1. INTRODUCTION

This is a clone of nginx (from https://github.com/nginx/nginx)
to demonstrate and benchmark TLDK library integration with real
world application.
A new nginx module is created and and BSD socket-like API is implemented
on top of native TLDK API.
Note, that right now only minimalistic subset of socket-like API is provided:
- accept
- close
- readv
- recv
- writev
so only limited nginx functionality is available for a moment.

2. HOW TO BUILD/RUN

  cd to your TLDK root directory
  Build TLDK as usual (and explained in README), then:
  export TLDK_ROOT=${PWD}
  cd app/nginx/
  auto/configure --prefix=${TLDK_ROOT}/${RTE_TARGET} --with-tldk \
  --with-cc-opt="-march=native -D_GNU_SOURCE"
  make install

  create a copy of app/nginx/conf/nginx-tldk.conf and modify it accrodingly
  to your system setup.
  ${TLDK_ROOT}/${RTE_TARGET}/sbin/nginx -c <path_to_your_config_file>

  On your peer system:
  make sure your net interface connected to the TLDK system is up and running
  add TLDK assigned ip address into ip neighbor table
  run your favorite web client
  as an example:
  ifconfig eth1 192.168.1.90/24 up
  ip neigh add 192.168.1.60 lladdr 3c:fd:fe:9f:ce:e9 nud permanent dev eth1
  wget --no-proxy 192.168.1.60:6000

3. NGINX.CONF TLDK RELATED PARAMETERS 

  Syntax:	tldk_main { ... }
  Default:	-
  Context:	main
  Provides the configuration file context in which the directives that affect
  global DPDK/TLDK startup parameters are specified. 

  Syntax:	eal_main <DPDK cmdline startup parameters>;
  Default:	""
  Context:	tldk_main
  Example:	eal_cmd --lcores=8-10 -n 4 -w 03:00.1; 
  Provides command-line arguments list for rte_eal_init().

  Syntax:	port <uint> mtu <uint> rx_offload <uint> tx_offload <uint> ipv4 <ipv4> ipv6 <ipv6>; 
  Default:	-
  Context:	tldk_main
  Example:	port 0 rx_offload 0xf tx_offload 0xf ipv4 192.168.1.60;
  Provides configuration information for particular DPDK ethdev port.
  port -	DPDK port id to be used to receive/send packets.
		It is an mandatory option.
  mtu - 	MTU to be used on that port (= application data size + L2/L3/L4
		headers sizes, default=1514). It is an optional option.
  rx_offload -	RX HW offload capabilities to enable/use on this port.
		(bitmask of DPDK DEV_RX_OFFLOAD_* values).
		It is an optional option.
  tx_offload -	TX HW offload capabilities to enable/use on this port.
		(bitmask of DPDK DEV_TX_OFFLOAD_* values).
		It is an optional option.
  ipv4 -	IPv4 network address that will be assigned to that port.
		At least one of ipv4/ipv6 has to be specified.
  ipv6 -	IPv6 network address that will be assigned to that port.
		At least one of ipv4/ipv6 has to be specified.

  For more details regarding TLDK related parameters in nginx config file,
  please refer to app/nginx/conf/nginx-tldk.conf. 

  Syntax:	tldk_ctx { ... }
  Default:	-
  Context:	main
  Provides the configuration for particular TLDK context.
  In current implementation there is one to one mapping between NGINX workers
  and TLDK contents:
  - each NGINX worker has to be assigned to work with only one TLDK context.
  - each TLDK context services only one NGINX worker.
  
  Syntax:	worker <uint>;
  Default:	-
  Context:	tldk_ctx
  Example:	worker 0;
  Associates given TLDK context with NGINX worker # 0.
  
  Syntax:	lcore <uint>;
  Default:	-
  Context:	tldk_ctx
  Example:	lcore 9;
  Specifies on which lcore given TLDK context will run on.
  
  Syntax:	be_in_worker;
  Default:	off
  Context:	tldk_ctx
  Example:	be_in_worker;
  Specifies should TLDK context processing (Back-End) run inside NGINX worker
  process, or as a separate thread (DPDK lcore) inside NGINX master process.
  
  Syntax:	tcp_timewait <uint>;
  Default:	120s
  Context:	tldk_ctx
  Example:	tcp_timewait 0;
  Specifies TCP TIME_WAIT state timeout duration in milliseconds for given
  TLDK context.
  
  Syntax:	mbufs <uint>;
  Default:	0x20000
  Context:	tldk_ctx
  Example:	mbufs 0x20000;
  Specifies maximum number of DPDK mbufs to be created for given TLDK context.
  
  Syntax:	sbufs <uint>;
  Default:	1
  Context:	tldk_ctx
  Example:	sbufs 0x100;
  Specifies maximum number of send mbufs per stream (connection)
  for given TLDK context.
  
  Syntax:	rbufs <uint>;
  Default:	1
  Context:	tldk_ctx
  Example:	rbufs 0x100;
  Specifies maximum number of recv mbufs per stream (connection)
  for given TLDK context.
  
  Syntax:	dev <uint> port <uint> queue <uint>;
  Default:	-
  Context:	tldk_ctx
  Example:	dev 0 port 0 queue 0;
  Assigns DPDK ethdev devices to the given TLDK context.
  dev -		dev id inside given TLDK context.
  port -	DPDK port id to be used to receive/send packets.
  queue -	DPDK queue id to be used to receive/send packets.
  
  Syntax:	dest dev <uint> addr <ipv4/ipv6> masklen <uint> mac <ether>
  Default:	-
  Context:	tldk_ctx
  Example:	dest dev 0 addr 192.168.1.0 masklen 24 mac 3C:FD:FE:9F:D1:E1;
  Specifies routing information for given TLDK context.
  dev -		dev id inside given TLDK context.
  addr -	ipv4/ipv6 destination address.
  masklen - 	destination network prefix length.
  mac - 	destination ethernet address.