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 void
  17 dnscrypt_memzero(void * const pnt, const size_t size)
  18 {
  19     volatile unsigned char *pnt_ = (volatile unsigned char *) pnt;
  20     size_t                     i = (size_t) 0U;
  21
  22     while (i < size) {
  23         pnt_[i++] = 0U;
  24     }
  25 }
  26
  27 uint64_t
  28 dnscrypt_hrtime(void)
  29 {
  30     struct timeval tv;
  31     uint64_t       ts = (uint64_t) 0U;
  32     int            ret;
  33
  34     ret = evutil_gettimeofday(&tv, NULL);
  35     assert(ret == 0);
  36     if (ret == 0) {
  37         ts = (uint64_t) tv.tv_sec * 1000000U + (uint64_t) tv.tv_usec;
  38     }
  39     return ts;
  40 }
  41
  42 #ifndef _WIN32
  43 static unsigned int
  44 open_max(void)
  45 {
  46     long z;
  47
  48     if ((z = (long) sysconf(_SC_OPEN_MAX)) < 0L) {
  49         logger_error(NULL, "_SC_OPEN_MAX");
  50         return 2U;
  51     }
  52     return (unsigned int) z;
  53 }
  54
  55 int
  56 closedesc_all(const int closestdin)
  57 {
  58     int fodder;
  59
  60     if (closestdin != 0) {
  61         (void) close(0);
  62         if ((fodder = open(_PATH_DEVNULL, O_RDONLY)) == -1) {
  63             return -1;
  64         }
  65         (void) dup2(fodder, 0);
  66         if (fodder > 0) {
  67             (void) close(fodder);
  68         }
  69     }
  70     if ((fodder = open(_PATH_DEVNULL, O_WRONLY)) == -1) {
  71         return -1;
  72     }
  73     (void) dup2(fodder, 1);
  74     (void) dup2(1, 2);
  75     if (fodder > 2) {
  76         (void) close(fodder);
  77     }
  78
  79     return 0;
  80 }
  81
  82 int
  83 do_daemonize(void)
  84 {
  85     pid_t        child;
  86     unsigned int i;
  87
  88     if ((child = fork()) == (pid_t) -1) {
  89         logger_error(NULL, "Unable to fork() in order to daemonize");
  90         return -1;
  91     } else if (child != (pid_t) 0) {
  92         _exit(0);
  93     }
  94     if (setsid() == (pid_t) -1) {
  95         logger_error(NULL, "Unable to setsid()");
  96     }
  97     i = open_max();
  98     do {
  99         if (isatty((int) i)) {
 100             (void) close((int) i);
 101         }
 102         i--;
 103     } while (i > 2U);
 104     if (closedesc_all(1) != 0) {
 105         logger_error(NULL, _PATH_DEVNULL " duplication");
 106         return -1;
 107     }
 108     return 0;
 109 }
 110
 111 #else /* _WIN32 */
 112
 113 int
 114 closedesc_all(const int closestdin)
 115 {
 116     (void) closestdin;
 117     return 0;
 118 }
 119
 120 int
 121 do_daemonize(void)
 122 {
 123     return 0;
 124 }
 125
 126 #endif