pure-uploadscript
pure-uploadscript(8) Pure-FTPd pure-uploadscript(8)
NAME
pure-uploadscript - Automatically run an external program after a suc-
cessful upload
SYNTAX
pure-uploadscript [-p </path/to/pidfile>] [-B] [-g <gid>] [-h] -r
<program to run> [-u <uid>]
DESCRIPTION
If Pure-FTPd is compiled with --with-uploadscript (default in binary
distributions), and if the -o (or --uploadscript) is passed to the
server, a named pipe called /var/run/pure-ftpd.upload.pipe is created.
You will also notice an important file called
/var/run/pure-ftpd.upload.lock, used for locking.
After a successful upload, the file name is written to the pipe.
pure-uploadscript reads this pipe to automatically run any program or
script to process the newly uploaded file.
OPTIONS
-B Daemonize the process and fork it in background.
-g <gid>
Switch the group ID to <gid>.
-h or --help
Display available options.
-r <program to run>
Tell what program/script to run. It has to be an absolute file-
name, the PATH environment variable is ignored. The first
argument of that program will be the unquoted name of the newly
uploaded file. Environment variables aren’t cleared. So don’t
put sensitive data in them before calling pure-uploadscript if
you switch uid.
-u <uid>
Switch the user ID to <uid>.
ENVIRONMENT
When the upload script is run, the name of the newly uploaded file is
the first argument passed to the script (referenced as $1 by most
shells) . Some environment variables are also filled by useful info
about the file. UPLOAD_SIZE The size of the file, in bytes.
UPLOAD_PERMS The permissions, as an octal integer. UPLOAD_UID The
numerical UID of the owner. UPLOAD_GID The numerical GID of the
owner. UPLOAD_USER The login of the owner. UPLOAD_GROUP The group
name the files belongs to. UPLOAD_VUSER The full user name, or the
virtual user name (127 chars max) .
FILES
/var/run/pure-ftpd.upload.pipe /var/run/pure-ftpd.upload.lock
/var/run/pure-uploadscript.pid
SECURITY
pure-ftpd and pure-uploadscript are trying to limit security implica-
tions of such a feature.
- The pipe can only be created and opened by root. It must have perms
600, with uid 0, or it will be ignored.
- The argument passed to an external program/script is always an exact
absolute path name. It doesn’t get fooled by chroot()ed environments,
and by absolute or relative paths added to the STOR command.
- UID and GID are set just after parsing command-line options, and
pure-uploadscript never gets back supervisor privileges.
- Descriptors to the pipe are never passed to external pro-
grams/scripts. So when UID switched, the target user can’t mess the
pipe.
- Only regular files are processed, control characters are rejected,
and a header+footer avoid partial file names.
- Two external programs/scripts can’t run at the same time. Uploads
are always processed sequentially, in chronological order. This is to
avoid denial-of-services by issuing a lot of simultaneous STOR com-
mands in order to launch a fork bomb on the server. For this reason,
your programs shouldn’t take a long time to complete (but they can run
themselves in background) .
EXAMPLES
A sample script could be :
#! /bin/sh
echo "$1 uploaded" | /usr/bin/mutt -s "New upload : $1" \ ftpad-
min@dom.ai.n
Never forget to quote ("variable") all variables in all your shell
scripts to avoid security flaws.
AUTHORS
Frank DENIS <j@pureftpd.org>
SEE ALSO
ftp(1), pure-ftpd(8) pure-ftpwho(8) pure-mrtginfo(8) pure-upload-
script(8) pure-statsdecode(8) pure-pw(8) pure-quotacheck(8) pure-
authd(8)
RFC 959, RFC 2228, RFC 2389 and RFC 2428.
Pure-FTPd team 1.0.2 pure-uploadscript(8)
