[NETFILTER]: TCP conntrack: factorize out the PUSH flag

The PUSH flag is accepted with every other valid combination.
Let's get it out of the tcp_valid_flags table and reduce the
number of combinations we have to handle. This does not
significantly reduce the table size however (8 bytes).

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 13 deletions

diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index 926e302494f3..a1363626bccc 100644
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -764,27 +764,18 @@ EXPORT_SYMBOL_GPL(nf_conntrack_tcp_update);
 #define TH_ECE  0x40
 #define TH_CWR  0x80
 
-/* table of valid flag combinations - ECE and CWR are always valid */
-static u8 tcp_valid_flags[(TH_FIN|TH_SYN|TH_RST|TH_PUSH|TH_ACK|TH_URG) + 1] =
+/* table of valid flag combinations - PUSH, ECE and CWR are always valid */
+static u8 tcp_valid_flags[(TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG) + 1] =
 {
         [TH_SYN]                        = 1,
-        [TH_SYN|TH_PUSH]                = 1,
         [TH_SYN|TH_URG]                 = 1,
-        [TH_SYN|TH_PUSH|TH_URG]         = 1,
         [TH_SYN|TH_ACK]                 = 1,
-        [TH_SYN|TH_ACK|TH_PUSH]         = 1,
         [TH_RST]                        = 1,
-        [TH_RST|TH_PUSH]                = 1,
         [TH_RST|TH_ACK]                 = 1,
-        [TH_RST|TH_ACK|TH_PUSH]         = 1,
         [TH_FIN|TH_ACK]                 = 1,
+        [TH_FIN|TH_ACK|TH_URG]          = 1,
         [TH_ACK]                        = 1,
-        [TH_ACK|TH_PUSH]                = 1,
         [TH_ACK|TH_URG]                 = 1,
-        [TH_ACK|TH_URG|TH_PUSH]         = 1,
-        [TH_FIN|TH_ACK|TH_PUSH]         = 1,
-        [TH_FIN|TH_ACK|TH_URG]          = 1,
-        [TH_FIN|TH_ACK|TH_URG|TH_PUSH]  = 1,
 };
 
 /* Protect conntrack agaist broken packets. Code taken from ipt_unclean.c.  */
@@ -831,7 +822,7 @@ static int tcp_error(struct sk_buff *skb,
         }
 
         /* Check TCP flags. */
-        tcpflags = (((u_int8_t *)th)[13] & ~(TH_ECE|TH_CWR));
+        tcpflags = (((u_int8_t *)th)[13] & ~(TH_ECE|TH_CWR|TH_PUSH));
         if (!tcp_valid_flags[tcpflags]) {
                 if (LOG_INVALID(IPPROTO_TCP))
                         nf_log_packet(pf, 0, skb, NULL, NULL, NULL,