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-rw-r--r--src/libsystemd-network/icmp6-util.c217
1 files changed, 217 insertions, 0 deletions
diff --git a/src/libsystemd-network/icmp6-util.c b/src/libsystemd-network/icmp6-util.c
new file mode 100644
index 0000000..e535b12
--- /dev/null
+++ b/src/libsystemd-network/icmp6-util.c
@@ -0,0 +1,217 @@
+/* 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/socket.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 index = mreq->ipv6mr_interface;
+ _cleanup_close_ int s = -1;
+ char ifname[IF_NAMESIZE] = "";
+ 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, index);
+ 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;
+
+ 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 = IOVEC_MAKE(buffer, size);
+
+ len = recvmsg(fd, &msg, MSG_DONTWAIT);
+ if (len < 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;
+}