moved address selection logic to a new 'get_buffer_route'.

- IPv4 now assumes the addresses it is supplied in send_routed_data are already the appropriate ones.
 - made the Data(), operator* and operator-> methods in NetBufferFieldReader const so we can use them in the same expression as the constructor.
 - fixed an issue with UDP where the wrong source address could be used in the calculating the checksum.
 - changed ipv4_print_address to use the more common 0.0.0.0 format.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@20660 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/net/NetBufferUtilities.h

@@ -22,56 +22,49 @@ class NetBufferFieldReader {
 	public:
 		NetBufferFieldReader(net_buffer *buffer)
 			:
-			fBuffer(buffer),
-			fStatus(B_BAD_VALUE)
+			fBuffer(buffer)
 		{
-			if ((Offset + sizeof(Type)) <= buffer->size) {
-				fStatus = Module::Get()->direct_access(fBuffer, Offset,
-					sizeof(Type), (void **)&fData);
-				if (fStatus != B_OK) {
-					fData = NULL;
-					fStatus = Module::Get()->read(fBuffer, Offset,
-						&fDataBuffer, sizeof(Type));
-				}
+			fStatus = Module::Get()->direct_access(fBuffer, Offset,
+				sizeof(Type), (void **)&fData);
+			if (fStatus != B_OK) {
+				fStatus = Module::Get()->read(fBuffer, Offset,
+					&fDataBuffer, sizeof(Type));
+				fData = &fDataBuffer;
 			}
 		}
 
 		status_t
-		Status()
+		Status() const
 		{
 			return fStatus;
 		}
 
 		Type &
-		Data()
+		Data() const
 		{
-			if (fData != NULL)
-				return *fData;
-
-			return fDataBuffer;
+			return *fData;
 		}
 
 		Type *
-		operator->()
+		operator->() const
 		{
-			return &Data();
+			return fData;
 		}
 
 		Type &
-		operator*()
+		operator*() const
 		{
-			return Data();
+			return *fData;
 		}
 
 		void
 		Sync()
 		{
-			if (fBuffer == NULL)
+			if (fBuffer == NULL || fStatus < B_OK)
 				return;
 
-			if (fData == NULL)
-				Module::Get()->write(fBuffer, Offset, &fDataBuffer,
-					sizeof(Type));
+			if (fData == &fDataBuffer)
+				Module::Get()->write(fBuffer, Offset, fData, sizeof(Type));
 
 			fBuffer = NULL;
 		}
@@ -138,15 +131,14 @@ class NetBufferHeaderRemover : public NetBufferHeaderReader<Type, Module> {
 template<typename Type, typename Module = NetBufferModuleGetter>
 class NetBufferPrepend : public NetBufferFieldReader<Type, 0, Module> {
 	public:
-		NetBufferPrepend(net_buffer *buffer, size_t size = 0)
+		NetBufferPrepend(net_buffer *buffer, size_t size = sizeof(Type))
 		{
 			fBuffer = buffer;
-			fData = NULL;
 
-			if (size == 0)
-				size = sizeof(Type);
-
-			fStatus = Module::Get()->prepend_size(buffer, size, (void **)&fData);
+			fStatus = Module::Get()->prepend_size(buffer, size,
+				(void **)&fData);
+			if (fStatus == B_OK && fData == NULL)
+				fData = &fDataBuffer;
 		}
 
 		~NetBufferPrepend()

headers/private/net/net_datalink.h

@@ -79,6 +79,8 @@ struct net_datalink_module_info {
 					const struct net_route *route);
 	struct net_route *(*get_route)(struct net_domain *domain,
 					const struct sockaddr *address);
+	status_t (*get_buffer_route)(struct net_domain *domain,
+		struct net_buffer *buffer, struct net_route **_route);
 	void (*put_route)(struct net_domain *domain, struct net_route *route);
 
 	status_t (*register_route_info)(struct net_domain *domain,
@@ -118,6 +120,8 @@ struct net_address_module_info {
 	status_t (*set_to)(sockaddr *address, const sockaddr *from);
 	status_t (*set_to_empty_address)(sockaddr *address);
 
+	status_t (*update_to)(sockaddr *address, const sockaddr *from);
+
 	uint32 (*hash_address_pair)(const sockaddr *ourAddress, 
 					const sockaddr *peerAddress);
 

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

@@ -257,8 +257,8 @@ icmp_receive_data(net_buffer *buffer)
 
 			header.Sync();
 
-			ICMPChecksumField checksum(reply);
-			*checksum = gBufferModule->checksum(reply, 0, reply->size, true);
+			*ICMPChecksumField(reply) = gBufferModule->checksum(reply, 0,
+					reply->size, true);
 
 			status_t status = domain->module->send_data(NULL, reply);
 			if (status < B_OK) {

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

@@ -671,15 +671,6 @@ receiving_protocol(uint8 protocol)
 }
 
 
-static void
-update_checksum(net_buffer *buffer)
-{
-	IPChecksumField checksum(buffer);
-
-	*checksum = gBufferModule->checksum(buffer, 0, sizeof(ipv4_header), true);
-}
-
-
 //	#pragma mark -
 
 
@@ -928,49 +919,31 @@ ipv4_send_routed_data(net_protocol *_protocol, struct net_route *route,
 	TRACE(("someone tries to send some actual routed data!\n"));
 
 	sockaddr_in &source = *(sockaddr_in *)&buffer->source;
-	if (source.sin_addr.s_addr == INADDR_ANY && route->interface->address != NULL) {
-		// replace an unbound source address with the address of the interface
-		// TODO: couldn't we replace all addresses here?
-		source.sin_addr.s_addr = ((sockaddr_in *)route->interface->address)->sin_addr.s_addr;
-	}
+	sockaddr_in &destination = *(sockaddr_in *)&buffer->destination;
 
-	bool headerIncluded = false;
+	bool headerIncluded = false, checksumNeeded = true;
 	if (protocol != NULL)
 		headerIncluded = (protocol->flags & IP_FLAG_HEADER_INCLUDED) != 0;
 
 	// Add IP header (if needed)
 
 	if (!headerIncluded) {
-		NetBufferPrepend<ipv4_header> bufferHeader(buffer);
-		if (bufferHeader.Status() < B_OK)
-			return bufferHeader.Status();
+		NetBufferPrepend<ipv4_header> header(buffer);
+		if (header.Status() < B_OK)
+			return header.Status();
 
-		ipv4_header &header = bufferHeader.Data();
-
-		header.version = IP_VERSION;
-		header.header_length = sizeof(ipv4_header) >> 2;
-		header.service_type = protocol ? protocol->service_type : 0;
-		header.total_length = htons(buffer->size);
-		header.id = htons(atomic_add(&sPacketID, 1));
-		header.fragment_offset = 0;
-		header.time_to_live = protocol ? protocol->time_to_live : 254;
-		header.protocol = protocol ? protocol->socket->protocol : buffer->protocol;
-		header.checksum = 0;
-		if (route->interface->address != NULL) {
-			header.source = ((sockaddr_in *)route->interface->address)->sin_addr.s_addr;
-				// always use the actual used source address
-		} else
-			header.source = 0;
-
-		header.destination = ((sockaddr_in *)&buffer->destination)->sin_addr.s_addr;
-
-		bufferHeader.Sync();
-			// make sure the IP-header is already written to the
-			// buffer at this point
-
-		update_checksum(buffer);
-		//dump_ipv4_header(header);
+		header->version = IP_VERSION;
+		header->header_length = sizeof(ipv4_header) / 4;
+		header->service_type = protocol ? protocol->service_type : 0;
+		header->total_length = htons(buffer->size);
+		header->id = htons(atomic_add(&sPacketID, 1));
+		header->fragment_offset = 0;
+		header->time_to_live = protocol ? protocol->time_to_live : 254;
+		header->protocol = protocol ? protocol->socket->protocol : buffer->protocol;
+		header->checksum = 0;
 
+		header->source = source.sin_addr.s_addr;
+		header->destination = destination.sin_addr.s_addr;
 	} else {
 		// if IP_HDRINCL, check if the source address is set
 		NetBufferHeaderReader<ipv4_header> header(buffer);
@@ -980,22 +953,24 @@ ipv4_send_routed_data(net_protocol *_protocol, struct net_route *route,
 		if (header->source == 0) {
 			header->source = source.sin_addr.s_addr;
 			header->checksum = 0;
-
 			header.Sync();
-
-			update_checksum(buffer);
-		}
+		} else
+			checksumNeeded = false;
 	}
 
 	if (buffer->size > 0xffff)
 		return EMSGSIZE;
 
+	if (checksumNeeded)
+		*IPChecksumField(buffer) = gBufferModule->checksum(buffer, 0,
+			sizeof(ipv4_header), true);
+
 	TRACE(("header chksum: %ld, buffer checksum: %ld\n",
 		gBufferModule->checksum(buffer, 0, sizeof(ipv4_header), true),
 		gBufferModule->checksum(buffer, 0, buffer->size, true)));
 
 	TRACE(("destination-IP: buffer=%p addr=%p %08lx\n", buffer, &buffer->destination,
-		ntohl(((sockaddr_in *)&buffer->destination)->sin_addr.s_addr)));
+		ntohl(destination->sin_addr.s_addr)));
 
 	uint32 mtu = route->mtu ? route->mtu : interface->mtu;
 	if (buffer->size > mtu) {
@@ -1012,14 +987,13 @@ ipv4_send_data(net_protocol *protocol, net_buffer *buffer)
 {
 	TRACE(("someone tries to send some actual data!\n"));
 
-	// find route
-	struct net_route *route = sDatalinkModule->get_route(sDomain,
-		(sockaddr *)&buffer->destination);
-	if (route == NULL)
-		return ENETUNREACH;
-
-	status_t status = ipv4_send_routed_data(protocol, route, buffer);
-	sDatalinkModule->put_route(sDomain, route);
+	net_route *route = NULL;
+	status_t status = sDatalinkModule->get_buffer_route(sDomain, buffer,
+		&route);
+	if (status >= B_OK) {
+		status = ipv4_send_routed_data(protocol, route, buffer);
+		sDatalinkModule->put_route(sDomain, route);
+	}
 
 	return status;
 }

src/add-ons/kernel/network/protocols/ipv4/ipv4_address.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006, Haiku, Inc. All Rights Reserved.
+ * Copyright 2006-2007, Haiku, Inc. All Rights Reserved.
  * Distributed under the terms of the MIT License.
  *
  * Authors:
@@ -251,24 +251,35 @@ ipv4_check_mask(const sockaddr *_mask)
 	\return B_NO_MEMORY if the buffer could not be allocated
 */
 static status_t
-ipv4_print_address(const sockaddr *address, char **_buffer, bool printPort)
+ipv4_print_address(const sockaddr *_address, char **_buffer, bool printPort)
 {
+	const sockaddr_in *address = (const sockaddr_in *)_address;
+
 	if (_buffer == NULL)
 		return B_BAD_VALUE;
 
-	int bufLen = printPort ? 15 : 9;
-	char *buffer  = (char *)malloc(bufLen);
-	if (buffer == NULL)
-		return B_NO_MEMORY;
+	char tmp[64];
 
 	if (address == NULL)
-		strcpy(buffer, "<none>");
-	else if (printPort) {
-		sprintf(buffer, "%08lx:%u", ntohl(((sockaddr_in *)address)->sin_addr.s_addr),
-			ntohs(((sockaddr_in *)address)->sin_port));
-	} else
-		sprintf(buffer, "%08lx", ntohl(((sockaddr_in *)address)->sin_addr.s_addr));
-	*_buffer = buffer;
+		strcpy(tmp, "<none>");
+	else {
+		unsigned int addr = ntohl(address->sin_addr.s_addr);
+
+		if (printPort)
+			sprintf(tmp, "%u.%u.%u.%u:%u", (addr >> 24) & 0xff,
+				(addr >> 16) & 0xff, (addr >> 8) & 0xff, addr & 0xff,
+				ntohs(address->sin_port));
+		else
+			sprintf(tmp, "%u.%u.%u.%u", (addr >> 24) & 0xff,
+				(addr >> 16) & 0xff, (addr >> 8) & 0xff, addr & 0xff);
+	}
+
+	*_buffer = strdup(tmp);
+	if (*_buffer == NULL)
+		return B_NO_MEMORY;
+
+
+
 	return B_OK;
 }
 
@@ -324,6 +335,31 @@ ipv4_set_to(sockaddr *address, const sockaddr *from)
 }
 
 
+static status_t
+ipv4_update_to(sockaddr *_address, const sockaddr *_from)
+{
+	sockaddr_in *address = (sockaddr_in *)_address;
+	const sockaddr_in *from = (const sockaddr_in *)_from;
+
+	if (address == NULL || from == NULL)
+		return B_BAD_VALUE;
+
+	if (from->sin_family != AF_INET)
+		return B_BAD_VALUE;
+
+	address->sin_family = AF_INET;
+	address->sin_len = sizeof(sockaddr_in);
+
+	if (address->sin_port == 0)
+		address->sin_port = from->sin_port;
+
+	if (address->sin_addr.s_addr == INADDR_ANY)
+		address->sin_addr.s_addr = from->sin_addr.s_addr;
+
+	return B_OK;
+}
+
+
 /*!
 	Sets \a address to the empty address (0.0.0.0).
 	\return B_OK if \a address has been set
@@ -394,6 +430,7 @@ net_address_module_info gIPv4AddressModule = {
 	ipv4_set_port,
 	ipv4_set_to,
 	ipv4_set_to_empty_address,
+	ipv4_update_to,
 	ipv4_hash_address_pair,
 	ipv4_checksum_address,
 	NULL // ipv4_matches_broadcast_address,

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

@@ -170,8 +170,7 @@ add_tcp_header(tcp_segment_header &segment, net_buffer *buffer)
 		<< (uint16)htons(buffer->size)
 		<< Checksum::BufferHelper(buffer, gBufferModule);
 
-	TCPChecksumField checksumField(buffer);
-	*checksumField = checksum;
+	*TCPChecksumField(buffer) = checksum;
 
 	return B_OK;
 }

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

@@ -47,6 +47,10 @@ struct udp_header {
 } _PACKED;
 
 
+typedef NetBufferField<uint16, offsetof(udp_header, udp_checksum)>
+	UDPChecksumField;
+
+
 class UdpEndpoint : public net_protocol {
 public:
 	UdpEndpoint(net_socket *socket);
@@ -766,43 +770,44 @@ UdpEndpoint::SendData(net_buffer *buffer, net_route *route)
 {
 	if (buffer->size > (0xffff - sizeof(udp_header)))
 		return EMSGSIZE;
-	
+
 	buffer->protocol = IPPROTO_UDP;
 
-	{	// scope for lifetime of bufferHeader
+	// add and fill UDP-specific header:
+	NetBufferPrepend<udp_header> header(buffer);
+	if (header.Status() < B_OK)
+		return header.Status();
 
-		// add and fill UDP-specific header:
-		NetBufferPrepend<udp_header> bufferHeader(buffer);
-		if (bufferHeader.Status() < B_OK)
-			return bufferHeader.Status();
-	
-		udp_header &header = bufferHeader.Data();
-	
-		header.source_port = sAddressModule->get_port((sockaddr *)&buffer->source);
-		header.destination_port = sAddressModule->get_port(
-			(sockaddr *)&buffer->destination);
-		header.udp_length = htons(buffer->size);
-			// the udp-header is already included in the buffer-size
-		header.udp_checksum = 0;
+	header->source_port = sAddressModule->get_port((sockaddr *)&buffer->source);
+	header->destination_port = sAddressModule->get_port(
+		(sockaddr *)&buffer->destination);
+	header->udp_length = htons(buffer->size);
+		// the udp-header is already included in the buffer-size
+	header->udp_checksum = 0;
+
+	header.Sync();
+
+	// generate UDP-checksum (simulating a so-called "pseudo-header"):
+	Checksum udpChecksum;
+	sAddressModule->checksum_address(&udpChecksum,
+		(sockaddr *)route->interface->address);
+	sAddressModule->checksum_address(&udpChecksum,
+		(sockaddr *)&buffer->destination);
+	udpChecksum
+		<< (uint16)htons(IPPROTO_UDP)
+		<< (uint16)htons(buffer->size)
+				// peculiar but correct: UDP-len is used twice for checksum
+				// (as it is already contained in udp_header)
+		<< Checksum::BufferHelper(buffer, gBufferModule);
+
+	uint16 calculatedChecksum = udpChecksum;
+	if (calculatedChecksum == 0)
+		calculatedChecksum = 0xffff;
+
+	*UDPChecksumField(buffer) = calculatedChecksum;
+
+	TRACE_BLOCK(((char*)&header, sizeof(udp_header), "udp-hdr: "));
 
-		// generate UDP-checksum (simulating a so-called "pseudo-header"):
-		Checksum udpChecksum;
-		sAddressModule->checksum_address(&udpChecksum, 
-			(sockaddr *)route->interface->address);
-		sAddressModule->checksum_address(&udpChecksum, 
-			(sockaddr *)&buffer->destination);
-		udpChecksum 
-			<< (uint16)htons(IPPROTO_UDP)
-			<< (uint16)htons(buffer->size)
-					// peculiar but correct: UDP-len is used twice for checksum
-					// (as it is already contained in udp_header)
-			<< Checksum::BufferHelper(buffer, gBufferModule);
-		header.udp_checksum = udpChecksum;
-		if (header.udp_checksum == 0)
-			header.udp_checksum = 0xFFFF;
-	
-		TRACE_BLOCK(((char*)&header, sizeof(udp_header), "udp-hdr: "));
-	}
 	return next->module->send_routed_data(next, route, buffer);
 }
 
@@ -966,8 +971,8 @@ udp_send_routed_data(net_protocol *protocol, struct net_route *route,
 	net_buffer *buffer)
 {
 	TRACE(("udp_send_routed_data(%p) size=%lu\n", protocol, buffer->size));
-	UdpEndpoint *udpEndpoint = (UdpEndpoint *)protocol;
-	return udpEndpoint->SendData(buffer, route);
+
+	return ((UdpEndpoint *)protocol)->SendData(buffer, route);
 }
 
 
@@ -976,14 +981,14 @@ udp_send_data(net_protocol *protocol, net_buffer *buffer)
 {
 	TRACE(("udp_send_data(%p) size=%lu\n", protocol, buffer->size));
 
-	struct net_route *route = sDatalinkModule->get_route(sDomain,
-		(sockaddr *)&buffer->destination);
-	if (route == NULL)
-		return ENETUNREACH;
+	net_route *route = NULL;
+	status_t status = sDatalinkModule->get_buffer_route(sDomain, buffer,
+		&route);
+	if (status >= B_OK) {
+		status = udp_send_routed_data(protocol, route, buffer);
+		sDatalinkModule->put_route(sDomain, route);
+	}
 
-	UdpEndpoint *udpEndpoint = (UdpEndpoint *)protocol;
-	status_t status = udpEndpoint->SendData(buffer, route);
-	sDatalinkModule->put_route(sDomain, route);
 	return status;
 }
 

src/add-ons/kernel/network/stack/datalink.cpp

@@ -749,6 +749,7 @@ net_datalink_module_info gNetDatalinkModule = {
 	add_route,
 	remove_route,
 	get_route,
+	get_buffer_route,
 	put_route,
 	register_route_info,
 	unregister_route_info,

src/add-ons/kernel/network/stack/routes.cpp

@@ -535,6 +535,43 @@ get_route(struct net_domain *_domain, const struct sockaddr *address)
 }
 
 
+status_t
+get_buffer_route(net_domain *_domain, net_buffer *buffer, net_route **_route)
+{
+	net_domain_private *domain = (net_domain_private *)_domain;
+
+	BenaphoreLocker _(domain->lock);
+
+	net_route *route = get_route_internal(domain,
+		(sockaddr *)&buffer->destination);
+	if (route == NULL)
+		return ENETUNREACH;
+
+	status_t status = B_OK;
+	sockaddr *source = (sockaddr *)&buffer->source;
+
+	// TODO we are quite relaxed in the address checking here
+	//      as we might proceed with srcaddr=INADDR_ANY.
+
+	if (route->interface && route->interface->address) {
+		sockaddr *interfaceAddress = route->interface->address;
+		net_address_module_info *addressModule = domain->address_module;
+
+		if (addressModule->is_empty_address(source, true))
+			addressModule->set_to(source, interfaceAddress);
+		else
+			status = addressModule->update_to(source, interfaceAddress);
+	}
+
+	if (status != B_OK)
+		put_route_internal(domain, route);
+	else
+		*_route = route;
+
+	return status;
+}
+
+
 void
 put_route(struct net_domain *_domain, net_route *route)
 {

src/add-ons/kernel/network/stack/routes.h

@@ -42,6 +42,8 @@ status_t get_route_information(struct net_domain *domain, void *buffer,
 void invalidate_routes(net_domain *, net_interface *);
 struct net_route *get_route(struct net_domain *domain,
 				const struct sockaddr *address);
+status_t get_buffer_route(struct net_domain *domain,
+	struct net_buffer *buffer, struct net_route **_route);
 void put_route(struct net_domain *domain, struct net_route *route);
 
 status_t register_route_info(struct net_domain *domain,