1 /* 2 * prettydate - convert a time stamp to something readable 3 */ 4 #include <stdio.h> 5 6 #include "ntp_fp.h" 7 #include "ntp_unixtime.h" /* includes <sys/time.h> */ 8 #include "lib_strbuf.h" 9 #include "ntp_stdlib.h" 10 11 static const char *months[] = { 12 "Jan", "Feb", "Mar", "Apr", "May", "Jun", 13 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" 14 }; 15 16 static const char *days[] = { 17 "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" 18 }; 19 20 /* Helper function to handle possible wraparound of the ntp epoch. 21 22 Works by assuming that the localtime/gmtime library functions 23 have been updated so that they work 24 */ 25 26 #define MAX_EPOCH_NR 1000 27 28 struct tm * 29 ntp2unix_tm( 30 u_long ntp, int local 31 ) 32 { 33 time_t t, curr; 34 struct tm *tm; 35 int curr_year, epoch_nr; 36 37 /* First get the current year: */ 38 curr = time(NULL); 39 tm = local ? localtime(&curr) : gmtime(&curr); 40 if (!tm) return NULL; 41 42 curr_year = 1900 + tm->tm_year; 43 44 /* Convert the ntp timestamp to a unix utc seconds count: */ 45 t = (time_t) ntp - JAN_1970; 46 47 /* Check that the ntp timestamp is not before a 136 year window centered 48 around the current year: 49 50 Failsafe in case of an infinite loop: 51 Allow up to 1000 epochs of 136 years each! 52 */ 53 for (epoch_nr = 0; epoch_nr < MAX_EPOCH_NR; epoch_nr++) { 54 tm = local ? localtime(&t) : gmtime(&t); 55 56 #if SIZEOF_TIME_T < 4 57 # include "Bletch: sizeof(time_t) < 4!" 58 #endif 59 60 #if SIZEOF_TIME_T == 4 61 /* If 32 bits, then year is 1970-2038, so no sense looking */ 62 epoch_nr = MAX_EPOCH_NR; 63 #else /* SIZEOF_TIME_T > 4 */ 64 /* Check that the resulting year is in the correct epoch: */ 65 if (1900 + tm->tm_year > curr_year - 68) break; 66 67 /* Epoch wraparound: Add 2^32 seconds! */ 68 t += (time_t) 65536 << 16; 69 #endif /* SIZEOF_TIME_T > 4 */ 70 } 71 return tm; 72 } 73 74 char * 75 prettydate( 76 l_fp *ts 77 ) 78 { 79 char *bp; 80 struct tm *tm; 81 time_t sec; 82 u_long msec; 83 84 LIB_GETBUF(bp); 85 86 sec = ts->l_ui; 87 msec = ts->l_uf / 4294967; /* fract / (2 ** 32 / 1000) */ 88 89 tm = ntp2unix_tm(sec, 1); 90 if (!tm) { 91 (void) sprintf(bp, "%08lx.%08lx --- --- -- ---- --:--:--", 92 (u_long)ts->l_ui, (u_long)ts->l_uf); 93 } 94 else { 95 (void) sprintf(bp, "%08lx.%08lx %s, %s %2d %4d %2d:%02d:%02d.%03lu", 96 (u_long)ts->l_ui, (u_long)ts->l_uf, days[tm->tm_wday], 97 months[tm->tm_mon], tm->tm_mday, 1900 + tm->tm_year, 98 tm->tm_hour,tm->tm_min, tm->tm_sec, msec); 99 } 100 101 return bp; 102 } 103 104 char * 105 gmprettydate( 106 l_fp *ts 107 ) 108 { 109 char *bp; 110 struct tm *tm; 111 time_t sec; 112 u_long msec; 113 114 LIB_GETBUF(bp); 115 116 sec = ts->l_ui; 117 msec = ts->l_uf / 4294967; /* fract / (2 ** 32 / 1000) */ 118 119 tm = ntp2unix_tm(sec, 0); 120 if (!tm) { 121 (void) sprintf(bp, "%08lx.%08lx --- --- -- ---- --:--:--", 122 (u_long)ts->l_ui, (u_long)ts->l_uf); 123 } 124 else { 125 (void) sprintf(bp, "%08lx.%08lx %s, %s %2d %4d %2d:%02d:%02d.%03lu", 126 (u_long)ts->l_ui, (u_long)ts->l_uf, days[tm->tm_wday], 127 months[tm->tm_mon], tm->tm_mday, 1900 + tm->tm_year, 128 tm->tm_hour,tm->tm_min, tm->tm_sec, msec); 129 } 130 131 return bp; 132 } 133