Only set IP_ECN when IP_TOS isn't supported. Only set ECN or TOS when…

… ECN and DSCP are non-default
microsoft · Feb 4, 2025 · cc4d4f8 · cc4d4f8
1 parent 7fc999b
commit cc4d4f8
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Showing 3 changed files with 48 additions and 43 deletions.
diff --git a/src/platform/datapath_raw_socket.c b/src/platform/datapath_raw_socket.c
@@ -366,7 +366,7 @@ CxPlatDpRawParseIPv6(
     } VersionClassEcnFlow;
     VersionClassEcnFlow.Value = CxPlatByteSwapUint32(IP->VersionClassEcnFlow);
 
-    Packet->TypeOfService = ((uint8_t)VersionClassEcnFlow.EcnField) | (uint8_t)(VersionClassEcnFlow.Class << 2);
+    Packet->TypeOfService = (uint8_t)(VersionClassEcnFlow.EcnField | (VersionClassEcnFlow.Class << 2));
     Packet->HopLimitTTL = IP->HopLimit;
     Packet->Route->RemoteAddress.Ipv6.sin6_family = AF_INET6;
     CxPlatCopyMemory(&Packet->Route->RemoteAddress.Ipv6.sin6_addr, IP->Source, sizeof(IP->Source));

diff --git a/src/platform/datapath_winkernel.c b/src/platform/datapath_winkernel.c
@@ -2929,8 +2929,7 @@ SocketSend(
     //
     BYTE CMsgBuffer[
         WSA_CMSG_SPACE(sizeof(IN6_PKTINFO)) +   // IP_PKTINFO
-        WSA_CMSG_SPACE(sizeof(INT)) +           // IP_ECN
-        WSA_CMSG_SPACE(sizeof(INT)) +           // IP_TOS/IPV6_TCLASS
+        WSA_CMSG_SPACE(sizeof(INT)) +           // IP_ECN or IP_TOS
         WSA_CMSG_SPACE(sizeof(*SegmentSize))    // UDP_SEND_MSG_SIZE
         ];
     PWSACMSGHDR CMsg = (PWSACMSGHDR)CMsgBuffer;
@@ -2961,30 +2960,33 @@ SocketSend(
         }
     }
 
-    if (SendData->ECN != CXPLAT_ECN_NON_ECT) {
-        CMsg = (PWSACMSGHDR)&CMsgBuffer[CMsgLen];
-        CMsgLen += WSA_CMSG_SPACE(sizeof(INT));
-        CMsg->cmsg_level =
-            Route->LocalAddress.si_family == QUIC_ADDRESS_FAMILY_INET ?
-                IPPROTO_IP : IPPROTO_IPV6;
-        CMsg->cmsg_type = IP_ECN; // == IPV6_ECN
-        CMsg->cmsg_len = WSA_CMSG_LEN(sizeof(INT));
-
-        *(PINT)WSA_CMSG_DATA(CMsg) = SendData->ECN;
-    }
-
     if (Binding->Datapath->Features & CXPLAT_DATAPATH_FEATURE_SEND_DSCP) {
-        CMsg = (PWSACMSGHDR)&CMsgBuffer[CMsgLen];
-        CMsgLen += WSA_CMSG_SPACE(sizeof(INT));
-        CMsg->cmsg_level =
-            Route->LocalAddress.si_family == QUIC_ADDRESS_FAMILY_INET ?
-                IPPROTO_IP : IPPROTO_IPV6;
-        CMsg->cmsg_type =
-            Route->LocalAddress.si_family == QUIC_ADDRESS_FAMILY_INET ?
-                IP_TOS : IPV6_TCLASS;
-        CMsg->cmsg_len = WSA_CMSG_LEN(sizeof(INT));
-
-        *(PINT)WSA_CMSG_DATA(CMsg) = SendData->ECN | (SendData->DSCP << 2);
+        if (SendData->ECN != CXPLAT_ECN_NON_ECT || SendData->DSCP != CXPLAT_DSCP_CS0) {
+            CMsg = (PWSACMSGHDR)&CMsgBuffer[CMsgLen];
+            CMsgLen += WSA_CMSG_SPACE(sizeof(INT));
+            if (Route->LocalAddress.si_family == QUIC_ADDRESS_FAMILY_INET) {
+                CMsg->cmsg_level = IPPROTO_IP;
+                CMsg->cmsg_type = IP_TOS;
+            } else {
+                CMsg->cmsg_level = IPPROTO_IPV6;
+                CMsg->cmsg_type = IPV6_TCLASS;
+            }
+            CMsg->cmsg_len = WSA_CMSG_LEN(sizeof(INT));
+
+            *(PINT)WSA_CMSG_DATA(CMsg) = SendData->ECN | (SendData->DSCP << 2);
+        }
+    } else {
+        if (SendData->ECN != CXPLAT_ECN_NON_ECT) {
+            CMsg = (PWSACMSGHDR)&CMsgBuffer[CMsgLen];
+            CMsgLen += WSA_CMSG_SPACE(sizeof(INT));
+            CMsg->cmsg_level =
+                Route->LocalAddress.si_family == QUIC_ADDRESS_FAMILY_INET ?
+                    IPPROTO_IP : IPPROTO_IPV6;
+            CMsg->cmsg_type = IP_ECN; // == IPV6_ECN
+            CMsg->cmsg_len = WSA_CMSG_LEN(sizeof(INT));
+
+            *(PINT)WSA_CMSG_DATA(CMsg) = SendData->ECN;
+        }
     }
 
     if (SendData->SegmentSize > 0) {

diff --git a/src/platform/datapath_winuser.c b/src/platform/datapath_winuser.c
@@ -273,8 +273,7 @@ typedef struct CXPLAT_SEND_DATA {
     char CtrlBuf[
         RIO_CMSG_BASE_SIZE +
         WSA_CMSG_SPACE(sizeof(IN6_PKTINFO)) +   // IP_PKTINFO
-        WSA_CMSG_SPACE(sizeof(INT)) +           // IP_ECN
-        WSA_CMSG_SPACE(sizeof(INT)) +           // IP_TOS
+        WSA_CMSG_SPACE(sizeof(INT)) +           // IP_ECN or IP_TOS
         WSA_CMSG_SPACE(sizeof(DWORD))           // UDP_SEND_MSG_SIZE
         ];
 
@@ -4520,22 +4519,26 @@ CxPlatSocketSendInline(
             PktInfo->ipi_addr = LocalAddress->Ipv4.sin_addr;
         }
 
-        WSAMhdr.Control.len += WSA_CMSG_SPACE(sizeof(INT));
-        CMsg = WSA_CMSG_NXTHDR(&WSAMhdr, CMsg);
-        CXPLAT_DBG_ASSERT(CMsg != NULL);
-        CMsg->cmsg_level = IPPROTO_IP;
-        CMsg->cmsg_type = IP_ECN;
-        CMsg->cmsg_len = WSA_CMSG_LEN(sizeof(INT));
-        *(PINT)WSA_CMSG_DATA(CMsg) = SendData->ECN;
-
         if (Socket->Datapath->Features & CXPLAT_DATAPATH_FEATURE_SEND_DSCP) {
-            WSAMhdr.Control.len += WSA_CMSG_SPACE(sizeof(INT));
-            CMsg = WSA_CMSG_NXTHDR(&WSAMhdr, CMsg);
-            CXPLAT_DBG_ASSERT(CMsg != NULL);
-            CMsg->cmsg_level = IPPROTO_IP;
-            CMsg->cmsg_type = IP_TOS;
-            CMsg->cmsg_len = WSA_CMSG_LEN(sizeof(INT));
-            *(PINT)WSA_CMSG_DATA(CMsg) = SendData->ECN | (SendData->DSCP << 2);
+            if (SendData->ECN != CXPLAT_ECN_NON_ECT || SendData->DSCP != CXPLAT_DSCP_CS0) {
+                WSAMhdr.Control.len += WSA_CMSG_SPACE(sizeof(INT));
+                CMsg = WSA_CMSG_NXTHDR(&WSAMhdr, CMsg);
+                CXPLAT_DBG_ASSERT(CMsg != NULL);
+                CMsg->cmsg_level = IPPROTO_IP;
+                CMsg->cmsg_type = IP_TOS;
+                CMsg->cmsg_len = WSA_CMSG_LEN(sizeof(INT));
+                *(PINT)WSA_CMSG_DATA(CMsg) = SendData->ECN | (SendData->DSCP << 2);
+            }
+        } else {
+            if (SendData->ECN != CXPLAT_ECN_NON_ECT) {
+                WSAMhdr.Control.len += WSA_CMSG_SPACE(sizeof(INT));
+                CMsg = WSA_CMSG_NXTHDR(&WSAMhdr, CMsg);
+                CXPLAT_DBG_ASSERT(CMsg != NULL);
+                CMsg->cmsg_level = IPPROTO_IP;
+                CMsg->cmsg_type = IP_ECN;
+                CMsg->cmsg_len = WSA_CMSG_LEN(sizeof(INT));
+                *(PINT)WSA_CMSG_DATA(CMsg) = SendData->ECN;
+            }
         }
 
     } else {