xmppipe: stdio over XMPP ======================== xmppipe redirects stdin/stdout in a shell pipeline to an XMPP MUC (XEP-0045). xmppipe supports flow control using stream management (XEP-0198) and can optionally deal with overload by acting as a circuit breaker or by discarding messages. xmppipe works with line oriented tools like grep, sed and awk by outputting each message as a newline terminated, [percent-encoded](https://en.wikipedia.org/wiki/Percent-encoding) string. xmppipe can be used in shell scripts to quickly write interactive bots for monitoring systems or for sending alerts. Usage ----- xmppipe [*options*] XMPPIPE_USERNAME=me@example.com XMPPIPE_PASSWORD="password" # default name: stdout-*hostname*-*uid* xmpipe xmppipe muc xmppipe muc@example.com Requirements ------------ * [libstrophe](https://github.com/strophe/libstrophe) libstrophe 0.9.2 or later is required for [TLS certificate verification](https://github.com/strophe/libstrophe/issues/100). Build ----- $ make Tests ----- # Install bats: # apt-get install bats # git clone https://github.com/sstephenson/bats.git # or from git make test Sandboxing ---------- xmppipe applies 2 sandboxes: * a permissive "init" sandbox allowing network connections to the XMPP server * once the connection is established, a stricter "stdio" sandbox limits the process to stdio The effectiveness of the sandbox depends on which mechanism is used. By default: * Linux: * init: seccomp(2) * stdio: seccomp(2) * OpenBSD: * init: pledge(2) * stdio: pledge(2) * FreeBSD: * init: setrlimit(2) * stdio: setrlimit(2)/capsicum(4) * other: setrlimit(2) * init: setrlimit(2) * stdio: setrlimit(2) Selecting the sandbox is done at compile time. For example, to use the "rlimit" sandbox: XMPPIPE_SANDBOX=rlimit make If a sandbox is interfering with normal operation, please open an issue. To disable the sandbox, compile using the "null" sandbox: XMPPIPE_SANDBOX=null make Options ------- -u, --username *JID* : XMPP username: takes precedence over environment variable -p, --password *password* : XMPP password: takes precedence over environment variable -r, --resource *resource* : XMPP resource, used as the nickname in the MUC -S, --subject *subject* : XMPP MUC subject -a, --address *address:port* : Specify the IP address and port of the XMPP server -F, --format *text:csv* : stdin is text (default) or colon separated values -d, --discard : Discard stdin when MUC is empty -D, --discard-to-stdout : Discard stdin and print to local stdout -e, --ignore-eof : Ignore stdin EOF -s, --exit-when-empty : Exit when MUC is empty -x, --base64 : Base64 encode/decode data -b, --buffer-size *size* : Size of read buffer -I, --interval *interval* : Request stream management status every interval messages -k, --keepalive *seconds* : Periodically send a keepalive -K, --keepalive-failures *count* : Number of keepalive failures before exiting -P, --poll-delay *ms* : Poll delay -v, --verbose : Increase verbosity --chat : Use one to one chat --no-tls-verify : Disable TLS certificate verification Decoding Percent-Encoded Strings -------------------------------- Using bash: ~~~ shell decode() { printf '%b' "${1//%/\\x}" } ~~~ Examples -------- ### Shell Bot An interactive XMPP bot written in the shell: ~~~ shell #!/bin/bash set -o errexit set -o nounset set -o pipefail trap cleanup EXIT TMPDIR=$(mktemp -d) in="$TMPDIR/stdin" out="$TMPDIR/stdout" mkfifo $in mkfifo $out cleanup() { rm -rf $TMPDIR } decode() { printf '%b' "${1//%/\\x}" } bot() { while IFS=: read -r stanza type from to body; do case "$stanza" in m) ;; p) decode "$stanza:$type:$from:$to" 1>&2 echo 1>&2 continue ;; *) continue ;; esac USER="$(decode ${from#*/})" MSG="$(decode ${body})" case $MSG in *"has set the subject to:"*) ;; "sudo make me a sandwich") echo "$USER: you're a sandwich" ;; sudo*) echo "I'm sorry, $USER. I'm afraid I can't do that." ;; uptime) uptime ;; exit) echo "exiting ..." exit 0 ;; *) echo "$MSG" ;; esac done < $out } bot > $in & xmppipe "$@" <$in >$out ~~~ ### Sending Notifications/Alerts Start `xmppipe` attached to a pipe: ~~~ shell mkfifo /tmp/xmpp xmppipe -o groupchat <> /tmp/xmpp ~~~ Any data written to the pipe will be sent to the groupchat: ~~~ shell echo "test" > /tmp/xmpp df -h > /tmp/mpp git diff > /tmp/xmpp ~~~ ### SSH over XMPP See [examples/ssh-over-xmpp](https://github.com/msantos/xmppipe/blob/master/examples/ssh-over-xmpp): ~~~ shell # Server: has access to the destination SSH server # ssh-over-xmpp server ssh-over-xmpp server sshxmpp 1.2.3.4 22 ## Client: has access to the XMPP server ssh -o ProxyCommand="ssh-over-xmpp client sshxmpp" 127.0.0.1 ~~~ ### Stream Events from Riemann This example will stream events from a query to an XMPP MUC using [Riemann's](https://github.com/riemann/riemann) SSE interface. The events are written to a named pipe to avoid buffering. ~~~ shell mkfifo riemann curl -s --get --data subscribe=true \ --data-urlencode 'query=(service ~= "^example")' \ http://example.com:80/index < /dev/null > riemann & xmppipe --verbose --verbose \ --discard --subject "riemann events" muc < riemann ~~~ ### Desktop Notifications ~~~ shell #!/bin/bash set -o errexit set -o nounset set -o pipefail decode() { printf '%b' "${1//%/\\x}" } MUC="" while getopts ":o:" opt; do case $opt in o) MUC="$OPTARG" ;; *) ;; esac done xmppipe "$@" | while IFS=: read stanza type from to body; do case "$stanza" in m) notify-send "$MUC" "$(decode $body)" ;; *) continue ;; esac done ~~~ ### Mirror a terminal session using script(1) * user ~~~ shell #!/bin/bash MUC=console TMPDIR=$(mktemp -d) FIFO=$TMPDIR/console mkfifo $FIFO stty cols 80 rows 24 (cat $FIFO | xmppipe --resource user -x $MUC) > /dev/null 2> $TMPDIR/stderr & script -q -f $FIFO ~~~ * viewers ~~~ shell #!/bin/bash decode() { printf '%b' "${1//%/\\x}" } stty cols 80 rows 24 xmppipe --resource viewer --base64 console | \ while IFS=: read -r x s f t m; do [ "$m" = "m" ] && decode "$m" done ~~~ ### Mirror a terminal session to a web page Environment Variables --------------------- * XMPPIPE_USERNAME: XMPP jid * XMPPIPE_PASSWORD: XMPP password Format ------ Each message is terminated by a new line. Message fields are separated by ":" and percent encoded. Colon separated valued are accepted as input if the input format type is set to csv (`--format=csv`). ### Presence p::: Input/Output: Both Example: p:available:test@muc.example.com/xmppipe:occupant@example.com/1234 ### Message m:::: Input/Output: Both Example: m:groupchat:test@muc.example.com/mobile:user1@example.com/1234:Hello m:chat:user1@example.com/mobile:user2@example.com:Message%20goes%20here ### Inline Image Inline images will add a hint so clients (notably [Conversations](https://github.com/iNPUTmice/Conversations) will display the image instead of a URL. * type, from and to are optional * message body: the percent escaped URL I:::: Input/Output: Input only Example: I::::https%3A%2F%2Fhttpstatusdogs.com%2Fimg%2F500.jpg ### XEP-0363: HTTP Upload HTTP uploads create an upload slot. The XMPP server will respond with `get` and `put` URLs. The `put` URL can be used to upload the file using, e.g., `curl`. The `get` URL is used by clients for downloading the file. Note: currently xmppipe creates the slot but does not upload the file. The input format is: * type, from and to are optional * message body: percent escaped, pipe separated value * filename * size * optional: MIME type u::::|[|] The output format is: * type, from and to are optional * message body: percent escaped, pipe separated value * get URL * put URL U::::| Example: # $ stat --format="%s" example.png # 16698 u::::example.png%7C16698 # also specify content type u::::example.png%7C16698%7Cimage%2Fpng # server response: slot created U:groupchat:upload.example.com:user@example.com/123:https%3A//example.com/upload/0b9da82fea20a78778cbeddeab0472286cc35ed1/xyEaWFVZv3sv5ay9AGH5qBU02gglZRyUeGbjQg3k/example.png%7chttps%3A//example.com/upload/0b9da82fea20a78778cbeddeab0472286cc35ed1/xyEaWFVZv3sv5ay9AGH5qBU02gglZRyUeGbjQg3k/example.png # to upload the file curl https://example.com/upload/0b9da82fea20a78778cbeddeab0472286cc35ed1/xyEaWFVZv3sv5ay9AGH5qBU02gglZRyUeGbjQg3k/example.png --upload-file example.png Compatibility ------------- Testing is done with ejabberd. Also confirmed to work with: * ejabberd ([creep.im](https://compliance.conversations.im/server/creep.im/)) * prosody ([dismail.de](https://compliance.conversations.im/server/dismail.de/)) * openfire ([jab.im](https://compliance.conversations.im/server/jab.im/)) * tigase ([tigase.im](https://compliance.conversations.im/server/tigase.im/)) * mongooseim License ------- Copyright (c) 2015-2020, Michael Santos Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies. THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. TODO ---- * support [XEP-0384: OMEMO Encryption](https://xmpp.org/extensions/xep-0384.html) * support alternative input modes * "raw" mode: XML input/output * HTTP Upload * support PUT header elements * handle error conditions Questions: * save the maximum file size returned by the server and disallow uploads larger than the value? * xmppipe is "pinned" to the upload server returned in the IQ reply (the "to" field is ignored) * allow other upload servers? * error if different upload server is specified in "u::"?