Re: [ovs-dev] [RFC net-next 4/7] selftests: openvswitch: Add support for tunnel() key.

Simon Horman [off-list ref] writes:

On Thu, Jun 13, 2024 at 02:13:30PM -0400, Aaron Conole wrote:

quoted

This will be used when setting details about the tunnel to use as
transport.  There is a difference between the ODP format between tunnel():
the 'key' flag is not actually a flag field, so we don't support it in the
same way that the vswitchd userspace supports displaying it.

Signed-off-by: Aaron Conole <aconole@redhat.com>

...

quoted

@@ -1265,6 +1265,165 @@ class ovskey(nla):
                 init=init,
             )
 
+    class ovs_key_tunnel(nla):
+        nla_flags = NLA_F_NESTED
+
+        nla_map = (
+            ("OVS_TUNNEL_KEY_ATTR_ID", "be64"),
+            ("OVS_TUNNEL_KEY_ATTR_IPV4_SRC", "ipaddr"),
+            ("OVS_TUNNEL_KEY_ATTR_IPV4_DST", "ipaddr"),
+            ("OVS_TUNNEL_KEY_ATTR_TOS", "uint8"),
+            ("OVS_TUNNEL_KEY_ATTR_TTL", "uint8"),
+            ("OVS_TUNNEL_KEY_ATTR_DONT_FRAGMENT", "flag"),
+            ("OVS_TUNNEL_KEY_ATTR_CSUM", "flag"),
+            ("OVS_TUNNEL_KEY_ATTR_OAM", "flag"),
+            ("OVS_TUNNEL_KEY_ATTR_GENEVE_OPTS", "array(uint32)"),
+            ("OVS_TUNNEL_KEY_ATTR_TP_SRC", "be16"),
+            ("OVS_TUNNEL_KEY_ATTR_TP_DST", "be16"),
+            ("OVS_TUNNEL_KEY_ATTR_VXLAN_OPTS", "none"),
+            ("OVS_TUNNEL_KEY_ATTR_IPV6_SRC", "ipaddr"),
+            ("OVS_TUNNEL_KEY_ATTR_IPV6_DST", "ipaddr"),
+            ("OVS_TUNNEL_KEY_ATTR_PAD", "none"),
+            ("OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS", "none"),
+            ("OVS_TUNNEL_KEY_ATTR_IPV4_INFO_BRIDGE", "flag"),
+        )
+
+        def parse(self, flowstr, mask=None):
+            if not flowstr.startswith("tunnel("):
+                return None, None
+
+            k = ovskey.ovs_key_tunnel()
+            if mask is not None:
+                mask = ovskey.ovs_key_tunnel()
+
+            flowstr = flowstr[len("tunnel("):]
+
+            v6_address = None
+
+            fields = [
+                ("tun_id=", r"(\d+)", int, "OVS_TUNNEL_KEY_ATTR_ID",
+                 0xffffffffffffffff, None, None),
+
+                ("src=", r"([0-9a-fA-F\.]+)", str,
+                 "OVS_TUNNEL_KEY_ATTR_IPV4_SRC", "255.255.255.255", "0.0.0.0",
+                 False),
+                ("dst=", r"([0-9a-fA-F\.]+)", str,
+                 "OVS_TUNNEL_KEY_ATTR_IPV4_DST", "255.255.255.255", "0.0.0.0",
+                 False),
+
+                ("ipv6_src=", r"([0-9a-fA-F:]+)", str,
+                 "OVS_TUNNEL_KEY_ATTR_IPV6_SRC",
+                 "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff", "::", True),
+                ("ipv6_dst=", r"([0-9a-fA-F:]+)", str,
+                 "OVS_TUNNEL_KEY_ATTR_IPV6_DST",
+                 "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff", "::", True),
+
+                ("tos=", r"(\d+)", int, "OVS_TUNNEL_KEY_ATTR_TOS", 255, 0,
+                 None),
+                ("ttl=", r"(\d+)", int, "OVS_TUNNEL_KEY_ATTR_TTL", 255, 0,
+                 None),
+
+                ("tp_src=", r"(\d+)", int, "OVS_TUNNEL_KEY_ATTR_TP_SRC",
+                 65535, 0, None),
+                ("tp_dst=", r"(\d+)", int, "OVS_TUNNEL_KEY_ATTR_TP_DST",
+                 65535, 0, None),
+            ]
+
+            forced_include = ["OVS_TUNNEL_KEY_ATTR_TTL"]
+
+            for prefix, regex, typ, attr_name, mask_val, default_val, v46_flag in fields:
+                flowstr, value = parse_extract_field(flowstr, prefix, regex, typ, False)
+                if not attr_name:
+                    raise Exception("Bad list value in tunnel fields")
+
+                if value is None and attr_name in forced_include:
+                    value = default_val
+                    mask_val = default_val
+
+                if value is not None:
+                    if v6_address is None and v46_flag is not None:
+                        v6_address = v46_flag

By my reading, at this point v6_address will only be None if v46_flag is
not None.  IF so, the condition below seems excessive.

Agreed - thanks for the suggestions.

quoted

+                    if v6_address is not None and v46_flag is not None \
+                       and v46_flag != v6_address:
+                        raise ValueError("Cannot mix v6 and v4 addresses")

I wonder if we can instead express this as (completely untested!):

                    if v46_flag is not None:
                        if v6_address is None:
                            v6_address = v46_flag
                        if v46_flag != v6_address:
                            raise ValueError("Cannot mix v6 and v4 addresses")

quoted

+                    k["attrs"].append([attr_name, value])
+                    if mask is not None:
+                        mask["attrs"].append([attr_name, mask_val])
+                else:
+                    if v6_address is not None and v46_flag is not None \
+                       and v46_flag != v6_address:
+                        continue
+                    if v6_address is None and v46_flag is not None:
+                        continue

And I wonder if this is a bit easier on the eyes (also completely untested):

                    if v46_flag is not None:
                        if v6_address is None or v46_flag != v6_address:
                            continue

I folded both of these in and did some quick testing.  Thanks Simon!

quoted

+                    if mask is not None:
+                        mask["attrs"].append([attr_name, default_val])
+
+            if k["attrs"][0][0] != "OVS_TUNNEL_KEY_ATTR_ID":
+                raise ValueError("Needs a tunid set")

...

quoted

@@ -1745,7 +1905,7 @@ class OvsVport(GenericNetlinkSocket):
         )
 
         TUNNEL_DEFAULTS = [("geneve", 6081),
-                           ("vxlan", 4798)]
+                           ("vxlan", 4789)]
 
         for tnl in TUNNEL_DEFAULTS:
             if ptype == tnl[0]:

As noted in my response to PATCH 1/7, I think that the
change in the hunk above belongs there rather than here.