Add a utility function for checking kernel versions.

Test: test-only change, covered in upcoming CL
Change-Id: Ia356f43c6ec3d0ee84e87489e6c7968a0705f72a

1 files changed, 26 insertions, 0 deletions

diff --git a/net/test/net_test.py b/net/test/net_test.py
index 0dae1c2..bbff4e7 100644
--- a/net/test/net_test.py
+++ b/net/test/net_test.py
@@ -96,6 +96,32 @@ KERN_INFO = 6
 LINUX_VERSION = csocket.LinuxVersion()
 LINUX_ANY_VERSION = (0, 0)
 
+def KernelAtLeast(versions):
+  """Checks the kernel version matches the specified versions.
+
+  Args:
+    versions: a list of versions expressed as tuples,
+    e.g., [(5, 10, 108), (5, 15, 31)]. The kernel version matches if it's
+    between each specified version and the next minor version with last digit
+    set to 0. In this example, the kernel version must match either:
+      >= 5.10.108 and < 5.15.0
+      >= 5.15.31
+    While this is less flexible than matching exact tuples, it allows the caller
+    to pass in fewer arguments, because Android only supports certain minor
+    versions (4.19, 5.4, 5.10, ...)
+
+  Returns:
+    True if the kernel version matches, False otherwise
+  """
+  maxversion = (1000, 255, 65535)
+  for version in sorted(versions, reverse=True):
+    if version[:2] == maxversion[:2]:
+      raise ValueError("Duplicate minor version: %s %s", (version, maxversion))
+    if LINUX_VERSION >= version and LINUX_VERSION < maxversion:
+      return True
+    maxversion = (version[0], version[1], 0)
+  return False
+
 def ByteToHex(b):
   return "%02x" % (ord(b) if isinstance(b, str) else b)