/* "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. */
-int ip_ct_tcp_be_liberal = 0;
+int ip_ct_tcp_be_liberal __read_mostly = 0;
-/* When connection is picked up from the middle, how many packets are required
- to pass in each direction when we assume we are in sync - if any side uses
- window scaling, we lost the game.
- If it is set to zero, we disable picking up already established
+/* If it is set to zero, we disable picking up already established
connections. */
-int ip_ct_tcp_loose = 3;
+int ip_ct_tcp_loose __read_mostly = 1;
/* Max number of the retransmitted packets without receiving an (acceptable)
ACK from the destination. If this number is reached, a shorter timer
will be started. */
-int ip_ct_tcp_max_retrans = 3;
+int ip_ct_tcp_max_retrans __read_mostly = 3;
/* FIXME: Examine ipfilter's timeouts and conntrack transitions more
closely. They're more complex. --RR */
#define HOURS * 60 MINS
#define DAYS * 24 HOURS
-unsigned int ip_ct_tcp_timeout_syn_sent = 2 MINS;
-unsigned int ip_ct_tcp_timeout_syn_recv = 60 SECS;
-unsigned int ip_ct_tcp_timeout_established = 5 DAYS;
-unsigned int ip_ct_tcp_timeout_fin_wait = 2 MINS;
-unsigned int ip_ct_tcp_timeout_close_wait = 60 SECS;
-unsigned int ip_ct_tcp_timeout_last_ack = 30 SECS;
-unsigned int ip_ct_tcp_timeout_time_wait = 2 MINS;
-unsigned int ip_ct_tcp_timeout_close = 10 SECS;
+unsigned int ip_ct_tcp_timeout_syn_sent __read_mostly = 2 MINS;
+unsigned int ip_ct_tcp_timeout_syn_recv __read_mostly = 60 SECS;
+unsigned int ip_ct_tcp_timeout_established __read_mostly = 5 DAYS;
+unsigned int ip_ct_tcp_timeout_fin_wait __read_mostly = 2 MINS;
+unsigned int ip_ct_tcp_timeout_close_wait __read_mostly = 60 SECS;
+unsigned int ip_ct_tcp_timeout_last_ack __read_mostly = 30 SECS;
+unsigned int ip_ct_tcp_timeout_time_wait __read_mostly = 2 MINS;
+unsigned int ip_ct_tcp_timeout_close __read_mostly = 10 SECS;
/* RFC1122 says the R2 limit should be at least 100 seconds.
Linux uses 15 packets as limit, which corresponds
to ~13-30min depending on RTO. */
-unsigned int ip_ct_tcp_timeout_max_retrans = 5 MINS;
+unsigned int ip_ct_tcp_timeout_max_retrans __read_mostly = 5 MINS;
static const unsigned int * tcp_timeouts[]
= { NULL, /* TCP_CONNTRACK_NONE */
/* Fast path for timestamp-only option */
if (length == TCPOLEN_TSTAMP_ALIGNED*4
- && *(__u32 *)ptr ==
- __constant_ntohl((TCPOPT_NOP << 24)
+ && *(__be32 *)ptr ==
+ __constant_htonl((TCPOPT_NOP << 24)
| (TCPOPT_NOP << 16)
| (TCPOPT_TIMESTAMP << 8)
| TCPOLEN_TIMESTAMP))
for (i = 0;
i < (opsize - TCPOLEN_SACK_BASE);
i += TCPOLEN_SACK_PERBLOCK) {
- tmp = ntohl(*((u_int32_t *)(ptr+i)+1));
+ tmp = ntohl(*((__be32 *)(ptr+i)+1));
if (after(tmp, *sack))
*sack = tmp;
before(sack, receiver->td_end + 1),
after(ack, receiver->td_end - MAXACKWINDOW(sender)));
- if (sender->loose || receiver->loose ||
- (before(seq, sender->td_maxend + 1) &&
- after(end, sender->td_end - receiver->td_maxwin - 1) &&
- before(sack, receiver->td_end + 1) &&
- after(ack, receiver->td_end - MAXACKWINDOW(sender)))) {
+ if (before(seq, sender->td_maxend + 1) &&
+ after(end, sender->td_end - receiver->td_maxwin - 1) &&
+ before(sack, receiver->td_end + 1) &&
+ after(ack, receiver->td_end - MAXACKWINDOW(sender))) {
/*
* Take into account window scaling (RFC 1323).
*/
if (state->last_dir == dir
&& state->last_seq == seq
&& state->last_ack == ack
- && state->last_end == end)
+ && state->last_end == end
+ && state->last_win == win)
state->retrans++;
else {
state->last_dir = dir;
state->last_seq = seq;
state->last_ack = ack;
state->last_end = end;
+ state->last_win = win;
state->retrans = 0;
}
}
- /*
- * Close the window of disabled window tracking :-)
- */
- if (sender->loose)
- sender->loose--;
-
res = 1;
} else {
- if (LOG_INVALID(IPPROTO_TCP))
+ res = 0;
+ if (sender->flags & IP_CT_TCP_FLAG_BE_LIBERAL ||
+ ip_ct_tcp_be_liberal)
+ res = 1;
+ if (!res && LOG_INVALID(IPPROTO_TCP))
nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
"ip_ct_tcp: %s ",
before(seq, sender->td_maxend + 1) ?
: "ACK is over the upper bound (ACKed data not seen yet)"
: "SEQ is under the lower bound (already ACKed data retransmitted)"
: "SEQ is over the upper bound (over the window of the receiver)");
-
- res = ip_ct_tcp_be_liberal;
}
DEBUGP("tcp_in_window: res=%i sender end=%u maxend=%u maxwin=%u "
/* Checksum invalid? Ignore.
* We skip checking packets on the outgoing path
- * because the semantic of CHECKSUM_HW is different there
- * and moreover root might send raw packets.
+ * because it is assumed to be correct.
*/
/* FIXME: Source route IP option packets --RR */
if (ip_conntrack_checksum && hooknum == NF_IP_PRE_ROUTING &&
tcp_options(skb, iph, th, &conntrack->proto.tcp.seen[0]);
conntrack->proto.tcp.seen[1].flags = 0;
- conntrack->proto.tcp.seen[0].loose =
- conntrack->proto.tcp.seen[1].loose = 0;
} else if (ip_ct_tcp_loose == 0) {
/* Don't try to pick up connections. */
return 0;
conntrack->proto.tcp.seen[0].td_maxwin;
conntrack->proto.tcp.seen[0].td_scale = 0;
- /* We assume SACK. Should we assume window scaling too? */
+ /* We assume SACK and liberal window checking to handle
+ * window scaling */
conntrack->proto.tcp.seen[0].flags =
- conntrack->proto.tcp.seen[1].flags = IP_CT_TCP_FLAG_SACK_PERM;
- conntrack->proto.tcp.seen[0].loose =
- conntrack->proto.tcp.seen[1].loose = ip_ct_tcp_loose;
+ conntrack->proto.tcp.seen[1].flags = IP_CT_TCP_FLAG_SACK_PERM |
+ IP_CT_TCP_FLAG_BE_LIBERAL;
}
conntrack->proto.tcp.seen[1].td_end = 0;