Bug 1236

Summary:

SCP inappropriate truncate error when copying to FIFO file

Product:

Portable OpenSSH

Reporter:

Tom Wood <wood>

Component:

scp

Assignee:

Damien Miller <djm>

Status:

CLOSED FIXED

Severity:

normal

Priority:

Version:

4.3p2

Hardware:

ix86

OS:

All

Bug Depends on:

Bug Blocks:

1289

Attachments:

Description	Flags
Add test for FIFO file in scp.c prior to truncate attempt.	none
Truncate only for regular files that already existed	none

Description Tom Wood 2006-09-25 11:43:50 AEST

This is an obscure error, but one that I have encountered in a real world application.
When you use scp to copy a file to a remote FIFO file,
the internal function call to ftruncate() has to fail, 
since a FIFO cannot be
truncated to the size of the original file. This results in
a reported error at the command line, even though the data actually
copies as commanded.

Example:
------------------------------------------------------
#scp -B -q afile auser@aserver.com:/tmp/fifofile_input

scp: /tmp/fifofile_input: truncate: Invalid argument
----------------------------------------------
This results in the contents of the file 'afile' being copied
into the remote fifo, but the error is reported and
the exit status is also set to 1.

Suggested fix:
One must add a file status check that the destination file is not
a FIFO file before trying the truncate call (line 994 in unpatched 4.3p2 scp.c).

Comment 1 Tom Wood 2006-09-25 11:46:35 AEST

Created attachment 1189 [details]
Add test for FIFO file in scp.c prior to truncate attempt.

Comment 2 Damien Miller 2007-06-12 21:26:30 AEST

Created attachment 1304 [details]
Truncate only for regular files that already existed

I think this patch is a little better - it will skip the truncate if the file did not already exist or if the target is anything but a regular file.

Comment 3 Tom Wood 2007-06-13 01:20:02 AEST

Damien,
   Your fix to this problem

    "if (wrerr == NO && (!exists || S_ISREG(stb.st_mode)) &&
		    ftruncate(ofd, size) != 0) {"

 looks like it will work just fine with a FIFO file target.This logic
 restricts the ftruncate test much more than my fix. As lonk as
 thats appropriate for all mode types, I agrre it is the right thing to 
 do.
 

Thanks
Tom

Comment 4 Damien Miller 2007-06-13 10:21:12 AEST

Fix applied, this will be in OpenSSH 4.7 - thanks!

Comment 5 Damien Miller 2008-04-04 09:56:18 AEDT

Close resolved bugs after release.