Improve netlink message debugging.

1. Add a method to convert a message to a string. The code didn't
   have anything that did just that; all string conversions were
   part of the debugging code. This method can be used by
   external callers that just want to parse raw messages obtained
   by other means (e.g., strace).
2. Teach the code about FRA_FWMASK.
3. Fix a bug in the parsing error handling due to attempting to
   catch the wrong exception.

Also fix a couple of lint errors.

Change-Id: I1915ab984934810ddbef7040c78d58e8657bb028

1 files changed, 20 insertions, 10 deletions

diff --git a/tests/net_test/iproute.py b/tests/net_test/iproute.py
index df1c1210..cf1f282a 100644
--- a/tests/net_test/iproute.py
+++ b/tests/net_test/iproute.py
@@ -160,6 +160,7 @@ FRA_PRIORITY = 6
 FRA_FWMARK = 10
 FRA_SUPPRESS_PREFIXLEN = 14
 FRA_TABLE = 15
+FRA_FWMASK = 16
 FRA_OIFNAME = 17
 FRA_UID_START = 18
 FRA_UID_END = 19
@@ -185,6 +186,7 @@ IFLA_NUM_TX_QUEUES = 31
 IFLA_NUM_RX_QUEUES = 32
 IFLA_CARRIER = 33
 
+
 def CommandVerb(command):
   return ["NEW", "DEL", "GET", "SET"][command % 4]
 
@@ -196,7 +198,7 @@ def CommandSubject(command):
 def CommandName(command):
   try:
     return "RTM_%s%s" % (CommandVerb(command), CommandSubject(command))
-  except KeyError:
+  except IndexError:
     return "RTM_%d" % command
 
 
@@ -293,7 +295,7 @@ class IPRoute(object):
       # Don't know what this is. Leave it as an integer.
       name = nla_type
 
-    if name in ["FRA_PRIORITY", "FRA_FWMARK", "FRA_TABLE",
+    if name in ["FRA_PRIORITY", "FRA_FWMARK", "FRA_TABLE", "FRA_FWMASK",
                 "FRA_UID_START", "FRA_UID_END",
                 "RTA_OIF", "RTA_PRIORITY", "RTA_TABLE", "RTA_MARK",
                 "IFLA_MTU", "IFLA_TXQLEN", "IFLA_GROUP", "IFLA_EXT_MASK",
@@ -518,12 +520,10 @@ class IPRoute(object):
       self._ExpectDone()
     return out
 
-  def MaybeDebugCommand(self, command, data):
-    subject = CommandSubject(command)
-    if "ALL" not in self.NL_DEBUG and subject not in self.NL_DEBUG:
-      return
-    name = CommandName(command)
+  def CommandToString(self, command, data):
     try:
+      name = CommandName(command)
+      subject = CommandSubject(command)
       struct_type = {
           "ADDR": IfAddrMsg,
           "LINK": IfinfoMsg,
@@ -532,14 +532,24 @@ class IPRoute(object):
           "RULE": RTMsg,
       }[subject]
       parsed = self._ParseNLMsg(data, struct_type)
-      print "%s %s" % (name, str(parsed))
-    except KeyError:
+      return "%s %s" % (name, str(parsed))
+    except IndexError:
       raise ValueError("Don't know how to print command type %s" % name)
 
+  def MaybeDebugCommand(self, command, data):
+    subject = CommandSubject(command)
+    if "ALL" not in self.NL_DEBUG and subject not in self.NL_DEBUG:
+      return
+    print self.CommandToString(command, data)
+
   def MaybeDebugMessage(self, message):
     hdr = NLMsgHdr(message)
     self.MaybeDebugCommand(hdr.type, message)
 
+  def PrintMessage(self, message):
+    hdr = NLMsgHdr(message)
+    print self.CommandToString(hdr.type, message)
+
   def _Dump(self, command, msg, msgtype):
     """Sends a dump request and returns a list of decoded messages."""
     # Create a netlink dump request containing the msg.
@@ -672,7 +682,7 @@ class IPRoute(object):
     self._Neighbour(version, False, addr, lladdr, dev, 0)
 
   def DumpNeighbours(self, version):
-    ndmsg = NdMsg((0, 0, 0, 0, 0))
+    ndmsg = NdMsg((self._AddressFamily(version), 0, 0, 0, 0))
     return self._Dump(RTM_GETNEIGH, ndmsg, NdMsg)