release/src/router/dnscrypt/src/proxy/utils.c

   1
   2 #include <config.h>
   3 #include <sys/types.h>
   4 #include <sys/time.h>
   5
   6 #include <assert.h>
   7 #include <fcntl.h>
   8 #include <unistd.h>
   9
  10 #include <event2/util.h>
  11
  12 #include "logger.h"
  13 #include "pathnames.h"
  14 #include "utils.h"
  15
  16 uint64_t
  17 dnscrypt_hrtime(void)
  18 {
  19     struct timeval tv;
  20     uint64_t       ts = (uint64_t) 0U;
  21     int            ret;
  22
  23     ret = evutil_gettimeofday(&tv, NULL);
  24     assert(ret == 0);
  25     if (ret == 0) {
  26         ts = (uint64_t) tv.tv_sec * 1000000U + (uint64_t) tv.tv_usec;
  27     }
  28     return ts;
  29 }
  30
  31 #ifndef _WIN32
  32 static unsigned int
  33 open_max(void)
  34 {
  35     long z;
  36
  37     if ((z = (long) sysconf(_SC_OPEN_MAX)) < 0L) {
  38         logger_error(NULL, "_SC_OPEN_MAX");
  39         return 2U;
  40     }
  41     return (unsigned int) z;
  42 }
  43
  44 int
  45 closedesc_all(const int closestdin)
  46 {
  47     int fodder;
  48
  49     if (closestdin != 0) {
  50         (void) close(0);
  51         if ((fodder = open(_PATH_DEVNULL, O_RDONLY)) == -1) {
  52             return -1;
  53         }
  54         (void) dup2(fodder, 0);
  55         if (fodder > 0) {
  56             (void) close(fodder);
  57         }
  58     }
  59     if ((fodder = open(_PATH_DEVNULL, O_WRONLY)) == -1) {
  60         return -1;
  61     }
  62     (void) dup2(fodder, 1);
  63     (void) dup2(1, 2);
  64     if (fodder > 2) {
  65         (void) close(fodder);
  66     }
  67
  68     return 0;
  69 }
  70
  71 int
  72 do_daemonize(void)
  73 {
  74     pid_t        child;
  75     unsigned int i;
  76
  77     if ((child = fork()) == (pid_t) -1) {
  78         logger_error(NULL, "Unable to fork() in order to daemonize");
  79         return -1;
  80     } else if (child != (pid_t) 0) {
  81         _exit(0);
  82     }
  83     if (setsid() == (pid_t) -1) {
  84         logger_error(NULL, "Unable to setsid()");
  85     }
  86     i = open_max();
  87     do {
  88         if (isatty((int) i)) {
  89             (void) close((int) i);
  90         }
  91         i--;
  92     } while (i > 2U);
  93     if (closedesc_all(1) != 0) {
  94         logger_error(NULL, _PATH_DEVNULL " duplication");
  95         return -1;
  96     }
  97     return 0;
  98 }
  99
 100 #else /* _WIN32 */
 101
 102 int
 103 closedesc_all(const int closestdin)
 104 {
 105     (void) closestdin;
 106     return 0;
 107 }
 108
 109 int
 110 do_daemonize(void)
 111 {
 112     return 0;
 113 }
 114
 115 #endif