[ftp] Add support for the FTP SIZE command

The FTP SIZE command allows us to get the size of a particular file,
as a consequence, we can now show proper transfer progression while
fetching a file using the FTP protocol.

Signed-off-by: Marin Hannache <git@mareo.fr>
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/net/tcp/ftp.c

@@ -1,3 +1,22 @@
+/*
+ * Copyright (C) 2007 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
 #include <stdint.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -34,6 +53,7 @@ enum ftp_state {
 	FTP_USER,
 	FTP_PASS,
 	FTP_TYPE,
+	FTP_SIZE,
 	FTP_PASV,
 	FTP_RETR,
 	FTP_WAIT,
@@ -68,6 +88,8 @@ struct ftp_request {
 	char status_text[5];
 	/** Passive-mode parameters, as text */
 	char passive_text[24]; /* "aaa,bbb,ccc,ddd,eee,fff" */
+	/** File size, as text */
+	char filesize[20];
 };
 
 /**
@@ -157,6 +179,7 @@ static struct ftp_control_string ftp_strings[] = {
 	[FTP_USER]	= { "USER ", ftp_user },
 	[FTP_PASS]	= { "PASS ", ftp_password },
 	[FTP_TYPE]	= { "TYPE I", NULL },
+	[FTP_SIZE]	= { "SIZE ", ftp_uri_path },
 	[FTP_PASV]	= { "PASV", NULL },
 	[FTP_RETR]	= { "RETR ", ftp_uri_path },
 	[FTP_WAIT]	= { NULL, NULL },
@@ -234,6 +257,14 @@ static void ftp_reply ( struct ftp_request *ftp ) {
 	if ( status_major == '1' )
 		return;
 
+	/* If the SIZE command is not supported by the server, we go to
+	 * the next step.
+	 */
+	if ( ( status_major == '5' ) && ( ftp->state == FTP_SIZE ) ) {
+		ftp_next_state ( ftp );
+		return;
+	}
+
 	/* Anything other than success (2xx) or, in the case of a
 	 * repsonse to a "USER" command, a password prompt (3xx), is a
 	 * fatal error.
@@ -245,6 +276,26 @@ static void ftp_reply ( struct ftp_request *ftp ) {
 		return;
 	}
 
+	/* Parse file size */
+	if ( ftp->state == FTP_SIZE ) {
+		size_t filesize;
+		char *endptr;
+
+		/* Parse size */
+		filesize = strtoul ( ftp->filesize, &endptr, 10 );
+		if ( *endptr != '\0' ) {
+			DBGC ( ftp, "FTP %p invalid SIZE \"%s\"\n",
+			       ftp, ftp->filesize );
+			ftp_done ( ftp, -EPROTO );
+			return;
+		}
+
+		/* Use seek() to notify recipient of filesize */
+		DBGC ( ftp, "FTP %p file size is %zd bytes\n", ftp, filesize );
+		xfer_seek ( &ftp->xfer, filesize );
+		xfer_seek ( &ftp->xfer, 0 );
+	}
+
 	/* Open passive connection when we get "PASV" response */
 	if ( ftp->state == FTP_PASV ) {
 		char *ptr = ftp->passive_text;
@@ -295,35 +346,33 @@ static int ftp_control_deliver ( struct ftp_request *ftp,
 	
 	while ( len-- ) {
 		c = *(data++);
-		switch ( c ) {
-		case '\r' :
-		case '\n' :
+		if ( ( c == '\r' ) || ( c == '\n' ) ) {
 			/* End of line: call ftp_reply() to handle
 			 * completed reply.  Avoid calling ftp_reply()
 			 * twice if we receive both \r and \n.
 			 */
-			if ( recvsize == 0 )
+			if ( recvbuf != ftp->status_text )
 				ftp_reply ( ftp );
 			/* Start filling up the status code buffer */
 			recvbuf = ftp->status_text;
 			recvsize = sizeof ( ftp->status_text ) - 1;
-			break;
-		case '(' :
+		} else if ( ( ftp->state == FTP_PASV ) && ( c == '(' ) ) {
 			/* Start filling up the passive parameter buffer */
 			recvbuf = ftp->passive_text;
 			recvsize = sizeof ( ftp->passive_text ) - 1;
-			break;
-		case ')' :
+		} else if ( ( ftp->state == FTP_PASV ) && ( c == ')' ) ) {
 			/* Stop filling the passive parameter buffer */
 			recvsize = 0;
-			break;
-		default :
+		} else if ( ( ftp->state == FTP_SIZE ) && ( c == ' ' ) ) {
+			/* Start filling up the file size buffer */
+			recvbuf = ftp->filesize;
+			recvsize = sizeof ( ftp->filesize ) - 1;
+		} else {
 			/* Fill up buffer if applicable */
 			if ( recvsize > 0 ) {
 				*(recvbuf++) = c;
 				recvsize--;
 			}
-			break;
 		}
 	}