Convert tcp_now() time counter to 64 bit.

After changing tcp now tick to milliseconds, 32 bits will wrap
around after 49 days of uptime.  That may be a problem in some
places of our stack.  Better use a 64 bit counter.

As timestamp option is 32 bit in TCP protocol, use the lower 32 bit
there.  There are casts to 32 bits that should behave correctly.

Start with random 63 bit offset to avoid uptime leakage.  2^63
milliseconds result in 2.9*10^8 years of possible uptime.

OK yasuoka@

1 files changed, 19 insertions, 19 deletions

diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
index e071961dab4..284f2b6254e 100644
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tcp_var.h,v 1.168 2023/07/02 19:59:15 bluhm Exp $	*/
+/*	$OpenBSD: tcp_var.h,v 1.169 2023/07/06 09:15:24 bluhm Exp $	*/
 /*	$NetBSD: tcp_var.h,v 1.17 1996/02/13 23:44:24 christos Exp $	*/
 
 /*
@@ -150,8 +150,8 @@ struct tcpcb {
 					 */
 
 /* auto-sizing variables */
+	uint64_t rfbuf_ts;	/* recv buffer autoscaling time stamp */
 	u_int	rfbuf_cnt;	/* recv buffer autoscaling byte count */
-	u_int32_t rfbuf_ts;	/* recv buffer autoscaling time stamp */
 
 	u_short	t_maxopd;		/* mss plus options */
 	u_short	t_peermss;		/* peer's maximum segment size */
@@ -160,11 +160,11 @@ struct tcpcb {
  * transmit timing stuff.  See below for scale of srtt and rttvar.
  * "Variance" is actually smoothed difference.
  */
-	uint32_t t_rcvtime;		/* time last segment received */
-	uint32_t t_rcvacktime;		/* time last ack received */
-	uint32_t t_sndtime;		/* time last segment sent */
-	uint32_t t_sndacktime;		/* time last ack sent */
-	uint32_t t_rtttime;		/* time we started measuring rtt */
+	uint64_t t_rcvtime;		/* time last segment received */
+	uint64_t t_rcvacktime;		/* time last ack received */
+	uint64_t t_sndtime;		/* time last segment sent */
+	uint64_t t_sndacktime;		/* time last ack sent */
+	uint64_t t_rtttime;		/* time we started measuring rtt */
 	tcp_seq	t_rtseq;		/* sequence number being timed */
 	int	t_srtt;			/* smoothed round-trip time */
 	int	t_rttvar;		/* variance in round-trip time */
@@ -183,9 +183,9 @@ struct tcpcb {
 	u_char	rcv_scale;		/* window scaling for recv window */
 	u_char	request_r_scale;	/* pending window scaling */
 	u_char	requested_s_scale;
-	u_int32_t ts_recent;		/* timestamp echo data */
-	u_int32_t ts_modulate;		/* modulation on timestamp */
-	u_int32_t ts_recent_age;	/* when last updated */
+	uint32_t ts_recent;		/* timestamp echo data */
+	uint32_t ts_modulate;		/* modulation on timestamp */
+	uint64_t ts_recent_age;		/* when last updated */
 	tcp_seq	last_ack_sent;
 
 /* pointer for syn cache entries*/
@@ -250,12 +250,9 @@ struct syn_cache {
 	long sc_win;				/* advertised window */
 	struct syn_cache_head *sc_buckethead;	/* our bucket index */
 	struct syn_cache_set *sc_set;		/* our syn cache set */
+	u_int64_t sc_timestamp;			/* timestamp from SYN */
 	u_int32_t sc_hash;
-	u_int32_t sc_timestamp;			/* timestamp from SYN */
 	u_int32_t sc_modulate;			/* our timestamp modulator */
-#if 0
-	u_int32_t sc_timebase;			/* our local timebase */
-#endif
 	union syn_cache_sa sc_src;
 	union syn_cache_sa sc_dst;
 	tcp_seq sc_irs;
@@ -657,10 +654,13 @@ tcpstat_pkt(enum tcpstat_counters pcounter, enum tcpstat_counters bcounter,
 	counters_pkt(tcpcounters, pcounter, bcounter, v);
 }
 
-static inline uint32_t
+extern uint64_t tcp_starttime;
+
+static inline uint64_t
 tcp_now(void)
 {
-	return (getnsecruntime() / 1000000);
+	/* TCP time ticks in 63 bit milliseconds with 63 bit random offset. */
+	return tcp_starttime + (getnsecruntime() / 1000000ULL);
 }
 
 #define TCP_TIME(_sec)	((_sec) * 1000)	/* tcp_now() is in milliseconds */
@@ -712,7 +712,7 @@ struct tcpcb *
 struct tcpcb *
 	 tcp_drop(struct tcpcb *, int);
 int	 tcp_dooptions(struct tcpcb *, u_char *, int, struct tcphdr *,
-		struct mbuf *, int, struct tcp_opt_info *, u_int, uint32_t);
+		struct mbuf *, int, struct tcp_opt_info *, u_int, uint64_t);
 void	 tcp_init(void);
 int	 tcp_input(struct mbuf **, int *, int, int);
 int	 tcp_mss(struct tcpcb *, int);
@@ -735,7 +735,7 @@ void	 tcp_pulloutofband(struct socket *, u_int, struct mbuf *, int);
 int	 tcp_reass(struct tcpcb *, struct tcphdr *, struct mbuf *, int *);
 void	 tcp_rscale(struct tcpcb *, u_long);
 void	 tcp_respond(struct tcpcb *, caddr_t, struct tcphdr *, tcp_seq,
-		tcp_seq, int, u_int, uint32_t);
+		tcp_seq, int, u_int, uint64_t);
 void	 tcp_setpersist(struct tcpcb *);
 void	 tcp_update_sndspace(struct tcpcb *);
 void	 tcp_update_rcvspace(struct tcpcb *);
@@ -767,7 +767,7 @@ int	 tcp_sense(struct socket *, struct stat *);
 int	 tcp_rcvoob(struct socket *, struct mbuf *, int);
 int	 tcp_sendoob(struct socket *, struct mbuf *, struct mbuf *,
 	     struct mbuf *);
-void	 tcp_xmit_timer(struct tcpcb *, int);
+void	 tcp_xmit_timer(struct tcpcb *, int32_t);
 void	 tcpdropoldhalfopen(struct tcpcb *, u_int16_t);
 void	 tcp_sack_option(struct tcpcb *,struct tcphdr *,u_char *,int);
 void	 tcp_update_sack_list(struct tcpcb *tp, tcp_seq, tcp_seq);