linux 2.6.16.38 w/ vs2.0.3-rc1

[linux-2.6.git] / net / ipv4 / tcp_timer.c

diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index 7c1bde3..e188095 100644 (file)
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -119,10 +119,8 @@ 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)
 {
-       struct inet_connection_sock *icsk = inet_csk(sk);
-       struct tcp_sock *tp = tcp_sk(sk);
+       const struct inet_connection_sock *icsk = inet_csk(sk);
        int retry_until;
-       int mss;
 
        if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
                if (icsk->icsk_retransmits)
@@ -130,19 +128,25 @@ 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) {
-                       /* 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);
-                               }
-                       }
+                       /* 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 :-).
+                  */
 
                        dst_negative_advice(&sk->sk_dst_cache);
                }