * allocates an mbuf and initializes it to contain a packet header 184 * and internal data. 185 */ 186#define MGET(m, how, type) { \ 187 int _ms = splimp(); \ 188 if (mmbfree == 0) \ 189 (void)m_mballoc(1, (how)); \ 190 if (((m) = mmbfree) != 0) { \ 191 mmbfree = (m)->m_next; \ 192 mbstat.m_mtypes[MT_FREE]--; \ 193 (m)->m_type = (type); \ 194 mbstat.m_mtypes[type]++; \ 195 (m)->m_next = (struct mbuf *)NULL; \ 196 (m)->m_nextpkt = (struct mbuf *)NULL; \ 197 (m)->m_data = (m)->m_dat; \ 198 (m)->m_flags = 0; \ 199 splx(_ms); \ 200 } else { \ 201 splx(_ms); \ 202 (m) = m_retry((how), (type)); \ 203 } \ 204} 205 206#define MGETHDR(m, how, type) { \ 207 int _ms = splimp(); \ 208 if (mmbfree == 0) \ 209 (void)m_mballoc(1, (how)); \ 210 if (((m) = mmbfree) != 0) { \ 211 mmbfree = (m)->m_next; \ 212 mbstat.m_mtypes[MT_FREE]--; \ 213 (m)->m_type = (type); \ 214 mbstat.m_mtypes[type]++; \ 215 (m)->m_next = (struct mbuf *)NULL; \ 216 (m)->m_nextpkt = (struct mbuf *)NULL; \ 217 (m)->m_data = (m)->m_pktdat; \ 218 (m)->m_flags = M_PKTHDR; \ 219 splx(_ms); \ 220 } else { \ 221 splx(_ms); \ 222 (m) = m_retryhdr((how), (type)); \ 223 } \ 224} 225 226/* 227 * Mbuf cluster macros. 228 * MCLALLOC(caddr_t p, int how) allocates an mbuf cluster. 229 * MCLGET adds such clusters to a normal mbuf; 230 * the flag M_EXT is set upon success. 231 * MCLFREE releases a reference to a cluster allocated by MCLALLOC, 232 * freeing the cluster if the reference count has reached 0. 233 */ 234#define MCLALLOC(p, how) \ 235 MBUFLOCK( \ 236 if (mclfree == 0) \ 237 (void)m_clalloc(1, (how)); \ 238 if (((p) = (caddr_t)mclfree) != 0) { \ 239 ++mclrefcnt[mtocl(p)]; \ 240 mbstat.m_clfree--; \ 241 mclfree = ((union mcluster *)(p))->mcl_next; \ 242 } \ 243 ) 244 245#define MCLGET(m, how) \ 246 { MCLALLOC((m)->m_ext.ext_buf, (how)); \ 247 if ((m)->m_ext.ext_buf != NULL) { \ 248 (m)->m_data = (m)->m_ext.ext_buf; \ 249 (m)->m_flags |= M_EXT; \ 250 (m)->m_ext.ext_size = MCLBYTES; \ 251 } \ 252 } 253 254#define MCLFREE(p) \ 255 MBUFLOCK ( \ 256 if (--mclrefcnt[mtocl(p)] == 0) { \ 257 ((union mcluster *)(p))->mcl_next = mclfree; \ 258 mclfree = (union mcluster *)(p); \ 259 mbstat.m_clfree++; \ 260 } \ 261 ) 262 263/* 264 * MFREE(struct mbuf *m, struct mbuf *n) 265 * Free a single mbuf and associated external storage. 266 * Place the successor, if any, in n. 267 */ 268#ifdef notyet 269#define MFREE(m, n) \ 270 { MBUFLOCK(mbstat.m_mtypes[(m)->m_type]--;) \ 271 if ((m)->m_flags & M_EXT) { \ 272 if ((m)->m_ext.ext_free) \ 273 (*((m)->m_ext.ext_free))((m)->m_ext.ext_buf, \ 274 (m)->m_ext.ext_size); \ 275 else { \ 276 char *p = (m)->m_ext.ext_buf; \ 277 if (--mclrefcnt[mtocl(p)] == 0) { \ 278 ((union mcluster *)(p))->mcl_next = mclfree; \ 279 mclfree = (union mcluster *)(p); \ 280 mbstat.m_clfree++; \ 281 } \ 282 } \ 283 (n) = (m)->m_next; \ 284 (m)->m_type = MT_FREE; \ 285 mbstat.m_mtypes[MT_FREE]++; \ 286 (m)->m_next = mmbfree; \ 287 mmbfree = (m); \ 288 } 289#else /* notyet */ 290#define MFREE(m, nn) \ 291 MBUFLOCK ( \ 292 mbstat.m_mtypes[(m)->m_type]--; \ 293 if ((m)->m_flags & M_EXT) { \ 294 char *p = (m)->m_ext.ext_buf; \ 295 if (--mclrefcnt[mtocl(p)] == 0) { \ 296 ((union mcluster *)(p))->mcl_next = mclfree; \ 297 mclfree = (union mcluster *)(p); \ 298 mbstat.m_clfree++; \ 299 } \ 300 } \ 301 (nn) = (m)->m_next; \ 302 (m)->m_type = MT_FREE; \ 303 mbstat.m_mtypes[MT_FREE]++; \ 304 (m)->m_next = mmbfree; \ 305 mmbfree = (m); \ 306 ) 307#endif 308 309/* 310 * Copy mbuf pkthdr from from to to. 311 * from must have M_PKTHDR set, and to must be empty. 312 */ 313#define M_COPY_PKTHDR(to, from) { \ 314 (to)->m_pkthdr = (from)->m_pkthdr; \ 315 (to)->m_flags = (from)->m_flags & M_COPYFLAGS; \ 316 (to)->m_data = (to)->m_pktdat; \ 317} 318 319/* 320 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place 321 * an object of the specified size at the end of the mbuf, longword aligned. 322 */ 323#define M_ALIGN(m, len) \ 324 { (m)->m_data += (MLEN - (len)) &~ (sizeof(long) - 1); } 325/* 326 * As above, for mbufs allocated with m_gethdr/MGETHDR 327 * or initialized by M_COPY_PKTHDR. 328 */ 329#define MH_ALIGN(m, len) \ 330 { (m)->m_data += (MHLEN - (len)) &~ (sizeof(long) - 1); } 331 332/* 333 * Compute the amount of space available 334 * before the current start of data in an mbuf. 335 */ 336#define M_LEADINGSPACE(m) \ 337 ((m)->m_flags & M_EXT ? /* (m)->m_data - (m)->m_ext.ext_buf */ 0 : \ 338 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 339 (m)->m_data - (m)->m_dat) 340 341/* 342 * Compute the amount of space available 343 * after the end of data in an mbuf. 344 */ 345#define M_TRAILINGSPACE(m) \ 346 ((m)->m_flags & M_EXT ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size - \ 347 ((m)->m_data + (m)->m_len) : \ 348 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 349 350/* 351 * Arrange to prepend space of size plen to mbuf m. 352 * If a new mbuf must be allocated, how specifies whether to wait. 353 * If how is M_DONTWAIT and allocation fails, the original mbuf chain 354 * is freed and m is set to NULL. 355 */ 356#define M_PREPEND(m, plen, how) { \ 357 if (M_LEADINGSPACE(m) >= (plen)) { \ 358 (m)->m_data -= (plen); \ 359 (m)->m_len += (plen); \ 360 } else \ 361 (m) = m_prepend((m), (plen), (how)); \ 362 if ((m) && (m)->m_flags & M_PKTHDR) \ 363 (m)->m_pkthdr.len += (plen); \ 364} 365 366/* change mbuf to new type */ 367#define MCHTYPE(m, t) { \ 368 MBUFLOCK(mbstat.m_mtypes[(m)->m_type]--; mbstat.m_mtypes[t]++;) \ 369 (m)->m_type = t;\ 370} 371 372/* length to m_copy to copy all */ 373#define M_COPYALL 1000000000 374 375/* compatibility with 4.3 */ 376#define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT) 377 378/* 379 * Mbuf statistics. 380 */ 381struct mbstat { 382 u_long m_mbufs; /* mbufs obtained from page pool */ 383 u_long m_clusters; /* clusters obtained from page pool */ 384 u_long m_spare; /* spare field */ 385 u_long m_clfree; /* free clusters */ 386 u_long m_drops; /* times failed to find space */ 387 u_long m_wait; /* times waited for space */ 388 u_long m_drain; /* times drained protocols for space */ 389 u_short m_mtypes[256]; /* type specific mbuf allocations */ 390}; 391 392#ifdef KERNEL 393extern struct mbuf *mbutl; /* virtual address of mclusters */ 394extern char *mclrefcnt; /* cluster reference counts */ 395extern struct mbstat mbstat; 396extern int nmbclusters; 397extern struct mbuf *mmbfree; 398extern union mcluster *mclfree; 399extern int max_linkhdr; /* largest link-level header */ 400extern int max_protohdr; /* largest protocol header */ 401extern int max_hdr; /* largest link+protocol header */ 402extern int max_datalen; /* MHLEN - max_hdr */ 403extern int mbtypes[]; /* XXX */ 404 405struct mbuf *m_copym __P((struct mbuf *, int, int, int)); 406struct mbuf *m_copypacket __P((struct mbuf *, int)); 407struct mbuf *m_devget __P((char *, int, int, struct ifnet *, 408 void (*copy)(char *, caddr_t, u_int))); 409struct mbuf *m_free __P((struct mbuf *)); 410struct mbuf *m_get __P((int, int)); 411struct mbuf *m_getclr __P((int, int)); 412struct mbuf *m_gethdr __P((int, int)); 413struct mbuf *m_prepend __P((struct mbuf *,int,int)); 414struct mbuf *m_pullup __P((struct mbuf *, int)); 415struct mbuf *m_retry __P((int, int)); 416struct mbuf *m_retryhdr __P((int, int)); 417struct mbuf *m_split __P((struct mbuf *,int,int)); 418void m_adj __P((struct mbuf *, int)); 419void m_cat __P((struct mbuf *,struct mbuf *)); 420int m_mballoc __P((int, int)); 421int m_clalloc __P((int, int)); 422void m_copyback __P((struct mbuf *, int, int, caddr_t)); 423void m_copydata __P((struct mbuf *,int,int,caddr_t)); 424void m_freem __P((struct mbuf *)); 425 426#ifdef MBTYPES 427int mbtypes[] = { /* XXX */ 428 M_FREE, /* MT_FREE 0 should be on free list */ 429 M_MBUF, /* MT_DATA 1 dynamic (data) allocation */ 430 M_MBUF, /* MT_HEADER 2 packet header */ 431 M_SOCKET, /* MT_SOCKET 3 socket structure */ 432 M_PCB, /* MT_PCB 4 protocol control block */ 433 M_RTABLE, /* MT_RTABLE 5 routing tables */ 434 M_HTABLE, /* MT_HTABLE 6 IMP host tables */ 435 0, /* MT_ATABLE 7 address resolution tables */ 436 M_MBUF, /* MT_SONAME 8 socket name */ 437 0, /* 9 */ 438 M_SOOPTS, /* MT_SOOPTS 10 socket options */ 439 M_FTABLE, /* MT_FTABLE 11 fragment reassembly header */ 440 M_MBUF, /* MT_RIGHTS 12 access rights */ 441 M_IFADDR, /* MT_IFADDR 13 interface address */ 442 M_MBUF, /* MT_CONTROL 14 extra-data protocol message */ 443 M_MBUF, /* MT_OOBDATA 15 expedited data */ 444#ifdef DATAKIT 445 25, 26, 27, 28, 29, 30, 31, 32 /* datakit ugliness */ 446#endif 447}; 448#endif 449#endif 450 451#endif /* !_SYS_MBUF_H_ */ 452