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
50multicast_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
63multicast_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
95multicast_list_program(struct multicast_list * mc_list,
96		       struct ifnet * source_ifp,
97		       struct ifnet * target_ifp)
98{
99    int				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}
157