res_pjsip_logger: Preserve logging state on reloads.

Currently, reloading res_pjsip will cause logging
to be disabled. This is because logging can also
be controlled via the debug option in pjsip.conf
and this defaults to "no".

To improve this, logging is no longer disabled on
reloads if logging had not been previously
enabled using the debug option from the config.
This ensures that logging enabled from the CLI
will persist through a reload.

ASTERISK-29912 #close

Resolves: #246

UserNote: Issuing "pjsip reload" will no longer disable
logging if it was previously enabled from the CLI.

res/res_pjsip_logger.c

@@ -598,6 +598,19 @@ static char *pjsip_set_logger_pcap(int fd, const char *arg)
 	return CLI_SUCCESS;
 }
 
+enum pjsip_logger_mask {
+	AST_PJSIP_LOGGER_UNSET = 0,
+	AST_PJSIP_LOGGER_NONE = (1 << 0),
+	AST_PJSIP_LOGGER_HOST = (1 << 1),
+	AST_PJSIP_LOGGER_METHOD = (1 << 2),
+	AST_PJSIP_LOGGER_VERBOSE = (1 << 3),
+	AST_PJSIP_LOGGER_PCAP = (1 << 4),
+	AST_PJSIP_LOGGER_ALL = (1 << 5),
+};
+
+static enum pjsip_logger_mask logger_cli_settings = AST_PJSIP_LOGGER_UNSET;
+static enum pjsip_logger_mask logger_config_settings = AST_PJSIP_LOGGER_UNSET;
+
 static char *pjsip_set_logger(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
 {
 	static const char * const method_choices[] = {
@@ -633,22 +646,30 @@ static char *pjsip_set_logger(struct ast_cli_entry *e, int cmd, struct ast_cli_a
 
 	if (a->argc == e->args) {        /* on/off */
 		if (!strcasecmp(what, "on")) {
+			logger_cli_settings |= AST_PJSIP_LOGGER_ALL;
 			return pjsip_enable_logger_all(a->fd);
 		} else if (!strcasecmp(what, "off")) {
+			logger_cli_settings = AST_PJSIP_LOGGER_NONE;
 			return pjsip_disable_logger(a->fd);
 		}
 	} else if (a->argc == e->args + 1) {
 		if (!strcasecmp(what, "host")) {
+			logger_cli_settings |= AST_PJSIP_LOGGER_HOST;
 			return pjsip_enable_logger_host(a->fd, a->argv[e->args], 0);
 		} else if (!strcasecmp(what, "add")) {
+			logger_cli_settings |= AST_PJSIP_LOGGER_HOST;
 			return pjsip_enable_logger_host(a->fd, a->argv[e->args], 1);
 		} else if (!strcasecmp(what, "method")) {
+			logger_cli_settings |= AST_PJSIP_LOGGER_METHOD;
 			return pjsip_enable_logger_method(a->fd, a->argv[e->args], 0);
 		} else if (!strcasecmp(what, "methodadd")) {
+			logger_cli_settings |= AST_PJSIP_LOGGER_METHOD;
 			return pjsip_enable_logger_method(a->fd, a->argv[e->args], 1);
 		} else if (!strcasecmp(what, "verbose")) {
+			logger_cli_settings |= AST_PJSIP_LOGGER_VERBOSE;
 			return pjsip_set_logger_verbose(a->fd, a->argv[e->args]);
 		} else if (!strcasecmp(what, "pcap")) {
+			logger_cli_settings |= AST_PJSIP_LOGGER_PCAP;
 			return pjsip_set_logger_pcap(a->fd, a->argv[e->args]);
 		}
 	}
@@ -664,16 +685,41 @@ static void check_debug(void)
 {
 	RAII_VAR(char *, debug, ast_sip_get_debug(), ast_free);
 
+	/* Got directive to disable debug */
 	if (ast_false(debug)) {
+		/* If the logger was enabled via the CLI instead of through the config file,
+		 * then we shouldn't disable it on a reload.
+		 * Only disable logging if logging isn't enabled via the CLI. */
+		if (logger_cli_settings == AST_PJSIP_LOGGER_NONE || logger_cli_settings == AST_PJSIP_LOGGER_UNSET) {
+			/* Logger not enabled via CLI currently so good to go ahead and disable. */
 			pjsip_disable_logger(-1);
+		} else {
+			ast_debug(3, "Leaving logger enabled since logging settings overridden using CLI\n");
+		}
+		logger_config_settings = AST_PJSIP_LOGGER_NONE;
 		return;
 	}
 
+	/* Got directive to enable debug */
 	if (ast_true(debug)) {
+		if (logger_cli_settings != AST_PJSIP_LOGGER_UNSET) {
+			/* Logging was modified using the CLI command,
+			 * and this overrides the default from the config. */
+			ast_debug(3, "Leaving logger alone since logging has been overridden using CLI\n");
+			return;
+		}
+		/* If logger already enabled via config, then nothing has changed. */
+		if (!(logger_config_settings & AST_PJSIP_LOGGER_ALL)) {
+			/* Logging was not previously enabled via config,
+			 * but has been enabled via CLI. */
+			logger_config_settings |= AST_PJSIP_LOGGER_ALL;
 			pjsip_enable_logger_all(-1);
+		}
 		return;
 	}
 
+	/* Enabling debug, only for specific host */
+	logger_config_settings = AST_PJSIP_LOGGER_HOST;
 	if (pjsip_enable_logger_host(-1, debug, 0) != CLI_SUCCESS) {
 		ast_log(LOG_WARNING, "Could not resolve host %s for debug "
 			"logging\n", debug);