bpf:cgroup: add Cgroup operations definition

Add MSG_OP_CGROUP and its sub operations. These operations will be
forwarded to the ring buffer for logging and debugging purpose, except
for MSG_OP_CGROUP_ATTACH_TASK that is used to discover cgroup config.

- MSG_OP_CGROUP_MKDIR: is when cgroup is created, we send event for debugging.
- MSG_OP_CGROUP_RMDIR: is when cgroup is removed from fs, used for debugging.
- MSG_OP_CGROUP_RELEASE: is when cgroup is released, used for debugging.
- MSG_OP_CGROUP_ATTACH_TASK: is when a task is migrated to a cgroup, used to
  migrate Tetragon so it discover current cgroup environment.

Signed-off-by: Djalal Harouni <[email protected]>

Author: tixxdz

bpf/lib/msg_types.h

@@ -26,6 +26,20 @@ enum msg_ops {
 
 	MSG_OP_DATA = 24,
 
+	MSG_OP_CGROUP = 25,
+
 	MSG_OP_MAX,
 };
+
+enum msg_cgroup_ops {
+	MSG_OP_CGROUP_UNDEF = 0,
+	MSG_OP_CGROUP_MKDIR =
+		1, /* cgroup_mkdir tracepoint, used for debugging */
+	MSG_OP_CGROUP_RMDIR =
+		2, /* cgroup_rmdir tracepoint, used for debugging */
+	MSG_OP_CGROUP_RELEASE =
+		3, /* cgroup_release tracepoint, used for debugging */
+	MSG_OP_CGROUP_ATTACH_TASK = 10, /* cgroup_attach_task tracepoint */
+};
+
 #endif // _MSG_TYPES_