4. CNDPFWD Sample Application¶

$ ./builddir/examples/cndpfwd/cndpfwd -c examples/cndpfwd/fwd.jsonc

Usage: ./builddir/examples/cndpfwd/cndpfwd [-h] [-c json_file] [-b burst] <mode>
  <mode>         Mode types [drop | rx-only], tx-only, [lb | loopback], fwd, tx-only-rx,
                 acl-strict or acl-permissive
  -a <api>       The API type to use xskdev or pktdev APIs, default is xskdev.\n"
                 The -a option overrides JSON file.\n"
  -b <burst>     Burst size. If not present default burst size 256 max 256.
  -c <json-file> The JSON configuration file
  -C             Wait on unix domain socket for JSON or JSON-C file
  -d             More debug stats are displayed
  -D             JCFG debug decoding
  -V             JCFG information verbose
  -P             JCFG debug parsing
  -h             Display the help information

./tools/rcndp cndpfwd -c /tmp/fwd.jsonc

{
    // (R) - Required entry
    // (O) - Optional entry
    // All descriptions are optional and short form is 'desc'
    // The order of the entries in this file are handled when it is parsed and the
    // entries can be in any order.

    // (R) Application information
    //    name        - (O) the name of the application
    //    description - (O) the description of the application
    "application": {
        "name": "cndpfwd",
        "description": "A simple packet forwarder for pktdev and xskdev"
    },

    // (O) Default values
    //    bufcnt - (O) UMEM default buffer count in 1K increments
    //    bufsz  - (O) UMEM buffer size in 1K increments
    //    rxdesc - (O) Number of RX ring descriptors in 1K increments
    //    txdesc - (O) Number of TX ring descriptors in 1K increments
    //    cache  - (O) MBUF Pool cache size in number of entries
    //    mtype  - (O) Memory type for mmap allocations
    "defaults": {
        "bufcnt": 16,
        "bufsz": 2,
        "rxdesc": 2,
        "txdesc": 2,
        "cache": 128,
        "mtype": "2MB"
    },

    // List of all UMEM's to be created
    // key/val - (R) The 'key' is the name of the umem for later reference.
    //               The 'val' is the object describing the UMEM buffer.
    //               Multiple umem regions can be defined.
    // A UMEM can support multiple lports using the regions array. Each lports can use
    // one of the regions.
    //    bufcnt  - (R) The number of buffers in 1K increments in the UMEM space.
    //    bufsz   - (R) The size in 1K increments of each buffer in the UMEM space.
    //    mtype   - (O) If missing or empty string or missing means use 4KB or default system pages.
    //    regions - (O) Array of sizes one per region in 1K increments, total must be <= bufcnt
    //    rxdesc  - (O) Number of RX descriptors to be allocated in 1K increments,
    //                  if not present or zero use defaults.rxdesc, normally zero.
    //    txdesc  - (O) Number of TX descriptors to be allocated in 1K increments,
    //                  if not present or zero use defaults.txdesc, normally zero.
    //    description | desc - (O) Description of the umem space.
    "umems": {
        "umem0": {
            "bufcnt": 32,
            "bufsz": 2,
            "mtype": "2MB",
            "regions": [
                16,
                16
            ],
            "rxdesc": 0,
            "txdesc": 0,
            "description": "UMEM Description 0"
        }
    },

    // List of all lports to be used in the application
    // An lport is defined by a netdev/queue ID pair, which is a socket containing a Rx/Tx ring pair.
    // Each queue ID is assigned to a single socket or a socket is the lport defined by netdev/qid.
    // Note: A netdev can be shared between lports as the qid is unique per lport
    //       If netdev is not defined or empty then it must be a virtual interface and not
    //       associated with a netdev/queue ID.
    // key/val - (R) The 'key' is the logical name e.g. 'eth0:0', 'eth1:0', ... to be used by the
    //               application to reference an lport. The 'val' object contains information about
    //               each lport.
    //    netdev        - (R) The netdev device to be used, the part before the colon
    //                     must reflect the netdev name
    //    pmd           - (R) All PMDs have a name i.e. 'net_af_xdp', 'ring', ...
    //    qid           - (R) Is the queue id to use for this lport, defined by ethtool command line
    //    umem          - (R) The UMEM assigned to this lport
    //    region        - (O) UMEM region index value, default region 0
    //    busy_poll     - (O) Enable busy polling support, true or false, default false
    //    busy_timeout  - (O) 1-65535 or 0 - use default value, values in milliseconds
    //    busy_budget   - (O) 0xFFFF disabled, 0 use default, >0 budget value
    //    unprivileged  - (O) inhibit loading the BPF program if true, default false
    //    force_wakeup  - (O) force TX wakeup calls for CVL NIC, default false
    //    skb_mode      - (O) Enable XDP_FLAGS_SKB_MODE when creating af_xdp socket, forces copy mode, default false
    //    description   - (O) the description, 'desc' can be used as well
    "lports": {
        "eth0:0": {
            "pmd": "net_af_xdp",
            "qid": 11,
            "umem": "umem0",
            "region": 0,
            "description": "LAN 0 port"
        },
        "eth1:0": {
            "pmd": "net_af_xdp",
            "qid": 12,
            "umem": "umem0",
            "region": 1,
            "description": "LAN 1 port"
        }
    },

    // (O) Define the lcore groups for each thread to run
    //     Can be integers or a string for a range of lcores
    //     e.g. [10], [10-14,16], [10-12, 14-15, 17-18, 20]
    // Names of a lcore group and its lcores assigned to the group.
    // The initial group is for the main thread of the application.
    // The default group is special and is used if a thread if not assigned to a group.
    "lcore-groups": {
        "initial": [10],
        "group0": [13],
        "group1": [14],
        "default": ["15-16"]
    },

    // (O) Set of common options application defined.
    //     The Key can be any string and value can be boolean, string, array or integer
    //     An array must contain only a single value type, boolean, integer, string and
    //     can't be a nested array.
    //   pkt_api    - (O) Set the type of packet API xskdev or pktdev
    //   no-metrics - (O) Disable metrics gathering and thread
    //   no-restapi - (O) Disable RestAPI support
    //   cli        - (O) Enable/Disable CLI supported
    //   mode       - (O) Mode type [drop | rx-only], tx-only, [lb | loopback], fwd, tx-only-rx
    //                    acl-strict, acl-permissive
    //   uds_path   - (0) Path to unix domain socket to get xsk map fd
    "options": {
        "pkt_api": "xskdev",
        "no-metrics": false,
        "no-restapi": false,
        "cli": true,
        "mode": "drop"
    },

    // List of threads to start and information for that thread. Application can start
    // it's own threads for any reason and are not required to be configured by this file.
    //
    //   Key/Val   - (R) A unique thread name.
    //                   The format is <type-string>[:<identifier>] the ':' and identifier
    //                   are optional if all thread names are unique
    //      group  - (O) The lcore-group this thread belongs to. The
    //      lports - (O) The list of lports assigned to this thread and can not shared lports.
    //      description | desc - (O) The description
    "threads": {
        "main": {
            "group": "initial",
            "description": "CLI Thread"
        },
        "fwd:0": {
            "group": "group0",
            "lports": ["eth0:0"],
            "description": "Thread 0"
        },
        "fwd:1": {
            "group": "group1",
            "lports": ["eth1:0"],
            "description": "Thread 1"
        }
    }
}