emissary provides a command to multiplex TCP services on the same port, and route connections to different upstream addresses based on their starting bytes.
Upstreams are configured through upstream rules, which are a simple regexp/remote address pair.
$ go get github.com/darvid/emissaryThe latest releases can be downloaded from Github.
$ git clone https://github.com/darvid/emissary.git
$ cd emissary
# Requires Glide to be installed - https://glide.sh/
$ glide install
$ make build# Forward all HTTP GET requests to httpbin.org
$ emissary -bind localhost:1080 -upstream '/^GET/:httpbin.org:80'
# Forward SOCKS5 traffic to a local SOCKS5 server
$ emissary -bind localhost:1080 -upstream '/^\x05/:localhost:1081'Any number of upstreams may be chained together.
Usage of emissary:
-alsologtostderr
log to standard error as well as files
-bind string
bind address (default "localhost:1080")
-buffersize int
buffer size for first read (default 4096)
-log_backtrace_at value
when logging hits line file:N, emit a stack trace (default :0)
-log_dir string
If non-empty, write log files in this directory
-logtostderr
log to standard error instead of files
-stderrthreshold value
logs at or above this threshold go to stderr
-upstream value
list of upstream rules (default [])
-v value
log level for V logs
-version
show version
-vmodule value
comma-separated list of pattern=N settings for file-filtered logging
A few projects exist that provide TCP service muxing. The ones mentioned below are libraries which require writing custom applications or scripts, which may be preferential to some, depending on the use case.