From: Vittorio Gambaletta (VittGam) Date: Fri, 25 Sep 2015 02:52:25 +0000 (+0200) Subject: Fix DecrementTTL option for packets destined to the local node. X-Git-Tag: release-1.0.27~30 X-Git-Url: https://git.tinc-vpn.org/git/browse?a=commitdiff_plain;h=225e403c82f3ad20870ad8e77208723a1b6bcb0c;p=tinc Fix DecrementTTL option for packets destined to the local node. Signed-off-by: Vittorio Gambaletta --- diff --git a/src/route.c b/src/route.c index c1be6cb0..1b539aa1 100644 --- a/src/route.c +++ b/src/route.c @@ -53,6 +53,8 @@ static const size_t icmp6_size = sizeof(struct icmp6_hdr); static const size_t ns_size = sizeof(struct nd_neighbor_solicit); static const size_t opt_size = sizeof(struct nd_opt_hdr); +static bool do_decrement_ttl(node_t *source, vpn_packet_t *packet); + #ifndef MAX #define MAX(a, b) ((a) > (b) ? (a) : (b)) #endif @@ -251,6 +253,14 @@ void age_subnets(void) { } } +static void broadcast_packet_helper(node_t *source, vpn_packet_t *packet) { + if(decrement_ttl && source != myself) + if(!do_decrement_ttl(source, packet)) + return; + + broadcast_packet(source, 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) { @@ -426,6 +436,10 @@ static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) { if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself) return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO); + if(decrement_ttl && source != myself && subnet->owner != myself) + if(!do_decrement_ttl(source, packet)) + return; + if(priorityinheritance) packet->priority = packet->data[15]; @@ -465,7 +479,7 @@ static void route_ipv4(node_t *source, vpn_packet_t *packet) { packet->data[31] == 255 && packet->data[32] == 255 && packet->data[33] == 255))) - broadcast_packet(source, packet); + broadcast_packet_helper(source, packet); else route_ipv4_unicast(source, packet); } @@ -606,6 +620,10 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) { 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); + if(decrement_ttl && source != myself && subnet->owner != myself) + if(!do_decrement_ttl(source, packet)) + return; + via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via; if(via == source) { @@ -722,6 +740,10 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) { if(subnet->owner == myself) return; /* silently ignore */ + if(decrement_ttl) + if(!do_decrement_ttl(source, packet)) + return; + /* Create neighbor advertation reply */ memcpy(packet->data, packet->data + ETH_ALEN, ETH_ALEN); /* copy destination address */ @@ -779,7 +801,7 @@ static void route_ipv6(node_t *source, vpn_packet_t *packet) { } if(broadcast_mode && packet->data[38] == 255) - broadcast_packet(source, packet); + broadcast_packet_helper(source, packet); else route_ipv6_unicast(source, packet); } @@ -832,6 +854,10 @@ static void route_arp(node_t *source, vpn_packet_t *packet) { if(subnet->owner == myself) return; /* silently ignore */ + if(decrement_ttl) + if(!do_decrement_ttl(source, packet)) + return; + 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 */ @@ -868,7 +894,7 @@ static void route_mac(node_t *source, vpn_packet_t *packet) { subnet = lookup_subnet_mac(NULL, &dest); if(!subnet) { - broadcast_packet(source, packet); + broadcast_packet_helper(source, packet); return; } @@ -880,6 +906,10 @@ static void route_mac(node_t *source, vpn_packet_t *packet) { if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself) return; + if(decrement_ttl && source != myself && subnet->owner != myself) + if(!do_decrement_ttl(source, packet)) + return; + uint16_t type = packet->data[12] << 8 | packet->data[13]; if(priorityinheritance && type == ETH_P_IP && packet->len >= ether_size + ip_size) @@ -982,10 +1012,6 @@ void route(node_t *source, vpn_packet_t *packet) { if(!checklength(source, packet, ether_size)) return; - if(decrement_ttl && source != myself) - if(!do_decrement_ttl(source, packet)) - return; - switch (routing_mode) { case RMODE_ROUTER: { @@ -1016,7 +1042,7 @@ void route(node_t *source, vpn_packet_t *packet) { break; case RMODE_HUB: - broadcast_packet(source, packet); + broadcast_packet_helper(source, packet); break; } }