logger: Add channel-based filtering.

This adds the ability to filter console
logging by channel or groups of channels.
This can be useful on busy systems where
an administrator would like to analyze certain
calls in detail. A dialplan function is also
included for the purpose of assigning a channel
to a group (e.g. by tenant, or some other metric).

ASTERISK-30483 #close

Resolves: #242

UserNote: The console log can now be filtered by
channels or groups of channels, using the
logger filter CLI commands.

main/logger.c

@@ -176,6 +176,7 @@ struct logmsg {
 	int line;
 	int lwp;
 	ast_callid callid;
+	unsigned int hidecli:1;		/*!< Whether to suppress log message from CLI output (but log normally to other log channels */
 	AST_DECLARE_STRING_FIELDS(
 		AST_STRING_FIELD(date);
 		AST_STRING_FIELD(file);
@@ -1645,6 +1646,271 @@ static char *handle_logger_remove_channel(struct ast_cli_entry *e, int cmd, stru
 	}
 }
 
+/* Call ID filtering */
+
+AST_THREADSTORAGE(callid_group_name);
+
+/*! \brief map call ID to group */
+struct chan_group_lock {
+	AST_RWLIST_ENTRY(chan_group_lock) entry;
+	char name[0];
+};
+
+AST_RWLIST_HEAD_STATIC(chan_group_lock_list, chan_group_lock);
+
+static int callid_filtering = 0;
+
+static const char *get_callid_group(void)
+{
+	char **callid_group;
+	callid_group = ast_threadstorage_get(&callid_group_name, sizeof(*callid_group));
+	return callid_group ? *callid_group : NULL;
+}
+
+static int callid_set_chanloggroup(const char *group)
+{
+	/* Use threadstorage for constant time access, rather than a linked list */
+	ast_callid callid;
+	char **callid_group;
+
+	callid = ast_read_threadstorage_callid();
+	if (!callid) {
+		/* Should never be called on non-PBX threads */
+		ast_assert(0);
+		return -1;
+	}
+
+	callid_group = ast_threadstorage_get(&callid_group_name, sizeof(*callid_group));
+
+	if (!group) {
+		/* Remove from list */
+		if (!*callid_group) {
+			return 0; /* Wasn't in any group to begin with */
+		}
+		ast_free(*callid_group);
+		return 0; /* Set Call ID group for the first time */
+	}
+	/* Existing group */
+	ast_free(*callid_group);
+	*callid_group = ast_strdup(group);
+	if (!*callid_group) {
+		return -1;
+	}
+	return 0; /* Set Call ID group for the first time */
+}
+
+static int callid_group_remove_filters(void)
+{
+	int i = 0;
+	struct chan_group_lock *cgl;
+
+	AST_RWLIST_WRLOCK(&chan_group_lock_list);
+	while ((cgl = AST_RWLIST_REMOVE_HEAD(&chan_group_lock_list, entry))) {
+		ast_free(cgl);
+		i++;
+	}
+	callid_filtering = 0;
+	AST_RWLIST_UNLOCK(&chan_group_lock_list);
+	return i;
+}
+
+static int callid_group_set_filter(const char *group, int enabled)
+{
+	struct chan_group_lock *cgl;
+
+	AST_RWLIST_WRLOCK(&chan_group_lock_list);
+	AST_RWLIST_TRAVERSE_SAFE_BEGIN(&chan_group_lock_list, cgl, entry) {
+		if (!strcmp(group, cgl->name)) {
+			if (!enabled) {
+				AST_RWLIST_REMOVE_CURRENT(entry);
+				ast_free(cgl);
+			}
+			break;
+		}
+	}
+	AST_RWLIST_TRAVERSE_SAFE_END;
+
+	if (!enabled) {
+		if (AST_LIST_EMPTY(&chan_group_lock_list)) {
+			callid_filtering = 0;
+		}
+		AST_RWLIST_UNLOCK(&chan_group_lock_list);
+		return 0;
+	}
+
+	if (!cgl) {
+		cgl = ast_calloc(1, sizeof(*cgl) + strlen(group) + 1);
+		if (!cgl) {
+			AST_RWLIST_UNLOCK(&chan_group_lock_list);
+			return -1;
+		}
+		strcpy(cgl->name, group); /* Safe */
+		AST_RWLIST_INSERT_HEAD(&chan_group_lock_list, cgl, entry);
+	} /* else, already existed, and was already enabled, no change */
+	callid_filtering = 1;
+	AST_RWLIST_UNLOCK(&chan_group_lock_list);
+	return 0;
+}
+
+static int callid_logging_enabled(void)
+{
+	struct chan_group_lock *cgl;
+	const char *callidgroup;
+
+	if (!callid_filtering) {
+		return 1; /* Everything enabled by default, if no filtering */
+	}
+
+	callidgroup = get_callid_group();
+	if (!callidgroup) {
+		return 0; /* Filtering, but no call group, not enabled */
+	}
+
+	AST_RWLIST_RDLOCK(&chan_group_lock_list);
+	AST_RWLIST_TRAVERSE(&chan_group_lock_list, cgl, entry) {
+		if (!strcmp(callidgroup, cgl->name)) {
+			break;
+		}
+	}
+	AST_RWLIST_UNLOCK(&chan_group_lock_list);
+	return cgl ? 1 : 0; /* If found, enabled, otherwise not */
+}
+
+/*** DOCUMENTATION
+	<function name="LOG_GROUP" language="en_US">
+		<synopsis>
+			Set the channel group name for log filtering on this channel
+		</synopsis>
+		<syntax>
+			<parameter name="group" required="false">
+				<para>Channel log group name. Leave empty to remove any existing group membership.</para>
+				<para>You can use any arbitrary alphanumeric name that can then be used by the
+				"logger filter changroup" CLI command to filter dialplan output by group name.</para>
+			</parameter>
+		</syntax>
+		<description>
+			<para>Assign a channel to a group for log filtering.</para>
+			<para>Because this application can result in dialplan execution logs
+			being suppressed (or unsuppressed) from the CLI if filtering is active,
+			it is recommended to call this as soon as possible when dialplan execution begins.</para>
+			<para>Calling this multiple times will replace any previous group assignment.</para>
+			<example title="Associate channel with group test">
+			exten => s,1,Set(LOG_GROUP()=test)
+				same => n,NoOp() ; if a logging call ID group filter name is enabled but test is not included, you will not see this
+			</example>
+			<example title="Associate channel with group important">
+			exten => s,1,Set(LOG_GROUP()=important)
+				same => n,Set(foo=bar) ; do some important things to show on the CLI (assuming it is filtered with important enabled)
+				same => n,Set(LOG_GROUP()=) ; remove from group important to stop showing execution on the CLI
+				same => n,Wait(5) ; do some unimportant stuff
+			</example>
+		</description>
+		<see-also>
+			<ref type="application">Log</ref>
+		</see-also>
+	</function>
+ ***/
+
+static int log_group_write(struct ast_channel *chan, const char *cmd, char *data, const char *value)
+{
+	int res = callid_set_chanloggroup(value);
+	if (res) {
+		ast_log(LOG_ERROR, "Failed to set channel log group for %s\n", ast_channel_name(chan));
+		return -1;
+	}
+	return 0;
+}
+
+static struct ast_custom_function log_group_function = {
+	.name = "LOG_GROUP",
+	.write = log_group_write,
+};
+
+static char *handle_logger_chanloggroup_filter(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
+{
+	int enabled;
+
+	switch (cmd) {
+	case CLI_INIT:
+		e->command = "logger filter changroup";
+		e->usage =
+			"Usage: logger filter changroup <group> {on|off}\n"
+			"       Add or remove channel groups from log filtering.\n"
+			"       If filtering is active, only channels assigned\n"
+			"       to a group that has been enabled using this command\n"
+			"       will have execution shown in the CLI.\n";
+		return NULL;
+	case CLI_GENERATE:
+		return NULL;
+	}
+
+	if (a->argc < 5) {
+		return CLI_SHOWUSAGE;
+	}
+
+	enabled = ast_true(a->argv[4]) ? 1 : 0;
+	if (callid_group_set_filter(a->argv[3], enabled)) {
+		ast_cli(a->fd, "Failed to set channel group filter for group %s\n", a->argv[3]);
+		return CLI_FAILURE;
+	}
+
+	ast_cli(a->fd, "Logging of channel group '%s' is now %s\n", a->argv[3], enabled ? "enabled" : "disabled");
+	return CLI_SUCCESS;
+}
+
+static char *handle_logger_filter_show(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
+{
+	int i = 0;
+	struct chan_group_lock *cgl;
+
+	switch (cmd) {
+	case CLI_INIT:
+		e->command = "logger filter show";
+		e->usage =
+			"Usage: logger filter show\n"
+			"       Show current logger filtering settings.\n";
+		return NULL;
+	case CLI_GENERATE:
+		return NULL;
+	}
+
+	AST_RWLIST_RDLOCK(&chan_group_lock_list);
+	AST_RWLIST_TRAVERSE(&chan_group_lock_list, cgl, entry) {
+		ast_cli(a->fd, "%3d %-32s\n", ++i, cgl->name);
+	}
+	AST_RWLIST_UNLOCK(&chan_group_lock_list);
+
+	if (i) {
+		ast_cli(a->fd, "%d channel group%s currently enabled\n", i, ESS(i));
+	} else {
+		ast_cli(a->fd, "No filtering currently active\n");
+	}
+	return CLI_SUCCESS;
+}
+
+static char *handle_logger_filter_reset(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
+{
+	int removed;
+
+	switch (cmd) {
+	case CLI_INIT:
+		e->command = "logger filter reset";
+		e->usage =
+			"Usage: logger filter reset\n"
+			"       Reset the logger filter.\n"
+			"       This removes any channel groups from filtering\n"
+			"       (all channel execution will be shown)\n";
+		return NULL;
+	case CLI_GENERATE:
+		return NULL;
+	}
+
+	removed = callid_group_remove_filters();
+
+	ast_cli(a->fd, "Log filtering has been reset (%d filter%s removed)\n", removed, ESS(removed));
+	return CLI_SUCCESS;
+}
+
 static struct ast_cli_entry cli_logger[] = {
 	AST_CLI_DEFINE(handle_logger_show_channels, "List configured log channels"),
 	AST_CLI_DEFINE(handle_logger_show_levels, "List configured log levels"),
@@ -1653,6 +1919,9 @@ static struct ast_cli_entry cli_logger[] = {
 	AST_CLI_DEFINE(handle_logger_set_level, "Enables/Disables a specific logging level for this console"),
 	AST_CLI_DEFINE(handle_logger_add_channel, "Adds a new logging channel"),
 	AST_CLI_DEFINE(handle_logger_remove_channel, "Removes a logging channel"),
+	AST_CLI_DEFINE(handle_logger_chanloggroup_filter, "Filter PBX logs by channel log group"),
+	AST_CLI_DEFINE(handle_logger_filter_show, "Show current PBX channel filtering"),
+	AST_CLI_DEFINE(handle_logger_filter_reset, "Reset PBX channel filtering"),
 };
 
 static void _handle_SIGXFSZ(int sig)
@@ -1709,7 +1978,7 @@ static void logger_print_normal(struct logmsg *logmsg)
 				}
 				break;
 			case LOGTYPE_CONSOLE:
-				if (!chan->formatter.format_log(chan, logmsg, buf, sizeof(buf))) {
+				if (!logmsg->hidecli && !chan->formatter.format_log(chan, logmsg, buf, sizeof(buf))) {
 					ast_console_puts_mutable_full(buf, logmsg->level, logmsg->sublevel);
 				}
 				break;
@@ -1977,6 +2246,7 @@ int init_logger(void)
 
 	/* register the logger cli commands */
 	ast_cli_register_multiple(cli_logger, ARRAY_LEN(cli_logger));
+	ast_custom_function_register(&log_group_function);
 
 	ast_mkdir(ast_config_AST_LOG_DIR, 0777);
 
@@ -2001,6 +2271,7 @@ void close_logger(void)
 
 	ast_logger_category_unload();
 
+	ast_custom_function_unregister(&log_group_function);
 	ast_cli_unregister_multiple(cli_logger, ARRAY_LEN(cli_logger));
 
 	logger_initialized = 0;
@@ -2030,6 +2301,8 @@ void close_logger(void)
 		ast_free(f);
 	}
 
+	callid_group_remove_filters();
+
 	closelog(); /* syslog */
 
 	AST_RWLIST_UNLOCK(&logchannels);
@@ -2140,12 +2413,26 @@ static void __attribute__((format(printf, 7, 0))) ast_log_full(int level, int su
 	const char *file, int line, const char *function, ast_callid callid,
 	const char *fmt, va_list ap)
 {
+	int hidecli = 0;
 	struct logmsg *logmsg = NULL;
 
 	if (level == __LOG_VERBOSE && ast_opt_remote && ast_opt_exec) {
 		return;
 	}
 
+	if (callid_filtering && !callid_logging_enabled()) {
+		switch (level) {
+		case __LOG_VERBOSE:
+		case __LOG_DEBUG:
+		case __LOG_TRACE:
+		case __LOG_DTMF:
+			hidecli = 1; /* Hide the message from the CLI, but still log to any log files */
+		default: /* Always show NOTICE, WARNING, ERROR, etc. */
+			break;
+		}
+		return;
+	}
+
 	AST_LIST_LOCK(&logmsgs);
 	if (logger_queue_size >= logger_queue_limit && !close_logger_thread) {
 		logger_messages_discarded++;
@@ -2166,6 +2453,8 @@ static void __attribute__((format(printf, 7, 0))) ast_log_full(int level, int su
 		return;
 	}
 
+	logmsg->hidecli = hidecli;
+
 	/* If the logger thread is active, append it to the tail end of the list - otherwise skip that step */
 	if (logthread != AST_PTHREADT_NULL) {
 		AST_LIST_LOCK(&logmsgs);