README:

  Usage: firehose [OPTION]... <callback.so>

  Firehose: Execute C callback functions directly on live traffic.

  The callback function is provided as a shared library (.so file) and
  is called with each packet received from one or more 10-Gigabit (Intel
  82599) network interfaces.

  Receive overhead is very low. firehose can process tens of millions of
  packets per second with one CPU core.

  Print the example (-e option) and header file (-H option) for
  instructions on how to write a callback library.

  Options:

    -H, --print-header   Print a copy of firehose.h.
                         You need this to compile your callback library.
    -e, --example        Print instructions for compiling an example library.
    -i PCI, --input PCI  Receive packets from port with PCI address.
    -t SECONDS, --time SECONDS

Example usage:

  Instructions for creating an example program for firehose.

  This example assumes that you have the 'firehose' executable in your
  path. If you are using the 'snabb' executable then use a syntax like
  'snabb firehose' or './snabb firehose' instead as appropirate.

  Step 1: Create firehose.h

    Create firehose.h with this command:
    $ firehose -H > firehose.h

  Step 2: Create firehose_example.c

    Create the file firehose_example.c with these contents:

      #include <stdio.h>
      #include "firehose.h" // generated by 'firehose -h'

      static int packets;
      void firehose_start() { printf("Starting\n"); }
      void firehose_stop()  { printf("Stopping after %d packets\n", packets); }
      void firehose_packet(const char *pci, char *data, int length) { packets++; }

  Step 3: Compile the callback library

   Compile firehose_example.so callback shared library:
    $ gcc -O2 -fPIC -shared -o firehose_example.so firehose_example.c

  Step 4: Run the example on one or more 10G ports

    Indentify the PCI addresses of the (Intel 82599) network ports that
    you want to test with and run firehose:

    $ sudo firehose -i 0000:01:00.0 -i 0000:01:00.1 \
                    -i 0000:02:00.0 -i 0000:02:00.1 \
                    -t 1 ./firehose_example.so
    Loading shared object: ./firehose_example.so
    Initializing NIC: 0000:01:00.0
    Initializing NIC: 0000:01:00.1
    Initializing NIC: 0000:02:00.0
    Initializing NIC: 0000:02:00.1
    Initializing callback library
    Starting
    Processing traffic...
    Stopping after 41136315 packets

    which shows 41 million packets being processed in one
    second. (This is not the performance limit: that was the total
    traffic being received on the links for this example.)