Andrey Vagin says:

====================
If a TCP socket will get live-migrated from one box to another the
timestamps (which are typically ON) will get screwed up -- the new
kernel will generate TS values that has nothing to do with what they
were on dump. The solution is to yet again fix the kernel and put a
"timestamp offset" on a socket.

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.

For time-wait sockets offset is inhereted by a proper tcp_sock.

A per-socket offset can be set only for sockets in repair mode.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2013-02-13 13:22:24 -05:00
Родитель d0023f820e ee684b6f28
Коммит b8fa410035
8 изменённых файлов: 47 добавлений и 17 удалений

Просмотреть файл

@ -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

Просмотреть файл

@ -111,6 +111,7 @@ enum {
#define TCP_QUEUE_SEQ 21
#define TCP_REPAIR_OPTIONS 22
#define TCP_FASTOPEN 23 /* Enable FastOpen on listeners */
#define TCP_TIMESTAMP 24
struct tcp_repair_opt {
__u32 opt_code;

Просмотреть файл

@ -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;
@ -2712,6 +2714,12 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
else
err = -EINVAL;
break;
case TCP_TIMESTAMP:
if (!tp->repair)
err = -EPERM;
else
tp->tsoffset = val - tcp_time_stamp;
break;
default:
err = -ENOPROTOOPT;
break;
@ -2960,6 +2968,9 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
case TCP_USER_TIMEOUT:
val = jiffies_to_msecs(icsk->icsk_user_timeout);
break;
case TCP_TIMESTAMP:
val = tcp_time_stamp + tp->tsoffset;
break;
default:
return -ENOPROTOOPT;
}

Просмотреть файл

@ -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;
@ -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;
}
@ -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:

Просмотреть файл

@ -726,7 +726,7 @@ release_sk1:
*/
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)
{
@ -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;
}
@ -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) |
@ -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),
@ -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,

Просмотреть файл

@ -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);
@ -288,6 +289,7 @@ 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 +501,7 @@ 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))

Просмотреть файл

@ -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;
}
@ -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;
}

Просмотреть файл

@ -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;
@ -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)
@ -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
@ -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:
@ -871,10 +872,11 @@ release_sk1:
#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)
@ -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);
@ -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);
}