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authorAndrey Vagin <avagin@openvz.org>2013-02-11 05:50:17 +0000
committerDavid S. Miller <davem@davemloft.net>2013-02-13 13:22:15 -0500
commitceaa1fef65a7c2e017b260b879b310dd24888083 (patch)
treef511458ce6431cd4b5f5b46f4c633f73e49a3589
parentd0023f820e003857248d14f2213ac3930283f16c (diff)
downloadlinux-stericsson-ceaa1fef65a7c2e017b260b879b310dd24888083.tar.gz
tcp: adding a per-socket timestamp offset
This functionality is used for restoring tcp sockets. A tcp timestamp depends on how long a system has been running, so it's differ for each host. The solution is to set a per-socket offset. A per-socket offset for a TIME_WAIT socket is inherited from a proper tcp socket. tcp_request_sock doesn't have a timestamp offset, because the repair mode for them are not implemented. Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: James Morris <jmorris@namei.org> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Patrick McHardy <kaber@trash.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrey Vagin <avagin@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/linux/tcp.h3
-rw-r--r--net/ipv4/tcp.c2
-rw-r--r--net/ipv4/tcp_minisocks.c2
3 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 6d0d46138ae8..f28408c07dc2 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -162,6 +162,8 @@ struct tcp_sock {
u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */
u32 lsndtime; /* timestamp of last sent data packet (for restart window) */
+ u32 tsoffset; /* timestamp offset */
+
struct list_head tsq_node; /* anchor in tsq_tasklet.head list */
unsigned long tsq_flags;
@@ -353,6 +355,7 @@ struct tcp_timewait_sock {
u32 tw_rcv_nxt;
u32 tw_snd_nxt;
u32 tw_rcv_wnd;
+ u32 tw_ts_offset;
u32 tw_ts_recent;
long tw_ts_recent_stamp;
#ifdef CONFIG_TCP_MD5SIG
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 2c7e5963c2ea..8a90bda96038 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -400,6 +400,8 @@ void tcp_init_sock(struct sock *sk)
tcp_enable_early_retrans(tp);
icsk->icsk_ca_ops = &tcp_init_congestion_ops;
+ tp->tsoffset = 0;
+
sk->sk_state = TCP_CLOSE;
sk->sk_write_space = sk_stream_write_space;
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index f0409287b5f4..4dfc99f54f67 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -288,6 +288,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo)
tcptw->tw_rcv_wnd = tcp_receive_window(tp);
tcptw->tw_ts_recent = tp->rx_opt.ts_recent;
tcptw->tw_ts_recent_stamp = tp->rx_opt.ts_recent_stamp;
+ tcptw->tw_ts_offset = tp->tsoffset;
#if IS_ENABLED(CONFIG_IPV6)
if (tw->tw_family == PF_INET6) {
@@ -499,6 +500,7 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req,
newtp->rx_opt.ts_recent_stamp = 0;
newtp->tcp_header_len = sizeof(struct tcphdr);
}
+ newtp->tsoffset = 0;
#ifdef CONFIG_TCP_MD5SIG
newtp->md5sig_info = NULL; /*XXX*/
if (newtp->af_specific->md5_lookup(sk, newsk))