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/*
* Author: Steven Barth <steven at midlink.org>
*
* Copyright 2015 Deutsche Telekom AG
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <alloca.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <linux/mroute6.h>
#include <libubox/list.h>
#include <libubox/avl.h>
#include "client.h"
// Add / update / remove a client entry for a multicast group
int client_set(struct client *client, const struct in6_addr *group,
bool include, const struct in6_addr sources[], size_t cnt)
{
int family = (IN6_IS_ADDR_V4MAPPED(group)) ? AF_INET : AF_INET6;
int sol = (family == AF_INET) ? SOL_IP : SOL_IPV6;
char addrbuf[INET6_ADDRSTRLEN];
size_t len = sizeof(struct group_filter) + cnt * sizeof(struct sockaddr_storage);
struct {
struct group_filter f;
struct sockaddr_storage s[];
} *filter = alloca(len);
struct sockaddr_in *in_addr = (struct sockaddr_in*)&filter->f.gf_group;
struct sockaddr_in6 *in6_addr = (struct sockaddr_in6*)&filter->f.gf_group;
inet_ntop(AF_INET6, group, addrbuf, sizeof(addrbuf));
L_DEBUG("%s: %s on %d => %s (+%d sources)", __FUNCTION__, addrbuf,
client->ifindex, (include) ? "include" : "exclude", (int)cnt);
// Construct MSFILTER for outgoing IGMP / MLD
memset(filter, 0, len);
filter->f.gf_interface = client->ifindex;
filter->f.gf_fmode = include ? MCAST_INCLUDE : MCAST_EXCLUDE;
filter->f.gf_group.ss_family = family;
filter->f.gf_numsrc = cnt;
if (family == AF_INET)
client_unmap(&in_addr->sin_addr, group);
else
in6_addr->sin6_addr = *group;
for (size_t i = 0; i < cnt; ++i) {
filter->f.gf_slist[i].ss_family = family;
in_addr = (struct sockaddr_in*)&filter->f.gf_slist[i];
in6_addr = (struct sockaddr_in6*)&filter->f.gf_slist[i];
if (family == AF_INET)
client_unmap(&in_addr->sin_addr, &sources[i]);
else
in6_addr->sin6_addr = sources[i];
}
int fd = (family == AF_INET) ? client->igmp_fd : client->mld_fd;
setsockopt(fd, sol, MCAST_LEAVE_GROUP, filter, sizeof(struct group_req));
if (!include || cnt > 0) {
if (setsockopt(fd, sol, MCAST_JOIN_GROUP, filter, sizeof(struct group_req))
&& family == AF_INET && errno == ENOBUFS) {
L_WARN("proxy: kernel denied joining multicast group. check igmp_max_memberships?");
return -errno;
}
if (setsockopt(fd, sol, MCAST_MSFILTER, filter, len))
return -errno;
}
return 0;
}
// Initialize client-instance
int client_init(struct client *client, int ifindex)
{
client->igmp_fd = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
if (client->igmp_fd < 0)
return -errno;
client->mld_fd = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0);
if (client->mld_fd < 0)
return -errno;
client->ifindex = ifindex;
return 0;
}
// Cleanup client-instance
void client_deinit(struct client *client)
{
if (client->ifindex) {
close(client->igmp_fd);
close(client->mld_fd);
client->igmp_fd = -1;
client->mld_fd = -1;
client->ifindex = 0;
}
}
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