IB: IP address based RDMA connection manager

Kernel connection management agent over InfiniBand that connects based
on IP addresses.  The agent defines a generic RDMA connection
abstraction to support clients wanting to connect over different RDMA
devices.

The agent also handles RDMA device hotplug events on behalf of clients.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 256 insertions, 0 deletions

diff --git a/include/rdma/rdma_cm.h b/include/rdma/rdma_cm.h
new file mode 100644
index 000000000000..402c63d7226b
--- /dev/null
+++ b/include/rdma/rdma_cm.h
@@ -0,0 +1,256 @@
+/*
+ * Copyright (c) 2005 Voltaire Inc.  All rights reserved.
+ * Copyright (c) 2005 Intel Corporation.  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.
+ *
+ */
+
+#if !defined(RDMA_CM_H)
+#define RDMA_CM_H
+
+#include <linux/socket.h>
+#include <linux/in6.h>
+#include <rdma/ib_addr.h>
+#include <rdma/ib_sa.h>
+
+/*
+ * Upon receiving a device removal event, users must destroy the associated
+ * RDMA identifier and release all resources allocated with the device.
+ */
+enum rdma_cm_event_type {
+	RDMA_CM_EVENT_ADDR_RESOLVED,
+	RDMA_CM_EVENT_ADDR_ERROR,
+	RDMA_CM_EVENT_ROUTE_RESOLVED,
+	RDMA_CM_EVENT_ROUTE_ERROR,
+	RDMA_CM_EVENT_CONNECT_REQUEST,
+	RDMA_CM_EVENT_CONNECT_RESPONSE,
+	RDMA_CM_EVENT_CONNECT_ERROR,
+	RDMA_CM_EVENT_UNREACHABLE,
+	RDMA_CM_EVENT_REJECTED,
+	RDMA_CM_EVENT_ESTABLISHED,
+	RDMA_CM_EVENT_DISCONNECTED,
+	RDMA_CM_EVENT_DEVICE_REMOVAL,
+};
+
+enum rdma_port_space {
+	RDMA_PS_SDP  = 0x0001,
+	RDMA_PS_TCP  = 0x0106,
+	RDMA_PS_UDP  = 0x0111,
+	RDMA_PS_SCTP = 0x0183
+};
+
+struct rdma_addr {
+	struct sockaddr src_addr;
+	u8		src_pad[sizeof(struct sockaddr_in6) -
+				sizeof(struct sockaddr)];
+	struct sockaddr dst_addr;
+	u8		dst_pad[sizeof(struct sockaddr_in6) -
+				sizeof(struct sockaddr)];
+	struct rdma_dev_addr dev_addr;
+};
+
+struct rdma_route {
+	struct rdma_addr addr;
+	struct ib_sa_path_rec *path_rec;
+	int num_paths;
+};
+
+struct rdma_cm_event {
+	enum rdma_cm_event_type	 event;
+	int			 status;
+	void			*private_data;
+	u8			 private_data_len;
+};
+
+struct rdma_cm_id;
+
+/**
+ * rdma_cm_event_handler - Callback used to report user events.
+ *
+ * Notes: Users may not call rdma_destroy_id from this callback to destroy
+ *   the passed in id, or a corresponding listen id.  Returning a
+ *   non-zero value from the callback will destroy the passed in id.
+ */
+typedef int (*rdma_cm_event_handler)(struct rdma_cm_id *id,
+				     struct rdma_cm_event *event);
+
+struct rdma_cm_id {
+	struct ib_device	*device;
+	void			*context;
+	struct ib_qp		*qp;
+	rdma_cm_event_handler	 event_handler;
+	struct rdma_route	 route;
+	enum rdma_port_space	 ps;
+	u8			 port_num;
+};
+
+/**
+ * rdma_create_id - Create an RDMA identifier.
+ *
+ * @event_handler: User callback invoked to report events associated with the
+ *   returned rdma_id.
+ * @context: User specified context associated with the id.
+ * @ps: RDMA port space.
+ */
+struct rdma_cm_id *rdma_create_id(rdma_cm_event_handler event_handler,
+				  void *context, enum rdma_port_space ps);
+
+void rdma_destroy_id(struct rdma_cm_id *id);
+
+/**
+ * rdma_bind_addr - Bind an RDMA identifier to a source address and
+ *   associated RDMA device, if needed.
+ *
+ * @id: RDMA identifier.
+ * @addr: Local address information.  Wildcard values are permitted.
+ *
+ * This associates a source address with the RDMA identifier before calling
+ * rdma_listen.  If a specific local address is given, the RDMA identifier will
+ * be bound to a local RDMA device.
+ */
+int rdma_bind_addr(struct rdma_cm_id *id, struct sockaddr *addr);
+
+/**
+ * rdma_resolve_addr - Resolve destination and optional source addresses
+ *   from IP addresses to an RDMA address.  If successful, the specified
+ *   rdma_cm_id will be bound to a local device.
+ *
+ * @id: RDMA identifier.
+ * @src_addr: Source address information.  This parameter may be NULL.
+ * @dst_addr: Destination address information.
+ * @timeout_ms: Time to wait for resolution to complete.
+ */
+int rdma_resolve_addr(struct rdma_cm_id *id, struct sockaddr *src_addr,
+		      struct sockaddr *dst_addr, int timeout_ms);
+
+/**
+ * rdma_resolve_route - Resolve the RDMA address bound to the RDMA identifier
+ *   into route information needed to establish a connection.
+ *
+ * This is called on the client side of a connection.
+ * Users must have first called rdma_resolve_addr to resolve a dst_addr
+ * into an RDMA address before calling this routine.
+ */
+int rdma_resolve_route(struct rdma_cm_id *id, int timeout_ms);
+
+/**
+ * rdma_create_qp - Allocate a QP and associate it with the specified RDMA
+ * identifier.
+ *
+ * QPs allocated to an rdma_cm_id will automatically be transitioned by the CMA
+ * through their states.
+ */
+int rdma_create_qp(struct rdma_cm_id *id, struct ib_pd *pd,
+		   struct ib_qp_init_attr *qp_init_attr);
+
+/**
+ * rdma_destroy_qp - Deallocate the QP associated with the specified RDMA
+ * identifier.
+ *
+ * Users must destroy any QP associated with an RDMA identifier before
+ * destroying the RDMA ID.
+ */
+void rdma_destroy_qp(struct rdma_cm_id *id);
+
+/**
+ * rdma_init_qp_attr - Initializes the QP attributes for use in transitioning
+ *   to a specified QP state.
+ * @id: Communication identifier associated with the QP attributes to
+ *   initialize.
+ * @qp_attr: On input, specifies the desired QP state.  On output, the
+ *   mandatory and desired optional attributes will be set in order to
+ *   modify the QP to the specified state.
+ * @qp_attr_mask: The QP attribute mask that may be used to transition the
+ *   QP to the specified state.
+ *
+ * Users must set the @qp_attr->qp_state to the desired QP state.  This call
+ * will set all required attributes for the given transition, along with
+ * known optional attributes.  Users may override the attributes returned from
+ * this call before calling ib_modify_qp.
+ *
+ * Users that wish to have their QP automatically transitioned through its
+ * states can associate a QP with the rdma_cm_id by calling rdma_create_qp().
+ */
+int rdma_init_qp_attr(struct rdma_cm_id *id, struct ib_qp_attr *qp_attr,
+		       int *qp_attr_mask);
+
+struct rdma_conn_param {
+	const void *private_data;
+	u8 private_data_len;
+	u8 responder_resources;
+	u8 initiator_depth;
+	u8 flow_control;
+	u8 retry_count;		/* ignored when accepting */
+	u8 rnr_retry_count;
+	/* Fields below ignored if a QP is created on the rdma_cm_id. */
+	u8 srq;
+	u32 qp_num;
+	enum ib_qp_type qp_type;
+};
+
+/**
+ * rdma_connect - Initiate an active connection request.
+ *
+ * Users must have resolved a route for the rdma_cm_id to connect with
+ * by having called rdma_resolve_route before calling this routine.
+ */
+int rdma_connect(struct rdma_cm_id *id, struct rdma_conn_param *conn_param);
+
+/**
+ * rdma_listen - This function is called by the passive side to
+ *   listen for incoming connection requests.
+ *
+ * Users must have bound the rdma_cm_id to a local address by calling
+ * rdma_bind_addr before calling this routine.
+ */
+int rdma_listen(struct rdma_cm_id *id, int backlog);
+
+/**
+ * rdma_accept - Called to accept a connection request or response.
+ * @id: Connection identifier associated with the request.
+ * @conn_param: Information needed to establish the connection.  This must be
+ *   provided if accepting a connection request.  If accepting a connection
+ *   response, this parameter must be NULL.
+ *
+ * Typically, this routine is only called by the listener to accept a connection
+ * request.  It must also be called on the active side of a connection if the
+ * user is performing their own QP transitions.
+ */
+int rdma_accept(struct rdma_cm_id *id, struct rdma_conn_param *conn_param);
+
+/**
+ * rdma_reject - Called to reject a connection request or response.
+ */
+int rdma_reject(struct rdma_cm_id *id, const void *private_data,
+		u8 private_data_len);
+
+/**
+ * rdma_disconnect - This function disconnects the associated QP and
+ *   transitions it into the error state.
+ */
+int rdma_disconnect(struct rdma_cm_id *id);
+
+#endif /* RDMA_CM_H */
+