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

NAME

       rdma_accept - Called to accept a connection request.

SYNOPSIS

       #include <rdma/rdma_cma.h>

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

ARGUMENTS

       id          Connection identifier associated with the request.

       conn_param  Information  needed  to  establish  the  connection.    See
                   CONNECTION PROPERTIES below for details.

DESCRIPTION

       Called  from  the  listening  side  to  accept a connection or datagram
       service lookup request.

RETURN VALUE

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

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.

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.

       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  the
              responder_resources value reported in the connect request event.

       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.

       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
              This value is ignored.

       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.

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.

       The RNR retry count is a 3-bit value.

SEE ALSO

       rdma_listen(3), rdma_reject(3), rdma_get_cm_event(3)