rename clock.py to linux.py and add if_nametoindex

1 files changed, 35 insertions, 0 deletions

diff --git a/linux.py b/linux.py
new file mode 100644
index 0000000..5da6b0e
--- /dev/null
+++ b/linux.py
@@ -0,0 +1,35 @@
+# Courtesy of Armin Ronacher, found at StackOverflow
+
+import ctypes
+import os
+
+CLOCK_MONOTONIC = 1 # see <linux/time.h>
+
+class _timespec(ctypes.Structure):
+    _fields_ = [
+        ('tv_sec', ctypes.c_long),
+        ('tv_nsec', ctypes.c_long)
+    ]
+
+_librt = ctypes.CDLL('librt.so.1', use_errno=True)
+_libc = ctypes.CDLL('libc.so.6', use_errno=True)
+
+_clock_gettime = _librt.clock_gettime
+_clock_gettime.argtypes = [ctypes.c_int, ctypes.POINTER(_timespec)]
+
+_if_nametoindex = _libc.if_nametoindex
+_if_nametoindex.argtype = [ctypes.c_uint, ctypes.c_char_p]
+
+def now():
+    t = _timespec()
+    if _clock_gettime(CLOCK_MONOTONIC, ctypes.pointer(t)) != 0:
+        errno_ = ctypes.get_errno()
+        raise OSError(errno_, os.strerror(errno_))
+    return t.tv_sec + t.tv_nsec * 1e-9
+
+def if_nametoindex(interfaceName):
+    rv = _if_nametoindex(interfaceName)
+    if rv == 0:
+        errno_= ctypes.get_errno()
+        raise OSError(errno_, os.strerror(errno_))
+    return rv