Add sanity checks for NDP and MTU parameters from RAs

[odhcp6c.git] / src / ra.c

diff --git a/src/ra.c b/src/ra.c
index 7d1ded0199a512eca16828b86d32d75c75b44bab..b1526aed6ccacaba046b10072fd8e8887628fb29 100644 (file)
--- a/src/ra.c
+++ b/src/ra.c
@@ -155,12 +155,16 @@ static bool ra_deduplicate(const struct in6_addr *any, uint8_t length)
 bool ra_rtnl_process(void)
 {
        bool found = false;
+       uint32_t elapsed = odhcp6c_elapsed();
        uint8_t buf[8192];
        while (true) {
                ssize_t len = recv(rtnl_sock, buf, sizeof(buf), MSG_DONTWAIT);
                if (len < 0)
                        break;
 
+               if (elapsed > 10)
+                       continue;
+
                for (struct nlmsghdr *nh = (struct nlmsghdr*)buf; NLMSG_OK(nh, (size_t)len);
                                        nh = NLMSG_NEXT(nh, len)) {
                        struct ifaddrmsg *ifa = NLMSG_DATA(nh);
@@ -197,7 +201,6 @@ bool ra_process(void)
        struct nd_router_advert *adv = (struct nd_router_advert*)buf;
        struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, IN6ADDR_ANY_INIT, 0, 0};
        const struct in6_addr any = IN6ADDR_ANY_INIT;
-       odhcp6c_expire();
 
        while (true) {
                struct sockaddr_in6 from;
@@ -214,10 +217,15 @@ bool ra_process(void)
                        rs_attempt = 0;
                }
 
-               found = true;
+               if (!found) {
+                       odhcp6c_expire();
+                       found = true;
+               }
                uint32_t router_valid = ntohs(adv->nd_ra_router_lifetime);
 
                // Parse default route
+               entry.target = any;
+               entry.length = 0;
                entry.router = from.sin6_addr;
                entry.priority = pref_to_priority(adv->nd_ra_flags_reserved);
                if (entry.priority < 0)
@@ -227,10 +235,10 @@ bool ra_process(void)
                odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
 
                // Parse ND parameters
-               if (adv->nd_ra_reachable)
+               if (ntohl(adv->nd_ra_reachable) <= 3600000)
                        update_proc("neigh", "base_reachable_time_ms", ntohl(adv->nd_ra_reachable));
 
-               if (adv->nd_ra_retransmit)
+               if (ntohl(adv->nd_ra_retransmit) <= 60000)
                        update_proc("neigh", "retrans_time_ms", ntohl(adv->nd_ra_retransmit));
 
 
@@ -239,7 +247,8 @@ bool ra_process(void)
                icmpv6_for_each_option(opt, &adv[1], &buf[len]) {
                        if (opt->type == ND_OPT_MTU) {
                                uint32_t *mtu = (uint32_t*)&opt->data[2];
-                               update_proc("conf", "mtu", ntohl(*mtu));
+                               if (ntohl(*mtu) >= 1280 && ntohl(*mtu) <= 65535)
+                                       update_proc("conf", "mtu", ntohl(*mtu));
                        } else if (opt->type == ND_OPT_ROUTE_INFORMATION && opt->len <= 3) {
                                entry.router = from.sin6_addr;
                                entry.target = any;
@@ -306,6 +315,8 @@ bool ra_process(void)
                                entry[i].valid = router_valid;
        }
 
-       odhcp6c_expire();
+       if (found)
+               odhcp6c_expire();
+
        return found;
 }