1 files changed, 374 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.10/610-v5.13-19-netfilter-flowtable-use-dev_fill_forward_path-to-obt.patch b/target/linux/generic/backport-5.10/610-v5.13-19-netfilter-flowtable-use-dev_fill_forward_path-to-obt.patch
new file mode 100644
index 0000000000..e42d2558f2
--- /dev/null
+++ b/target/linux/generic/backport-5.10/610-v5.13-19-netfilter-flowtable-use-dev_fill_forward_path-to-obt.patch
@@ -0,0 +1,374 @@
+From: Pablo Neira Ayuso <pablo@netfilter.org>
+Date: Wed, 24 Mar 2021 02:30:40 +0100
+Subject: [PATCH] netfilter: flowtable: use dev_fill_forward_path() to
+ obtain egress device
+
+The egress device in the tuple is obtained from route. Use
+dev_fill_forward_path() instead to provide the real egress device for
+this flow whenever this is available.
+
+The new FLOW_OFFLOAD_XMIT_DIRECT type uses dev_queue_xmit() to transmit
+ethernet frames. Cache the source and destination hardware address to
+use dev_queue_xmit() to transfer packets.
+
+The FLOW_OFFLOAD_XMIT_DIRECT replaces FLOW_OFFLOAD_XMIT_NEIGH if
+dev_fill_forward_path() finds a direct transmit path.
+
+In case of topology updates, if peer is moved to different bridge port,
+the connection will time out, reconnect will result in a new entry with
+the correct path. Snooping fdb updates would allow for cleaning up stale
+flowtable entries.
+
+Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
+---
+
+--- a/include/net/netfilter/nf_flow_table.h
++++ b/include/net/netfilter/nf_flow_table.h
+@@ -92,6 +92,7 @@ enum flow_offload_tuple_dir {
+ enum flow_offload_xmit_type {
+ 	FLOW_OFFLOAD_XMIT_NEIGH		= 0,
+ 	FLOW_OFFLOAD_XMIT_XFRM,
++	FLOW_OFFLOAD_XMIT_DIRECT,
+ };
+ 
+ struct flow_offload_tuple {
+@@ -120,8 +121,14 @@ struct flow_offload_tuple {
+ 					xmit_type:2;
+ 
+ 	u16				mtu;
+-
+-	struct dst_entry		*dst_cache;
++	union {
++		struct dst_entry	*dst_cache;
++		struct {
++			u32		ifidx;
++			u8		h_source[ETH_ALEN];
++			u8		h_dest[ETH_ALEN];
++		} out;
++	};
+ };
+ 
+ struct flow_offload_tuple_rhash {
+@@ -168,6 +175,11 @@ struct nf_flow_route {
+ 		struct {
+ 			u32			ifindex;
+ 		} in;
++		struct {
++			u32			ifindex;
++			u8			h_source[ETH_ALEN];
++			u8			h_dest[ETH_ALEN];
++		} out;
+ 		enum flow_offload_xmit_type	xmit_type;
+ 	} tuple[FLOW_OFFLOAD_DIR_MAX];
+ };
+--- a/net/netfilter/nf_flow_table_core.c
++++ b/net/netfilter/nf_flow_table_core.c
+@@ -81,9 +81,6 @@ static int flow_offload_fill_route(struc
+ 	struct flow_offload_tuple *flow_tuple = &flow->tuplehash[dir].tuple;
+ 	struct dst_entry *dst = route->tuple[dir].dst;
+ 
+-	if (!dst_hold_safe(route->tuple[dir].dst))
+-		return -1;
+-
+ 	switch (flow_tuple->l3proto) {
+ 	case NFPROTO_IPV4:
+ 		flow_tuple->mtu = ip_dst_mtu_maybe_forward(dst, true);
+@@ -94,12 +91,36 @@ static int flow_offload_fill_route(struc
+ 	}
+ 
+ 	flow_tuple->iifidx = route->tuple[dir].in.ifindex;
++
++	switch (route->tuple[dir].xmit_type) {
++	case FLOW_OFFLOAD_XMIT_DIRECT:
++		memcpy(flow_tuple->out.h_dest, route->tuple[dir].out.h_dest,
++		       ETH_ALEN);
++		memcpy(flow_tuple->out.h_source, route->tuple[dir].out.h_source,
++		       ETH_ALEN);
++		flow_tuple->out.ifidx = route->tuple[dir].out.ifindex;
++		break;
++	case FLOW_OFFLOAD_XMIT_XFRM:
++	case FLOW_OFFLOAD_XMIT_NEIGH:
++		if (!dst_hold_safe(route->tuple[dir].dst))
++			return -1;
++
++		flow_tuple->dst_cache = dst;
++		break;
++	}
+ 	flow_tuple->xmit_type = route->tuple[dir].xmit_type;
+-	flow_tuple->dst_cache = dst;
+ 
+ 	return 0;
+ }
+ 
++static void nft_flow_dst_release(struct flow_offload *flow,
++				 enum flow_offload_tuple_dir dir)
++{
++	if (flow->tuplehash[dir].tuple.xmit_type == FLOW_OFFLOAD_XMIT_NEIGH ||
++	    flow->tuplehash[dir].tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)
++		dst_release(flow->tuplehash[dir].tuple.dst_cache);
++}
++
+ int flow_offload_route_init(struct flow_offload *flow,
+ 			    const struct nf_flow_route *route)
+ {
+@@ -118,7 +139,7 @@ int flow_offload_route_init(struct flow_
+ 	return 0;
+ 
+ err_route_reply:
+-	dst_release(route->tuple[FLOW_OFFLOAD_DIR_ORIGINAL].dst);
++	nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
+ 
+ 	return err;
+ }
+@@ -169,8 +190,8 @@ static void flow_offload_fixup_ct(struct
+ 
+ static void flow_offload_route_release(struct flow_offload *flow)
+ {
+-	dst_release(flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_cache);
+-	dst_release(flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_cache);
++	nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
++	nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_REPLY);
+ }
+ 
+ void flow_offload_free(struct flow_offload *flow)
+--- a/net/netfilter/nf_flow_table_ip.c
++++ b/net/netfilter/nf_flow_table_ip.c
+@@ -207,6 +207,24 @@ static unsigned int nf_flow_xmit_xfrm(st
+ 	return NF_STOLEN;
+ }
+ 
++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 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);
++	dev_queue_xmit(skb);
++
++	return NF_STOLEN;
++}
++
+ unsigned int
+ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
+ 			const struct nf_hook_state *state)
+@@ -222,6 +240,7 @@ nf_flow_offload_ip_hook(void *priv, stru
+ 	struct iphdr *iph;
+ 	__be32 nexthop;
+ 	u32 hdrsize;
++	int ret;
+ 
+ 	if (skb->protocol != htons(ETH_P_IP))
+ 		return NF_ACCEPT;
+@@ -244,9 +263,13 @@ nf_flow_offload_ip_hook(void *priv, stru
+ 	if (nf_flow_state_check(flow, iph->protocol, skb, thoff))
+ 		return NF_ACCEPT;
+ 
+-	if (!dst_check(&rt->dst, 0)) {
+-		flow_offload_teardown(flow);
+-		return NF_ACCEPT;
++	if (tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_NEIGH ||
++	    tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM) {
++		rt = (struct rtable *)tuplehash->tuple.dst_cache;
++		if (!dst_check(&rt->dst, 0)) {
++			flow_offload_teardown(flow);
++			return NF_ACCEPT;
++		}
+ 	}
+ 
+ 	if (skb_try_make_writable(skb, thoff + hdrsize))
+@@ -263,8 +286,6 @@ nf_flow_offload_ip_hook(void *priv, stru
+ 	if (flow_table->flags & NF_FLOWTABLE_COUNTER)
+ 		nf_ct_acct_update(flow->ct, tuplehash->tuple.dir, skb->len);
+ 
+-	rt = (struct rtable *)tuplehash->tuple.dst_cache;
+-
+ 	if (unlikely(tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)) {
+ 		memset(skb->cb, 0, sizeof(struct inet_skb_parm));
+ 		IPCB(skb)->iif = skb->dev->ifindex;
+@@ -272,13 +293,23 @@ nf_flow_offload_ip_hook(void *priv, stru
+ 		return nf_flow_xmit_xfrm(skb, state, &rt->dst);
+ 	}
+ 
+-	outdev = rt->dst.dev;
+-	skb->dev = outdev;
+-	nexthop = rt_nexthop(rt, flow->tuplehash[!dir].tuple.src_v4.s_addr);
+-	skb_dst_set_noref(skb, &rt->dst);
+-	neigh_xmit(NEIGH_ARP_TABLE, outdev, &nexthop, skb);
++	switch (tuplehash->tuple.xmit_type) {
++	case FLOW_OFFLOAD_XMIT_NEIGH:
++		outdev = rt->dst.dev;
++		skb->dev = outdev;
++		nexthop = rt_nexthop(rt, flow->tuplehash[!dir].tuple.src_v4.s_addr);
++		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)
++			flow_offload_teardown(flow);
++		break;
++	}
+ 
+-	return NF_STOLEN;
++	return ret;
+ }
+ EXPORT_SYMBOL_GPL(nf_flow_offload_ip_hook);
+ 
+@@ -444,6 +475,7 @@ nf_flow_offload_ipv6_hook(void *priv, st
+ 	struct ipv6hdr *ip6h;
+ 	struct rt6_info *rt;
+ 	u32 hdrsize;
++	int ret;
+ 
+ 	if (skb->protocol != htons(ETH_P_IPV6))
+ 		return NF_ACCEPT;
+@@ -465,9 +497,13 @@ nf_flow_offload_ipv6_hook(void *priv, st
+ 				sizeof(*ip6h)))
+ 		return NF_ACCEPT;
+ 
+-	if (!dst_check(&rt->dst, 0)) {
+-		flow_offload_teardown(flow);
+-		return NF_ACCEPT;
++	if (tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_NEIGH ||
++	    tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM) {
++		rt = (struct rt6_info *)tuplehash->tuple.dst_cache;
++		if (!dst_check(&rt->dst, 0)) {
++			flow_offload_teardown(flow);
++			return NF_ACCEPT;
++		}
+ 	}
+ 
+ 	if (skb_try_make_writable(skb, sizeof(*ip6h) + hdrsize))
+@@ -484,8 +520,6 @@ nf_flow_offload_ipv6_hook(void *priv, st
+ 	if (flow_table->flags & NF_FLOWTABLE_COUNTER)
+ 		nf_ct_acct_update(flow->ct, tuplehash->tuple.dir, skb->len);
+ 
+-	rt = (struct rt6_info *)tuplehash->tuple.dst_cache;
+-
+ 	if (unlikely(tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)) {
+ 		memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
+ 		IP6CB(skb)->iif = skb->dev->ifindex;
+@@ -493,12 +527,22 @@ nf_flow_offload_ipv6_hook(void *priv, st
+ 		return nf_flow_xmit_xfrm(skb, state, &rt->dst);
+ 	}
+ 
+-	outdev = rt->dst.dev;
+-	skb->dev = outdev;
+-	nexthop = rt6_nexthop(rt, &flow->tuplehash[!dir].tuple.src_v6);
+-	skb_dst_set_noref(skb, &rt->dst);
+-	neigh_xmit(NEIGH_ND_TABLE, outdev, nexthop, skb);
++	switch (tuplehash->tuple.xmit_type) {
++	case FLOW_OFFLOAD_XMIT_NEIGH:
++		outdev = rt->dst.dev;
++		skb->dev = outdev;
++		nexthop = rt6_nexthop(rt, &flow->tuplehash[!dir].tuple.src_v6);
++		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)
++			flow_offload_teardown(flow);
++		break;
++	}
+ 
+-	return NF_STOLEN;
++	return ret;
+ }
+ EXPORT_SYMBOL_GPL(nf_flow_offload_ipv6_hook);
+--- a/net/netfilter/nft_flow_offload.c
++++ b/net/netfilter/nft_flow_offload.c
+@@ -39,12 +39,11 @@ static void nft_default_forward_path(str
+ static int nft_dev_fill_forward_path(const struct nf_flow_route *route,
+ 				     const struct dst_entry *dst_cache,
+ 				     const struct nf_conn *ct,
+-				     enum ip_conntrack_dir dir,
++				     enum ip_conntrack_dir dir, u8 *ha,
+ 				     struct net_device_path_stack *stack)
+ {
+ 	const void *daddr = &ct->tuplehash[!dir].tuple.src.u3;
+ 	struct net_device *dev = dst_cache->dev;
+-	unsigned char ha[ETH_ALEN];
+ 	struct neighbour *n;
+ 	u8 nud_state;
+ 
+@@ -66,27 +65,43 @@ static int nft_dev_fill_forward_path(con
+ 
+ struct nft_forward_info {
+ 	const struct net_device *indev;
++	const struct net_device *outdev;
++	u8 h_source[ETH_ALEN];
++	u8 h_dest[ETH_ALEN];
++	enum flow_offload_xmit_type xmit_type;
+ };
+ 
+ static void nft_dev_path_info(const struct net_device_path_stack *stack,
+-			      struct nft_forward_info *info)
++			      struct nft_forward_info *info,
++			      unsigned char *ha)
+ {
+ 	const struct net_device_path *path;
+ 	int i;
+ 
++	memcpy(info->h_dest, ha, ETH_ALEN);
++
+ 	for (i = 0; i < stack->num_paths; i++) {
+ 		path = &stack->path[i];
+ 		switch (path->type) {
+ 		case DEV_PATH_ETHERNET:
+ 			info->indev = path->dev;
++			if (is_zero_ether_addr(info->h_source))
++				memcpy(info->h_source, path->dev->dev_addr, ETH_ALEN);
+ 			break;
+-		case DEV_PATH_VLAN:
+ 		case DEV_PATH_BRIDGE:
++			if (is_zero_ether_addr(info->h_source))
++				memcpy(info->h_source, path->dev->dev_addr, ETH_ALEN);
++
++			info->xmit_type = FLOW_OFFLOAD_XMIT_DIRECT;
++			break;
++		case DEV_PATH_VLAN:
+ 		default:
+ 			info->indev = NULL;
+ 			break;
+ 		}
+ 	}
++	if (!info->outdev)
++		info->outdev = info->indev;
+ }
+ 
+ static bool nft_flowtable_find_dev(const struct net_device *dev,
+@@ -114,14 +129,22 @@ static void nft_dev_forward_path(struct
+ 	const struct dst_entry *dst = route->tuple[dir].dst;
+ 	struct net_device_path_stack stack;
+ 	struct nft_forward_info info = {};
++	unsigned char ha[ETH_ALEN];
+ 
+-	if (nft_dev_fill_forward_path(route, dst, ct, dir, &stack) >= 0)
+-		nft_dev_path_info(&stack, &info);
++	if (nft_dev_fill_forward_path(route, dst, ct, dir, ha, &stack) >= 0)
++		nft_dev_path_info(&stack, &info, ha);
+ 
+ 	if (!info.indev || !nft_flowtable_find_dev(info.indev, ft))
+ 		return;
+ 
+ 	route->tuple[!dir].in.ifindex = info.indev->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].xmit_type = info.xmit_type;
++	}
+ }
+ 
+ static int nft_flow_route(const struct nft_pktinfo *pkt,