tools/testing/selftests/mqueue/mq_open_tests.c

   1 /*
   2  * This application is Copyright 2012 Red Hat, Inc.
   3  *      Doug Ledford <dledford@redhat.com>
   4  *
   5  * mq_open_tests is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, version 3.
   8  *
   9  * mq_open_tests is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * For the full text of the license, see <http://www.gnu.org/licenses/>.
  15  *
  16  * mq_open_tests.c
  17  *   Tests the various situations that should either succeed or fail to
  18  *   open a posix message queue and then reports whether or not they
  19  *   did as they were supposed to.
  20  *
  21  */
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <unistd.h>
  25 #include <fcntl.h>
  26 #include <string.h>
  27 #include <limits.h>
  28 #include <errno.h>
  29 #include <sys/types.h>
  30 #include <sys/time.h>
  31 #include <sys/resource.h>
  32 #include <sys/stat.h>
  33 #include <mqueue.h>
  34
  35 static char *usage =
  36 "Usage:\n"
  37 "  %s path\n"
  38 "\n"
  39 "       path    Path name of the message queue to create\n"
  40 "\n"
  41 "       Note: this program must be run as root in order to enable all tests\n"
  42 "\n";
  43
  44 char *DEF_MSGS = "/proc/sys/fs/mqueue/msg_default";
  45 char *DEF_MSGSIZE = "/proc/sys/fs/mqueue/msgsize_default";
  46 char *MAX_MSGS = "/proc/sys/fs/mqueue/msg_max";
  47 char *MAX_MSGSIZE = "/proc/sys/fs/mqueue/msgsize_max";
  48
  49 int default_settings;
  50 struct rlimit saved_limits, cur_limits;
  51 int saved_def_msgs, saved_def_msgsize, saved_max_msgs, saved_max_msgsize;
  52 int cur_def_msgs, cur_def_msgsize, cur_max_msgs, cur_max_msgsize;
  53 FILE *def_msgs, *def_msgsize, *max_msgs, *max_msgsize;
  54 char *queue_path;
  55 mqd_t queue = -1;
  56
  57 static inline void __set(FILE *stream, int value, char *err_msg);
  58 void shutdown(int exit_val, char *err_cause, int line_no);
  59 static inline int get(FILE *stream);
  60 static inline void set(FILE *stream, int value);
  61 static inline void getr(int type, struct rlimit *rlim);
  62 static inline void setr(int type, struct rlimit *rlim);
  63 void validate_current_settings();
  64 static inline void test_queue(struct mq_attr *attr, struct mq_attr *result);
  65 static inline int test_queue_fail(struct mq_attr *attr, struct mq_attr *result);
  66
  67 static inline void __set(FILE *stream, int value, char *err_msg)
  68 {
  69         rewind(stream);
  70         if (fprintf(stream, "%d", value) < 0)
  71                 perror(err_msg);
  72 }
  73
  74
  75 void shutdown(int exit_val, char *err_cause, int line_no)
  76 {
  77         static int in_shutdown = 0;
  78
  79         /* In case we get called recursively by a set() call below */
  80         if (in_shutdown++)
  81                 return;
  82
  83         if (seteuid(0) == -1)
  84                 perror("seteuid() failed");
  85
  86         if (queue != -1)
  87                 if (mq_close(queue))
  88                         perror("mq_close() during shutdown");
  89         if (queue_path)
  90                 /*
  91                  * Be silent if this fails, if we cleaned up already it's
  92                  * expected to fail
  93                  */
  94                 mq_unlink(queue_path);
  95         if (default_settings) {
  96                 if (saved_def_msgs)
  97                         __set(def_msgs, saved_def_msgs,
  98                               "failed to restore saved_def_msgs");
  99                 if (saved_def_msgsize)
 100                         __set(def_msgsize, saved_def_msgsize,
 101                               "failed to restore saved_def_msgsize");
 102         }
 103         if (saved_max_msgs)
 104                 __set(max_msgs, saved_max_msgs,
 105                       "failed to restore saved_max_msgs");
 106         if (saved_max_msgsize)
 107                 __set(max_msgsize, saved_max_msgsize,
 108                       "failed to restore saved_max_msgsize");
 109         if (exit_val)
 110                 error(exit_val, errno, "%s at %d", err_cause, line_no);
 111         exit(0);
 112 }
 113
 114 static inline int get(FILE *stream)
 115 {
 116         int value;
 117         rewind(stream);
 118         if (fscanf(stream, "%d", &value) != 1)
 119                 shutdown(4, "Error reading /proc entry", __LINE__ - 1);
 120         return value;
 121 }
 122
 123 static inline void set(FILE *stream, int value)
 124 {
 125         int new_value;
 126
 127         rewind(stream);
 128         if (fprintf(stream, "%d", value) < 0)
 129                 return shutdown(5, "Failed writing to /proc file",
 130                                 __LINE__ - 1);
 131         new_value = get(stream);
 132         if (new_value != value)
 133                 return shutdown(5, "We didn't get what we wrote to /proc back",
 134                                 __LINE__ - 1);
 135 }
 136
 137 static inline void getr(int type, struct rlimit *rlim)
 138 {
 139         if (getrlimit(type, rlim))
 140                 shutdown(6, "getrlimit()", __LINE__ - 1);
 141 }
 142
 143 static inline void setr(int type, struct rlimit *rlim)
 144 {
 145         if (setrlimit(type, rlim))
 146                 shutdown(7, "setrlimit()", __LINE__ - 1);
 147 }
 148
 149 void validate_current_settings()
 150 {
 151         int rlim_needed;
 152
 153         if (cur_limits.rlim_cur < 4096) {
 154                 printf("Current rlimit value for POSIX message queue bytes is "
 155                        "unreasonably low,\nincreasing.\n\n");
 156                 cur_limits.rlim_cur = 8192;
 157                 cur_limits.rlim_max = 16384;
 158                 setr(RLIMIT_MSGQUEUE, &cur_limits);
 159         }
 160
 161         if (default_settings) {
 162                 rlim_needed = (cur_def_msgs + 1) * (cur_def_msgsize + 1 +
 163                                                     2 * sizeof(void *));
 164                 if (rlim_needed > cur_limits.rlim_cur) {
 165                         printf("Temporarily lowering default queue parameters "
 166                                "to something that will work\n"
 167                                "with the current rlimit values.\n\n");
 168                         set(def_msgs, 10);
 169                         cur_def_msgs = 10;
 170                         set(def_msgsize, 128);
 171                         cur_def_msgsize = 128;
 172                 }
 173         } else {
 174                 rlim_needed = (cur_max_msgs + 1) * (cur_max_msgsize + 1 +
 175                                                     2 * sizeof(void *));
 176                 if (rlim_needed > cur_limits.rlim_cur) {
 177                         printf("Temporarily lowering maximum queue parameters "
 178                                "to something that will work\n"
 179                                "with the current rlimit values in case this is "
 180                                "a kernel that ties the default\n"
 181                                "queue parameters to the maximum queue "
 182                                "parameters.\n\n");
 183                         set(max_msgs, 10);
 184                         cur_max_msgs = 10;
 185                         set(max_msgsize, 128);
 186                         cur_max_msgsize = 128;
 187                 }
 188         }
 189 }
 190
 191 /*
 192  * test_queue - Test opening a queue, shutdown if we fail.  This should
 193  * only be called in situations that should never fail.  We clean up
 194  * after ourselves and return the queue attributes in *result.
 195  */
 196 static inline void test_queue(struct mq_attr *attr, struct mq_attr *result)
 197 {
 198         int flags = O_RDWR | O_EXCL | O_CREAT;
 199         int perms = DEFFILEMODE;
 200
 201         if ((queue = mq_open(queue_path, flags, perms, attr)) == -1)
 202                 shutdown(1, "mq_open()", __LINE__);
 203         if (mq_getattr(queue, result))
 204                 shutdown(1, "mq_getattr()", __LINE__);
 205         if (mq_close(queue))
 206                 shutdown(1, "mq_close()", __LINE__);
 207         queue = -1;
 208         if (mq_unlink(queue_path))
 209                 shutdown(1, "mq_unlink()", __LINE__);
 210 }
 211
 212 /*
 213  * Same as test_queue above, but failure is not fatal.
 214  * Returns:
 215  * 0 - Failed to create a queue
 216  * 1 - Created a queue, attributes in *result
 217  */
 218 static inline int test_queue_fail(struct mq_attr *attr, struct mq_attr *result)
 219 {
 220         int flags = O_RDWR | O_EXCL | O_CREAT;
 221         int perms = DEFFILEMODE;
 222
 223         if ((queue = mq_open(queue_path, flags, perms, attr)) == -1)
 224                 return 0;
 225         if (mq_getattr(queue, result))
 226                 shutdown(1, "mq_getattr()", __LINE__);
 227         if (mq_close(queue))
 228                 shutdown(1, "mq_close()", __LINE__);
 229         queue = -1;
 230         if (mq_unlink(queue_path))
 231                 shutdown(1, "mq_unlink()", __LINE__);
 232         return 1;
 233 }
 234
 235 int main(int argc, char *argv[])
 236 {
 237         struct mq_attr attr, result;
 238
 239         if (argc != 2) {
 240                 fprintf(stderr, "Must pass a valid queue name\n\n");
 241                 fprintf(stderr, usage, argv[0]);
 242                 exit(1);
 243         }
 244
 245         /*
 246          * Although we can create a msg queue with a non-absolute path name,
 247          * unlink will fail.  So, if the name doesn't start with a /, add one
 248          * when we save it.
 249          */
 250         if (*argv[1] == '/')
 251                 queue_path = strdup(argv[1]);
 252         else {
 253                 queue_path = malloc(strlen(argv[1]) + 2);
 254                 if (!queue_path) {
 255                         perror("malloc()");
 256                         exit(1);
 257                 }
 258                 queue_path[0] = '/';
 259                 queue_path[1] = 0;
 260                 strcat(queue_path, argv[1]);
 261         }
 262
 263         if (getuid() != 0) {
 264                 fprintf(stderr, "Not running as root, but almost all tests "
 265                         "require root in order to modify\nsystem settings.  "
 266                         "Exiting.\n");
 267                 exit(1);
 268         }
 269
 270         /* Find out what files there are for us to make tweaks in */
 271         def_msgs = fopen(DEF_MSGS, "r+");
 272         def_msgsize = fopen(DEF_MSGSIZE, "r+");
 273         max_msgs = fopen(MAX_MSGS, "r+");
 274         max_msgsize = fopen(MAX_MSGSIZE, "r+");
 275
 276         if (!max_msgs)
 277                 shutdown(2, "Failed to open msg_max", __LINE__);
 278         if (!max_msgsize)
 279                 shutdown(2, "Failed to open msgsize_max", __LINE__);
 280         if (def_msgs || def_msgsize)
 281                 default_settings = 1;
 282
 283         /* Load up the current system values for everything we can */
 284         getr(RLIMIT_MSGQUEUE, &saved_limits);
 285         cur_limits = saved_limits;
 286         if (default_settings) {
 287                 saved_def_msgs = cur_def_msgs = get(def_msgs);
 288                 saved_def_msgsize = cur_def_msgsize = get(def_msgsize);
 289         }
 290         saved_max_msgs = cur_max_msgs = get(max_msgs);
 291         saved_max_msgsize = cur_max_msgsize = get(max_msgsize);
 292
 293         /* Tell the user our initial state */
 294         printf("\nInitial system state:\n");
 295         printf("\tUsing queue path:\t\t%s\n", queue_path);
 296         printf("\tRLIMIT_MSGQUEUE(soft):\t\t%ld\n",
 297                 (long) saved_limits.rlim_cur);
 298         printf("\tRLIMIT_MSGQUEUE(hard):\t\t%ld\n",
 299                 (long) saved_limits.rlim_max);
 300         printf("\tMaximum Message Size:\t\t%d\n", saved_max_msgsize);
 301         printf("\tMaximum Queue Size:\t\t%d\n", saved_max_msgs);
 302         if (default_settings) {
 303                 printf("\tDefault Message Size:\t\t%d\n", saved_def_msgsize);
 304                 printf("\tDefault Queue Size:\t\t%d\n", saved_def_msgs);
 305         } else {
 306                 printf("\tDefault Message Size:\t\tNot Supported\n");
 307                 printf("\tDefault Queue Size:\t\tNot Supported\n");
 308         }
 309         printf("\n");
 310
 311         validate_current_settings();
 312
 313         printf("Adjusted system state for testing:\n");
 314         printf("\tRLIMIT_MSGQUEUE(soft):\t\t%ld\n", (long) cur_limits.rlim_cur);
 315         printf("\tRLIMIT_MSGQUEUE(hard):\t\t%ld\n", (long) cur_limits.rlim_max);
 316         printf("\tMaximum Message Size:\t\t%d\n", cur_max_msgsize);
 317         printf("\tMaximum Queue Size:\t\t%d\n", cur_max_msgs);
 318         if (default_settings) {
 319                 printf("\tDefault Message Size:\t\t%d\n", cur_def_msgsize);
 320                 printf("\tDefault Queue Size:\t\t%d\n", cur_def_msgs);
 321         }
 322
 323         printf("\n\nTest series 1, behavior when no attr struct "
 324                "passed to mq_open:\n");
 325         if (!default_settings) {
 326                 test_queue(NULL, &result);
 327                 printf("Given sane system settings, mq_open without an attr "
 328                        "struct succeeds:\tPASS\n");
 329                 if (result.mq_maxmsg != cur_max_msgs ||
 330                     result.mq_msgsize != cur_max_msgsize) {
 331                         printf("Kernel does not support setting the default "
 332                                "mq attributes,\nbut also doesn't tie the "
 333                                "defaults to the maximums:\t\t\tPASS\n");
 334                 } else {
 335                         set(max_msgs, ++cur_max_msgs);
 336                         set(max_msgsize, ++cur_max_msgsize);
 337                         test_queue(NULL, &result);
 338                         if (result.mq_maxmsg == cur_max_msgs &&
 339                             result.mq_msgsize == cur_max_msgsize)
 340                                 printf("Kernel does not support setting the "
 341                                        "default mq attributes and\n"
 342                                        "also ties system wide defaults to "
 343                                        "the system wide maximums:\t\t"
 344                                        "FAIL\n");
 345                         else
 346                                 printf("Kernel does not support setting the "
 347                                        "default mq attributes,\n"
 348                                        "but also doesn't tie the defaults to "
 349                                        "the maximums:\t\t\tPASS\n");
 350                 }
 351         } else {
 352                 printf("Kernel supports setting defaults separately from "
 353                        "maximums:\t\tPASS\n");
 354                 /*
 355                  * While we are here, go ahead and test that the kernel
 356                  * properly follows the default settings
 357                  */
 358                 test_queue(NULL, &result);
 359                 printf("Given sane values, mq_open without an attr struct "
 360                        "succeeds:\t\tPASS\n");
 361                 if (result.mq_maxmsg != cur_def_msgs ||
 362                     result.mq_msgsize != cur_def_msgsize)
 363                         printf("Kernel supports setting defaults, but does "
 364                                "not actually honor them:\tFAIL\n\n");
 365                 else {
 366                         set(def_msgs, ++cur_def_msgs);
 367                         set(def_msgsize, ++cur_def_msgsize);
 368                         /* In case max was the same as the default */
 369                         set(max_msgs, ++cur_max_msgs);
 370                         set(max_msgsize, ++cur_max_msgsize);
 371                         test_queue(NULL, &result);
 372                         if (result.mq_maxmsg != cur_def_msgs ||
 373                             result.mq_msgsize != cur_def_msgsize)
 374                                 printf("Kernel supports setting defaults, but "
 375                                        "does not actually honor them:\t"
 376                                        "FAIL\n");
 377                         else
 378                                 printf("Kernel properly honors default setting "
 379                                        "knobs:\t\t\t\tPASS\n");
 380                 }
 381                 set(def_msgs, cur_max_msgs + 1);
 382                 cur_def_msgs = cur_max_msgs + 1;
 383                 set(def_msgsize, cur_max_msgsize + 1);
 384                 cur_def_msgsize = cur_max_msgsize + 1;
 385                 if (cur_def_msgs * (cur_def_msgsize + 2 * sizeof(void *)) >=
 386                     cur_limits.rlim_cur) {
 387                         cur_limits.rlim_cur = (cur_def_msgs + 2) *
 388                                 (cur_def_msgsize + 2 * sizeof(void *));
 389                         cur_limits.rlim_max = 2 * cur_limits.rlim_cur;
 390                         setr(RLIMIT_MSGQUEUE, &cur_limits);
 391                 }
 392                 if (test_queue_fail(NULL, &result)) {
 393                         if (result.mq_maxmsg == cur_max_msgs &&
 394                             result.mq_msgsize == cur_max_msgsize)
 395                                 printf("Kernel properly limits default values "
 396                                        "to lesser of default/max:\t\tPASS\n");
 397                         else
 398                                 printf("Kernel does not properly set default "
 399                                        "queue parameters when\ndefaults > "
 400                                        "max:\t\t\t\t\t\t\t\tFAIL\n");
 401                 } else
 402                         printf("Kernel fails to open mq because defaults are "
 403                                "greater than maximums:\tFAIL\n");
 404                 set(def_msgs, --cur_def_msgs);
 405                 set(def_msgsize, --cur_def_msgsize);
 406                 cur_limits.rlim_cur = cur_limits.rlim_max = cur_def_msgs *
 407                         cur_def_msgsize;
 408                 setr(RLIMIT_MSGQUEUE, &cur_limits);
 409                 if (test_queue_fail(NULL, &result))
 410                         printf("Kernel creates queue even though defaults "
 411                                "would exceed\nrlimit setting:"
 412                                "\t\t\t\t\t\t\t\tFAIL\n");
 413                 else
 414                         printf("Kernel properly fails to create queue when "
 415                                "defaults would\nexceed rlimit:"
 416                                "\t\t\t\t\t\t\t\tPASS\n");
 417         }
 418
 419         /*
 420          * Test #2 - open with an attr struct that exceeds rlimit
 421          */
 422         printf("\n\nTest series 2, behavior when attr struct is "
 423                "passed to mq_open:\n");
 424         cur_max_msgs = 32;
 425         cur_max_msgsize = cur_limits.rlim_max >> 4;
 426         set(max_msgs, cur_max_msgs);
 427         set(max_msgsize, cur_max_msgsize);
 428         attr.mq_maxmsg = cur_max_msgs;
 429         attr.mq_msgsize = cur_max_msgsize;
 430         if (test_queue_fail(&attr, &result))
 431                 printf("Queue open in excess of rlimit max when euid = 0 "
 432                        "succeeded:\t\tFAIL\n");
 433         else
 434                 printf("Queue open in excess of rlimit max when euid = 0 "
 435                        "failed:\t\tPASS\n");
 436         attr.mq_maxmsg = cur_max_msgs + 1;
 437         attr.mq_msgsize = 10;
 438         if (test_queue_fail(&attr, &result))
 439                 printf("Queue open with mq_maxmsg > limit when euid = 0 "
 440                        "succeeded:\t\tPASS\n");
 441         else
 442                 printf("Queue open with mq_maxmsg > limit when euid = 0 "
 443                        "failed:\t\tFAIL\n");
 444         attr.mq_maxmsg = 1;
 445         attr.mq_msgsize = cur_max_msgsize + 1;
 446         if (test_queue_fail(&attr, &result))
 447                 printf("Queue open with mq_msgsize > limit when euid = 0 "
 448                        "succeeded:\t\tPASS\n");
 449         else
 450                 printf("Queue open with mq_msgsize > limit when euid = 0 "
 451                        "failed:\t\tFAIL\n");
 452         attr.mq_maxmsg = 65536;
 453         attr.mq_msgsize = 65536;
 454         if (test_queue_fail(&attr, &result))
 455                 printf("Queue open with total size > 2GB when euid = 0 "
 456                        "succeeded:\t\tFAIL\n");
 457         else
 458                 printf("Queue open with total size > 2GB when euid = 0 "
 459                        "failed:\t\t\tPASS\n");
 460
 461         if (seteuid(99) == -1) {
 462                 perror("seteuid() failed");
 463                 exit(1);
 464         }
 465
 466         attr.mq_maxmsg = cur_max_msgs;
 467         attr.mq_msgsize = cur_max_msgsize;
 468         if (test_queue_fail(&attr, &result))
 469                 printf("Queue open in excess of rlimit max when euid = 99 "
 470                        "succeeded:\t\tFAIL\n");
 471         else
 472                 printf("Queue open in excess of rlimit max when euid = 99 "
 473                        "failed:\t\tPASS\n");
 474         attr.mq_maxmsg = cur_max_msgs + 1;
 475         attr.mq_msgsize = 10;
 476         if (test_queue_fail(&attr, &result))
 477                 printf("Queue open with mq_maxmsg > limit when euid = 99 "
 478                        "succeeded:\t\tFAIL\n");
 479         else
 480                 printf("Queue open with mq_maxmsg > limit when euid = 99 "
 481                        "failed:\t\tPASS\n");
 482         attr.mq_maxmsg = 1;
 483         attr.mq_msgsize = cur_max_msgsize + 1;
 484         if (test_queue_fail(&attr, &result))
 485                 printf("Queue open with mq_msgsize > limit when euid = 99 "
 486                        "succeeded:\t\tFAIL\n");
 487         else
 488                 printf("Queue open with mq_msgsize > limit when euid = 99 "
 489                        "failed:\t\tPASS\n");
 490         attr.mq_maxmsg = 65536;
 491         attr.mq_msgsize = 65536;
 492         if (test_queue_fail(&attr, &result))
 493                 printf("Queue open with total size > 2GB when euid = 99 "
 494                        "succeeded:\t\tFAIL\n");
 495         else
 496                 printf("Queue open with total size > 2GB when euid = 99 "
 497                        "failed:\t\t\tPASS\n");
 498
 499         shutdown(0,"",0);
 500 }