fixes #540 nni_ep_opttype serves no purpose

fixes #538 setopt should have an explicit chkopt routine
fixes #537 Internal TCP API needs better name separation
fixes #524 Option types should be "typed"

This is a rework of the option management code, to make it both clearer
and to prepare for further work to break up endpoints.  This reduces
a certain amount of dead or redundant code, and actually saves cycles
when setting options, as some loops were not terminated that should have
been.

1 files changed, 64 insertions, 70 deletions

diff --git a/src/core/transport.h b/src/core/transport.h
index 1046901c..e45aa7ec 100644
--- a/src/core/transport.h
+++ b/src/core/transport.h
@@ -47,39 +47,44 @@ struct nni_tran {
 // older versions in the future.
 #define NNI_TRANSPORT_V0 0x54520000
 #define NNI_TRANSPORT_V1 0x54520001
-#define NNI_TRANSPORT_VERSION NNI_TRANSPORT_V1
+#define NNI_TRANSPORT_V2 0x54520002
+#define NNI_TRANSPORT_VERSION NNI_TRANSPORT_V2
 
-// Endpoint option handlers.
-struct nni_tran_ep_option {
-	// eo_name is the name of the option.
-	const char *eo_name;
+// Option handlers.
+struct nni_tran_option {
+	// o_name is the name of the option.
+	const char *o_name;
 
-	// eo_type is the type of the option.
-	int eo_type;
+	// o_type is the type of the option.
+	nni_opt_type o_type;
 
-	// eo_getopt retrieves the value of the option.
-	int (*eo_getopt)(void *, void *, size_t *, int);
+	// o_get retrieves the value of the option. The first argument is the
+	// dialer, listener, or pipe where the request is being made.
+	int (*o_get)(void *, void *, size_t *, nni_opt_type);
 
-	// eo_set sets the value of the option.  If the first argument
-	// (the endpoint) is NULL, then no actual set operation should be
-	// performed, but the option should be sanity tested for presence
-	// and size.  (This permits the core to validate that an option
-	// is reasonable and be set even before endpoints are created.)
-	int (*eo_setopt)(void *, const void *, size_t, int);
+	// o_set sets the value of the option.  The first argument is the
+	// dialer, listener, or pipe where the request is being made.
+	int (*o_set)(void *, const void *, size_t, nni_opt_type);
+
+	// o_chk checks to see if the proposed value is legal -- this is
+	// checks only the type, size, and generic range validation.  This
+	// function can be called before any transport objects are created.
+	int (*o_chk)(const void *, size_t, nni_opt_type);
 };
 
-// Endpoint operations are called by the socket in a protocol-independent
-// fashion.  The socket makes individual calls, which are expected to block
-// if appropriate (except for destroy), or run asynchronously if an aio
-// is provided. Endpoints are unable to call back into the socket, to prevent
-// recusive entry and deadlock.
+// Endpoint operations are called by the socket in a
+// protocol-independent fashion.  The socket makes individual calls,
+// which are expected to block if appropriate (except for destroy), or
+// run asynchronously if an aio is provided. Endpoints are unable to
+// call back into the socket, to prevent recusive entry and deadlock.
 //
 // For a given endpoint, the framework holds a lock so that each entry
 // point is run exclusively of the others. (Transports must still guard
 // against any asynchronous operations they manage themselves, though.)
 struct nni_tran_ep_ops {
 	// ep_init creates a vanilla endpoint. The value created is
-	// used for the first argument for all other endpoint functions.
+	// used for the first argument for all other endpoint
+	// functions.
 	int (*ep_init)(void **, nni_url *, nni_sock *, int);
 
 	// ep_fini frees the resources associated with the endpoint.
@@ -87,8 +92,8 @@ struct nni_tran_ep_ops {
 	void (*ep_fini)(void *);
 
 	// ep_connect establishes a connection.  It can return errors
-	// NNG_EACCESS, NNG_ECONNREFUSED, NNG_EBADADDR, NNG_ECONNFAILED,
-	// NNG_ETIMEDOUT, and NNG_EPROTO.
+	// NNG_EACCESS, NNG_ECONNREFUSED, NNG_EBADADDR,
+	// NNG_ECONNFAILED, NNG_ETIMEDOUT, and NNG_EPROTO.
 	void (*ep_connect)(void *, nni_aio *);
 
 	// ep_bind just does the bind() and listen() work,
@@ -101,45 +106,34 @@ struct nni_tran_ep_ops {
 	// ep_accept accepts an inbound connection.
 	void (*ep_accept)(void *, nni_aio *);
 
-	// ep_close stops the endpoint from operating altogether.  It does
-	// not affect pipes that have already been created.  It is nonblocking.
+	// ep_close stops the endpoint from operating altogether.  It
+	// does not affect pipes that have already been created.  It is
+	// nonblocking.
 	void (*ep_close)(void *);
 
-	// ep_options is an array of endpoint options.  The final element must
-	// have a NULL name. If this member is NULL, then no transport specific
-	// options are available.
-	nni_tran_ep_option *ep_options;
-};
-
-// Pipe option handlers.  We only have get for pipes; once a pipe is created
-// no options may be set on it.
-struct nni_tran_pipe_option {
-	// po_name is the name of the option.
-	const char *po_name;
-
-	// po_type is the type of the option.
-	int po_type;
-
-	// po_getopt retrieves the value of the option.
-	int (*po_getopt)(void *, void *, size_t *, int);
+	// ep_options is an array of endpoint options.  The final
+	// element must have a NULL name. If this member is NULL, then
+	// no transport specific options are available.
+	nni_tran_option *ep_options;
 };
 
-// Pipe operations are entry points called by the socket. These may be called
-// with socket locks held, so it is forbidden for the transport to call
-// back into the socket at this point.  (Which is one reason pointers back
-// to socket or even enclosing pipe state, are not provided.)
+// Pipe operations are entry points called by the socket. These may be
+// called with socket locks held, so it is forbidden for the transport
+// to call back into the socket at this point.  (Which is one reason
+// pointers back to socket or even enclosing pipe state, are not
+// provided.)
 struct nni_tran_pipe_ops {
 	// p_fini destroys the pipe.  This should clean up all local
-	// resources, including closing files and freeing memory, used by
-	// the pipe.  After this call returns, the system will not make
-	// further calls on the same pipe.
+	// resources, including closing files and freeing memory, used
+	// by the pipe.  After this call returns, the system will not
+	// make further calls on the same pipe.
 	void (*p_fini)(void *);
 
 	// p_start starts the pipe running.  This gives the transport a
-	// chance to hook into any transport specific negotiation phase.
-	// The pipe will not have its p_send or p_recv calls started, and
-	// will not be access by the "socket" until the pipe has indicated
-	// its readiness by finishing the aio.
+	// chance to hook into any transport specific negotiation
+	// phase. The pipe will not have its p_send or p_recv calls
+	// started, and will not be access by the "socket" until the
+	// pipe has indicated its readiness by finishing the aio.
 	void (*p_start)(void *, nni_aio *);
 
 	// p_stop stops the pipe, waiting for any callbacks that are
@@ -147,31 +141,31 @@ struct nni_tran_pipe_ops {
 	// resources with p_fini.
 	void (*p_stop)(void *);
 
-	// p_aio_send queues the message for transmit.  If this fails, then
-	// the caller may try again with the same message (or free it).  If
-	// the call succeeds, then the transport has taken ownership of the
-	// message, and the caller may not use it again.  The transport will
-	// have the responsibility to free the message (nng_msg_free()) when
-	// it is finished with it.
+	// p_aio_send queues the message for transmit.  If this fails,
+	// then the caller may try again with the same message (or free
+	// it).  If the call succeeds, then the transport has taken
+	// ownership of the message, and the caller may not use it
+	// again.  The transport will have the responsibility to free
+	// the message (nng_msg_free()) when it is finished with it.
 	void (*p_send)(void *, nni_aio *);
 
-	// p_recv schedules a message receive. This will be performed even for
-	// cases where no data is expected, to allow detection of a remote
-	// disconnect.
+	// p_recv schedules a message receive. This will be performed
+	// even for cases where no data is expected, to allow detection
+	// of a remote disconnect.
 	void (*p_recv)(void *, nni_aio *);
 
-	// p_close closes the pipe.  Further recv or send operations should
-	// return back NNG_ECLOSED.
+	// p_close closes the pipe.  Further recv or send operations
+	// should return back NNG_ECLOSED.
 	void (*p_close)(void *);
 
-	// p_peer returns the peer protocol. This may arrive in whatever
-	// transport specific manner is appropriate.
+	// p_peer returns the peer protocol. This may arrive in
+	// whatever transport specific manner is appropriate.
 	uint16_t (*p_peer)(void *);
 
-	// p_options is an array of pipe options.  The final element must have
-	// a NULL name. If this member is NULL, then no transport specific
-	// options are available.
-	nni_tran_pipe_option *p_options;
+	// p_options is an array of pipe options.  The final element
+	// must have a NULL name. If this member is NULL, then no
+	// transport specific options are available.
+	nni_tran_option *p_options;
 };
 
 // These APIs are used by the framework internally, and not for use by