Fix DSCP tagging for dual-stack sockets on Linux

LizardByte · Feb 4, 2024 · be6f856 · be6f856
1 parent b7a3985
commit be6f856
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/src/platform/linux/misc.cpp b/src/platform/linux/misc.cpp
@@ -628,7 +628,10 @@ namespace platf {
     if (dscp_tagging) {
       int level;
       int option;
-      if (address.is_v6()) {
+
+      // With dual-stack sockets, Linux uses IPV6_TCLASS for IPv6 traffic
+      // and IP_TOS for IPv4 traffic.
+      if (address.is_v6() && !address.to_v6().is_v4_mapped()) {
         level = SOL_IPV6;
         option = IPV6_TCLASS;
       }