Fix: backward relayd communication compatibility.

The size of LTTNG_HOST_NAME_MAX changed from 64 to 256 in commit id
b867041c62b48e89c9f00430cde4c33f13a2da09.

This change result in breaking compatibility with older relayd.

Freeze size of struct used for relayd communication.

Confirmed by lttng-ivc project.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/src/common/sessiond-comm/relayd.h b/src/common/sessiond-comm/relayd.h
index 3bfa3eb28070a46d9d9503272735088862af7542..306e2e4dd7bcd8e25c6f4caf5b0440c07e952105 100644 (file)
--- a/src/common/sessiond-comm/relayd.h
+++ b/src/common/sessiond-comm/relayd.h
@@ -29,6 +29,11 @@
 #define RELAYD_VERSION_COMM_MAJOR             VERSION_MAJOR
 #define RELAYD_VERSION_COMM_MINOR             VERSION_MINOR
 
+#define RELAYD_COMM_LTTNG_HOST_NAME_MAX_2_4    64
+#define RELAYD_COMM_LTTNG_NAME_MAX_2_4 255
+#define RELAYD_COMM_LTTNG_PATH_MAX     4096
+#define RELAYD_COMM_DEFAULT_STREAM_NAME_LEN    264 /* 256 + 8 */
+
 /*
  * lttng-relayd communication header.
  */
@@ -64,8 +69,8 @@ struct lttcomm_relayd_status_session {
  * Used to add a stream on the relay daemon.
  */
 struct lttcomm_relayd_add_stream {
-       char channel_name[DEFAULT_STREAM_NAME_LEN];
-       char pathname[LTTNG_PATH_MAX];
+       char channel_name[RELAYD_COMM_DEFAULT_STREAM_NAME_LEN];
+       char pathname[RELAYD_COMM_LTTNG_PATH_MAX];
 } LTTNG_PACKED;
 
 /*
@@ -73,8 +78,8 @@ struct lttcomm_relayd_add_stream {
  * Protocol version 2.2
  */
 struct lttcomm_relayd_add_stream_2_2 {
-       char channel_name[DEFAULT_STREAM_NAME_LEN];
-       char pathname[LTTNG_PATH_MAX];
+       char channel_name[RELAYD_COMM_DEFAULT_STREAM_NAME_LEN];
+       char pathname[RELAYD_COMM_LTTNG_PATH_MAX];
        uint64_t tracefile_size;
        uint64_t tracefile_count;
 } LTTNG_PACKED;
@@ -180,8 +185,8 @@ static inline size_t lttcomm_relayd_index_len(uint32_t major, uint32_t minor)
  * Create session in 2.4 adds additionnal parameters for live reading.
  */
 struct lttcomm_relayd_create_session_2_4 {
-       char session_name[LTTNG_NAME_MAX];
-       char hostname[LTTNG_HOST_NAME_MAX];
+       char session_name[RELAYD_COMM_LTTNG_NAME_MAX_2_4];
+       char hostname[RELAYD_COMM_LTTNG_HOST_NAME_MAX_2_4];
        uint32_t live_timer;
        uint32_t snapshot;
 } LTTNG_PACKED;