Proof-of-concept FTP implementation

src/include/gpxe/ftp.h

@@ -0,0 +1,68 @@
+#ifndef _GPXE_FTP_H
+#define _GPXE_FTP_H
+
+/** @file
+ *
+ * File transfer protocol
+ *
+ */
+
+#include <stdint.h>
+#include <gpxe/tcp.h>
+
+enum ftp_state {
+	FTP_CONNECT = 0,
+	FTP_USER,
+	FTP_PASS,
+	FTP_TYPE,
+	FTP_PASV,
+	FTP_RETR,
+	FTP_QUIT,
+	FTP_DONE,
+};
+
+/**
+ * An FTP request
+ *
+ */
+struct ftp_request {
+	/** TCP connection for this request */
+	struct tcp_connection tcp;
+	/** File to download */
+	const char *filename;
+	/** Callback function
+	 *
+	 * @v data	Received data
+	 * @v len	Length of received data
+	 *
+	 * This function is called for all data received from the
+	 * remote server.
+	 */
+	void ( *callback ) ( char *data, size_t len );
+	/** Completion indicator
+	 *
+	 * This will be set to a non-zero value when the transfer is
+	 * complete.  A negative value indicates an error.
+	 */
+	int complete;
+
+	/** Current state */
+	enum ftp_state state;
+	/** Amount of current message already transmitted */
+	size_t already_sent;
+	/** Buffer to be filled with data received via the control channel */
+	char *recvbuf;
+	/** Remaining size of recvbuf */
+	size_t recvsize;
+	/** FTP status code, as text */
+	char status_text[4];
+	/** Passive-mode parameters, as text */
+	char passive_text[24]; /* "aaa,bbb,ccc,ddd,eee,fff" */
+
+	/** TCP connection for the data channel */
+	struct tcp_connection tcp_data;
+};
+
+extern void ftp_connect ( struct ftp_request *ftp );
+
+#endif

src/net/tcp/ftp.c

@@ -0,0 +1,263 @@
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <vsprintf.h>
+#include <assert.h>
+#include <errno.h>
+#include <gpxe/ftp.h>
+
+/** @file
+ *
+ * File transfer protocol
+ *
+ */
+
+const char *ftp_strings[] = {
+	[FTP_CONNECT] = "",
+	[FTP_USER] = "USER anonymous\r\n",
+	[FTP_PASS] = "PASS etherboot@etherboot.org\r\n",
+	[FTP_TYPE] = "TYPE I\r\n",
+	[FTP_PASV] = "PASV\r\n",
+	[FTP_RETR] = "RETR %s\r\n",
+	[FTP_QUIT] = "QUIT\r\n",
+	[FTP_DONE] = "",
+};
+
+static inline struct ftp_request *
+tcp_to_ftp ( struct tcp_connection *conn ) {
+	return container_of ( conn, struct ftp_request, tcp );
+}
+
+static inline struct ftp_request *
+tcp_to_ftp_data ( struct tcp_connection *conn ) {
+	return container_of ( conn, struct ftp_request, tcp_data );
+}
+
+static void ftp_complete ( struct ftp_request *ftp, int complete ) {
+	ftp->complete = complete;
+	tcp_close ( &ftp->tcp_data );
+	tcp_close ( &ftp->tcp );
+}
+
+
+static void ftp_aborted ( struct tcp_connection *conn ) {
+	struct ftp_request *ftp = tcp_to_ftp ( conn );
+
+	ftp_complete ( ftp, -ECONNABORTED );
+}
+
+static void ftp_timedout ( struct tcp_connection *conn ) {
+	struct ftp_request *ftp = tcp_to_ftp ( conn );
+
+	ftp_complete ( ftp, -ETIMEDOUT );
+}
+
+static void ftp_closed ( struct tcp_connection *conn ) {
+	struct ftp_request *ftp = tcp_to_ftp ( conn );
+
+	ftp_complete ( ftp, 1 );
+}
+
+static void ftp_connected ( struct tcp_connection *conn ) {
+	struct ftp_request *ftp = tcp_to_ftp ( conn );
+
+	/* Nothing to do */
+}
+
+static void ftp_acked ( struct tcp_connection *conn, size_t len ) {
+	struct ftp_request *ftp = tcp_to_ftp ( conn );
+	
+	ftp->already_sent += len;
+}
+
+static int ftp_open_passive ( struct ftp_request *ftp ) {
+	char *ptr = ftp->passive_text;
+	uint8_t *byte = ( uint8_t * ) ( &ftp->tcp_data.sin );
+	int i;
+
+	/* Parse the IP address and port from the PASV repsonse */
+	for ( i = 6 ; i ; i-- ) {
+		if ( ! *ptr )
+			return -EINVAL;
+		*(byte++) = strtoul ( ptr, &ptr, 10 );
+		if ( *ptr )
+			ptr++;
+	}
+	if ( *ptr )
+		return -EINVAL;
+
+	tcp_connect ( &ftp->tcp_data );
+	return 0;
+}
+
+static void ftp_reply ( struct ftp_request *ftp ) {
+	char status_major = ftp->status_text[0];
+	int success;
+
+	/* Ignore "intermediate" messages */
+	if ( status_major == '1' )
+		return;
+
+	/* Check for success */
+	success = ( status_major == '2' );
+
+	/* Special-case the "USER"-"PASS" sequence */
+	if ( ftp->state == FTP_USER ) {
+		if ( success ) {
+			/* No password was asked for; pretend we have
+			 * already entered it
+			 */
+			ftp->state = FTP_PASS;
+		} else if ( status_major == '3' ) {
+			/* Password requested, treat this as success
+			 * for our purposes
+			 */
+			success = 1;
+		}
+	}
+	
+	/* Abort on failure */
+	if ( ! success )
+		goto err;
+
+	/* Open passive connection when we get "PASV" response */
+	if ( ftp->state == FTP_PASV ) {
+		if ( ftp_open_passive ( ftp ) != 0 )
+			goto err;
+	}
+
+	/* Move to next state */
+	if ( ftp->state < FTP_DONE )
+		ftp->state++;
+	ftp->already_sent = 0;
+	return;
+
+ err:
+	ftp->complete = -EPROTO;
+	tcp_close ( &ftp->tcp );
+}
+
+static void ftp_newdata ( struct tcp_connection *conn,
+			  void *data, size_t len ) {
+	struct ftp_request *ftp = tcp_to_ftp ( conn );
+	char c;
+
+	for ( ; len ; data++, len-- ) {
+		c = * ( ( char * ) data );
+		if ( ( c == '\r' ) || ( c == '\n' ) ) {
+			if ( ftp->recvsize == 0 )
+				ftp_reply ( ftp );
+			ftp->recvbuf = ftp->status_text;
+			ftp->recvsize = sizeof ( ftp->status_text ) - 1;
+		} else if ( c == '(' ) {
+			ftp->recvbuf = ftp->passive_text;
+			ftp->recvsize = sizeof ( ftp->passive_text ) - 1;
+		} else if ( c == ')' ) {
+			ftp->recvsize = 0;
+		} else if ( ftp->recvsize > 0 ) {
+			*(ftp->recvbuf++) = c;
+			ftp->recvsize--;
+		}
+	}
+}
+
+static void ftp_senddata ( struct tcp_connection *conn ) {
+	struct ftp_request *ftp = tcp_to_ftp ( conn );
+	const char *format;
+	const char *data;
+	size_t len;
+
+	/* Select message format string and data */
+	format = ftp_strings[ftp->state];
+	switch ( ftp->state ) {
+	case FTP_RETR:
+		data = ftp->filename;
+		break;
+	default:
+		data = NULL;
+		break;
+	}
+	if ( ! data )
+		data = "";
+	
+	/* Build message */
+	len = snprintf ( tcp_buffer, tcp_buflen, format, data );
+	tcp_send ( conn, tcp_buffer + ftp->already_sent,
+		   len - ftp->already_sent );
+}
+
+static struct tcp_operations ftp_tcp_operations = {
+	.aborted	= ftp_aborted,
+	.timedout	= ftp_timedout,
+	.closed		= ftp_closed,
+	.connected	= ftp_connected,
+	.acked		= ftp_acked,
+	.newdata	= ftp_newdata,
+	.senddata	= ftp_senddata,
+};
+
+static void ftp_data_aborted ( struct tcp_connection *conn ) {
+	struct ftp_request *ftp = tcp_to_ftp_data ( conn );
+
+	ftp_complete ( ftp, -ECONNABORTED );
+}
+
+static void ftp_data_timedout ( struct tcp_connection *conn ) {
+	struct ftp_request *ftp = tcp_to_ftp_data ( conn );
+
+	ftp_complete ( ftp, -ETIMEDOUT );
+}
+
+static void ftp_data_closed ( struct tcp_connection *conn ) {
+	struct ftp_request *ftp = tcp_to_ftp_data ( conn );
+
+	/* Nothing to do */
+}
+
+static void ftp_data_connected ( struct tcp_connection *conn ) {
+	struct ftp_request *ftp = tcp_to_ftp_data ( conn );
+
+	/* Nothing to do */
+}
+
+static void ftp_data_acked ( struct tcp_connection *conn, size_t len ) {
+	struct ftp_request *ftp = tcp_to_ftp_data ( conn );
+	
+	/* Nothing to do */
+}
+
+static void ftp_data_newdata ( struct tcp_connection *conn,
+			       void *data, size_t len ) {
+	struct ftp_request *ftp = tcp_to_ftp_data ( conn );
+
+	ftp->callback ( data, len );
+}
+
+static void ftp_data_senddata ( struct tcp_connection *conn ) {
+	struct ftp_request *ftp = tcp_to_ftp_data ( conn );
+	
+	/* Nothing to do */
+}
+
+static struct tcp_operations ftp_data_tcp_operations = {
+	.aborted	= ftp_data_aborted,
+	.timedout	= ftp_data_timedout,
+	.closed		= ftp_data_closed,
+	.connected	= ftp_data_connected,
+	.acked		= ftp_data_acked,
+	.newdata	= ftp_data_newdata,
+	.senddata	= ftp_data_senddata,
+};
+
+/**
+ * Initiate an FTP connection
+ *
+ * @v ftp	FTP request
+ */
+void ftp_connect ( struct ftp_request *ftp ) {
+	ftp->tcp.tcp_op = &ftp_tcp_operations;
+	ftp->tcp_data.tcp_op = &ftp_data_tcp_operations;
+	ftp->recvbuf = ftp->status_text;
+	ftp->recvsize = sizeof ( ftp->status_text ) - 1;
+	tcp_connect ( &ftp->tcp );
+}