Fix incorrect teredo MTU calculation

libUTP overestimated maximum payload size for UDP packets, which resulted in fragmented datagrams on IPv6 links with MTU 1280 (e.g. teredo, 6to4, etc).
kssalanio · Jan 22, 2013 · bace1f9 · bace1f9
1 parent a9caf98
commit bace1f9
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/utp_utils.cpp b/utp_utils.cpp
@@ -184,7 +184,7 @@ uint32 UTP_GetMilliseconds()
 
 #define UDP_IPV4_MTU (ETHERNET_MTU - IPV4_HEADER_SIZE - UDP_HEADER_SIZE - GRE_HEADER_SIZE - PPPOE_HEADER_SIZE - MPPE_HEADER_SIZE - FUDGE_HEADER_SIZE)
 #define UDP_IPV6_MTU (ETHERNET_MTU - IPV6_HEADER_SIZE - UDP_HEADER_SIZE - GRE_HEADER_SIZE - PPPOE_HEADER_SIZE - MPPE_HEADER_SIZE - FUDGE_HEADER_SIZE)
-#define UDP_TEREDO_MTU (TEREDO_MTU - UDP_HEADER_SIZE)
+#define UDP_TEREDO_MTU (TEREDO_MTU - IPV6_HEADER_SIZE - UDP_HEADER_SIZE)
 
 uint16 UTP_GetUDPMTU(const struct sockaddr *remote, socklen_t remotelen)
 {