contrib/ntp/libntp/buftvtots.c

   1 /*
   2  * buftvtots - pull a Unix-format (struct timeval) time stamp out of
   3  *             an octet stream and convert it to a l_fp time stamp.
   4  *             This is useful when using the clock line discipline.
   5  */
   6
   7 #ifdef HAVE_CONFIG_H
   8 #include "config.h"
   9 #endif
  10 #include "ntp_fp.h"
  11 #include "ntp_unixtime.h"
  12
  13 int
  14 buftvtots(
  15         const char *bufp,
  16         l_fp *ts
  17         )
  18 {
  19         register const u_char *bp;
  20         register u_long sec;
  21         register u_long usec;
  22         struct timeval tv;
  23
  24 #ifdef WORDS_BIGENDIAN
  25         bp = (const u_char *)bufp;
  26
  27         sec = (u_long)*bp++ & 0xff;
  28         sec <<= 8;
  29         sec += (u_long)*bp++ & 0xff;
  30         sec <<= 8;
  31         sec += (u_long)*bp++ & 0xff;
  32         sec <<= 8;
  33         sec += (u_long)*bp++ & 0xff;
  34
  35         if (sizeof(tv.tv_sec) == 8) {
  36                 sec += (u_long)*bp++ & 0xff;
  37                 sec <<= 8;
  38                 sec += (u_long)*bp++ & 0xff;
  39                 sec <<= 8;
  40                 sec += (u_long)*bp++ & 0xff;
  41                 sec <<= 8;
  42                 sec += (u_long)*bp++ & 0xff;
  43         }
  44
  45         usec = (u_long)*bp++ & 0xff;
  46         usec <<= 8;
  47         usec += (u_long)*bp++ & 0xff;
  48         usec <<= 8;
  49         usec += (u_long)*bp++ & 0xff;
  50         usec <<= 8;
  51         usec += (u_long)*bp++ & 0xff;
  52
  53         if (sizeof(tv.tv_usec) == 8) {
  54                 usec += (u_long)*bp++ & 0xff;
  55                 usec <<= 8;
  56                 usec += (u_long)*bp++ & 0xff;
  57                 usec <<= 8;
  58                 usec += (u_long)*bp++ & 0xff;
  59                 usec <<= 8;
  60                 usec += (u_long)*bp & 0xff;
  61         }
  62 #else
  63         bp = (const u_char *)bufp + 7;
  64
  65         usec = (u_long)*bp-- & 0xff;
  66         usec <<= 8;
  67         usec += (u_long)*bp-- & 0xff;
  68         usec <<= 8;
  69         usec += (u_long)*bp-- & 0xff;
  70         usec <<= 8;
  71         usec += (u_long)*bp-- & 0xff;
  72
  73         if (sizeof(tv.tv_usec) == 8) {
  74                 usec += (u_long)*bp-- & 0xff;
  75                 usec <<= 8;
  76                 usec += (u_long)*bp-- & 0xff;
  77                 usec <<= 8;
  78                 usec += (u_long)*bp-- & 0xff;
  79                 usec <<= 8;
  80                 usec += (u_long)*bp-- & 0xff;
  81         }
  82
  83         sec = (u_long)*bp-- & 0xff;
  84         sec <<= 8;
  85         sec += (u_long)*bp-- & 0xff;
  86         sec <<= 8;
  87         sec += (u_long)*bp-- & 0xff;
  88         sec <<= 8;
  89         sec += (u_long)*bp-- & 0xff;
  90
  91         if (sizeof (tv.tv_sec) == 8) {
  92                 sec += (u_long)*bp-- & 0xff;
  93                 sec <<= 8;
  94                 sec += (u_long)*bp-- & 0xff;
  95                 sec <<= 8;
  96                 sec += (u_long)*bp-- & 0xff;
  97                 sec <<= 8;
  98                 sec += (u_long)*bp & 0xff;
  99         }
 100 #endif
 101         ts->l_ui = sec + (u_long)JAN_1970;
 102         if (usec > 999999)
 103             return 0;
 104         TVUTOTSF(usec, ts->l_uf);
 105         return 1;
 106 }