From 75e78bcaab847557ce1782eb2dea9dff9a029171 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Thu, 30 Mar 2023 14:14:11 +0200 Subject: [PATCH] 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 --- ...-netfilter_optional_tcp_window_check.patch | 73 ---------------- ...-netfilter_optional_tcp_window_check.patch | 83 ------------------- 2 files changed, 156 deletions(-) delete mode 100644 target/linux/generic/pending-5.10/613-netfilter_optional_tcp_window_check.patch delete mode 100644 target/linux/generic/pending-5.15/613-netfilter_optional_tcp_window_check.patch diff --git a/target/linux/generic/pending-5.10/613-netfilter_optional_tcp_window_check.patch b/target/linux/generic/pending-5.10/613-netfilter_optional_tcp_window_check.patch deleted file mode 100644 index 79fd2762b326..000000000000 --- a/target/linux/generic/pending-5.10/613-netfilter_optional_tcp_window_check.patch +++ /dev/null @@ -1,73 +0,0 @@ -From: Felix Fietkau -Subject: netfilter: optional tcp window check - -Signed-off-by: Felix Fietkau ---- - 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 - #include - -+/* 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 - #include - -+/* 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); -@@ -657,6 +660,7 @@ 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, - }; - -@@ -993,6 +997,13 @@ 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, -+ }, - {} - }; - diff --git a/target/linux/generic/pending-5.15/613-netfilter_optional_tcp_window_check.patch b/target/linux/generic/pending-5.15/613-netfilter_optional_tcp_window_check.patch deleted file mode 100644 index cb3b63cdb1d1..000000000000 --- a/target/linux/generic/pending-5.15/613-netfilter_optional_tcp_window_check.patch +++ /dev/null @@ -1,83 +0,0 @@ -From: Felix Fietkau -Subject: netfilter: optional tcp window check - -Signed-off-by: Felix Fietkau -Signed-off-by: Christian 'Ansuel' Marangi ---- - 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 -@@ -465,6 +465,9 @@ static bool tcp_in_window(struct nf_conn - s32 receiver_offset; - bool res, in_recv_win; - -+ if (tn->tcp_no_window_check) -+ return true; -+ - /* - * Get the required data from the packet. - */ -@@ -1191,7 +1194,7 @@ 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 (!tn->tcp_no_window_check && ct->proto.tcp.last_win == 0 && - timeouts[new_state] > timeouts[TCP_CONNTRACK_RETRANS]) - timeout = timeouts[TCP_CONNTRACK_RETRANS]; - else -@@ -1507,6 +1510,9 @@ void nf_conntrack_tcp_init_net(struct ne - */ - tn->tcp_be_liberal = 0; - -+ /* Skip Windows Check */ -+ tn->tcp_no_window_check = 0; -+ - /* If it's non-zero, we turn off RST sequence number check */ - tn->tcp_ignore_invalid_rst = 0; - ---- a/net/netfilter/nf_conntrack_standalone.c -+++ b/net/netfilter/nf_conntrack_standalone.c -@@ -633,6 +633,7 @@ enum nf_ct_sysctl_index { - #endif - NF_SYSCTL_CT_PROTO_TCP_LOOSE, - NF_SYSCTL_CT_PROTO_TCP_LIBERAL, -+ NF_SYSCTL_CT_PROTO_TCP_NO_WINDOW_CHECK, - NF_SYSCTL_CT_PROTO_TCP_IGNORE_INVALID_RST, - NF_SYSCTL_CT_PROTO_TCP_MAX_RETRANS, - NF_SYSCTL_CT_PROTO_TIMEOUT_UDP, -@@ -848,6 +849,14 @@ static struct ctl_table nf_ct_sysctl_tab - .extra1 = SYSCTL_ZERO, - .extra2 = SYSCTL_ONE, - }, -+ [NF_SYSCTL_CT_PROTO_TCP_NO_WINDOW_CHECK] = { -+ .procname = "nf_conntrack_tcp_no_window_check", -+ .maxlen = sizeof(u8), -+ .mode = 0644, -+ .proc_handler = proc_dou8vec_minmax, -+ .extra1 = SYSCTL_ZERO, -+ .extra2 = SYSCTL_ONE, -+ }, - [NF_SYSCTL_CT_PROTO_TCP_IGNORE_INVALID_RST] = { - .procname = "nf_conntrack_tcp_ignore_invalid_rst", - .maxlen = sizeof(u8), -@@ -1058,6 +1067,7 @@ static void nf_conntrack_standalone_init - - XASSIGN(LOOSE, &tn->tcp_loose); - XASSIGN(LIBERAL, &tn->tcp_be_liberal); -+ XASSIGN(NO_WINDOW_CHECK, &tn->tcp_no_window_check); - XASSIGN(MAX_RETRANS, &tn->tcp_max_retrans); - XASSIGN(IGNORE_INVALID_RST, &tn->tcp_ignore_invalid_rst); - #undef XASSIGN ---- a/include/net/netns/conntrack.h -+++ b/include/net/netns/conntrack.h -@@ -26,6 +26,7 @@ struct nf_tcp_net { - unsigned int timeouts[TCP_CONNTRACK_TIMEOUT_MAX]; - u8 tcp_loose; - u8 tcp_be_liberal; -+ u8 tcp_no_window_check; - u8 tcp_max_retrans; - u8 tcp_ignore_invalid_rst; - #if IS_ENABLED(CONFIG_NF_FLOW_TABLE) -- 2.30.2