sys/net/if_var.h

   1 /*-
   2  * Copyright (c) 1982, 1986, 1989, 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  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      From: @(#)if.h  8.1 (Berkeley) 6/10/93
  30  * $FreeBSD$
  31  */
  32
  33 #ifndef _NET_IF_VAR_H_
  34 #define _NET_IF_VAR_H_
  35
  36 /*
  37  * Structures defining a network interface, providing a packet
  38  * transport mechanism (ala level 0 of the PUP protocols).
  39  *
  40  * Each interface accepts output datagrams of a specified maximum
  41  * length, and provides higher level routines with input datagrams
  42  * received from its medium.
  43  *
  44  * Output occurs when the routine if_output is called, with three parameters:
  45  *      (*ifp->if_output)(ifp, m, dst, rt)
  46  * Here m is the mbuf chain to be sent and dst is the destination address.
  47  * The output routine encapsulates the supplied datagram if necessary,
  48  * and then transmits it on its medium.
  49  *
  50  * On input, each interface unwraps the data received by it, and either
  51  * places it on the input queue of an internetwork datagram routine
  52  * and posts the associated software interrupt, or passes the datagram to a raw
  53  * packet input routine.
  54  *
  55  * Routines exist for locating interfaces by their addresses
  56  * or for locating an interface on a certain network, as well as more general
  57  * routing and gateway routines maintaining information used to locate
  58  * interfaces.  These routines live in the files if.c and route.c
  59  */
  60
  61 #ifdef __STDC__
  62 /*
  63  * Forward structure declarations for function prototypes [sic].
  64  */
  65 struct  mbuf;
  66 struct  thread;
  67 struct  rtentry;
  68 struct  rt_addrinfo;
  69 struct  socket;
  70 struct  ether_header;
  71 struct  carp_if;
  72 #endif
  73
  74 #include <sys/queue.h>          /* get TAILQ macros */
  75
  76 #ifdef _KERNEL
  77 #include <sys/mbuf.h>
  78 #include <sys/eventhandler.h>
  79 #endif /* _KERNEL */
  80 #include <sys/lock.h>           /* XXX */
  81 #include <sys/mutex.h>          /* XXX */
  82 #include <sys/event.h>          /* XXX */
  83 #include <sys/_task.h>
  84
  85 #define IF_DUNIT_NONE   -1
  86
  87 #include <altq/if_altq.h>
  88
  89 TAILQ_HEAD(ifnethead, ifnet);   /* we use TAILQs so that the order of */
  90 TAILQ_HEAD(ifaddrhead, ifaddr); /* instantiation is preserved in the list */
  91 TAILQ_HEAD(ifprefixhead, ifprefix);
  92 TAILQ_HEAD(ifmultihead, ifmultiaddr);
  93
  94 /*
  95  * Structure defining a queue for a network interface.
  96  */
  97 struct  ifqueue {
  98         struct  mbuf *ifq_head;
  99         struct  mbuf *ifq_tail;
 100         int     ifq_len;
 101         int     ifq_maxlen;
 102         int     ifq_drops;
 103         struct  mtx ifq_mtx;
 104 };
 105
 106 /*
 107  * Structure defining a network interface.
 108  *
 109  * (Would like to call this struct ``if'', but C isn't PL/1.)
 110  */
 111
 112 struct ifnet {
 113         void    *if_softc;              /* pointer to driver state */
 114         void    *if_l2com;              /* pointer to protocol bits */
 115         TAILQ_ENTRY(ifnet) if_link;     /* all struct ifnets are chained */
 116         char    if_xname[IFNAMSIZ];     /* external name (name + unit) */
 117         const char *if_dname;           /* driver name */
 118         int     if_dunit;               /* unit or IF_DUNIT_NONE */
 119         struct  ifaddrhead if_addrhead; /* linked list of addresses per if */
 120                 /*
 121                  * if_addrhead is the list of all addresses associated to
 122                  * an interface.
 123                  * Some code in the kernel assumes that first element
 124                  * of the list has type AF_LINK, and contains sockaddr_dl
 125                  * addresses which store the link-level address and the name
 126                  * of the interface.
 127                  * However, access to the AF_LINK address through this
 128                  * field is deprecated. Use ifaddr_byindex() instead.
 129                  */
 130         struct  knlist if_klist;        /* events attached to this if */
 131         int     if_pcount;              /* number of promiscuous listeners */
 132         struct  carp_if *if_carp;       /* carp interface structure */
 133         struct  bpf_if *if_bpf;         /* packet filter structure */
 134         u_short if_index;               /* numeric abbreviation for this if  */
 135         short   if_timer;               /* time 'til if_watchdog called */
 136         u_short if_nvlans;              /* number of active vlans */
 137         int     if_flags;               /* up/down, broadcast, etc. */
 138         int     if_capabilities;        /* interface capabilities */
 139         int     if_capenable;           /* enabled features */
 140         void    *if_linkmib;            /* link-type-specific MIB data */
 141         size_t  if_linkmiblen;          /* length of above data */
 142         struct  if_data if_data;
 143         struct  ifmultihead if_multiaddrs; /* multicast addresses configured */
 144         int     if_amcount;             /* number of all-multicast requests */
 145 /* procedure handles */
 146         int     (*if_output)            /* output routine (enqueue) */
 147                 (struct ifnet *, struct mbuf *, struct sockaddr *,
 148                      struct rtentry *);
 149         void    (*if_input)             /* input routine (from h/w driver) */
 150                 (struct ifnet *, struct mbuf *);
 151         void    (*if_start)             /* initiate output routine */
 152                 (struct ifnet *);
 153         int     (*if_ioctl)             /* ioctl routine */
 154                 (struct ifnet *, u_long, caddr_t);
 155         void    (*if_watchdog)          /* timer routine */
 156                 (struct ifnet *);
 157         void    (*if_init)              /* Init routine */
 158                 (void *);
 159         int     (*if_resolvemulti)      /* validate/resolve multicast */
 160                 (struct ifnet *, struct sockaddr **, struct sockaddr *);
 161         void    *if_spare1;             /* spare pointer 1 */
 162         void    *if_spare2;             /* spare pointer 2 */
 163         void    *if_spare3;             /* spare pointer 3 */
 164         u_int   if_spare_flags1;        /* spare flags 1 */
 165         u_int   if_spare_flags2;        /* spare flags 2 */
 166         struct  ifaltq if_snd;          /* output queue (includes altq) */
 167         const u_int8_t *if_broadcastaddr; /* linklevel broadcast bytestring */
 168
 169         void    *if_bridge;             /* bridge glue */
 170
 171         struct  lltable *lltables;      /* list of L3-L2 resolution tables */
 172
 173         struct  label *if_label;        /* interface MAC label */
 174
 175         /* these are only used by IPv6 */
 176         struct  ifprefixhead if_prefixhead; /* list of prefixes per if */
 177         void    *if_afdata[AF_MAX];
 178         int     if_afdata_initialized;
 179         struct  mtx if_afdata_mtx;
 180         struct  task if_starttask;      /* task for IFF_NEEDSGIANT */
 181         struct  task if_linktask;       /* task for link change events */
 182 };
 183
 184 typedef void if_init_f_t(void *);
 185
 186 /*
 187  * XXX These aliases are terribly dangerous because they could apply
 188  * to anything.
 189  */
 190 #define if_mtu          if_data.ifi_mtu
 191 #define if_type         if_data.ifi_type
 192 #define if_physical     if_data.ifi_physical
 193 #define if_addrlen      if_data.ifi_addrlen
 194 #define if_hdrlen       if_data.ifi_hdrlen
 195 #define if_metric       if_data.ifi_metric
 196 #define if_link_state   if_data.ifi_link_state
 197 #define if_baudrate     if_data.ifi_baudrate
 198 #define if_hwassist     if_data.ifi_hwassist
 199 #define if_ipackets     if_data.ifi_ipackets
 200 #define if_ierrors      if_data.ifi_ierrors
 201 #define if_opackets     if_data.ifi_opackets
 202 #define if_oerrors      if_data.ifi_oerrors
 203 #define if_collisions   if_data.ifi_collisions
 204 #define if_ibytes       if_data.ifi_ibytes
 205 #define if_obytes       if_data.ifi_obytes
 206 #define if_imcasts      if_data.ifi_imcasts
 207 #define if_omcasts      if_data.ifi_omcasts
 208 #define if_iqdrops      if_data.ifi_iqdrops
 209 #define if_noproto      if_data.ifi_noproto
 210 #define if_lastchange   if_data.ifi_lastchange
 211 #define if_recvquota    if_data.ifi_recvquota
 212 #define if_xmitquota    if_data.ifi_xmitquota
 213 #define if_rawoutput(if, m, sa) if_output(if, m, sa, (struct rtentry *)NULL)
 214
 215 /* for compatibility with other BSDs */
 216 #define if_addrlist     if_addrhead
 217 #define if_list         if_link
 218
 219 /*
 220  * Output queues (ifp->if_snd) and slow device input queues (*ifp->if_slowq)
 221  * are queues of messages stored on ifqueue structures
 222  * (defined above).  Entries are added to and deleted from these structures
 223  * by these macros, which should be called with ipl raised to splimp().
 224  */
 225 #define IF_LOCK(ifq)            mtx_lock(&(ifq)->ifq_mtx)
 226 #define IF_UNLOCK(ifq)          mtx_unlock(&(ifq)->ifq_mtx)
 227 #define IF_LOCK_ASSERT(ifq)     mtx_assert(&(ifq)->ifq_mtx, MA_OWNED)
 228 #define _IF_QFULL(ifq)          ((ifq)->ifq_len >= (ifq)->ifq_maxlen)
 229 #define _IF_DROP(ifq)           ((ifq)->ifq_drops++)
 230 #define _IF_QLEN(ifq)           ((ifq)->ifq_len)
 231
 232 #define _IF_ENQUEUE(ifq, m) do {                                \
 233         (m)->m_nextpkt = NULL;                                  \
 234         if ((ifq)->ifq_tail == NULL)                            \
 235                 (ifq)->ifq_head = m;                            \
 236         else                                                    \
 237                 (ifq)->ifq_tail->m_nextpkt = m;                 \
 238         (ifq)->ifq_tail = m;                                    \
 239         (ifq)->ifq_len++;                                       \
 240 } while (0)
 241
 242 #define IF_ENQUEUE(ifq, m) do {                                 \
 243         IF_LOCK(ifq);                                           \
 244         _IF_ENQUEUE(ifq, m);                                    \
 245         IF_UNLOCK(ifq);                                         \
 246 } while (0)
 247
 248 #define _IF_PREPEND(ifq, m) do {                                \
 249         (m)->m_nextpkt = (ifq)->ifq_head;                       \
 250         if ((ifq)->ifq_tail == NULL)                            \
 251                 (ifq)->ifq_tail = (m);                          \
 252         (ifq)->ifq_head = (m);                                  \
 253         (ifq)->ifq_len++;                                       \
 254 } while (0)
 255
 256 #define IF_PREPEND(ifq, m) do {                                 \
 257         IF_LOCK(ifq);                                           \
 258         _IF_PREPEND(ifq, m);                                    \
 259         IF_UNLOCK(ifq);                                         \
 260 } while (0)
 261
 262 #define _IF_DEQUEUE(ifq, m) do {                                \
 263         (m) = (ifq)->ifq_head;                                  \
 264         if (m) {                                                \
 265                 if (((ifq)->ifq_head = (m)->m_nextpkt) == NULL) \
 266                         (ifq)->ifq_tail = NULL;                 \
 267                 (m)->m_nextpkt = NULL;                          \
 268                 (ifq)->ifq_len--;                               \
 269         }                                                       \
 270 } while (0)
 271
 272 #define IF_DEQUEUE(ifq, m) do {                                 \
 273         IF_LOCK(ifq);                                           \
 274         _IF_DEQUEUE(ifq, m);                                    \
 275         IF_UNLOCK(ifq);                                         \
 276 } while (0)
 277
 278 #define _IF_POLL(ifq, m)        ((m) = (ifq)->ifq_head)
 279 #define IF_POLL(ifq, m)         _IF_POLL(ifq, m)
 280
 281 #define _IF_DRAIN(ifq) do {                                     \
 282         struct mbuf *m;                                         \
 283         for (;;) {                                              \
 284                 _IF_DEQUEUE(ifq, m);                            \
 285                 if (m == NULL)                                  \
 286                         break;                                  \
 287                 m_freem(m);                                     \
 288         }                                                       \
 289 } while (0)
 290
 291 #define IF_DRAIN(ifq) do {                                      \
 292         IF_LOCK(ifq);                                           \
 293         _IF_DRAIN(ifq);                                         \
 294         IF_UNLOCK(ifq);                                         \
 295 } while(0)
 296
 297 #ifdef _KERNEL
 298 /* interface address change event */
 299 typedef void (*ifaddr_event_handler_t)(void *, struct ifnet *);
 300 EVENTHANDLER_DECLARE(ifaddr_event, ifaddr_event_handler_t);
 301 /* new interface arrival event */
 302 typedef void (*ifnet_arrival_event_handler_t)(void *, struct ifnet *);
 303 EVENTHANDLER_DECLARE(ifnet_arrival_event, ifnet_arrival_event_handler_t);
 304 /* interface departure event */
 305 typedef void (*ifnet_departure_event_handler_t)(void *, struct ifnet *);
 306 EVENTHANDLER_DECLARE(ifnet_departure_event, ifnet_departure_event_handler_t);
 307
 308 #define IF_AFDATA_LOCK_INIT(ifp)        \
 309     mtx_init(&(ifp)->if_afdata_mtx, "if_afdata", NULL, MTX_DEF)
 310 #define IF_AFDATA_LOCK(ifp)     mtx_lock(&(ifp)->if_afdata_mtx)
 311 #define IF_AFDATA_TRYLOCK(ifp)  mtx_trylock(&(ifp)->if_afdata_mtx)
 312 #define IF_AFDATA_UNLOCK(ifp)   mtx_unlock(&(ifp)->if_afdata_mtx)
 313 #define IF_AFDATA_DESTROY(ifp)  mtx_destroy(&(ifp)->if_afdata_mtx)
 314
 315 #define IFF_LOCKGIANT(ifp) do {                                         \
 316         if ((ifp)->if_flags & IFF_NEEDSGIANT)                           \
 317                 mtx_lock(&Giant);                                       \
 318 } while (0)
 319
 320 #define IFF_UNLOCKGIANT(ifp) do {                                       \
 321         if ((ifp)->if_flags & IFF_NEEDSGIANT)                           \
 322                 mtx_unlock(&Giant);                                     \
 323 } while (0)
 324
 325 int     if_handoff(struct ifqueue *ifq, struct mbuf *m, struct ifnet *ifp,
 326             int adjust);
 327 #define IF_HANDOFF(ifq, m, ifp)                 \
 328         if_handoff((struct ifqueue *)ifq, m, ifp, 0)
 329 #define IF_HANDOFF_ADJ(ifq, m, ifp, adj)        \
 330         if_handoff((struct ifqueue *)ifq, m, ifp, adj)
 331
 332 void    if_start(struct ifnet *);
 333
 334 #define IFQ_ENQUEUE(ifq, m, err)                                        \
 335 do {                                                                    \
 336         IF_LOCK(ifq);                                                   \
 337         if (ALTQ_IS_ENABLED(ifq))                                       \
 338                 ALTQ_ENQUEUE(ifq, m, NULL, err);                        \
 339         else {                                                          \
 340                 if (_IF_QFULL(ifq)) {                                   \
 341                         m_freem(m);                                     \
 342                         (err) = ENOBUFS;                                \
 343                 } else {                                                \
 344                         _IF_ENQUEUE(ifq, m);                            \
 345                         (err) = 0;                                      \
 346                 }                                                       \
 347         }                                                               \
 348         if (err)                                                        \
 349                 (ifq)->ifq_drops++;                                     \
 350         IF_UNLOCK(ifq);                                                 \
 351 } while (0)
 352
 353 #define IFQ_DEQUEUE_NOLOCK(ifq, m)                                      \
 354 do {                                                                    \
 355         if (TBR_IS_ENABLED(ifq))                                        \
 356                 (m) = tbr_dequeue_ptr(ifq, ALTDQ_REMOVE);               \
 357         else if (ALTQ_IS_ENABLED(ifq))                                  \
 358                 ALTQ_DEQUEUE(ifq, m);                                   \
 359         else                                                            \
 360                 _IF_DEQUEUE(ifq, m);                                    \
 361 } while (0)
 362
 363 #define IFQ_DEQUEUE(ifq, m)                                             \
 364 do {                                                                    \
 365         IF_LOCK(ifq);                                                   \
 366         IFQ_DEQUEUE_NOLOCK(ifq, m);                                     \
 367         IF_UNLOCK(ifq);                                                 \
 368 } while (0)
 369
 370 #define IFQ_POLL_NOLOCK(ifq, m)                                         \
 371 do {                                                                    \
 372         if (TBR_IS_ENABLED(ifq))                                        \
 373                 (m) = tbr_dequeue_ptr(ifq, ALTDQ_POLL);                 \
 374         else if (ALTQ_IS_ENABLED(ifq))                                  \
 375                 ALTQ_POLL(ifq, m);                                      \
 376         else                                                            \
 377                 _IF_POLL(ifq, m);                                       \
 378 } while (0)
 379
 380 #define IFQ_POLL(ifq, m)                                                \
 381 do {                                                                    \
 382         IF_LOCK(ifq);                                                   \
 383         IFQ_POLL_NOLOCK(ifq, m);                                        \
 384         IF_UNLOCK(ifq);                                                 \
 385 } while (0)
 386
 387 #define IFQ_PURGE_NOLOCK(ifq)                                           \
 388 do {                                                                    \
 389         if (ALTQ_IS_ENABLED(ifq)) {                                     \
 390                 ALTQ_PURGE(ifq);                                        \
 391         } else                                                          \
 392                 _IF_DRAIN(ifq);                                         \
 393 } while (0)
 394
 395 #define IFQ_PURGE(ifq)                                                  \
 396 do {                                                                    \
 397         IF_LOCK(ifq);                                                   \
 398         IFQ_PURGE_NOLOCK(ifq);                                          \
 399         IF_UNLOCK(ifq);                                                 \
 400 } while (0)
 401
 402 #define IFQ_SET_READY(ifq)                                              \
 403         do { ((ifq)->altq_flags |= ALTQF_READY); } while (0)
 404
 405 #define IFQ_LOCK(ifq)                   IF_LOCK(ifq)
 406 #define IFQ_UNLOCK(ifq)                 IF_UNLOCK(ifq)
 407 #define IFQ_LOCK_ASSERT(ifq)            IF_LOCK_ASSERT(ifq)
 408 #define IFQ_IS_EMPTY(ifq)               ((ifq)->ifq_len == 0)
 409 #define IFQ_INC_LEN(ifq)                ((ifq)->ifq_len++)
 410 #define IFQ_DEC_LEN(ifq)                (--(ifq)->ifq_len)
 411 #define IFQ_INC_DROPS(ifq)              ((ifq)->ifq_drops++)
 412 #define IFQ_SET_MAXLEN(ifq, len)        ((ifq)->ifq_maxlen = (len))
 413
 414 #define IFQ_HANDOFF_ADJ(ifp, m, adj, err)                               \
 415 do {                                                                    \
 416         int len;                                                        \
 417         short mflags;                                                   \
 418                                                                         \
 419         len = (m)->m_pkthdr.len;                                        \
 420         mflags = (m)->m_flags;                                          \
 421         IFQ_ENQUEUE(&(ifp)->if_snd, m, err);                            \
 422         if ((err) == 0) {                                               \
 423                 (ifp)->if_obytes += len + (adj);                        \
 424                 if (mflags & M_MCAST)                                   \
 425                         (ifp)->if_omcasts++;                            \
 426                 if (((ifp)->if_flags & IFF_OACTIVE) == 0)               \
 427                         if_start(ifp);                                  \
 428         }                                                               \
 429 } while (0)
 430
 431 #define IFQ_HANDOFF(ifp, m, err)                                        \
 432         IFQ_HANDOFF_ADJ(ifp, m, 0, err)
 433
 434 #define IFQ_DRV_DEQUEUE(ifq, m)                                         \
 435 do {                                                                    \
 436         (m) = (ifq)->ifq_drv_head;                                      \
 437         if (m) {                                                        \
 438                 if (((ifq)->ifq_drv_head = (m)->m_nextpkt) == NULL)     \
 439                         (ifq)->ifq_drv_tail = NULL;                     \
 440                 (m)->m_nextpkt = NULL;                                  \
 441                 (ifq)->ifq_drv_len--;                                   \
 442         } else {                                                        \
 443                 IFQ_LOCK(ifq);                                          \
 444                 IFQ_DEQUEUE_NOLOCK(ifq, m);                             \
 445                 while ((ifq)->ifq_drv_len < (ifq)->ifq_drv_maxlen) {    \
 446                         struct mbuf *m0;                                \
 447                         IFQ_DEQUEUE_NOLOCK(ifq, m0);                    \
 448                         if (m0 == NULL)                                 \
 449                                 break;                                  \
 450                         m0->m_nextpkt = NULL;                           \
 451                         if ((ifq)->ifq_drv_tail == NULL)                \
 452                                 (ifq)->ifq_drv_head = m0;               \
 453                         else                                            \
 454                                 (ifq)->ifq_drv_tail->m_nextpkt = m0;    \
 455                         (ifq)->ifq_drv_tail = m0;                       \
 456                         (ifq)->ifq_drv_len++;                           \
 457                 }                                                       \
 458                 IFQ_UNLOCK(ifq);                                        \
 459         }                                                               \
 460 } while (0)
 461
 462 #define IFQ_DRV_PREPEND(ifq, m)                                         \
 463 do {                                                                    \
 464         (m)->m_nextpkt = (ifq)->ifq_drv_head;                           \
 465         if ((ifq)->ifq_drv_tail == NULL)                                \
 466                 (ifq)->ifq_drv_tail = (m);                              \
 467         (ifq)->ifq_drv_head = (m);                                      \
 468         (ifq)->ifq_drv_len++;                                           \
 469 } while (0)
 470
 471 #define IFQ_DRV_IS_EMPTY(ifq)                                           \
 472         (((ifq)->ifq_drv_len == 0) && ((ifq)->ifq_len == 0))
 473
 474 #define IFQ_DRV_PURGE(ifq)                                              \
 475 do {                                                                    \
 476         struct mbuf *m, *n = (ifq)->ifq_drv_head;                       \
 477         while((m = n) != NULL) {                                        \
 478                 n = m->m_nextpkt;                                       \
 479                 m_freem(m);                                             \
 480         }                                                               \
 481         (ifq)->ifq_drv_head = (ifq)->ifq_drv_tail = NULL;               \
 482         (ifq)->ifq_drv_len = 0;                                         \
 483         IFQ_PURGE(ifq);                                                 \
 484 } while (0)
 485
 486 /*
 487  * 72 was chosen below because it is the size of a TCP/IP
 488  * header (40) + the minimum mss (32).
 489  */
 490 #define IF_MINMTU       72
 491 #define IF_MAXMTU       65535
 492
 493 #endif /* _KERNEL */
 494
 495 /*
 496  * The ifaddr structure contains information about one address
 497  * of an interface.  They are maintained by the different address families,
 498  * are allocated and attached when an address is set, and are linked
 499  * together so all addresses for an interface can be located.
 500  *
 501  * NOTE: a 'struct ifaddr' is always at the beginning of a larger
 502  * chunk of malloc'ed memory, where we store the three addresses
 503  * (ifa_addr, ifa_dstaddr and ifa_netmask) referenced here.
 504  */
 505 struct ifaddr {
 506         struct  sockaddr *ifa_addr;     /* address of interface */
 507         struct  sockaddr *ifa_dstaddr;  /* other end of p-to-p link */
 508 #define ifa_broadaddr   ifa_dstaddr     /* broadcast address interface */
 509         struct  sockaddr *ifa_netmask;  /* used to determine subnet */
 510         struct  if_data if_data;        /* not all members are meaningful */
 511         struct  ifnet *ifa_ifp;         /* back-pointer to interface */
 512         TAILQ_ENTRY(ifaddr) ifa_link;   /* queue macro glue */
 513         void    (*ifa_rtrequest)        /* check or clean routes (+ or -)'d */
 514                 (int, struct rtentry *, struct rt_addrinfo *);
 515         u_short ifa_flags;              /* mostly rt_flags for cloning */
 516         u_int   ifa_refcnt;             /* references to this structure */
 517         int     ifa_metric;             /* cost of going out this interface */
 518         int (*ifa_claim_addr)           /* check if an addr goes to this if */
 519                 (struct ifaddr *, struct sockaddr *);
 520         struct mtx ifa_mtx;
 521 };
 522 #define IFA_ROUTE       RTF_UP          /* route installed */
 523
 524 /* for compatibility with other BSDs */
 525 #define ifa_list        ifa_link
 526
 527 #define IFA_LOCK_INIT(ifa)      \
 528     mtx_init(&(ifa)->ifa_mtx, "ifaddr", NULL, MTX_DEF)
 529 #define IFA_LOCK(ifa)           mtx_lock(&(ifa)->ifa_mtx)
 530 #define IFA_UNLOCK(ifa)         mtx_unlock(&(ifa)->ifa_mtx)
 531 #define IFA_DESTROY(ifa)        mtx_destroy(&(ifa)->ifa_mtx)
 532
 533 /*
 534  * The prefix structure contains information about one prefix
 535  * of an interface.  They are maintained by the different address families,
 536  * are allocated and attached when a prefix or an address is set,
 537  * and are linked together so all prefixes for an interface can be located.
 538  */
 539 struct ifprefix {
 540         struct  sockaddr *ifpr_prefix;  /* prefix of interface */
 541         struct  ifnet *ifpr_ifp;        /* back-pointer to interface */
 542         TAILQ_ENTRY(ifprefix) ifpr_list; /* queue macro glue */
 543         u_char  ifpr_plen;              /* prefix length in bits */
 544         u_char  ifpr_type;              /* protocol dependent prefix type */
 545 };
 546
 547 /*
 548  * Multicast address structure.  This is analogous to the ifaddr
 549  * structure except that it keeps track of multicast addresses.
 550  * Also, the reference count here is a count of requests for this
 551  * address, not a count of pointers to this structure.
 552  */
 553 struct ifmultiaddr {
 554         TAILQ_ENTRY(ifmultiaddr) ifma_link; /* queue macro glue */
 555         struct  sockaddr *ifma_addr;    /* address this membership is for */
 556         struct  sockaddr *ifma_lladdr;  /* link-layer translation, if any */
 557         struct  ifnet *ifma_ifp;        /* back-pointer to interface */
 558         u_int   ifma_refcount;          /* reference count */
 559         void    *ifma_protospec;        /* protocol-specific state, if any */
 560 };
 561
 562 #ifdef _KERNEL
 563 #define IFAFREE(ifa)                                    \
 564         do {                                            \
 565                 IFA_LOCK(ifa);                          \
 566                 KASSERT((ifa)->ifa_refcnt > 0,          \
 567                     ("ifa %p !(ifa_refcnt > 0)", ifa)); \
 568                 if (--(ifa)->ifa_refcnt == 0) {         \
 569                         IFA_DESTROY(ifa);               \
 570                         free(ifa, M_IFADDR);            \
 571                 } else                                  \
 572                         IFA_UNLOCK(ifa);                \
 573         } while (0)
 574
 575 #define IFAREF(ifa)                                     \
 576         do {                                            \
 577                 IFA_LOCK(ifa);                          \
 578                 ++(ifa)->ifa_refcnt;                    \
 579                 IFA_UNLOCK(ifa);                        \
 580         } while (0)
 581
 582 extern  struct mtx ifnet_lock;
 583 #define IFNET_LOCK_INIT() \
 584     mtx_init(&ifnet_lock, "ifnet", NULL, MTX_DEF | MTX_RECURSE)
 585 #define IFNET_WLOCK()           mtx_lock(&ifnet_lock)
 586 #define IFNET_WUNLOCK()         mtx_unlock(&ifnet_lock)
 587 #define IFNET_RLOCK()           IFNET_WLOCK()
 588 #define IFNET_RUNLOCK()         IFNET_WUNLOCK()
 589
 590 struct ifindex_entry {
 591         struct  ifnet *ife_ifnet;
 592         struct  ifaddr *ife_ifnet_addr;
 593         struct cdev *ife_dev;
 594 };
 595
 596 #define ifnet_byindex(idx)      ifindex_table[(idx)].ife_ifnet
 597 /*
 598  * Given the index, ifaddr_byindex() returns the one and only
 599  * link-level ifaddr for the interface. You are not supposed to use
 600  * it to traverse the list of addresses associated to the interface.
 601  */
 602 #define ifaddr_byindex(idx)     ifindex_table[(idx)].ife_ifnet_addr
 603 #define ifdev_byindex(idx)      ifindex_table[(idx)].ife_dev
 604
 605 extern  struct ifnethead ifnet;
 606 extern  struct ifindex_entry *ifindex_table;
 607 extern  int ifqmaxlen;
 608 extern  struct ifnet *loif;     /* first loopback interface */
 609 extern  int if_index;
 610
 611 int     if_addmulti(struct ifnet *, struct sockaddr *, struct ifmultiaddr **);
 612 int     if_allmulti(struct ifnet *, int);
 613 struct  ifnet* if_alloc(u_char);
 614 void    if_attach(struct ifnet *);
 615 int     if_delmulti(struct ifnet *, struct sockaddr *);
 616 void    if_detach(struct ifnet *);
 617 void    if_purgeaddrs(struct ifnet *);
 618 void    if_down(struct ifnet *);
 619 void    if_free(struct ifnet *);
 620 void    if_free_type(struct ifnet *, u_char);
 621 void    if_initname(struct ifnet *, const char *, int);
 622 void    if_link_state_change(struct ifnet *, int);
 623 int     if_printf(struct ifnet *, const char *, ...) __printflike(2, 3);
 624 int     if_setlladdr(struct ifnet *, const u_char *, int);
 625 void    if_up(struct ifnet *);
 626 /*void  ifinit(void);*/ /* declared in systm.h for main() */
 627 int     ifioctl(struct socket *, u_long, caddr_t, struct thread *);
 628 int     ifpromisc(struct ifnet *, int);
 629 struct  ifnet *ifunit(const char *);
 630
 631 struct  ifaddr *ifa_ifwithaddr(struct sockaddr *);
 632 struct  ifaddr *ifa_ifwithdstaddr(struct sockaddr *);
 633 struct  ifaddr *ifa_ifwithnet(struct sockaddr *);
 634 struct  ifaddr *ifa_ifwithroute(int, struct sockaddr *, struct sockaddr *);
 635 struct  ifaddr *ifaof_ifpforaddr(struct sockaddr *, struct ifnet *);
 636
 637 struct  ifmultiaddr *ifmaof_ifpforaddr(struct sockaddr *, struct ifnet *);
 638 int     if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen);
 639
 640 typedef void *if_com_alloc_t(u_char type, struct ifnet *ifp);
 641 typedef void if_com_free_t(void *com, u_char type);
 642 void    if_register_com_alloc(u_char type, if_com_alloc_t *a, if_com_free_t *f);
 643 void    if_deregister_com_alloc(u_char type);
 644
 645 #define IF_LLADDR(ifp)                                                  \
 646     LLADDR((struct sockaddr_dl *) ifaddr_byindex((ifp)->if_index)->ifa_addr)
 647
 648 #ifdef DEVICE_POLLING
 649 enum poll_cmd { POLL_ONLY, POLL_AND_CHECK_STATUS, POLL_DEREGISTER };
 650
 651 typedef void poll_handler_t(struct ifnet *ifp, enum poll_cmd cmd, int count);
 652 int    ether_poll_register(poll_handler_t *h, struct ifnet *ifp);
 653 int    ether_poll_deregister(struct ifnet *ifp);
 654 #endif /* DEVICE_POLLING */
 655
 656 #endif /* _KERNEL */
 657
 658 #endif /* !_NET_IF_VAR_H_ */