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/***
This file is part of systemd.
Copyright (C) 2014 Intel Corporation. All rights reserved.
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <errno.h>
#include <netinet/icmp6.h>
#include <netinet/in.h>
#include <netinet/ip6.h>
#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
#include <net/if.h>
#include <linux/if_packet.h>
#include "fd-util.h"
#include "icmp6-util.h"
#include "socket-util.h"
#define IN6ADDR_ALL_ROUTERS_MULTICAST_INIT \
{ { { 0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02 } } }
#define IN6ADDR_ALL_NODES_MULTICAST_INIT \
{ { { 0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 } } }
static int icmp6_bind_router_message(const struct icmp6_filter *filter,
const struct ipv6_mreq *mreq) {
int index = mreq->ipv6mr_interface;
_cleanup_close_ int s = -1;
char ifname[IF_NAMESIZE] = "";
static const int zero = 0, one = 1, hops = 255;
int r;
s = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC | SOCK_NONBLOCK, IPPROTO_ICMPV6);
if (s < 0)
return -errno;
r = setsockopt(s, IPPROTO_ICMPV6, ICMP6_FILTER, filter, sizeof(*filter));
if (r < 0)
return -errno;
r = setsockopt(s, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, mreq, sizeof(*mreq));
if (r < 0)
return -errno;
/* RFC 3315, section 6.7, bullet point 2 may indicate that an
IPV6_PKTINFO socket option also applies for ICMPv6 multicast.
Empirical experiments indicates otherwise and therefore an
IPV6_MULTICAST_IF socket option is used here instead */
r = setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_IF, &index, sizeof(index));
if (r < 0)
return -errno;
r = setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &zero, sizeof(zero));
if (r < 0)
return -errno;
r = setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &hops, sizeof(hops));
if (r < 0)
return -errno;
r = setsockopt(s, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &hops, sizeof(hops));
if (r < 0)
return -errno;
r = setsockopt(s, SOL_IPV6, IPV6_RECVHOPLIMIT, &one, sizeof(one));
if (r < 0)
return -errno;
r = setsockopt(s, SOL_SOCKET, SO_TIMESTAMP, &one, sizeof(one));
if (r < 0)
return -errno;
if (if_indextoname(index, ifname) == 0)
return -errno;
r = setsockopt(s, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
if (r < 0)
return -errno;
r = s;
s = -1;
return r;
}
int icmp6_bind_router_solicitation(int index) {
struct icmp6_filter filter = {};
struct ipv6_mreq mreq = {
.ipv6mr_multiaddr = IN6ADDR_ALL_NODES_MULTICAST_INIT,
.ipv6mr_interface = index,
};
ICMP6_FILTER_SETBLOCKALL(&filter);
ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filter);
return icmp6_bind_router_message(&filter, &mreq);
}
int icmp6_bind_router_advertisement(int index) {
struct icmp6_filter filter = {};
struct ipv6_mreq mreq = {
.ipv6mr_multiaddr = IN6ADDR_ALL_ROUTERS_MULTICAST_INIT,
.ipv6mr_interface = index,
};
ICMP6_FILTER_SETBLOCKALL(&filter);
ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filter);
return icmp6_bind_router_message(&filter, &mreq);
}
int icmp6_send_router_solicitation(int s, const struct ether_addr *ether_addr) {
struct sockaddr_in6 dst = {
.sin6_family = AF_INET6,
.sin6_addr = IN6ADDR_ALL_ROUTERS_MULTICAST_INIT,
};
struct {
struct nd_router_solicit rs;
struct nd_opt_hdr rs_opt;
struct ether_addr rs_opt_mac;
} _packed_ rs = {
.rs.nd_rs_type = ND_ROUTER_SOLICIT,
.rs_opt.nd_opt_type = ND_OPT_SOURCE_LINKADDR,
.rs_opt.nd_opt_len = 1,
};
struct iovec iov = {
.iov_base = &rs,
.iov_len = sizeof(rs),
};
struct msghdr msg = {
.msg_name = &dst,
.msg_namelen = sizeof(dst),
.msg_iov = &iov,
.msg_iovlen = 1,
};
int r;
assert(s >= 0);
assert(ether_addr);
rs.rs_opt_mac = *ether_addr;
r = sendmsg(s, &msg, 0);
if (r < 0)
return -errno;
return 0;
}
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