Adjust the sent and received TCP timestamp value by a scalar value
in the tcp_sock structure. This will be zero most of the time, except
when the socket has been migrated with c/r. If a socket is re-migrated,
we take the new adjusted value as the saved value so that on restart it
can be re-adjusted. Also, copy this into the timewait sock so that
timestamps can continue to be adjusted in timewait state in the
minisocks code.
Note that TCP timestamps are just a jiffies stamp, which means they
have no relation to wall-clock time and thus a simple correction
factor should be enough to ensure correctness.
Signed-off-by: Dan Smith <danms@xxxxxxxxxx>
---
include/linux/checkpoint_hdr.h | 2 ++
include/linux/tcp.h | 3 +++
include/net/tcp.h | 3 ++-
net/ipv4/checkpoint.c | 8 ++++++++
net/ipv4/syncookies.c | 2 +-
net/ipv4/tcp_input.c | 14 +++++++-------
net/ipv4/tcp_ipv4.c | 2 +-
net/ipv4/tcp_minisocks.c | 8 ++++++--
net/ipv4/tcp_output.c | 20 ++++++++++----------
net/ipv6/syncookies.c | 2 +-
net/ipv6/tcp_ipv6.c | 2 +-
11 files changed, 42 insertions(+), 24 deletions(-)
diff --git a/include/linux/checkpoint_hdr.h b/include/linux/checkpoint_hdr.h
index 0c10657..9c2f13d 100644
--- a/include/linux/checkpoint_hdr.h
+++ b/include/linux/checkpoint_hdr.h
@@ -649,6 +649,8 @@ struct ckpt_hdr_socket_inet {
__u32 keepalive_time;
__u32 keepalive_intvl;
+ __s32 tcp_ts;
+
__u16 urg_data;
__u16 advmss;
__u8 frto_counter;
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 8afac76..b845e21 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -399,6 +399,8 @@ struct tcp_sock {
u32 probe_seq_end;
} mtu_probe;
+ s32 ts_adjust; /* tcp_time_stamp adjustment factor */
+
#ifdef CONFIG_TCP_MD5SIG
/* TCP AF-Specific parts; only used by MD5 Signature support so far */
struct tcp_sock_af_ops *af_specific;
@@ -420,6 +422,7 @@ struct tcp_timewait_sock {
u32 tw_rcv_wnd;
u32 tw_ts_recent;
long tw_ts_recent_stamp;
+ s32 tw_ts_adjust;
#ifdef CONFIG_TCP_MD5SIG
u16 tw_md5_keylen;
u8 tw_md5_key[TCP_MD5SIG_MAXKEYLEN];
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 88af843..96b4b27 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -409,7 +409,8 @@ extern int tcp_recvmsg(struct kiocb *iocb, struct sock *sk,
extern void tcp_parse_options(struct sk_buff *skb,
struct tcp_options_received *opt_rx,
- int estab);
+ int estab,
+ s32 ts_adjust);
extern u8 *tcp_parse_md5sig_option(struct tcphdr *th);
diff --git a/net/ipv4/checkpoint.c b/net/ipv4/checkpoint.c
index 5913652..f858dbc 100644
--- a/net/ipv4/checkpoint.c
+++ b/net/ipv4/checkpoint.c
@@ -178,6 +178,14 @@ static int sock_inet_tcp_cptrst(struct ckpt_ctx *ctx,
CKPT_COPY(op, hh->tcp.keepalive_time, sk->keepalive_time);
CKPT_COPY(op, hh->tcp.keepalive_intvl, sk->keepalive_intvl);
+ if (op == CKPT_CPT)
+ hh->tcp.tcp_ts = tcp_time_stamp + sk->ts_adjust;
+ else
+ sk->ts_adjust = hh->tcp.tcp_ts - tcp_time_stamp;
+
+ ckpt_debug("TCP tcp_ts %i ts_adjust %i\n",
+ hh->tcp.tcp_ts, sk->ts_adjust);
+
return 0;
}
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index cd2b97f..31eafef 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -277,7 +277,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
/* check for timestamp cookie support */
memset(&tcp_opt, 0, sizeof(tcp_opt));
- tcp_parse_options(skb, &tcp_opt, 0);
+ tcp_parse_options(skb, &tcp_opt, 0, tp->ts_adjust);
if (tcp_opt.saw_tstamp)
cookie_check_timestamp(&tcp_opt);
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 2bdb0da..63cac78 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3699,7 +3699,7 @@ old_ack:
* the fast version below fails.
*/
void tcp_parse_options(struct sk_buff *skb, struct tcp_options_received *opt_rx,
- int estab)
+ int estab, s32 ts_adjust)
{
unsigned char *ptr;
struct tcphdr *th = tcp_hdr(skb);
@@ -3756,8 +3756,8 @@ void tcp_parse_options(struct sk_buff *skb, struct tcp_options_received *opt_rx,
((estab && opt_rx->tstamp_ok) ||
(!estab && sysctl_tcp_timestamps))) {
opt_rx->saw_tstamp = 1;
- opt_rx->rcv_tsval = get_unaligned_be32(ptr);
- opt_rx->rcv_tsecr = get_unaligned_be32(ptr + 4);
+ opt_rx->rcv_tsval = get_unaligned_be32(ptr) + ts_adjust;
+ opt_rx->rcv_tsecr = get_unaligned_be32(ptr + 4) + ts_adjust;
}
break;
case TCPOPT_SACK_PERM:
@@ -3799,9 +3799,9 @@ static int tcp_parse_aligned_timestamp(struct tcp_sock *tp, struct tcphdr *th)
| (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP)) {
tp->rx_opt.saw_tstamp = 1;
++ptr;
- tp->rx_opt.rcv_tsval = ntohl(*ptr);
+ tp->rx_opt.rcv_tsval = ntohl(*ptr) + tp->ts_adjust;
++ptr;
- tp->rx_opt.rcv_tsecr = ntohl(*ptr);
+ tp->rx_opt.rcv_tsecr = ntohl(*ptr) + tp->ts_adjust;
return 1;
}
return 0;
@@ -3821,7 +3821,7 @@ static int tcp_fast_parse_options(struct sk_buff *skb, struct tcphdr *th,
if (tcp_parse_aligned_timestamp(tp, th))
return 1;
}
- tcp_parse_options(skb, &tp->rx_opt, 1);
+ tcp_parse_options(skb, &tp->rx_opt, 1, tp->ts_adjust);
return 1;
}
@@ -5366,7 +5366,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
struct inet_connection_sock *icsk = inet_csk(sk);
int saved_clamp = tp->rx_opt.mss_clamp;
- tcp_parse_options(skb, &tp->rx_opt, 0);
+ tcp_parse_options(skb, &tp->rx_opt, 0, tp->ts_adjust);
if (th->ack) {
/* rfc793:
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 6d88219..e8efe7f 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1222,7 +1222,7 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
tmp_opt.mss_clamp = 536;
tmp_opt.user_mss = tcp_sk(sk)->rx_opt.user_mss;
- tcp_parse_options(skb, &tmp_opt, 0);
+ tcp_parse_options(skb, &tmp_opt, 0, 0);
if (want_cookie && !tmp_opt.saw_tstamp)
tcp_clear_options(&tmp_opt);
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index f8d67cc..4c72954 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -102,7 +102,7 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb,
tmp_opt.saw_tstamp = 0;
if (th->doff > (sizeof(*th) >> 2) && tcptw->tw_ts_recent_stamp) {
- tcp_parse_options(skb, &tmp_opt, 0);
+ tcp_parse_options(skb, &tmp_opt, 0, tcptw->tw_ts_adjust);
if (tmp_opt.saw_tstamp) {
tmp_opt.ts_recent = tcptw->tw_ts_recent;
@@ -292,6 +292,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo)
tcptw->tw_snd_nxt = tp->snd_nxt;
tcptw->tw_rcv_wnd = tcp_receive_window(tp);
tcptw->tw_ts_recent = tp->rx_opt.ts_recent;
+ tcptw->tw_ts_adjust = tp->ts_adjust;
tcptw->tw_ts_recent_stamp = tp->rx_opt.ts_recent_stamp;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
@@ -503,7 +504,10 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
tmp_opt.saw_tstamp = 0;
if (th->doff > (sizeof(struct tcphdr)>>2)) {
- tcp_parse_options(skb, &tmp_opt, 0);
+ /* C/R doesn't support request sockets yet, so we
+ * don't need to worry about passing a ts_adjust here
+ */
+ tcp_parse_options(skb, &tmp_opt, 0, 0);
if (tmp_opt.saw_tstamp) {
tmp_opt.ts_recent = req->ts_recent;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index bd62712..38c165e 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1487,7 +1487,7 @@ static int tcp_mtu_probe(struct sock *sk)
/* We're ready to send. If this fails, the probe will
* be resegmented into mss-sized pieces by tcp_write_xmit(). */
- TCP_SKB_CB(nskb)->when = tcp_time_stamp;
+ TCP_SKB_CB(nskb)->when = tcp_time_stamp + tp->ts_adjust;
if (!tcp_transmit_skb(sk, nskb, 1, GFP_ATOMIC)) {
/* Decrement cwnd here because we are sending
* effectively two packets. */
@@ -1568,7 +1568,7 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
unlikely(tso_fragment(sk, skb, limit, mss_now)))
break;
- TCP_SKB_CB(skb)->when = tcp_time_stamp;
+ TCP_SKB_CB(skb)->when = tcp_time_stamp + tp->ts_adjust;
if (unlikely(tcp_transmit_skb(sk, skb, 1, gfp)))
break;
@@ -1922,7 +1922,7 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
/* Make a copy, if the first transmission SKB clone we made
* is still in somebody's hands, else make a clone.
*/
- TCP_SKB_CB(skb)->when = tcp_time_stamp;
+ TCP_SKB_CB(skb)->when = tcp_time_stamp + tp->ts_adjust;
err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
@@ -2138,7 +2138,7 @@ void tcp_send_active_reset(struct sock *sk, gfp_t priority)
tcp_init_nondata_skb(skb, tcp_acceptable_seq(sk),
TCPCB_FLAG_ACK | TCPCB_FLAG_RST);
/* Send it off. */
- TCP_SKB_CB(skb)->when = tcp_time_stamp;
+ TCP_SKB_CB(skb)->when = tcp_time_stamp + tcp_sk(sk)->ts_adjust;
if (tcp_transmit_skb(sk, skb, 0, priority))
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTFAILED);
@@ -2176,7 +2176,7 @@ int tcp_send_synack(struct sock *sk)
TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_ACK;
TCP_ECN_send_synack(tcp_sk(sk), skb);
}
- TCP_SKB_CB(skb)->when = tcp_time_stamp;
+ TCP_SKB_CB(skb)->when = tcp_time_stamp + tcp_sk(sk)->ts_adjust;
return tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
}
@@ -2229,7 +2229,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
TCP_SKB_CB(skb)->when = cookie_init_timestamp(req);
else
#endif
- TCP_SKB_CB(skb)->when = tcp_time_stamp;
+ TCP_SKB_CB(skb)->when = tcp_time_stamp + tp->ts_adjust;
tcp_header_size = tcp_synack_options(sk, req, mss,
skb, &opts, &md5) +
sizeof(struct tcphdr);
@@ -2352,7 +2352,7 @@ int tcp_connect(struct sock *sk)
TCP_ECN_send_syn(sk, buff);
/* Send it off. */
- TCP_SKB_CB(buff)->when = tcp_time_stamp;
+ TCP_SKB_CB(buff)->when = tcp_time_stamp + tp->ts_adjust;
tp->retrans_stamp = TCP_SKB_CB(buff)->when;
skb_header_release(buff);
__tcp_add_write_queue_tail(sk, buff);
@@ -2457,7 +2457,7 @@ void tcp_send_ack(struct sock *sk)
tcp_init_nondata_skb(buff, tcp_acceptable_seq(sk), TCPCB_FLAG_ACK);
/* Send it off, this clears delayed acks for us. */
- TCP_SKB_CB(buff)->when = tcp_time_stamp;
+ TCP_SKB_CB(buff)->when = tcp_time_stamp + tcp_sk(sk)->ts_adjust;
tcp_transmit_skb(sk, buff, 0, GFP_ATOMIC);
}
@@ -2489,7 +2489,7 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent)
* send it.
*/
tcp_init_nondata_skb(skb, tp->snd_una - !urgent, TCPCB_FLAG_ACK);
- TCP_SKB_CB(skb)->when = tcp_time_stamp;
+ TCP_SKB_CB(skb)->when = tcp_time_stamp + tp->ts_adjust;
return tcp_transmit_skb(sk, skb, 0, GFP_ATOMIC);
}
@@ -2524,7 +2524,7 @@ int tcp_write_wakeup(struct sock *sk)
tcp_set_skb_tso_segs(sk, skb, mss);
TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
- TCP_SKB_CB(skb)->when = tcp_time_stamp;
+ TCP_SKB_CB(skb)->when = tcp_time_stamp + tp->ts_adjust;
err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
if (!err)
tcp_event_new_data_sent(sk, skb);
diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index 8c25139..9337ec6 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -185,7 +185,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
/* check for timestamp cookie support */
memset(&tcp_opt, 0, sizeof(tcp_opt));
- tcp_parse_options(skb, &tcp_opt, 0);
+ tcp_parse_options(skb, &tcp_opt, 0, tp->ts_adjust);
if (tcp_opt.saw_tstamp)
cookie_check_timestamp(&tcp_opt);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index d849dd5..3a83570 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1202,7 +1202,7 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
tmp_opt.user_mss = tp->rx_opt.user_mss;
- tcp_parse_options(skb, &tmp_opt, 0);
+ tcp_parse_options(skb, &tmp_opt, 0, 0);
if (want_cookie && !tmp_opt.saw_tstamp)
tcp_clear_options(&tmp_opt);
--
1.6.2.5
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