1 files changed, 46 insertions, 32 deletions
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 7121d8573928..fb9349be36b8 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -44,7 +44,7 @@ tcp_timewait_check_oow_rate_limit(struct inet_timewait_sock *tw,
 		/* Send ACK. Note, we do not put the bucket,
 		 * it will be released by caller.
 		 */
-		return TCP_TW_ACK;
+		return TCP_TW_ACK_OOW;
 	}
 
 	/* We are rate-limiting, so just release the tw sock and drop skb. */
@@ -157,8 +157,11 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb,
 				    rcv_nxt);
 
 		if (tmp_opt.saw_tstamp) {
+			u64 ts = tcp_clock_ms();
+
+			WRITE_ONCE(tw->tw_entry_stamp, ts);
 			WRITE_ONCE(tcptw->tw_ts_recent_stamp,
-				  ktime_get_seconds());
+				   div_u64(ts, MSEC_PER_SEC));
 			WRITE_ONCE(tcptw->tw_ts_recent,
 				   tmp_opt.rcv_tsval);
 		}
@@ -261,7 +264,7 @@ kill:
 	inet_twsk_put(tw);
 	return TCP_TW_SUCCESS;
 }
-EXPORT_SYMBOL(tcp_timewait_state_process);
+EXPORT_IPV6_MOD(tcp_timewait_state_process);
 
 static void tcp_time_wait_init(struct sock *sk, struct tcp_timewait_sock *tcptw)
 {
@@ -316,6 +319,8 @@ void tcp_time_wait(struct sock *sk, int state, int timeo)
 		tw->tw_mark		= sk->sk_mark;
 		tw->tw_priority		= READ_ONCE(sk->sk_priority);
 		tw->tw_rcv_wscale	= tp->rx_opt.rcv_wscale;
+		/* refreshed when we enter true TIME-WAIT state */
+		tw->tw_entry_stamp	= tcp_time_stamp_ms(tp);
 		tcptw->tw_rcv_nxt	= tp->rcv_nxt;
 		tcptw->tw_snd_nxt	= tp->snd_nxt;
 		tcptw->tw_rcv_wnd	= tcp_receive_window(tp);
@@ -393,7 +398,7 @@ void tcp_twsk_destructor(struct sock *sk)
 #endif
 	tcp_ao_destroy_sock(sk, true);
 }
-EXPORT_SYMBOL_GPL(tcp_twsk_destructor);
+EXPORT_IPV6_MOD_GPL(tcp_twsk_destructor);
 
 void tcp_twsk_purge(struct list_head *net_exit_list)
 {
@@ -452,12 +457,13 @@ void tcp_openreq_init_rwin(struct request_sock *req,
 		rcv_wnd);
 	ireq->rcv_wscale = rcv_wscale;
 }
-EXPORT_SYMBOL(tcp_openreq_init_rwin);
 
 static void tcp_ecn_openreq_child(struct tcp_sock *tp,
 				  const struct request_sock *req)
 {
-	tp->ecn_flags = inet_rsk(req)->ecn_ok ? TCP_ECN_OK : 0;
+	tcp_ecn_mode_set(tp, inet_rsk(req)->ecn_ok ?
+			     TCP_ECN_MODE_RFC3168 :
+			     TCP_ECN_DISABLED);
 }
 
 void tcp_ca_openreq_child(struct sock *sk, const struct dst_entry *dst)
@@ -487,7 +493,7 @@ void tcp_ca_openreq_child(struct sock *sk, const struct dst_entry *dst)
 
 	tcp_set_ca_state(sk, TCP_CA_Open);
 }
-EXPORT_SYMBOL_GPL(tcp_ca_openreq_child);
+EXPORT_IPV6_MOD_GPL(tcp_ca_openreq_child);
 
 static void smc_check_reset_syn_req(const struct tcp_sock *oldtp,
 				    struct request_sock *req,
@@ -561,8 +567,7 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
 	WRITE_ONCE(newtp->write_seq, newtp->pushed_seq = treq->snt_isn + 1);
 
 	if (sock_flag(newsk, SOCK_KEEPOPEN))
-		inet_csk_reset_keepalive_timer(newsk,
-					       keepalive_time_when(newtp));
+		tcp_reset_keepalive_timer(newsk, keepalive_time_when(newtp));
 
 	newtp->rx_opt.tstamp_ok = ireq->tstamp_ok;
 	newtp->rx_opt.sack_ok = ireq->sack_ok;
@@ -582,7 +587,7 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
 
 	if (newtp->rx_opt.tstamp_ok) {
 		newtp->tcp_usec_ts = treq->req_usec_ts;
-		newtp->rx_opt.ts_recent = READ_ONCE(req->ts_recent);
+		newtp->rx_opt.ts_recent = req->ts_recent;
 		newtp->rx_opt.ts_recent_stamp = ktime_get_seconds();
 		newtp->tcp_header_len = sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED;
 	} else {
@@ -654,12 +659,14 @@ EXPORT_SYMBOL(tcp_create_openreq_child);
 
 struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
 			   struct request_sock *req,
-			   bool fastopen, bool *req_stolen)
+			   bool fastopen, bool *req_stolen,
+			   enum skb_drop_reason *drop_reason)
 {
 	struct tcp_options_received tmp_opt;
 	struct sock *child;
 	const struct tcphdr *th = tcp_hdr(skb);
 	__be32 flg = tcp_flag_word(th) & (TCP_FLAG_RST|TCP_FLAG_SYN|TCP_FLAG_ACK);
+	bool tsecr_reject = false;
 	bool paws_reject = false;
 	bool own_req;
 
@@ -668,9 +675,14 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
 		tcp_parse_options(sock_net(sk), skb, &tmp_opt, 0, NULL);
 
 		if (tmp_opt.saw_tstamp) {
-			tmp_opt.ts_recent = READ_ONCE(req->ts_recent);
-			if (tmp_opt.rcv_tsecr)
+			tmp_opt.ts_recent = req->ts_recent;
+			if (tmp_opt.rcv_tsecr) {
+				if (inet_rsk(req)->tstamp_ok && !fastopen)
+					tsecr_reject = !between(tmp_opt.rcv_tsecr,
+							tcp_rsk(req)->snt_tsval_first,
+							READ_ONCE(tcp_rsk(req)->snt_tsval_last));
 				tmp_opt.rcv_tsecr -= tcp_rsk(req)->ts_off;
+			}
 			/* We do not store true stamp, but it is not required,
 			 * it can be estimated (approximately)
 			 * from another data.
@@ -785,37 +797,34 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
 	     tcp_rsk(req)->snt_isn + 1))
 		return sk;
 
-	/* Also, it would be not so bad idea to check rcv_tsecr, which
-	 * is essentially ACK extension and too early or too late values
-	 * should cause reset in unsynchronized states.
-	 */
-
 	/* RFC793: "first check sequence number". */
 
-	if (paws_reject || !tcp_in_window(TCP_SKB_CB(skb)->seq,
-					  TCP_SKB_CB(skb)->end_seq,
-					  tcp_rsk(req)->rcv_nxt,
-					  tcp_rsk(req)->rcv_nxt +
-					  tcp_synack_window(req))) {
+	if (paws_reject || tsecr_reject ||
+	    !tcp_in_window(TCP_SKB_CB(skb)->seq,
+			   TCP_SKB_CB(skb)->end_seq,
+			   tcp_rsk(req)->rcv_nxt,
+			   tcp_rsk(req)->rcv_nxt +
+			   tcp_synack_window(req))) {
 		/* Out of window: send ACK and drop. */
 		if (!(flg & TCP_FLAG_RST) &&
 		    !tcp_oow_rate_limited(sock_net(sk), skb,
 					  LINUX_MIB_TCPACKSKIPPEDSYNRECV,
 					  &tcp_rsk(req)->last_oow_ack_time))
 			req->rsk_ops->send_ack(sk, skb, req);
-		if (paws_reject)
+		if (paws_reject) {
+			SKB_DR_SET(*drop_reason, TCP_RFC7323_PAWS);
 			NET_INC_STATS(sock_net(sk), LINUX_MIB_PAWSESTABREJECTED);
+		} else if (tsecr_reject) {
+			SKB_DR_SET(*drop_reason, TCP_RFC7323_TSECR);
+			NET_INC_STATS(sock_net(sk), LINUX_MIB_TSECRREJECTED);
+		} else {
+			SKB_DR_SET(*drop_reason, TCP_OVERWINDOW);
+		}
 		return NULL;
 	}
 
 	/* In sequence, PAWS is OK. */
 
-	/* TODO: We probably should defer ts_recent change once
-	 * we take ownership of @req.
-	 */
-	if (tmp_opt.saw_tstamp && !after(TCP_SKB_CB(skb)->seq, tcp_rsk(req)->rcv_nxt))
-		WRITE_ONCE(req->ts_recent, tmp_opt.rcv_tsval);
-
 	if (TCP_SKB_CB(skb)->seq == tcp_rsk(req)->rcv_isn) {
 		/* Truncate SYN, it is out of window starting
 		   at tcp_rsk(req)->rcv_isn + 1. */
@@ -864,6 +873,10 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
 	if (!child)
 		goto listen_overflow;
 
+	if (own_req && tmp_opt.saw_tstamp &&
+	    !after(TCP_SKB_CB(skb)->seq, tcp_rsk(req)->rcv_nxt))
+		tcp_sk(child)->rx_opt.ts_recent = tmp_opt.rcv_tsval;
+
 	if (own_req && rsk_drop_req(req)) {
 		reqsk_queue_removed(&inet_csk(req->rsk_listener)->icsk_accept_queue, req);
 		inet_csk_reqsk_queue_drop_and_put(req->rsk_listener, req);
@@ -876,6 +889,7 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
 	return inet_csk_complete_hashdance(sk, child, req, own_req);
 
 listen_overflow:
+	SKB_DR_SET(*drop_reason, TCP_LISTEN_OVERFLOW);
 	if (sk != req->rsk_listener)
 		__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMIGRATEREQFAILURE);
 
@@ -905,7 +919,7 @@ embryonic_reset:
 	}
 	return NULL;
 }
-EXPORT_SYMBOL(tcp_check_req);
+EXPORT_IPV6_MOD(tcp_check_req);
 
 /*
  * Queue segment on the new socket if the new socket is active,
@@ -947,4 +961,4 @@ enum skb_drop_reason tcp_child_process(struct sock *parent, struct sock *child,
 	sock_put(child);
 	return reason;
 }
-EXPORT_SYMBOL(tcp_child_process);
+EXPORT_IPV6_MOD(tcp_child_process);