Detect a global ipv6 address via "ip" command.

1 files changed, 28 insertions, 0 deletions

diff --git a/Global6.hs b/Global6.hs
new file mode 100644
index 00000000..346be708
--- /dev/null
+++ b/Global6.hs
@@ -0,0 +1,28 @@
+module Global6 where
+
+import Control.Monad
+import Data.IP
+import Data.List
+import Data.Maybe
+import Network.Socket
+import System.Process
+import Text.Read
+
+parseIpAddr :: String -> Maybe IPv6
+parseIpAddr s = do
+    let ws        = words s
+        (addr,bs) = splitAt 1 $ drop 1 $ dropWhile (/= "inet6") ws
+    guard ("global" `elem` bs)
+    addr <- listToMaybe addr
+    guard (not $ isPrefixOf "fd" addr)
+    guard (not $ isPrefixOf "fc" addr)
+    let (addr',slash) = break (=='/') addr
+    ip6 <- readMaybe addr'
+    return $ (ip6 :: IPv6)
+
+
+global6 :: IO (Maybe IPv6)
+global6 = do
+    addrs <- lines <$> readProcess "ip" ["-o","-6","addr"] ""
+    return $ foldr1 mplus $ map parseIpAddr addrs
+