diff options
Diffstat (limited to 'src/ndp.c')
| -rw-r--r-- | src/ndp.c | 38 |
1 files changed, 38 insertions, 0 deletions
@@ -295,6 +295,33 @@ static void ping6(struct in6_addr *addr, netlink_setup_route(addr, 128, iface->ifindex, NULL, 128, false); } +/* Send a Neighbor Advertisement. */ +static void send_na(struct in6_addr *to_addr, + const struct interface *iface, struct in6_addr *for_addr, + const uint8_t *mac) +{ + struct sockaddr_in6 dest = { .sin6_family = AF_INET6, .sin6_addr = *to_addr }; + char pbuf[sizeof(struct nd_neighbor_advert) + sizeof(struct nd_opt_hdr) + 6]; + struct nd_neighbor_advert *adv = (struct nd_neighbor_advert*)pbuf; + struct nd_opt_hdr *opt = (struct nd_opt_hdr*) &pbuf[sizeof(struct nd_neighbor_advert)]; + struct iovec iov = { .iov_base = &pbuf, .iov_len = sizeof(pbuf) }; + char ipbuf[INET6_ADDRSTRLEN]; + + memset(pbuf, 0, sizeof(pbuf)); + adv->nd_na_hdr = (struct icmp6_hdr) { + .icmp6_type = ND_NEIGHBOR_ADVERT, + .icmp6_dataun.icmp6_un_data32 = { 0x40000000L } + }; + adv->nd_na_target = *for_addr; + *opt = (struct nd_opt_hdr) { .nd_opt_type = ND_OPT_TARGET_LINKADDR, .nd_opt_len = 1 }; + memcpy(&pbuf[sizeof(struct nd_neighbor_advert) + sizeof(struct nd_opt_hdr)], mac, 6); + + inet_ntop(AF_INET6, to_addr, ipbuf, sizeof(ipbuf)); + syslog(LOG_DEBUG, "Answering NS to %s on %s", ipbuf, iface->ifname); + + odhcpd_send(iface->ndp_ping_fd, &dest, &iov, 1, iface); +} + /* Handle solicitations */ static void handle_solicit(void *addr, void *data, size_t len, struct interface *iface, _unused void *dest) @@ -335,6 +362,17 @@ static void handle_solicit(void *addr, void *data, size_t len, (ns_is_dad || !c->external)) ping6(&req->nd_ns_target, c); } + + /* Catch global-addressed NS and answer them manually. + * The kernel won't answer these and cannot route them either. */ + if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) && + IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { + bool is_proxy_neigh = netlink_get_interface_proxy_neigh(iface->ifindex, + &req->nd_ns_target) == 1; + + if (is_proxy_neigh) + send_na(&ip6->ip6_src, iface, &req->nd_ns_target, mac); + } } /* Use rtnetlink to modify kernel routes */ |