bsd/net/multicast_list.c

   1 /*
   2  * Copyright (c) 2004 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
  23 /*
  24  * multicast_util.c:
  25  * - keep track of multicast addresses added to one interface based on the
  26  *   actual multicast addresses in another
  27  * - used by VLAN and BOND
  28  */
  29
  30 /*
  31  * Modification History:
  32  *
  33  * April 29, 2004       Dieter Siegmund (dieter@apple.com)
  34  * - created
  35  */
  36
  37 #include <net/multicast_list.h>
  38 #include <sys/param.h>
  39 #include <sys/systm.h>
  40 #include <sys/malloc.h>
  41 #include <net/if_dl.h>
  42
  43 __private_extern__ void
  44 multicast_list_init(struct multicast_list * mc_list)
  45 {
  46     SLIST_INIT(mc_list);
  47     return;
  48 }
  49
  50 /*
  51  * Function: multicast_list_remove
  52  * Purpose:
  53  *   Remove the given list of multicast addresses from the interface and from
  54  *   the multicast list structure.
  55  */
  56 __private_extern__ int
  57 multicast_list_remove(struct multicast_list * mc_list)
  58 {
  59     int                         error;
  60     struct multicast_entry *    mc;
  61     int                         result = 0;
  62
  63     while ((mc = SLIST_FIRST(mc_list)) != NULL) {
  64         error = ifnet_remove_multicast(mc->mc_ifma);
  65         if (error != 0) {
  66             result = error;
  67         }
  68         SLIST_REMOVE_HEAD(mc_list, mc_entries);
  69         ifmaddr_release(mc->mc_ifma);
  70         FREE(mc, M_DEVBUF);
  71     }
  72     return (result);
  73 }
  74
  75 /*
  76  * Function: multicast_list_program
  77  * Purpose:
  78  *   Program the multicast filter on "target_ifp" using the values from
  79  *   "source_ifp", and saving the result in "mc_list"
  80  *
  81  *   We build a new list of multicast addresses while programming the new list.
  82  *   If that completes successfully, we remove the old list, and return the
  83  *   new list.
  84  *
  85  *   If it fails, we remove what we've added to the new list, and
  86  *   return an error.
  87  */
  88 __private_extern__ int
  89 multicast_list_program(struct multicast_list * mc_list,
  90                        struct ifnet * source_ifp,
  91                        struct ifnet * target_ifp)
  92 {
  93     int                         alen;
  94     int                         error = 0;
  95     int                         i;
  96     struct multicast_entry *    mc = NULL;
  97     struct multicast_list       new_mc_list;
  98     struct sockaddr_dl          source_sdl;
  99     ifmultiaddr_t *             source_multicast_list;
 100     struct sockaddr_dl          target_sdl;
 101
 102     alen = target_ifp->if_addrlen;
 103     bzero((char *)&target_sdl, sizeof(target_sdl));
 104     target_sdl.sdl_len = sizeof(target_sdl);
 105     target_sdl.sdl_family = AF_LINK;
 106     target_sdl.sdl_type = target_ifp->if_type;
 107     target_sdl.sdl_alen = alen;
 108     target_sdl.sdl_index = target_ifp->if_index;
 109
 110     /* build a new list */
 111     multicast_list_init(&new_mc_list);
 112     error = ifnet_get_multicast_list(source_ifp, &source_multicast_list);
 113     if (error != 0) {
 114         printf("multicast_list_program: "
 115                "ifnet_get_multicast_list(%s%d) failed, %d\n",
 116                source_ifp->if_name, source_ifp->if_unit, error);
 117         return (error);
 118     }
 119     for (i = 0; source_multicast_list[i] != NULL; i++) {
 120         if (ifmaddr_address(source_multicast_list[i],
 121                             (struct sockaddr *)&source_sdl,
 122                             sizeof(source_sdl)) != 0
 123             || source_sdl.sdl_family != AF_LINK) {
 124             continue;
 125         }
 126         mc = _MALLOC(sizeof(struct multicast_entry), M_DEVBUF, M_WAITOK);
 127         bcopy(LLADDR(&source_sdl), LLADDR(&target_sdl), alen);
 128         error = ifnet_add_multicast(target_ifp, (struct sockaddr *)&target_sdl,
 129                                     &mc->mc_ifma);
 130         if (error != 0) {
 131             FREE(mc, M_DEVBUF);
 132             break;
 133         }
 134         SLIST_INSERT_HEAD(&new_mc_list, mc, mc_entries);
 135     }
 136     if (error != 0) {
 137         /* restore previous state */
 138         (void)multicast_list_remove(&new_mc_list);
 139     } else {
 140         /* remove the old entries, and return the new list */
 141         (void)multicast_list_remove(mc_list);
 142         *mc_list = new_mc_list;
 143     }
 144     return (error);
 145 }