router: don't announce prefixes with valid lifetime equal to 0
[project/odhcpd.git] / src / router.c
index 51fd954..e8a9aa9 100644 (file)
@@ -20,6 +20,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <stdbool.h>
+#include <arpa/inet.h>
 #include <net/route.h>
 
 #include "router.h"
@@ -34,11 +35,12 @@ static void handle_icmpv6(void *addr, void *data, size_t len,
 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};
+static struct odhcpd_event router_event = {.uloop = {.fd = -1}, .handle_dgram = handle_icmpv6, };
 
 static FILE *fp_route = NULL;
 #define RA_IOV_LEN 6
 
+#define TIME_LEFT(t1, now) ((t1) != UINT32_MAX ? (t1) - (now) : UINT32_MAX)
 
 int init_router(void)
 {
@@ -98,6 +100,9 @@ int setup_router_interface(struct interface *iface, bool enable)
        uloop_timeout_cancel(&iface->timer_rs);
        iface->timer_rs.cb = NULL;
 
+       if (iface->ifindex <= 0)
+               return -1;
+
        setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP,
                        &all_nodes, sizeof(all_nodes));
        setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP,
@@ -114,7 +119,7 @@ int setup_router_interface(struct interface *iface, bool enable)
                        forward_router_solicitation(iface);
                } else if (iface->ra == RELAYD_SERVER && !iface->master) {
                        iface->timer_rs.cb = trigger_router_advert;
-                       trigger_router_advert(&iface->timer_rs);
+                       uloop_timeout_set(&iface->timer_rs, 1000);
                }
 
                if (iface->ra == RELAYD_RELAY || (iface->ra == RELAYD_SERVER && !iface->master))
@@ -206,9 +211,53 @@ static bool parse_routes(struct odhcpd_ipaddr *n, ssize_t len)
        return found_default;
 }
 
+static int calc_adv_interval(struct interface *iface, uint32_t minvalid,
+               uint32_t *maxival)
+{
+       uint32_t minival = iface->ra_mininterval;
+       int msecs;
+
+       *maxival = iface->ra_maxinterval;
+
+       if (*maxival > minvalid/3)
+               *maxival = minvalid/3;
+
+       if (*maxival > MaxRtrAdvInterval)
+               *maxival = MaxRtrAdvInterval;
+       else if (*maxival < 4)
+               *maxival = 4;
+
+       if (minival < MinRtrAdvInterval)
+               minival = MinRtrAdvInterval;
+       else if (minival > (*maxival * 3)/4)
+               minival = (*maxival >= 9 ? *maxival/3 : *maxival);
+
+       odhcpd_urandom(&msecs, sizeof(msecs));
+       msecs = (labs(msecs) % ((*maxival != minival) ? (*maxival - minival)*1000 : 500)) +
+                       minival*1000;
+
+       return msecs;
+}
+
+static uint16_t calc_ra_lifetime(struct interface *iface, uint32_t maxival)
+{
+       uint16_t lifetime = 3*maxival;
+
+       if (iface->ra_lifetime >= 0) {
+               lifetime = iface->ra_lifetime;
+               if (lifetime < maxival)
+                       lifetime = maxival;
+               else if (lifetime > 9000)
+                       lifetime = 9000;
+       }
+
+       return lifetime;
+}
+
 // Router Advert server mode
 static uint64_t send_router_advert(struct interface *iface, const struct in6_addr *from)
 {
+       time_t now = odhcpd_time();
        int mtu = odhcpd_get_interface_config(iface->ifname, "mtu");
        int hlim = odhcpd_get_interface_config(iface->ifname, "hop_limit");
 
@@ -219,7 +268,7 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
                struct nd_router_advert h;
                struct icmpv6_opt lladdr;
                struct nd_opt_mtu mtu;
-               struct nd_opt_prefix_info prefix[RELAYD_MAX_PREFIXES];
+               struct nd_opt_prefix_info prefix[sizeof(iface->ia_addr) / sizeof(*iface->ia_addr)];
        } adv = {
                .h = {{.icmp6_type = ND_ROUTER_ADVERT, .icmp6_code = 0}, 0, 0},
                .lladdr = {ND_OPT_SOURCE_LINKADDR, 1, {0}},
@@ -242,38 +291,48 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
        odhcpd_get_mac(iface, adv.lladdr.data);
 
        // If not currently shutting down
-       struct odhcpd_ipaddr addrs[RELAYD_MAX_PREFIXES];
+       struct odhcpd_ipaddr addrs[RELAYD_MAX_ADDRS];
        ssize_t ipcnt = 0;
-       uint64_t minvalid = UINT64_MAX;
-       uint64_t maxvalid = 0;
+       uint32_t minvalid = UINT32_MAX;
+       bool default_route = false;
+       bool valid_prefix = false;
 
        // If not shutdown
        if (iface->timer_rs.cb) {
-               ipcnt = odhcpd_get_interface_addresses(iface->ifindex,
-                               addrs, ARRAY_SIZE(addrs));
+               ipcnt = iface->ia_addr_len;
+               memcpy(addrs, iface->ia_addr, ipcnt * sizeof(*addrs));
 
                // Check default route
-               if (parse_routes(addrs, ipcnt) || iface->default_router > 1)
-                       adv.h.nd_ra_router_lifetime = 1;
+               if (iface->default_router) {
+                       default_route = true;
+
+                       if (iface->default_router > 1)
+                               valid_prefix = true;
+               } else if (parse_routes(addrs, ipcnt))
+                       default_route = true;
        }
 
        // Construct Prefix Information options
        size_t cnt = 0;
 
-       struct in6_addr dns_pref = IN6ADDR_ANY_INIT, *dns_addr = &dns_pref;
-       uint32_t dns_time = 0;
+       struct in6_addr dns_pref, *dns_addr = &dns_pref;
        size_t dns_cnt = 1;
 
+       odhcpd_get_linklocal_interface_address(iface->ifindex, &dns_pref);
+
        for (ssize_t i = 0; i < ipcnt; ++i) {
                struct odhcpd_ipaddr *addr = &addrs[i];
-               if (addr->prefix > 96)
-                       continue; // Address not suitable
+               uint32_t preferred = 0;
+               uint32_t valid = 0;
 
-               if (addr->preferred > MaxValidTime)
-                       addr->preferred = MaxValidTime;
+               if (addr->prefix > 96 || addr->valid <= (uint32_t)now) {
+                       char namebuf[INET6_ADDRSTRLEN];
 
-               if (addr->valid > MaxValidTime)
-                       addr->valid = MaxValidTime;
+                       inet_ntop(AF_INET6, addr, namebuf, sizeof(namebuf));
+                       syslog(LOG_INFO, "Address %s (prefix %d, valid %u) not suitable as RA prefix on %s",
+                                       namebuf, addr->prefix, addr->valid, iface->ifname);
+                       continue;
+               }
 
                struct nd_opt_prefix_info *p = NULL;
                for (size_t i = 0; i < cnt; ++i) {
@@ -290,15 +349,23 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
                        p = &adv.prefix[cnt++];
                }
 
-               if (addr->preferred > 0) {
-                       if (minvalid > 1000ULL * addr->valid)
-                               minvalid = 1000ULL * addr->valid;
+               if (addr->preferred > (uint32_t)now) {
+                       preferred = TIME_LEFT(addr->preferred, now);
 
-                       if (maxvalid < 1000ULL * addr->valid && (iface->default_router ||
-                                       (addr->addr.s6_addr[0] & 0xfe) != 0xfc))
-                               maxvalid = 1000ULL * addr->valid;
+                       if (iface->ra_useleasetime &&
+                                       preferred > iface->dhcpv4_leasetime)
+                               preferred = iface->dhcpv4_leasetime;
                }
 
+               valid = TIME_LEFT(addr->valid, now);
+               if (iface->ra_useleasetime && valid > iface->dhcpv4_leasetime)
+                       valid = iface->dhcpv4_leasetime;
+
+               if (minvalid > valid)
+                       minvalid = valid;
+
+               if (!IN6_IS_ADDR_ULA(&addr->addr) || iface->default_router)
+                       valid_prefix = true;
 
                odhcpd_bmemcpy(&p->nd_opt_pi_prefix, &addr->addr,
                                (iface->ra_advrouter) ? 128 : addr->prefix);
@@ -312,26 +379,31 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
                        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_pref = addr->addr;
-               }
+               p->nd_opt_pi_preferred_time = htonl(preferred);
+               p->nd_opt_pi_valid_time = htonl(valid);
        }
 
-       if (!maxvalid && !iface->default_router && adv.h.nd_ra_router_lifetime) {
-               syslog(LOG_WARNING, "A default route is present but there is no public prefix "
-                               "on %s thus we don't announce a default route!", iface->ifname);
+       // Calculate periodic transmit
+       uint32_t maxival;
+       int msecs = calc_adv_interval(iface, minvalid, &maxival);
+
+       if (default_route) {
+               if (!valid_prefix) {
+                       syslog(LOG_WARNING, "A default route is present but there is no public prefix "
+                                       "on %s thus we don't announce a default route!", iface->ifname);
+                       adv.h.nd_ra_router_lifetime = 0;
+               } else
+                       adv.h.nd_ra_router_lifetime = htons(calc_ra_lifetime(iface, maxival));
+
+       } else
                adv.h.nd_ra_router_lifetime = 0;
-       }
+
+       syslog(LOG_INFO, "Using a RA lifetime of %d seconds on %s", ntohs(adv.h.nd_ra_router_lifetime), iface->ifname);
 
        // DNS Recursive DNS
        if (iface->dns_cnt > 0) {
                dns_addr = iface->dns;
                dns_cnt = iface->dns_cnt;
-               dns_time = 2 * MaxRtrAdvInterval;
        }
 
        if (!dns_addr || IN6_IS_ADDR_UNSPECIFIED(dns_addr))
@@ -343,7 +415,7 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
                uint8_t pad;
                uint8_t pad2;
                uint32_t lifetime;
-       } dns = {ND_OPT_RECURSIVE_DNS, (1 + (2 * dns_cnt)), 0, 0, htonl(dns_time)};
+       } dns = {ND_OPT_RECURSIVE_DNS, (1 + (2 * dns_cnt)), 0, 0, 0};
 
 
 
@@ -376,7 +448,6 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
        search->len = search_len ? ((sizeof(*search) + search_padded) / 8) : 0;
        search->pad = 0;
        search->pad2 = 0;
-       search->lifetime = htonl(2 * MaxRtrAdvInterval);;
        memcpy(search->name, search_domain, search_len);
        memset(&search->name[search_len], 0, search_padded - search_len);
 
@@ -393,7 +464,7 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
 
        for (ssize_t i = 0; i < ipcnt; ++i) {
                struct odhcpd_ipaddr *addr = &addrs[i];
-               if (addr->dprefix > 64 || addr->dprefix == 0 ||
+               if (addr->dprefix > 64 || addr->dprefix == 0 || addr->valid <= (uint32_t)now ||
                                (addr->dprefix == 64 && addr->prefix == 64)) {
                        continue; // Address not suitable
                } else if (addr->dprefix > 32) {
@@ -411,7 +482,7 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
                        routes[routes_cnt].flags |= ND_RA_PREF_LOW;
                else if (iface->route_preference > 0)
                        routes[routes_cnt].flags |= ND_RA_PREF_HIGH;
-               routes[routes_cnt].lifetime = htonl(addr->valid);
+               routes[routes_cnt].lifetime = htonl(TIME_LEFT(addr->valid, now));
                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] = 0;
@@ -420,32 +491,13 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
                ++routes_cnt;
        }
 
-       // Calculate periodic transmit
-       int msecs = 0;
-       uint32_t maxival = iface->ra_maxinterval * 1000;
-       uint32_t minival;
-
-       if (maxival < 4000 || maxival > MaxRtrAdvInterval * 1000)
-               maxival = MaxRtrAdvInterval * 1000;
-
-       if (minvalid < maxival / 3) {
-               maxival = minvalid / 3;
-
-               if (maxival < 4000)
-                       maxival = 4000;
-       }
-
-       minival = (maxival * 3) / 4;
-       if (adv.h.nd_ra_router_lifetime)
-               adv.h.nd_ra_router_lifetime = htons(maxvalid / 1000);
-
-       odhcpd_urandom(&msecs, sizeof(msecs));
-       msecs = (labs(msecs) % (maxival - minival)) + minival;
+       search->lifetime = htonl(maxival*10);
+       dns.lifetime = search->lifetime;
 
        struct icmpv6_opt adv_interval = {
                .type = ND_OPT_RTR_ADV_INTERVAL,
                .len = 1,
-               .data = {0, 0, maxival >> 24, maxival >> 16, maxival >> 8, maxival}
+               .data = {0, 0, (maxival*1000) >> 24, (maxival*1000) >> 16, (maxival*1000) >> 8, maxival*1000}
        };
 
        struct iovec iov[RA_IOV_LEN] = {
@@ -564,7 +616,7 @@ static void forward_router_advertisement(uint8_t *data, size_t len)
                        size_t rewrite_cnt = iface->dns_cnt;
 
                        if (rewrite_cnt == 0) {
-                               if (odhcpd_get_preferred_interface_address(iface->ifindex, &addr) < 1)
+                               if (odhcpd_get_linklocal_interface_address(iface->ifindex, &addr))
                                        continue; // Unable to comply
 
                                rewrite = &addr;