Add the nmap.get_interface and nmap.get_interface_info functions by

Djalal Harouni.

CHANGELOG

@@ -1,5 +1,9 @@
 # Nmap Changelog ($Id$); -*-text-*-
 
+o [NSE] Added nmap.get_interface and nmap.get_interface_info functions
+  so scripts can access characteristics of the scanning interface.
+  [Djalal]
+
 o [NSE] Added epmd-info.nse, which gets a list of Erlang node port
   numbers. [Toni Ruottu]
 

nse_dnet.cc

@@ -47,6 +47,72 @@ LUALIB_API int l_dnet_new (lua_State *L)
   return 1;
 }
 
+LUALIB_API int l_dnet_get_interface_info (lua_State *L)
+{
+  char ipstr[INET6_ADDRSTRLEN];
+  struct addr src, bcast;
+  struct interface_info *ii = getInterfaceByName(luaL_checkstring(L, 1));
+
+  if (ii == NULL) {
+    lua_pushnil(L);
+    lua_pushstring(L, "failed to find interface");
+    return 2;
+  }
+
+  memset(ipstr, 0, INET6_ADDRSTRLEN);
+  memset(&src, 0, sizeof(src));
+  memset(&bcast, 0, sizeof(bcast));
+  lua_newtable(L);
+
+  setsfield(L, -1, "device", ii->devfullname);
+  setsfield(L, -1, "shortname", ii->devname);
+  setnfield(L, -1, "netmask", ii->netmask_bits);
+
+  if (ii->addr.ss_family == AF_INET)
+    inet_ntop(AF_INET, &((struct sockaddr_in *)&ii->addr)->sin_addr,
+              ipstr, INET6_ADDRSTRLEN);
+  else if (ii->addr.ss_family == AF_INET6)
+    inet_ntop(AF_INET6, &((struct sockaddr_in6 *)&ii->addr)->sin6_addr,
+              ipstr, INET6_ADDRSTRLEN);
+  else
+    luaL_error(L, "unknown protocol");
+
+  setsfield(L, -1, "address", ipstr);
+
+  switch (ii->device_type) {
+    case devt_ethernet:
+      setsfield(L, -1, "link", "ethernet");
+      lua_pushlstring(L, (const char *) ii->mac, 6);
+      lua_setfield(L, -2, "mac");
+
+      /* calculate the broadcast address */
+      if (ii->addr.ss_family == AF_INET) {
+        src.addr_type = ADDR_TYPE_IP;
+        src.addr_bits = ii->netmask_bits;
+        src.addr_ip = ((struct sockaddr_in *)&ii->addr)->sin_addr.s_addr;
+        addr_bcast(&src, &bcast);
+        memset(ipstr, 0, INET6_ADDRSTRLEN);
+        if (addr_ntop(&bcast, ipstr, INET6_ADDRSTRLEN) != NULL)
+          setsfield(L, -1, "broadcast", ipstr);
+      }
+      break;
+    case devt_loopback:
+      setsfield(L, -1, "link", "loopback");
+      break;
+    case devt_p2p:
+      setsfield(L, -1, "link", "p2p");
+      break;
+    case devt_other:
+    default:
+      setsfield(L, -1, "link", "other");
+  }
+
+  setsfield(L, -1, "up", (ii->device_up ? "up" : "down"));
+  setnfield(L, -1, "mtu", ii->mtu);
+
+  return 1;
+}
+
 LUALIB_API int l_dnet_get_interface_link (lua_State *L)
 {
   struct interface_info *ii = getInterfaceByName(luaL_checkstring(L, 1));

nse_dnet.h

@@ -3,6 +3,7 @@
 
 LUALIB_API int l_dnet_new (lua_State *);
 LUALIB_API int l_dnet_get_interface_link (lua_State *);
+LUALIB_API int l_dnet_get_interface_info (lua_State *);
 LUALIB_API int luaopen_dnet (lua_State *L);
 
 #endif

nse_nmaplib.cc

@@ -741,6 +741,18 @@ static int l_address_family(lua_State *L)
   return 1;
 }
 
+/* return the interface name that was specified with
+ * the -e option
+ */
+static int l_get_interface (lua_State *L)
+{
+  if (*o.device)
+    lua_pushstring(L, o.device);
+  else
+    lua_pushnil(L);
+  return 1;
+}
+
 int luaopen_nmap (lua_State *L)
 {
   static const luaL_reg nmaplib [] = {
@@ -767,6 +779,8 @@ int luaopen_nmap (lua_State *L)
     {"is_privileged", l_is_privileged},
     {"resolve", l_resolve},
     {"address_family", l_address_family},
+    {"get_interface", l_get_interface},
+    {"get_interface_info", l_dnet_get_interface_info},
     {NULL, NULL}
   };
 

nselib/nmap.luadoc

@@ -61,6 +61,54 @@ function resolve(host, family)
 -- @usage local family = nmap.address_family()
 function address_family()
 
+--- Returns the interface name (dnet-style) that Nmap is using.
+--
+-- For example in the pre-scanning (<code>"prerule"</code> scripts) phase
+-- if Nmap is run with the <code>-e eth0</code>, then "eth0" can be
+-- returned, however Nmap can return an other interface name since it
+-- can determine the best interface suited for the job.
+-- Other <code>"hostrule"</code> and <code>"portrule"</code> scripts
+-- should use the interface field of the </code>host</code> table:
+-- <code>host.interface</code>.
+--
+-- The result of this function can be used to get the interface information
+-- table, example: <code>nmap.get_interface_info("eth0")</code>.
+--
+-- @return A string containing the interface name (dnet-style) on
+success, or a nil value on failures.
+-- @usage local interface_name = nmap.get_interface()
+function get_interface()
+
+--- Gets the interface network information.
+--
+-- This function takes a dnet-style interface name and returns a table
+-- containing the network information of the interface.
+--
+-- @param interface_name The name of the interface.
+-- @return Table containing the network information of the interface on
+--  success, or nil and an error message on failures.
+-- @usage local iface, err = nmap.get_interface_info("eth0")
+--
+-- Keys of the returned table:
+-- <code>device</code> The interface name, can be an interface aliase.
+-- <code>shortname</code> A simple short name of the device.
+-- <code>netmask</code> The netmask bits (CIDR) of the interface.
+-- <code>address</code> The string representing the IP address assigned
+-- to the interface.
+-- <code>link</code> The string representing the hardware type of the
+-- interface. Possible values are: <code>"ethernet"</code>,
+-- <code>"loopback"</code>, <code>"p2p"</code> or <code>"other"</code>.
+-- <code>mac</code> MAC address (six-byte-long binary string) of the
+-- interface if the type of the interface is <code>"ethernet"</code>,
+-- otherwise it is nil.
+-- <code>broadcast</code> The string representing the broadcast address
+-- assigned to the interface if the interface type is <code>"ethernet"</code>
+-- and if the used address is IPv4, otherwise it is nil.
+-- <code>up</code> The state of the interface, possible values are:
+-- <code>"up"</code> or <code>"down"</code>.
+-- <code>mtu</code> The MTU size of the interface.
+function get_interface_info(interface_name)
+
 --- Searches for the specified file and returns a string containing its path if
 -- it is found and readable (to the process).
 --