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Updated: Thursday, June 13, 2019
 
 

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.

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)


       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/.



librdmacm                         2014-05-27                    RDMA_ACCEPT(3)