router: Fix infinite lifetimes

diff --git a/src/router.c b/src/router.c
index 1a008e129f26ca90112da30a290a07739725618d..d7452f553fce2ed59b7561801dc788de95eba618 100644 (file)
--- a/src/router.c
+++ b/src/router.c
@@ -39,6 +39,7 @@ static struct odhcpd_event router_event = {{.fd = -1}, 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)
 {
@@ -288,15 +289,15 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
                }
 
                if (addr->preferred > (uint32_t)now &&
-                               minvalid > 1000LL * (addr->valid - now))
-                       minvalid = 1000LL * (addr->valid - now);
+                               minvalid > 1000LL * TIME_LEFT(addr->valid, now))
+                       minvalid = 1000LL * TIME_LEFT(addr->valid, now);
 
-               if (maxvalid < 1000LL * (addr->valid - now))
-                       maxvalid = 1000LL * (addr->valid - now);
+               if (maxvalid < 1000LL * TIME_LEFT(addr->valid, now))
+                       maxvalid = 1000LL * TIME_LEFT(addr->valid, now);
 
                if (((addr->addr.s6_addr[0] & 0xfe) != 0xfc || iface->default_router)
-                               && ntohs(adv.h.nd_ra_router_lifetime) < addr->valid - now)
-                       adv.h.nd_ra_router_lifetime = htons(addr->valid - now);
+                               && ntohs(adv.h.nd_ra_router_lifetime) < TIME_LEFT(addr->valid, now))
+                       adv.h.nd_ra_router_lifetime = htons(TIME_LEFT(addr->valid, now));
 
                odhcpd_bmemcpy(&p->nd_opt_pi_prefix, &addr->addr,
                                (iface->ra_advrouter) ? 128 : addr->prefix);
@@ -310,13 +311,13 @@ 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 - now);
+               p->nd_opt_pi_valid_time = htonl(TIME_LEFT(addr->valid, now));
                if (addr->preferred > (uint32_t)now)
-                       p->nd_opt_pi_preferred_time = htonl(addr->preferred - now);
+                       p->nd_opt_pi_preferred_time = htonl(TIME_LEFT(addr->preferred, now));
 
 
-               if (addr->preferred - now > dns_time) {
-                       dns_time = addr->preferred - now;
+               if (TIME_LEFT(addr->preferred, now) > dns_time) {
+                       dns_time = TIME_LEFT(addr->preferred, now);
                        dns_pref = addr->addr;
                }
        }
@@ -410,7 +411,7 @@ 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 - now);
+               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;