Add n:igmp(), a function for building igmp protocol blocks.

2 files changed, 73 insertions, 0 deletions

diff --git a/lua/net.c b/lua/net.c
index 5c67e05..356813f 100644
--- a/lua/net.c
+++ b/lua/net.c
@@ -558,6 +558,31 @@ static int lnet_data (lua_State *L)
 }
 
 /*-
+-- ptag = net:igmp{type=NUM, code=NUM, ip=IP, payload=STR, ptag=int}
+
+Build IGMP packet inside net context.
+
+ptag is optional, defaults to creating a new protocol block
+*/
+static int lnet_igmp (lua_State *L)
+{
+    libnet_t* ud = checkudata(L);
+    int type = v_arg_integer(L, 2, "type");
+    int code = v_arg_integer(L, 2, "code");
+    const char* ip = v_arg_string(L, 2, "ip");
+    uint32_t ip_n = check_ip_pton(L, ip, "ip");
+    uint32_t payloadsz = 0;
+    const uint8_t* payload = checkpayload(L, 2, &payloadsz);
+    int cksum = 0;
+    int ptag = lnet_arg_ptag(L, ud, 2, LIBNET_PBLOCK_IGMP_H);
+
+    ptag = libnet_build_igmp(type, code, cksum, ip_n, payload, payloadsz, ud, ptag);
+    check_error(L, ud, ptag);
+    lua_pushinteger(L, ptag);
+    return 1;
+}
+
+/*-
 -- ptag = net:udp{src=NUM, dst=NUM, len=NUM, payload=STR, ptag=int}
 
 Build UDP packet inside net context.
@@ -1364,6 +1389,7 @@ static const luaL_reg net_methods[] =
   {"fd", lnet_getfd},
   {"device", lnet_getdevice},
   {"data", lnet_data},
+  {"igmp", lnet_igmp},
   {"udp", lnet_udp},
   {"get_udp", lnet_get_udp},
   {"tcp", lnet_tcp},
diff --git a/lua/test-igmp.lua b/lua/test-igmp.lua
new file mode 100644
index 0000000..cb8e810
--- /dev/null
+++ b/lua/test-igmp.lua
@@ -0,0 +1,47 @@
+dofile"setup.lua"
+
+test("+igmp", function()
+  local n = net.init()
+  local igmpt = {type=3, code=5, ip="1.2.3.4"}
+  local ipt = {src="1.2.3.4", dst="5.6.7.8", protocol=2}
+  local etht = {src="01:02:03:01:02:03", dst="04:05:06:04:05:06"}
+  local pkt = "0405060405060102030102030800".. -- eth
+              "4500001c0000000040026acd0102030405060708".. -- ip
+              "0305f6f604030201" -- igmp
+
+  print"  w/no-payload"
+
+  local gtag = n:igmp(igmpt)
+  local itag = n:ipv4(ipt)
+  local etag = n:eth(etht)
+  local b = n:block()
+
+  dump(n)
+
+  print("want", pkt)
+  print("have", h(b))
+
+  assert(pkt == h(b), h(b))
+
+  print"ok"
+
+  print"  w/payload"
+
+  igmpt.payload = "\0\0\0"
+  igmpt.ptag = gtag
+
+  local gtag = n:igmp(igmpt)
+  local b = n:block()
+
+  dump(n)
+
+  print("want", pkt)
+  print("have", h(b))
+
+  assert(pkt.."000000" == h(b), h(b))
+
+  print"ok"
+
+  n:destroy()
+end)
+