bsd/net/multicast_list.c

   1 /*
   2  * Copyright (c) 2004-2010 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_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. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 /*
  30  * multicast_util.c:
  31  * - keep track of multicast addresses added to one interface based on the
  32  *   actual multicast addresses in another
  33  * - used by VLAN and BOND
  34  */
  35
  36 /*
  37  * Modification History:
  38  *
  39  * April 29, 2004       Dieter Siegmund (dieter@apple.com)
  40  * - created
  41  */
  42
  43 #include <net/multicast_list.h>
  44 #include <sys/param.h>
  45 #include <sys/systm.h>
  46 #include <sys/malloc.h>
  47 #include <net/if_dl.h>
  48
  49 __private_extern__ void
  50 multicast_list_init(struct multicast_list * mc_list)
  51 {
  52         SLIST_INIT(mc_list);
  53         return;
  54 }
  55
  56 /*
  57  * Function: multicast_list_remove
  58  * Purpose:
  59  *   Remove the given list of multicast addresses from the interface and from
  60  *   the multicast list structure.
  61  */
  62 __private_extern__ int
  63 multicast_list_remove(struct multicast_list * mc_list)
  64 {
  65         int                         error;
  66         struct multicast_entry *    mc;
  67         int                         result = 0;
  68
  69         while ((mc = SLIST_FIRST(mc_list)) != NULL) {
  70                 error = ifnet_remove_multicast(mc->mc_ifma);
  71                 if (error != 0) {
  72                         result = error;
  73                 }
  74                 SLIST_REMOVE_HEAD(mc_list, mc_entries);
  75                 ifmaddr_release(mc->mc_ifma);
  76                 FREE(mc, M_DEVBUF);
  77         }
  78         return result;
  79 }
  80
  81 /*
  82  * Function: multicast_list_program
  83  * Purpose:
  84  *   Program the multicast filter on "target_ifp" using the values from
  85  *   "source_ifp", and saving the result in "mc_list"
  86  *
  87  *   We build a new list of multicast addresses while programming the new list.
  88  *   If that completes successfully, we remove the old list, and return the
  89  *   new list.
  90  *
  91  *   If it fails, we remove what we've added to the new list, and
  92  *   return an error.
  93  */
  94 __private_extern__ int
  95 multicast_list_program(struct multicast_list * mc_list,
  96     struct ifnet * source_ifp,
  97     struct ifnet * target_ifp)
  98 {
  99         u_char                      alen;
 100         int                         error = 0;
 101         int                         i;
 102         struct multicast_entry *    mc = NULL;
 103         struct multicast_list       new_mc_list;
 104         struct sockaddr_dl          source_sdl = {};
 105         ifmultiaddr_t *             source_multicast_list;
 106         struct sockaddr_dl          target_sdl;
 107
 108         alen = target_ifp->if_addrlen;
 109         bzero((char *)&target_sdl, sizeof(target_sdl));
 110         target_sdl.sdl_len = sizeof(target_sdl);
 111         target_sdl.sdl_family = AF_LINK;
 112         target_sdl.sdl_type = target_ifp->if_type;
 113         target_sdl.sdl_alen = alen;
 114         target_sdl.sdl_index = target_ifp->if_index;
 115
 116         /* build a new list */
 117         multicast_list_init(&new_mc_list);
 118         error = ifnet_get_multicast_list(source_ifp, &source_multicast_list);
 119         if (error != 0) {
 120                 printf("multicast_list_program: "
 121                     "ifnet_get_multicast_list(%s%d) failed, %d\n",
 122                     source_ifp->if_name, source_ifp->if_unit, error);
 123                 return error;
 124         }
 125         for (i = 0; source_multicast_list[i] != NULL; i++) {
 126                 if (ifmaddr_address(source_multicast_list[i],
 127                     (struct sockaddr *)&source_sdl,
 128                     sizeof(source_sdl)) != 0
 129                     || source_sdl.sdl_family != AF_LINK) {
 130                         continue;
 131                 }
 132                 mc = _MALLOC(sizeof(struct multicast_entry), M_DEVBUF, M_WAITOK);
 133                 if (mc == NULL) {
 134                         error = ENOBUFS;
 135                         break;
 136                 }
 137                 bcopy(LLADDR(&source_sdl), LLADDR(&target_sdl), alen);
 138                 error = ifnet_add_multicast(target_ifp, (struct sockaddr *)&target_sdl,
 139                     &mc->mc_ifma);
 140                 if (error != 0) {
 141                         FREE(mc, M_DEVBUF);
 142                         break;
 143                 }
 144                 SLIST_INSERT_HEAD(&new_mc_list, mc, mc_entries);
 145         }
 146         if (error != 0) {
 147                 /* restore previous state */
 148                 (void)multicast_list_remove(&new_mc_list);
 149         } else {
 150                 /* remove the old entries, and return the new list */
 151                 (void)multicast_list_remove(mc_list);
 152                 *mc_list = new_mc_list;
 153         }
 154         ifnet_free_multicast_list(source_multicast_list);
 155         return error;
 156 }