From:
Operating system: All
PHP version: 5.3.8
Package: FTP related
Bug Type: Bug
Bug description:Bug resulting in out of sync ftp responses
Description:
------------
Our servers make several hundred FTP-connections via PHP every day. About
one
out of every thousand connections PHP throws a warning with a
server-response
that is not even related to the executed command.
I've looked into the sourcecode and found a bug in the core of the ftp
extension. This bug appears whenever the ftp-server sends an extra response
that
PHP was not expecting, resulting in the response-buffer permanently running
out
of sync. Because of this, PHP will keep reading the wrong response lines
(and
thus often receiving the wrong ftp status codes) and will report most ftp
commands as failed after this.
Looking at different complaints scatterred across the internet about
receiving
unexpected responses from the PHP FTP extension after receiving 1 warning,
this
bug has been bugging people for quite some time now. Some of the current
ftp-
bugreports are a direct result of this bug.
Bugfix:
Clearing the 'extra' buffer object from the last response, before sending a
new
command.
# diff -urN ftp_old.c ftp.c
--- ftp_old.c 2011-11-01 00:28:05.000000000 +0100
+++ ftp.c 2011-11-01 00:29:29.000000000 +0100
@@ -1122,6 +1122,9 @@
data = ftp->outbuf;
+ /* Clear the extra-lines buffer */
+ ftp->extra = NULL;
+
if (my_send(ftp, ftp->fd, data, size) != size) {
return 0;
}
Test script:
---------------
How to reproduce:
Let the ftp-server send an extra (unexpected) server response, or simulate
one:
diff -urN ftp_old.c ftp.c
--- ftp_old.c 2011-11-01 00:28:05.000000000 +0100
+++ ftp.c 2011-11-01 01:07:34.000000000 +0100
@@ -1294,6 +1294,19 @@
#if HAVE_OPENSSL_EXT
}
#endif
+
+ /* Simulate an extra unexpected server command
+ in this case right after entering passive mode (code 227) */
+ char cmd[] = "200 OK.\n";
+ if (nr_bytes > 0)
+ {
+ if (!strncmp(buf, "227 ", 4))
+ {
+ strcat(ftp->inbuf, cmd);
+ nr_bytes += sizeof(cmd)-1;
+ }
+ }
+
return (nr_bytes);
}
/* }}} */
Expected result:
----------------
Expected result:
A warning.
Actual result:
--------------
Actual result:
A warning, but all commands followed by the last one are running out of
sync/failing. Also the warning thrown shows the wrong server response since
the
buffer is running out of sync.
--
Edit bug report at https://bugs.php.net/bug.php?id=60183&edit=1
--
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Fixed in SVN:
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Fixed in SVN and need be documented:
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Fixed in release:
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Not developer issue:
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Expected behavior:
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Submitted twice:
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register_globals:
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MySQL Configuration Error:
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