bsd/net/multicast_list.c

   1 /*
   2  * Copyright (c) 2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 /*
  25  * multicast_util.c:
  26  * - keep track of multicast addresses added to one interface based on the
  27  *   actual multicast addresses in another
  28  * - used by VLAN and BOND
  29  */
  30
  31 /*
  32  * Modification History:
  33  *
  34  * April 29, 2004       Dieter Siegmund (dieter@apple.com)
  35  * - created
  36  */
  37
  38 #include <net/multicast_list.h>
  39 #include <sys/param.h>
  40 #include <sys/systm.h>
  41 #include <sys/malloc.h>
  42 #include <net/if_dl.h>
  43
  44 __private_extern__ void
  45 multicast_list_init(struct multicast_list * mc_list)
  46 {
  47     SLIST_INIT(mc_list);
  48     return;
  49 }
  50
  51 /*
  52  * Function: multicast_list_remove
  53  * Purpose:
  54  *   Remove the given list of multicast addresses from the interface and from
  55  *   the multicast list structure.
  56  */
  57 __private_extern__ int
  58 multicast_list_remove(struct multicast_list * mc_list)
  59 {
  60     int                         error;
  61     struct multicast_entry *    mc;
  62     int                         result = 0;
  63
  64     while ((mc = SLIST_FIRST(mc_list)) != NULL) {
  65         error = ifnet_remove_multicast(mc->mc_ifma);
  66         if (error != 0) {
  67             result = error;
  68         }
  69         SLIST_REMOVE_HEAD(mc_list, mc_entries);
  70         ifmaddr_release(mc->mc_ifma);
  71         FREE(mc, M_DEVBUF);
  72     }
  73     return (result);
  74 }
  75
  76 /*
  77  * Function: multicast_list_program
  78  * Purpose:
  79  *   Program the multicast filter on "target_ifp" using the values from
  80  *   "source_ifp", and saving the result in "mc_list"
  81  *
  82  *   We build a new list of multicast addresses while programming the new list.
  83  *   If that completes successfully, we remove the old list, and return the
  84  *   new list.
  85  *
  86  *   If it fails, we remove what we've added to the new list, and
  87  *   return an error.
  88  */
  89 __private_extern__ int
  90 multicast_list_program(struct multicast_list * mc_list,
  91                        struct ifnet * source_ifp,
  92                        struct ifnet * target_ifp)
  93 {
  94     int                         alen;
  95     int                         error = 0;
  96     int                         i;
  97     struct multicast_entry *    mc = NULL;
  98     struct multicast_list       new_mc_list;
  99     struct sockaddr_dl          source_sdl;
 100     ifmultiaddr_t *             source_multicast_list;
 101     struct sockaddr_dl          target_sdl;
 102
 103     alen = target_ifp->if_addrlen;
 104     bzero((char *)&target_sdl, sizeof(target_sdl));
 105     target_sdl.sdl_len = sizeof(target_sdl);
 106     target_sdl.sdl_family = AF_LINK;
 107     target_sdl.sdl_type = target_ifp->if_type;
 108     target_sdl.sdl_alen = alen;
 109     target_sdl.sdl_index = target_ifp->if_index;
 110
 111     /* build a new list */
 112     multicast_list_init(&new_mc_list);
 113     error = ifnet_get_multicast_list(source_ifp, &source_multicast_list);
 114     if (error != 0) {
 115         printf("multicast_list_program: "
 116                "ifnet_get_multicast_list(%s%d) failed, %d\n",
 117                source_ifp->if_name, source_ifp->if_unit, error);
 118         return (error);
 119     }
 120     for (i = 0; source_multicast_list[i] != NULL; i++) {
 121         if (ifmaddr_address(source_multicast_list[i],
 122                             (struct sockaddr *)&source_sdl,
 123                             sizeof(source_sdl)) != 0
 124             || source_sdl.sdl_family != AF_LINK) {
 125             continue;
 126         }
 127         mc = _MALLOC(sizeof(struct multicast_entry), M_DEVBUF, M_WAITOK);
 128         bcopy(LLADDR(&source_sdl), LLADDR(&target_sdl), alen);
 129         error = ifnet_add_multicast(target_ifp, (struct sockaddr *)&target_sdl,
 130                                     &mc->mc_ifma);
 131         if (error != 0) {
 132             FREE(mc, M_DEVBUF);
 133             break;
 134         }
 135         SLIST_INSERT_HEAD(&new_mc_list, mc, mc_entries);
 136     }
 137     if (error != 0) {
 138         /* restore previous state */
 139         (void)multicast_list_remove(&new_mc_list);
 140     } else {
 141         /* remove the old entries, and return the new list */
 142         (void)multicast_list_remove(mc_list);
 143         *mc_list = new_mc_list;
 144     }
 145     return (error);
 146 }