dhcpv6: fix handling of infinite lifetimes
[project/odhcpd.git] / src / router.c
index dfbcf60..60d6b3f 100644 (file)
@@ -30,8 +30,8 @@ static void forward_router_solicitation(const struct interface *iface);
 static void forward_router_advertisement(uint8_t *data, size_t len);
 
 static void handle_icmpv6(void *addr, void *data, size_t len,
-               struct interface *iface);
-static void send_router_advert(struct uloop_timeout *event);
+               struct interface *iface, void *dest);
+static void trigger_router_advert(struct uloop_timeout *event);
 static void sigusr1_refresh(int signal);
 
 static struct odhcpd_event router_event = {{.fd = -1}, handle_icmpv6};
@@ -88,6 +88,9 @@ int init_router(void)
 
 int setup_router_interface(struct interface *iface, bool enable)
 {
+       if (!fp_route || router_event.uloop.fd < 0)
+               return -1;
+
        struct ipv6_mreq all_nodes = {ALL_IPV6_NODES, iface->ifindex};
        struct ipv6_mreq all_routers = {ALL_IPV6_ROUTERS, iface->ifindex};
 
@@ -101,7 +104,7 @@ int setup_router_interface(struct interface *iface, bool enable)
 
        if (!enable) {
                if (iface->ra)
-                       send_router_advert(&iface->timer_rs);
+                       trigger_router_advert(&iface->timer_rs);
        } else {
                void *mreq = &all_routers;
 
@@ -109,8 +112,8 @@ int setup_router_interface(struct interface *iface, bool enable)
                        mreq = &all_nodes;
                        forward_router_solicitation(iface);
                } else if (iface->ra == RELAYD_SERVER && !iface->master) {
-                       iface->timer_rs.cb = send_router_advert;
-                       send_router_advert(&iface->timer_rs);
+                       iface->timer_rs.cb = trigger_router_advert;
+                       trigger_router_advert(&iface->timer_rs);
                }
 
                if (iface->ra == RELAYD_RELAY || (iface->ra == RELAYD_SERVER && !iface->master))
@@ -165,40 +168,6 @@ static bool router_icmpv6_valid(struct sockaddr_in6 *source, uint8_t *data, size
        return opt == end;
 }
 
-// Event handler for incoming ICMPv6 packets
-static void handle_icmpv6(void *addr, void *data, size_t len,
-               struct interface *iface)
-{
-       struct icmp6_hdr *hdr = data;
-
-       if (!router_icmpv6_valid(addr, data, len))
-               return;
-
-       if ((iface->ra == RELAYD_SERVER && !iface->master)) { // Server mode
-               if (hdr->icmp6_type == ND_ROUTER_SOLICIT)
-                       send_router_advert(&iface->timer_rs);
-       } else if (iface->ra == RELAYD_RELAY) { // Relay mode
-               if (hdr->icmp6_type == ND_ROUTER_ADVERT && iface->master)
-                       forward_router_advertisement(data, len);
-               else if (hdr->icmp6_type == ND_ROUTER_SOLICIT && !iface->master)
-                       forward_router_solicitation(odhcpd_get_master_interface());
-       }
-}
-
-
-static bool match_route(const struct odhcpd_ipaddr *n, const struct in6_addr *addr)
-{
-       if (n->prefix <= 32)
-               return ntohl(n->addr.s6_addr32[0]) >> (32 - n->prefix) ==
-                               ntohl(addr->s6_addr32[0]) >> (32 - n->prefix);
-
-       if (n->addr.s6_addr32[0] != addr->s6_addr32[0])
-               return false;
-
-       return ntohl(n->addr.s6_addr32[1]) >> (64 - n->prefix) ==
-                       ntohl(addr->s6_addr32[1]) >> (64 - n->prefix);
-}
-
 
 // Detect whether a default route exists, also find the source prefixes
 static bool parse_routes(struct odhcpd_ipaddr *n, ssize_t len)
@@ -207,7 +176,7 @@ static bool parse_routes(struct odhcpd_ipaddr *n, ssize_t len)
 
        char line[512], ifname[16];
        bool found_default = false;
-       struct odhcpd_ipaddr p = {IN6ADDR_ANY_INIT, 0, false, 0, 0, 0};
+       struct odhcpd_ipaddr p = {IN6ADDR_ANY_INIT, 0, 0, 0, 0};
        while (fgets(line, sizeof(line), fp_route)) {
                uint32_t rflags;
                if (sscanf(line, "00000000000000000000000000000000 00 "
@@ -224,8 +193,8 @@ static bool parse_routes(struct odhcpd_ipaddr *n, ssize_t len)
 
                        for (ssize_t i = 0; i < len; ++i) {
                                if (n[i].prefix <= 64 && n[i].prefix >= p.prefix &&
-                                               match_route(&p, &n[i].addr)) {
-                                       n[i].prefix = p.prefix;
+                                               !odhcpd_bmemcmp(&p.addr, &n[i].addr, p.prefix)) {
+                                       n[i].dprefix = p.prefix;
                                        break;
                                }
                        }
@@ -238,11 +207,8 @@ static bool parse_routes(struct odhcpd_ipaddr *n, ssize_t len)
 
 
 // Router Advert server mode
-static void send_router_advert(struct uloop_timeout *event)
+static uint64_t send_router_advert(struct interface *iface, const struct in6_addr *from)
 {
-       struct interface *iface =
-                       container_of(event, struct interface, timer_rs);
-
        int mtu = odhcpd_get_interface_mtu(iface->ifname);
        if (mtu < 0)
                mtu = 1500;
@@ -273,9 +239,10 @@ static void send_router_advert(struct uloop_timeout *event)
        // If not currently shutting down
        struct odhcpd_ipaddr addrs[RELAYD_MAX_PREFIXES];
        ssize_t ipcnt = 0;
+       uint64_t maxpreferred = 0;
 
        // If not shutdown
-       if (event->cb) {
+       if (iface->timer_rs.cb) {
                ipcnt = odhcpd_get_interface_addresses(iface->ifindex,
                                addrs, ARRAY_SIZE(addrs));
 
@@ -289,13 +256,13 @@ static void send_router_advert(struct uloop_timeout *event)
        bool have_public = false;
        size_t cnt = 0;
 
-       struct in6_addr *dns_addr = NULL;
+       struct in6_addr dns_pref = IN6ADDR_ANY_INIT, *dns_addr = &dns_pref;
        uint32_t dns_time = 0;
        size_t dns_cnt = 1;
 
        for (ssize_t i = 0; i < ipcnt; ++i) {
                struct odhcpd_ipaddr *addr = &addrs[i];
-               if (addr->prefix > 64 || addr->has_class)
+               if (addr->prefix > 96)
                        continue; // Address not suitable
 
                if (addr->preferred > MaxPreferredTime)
@@ -306,8 +273,9 @@ static void send_router_advert(struct uloop_timeout *event)
 
                struct nd_opt_prefix_info *p = NULL;
                for (size_t i = 0; i < cnt; ++i) {
-                       if (!memcmp(&adv.prefix[i].nd_opt_pi_prefix,
-                                       &addr->addr, 8))
+                       if (addr->prefix == adv.prefix[i].nd_opt_pi_prefix_len &&
+                                       !odhcpd_bmemcmp(&adv.prefix[i].nd_opt_pi_prefix,
+                                       &addr->addr, addr->prefix))
                                p = &adv.prefix[i];
                }
 
@@ -318,24 +286,31 @@ static void send_router_advert(struct uloop_timeout *event)
                        p = &adv.prefix[cnt++];
                }
 
-               if ((addr->addr.s6_addr[0] & 0xfe) != 0xfc && addr->preferred > 0)
+               if ((addr->addr.s6_addr[0] & 0xfe) != 0xfc && addr->preferred > 0) {
                        have_public = true;
 
-               memcpy(&p->nd_opt_pi_prefix, &addr->addr, 8);
+                       if (maxpreferred < 1000 * addr->preferred)
+                               maxpreferred = 1000 * addr->preferred;
+               }
+
+               odhcpd_bmemcpy(&p->nd_opt_pi_prefix, &addr->addr,
+                               (iface->ra_advrouter) ? 128 : addr->prefix);
                p->nd_opt_pi_type = ND_OPT_PREFIX_INFORMATION;
                p->nd_opt_pi_len = 4;
-               p->nd_opt_pi_prefix_len = 64;
+               p->nd_opt_pi_prefix_len = (addr->prefix < 64) ? 64 : addr->prefix;
                p->nd_opt_pi_flags_reserved = 0;
                if (!iface->ra_not_onlink)
                        p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_ONLINK;
-               if (iface->managed < RELAYD_MANAGED_NO_AFLAG)
+               if (iface->managed < RELAYD_MANAGED_NO_AFLAG && addr->prefix <= 64)
                        p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_AUTO;
+               if (iface->ra_advrouter)
+                       p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_RADDR;
                p->nd_opt_pi_valid_time = htonl(addr->valid);
                p->nd_opt_pi_preferred_time = htonl(addr->preferred);
 
                if (addr->preferred > dns_time) {
                        dns_time = addr->preferred;
-                       dns_addr = &addr->addr;
+                       dns_pref = addr->addr;
                }
        }
 
@@ -352,7 +327,7 @@ static void send_router_advert(struct uloop_timeout *event)
                dns_time = 2 * MaxRtrAdvInterval;
        }
 
-       if (!dns_addr)
+       if (!dns_addr || IN6_IS_ADDR_UNSPECIFIED(dns_addr))
                dns_cnt = 0;
 
        struct {
@@ -390,10 +365,6 @@ static void send_router_advert(struct uloop_timeout *event)
                uint8_t name[];
        } *search = alloca(sizeof(*search) + search_padded);
 
-       if (!search) {
-               syslog(LOG_ERR, "Alloca failed for dns search on interface %s", iface->ifname);
-               return;
-       }
        search->type = ND_OPT_DNS_SEARCH;
        search->len = search_len ? ((sizeof(*search) + search_padded) / 8) : 0;
        search->pad = 0;
@@ -415,18 +386,19 @@ static void send_router_advert(struct uloop_timeout *event)
 
        for (ssize_t i = 0; i < ipcnt; ++i) {
                struct odhcpd_ipaddr *addr = &addrs[i];
-               if (addr->prefix > 64 || addr->prefix == 0) {
+               if (addr->dprefix > 64 || addr->dprefix == 0 ||
+                               (addr->dprefix == 64 && addr->prefix == 64)) {
                        continue; // Address not suitable
-               } else if (addr->prefix > 32) {
-                       addr->addr.s6_addr32[1] &= htonl(~((1U << (64 - addr->prefix)) - 1));
-               } else if (addr->prefix <= 32) {
-                       addr->addr.s6_addr32[0] &= htonl(~((1U << (32 - addr->prefix)) - 1));
+               } else if (addr->dprefix > 32) {
+                       addr->addr.s6_addr32[1] &= htonl(~((1U << (64 - addr->dprefix)) - 1));
+               } else if (addr->dprefix <= 32) {
+                       addr->addr.s6_addr32[0] &= htonl(~((1U << (32 - addr->dprefix)) - 1));
                        addr->addr.s6_addr32[1] = 0;
                }
 
                routes[routes_cnt].type = ND_OPT_ROUTE_INFO;
                routes[routes_cnt].len = sizeof(*routes) / 8;
-               routes[routes_cnt].prefix = addr->prefix;
+               routes[routes_cnt].prefix = addr->dprefix;
                routes[routes_cnt].flags = 0;
                if (iface->route_preference < 0)
                        routes[routes_cnt].flags |= ND_RA_PREF_LOW;
@@ -435,29 +407,84 @@ static void send_router_advert(struct uloop_timeout *event)
                routes[routes_cnt].lifetime = htonl(addr->valid);
                routes[routes_cnt].addr[0] = addr->addr.s6_addr32[0];
                routes[routes_cnt].addr[1] = addr->addr.s6_addr32[1];
-               routes[routes_cnt].addr[2] = addr->addr.s6_addr32[2];
-               routes[routes_cnt].addr[3] = addr->addr.s6_addr32[3];
+               routes[routes_cnt].addr[2] = 0;
+               routes[routes_cnt].addr[3] = 0;
 
                ++routes_cnt;
        }
 
+       // Calculate periodic transmit
+       int msecs = 0;
+       uint32_t maxival = MaxRtrAdvInterval * 1000;
+       uint32_t minival = MinRtrAdvInterval * 1000;
+
+       if (maxpreferred > 0 && maxival > maxpreferred / 2) {
+               maxival = maxpreferred / 2;
+               if (maxival < 4000)
+                       maxival = 4000;
+
+               if (maxival >= 9000)
+                       minival = maxival / 3;
+               else
+                       minival = (maxival * 3) / 4;
+       }
+
+       odhcpd_urandom(&msecs, sizeof(msecs));
+       msecs = (labs(msecs) % (maxival - minival)) + minival;
+
+       struct icmpv6_opt adv_interval = {
+               .type = ND_OPT_RTR_ADV_INTERVAL,
+               .len = 1,
+               .data = {0, 0, maxival >> 24, maxival >> 16, maxival >> 8, maxival}
+       };
 
        struct iovec iov[] = {{&adv, (uint8_t*)&adv.prefix[cnt] - (uint8_t*)&adv},
                        {&routes, routes_cnt * sizeof(*routes)},
                        {&dns, (dns_cnt) ? sizeof(dns) : 0},
                        {dns_addr, dns_cnt * sizeof(*dns_addr)},
-                       {search, search->len * 8}};
-       struct sockaddr_in6 all_nodes = {AF_INET6, 0, 0, ALL_IPV6_NODES, 0};
+                       {search, search->len * 8},
+                       {&adv_interval, adv_interval.len * 8}};
+       struct sockaddr_in6 dest = {AF_INET6, 0, 0, ALL_IPV6_NODES, 0};
+
+       if (from && !IN6_IS_ADDR_UNSPECIFIED(from))
+               dest.sin6_addr = *from;
+
        odhcpd_send(router_event.uloop.fd,
-                       &all_nodes, iov, ARRAY_SIZE(iov), iface);
+                       &dest, iov, ARRAY_SIZE(iov), iface);
+
+       return msecs;
+}
+
+
+static void trigger_router_advert(struct uloop_timeout *event)
+{
+       struct interface *iface = container_of(event, struct interface, timer_rs);
+       int msecs = send_router_advert(iface, NULL);
 
        // Rearm timer if not shut down
-       if (event->cb) {
-               int msecs;
-               odhcpd_urandom(&msecs, sizeof(msecs));
-               msecs = (labs(msecs) % (1000 * (MaxRtrAdvInterval
-                               - MinRtrAdvInterval))) + (MinRtrAdvInterval * 1000);
-               uloop_timeout_set(&iface->timer_rs, msecs);
+       if (event->cb)
+               uloop_timeout_set(event, msecs);
+}
+
+
+// Event handler for incoming ICMPv6 packets
+static void handle_icmpv6(void *addr, void *data, size_t len,
+               struct interface *iface, _unused void *dest)
+{
+       struct icmp6_hdr *hdr = data;
+       struct sockaddr_in6 *from = addr;
+
+       if (!router_icmpv6_valid(addr, data, len))
+               return;
+
+       if ((iface->ra == RELAYD_SERVER && !iface->master)) { // Server mode
+               if (hdr->icmp6_type == ND_ROUTER_SOLICIT)
+                       send_router_advert(iface, &from->sin6_addr);
+       } else if (iface->ra == RELAYD_RELAY) { // Relay mode
+               if (hdr->icmp6_type == ND_ROUTER_ADVERT && iface->master)
+                       forward_router_advertisement(data, len);
+               else if (hdr->icmp6_type == ND_ROUTER_SOLICIT && !iface->master)
+                       forward_router_solicitation(odhcpd_get_master_interface());
        }
 }
 
@@ -510,7 +537,6 @@ static void forward_router_advertisement(uint8_t *data, size_t len)
        struct sockaddr_in6 all_nodes = {AF_INET6, 0, 0, ALL_IPV6_NODES, 0};
        struct iovec iov = {data, len};
 
-       struct odhcpd_ipaddr addr;
        struct interface *iface;
        list_for_each_entry(iface, &interfaces, head) {
                if (iface->ra != RELAYD_RELAY || iface->master)
@@ -523,13 +549,14 @@ static void forward_router_advertisement(uint8_t *data, size_t len)
                // If we have to rewrite DNS entries
                if (iface->always_rewrite_dns && dns_ptr && dns_count > 0) {
                        const struct in6_addr *rewrite = iface->dns;
+                       struct in6_addr addr;
                        size_t rewrite_cnt = iface->dns_cnt;
 
                        if (rewrite_cnt == 0) {
-                               if (odhcpd_get_interface_addresses(iface->ifindex, &addr, 1) < 1)
+                               if (odhcpd_get_preferred_interface_address(iface->ifindex, &addr) < 1)
                                        continue; // Unable to comply
 
-                               rewrite = &addr.addr;
+                               rewrite = &addr;
                                rewrite_cnt = 1;
                        }