Merge branch 'net-timestamps-y2038'

Deepa Dinamani says:

====================
Convert network timestamps to be y2038 safe

Introduction:

The series is aimed at transitioning network timestamps to being
y2038 safe.
All patches can be reviewed and merged independently.

Socket timestamps and ioctl calls will be handled separately.

Thanks to Arnd Bergmann for discussing solution options with me.

Solution:

Data type struct timespec is not y2038 safe.
Replace timespec with struct timespec64 which is y2038 safe.

Changes v1 -> v2:
  Move and rename inet_current_time() as discussed
  Squash patches 1 and 2
  Reword commit text for patch 2/3
  Carry over review tags
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip.h

@@ -240,6 +240,8 @@ static inline int inet_is_local_reserved_port(struct net *net, int port)
 }
 #endif
 
+__be32 inet_current_timestamp(void);
+
 /* From inetpeer.c */
 extern int inet_peer_threshold;
 extern int inet_peer_minttl;

net/ipv4/af_inet.c

@@ -1380,6 +1380,32 @@ out:
 	return pp;
 }
 
+#define SECONDS_PER_DAY	86400
+
+/* inet_current_timestamp - Return IP network timestamp
+ *
+ * Return milliseconds since midnight in network byte order.
+ */
+__be32 inet_current_timestamp(void)
+{
+	u32 secs;
+	u32 msecs;
+	struct timespec64 ts;
+
+	ktime_get_real_ts64(&ts);
+
+	/* Get secs since midnight. */
+	(void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
+	/* Convert to msecs. */
+	msecs = secs * MSEC_PER_SEC;
+	/* Convert nsec to msec. */
+	msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
+
+	/* Convert to network byte order. */
+	return htons(msecs);
+}
+EXPORT_SYMBOL(inet_current_timestamp);
+
 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 {
 	if (sk->sk_family == AF_INET)

net/ipv4/icmp.c

@@ -931,7 +931,6 @@ static bool icmp_echo(struct sk_buff *skb)
  */
 static bool icmp_timestamp(struct sk_buff *skb)
 {
-	struct timespec tv;
 	struct icmp_bxm icmp_param;
 	/*
 	 *	Too short.
@@ -942,9 +941,7 @@ static bool icmp_timestamp(struct sk_buff *skb)
 	/*
 	 *	Fill in the current time as ms since midnight UT:
 	 */
-	getnstimeofday(&tv);
-	icmp_param.data.times[1] = htonl((tv.tv_sec % 86400) * MSEC_PER_SEC +
-					 tv.tv_nsec / NSEC_PER_MSEC);
+	icmp_param.data.times[1] = inet_current_timestamp();
 	icmp_param.data.times[2] = icmp_param.data.times[1];
 	if (skb_copy_bits(skb, 0, &icmp_param.data.times[0], 4))
 		BUG();

net/ipv4/ip_options.c

@@ -58,10 +58,9 @@ void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
 		if (opt->ts_needaddr)
 			ip_rt_get_source(iph+opt->ts+iph[opt->ts+2]-9, skb, rt);
 		if (opt->ts_needtime) {
-			struct timespec tv;
 			__be32 midtime;
-			getnstimeofday(&tv);
-			midtime = htonl((tv.tv_sec % 86400) * MSEC_PER_SEC + tv.tv_nsec / NSEC_PER_MSEC);
+
+			midtime = inet_current_timestamp();
 			memcpy(iph+opt->ts+iph[opt->ts+2]-5, &midtime, 4);
 		}
 		return;
@@ -415,11 +414,10 @@ int ip_options_compile(struct net *net,
 					break;
 				}
 				if (timeptr) {
-					struct timespec tv;
-					u32  midtime;
-					getnstimeofday(&tv);
-					midtime = (tv.tv_sec % 86400) * MSEC_PER_SEC + tv.tv_nsec / NSEC_PER_MSEC;
-					put_unaligned_be32(midtime, timeptr);
+					__be32 midtime;
+
+					midtime = inet_current_timestamp();
+					memcpy(timeptr, &midtime, 4);
 					opt->is_changed = 1;
 				}
 			} else if ((optptr[3]&0xF) != IPOPT_TS_PRESPEC) {

net/ipv4/tcp_probe.c

@@ -187,13 +187,13 @@ static int tcpprobe_sprint(char *tbuf, int n)
 {
 	const struct tcp_log *p
 		= tcp_probe.log + tcp_probe.tail;
-	struct timespec tv
-		= ktime_to_timespec(ktime_sub(p->tstamp, tcp_probe.start));
+	struct timespec64 ts
+		= ktime_to_timespec64(ktime_sub(p->tstamp, tcp_probe.start));
 
 	return scnprintf(tbuf, n,
 			"%lu.%09lu %pISpc %pISpc %d %#x %#x %u %u %u %u %u\n",
-			(unsigned long)tv.tv_sec,
-			(unsigned long)tv.tv_nsec,
+			(unsigned long)ts.tv_sec,
+			(unsigned long)ts.tv_nsec,
 			&p->src, &p->dst, p->length, p->snd_nxt, p->snd_una,
 			p->snd_cwnd, p->ssthresh, p->snd_wnd, p->srtt, p->rcv_wnd);
 }

net/sctp/probe.c

@@ -65,7 +65,7 @@ static struct {
 	struct kfifo	  fifo;
 	spinlock_t	  lock;
 	wait_queue_head_t wait;
-	struct timespec	  tstart;
+	struct timespec64 tstart;
 } sctpw;
 
 static __printf(1, 2) void printl(const char *fmt, ...)
@@ -85,7 +85,7 @@ static __printf(1, 2) void printl(const char *fmt, ...)
 static int sctpprobe_open(struct inode *inode, struct file *file)
 {
 	kfifo_reset(&sctpw.fifo);
-	getnstimeofday(&sctpw.tstart);
+	ktime_get_ts64(&sctpw.tstart);
 
 	return 0;
 }
@@ -138,7 +138,7 @@ static sctp_disposition_t jsctp_sf_eat_sack(struct net *net,
 	struct sk_buff *skb = chunk->skb;
 	struct sctp_transport *sp;
 	static __u32 lcwnd = 0;
-	struct timespec now;
+	struct timespec64 now;
 
 	sp = asoc->peer.primary_path;
 
@@ -149,8 +149,8 @@ static sctp_disposition_t jsctp_sf_eat_sack(struct net *net,
 	    (full || sp->cwnd != lcwnd)) {
 		lcwnd = sp->cwnd;
 
-		getnstimeofday(&now);
-		now = timespec_sub(now, sctpw.tstart);
+		ktime_get_ts64(&now);
+		now = timespec64_sub(now, sctpw.tstart);
 
 		printl("%lu.%06lu ", (unsigned long) now.tv_sec,
 		       (unsigned long) now.tv_nsec / NSEC_PER_USEC);