[NETFILTER]: x_tables: add xt_{match,target} arguments to match/target functions

[safe/jmp/linux-2.6] / net / ipv4 / tcp_timer.c

diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index e188095..7c1bde3 100644 (file)
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -119,8 +119,10 @@ static int tcp_orphan_retries(struct sock *sk, int alive)
 /* A write timeout has occurred. Process the after effects. */
 static int tcp_write_timeout(struct sock *sk)
 {
-       const struct inet_connection_sock *icsk = inet_csk(sk);
+       struct inet_connection_sock *icsk = inet_csk(sk);
+       struct tcp_sock *tp = tcp_sk(sk);
        int retry_until;
+       int mss;
 
        if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
                if (icsk->icsk_retransmits)
@@ -128,25 +130,19 @@ static int tcp_write_timeout(struct sock *sk)
                retry_until = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
        } else {
                if (icsk->icsk_retransmits >= sysctl_tcp_retries1) {
-                       /* NOTE. draft-ietf-tcpimpl-pmtud-01.txt requires pmtu black
-                          hole detection. :-(
-
-                          It is place to make it. It is not made. I do not want
-                          to make it. It is disgusting. It does not work in any
-                          case. Let me to cite the same draft, which requires for
-                          us to implement this:
-
-   "The one security concern raised by this memo is that ICMP black holes
-   are often caused by over-zealous security administrators who block
-   all ICMP messages.  It is vitally important that those who design and
-   deploy security systems understand the impact of strict filtering on
-   upper-layer protocols.  The safest web site in the world is worthless
-   if most TCP implementations cannot transfer data from it.  It would
-   be far nicer to have all of the black holes fixed rather than fixing
-   all of the TCP implementations."
-
-                           Golden words :-).
-                  */
+                       /* Black hole detection */
+                       if (sysctl_tcp_mtu_probing) {
+                               if (!icsk->icsk_mtup.enabled) {
+                                       icsk->icsk_mtup.enabled = 1;
+                                       tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
+                               } else {
+                                       mss = min(sysctl_tcp_base_mss,
+                                                 tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_low)/2);
+                                       mss = max(mss, 68 - tp->tcp_header_len);
+                                       icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, mss);
+                                       tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
+                               }
+                       }
 
                        dst_negative_advice(&sk->sk_dst_cache);
                }