ip_gre: do not report erspan version on GRE interface

[ Upstream commit ee496694b9eea651ae1aa4c4667d886cdf74aa3b ]

Although the type I ERSPAN is based on the barebones IP + GRE
encapsulation and no extra ERSPAN header. Report erspan version on GRE
interface looks unreasonable. Fix this by separating the erspan and gre
fill info.

IPv6 GRE does not have this info as IPv6 only supports erspan version
1 and 2.

Reported-by: Jianlin Shi <jishi@redhat.com>
Fixes: f989d546a2d5 ("erspan: Add type I version 0 support.")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: William Tu <u9012063@gmail.com>
Link: https://lore.kernel.org/r/20221203032858.3130339-1-liuhangbin@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index fc74a3e3b3e1262ef5ad5996889a5a45f8c4bb65..454c4357a297978abe8a52d3e374583f2eb9ca4a 100644 (file)
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -1498,24 +1498,6 @@ static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
        struct ip_tunnel_parm *p = &t->parms;
        __be16 o_flags = p->o_flags;
 
-       if (t->erspan_ver <= 2) {
-               if (t->erspan_ver != 0 && !t->collect_md)
-                       o_flags |= TUNNEL_KEY;
-
-               if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver))
-                       goto nla_put_failure;
-
-               if (t->erspan_ver == 1) {
-                       if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index))
-                               goto nla_put_failure;
-               } else if (t->erspan_ver == 2) {
-                       if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir))
-                               goto nla_put_failure;
-                       if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid))
-                               goto nla_put_failure;
-               }
-       }
-
        if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
            nla_put_be16(skb, IFLA_GRE_IFLAGS,
                         gre_tnl_flags_to_gre_flags(p->i_flags)) ||
@@ -1556,6 +1538,34 @@ nla_put_failure:
        return -EMSGSIZE;
 }
 
+static int erspan_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+       struct ip_tunnel *t = netdev_priv(dev);
+
+       if (t->erspan_ver <= 2) {
+               if (t->erspan_ver != 0 && !t->collect_md)
+                       t->parms.o_flags |= TUNNEL_KEY;
+
+               if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver))
+                       goto nla_put_failure;
+
+               if (t->erspan_ver == 1) {
+                       if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index))
+                               goto nla_put_failure;
+               } else if (t->erspan_ver == 2) {
+                       if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir))
+                               goto nla_put_failure;
+                       if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid))
+                               goto nla_put_failure;
+               }
+       }
+
+       return ipgre_fill_info(skb, dev);
+
+nla_put_failure:
+       return -EMSGSIZE;
+}
+
 static void erspan_setup(struct net_device *dev)
 {
        struct ip_tunnel *t = netdev_priv(dev);
@@ -1634,7 +1644,7 @@ static struct rtnl_link_ops erspan_link_ops __read_mostly = {
        .changelink     = erspan_changelink,
        .dellink        = ip_tunnel_dellink,
        .get_size       = ipgre_get_size,
-       .fill_info      = ipgre_fill_info,
+       .fill_info      = erspan_fill_info,
        .get_link_net   = ip_tunnel_get_link_net,
 };