minix/tests/test46.c

   1 /* Test46.c
   2  *
   3  * Test getgroups(...) and setgroups system calls
   4  *
   5  * Please note that getgroups is POSIX defined, but setgroups is not. Errors
   6  * related to setgroups are thus not POSIX conformance issues.
   7  */
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <unistd.h>
  11 #include <errno.h>
  12 #include <string.h>
  13 #include <limits.h>
  14 #include <dirent.h>
  15 #include <sys/types.h>
  16 #include <sys/wait.h>
  17 #include <sys/stat.h>
  18 #include <fcntl.h>
  19
  20 void api_test(void);
  21 void e(int error_no);
  22 void group_test(void);
  23 void limit_test(void);
  24 void group_test_1(void);
  25 void group_test_2(void);
  26 void group_test_3(void);
  27 void group_test_4(void);
  28 void group_test_5(void);
  29 int dotest(void (*testfunc)(void));
  30
  31 int max_error = 5;
  32 #include "common.h"
  33
  34 #define IMAGINARY_GID 100
  35 #define IMAGINARY_GID_STR "100"
  36 #define IMAGINARY_UID 101
  37 #define IMAGINARY_UID_STR "101"
  38 #define SET_CREDENTIALS do { \
  39                           setgid((IMAGINARY_GID) + 1 ); \
  40                           setuid(IMAGINARY_UID); \
  41                         } while(0)
  42
  43 int subtest = -1, errorct = 0;
  44
  45 int main(int argc, char *argv[])
  46 {
  47   start(46);
  48
  49   setuid(geteuid());
  50
  51   if(getuid() != 0) {
  52         printf("Test 46 has to be run as root; test aborted\n");
  53         exit(1);
  54   }
  55
  56   limit_test(); /* Perform some tests on POSIX limits */
  57   api_test();   /* Perform some very basic API tests */
  58   group_test(); /* Perform some tests that mimic actual use */
  59
  60   quit();
  61
  62   return(-1);   /* Unreachable */
  63 }
  64
  65 void limit_test() {
  66 /* According to POSIX 2008 a process can have up to NGROUPS_MAX simultaneous
  67  * supplementary group IDs. The minimum acceptable value is _POSIX_NGROUPS_MAX.
  68  * In turn, _POSIX_NGROUPS_MAX is defined as 8. */
  69
  70   subtest = 1;
  71   if (_POSIX_NGROUPS_MAX < 8) e(1);
  72   if (NGROUPS_MAX < _POSIX_NGROUPS_MAX) e(2);
  73 }
  74
  75 void api_test() {
  76 /* int getgroups( int gidsetsize, gid_t grouplist[]);
  77  * int setgroups( int size_t size, const gid_t grouplist[]);
  78  */
  79 /* The getgroups() function shall fill in the array grouplist with the current
  80  * supplementary group IDs of the calling process. It is implementation-
  81  * defined whether getgroups() also returns the effective group ID in the
  82  * grouplist array.
  83  * The gidsetsize argument specifies the number of elements in the array
  84  * grouplist. The actual number of group IDs stored in the array shall be
  85  * returned. The values of array entries with indices greater than or equal to
  86  * the value returned are undefined.
  87  * If gidsetsize is 0, getgroups shall return the number of group IDs that it
  88  * would otherwise return without modifying the array pointed to by grouplist.
  89  *
  90  * setgroups() sets the supplementary group IDs for the calling process. The
  91  * size argument specifies the number of supplementary group IDs in the buffer
  92  * pointed to by grouplist. setgroups() is a privileged operation.
  93  */
  94
  95  /* Minix does not return the effective group ID with the supplementary groups.
  96   * Use getegid() to get that value. In order to call setgroups, a process
  97   * must have super user privileges.
  98   */
  99
 100   int i;
 101   gid_t *grouplist, *grouplist2;
 102   long ngroups_max;
 103
 104   subtest = 2;
 105
 106   /* Ask the system how many groups we're allowed to set */
 107   ngroups_max = sysconf(_SC_NGROUPS_MAX);
 108   grouplist = malloc(ngroups_max *sizeof(gid_t));
 109   grouplist2 = malloc(ngroups_max *sizeof(gid_t));
 110
 111   /* Let's invent some imaginary groups */
 112 #define START_GID 20001
 113   for (i = 0; i < ngroups_max; i++)
 114         grouplist[i] = i + START_GID;
 115
 116   /* Normal usage */
 117   if (setgroups(ngroups_max, grouplist) != 0) e(1);
 118
 119   /* Try one less than max supported groups */
 120   if (setgroups(ngroups_max - 1, grouplist) != 0) e(2);
 121
 122   /* Try just one group */
 123   if (setgroups(1, grouplist) != 0) e(3);
 124
 125   /* Unset all supplementary groups */
 126   if (setgroups(0, grouplist) != 0) e(4);
 127
 128   /* Should not be allowed to use a negative set size */
 129   if (setgroups(-1, grouplist) == 0) e(5);
 130   else if(errno != EINVAL) e(6); /* error must be EINVAL */
 131
 132   /* Should not be allowed to set more groups than supported by the system */
 133   if (setgroups(ngroups_max + 1, grouplist) == 0) e(7);
 134   else if(errno != EINVAL) e(8); /* error must be EINVAL */
 135
 136   /* Should not be allowed to provide an invalid grouplist address */
 137   if (setgroups(ngroups_max, NULL) == 0) e(9);
 138   else if(errno != EFAULT) e(10); /* error must be EFAULT */
 139
 140   /* The last time we called setgroups with proper parameters, we effectively
 141    * cleared the list. Verify that with getgroups(). */
 142   if (getgroups(ngroups_max, grouplist2) != 0) e(11);
 143
 144   /* Repopulate grouplist with values and read them back */
 145   if (setgroups(ngroups_max, grouplist) != 0) e(12);
 146   if (getgroups(0, grouplist2) != ngroups_max) e(13);
 147   if (getgroups(ngroups_max, grouplist2) != ngroups_max) e(14);
 148   for (i = 0; i < ngroups_max; i++) {
 149         if(grouplist[i] != grouplist2[i]) {
 150                 e(15);
 151                 break; /* One error message should be enough here */
 152         }
 153   }
 154
 155   /* Should not be able to read less groups than are actually stored. */
 156   if (getgroups(ngroups_max - 1, grouplist2) != -1) e(16);
 157
 158   /* Repopulate grouplist with only half the groups and read them back */
 159   memset(grouplist2, 0, ngroups_max * sizeof(gid_t)); /* Clear array */
 160 #define HALF_LIST_SIZE ngroups_max / 2
 161   if (setgroups(HALF_LIST_SIZE, grouplist) != 0) e(17);
 162   if (getgroups(0, grouplist2) != HALF_LIST_SIZE) e(18);
 163   if (getgroups(HALF_LIST_SIZE, grouplist2) != HALF_LIST_SIZE) e(19);
 164   for (i = 0; i < HALF_LIST_SIZE; i++) {
 165         if(grouplist[i] != grouplist2[i]) {
 166                 e(20);
 167                 break; /* Also here one message ought to be enough */
 168         }
 169   }
 170
 171   /* Try to read more groups than we have set */
 172   memset(grouplist2, 0, ngroups_max * sizeof(gid_t)); /* Clear array */
 173   if (getgroups(ngroups_max, grouplist2) != HALF_LIST_SIZE) e(21);
 174   for (i = 0; i < HALF_LIST_SIZE; i++) {
 175         /* Anything above indices 'HALF_LIST_SIZE' is undefined */
 176         if(grouplist[i] != grouplist2[i]) {
 177                 e(22);
 178                 break;
 179         }
 180   }
 181
 182   /* Try to set too high a group ID */
 183   grouplist2[0] = GID_MAX + 1;  /* Out of range */
 184   if (setgroups(1, grouplist2) == 0) e(23);
 185   if (errno != EINVAL) e(24);
 186
 187   free(grouplist);
 188   free(grouplist2);
 189 }
 190
 191 void group_test() {
 192 /* To test supplemental group support we're going to create a temporary
 193  * directory that can only be accessed (x bit) by members of our imaginary
 194  * group, read from (r bit) and written to (w bit).
 195  * Then we're going to create a file in that directory that's only readable and
 196  * writable by the owner, also readable, writable, and both (in that order) by
 197  * the imaginary group, and readable, writable, and both by everyone else (2).
 198  */
 199
 200   int i, round;
 201   gid_t *grouplist;
 202   long ngroups_max;
 203 #define ROUNDS 8
 204
 205   subtest = 3;
 206
 207   ngroups_max = sysconf(_SC_NGROUPS_MAX);
 208   grouplist = malloc(ngroups_max *sizeof(gid_t));
 209
 210   /* Let's invent imaginary groups and user id */
 211   grouplist = malloc(ngroups_max * sizeof(gid_t));
 212
 213   /* Now loop a few tests while using different group set sizes */
 214   for(round = 0; round < ROUNDS; round++) {
 215         grouplist[round] = IMAGINARY_GID;
 216         for(i = 0; i < ngroups_max; i++) {
 217                 if(i == round) continue;
 218                 grouplist[i] = IMAGINARY_GID + i + ngroups_max;
 219         }
 220         setgroups(round+1, grouplist);
 221
 222         system("rm -rf DIR_046 > /dev/null 2>&1");
 223         system("mkdir DIR_046");
 224         system("chmod u=rwx,g=,o= DIR_046"); /* Only access for superuser */
 225         system("chgrp "IMAGINARY_GID_STR" DIR_046"); /* Make imaginary group
 226                                                       * owner */
 227
 228         /* Test group access on directories */
 229         if(dotest(group_test_1) != 0) e(1);
 230         system("chmod g+r DIR_046"); /* Allow group read access */
 231         if(dotest(group_test_1) == 0) e(2);
 232
 233         system("chmod g= DIR_046");
 234         if(dotest(group_test_2) != 0) e(3);
 235         system("chmod g+x DIR_046"); /* Allow 'search' (i.e., inode data)
 236                                       * access */
 237         if(dotest(group_test_2) == 0) e(4);
 238
 239         if(dotest(group_test_3) != 0) e(5);
 240         system("chmod g+w DIR_046"); /* Allow group write access */
 241         if(dotest(group_test_3) == 0) e(6);
 242
 243         system("chmod g-wx DIR_046"); /* Remove write and 'search' permission */
 244         if(dotest(group_test_4) != 0) e(7);
 245         system("chmod g+w DIR_046"); /* Add write permission */
 246         if(dotest(group_test_4) != 0) e(8);
 247         system("chmod g+x DIR_046"); /* Add 'search' permission */
 248         if(dotest(group_test_4) == 0) e(9);
 249
 250         /* Subdirectories */
 251         system("mkdir -p DIR_046/sub");
 252         system("chmod u=rwx,g=,o= DIR_046");
 253         system("chmod u=rwx,g=,o= DIR_046/sub");
 254         system("chgrp "IMAGINARY_GID_STR" DIR_046/sub");
 255
 256         if(dotest(group_test_1) != 0) e(10);
 257         if(dotest(group_test_5) != 0) e(11);
 258
 259         system("chmod g+r DIR_046");
 260         if(dotest(group_test_1) == 0) e(12);
 261         if(dotest(group_test_5) != 0) e(13);
 262
 263         system("chmod g= DIR_046");
 264         if(dotest(group_test_5) != 0) e(14);
 265         system("chmod g+r DIR_046/sub");
 266         if(dotest(group_test_5) != 0) e(15); /* We need search permission for
 267                                               * sub directory DIR_046 to be
 268                                               * able to read the contents of
 269                                               * DIR_046/sub */
 270         system("chmod g+x DIR_046");
 271         if(dotest(group_test_1) != 0) e(16);
 272         if(dotest(group_test_5) == 0) e(17);
 273         system("chmod g+r DIR_046");
 274         if(dotest(group_test_5) == 0) e(18);
 275   }
 276   system("rm -rf DIR_046");
 277   free(grouplist);
 278 }
 279
 280 int dotest( void (*func)(void) ) {
 281   int test_result;
 282
 283   if(fork() == 0) {
 284         (*func)();
 285         exit(1); /* not supposed to be reached */
 286   }
 287   else wait(&test_result);
 288
 289   return(test_result);
 290 }
 291
 292 void group_test_1() {
 293 /* Test x bit for group access. Exit value is 1 when we were able to read from
 294  * the directory and 0 otherwise. */
 295   DIR *dirp = NULL;
 296
 297   SET_CREDENTIALS;
 298
 299   dirp = opendir("DIR_046");
 300   exit(dirp != NULL); /* If not NULL, we were able to access it */
 301 }
 302
 303 void group_test_2() {
 304 /* Test x bit for group access. Exit value is 1 when we were able to access
 305  * inode data of the directory and 0 otherwise. */
 306   struct stat buf;
 307   int res;
 308
 309   SET_CREDENTIALS;
 310
 311   res = stat("DIR_046/.", &buf);
 312   exit(res == 0);
 313 }
 314
 315 void group_test_3() {
 316 /* Test wx bits for group access. Exit value is 1 when we were able to write to
 317  * the directory and 0 otherwise. */
 318   int fd;
 319
 320   SET_CREDENTIALS;
 321
 322   fd = open("DIR_046/writetest", O_WRONLY|O_CREAT);
 323
 324   exit(fd != -1);
 325 }
 326
 327 void group_test_4() {
 328 /* Test w bit for group access. Exit value is 1 when we were able to rename a
 329  * the directory and 0 otherwise. */
 330   int res;
 331
 332   SET_CREDENTIALS;
 333
 334   res = rename("DIR_046/writetest", "DIR_046/renametest");
 335
 336   exit(res == 0);
 337 }
 338
 339 void group_test_5() {
 340 /* Test x bit for group access. Exit value is 1 when we were able to read from
 341  * the directory and 0 otherwise. */
 342   DIR *dirp = NULL;
 343
 344   SET_CREDENTIALS;
 345
 346   dirp = opendir("DIR_046/sub");
 347   exit(dirp != NULL); /* If not NULL, we were able to access it */
 348 }