Moved uIP and tcp.c from proto/ to net/

1 files changed, 164 insertions, 0 deletions

diff --git a/src/net/tcp.c b/src/net/tcp.c
new file mode 100644
index 00000000..69fe95f5
--- /dev/null
+++ b/src/net/tcp.c
@@ -0,0 +1,164 @@
+#include <string.h>
+#include <assert.h>
+#include <byteswap.h>
+#include <gpxe/tcp.h>
+#include "uip/uip.h"
+
+/** @file
+ *
+ * TCP protocol
+ *
+ * The gPXE TCP stack is currently implemented on top of the uIP
+ * protocol stack.  This file provides wrappers around uIP so that
+ * higher-level protocol implementations do not need to talk directly
+ * to uIP (which has a somewhat baroque API).
+ *
+ * Basic operation is to create a #tcp_connection structure, call
+ * tcp_connect() and then call run_tcpip() in a loop until the
+ * operation has completed.  The TCP stack will call the various
+ * methods defined in the #tcp_operations structure in order to send
+ * and receive data.
+ *
+ * See hello.c for a trivial example of a TCP protocol using this
+ * API.
+ *
+ */
+
+/**
+ * TCP transmit buffer
+ *
+ * When a tcp_operations::senddata() method is called, it is
+ * guaranteed to be able to use this buffer as temporary space for
+ * constructing the data to be sent.  For example, code such as
+ *
+ * @code
+ *
+ *     static void my_senddata ( struct tcp_connection *conn ) {
+ *         int len;
+ *
+ *         len = snprintf ( tcp_buffer, tcp_buflen, "FETCH %s\r\n", filename );
+ *         tcp_send ( conn, tcp_buffer + already_sent, len - already_sent );
+ *     }
+ *
+ * @endcode
+ *
+ * is allowed, and is probably the best way to deal with
+ * variably-sized data.
+ *
+ * Note that you cannot use this simple mechanism if you want to be
+ * able to construct single data blocks of more than #tcp_buflen
+ * bytes.
+ */
+void *tcp_buffer = uip_buf + ( 40 + UIP_LLH_LEN );
+
+/** Size of #tcp_buffer */
+size_t tcp_buflen = UIP_BUFSIZE - ( 40 + UIP_LLH_LEN );
+
+/**
+ * Open a TCP connection
+ *
+ * @v conn	TCP connection
+ * @ret 0	Success
+ * @ret <0	Failure
+ * 
+ * This sets up a new TCP connection to the remote host specified in
+ * tcp_connection::sin.  The actual SYN packet will not be sent out
+ * until run_tcpip() is called for the first time.
+ *
+ * @todo Use linked lists instead of a static buffer, and thereby
+ *       remove the only potential failure case, giving this function
+ *       a void return type.
+ */
+int tcp_connect ( struct tcp_connection *conn ) {
+	struct uip_conn *uip_conn;
+	u16_t ipaddr[2];
+
+	assert ( conn->sin.sin_addr.s_addr != 0 );
+	assert ( conn->sin.sin_port != 0 );
+	assert ( conn->tcp_op != NULL );
+	assert ( sizeof ( uip_conn->appstate ) == sizeof ( conn ) );
+
+	* ( ( uint32_t * ) ipaddr ) = conn->sin.sin_addr.s_addr;
+	uip_conn = uip_connect ( ipaddr, conn->sin.sin_port );
+	if ( ! uip_conn )
+		return -1;
+
+	*( ( void ** ) uip_conn->appstate ) = conn;
+	return 0;
+}
+
+/**
+ * Send data via a TCP connection
+ *
+ * @v conn	TCP connection
+ * @v data	Data to send
+ * @v len	Length of data
+ *
+ * Data will be automatically limited to the current TCP window size.
+ *
+ * If retransmission is required, the connection's
+ * tcp_operations::senddata() method will be called again in order to
+ * regenerate the data.
+ */
+void tcp_send ( struct tcp_connection *conn __unused,
+		const void *data, size_t len ) {
+
+	assert ( conn = *( ( void ** ) uip_conn->appstate ) );
+
+	if ( len > tcp_buflen )
+		len = tcp_buflen;
+	memmove ( tcp_buffer, data, len );
+
+	uip_send ( tcp_buffer, len );
+}
+
+/**
+ * Close a TCP connection
+ *
+ * @v conn	TCP connection
+ */
+void tcp_close ( struct tcp_connection *conn __unused ) {
+	assert ( conn = *( ( void ** ) uip_conn->appstate ) );
+	uip_close();
+}
+
+/**
+ * uIP TCP application call interface
+ *
+ * This is the entry point of gPXE from the point of view of the uIP
+ * protocol stack.  This function calls the appropriate methods from
+ * the connection's @tcp_operations table in order to process received
+ * data, transmit new data etc.
+ */
+void uip_tcp_appcall ( void ) {
+	struct tcp_connection *conn = *( ( void ** ) uip_conn->appstate );
+	struct tcp_operations *op = conn->tcp_op;
+
+	assert ( conn->tcp_op->closed != NULL );
+	assert ( conn->tcp_op->connected != NULL );
+	assert ( conn->tcp_op->acked != NULL );
+	assert ( conn->tcp_op->newdata != NULL );
+	assert ( conn->tcp_op->senddata != NULL );
+
+	if ( uip_aborted() && op->aborted ) /* optional method */
+		op->aborted ( conn );
+	if ( uip_timedout() && op->timedout ) /* optional method */
+		op->timedout ( conn );
+	if ( uip_closed() && op->closed ) /* optional method */
+		op->closed ( conn );
+	if ( uip_connected() )
+		op->connected ( conn );
+	if ( uip_acked() )
+		op->acked ( conn, uip_conn->len );
+	if ( uip_newdata() )
+		op->newdata ( conn, ( void * ) uip_appdata, uip_len );
+	if ( uip_rexmit() || uip_newdata() || uip_acked() ||
+	     uip_connected() || uip_poll() )
+		op->senddata ( conn );
+}
+
+/* Present here to allow everything to link.  Will go into separate
+ * udp.c file
+ */
+void uip_udp_appcall ( void ) {
+}