Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B5C743DC4D8; Mon, 17 Aug 2026 13:54:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786974899; cv=none; b=mUUfYxMEI1EUctMJOiv/yTeQALrshVlpJIybu/p/DL+AJqPcs6y4mjIgxHIfiDVldj+ABB6ty1/XHmO2jQShaYk7EN1VsF0067NePcgf7TPd7iLnguSghecvR3dJTL4PqjDn/ltL86qUY5WyNBYrW18KuYaFzSjj8e5Mc50D8JM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786974899; c=relaxed/simple; bh=Dpo74xK7TEFDkH5k0bqsr8E+96FKmZrlQgiW4ZiYpNc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pdMp8wy8wJ504R+XfwPeIDKXC+Yx1lJA+ZX8ORb6imQ2d3zEo8b87k3HtAYzrBiqDHOsdTX4XI63r9EK24SXIwdzsFxPod2F33liZBPMDl2Jfm7ceZMKay9e0TI74p7/cZ7xsIOX6jvH/FwvWB+8YYGg0qGR24mzkYcyFU5gCdc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JQ7aMgWd; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="JQ7aMgWd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B875C1F000E9; Mon, 17 Aug 2026 13:54:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786974895; bh=cTqX2xhzmOBeNo3arBfMnpHjBWfUDYF/2284AhN6Ul4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=JQ7aMgWdLcudiuWh1vJ6dDuVzhPD++LPrBSVxmhutovrPY8HKfjOMdO7EgPKH3hFF 0TfYstNAt3o/ZnFPmlU/BR1toqmr0tVCpYiSpL+5m68P7xRfNwoW3whcF5NazPxUOa kvCZC7msA8Rcc0te77/l7pKiJOEZ6YM7Qgc4xxS8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Pablo Neira Ayuso , Sasha Levin Subject: [PATCH 6.18 091/250] netfilter: flowtable: consolidate xmit path Date: Mon, 17 Aug 2026 15:30:52 +0200 Message-ID: <20260817132540.201689620@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260817132536.466235697@linuxfoundation.org> References: <20260817132536.466235697@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pablo Neira Ayuso [ Upstream commit b5964aac51e0c286a50e68225e0dfcf11fb554cb ] Use dev_queue_xmit() for the XMIT_NEIGH case. Store the interface index of the real device behind the vlan/pppoe device, this introduces an extra lookup for the real device in the xmit path because rt->dst.dev provides the vlan/pppoe device. XMIT_NEIGH now looks more similar to XMIT_DIRECT but the check for stale dst and the neighbour lookup still remain in place which is convenient to deal with network topology changes. Note that nft_flow_route() needs to relax the check for _XMIT_NEIGH so the existing basic xfrm offload (which only works in one direction) does not break. Signed-off-by: Pablo Neira Ayuso Stable-dep-of: 8aecf0bbcc72 ("netfilter: nf_flow_table: drop existing skb dst before skb_dst_set_noref()") Signed-off-by: Sasha Levin --- include/net/netfilter/nf_flow_table.h | 1 + net/netfilter/nf_flow_table_core.c | 1 + net/netfilter/nf_flow_table_ip.c | 87 ++++++++++++++++----------- net/netfilter/nf_flow_table_path.c | 7 +-- 4 files changed, 57 insertions(+), 39 deletions(-) diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h index e9f72d2558e90..7c330caae52bf 100644 --- a/include/net/netfilter/nf_flow_table.h +++ b/include/net/netfilter/nf_flow_table.h @@ -141,6 +141,7 @@ struct flow_offload_tuple { union { struct { struct dst_entry *dst_cache; + u32 ifidx; u32 dst_cookie; }; struct { diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c index d3104816b7f71..595a0f19d15e7 100644 --- a/net/netfilter/nf_flow_table_core.c +++ b/net/netfilter/nf_flow_table_core.c @@ -132,6 +132,7 @@ static int flow_offload_fill_route(struct flow_offload *flow, break; case FLOW_OFFLOAD_XMIT_XFRM: case FLOW_OFFLOAD_XMIT_NEIGH: + flow_tuple->ifidx = route->tuple[dir].out.ifindex; flow_tuple->dst_cache = dst; flow_tuple->dst_cookie = flow_offload_dst_cookie(flow_tuple); break; diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c index 8cd4cf7ae2112..eb4f6a11e779f 100644 --- a/net/netfilter/nf_flow_table_ip.c +++ b/net/netfilter/nf_flow_table_ip.c @@ -333,19 +333,18 @@ static void nf_flow_encap_pop(struct sk_buff *skb, } } +struct nf_flow_xmit { + const void *dest; + const void *source; + struct net_device *outdev; +}; + static unsigned int nf_flow_queue_xmit(struct net *net, struct sk_buff *skb, - const struct flow_offload_tuple_rhash *tuplehash, - unsigned short type) + struct nf_flow_xmit *xmit) { - struct net_device *outdev; - - outdev = dev_get_by_index_rcu(net, tuplehash->tuple.out.ifidx); - if (!outdev) - return NF_DROP; - - skb->dev = outdev; - dev_hard_header(skb, skb->dev, type, tuplehash->tuple.out.h_dest, - tuplehash->tuple.out.h_source, skb->len); + skb->dev = xmit->outdev; + dev_hard_header(skb, skb->dev, ntohs(skb->protocol), + xmit->dest, xmit->source, skb->len); dev_queue_xmit(skb); return NF_STOLEN; @@ -424,10 +423,10 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb, struct nf_flowtable_ctx ctx = { .in = state->in, }; + struct nf_flow_xmit xmit = {}; struct flow_offload *flow; - struct net_device *outdev; + struct neighbour *neigh; struct rtable *rt; - __be32 nexthop; int ret; tuplehash = nf_flow_offload_lookup(&ctx, flow_table, skb); @@ -454,25 +453,34 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb, switch (tuplehash->tuple.xmit_type) { case FLOW_OFFLOAD_XMIT_NEIGH: rt = dst_rtable(tuplehash->tuple.dst_cache); - outdev = rt->dst.dev; - skb->dev = outdev; - nexthop = rt_nexthop(rt, flow->tuplehash[!dir].tuple.src_v4.s_addr); + xmit.outdev = dev_get_by_index_rcu(state->net, tuplehash->tuple.ifidx); + if (!xmit.outdev) { + flow_offload_teardown(flow); + return NF_DROP; + } + neigh = ip_neigh_gw4(rt->dst.dev, rt_nexthop(rt, flow->tuplehash[!dir].tuple.src_v4.s_addr)); + if (IS_ERR(neigh)) { + flow_offload_teardown(flow); + return NF_DROP; + } + xmit.dest = neigh->ha; skb_dst_set_noref(skb, &rt->dst); - neigh_xmit(NEIGH_ARP_TABLE, outdev, &nexthop, skb); - ret = NF_STOLEN; break; case FLOW_OFFLOAD_XMIT_DIRECT: - ret = nf_flow_queue_xmit(state->net, skb, tuplehash, ETH_P_IP); - if (ret == NF_DROP) + xmit.outdev = dev_get_by_index_rcu(state->net, tuplehash->tuple.out.ifidx); + if (!xmit.outdev) { flow_offload_teardown(flow); + return NF_DROP; + } + xmit.dest = tuplehash->tuple.out.h_dest; + xmit.source = tuplehash->tuple.out.h_source; break; default: WARN_ON_ONCE(1); - ret = NF_DROP; - break; + return NF_DROP; } - return ret; + return nf_flow_queue_xmit(state->net, skb, &xmit); } EXPORT_SYMBOL_GPL(nf_flow_offload_ip_hook); @@ -719,9 +727,9 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb, struct nf_flowtable_ctx ctx = { .in = state->in, }; - const struct in6_addr *nexthop; + struct nf_flow_xmit xmit = {}; struct flow_offload *flow; - struct net_device *outdev; + struct neighbour *neigh; struct rt6_info *rt; int ret; @@ -749,24 +757,33 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb, switch (tuplehash->tuple.xmit_type) { case FLOW_OFFLOAD_XMIT_NEIGH: rt = dst_rt6_info(tuplehash->tuple.dst_cache); - outdev = rt->dst.dev; - skb->dev = outdev; - nexthop = rt6_nexthop(rt, &flow->tuplehash[!dir].tuple.src_v6); + xmit.outdev = dev_get_by_index_rcu(state->net, tuplehash->tuple.ifidx); + if (!xmit.outdev) { + flow_offload_teardown(flow); + return NF_DROP; + } + neigh = ip_neigh_gw6(rt->dst.dev, rt6_nexthop(rt, &flow->tuplehash[!dir].tuple.src_v6)); + if (IS_ERR(neigh)) { + flow_offload_teardown(flow); + return NF_DROP; + } + xmit.dest = neigh->ha; skb_dst_set_noref(skb, &rt->dst); - neigh_xmit(NEIGH_ND_TABLE, outdev, nexthop, skb); - ret = NF_STOLEN; break; case FLOW_OFFLOAD_XMIT_DIRECT: - ret = nf_flow_queue_xmit(state->net, skb, tuplehash, ETH_P_IPV6); - if (ret == NF_DROP) + xmit.outdev = dev_get_by_index_rcu(state->net, tuplehash->tuple.out.ifidx); + if (!xmit.outdev) { flow_offload_teardown(flow); + return NF_DROP; + } + xmit.dest = tuplehash->tuple.out.h_dest; + xmit.source = tuplehash->tuple.out.h_source; break; default: WARN_ON_ONCE(1); - ret = NF_DROP; - break; + return NF_DROP; } - return ret; + return nf_flow_queue_xmit(state->net, skb, &xmit); } EXPORT_SYMBOL_GPL(nf_flow_offload_ipv6_hook); diff --git a/net/netfilter/nf_flow_table_path.c b/net/netfilter/nf_flow_table_path.c index 76d4ff1454398..da56fda2c2b39 100644 --- a/net/netfilter/nf_flow_table_path.c +++ b/net/netfilter/nf_flow_table_path.c @@ -213,11 +213,11 @@ static void nft_dev_forward_path(struct nf_flow_route *route, } route->tuple[!dir].in.num_encaps = info.num_encaps; route->tuple[!dir].in.ingress_vlans = info.ingress_vlans; + route->tuple[dir].out.ifindex = info.outdev->ifindex; if (info.xmit_type == FLOW_OFFLOAD_XMIT_DIRECT) { memcpy(route->tuple[dir].out.h_source, info.h_source, ETH_ALEN); memcpy(route->tuple[dir].out.h_dest, info.h_dest, ETH_ALEN); - route->tuple[dir].out.ifindex = info.outdev->ifindex; route->tuple[dir].out.hw_ifindex = info.hw_outdev->ifindex; route->tuple[dir].xmit_type = info.xmit_type; } @@ -265,11 +265,10 @@ int nft_flow_route(const struct nft_pktinfo *pkt, const struct nf_conn *ct, nft_default_forward_path(route, this_dst, dir); nft_default_forward_path(route, other_dst, !dir); - if (route->tuple[dir].xmit_type == FLOW_OFFLOAD_XMIT_NEIGH && - route->tuple[!dir].xmit_type == FLOW_OFFLOAD_XMIT_NEIGH) { + if (route->tuple[dir].xmit_type == FLOW_OFFLOAD_XMIT_NEIGH) nft_dev_forward_path(route, ct, dir, ft); + if (route->tuple[!dir].xmit_type == FLOW_OFFLOAD_XMIT_NEIGH) nft_dev_forward_path(route, ct, !dir, ft); - } return 0; } -- 2.53.0