Line data Source code
1 : /***
2 : This file is part of systemd.
3 :
4 : Copyright (C) 2014 Intel Corporation. All rights reserved.
5 :
6 : systemd is free software; you can redistribute it and/or modify it
7 : under the terms of the GNU Lesser General Public License as published by
8 : the Free Software Foundation; either version 2.1 of the License, or
9 : (at your option) any later version.
10 :
11 : systemd is distributed in the hope that it will be useful, but
12 : WITHOUT ANY WARRANTY; without even the implied warranty of
13 : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 : Lesser General Public License for more details.
15 :
16 : You should have received a copy of the GNU Lesser General Public License
17 : along with systemd; If not, see <http://www.gnu.org/licenses/>.
18 : ***/
19 :
20 : #include <errno.h>
21 : #include <sys/types.h>
22 : #include <sys/socket.h>
23 : #include <string.h>
24 : #include <linux/if_packet.h>
25 : #include <stdio.h>
26 : #include <unistd.h>
27 : #include <netinet/ip6.h>
28 : #include <netinet/icmp6.h>
29 : #include <netinet/in.h>
30 :
31 : #include "socket-util.h"
32 :
33 : #include "dhcp6-internal.h"
34 : #include "dhcp6-protocol.h"
35 :
36 : #define IN6ADDR_ALL_ROUTERS_MULTICAST_INIT \
37 : { { { 0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
38 : 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02 } } }
39 :
40 : #define IN6ADDR_ALL_NODES_MULTICAST_INIT \
41 : { { { 0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
42 : 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 } } }
43 :
44 0 : int dhcp_network_icmp6_bind_router_solicitation(int index)
45 : {
46 0 : struct icmp6_filter filter = { };
47 0 : struct ipv6_mreq mreq = {
48 : .ipv6mr_multiaddr = IN6ADDR_ALL_NODES_MULTICAST_INIT,
49 : .ipv6mr_interface = index,
50 : };
51 0 : _cleanup_close_ int s = -1;
52 0 : int r, zero = 0, hops = 255;
53 :
54 0 : s = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC | SOCK_NONBLOCK,
55 : IPPROTO_ICMPV6);
56 0 : if (s < 0)
57 0 : return -errno;
58 :
59 0 : ICMP6_FILTER_SETBLOCKALL(&filter);
60 0 : ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filter);
61 0 : r = setsockopt(s, IPPROTO_ICMPV6, ICMP6_FILTER, &filter,
62 : sizeof(filter));
63 0 : if (r < 0)
64 0 : return -errno;
65 :
66 : /* RFC 3315, section 6.7, bullet point 2 may indicate that an
67 : IPV6_PKTINFO socket option also applies for ICMPv6 multicast.
68 : Empirical experiments indicates otherwise and therefore an
69 : IPV6_MULTICAST_IF socket option is used here instead */
70 0 : r = setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_IF, &index,
71 : sizeof(index));
72 0 : if (r < 0)
73 0 : return -errno;
74 :
75 0 : r = setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &zero,
76 : sizeof(zero));
77 0 : if (r < 0)
78 0 : return -errno;
79 :
80 0 : r = setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &hops,
81 : sizeof(hops));
82 0 : if (r < 0)
83 0 : return -errno;
84 :
85 0 : r = setsockopt(s, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq,
86 : sizeof(mreq));
87 0 : if (r < 0)
88 0 : return -errno;
89 :
90 0 : r = s;
91 0 : s = -1;
92 0 : return r;
93 : }
94 :
95 0 : int dhcp_network_icmp6_send_router_solicitation(int s, const struct ether_addr *ether_addr)
96 : {
97 0 : struct sockaddr_in6 dst = {
98 : .sin6_family = AF_INET6,
99 : .sin6_addr = IN6ADDR_ALL_ROUTERS_MULTICAST_INIT,
100 : };
101 : struct {
102 : struct nd_router_solicit rs;
103 : struct nd_opt_hdr rs_opt;
104 : struct ether_addr rs_opt_mac;
105 0 : } _packed_ rs = {
106 : .rs.nd_rs_type = ND_ROUTER_SOLICIT,
107 : };
108 0 : struct iovec iov[1] = {
109 : { &rs, },
110 : };
111 0 : struct msghdr msg = {
112 : .msg_name = &dst,
113 : .msg_namelen = sizeof(dst),
114 : .msg_iov = iov,
115 : .msg_iovlen = 1,
116 : };
117 : int r;
118 :
119 0 : if (ether_addr) {
120 0 : memcpy(&rs.rs_opt_mac, ether_addr, ETH_ALEN);
121 0 : rs.rs_opt.nd_opt_type = ND_OPT_SOURCE_LINKADDR;
122 0 : rs.rs_opt.nd_opt_len = 1;
123 0 : iov[0].iov_len = sizeof(rs);
124 : } else
125 0 : iov[0].iov_len = sizeof(rs.rs);
126 :
127 0 : r = sendmsg(s, &msg, 0);
128 0 : if (r < 0)
129 0 : return -errno;
130 :
131 0 : return 0;
132 : }
133 :
134 0 : int dhcp6_network_bind_udp_socket(int index, struct in6_addr *local_address) {
135 0 : struct in6_pktinfo pktinfo = {
136 : .ipi6_ifindex = index,
137 : };
138 0 : union sockaddr_union src = {
139 : .in6.sin6_family = AF_INET6,
140 0 : .in6.sin6_port = htobe16(DHCP6_PORT_CLIENT),
141 : .in6.sin6_addr = IN6ADDR_ANY_INIT,
142 : };
143 0 : _cleanup_close_ int s = -1;
144 0 : int r, off = 0, on = 1;
145 :
146 0 : if (local_address)
147 0 : memcpy(&src.in6.sin6_addr, local_address,
148 : sizeof(src.in6.sin6_addr));
149 :
150 0 : s = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
151 : IPPROTO_UDP);
152 0 : if (s < 0)
153 0 : return -errno;
154 :
155 0 : r = setsockopt(s, IPPROTO_IPV6, IPV6_PKTINFO, &pktinfo,
156 : sizeof(pktinfo));
157 0 : if (r < 0)
158 0 : return -errno;
159 :
160 0 : r = setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on));
161 0 : if (r < 0)
162 0 : return -errno;
163 :
164 0 : r = setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &off, sizeof(off));
165 0 : if (r < 0)
166 0 : return -errno;
167 :
168 0 : r = bind(s, &src.sa, sizeof(src.in6));
169 0 : if (r < 0)
170 0 : return -errno;
171 :
172 0 : r = s;
173 0 : s = -1;
174 0 : return r;
175 : }
176 :
177 0 : int dhcp6_network_send_udp_socket(int s, struct in6_addr *server_address,
178 : const void *packet, size_t len) {
179 0 : union sockaddr_union dest = {
180 : .in6.sin6_family = AF_INET6,
181 0 : .in6.sin6_port = htobe16(DHCP6_PORT_SERVER),
182 : };
183 : int r;
184 :
185 0 : assert(server_address);
186 :
187 0 : memcpy(&dest.in6.sin6_addr, server_address, sizeof(dest.in6.sin6_addr));
188 :
189 0 : r = sendto(s, packet, len, 0, &dest.sa, sizeof(dest.in6));
190 0 : if (r < 0)
191 0 : return -errno;
192 :
193 0 : return 0;
194 : }
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