bsd/sys/mbuf.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /* Copyright (c) 1998, 1999 Apple Computer, Inc. All Rights Reserved */
  23 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  24 /*
  25  * Mach Operating System
  26  * Copyright (c) 1987 Carnegie-Mellon University
  27  * All rights reserved.  The CMU software License Agreement specifies
  28  * the terms and conditions for use and redistribution.
  29  */
  30 /*
  31  * Copyright (c) 1994 NeXT Computer, Inc. All rights reserved.
  32  *
  33  * Copyright (c) 1982, 1986, 1988 Regents of the University of California.
  34  * All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 3. All advertising materials mentioning features or use of this software
  45  *    must display the following acknowledgement:
  46  *      This product includes software developed by the University of
  47  *      California, Berkeley and its contributors.
  48  * 4. Neither the name of the University nor the names of its contributors
  49  *    may be used to endorse or promote products derived from this software
  50  *    without specific prior written permission.
  51  *
  52  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  62  * SUCH DAMAGE.
  63  *
  64  *      @(#)mbuf.h      8.3 (Berkeley) 1/21/94
  65  **********************************************************************
  66  * HISTORY
  67  * 20-May-95  Mac Gillon (mgillon) at NeXT
  68  *      New version based on 4.4
  69  *      Purged old history
  70  */
  71
  72 #ifndef _SYS_MBUF_H_
  73 #define _SYS_MBUF_H_
  74
  75 #include <sys/lock.h>
  76
  77 /*
  78  * Mbufs are of a single size, MSIZE (machine/param.h), which
  79  * includes overhead.  An mbuf may add a single "mbuf cluster" of size
  80  * MCLBYTES (also in machine/param.h), which has no additional overhead
  81  * and is used instead of the internal data area; this is done when
  82  * at least MINCLSIZE of data must be stored.
  83  */
  84
  85 #define MLEN            (MSIZE - sizeof(struct m_hdr))  /* normal data len */
  86 #define MHLEN           (MLEN - sizeof(struct pkthdr))  /* data len w/pkthdr */
  87
  88 #define MINCLSIZE       (MHLEN + MLEN)  /* smallest amount to put in cluster */
  89 #define M_MAXCOMPRESS   (MHLEN / 2)     /* max amount to copy for compression */
  90
  91 #define NMBPCL          (sizeof(union mcluster) / sizeof(struct mbuf))
  92
  93
  94 /*
  95  * Macros for type conversion
  96  * mtod(m,t) -  convert mbuf pointer to data pointer of correct type
  97  * dtom(x) -    convert data pointer within mbuf to mbuf pointer (XXX)
  98  * mtocl(x) -   convert pointer within cluster to cluster index #
  99  * cltom(x) -   convert cluster # to ptr to beginning of cluster
 100  */
 101 #define mtod(m,t)       ((t)((m)->m_data))
 102 #define dtom(x)         ((struct mbuf *)((u_long)(x) & ~(MSIZE-1)))
 103 #define mtocl(x)        ((union mcluster *)(x) - (union mcluster *)mbutl)
 104 #define cltom(x)        ((union mcluster *)(mbutl + (x)))
 105
 106 #define MCLREF(p)       (++mclrefcnt[mtocl(p)])
 107 #define MCLUNREF(p)     (--mclrefcnt[mtocl(p)] == 0)
 108
 109 /* header at beginning of each mbuf: */
 110 struct m_hdr {
 111         struct  mbuf *mh_next;          /* next buffer in chain */
 112         struct  mbuf *mh_nextpkt;       /* next chain in queue/record */
 113         long    mh_len;                 /* amount of data in this mbuf */
 114         caddr_t mh_data;                /* location of data */
 115         short   mh_type;                /* type of data in this mbuf */
 116         short   mh_flags;               /* flags; see below */
 117 };
 118
 119 /* record/packet header in first mbuf of chain; valid if M_PKTHDR set */
 120 struct  pkthdr {
 121         int     len;                    /* total packet length */
 122         struct  ifnet *rcvif;           /* rcv interface */
 123
 124         /* variables for ip and tcp reassembly */
 125         void    *header;                /* pointer to packet header */
 126         /* variables for hardware checksum */
 127         int     csum_flags;             /* flags regarding checksum */
 128         int     csum_data;              /* data field used by csum routines */
 129         struct mbuf *aux;               /* extra data buffer; ipsec/others */
 130         void    *reserved1;             /* for future use */
 131         void    *reserved2;             /* for future use */
 132 };
 133
 134
 135 /* description of external storage mapped into mbuf, valid if M_EXT set */
 136 struct m_ext {
 137         caddr_t ext_buf;                /* start of buffer */
 138         void    (*ext_free)();          /* free routine if not the usual */
 139         u_int   ext_size;               /* size of buffer, for ext_free */
 140         caddr_t ext_arg;                /* additional ext_free argument */
 141         struct  ext_refsq {             /* references held */
 142                 struct ext_refsq *forward, *backward;
 143         } ext_refs;
 144 };
 145
 146 struct mbuf {
 147         struct  m_hdr m_hdr;
 148         union {
 149                 struct {
 150                         struct  pkthdr MH_pkthdr;       /* M_PKTHDR set */
 151                         union {
 152                                 struct  m_ext MH_ext;   /* M_EXT set */
 153                                 char    MH_databuf[MHLEN];
 154                         } MH_dat;
 155                 } MH;
 156                 char    M_databuf[MLEN];                /* !M_PKTHDR, !M_EXT */
 157         } M_dat;
 158 };
 159
 160 #define m_next          m_hdr.mh_next
 161 #define m_len           m_hdr.mh_len
 162 #define m_data          m_hdr.mh_data
 163 #define m_type          m_hdr.mh_type
 164 #define m_flags         m_hdr.mh_flags
 165 #define m_nextpkt       m_hdr.mh_nextpkt
 166 #define m_act           m_nextpkt
 167 #define m_pkthdr        M_dat.MH.MH_pkthdr
 168 #define m_ext           M_dat.MH.MH_dat.MH_ext
 169 #define m_pktdat        M_dat.MH.MH_dat.MH_databuf
 170 #define m_dat           M_dat.M_databuf
 171
 172 /* mbuf flags */
 173 #define M_EXT           0x0001  /* has associated external storage */
 174 #define M_PKTHDR        0x0002  /* start of record */
 175 #define M_EOR           0x0004  /* end of record */
 176 #define M_PROTO1        0x0008  /* protocol-specific */
 177
 178 #define M_MIP6TUNNEL    0x0010  /* MIP6 temporary use */
 179
 180 /* mbuf pkthdr flags, also in m_flags */
 181 #define M_BCAST         0x0100  /* send/received as link-level broadcast */
 182 #define M_MCAST         0x0200  /* send/received as link-level multicast */
 183 #define M_FRAG          0x0400  /* packet is a fragment of a larger packet */
 184 #define M_ANYCAST6      0x0800  /* received as IPv6 anycast */
 185
 186 /* mbuf pkthdr flags, also in m_flags */
 187 #define M_AUTHIPHDR     0x1000  /* data origin authentication for IP header */
 188 #define M_DECRYPTED     0x2000  /* confidentiality */
 189 #define M_LOOP          0x4000  /* for Mbuf statistics */
 190 #define M_AUTHIPDGM     0x8000  /* data origin authentication */
 191
 192 /* flags copied when copying m_pkthdr */
 193 #define M_COPYFLAGS     (M_PKTHDR|M_EOR|M_BCAST|M_MCAST|M_FRAG|M_ANYCAST6|M_AUTHIPHDR|M_DECRYPTED|M_LOOP|M_AUTHIPDGM)
 194
 195 /* flags indicating hw checksum support and sw checksum requirements [freebsd4.1]*/
 196 #define CSUM_IP                 0x0001          /* will csum IP */
 197 #define CSUM_TCP                0x0002          /* will csum TCP */
 198 #define CSUM_UDP                0x0004          /* will csum UDP */
 199 #define CSUM_IP_FRAGS           0x0008          /* will csum IP fragments */
 200 #define CSUM_FRAGMENT           0x0010          /* will do IP fragmentation */
 201
 202 #define CSUM_IP_CHECKED         0x0100          /* did csum IP */
 203 #define CSUM_IP_VALID           0x0200          /*   ... the csum is valid */
 204 #define CSUM_DATA_VALID         0x0400          /* csum_data field is valid */
 205 #define CSUM_PSEUDO_HDR         0x0800          /* csum_data has pseudo hdr */
 206 #define CSUM_TCP_SUM16          0x1000          /* simple TCP Sum16 computation */
 207
 208 #define CSUM_DELAY_DATA         (CSUM_TCP | CSUM_UDP)
 209 #define CSUM_DELAY_IP           (CSUM_IP)       /* XXX add ipv6 here too? */
 210
 211
 212 /* mbuf types */
 213 #define MT_FREE         0       /* should be on free list */
 214 #define MT_DATA         1       /* dynamic (data) allocation */
 215 #define MT_HEADER       2       /* packet header */
 216 #define MT_SOCKET       3       /* socket structure */
 217 #define MT_PCB          4       /* protocol control block */
 218 #define MT_RTABLE       5       /* routing tables */
 219 #define MT_HTABLE       6       /* IMP host tables */
 220 #define MT_ATABLE       7       /* address resolution tables */
 221 #define MT_SONAME       8       /* socket name */
 222 #define MT_SOOPTS       10      /* socket options */
 223 #define MT_FTABLE       11      /* fragment reassembly header */
 224 #define MT_RIGHTS       12      /* access rights */
 225 #define MT_IFADDR       13      /* interface address */
 226 #define MT_CONTROL      14      /* extra-data protocol message */
 227 #define MT_OOBDATA      15      /* expedited data  */
 228 #define MT_MAX          32      /* enough? */
 229
 230 /* flags to m_get/MGET */
 231 /* Need to include malloc.h to get right options for malloc  */
 232 #include        <sys/malloc.h>
 233
 234 #define M_DONTWAIT      M_NOWAIT
 235 #define M_WAIT          M_WAITOK
 236
 237 /*
 238  * mbuf utility macros:
 239  *
 240  *      MBUFLOCK(code)
 241  * prevents a section of code from from being interrupted by network
 242  * drivers.
 243  */
 244
 245
 246 extern
 247 decl_simple_lock_data(, mbuf_slock);
 248 #define MBUF_LOCK() usimple_lock(&mbuf_slock);
 249 #define MBUF_UNLOCK() usimple_unlock(&mbuf_slock);
 250 #define MBUF_LOCKINIT() simple_lock_init(&mbuf_slock);
 251
 252
 253 /*
 254  * mbuf allocation/deallocation macros:
 255  *
 256  *      MGET(struct mbuf *m, int how, int type)
 257  * allocates an mbuf and initializes it to contain internal data.
 258  *
 259  *      MGETHDR(struct mbuf *m, int how, int type)
 260  * allocates an mbuf and initializes it to contain a packet header
 261  * and internal data.
 262  */
 263
 264 #if 1
 265 #define MCHECK(m) if ((m)->m_type != MT_FREE) panic("mget MCHECK: m_type=%x m=%x", m->m_type, m)
 266 #else
 267 #define MCHECK(m)
 268 #endif
 269
 270 extern struct mbuf *mfree;                              /* mbuf free list */
 271 extern simple_lock_data_t   mbuf_slock;
 272
 273 #define _MINTGET(m, type) {                                             \
 274         MBUF_LOCK();                                                    \
 275         if (((m) = mfree) != 0) {                                       \
 276                 MCHECK(m);                                                              \
 277                 ++mclrefcnt[mtocl(m)];                                  \
 278                 mbstat.m_mtypes[MT_FREE]--;                             \
 279                 mbstat.m_mtypes[type]++;                                \
 280                 mfree = (m)->m_next;                                    \
 281         }                                                               \
 282         MBUF_UNLOCK();                                                  \
 283 }
 284
 285 #define MGET(m, how, type) {                                            \
 286         _MINTGET(m, type);                                              \
 287         if (m) {                                                        \
 288                 (m)->m_next = (m)->m_nextpkt = 0;                       \
 289                 (m)->m_type = (type);                                   \
 290                 (m)->m_data = (m)->m_dat;                               \
 291                 (m)->m_flags = 0;                                       \
 292         } else                                                          \
 293                 (m) = m_retry((how), (type));                           \
 294 }
 295
 296 #define MGETHDR(m, how, type) {                                         \
 297         _MINTGET(m, type);                                              \
 298         if (m) {                                                        \
 299                 (m)->m_next = (m)->m_nextpkt = 0;                       \
 300                 (m)->m_type = (type);                                   \
 301                 (m)->m_data = (m)->m_pktdat;                            \
 302                 (m)->m_flags = M_PKTHDR;                                \
 303                 (m)->m_pkthdr.rcvif = NULL;                             \
 304                 (m)->m_pkthdr.header = NULL;                            \
 305                 (m)->m_pkthdr.csum_flags = 0;                           \
 306                 (m)->m_pkthdr.csum_data = 0;                            \
 307                 (m)->m_pkthdr.aux = (struct mbuf *)NULL;                \
 308                 (m)->m_pkthdr.reserved1 = NULL;                         \
 309                 (m)->m_pkthdr.reserved2 = NULL;                         \
 310         } else                                                          \
 311                 (m) = m_retryhdr((how), (type));                        \
 312 }
 313
 314 /*
 315  * Mbuf cluster macros.
 316  * MCLALLOC(caddr_t p, int how) allocates an mbuf cluster.
 317  * MCLGET adds such clusters to a normal mbuf;
 318  * the flag M_EXT is set upon success.
 319  * MCLFREE releases a reference to a cluster allocated by MCLALLOC,
 320  * freeing the cluster if the reference count has reached 0.
 321  *
 322  * Normal mbuf clusters are normally treated as character arrays
 323  * after allocation, but use the first word of the buffer as a free list
 324  * pointer while on the free list.
 325  */
 326 union mcluster {
 327         union   mcluster *mcl_next;
 328         char    mcl_buf[MCLBYTES];
 329 };
 330
 331 #define MCLALLOC(p, how) {                                                      \
 332         (void)m_clalloc(1, (how));                                              \
 333         if (((p) = (caddr_t)mclfree)) {                                         \
 334                 ++mclrefcnt[mtocl(p)];                                          \
 335                 mbstat.m_clfree--;                                                      \
 336                 mclfree = ((union mcluster *)(p))->mcl_next;            \
 337         }                                                               \
 338         MBUF_UNLOCK();                                                  \
 339 }
 340
 341 #define MCLGET(m, how) {                                                \
 342         MCLALLOC((m)->m_ext.ext_buf, (how));                            \
 343         if ((m)->m_ext.ext_buf) {                                       \
 344                 (m)->m_data = (m)->m_ext.ext_buf;                       \
 345                 (m)->m_flags |= M_EXT;                                  \
 346                 (m)->m_ext.ext_size = MCLBYTES;                         \
 347                 (m)->m_ext.ext_free = 0;                                \
 348                 (m)->m_ext.ext_refs.forward = (m)->m_ext.ext_refs.backward = \
 349                         &(m)->m_ext.ext_refs; \
 350         }                                                               \
 351 }
 352
 353 #define MCLFREE(p) {                                                    \
 354         MBUF_LOCK();                                                    \
 355         if (--mclrefcnt[mtocl(p)] == 0) {                               \
 356                 ((union mcluster *)(p))->mcl_next = mclfree;            \
 357                 mclfree = (union mcluster *)(p);                        \
 358                 mbstat.m_clfree++;                                      \
 359         }                                                               \
 360         MBUF_UNLOCK();                                                  \
 361 }
 362
 363 #define MCLHASREFERENCE(m) \
 364         ((m)->m_ext.ext_refs.forward != &((m)->m_ext.ext_refs))
 365
 366 /*
 367  * MFREE(struct mbuf *m, struct mbuf *n)
 368  * Free a single mbuf and associated external storage.
 369  * Place the successor, if any, in n.
 370  */
 371
 372 #define MFREE(m, n) (n) = m_free(m)
 373
 374 /*
 375  * Copy mbuf pkthdr from from to to.
 376  * from must have M_PKTHDR set, and to must be empty.
 377  * aux pointer will be moved to `to'.
 378  */
 379 #define M_COPY_PKTHDR(to, from) { \
 380         (to)->m_pkthdr = (from)->m_pkthdr; \
 381         (from)->m_pkthdr.aux = (struct mbuf *)NULL; \
 382         (to)->m_flags = (from)->m_flags & M_COPYFLAGS; \
 383         (to)->m_data = (to)->m_pktdat; \
 384 }
 385
 386 /*
 387  * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place
 388  * an object of the specified size at the end of the mbuf, longword aligned.
 389  */
 390 #define M_ALIGN(m, len)                                                 \
 391         { (m)->m_data += (MLEN - (len)) &~ (sizeof(long) - 1); }
 392 /*
 393  * As above, for mbufs allocated with m_gethdr/MGETHDR
 394  * or initialized by M_COPY_PKTHDR.
 395  */
 396 #define MH_ALIGN(m, len) \
 397         { (m)->m_data += (MHLEN - (len)) &~ (sizeof(long) - 1); }
 398
 399 /*
 400  * Compute the amount of space available
 401  * before the current start of data in an mbuf.
 402  * Subroutine - data not available if certain references.
 403  */
 404 int m_leadingspace(struct mbuf *);
 405 #define M_LEADINGSPACE(m)       m_leadingspace(m)
 406
 407 /*
 408  * Compute the amount of space available
 409  * after the end of data in an mbuf.
 410  * Subroutine - data not available if certain references.
 411  */
 412 int m_trailingspace(struct mbuf *);
 413 #define M_TRAILINGSPACE(m)      m_trailingspace(m)
 414
 415 /*
 416  * Arrange to prepend space of size plen to mbuf m.
 417  * If a new mbuf must be allocated, how specifies whether to wait.
 418  * If how is M_DONTWAIT and allocation fails, the original mbuf chain
 419  * is freed and m is set to NULL.
 420  */
 421 #define M_PREPEND(m, plen, how) {                                       \
 422         if (M_LEADINGSPACE(m) >= (plen)) {                              \
 423                 (m)->m_data -= (plen);                                  \
 424                 (m)->m_len += (plen);                                   \
 425         } else                                                          \
 426                 (m) = m_prepend((m), (plen), (how));                    \
 427         if ((m) && (m)->m_flags & M_PKTHDR)                             \
 428                 (m)->m_pkthdr.len += (plen);                            \
 429 }
 430
 431 /* change mbuf to new type */
 432 #define MCHTYPE(m, t) {                                                 \
 433         MBUF_LOCK();                                                    \
 434         mbstat.m_mtypes[(m)->m_type]--;                                 \
 435         mbstat.m_mtypes[t]++;                                           \
 436         (m)->m_type = t;                                                \
 437         MBUF_UNLOCK();                                                  \
 438 }
 439
 440 /* length to m_copy to copy all */
 441 #define M_COPYALL       1000000000
 442
 443 /* compatiblity with 4.3 */
 444 #define  m_copy(m, o, l)        m_copym((m), (o), (l), M_DONTWAIT)
 445
 446 /*
 447  * Mbuf statistics.
 448  */
 449 struct mbstat {
 450         u_long  m_mbufs;        /* mbufs obtained from page pool */
 451         u_long  m_clusters;     /* clusters obtained from page pool */
 452         u_long  m_spare;        /* spare field */
 453         u_long  m_clfree;       /* free clusters */
 454         u_long  m_drops;        /* times failed to find space */
 455         u_long  m_wait;         /* times waited for space */
 456         u_long  m_drain;        /* times drained protocols for space */
 457         u_short m_mtypes[256];  /* type specific mbuf allocations */
 458         u_long  m_mcfail;       /* times m_copym failed */
 459         u_long  m_mpfail;       /* times m_pullup failed */
 460         u_long  m_msize;        /* length of an mbuf */
 461         u_long  m_mclbytes;     /* length of an mbuf cluster */
 462         u_long  m_minclsize;    /* min length of data to allocate a cluster */
 463         u_long  m_mlen;         /* length of data in an mbuf */
 464         u_long  m_mhlen;        /* length of data in a header mbuf */
 465 };
 466
 467 /*
 468  * pkthdr.aux type tags.
 469  */
 470 struct mauxtag {
 471         int af;
 472         int type;
 473 };
 474
 475 #ifdef  KERNEL
 476 extern union    mcluster *mbutl;        /* virtual address of mclusters */
 477 extern union    mcluster *embutl;       /* ending virtual address of mclusters */
 478 extern short    *mclrefcnt;             /* cluster reference counts */
 479 extern int      *mcl_paddr;             /* physical addresses of clusters */
 480 extern struct   mbstat mbstat;          /* statistics */
 481 extern int      nmbclusters;            /* number of mapped clusters */
 482 extern union    mcluster *mclfree;      /* free mapped cluster list */
 483 extern int      max_linkhdr;            /* largest link-level header */
 484 extern int      max_protohdr;           /* largest protocol header */
 485 extern int      max_hdr;                /* largest link+protocol header */
 486 extern int      max_datalen;            /* MHLEN - max_hdr */
 487
 488 struct  mbuf *m_copym __P((struct mbuf *, int, int, int));
 489 struct  mbuf *m_free __P((struct mbuf *));
 490 struct  mbuf *m_get __P((int, int));
 491 struct  mbuf *m_getpacket __P((void));
 492 struct  mbuf *m_getclr __P((int, int));
 493 struct  mbuf *m_gethdr __P((int, int));
 494 struct  mbuf *m_prepend __P((struct mbuf *, int, int));
 495 struct  mbuf *m_pullup __P((struct mbuf *, int));
 496 struct  mbuf *m_retry __P((int, int));
 497 struct  mbuf *m_retryhdr __P((int, int));
 498 void m_adj __P((struct mbuf *, int));
 499 int      m_clalloc __P((int, int));
 500 void m_freem __P((struct mbuf *));
 501 int m_freem_list __P((struct mbuf *));
 502 struct  mbuf *m_devget __P((char *, int, int, struct ifnet *, void (*)()));
 503 char   *mcl_to_paddr __P((char *));
 504 struct mbuf *m_aux_add __P((struct mbuf *, int, int));
 505 struct mbuf *m_aux_find __P((struct mbuf *, int, int));
 506 void m_aux_delete __P((struct mbuf *, struct mbuf *));
 507 #endif
 508 #endif  /* !_SYS_MBUF_H_ */