From 499f32f0eb56603af2930ba67b4eb82fc1437264 Mon Sep 17 00:00:00 2001 From: Hangbin Liu Date: Thu, 8 Oct 2026 16:24:01 +0800 Subject: [PATCH] net: lwtunnel: change encap fill order I plan to add lwtunnel encap attributes to the YNL rt-route.yaml spec. When decoding submessages, YNL expects to read the "selector" (encap-type) first. Currently lwtunnel writes the encap payload first, which makes YNL fail to parse the lwtunnel encap message. Fixing this within YNL itself would be complicated. Instead, reorder the netlink attributes in the kernel to output encap_type first. This is a preparatory change for the upcoming rt-route spec updates. Reviewed-by: Ido Schimmel Signed-off-by: Hangbin Liu Link: https://patch.msgid.link/20261008-ynl_rt_encap-v4-1-4ed2ccf7f949@kylinos.cn Signed-off-by: Jakub Kicinski --- net/core/lwtunnel.c | 37 +++++++++++++++++++------------------ 1 file changed, 19 insertions(+), 18 deletions(-) diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c index b01a395d9a96..8223c44f10c8 100644 --- a/net/core/lwtunnel.c +++ b/net/core/lwtunnel.c @@ -231,7 +231,7 @@ int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate, { const struct lwtunnel_encap_ops *ops; struct nlattr *nest; - int ret; + int ret = 0; if (!lwtstate) return 0; @@ -240,30 +240,31 @@ int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate, lwtstate->type > LWTUNNEL_ENCAP_MAX) return 0; - nest = nla_nest_start_noflag(skb, encap_attr); - if (!nest) - return -EMSGSIZE; - - ret = -EOPNOTSUPP; rcu_read_lock(); - ops = rcu_dereference(lwtun_encaps[lwtstate->type]); - if (likely(ops && ops->fill_encap)) - ret = ops->fill_encap(skb, lwtstate); - rcu_read_unlock(); - if (ret) - goto nla_put_failure; - nla_nest_end(skb, nest); + ops = rcu_dereference(lwtun_encaps[lwtstate->type]); + if (unlikely(!ops || !ops->fill_encap)) + goto unlock_out; + ret = nla_put_u16(skb, encap_type_attr, lwtstate->type); if (ret) - goto nla_put_failure; + goto unlock_out; - return 0; + nest = nla_nest_start_noflag(skb, encap_attr); + if (!nest) { + ret = -EMSGSIZE; + goto unlock_out; + } -nla_put_failure: - nla_nest_cancel(skb, nest); + ret = ops->fill_encap(skb, lwtstate); + if (ret) + nla_nest_cancel(skb, nest); + else + nla_nest_end(skb, nest); - return (ret == -EOPNOTSUPP ? 0 : ret); +unlock_out: + rcu_read_unlock(); + return ret; } EXPORT_SYMBOL_GPL(lwtunnel_fill_encap);