datapath: Kernel flow metadata parsing should be less restrictive

The function flow_metadata_from_nlattrs() is very restrictive
about the ordering and type of metadata attributes that it receives.
This patch will change flow_metadata_from_nlattrs() behavior by
ignoring attributes that it does not understand and allowing them
to be passed in arbitrary order.

Issue #8167

Signed-off-by: Ansis Atteka <aatteka@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>

diff --git a/datapath/flow.c b/datapath/flow.c
index 55e3494..152d9be 100644 (file)
--- a/datapath/flow.c
+++ b/datapath/flow.c
@@ -1160,43 +1160,35 @@ int flow_metadata_from_nlattrs(u32 *priority, u16 *in_port, __be64 *tun_id,
                               const struct nlattr *attr)
 {
        const struct nlattr *nla;
-       u16 prev_type;
        int rem;
 
        *in_port = USHRT_MAX;
        *tun_id = 0;
        *priority = 0;
 
-       prev_type = OVS_KEY_ATTR_UNSPEC;
        nla_for_each_nested(nla, attr, rem) {
                int type = nla_type(nla);
 
-               if (type > OVS_KEY_ATTR_MAX || nla_len(nla) != ovs_key_lens[type])
-                       return -EINVAL;
-
-               switch (TRANSITION(prev_type, type)) {
-               case TRANSITION(OVS_KEY_ATTR_UNSPEC, OVS_KEY_ATTR_PRIORITY):
-                       *priority = nla_get_u32(nla);
-                       break;
+               if (type <= OVS_KEY_ATTR_MAX && ovs_key_lens[type] != 0) {
+                       if (nla_len(nla) != ovs_key_lens[type])
+                               return -EINVAL;
 
-               case TRANSITION(OVS_KEY_ATTR_UNSPEC, OVS_KEY_ATTR_TUN_ID):
-               case TRANSITION(OVS_KEY_ATTR_PRIORITY, OVS_KEY_ATTR_TUN_ID):
-                       *tun_id = nla_get_be64(nla);
-                       break;
+                       switch (type) {
+                       case OVS_KEY_ATTR_PRIORITY:
+                               *priority = nla_get_u32(nla);
+                               break;
 
-               case TRANSITION(OVS_KEY_ATTR_UNSPEC, OVS_KEY_ATTR_IN_PORT):
-               case TRANSITION(OVS_KEY_ATTR_PRIORITY, OVS_KEY_ATTR_IN_PORT):
-               case TRANSITION(OVS_KEY_ATTR_TUN_ID, OVS_KEY_ATTR_IN_PORT):
-                       if (nla_get_u32(nla) >= DP_MAX_PORTS)
-                               return -EINVAL;
-                       *in_port = nla_get_u32(nla);
-                       break;
+                       case OVS_KEY_ATTR_TUN_ID:
+                               *tun_id = nla_get_be64(nla);
+                               break;
 
-               default:
-                       return 0;
+                       case OVS_KEY_ATTR_IN_PORT:
+                               if (nla_get_u32(nla) >= DP_MAX_PORTS)
+                                       return -EINVAL;
+                               *in_port = nla_get_u32(nla);
+                               break;
+                       }
                }
-
-               prev_type = type;
        }
        if (rem)
                return -EINVAL;