feat(ifwait): add ifbridgeable script

This enable to wait for bridgeability of a WLAN interface via
`iwinfo`.

Signed-off-by: Raito Bezarius <masterancpp@gmail.com>

pkgs/anoia/Makefile

@@ -1,5 +1,5 @@
 
-default: fs.lua init.lua nl.lua svc.lua net/constants.lua
+default: wlan.lua fs.lua init.lua nl.lua svc.lua net/constants.lua
 
 test:
 	ln -s . anoia

pkgs/anoia/default.nix

@@ -4,6 +4,7 @@
 , linotify
 , lua
 , lualinux
+, iwinfo
 , cpio
 }:
 let pname =  "anoia";
@@ -12,7 +13,7 @@ in stdenv.mkDerivation {
   version = "0.1";
   src = ./.;
   nativeBuildInputs = [ fennel cpio ];
-  buildInputs = with lua.pkgs; [ linotify lualinux ];
+  buildInputs = with lua.pkgs; [ linotify lualinux iwinfo ];
   outputs = [ "out" "dev" ];
 
   doCheck = true;

pkgs/anoia/wlan.fnl

@@ -0,0 +1,8 @@
+(local { : nl80211 } (require :iwinfo))
+
+(fn is-bridgeable [ifname]
+  (let [mode (nl80211.mode ifname)]
+    (or (= mode "Master") (= mode "Master (VLAN)"))
+))
+
+{ : is-bridgeable }

pkgs/ifwait/default.nix

@@ -1,6 +1,8 @@
 {
   lua
 , netlink-lua
+, lualinux
+, iwinfo
 , writeFennelScript
 , runCommand
 , anoia
@@ -8,4 +10,5 @@
 runCommand "ifwait" {} ''
   mkdir -p $out/bin
   cp -p ${writeFennelScript "ifwait" [ anoia netlink-lua ] ./ifwait.fnl} $out/bin/ifwait
+  cp -p ${writeFennelScript "ifbridgeable" [ anoia lualinux iwinfo ] ./ifbridgeable.fnl} $out/bin/ifbridgeable
 ''

pkgs/ifwait/ifbridgeable.fnl

@@ -0,0 +1,30 @@
+(local wlan (require :anoia.wlan))
+(local { : assoc } (require :anoia))
+(local { : msleep } (require :lualinux))
+
+(fn parse-args [args]
+  (match args
+    ["-v" & rest]  (assoc (parse-args rest) :verbose true)
+    [linkname] {:link linkname}
+    _  nil))
+
+(fn run [args poll-fn]
+  (let [parameters
+        (assert (parse-args args)
+                (.. "Usage: ifbridgeable [-v] ifname"))]
+    (when parameters.verbose
+      (print (.. "ifbridgeable: waiting for "
+                 parameters.link " to be bridgeable")))
+
+    (while (not (poll-fn parameters.link))
+      (when parameters.verbose
+        (print (.. "ifbridgeable: waiting for " parameters.link " to be bridgeable")))
+      (msleep 500)
+    )
+  )
+)
+
+(when (not (= (. arg 0) "test"))
+  (run arg wlan.is-bridgeable))
+
+{ : run  }