router: add syslog debug tracing for trouble shooting
[project/odhcpd.git] / src / ndp.c
index c1ac063..d2fbe07 100644 (file)
--- a/src/ndp.c
+++ b/src/ndp.c
@@ -29,6 +29,7 @@
 #include <linux/rtnetlink.h>
 #include <linux/filter.h>
 #include "router.h"
+#include "dhcpv6.h"
 #include "ndp.h"
 
 
@@ -37,12 +38,11 @@ static void handle_solicit(void *addr, void *data, size_t len,
                struct interface *iface, void *dest);
 static void handle_rtnetlink(void *addr, void *data, size_t len,
                struct interface *iface, void *dest);
-static ssize_t ping6(struct in6_addr *addr,
-               const struct interface *iface);
+static void catch_rtnetlink(int error);
 
 static uint32_t rtnl_seqid = 0;
 static int ping_socket = -1;
-static struct odhcpd_event rtnl_event = {{.fd = -1}, handle_rtnetlink};
+static struct odhcpd_event rtnl_event = {{.fd = -1}, handle_rtnetlink, catch_rtnetlink};
 
 
 // Filter ICMPv6 messages of type neighbor soliciation
@@ -61,10 +61,15 @@ static const struct sock_fprog bpf_prog = {sizeof(bpf) / sizeof(*bpf), bpf};
 // Initialize NDP-proxy
 int init_ndp(void)
 {
+       int val = 256 * 1024;
+
        // Setup netlink socket
        if ((rtnl_event.uloop.fd = odhcpd_open_rtnl()) < 0)
                return -1;
 
+       if (setsockopt(rtnl_event.uloop.fd, SOL_SOCKET, SO_RCVBUF, &val, sizeof(val)))
+               setsockopt(rtnl_event.uloop.fd, SOL_SOCKET, SO_RCVBUFFORCE, &val, sizeof(val));
+
        // Receive netlink neighbor and ip-address events
        uint32_t group = RTNLGRP_IPV6_IFADDR;
        setsockopt(rtnl_event.uloop.fd, SOL_NETLINK,
@@ -73,16 +78,6 @@ int init_ndp(void)
        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);
 
        // Open ICMPv6 socket
@@ -92,7 +87,7 @@ int init_ndp(void)
                        return -1;
        }
 
-       int val = 2;
+       val = 2;
        setsockopt(ping_socket, IPPROTO_RAW, IPV6_CHECKSUM, &val, sizeof(val));
 
        // This is required by RFC 4861
@@ -125,6 +120,7 @@ static void dump_neigh_table(bool proxy)
                {.ndm_family = AF_INET6, .ndm_flags = (proxy) ? NTF_PROXY : 0}
        };
        send(rtnl_event.uloop.fd, &req, sizeof(req), MSG_DONTWAIT);
+       odhcpd_process(&rtnl_event);
 }
 
 
@@ -135,17 +131,34 @@ int setup_ndp_interface(struct interface *iface, bool enable)
        int procfd = open(procbuf, O_WRONLY);
        bool dump_neigh = false;
 
-       if (iface->ndp_event.uloop.fd >= 0) {
+       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;
 
-               write(procfd, "0\n", 2);
+               if (!enable || iface->ndp != RELAYD_RELAY)
+                       if (write(procfd, "0\n", 2) < 0) {}
+
                dump_neigh = true;
        }
 
+       if (enable && (iface->ra == RELAYD_SERVER ||
+                       iface->dhcpv6 == RELAYD_SERVER || iface->ndp == RELAYD_RELAY)) {
+               // 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, .ifa_index = iface->ifindex}
+               };
+               send(rtnl_event.uloop.fd, &req2, sizeof(req2), MSG_DONTWAIT);
+       }
+
        if (enable && iface->ndp == RELAYD_RELAY) {
-               write(procfd, "1\n", 2);
+               if (write(procfd, "1\n", 2) < 0) {}
+               close(procfd);
 
                int sock = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC, htons(ETH_P_IPV6));
                if (sock < 0) {
@@ -169,6 +182,10 @@ int setup_ndp_interface(struct interface *iface, bool enable)
                        .sll_family = AF_PACKET,
                        .sll_ifindex = iface->ifindex,
                        .sll_protocol = htons(ETH_P_IPV6),
+                       .sll_hatype = 0,
+                       .sll_pkttype = 0,
+                       .sll_halen = 0,
+                       .sll_addr = {0},
                };
                bind(sock, (struct sockaddr*)&ll, sizeof(ll));
 
@@ -184,8 +201,9 @@ int setup_ndp_interface(struct interface *iface, bool enable)
                        dump_neigh_table(false);
                else
                        dump_neigh = false;
+       } else {
+               close(procfd);
        }
-       close(procfd);
 
        if (dump_neigh)
                dump_neigh_table(true);
@@ -196,17 +214,16 @@ int setup_ndp_interface(struct interface *iface, bool enable)
 
 // 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,
+static void ping6(struct in6_addr *addr,
                const struct interface *iface)
 {
-       struct sockaddr_in6 dest = {AF_INET6, 0, 0, *addr, 0};
+       struct sockaddr_in6 dest = {AF_INET6, 0, 0, *addr, iface->ifindex};
        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);
+       odhcpd_setup_route(addr, 128, iface, NULL, 128, true);
+       odhcpd_send(ping_socket, &dest, &iov, 1, iface);
+       odhcpd_setup_route(addr, 128, iface, NULL, 128, false);
 }
 
 
@@ -246,69 +263,74 @@ static void handle_solicit(void *addr, void *data, size_t len,
        struct interface *c;
        list_for_each_entry(c, &interfaces, head)
                if (iface->ndp == RELAYD_RELAY && iface != c &&
-                               (!ns_is_dad || !c->external == false))
+                               (ns_is_dad || !c->external))
                        ping6(&req->nd_ns_target, c);
 }
 
-
-void odhcpd_setup_route(const struct in6_addr *addr, int prefixlen,
-               const struct interface *iface, const struct in6_addr *gw, bool add)
+// Use rtnetlink to modify kernel routes
+static void setup_route(struct in6_addr *addr, struct interface *iface, 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;
+       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->ifname);
 
-       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;
-       }
+       if (iface->learn_routes)
+               odhcpd_setup_route(addr, 128, iface, NULL, 1024, add);
+}
 
-       size_t reqlen = (gw) ? sizeof(req) : offsetof(struct req, rta_gw);
-       send(rtnl_event.uloop.fd, &req, reqlen, MSG_DONTWAIT);
+// compare prefixes
+static int prefixcmp(const void *va, const void *vb)
+{
+       const struct odhcpd_ipaddr *a = va, *b = vb;
+       uint32_t a_pref = ((a->addr.s6_addr[0] & 0xfe) != 0xfc) ? a->preferred : 1;
+       uint32_t b_pref = ((b->addr.s6_addr[0] & 0xfe) != 0xfc) ? b->preferred : 1;
+       return (a_pref < b_pref) ? 1 : (a_pref > b_pref) ? -1 : 0;
 }
 
-// Use rtnetlink to modify kernel routes
-static void setup_route(struct in6_addr *addr, struct interface *iface,
-               bool add)
+// Check address update
+static void check_updates(struct interface *iface)
 {
-       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 odhcpd_ipaddr addr[RELAYD_MAX_ADDRS] = {{IN6ADDR_ANY_INIT, 0, 0, 0, 0}};
+       time_t now = odhcpd_time();
+       ssize_t len = odhcpd_get_interface_addresses(iface->ifindex, addr, ARRAY_SIZE(addr));
 
-       if (!iface || !iface->learn_routes)
+       if (len < 0)
                return;
 
-       odhcpd_setup_route(addr, 128, iface, NULL, add);
+       qsort(addr, len, sizeof(*addr), prefixcmp);
+
+       for (int i = 0; i < len; ++i) {
+               addr[i].addr.s6_addr32[3] = 0;
+
+               if (addr[i].preferred < UINT32_MAX - now)
+                       addr[i].preferred += now;
+
+               if (addr[i].valid < UINT32_MAX - now)
+                       addr[i].valid += now;
+       }
+
+       bool change = len != (ssize_t)iface->ia_addr_len;
+       for (ssize_t i = 0; !change && i < len; ++i)
+               if (!IN6_ARE_ADDR_EQUAL(&addr[i].addr, &iface->ia_addr[i].addr) ||
+                               (addr[i].preferred > 0) != (iface->ia_addr[i].preferred > 0) ||
+                               addr[i].valid < iface->ia_addr[i].valid ||
+                               addr[i].preferred < iface->ia_addr[i].preferred)
+                       change = true;
+
+       if (change)
+               dhcpv6_ia_preupdate(iface);
+
+       memcpy(iface->ia_addr, addr, len * sizeof(*addr));
+       iface->ia_addr_len = len;
+
+       if (change)
+               dhcpv6_ia_postupdate(iface, now);
+
+       if (change) {
+               syslog(LOG_DEBUG, "Raising SIGUSR1 due to address change");
+               raise(SIGUSR1);
+       }
 }
 
 
@@ -322,43 +344,50 @@ static void handle_rtnetlink(_unused void *addr, void *data, size_t len,
 
        for (struct nlmsghdr *nh = data; NLMSG_OK(nh, len);
                        nh = NLMSG_NEXT(nh, len)) {
+               struct ndmsg *ndm = NLMSG_DATA(nh);
                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);
+               bool is_route = (nh->nlmsg_type == RTM_NEWROUTE
+                               || nh->nlmsg_type == RTM_DELROUTE);
+               bool is_neigh = (nh->nlmsg_type == RTM_NEWNEIGH
+                               || nh->nlmsg_type == RTM_DELNEIGH);
 
                // Family and ifindex are on the same offset for NEIGH and ADDR
-               if (NLMSG_PAYLOAD(nh, 0) < sizeof(*ndm)
+               if ((!is_addr && !is_route && !is_neigh)
+                               || NLMSG_PAYLOAD(nh, 0) < sizeof(*ndm)
                                || ndm->ndm_family != AF_INET6)
-                       continue; //
+                       continue;
+
+               if (is_route) {
+                       // Inform about a change in default route
+                       if (rtm->rtm_dst_len == 0) {
+                               syslog(LOG_DEBUG, "Raising SIGUSR1 due to default route change");
+                               raise(SIGUSR1);
+                       }
 
-               // Lookup interface
-               struct interface *iface;
-               if (!(iface = odhcpd_get_interface_by_index(ndm->ndm_ifindex)))
                        continue;
+               }
 
                // Data to retrieve
-               size_t rta_offset = (is_addr) ? sizeof(*ifa) : sizeof(*ndm);
+               size_t rta_offset = (is_addr) ? sizeof(struct ifaddrmsg) : 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))
+                               RTA_OK(rta, alen); rta = RTA_NEXT(rta, alen)) {
                        if (rta->rta_type == atype &&
-                                       RTA_PAYLOAD(rta) >= sizeof(*addr))
+                                       RTA_PAYLOAD(rta) >= sizeof(*addr)) {
                                addr = RTA_DATA(rta);
+                       }
+               }
+
+               // Lookup interface
+               struct interface *iface = odhcpd_get_interface_by_index(ndm->ndm_ifindex);
+               if (!iface)
+                       continue;
 
                // Address not specified or unrelated
                if (!addr || IN6_IS_ADDR_LINKLOCAL(addr) ||
@@ -394,6 +423,7 @@ static void handle_rtnetlink(_unused void *addr, void *data, size_t len,
                                if (nh->nlmsg_type == RTM_NEWNEIGH) {
                                        req.ndm.ndm_ifindex = iface->ifindex;
                                        send(rtnl_event.uloop.fd, &req, sizeof(req), MSG_DONTWAIT);
+                                       setup_route(addr, iface, false);
                                        dump_neigh = true;
                                }
                        } else if (add) {
@@ -447,8 +477,7 @@ static void handle_rtnetlink(_unused void *addr, void *data, size_t len,
                }
 
                if (is_addr) {
-                       if (iface->ra == RELAYD_SERVER)
-                               raise(SIGUSR1); // Inform about a change in addresses
+                       check_updates(iface);
 
                        if (iface->dhcpv6 == RELAYD_SERVER)
                                iface->ia_reconf = true;
@@ -463,7 +492,7 @@ static void handle_rtnetlink(_unused void *addr, void *data, size_t len,
                                struct interface *c;
                                list_for_each_entry(c, &interfaces, head) {
                                        if (c->ndp == RELAYD_RELAY && !c->master) {
-                                               ifa->ifa_index = c->ifindex;
+                                               ndm->ndm_ifindex = c->ifindex;
                                                send(rtnl_event.uloop.fd, nh, nh->nlmsg_len, MSG_DONTWAIT);
                                        }
                                }
@@ -474,3 +503,18 @@ static void handle_rtnetlink(_unused void *addr, void *data, size_t len,
        if (dump_neigh)
                dump_neigh_table(false);
 }
+
+static void catch_rtnetlink(int error)
+{
+       if (error == ENOBUFS) {
+               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);
+       }
+}