#include <signal.h>
#include <errno.h>
+#include <fcntl.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
struct interface *iface, void *dest);
static void handle_rtnetlink(void *addr, void *data, size_t len,
struct interface *iface, void *dest);
-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;
-
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};
group = RTNLGRP_NEIGH;
setsockopt(rtnl_event.uloop.fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &group, sizeof(group));
- // 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);
-
return 0;
}
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);
+ char procbuf[64];
+ snprintf(procbuf, sizeof(procbuf), "/proc/sys/net/ipv6/conf/%s/proxy_ndp", iface->ifname);
+ int procfd = open(procbuf, O_WRONLY);
- 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)) {
- char *sep;
- 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;
-
- sep = strchr(entry, '/');
- if (!sep) {
- free(n);
- syslog(LOG_ERR, "Invalid static NDP-prefix %s", entry);
- return -1;
- }
-
- *sep = 0;
- n->len = atoi(sep + 1);
- if (inet_pton(AF_INET6, entry, &n->addr) != 1 || n->len > 128) {
- free(n);
- syslog(LOG_ERR, "Invalid static NDP-prefix %s/%s", entry, sep + 1);
- return -1;
- }
+ 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;
- list_add(&n->head, &neighbors);
- }
- }
+ write(procfd, "0\n", 2);
}
- bool enable_packet = false;
- struct interface *i;
- list_for_each_entry(i, &interfaces, head) {
- if (i == iface && !enable)
- continue;
-
- if (i->ndp == RELAYD_RELAY)
- enable_packet = true;
- }
+ if (enable && iface->ndp == RELAYD_RELAY) {
+ write(procfd, "1\n", 2);
- if (enable_packet && ndp_event.uloop.fd < 0) {
- // 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
+ int sock = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC, htons(ETH_P_IPV6));
if (sock < 0) {
syslog(LOG_ERR, "Unable to open packet socket: %s",
strerror(errno));
return -1;
}
+#ifdef PACKET_RECV_TYPE
+ int pktt = 1 << PACKET_MULTICAST;
+ setsockopt(sock, SOL_PACKET, PACKET_RECV_TYPE, &pktt, sizeof(pktt));
+#endif
+
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;
}
- ndp_event.uloop.fd = sock;
- odhcpd_register(&ndp_event);
- } else if (!enable_packet && ndp_event.uloop.fd >= 0) {
- close(ndp_event.uloop.fd);
- ndp_event.uloop.fd = -1;
+ struct sockaddr_ll ll = {
+ .sll_family = AF_PACKET,
+ .sll_ifindex = iface->ifindex,
+ .sll_protocol = htons(ETH_P_IPV6),
+ };
+ bind(sock, (struct sockaddr*)&ll, sizeof(ll));
+
+ struct packet_mreq mreq = {iface->ifindex, PACKET_MR_ALLMULTI, ETH_ALEN, {0}};
+ setsockopt(sock, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mreq, sizeof(mreq));
+
+ iface->ndp_event.uloop.fd = sock;
+ iface->ndp_event.handle_dgram = handle_solicit;
+ odhcpd_register(&iface->ndp_event);
+
+ // Dump 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);
}
+ close(procfd);
return 0;
}
uint8_t mac[6];
odhcpd_get_mac(iface, mac);
- if (!memcmp(ll->sll_addr, mac, sizeof(mac)) &&
- ll->sll_pkttype != PACKET_OUTGOING)
+ if (!memcmp(ll->sll_addr, mac, sizeof(mac)))
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_DEBUG, "%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);
- }
+ struct interface *c;
+ list_for_each_entry(c, &interfaces, head)
+ if (iface->ndp == RELAYD_RELAY && iface != c &&
+ (!ns_is_dad || !c->external == false))
+ ping6(&req->nd_ns_target, c);
}
odhcpd_setup_route(addr, 128, iface, NULL, add);
}
-static void free_neighbor(struct ndp_neighbor *n)
-{
- setup_route(&n->addr, n->iface, false);
- list_del(&n->head);
- free(n);
- --neighbor_count;
-}
-
-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 && !odhcpd_bmemcmp(&n->addr, addr, n->len)) ||
- (n->len == 128 && IN6_ARE_ADDR_EQUAL(&n->addr, addr)))
- return n;
-
- if (!n->iface && abs(n->timeout - now) >= 5)
- free_neighbor(n);
- }
- return NULL;
-}
-
-
-// Modified our own neighbor-entries
-static void modify_neighbor(struct in6_addr *addr,
- struct interface *iface, bool add)
-{
- if (!addr || (void*)addr == (void*)iface)
- return;
-
- 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.
-}
-
// 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, _unused void *dest)
{
+ bool dump_neigh = false;
+ struct in6_addr last_solicited = IN6ADDR_ANY_INIT;
+
for (struct nlmsghdr *nh = data; NLMSG_OK(nh, len);
nh = NLMSG_NEXT(nh, len)) {
struct rtmsg *rtm = NLMSG_DATA(nh);
(NUD_REACHABLE | NUD_STALE | NUD_DELAY | NUD_PROBE
| NUD_PERMANENT | NUD_NOARP)));
- if (iface->ndp == RELAYD_RELAY)
- modify_neighbor(addr, iface, add);
+ if (iface->ndp == RELAYD_RELAY) {
+ // Replay change to all neighbor cache
+ struct {
+ struct nlmsghdr nh;
+ struct ndmsg ndm;
+ struct nlattr nla_dst;
+ struct in6_addr dst;
+ } req = {
+ {sizeof(req), RTM_DELNEIGH, NLM_F_REQUEST,
+ ++rtnl_seqid, 0},
+ {.ndm_family = AF_INET6, .ndm_flags = NTF_PROXY},
+ {sizeof(struct nlattr) + sizeof(struct in6_addr), NDA_DST},
+ *addr
+ };
+
+ if (add) {
+ req.nh.nlmsg_type = RTM_NEWNEIGH;
+ req.nh.nlmsg_flags |= NLM_F_CREATE;
+
+ struct interface *c;
+ list_for_each_entry(c, &interfaces, head) {
+ if (c->ndp == RELAYD_RELAY && iface != c) {
+ req.ndm.ndm_ifindex = c->ifindex;
+ send(rtnl_event.uloop.fd, &req, sizeof(req), MSG_DONTWAIT);
+ }
+ }
+
+ setup_route(addr, iface, true);
+ } else {
+ if (nh->nlmsg_type == RTM_NEWNEIGH) {
+ // might be locally originating
+ if (!IN6_ARE_ADDR_EQUAL(&last_solicited, addr)) {
+ last_solicited = *addr;
+
+ struct interface *c;
+ list_for_each_entry(c, &interfaces, head)
+ if (iface->ndp == RELAYD_RELAY && iface != c &&
+ !c->external == false)
+ ping6(addr, c);
+ }
+ } else {
+ struct interface *c;
+ list_for_each_entry(c, &interfaces, head) {
+ if (c->ndp == RELAYD_RELAY && iface != c) {
+ req.ndm.ndm_ifindex = c->ifindex;
+ send(rtnl_event.uloop.fd, &req, sizeof(req), MSG_DONTWAIT);
+ }
+ }
+ setup_route(addr, iface, false);
+
+ // also: dump to add proxies back in case it moved elsewhere
+ dump_neigh = true;
+ }
+ }
+ }
if (is_addr && iface->ra == RELAYD_SERVER)
raise(SIGUSR1); // Inform about a change in addresses
}
}
}
+ }
- /* 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);
+ if (dump_neigh) {
+ 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);
}
}
projects / oweals / odhcpd.git / commitdiff