| 1 | --- a/net/netfilter/nf_conntrack_proto_tcp.c |
| 2 | +++ b/net/netfilter/nf_conntrack_proto_tcp.c |
| 3 | @@ -29,6 +29,9 @@ |
| 4 | #include <net/netfilter/ipv4/nf_conntrack_ipv4.h> |
| 5 | #include <net/netfilter/ipv6/nf_conntrack_ipv6.h> |
| 6 | |
| 7 | +/* Do not check the TCP window for incoming packets */ |
| 8 | +static int nf_ct_tcp_no_window_check __read_mostly = 1; |
| 9 | + |
| 10 | /* "Be conservative in what you do, |
| 11 | be liberal in what you accept from others." |
| 12 | If it's non-zero, we mark only out of window RST segments as INVALID. */ |
| 13 | @@ -524,6 +527,9 @@ static bool tcp_in_window(const struct n |
| 14 | s16 receiver_offset; |
| 15 | bool res; |
| 16 | |
| 17 | + if (nf_ct_tcp_no_window_check) |
| 18 | + return true; |
| 19 | + |
| 20 | /* |
| 21 | * Get the required data from the packet. |
| 22 | */ |
| 23 | @@ -1321,6 +1327,13 @@ static struct ctl_table tcp_sysctl_table |
| 24 | .proc_handler = proc_dointvec, |
| 25 | }, |
| 26 | { |
| 27 | + .procname = "nf_conntrack_tcp_no_window_check", |
| 28 | + .data = &nf_ct_tcp_no_window_check, |
| 29 | + .maxlen = sizeof(unsigned int), |
| 30 | + .mode = 0644, |
| 31 | + .proc_handler = proc_dointvec, |
| 32 | + }, |
| 33 | + { |
| 34 | .procname = "nf_conntrack_tcp_be_liberal", |
| 35 | .data = &nf_ct_tcp_be_liberal, |
| 36 | .maxlen = sizeof(unsigned int), |
| 37 | |
