add --bridge <interface> option to packetblaster lwaftr

src/apps/test/lwaftr.lua

@@ -276,6 +276,8 @@ function Lwaftrgen:pull ()
 
    local output = self.output.output
    local input = self.input.input
+   local bridge_in = self.input.output
+   local bridge_out = self.output.input
    local ipv6_packets = self.ipv6_packets
    local ipv6_bytes = self.ipv6_bytes
    local ipv4_packets = self.ipv4_packets
@@ -288,6 +290,14 @@ function Lwaftrgen:pull ()
       main.exit(0)
    end
 
+   -- optional passthru of packets from a bridged interface
+   if bridge_in then
+      for _=1,link.nreadable(bridge_in) do
+         local pkt = receive(bridge_in)
+         transmit(output, pkt)
+      end
+   end
+
    -- count and trash incoming packets
    for _=1,link.nreadable(input) do
       local pkt = receive(input)
@@ -300,6 +310,13 @@ function Lwaftrgen:pull ()
                lost_packets = lost_packets + payload.number - self.last_rx_ipv6_packet_number - 1  
             end
             self.last_rx_ipv6_packet_number = payload.number
+            packet.free(pkt)
+         else
+            if bridge_out then
+               transmit(bridge_out, pkt)
+            else
+               packet.free(pkt)
+            end
          end
       else
          ipv4_bytes = ipv4_bytes + pkt.length
@@ -310,9 +327,15 @@ function Lwaftrgen:pull ()
                lost_packets = lost_packets + payload.number - self.last_rx_ipv4_packet_number - 1  
             end
             self.last_rx_ipv4_packet_number = payload.number
+            packet.free(pkt)
+         else
+            if bridge_out then
+               transmit(bridge_out, pkt)
+            else
+               packet.free(pkt)
+            end
          end
       end
-      packet.free(pkt)
    end
 
    local cur_now = tonumber(app.now())

src/program/packetblaster/lwaftr/README

@@ -14,6 +14,8 @@ Usage: packetblaster lwaftr [OPTIONS]
 
   --sock <SOCKET>       Socket name for virtio interface
 
+  --bridge <interface>  Bridge traffic to Linux interface (optional)
+
   --vlan VLANID         VLAN tag traffic with VLANID if set
 
   --src_mac SOURCE
@@ -169,3 +171,25 @@ Example with Linux tap interface:
 14:04:43.573161 00:00:00:00:00:00 > 00:00:00:00:00:00, ethertype IPv4 (0x0800), length 608: 8.8.8.8.12345 > 0.0.0.0.1024: UDP, length 558
   14:04:43.573297 00:00:00:00:00:00 > 00:00:00:00:00:00, ethertype IPv4 (0x0800), length 1514: 8.8.8.8.12345 > 0.0.0.0.1024: UDP, length 1464
   14:04:43.573430 00:00:00:00:00:00 > 00:00:00:00:00:00, ethertype IPv4 (0x0800), length 78: 8.8.8.8.12345 > 0.0.0.0.1024: UDP, length 28
+
+
+Example with non-generator traffic bridged to a Linux interface:
+
+In addition to just generating traffic and measuring the return rate, it is also possible to transparently
+pass packets from a Linux network interface thru packetblaster in both directions. This allows e.g.
+to offer network connectivity between a 10GE port and a linux interface (e.g. eno1), while injecting 
+traffic at the same time:
+
+$ sudo ./snabb packetblaster lwaftr -4 --pci 0000:04:00.0 --bridge eth0 --rate 1
+
+IPv4: 8.8.8.8:12345 > 10.0.0.0:1024
+      destination IPv4 and Port adjusted per client
+IPv4 packet sizes: 64
+Bridge traffic to interface eno1
+v6+v4: 0.000+0.000 = 0.000000 MPPS, 0.000+0.000 = 0.000000 Gbps, lost nan%
+v6+v4: 0.000+0.358 = 0.357769 MPPS, 0.000+0.223 = 0.223248 Gbps, lost 20.232%
+v6+v4: 0.000+2.000 = 2.000007 MPPS, 0.000+1.248 = 1.248004 Gbps, lost 0.000%
+v6+v4: 0.000+2.000 = 1.999986 MPPS, 0.000+1.248 = 1.247996 Gbps, lost 0.000%
+
+
+

src/program/packetblaster/lwaftr/lwaftr.lua

@@ -13,6 +13,7 @@ local Tap       = require("apps.tap.tap").Tap
 local raw       = require("apps.socket.raw")
 local pcap      = require("apps.pcap.pcap")
 local VhostUser = require("apps.vhost.vhost_user").VhostUser
+local raw       = require("apps.socket.raw")
 local lib       = require("core.lib")
 local ffi       = require("ffi")
 
@@ -37,6 +38,7 @@ local long_opts = {
    rate         = "r",    -- rate in MPPS (0 => listen only)
    v4only       = "4",    -- generate only public IPv4 traffic
    v6only       = "6",    -- generate only public IPv6 encapsulated traffic
+   bridge       = "B",    -- optional bridge to raw interface
    pcap         = "o"     -- output packet to the pcap file
 }
 
@@ -160,7 +162,12 @@ function run (args)
       single_pass = true
    end
 
-   args = lib.dogetopt(args, opt, "VD:hS:s:a:d:b:iI:c:r:46p:v:o:t:i:k:", long_opts)
+   local bridge = nil
+   function opt.B (arg) 
+      bridge = arg
+   end
+
+   args = lib.dogetopt(args, opt, "VD:hS:s:a:d:b:iI:c:r:46p:v:o:t:i:k:B:", long_opts)
 
    if not target then
       print("either --pci, --tap, --sock, --int or --pcap are required parameters")
@@ -195,6 +202,13 @@ function run (args)
       public_ipv4 = public_ipv4, single_pass = single_pass,
       ipv4_only = ipv4_only, ipv6_only = ipv6_only })
 
+   if bridge then
+      print("Bridge traffic to interface " .. bridge)
+      config.app(c, "raw", raw.RawSocket, bridge)
+      config.link(c, "generator.input -> raw.rx")
+      config.link(c, "raw.tx -> generator.output")
+   end
+
    local input, output
 
    if tap_interface then