Support and document SIGHUP for xrdp-sesman

[matt335672]

Fixes #2414

@yxzzx - can you take a look at this please?

[yxzzx]

Isn't it a little bit asymmetric to do the kill with "xrdp-sesman --kill" and the reload with "kill -HUP $MAINPID". I think it would be cleaner to either remove the "--kill" code from sesman or add a "--reload" option to sesman. But that's probably just me being my usual obsessive-compulsive self...

Anyway, I think your commit will be doing the job just fine. Thanks for the fix and the documentation.

[matt335672]

Hi @yxzzx

Thanks for the swift reply.

No - that's a very good point. It absolutely should be consistent. Leave it with me.

[metalefty]

Changes LGTM.

BTW, is the log file reopened after reloading?

[matt335672]

The code for a log restart was added for 2484928 :-

xrdp/common/log.c

Lines 727 to 782 in 4ff968b

	/**
	* Restarts the logging.
	*
	* The logging file is never changed, as it is common in xrdp to share a
	* log file between parents and children. The end result would be
	* confusing for the user.
	*/
	static enum logReturns
	log_restart_from_param(const struct log_config *lc)
	{
	enum logReturns rv = LOG_GENERAL_ERROR;
	if (g_staticLogConfig == NULL)
	{
	log_message(LOG_LEVEL_ALWAYS, "Log not already initialized");
	}
	else if (lc == NULL)
	{
	g_writeln("lc to log_start_from_param is NULL");
	}
	else
	{
	if (g_staticLogConfig->fd >= 0 &&
	g_strcmp(g_staticLogConfig->log_file, lc->log_file) != 0)
	{
	log_message(LOG_LEVEL_WARNING,
	"Unable to change log file name from %s to %s",
	g_staticLogConfig->log_file,
	lc->log_file);
	}
	/* Reconfigure syslog logging, allowing for a program_name change */
	if (g_staticLogConfig->enable_syslog)
	{
	closelog();
	}
	if (lc->enable_syslog)
	{
	openlog(lc->program_name, LOG_CONS | LOG_PID, LOG_DAEMON);
	}
	/* Copy over simple values... */
	#ifdef LOG_ENABLE_THREAD
	g_staticLogConfig->log_lock = lc->log_lock;
	g_staticLogConfig->log_lock_attr = lc->log_lock_attr;
	#endif
	g_staticLogConfig->program_name = lc->program_name;
	g_staticLogConfig->enable_pid = lc->enable_pid;
	g_staticLogConfig->dump_on_start = lc->dump_on_start;
	/* ... and the log levels */
	internal_log_config_copy_levels(g_staticLogConfig, lc);
	rv = LOG_STARTUP_OK;
	}
	return rv;
	}

Since the log file is shared, we never change it, as we've got no way of telling any child processes that the log file has changed. If the user tries to change it we log a warning and carry on using the old one.

That's the current behaviour anyway.

[danielperna84]

Will this also affect #1317 ?

[matt335672]

@danielperna84 - thanks for the heads-up.

As far as I can tell, #1317 isn't actually a problem. More information would be required to figure out exactly what was going on there.