bsd/net/tokensr.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) 1993 NeXT Computer, Inc.  All rights reserved.
  23  *
  24  * tokensr.h - Token-ring IEEE 802.5 source routing utility functions.
  25  *
  26  *      We currently make these functions static inlines.  These should
  27  *      be considered for movement to a library and made public (after
  28  *      sanitizing API).
  29  *
  30  * HISTORY
  31  *
  32  * 22-Jul-94 John Immordino (jimmord) at NeXT
  33  *      Converted static array of source routes to a hash table.
  34  *      Loosely coupled hash table entries to arp table entries, ie.
  35  *      when hash table is full, delete the first entry for which there
  36  *      is no arp entry before inserting the next source route.
  37  *
  38  * 26-Apr-94 John Immordino (jimmord) at NeXT
  39  *      Cleaned up.  Fixed byte-swap problems, converted all addresses to
  40  *      character arrays, etc.
  41  *
  42  * 07-Apr-93 Joel Greenblatt at NeXT
  43  *      Created
  44  *
  45  */
  46
  47 #ifdef DRIVER_PRIVATE
  48
  49 #ifndef _TOKENSR_
  50 #define _TOKENSR_
  51
  52 #include <sys/socket.h>
  53 #include <net/tokendefs.h>
  54 #include <net/if.h>
  55 #include <net/if_arp.h>
  56 #include <netinet/in.h>
  57 #include <netinet/if_ether.h>
  58 #include <objc/hashtable.h>     /* Not an Obj-C header */
  59
  60 /*
  61  * Virtual driver parameters
  62  * Used by if_vtrXX modules
  63  */
  64 typedef struct {
  65         int vunit;
  66         int vflags;
  67         int vmtu;
  68         int vtokpri;
  69 } vparms_t;
  70
  71
  72 /*
  73  * Source routing table entry
  74  * Note: ipAddr must be the first element in order for our hash table
  75  * code to work properly.
  76  */
  77 typedef struct  {
  78     unsigned long       ipAddr;         /* IP address of this entry - */
  79                                         /* needed for our temporary   */
  80                                         /* arp table lookup scheme    */
  81     sroute_t            ri;             /* routing information field  */
  82 } srtable_t;
  83
  84
  85 /*
  86  * Encoded source-routing broadcast type (used as parameter to
  87  * source routing routines).
  88  */
  89 typedef enum {
  90         SRB_OFF,                /* no source-route broadcast */
  91         SRB_AR,                 /* all-routes broadcast */
  92         SRB_SR,                 /* single-route broadcast */
  93         SRB_INVALID             /* invalid entry */
  94 } srbcast_t;
  95
  96 /*
  97  * ARP code taken from bsd/netinet/if_ether.c.  Need this in order
  98  * to perform lookups of IP addresses to determine which source route
  99  * entry to remove from the table.  The first source route entry without
 100  * a corresponding ARP entry will be removed.
 101  */
 102 #ifdef GATEWAY
 103 #define ARPTAB_BSIZ     16              /* bucket size */
 104 #define ARPTAB_NB       37              /* number of buckets */
 105 #else
 106 #define ARPTAB_BSIZ     9               /* bucket size */
 107 #define ARPTAB_NB       19              /* number of buckets */
 108 #endif
 109
 110 extern struct arptab arptab[];
 111
 112 #define ARPTAB_HASH(a) \
 113         ((u_long)(a) % ARPTAB_NB)
 114
 115 /*
 116  *  Change to permit multiple heterogenous interfaces to co-exist.
 117  */
 118 #define ARPTAB_LOOK(at,addr,ifp) { \
 119         register n; \
 120         at = &arptab[ARPTAB_HASH(addr) * ARPTAB_BSIZ]; \
 121         for (n = 0 ; n < ARPTAB_BSIZ ; n++,at++) \
 122                 if (at->at_iaddr.s_addr == addr && \
 123                     (!(ifp) || at->at_if == (ifp))) \
 124                         break; \
 125         if (n >= ARPTAB_BSIZ) \
 126                 at = 0; \
 127 }
 128
 129
 130 /*
 131  * Initialize callers source routing table.
 132  */
 133 static __inline__
 134 void init_src_routing(NXHashTable **sourceRouteTable)
 135 {
 136     extern NXHashTablePrototype SRTablePrototype;
 137     *sourceRouteTable = NXCreateHashTable(SRTablePrototype, 0, NULL);
 138 }
 139
 140 /*
 141  * Search for a source route (given a destination address).
 142  */
 143 static __inline__
 144 sroute_t *find_sr(NXHashTable *sourceRouteTable, unsigned long idst)
 145 {
 146     srtable_t *sourceRouteEntry = NXHashGet(sourceRouteTable,
 147         (const void *)&idst);
 148     if (sourceRouteEntry) {
 149         return &sourceRouteEntry->ri;
 150     }
 151     return NULL;
 152 }
 153
 154 /*
 155  * Add an entry to the callers source routing table.
 156  */
 157 static __inline__
 158 void add_sr(netif_t netif, NXHashTable *sourceRouteTable, unsigned long ipAddr,
 159         sroute_t *rip, unsigned long srLimit)
 160 {
 161     srtable_t           *sourceRouteEntry;
 162     struct ifnet        *ifp = (struct ifnet *)netif;
 163
 164     if ((rip->rc.len > 18)|| (rip->rc.len < 2) || (rip->rc.len & 1))
 165         return;
 166
 167     /*
 168      * See if the entry is already in the table
 169      */
 170     sourceRouteEntry = NXHashGet(sourceRouteTable,&ipAddr);
 171     if (sourceRouteEntry) {
 172         bcopy(rip, &sourceRouteEntry->ri, rip->rc.len);
 173         sourceRouteEntry->ri.rc.bcast = 0;              /* make non-bcast */
 174         sourceRouteEntry->ri.rc.dir = ~sourceRouteEntry->ri.rc.dir;
 175         return;
 176     }
 177
 178     /*
 179      * See if there's room in the table for another entry.
 180      */
 181     if (NXCountHashTable(sourceRouteTable) >= srLimit) {
 182         BOOL            dumpedOne = NO;
 183         NXHashState     state = NXInitHashState(sourceRouteTable);
 184
 185         /*
 186          * Need to delete an entry.
 187          */
 188         while (NXNextHashState(sourceRouteTable, &state,
 189                 (void **)&sourceRouteEntry)) {
 190
 191             struct arptab *at;
 192
 193             /*
 194              * Look for an entry without a corresponding entry in the
 195              * arp table.
 196              */
 197             ARPTAB_LOOK(at, sourceRouteEntry->ipAddr, ifp);
 198             if (at == NULL) {
 199                 /*
 200                  * Found one - try to remove it
 201                  */
 202                 sourceRouteEntry =
 203                     NXHashRemove(sourceRouteTable,
 204                         (const void *)&sourceRouteEntry->ipAddr);
 205                 if (sourceRouteEntry) {
 206                     kfree(sourceRouteEntry,sizeof(srtable_t));
 207                     dumpedOne = YES;
 208                     break;
 209                 }
 210             }
 211         }
 212         if (dumpedOne == NO) {
 213             printf("add_sr: source route table overflow\n");
 214             return;
 215         }
 216     }
 217
 218     sourceRouteEntry = (srtable_t *)kalloc(sizeof(srtable_t));
 219
 220     sourceRouteEntry->ipAddr = ipAddr;
 221     bcopy(rip, &sourceRouteEntry->ri, rip->rc.len);
 222     sourceRouteEntry->ri.rc.bcast = 0;                  /* make non-bcast */
 223     sourceRouteEntry->ri.rc.dir = ~sourceRouteEntry->ri.rc.dir;
 224
 225     sourceRouteEntry =
 226         NXHashInsert(sourceRouteTable,(const void *)&sourceRouteEntry->ipAddr);
 227     if (sourceRouteEntry)       /* shouldn't happen */
 228         kfree(sourceRouteEntry,sizeof(srtable_t));
 229 }
 230
 231 /*
 232  * Find & return the source route to the callers address.
 233  */
 234 static __inline__
 235 void get_src_route(NXHashTable *sourceRouteTable, unsigned long idst,
 236     unsigned char *da, tokenHeader_t *th)
 237 {
 238     sroute_t    *sourceRoute;
 239
 240     if (da[0] & 0x80)
 241         return;                         /* don't handle group addresses */
 242
 243     /*
 244      * Find source route in srtable and copy to caller's
 245      * tokenHeader_t (or turn off sri bit).
 246      */
 247     sourceRoute = find_sr(sourceRouteTable, idst);
 248     if (sourceRoute) {
 249         bcopy(sourceRoute, &th->ri, sourceRoute->rc.len);
 250         th->sa[0] |= TR_RII;
 251     }
 252     else
 253         th->sa[0] &= ~TR_RII;           /* turn off source routing bit */
 254 }
 255
 256 /*
 257  * Save the source route in the callers MAC header.
 258  */
 259 static __inline__
 260 void save_src_route(netif_t netif, NXHashTable *sourceRouteTable,
 261     unsigned long ipAddr, tokenHeader_t *th, unsigned long srLimit)
 262 {
 263     /*
 264      * If frame has a routing field > 2 then save it (i.e. it's been
 265      * thru at least one bridge).
 266      */
 267     if ((th->sa[0] & TR_RII) && (th->ri.rc.len > 2))
 268         add_sr(netif, sourceRouteTable, ipAddr, &th->ri, srLimit);
 269 }
 270
 271
 272 /*
 273  * Returns length of the source routing field in callers MAC header.
 274  * Returns -1 if the header is invalid.
 275  */
 276 static __inline__
 277 int get_ri_len(tokenHeader_t *th)
 278 {
 279     int         ri_len = 0;
 280     sroute_t    *rif = (sroute_t *)&th->ri;
 281
 282     if (th->sa[0] & 0x80) {
 283         ri_len = (int)rif->rc.len;
 284         if ((ri_len & 1) || (ri_len < 2) || (ri_len > 18)) {
 285             ri_len = -1;
 286         }
 287     }
 288     return ri_len;
 289 }
 290
 291 /*
 292  * Returns the length of an 802.5 MAC header (including routing field).
 293  */
 294 static __inline__
 295 int get_8025_hdr_len(tokenHeader_t *th)
 296 {
 297     int ri_len;
 298
 299     ri_len = get_ri_len(th);
 300     if (ri_len < 0)
 301         return ri_len; // bad header
 302
 303     return ri_len + MAC_HDR_MIN;
 304 }
 305
 306 /*
 307  * Returns 1 if mac address is any type of broadcast, zero otherwise.
 308  */
 309 static __inline__
 310 int check_mac_bcast(tokenHeader_t *th)
 311 {
 312     if (th->da[0] & 0x80)
 313         return 1;               // group address (I/G bit)
 314     return 0;
 315 }
 316
 317 /*
 318  * Build a broadcast routing field in the callers MAC header.
 319  */
 320 static __inline__
 321 void make_sr_bcast(tokenHeader_t *th, srbcast_t type)
 322 {
 323     if ((type == SRB_OFF) || (type >= SRB_INVALID)) {
 324         th->sa[0] &= ~TR_RII;
 325         return;
 326     }
 327
 328     th->sa[0] |= TR_RII;        /* turn on rii bit to ind. src rtng field */
 329
 330     /*
 331      * Build the routing control field for the requested
 332      * broadcast type.
 333      */
 334     if (type == SRB_AR)
 335         th->ri.rc.bcast = BI_AR_BCAST;
 336     else
 337         th->ri.rc.bcast = BI_SR_BCAST;
 338
 339     th->ri.rc.len = 2;
 340     th->ri.rc.dir = 0;
 341     th->ri.rc.longf = LF_BCAST;
 342     th->ri.rc.rsrvd = 0;
 343 }
 344
 345 /*
 346  * Make the callers MAC header a reply to sender.
 347  */
 348 static __inline__
 349 void make_mac_reply(tokenHeader_t *th)
 350 {
 351
 352     /*
 353      * Copy source address to destination address.  Turn off RII bit in
 354      * the destination address.
 355      */
 356     bcopy(th->sa, th->da, sizeof(th->da));
 357     th->da[0] &= ~TR_RII;
 358
 359     /*
 360      * Convert the source routing field to a reply (flip direction
 361      * bit & turn off broadcast bits).
 362      */
 363     if (th->sa[0] & TR_RII) {
 364         th->ri.rc.dir = ~th->ri.rc.dir;
 365         th->ri.rc.bcast = 0;
 366     }
 367 }
 368
 369
 370 #endif /* _TOKENSR_ */
 371
 372 #endif /* DRIVER_PRIVATE */