Go to main content

man pages section 3: Library Interfaces and Headers

Exit Print View

Updated: Wednesday, July 27, 2022
 
 

rdma_accept (3)

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);

Description

Librdmacm Programmer's Manual                                   RDMA_ACCEPT(3)



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  CON-
                   NECTION PROPERTIES below for details.

DESCRIPTION
       Called  from the listening side to accept a connection or datagram ser-
       vice 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.


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+-----------------------+
       |ATTRIBUTE TYPE |   ATTRIBUTE VALUE     |
       +---------------+-----------------------+
       |Availability   | network/open-fabrics  |
       +---------------+-----------------------+
       |Stability      | Pass-through volatile |
       +---------------+-----------------------+

NOTES
       Unlike  the  socket accept routine, rdma_accept is not called on a lis-
       tening 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.

       Source code for open source software components in Oracle  Solaris  can
       be found at https://www.oracle.com/downloads/opensource/solaris-source-
       code-downloads.html.

       This    software    was    built    from    source     available     at
       https://github.com/oracle/solaris-userland.    The  original  community
       source   was   downloaded   from    ['https://www.openfabrics.org/down-
       loads/ibutils/ibutils-1.5.7-0.2.gbd7e502.tar.gz', 'https://www.openfab-
       rics.org/downloads/libibverbs/libibverbs-1.1.8.tar.gz',
       'https://www.openfabrics.org/downloads/libmlx4/libmlx4-1.0.6.tar.gz',
       'https://www.openfabrics.org/downloads/libsdp/lib-
       sdp-1.1.108-0.15.gd7fdb72.tar.gz',   'https://www.openfabrics.org/down-
       loads/management/infiniband-diags-1.6.5.tar.gz',  'https://www.openfab-
       rics.org/downloads/management/libibmad-1.3.12.tar.gz',
       'https://www.openfabrics.org/downloads/management/libibu-
       mad-1.3.10.2.tar.gz',    'https://www.openfabrics.org/downloads/manage-
       ment/opensm-3.3.19.tar.gz',          'https://www.openfabrics.org/down-
       loads/perftest/perftest-1.3.0-0.42.gf350d3d.tar.gz', 'https://www.open-
       fabrics.org/downloads/qperf/qperf-0.4.9.tar.gz',  'https://www.openfab-
       rics.org/downloads/rdmacm/librdmacm-1.0.21.tar.gz',  'https://www.open-
       fabrics.org/downloads/rds-tools/rds-tools-2.0.4.tar.gz'].

       Further information about this software can be found on the open source
       community website at http://www.openfabrics.org/.

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  appropri-
       ate  values  for  these fields when accepting.  Users may reference the
       rdma_conn_param structure in the connection event directly, or can ref-
       erence  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.

       If the conn_param parameter is NULL, the values reported in the connec-
       tion request event are used, adjusted  down  based  on  local  hardware
       restrictions.

       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  opera-
              tions  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.

       initiator_depth
              The  maximum  number  of outstanding RDMA read and atomic opera-
              tions 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 ini-
              tiator_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  Infini-
       Band Subnet Administrator and is part of the route (path record) infor-
       mation 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.

       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.

SEE ALSO
       rdma_listen(3), rdma_reject(3), rdma_get_cm_event(3)




librdmacm                         2014-05-27                    RDMA_ACCEPT(3)