X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fcmd.c;h=0c34d163841dbc35db367173174a08ad2fc5117e;hb=e98a44b093e3b566c0d26bfe52d4fac13df4a5a2;hp=30cfc21c4f07fc5f90d637d260a8cbe3740b5a41;hpb=1a29cff2973695e90fa1688b15760c8e98863d6b;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index 30cfc21c4..0c34d1638 100644
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -268,8 +268,7 @@ static int list_lttng_ust_global_events(char *channel_name,
 
 	uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
 
-	nb_event += lttng_ht_get_count(uchan->events);
-
+	nb_event = lttng_ht_get_count(uchan->events);
 	if (nb_event == 0) {
 		ret = nb_event;
 		goto error;
@@ -284,6 +283,11 @@ static int list_lttng_ust_global_events(char *channel_name,
 	}
 
 	cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
+		if (uevent->internal) {
+			/* This event should remain hidden from clients */
+			nb_event--;
+			continue;
+		}
 		strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
 		tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 		tmp[i].enabled = uevent->enabled;
@@ -1415,16 +1419,58 @@ end:
 	return ret;
 }
 
+static inline bool name_starts_with(const char *name, const char *prefix)
+{
+	const size_t max_cmp_len = min(strlen(prefix), LTTNG_SYMBOL_NAME_LEN);
+
+	return !strncmp(name, prefix, max_cmp_len);
+}
+
+/* Perform userspace-specific event name validation */
+static int validate_ust_event_name(const char *name)
+{
+	int ret = 0;
+
+	if (!name) {
+		ret = -1;
+		goto end;
+	}
+
+	/*
+	 * Check name against all internal UST event component namespaces used
+	 * by the agents.
+	 */
+	if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
+		name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
+		name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
+		ret = -1;
+	}
+
+end:
+	return ret;
+}
+
+static int cmd_enable_event_internal(struct ltt_session *session,
+		struct lttng_domain *domain,
+		char *channel_name, struct lttng_event *event,
+		char *filter_expression,
+		struct lttng_filter_bytecode *filter,
+		struct lttng_event_exclusion *exclusion,
+		int wpipe);
+
 /*
- * Command LTTNG_ENABLE_EVENT processed by the client thread.
- * We own filter, exclusion, and filter_expression.
+ * Internal version of cmd_enable_event() with a supplemental
+ * "internal_event" flag which is used to enable internal events which should
+ * be hidden from clients. Such events are used in the agent implementation to
+ * enable the events through which all "agent" events are funeled.
  */
-int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain,
+static int _cmd_enable_event(struct ltt_session *session,
+		struct lttng_domain *domain,
 		char *channel_name, struct lttng_event *event,
 		char *filter_expression,
 		struct lttng_filter_bytecode *filter,
 		struct lttng_event_exclusion *exclusion,
-		int wpipe)
+		int wpipe, bool internal_event)
 {
 	int ret, channel_created = 0;
 	struct lttng_channel *attr;
@@ -1618,9 +1664,25 @@ int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain,
 			assert(uchan);
 		}
 
+		if (!internal_event) {
+			/*
+			 * Ensure the event name is not reserved for internal
+			 * use.
+			 */
+			ret = validate_ust_event_name(event->name);
+			if (ret) {
+			        WARN("Userspace event name %s failed validation.",
+						event->name ?
+						event->name : "NULL");
+				ret = LTTNG_ERR_INVALID_EVENT_NAME;
+				goto error;
+			}
+		}
+
 		/* At this point, the session and channel exist on the tracer */
 		ret = event_ust_enable_tracepoint(usess, uchan, event,
-				filter_expression, filter, exclusion);
+				filter_expression, filter, exclusion,
+				internal_event);
 		/* We have passed ownership */
 		filter_expression = NULL;
 		filter = NULL;
@@ -1683,7 +1745,7 @@ int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain,
 			default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
 			break;
 		default:
-			/* The switch/case we are in should avoid this else big problem */
+			/* The switch/case we are in makes this impossible */
 			assert(0);
 		}
 
@@ -1703,7 +1765,7 @@ int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain,
 					+ filter->len);
 			}
 
-			ret = cmd_enable_event(session, &tmp_dom,
+			ret = cmd_enable_event_internal(session, &tmp_dom,
 					(char *) default_chan_name,
 					&uevent, filter_expression, filter_copy,
 					NULL, wpipe);
@@ -1744,6 +1806,38 @@ error:
 	return ret;
 }
 
+/*
+ * Command LTTNG_ENABLE_EVENT processed by the client thread.
+ * We own filter, exclusion, and filter_expression.
+ */
+int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain,
+		char *channel_name, struct lttng_event *event,
+		char *filter_expression,
+		struct lttng_filter_bytecode *filter,
+		struct lttng_event_exclusion *exclusion,
+		int wpipe)
+{
+	return _cmd_enable_event(session, domain, channel_name, event,
+			filter_expression, filter, exclusion, wpipe, false);
+}
+
+/*
+ * Enable an event which is internal to LTTng. An internal should
+ * never be made visible to clients and are immune to checks such as
+ * reserved names.
+ */
+static int cmd_enable_event_internal(struct ltt_session *session,
+		struct lttng_domain *domain,
+		char *channel_name, struct lttng_event *event,
+		char *filter_expression,
+		struct lttng_filter_bytecode *filter,
+		struct lttng_event_exclusion *exclusion,
+		int wpipe)
+{
+	return _cmd_enable_event(session, domain, channel_name, event,
+			filter_expression, filter, exclusion, wpipe, true);
+}
+
 /*
  * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
  */