sd-icmp6-nd: Add Router Solicitation and Advertisement support

[elogind.git] / src / libsystemd-network / dhcp6-network.c

diff --git a/src/libsystemd-network/dhcp6-network.c b/src/libsystemd-network/dhcp6-network.c
new file mode 100644 (file)
index 0000000..53ce23d
--- /dev/null
+++ b/src/libsystemd-network/dhcp6-network.c
@@ -0,0 +1,131 @@
+/***
+  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 <sys/types.h>
+#include <sys/socket.h>
+#include <string.h>
+#include <linux/if_packet.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <netinet/ip6.h>
+#include <netinet/icmp6.h>
+#include <netinet/in.h>
+
+#include "socket-util.h"
+
+#include "dhcp6-internal.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 } } }
+
+int dhcp_network_icmp6_bind_router_solicitation(int index)
+{
+        struct icmp6_filter filter = { };
+        struct ipv6_mreq mreq = {
+                .ipv6mr_multiaddr = IN6ADDR_ALL_NODES_MULTICAST_INIT,
+                .ipv6mr_interface = index,
+        };
+        _cleanup_close_ int s = -1;
+        int r, zero = 0, hops = 255;
+
+        s = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC | SOCK_NONBLOCK,
+                   IPPROTO_ICMPV6);
+        if (s < 0)
+                return -errno;
+
+        ICMP6_FILTER_SETBLOCKALL(&filter);
+        ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filter);
+        r = setsockopt(s, IPPROTO_ICMPV6, ICMP6_FILTER, &filter,
+                       sizeof(filter));
+        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_ADD_MEMBERSHIP, &mreq,
+                       sizeof(mreq));
+        if (r < 0)
+                return -errno;
+
+        r = s;
+        s = -1;
+        return r;
+}
+
+int dhcp_network_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,
+        };
+        struct iovec iov[1] = {
+                { &rs, },
+        };
+        struct msghdr msg = {
+                .msg_name = &dst,
+                .msg_namelen = sizeof(dst),
+                .msg_iov = iov,
+                .msg_iovlen = 1,
+        };
+        int r;
+
+        if (ether_addr) {
+                memcpy(&rs.rs_opt_mac, ether_addr, ETH_ALEN);
+                rs.rs_opt.nd_opt_type = ND_OPT_SOURCE_LINKADDR;
+                rs.rs_opt.nd_opt_len = 1;
+                iov[0].iov_len = sizeof(rs);
+        } else
+                iov[0].iov_len = sizeof(rs.rs);
+
+        r = sendmsg(s, &msg, 0);
+        if (r < 0)
+                return -errno;
+
+        return 0;
+}