librdmacm/man/rdma_accept.3 - linux-rdma/rdma-core - Git at Google

 .\" Licensed under the OpenIB.org BSD license (FreeBSD Variant) - See COPYING.md
 .TH "RDMA_ACCEPT" 3 "2014-05-27" "librdmacm" "Librdmacm Programmer's Manual" librdmacm
 .SH NAME
 rdma_accept \- Called to accept a connection request.
 .SH SYNOPSIS
 .B "#include <rdma/rdma_cma.h>"
 .P
 .B "int" rdma_accept
 .BI "(struct rdma_cm_id *" id ","
 .BI "struct rdma_conn_param *" conn_param ");"
 .SH ARGUMENTS
 .IP "id" 12
 Connection identifier associated with the request.
 .IP "conn_param" 12
 Information needed to establish the connection.  See CONNECTION PROPERTIES
 below for details.
 .SH "DESCRIPTION"
 Called from the listening side to accept a connection or datagram
 service lookup request.
 .SH "RETURN VALUE"
 Returns 0 on success, or -1 on error.  If an error occurs, errno will be
 set to indicate the failure reason.
 .SH "NOTES"
 Unlike the socket accept routine, rdma_accept is not called on a
 listening rdma_cm_id.  Instead, after calling rdma_listen, the user
 waits for an RDMA_CM_EVENT_CONNECT_REQUEST event to occur.  Connection request
 events give the user a newly created rdma_cm_id, similar to a new
 socket, but the rdma_cm_id is bound to a specific RDMA device.
 rdma_accept is called on the new rdma_cm_id.
 .SH "CONNECTION PROPERTIES"
 The following properties are used to configure the communication and specified
 by the conn_param parameter when accepting a connection or datagram
 communication request.  Users should use the rdma_conn_param values reported
 in the connection request event to determine appropriate values for these
 fields when accepting.  Users may reference the rdma_conn_param structure in
 the connection event directly, or can reference their own structure.  If the
 rdma_conn_param structure from an event is referenced, the event must not be
 acked until after this call returns.
 .P
 If the conn_param parameter is NULL, the values reported in the connection
 request event are used, adjusted down based on local hardware restrictions.
 .IP private_data
 References a user-controlled data buffer.  The contents of the buffer are
 copied and transparently passed to the remote side as part of the
 communication request.  May be NULL if private_data is not required.
 .IP private_data_len
 Specifies the size of the user-controlled data buffer.  Note that the actual
 amount of data transferred to the remote side is transport dependent and may
 be larger than that requested.
 .IP responder_resources
 The maximum number of outstanding RDMA read and atomic operations that the
 local side will accept from the remote side.  Applies only to RDMA_PS_TCP.
 This value must be less than or equal to the local RDMA device attribute
 max_qp_rd_atom, but preferably greater than or equal to the responder_resources
 value reported in the connect request event.
 .IP initiator_depth
 The maximum number of outstanding RDMA read and atomic operations that the
 local side will have to the remote side.  Applies only to RDMA_PS_TCP.
 This value must be less than or equal to the local RDMA device attribute
 max_qp_init_rd_atom and the initiator_depth value reported in the connect
 request event.
 .IP flow_control
 Specifies if hardware flow control is available.  This value is exchanged
 with the remote peer and is not used to configure the QP.  Applies only to
 RDMA_PS_TCP.
 .IP retry_count
 This value is ignored.
 .IP rnr_retry_count
 The maximum number of times that a send operation from the remote peer
 should be retried on a connection after receiving a receiver not ready (RNR)
 error.  RNR errors are generated when a send request arrives before a buffer
 has been posted to receive the incoming data.  Applies only to RDMA_PS_TCP.
 .IP srq
 Specifies if the QP associated with the connection is using a shared receive
 queue.  This field is ignored by the library if a QP has been created on the
 rdma_cm_id.  Applies only to RDMA_PS_TCP.
 .IP qp_num
 Specifies the QP number associated with the connection.  This field is ignored
 by the library if a QP has been created on the rdma_cm_id.
 .SH "INFINIBAND SPECIFIC"
 In addition to the connection properties defined above, InfiniBand QPs are
 configured with minimum RNR NAK timer and local ACK timeout values.  The
 minimum RNR NAK timer value is set to 0, for a delay of 655 ms.
 The local ACK timeout is calculated based on the packet lifetime and local
 HCA ACK delay.  The packet lifetime is determined by the InfiniBand Subnet
 Administrator and is part of the route (path record) information obtained
 by the active side of the connection.  The HCA ACK delay is a property of
 the locally used HCA.
 .P
 The RNR retry count is a 3-bit value.
 .P
 The length of the private data provided by the user is limited to 196 bytes
 for RDMA_PS_TCP, or 136 bytes for RDMA_PS_UDP.
 .SH "SEE ALSO"
 rdma_listen(3), rdma_reject(3), rdma_get_cm_event(3)
	.\" Licensed under the OpenIB.org BSD license (FreeBSD Variant) - See COPYING.md
	.TH "RDMA_ACCEPT" 3 "2014-05-27" "librdmacm" "Librdmacm Programmer's Manual" librdmacm
	.SH NAME
	rdma_accept \- Called to accept a connection request.
	.SH SYNOPSIS
	.B "#include <rdma/rdma_cma.h>"
	.P
	.B "int" rdma_accept
	.BI "(struct rdma_cm_id *" id ","
	.BI "struct rdma_conn_param *" conn_param ");"
	.SH ARGUMENTS
	.IP "id" 12
	Connection identifier associated with the request.
	.IP "conn_param" 12
	Information needed to establish the connection. See CONNECTION PROPERTIES
	below for details.
	.SH "DESCRIPTION"
	Called from the listening side to accept a connection or datagram
	service lookup request.
	.SH "RETURN VALUE"
	Returns 0 on success, or -1 on error. If an error occurs, errno will be
	set to indicate the failure reason.
	.SH "NOTES"
	Unlike the socket accept routine, rdma_accept is not called on a
	listening rdma_cm_id. Instead, after calling rdma_listen, the user
	waits for an RDMA_CM_EVENT_CONNECT_REQUEST event to occur. Connection request
	events give the user a newly created rdma_cm_id, similar to a new
	socket, but the rdma_cm_id is bound to a specific RDMA device.
	rdma_accept is called on the new rdma_cm_id.
	.SH "CONNECTION PROPERTIES"
	The following properties are used to configure the communication and specified
	by the conn_param parameter when accepting a connection or datagram
	communication request. Users should use the rdma_conn_param values reported
	in the connection request event to determine appropriate values for these
	fields when accepting. Users may reference the rdma_conn_param structure in
	the connection event directly, or can reference their own structure. If the
	rdma_conn_param structure from an event is referenced, the event must not be
	acked until after this call returns.
	.P
	If the conn_param parameter is NULL, the values reported in the connection
	request event are used, adjusted down based on local hardware restrictions.
	.IP private_data
	References a user-controlled data buffer. The contents of the buffer are
	copied and transparently passed to the remote side as part of the
	communication request. May be NULL if private_data is not required.
	.IP private_data_len
	Specifies the size of the user-controlled data buffer. Note that the actual
	amount of data transferred to the remote side is transport dependent and may
	be larger than that requested.
	.IP responder_resources
	The maximum number of outstanding RDMA read and atomic operations that the
	local side will accept from the remote side. Applies only to RDMA_PS_TCP.
	This value must be less than or equal to the local RDMA device attribute
	max_qp_rd_atom, but preferably greater than or equal to the responder_resources
	value reported in the connect request event.
	.IP initiator_depth
	The maximum number of outstanding RDMA read and atomic operations that the
	local side will have to the remote side. Applies only to RDMA_PS_TCP.
	This value must be less than or equal to the local RDMA device attribute
	max_qp_init_rd_atom and the initiator_depth value reported in the connect
	request event.
	.IP flow_control
	Specifies if hardware flow control is available. This value is exchanged
	with the remote peer and is not used to configure the QP. Applies only to
	RDMA_PS_TCP.
	.IP retry_count
	This value is ignored.
	.IP rnr_retry_count
	The maximum number of times that a send operation from the remote peer
	should be retried on a connection after receiving a receiver not ready (RNR)
	error. RNR errors are generated when a send request arrives before a buffer
	has been posted to receive the incoming data. Applies only to RDMA_PS_TCP.
	.IP srq
	Specifies if the QP associated with the connection is using a shared receive
	queue. This field is ignored by the library if a QP has been created on the
	rdma_cm_id. Applies only to RDMA_PS_TCP.
	.IP qp_num
	Specifies the QP number associated with the connection. This field is ignored
	by the library if a QP has been created on the rdma_cm_id.
	.SH "INFINIBAND SPECIFIC"
	In addition to the connection properties defined above, InfiniBand QPs are
	configured with minimum RNR NAK timer and local ACK timeout values. The
	minimum RNR NAK timer value is set to 0, for a delay of 655 ms.
	The local ACK timeout is calculated based on the packet lifetime and local
	HCA ACK delay. The packet lifetime is determined by the InfiniBand Subnet
	Administrator and is part of the route (path record) information obtained
	by the active side of the connection. The HCA ACK delay is a property of
	the locally used HCA.
	.P
	The RNR retry count is a 3-bit value.
	.P
	The length of the private data provided by the user is limited to 196 bytes
	for RDMA_PS_TCP, or 136 bytes for RDMA_PS_UDP.
	.SH "SEE ALSO"
	rdma_listen(3), rdma_reject(3), rdma_get_cm_event(3)