document how dynamic clients work

so people don't have to read all of the code to figure it out

diff --git a/src/lib/io/master.c b/src/lib/io/master.c
index 2860e4dadb1cbcfdd2dbaa1491f8744bfb11e8ec..a128bb856655fd5908326cb6e5bbe66840c1e93e 100644 (file)
--- a/src/lib/io/master.c
+++ b/src/lib/io/master.c
@@ -74,6 +74,22 @@ typedef enum {
        PR_CLIENT_PENDING,                              //!< dynamic client pending definition
 } fr_io_client_state_t;
 
+/*
+ *     Dynamic clients are run through the normal src/process/foo state machine.
+ *
+ *     request->async->packet_ctx is an fr_io_track_t
+ *
+ *     track->dynamic is set to a non-zero value.
+ *
+ *     The dynamic client code returns a buffer of 1 byte for a NAK.
+ *
+ *     If the client creation is successful, then it does talloc(NULL, fr_client_t),
+ *     fills out the structure, and sends the pointer in the buffer (8 bytes).
+ *
+ *     This code will take over ownership of the structure, and
+ *     create the dynamic client.
+ */
+
 typedef struct fr_io_connection_s fr_io_connection_t;
 
 /** Client definitions for master IO