/* SPDX-License-Identifier: LGPL-2.1+ */
/***
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 .
***/
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include "fd-util.h"
#include "icmp6-util.h"
#include "socket-util.h"
#include "in-addr-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 index = mreq->ipv6mr_interface;
_cleanup_close_ int s = -1;
char ifname[IF_NAMESIZE] = "";
static const int zero = 0, one = 1, hops = 255;
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(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_UNICAST_HOPS, &hops, sizeof(hops));
if (r < 0)
return -errno;
r = setsockopt(s, SOL_IPV6, IPV6_RECVHOPLIMIT, &one, sizeof(one));
if (r < 0)
return -errno;
r = setsockopt(s, SOL_SOCKET, SO_TIMESTAMP, &one, sizeof(one));
if (r < 0)
return -errno;
if (if_indextoname(index, ifname) == 0)
return -errno;
r = setsockopt(s, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
if (r < 0)
return -errno;
return TAKE_FD(s);
}
int icmp6_bind_router_solicitation(int index) {
struct icmp6_filter filter = {};
struct ipv6_mreq mreq = {
.ipv6mr_multiaddr = IN6ADDR_ALL_NODES_MULTICAST_INIT,
.ipv6mr_interface = index,
};
ICMP6_FILTER_SETBLOCKALL(&filter);
ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filter);
return icmp6_bind_router_message(&filter, &mreq);
}
int icmp6_bind_router_advertisement(int index) {
struct icmp6_filter filter = {};
struct ipv6_mreq mreq = {
.ipv6mr_multiaddr = IN6ADDR_ALL_ROUTERS_MULTICAST_INIT,
.ipv6mr_interface = index,
};
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) {
union {
struct cmsghdr cmsghdr;
uint8_t buf[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.iov_base = buffer;
iov.iov_len = size;
len = recvmsg(fd, &msg, MSG_DONTWAIT);
if (len < 0) {
if (IN_SET(errno, EAGAIN, EINTR))
return 0;
return -errno;
}
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;
}