From: Wilson Peng <[email protected]> If ovs node running on Windows is processing NAT action on the RX side, it will reset pseudo header checksum only if the L4 checksum is same as the calculated pseudo header checksum before NAT action.
Without the fix, if the L4 header checksum is filled with a pseudo header checksum (sourceip, dstip, protocol, tcppayloadlen+tcpheaderlen) OVS will still do the checksum update(replace some IP and port and recalculate the checksum). It will lead to incorrect L4 header checksum. Reported-at:https://github.com/openvswitch/ovs-issues/issues/265 Signed-off-by: Wilson Peng <[email protected]> --- datapath-windows/ovsext/Actions.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/datapath-windows/ovsext/Actions.c b/datapath-windows/ovsext/Actions.c index 2f44086b4..7d72a2276 100644 --- a/datapath-windows/ovsext/Actions.c +++ b/datapath-windows/ovsext/Actions.c @@ -1514,6 +1514,8 @@ OvsUpdateAddressAndPort(OvsForwardingContext *ovsFwdCtx, UINT16 *checkField = NULL; BOOLEAN l4Offload = FALSE; NDIS_TCP_IP_CHECKSUM_NET_BUFFER_LIST_INFO csumInfo; + UINT16 PreNatPseudoChecksum = 0; + BOOLEAN PreNatChecksumIsPseudoChecksum = FALSE; ASSERT(layers->value != 0); @@ -1550,6 +1552,10 @@ OvsUpdateAddressAndPort(OvsForwardingContext *ovsFwdCtx, */ /*Only tx direction the checksum value will be reset to be PseudoChecksum*/ + PreNatPseudoChecksum = IPPseudoChecksum(&ipHdr->saddr, &ipHdr->daddr, + tcpHdr ? IPPROTO_TCP : IPPROTO_UDP, + ntohs(ipHdr->tot_len) - ipHdr->ihl * 4); + if (isSource) { addrField = &ipHdr->saddr; if (tcpHdr) { @@ -1565,7 +1571,12 @@ OvsUpdateAddressAndPort(OvsForwardingContext *ovsFwdCtx, ((BOOLEAN)csumInfo.Receive.UdpChecksumSucceeded || (BOOLEAN)csumInfo.Receive.UdpChecksumFailed); } - if (isTx && l4Offload) { + if (!isTx && l4Offload) { + if (*checkField == PreNatPseudoChecksum) { + PreNatChecksumIsPseudoChecksum = TRUE; + } + } + if (isTx && l4Offload || PreNatChecksumIsPseudoChecksum) { *checkField = IPPseudoChecksum(&newAddr, &ipHdr->daddr, tcpHdr ? IPPROTO_TCP : IPPROTO_UDP, ntohs(ipHdr->tot_len) - ipHdr->ihl * 4); @@ -1585,8 +1596,13 @@ OvsUpdateAddressAndPort(OvsForwardingContext *ovsFwdCtx, ((BOOLEAN)csumInfo.Receive.UdpChecksumSucceeded || (BOOLEAN)csumInfo.Receive.UdpChecksumFailed); } + if (!isTx && l4Offload) { + if (*checkField == PreNatPseudoChecksum) { + PreNatChecksumIsPseudoChecksum = TRUE; + } + } - if (isTx && l4Offload) { + if (isTx && l4Offload || PreNatChecksumIsPseudoChecksum) { *checkField = IPPseudoChecksum(&ipHdr->saddr, &newAddr, tcpHdr ? IPPROTO_TCP : IPPROTO_UDP, ntohs(ipHdr->tot_len) - ipHdr->ihl * 4); @@ -1595,7 +1611,8 @@ OvsUpdateAddressAndPort(OvsForwardingContext *ovsFwdCtx, if (*addrField != newAddr) { UINT32 oldAddr = *addrField; - if ((checkField && *checkField != 0) && (!l4Offload || !isTx)) { + if ((checkField && *checkField != 0) && + (!l4Offload || (!isTx && !PreNatChecksumIsPseudoChecksum))) { /* Recompute total checksum. */ *checkField = ChecksumUpdate32(*checkField, oldAddr, newAddr); @@ -1609,7 +1626,8 @@ OvsUpdateAddressAndPort(OvsForwardingContext *ovsFwdCtx, } if (portField && *portField != newPort) { - if ((checkField) && (!l4Offload || !isTx)) { + if ((checkField) && + (!l4Offload || (!isTx && !PreNatChecksumIsPseudoChecksum))) { /* Recompute total checksum. */ *checkField = ChecksumUpdate16(*checkField, *portField, newPort); -- 2.32.1 (Apple Git-133) _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
