[horde] VFS SSH2 download problem

[Steffen]

On Wed, 9 Oct 2013, Jan Schneider wrote:

> Zitat von Steffen <skhorde at smail.inf.fh-bonn-rhein-sieg.de>:
>
>> Hi,
>> 
>> I've configured Gollem to use the SSH2 backend, with
>> 
>> $backends['ssh2']['disabled'] = false;
>> $backends['ssh2']['name'] = <host>;
>> $backends['ssh2']['hordeauth'] = 'full';
>> $backends['ssh2']['params']['hostspec'] = <host>;
>> $backends['ssh2']['params']['timeout'] = 20;
>> 
>> $backends['ssh2']['home'] = '/';
>> $backends['ssh2']['params']['vfsroot'] =
>>  '/home/'.$GLOBALS['registry']->getAuth();
>> 
>> All operations seems to work, except "download", "edit" and the like.
>> If I leave the parameters home and vfsroot unconfigured, the problem 
>> remains.
>> 
>> When I try to download a file, Horde Vfs Ssh2 readStream() is called, the 
>> generated URL looks OK: ssh2.sftp://<user>:<pwd>@<host>:22/<path>//<file>
>> 
>> but the Apache process surfing my request allocates 100% CPU and endlessly 
>> calls recvfrom/sendto syscalls with data actually. The file descriptor of 
>> the syscalls is the SSH connection.
>> 
>> If I assemble a test PHP script like this:
>> 
>> $fp = fopen('ssh2.sftp://URL', 'r'); // The URL is a Copy'n'Paste from
>> 	// the log generated by:
>> 	// Horde::log("Vfs::Ssh2::fopen(".$this->_wrap($this->_getPath($path, 
>> $name)).")", 'ERR');
>> 
>> while ($line = fgets($fp, 100)) {
>> 	echo $line."<br />";
>> }
>> fclose($fp);
>> 
>> I get the file successfully.
>> 
>> If I comment out readStream() in /usr/share/php/Horde/Vfs/Ssh2.php to force 
>> the use of readFile(), I can download files successfully.
>> 
>> Can I do something to debug this issue further?
>
> You can track this further down in Gollem_Application::download().

The problem is in /var/www/horde/services/download/index.php, the loop to 
read the file:

if (is_resource($res['data'])) {
     rewind($res['data']);
     while (!feof($res['data'])) {
         echo fread($res['data'], 8192);
     }
     fclose($res['data']);

seems to hit this bug (or something similiar) 
https://bugs.php.net/bug.php?id=59138, I use Debian Squeeze with packaged 
libssh2-php 0.11.0-2.1. feof() never returns true.

fgets() works, as shown in my sample script, e.g.:

while ($line = fgets($fp, 100)) {
  	echo $line."<br />";
}
if(feof($fp)) {
 	echo "EOF\n";
} else {
 	echo "NO EOF!!!\n";
}

triggers "no eof", but stops eventually.

I upgraded the ssh2 extension with

pecl install -a "channel://pecl.php.net/ssh2-0.12"

, because there is no newer package for Squeeze. Now the 
while(feof($res['data'])) loop terminates.

Maybe you add a check & warning about the version number of the ssh2 
extension to test.php or something?

Kind regards,

-- 
Steffen