1pure-uploadscript(8) Pure-FTPd pure-uploadscript(8)
2
3
4
6 pure-uploadscript - Automatically run an external program after a suc‐
7 cessful upload
8
10 pure-uploadscript [-p </path/to/pidfile>] [-B] [-g <gid>] [-h] -r <pro‐
11 gram to run> [-u <uid>]
12
14 If Pure-FTPd is compiled with --with-uploadscript (default in binary
15 distributions), and if the -o (or --uploadscript) is passed to the
16 server, a named pipe called /var/run/pure-ftpd.upload.pipe is created.
17 You will also notice an important file called
18 /var/run/pure-ftpd.upload.lock, used for locking.
19 After a successful upload, the file name is written to the pipe.
20 pure-uploadscript reads this pipe to automatically run any program or
21 script to process the newly uploaded file.
22
24 -B Daemonize the process and fork it in background.
25
26 -g <gid>
27 Switch the group ID to <gid>.
28
29 -h or --help
30 Display available options.
31
32 -r <program to run>
33 Tell what program/script to run. It has to be an absolute file‐
34 name, the PATH environment variable is ignored. The first argu‐
35 ment of that program will be the unquoted name of the newly
36 uploaded file. Environment variables aren't cleared. So don't
37 put sensitive data in them before calling pure-uploadscript if
38 you switch uid.
39
40 -u <uid>
41 Switch the user ID to <uid>.
42
44 When the upload script is run, the name of the newly uploaded file is
45 the first argument passed to the script (referenced as $1 by most
46 shells) . Some environment variables are also filled by useful info
47 about the file. UPLOAD_SIZE The size of the file, in bytes.
48 UPLOAD_PERMS The permissions, as an octal integer. UPLOAD_UID The
49 numerical UID of the owner. UPLOAD_GID The numerical GID of the owner.
50 UPLOAD_USER The login of the owner. UPLOAD_GROUP The group name the
51 files belongs to. UPLOAD_VUSER The full user name, or the virtual user
52 name (127 chars max) .
53
55 /var/run/pure-ftpd.upload.pipe /var/run/pure-ftpd.upload.lock
56 /var/run/pure-uploadscript.pid
57
59 pure-ftpd and pure-uploadscript are trying to limit security implica‐
60 tions of such a feature.
61
62 - The pipe can only be created and opened by root. It must have perms
63 600, with uid 0, or it will be ignored.
64
65 - The argument passed to an external program/script is always an exact
66 absolute path name. It doesn't get fooled by chroot()ed environments,
67 and by absolute or relative paths added to the STOR command.
68
69 - UID and GID are set just after parsing command-line options, and
70 pure-uploadscript never gets back supervisor privileges.
71
72 - Descriptors to the pipe are never passed to external pro‐
73 grams/scripts. So when UID switched, the target user can't mess the
74 pipe.
75
76 - Only regular files are processed, control characters are rejected,
77 and a header+footer avoid partial file names.
78
79 - Two external programs/scripts can't run at the same time. Uploads are
80 always processed sequentially, in chronological order. This is to avoid
81 denial-of-services by issuing a lot of simultaneous STOR commands in
82 order to launch a fork bomb on the server. For this reason, your pro‐
83 grams shouldn't take a long time to complete (but they can run them‐
84 selves in background) .
85
87 A sample script could be :
88
89 #! /bin/sh
90 echo "$1 uploaded" | /usr/bin/mutt -s "New upload : $1" \ ftpad‐
91 min@dom.ai.n
92
93 Never forget to quote ("variable") all variables in all your shell
94 scripts to avoid security flaws.
95
96
98 Frank DENIS <j at pureftpd dot org>
99
100
102 ftp(1), pure-ftpd(8) pure-ftpwho(8) pure-mrtginfo(8) pure-upload‐
103 script(8) pure-statsdecode(8) pure-pw(8) pure-quotacheck(8) pure-
104 authd(8)
105
106 RFC 959, RFC 2228, RFC 2389 and RFC 2428.
107
108
109
110Pure-FTPd team 1.0.32 pure-uploadscript(8)