firebase-upstream-server is an implementation of the Firebase XMPP Connection Server protocol in C.
It connects to the FCM XMPP servers using a configuration file (--conf <file>), and sends line-delimited JSON to stdout.
Informational, debug, and error messages are sent to stderr.
There are command line options available for alternative JSON-streaming formats:
- application/json-seq (
--seq) - length-prefixed (
--len-prefixed) - concatenated (
--concat) - NUL-terminated (
--null,-Z)
It is currently minimally functional.
- Supports simultaneous connections to multiple servers using multiple accounts.
- Connection draining support using threading (untested).
- Automatic reconnection using exponential back-off (128 second maximum between retries).
From the src directory, run the following commands (other C compilers are available):
gcc -c config-parse.c
gcc -c firebase-upstream-server.c
gcc -o firebase-upstream-server firebase-upstream-server.o config-parse.o -lconfig -lssl -lcrypto -lstrophe -ljson-c -lpthread
firebase-upstream-server requires:
See conf/xmpp.conf.example for an example configuration file.