[patch net-next 10/17] ipv6: fib: Add offload indication to routes

[Jiri Pirko]

From: Ido Schimmel <ido...@mellanox.com>

Allow user space applications to see which routes are offloaded and
which aren't by setting the RTNH_F_OFFLOAD flag when dumping them.

To be consistent with IPv4, a multipath route is marked as offloaded if
one of its nexthops is offloaded. Individual nexthops aren't marked with
the 'offload' flag.

Signed-off-by: Ido Schimmel <ido...@mellanox.com>
Signed-off-by: Jiri Pirko <j...@mellanox.com>
---
 include/uapi/linux/ipv6_route.h |  1 +
 net/ipv6/route.c                | 19 ++++++++++++++++---
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/include/uapi/linux/ipv6_route.h b/include/uapi/linux/ipv6_route.h
index d496c02..33e2a57 100644
--- a/include/uapi/linux/ipv6_route.h
+++ b/include/uapi/linux/ipv6_route.h
@@ -35,6 +35,7 @@
 #define RTF_PREF(pref) ((pref) << 27)
 #define RTF_PREF_MASK  0x18000000
 
+#define RTF_OFFLOAD    0x20000000      /* offloaded route              */
 #define RTF_PCPU       0x40000000      /* read-only: can not be set by user */
 #define RTF_LOCAL      0x80000000
 
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 4d30c96..924e02d 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1820,6 +1820,11 @@ static struct rt6_info *ip6_route_info_create(struct 
fib6_config *cfg,
                goto out;
        }
 
+       if (cfg->fc_flags & RTF_OFFLOAD) {
+               NL_SET_ERR_MSG(extack, "Userspace can not set RTF_OFFLOAD");
+               goto out;
+       }
+
        if (cfg->fc_dst_len > 128) {
                NL_SET_ERR_MSG(extack, "Invalid prefix length");
                goto out;
@@ -3327,6 +3332,9 @@ static int rt6_nexthop_info(struct sk_buff *skb, struct 
rt6_info *rt,
                        goto nla_put_failure;
        }
 
+       if (rt->rt6i_flags & RTF_OFFLOAD)
+               *flags |= RTNH_F_OFFLOAD;
+
        /* not needed for multipath encoding b/c it has a rtnexthop struct */
        if (!skip_oif && rt->dst.dev &&
            nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
@@ -3343,7 +3351,8 @@ static int rt6_nexthop_info(struct sk_buff *skb, struct 
rt6_info *rt,
 }
 
 /* add multipath next hop */
-static int rt6_add_nexthop(struct sk_buff *skb, struct rt6_info *rt)
+static int rt6_add_nexthop(struct sk_buff *skb, struct rt6_info *rt,
+                          unsigned int *rtm_flags)
 {
        struct rtnexthop *rtnh;
        unsigned int flags = 0;
@@ -3359,6 +3368,10 @@ static int rt6_add_nexthop(struct sk_buff *skb, struct 
rt6_info *rt)
                goto nla_put_failure;
 
        rtnh->rtnh_flags = flags;
+       if (rtnh->rtnh_flags & RTNH_F_OFFLOAD) {
+               rtnh->rtnh_flags &= ~RTNH_F_OFFLOAD;
+               *rtm_flags |= RTNH_F_OFFLOAD;
+       }
 
        /* length of rtnetlink header + attributes */
        rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
@@ -3499,12 +3512,12 @@ static int rt6_fill_node(struct net *net,
                if (!mp)
                        goto nla_put_failure;
 
-               if (rt6_add_nexthop(skb, rt) < 0)
+               if (rt6_add_nexthop(skb, rt, &rtm->rtm_flags) < 0)
                        goto nla_put_failure;
 
                list_for_each_entry_safe(sibling, next_sibling,
                                         &rt->rt6i_siblings, rt6i_siblings) {
-                       if (rt6_add_nexthop(skb, sibling) < 0)
+                       if (rt6_add_nexthop(skb, sibling, &rtm->rtm_flags) < 0)
                                goto nla_put_failure;
                }
 
-- 
2.9.3