SYNOPSIS

xmppipe [options] [jid]

DESCRIPTION

xmppipe - stdio over XMPP

xmppipe redirects stdin/stdout in a shell pipeline to an XMPP MUC (XEP-0045) or a one to one chat:

• supports flow control using stream management (XEP-0198)
• optionally deals with overload by acting as a circuit breaker or by discarding messages
• works with line oriented tools like grep, sed and awk by outputting each message as a newline terminated, percent-encoded 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

  libstrophe 0.9.2 or later is required for TLS certificate verification.

BUILD

$ make

Tests

# Install bats:
# apt-get install bats
# git clone https://github.com/sstephenson/bats.git # or from git
make test

PROCESS RESTRICTIONS

xmppipe restricts process operations at 2 points:

• a permissive "init" sandbox allowing network connections to the XMPP server

• once the connection is established, a stricter "stdio" sandbox limits the process to I/O operations

The effectiveness of the process restrictions depend 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 which process restrictions are enforced is done at compile time. For example, to use the "rlimit" process restrictions:

RESTRICT_PROCESS=rlimit make

If the process restrictions are interfering with normal operation, please open an issue. To disable all process restrictions, compile using the "null" sandbox:

RESTRICT_PROCESS=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

-V, --version

Display version

--chat

Use one to one chat

--no-tls-verify

Disable TLS certificate verification

ENVIRONMENT VARIABLES

XMPPIPE_USERNAME

XMPP jid

XMPPIPE_PASSWORD

XMPP password

DECODING PERCENT-ENCODED STRINGS

Using bash:

decode() {
  printf '%b' "${1//%/\\x}"
}

EXAMPLES

Shell Bot

An interactive XMPP bot written in the shell:

#!/bin/bash

set -o errexit
set -o nounset
set -o pipefail

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
}

coproc bot
xmppipe "$@" <&"${COPROC[0]}" >&"${COPROC[1]}"

Sending Notifications/Alerts

Start xmppipe attached to a pipe:

mkfifo /tmp/xmpp

xmppipe -o groupchat <>/tmp/xmpp

Any data written to the pipe will be sent to the groupchat:

echo "test" >/tmp/xmpp

df -h >/tmp/xmpp

git diff >/tmp/xmpp

SSH over XMPP

See examples/ssh-over-xmpp:

# Server: has access to the destination SSH server
# ssh-over-xmpp server <conference> <IP address> <port>
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 SSE interface. The events are written to a named pipe to avoid buffering.

coproc curl -s --get --data subscribe=true \
  --data-urlencode 'query=(service ~= "^example")' \
  http://example.com:80/index </dev/null
xmppipe --verbose --verbose \
  --discard --subject "riemann events" muc <&"${COPROC[0]}"

Desktop Notifications

#!/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

#!/bin/bash

MUC=console

TMPDIR=$(mktemp -d)
FIFO=$TMPDIR/console
mkfifo "$FIFO"

stty cols 80 rows 24
xmppipe --resource user -x $MUC < "$FIFO" >/dev/null 2>"$TMPDIR/stderr" &
script -q -f "$FIFO"

• viewers

#!/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

Image Upload

Upload an image using HTTP Upload (XEP-0363) then display it inline.

See examples/image-upload:

image-upload -o groupchat

# file must be in the same working directory as image-upload
echo "upload::::example.png" >/tmp/image_upload/stdin

FORMAT

Each message is terminated by a new line. Message fields are separated by ":" and percent encoded.

Colon separated values are accepted as input if the input format type is set to csv (--format=csv).

Presence

p:<available|unavailable>:<to jid>:<from jid>

Input/Output

Both

Example

p:available:test@muc.example.com/xmppipe:occupant@example.com/1234

Message

m:<chat|groupchat|normal|headline>:<from jid>:<to jid>:<message body>

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) will display the image instead of a URL.

• type, from and to are optional
• message body: the percent escaped URL

I:<chat|groupchat|normal|headline>:<from jid>:<to jid>:<url>

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: xmppipe creates the upload slot. Another utility, such as curl, can be used to 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:<chat|groupchat|normal|headline>:<from jid>:<to jid>:<filename>|<size (bytes)>[|<content-type>]

The output format is:

• type, from and to are optional
• message body: percent escaped, pipe separated value
  • get URL
  • put URL

U:<chat|groupchat|normal|headline>:<from jid>:<to jid>:<get URL>|<put URL>

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)
• prosody (dismail.de)
• openfire (jab.im)
• tigase (tigase.im)
• mongooseim

LICENSE

Copyright (c) 2015-2023, Michael Santos michael.santos@gmail.com

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

• support alternative input modes

  • "raw" mode: XML input/output

• HTTP Upload

  • support PUT header elements
  • handle error conditions