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tcp: send packets with a socket timestamp
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A socket timestamp is a sum of the global tcp_time_stamp and
a per-socket offset.

A socket offset is added in places where externally visible
tcp timestamp option is parsed/initialized.

Connections in the SYN_RECV state are not supported, global
tcp_time_stamp is used for them, because repair mode doesn't support
this state. In a future it can be implemented by the similar way
as for TIME_WAIT sockets.

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>
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Andrey Vagin authored and David S. Miller committed Feb 13, 2013
1 parent 93be6ce commit ee684b6
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Showing 5 changed files with 30 additions and 17 deletions.
8 changes: 7 additions & 1 deletion net/ipv4/tcp_input.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3860,7 +3860,7 @@ static bool tcp_parse_aligned_timestamp(struct tcp_sock *tp, const struct tcphdr
++ptr;
tp->rx_opt.rcv_tsval = ntohl(*ptr);
++ptr;
tp->rx_opt.rcv_tsecr = ntohl(*ptr);
tp->rx_opt.rcv_tsecr = ntohl(*ptr) - tp->tsoffset;
return true;
}
return false;
Expand All @@ -3884,7 +3884,11 @@ static bool tcp_fast_parse_options(const struct sk_buff *skb,
if (tcp_parse_aligned_timestamp(tp, th))
return true;
}

tcp_parse_options(skb, &tp->rx_opt, hvpp, 1, NULL);
if (tp->rx_opt.saw_tstamp)
tp->rx_opt.rcv_tsecr -= tp->tsoffset;

return true;
}

Expand Down Expand Up @@ -5665,6 +5669,8 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
int saved_clamp = tp->rx_opt.mss_clamp;

tcp_parse_options(skb, &tp->rx_opt, &hash_location, 0, &foc);
if (tp->rx_opt.saw_tstamp)
tp->rx_opt.rcv_tsecr -= tp->tsoffset;

if (th->ack) {
/* rfc793:
Expand Down
12 changes: 7 additions & 5 deletions net/ipv4/tcp_ipv4.c
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Original file line number Diff line number Diff line change
Expand Up @@ -726,7 +726,7 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
*/

static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
u32 win, u32 ts, int oif,
u32 win, u32 tsval, u32 tsecr, int oif,
struct tcp_md5sig_key *key,
int reply_flags, u8 tos)
{
Expand All @@ -747,12 +747,12 @@ static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack,

arg.iov[0].iov_base = (unsigned char *)&rep;
arg.iov[0].iov_len = sizeof(rep.th);
if (ts) {
if (tsecr) {
rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
(TCPOPT_TIMESTAMP << 8) |
TCPOLEN_TIMESTAMP);
rep.opt[1] = htonl(tcp_time_stamp);
rep.opt[2] = htonl(ts);
rep.opt[1] = htonl(tsval);
rep.opt[2] = htonl(tsecr);
arg.iov[0].iov_len += TCPOLEN_TSTAMP_ALIGNED;
}

Expand All @@ -767,7 +767,7 @@ static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack,

#ifdef CONFIG_TCP_MD5SIG
if (key) {
int offset = (ts) ? 3 : 0;
int offset = (tsecr) ? 3 : 0;

rep.opt[offset++] = htonl((TCPOPT_NOP << 24) |
(TCPOPT_NOP << 16) |
Expand Down Expand Up @@ -802,6 +802,7 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)

tcp_v4_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
tcp_time_stamp + tcptw->tw_ts_offset,
tcptw->tw_ts_recent,
tw->tw_bound_dev_if,
tcp_twsk_md5_key(tcptw),
Expand All @@ -821,6 +822,7 @@ static void tcp_v4_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
tcp_v4_send_ack(skb, (sk->sk_state == TCP_LISTEN) ?
tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
tcp_rsk(req)->rcv_nxt, req->rcv_wnd,
tcp_time_stamp,
req->ts_recent,
0,
tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&ip_hdr(skb)->daddr,
Expand Down
1 change: 1 addition & 0 deletions net/ipv4/tcp_minisocks.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -102,6 +102,7 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb,
tcp_parse_options(skb, &tmp_opt, &hash_location, 0, NULL);

if (tmp_opt.saw_tstamp) {
tmp_opt.rcv_tsecr -= tcptw->tw_ts_offset;
tmp_opt.ts_recent = tcptw->tw_ts_recent;
tmp_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp;
paws_reject = tcp_paws_reject(&tmp_opt, th->rst);
Expand Down
4 changes: 2 additions & 2 deletions net/ipv4/tcp_output.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -622,7 +622,7 @@ static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb,

if (likely(sysctl_tcp_timestamps && *md5 == NULL)) {
opts->options |= OPTION_TS;
opts->tsval = TCP_SKB_CB(skb)->when;
opts->tsval = TCP_SKB_CB(skb)->when + tp->tsoffset;
opts->tsecr = tp->rx_opt.ts_recent;
remaining -= TCPOLEN_TSTAMP_ALIGNED;
}
Expand Down Expand Up @@ -806,7 +806,7 @@ static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb

if (likely(tp->rx_opt.tstamp_ok)) {
opts->options |= OPTION_TS;
opts->tsval = tcb ? tcb->when : 0;
opts->tsval = tcb ? tcb->when + tp->tsoffset : 0;
opts->tsecr = tp->rx_opt.ts_recent;
size += TCPOLEN_TSTAMP_ALIGNED;
}
Expand Down
22 changes: 13 additions & 9 deletions net/ipv6/tcp_ipv6.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -713,7 +713,8 @@ static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
#endif

static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
u32 ts, struct tcp_md5sig_key *key, int rst, u8 tclass)
u32 tsval, u32 tsecr,
struct tcp_md5sig_key *key, int rst, u8 tclass)
{
const struct tcphdr *th = tcp_hdr(skb);
struct tcphdr *t1;
Expand All @@ -725,7 +726,7 @@ static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
struct dst_entry *dst;
__be32 *topt;

if (ts)
if (tsecr)
tot_len += TCPOLEN_TSTAMP_ALIGNED;
#ifdef CONFIG_TCP_MD5SIG
if (key)
Expand Down Expand Up @@ -755,11 +756,11 @@ static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,

topt = (__be32 *)(t1 + 1);

if (ts) {
if (tsecr) {
*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
(TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
*topt++ = htonl(tcp_time_stamp);
*topt++ = htonl(ts);
*topt++ = htonl(tsval);
*topt++ = htonl(tsecr);
}

#ifdef CONFIG_TCP_MD5SIG
Expand Down Expand Up @@ -860,7 +861,7 @@ static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
(th->doff << 2);

tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1, 0);
tcp_v6_send_response(skb, seq, ack_seq, 0, 0, 0, key, 1, 0);

#ifdef CONFIG_TCP_MD5SIG
release_sk1:
Expand All @@ -871,10 +872,11 @@ static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
#endif
}

static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts,
static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
u32 win, u32 tsval, u32 tsecr,
struct tcp_md5sig_key *key, u8 tclass)
{
tcp_v6_send_response(skb, seq, ack, win, ts, key, 0, tclass);
tcp_v6_send_response(skb, seq, ack, win, tsval, tsecr, key, 0, tclass);
}

static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
Expand All @@ -884,6 +886,7 @@ static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)

tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
tcp_time_stamp + tcptw->tw_ts_offset,
tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw),
tw->tw_tclass);

Expand All @@ -893,7 +896,8 @@ static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
struct request_sock *req)
{
tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent,
tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1,
req->rcv_wnd, tcp_time_stamp, req->ts_recent,
tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr), 0);
}

Expand Down

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