Initial (untested) implementation of TFTP over the new UDP API.

1 files changed, 471 insertions, 0 deletions

diff --git a/src/net/udp/tftp.c b/src/net/udp/tftp.c
new file mode 100644
index 00000000..39839bea
--- /dev/null
+++ b/src/net/udp/tftp.c
@@ -0,0 +1,471 @@
+/*
+ * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <byteswap.h>
+#include <errno.h>
+#include <assert.h>
+#include <vsprintf.h>
+#include <gpxe/async.h>
+#include <gpxe/tftp.h>
+
+/** @file
+ *
+ * TFTP protocol
+ *
+ */
+
+/** A TFTP option */
+struct tftp_option {
+	/** Option name */
+	const char *name;
+	/** Option processor
+	 *
+	 * @v tftp	TFTP connection
+	 * @v value	Option value
+	 * @ret rc	Return status code
+	 */
+	int ( * process ) ( struct tftp_session *tftp, const char *value );
+};
+
+/**
+ * Process TFTP "blksize" option
+ *
+ * @v tftp		TFTP connection
+ * @v value		Option value
+ * @ret rc		Return status code
+ */
+static int tftp_process_blksize ( struct tftp_session *tftp,
+				  const char *value ) {
+	char *end;
+
+	tftp->blksize = strtoul ( value, &end, 10 );
+	if ( *end ) {
+		DBG ( "TFTP %p got invalid blksize \"%s\"\n", tftp, value );
+		return -EINVAL;
+	}
+	DBG ( "TFTP %p blksize=%d\n", tftp, tftp->blksize );
+
+	return 0;
+}
+
+/**
+ * Process TFTP "tsize" option
+ *
+ * @v tftp		TFTP connection
+ * @v value		Option value
+ * @ret rc		Return status code
+ */
+static int tftp_process_tsize ( struct tftp_session *tftp,
+				const char *value ) {
+	char *end;
+
+	tftp->tsize = strtoul ( value, &end, 10 );
+	if ( *end ) {
+		DBG ( "TFTP %p got invalid tsize \"%s\"\n", tftp, value );
+		return -EINVAL;
+	}
+	DBG ( "TFTP %p tsize=%ld\n", tftp, tftp->tsize );
+
+	return 0;
+}
+
+/** Recognised TFTP options */
+static struct tftp_option tftp_options[] = {
+	{ "blksize", tftp_process_blksize },
+	{ "tsize", tftp_process_tsize },
+	{ NULL, NULL }
+};
+
+/**
+ * Process TFTP option
+ *
+ * @v tftp		TFTP connection
+ * @v name		Option name
+ * @v value		Option value
+ * @ret rc		Return status code
+ */
+static int tftp_process_option ( struct tftp_session *tftp,
+				 const char *name, const char *value ) {
+	struct tftp_option *option;
+
+	for ( option = tftp_options ; option->name ; option++ ) {
+		if ( strcasecmp ( name, option->name ) == 0 )
+			return option->process ( tftp, value );
+	}
+
+	DBG ( "TFTP %p received unknown option \"%s\" = \"%s\"\n",
+	      tftp, name, value );
+
+	return -EINVAL;
+}
+
+/** Translation between TFTP errors and internal error numbers */
+static const uint8_t tftp_errors[] = {
+	[TFTP_ERR_FILE_NOT_FOUND]	= PXENV_STATUS_TFTP_FILE_NOT_FOUND,
+	[TFTP_ERR_ACCESS_DENIED]	= PXENV_STATUS_TFTP_ACCESS_VIOLATION,
+	[TFTP_ERR_ILLEGAL_OP]		= PXENV_STATUS_TFTP_UNKNOWN_OPCODE,
+};
+
+/**
+ * Mark TFTP session as complete
+ *
+ * @v tftp		TFTP connection
+ * @v rc		Return status code
+ */
+static void tftp_done ( struct tftp_session *tftp, int rc ) {
+
+	/* Stop the retry timer */
+	stop_timer ( &tftp->timer );
+
+	/* Close UDP connection */
+	udp_close ( &tftp->udp );
+
+	/* Mark async operation as complete */
+	async_done ( &tftp->aop, rc );
+}
+
+/**
+ * Send next packet in TFTP session
+ *
+ * @v tftp		TFTP connection
+ */
+static void tftp_send_packet ( struct tftp_session *tftp ) {
+	start_timer ( &tftp->timer );
+	udp_senddata ( &tftp->udp );
+}
+
+/**
+ * Handle TFTP retransmission timer expiry
+ *
+ * @v timer		Retry timer
+ * @v fail		Failure indicator
+ */
+static void tftp_timer_expired ( struct retry_timer *timer, int fail ) {
+	struct tftp_session *tftp =
+		container_of ( timer, struct tftp_session, timer );
+
+	if ( fail ) {
+		tftp_done ( tftp, -ETIMEDOUT );
+	} else {
+		tftp_send_packet ( tftp );
+	}
+}
+
+/**
+ * Mark TFTP block as received
+ *
+ * @v tftp		TFTP connection
+ * @v block		Block number
+ */
+static void tftp_received ( struct tftp_session *tftp, unsigned int block ) {
+
+	/* Stop the retry timer */
+	stop_timer ( &tftp->timer );
+
+	/* Update state to indicate which block we're now waiting for */
+	tftp->state = block;
+
+	/* Send next packet */
+	tftp_send_packet ( tftp );
+}
+
+/**
+ * Transmit RRQ
+ *
+ * @v tftp		TFTP connection
+ * @v buf		Temporary data buffer
+ * @v len		Length of temporary data buffer
+ * @ret rc		Return status code
+ */
+static int tftp_send_rrq ( struct tftp_session *tftp, void *buf, size_t len ) {
+	struct tftp_rrq *rrq = buf;
+	void *data;
+	void *end;
+
+	DBG ( "TFTP %p requesting \"%s\"\n", tftp, tftp->filename );
+
+	data = rrq->data;
+	end = ( buf + len );
+	if ( data > end )
+		goto overflow;
+	data += snprintf ( data, ( end - data ),
+			   "%s%coctet%cblksize%c%d%ctsize%c0",
+			   tftp->filename, 0, 0, 0, tftp->blksize, 0, 0 ) + 1;
+	if ( data > end )
+		goto overflow;
+	rrq->opcode = htons ( TFTP_RRQ );
+
+	return udp_send ( &tftp->udp, buf, ( data - buf ) );
+
+ overflow:
+	DBG ( "TFTP %p RRQ out of space\n", tftp );
+	return -ENOBUFS;
+}
+
+/**
+ * Receive OACK
+ *
+ * @v tftp		TFTP connection
+ * @v buf		Temporary data buffer
+ * @v len		Length of temporary data buffer
+ * @ret rc		Return status code
+ */
+static int tftp_rx_oack ( struct tftp_session *tftp, void *buf, size_t len ) {
+	struct tftp_oack *oack = buf;
+	char *end = buf + len;
+	char *name;
+	char *value;
+	int rc;
+
+	/* Sanity check */
+	if ( len < sizeof ( *oack ) ) {
+		DBG ( "TFTP %p received underlength OACK packet length %d\n",
+		      tftp, len );
+		return -EINVAL;
+	}
+	if ( end[-1] != '\0' ) {
+		DBG ( "TFTP %p received OACK missing final NUL\n", tftp );
+		return -EINVAL;
+	}
+
+	/* Process each option in turn */
+	name = oack->data;
+	while ( name < end ) {
+		value = ( name + strlen ( name ) + 1 );
+		if ( value == end ) {
+			DBG ( "TFTP %p received OACK missing value for option "
+			      "\"%s\"\n", tftp, name );
+			return -EINVAL;
+		}
+		if ( ( rc = tftp_process_option ( tftp, name, value ) ) != 0 )
+			return rc;
+		name = ( value + strlen ( value ) + 1 );
+	}
+
+	/* Mark as received block 0 (the OACK) */
+	tftp_received ( tftp, 0 );
+
+	return 0;
+}
+
+/**
+ * Receive DATA
+ *
+ * @v tftp		TFTP connection
+ * @v buf		Temporary data buffer
+ * @v len		Length of temporary data buffer
+ * @ret rc		Return status code
+ */
+static int tftp_rx_data ( struct tftp_session *tftp, void *buf, size_t len ) {
+	struct tftp_data *data = buf;
+	unsigned int block;
+	size_t data_len;
+
+	/* Sanity check */
+	if ( len < sizeof ( *data ) ) {
+		DBG ( "TFTP %p received underlength DATA packet length %d\n",
+		      tftp, len );
+		return -EINVAL;
+	}
+
+	/* Pass to callback */
+	block = ntohs ( data->block );
+	data_len = ( len - offsetof ( typeof ( *data ), data ) );
+	tftp->callback ( tftp, block, data->data, data_len );
+
+	/* Mark block as received */
+	tftp_received ( tftp, block );
+
+	/* Finish when final block received */
+	if ( data_len < tftp->blksize )
+		tftp_done ( tftp, 0 );
+
+	return 0;
+}
+
+/**
+ * Transmit ACK
+ *
+ * @v tftp		TFTP connection
+ * @v buf		Temporary data buffer
+ * @v len		Length of temporary data buffer
+ * @ret rc		Return status code
+ */
+static int tftp_send_ack ( struct tftp_session *tftp ) {
+	struct tftp_ack ack;
+
+	ack.opcode = htons ( TFTP_ACK );
+	ack.block = htons ( tftp->state );
+	return udp_send ( &tftp->udp, &ack, sizeof ( ack ) );
+}
+
+/**
+ * Receive ERROR
+ *
+ * @v tftp		TFTP connection
+ * @v buf		Temporary data buffer
+ * @v len		Length of temporary data buffer
+ * @ret rc		Return status code
+ */
+static int tftp_rx_error ( struct tftp_session *tftp, void *buf, size_t len ) {
+	struct tftp_error *error = buf;
+	unsigned int err;
+	int rc = 0;
+
+	/* Sanity check */
+	if ( len < sizeof ( *error ) ) {
+		DBG ( "TFTP %p received underlength ERROR packet length %d\n",
+		      tftp, len );
+		return -EINVAL;
+	}
+
+	DBG ( "TFTP %p received ERROR packet with code %d, message \"%s\"\n",
+	      tftp, ntohs ( error->errcode ), error->errmsg );
+	
+	/* Determine final operation result */
+	err = ntohs ( error->errcode );
+	if ( err < ( sizeof ( tftp_errors ) / sizeof ( tftp_errors[0] ) ) )
+		rc = -tftp_errors[err];
+	if ( ! rc )
+		rc = -PXENV_STATUS_TFTP_CANNOT_OPEN_CONNECTION;
+
+	/* Close TFTP session */
+	tftp_done ( tftp, rc );
+
+	return 0;
+}
+
+/**
+ * Transmit data
+ *
+ * @v conn		UDP connection
+ * @v buf		Temporary data buffer
+ * @v len		Length of temporary data buffer
+ * @ret rc		Return status code
+ */
+static int tftp_senddata ( struct udp_connection *conn,
+			   void *buf, size_t len ) {
+	struct tftp_session *tftp = 
+		container_of ( conn, struct tftp_session, udp );
+
+	if ( tftp->state < 0 ) {
+		return tftp_send_rrq ( tftp, buf, len );
+	} else {
+		return tftp_send_ack ( tftp );
+	}
+}
+
+/**
+ * Receive new data
+ *
+ * @v udp		UDP connection
+ * @v data		Received data
+ * @v len		Length of received data
+ * @v st_src		Partially-filled source address
+ * @v st_dest		Partially-filled destination address
+ */
+static int tftp_newdata ( struct udp_connection *conn, void *data, size_t len,
+			  struct sockaddr_tcpip *st_src __unused,
+			  struct sockaddr_tcpip *st_dest __unused ) {
+	struct tftp_session *tftp = 
+		container_of ( conn, struct tftp_session, udp );
+	struct tftp_common *common = data;
+	
+	if ( len < sizeof ( *common ) ) {
+		DBG ( "TFTP %p received underlength packet length %d\n",
+		      tftp, len );
+		return -EINVAL;
+	}
+
+	/* Filter by TID.  Set TID on first response received */
+	if ( tftp->tid ) {
+		if ( tftp->tid != st_src->st_port ) {
+			DBG ( "TFTP %p received packet from wrong port "
+			      "(got %d, wanted %d)\n", tftp,
+			      ntohs ( st_src->st_port ), ntohs ( tftp->tid ) );
+			return -EINVAL;
+		}
+	} else {
+		tftp->tid = st_src->st_port;
+		DBG ( "TFTP %p using remote port %d\n", tftp,
+		      ntohs ( tftp->tid ) );
+		udp_connect_port ( &tftp->udp, tftp->tid );
+	}
+
+	/* Filter by source address */
+	if ( memcmp ( st_src, udp_peer ( &tftp->udp ),
+		      sizeof ( *st_src ) ) != 0 ) {
+		DBG ( "TFTP %p received packet from foreign source\n", tftp );
+		return -EINVAL;
+	}
+
+	switch ( common->opcode ) {
+	case htons ( TFTP_OACK ):
+		return tftp_rx_oack ( tftp, data, len );
+	case htons ( TFTP_DATA ):
+		return tftp_rx_data ( tftp, data, len );
+	case htons ( TFTP_ERROR ):
+		return tftp_rx_error ( tftp, data, len );
+	default:
+		DBG ( "TFTP %p received strange packet type %d\n", tftp,
+		      ntohs ( common->opcode ) );
+		return -EINVAL;
+	};
+}
+
+/** TFTP UDP operations */
+static struct udp_operations tftp_udp_operations = {
+	.senddata = tftp_senddata,
+	.newdata = tftp_newdata,
+};
+
+/**
+ * Initiate TFTP download
+ *
+ * @v tftp		TFTP session
+ * @ret aop		Asynchronous operation
+ */
+struct async_operation * tftp_get ( struct tftp_session *tftp ) {
+	int rc;
+
+	assert ( tftp->filename != NULL );
+	assert ( tftp->callback != NULL );
+	assert ( tftp->udp.peer.st_family != 0 );
+
+	/* Initialise TFTP session */
+	tftp->udp.udp_op = &tftp_udp_operations;
+	tftp->timer.expired = tftp_timer_expired;
+	tftp->state = -1;
+	tftp->blksize = TFTP_DEFAULT_BLKSIZE;
+
+	/* Open UDP connection */
+	if ( ( rc = udp_open ( &tftp->udp, 0 ) ) != 0 ) {
+		async_done ( &tftp->aop, rc );
+		goto out;
+	}
+
+	/* Transmit initial RRQ */
+	tftp_send_packet ( tftp );
+
+ out:
+	return &tftp->aop;
+}