created interface for transport-network interface

1 files changed, 90 insertions, 0 deletions

diff --git a/src/include/gpxe/interface.h b/src/include/gpxe/interface.h
new file mode 100644
index 000000000..d0f68b840
--- /dev/null
+++ b/src/include/gpxe/interface.h
@@ -0,0 +1,90 @@
+#ifndef _GPXE_INTERFACE_H
+#define _GPXE_INTERFACE_H
+
+/** @file
+ *
+ * Transport-network layer interface
+ *
+ */
+
+#include <stdint.h>
+#include <gpxe/in.h>
+#include <gpxe/tables.h>
+
+struct pk_buff;
+struct net_protocol;
+struct trans_protocol;
+struct tcpip_net_protocol;
+
+/** 
+ * A transport-layer protocol
+ */
+struct trans_protocol {
+	/** Protocol name */
+	const char *name;
+       	/**
+         * Process received packet
+         *
+         * @v pkb       Packet buffer
+         * @v netdev    Network device
+         * @v ll_source Link-layer source address
+         *
+         * This method takes ownership of the packet buffer.
+         */
+        void ( * rx ) ( struct pk_buff *pkb, struct in_addr *src_net_addr, struct in_addr *dest_net_addr );
+        /** 
+	 * Transport-layer protocol number
+	 *
+	 * This is a constant of the type IP_XXX
+         */
+        uint8_t trans_proto;
+};
+
+/**
+ * A TCPIP supporting protocol
+ */
+struct tcpip_net_protocol {
+	/** Network protocol */
+	struct net_protocol *net_protocol;
+	/** Network address family */
+	sa_family_t sa_family;
+	/** Complete transport-layer checksum calculation
+	 *
+	 * @v pkb		Packet buffer
+	 * @v trans_proto	Transport-layer protocol number
+	 *
+	 * This function expects a network-layer datagram in its packet with the protocol field in the
+	 * IP header to be filled up. It constructs a psuedo-header using the information provided in
+	 * the IP header and computes the checksum over the pseudo-header. The checksum offset in the
+	 * transport layer header can be determined without the need of an offset value as
+	 * 
+	 * void *csum_offset = pkb->data + NET_HLEN + csum_offset ( trans_proto );
+	 * 
+	 * where,
+	 * csum_offset ( IP_TCP ) = 16
+	 * csum_offset ( IP_UDP ) = 6
+	 */
+	void ( * tx_csum ) ( struct pk_buff *pkb );
+};
+
+/**
+ * Register a transport-layer protocol
+ *
+ * @v protocol          Transport-layer protocol
+ */
+#define TRANS_PROTOCOL( protocol ) \
+        struct trans_protocol protocol __table ( trans_protocols, 01 )
+
+#define TCPIP_NET_PROTOCOL( protocol ) \
+        struct tcpip_net_protocol protocol __table ( tcpip_net_protocols, 01 )
+
+extern void trans_rx ( struct pk_buff *pkb, uint8_t trans_proto, struct in_addr *src, struct in_addr *dest );
+extern int trans_tx ( struct pk_buff *pkb, uint8_t trans_proto, struct sockaddr *dest );
+
+extern uint16_t calc_chksum ( void *data, size_t len );
+
+/** Do we need these functions? -Nikhil, 24-6-06 */
+extern struct trans_protocol * find_trans_protocol ( uint8_t trans_proto );
+extern struct tcpip_net_protocol * find_tcpip_net_protocol ( sa_family_t sa_family );
+
+#endif /* _GPXE_INTERFACE_H */