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/* SPDX-License-Identifier: LGPL-2.1-or-later */
/***
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 "iovec-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 = -EBADF;
int r;
assert(filter);
assert(mreq);
s = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC | SOCK_NONBLOCK, IPPROTO_ICMPV6);
if (s < 0)
return -errno;
if (setsockopt(s, IPPROTO_ICMPV6, ICMP6_FILTER, filter, sizeof(*filter)) < 0)
return -errno;
if (setsockopt(s, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, mreq, sizeof(*mreq)) < 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,
};
assert(s >= 0);
assert(ether_addr);
rs.rs_opt_mac = *ether_addr;
if (sendmsg(s, &msg, 0) < 0)
return -errno;
return 0;
}
int icmp6_receive(
int fd,
void *buffer,
size_t size,
struct in6_addr *ret_sender,
triple_timestamp *ret_timestamp) {
/* This needs to be initialized with zero. See #20741. */
CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(int)) + /* ttl */
CMSG_SPACE_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;
struct in6_addr addr = {};
triple_timestamp t = {};
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) {
addr = sa.in6.sin6_addr;
if (!in6_addr_is_link_local(&addr) && !in6_addr_is_null(&addr))
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_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 = *CMSG_TYPED_DATA(cmsg, int);
if (hops != 255)
return -EMULTIHOP;
}
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_TIMESTAMP &&
cmsg->cmsg_len == CMSG_LEN(sizeof(struct timeval))) {
struct timeval *tv = memcpy(&(struct timeval) {}, CMSG_DATA(cmsg), sizeof(struct timeval));
triple_timestamp_from_realtime(&t, timeval_load(tv));
}
}
if (ret_timestamp) {
if (triple_timestamp_is_set(&t))
*ret_timestamp = t;
else
triple_timestamp_get(ret_timestamp);
}
if (ret_sender)
*ret_sender = addr;
return 0;
}
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