[openwrt/openwrt] kernel: remove obsolete netfilter tcp window size check bypass patch

[LEDE Commits]

nbd pushed a commit to openwrt/openwrt.git, branch openwrt-21.02:
https://git.openwrt.org/cbe73ea33d027dbb4b2cf1eca947ae746119e7d2

commit cbe73ea33d027dbb4b2cf1eca947ae746119e7d2
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Thu Mar 30 14:18:04 2023 +0200

    kernel: remove obsolete netfilter tcp window size check bypass patch
    
    On any currently supported hardware, the performance impact should not
    matter anymore.
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
    (cherry picked from commit 75e78bcaab847557ce1782eb2dea9dff9a029171)
---
 .../613-netfilter_optional_tcp_window_check.patch  | 73 ----------------------
 1 file changed, 73 deletions(-)

diff --git a/target/linux/generic/pending-5.4/613-netfilter_optional_tcp_window_check.patch b/target/linux/generic/pending-5.4/613-netfilter_optional_tcp_window_check.patch
deleted file mode 100644
index f6a3a82eca..0000000000
--- a/target/linux/generic/pending-5.4/613-netfilter_optional_tcp_window_check.patch
+++ /dev/null
@@ -1,73 +0,0 @@
-From: Felix Fietkau <nbd at nbd.name>
-Subject: netfilter: optional tcp window check
-
-Signed-off-by: Felix Fietkau <nbd at nbd.name>
----
- net/netfilter/nf_conntrack_proto_tcp.c | 13 +++++++++++++
- 1 file changed, 13 insertions(+)
-
---- a/net/netfilter/nf_conntrack_proto_tcp.c
-+++ b/net/netfilter/nf_conntrack_proto_tcp.c
-@@ -31,6 +31,9 @@
- #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
- #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
- 
-+/* Do not check the TCP window for incoming packets  */
-+static int nf_ct_tcp_no_window_check __read_mostly = 1;
-+
- /* "Be conservative in what you do,
-     be liberal in what you accept from others."
-     If it's non-zero, we mark only out of window RST segments as INVALID. */
-@@ -476,6 +479,9 @@ static bool tcp_in_window(const struct n
- 	s32 receiver_offset;
- 	bool res, in_recv_win;
- 
-+	if (nf_ct_tcp_no_window_check)
-+		return true;
-+
- 	/*
- 	 * Get the required data from the packet.
- 	 */
-@@ -1139,7 +1145,7 @@ int nf_conntrack_tcp_packet(struct nf_co
- 		 IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED &&
- 		 timeouts[new_state] > timeouts[TCP_CONNTRACK_UNACK])
- 		timeout = timeouts[TCP_CONNTRACK_UNACK];
--	else if (ct->proto.tcp.last_win == 0 &&
-+	else if (!nf_ct_tcp_no_window_check && ct->proto.tcp.last_win == 0 &&
- 		 timeouts[new_state] > timeouts[TCP_CONNTRACK_RETRANS])
- 		timeout = timeouts[TCP_CONNTRACK_RETRANS];
- 	else
---- a/net/netfilter/nf_conntrack_standalone.c
-+++ b/net/netfilter/nf_conntrack_standalone.c
-@@ -25,6 +25,9 @@
- #include <net/netfilter/nf_conntrack_timestamp.h>
- #include <linux/rculist_nulls.h>
- 
-+/* Do not check the TCP window for incoming packets  */
-+static int nf_ct_tcp_no_window_check __read_mostly = 1;
-+
- static bool enable_hooks __read_mostly;
- MODULE_PARM_DESC(enable_hooks, "Always enable conntrack hooks");
- module_param(enable_hooks, bool, 0000);
-@@ -649,6 +652,7 @@ enum nf_ct_sysctl_index {
- 	NF_SYSCTL_CT_PROTO_TIMEOUT_GRE_STREAM,
- #endif
- 
-+	NF_SYSCTL_CT_PROTO_TCP_NO_WINDOW_CHECK,
- 	__NF_SYSCTL_CT_LAST_SYSCTL,
- };
- 
-@@ -969,6 +973,13 @@ static struct ctl_table nf_ct_sysctl_tab
- 		.proc_handler   = proc_dointvec_jiffies,
- 	},
- #endif
-+	[NF_SYSCTL_CT_PROTO_TCP_NO_WINDOW_CHECK] = {
-+		.procname       = "nf_conntrack_tcp_no_window_check",
-+		.data           = &nf_ct_tcp_no_window_check,
-+		.maxlen         = sizeof(unsigned int),
-+		.mode           = 0644,
-+		.proc_handler   = proc_dointvec,
-+	},
- 	{}
- };
-