mbuf.h revision 1542
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 */ 35 36#ifndef M_WAITOK 37#include <sys/malloc.h> 38#endif 39 40/* 41 * Mbufs are of a single size, MSIZE (machine/machparam.h), which 42 * includes overhead. An mbuf may add a single "mbuf cluster" of size 43 * MCLBYTES (also in machine/machparam.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 + MLEN) /* 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 *)((int)(x) & ~(MSIZE-1))) 63#define mtocl(x) (((u_int)(x) - (u_int)mbutl) >> MCLSHIFT) 64#define cltom(x) ((caddr_t)((u_int)mbutl + ((u_int)(x) << MCLSHIFT))) 65 66/* header at beginning of each mbuf: */ 67struct m_hdr { 68 struct mbuf *mh_next; /* next buffer in chain */ 69 struct mbuf *mh_nextpkt; /* next chain in queue/record */ 70 int mh_len; /* amount of data in this mbuf */ 71 caddr_t mh_data; /* location of data */ 72 short mh_type; /* type of data in this mbuf */ 73 short mh_flags; /* flags; see below */ 74}; 75 76/* record/packet header in first mbuf of chain; valid if M_PKTHDR set */ 77struct pkthdr { 78 int len; /* total packet length */ 79 struct ifnet *rcvif; /* rcv interface */ 80}; 81 82/* description of external storage mapped into mbuf, valid if M_EXT set */ 83struct m_ext { 84 caddr_t ext_buf; /* start of buffer */ 85 void (*ext_free)(); /* free routine if not the usual */ 86 u_int ext_size; /* size of buffer, for ext_free */ 87}; 88 89struct mbuf { 90 struct m_hdr m_hdr; 91 union { 92 struct { 93 struct pkthdr MH_pkthdr; /* M_PKTHDR set */ 94 union { 95 struct m_ext MH_ext; /* M_EXT set */ 96 char MH_databuf[MHLEN]; 97 } MH_dat; 98 } MH; 99 char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ 100 } M_dat; 101}; 102#define m_next m_hdr.mh_next 103#define m_len m_hdr.mh_len 104#define m_data m_hdr.mh_data 105#define m_type m_hdr.mh_type 106#define m_flags m_hdr.mh_flags 107#define m_nextpkt m_hdr.mh_nextpkt 108#define m_act m_nextpkt 109#define m_pkthdr M_dat.MH.MH_pkthdr 110#define m_ext M_dat.MH.MH_dat.MH_ext 111#define m_pktdat M_dat.MH.MH_dat.MH_databuf 112#define m_dat M_dat.M_databuf 113 114/* mbuf flags */ 115#define M_EXT 0x0001 /* has associated external storage */ 116#define M_PKTHDR 0x0002 /* start of record */ 117#define M_EOR 0x0004 /* end of record */ 118 119/* mbuf pkthdr flags, also in m_flags */ 120#define M_BCAST 0x0100 /* send/received as link-level broadcast */ 121#define M_MCAST 0x0200 /* send/received as link-level multicast */ 122 123/* flags copied when copying m_pkthdr */ 124#define M_COPYFLAGS (M_PKTHDR|M_EOR|M_BCAST|M_MCAST) 125 126/* mbuf types */ 127#define MT_FREE 0 /* should be on free list */ 128#define MT_DATA 1 /* dynamic (data) allocation */ 129#define MT_HEADER 2 /* packet header */ 130#define MT_SOCKET 3 /* socket structure */ 131#define MT_PCB 4 /* protocol control block */ 132#define MT_RTABLE 5 /* routing tables */ 133#define MT_HTABLE 6 /* IMP host tables */ 134#define MT_ATABLE 7 /* address resolution tables */ 135#define MT_SONAME 8 /* socket name */ 136#define MT_SOOPTS 10 /* socket options */ 137#define MT_FTABLE 11 /* fragment reassembly header */ 138#define MT_RIGHTS 12 /* access rights */ 139#define MT_IFADDR 13 /* interface address */ 140#define MT_CONTROL 14 /* extra-data protocol message */ 141#define MT_OOBDATA 15 /* expedited data */ 142 143/* flags to m_get/MGET */ 144#define M_DONTWAIT M_NOWAIT 145#define M_WAIT M_WAITOK 146 147/* 148 * mbuf utility macros: 149 * 150 * MBUFLOCK(code) 151 * prevents a section of code from from being interrupted by network 152 * drivers. 153 */ 154#define MBUFLOCK(code) \ 155 { int ms = splimp(); \ 156 { code } \ 157 splx(ms); \ 158 } 159 160/* 161 * mbuf allocation/deallocation macros: 162 * 163 * MGET(struct mbuf *m, int how, int type) 164 * allocates an mbuf and initializes it to contain internal data. 165 * 166 * MGETHDR(struct mbuf *m, int how, int type) 167 * allocates an mbuf and initializes it to contain a packet header 168 * and internal data. 169 */ 170#define MGET(m, how, type) { \ 171 MALLOC((m), struct mbuf *, MSIZE, mbtypes[type], (how)); \ 172 if (m) { \ 173 (m)->m_type = (type); \ 174 MBUFLOCK(mbstat.m_mtypes[type]++;) \ 175 (m)->m_next = (struct mbuf *)NULL; \ 176 (m)->m_nextpkt = (struct mbuf *)NULL; \ 177 (m)->m_data = (m)->m_dat; \ 178 (m)->m_flags = 0; \ 179 } else \ 180 (m) = m_retry((how), (type)); \ 181} 182 183#define MGETHDR(m, how, type) { \ 184 MALLOC((m), struct mbuf *, MSIZE, mbtypes[type], (how)); \ 185 if (m) { \ 186 (m)->m_type = (type); \ 187 MBUFLOCK(mbstat.m_mtypes[type]++;) \ 188 (m)->m_next = (struct mbuf *)NULL; \ 189 (m)->m_nextpkt = (struct mbuf *)NULL; \ 190 (m)->m_data = (m)->m_pktdat; \ 191 (m)->m_flags = M_PKTHDR; \ 192 } else \ 193 (m) = m_retryhdr((how), (type)); \ 194} 195 196/* 197 * Mbuf cluster macros. 198 * MCLALLOC(caddr_t p, int how) allocates an mbuf cluster. 199 * MCLGET adds such clusters to a normal mbuf; 200 * the flag M_EXT is set upon success. 201 * MCLFREE releases a reference to a cluster allocated by MCLALLOC, 202 * freeing the cluster if the reference count has reached 0. 203 * 204 * Normal mbuf clusters are normally treated as character arrays 205 * after allocation, but use the first word of the buffer as a free list 206 * pointer while on the free list. 207 */ 208union mcluster { 209 union mcluster *mcl_next; 210 char mcl_buf[MCLBYTES]; 211}; 212 213#define MCLALLOC(p, how) \ 214 MBUFLOCK( \ 215 if (mclfree == 0) \ 216 (void)m_clalloc(1, (how)); \ 217 if ((p) = (caddr_t)mclfree) { \ 218 ++mclrefcnt[mtocl(p)]; \ 219 mbstat.m_clfree--; \ 220 mclfree = ((union mcluster *)(p))->mcl_next; \ 221 } \ 222 ) 223 224#define MCLGET(m, how) \ 225 { MCLALLOC((m)->m_ext.ext_buf, (how)); \ 226 if ((m)->m_ext.ext_buf != NULL) { \ 227 (m)->m_data = (m)->m_ext.ext_buf; \ 228 (m)->m_flags |= M_EXT; \ 229 (m)->m_ext.ext_size = MCLBYTES; \ 230 } \ 231 } 232 233#define MCLFREE(p) \ 234 MBUFLOCK ( \ 235 if (--mclrefcnt[mtocl(p)] == 0) { \ 236 ((union mcluster *)(p))->mcl_next = mclfree; \ 237 mclfree = (union mcluster *)(p); \ 238 mbstat.m_clfree++; \ 239 } \ 240 ) 241 242/* 243 * MFREE(struct mbuf *m, struct mbuf *n) 244 * Free a single mbuf and associated external storage. 245 * Place the successor, if any, in n. 246 */ 247#ifdef notyet 248#define MFREE(m, n) \ 249 { MBUFLOCK(mbstat.m_mtypes[(m)->m_type]--;) \ 250 if ((m)->m_flags & M_EXT) { \ 251 if ((m)->m_ext.ext_free) \ 252 (*((m)->m_ext.ext_free))((m)->m_ext.ext_buf, \ 253 (m)->m_ext.ext_size); \ 254 else \ 255 MCLFREE((m)->m_ext.ext_buf); \ 256 } \ 257 (n) = (m)->m_next; \ 258 FREE((m), mbtypes[(m)->m_type]); \ 259 } 260#else /* notyet */ 261#define MFREE(m, nn) \ 262 { MBUFLOCK(mbstat.m_mtypes[(m)->m_type]--;) \ 263 if ((m)->m_flags & M_EXT) { \ 264 MCLFREE((m)->m_ext.ext_buf); \ 265 } \ 266 (nn) = (m)->m_next; \ 267 FREE((m), mbtypes[(m)->m_type]); \ 268 } 269#endif 270 271/* 272 * Copy mbuf pkthdr from from to to. 273 * from must have M_PKTHDR set, and to must be empty. 274 */ 275#define M_COPY_PKTHDR(to, from) { \ 276 (to)->m_pkthdr = (from)->m_pkthdr; \ 277 (to)->m_flags = (from)->m_flags & M_COPYFLAGS; \ 278 (to)->m_data = (to)->m_pktdat; \ 279} 280 281/* 282 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place 283 * an object of the specified size at the end of the mbuf, longword aligned. 284 */ 285#define M_ALIGN(m, len) \ 286 { (m)->m_data += (MLEN - (len)) &~ (sizeof(long) - 1); } 287/* 288 * As above, for mbufs allocated with m_gethdr/MGETHDR 289 * or initialized by M_COPY_PKTHDR. 290 */ 291#define MH_ALIGN(m, len) \ 292 { (m)->m_data += (MHLEN - (len)) &~ (sizeof(long) - 1); } 293 294/* 295 * Compute the amount of space available 296 * before the current start of data in an mbuf. 297 */ 298#define M_LEADINGSPACE(m) \ 299 ((m)->m_flags & M_EXT ? /* (m)->m_data - (m)->m_ext.ext_buf */ 0 : \ 300 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ 301 (m)->m_data - (m)->m_dat) 302 303/* 304 * Compute the amount of space available 305 * after the end of data in an mbuf. 306 */ 307#define M_TRAILINGSPACE(m) \ 308 ((m)->m_flags & M_EXT ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size - \ 309 ((m)->m_data + (m)->m_len) : \ 310 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) 311 312/* 313 * Arrange to prepend space of size plen to mbuf m. 314 * If a new mbuf must be allocated, how specifies whether to wait. 315 * If how is M_DONTWAIT and allocation fails, the original mbuf chain 316 * is freed and m is set to NULL. 317 */ 318#define M_PREPEND(m, plen, how) { \ 319 if (M_LEADINGSPACE(m) >= (plen)) { \ 320 (m)->m_data -= (plen); \ 321 (m)->m_len += (plen); \ 322 } else \ 323 (m) = m_prepend((m), (plen), (how)); \ 324 if ((m) && (m)->m_flags & M_PKTHDR) \ 325 (m)->m_pkthdr.len += (plen); \ 326} 327 328/* change mbuf to new type */ 329#define MCHTYPE(m, t) { \ 330 MBUFLOCK(mbstat.m_mtypes[(m)->m_type]--; mbstat.m_mtypes[t]++;) \ 331 (m)->m_type = t;\ 332} 333 334/* length to m_copy to copy all */ 335#define M_COPYALL 1000000000 336 337/* compatiblity with 4.3 */ 338#define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT) 339 340/* 341 * Mbuf statistics. 342 */ 343struct mbstat { 344 u_long m_mbufs; /* mbufs obtained from page pool */ 345 u_long m_clusters; /* clusters obtained from page pool */ 346 u_long m_spare; /* spare field */ 347 u_long m_clfree; /* free clusters */ 348 u_long m_drops; /* times failed to find space */ 349 u_long m_wait; /* times waited for space */ 350 u_long m_drain; /* times drained protocols for space */ 351 u_short m_mtypes[256]; /* type specific mbuf allocations */ 352}; 353 354#ifdef KERNEL 355extern struct mbuf *mbutl; /* virtual address of mclusters */ 356extern char *mclrefcnt; /* cluster reference counts */ 357struct mbstat mbstat; 358extern int nmbclusters; 359union mcluster *mclfree; 360int max_linkhdr; /* largest link-level header */ 361int max_protohdr; /* largest protocol header */ 362int max_hdr; /* largest link+protocol header */ 363int max_datalen; /* MHLEN - max_hdr */ 364extern int mbtypes[]; /* XXX */ 365 366struct mbuf *m_copym __P((struct mbuf *, int, int, int)); 367struct mbuf *m_free __P((struct mbuf *)); 368struct mbuf *m_get __P((int, int)); 369struct mbuf *m_getclr __P((int, int)); 370struct mbuf *m_gethdr __P((int, int)); 371struct mbuf *m_prepend __P((struct mbuf *, int, int)); 372struct mbuf *m_pullup __P((struct mbuf *, int)); 373struct mbuf *m_retry __P((int, int)); 374struct mbuf *m_retryhdr __P((int, int)); 375int m_clalloc __P((int, int)); 376void m_copyback __P((struct mbuf *, int, int, caddr_t)); 377void m_freem __P((struct mbuf *)); 378 379#ifdef MBTYPES 380int mbtypes[] = { /* XXX */ 381 M_FREE, /* MT_FREE 0 should be on free list */ 382 M_MBUF, /* MT_DATA 1 dynamic (data) allocation */ 383 M_MBUF, /* MT_HEADER 2 packet header */ 384 M_SOCKET, /* MT_SOCKET 3 socket structure */ 385 M_PCB, /* MT_PCB 4 protocol control block */ 386 M_RTABLE, /* MT_RTABLE 5 routing tables */ 387 M_HTABLE, /* MT_HTABLE 6 IMP host tables */ 388 0, /* MT_ATABLE 7 address resolution tables */ 389 M_MBUF, /* MT_SONAME 8 socket name */ 390 0, /* 9 */ 391 M_SOOPTS, /* MT_SOOPTS 10 socket options */ 392 M_FTABLE, /* MT_FTABLE 11 fragment reassembly header */ 393 M_MBUF, /* MT_RIGHTS 12 access rights */ 394 M_IFADDR, /* MT_IFADDR 13 interface address */ 395 M_MBUF, /* MT_CONTROL 14 extra-data protocol message */ 396 M_MBUF, /* MT_OOBDATA 15 expedited data */ 397#ifdef DATAKIT 398 25, 26, 27, 28, 29, 30, 31, 32 /* datakit ugliness */ 399#endif 400}; 401#endif 402#endif 403