1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
/* SPDX-License-Identifier: LGPL-2.1+ */
/***
Copyright © 2014 Intel Corporation. All rights reserved.
***/
#include <errno.h>
#include <netinet/icmp6.h>
#include <netinet/in.h>
#include <netinet/ip6.h>
#include <stdio.h>
#include <string.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 "in-addr-util.h"
#include "io-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 ifindex = mreq->ipv6mr_interface;
_cleanup_close_ int s = -1;
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_int(s, IPPROTO_IPV6, IPV6_MULTICAST_IF, ifindex);
if (r < 0)
return r;
r = setsockopt_int(s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, false);
if (r < 0)
return r;
r = setsockopt_int(s, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, 255);
if (r < 0)
return r;
r = setsockopt_int(s, IPPROTO_IPV6, IPV6_UNICAST_HOPS, 255);
if (r < 0)
return r;
r = setsockopt_int(s, SOL_IPV6, IPV6_RECVHOPLIMIT, true);
if (r < 0)
return r;
r = setsockopt_int(s, SOL_SOCKET, SO_TIMESTAMP, true);
if (r < 0)
return r;
r = socket_bind_to_ifindex(s, ifindex);
if (r < 0)
return r;
return TAKE_FD(s);
}
int icmp6_bind_router_solicitation(int ifindex) {
struct icmp6_filter filter = {};
struct ipv6_mreq mreq = {
.ipv6mr_multiaddr = IN6ADDR_ALL_NODES_MULTICAST_INIT,
.ipv6mr_interface = ifindex,
};
ICMP6_FILTER_SETBLOCKALL(&filter);
ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filter);
return icmp6_bind_router_message(&filter, &mreq);
}
int icmp6_bind_router_advertisement(int ifindex) {
struct icmp6_filter filter = {};
struct ipv6_mreq mreq = {
.ipv6mr_multiaddr = IN6ADDR_ALL_ROUTERS_MULTICAST_INIT,
.ipv6mr_interface = ifindex,
};
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;
}
int icmp6_receive(int fd, void *buffer, size_t size, struct in6_addr *dst,
triple_timestamp *timestamp) {
CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(int)) + /* ttl */
CMSG_SPACE(sizeof(struct timeval))) control;
struct iovec iov = {};
union sockaddr_union sa = {};
struct msghdr msg = {
.msg_name = &sa.sa,
.msg_namelen = sizeof(sa),
.msg_iov = &iov,
.msg_iovlen = 1,
.msg_control = &control,
.msg_controllen = sizeof(control),
};
struct cmsghdr *cmsg;
ssize_t len;
iov = IOVEC_MAKE(buffer, size);
len = recvmsg_safe(fd, &msg, MSG_DONTWAIT);
if (len < 0)
return (int) len;
if ((size_t) len != size)
return -EINVAL;
if (msg.msg_namelen == sizeof(struct sockaddr_in6) &&
sa.in6.sin6_family == AF_INET6) {
*dst = sa.in6.sin6_addr;
if (in_addr_is_link_local(AF_INET6, (union in_addr_union*) dst) <= 0)
return -EADDRNOTAVAIL;
} else if (msg.msg_namelen > 0)
return -EPFNOSUPPORT;
/* namelen == 0 only happens when running the test-suite over a socketpair */
assert(!(msg.msg_flags & MSG_CTRUNC));
assert(!(msg.msg_flags & MSG_TRUNC));
CMSG_FOREACH(cmsg, &msg) {
if (cmsg->cmsg_level == SOL_IPV6 &&
cmsg->cmsg_type == IPV6_HOPLIMIT &&
cmsg->cmsg_len == CMSG_LEN(sizeof(int))) {
int hops = *(int*) CMSG_DATA(cmsg);
if (hops != 255)
return -EMULTIHOP;
}
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SO_TIMESTAMP &&
cmsg->cmsg_len == CMSG_LEN(sizeof(struct timeval)))
triple_timestamp_from_realtime(timestamp, timeval_load((struct timeval*) CMSG_DATA(cmsg)));
}
if (!triple_timestamp_is_set(timestamp))
triple_timestamp_get(timestamp);
return 0;
}
|
