Avoid updating too often if ISP spams RAs

1 files changed, 7 insertions, 6 deletions

diff --git a/src/ra.c b/src/ra.c
index 83f1758..f41602a 100644
--- a/src/ra.c
+++ b/src/ra.c
@@ -120,6 +120,7 @@ static void update_proc(const char *sect, const char *opt, uint32_t value)
 bool ra_process(void)
 {
 	bool found = false;
+	bool changed = false;
 	uint8_t buf[1500], cmsg_buf[128];
 	struct nd_router_advert *adv = (struct nd_router_advert*)buf;
 	struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, IN6ADDR_ANY_INIT, 0, 0, 0};
@@ -183,7 +184,7 @@ bool ra_process(void)
 			entry.priority = pref_to_priority(0);
 		entry.valid = router_valid;
 		entry.preferred = entry.valid;
-		odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
+		changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
 
 		// Parse ND parameters
 		if (ntohl(adv->nd_ra_reachable) <= 3600000)
@@ -215,7 +216,7 @@ bool ra_process(void)
 					continue;
 
 				if (entry.priority > 0)
-					odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
+					changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
 			} else if (opt->type == ND_OPT_PREFIX_INFORMATION && opt->len == 4) {
 				struct nd_opt_prefix_info *pinfo = (struct nd_opt_prefix_info*)opt;
 				entry.router = any;
@@ -232,7 +233,7 @@ bool ra_process(void)
 					continue;
 
 				if (pinfo->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_ONLINK)
-					odhcp6c_update_entry_safe(STATE_RA_ROUTE, &entry, 7200);
+					changed |= odhcp6c_update_entry_safe(STATE_RA_ROUTE, &entry, 7200);
 
 				if (!(pinfo->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_AUTO) ||
 						pinfo->nd_opt_pi_prefix_len != 64)
@@ -241,7 +242,7 @@ bool ra_process(void)
 				entry.target.s6_addr32[2] = lladdr.s6_addr32[2];
 				entry.target.s6_addr32[3] = lladdr.s6_addr32[3];
 
-				odhcp6c_update_entry_safe(STATE_RA_PREFIX, &entry, 7200);
+				changed |= odhcp6c_update_entry_safe(STATE_RA_PREFIX, &entry, 7200);
 			} else if (opt->type == ND_OPT_RECURSIVE_DNS && opt->len > 2) {
 				entry.router = from.sin6_addr;
 				entry.priority = 0;
@@ -253,7 +254,7 @@ bool ra_process(void)
 				for (ssize_t i = 0; i < (opt->len - 1) / 2; ++i) {
 					memcpy(&entry.target, &opt->data[6 + i * sizeof(entry.target)],
 							sizeof(entry.target));
-					odhcp6c_update_entry(STATE_RA_DNS, &entry);
+					changed |= odhcp6c_update_entry(STATE_RA_DNS, &entry);
 				}
 			}
 		}
@@ -269,5 +270,5 @@ bool ra_process(void)
 	if (found)
 		odhcp6c_expire();
 
-	return found;
+	return found && changed;
 }