network/protocols: Set and check L3/L4_CHECKSUM_VALID flags.

iperf3 TCP on loopback, 1 core (in VMware) goes from ~7.2 Gbits/sec
to ~9.4 Gbits/sec.

Change-Id: I0c93254fab9ee1b5040ef5f71000982bac1a5d15
Reviewed-on: https://review.haiku-os.org/c/haiku/+/7917
Haiku-Format: Haiku-format Bot <[email protected]>
Reviewed-by: waddlesplash <[email protected]>

src/add-ons/kernel/network/protocols/ipv4/ipv4.cpp

@@ -1559,6 +1559,7 @@ ipv4_send_routed_data(net_protocol* _protocol, struct net_route* route,
 	if (checksumNeeded) {
 		*IPChecksumField(buffer) = gBufferModule->checksum(buffer, 0,
 			sizeof(ipv4_header), true);
+		buffer->buffer_flags |= NET_BUFFER_L3_CHECKSUM_VALID;
 	}
 
 	if ((buffer->msg_flags & MSG_MCAST) != 0
@@ -1741,9 +1742,10 @@ ipv4_receive_data(net_buffer* buffer)
 		|| headerLength < sizeof(ipv4_header))
 		return B_BAD_DATA;
 
-	// TODO: would be nice to have a direct checksum function somewhere
-	if (gBufferModule->checksum(buffer, 0, headerLength, true) != 0)
-		return B_BAD_DATA;
+	if ((buffer->buffer_flags & NET_BUFFER_L3_CHECKSUM_VALID) == 0) {
+		if (gBufferModule->checksum(buffer, 0, headerLength, true) != 0)
+			return B_BAD_DATA;
+	}
 
 	// lower layers notion of broadcast or multicast have no relevance to us
 	// other than deciding whether to send an ICMP error

src/add-ons/kernel/network/protocols/tcp/tcp.cpp

@@ -435,6 +435,7 @@ add_tcp_header(net_address_module_info* addressModule,
 
 	*TCPChecksumField(buffer) = Checksum::PseudoHeader(addressModule,
 		gBufferModule, buffer, IPPROTO_TCP);
+	buffer->buffer_flags |= NET_BUFFER_L4_CHECKSUM_VALID;
 
 	return B_OK;
 }
@@ -698,9 +699,10 @@ tcp_receive_data(net_buffer* buffer)
 	if (headerLength < sizeof(tcp_header))
 		return B_BAD_DATA;
 
-	if (Checksum::PseudoHeader(addressModule, gBufferModule, buffer,
-			IPPROTO_TCP) != 0)
-		return B_BAD_DATA;
+	if ((buffer->buffer_flags & NET_BUFFER_L4_CHECKSUM_VALID) == 0) {
+		if (Checksum::PseudoHeader(addressModule, gBufferModule, buffer, IPPROTO_TCP) != 0)
+			return B_BAD_DATA;
+	}
 
 	addressModule->set_port(buffer->source, header.source_port);
 	addressModule->set_port(buffer->destination, header.destination_port);

src/add-ons/kernel/network/protocols/udp/udp.cpp

@@ -828,7 +828,7 @@ UdpEndpointManager::Deframe(net_buffer* buffer)
 	if (buffer->size > udpLength)
 		gBufferModule->trim(buffer, udpLength);
 
-	if (header.udp_checksum != 0) {
+	if (header.udp_checksum != 0 && (buffer->buffer_flags & NET_BUFFER_L4_CHECKSUM_VALID) == 0) {
 		// check UDP-checksum (simulating a so-called "pseudo-header"):
 		uint16 sum = Checksum::PseudoHeader(addressModule, gBufferModule,
 			buffer, IPPROTO_UDP);
@@ -1042,6 +1042,7 @@ UdpEndpoint::SendRoutedData(net_buffer *buffer, net_route *route)
 		calculatedChecksum = 0xffff;
 
 	*UDPChecksumField(buffer) = calculatedChecksum;
+	buffer->buffer_flags |= NET_BUFFER_L4_CHECKSUM_VALID;
 
 	return next->module->send_routed_data(next, route, buffer);
 }