Add a utility method for value clamping.

2 files changed, 8 insertions, 0 deletions

diff --git a/paramiko/util.py b/paramiko/util.py
index f4ee3adc..d029f52e 100644
--- a/paramiko/util.py
+++ b/paramiko/util.py
@@ -320,3 +320,6 @@ def constant_time_bytes_eq(a, b):
     for i in (xrange if PY2 else range)(len(a)):
         res |= byte_ord(a[i]) ^ byte_ord(b[i])
     return res == 0
+
+def clamp_value(minimum, val, maximum):
+    return max(minimum, min(val, maximum))
diff --git a/tests/test_util.py b/tests/test_util.py
index 69c75518..24f58076 100644
--- a/tests/test_util.py
+++ b/tests/test_util.py
@@ -333,3 +333,8 @@ IdentityFile something_%l_using_fqdn
 """
         config = paramiko.util.parse_ssh_config(StringIO(test_config))
         assert config.lookup('meh')  # will die during lookup() if bug regresses
+
+    def test_12_clamp_value(self):
+        self.assertEqual(32768, paramiko.util.clamp_value(32767, 32768, 32769))
+        self.assertEqual(32767, paramiko.util.clamp_value(32767, 32765, 32769))
+        self.assertEqual(32769, paramiko.util.clamp_value(32767, 32770, 32769))