[PATCH ebtables-nft] nft-bridge: work around recent "among" decode breakage

[PATCH ebtables-nft] nft-bridge: work around recent "among" decode breakage

[Florian Westphal]

ebtables-nft-save will fail with
"unknown meta key" when decoding "among" emulation with ipv4 or ipv6
addresses included.

This is because "meta protocol ip" is used as a dependency, but
its never decoded anywhere.

Skip this for now to restore the "ebtables/0006-flush_0"
test case.

Fixes: 25883ce88bfb ("nft: check for unknown meta keys")
Signed-off-by: Florian Westphal <fw@strlen.de>
---
 iptables/nft-bridge.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/iptables/nft-bridge.c b/iptables/nft-bridge.c
index 3180091364fa..50e90b22cf2f 100644
--- a/iptables/nft-bridge.c
+++ b/iptables/nft-bridge.c
@@ -197,6 +197,11 @@ static void nft_bridge_parse_meta(struct nft_xt_ctx *ctx,
 	uint8_t invflags = 0;
 	char iifname[IFNAMSIZ] = {}, oifname[IFNAMSIZ] = {};
 
+	switch (reg->meta_dreg.key) {
+	case NFT_META_PROTOCOL:
+		return;
+	}
+
 	if (parse_meta(ctx, e, reg->meta_dreg.key, iifname, NULL, oifname, NULL, &invflags) < 0) {
 		ctx->errmsg = "unknown meta key";
 		return;
-- 
2.38.1

Re: [PATCH ebtables-nft] nft-bridge: work around recent "among" decode breakage

[Phil Sutter]

On Wed, Nov 30, 2022 at 11:38:12AM +0100, Florian Westphal wrote:
> ebtables-nft-save will fail with
> "unknown meta key" when decoding "among" emulation with ipv4 or ipv6
> addresses included.
> 
> This is because "meta protocol ip" is used as a dependency, but
> its never decoded anywhere.
> 
> Skip this for now to restore the "ebtables/0006-flush_0"
> test case.
> 
> Fixes: 25883ce88bfb ("nft: check for unknown meta keys")
> Signed-off-by: Florian Westphal <fw@strlen.de>

Best-effort approach. :)

Acked-by: Phil Sutter <phil@nwl.cc>