#include <signal.h>
#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <net/ethernet.h>
#include <netinet/icmp6.h>
#include <netpacket/packet.h>
-#include <linux/rtnetlink.h>
#include <linux/filter.h>
-#include "router.h"
-#include "ndp.h"
+#include <linux/neighbour.h>
+#include "dhcpv6.h"
+#include "odhcpd.h"
+static void ndp_netevent_cb(unsigned long event, struct netevent_handler_info *info);
+static void setup_route(struct in6_addr *addr, struct interface *iface, bool add);
+static void setup_addr_for_relaying(struct in6_addr *addr, struct interface *iface, bool add);
static void handle_solicit(void *addr, void *data, size_t len,
- struct interface *iface);
-static void handle_rtnetlink(void *addr, void *data, size_t len,
- struct interface *iface);
-static struct ndp_neighbor* find_neighbor(struct in6_addr *addr, bool strict);
-static void modify_neighbor(struct in6_addr *addr, struct interface *iface,
- bool add);
-static ssize_t ping6(struct in6_addr *addr,
- const struct interface *iface);
-
-static struct list_head neighbors = LIST_HEAD_INIT(neighbors);
-static size_t neighbor_count = 0;
-static uint32_t rtnl_seqid = 0;
+ struct interface *iface, void *dest);
static int ping_socket = -1;
-static struct odhcpd_event ndp_event = {{.fd = -1}, handle_solicit};
-static struct odhcpd_event rtnl_event = {{.fd = -1}, handle_rtnetlink};
-
-// Filter ICMPv6 messages of type neighbor soliciation
+/* Filter ICMPv6 messages of type neighbor soliciation */
static struct sock_filter bpf[] = {
BPF_STMT(BPF_LD | BPF_B | BPF_ABS, offsetof(struct ip6_hdr, ip6_nxt)),
BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, IPPROTO_ICMPV6, 0, 3),
BPF_STMT(BPF_RET | BPF_K, 0),
};
static const struct sock_fprog bpf_prog = {sizeof(bpf) / sizeof(*bpf), bpf};
+static struct netevent_handler ndp_netevent_handler = { .cb = ndp_netevent_cb, };
-
-// Initialize NDP-proxy
-int init_ndp(void)
+/* Initialize NDP-proxy */
+int ndp_init(void)
{
- // Setup netlink socket
- if ((rtnl_event.uloop.fd = odhcpd_open_rtnl()) < 0)
- return -1;
-
- // Receive netlink neighbor and ip-address events
- uint32_t group = RTNLGRP_IPV6_IFADDR;
- setsockopt(rtnl_event.uloop.fd, SOL_NETLINK,
- NETLINK_ADD_MEMBERSHIP, &group, sizeof(group));
- group = RTNLGRP_IPV6_ROUTE;
- setsockopt(rtnl_event.uloop.fd, SOL_NETLINK,
- NETLINK_ADD_MEMBERSHIP, &group, sizeof(group));
-
- // Synthesize initial address events
- struct {
- struct nlmsghdr nh;
- struct ifaddrmsg ifa;
- } req2 = {
- {sizeof(req2), RTM_GETADDR, NLM_F_REQUEST | NLM_F_DUMP,
- ++rtnl_seqid, 0},
- {.ifa_family = AF_INET6}
- };
- send(rtnl_event.uloop.fd, &req2, sizeof(req2), MSG_DONTWAIT);
- odhcpd_register(&rtnl_event);
-
-
- // Create socket for intercepting NDP
- int sock = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
- htons(ETH_P_ALL)); // ETH_P_ALL for ingress + egress
- if (sock < 0) {
- syslog(LOG_ERR, "Unable to open packet socket: %s",
- strerror(errno));
- return -1;
+ struct icmp6_filter filt;
+ int val = 2, ret = 0;
+
+ /* Open ICMPv6 socket */
+ ping_socket = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC, IPPROTO_ICMPV6);
+ if (ping_socket < 0) {
+ syslog(LOG_ERR, "socket(AF_INET6): %m");
+ ret = -1;
+ goto out;
}
- if (setsockopt(sock, SOL_SOCKET, SO_ATTACH_FILTER,
- &bpf_prog, sizeof(bpf_prog))) {
- syslog(LOG_ERR, "Failed to set BPF: %s", strerror(errno));
- return -1;
+ if (setsockopt(ping_socket, IPPROTO_RAW, IPV6_CHECKSUM,
+ &val, sizeof(val)) < 0) {
+ syslog(LOG_ERR, "setsockopt(IPV6_CHECKSUM): %m");
+ ret = -1;
+ goto out;
}
- ndp_event.uloop.fd = sock;
- odhcpd_register(&ndp_event);
+ /* This is required by RFC 4861 */
+ val = 255;
+ if (setsockopt(ping_socket, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
+ &val, sizeof(val)) < 0) {
+ syslog(LOG_ERR, "setsockopt(IPV6_MULTICAST_HOPS): %m");
+ ret = -1;
+ goto out;
+ }
- // Open ICMPv6 socket
- ping_socket = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC, IPPROTO_ICMPV6);
+ if (setsockopt(ping_socket, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
+ &val, sizeof(val)) < 0) {
+ syslog(LOG_ERR, "setsockopt(IPV6_UNICAST_HOPS): %m");
+ ret = -1;
+ goto out;
+ }
- int val = 2;
- setsockopt(ping_socket, IPPROTO_RAW, IPV6_CHECKSUM, &val, sizeof(val));
+ /* Filter all packages, we only want to send */
+ ICMP6_FILTER_SETBLOCKALL(&filt);
+ if (setsockopt(ping_socket, IPPROTO_ICMPV6, ICMP6_FILTER,
+ &filt, sizeof(filt)) < 0) {
+ syslog(LOG_ERR, "setsockopt(ICMP6_FILTER): %m");
+ ret = -1;
+ goto out;
+ }
- // This is required by RFC 4861
- val = 255;
- setsockopt(ping_socket, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &val, sizeof(val));
- setsockopt(ping_socket, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &val, sizeof(val));
+ netlink_add_netevent_handler(&ndp_netevent_handler);
- // Filter all packages, we only want to send
- struct icmp6_filter filt;
- ICMP6_FILTER_SETBLOCKALL(&filt);
- setsockopt(ping_socket, IPPROTO_ICMPV6, ICMP6_FILTER, &filt, sizeof(filt));
+out:
+ if (ret < 0 && ping_socket >= 0) {
+ close(ping_socket);
+ ping_socket = -1;
+ }
+ return ret;
+}
- // Netlink socket, continued...
- group = RTNLGRP_NEIGH;
- setsockopt(rtnl_event.uloop.fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &group, sizeof(group));
+int ndp_setup_interface(struct interface *iface, bool enable)
+{
+ int ret = 0, procfd;
+ bool dump_neigh = false;
+ char procbuf[64];
- // Synthesize initial neighbor events
- struct {
- struct nlmsghdr nh;
- struct ndmsg ndm;
- } req = {
- {sizeof(req), RTM_GETNEIGH, NLM_F_REQUEST | NLM_F_DUMP,
- ++rtnl_seqid, 0},
- {.ndm_family = AF_INET6}
- };
- send(rtnl_event.uloop.fd, &req, sizeof(req), MSG_DONTWAIT);
+ snprintf(procbuf, sizeof(procbuf), "/proc/sys/net/ipv6/conf/%s/proxy_ndp", iface->ifname);
+ procfd = open(procbuf, O_WRONLY);
- return 0;
-}
+ if (procfd < 0) {
+ ret = -1;
+ goto out;
+ }
+ if (iface->ndp_event.uloop.fd >= 0) {
+ uloop_fd_delete(&iface->ndp_event.uloop);
+ close(iface->ndp_event.uloop.fd);
+ iface->ndp_event.uloop.fd = -1;
-int setup_ndp_interface(struct interface *iface, bool enable)
-{
- struct packet_mreq mreq = {iface->ifindex, PACKET_MR_ALLMULTI, ETH_ALEN, {0}};
- setsockopt(ndp_event.uloop.fd, SOL_PACKET, PACKET_DROP_MEMBERSHIP, &mreq, sizeof(mreq));
-
- struct ndp_neighbor *c, *n;
- list_for_each_entry_safe(c, n, &neighbors, head)
- if (c->iface == iface && (c->timeout == 0 || iface->ndp != RELAYD_RELAY || !enable))
- modify_neighbor(&c->addr, c->iface, false);
-
- if (enable && iface->ndp == RELAYD_RELAY) {
- setsockopt(ndp_event.uloop.fd, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mreq, sizeof(mreq));
-
- if (iface->static_ndp_len) {
- char *entry = alloca(iface->static_ndp_len), *saveptr;
- if (!entry) {
- syslog(LOG_ERR, "Alloca failed for static NDP list");
- return -1;
- }
- memcpy(entry, iface->static_ndp, iface->static_ndp_len);
-
- for (entry = strtok_r(entry, " ", &saveptr); entry; entry = strtok_r(NULL, " ", &saveptr)) {
- struct ndp_neighbor *n = malloc(sizeof(*n));
- if (!n) {
- syslog(LOG_ERR, "Malloc failed for static NDP-prefix %s", entry);
- return -1;
- }
-
- n->iface = iface;
- n->timeout = 0;
-
- char ipbuf[INET6_ADDRSTRLEN];
- if (sscanf(entry, "%45s/%hhu", ipbuf, &n->len) < 2
- || n->len > 128 || inet_pton(AF_INET6, ipbuf, &n->addr) != 1) {
- syslog(LOG_ERR, "Invalid static NDP-prefix %s", entry);
- return -1;
- }
-
- list_add(&n->head, &neighbors);
- }
- }
+ if (!enable || iface->ndp != MODE_RELAY)
+ if (write(procfd, "0\n", 2) < 0) {}
+
+ dump_neigh = true;
}
- return 0;
-}
+ if (enable && iface->ndp == MODE_RELAY) {
+ struct sockaddr_ll ll;
+ struct packet_mreq mreq;
+ if (write(procfd, "1\n", 2) < 0) {}
-// Send an ICMP-ECHO. This is less for actually pinging but for the
-// neighbor cache to be kept up-to-date.
-static ssize_t ping6(struct in6_addr *addr,
- const struct interface *iface)
-{
- struct sockaddr_in6 dest = {AF_INET6, 0, 0, *addr, 0};
- struct icmp6_hdr echo = {.icmp6_type = ICMP6_ECHO_REQUEST};
- struct iovec iov = {&echo, sizeof(echo)};
-
- // Linux seems to not honor IPV6_PKTINFO on raw-sockets, so work around
- setsockopt(ping_socket, SOL_SOCKET, SO_BINDTODEVICE,
- iface->ifname, sizeof(iface->ifname));
- return odhcpd_send(ping_socket, &dest, &iov, 1, iface);
-}
+ iface->ndp_event.uloop.fd = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC, htons(ETH_P_IPV6));
+ if (iface->ndp_event.uloop.fd < 0) {
+ syslog(LOG_ERR, "socket(AF_PACKET): %m");
+ ret = -1;
+ goto out;
+ }
+#ifdef PACKET_RECV_TYPE
+ int pktt = 1 << PACKET_MULTICAST;
+ if (setsockopt(iface->ndp_event.uloop.fd, SOL_PACKET, PACKET_RECV_TYPE,
+ &pktt, sizeof(pktt)) < 0) {
+ syslog(LOG_ERR, "setsockopt(PACKET_RECV_TYPE): %m");
+ ret = -1;
+ goto out;
+ }
+#endif
-// Handle solicitations
-static void handle_solicit(void *addr, void *data, size_t len,
- struct interface *iface)
-{
- struct ip6_hdr *ip6 = data;
- struct nd_neighbor_solicit *req = (struct nd_neighbor_solicit*)&ip6[1];
- struct sockaddr_ll *ll = addr;
+ if (setsockopt(iface->ndp_event.uloop.fd, SOL_SOCKET, SO_ATTACH_FILTER,
+ &bpf_prog, sizeof(bpf_prog))) {
+ syslog(LOG_ERR, "setsockopt(SO_ATTACH_FILTER): %m");
+ ret = -1;
+ goto out;
+ }
- // Solicitation is for duplicate address detection
- bool ns_is_dad = IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src);
+ memset(&ll, 0, sizeof(ll));
+ ll.sll_family = AF_PACKET;
+ ll.sll_ifindex = iface->ifindex;
+ ll.sll_protocol = htons(ETH_P_IPV6);
- // Don't forward any non-DAD solicitation for external ifaces
- // TODO: check if we should even forward DADs for them
- if (iface->external && !ns_is_dad)
- return;
+ if (bind(iface->ndp_event.uloop.fd, (struct sockaddr*)&ll, sizeof(ll)) < 0) {
+ syslog(LOG_ERR, "bind(): %m");
+ ret = -1;
+ goto out;
+ }
- if (len < sizeof(*ip6) + sizeof(*req))
- return; // Invalid reqicitation
+ memset(&mreq, 0, sizeof(mreq));
+ mreq.mr_ifindex = iface->ifindex;
+ mreq.mr_type = PACKET_MR_ALLMULTI;
+ mreq.mr_alen = ETH_ALEN;
- if (IN6_IS_ADDR_LINKLOCAL(&req->nd_ns_target) ||
- IN6_IS_ADDR_LOOPBACK(&req->nd_ns_target) ||
- IN6_IS_ADDR_MULTICAST(&req->nd_ns_target))
- return; // Invalid target
+ if (setsockopt(iface->ndp_event.uloop.fd, SOL_PACKET, PACKET_ADD_MEMBERSHIP,
+ &mreq, sizeof(mreq)) < 0) {
+ syslog(LOG_ERR, "setsockopt(PACKET_ADD_MEMBERSHIP): %m");
+ ret = -1;
+ goto out;
+ }
- char ipbuf[INET6_ADDRSTRLEN];
- inet_ntop(AF_INET6, &req->nd_ns_target, ipbuf, sizeof(ipbuf));
- syslog(LOG_NOTICE, "Got a NS for %s", ipbuf);
+ iface->ndp_event.handle_dgram = handle_solicit;
+ odhcpd_register(&iface->ndp_event);
- uint8_t mac[6];
- odhcpd_get_mac(iface, mac);
- if (!memcmp(ll->sll_addr, mac, sizeof(mac)) &&
- ll->sll_pkttype != PACKET_OUTGOING)
- return; // Looped back
-
- time_t now = time(NULL);
-
- struct ndp_neighbor *n = find_neighbor(&req->nd_ns_target, false);
- if (n && (n->iface || abs(n->timeout - now) < 5)) {
- syslog(LOG_NOTICE, "%s is on %s", ipbuf,
- (n->iface) ? n->iface->ifname : "<pending>");
- if (!n->iface || n->iface == iface)
- return;
-
- // Found on other interface, answer with advertisement
- struct {
- struct nd_neighbor_advert body;
- struct nd_opt_hdr opt_ll_hdr;
- uint8_t mac[6];
- } advert = {
- .body = {
- .nd_na_hdr = {ND_NEIGHBOR_ADVERT,
- 0, 0, {{0}}},
- .nd_na_target = req->nd_ns_target,
- },
- .opt_ll_hdr = {ND_OPT_TARGET_LINKADDR, 1},
- };
-
- memcpy(advert.mac, mac, sizeof(advert.mac));
- advert.body.nd_na_flags_reserved = ND_NA_FLAG_ROUTER |
- ND_NA_FLAG_SOLICITED;
-
- struct sockaddr_in6 dest = {AF_INET6, 0, 0, ALL_IPV6_NODES, 0};
- if (!ns_is_dad) // If not DAD, then unicast to source
- dest.sin6_addr = ip6->ip6_src;
-
- // Linux seems to not honor IPV6_PKTINFO on raw-sockets, so work around
- setsockopt(ping_socket, SOL_SOCKET, SO_BINDTODEVICE,
- iface->ifname, sizeof(iface->ifname));
- struct iovec iov = {&advert, sizeof(advert)};
- odhcpd_send(ping_socket, &dest, &iov, 1, iface);
- } else {
- // Send echo to all other interfaces to see where target is on
- // This will trigger neighbor discovery which is what we want.
- // We will observe the neighbor cache to see results.
-
- ssize_t sent = 0;
- struct interface *c;
- list_for_each_entry(c, &interfaces, head)
- if (iface->ndp == RELAYD_RELAY && iface != c &&
- (!ns_is_dad || !c->external == false))
- sent += ping6(&req->nd_ns_target, c);
-
- if (sent > 0) // Sent a ping, add pending neighbor entry
- modify_neighbor(&req->nd_ns_target, NULL, true);
+ /* If we already were enabled dump is unnecessary, if not do dump */
+ if (!dump_neigh)
+ netlink_dump_neigh_table(false);
+ else
+ dump_neigh = false;
}
-}
+ if (dump_neigh)
+ netlink_dump_neigh_table(true);
-void odhcpd_setup_route(const struct in6_addr *addr, int prefixlen,
- const struct interface *iface, const struct in6_addr *gw, bool add)
-{
- struct req {
- struct nlmsghdr nh;
- struct rtmsg rtm;
- struct rtattr rta_dst;
- struct in6_addr dst_addr;
- struct rtattr rta_oif;
- uint32_t ifindex;
- struct rtattr rta_table;
- uint32_t table;
- struct rtattr rta_gw;
- struct in6_addr gw;
- } req = {
- {sizeof(req), 0, NLM_F_REQUEST, ++rtnl_seqid, 0},
- {AF_INET6, prefixlen, 0, 0, 0, 0, 0, 0, 0},
- {sizeof(struct rtattr) + sizeof(struct in6_addr), RTA_DST},
- *addr,
- {sizeof(struct rtattr) + sizeof(uint32_t), RTA_OIF},
- iface->ifindex,
- {sizeof(struct rtattr) + sizeof(uint32_t), RTA_TABLE},
- RT_TABLE_MAIN,
- {sizeof(struct rtattr) + sizeof(struct in6_addr), RTA_GATEWAY},
- IN6ADDR_ANY_INIT,
- };
-
- if (gw)
- req.gw = *gw;
-
- if (add) {
- req.nh.nlmsg_type = RTM_NEWROUTE;
- req.nh.nlmsg_flags |= (NLM_F_CREATE | NLM_F_REPLACE);
- req.rtm.rtm_protocol = RTPROT_BOOT;
- req.rtm.rtm_scope = (gw) ? RT_SCOPE_UNIVERSE : RT_SCOPE_LINK;
- req.rtm.rtm_type = RTN_UNICAST;
- } else {
- req.nh.nlmsg_type = RTM_DELROUTE;
- req.rtm.rtm_scope = RT_SCOPE_NOWHERE;
+ out:
+ if (ret < 0 && iface->ndp_event.uloop.fd >= 0) {
+ close(iface->ndp_event.uloop.fd);
+ iface->ndp_event.uloop.fd = -1;
}
- size_t reqlen = (gw) ? sizeof(req) : offsetof(struct req, rta_gw);
- send(rtnl_event.uloop.fd, &req, reqlen, MSG_DONTWAIT);
+ if (procfd >= 0)
+ close(procfd);
+
+ return ret;
}
-// Use rtnetlink to modify kernel routes
-static void setup_route(struct in6_addr *addr, struct interface *iface,
- bool add)
+static void ndp_netevent_cb(unsigned long event, struct netevent_handler_info *info)
{
- char namebuf[INET6_ADDRSTRLEN];
- inet_ntop(AF_INET6, addr, namebuf, sizeof(namebuf));
- syslog(LOG_NOTICE, "%s about %s on %s", (add) ? "Learned" : "Forgot",
- namebuf, (iface) ? iface->ifname : "<pending>");
+ struct interface *iface = info->iface;
+ bool add = true;
- if (!iface || !iface->learn_routes)
+ if (!iface || iface->ndp == MODE_DISABLED)
return;
- odhcpd_setup_route(addr, 128, iface, NULL, add);
+ switch (event) {
+ case NETEV_ADDR6_DEL:
+ add = false;
+ netlink_dump_neigh_table(false);
+ /* fall through */
+ case NETEV_ADDR6_ADD:
+ setup_addr_for_relaying(&info->addr.in6, iface, add);
+ break;
+ case NETEV_NEIGH6_DEL:
+ add = false;
+ /* fall through */
+ case NETEV_NEIGH6_ADD:
+ if (info->neigh.flags & NTF_PROXY) {
+ if (add) {
+ netlink_setup_proxy_neigh(&info->neigh.dst.in6, iface->ifindex, false);
+ setup_route(&info->neigh.dst.in6, iface, false);
+ netlink_dump_neigh_table(false);
+ }
+ break;
+ }
+
+ if (add &&
+ !(info->neigh.state &
+ (NUD_REACHABLE|NUD_STALE|NUD_DELAY|NUD_PROBE|NUD_PERMANENT|NUD_NOARP)))
+ break;
+
+ setup_addr_for_relaying(&info->neigh.dst.in6, iface, add);
+ setup_route(&info->neigh.dst.in6, iface, add);
+
+ if (!add)
+ netlink_dump_neigh_table(false);
+ break;
+ default:
+ break;
+ }
}
-static void free_neighbor(struct ndp_neighbor *n)
+/* Send an ICMP-ECHO. This is less for actually pinging but for the
+ * neighbor cache to be kept up-to-date. */
+static void ping6(struct in6_addr *addr,
+ const struct interface *iface)
{
- setup_route(&n->addr, n->iface, false);
- list_del(&n->head);
- free(n);
- --neighbor_count;
-}
+ struct sockaddr_in6 dest = { .sin6_family = AF_INET6, .sin6_addr = *addr, .sin6_scope_id = iface->ifindex, };
+ struct icmp6_hdr echo = { .icmp6_type = ICMP6_ECHO_REQUEST };
+ struct iovec iov = { .iov_base = &echo, .iov_len = sizeof(echo) };
+ char ipbuf[INET6_ADDRSTRLEN];
+ inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf));
+ syslog(LOG_NOTICE, "Pinging for %s on %s", ipbuf, iface->name);
-static bool match_neighbor(struct ndp_neighbor *n, struct in6_addr *addr)
-{
- if (n->len <= 32)
- return ntohl(n->addr.s6_addr32[0]) >> (32 - n->len) ==
- ntohl(addr->s6_addr32[0]) >> (32 - n->len);
+ netlink_setup_route(addr, 128, iface->ifindex, NULL, 128, true);
+ odhcpd_send(ping_socket, &dest, &iov, 1, iface);
+ netlink_setup_route(addr, 128, iface->ifindex, NULL, 128, false);
+}
- if (n->addr.s6_addr32[0] != addr->s6_addr32[0])
- return false;
+/* Handle solicitations */
+static void handle_solicit(void *addr, void *data, size_t len,
+ struct interface *iface, _unused void *dest)
+{
+ struct ip6_hdr *ip6 = data;
+ struct nd_neighbor_solicit *req = (struct nd_neighbor_solicit*)&ip6[1];
+ struct sockaddr_ll *ll = addr;
+ struct interface *c;
+ char ipbuf[INET6_ADDRSTRLEN];
+ uint8_t mac[6];
- if (n->len <= 64)
- return ntohl(n->addr.s6_addr32[1]) >> (64 - n->len) ==
- ntohl(addr->s6_addr32[1]) >> (64 - n->len);
+ /* Solicitation is for duplicate address detection */
+ bool ns_is_dad = IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src);
- if (n->addr.s6_addr32[1] != addr->s6_addr32[1])
- return false;
+ /* Don't process solicit messages on non relay interfaces
+ * Don't forward any non-DAD solicitation for external ifaces
+ * TODO: check if we should even forward DADs for them */
+ if (iface->ndp != MODE_RELAY || (iface->external && !ns_is_dad))
+ return;
- if (n->len <= 96)
- return ntohl(n->addr.s6_addr32[2]) >> (96 - n->len) ==
- ntohl(addr->s6_addr32[2]) >> (96 - n->len);
+ if (len < sizeof(*ip6) + sizeof(*req))
+ return; // Invalid reqicitation
- if (n->addr.s6_addr32[2] != addr->s6_addr32[2])
- return false;
+ if (IN6_IS_ADDR_LINKLOCAL(&req->nd_ns_target) ||
+ IN6_IS_ADDR_LOOPBACK(&req->nd_ns_target) ||
+ IN6_IS_ADDR_MULTICAST(&req->nd_ns_target))
+ return; /* Invalid target */
- return ntohl(n->addr.s6_addr32[3]) >> (128 - n->len) ==
- ntohl(addr->s6_addr32[3]) >> (128 - n->len);
-}
+ inet_ntop(AF_INET6, &req->nd_ns_target, ipbuf, sizeof(ipbuf));
+ syslog(LOG_DEBUG, "Got a NS for %s on %s", ipbuf, iface->name);
+ odhcpd_get_mac(iface, mac);
+ if (!memcmp(ll->sll_addr, mac, sizeof(mac)))
+ return; /* Looped back */
-static struct ndp_neighbor* find_neighbor(struct in6_addr *addr, bool strict)
-{
- time_t now = time(NULL);
- struct ndp_neighbor *n, *e;
- list_for_each_entry_safe(n, e, &neighbors, head) {
- if ((!strict && match_neighbor(n, addr)) ||
- (n->len == 128 && IN6_ARE_ADDR_EQUAL(&n->addr, addr)))
- return n;
-
- if (!n->iface && abs(n->timeout - now) >= 5)
- free_neighbor(n);
+ avl_for_each_element(&interfaces, c, avl) {
+ if (iface != c && c->ndp == MODE_RELAY &&
+ (ns_is_dad || !c->external))
+ ping6(&req->nd_ns_target, c);
}
- return NULL;
}
-
-// Modified our own neighbor-entries
-static void modify_neighbor(struct in6_addr *addr,
- struct interface *iface, bool add)
+/* Use rtnetlink to modify kernel routes */
+static void setup_route(struct in6_addr *addr, struct interface *iface, bool add)
{
- if (!addr || (void*)addr == (void*)iface)
- return;
+ char ipbuf[INET6_ADDRSTRLEN];
- struct ndp_neighbor *n = find_neighbor(addr, true);
- if (!add) { // Delete action
- if (n && (!n->iface || n->iface == iface))
- free_neighbor(n);
- } else if (!n) { // No entry yet, add one if possible
- if (neighbor_count >= NDP_MAX_NEIGHBORS ||
- !(n = malloc(sizeof(*n))))
- return;
-
- n->len = 128;
- n->addr = *addr;
- n->iface = iface;
- if (!n->iface)
- time(&n->timeout);
- list_add(&n->head, &neighbors);
- ++neighbor_count;
- setup_route(addr, n->iface, add);
- } else if (n->iface == iface) {
- if (!n->iface)
- time(&n->timeout);
- } else if (iface && (!n->iface ||
- (!iface->external && n->iface->external))) {
- setup_route(addr, n->iface, false);
- n->iface = iface;
- setup_route(addr, n->iface, add);
- }
- // TODO: In case a host switches interfaces we might want
- // to set its old neighbor entry to NUD_STALE and ping it
- // on the old interface to confirm if the MACs match.
-}
+ inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf));
+ syslog(LOG_NOTICE, "%s about %s%s on %s",
+ (add) ? "Learning" : "Forgetting",
+ iface->learn_routes ? "proxy routing for " : "",
+ ipbuf, iface->name);
+ if (iface->learn_routes)
+ netlink_setup_route(addr, 128, iface->ifindex, NULL, 1024, add);
+}
-// Handler for neighbor cache entries from the kernel. This is our source
-// to learn and unlearn hosts on interfaces.
-static void handle_rtnetlink(_unused void *addr, void *data, size_t len,
- _unused struct interface *iface)
+static void setup_addr_for_relaying(struct in6_addr *addr, struct interface *iface, bool add)
{
- for (struct nlmsghdr *nh = data; NLMSG_OK(nh, len);
- nh = NLMSG_NEXT(nh, len)) {
- struct rtmsg *rtm = NLMSG_DATA(nh);
- if ((nh->nlmsg_type == RTM_NEWROUTE ||
- nh->nlmsg_type == RTM_DELROUTE) &&
- rtm->rtm_dst_len == 0)
- raise(SIGUSR1); // Inform about a change in default route
-
- struct ndmsg *ndm = NLMSG_DATA(nh);
- struct ifaddrmsg *ifa = NLMSG_DATA(nh);
- if (nh->nlmsg_type != RTM_NEWNEIGH
- && nh->nlmsg_type != RTM_DELNEIGH
- && nh->nlmsg_type != RTM_NEWADDR
- && nh->nlmsg_type != RTM_DELADDR)
- continue; // Unrelated message type
- bool is_addr = (nh->nlmsg_type == RTM_NEWADDR
- || nh->nlmsg_type == RTM_DELADDR);
-
- // Family and ifindex are on the same offset for NEIGH and ADDR
- if (NLMSG_PAYLOAD(nh, 0) < sizeof(*ndm)
- || ndm->ndm_family != AF_INET6)
- continue; //
-
- // Lookup interface
- struct interface *iface;
- if (!(iface = odhcpd_get_interface_by_index(ndm->ndm_ifindex)))
- continue;
+ struct interface *c;
+ char ipbuf[INET6_ADDRSTRLEN];
+
+ inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf));
- // Data to retrieve
- size_t rta_offset = (is_addr) ? sizeof(*ifa) : sizeof(*ndm);
- uint16_t atype = (is_addr) ? IFA_ADDRESS : NDA_DST;
- ssize_t alen = NLMSG_PAYLOAD(nh, rta_offset);
- struct in6_addr *addr = NULL;
-
- for (struct rtattr *rta = (void*)(((uint8_t*)ndm) + rta_offset);
- RTA_OK(rta, alen); rta = RTA_NEXT(rta, alen))
- if (rta->rta_type == atype &&
- RTA_PAYLOAD(rta) >= sizeof(*addr))
- addr = RTA_DATA(rta);
-
- // Address not specified or unrelated
- if (!addr || IN6_IS_ADDR_LINKLOCAL(addr) ||
- IN6_IS_ADDR_MULTICAST(addr))
+ avl_for_each_element(&interfaces, c, avl) {
+ if (iface == c || c->ndp != MODE_RELAY)
continue;
- // Check for states
- bool add;
- if (is_addr)
- add = (nh->nlmsg_type == RTM_NEWADDR);
+ if (netlink_setup_proxy_neigh(addr, c->ifindex, add))
+ syslog(LOG_DEBUG, "Failed to %s proxy neighbour entry %s on %s",
+ add ? "add" : "delete", ipbuf, c->name);
else
- add = (nh->nlmsg_type == RTM_NEWNEIGH && (ndm->ndm_state &
- (NUD_REACHABLE | NUD_STALE | NUD_DELAY | NUD_PROBE
- | NUD_PERMANENT | NUD_NOARP)));
-
- if (iface->ndp == RELAYD_RELAY)
- modify_neighbor(addr, iface, add);
-
- if (is_addr && iface->ra == RELAYD_SERVER)
- raise(SIGUSR1); // Inform about a change in addresses
-
- if (is_addr && iface->dhcpv6 == RELAYD_SERVER)
- iface->ia_reconf = true;
-
- if (iface->ndp == RELAYD_RELAY && is_addr && iface->master) {
- // Replay address changes on all slave interfaces
- nh->nlmsg_flags = NLM_F_REQUEST;
-
- if (nh->nlmsg_type == RTM_NEWADDR)
- nh->nlmsg_flags |= NLM_F_CREATE | NLM_F_REPLACE;
-
- struct interface *c;
- list_for_each_entry(c, &interfaces, head) {
- if (c->ndp == RELAYD_RELAY && !c->master) {
- ifa->ifa_index = c->ifindex;
- send(rtnl_event.uloop.fd, nh, nh->nlmsg_len, MSG_DONTWAIT);
- }
- }
- }
-
- /* TODO: See if this is required for optimal operation
- // Keep neighbor entries alive so we don't loose routes
- */
- if (add && (ndm->ndm_state & NUD_STALE))
- ping6(addr, iface);
+ syslog(LOG_DEBUG, "%s proxy neighbour entry %s on %s",
+ add ? "Added" : "Deleted", ipbuf, c->name);
}
}