Fix segfault when dest->mtu is 0.

[tinc] / src / route.c

diff --git a/src/route.c b/src/route.c
index 8b7a13c..f8b11bb 100644 (file)
--- a/src/route.c
+++ b/src/route.c
@@ -116,8 +116,8 @@ static void swap_mac_addresses(vpn_packet_t *packet) {
 /* RFC 792 */
 
 static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, length_t ether_size, uint8_t type, uint8_t code) {
-       struct ip ip = {};
-       struct icmp icmp = {};
+       struct ip ip = {0};
+       struct icmp icmp = {0};
 
        struct in_addr ip_src;
        struct in_addr ip_dst;
@@ -218,7 +218,7 @@ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, length_
 
 static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, length_t ether_size, uint8_t type, uint8_t code) {
        struct ip6_hdr ip6;
-       struct icmp6_hdr icmp6 = {};
+       struct icmp6_hdr icmp6 = {0};
        uint16_t checksum;
 
        struct {
@@ -581,7 +581,7 @@ static void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet, length_t et
        ifdebug(TRAFFIC) logger(LOG_INFO, "Fragmenting packet of %d bytes to %s (%s)", packet->len, dest->name, dest->hostname);
 
        offset = packet->data + ether_size + ip_size;
-       maxlen = (dest->mtu - ether_size - ip_size) & ~0x7;
+       maxlen = (MAX(dest->mtu, 590) - ether_size - ip_size) & ~0x7;
        ip_off = ntohs(ip.ip_off);
        origf = ip_off & ~IP_OFFMASK;
        ip_off &= IP_OFFMASK;
@@ -632,11 +632,13 @@ static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) {
        }
 
        if(!subnet->owner->status.reachable) {
-               return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_UNREACH);
+               route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_UNREACH);
+               return;
        }
 
        if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself) {
-               return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO);
+               route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO);
+               return;
        }
 
        if(decrement_ttl && source != myself && subnet->owner != myself)
@@ -656,7 +658,8 @@ static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) {
        }
 
        if(directonly && subnet->owner != via) {
-               return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO);
+               route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO);
+               return;
        }
 
        if(via && packet->len > MAX(via->mtu, 590) && via != myself) {
@@ -723,17 +726,20 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) {
        }
 
        if(!subnet->owner->status.reachable) {
-               return route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE);
+               route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE);
+               return;
        }
 
        if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself) {
-               return route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
+               route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
+               return;
        }
 
-       if(decrement_ttl && source != myself && subnet->owner != myself)
+       if(decrement_ttl && source != myself && subnet->owner != myself) {
                if(!do_decrement_ttl(source, packet)) {
                        return;
                }
+       }
 
        if(priorityinheritance) {
                packet->priority = ((packet->data[14] & 0x0f) << 4) | (packet->data[15] >> 4);
@@ -747,7 +753,8 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) {
        }
 
        if(directonly && subnet->owner != via) {
-               return route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
+               route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
+               return;
        }
 
        if(via && packet->len > MAX(via->mtu, 1294) && via != myself) {
@@ -875,7 +882,7 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) {
        memcpy(packet->data, packet->data + ETH_ALEN, ETH_ALEN);        /* copy destination address */
        packet->data[ETH_ALEN * 2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */
 
-       ip6.ip6_dst = ip6.ip6_src;                      /* swap destination and source protocoll address */
+       ip6.ip6_dst = ip6.ip6_src;                      /* swap destination and source protocol address */
        ip6.ip6_src = ns.nd_ns_target;
 
        if(has_opt) {