Logging - neutrinolabs/xrdp GitHub Wiki
xrdp uses the following macros to emit log messages:
LOG : Logging macro for messages that are for a system administrator to configure and run xrdp on their machine.
LOG_DEVEL : Logging macro for messages that are for an xrdp developer to understand and debug xrdp code.
LOG_DEVEL_HEXDUMP : Logging macro for logging the contents of a byte array using a hex dump format.
Note: LOG, LOG_DEVEL, and LOG_DEVEL_HEXDUMP add the source code file name, line number, and function name as a prefix to the log message when XRDP is compiled with XRDP_DEBUG defined.
Note: LOG_DEVEL and LOG_DEVEL_HEXDUMP only emit log messages when xrdp is compiled with XRDP_DEBUG defined.
The logging macros above should be used instead of the log_message, log_message_with_location, and log_hexdump_with_location functions to ensure consistency of the logging features for all log messages.
For more details see the code of the logging macros
| Level | Purpose |
|---|---|
| ERROR | for describing non-recoverable error states in a request or method Note: all errors which results in a session disconnection should be logged with LOG(ERROR,) to ensure that user provided error reports contain the error messages. |
| WARNING | for describing recoverable error states in a request or method |
| INFO | for low verbosity and high level descriptions of normal operations |
| DEBUG | for medium verbosity and low level descriptions of normal operations |
| TRACE | for high verbosity and low level descriptions of normal operations (eg. method or wire tracing) |
xrdp supports logging to the following outputs:
- console
- syslog
- log file
The logging outputs are configured independently for xrdp, xrdp-sesman, xrdp-chansrv in xrdp.ini and sesman.ini respectively, and documented in the xrdp.ini.5 and sesman.ini.5 man pages.
The console output is only usable when xrdp is run with --no-daemon. This is because when xrdp is run as a daemon then stdout and stderr are redirected to /dev/null.
| Process Name | Default Log File | Multiplicity |
|---|---|---|
| xrdp | xrdp.log | 1 per server |
| xrdp-sesman | xrdp-sesman.log | 1 per server |
| xrdp-chansrv | xrdp-chansrv.%d.log | 1 per user display |
The directories containing the log files are OS dependent and can be found in the xrdp.ini man pages.
The xrdp and xrdp-sesman processes fork upon receiving connections and runs as multiple process. Therefore the log file is opened using O_APPEND to allow the multiple processes to write to the same file without corrupting the log messages.