1
0
Fork 0

[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>
hifive-unleashed-5.1
Willy Tarreau 2007-03-14 16:44:53 -07:00 committed by David S. Miller
parent 8f5bd99071
commit 5c8ce7c921
1 changed files with 5 additions and 14 deletions

View File

@ -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_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,
[TH_ACK] = 1,
[TH_ACK|TH_URG] = 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,