bsd/sys/mbuf.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /* Copyright (c) 1998, 1999 Apple Computer, Inc. All Rights Reserved */
  26 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  27 /*
  28  * Mach Operating System
  29  * Copyright (c) 1987 Carnegie-Mellon University
  30  * All rights reserved.  The CMU software License Agreement specifies
  31  * the terms and conditions for use and redistribution.
  32  */
  33 /*
  34  * Copyright (c) 1994 NeXT Computer, Inc. All rights reserved.
  35  *
  36  * Copyright (c) 1982, 1986, 1988 Regents of the University of California.
  37  * All rights reserved.
  38  *
  39  * Redistribution and use in source and binary forms, with or without
  40  * modification, are permitted provided that the following conditions
  41  * are met:
  42  * 1. Redistributions of source code must retain the above copyright
  43  *    notice, this list of conditions and the following disclaimer.
  44  * 2. Redistributions in binary form must reproduce the above copyright
  45  *    notice, this list of conditions and the following disclaimer in the
  46  *    documentation and/or other materials provided with the distribution.
  47  * 3. All advertising materials mentioning features or use of this software
  48  *    must display the following acknowledgement:
  49  *      This product includes software developed by the University of
  50  *      California, Berkeley and its contributors.
  51  * 4. Neither the name of the University nor the names of its contributors
  52  *    may be used to endorse or promote products derived from this software
  53  *    without specific prior written permission.
  54  *
  55  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  65  * SUCH DAMAGE.
  66  *
  67  *      @(#)mbuf.h      8.3 (Berkeley) 1/21/94
  68  **********************************************************************
  69  * HISTORY
  70  * 20-May-95  Mac Gillon (mgillon) at NeXT
  71  *      New version based on 4.4
  72  *      Purged old history
  73  */
  74
  75 #ifndef _SYS_MBUF_H_
  76 #define _SYS_MBUF_H_
  77
  78 #include <sys/appleapiopts.h>
  79 #include <sys/lock.h>
  80
  81 /*
  82  * Mbufs are of a single size, MSIZE (machine/param.h), which
  83  * includes overhead.  An mbuf may add a single "mbuf cluster" of size
  84  * MCLBYTES (also in machine/param.h), which has no additional overhead
  85  * and is used instead of the internal data area; this is done when
  86  * at least MINCLSIZE of data must be stored.
  87  */
  88
  89 #ifdef __APPLE_API_UNSTABLE
  90 #define MLEN            (MSIZE - sizeof(struct m_hdr))  /* normal data len */
  91 #define MHLEN           (MLEN - sizeof(struct pkthdr))  /* data len w/pkthdr */
  92
  93 #define MINCLSIZE       (MHLEN + MLEN)  /* smallest amount to put in cluster */
  94 #define M_MAXCOMPRESS   (MHLEN / 2)     /* max amount to copy for compression */
  95
  96 #define NMBPCL          (sizeof(union mcluster) / sizeof(struct mbuf))
  97
  98 /*
  99  * Macros for type conversion
 100  * mtod(m,t) -  convert mbuf pointer to data pointer of correct type
 101  * dtom(x) -    convert data pointer within mbuf to mbuf pointer (XXX)
 102  * mtocl(x) -   convert pointer within cluster to cluster index #
 103  * cltom(x) -   convert cluster # to ptr to beginning of cluster
 104  */
 105 #define mtod(m,t)       ((t)m_mtod(m))
 106 #define dtom(x)         m_dtom(x)
 107 #define mtocl(x)        m_mtocl(x)
 108 #define cltom(x)        m_cltom(x)
 109
 110 #define MCLREF(p)       m_mclref(p)
 111 #define MCLUNREF(p)     m_mclunref(p)
 112
 113 /* header at beginning of each mbuf: */
 114 struct m_hdr {
 115         struct  mbuf *mh_next;          /* next buffer in chain */
 116         struct  mbuf *mh_nextpkt;       /* next chain in queue/record */
 117         long    mh_len;                 /* amount of data in this mbuf */
 118         caddr_t mh_data;                /* location of data */
 119         short   mh_type;                /* type of data in this mbuf */
 120         short   mh_flags;               /* flags; see below */
 121 };
 122
 123 /* record/packet header in first mbuf of chain; valid if M_PKTHDR set */
 124 struct  pkthdr {
 125         int     len;                    /* total packet length */
 126         struct  ifnet *rcvif;           /* rcv interface */
 127
 128         /* variables for ip and tcp reassembly */
 129         void    *header;                /* pointer to packet header */
 130         /* variables for hardware checksum */
 131 #ifdef KERNEL_PRIVATE
 132         /* Note: csum_flags is used for hardware checksum and VLAN */
 133 #endif KERNEL_PRIVATE
 134         int     csum_flags;             /* flags regarding checksum */
 135         int     csum_data;              /* data field used by csum routines */
 136         struct mbuf *aux;               /* extra data buffer; ipsec/others */
 137 #ifdef KERNEL_PRIVATE
 138         u_short vlan_tag;               /* VLAN tag, host byte order */
 139         u_short reserved_1;             /* for future use */
 140 #else KERNEL_PRIVATE
 141         void    *reserved1;             /* for future use */
 142 #endif KERNEL_PRIVATE
 143         void    *reserved2;             /* for future use */
 144 };
 145
 146
 147 /* description of external storage mapped into mbuf, valid if M_EXT set */
 148 struct m_ext {
 149         caddr_t ext_buf;                /* start of buffer */
 150         void    (*ext_free)(caddr_t , u_int, caddr_t);  /* free routine if not the usual */
 151         u_int   ext_size;               /* size of buffer, for ext_free */
 152         caddr_t ext_arg;                /* additional ext_free argument */
 153         struct  ext_refsq {             /* references held */
 154                 struct ext_refsq *forward, *backward;
 155         } ext_refs;
 156 };
 157
 158 struct mbuf {
 159         struct  m_hdr m_hdr;
 160         union {
 161                 struct {
 162                         struct  pkthdr MH_pkthdr;       /* M_PKTHDR set */
 163                         union {
 164                                 struct  m_ext MH_ext;   /* M_EXT set */
 165                                 char    MH_databuf[MHLEN];
 166                         } MH_dat;
 167                 } MH;
 168                 char    M_databuf[MLEN];                /* !M_PKTHDR, !M_EXT */
 169         } M_dat;
 170 };
 171
 172 #define m_next          m_hdr.mh_next
 173 #define m_len           m_hdr.mh_len
 174 #define m_data          m_hdr.mh_data
 175 #define m_type          m_hdr.mh_type
 176 #define m_flags         m_hdr.mh_flags
 177 #define m_nextpkt       m_hdr.mh_nextpkt
 178 #define m_act           m_nextpkt
 179 #define m_pkthdr        M_dat.MH.MH_pkthdr
 180 #define m_ext           M_dat.MH.MH_dat.MH_ext
 181 #define m_pktdat        M_dat.MH.MH_dat.MH_databuf
 182 #define m_dat           M_dat.M_databuf
 183
 184 /* mbuf flags */
 185 #define M_EXT           0x0001  /* has associated external storage */
 186 #define M_PKTHDR        0x0002  /* start of record */
 187 #define M_EOR           0x0004  /* end of record */
 188 #define M_PROTO1        0x0008  /* protocol-specific */
 189 #define M_PROTO2        0x0010  /* protocol-specific */
 190 #define M_PROTO3        0x0020  /* protocol-specific */
 191 #define M_PROTO4        0x0040  /* protocol-specific */
 192 #define M_PROTO5        0x0080  /* protocol-specific */
 193
 194 /* mbuf pkthdr flags, also in m_flags */
 195 #define M_BCAST         0x0100  /* send/received as link-level broadcast */
 196 #define M_MCAST         0x0200  /* send/received as link-level multicast */
 197 #define M_FRAG          0x0400  /* packet is a fragment of a larger packet */
 198 #define M_FIRSTFRAG     0x0800  /* packet is first fragment */
 199 #define M_LASTFRAG      0x1000  /* packet is last fragment */
 200
 201 /* flags copied when copying m_pkthdr */
 202 #define M_COPYFLAGS     (M_PKTHDR|M_EOR|M_PROTO1|M_PROTO1|M_PROTO2|M_PROTO3 | \
 203                             M_PROTO4|M_PROTO5|M_BCAST|M_MCAST|M_FRAG)
 204
 205 /* flags indicating hw checksum support and sw checksum requirements [freebsd4.1]*/
 206 #define CSUM_IP                 0x0001          /* will csum IP */
 207 #define CSUM_TCP                0x0002          /* will csum TCP */
 208 #define CSUM_UDP                0x0004          /* will csum UDP */
 209 #define CSUM_IP_FRAGS           0x0008          /* will csum IP fragments */
 210 #define CSUM_FRAGMENT           0x0010          /* will do IP fragmentation */
 211
 212 #define CSUM_IP_CHECKED         0x0100          /* did csum IP */
 213 #define CSUM_IP_VALID           0x0200          /*   ... the csum is valid */
 214 #define CSUM_DATA_VALID         0x0400          /* csum_data field is valid */
 215 #define CSUM_PSEUDO_HDR         0x0800          /* csum_data has pseudo hdr */
 216 #define CSUM_TCP_SUM16          0x1000          /* simple TCP Sum16 computation */
 217
 218 #define CSUM_DELAY_DATA         (CSUM_TCP | CSUM_UDP)
 219 #define CSUM_DELAY_IP           (CSUM_IP)       /* XXX add ipv6 here too? */
 220 #ifdef KERNEL_PRIVATE
 221 /*
 222  * Note: see also IF_HWASSIST_CSUM defined in <net/if_var.h>
 223  */
 224 /* bottom 16 bits reserved for hardware checksum */
 225 #define CSUM_CHECKSUM_MASK      0xffff
 226
 227 /* VLAN tag present */
 228 #define CSUM_VLAN_TAG_VALID     0x10000         /* vlan_tag field is valid */
 229 #endif KERNEL_PRIVATE
 230
 231
 232 /* mbuf types */
 233 #define MT_FREE         0       /* should be on free list */
 234 #define MT_DATA         1       /* dynamic (data) allocation */
 235 #define MT_HEADER       2       /* packet header */
 236 #define MT_SOCKET       3       /* socket structure */
 237 #define MT_PCB          4       /* protocol control block */
 238 #define MT_RTABLE       5       /* routing tables */
 239 #define MT_HTABLE       6       /* IMP host tables */
 240 #define MT_ATABLE       7       /* address resolution tables */
 241 #define MT_SONAME       8       /* socket name */
 242 #define MT_SOOPTS       10      /* socket options */
 243 #define MT_FTABLE       11      /* fragment reassembly header */
 244 #define MT_RIGHTS       12      /* access rights */
 245 #define MT_IFADDR       13      /* interface address */
 246 #define MT_CONTROL      14      /* extra-data protocol message */
 247 #define MT_OOBDATA      15      /* expedited data  */
 248 #define MT_MAX          32      /* enough? */
 249
 250 /* flags to m_get/MGET */
 251 /* Need to include malloc.h to get right options for malloc  */
 252 #include        <sys/malloc.h>
 253
 254 #define M_DONTWAIT      M_NOWAIT
 255 #define M_WAIT          M_WAITOK
 256
 257 #ifdef __APPLE_API_PRIVATE
 258
 259 /*
 260  * mbuf utility macros:
 261  *
 262  *      MBUFLOCK(code)
 263  * prevents a section of code from from being interrupted by network
 264  * drivers.
 265  */
 266
 267
 268 extern
 269 decl_simple_lock_data(, mbuf_slock);
 270 #define MBUF_LOCK() usimple_lock(&mbuf_slock);
 271 #define MBUF_UNLOCK() usimple_unlock(&mbuf_slock);
 272 #define MBUF_LOCKINIT() simple_lock_init(&mbuf_slock);
 273
 274 #endif /* __APPLE_API_PRIVATE */
 275
 276 /*
 277  * mbuf allocation/deallocation macros:
 278  *
 279  *      MGET(struct mbuf *m, int how, int type)
 280  * allocates an mbuf and initializes it to contain internal data.
 281  *
 282  *      MGETHDR(struct mbuf *m, int how, int type)
 283  * allocates an mbuf and initializes it to contain a packet header
 284  * and internal data.
 285  */
 286
 287 #if 1
 288 #define MCHECK(m) m_mcheck(m)
 289 #else
 290 #define MCHECK(m)
 291 #endif
 292
 293 #ifdef __APPLE_API_PRIVATE
 294 extern struct mbuf *mfree;                              /* mbuf free list */
 295 extern simple_lock_data_t   mbuf_slock;
 296 #endif /* __APPLE_API_PRIVATE */
 297
 298
 299 #define MGET(m, how, type) ((m) = m_get((how), (type)))
 300
 301 #define MGETHDR(m, how, type)   ((m) = m_gethdr((how), (type)))
 302
 303 /*
 304  * Mbuf cluster macros.
 305  * MCLALLOC(caddr_t p, int how) allocates an mbuf cluster.
 306  * MCLGET adds such clusters to a normal mbuf;
 307  * the flag M_EXT is set upon success.
 308  * MCLFREE releases a reference to a cluster allocated by MCLALLOC,
 309  * freeing the cluster if the reference count has reached 0.
 310  *
 311  * Normal mbuf clusters are normally treated as character arrays
 312  * after allocation, but use the first word of the buffer as a free list
 313  * pointer while on the free list.
 314  */
 315 union mcluster {
 316         union   mcluster *mcl_next;
 317         char    mcl_buf[MCLBYTES];
 318 };
 319
 320 #define MCLALLOC(p, how)        ((p) = m_mclalloc(how))
 321
 322 #define MCLFREE(p)      m_mclfree(p)
 323
 324 #define MCLGET(m, how)  ((m) = m_mclget(m, how))
 325
 326 #define MCLHASREFERENCE(m) m_mclhasreference(m)
 327
 328 /*
 329  * MFREE(struct mbuf *m, struct mbuf *n)
 330  * Free a single mbuf and associated external storage.
 331  * Place the successor, if any, in n.
 332  */
 333
 334 #define MFREE(m, n) ((n) = m_free(m))
 335
 336 /*
 337  * Copy mbuf pkthdr from from to to.
 338  * from must have M_PKTHDR set, and to must be empty.
 339  * aux pointer will be moved to `to'.
 340  */
 341 #define M_COPY_PKTHDR(to, from)         m_copy_pkthdr(to, from)
 342
 343 /*
 344  * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place
 345  * an object of the specified size at the end of the mbuf, longword aligned.
 346  */
 347 #define M_ALIGN(m, len)                         \
 348         { (m)->m_data += (MLEN - (len)) &~ (sizeof(long) - 1); }
 349 /*
 350  * As above, for mbufs allocated with m_gethdr/MGETHDR
 351  * or initialized by M_COPY_PKTHDR.
 352  */
 353 #define MH_ALIGN(m, len) \
 354         { (m)->m_data += (MHLEN - (len)) &~ (sizeof(long) - 1); }
 355
 356 /*
 357  * Compute the amount of space available
 358  * before the current start of data in an mbuf.
 359  * Subroutine - data not available if certain references.
 360  */
 361 #define M_LEADINGSPACE(m)       m_leadingspace(m)
 362
 363 /*
 364  * Compute the amount of space available
 365  * after the end of data in an mbuf.
 366  * Subroutine - data not available if certain references.
 367  */
 368 #define M_TRAILINGSPACE(m)      m_trailingspace(m)
 369
 370 /*
 371  * Arrange to prepend space of size plen to mbuf m.
 372  * If a new mbuf must be allocated, how specifies whether to wait.
 373  * If how is M_DONTWAIT and allocation fails, the original mbuf chain
 374  * is freed and m is set to NULL.
 375  */
 376 #define M_PREPEND(m, plen, how)         ((m) = m_prepend_2((m), (plen), (how)))
 377
 378 /* change mbuf to new type */
 379 #define MCHTYPE(m, t)           m_mchtype(m, t)
 380
 381 /* length to m_copy to copy all */
 382 #define M_COPYALL       1000000000
 383
 384 /* compatiblity with 4.3 */
 385 #define  m_copy(m, o, l)        m_copym((m), (o), (l), M_DONTWAIT)
 386
 387 /*
 388  * Mbuf statistics.
 389  */
 390 struct mbstat {
 391         u_long  m_mbufs;        /* mbufs obtained from page pool */
 392         u_long  m_clusters;     /* clusters obtained from page pool */
 393         u_long  m_spare;        /* spare field */
 394         u_long  m_clfree;       /* free clusters */
 395         u_long  m_drops;        /* times failed to find space */
 396         u_long  m_wait;         /* times waited for space */
 397         u_long  m_drain;        /* times drained protocols for space */
 398         u_short m_mtypes[256];  /* type specific mbuf allocations */
 399         u_long  m_mcfail;       /* times m_copym failed */
 400         u_long  m_mpfail;       /* times m_pullup failed */
 401         u_long  m_msize;        /* length of an mbuf */
 402         u_long  m_mclbytes;     /* length of an mbuf cluster */
 403         u_long  m_minclsize;    /* min length of data to allocate a cluster */
 404         u_long  m_mlen;         /* length of data in an mbuf */
 405         u_long  m_mhlen;        /* length of data in a header mbuf */
 406 };
 407
 408 /*
 409  * pkthdr.aux type tags.
 410  */
 411 struct mauxtag {
 412         int af;
 413         int type;
 414 };
 415
 416 #ifdef  KERNEL
 417 extern union    mcluster *mbutl;        /* virtual address of mclusters */
 418 extern union    mcluster *embutl;       /* ending virtual address of mclusters */
 419 extern short    *mclrefcnt;             /* cluster reference counts */
 420 extern int      *mcl_paddr;             /* physical addresses of clusters */
 421 extern struct   mbstat mbstat;          /* statistics */
 422 extern int      nmbclusters;            /* number of mapped clusters */
 423 extern union    mcluster *mclfree;      /* free mapped cluster list */
 424 extern int      max_linkhdr;            /* largest link-level header */
 425 extern int      max_protohdr;           /* largest protocol header */
 426 extern int      max_hdr;                /* largest link+protocol header */
 427 extern int      max_datalen;            /* MHLEN - max_hdr */
 428
 429 struct  mbuf *m_copym __P((struct mbuf *, int, int, int));
 430 struct  mbuf *m_split __P((struct mbuf *, int, int));
 431 struct  mbuf *m_free __P((struct mbuf *));
 432 struct  mbuf *m_get __P((int, int));
 433 struct  mbuf *m_getpacket __P((void));
 434 struct  mbuf *m_getclr __P((int, int));
 435 struct  mbuf *m_gethdr __P((int, int));
 436 struct  mbuf *m_prepend __P((struct mbuf *, int, int));
 437 struct  mbuf *m_prepend_2 __P((struct mbuf *, int, int));
 438 struct  mbuf *m_pullup __P((struct mbuf *, int));
 439 struct  mbuf *m_retry __P((int, int));
 440 struct  mbuf *m_retryhdr __P((int, int));
 441 void m_adj __P((struct mbuf *, int));
 442 int      m_clalloc __P((int, int));
 443 void m_freem __P((struct mbuf *));
 444 int m_freem_list __P((struct mbuf *));
 445 struct  mbuf *m_devget __P((char *, int, int, struct ifnet *, void (*)()));
 446 char   *mcl_to_paddr __P((char *));
 447 struct mbuf *m_pulldown __P((struct mbuf*, int, int, int*));
 448 struct mbuf *m_aux_add __P((struct mbuf *, int, int));
 449 struct mbuf *m_aux_find __P((struct mbuf *, int, int));
 450 void m_aux_delete __P((struct mbuf *, struct mbuf *));
 451
 452 struct mbuf *m_mclget __P((struct mbuf *, int));
 453 caddr_t m_mclalloc __P((int));
 454 void m_mclfree __P((caddr_t p));
 455 int m_mclhasreference __P((struct mbuf *));
 456 void m_copy_pkthdr __P((struct mbuf *, struct mbuf*));
 457
 458 int m_mclref __P((struct mbuf *));
 459 int m_mclunref __P((struct mbuf *));
 460
 461 void *          m_mtod __P((struct mbuf *));
 462 struct mbuf *   m_dtom __P((void *));
 463 int             m_mtocl __P((void *));
 464 union mcluster *m_cltom __P((int ));
 465
 466 int m_trailingspace __P((struct mbuf *));
 467 int m_leadingspace __P((struct mbuf *));
 468
 469 void m_mchtype __P((struct mbuf *m, int t));
 470
 471 void m_mcheck __P((struct mbuf*));
 472
 473 #endif
 474 #endif /* __APPLE_API_UNSTABLE */
 475 #endif  /* !_SYS_MBUF_H_ */