tools/tests/darwintests/drop_priv.c

   1 #include <darwintest.h>
   2
   3 #include <TargetConditionals.h>
   4 #include <limits.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <string.h>
   8 #include <sys/errno.h>
   9 #include <unistd.h>
  10
  11 #if !TARGET_OS_OSX
  12 #include <pwd.h>
  13 #include <sys/types.h>
  14 #include <uuid/uuid.h>
  15 #endif
  16
  17 #if TARGET_OS_OSX
  18 #define INVOKER_UID "SUDO_UID"
  19 #define INVOKER_GID "SUDO_GID"
  20 #define ID_MAX (unsigned long)UINT_MAX
  21 static unsigned
  22 _get_sudo_invoker(const char *var)
  23 {
  24     char *value_str = getenv(var);
  25     T_QUIET; T_WITH_ERRNO; T_ASSERT_NOTNULL(value_str,
  26             "Not running under sudo, getenv(\"%s\") failed", var);
  27     T_QUIET; T_ASSERT_NE_CHAR(*value_str, '\0',
  28             "getenv(\"%s\") returned an empty string", var);
  29
  30     char *endp;
  31     unsigned long value = strtoul(value_str, &endp, 10);
  32     T_QUIET; T_WITH_ERRNO; T_ASSERT_EQ_CHAR(*endp, '\0',
  33             "strtoul(\"%s\") not called on a valid number", value_str);
  34     T_QUIET; T_WITH_ERRNO; T_ASSERT_NE_ULONG(value, ULONG_MAX,
  35             "strtoul(\"%s\") overflow", value_str);
  36
  37     T_QUIET; T_ASSERT_NE_ULONG(value, 0ul, "%s invalid", var);
  38     T_QUIET; T_ASSERT_LT_ULONG(value, ID_MAX, "%s invalid", var);
  39     return (unsigned)value;
  40 }
  41 #endif /* TARGET_OS_OSX */
  42
  43 void
  44 drop_priv(void);
  45 void
  46 drop_priv(void)
  47 {
  48 #if TARGET_OS_OSX
  49     uid_t lower_uid = _get_sudo_invoker(INVOKER_UID);
  50     gid_t lower_gid = _get_sudo_invoker(INVOKER_GID);
  51 #else
  52     struct passwd *pw = getpwnam("mobile");
  53     T_QUIET; T_WITH_ERRNO; T_ASSERT_NOTNULL(pw, "getpwnam(\"mobile\")");
  54     uid_t lower_uid = pw->pw_uid;
  55     gid_t lower_gid = pw->pw_gid;
  56 #endif
  57     T_ASSERT_POSIX_SUCCESS(setgid(lower_gid), "Change group to %u", lower_gid);
  58     T_ASSERT_POSIX_SUCCESS(setuid(lower_uid), "Change user to %u", lower_uid);
  59 }