ipv6nd: warn if router lifetime is set to zero

diff --git a/src/ipv6nd.c b/src/ipv6nd.c
index 36a945d8738723ae4423a70f0b15a2f68e8c27ae..6b6fac94a16a0887ad8d74ed27cd4d897739dfa3 100644 (file)
--- a/src/ipv6nd.c
+++ b/src/ipv6nd.c
@@ -750,6 +750,7 @@ ipv6nd_handlera(struct dhcpcd_ctx *ctx, struct interface *ifp,
        struct ipv6_addr *ap;
        struct dhcp_opt *dho;
        uint8_t new_rap, new_data;
+       uint32_t old_lifetime;
        __printflike(1, 2) void (*logfunc)(const char *, ...);
 #ifdef IPV6_MANAGETEMPADDR
        uint8_t new_ap;
@@ -858,7 +859,11 @@ ipv6nd_handlera(struct dhcpcd_ctx *ctx, struct interface *ifp,
 
        clock_gettime(CLOCK_MONOTONIC, &rap->acquired);
        rap->flags = nd_ra->nd_ra_flags_reserved;
+       old_lifetime = rap->lifetime;
        rap->lifetime = ntohs(nd_ra->nd_ra_router_lifetime);
+       if (!new_rap && rap->lifetime == 0 && old_lifetime != 0)
+               logwarnx("%s: %s: no longer a default router",
+                   ifp->name, rap->sfrom);
        if (nd_ra->nd_ra_reachable) {
                rap->reachable = ntohl(nd_ra->nd_ra_reachable);
                if (rap->reachable > MAX_REACHABLE_TIME)