From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Fri, 8 Nov 2019 22:45:20 +0000 (-0500)
Subject: Fix: relayd: disallow 0-length session names for 2.4+ peers
X-Git-Tag: v2.12.0-rc1~246
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=e7f8eff3a01708a32fc2a475b88420ab21ed821f

Fix: relayd: disallow 0-length session names for 2.4+ peers

The group-by-session-name feature assumes sessions are named for peers
more recent than 2.3. Enforce this assumption at session creation
time.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/src/bin/lttng-relayd/cmd-2-11.c b/src/bin/lttng-relayd/cmd-2-11.c
index 0da8d2834..4b6f39120 100644
--- a/src/bin/lttng-relayd/cmd-2-11.c
+++ b/src/bin/lttng-relayd/cmd-2-11.c
@@ -78,6 +78,10 @@ int cmd_create_session_2_11(const struct lttng_buffer_view *payload,
 		ret = -ENAMETOOLONG;
 		ERR("Length of session name (%" PRIu32 " bytes) received in create_session command exceeds maximum length (%d bytes)", header.session_name_len, LTTNG_NAME_MAX);
 		goto error;
+	} else if (header.session_name_len == 0) {
+		ret = -EINVAL;
+		ERR("Illegal session name length of 0 received");
+		goto error;
 	}
 	if (header.hostname_len > LTTNG_HOST_NAME_MAX) {
 		ret = -ENAMETOOLONG;
diff --git a/src/bin/lttng-relayd/cmd-2-4.c b/src/bin/lttng-relayd/cmd-2-4.c
index e20a838da..008be4cf0 100644
--- a/src/bin/lttng-relayd/cmd-2-4.c
+++ b/src/bin/lttng-relayd/cmd-2-4.c
@@ -52,6 +52,10 @@ int cmd_create_session_2_4(const struct lttng_buffer_view *payload,
 		ret = -ENAMETOOLONG;
 		ERR("Session name too long");
 		goto error;
+	} else if (len == 0) {
+		ret = -EINVAL;
+		ERR("Session name can't be of length 0");
+		goto error;
 	}
 	strncpy(session_name, session_info.session_name, LTTNG_NAME_MAX);
 
diff --git a/src/bin/lttng-relayd/session.h b/src/bin/lttng-relayd/session.h
index 288672dcc..8d60ed95f 100644
--- a/src/bin/lttng-relayd/session.h
+++ b/src/bin/lttng-relayd/session.h
@@ -53,6 +53,7 @@ struct relay_session {
 	 */
 	lttng_uuid sessiond_uuid;
 	LTTNG_OPTIONAL(time_t) creation_time;
+	/* Must _not_ be empty for 2.4+ peers. */
 	char session_name[LTTNG_NAME_MAX];
 	char hostname[LTTNG_HOST_NAME_MAX];
 	char base_path[LTTNG_PATH_MAX];