Provided by: librdmacm-dev_1.0.14.1-2_i386 bug

NAME

       rdma_connect - Initiate an active connection request.

SYNOPSIS

       #include <rdma/rdma_cma.h>

       int   rdma_connect   (struct  rdma_cm_id  *id,  struct  rdma_conn_param
       *conn_param);

ARGUMENTS

       id          RDMA identifier.

       conn_param  connection parameters.  See CONNECTION PROPERTIES below for
                   details.

DESCRIPTION

       For an rdma_cm_id of type RDMA_PS_TCP, this call initiates a connection
       request  to  a  remote  destination.   For  an   rdma_cm_id   of   type
       RDMA_PS_UDP,  it  initiates  a  lookup  of  the remote QP providing the
       datagram service.

RETURN VALUE

       Returns 0 on success, or -1 on error.  If an error occurs,  errno  will
       be set to indicate the failure reason.

NOTES

       Users  must  have resolved a route to the destination address by having
       called  rdma_resolve_route  or  rdma_create_ep  before   calling   this
       routine.

CONNECTION PROPERTIES

       The  following  properties  are used to configure the communication and
       specified by the conn_param parameter when connecting  or  establishing
       datagram communication.

       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.

       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.

       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 and
              remote RDMA device attribute  max_qp_init_rd_atom.   The  remote
              endpoint can adjust this value when accepting the connection.

       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
              remote   RDMA   device  attribute  max_qp_rd_atom.   The  remote
              endpoint can adjust this value when accepting the connection.

       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.

       retry_count
              The maximum number of  times  that  a  data  transfer  operation
              should  be retried on the connection when an error occurs.  This
              setting controls the number of times to retry  send,  RDMA,  and
              atomic   operations   when  timeouts  occur.   Applies  only  to
              RDMA_PS_TCP.

       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.

       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.

       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.  Applies only to RDMA_PS_TCP.

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 resolved route (path
       record)  information.   The  HCA ACK delay is a property of the locally
       used HCA.

       Retry count and RNR retry count values are 3-bit values.

IWARP SPECIFIC

       Connections established over iWarp RDMA devices currently require  that
       the active side of the connection send the first message.

SEE ALSO

       rdma_cm(7),          rdma_create_id(3),          rdma_resolve_route(3),
       rdma_disconnect(3), rdma_listen(3), rdma_get_cm_event(3)