kernel: fix issues with output routing in flow offload

Replace an old cleanup patch that never made it upstream with the proper
upstream fix. This patch was incompatible with the recent changes that
affected the way that the flow tuple dst entry was used.

Signed-off-by: Felix Fietkau <nbd@nbd.name>

2 files changed, 35 insertions, 92 deletions

diff --git a/target/linux/generic/hack-4.19/650-netfilter-add-xt_OFFLOAD-target.patch b/target/linux/generic/hack-4.19/650-netfilter-add-xt_OFFLOAD-target.patch
index 80bc1cdeff..b41e238eae 100644
--- a/target/linux/generic/hack-4.19/650-netfilter-add-xt_OFFLOAD-target.patch
+++ b/target/linux/generic/hack-4.19/650-netfilter-add-xt_OFFLOAD-target.patch
@@ -98,7 +98,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  obj-$(CONFIG_NETFILTER_XT_TARGET_LED) += xt_LED.o
 --- /dev/null
 +++ b/net/netfilter/xt_FLOWOFFLOAD.c
-@@ -0,0 +1,387 @@
+@@ -0,0 +1,421 @@
 +/*
 + * Copyright (C) 2018 Felix Fietkau <nbd@nbd.name>
 + *
@@ -307,10 +307,12 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 +	switch (xt_family(par)) {
 +	case NFPROTO_IPV4:
 +		fl.u.ip4.daddr = ct->tuplehash[dir].tuple.src.u3.ip;
++		fl.u.ip4.flowi4_oif = ifindex;
 +		break;
 +	case NFPROTO_IPV6:
 +		fl.u.ip6.saddr = ct->tuplehash[dir].tuple.dst.u3.in6;
 +		fl.u.ip6.daddr = ct->tuplehash[dir].tuple.src.u3.in6;
++		fl.u.ip6.flowi6_oif = ifindex;
 +		break;
 +	}
 +
@@ -460,10 +462,41 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 +	nf_flow_table_free(table);
 +}
 +
++static int flow_offload_netdev_event(struct notifier_block *this,
++				     unsigned long event, void *ptr)
++{
++	struct xt_flowoffload_hook *hook = NULL;
++	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
++
++	if (event != NETDEV_UNREGISTER)
++		return NOTIFY_DONE;
++
++	spin_lock_bh(&hooks_lock);
++	hook = flow_offload_lookup_hook(dev);
++	if (hook) {
++		hlist_del(&hook->list);
++	}
++	spin_unlock_bh(&hooks_lock);
++	if (hook) {
++		nf_unregister_net_hook(hook->net, &hook->ops);
++		kfree(hook);
++	}
++
++	nf_flow_table_cleanup(dev_net(dev), dev);
++
++	return NOTIFY_DONE;
++}
++
++static struct notifier_block flow_offload_netdev_notifier = {
++	.notifier_call	= flow_offload_netdev_event,
++};
++
 +static int __init xt_flowoffload_tg_init(void)
 +{
 +	int ret;
 +
++	register_netdevice_notifier(&flow_offload_netdev_notifier);
++
 +	INIT_DELAYED_WORK(&hook_work, xt_flowoffload_hook_work);
 +
 +	ret = xt_flowoffload_table_init(&nf_flowtable);
@@ -481,6 +514,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 +{
 +	xt_unregister_target(&offload_tg_reg);
 +	xt_flowoffload_table_cleanup(&nf_flowtable);
++	unregister_netdevice_notifier(&flow_offload_netdev_notifier);
 +}
 +
 +MODULE_LICENSE("GPL");
diff --git a/target/linux/generic/hack-4.19/940-cleanup-offload-hooks-on-netdev-unregister.patch b/target/linux/generic/hack-4.19/940-cleanup-offload-hooks-on-netdev-unregister.patch
deleted file mode 100644
index 1079d94fe3..0000000000
--- a/target/linux/generic/hack-4.19/940-cleanup-offload-hooks-on-netdev-unregister.patch
+++ /dev/null
@@ -1,91 +0,0 @@
-From ae56e27e30122f82d244f9eb35fcab8fa60e0d31 Mon Sep 17 00:00:00 2001
-From: Chen Minqiang <ptpt52@gmail.com>
-Date: Sun, 29 Apr 2018 14:08:57 +0800
-Subject: [PATCH] cleanup offload hooks on netdev unregister
-
-This should fix crashdump on reboot when FLOWOFFLOAD enabled
-
-kmsg:
-[   84.188081] Workqueue: events_power_efficient xt_flowoffload_hook_work [xt_FLOWOFFLOAD]
-[   84.209326] task: ffff88000ecd0c80 task.stack: ffffc90000068000
-[   84.224706] RIP: 0010:__nf_unregister_net_hook+0x1/0x90
-[   84.242911] RSP: 0018:ffffc9000006be30 EFLAGS: 00010202
-[   84.257405] RAX: 0000000000000000 RBX: ffff88000c5b3228 RCX: 0000000100170001
-[   84.292175] RDX: ffff88000ecd0c80 RSI: ffff88000c5b3228 RDI: 6b6b6b6b6b6b6b6b
-[   84.305095] RBP: ffffc9000006be58 R08: ffff88000c5b3578 R09: ffff88000c5b3538
-[   84.325980] R10: ffffc9000006be50 R11: ffff88000fc1f310 R12: ffffffff81e6c580
-[   84.396514] R13: ffff88000d1723d0 R14: ffff88000ec0fc00 R15: 0000000000000000
-[   84.459500] FS:  0000000000000000(0000) GS:ffff88000fc00000(0000) knlGS:0000000000000000
-[   84.525121] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
-[   84.565460] CR2: 0000000000a931d8 CR3: 0000000001e08006 CR4: 00000000000606f0
-[   84.638311] Call Trace:
-[   84.655229]  ? nf_unregister_net_hook+0x88/0xd0
-[   84.706898]  xt_flowoffload_hook_work+0x12a/0x17a [xt_FLOWOFFLOAD]
-[   84.765504]  process_one_work+0x1c4/0x310
-[   84.799558]  worker_thread+0x20b/0x3c0
-[   84.850119]  kthread+0x112/0x120
-[   84.884839]  ? process_one_work+0x310/0x310
-[   84.923571]  ? kthread_create_on_node+0x40/0x40
-[   84.966100]  ret_from_fork+0x35/0x40
-[   84.981738] Code: 41 5c 41 5d 41 5e 41 5f 5d c3 48 8b 05 c1 f1 99 00 55 48 89 e5 48 85 c0 75 02 0f 0b e8 b9 f6 30 00 5d c3 0f 1f 80 00 00 00 00 55 <0f> b7 0f 48 89 e5 48 89 c8 48 c1 e0 04 48 8d 54 07 08 31 c0 eb
-[   85.100453] RIP: __nf_unregister_net_hook+0x1/0x90 RSP: ffffc9000006be30
-[   85.111658] ---[ end trace 5c25a390045cac75 ]---
-[   85.124535] Kernel panic - not syncing: Fatal exception
-
-Signed-off-by: Chen Minqiang <ptpt52@gmail.com>
----
- net/netfilter/xt_FLOWOFFLOAD.c | 32 ++++++++++++++++++++++++++++++++
- 1 file changed, 32 insertions(+)
-
---- a/net/netfilter/xt_FLOWOFFLOAD.c
-+++ b/net/netfilter/xt_FLOWOFFLOAD.c
-@@ -343,10 +343,41 @@ static void xt_flowoffload_table_cleanup
- 	nf_flow_table_free(table);
- }
- 
-+static int flow_offload_netdev_event(struct notifier_block *this,
-+				     unsigned long event, void *ptr)
-+{
-+	struct xt_flowoffload_hook *hook = NULL;
-+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
-+
-+	if (event != NETDEV_UNREGISTER)
-+		return NOTIFY_DONE;
-+
-+	spin_lock_bh(&hooks_lock);
-+	hook = flow_offload_lookup_hook(dev);
-+	if (hook) {
-+		hlist_del(&hook->list);
-+	}
-+	spin_unlock_bh(&hooks_lock);
-+	if (hook) {
-+		nf_unregister_net_hook(hook->net, &hook->ops);
-+		kfree(hook);
-+	}
-+
-+	nf_flow_table_cleanup(dev_net(dev), dev);
-+
-+	return NOTIFY_DONE;
-+}
-+
-+static struct notifier_block flow_offload_netdev_notifier = {
-+	.notifier_call	= flow_offload_netdev_event,
-+};
-+
- static int __init xt_flowoffload_tg_init(void)
- {
- 	int ret;
- 
-+	register_netdevice_notifier(&flow_offload_netdev_notifier);
-+
- 	INIT_DELAYED_WORK(&hook_work, xt_flowoffload_hook_work);
- 
- 	ret = xt_flowoffload_table_init(&nf_flowtable);
-@@ -364,6 +395,7 @@ static void __exit xt_flowoffload_tg_exi
- {
- 	xt_unregister_target(&offload_tg_reg);
- 	xt_flowoffload_table_cleanup(&nf_flowtable);
-+	unregister_netdevice_notifier(&flow_offload_netdev_notifier);
- }
- 
- MODULE_LICENSE("GPL");