datapath: backport: ovs: allow nl 'flow set' to use ufid without flow key

Upstream commit:
    commit 6f15cdbf8a8ac2e22767cc8b1eae225702733c95
    Author: Samuel Gauthier <samuel.gauthier@6wind.com>

    ovs: allow nl 'flow set' to use ufid without flow key

    When we want to change a flow using netlink, we have to identify it to
    be able to perform a lookup. Both the flow key and unique flow ID
    (ufid) are valid identifiers, but we always have to specify the flow
    key in the netlink message. When both attributes are there, the ufid
    is used. The flow key is used to validate the actions provided by
    the userland.

    This commit allows to use the ufid without having to provide the flow
    key, as it is already done in the netlink 'flow get' and 'flow del'
    path. The flow key remains mandatory when an action is provided.

    Signed-off-by: Samuel Gauthier <samuel.gauthier@6wind.com>
    Reviewed-by: Simon Horman <simon.horman@netronome.com>
    Acked-by: Pravin B Shelar <pshelar@ovn.org>
    Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Pravin B Shelar <pshelar@ovn.org>
Acked-by: Jesse Gross <jesse@kernel.org>

diff --git a/datapath/datapath.c b/datapath/datapath.c
index 56bb86d54952216c2c7d898174d18022e003dba6..5c9ea0ef7eeb5a8a2fd773f86676429ef8168b5a 100644 (file)
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -1130,26 +1130,32 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct genl_info *info)
        struct sw_flow_match match;
        struct sw_flow_id sfid;
        u32 ufid_flags = ovs_nla_get_ufid_flags(a[OVS_FLOW_ATTR_UFID_FLAGS]);
-       int error;
+       int error = 0;
        bool log = !a[OVS_FLOW_ATTR_PROBE];
        bool ufid_present;
 
-       /* Extract key. */
-       error = -EINVAL;
-       if (!a[OVS_FLOW_ATTR_KEY]) {
-               OVS_NLERR(log, "Flow key attribute not present in set flow.");
-               goto error;
-       }
-
        ufid_present = ovs_nla_get_ufid(&sfid, a[OVS_FLOW_ATTR_UFID], log);
-       ovs_match_init(&match, &key, &mask);
-       error = ovs_nla_get_match(net, &match, a[OVS_FLOW_ATTR_KEY],
-                                 a[OVS_FLOW_ATTR_MASK], log);
+       if (a[OVS_FLOW_ATTR_KEY]) {
+               ovs_match_init(&match, &key, &mask);
+               error = ovs_nla_get_match(net, &match, a[OVS_FLOW_ATTR_KEY],
+                                         a[OVS_FLOW_ATTR_MASK], log);
+       } else if (!ufid_present) {
+               OVS_NLERR(log,
+                         "Flow set message rejected, Key attribute missing.");
+               error = -EINVAL;
+       }
        if (error)
                goto error;
 
        /* Validate actions. */
        if (a[OVS_FLOW_ATTR_ACTIONS]) {
+               if (!a[OVS_FLOW_ATTR_KEY]) {
+                       OVS_NLERR(log,
+                                 "Flow key attribute not present in set flow.");
+                       error = -EINVAL;
+                       goto error;
+               }
+
                acts = get_flow_actions(net, a[OVS_FLOW_ATTR_ACTIONS], &key,
                                        &mask, log);
                if (IS_ERR(acts)) {