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 #include <error.h>
  35
  36 static char *usage =
  37 "Usage:\n"
  38 "  %s path\n"
  39 "\n"
  40 "       path    Path name of the message queue to create\n"
  41 "\n"
  42 "       Note: this program must be run as root in order to enable all tests\n"
  43 "\n";
  44
  45 char *DEF_MSGS = "/proc/sys/fs/mqueue/msg_default";
  46 char *DEF_MSGSIZE = "/proc/sys/fs/mqueue/msgsize_default";
  47 char *MAX_MSGS = "/proc/sys/fs/mqueue/msg_max";
  48 char *MAX_MSGSIZE = "/proc/sys/fs/mqueue/msgsize_max";
  49
  50 int default_settings;
  51 struct rlimit saved_limits, cur_limits;
  52 int saved_def_msgs, saved_def_msgsize, saved_max_msgs, saved_max_msgsize;
  53 int cur_def_msgs, cur_def_msgsize, cur_max_msgs, cur_max_msgsize;
  54 FILE *def_msgs, *def_msgsize, *max_msgs, *max_msgsize;
  55 char *queue_path;
  56 mqd_t queue = -1;
  57
  58 static inline void __set(FILE *stream, int value, char *err_msg);
  59 void shutdown(int exit_val, char *err_cause, int line_no);
  60 static inline int get(FILE *stream);
  61 static inline void set(FILE *stream, int value);
  62 static inline void getr(int type, struct rlimit *rlim);
  63 static inline void setr(int type, struct rlimit *rlim);
  64 void validate_current_settings();
  65 static inline void test_queue(struct mq_attr *attr, struct mq_attr *result);
  66 static inline int test_queue_fail(struct mq_attr *attr, struct mq_attr *result);
  67
  68 static inline void __set(FILE *stream, int value, char *err_msg)
  69 {
  70         rewind(stream);
  71         if (fprintf(stream, "%d", value) < 0)
  72                 perror(err_msg);
  73 }
  74
  75
  76 void shutdown(int exit_val, char *err_cause, int line_no)
  77 {
  78         static int in_shutdown = 0;
  79
  80         /* In case we get called recursively by a set() call below */
  81         if (in_shutdown++)
  82                 return;
  83
  84         if (seteuid(0) == -1)
  85                 perror("seteuid() failed");
  86
  87         if (queue != -1)
  88                 if (mq_close(queue))
  89                         perror("mq_close() during shutdown");
  90         if (queue_path)
  91                 /*
  92                  * Be silent if this fails, if we cleaned up already it's
  93                  * expected to fail
  94                  */
  95                 mq_unlink(queue_path);
  96         if (default_settings) {
  97                 if (saved_def_msgs)
  98                         __set(def_msgs, saved_def_msgs,
  99                               "failed to restore saved_def_msgs");
 100                 if (saved_def_msgsize)
 101                         __set(def_msgsize, saved_def_msgsize,
 102                               "failed to restore saved_def_msgsize");
 103         }
 104         if (saved_max_msgs)
 105                 __set(max_msgs, saved_max_msgs,
 106                       "failed to restore saved_max_msgs");
 107         if (saved_max_msgsize)
 108                 __set(max_msgsize, saved_max_msgsize,
 109                       "failed to restore saved_max_msgsize");
 110         if (exit_val)
 111                 error(exit_val, errno, "%s at %d", err_cause, line_no);
 112         exit(0);
 113 }
 114
 115 static inline int get(FILE *stream)
 116 {
 117         int value;
 118         rewind(stream);
 119         if (fscanf(stream, "%d", &value) != 1)
 120                 shutdown(4, "Error reading /proc entry", __LINE__ - 1);
 121         return value;
 122 }
 123
 124 static inline void set(FILE *stream, int value)
 125 {
 126         int new_value;
 127
 128         rewind(stream);
 129         if (fprintf(stream, "%d", value) < 0)
 130                 return shutdown(5, "Failed writing to /proc file",
 131                                 __LINE__ - 1);
 132         new_value = get(stream);
 133         if (new_value != value)
 134                 return shutdown(5, "We didn't get what we wrote to /proc back",
 135                                 __LINE__ - 1);
 136 }
 137
 138 static inline void getr(int type, struct rlimit *rlim)
 139 {
 140         if (getrlimit(type, rlim))
 141                 shutdown(6, "getrlimit()", __LINE__ - 1);
 142 }
 143
 144 static inline void setr(int type, struct rlimit *rlim)
 145 {
 146         if (setrlimit(type, rlim))
 147                 shutdown(7, "setrlimit()", __LINE__ - 1);
 148 }
 149
 150 void validate_current_settings()
 151 {
 152         int rlim_needed;
 153
 154         if (cur_limits.rlim_cur < 4096) {
 155                 printf("Current rlimit value for POSIX message queue bytes is "
 156                        "unreasonably low,\nincreasing.\n\n");
 157                 cur_limits.rlim_cur = 8192;
 158                 cur_limits.rlim_max = 16384;
 159                 setr(RLIMIT_MSGQUEUE, &cur_limits);
 160         }
 161
 162         if (default_settings) {
 163                 rlim_needed = (cur_def_msgs + 1) * (cur_def_msgsize + 1 +
 164                                                     2 * sizeof(void *));
 165                 if (rlim_needed > cur_limits.rlim_cur) {
 166                         printf("Temporarily lowering default queue parameters "
 167                                "to something that will work\n"
 168                                "with the current rlimit values.\n\n");
 169                         set(def_msgs, 10);
 170                         cur_def_msgs = 10;
 171                         set(def_msgsize, 128);
 172                         cur_def_msgsize = 128;
 173                 }
 174         } else {
 175                 rlim_needed = (cur_max_msgs + 1) * (cur_max_msgsize + 1 +
 176                                                     2 * sizeof(void *));
 177                 if (rlim_needed > cur_limits.rlim_cur) {
 178                         printf("Temporarily lowering maximum queue parameters "
 179                                "to something that will work\n"
 180                                "with the current rlimit values in case this is "
 181                                "a kernel that ties the default\n"
 182                                "queue parameters to the maximum queue "
 183                                "parameters.\n\n");
 184                         set(max_msgs, 10);
 185                         cur_max_msgs = 10;
 186                         set(max_msgsize, 128);
 187                         cur_max_msgsize = 128;
 188                 }
 189         }
 190 }
 191
 192 /*
 193  * test_queue - Test opening a queue, shutdown if we fail.  This should
 194  * only be called in situations that should never fail.  We clean up
 195  * after ourselves and return the queue attributes in *result.
 196  */
 197 static inline void test_queue(struct mq_attr *attr, struct mq_attr *result)
 198 {
 199         int flags = O_RDWR | O_EXCL | O_CREAT;
 200         int perms = DEFFILEMODE;
 201
 202         if ((queue = mq_open(queue_path, flags, perms, attr)) == -1)
 203                 shutdown(1, "mq_open()", __LINE__);
 204         if (mq_getattr(queue, result))
 205                 shutdown(1, "mq_getattr()", __LINE__);
 206         if (mq_close(queue))
 207                 shutdown(1, "mq_close()", __LINE__);
 208         queue = -1;
 209         if (mq_unlink(queue_path))
 210                 shutdown(1, "mq_unlink()", __LINE__);
 211 }
 212
 213 /*
 214  * Same as test_queue above, but failure is not fatal.
 215  * Returns:
 216  * 0 - Failed to create a queue
 217  * 1 - Created a queue, attributes in *result
 218  */
 219 static inline int test_queue_fail(struct mq_attr *attr, struct mq_attr *result)
 220 {
 221         int flags = O_RDWR | O_EXCL | O_CREAT;
 222         int perms = DEFFILEMODE;
 223
 224         if ((queue = mq_open(queue_path, flags, perms, attr)) == -1)
 225                 return 0;
 226         if (mq_getattr(queue, result))
 227                 shutdown(1, "mq_getattr()", __LINE__);
 228         if (mq_close(queue))
 229                 shutdown(1, "mq_close()", __LINE__);
 230         queue = -1;
 231         if (mq_unlink(queue_path))
 232                 shutdown(1, "mq_unlink()", __LINE__);
 233         return 1;
 234 }
 235
 236 int main(int argc, char *argv[])
 237 {
 238         struct mq_attr attr, result;
 239
 240         if (argc != 2) {
 241                 fprintf(stderr, "Must pass a valid queue name\n\n");
 242                 fprintf(stderr, usage, argv[0]);
 243                 exit(1);
 244         }
 245
 246         /*
 247          * Although we can create a msg queue with a non-absolute path name,
 248          * unlink will fail.  So, if the name doesn't start with a /, add one
 249          * when we save it.
 250          */
 251         if (*argv[1] == '/')
 252                 queue_path = strdup(argv[1]);
 253         else {
 254                 queue_path = malloc(strlen(argv[1]) + 2);
 255                 if (!queue_path) {
 256                         perror("malloc()");
 257                         exit(1);
 258                 }
 259                 queue_path[0] = '/';
 260                 queue_path[1] = 0;
 261                 strcat(queue_path, argv[1]);
 262         }
 263
 264         if (getuid() != 0) {
 265                 fprintf(stderr, "Not running as root, but almost all tests "
 266                         "require root in order to modify\nsystem settings.  "
 267                         "Exiting.\n");
 268                 exit(1);
 269         }
 270
 271         /* Find out what files there are for us to make tweaks in */
 272         def_msgs = fopen(DEF_MSGS, "r+");
 273         def_msgsize = fopen(DEF_MSGSIZE, "r+");
 274         max_msgs = fopen(MAX_MSGS, "r+");
 275         max_msgsize = fopen(MAX_MSGSIZE, "r+");
 276
 277         if (!max_msgs)
 278                 shutdown(2, "Failed to open msg_max", __LINE__);
 279         if (!max_msgsize)
 280                 shutdown(2, "Failed to open msgsize_max", __LINE__);
 281         if (def_msgs || def_msgsize)
 282                 default_settings = 1;
 283
 284         /* Load up the current system values for everything we can */
 285         getr(RLIMIT_MSGQUEUE, &saved_limits);
 286         cur_limits = saved_limits;
 287         if (default_settings) {
 288                 saved_def_msgs = cur_def_msgs = get(def_msgs);
 289                 saved_def_msgsize = cur_def_msgsize = get(def_msgsize);
 290         }
 291         saved_max_msgs = cur_max_msgs = get(max_msgs);
 292         saved_max_msgsize = cur_max_msgsize = get(max_msgsize);
 293
 294         /* Tell the user our initial state */
 295         printf("\nInitial system state:\n");
 296         printf("\tUsing queue path:\t\t%s\n", queue_path);
 297         printf("\tRLIMIT_MSGQUEUE(soft):\t\t%ld\n",
 298                 (long) saved_limits.rlim_cur);
 299         printf("\tRLIMIT_MSGQUEUE(hard):\t\t%ld\n",
 300                 (long) saved_limits.rlim_max);
 301         printf("\tMaximum Message Size:\t\t%d\n", saved_max_msgsize);
 302         printf("\tMaximum Queue Size:\t\t%d\n", saved_max_msgs);
 303         if (default_settings) {
 304                 printf("\tDefault Message Size:\t\t%d\n", saved_def_msgsize);
 305                 printf("\tDefault Queue Size:\t\t%d\n", saved_def_msgs);
 306         } else {
 307                 printf("\tDefault Message Size:\t\tNot Supported\n");
 308                 printf("\tDefault Queue Size:\t\tNot Supported\n");
 309         }
 310         printf("\n");
 311
 312         validate_current_settings();
 313
 314         printf("Adjusted system state for testing:\n");
 315         printf("\tRLIMIT_MSGQUEUE(soft):\t\t%ld\n", (long) cur_limits.rlim_cur);
 316         printf("\tRLIMIT_MSGQUEUE(hard):\t\t%ld\n", (long) cur_limits.rlim_max);
 317         printf("\tMaximum Message Size:\t\t%d\n", cur_max_msgsize);
 318         printf("\tMaximum Queue Size:\t\t%d\n", cur_max_msgs);
 319         if (default_settings) {
 320                 printf("\tDefault Message Size:\t\t%d\n", cur_def_msgsize);
 321                 printf("\tDefault Queue Size:\t\t%d\n", cur_def_msgs);
 322         }
 323
 324         printf("\n\nTest series 1, behavior when no attr struct "
 325                "passed to mq_open:\n");
 326         if (!default_settings) {
 327                 test_queue(NULL, &result);
 328                 printf("Given sane system settings, mq_open without an attr "
 329                        "struct succeeds:\tPASS\n");
 330                 if (result.mq_maxmsg != cur_max_msgs ||
 331                     result.mq_msgsize != cur_max_msgsize) {
 332                         printf("Kernel does not support setting the default "
 333                                "mq attributes,\nbut also doesn't tie the "
 334                                "defaults to the maximums:\t\t\tPASS\n");
 335                 } else {
 336                         set(max_msgs, ++cur_max_msgs);
 337                         set(max_msgsize, ++cur_max_msgsize);
 338                         test_queue(NULL, &result);
 339                         if (result.mq_maxmsg == cur_max_msgs &&
 340                             result.mq_msgsize == cur_max_msgsize)
 341                                 printf("Kernel does not support setting the "
 342                                        "default mq attributes and\n"
 343                                        "also ties system wide defaults to "
 344                                        "the system wide maximums:\t\t"
 345                                        "FAIL\n");
 346                         else
 347                                 printf("Kernel does not support setting the "
 348                                        "default mq attributes,\n"
 349                                        "but also doesn't tie the defaults to "
 350                                        "the maximums:\t\t\tPASS\n");
 351                 }
 352         } else {
 353                 printf("Kernel supports setting defaults separately from "
 354                        "maximums:\t\tPASS\n");
 355                 /*
 356                  * While we are here, go ahead and test that the kernel
 357                  * properly follows the default settings
 358                  */
 359                 test_queue(NULL, &result);
 360                 printf("Given sane values, mq_open without an attr struct "
 361                        "succeeds:\t\tPASS\n");
 362                 if (result.mq_maxmsg != cur_def_msgs ||
 363                     result.mq_msgsize != cur_def_msgsize)
 364                         printf("Kernel supports setting defaults, but does "
 365                                "not actually honor them:\tFAIL\n\n");
 366                 else {
 367                         set(def_msgs, ++cur_def_msgs);
 368                         set(def_msgsize, ++cur_def_msgsize);
 369                         /* In case max was the same as the default */
 370                         set(max_msgs, ++cur_max_msgs);
 371                         set(max_msgsize, ++cur_max_msgsize);
 372                         test_queue(NULL, &result);
 373                         if (result.mq_maxmsg != cur_def_msgs ||
 374                             result.mq_msgsize != cur_def_msgsize)
 375                                 printf("Kernel supports setting defaults, but "
 376                                        "does not actually honor them:\t"
 377                                        "FAIL\n");
 378                         else
 379                                 printf("Kernel properly honors default setting "
 380                                        "knobs:\t\t\t\tPASS\n");
 381                 }
 382                 set(def_msgs, cur_max_msgs + 1);
 383                 cur_def_msgs = cur_max_msgs + 1;
 384                 set(def_msgsize, cur_max_msgsize + 1);
 385                 cur_def_msgsize = cur_max_msgsize + 1;
 386                 if (cur_def_msgs * (cur_def_msgsize + 2 * sizeof(void *)) >=
 387                     cur_limits.rlim_cur) {
 388                         cur_limits.rlim_cur = (cur_def_msgs + 2) *
 389                                 (cur_def_msgsize + 2 * sizeof(void *));
 390                         cur_limits.rlim_max = 2 * cur_limits.rlim_cur;
 391                         setr(RLIMIT_MSGQUEUE, &cur_limits);
 392                 }
 393                 if (test_queue_fail(NULL, &result)) {
 394                         if (result.mq_maxmsg == cur_max_msgs &&
 395                             result.mq_msgsize == cur_max_msgsize)
 396                                 printf("Kernel properly limits default values "
 397                                        "to lesser of default/max:\t\tPASS\n");
 398                         else
 399                                 printf("Kernel does not properly set default "
 400                                        "queue parameters when\ndefaults > "
 401                                        "max:\t\t\t\t\t\t\t\tFAIL\n");
 402                 } else
 403                         printf("Kernel fails to open mq because defaults are "
 404                                "greater than maximums:\tFAIL\n");
 405                 set(def_msgs, --cur_def_msgs);
 406                 set(def_msgsize, --cur_def_msgsize);
 407                 cur_limits.rlim_cur = cur_limits.rlim_max = cur_def_msgs *
 408                         cur_def_msgsize;
 409                 setr(RLIMIT_MSGQUEUE, &cur_limits);
 410                 if (test_queue_fail(NULL, &result))
 411                         printf("Kernel creates queue even though defaults "
 412                                "would exceed\nrlimit setting:"
 413                                "\t\t\t\t\t\t\t\tFAIL\n");
 414                 else
 415                         printf("Kernel properly fails to create queue when "
 416                                "defaults would\nexceed rlimit:"
 417                                "\t\t\t\t\t\t\t\tPASS\n");
 418         }
 419
 420         /*
 421          * Test #2 - open with an attr struct that exceeds rlimit
 422          */
 423         printf("\n\nTest series 2, behavior when attr struct is "
 424                "passed to mq_open:\n");
 425         cur_max_msgs = 32;
 426         cur_max_msgsize = cur_limits.rlim_max >> 4;
 427         set(max_msgs, cur_max_msgs);
 428         set(max_msgsize, cur_max_msgsize);
 429         attr.mq_maxmsg = cur_max_msgs;
 430         attr.mq_msgsize = cur_max_msgsize;
 431         if (test_queue_fail(&attr, &result))
 432                 printf("Queue open in excess of rlimit max when euid = 0 "
 433                        "succeeded:\t\tFAIL\n");
 434         else
 435                 printf("Queue open in excess of rlimit max when euid = 0 "
 436                        "failed:\t\tPASS\n");
 437         attr.mq_maxmsg = cur_max_msgs + 1;
 438         attr.mq_msgsize = 10;
 439         if (test_queue_fail(&attr, &result))
 440                 printf("Queue open with mq_maxmsg > limit when euid = 0 "
 441                        "succeeded:\t\tPASS\n");
 442         else
 443                 printf("Queue open with mq_maxmsg > limit when euid = 0 "
 444                        "failed:\t\tFAIL\n");
 445         attr.mq_maxmsg = 1;
 446         attr.mq_msgsize = cur_max_msgsize + 1;
 447         if (test_queue_fail(&attr, &result))
 448                 printf("Queue open with mq_msgsize > limit when euid = 0 "
 449                        "succeeded:\t\tPASS\n");
 450         else
 451                 printf("Queue open with mq_msgsize > limit when euid = 0 "
 452                        "failed:\t\tFAIL\n");
 453         attr.mq_maxmsg = 65536;
 454         attr.mq_msgsize = 65536;
 455         if (test_queue_fail(&attr, &result))
 456                 printf("Queue open with total size > 2GB when euid = 0 "
 457                        "succeeded:\t\tFAIL\n");
 458         else
 459                 printf("Queue open with total size > 2GB when euid = 0 "
 460                        "failed:\t\t\tPASS\n");
 461
 462         if (seteuid(99) == -1) {
 463                 perror("seteuid() failed");
 464                 exit(1);
 465         }
 466
 467         attr.mq_maxmsg = cur_max_msgs;
 468         attr.mq_msgsize = cur_max_msgsize;
 469         if (test_queue_fail(&attr, &result))
 470                 printf("Queue open in excess of rlimit max when euid = 99 "
 471                        "succeeded:\t\tFAIL\n");
 472         else
 473                 printf("Queue open in excess of rlimit max when euid = 99 "
 474                        "failed:\t\tPASS\n");
 475         attr.mq_maxmsg = cur_max_msgs + 1;
 476         attr.mq_msgsize = 10;
 477         if (test_queue_fail(&attr, &result))
 478                 printf("Queue open with mq_maxmsg > limit when euid = 99 "
 479                        "succeeded:\t\tFAIL\n");
 480         else
 481                 printf("Queue open with mq_maxmsg > limit when euid = 99 "
 482                        "failed:\t\tPASS\n");
 483         attr.mq_maxmsg = 1;
 484         attr.mq_msgsize = cur_max_msgsize + 1;
 485         if (test_queue_fail(&attr, &result))
 486                 printf("Queue open with mq_msgsize > limit when euid = 99 "
 487                        "succeeded:\t\tFAIL\n");
 488         else
 489                 printf("Queue open with mq_msgsize > limit when euid = 99 "
 490                        "failed:\t\tPASS\n");
 491         attr.mq_maxmsg = 65536;
 492         attr.mq_msgsize = 65536;
 493         if (test_queue_fail(&attr, &result))
 494                 printf("Queue open with total size > 2GB when euid = 99 "
 495                        "succeeded:\t\tFAIL\n");
 496         else
 497                 printf("Queue open with total size > 2GB when euid = 99 "
 498                        "failed:\t\t\tPASS\n");
 499
 500         shutdown(0,"",0);
 501 }