CA-420307: Construct synthetic page data as byte arrays

Build the synthetic page data as byte arrays, rather than as strings.
Convert the string portions in the synthetic page data as needed.

str.encode() does not deal with embedded bytes in strings, as when converting
using UTF-8 (the default), this will convert '\x80' into '\xC2\x80', which
leads to incorrect data getting reported.

Signed-off-by: Owen Smith <[email protected]>
Co-authored-by: Mark Syms <[email protected]>
Signed-off-by: Mark Syms <[email protected]>

Author: OwenSmith

libs/sm/core/scsiutil.py

@@ -340,21 +340,21 @@ def gen_synthetic_page_data(uuid):
     # we set the vendor ID to XENSRC
     # Note that the Page 80 serial number must be limited
     # to 16 characters
-    page80 = ""
-    page80 += "\x00\x80"
-    page80 += "\x00\x12"
-    page80 += uuid[0:16]
-    page80 += "  "
-
-    page83 = ""
-    page83 += "\x00\x83"
-    page83 += "\x00\x31"
-    page83 += "\x02\x01\x00\x2d"
-    page83 += "XENSRC  "
-    page83 += uuid
-    page83 += " "
-    return ["", base64.b64encode(str.encode(page80)).decode(),
-            base64.b64encode(str.encode(page83)).decode()]
+    page80 = b''
+    page80 += b'\x00\x80'
+    page80 += b'\x00\x12'
+    page80 += str.encode(uuid[0:16])
+    page80 += str.encode("  ")
+
+    page83 = b''
+    page83 += b'\x00\x83'
+    page83 += b'\x00\x31'
+    page83 += b'\x02\x01\x00\x2d'
+    page83 += str.encode("XENSRC  ")
+    page83 += str.encode(uuid)
+    page83 += str.encode(" ")
+    return ["", base64.b64encode(page80).decode(),
+            base64.b64encode(page83).decode()]
 
 
 def gen_raw_page_data(path):

tests/test_blktap2.py

@@ -1,3 +1,4 @@
+import base64
 import errno
 import json
 from io import StringIO
@@ -599,6 +600,17 @@ def find_by_path(path):
         # Assert
         mock_shutdown.assert_called_once()
 
+    def test_scsi_page_data(self):
+        """
+        Check that the scsi page data is correctly encoded
+        """
+        page_80 = base64.b64decode(self.vdi.xenstore_data["scsi/0x12/0x80"])
+        page_83 = base64.b64decode(self.vdi.xenstore_data["scsi/0x12/0x83"])
+
+        self.assertEqual(b'\x00\x80\x00\x12', page_80[:4])
+        self.assertEqual(b'\x00\x83\x00\x31\x02\x01\x00\x2d', page_83[:8])
+        self.assertEqual('XENSRC  ', page_83[8:16].decode())
+
 
 @mock.patch('sm.core.xs_errors.XML_DEFS', 'libs/sm/core/XE_SR_ERRORCODES.xml')
 class TestTapCtl(unittest.TestCase):