Better/more explicit support for nested attributes. am: ad7a79fd6amain-16k

Original change: https://android-review.googlesource.com/c/kernel/tests/+/2316958

Change-Id: Ie759f9744f878a4b5d18f4a1cd286756cf8e0c44
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

6 files changed, 22 insertions, 25 deletions

diff --git a/net/test/genetlink.py b/net/test/genetlink.py
index 6234677..aa46726 100755
--- a/net/test/genetlink.py
+++ b/net/test/genetlink.py
@@ -75,6 +75,7 @@ class GenericNetlinkControl(GenericNetlink):
   def _DecodeOps(self, data):
     ops = []
     Op = collections.namedtuple("Op", ["id", "flags"])
+    # TODO: call _ParseAttributes on the nested data instead of manual parsing.
     while data:
       # Skip the nest marker.
       datalen, index, data = data[:2], data[2:4], data[4:]
@@ -92,7 +93,7 @@ class GenericNetlinkControl(GenericNetlink):
       ops.append(Op(op_id, op_flags))
     return ops
 
-  def _Decode(self, command, msg, nla_type, nla_data):
+  def _Decode(self, command, msg, nla_type, nla_data, nested):
     """Decodes generic netlink control attributes to human-readable format."""
 
     name = self._GetConstantName(__name__, nla_type, "CTRL_ATTR_")
diff --git a/net/test/iproute.py b/net/test/iproute.py
index 313efc9..4483d93 100644
--- a/net/test/iproute.py
+++ b/net/test/iproute.py
@@ -264,7 +264,7 @@ class IPRoute(netlink.NetlinkSocket):
   def _GetConstantName(self, value, prefix):
     return super(IPRoute, self)._GetConstantName(__name__, value, prefix)
 
-  def _Decode(self, command, msg, nla_type, nla_data, nested=0):
+  def _Decode(self, command, msg, nla_type, nla_data, nested):
     """Decodes netlink attributes to Python types.
 
     Values for which the code knows the type (e.g., the fwmark ID in a
@@ -278,13 +278,11 @@ class IPRoute(netlink.NetlinkSocket):
           RTM_NEWROUTE command, attribute type 3 is the incoming interface and
           is an integer, but for a RTM_NEWRULE command, attribute type 3 is the
           incoming interface name and is a string.
-        - If negative, one of the following (negative) values:
-          - RTA_METRICS: Interpret as nested route metrics.
-          - IFLA_LINKINFO: Nested interface information.
       family: The address family. Used to convert IP addresses into strings.
       nla_type: An integer, then netlink attribute type.
       nla_data: A byte string, the netlink attribute data.
-      nested: An integer, how deep we're currently nested.
+      nested: A list, outermost first, of each of the attributes the NLAttrs are
+              nested inside. Empty for non-nested attributes.
 
     Returns:
       A tuple (name, data):
@@ -295,11 +293,12 @@ class IPRoute(netlink.NetlinkSocket):
          (e.g., RTACacheinfo), etc. If we didn't understand the attribute, it
          will be the raw byte string.
     """
-    if command == -RTA_METRICS:
+    lastnested = nested[-1] if nested else None
+    if lastnested == "RTA_METRICS":
       name = self._GetConstantName(nla_type, "RTAX_")
-    elif command == -IFLA_LINKINFO:
+    elif lastnested == "IFLA_LINKINFO":
       name = self._GetConstantName(nla_type, "IFLA_INFO_")
-    elif command == -IFLA_INFO_DATA:
+    elif lastnested == "IFLA_INFO_DATA":
       name = self._GetConstantName(nla_type, "IFLA_VTI_")
     elif CommandSubject(command) == "ADDR":
       name = self._GetConstantName(nla_type, "IFA_")
@@ -335,12 +334,8 @@ class IPRoute(netlink.NetlinkSocket):
     elif name in ["FRA_IIFNAME", "FRA_OIFNAME", "IFLA_IFNAME", "IFLA_QDISC",
                   "IFA_LABEL", "IFLA_INFO_KIND"]:
       data = nla_data.strip(b"\x00")
-    elif name == "RTA_METRICS":
-      data = self._ParseAttributes(-RTA_METRICS, None, nla_data, nested + 1)
-    elif name == "IFLA_LINKINFO":
-      data = self._ParseAttributes(-IFLA_LINKINFO, None, nla_data, nested + 1)
-    elif name == "IFLA_INFO_DATA":
-      data = self._ParseAttributes(-IFLA_INFO_DATA, None, nla_data)
+    elif name in ["RTA_METRICS", "IFLA_LINKINFO", "IFLA_INFO_DATA"]:
+      data = self._ParseAttributes(command, None, nla_data, nested + [name])
     elif name == "RTA_CACHEINFO":
       data = RTACacheinfo(nla_data)
     elif name == "IFA_CACHEINFO":
@@ -694,13 +689,13 @@ class IPRoute(netlink.NetlinkSocket):
   def GetIfaceStats(self, dev_name):
     """Returns an RtnlLinkStats64 stats object for the specified interface."""
     _, attrs = self.GetIfinfo(dev_name)
-    attrs = self._ParseAttributes(RTM_NEWLINK, IfinfoMsg, attrs)
+    attrs = self._ParseAttributes(RTM_NEWLINK, IfinfoMsg, attrs, [])
     return attrs["IFLA_STATS64"]
 
   def GetIfinfoData(self, dev_name):
     """Returns an IFLA_INFO_DATA dict object for the specified interface."""
     _, attrs = self.GetIfinfo(dev_name)
-    attrs = self._ParseAttributes(RTM_NEWLINK, IfinfoMsg, attrs)
+    attrs = self._ParseAttributes(RTM_NEWLINK, IfinfoMsg, attrs, [])
     return attrs["IFLA_LINKINFO"]["IFLA_INFO_DATA"]
 
   def GetRxTxPackets(self, dev_name):
diff --git a/net/test/netlink.py b/net/test/netlink.py
index 9821091..ae3b885 100644
--- a/net/test/netlink.py
+++ b/net/test/netlink.py
@@ -118,7 +118,7 @@ class NetlinkSocket(object):
         return name
     return value
 
-  def _Decode(self, command, msg, nla_type, nla_data):
+  def _Decode(self, command, msg, nla_type, nla_data, nested):
     """No-op, nonspecific version of decode."""
     return nla_type, nla_data
 
@@ -133,7 +133,7 @@ class NetlinkSocket(object):
 
     return nla, nla_data, data
 
-  def _ParseAttributes(self, command, msg, data, nested=0):
+  def _ParseAttributes(self, command, msg, data, nested):
     """Parses and decodes netlink attributes.
 
     Takes a block of NLAttr data structures, decodes them using Decode, and
@@ -143,7 +143,8 @@ class NetlinkSocket(object):
       command: An integer, the rtnetlink command being carried out.
       msg: A Struct, the type of the data after the netlink header.
       data: A byte string containing a sequence of NLAttr data structures.
-      nested: An integer, how deep we're currently nested.
+      nested: A list, outermost first, of each of the attributes the NLAttrs are
+              nested inside. Empty for non-nested attributes.
 
     Returns:
       A dictionary mapping attribute types (integers) to decoded values.
@@ -156,7 +157,7 @@ class NetlinkSocket(object):
       nla, nla_data, data = self._ReadNlAttr(data)
 
       # If it's an attribute we know about, try to decode it.
-      nla_name, nla_data = self._Decode(command, msg, nla.nla_type, nla_data)
+      nla_name, nla_data = self._Decode(command, msg, nla.nla_type, nla_data, nested)
 
       if nla_name in attributes and nla_name not in DUP_ATTRS_OK:
         raise ValueError("Duplicate attribute %s" % nla_name)
@@ -241,7 +242,7 @@ class NetlinkSocket(object):
 
     # Parse the attributes in the nlmsg.
     attrlen = nlmsghdr.length - len(nlmsghdr) - len(nlmsg)
-    attributes = self._ParseAttributes(nlmsghdr.type, nlmsg, data[:attrlen])
+    attributes = self._ParseAttributes(nlmsghdr.type, nlmsg, data[:attrlen], [])
     data = data[attrlen:]
     return (nlmsg, attributes), data
 
diff --git a/net/test/sock_diag.py b/net/test/sock_diag.py
index 30752ba..924d652 100755
--- a/net/test/sock_diag.py
+++ b/net/test/sock_diag.py
@@ -117,7 +117,7 @@ class SockDiag(netlink.NetlinkSocket):
   def __init__(self):
     super(SockDiag, self).__init__(netlink.NETLINK_SOCK_DIAG)
 
-  def _Decode(self, command, msg, nla_type, nla_data):
+  def _Decode(self, command, msg, nla_type, nla_data, nested):
     """Decodes netlink attributes to Python types."""
     if msg.family == AF_INET or msg.family == AF_INET6:
       if isinstance(msg, InetDiagReqV2):
diff --git a/net/test/tcp_metrics.py b/net/test/tcp_metrics.py
index c4e3d69..1076a55 100755
--- a/net/test/tcp_metrics.py
+++ b/net/test/tcp_metrics.py
@@ -62,7 +62,7 @@ class TcpMetrics(genetlink.GenericNetlink):
     ctrl = genetlink.GenericNetlinkControl()
     self.family = ctrl.GetFamily(TCP_METRICS_GENL_NAME)
 
-  def _Decode(self, command, msg, nla_type, nla_data):
+  def _Decode(self, command, msg, nla_type, nla_data, nested):
     """Decodes TCP metrics netlink attributes to human-readable format."""
 
     name = self._GetConstantName(__name__, nla_type, "TCP_METRICS_ATTR_")
diff --git a/net/test/xfrm.py b/net/test/xfrm.py
index 3cd1af9..d1e1871 100755
--- a/net/test/xfrm.py
+++ b/net/test/xfrm.py
@@ -368,7 +368,7 @@ class Xfrm(netlink.NetlinkSocket):
     else:
       print("%s" % cmdname)
 
-  def _Decode(self, command, unused_msg, nla_type, nla_data):
+  def _Decode(self, command, unused_msg, nla_type, nla_data, nested):
     """Decodes netlink attributes to Python types."""
     name = self._GetConstantName(nla_type, "XFRMA_")