1 /*
2 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
3 * Use is subject to license terms.
4 */
5
6
7 /*
8 * lib/crypto/os/c_ustime.c
9 *
10 * Copyright 1990,1991 by the Massachusetts Institute of Technology.
11 * All Rights Reserved.
12 *
13 * Export of this software from the United States of America may
14 * require a specific license from the United States Government.
15 * It is the responsibility of any person or organization contemplating
16 * export to obtain such a license before exporting.
17 *
18 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
19 * distribute this software and its documentation for any purpose and
20 * without fee is hereby granted, provided that the above copyright
21 * notice appear in all copies and that both that copyright notice and
22 * this permission notice appear in supporting documentation, and that
23 * the name of M.I.T. not be used in advertising or publicity pertaining
24 * to distribution of the software without specific, written prior
25 * permission. Furthermore if you modify this software you must label
26 * your software as modified software and not distribute it in such a
27 * fashion that it might be confused with the original M.I.T. software.
28 * M.I.T. makes no representations about the suitability of
29 * this software for any purpose. It is provided "as is" without express
30 * or implied warranty.
31 *
32 *
33 * krb5_mstimeofday for BSD 4.3
34 */
35
36 #include "k5-int.h"
37 #include "k5-thread.h"
38
39 k5_mutex_t krb5int_us_time_mutex = K5_MUTEX_PARTIAL_INITIALIZER;
40
41 struct time_now { krb5_int32 sec, usec; };
42
43 #if defined(_WIN32)
44
45 /* Microsoft Windows NT and 95 (32bit) */
46 /* This one works for WOW (Windows on Windows, ntvdm on Win-NT) */
47
48 #include <time.h>
49 #include <sys/timeb.h>
50 #include <string.h>
51
52 static krb5_error_code
get_time_now(struct time_now * n)53 get_time_now(struct time_now *n)
54 {
55 struct _timeb timeptr;
56 _ftime(&timeptr);
57 n->sec = timeptr.time;
58 n->usec = timeptr.millitm * 1000;
59 return 0;
60 }
61
62 #else
63
64 /* Everybody else is UNIX, right? POSIX 1996 doesn't give us
65 gettimeofday, but what real OS doesn't? */
66
67 static krb5_error_code
get_time_now(struct time_now * n)68 get_time_now(struct time_now *n)
69 {
70 struct timeval tv;
71 #ifdef _KERNEL
72 timestruc_t now;
73
74 gethrestime(&now);
75 tv.tv_sec = now.tv_sec;
76 tv.tv_usec = now.tv_nsec / (NANOSEC / MICROSEC);
77 #else
78 if (gettimeofday(&tv, (struct timezone *)0) == -1)
79 return errno;
80 #endif
81
82 n->sec = tv.tv_sec;
83 n->usec = tv.tv_usec;
84 return 0;
85 }
86
87 #endif
88
89 static struct time_now last_time;
90
91 krb5_error_code
krb5_crypto_us_timeofday(krb5_int32 * seconds,krb5_int32 * microseconds)92 krb5_crypto_us_timeofday(krb5_int32 *seconds, krb5_int32 *microseconds)
93 {
94 struct time_now now;
95 krb5_error_code err;
96
97 err = get_time_now(&now);
98 if (err)
99 return err;
100
101 err = k5_mutex_lock(&krb5int_us_time_mutex);
102 if (err)
103 return err;
104 /* Just guessing: If the number of seconds hasn't changed, yet the
105 microseconds are moving backwards, we probably just got a third
106 instance of returning the same clock value from the system, so
107 the saved value was artificially incremented.
108
109 On Windows, where we get millisecond accuracy currently, that's
110 quite likely. On UNIX, it appears that we always get new
111 microsecond values, so this case should never trigger. */
112 if ((now.sec == last_time.sec) && (now.usec <= last_time.usec)) {
113 /* Same as last time??? */
114 now.usec = ++last_time.usec;
115 if (now.usec >= 1000000) {
116 ++now.sec;
117 now.usec = 0;
118 }
119 /* For now, we're not worrying about the case of enough
120 returns of the same value that we roll over now.sec, and
121 the next call still gets the previous now.sec value. */
122 }
123 last_time.sec = now.sec; /* Remember for next time */
124 last_time.usec = now.usec;
125 (void) k5_mutex_unlock(&krb5int_us_time_mutex);
126
127 *seconds = now.sec;
128 *microseconds = now.usec;
129 return 0;
130 }
131