[PATCH net-next V2 4/8] net/sched: act_mirred: Add new tc_action_ops get_dev()

[Hadar Hen Zion]

Adding support to a new tc_action_ops.
get_dev is a general option which allows to get the underline
device when trying to offload a tc rule.

In case of mirred action the returned device is the mirred (egress)
device.

Signed-off-by: Hadar Hen Zion <had...@mellanox.com>
Reviewed-by: Jiri Pirko <j...@mellanox.com>
---
 include/net/act_api.h  |  2 ++
 net/sched/act_mirred.c | 12 ++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/include/net/act_api.h b/include/net/act_api.h
index d8eae87..9dddf77 100644
--- a/include/net/act_api.h
+++ b/include/net/act_api.h
@@ -119,6 +119,8 @@ struct tc_action_ops {
        int     (*walk)(struct net *, struct sk_buff *,
                        struct netlink_callback *, int, const struct 
tc_action_ops *);
        void    (*stats_update)(struct tc_action *, u64, u32, u64);
+       int     (*get_dev)(const struct tc_action *a, struct net *net,
+                          struct net_device **mirred_dev);
 };
 
 struct tc_action_net {
diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c
index 1af7baa..bb09ba3 100644
--- a/net/sched/act_mirred.c
+++ b/net/sched/act_mirred.c
@@ -315,6 +315,17 @@ static int mirred_device_event(struct notifier_block 
*unused,
        .notifier_call = mirred_device_event,
 };
 
+static int tcf_mirred_device(const struct tc_action *a, struct net *net,
+                            struct net_device **mirred_dev)
+{
+       int ifindex = tcf_mirred_ifindex(a);
+
+       *mirred_dev = __dev_get_by_index(net, ifindex);
+       if (!mirred_dev)
+               return -EINVAL;
+       return 0;
+}
+
 static struct tc_action_ops act_mirred_ops = {
        .kind           =       "mirred",
        .type           =       TCA_ACT_MIRRED,
@@ -327,6 +338,7 @@ static int mirred_device_event(struct notifier_block 
*unused,
        .walk           =       tcf_mirred_walker,
        .lookup         =       tcf_mirred_search,
        .size           =       sizeof(struct tcf_mirred),
+       .get_dev        =       tcf_mirred_device,
 };
 
 static __net_init int mirred_init_net(struct net *net)
-- 
1.8.3.1