[openib-general] cma header - change some things according to the list feedback

[Guy German]

This is the header file, embedding some of the feedbacks received from the list

According to this suggestion - the qp is modified to init/rtr/rts in the
cm abstraction.

The connection is done with a synchronous call to get a device for qp
creation. I think it can also be done the way Roland suggested, but I still 
believe this is simpler for consumers (especially for the iwarp oriented ones).

There are still unresolved issues discussed now on the list, but those are mainly 
on the implementation side.

I would like to hear the list opinion on the API, because I'm sure there are 
untied ends on the API side as well.

If someone has a totally different suggestion - can he post it to the list 
for review ?

Thanks,
Guy


/*
 * Copyright (c) 2005 Voltaire Inc.  All rights reserved.
 *
 * This Software is licensed under one of the following licenses:
 *
 * 1) under the terms of the "Common Public License 1.0" a copy of which is
 *    available from the Open Source Initiative, see
 *    http://www.opensource.org/licenses/cpl.php.
 *
 * 2) under the terms of the "The BSD License" a copy of which is
 *    available from the Open Source Initiative, see
 *    http://www.opensource.org/licenses/bsd-license.php.
 *
 * 3) under the terms of the "GNU General Public License (GPL) Version 2" a
 *    copy of which is available from the Open Source Initiative, see
 *    http://www.opensource.org/licenses/gpl-license.php.
 *
 * Licensee has the right to choose one of the above licenses.
 *
 * Redistributions of source code must retain the above copyright
 * notice and one of the license notices.
 *
 * Redistributions in binary form must reproduce both the above copyright
 * notice, one of the license notices in the documentation
 * and/or other materials provided with the distribution.
 *
 */

/*
 *  This header file as a preliminary proposition for a connection manager 
 *  abstraction layer (cma) for IB and iwarp 
 *  - there is an assumption that iwarp uses the same openib qp terminology in 
 *    the rest of the verbs, and the only place needs abstraction is the cm.
 *  - This proposition assumes that the address translation is done in the cma
 *    layer.
 *  - The cma also modifies the qp states to init/rtr/rts and error as needed.
 *  - for calling accept/reject or disconnect on the passive side you need to 
 *    use  the cma handle accepted in ib_cma_listen cb.
 *  - cma_id is created when calling connect or listen and destroyed when 
 *    accepting disconnected/rejected/unreachable events on either active
 *    side (connect cb) or passive side (accept cb)
 */

#ifndef IB_CMA_H
#define IB_CMA_H

#include <linux/socket.h>

enum ib_cma_event {
	IB_CMA_EVENT_ESTABLISHED,
	IB_CMA_EVENT_REJECTED,
	IB_CMA_EVENT_NON_PEER_REJECTED,
	IB_CMA_EVENT_DISCONNECTED,
	IB_CMA_EVENT_UNREACHABLE
};

enum ib_qos {
	IB_QOS_BEST_EFFORT = 0,
	IB_QOS_HIGH_THROUGHPUT = (1 << 0),
	IB_QOS_LOW_LATENCY = (1 << 1),
	IB_QOS_ECONOMY = (1 << 2),
	IB_QOS_PREMIUM = (1 << 3)
};

enum ib_connect_flags {
	IB_CONNECT_DEFAULT_FLAG = 0x00,
	IB_CONNECT_MULTIPATH_FLAG = 0x01
};

/* 
 * for ib_cma_get_src_ip - ib_cma_id will have to include 
 * the path data received in the request handler
 */
union ib_cma_id{
	struct ib_cm_id *cm_id;
	u32 iwarp_id;
};

typedef void (*ib_cma_rarp_handler)(struct sockaddr *src_ip, void *context);
typedef void (*ib_cma_ac_handler)(enum ib_cma_event event, void *context);
typedef void (*ib_cma_event_handler)(enum ib_cma_event event, void *context,
				     void *private_data);
typedef void (*ib_cma_listen_handler)(union ib_cma_id *cma_id, 
				      struct ib_device *device,
				      void *private_data, void *context);

struct ib_cma_conn {
	struct ib_qp *qp;
	struct ib_qp_attr *qp_attr;
	struct sockaddr *dst_ip;
	__be64 service_id;
	struct ib_recv_wr *recv_wr,
	u32 num_recv_wr,
	void *context;
	ib_cma_event_handler cma_event_handler;
	const void *private_data;
	u8 private_data_len;
	u32 timeout;
	enum ib_qos qos;
	enum ib_connect_flags connect_flags;
};


/**
 * ib_cma_get_device - Returns the device to be used according to
 *   the destination ip address (this can be detemined according 
 *   to the local routing table). Call this function before 
 *   creating the qp. If using link-local IPv6 addresses
 *   there is no need to call this function.
 * @remote_address: The destination address for connection
 * @device: The device to use (returned by the function)
 */
int ib_cma_get_device(struct sockaddr *remote_address,
		      enum ib_qos qos, struct ib_device **device);


/**
 * ib_cma_connect - this is the connect request function, called by 
 *   the active side. The consumer registers an upcall that will be 
 *   initiated by the cma with an appropriate connection event 
 *   notification (established/rejected/disconnected etc)
 * @cma_conn: This structure contains the following connection parameters:
 *   @qp: qp for establishing the connection
 *   @qp_attr: only relevant attributes are used
 *   @dst_ip: destination ip address
 *   @service_id: destination service id (port)
 *   @recv_wr: An array of work requests to post on the receive queue.before 
 *     sending the RTU
 *   @num_recv_wr: recv_wr array length - number of buffers to post recv
 *   @context: context to be returned in the callback
 *   @cma_event_handler: the upcall function for the active side
 *   @private_data: private data to be received at the listener upcall
 *   @private_data_len: private data length (max 255)
 *   @timeout: 
 *   @qos: Quality os service for the rc
 *   @connect_flags: default or multipath connection
 * @cma_id: This returned handle is a union (different in ib and iwarp)
 *   in ib - it is the cm_id.
 */
int ib_cma_connect(struct ib_cma_conn *cma_conn,
		   union ib_cma_id *cma_id);


/**
 * ib_cma_disconnect - this function disconnects the rc. It can be 
 *   called, by either the passive or active side
 * @qp: the connected qp to disconnect
 * @cma_id: On the active side- this handle is the one returned 
 *   when ib_cma_connect was called.
 *   On the passive side- this handle was accepted in cma_listen callback
 */
int ib_cma_disconnect(struct ib_qp *qp, union ib_cma_id *cma_id);


/**
 * ib_cma_sid_listen - this function is called by the passive side. It is
 *   listening on a the specified port (ib service id) for incomming 
 *   connection requests
 * @device:
 * @address:
 * @service_id: service id (port) to listen on
 * @context: user context to be returned in the callback
 * @cm_listen_handler: the listen callback 
 * @cma_id: cma handle for the passive side
 */
int ib_cma_sid_listen(struct ib_device *device, struct sockaddr *address,
		      __be64 service_id, void *context,
		      ib_cma_listen_handler cm_listen_handler,
		      union ib_cma_id *cma_id);


/**
 * ib_cma_sid_destroy - this functionis is called on the passive side, to 
 *   stop listenning on a certain sevice id
 * @cma_id: the same cma handle received when ib_cma_sid_listen was called
 */
int ib_cma_sid_destroy(union ib_cma_id *cma_id);


/**
 * ib_cma_accept - call on the passive side to accept a connection request
 * @cma_id: this handle was accepted in cma_listen callback
 * @qp: the connection's qp
 * @private_data: private data to send back to the initiator
 * @private_data_len: private data length
 * @recv_wr: An array of work requests to post on the receive queue.before 
 *   sending the REP
 * @num_recv_wr: recv_wr array length - number of buffers to post recv
 * @context: user context to be returned in the callback
 * @cm_accept_handler: the cma accept callback - triggered when RTU ack
 *   received
 */
int ib_cma_accept(union ib_cma_id *cma_id, struct ib_qp *qp, 
		  const void *private_data, u8 private_data_len,
		  struct ib_recv_wr *recv_wr, u32 num_recv_wr,
		  void *context, ib_cma_ac_handler cm_accept_handler);

/**
 * ib_cma_reject - call on the passive side to reject a connection request.
 *   This call destroys the cma_id, hence when the active side accepts
 *   the reject the cma_id is already destroyed.
 * @cma_id: this handle was accepted in cma_listen callback
 * @private_data: private data to send back to the initiator
 * @private_data_len: private data length
 */
int ib_cma_reject(union ib_cma_id *cma_id, const void *private_data,
		  u8 private_data_len);


/**
 * ib_cma_get_src_ip - this function performs "rarp", asynchronicly
 *   from cma_id to src ip
 * @cma_id: the cma_id will have to include the path data received 
 *   in the request handler
 * @src_ip: source ip of the initiator
 */
int ib_cma_get_src_ip(union ib_cma_id *cma_id,
		      ib_cma_rarp_handler rarp_handler,
		      void *context);

#endif /* IB_CMA_H */