The apasted program
apasted is the server-side program for the apaste package. It expects its stdin and stdout to be connected to the network, having being contacted by an apastec client. It reads a series of files transmitted by the client, stores it on the server, and sends back a slug to the client, i.e. an identifier for the stored files.
Interface
apasted [ -r rtimeout ] [ -w wtimeout ] [ -d rootdir ] [ -p prefix ] [ -n maxfiles ] [ -s maxsize ] [ -S maxtotalsize ]
- apasted reads data on its stdin, expecting the protocol spoken by the apastec client, containing one or more files.
- It creates a subdirectory subdir in its working directory,
and stores the files it receives under it.
- If it only receives one file, it stores it in subdir/index.txt.
- If it receives two or more files, it stores each file file as subdir/file.txt, and creates a subdir/index.html file with hyperlinks to every file in subdir.
- It sends the subdir name back to the client, as a slug.
- It exits 0
Exit codes
- 0
- Success.
- 1
- Protocol error. The client sent incorrectly formatted data.
- 100
- Bad usage. apasted was run in an incorrect way.
- 111
- System call failed. This usually signals an issue with the underlying operating system, or with the network in some way.
Options
- -r rtimeout
- If the client hasn't transmitted all its data within rtimeout milliseconds, give up. The default is 0, meaning infinite: apasted will wait forever for client data if necessary.
- -w wtimeout
- If apasted fails to send the slug to the client within wtimeout milliseconds, give up. The default is 0, meaning infinite: apasted will take as much time as it needs to send its answer.
- -d rootdir
- Switch to rootdir and store files there. The default is apasted's working directory.
- -p prefix
- When sending a slug to the client, prefix subdir with prefix, and append a slash at the end if prefix starts with http. This is useful when apasted writes its files to a web server's document hierarchy, which is the intended case. If prefix is the URL of apasted's base directory, then the slug can directly be used as a URL to access the client's files.
- -n maxfiles
- Accept a maximum of maxfiles files at a time from the client. The default is 0, meaning unlimited: the client can send as many files as it wants and apasted will still store them if it is possible.
- -s maxsize
- Accept a maximum of maxsize bytes for each file. 0 means unlimited: the files can be as big as the client wants, which is not a very good idea. The default is 1 MB.
- -S maxtotalsize
- Accept a maximum of maxtotalsize bytes for a single apaste transaction, all files included. 0 means unlimited: the transaction can be as large as the client wants, which is not a very good idea. The default is 10 MB.
Typical usage
- apasted is meant to be run under a super-server accepting client connections. Run it under inetd or s6-tcpserver for plaintext connections, and under s6-tlsserver for TLS-tunneled connections.
- To publish the data received and stored by apasted, the simplest way is to have a web server running and serving the hierarchy of apasted files. Use the -p option on the apasted command line to make sure the client receives a full URL to its files.
Caveats
- apaste is a push protocol: the client sends data to be stored on
the server. As such, it is very easy to abuse, and caution should be taken when
running an apasted server:
- If possible, have quotas on the filesystem hosting the apasted storage area
- Use the -n option to avoid trivial inode exhaustion attacks
- Use your super-server's options to mitigate client patterns of abuse, log and block the IPs of problematic clients
- Run scripts that regularly delete old subdirs (and their contents) in the apasted storage area.
- Be aware, and warn your users, that a pastebin is a service to the community, and that abusing the service is the best and quickest way to make it go away.
Notes
- apasted will store a file named file as file.txt so that a web server can always serve it as plain text. apaste is not meant to send binary files of an arbitrary MIME type.
- A unique file is stored as slug/index.txt; if apasted is run with -p http://example.com/ then the apaste client, on success, will print http://example.com/slug/. Make sure that your web server can automatically interpret that URL as http://example.com/slug/index.txt.