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Diffstat (limited to 'net/ipv4/tcp_ipv4.c')
-rw-r--r--net/ipv4/tcp_ipv4.c32
1 files changed, 26 insertions, 6 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index bea17f1e8302..44c09eddbb78 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -155,12 +155,26 @@ int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp)
and use initial timestamp retrieved from peer table.
*/
if (tcptw->tw_ts_recent_stamp &&
- (!twp || (reuse && get_seconds() - tcptw->tw_ts_recent_stamp > 1))) {
- tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2;
- if (tp->write_seq == 0)
- tp->write_seq = 1;
- tp->rx_opt.ts_recent = tcptw->tw_ts_recent;
- tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp;
+ (!twp || (reuse && time_after32(ktime_get_seconds(),
+ tcptw->tw_ts_recent_stamp)))) {
+ /* In case of repair and re-using TIME-WAIT sockets we still
+ * want to be sure that it is safe as above but honor the
+ * sequence numbers and time stamps set as part of the repair
+ * process.
+ *
+ * Without this check re-using a TIME-WAIT socket with TCP
+ * repair would accumulate a -1 on the repair assigned
+ * sequence number. The first time it is reused the sequence
+ * is -1, the second time -2, etc. This fixes that issue
+ * without appearing to create any others.
+ */
+ if (likely(!tp->repair)) {
+ tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2;
+ if (tp->write_seq == 0)
+ tp->write_seq = 1;
+ tp->rx_opt.ts_recent = tcptw->tw_ts_recent;
+ tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp;
+ }
sock_hold(sktw);
return 1;
}
@@ -2503,6 +2517,12 @@ static int __net_init tcp_sk_init(struct net *net)
if (res)
goto fail;
sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
+
+ /* Please enforce IP_DF and IPID==0 for RST and
+ * ACK sent in SYN-RECV and TIME-WAIT state.
+ */
+ inet_sk(sk)->pmtudisc = IP_PMTUDISC_DO;
+
*per_cpu_ptr(net->ipv4.tcp_sk, cpu) = sk;
}