test/src/checkaccess.c

   1 /* This is a baby program that is run as root from the runtest script. It is
   2 passed the Exim uid and gid as arguments, and the name of a file in the
   3 test-suite directory. It gives up all supplementary groups, changes to the
   4 given uid/gid, and then tries to read the file. The yield is 0 if that is
   5 successful, and non-zero otherwise (use different values to aid debugging). See
   6 comments in the exim.c source file about the use of setgroups() for getting rid
   7 of extraneous groups. */
   8
   9 #include <sys/types.h>
  10 #include <sys/stat.h>
  11 #include <fcntl.h>
  12 #include <unistd.h>
  13 #include <pwd.h>
  14 #include <grp.h>
  15
  16 #include <stdio.h>
  17
  18
  19 int main(int argc, char **argv)
  20 {
  21 int fd;
  22 gid_t group_list[10];
  23 struct passwd *pw = getpwnam(argv[2]);
  24 struct group *gr = getgrnam(argv[3]);
  25
  26 if (pw == NULL) return 1;
  27 if (gr == NULL) return 2;
  28 if (setgroups(0, NULL) != 0 && setgroups(1, group_list) != 0) return 4;
  29 if (setgid(gr->gr_gid) != 0) return 5;
  30 if (setuid(pw->pw_uid) != 0) return 6;
  31
  32 fd = open(argv[1], O_RDONLY);
  33 if (fd < 0) return 7;
  34
  35 close(fd);
  36 return 0;
  37 }
  38
  39 /* End */