/*** 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" #include "dhcp6-protocol.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; } int dhcp6_network_bind_udp_socket(int index, struct in6_addr *local_address) { struct in6_pktinfo pktinfo = { .ipi6_ifindex = index, }; union sockaddr_union src = { .in6.sin6_family = AF_INET6, .in6.sin6_port = htobe16(DHCP6_PORT_CLIENT), .in6.sin6_addr = IN6ADDR_ANY_INIT, }; _cleanup_close_ int s = -1; int r, off = 0, on = 1; if (local_address) memcpy(&src.in6.sin6_addr, local_address, sizeof(src.in6.sin6_addr)); s = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, IPPROTO_UDP); if (s < 0) return -errno; r = setsockopt(s, IPPROTO_IPV6, IPV6_PKTINFO, &pktinfo, sizeof(pktinfo)); if (r < 0) return -errno; r = setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)); if (r < 0) return -errno; r = setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &off, sizeof(off)); if (r < 0) return -errno; r = bind(s, &src.sa, sizeof(src.in6)); if (r < 0) return -errno; r = s; s = -1; return r; } int dhcp6_network_send_udp_socket(int s, struct in6_addr *server_address, const void *packet, size_t len) { union sockaddr_union dest = { .in6.sin6_family = AF_INET6, .in6.sin6_port = htobe16(DHCP6_PORT_SERVER), }; int r; assert(server_address); memcpy(&dest.in6.sin6_addr, server_address, sizeof(dest.in6.sin6_addr)); r = sendto(s, packet, len, 0, &dest.sa, sizeof(dest.in6)); if (r < 0) return -errno; return 0; }