svn commit: r227083 - stable/8/libexec/tftpd

[Sean Bruno]

Author: sbruno
Date: Fri Nov  4 15:57:38 2011
New Revision: 227083
URL: http://svn.freebsd.org/changeset/base/227083

Log:
  MFC r224536:
  Confirmed behavior of a Cisco 6509 in production.
  
  In the old TFTP server, there was an undocumented behavior where
  the block counter would rollover to 0 if a file larger
  than 65535 blocks was transferred.  With the default block size
  of 512 octets per block, this is a file size of approximately 32 megabytes.
  
  The new TFTP server code would report an error and stop transferring
  the file if a file was larger than 65535 blocks.
  
  This patch restores the old TFTP server's behavior to the new
  TFTP server code.  If a TFTP client transfers a file larger
  than 65535 blocks, and does *not* specify the "rollover" option,
  then automatically rollover the block counter to 0 every time
  we reach 65535 blocks.
  
  This restores interoperability with the FreeBSD 6 TFTP client.
  Without this change, if a FreeBSD 6 TFTP client tried to
  retrieve a file larger than 65535 blocks from a FreeBSD 9 TFTP server,
  the transfer would fail.  The same file could be retrieved successfully
  if the same FreeBSD 6 TFTP client was used against a FreeBSD 6 TFTP server.

Modified:
  stable/8/libexec/tftpd/tftp-transfer.c

Modified: stable/8/libexec/tftpd/tftp-transfer.c
==============================================================================
--- stable/8/libexec/tftpd/tftp-transfer.c	Fri Nov  4 15:34:31 2011	(r227082)
+++ stable/8/libexec/tftpd/tftp-transfer.c	Fri Nov  4 15:57:38 2011	(r227083)
@@ -129,14 +129,16 @@ tftp_send(int peer, uint16_t *block, str
 		(*block)++;
 		if (oldblock > *block) {
 			if (options[OPT_ROLLOVER].o_request == NULL) {
-				tftp_log(LOG_ERR,
-				    "Block rollover but not allowed.");
-				send_error(peer, EBADOP);
-				gettimeofday(&(ts->tstop), NULL);
-				return;
+				/*
+				 * "rollover" option not specified in
+				 * tftp client.  Default to rolling block
+				 * counter to 0.
+				 */
+				*block = 0;
+			} else {
+				*block = atoi(options[OPT_ROLLOVER].o_request);
 			}
 
-			*block = atoi(options[OPT_ROLLOVER].o_request);
 			ts->rollovers++;
 		}
 		gettimeofday(&(ts->tstop), NULL);
@@ -196,14 +198,16 @@ tftp_receive(int peer, uint16_t *block, 
 		(*block)++;
 		if (oldblock > *block) {
 			if (options[OPT_ROLLOVER].o_request == NULL) {
-				tftp_log(LOG_ERR,
-				    "Block rollover but not allowed.");
-				send_error(peer, EBADOP);
-				gettimeofday(&(ts->tstop), NULL);
-				return;
+				/*
+				 * "rollover" option not specified in
+				 * tftp client.  Default to rolling block
+				 * counter to 0.
+				 */
+				*block = 0;
+			} else {
+				*block = atoi(options[OPT_ROLLOVER].o_request);
 			}
 
-			*block = atoi(options[OPT_ROLLOVER].o_request);
 			ts->rollovers++;
 		}