ja-netfilter/README.md

ja-netfilter v1.1.0

A javaagent lib for network filter

Usage

• download from the releases page

• add -javaagent:/absolute/path/to/ja-netfilter.jar argument (Change to your actual path)

  • add as an argument of the java command. eg: java -javaagent:/absolute/path/to/ja-netfilter.jar -jar executable_jar_file.jar
  • some apps support the JVM Options file, you can add as a line of the JVM Options file.
  • WARNING: DO NOT put some unnecessary whitespace characters!

• edit your own rule list config file. The ja-netfilter will look for it in the following order(find one and stop searching):

  • passed as args of -javaagent. eg: -javaagent:/absolute/path/to/ja-netfilter.jar=/home/neo/downloads/janf_config.txt
  • file path in environment variable: JANF_CONFIG
  • file path in java startup property: janf.config. eg: java -Djanf.config="/home/neo/downloads/janf_config.txt"
  • some apps support the JVM Options file, you can add as a line of the JVM Options file. eg: -Djanf.config="/home/neo/downloads/janf_config.txt"
  • file path in the same dir as the ja-netfilter.jar, no need for additional configuration (PREFERRED!)
  • file path in your home directory, named: .janf_config.txt. eg: /home/neo/.janf_config.txt
  • file path in the subdirectory named .config in your home directory. eg: /home/neo/.config/janf_config.txt
  • file path in the subdirectory named .local/etc in your home directory. eg: /home/neo/.local/ect/janf_config.txt
  • file path in the directory named /usr/local/etc. eg: /usr/local/etc/janf_config.txt
  • file path in the directory named /etc. eg: /etc/janf_config.txt

• run your java application and enjoy~

Config file format

[ABC]
# for the specified plugin called "ABC"

[URL]
EQUAL,https://someurl

[DNS]
EQUAL,somedomain

# EQUAL     Use `equals` to compare
# KEYWORD   Use `contains` to compare
# PREFIX    Use `startsWith` to compare
# SUFFIX    Use `endsWith` to compare
# REGEXP    Use regular expressions to match

Debug info

• the ja-netfilter will NOT output debugging information by default
• add environment variable JANF_DEBUG=1 and start to enable it
• or add system property -Djanf.debug=1 to enable it

Plugin system

• for developer:

  • view the scaffold project written for the plug-in system
  • compile your plugin and publish it
  • just use your imagination~

• for user:

  • download the jar file of the plugin
  • put it in the subdirectory called plugins where the ja-netfilter.jar file is located
  • enjoy the new capabilities brought by the plugin