X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fcmd.c;h=e6c172ca51b6b30c880cb94376fab59f94d74118;hb=dac8e0462da102e089005c067ced055928610758;hp=a80668831076a4396d14bdd45d2c155a01e7641c;hpb=b5edb9e87b46c7aaa8f2c829e677a1441ca0a260;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index a80668831..e6c172ca5 100644
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -1383,6 +1383,7 @@ static int validate_event_name(const char *name)
 	int ret = 0;
 	const char *c = name;
 	const char *event_name_end = c + LTTNG_SYMBOL_NAME_LEN;
+	bool null_terminated = false;
 
 	/*
 	 * Make sure that unescaped wildcards are only used as the last
@@ -1391,6 +1392,7 @@ static int validate_event_name(const char *name)
 	while (c < event_name_end) {
 		switch (*c) {
 		case '\0':
+		        null_terminated = true;
 			goto end;
 		case '\\':
 			c++;
@@ -1406,20 +1408,65 @@ static int validate_event_name(const char *name)
 		}
 		c++;
 	}
+end:
+	if (!ret && !null_terminated) {
+		ret = LTTNG_ERR_INVALID_EVENT_NAME;
+	}
+	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;
@@ -1613,9 +1660,25 @@ 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;
@@ -1698,7 +1761,7 @@ 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);
@@ -1739,6 +1802,38 @@ 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.
  */
@@ -1898,9 +1993,7 @@ int cmd_start_trace(struct ltt_session *session)
 	 * possible to enable channel thus inform the client.
 	 */
 	if (usess && usess->domain_global.channels) {
-		rcu_read_lock();
 		nb_chan += lttng_ht_get_count(usess->domain_global.channels);
-		rcu_read_unlock();
 	}
 	if (ksession) {
 		nb_chan += ksession->channel_count;