upstream commit

Add monotime_ts and monotime_tv that return monotonic
timespec and timeval respectively.  Replace calls to gettimeofday() in packet
timing with monotime_tv so that the callers will work over a clock step.
Should prevent integer overflow during clock steps reported by wangle6 at
huawei.com. "I like" markus@

OpenBSD-Commit-ID: 74d684264814ff806f197948b87aa732cb1b0b8a

5 files changed, 60 insertions, 49 deletions

diff --git a/misc.c b/misc.c
index 2369361b3..dfa0bb33a 100644
--- a/misc.c
+++ b/misc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.c,v 1.118 2017/10/25 00:17:08 djm Exp $ */
+/* $OpenBSD: misc.c,v 1.119 2017/11/25 06:46:22 dtucker Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2005,2006 Damien Miller.  All rights reserved.
@@ -1259,8 +1259,8 @@ ms_subtract_diff(struct timeval *start, int *ms)
 {
         struct timeval diff, finish;
 
-        gettimeofday(&finish, NULL);
-        timersub(&finish, start, &diff);        
+        monotime_tv(&finish);
+        timersub(&finish, start, &diff);
         *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000);
 }
 
@@ -1273,54 +1273,63 @@ ms_to_timeval(struct timeval *tv, int ms)
         tv->tv_usec = (ms % 1000) * 1000;
 }
 
-time_t
-monotime(void)
+void
+monotime_ts(struct timespec *ts)
 {
-#if defined(HAVE_CLOCK_GETTIME) && \
-    (defined(CLOCK_MONOTONIC) || defined(CLOCK_BOOTTIME))
-        struct timespec ts;
+        struct timeval tv;
+#if defined(HAVE_CLOCK_GETTIME) && (defined(CLOCK_BOOTTIME) || \
+    defined(CLOCK_MONOTONIC) || defined(CLOCK_REALTIME))
         static int gettime_failed = 0;
 
         if (!gettime_failed) {
-#if defined(CLOCK_BOOTTIME)
-                if (clock_gettime(CLOCK_BOOTTIME, &ts) == 0)
-                        return (ts.tv_sec);
-#endif
-#if defined(CLOCK_MONOTONIC)
-                if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0)
-                        return (ts.tv_sec);
-#endif
+# ifdef CLOCK_BOOTTIME
+                if (clock_gettime(CLOCK_BOOTTIME, ts) == 0)
+                        return;
+# endif /* CLOCK_BOOTTIME */
+# ifdef CLOCK_MONOTONIC
+                if (clock_gettime(CLOCK_MONOTONIC, ts) == 0)
+                        return;
+# endif /* CLOCK_MONOTONIC */
+# ifdef CLOCK_REALTIME
+                /* Not monotonic, but we're almost out of options here. */
+                if (clock_gettime(CLOCK_REALTIME, ts) == 0)
+                        return;
+# endif /* CLOCK_REALTIME */
                 debug3("clock_gettime: %s", strerror(errno));
                 gettime_failed = 1;
         }
-#endif /* HAVE_CLOCK_GETTIME && (CLOCK_MONOTONIC || CLOCK_BOOTTIME */
+#endif /* HAVE_CLOCK_GETTIME && (BOOTTIME || MONOTONIC || REALTIME) */
+        gettimeofday(&tv, NULL);
+        ts->tv_sec = tv.tv_sec;
+        ts->tv_nsec = (long)tv.tv_usec * 1000;
+}
 
-        return time(NULL);
+void
+monotime_tv(struct timeval *tv)
+{
+        struct timespec ts;
+
+        monotime_ts(&ts);
+        tv->tv_sec = ts.tv_sec;
+        tv->tv_usec = ts.tv_nsec / 1000;
+}
+
+time_t
+monotime(void)
+{
+        struct timespec ts;
+
+        monotime_ts(&ts);
+        return ts.tv_sec;
 }
 
 double
 monotime_double(void)
 {
-#if defined(HAVE_CLOCK_GETTIME) && \
-    (defined(CLOCK_MONOTONIC) || defined(CLOCK_BOOTTIME))
         struct timespec ts;
-        static int gettime_failed = 0;
-
-        if (!gettime_failed) {
-#if defined(CLOCK_BOOTTIME)
-                if (clock_gettime(CLOCK_BOOTTIME, &ts) == 0)
-                        return (ts.tv_sec + (double)ts.tv_nsec / 1000000000);
-#endif
-#if defined(CLOCK_MONOTONIC)
-                if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0)
-                        return (ts.tv_sec + (double)ts.tv_nsec / 1000000000);
-#endif
-                debug3("clock_gettime: %s", strerror(errno));
-                gettime_failed = 1;
-        }
-#endif /* HAVE_CLOCK_GETTIME && (CLOCK_MONOTONIC || CLOCK_BOOTTIME */
 
-        return (double)time(NULL);
+        monotime_ts(&ts);
+        return ts.tv_sec + ((double)ts.tv_nsec / 1000000000);
 }
 
 void
@@ -1342,7 +1351,7 @@ bandwidth_limit(struct bwlimit *bw, size_t read_len)
         struct timespec ts, rm;
 
         if (!timerisset(&bw->bwstart)) {
-                gettimeofday(&bw->bwstart, NULL);
+                monotime_tv(&bw->bwstart);
                 return;
         }
 
@@ -1350,7 +1359,7 @@ bandwidth_limit(struct bwlimit *bw, size_t read_len)
         if (bw->lamt < bw->thresh)
                 return;
 
-        gettimeofday(&bw->bwend, NULL);
+        monotime_tv(&bw->bwend);
         timersub(&bw->bwend, &bw->bwstart, &bw->bwend);
         if (!timerisset(&bw->bwend))
                 return;
@@ -1384,7 +1393,7 @@ bandwidth_limit(struct bwlimit *bw, size_t read_len)
         }
 
         bw->lamt = 0;
-        gettimeofday(&bw->bwstart, NULL);
+        monotime_tv(&bw->bwstart);
 }
 
 /* Make a template filename for mk[sd]temp() */
diff --git a/misc.h b/misc.h
index 5ad30ce3b..4fa029a25 100644
--- a/misc.h
+++ b/misc.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.h,v 1.67 2017/10/25 00:17:08 djm Exp $ */
+/* $OpenBSD: misc.h,v 1.68 2017/11/25 06:46:22 dtucker Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -67,6 +67,8 @@ char	*tohex(const void *, size_t);
 void     sanitise_stdfd(void);
 void     ms_subtract_diff(struct timeval *, int *);
 void     ms_to_timeval(struct timeval *, int);
+void     monotime_ts(struct timespec *);
+void     monotime_tv(struct timeval *);
 time_t   monotime(void);
 double   monotime_double(void);
 void     lowercase(char *s);
diff --git a/packet.c b/packet.c
index 448da0964..832019492 100644
--- a/packet.c
+++ b/packet.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: packet.c,v 1.266 2017/10/25 00:17:08 djm Exp $ */
+/* $OpenBSD: packet.c,v 1.267 2017/11/25 06:46:22 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1332,7 +1332,7 @@ ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
                 for (;;) {
                         if (state->packet_timeout_ms != -1) {
                                 ms_to_timeval(&timeout, ms_remain);
-                                gettimeofday(&start, NULL);
+                                monotime_tv(&start);
                         }
                         if ((r = select(state->connection_in + 1, setp,
                             NULL, NULL, timeoutp)) >= 0)
@@ -1959,7 +1959,7 @@ ssh_packet_write_wait(struct ssh *ssh)
                 for (;;) {
                         if (state->packet_timeout_ms != -1) {
                                 ms_to_timeval(&timeout, ms_remain);
-                                gettimeofday(&start, NULL);
+                                monotime_tv(&start);
                         }
                         if ((ret = select(state->connection_out + 1,
                             NULL, setp, NULL, timeoutp)) >= 0)
diff --git a/ssh-keyscan.c b/ssh-keyscan.c
index 258123ae8..a816a220e 100644
--- a/ssh-keyscan.c
+++ b/ssh-keyscan.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keyscan.c,v 1.115 2017/06/30 04:17:23 dtucker Exp $ */
+/* $OpenBSD: ssh-keyscan.c,v 1.116 2017/11/25 06:46:22 dtucker Exp $ */
 /*
  * Copyright 1995, 1996 by David Mazieres <dm@lcs.mit.edu>.
  *
@@ -377,7 +377,7 @@ conalloc(char *iname, char *oname, int keytype)
         fdcon[s].c_len = 4;
         fdcon[s].c_off = 0;
         fdcon[s].c_keytype = keytype;
-        gettimeofday(&fdcon[s].c_tv, NULL);
+        monotime_tv(&fdcon[s].c_tv);
         fdcon[s].c_tv.tv_sec += timeout;
         TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
         FD_SET(s, read_wait);
@@ -411,7 +411,7 @@ static void
 contouch(int s)
 {
         TAILQ_REMOVE(&tq, &fdcon[s], c_link);
-        gettimeofday(&fdcon[s].c_tv, NULL);
+        monotime_tv(&fdcon[s].c_tv);
         fdcon[s].c_tv.tv_sec += timeout;
         TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
 }
@@ -545,7 +545,7 @@ conloop(void)
         con *c;
         int i;
 
-        gettimeofday(&now, NULL);
+        monotime_tv(&now);
         c = TAILQ_FIRST(&tq);
 
         if (c && (c->c_tv.tv_sec > now.tv_sec ||
diff --git a/sshconnect.c b/sshconnect.c
index dc7a704d2..e29b069c9 100644
--- a/sshconnect.c
+++ b/sshconnect.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect.c,v 1.287 2017/09/14 04:32:21 djm Exp $ */
+/* $OpenBSD: sshconnect.c,v 1.288 2017/11/25 06:46:22 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -344,7 +344,7 @@ waitrfd(int fd, int *timeoutp)
         struct timeval t_start;
         int oerrno, r;
 
-        gettimeofday(&t_start, NULL);
+        monotime_tv(&t_start);
         pfd.fd = fd;
         pfd.events = POLLIN;
         for (; *timeoutp >= 0;) {