• Tatyana Nikolova's avatar
    RDMA/core: Add support for iWARP Port Mapper user space service · 30dc5e63
    Tatyana Nikolova authored
    This patch adds iWARP Port Mapper (IWPM) Version 2 support.  The iWARP
    Port Mapper implementation is based on the port mapper specification
    section in the Sockets Direct Protocol paper -
    http://www.rdmaconsortium.org/home/draft-pinkerton-iwarp-sdp-v1.0.pdf
    
    Existing iWARP RDMA providers use the same IP address as the native
    TCP/IP stack when creating RDMA connections.  They need a mechanism to
    claim the TCP ports used for RDMA connections to prevent TCP port
    collisions when other host applications use TCP ports.  The iWARP Port
    Mapper provides a standard mechanism to accomplish this.  Without this
    service it is possible for RDMA application to bind/listen on the same
    port which is already being used by native TCP host application.  If
    that happens the incoming TCP connection data can be passed to the
    RDMA stack with error.
    
    The iWARP Port Mapper solution doesn't contain any changes to the
    existing network stack in the kernel space.  All the changes are
    contained with the infiniband tree and also in user space.
    
    The iWARP Port Mapper service is implemented as a user space daemon
    process.  Source for the IWPM service is located at
    http://git.openfabrics.org/git?p=~tnikolova/libiwpm-1.0.0/.git;a=summary
    
    The iWARP driver (port mapper client) sends to the IWPM service the
    local IP address and TCP port it has received from the RDMA
    application, when starting a connection.  The IWPM service performs a
    socket bind from user space to get an available TCP port, called a
    mapped port, and communicates it back to the client.  In that sense,
    the IWPM service is used to map the TCP port, which the RDMA
    application uses to any port available from the host TCP port
    space. The mapped ports are used in iWARP RDMA connections to avoid
    collisions with native TCP stack which is aware that these ports are
    taken. When an RDMA connection using a mapped port is terminated, the
    client notifies the IWPM service, which then releases the TCP port.
    
    The message exchange between the IWPM service and the iWARP drivers
    (between user space and kernel space) is implemented using netlink
    sockets.
    
    1) Netlink interface functions are added: ibnl_unicast() and
       ibnl_mulitcast() for sending netlink messages to user space
    
    2) The signature of the existing ibnl_put_msg() is changed to be more
       generic
    
    3) Two netlink clients are added: RDMA_NL_NES, RDMA_NL_C4IW
       corresponding to the two iWarp drivers - nes and cxgb4 which use
       the IWPM service
    
    4) Enums are added to enumerate the attributes in the netlink
       messages, which are exchanged between the user space IWPM service
       and the iWARP drivers
    Signed-off-by: default avatarTatyana Nikolova <tatyana.e.nikolova@intel.com>
    Signed-off-by: default avatarSteve Wise <swise@opengridcomputing.com>
    Reviewed-by: default avatarPJ Waskiewicz <pj.waskiewicz@solidfire.com>
    
    [ Fold in range checking fixes and nlh_next removal as suggested by Dan
      Carpenter and Steve Wise.  Fix sparse endianness in hash.  - Roland ]
    Signed-off-by: default avatarRoland Dreier <roland@purestorage.com>
    30dc5e63
iwpm_msg.c 22.4 KB