datapath: Accept any in_port mask but override to be exact match

Pre mega flow, netlink allows the in_port key attribute
to be missing. Missing in_port is interpreted as DP_MAX_PORTS.

For backward compatibility, mega flow implementation will always allow
the mask of in_port to be specified, as if the in_port key attribute
is always specified.

To prevent accidental match of the DP_MAX_PORTS, which value is opaque to
the user space, we will always force the mask to be exact match,
regardless of the value supplied by the netline message. Missing
in_port mask continue to mean wildcarded match, same as other masks.

Signed-off-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>

diff --git a/datapath/flow.c b/datapath/flow.c
index 29d3062..4d18aad 100644 (file)
--- a/datapath/flow.c
+++ b/datapath/flow.c
@@ -135,12 +135,9 @@ static bool ovs_match_validate(const struct sw_flow_match *match,
                        | (1ULL << OVS_KEY_ATTR_ARP)
                        | (1ULL << OVS_KEY_ATTR_ND));
 
-       /* Tunnel mask is always allowed. */
-       mask_allowed |= (1ULL << OVS_KEY_ATTR_TUNNEL);
-
-       if (match->key->phy.in_port == DP_MAX_PORTS &&
-           match->mask && (match->mask->key.phy.in_port == 0xffff))
-               mask_allowed |= (1ULL << OVS_KEY_ATTR_IN_PORT);
+       /* Always allowed mask fields. */
+       mask_allowed |= ((1ULL << OVS_KEY_ATTR_TUNNEL)
+                      | (1ULL << OVS_KEY_ATTR_IN_PORT));
 
        if (match->key->eth.type == htons(ETH_P_802_2) &&
            match->mask && (match->mask->key.eth.type == htons(0xffff)))
@@ -1315,8 +1312,11 @@ static int metadata_from_nlattrs(struct sw_flow_match *match,  u64 *attrs,
        if (*attrs & (1ULL << OVS_KEY_ATTR_IN_PORT)) {
                u32 in_port = nla_get_u32(a[OVS_KEY_ATTR_IN_PORT]);
 
-               if (!is_mask && in_port >= DP_MAX_PORTS)
+               if (is_mask)
+                       in_port = 0xffffffff; /* Always exact match in_port. */
+               else if (in_port >= DP_MAX_PORTS)
                        return -EINVAL;
+
                SW_FLOW_KEY_PUT(match, phy.in_port, in_port, is_mask);
                *attrs &= ~(1ULL << OVS_KEY_ATTR_IN_PORT);
        } else if (!is_mask) {