Quelle  mq_open_tests.c   Sprache: C

/*
 * This application is Copyright 2012 Red Hat, Inc.
 * Doug Ledford <dledford@redhat.com>
 *
 * mq_open_tests is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 3.
 *
 * mq_open_tests is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * For the full text of the license, see <http://www.gnu.org/licenses/>.
 *
 * mq_open_tests.c
 *   Tests the various situations that should either succeed or fail to
 *   open a posix message queue and then reports whether or not they
 *   did as they were supposed to.
 *
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <limits.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <mqueue.h>
#include <error.h>

#include "../kselftest.h"

static char *usage =
"Usage:\n"
" %s path\n"
"\n"
" path Path name of the message queue to create\n"
"\n"
" Note: this program must be run as root in order to enable all tests\n"
"\n";

char *DEF_MSGS = "/proc/sys/fs/mqueue/msg_default";
char *DEF_MSGSIZE = "/proc/sys/fs/mqueue/msgsize_default";
char *MAX_MSGS = "/proc/sys/fs/mqueue/msg_max";
char *MAX_MSGSIZE = "/proc/sys/fs/mqueue/msgsize_max";

int default_settings;
struct rlimit saved_limits, cur_limits;
int saved_def_msgs, saved_def_msgsize, saved_max_msgs, saved_max_msgsize;
int cur_def_msgs, cur_def_msgsize, cur_max_msgs, cur_max_msgsize;
FILE *def_msgs, *def_msgsize, *max_msgs, *max_msgsize;
char *queue_path;
char *default_queue_path = "/test1";
mqd_t queue = -1;

static inline void __set(FILE *stream, int value, char *err_msg);
void shutdown(int exit_val, char *err_cause, int line_no);
static inline int get(FILE *stream);
static inline void set(FILE *stream, int value);
static inline void getr(int type, struct rlimit *rlim);
static inline void setr(int type, struct rlimit *rlim);
void validate_current_settings();
static inline void test_queue(struct mq_attr *attr, struct mq_attr *result);
static inline int test_queue_fail(struct mq_attr *attr, struct mq_attr *result);

static inline void __set(FILE *stream, int value, char *err_msg)
{
 rewind(stream);
 if (fprintf(stream, "%d", value) < 0)
  perror(err_msg);
}


void shutdown(int exit_val, char *err_cause, int line_no)
{
 static int in_shutdown = 0;

 /* In case we get called recursively by a set() call below */
 if (in_shutdown++)
  return;

 if (seteuid(0) == -1)
  perror("seteuid() failed");

 if (queue != -1)
  if (mq_close(queue))
   perror("mq_close() during shutdown");
 if (queue_path)
  /*
 * Be silent if this fails, if we cleaned up already it's
 * expected to fail
 */
  mq_unlink(queue_path);
 if (default_settings) {
  if (saved_def_msgs)
   __set(def_msgs, saved_def_msgs,
         "failed to restore saved_def_msgs");
  if (saved_def_msgsize)
   __set(def_msgsize, saved_def_msgsize,
         "failed to restore saved_def_msgsize");
 }
 if (saved_max_msgs)
  __set(max_msgs, saved_max_msgs,
        "failed to restore saved_max_msgs");
 if (saved_max_msgsize)
  __set(max_msgsize, saved_max_msgsize,
        "failed to restore saved_max_msgsize");
 if (exit_val)
  error(exit_val, errno, "%s at %d", err_cause, line_no);
 exit(0);
}

static inline int get(FILE *stream)
{
 int value;
 rewind(stream);
 if (fscanf(stream, "%d", &value) != 1)
  shutdown(4, "Error reading /proc entry", __LINE__ - 1);
 return value;
}

static inline void set(FILE *stream, int value)
{
 int new_value;

 rewind(stream);
 if (fprintf(stream, "%d", value) < 0)
  return shutdown(5, "Failed writing to /proc file",
    __LINE__ - 1);
 new_value = get(stream);
 if (new_value != value)
  return shutdown(5, "We didn't get what we wrote to /proc back",
    __LINE__ - 1);
}

static inline void getr(int type, struct rlimit *rlim)
{
 if (getrlimit(type, rlim))
  shutdown(6, "getrlimit()", __LINE__ - 1);
}

static inline void setr(int type, struct rlimit *rlim)
{
 if (setrlimit(type, rlim))
  shutdown(7, "setrlimit()", __LINE__ - 1);
}

void validate_current_settings()
{
 int rlim_needed;

 if (cur_limits.rlim_cur < 4096) {
  printf("Current rlimit value for POSIX message queue bytes is "
         "unreasonably low,\nincreasing.\n\n");
  cur_limits.rlim_cur = 8192;
  cur_limits.rlim_max = 16384;
  setr(RLIMIT_MSGQUEUE, &cur_limits);
 }

 if (default_settings) {
  rlim_needed = (cur_def_msgs + 1) * (cur_def_msgsize + 1 +
          2 * sizeof(void *));
  if (rlim_needed > cur_limits.rlim_cur) {
   printf("Temporarily lowering default queue parameters "
          "to something that will work\n"
          "with the current rlimit values.\n\n");
   set(def_msgs, 10);
   cur_def_msgs = 10;
   set(def_msgsize, 128);
   cur_def_msgsize = 128;
  }
 } else {
  rlim_needed = (cur_max_msgs + 1) * (cur_max_msgsize + 1 +
          2 * sizeof(void *));
  if (rlim_needed > cur_limits.rlim_cur) {
   printf("Temporarily lowering maximum queue parameters "
          "to something that will work\n"
          "with the current rlimit values in case this is "
          "a kernel that ties the default\n"
          "queue parameters to the maximum queue "
          "parameters.\n\n");
   set(max_msgs, 10);
   cur_max_msgs = 10;
   set(max_msgsize, 128);
   cur_max_msgsize = 128;
  }
 }
}

/*
 * test_queue - Test opening a queue, shutdown if we fail.  This should
 * only be called in situations that should never fail.  We clean up
 * after ourselves and return the queue attributes in *result.
 */
static inline void test_queue(struct mq_attr *attr, struct mq_attr *result)
{
 int flags = O_RDWR | O_EXCL | O_CREAT;
 int perms = DEFFILEMODE;

 if ((queue = mq_open(queue_path, flags, perms, attr)) == -1)
  shutdown(1, "mq_open()", __LINE__);
 if (mq_getattr(queue, result))
  shutdown(1, "mq_getattr()", __LINE__);
 if (mq_close(queue))
  shutdown(1, "mq_close()", __LINE__);
 queue = -1;
 if (mq_unlink(queue_path))
  shutdown(1, "mq_unlink()", __LINE__);
}

/*
 * Same as test_queue above, but failure is not fatal.
 * Returns:
 * 0 - Failed to create a queue
 * 1 - Created a queue, attributes in *result
 */
static inline int test_queue_fail(struct mq_attr *attr, struct mq_attr *result)
{
 int flags = O_RDWR | O_EXCL | O_CREAT;
 int perms = DEFFILEMODE;

 if ((queue = mq_open(queue_path, flags, perms, attr)) == -1)
  return 0;
 if (mq_getattr(queue, result))
  shutdown(1, "mq_getattr()", __LINE__);
 if (mq_close(queue))
  shutdown(1, "mq_close()", __LINE__);
 queue = -1;
 if (mq_unlink(queue_path))
  shutdown(1, "mq_unlink()", __LINE__);
 return 1;
}

int main(int argc, char *argv[])
{
 struct mq_attr attr, result;

 if (argc != 2) {
  printf("Using Default queue path - %s\n", default_queue_path);
  queue_path = default_queue_path;
 } else {

 /*
 * Although we can create a msg queue with a non-absolute path name,
 * unlink will fail.  So, if the name doesn't start with a /, add one
 * when we save it.
 */
  if (*argv[1] == '/')
   queue_path = strdup(argv[1]);
  else {
   queue_path = malloc(strlen(argv[1]) + 2);
   if (!queue_path) {
    perror("malloc()");
    exit(1);
   }
   queue_path[0] = '/';
   queue_path[1] = 0;
   strcat(queue_path, argv[1]);
  }
 }

 if (getuid() != 0)
  ksft_exit_skip("Not running as root, but almost all tests "
   "require root in order to modify\nsystem settings. "
   "Exiting.\n");

 /* Find out what files there are for us to make tweaks in */
 def_msgs = fopen(DEF_MSGS, "r+");
 def_msgsize = fopen(DEF_MSGSIZE, "r+");
 max_msgs = fopen(MAX_MSGS, "r+");
 max_msgsize = fopen(MAX_MSGSIZE, "r+");

 if (!max_msgs)
  shutdown(2, "Failed to open msg_max", __LINE__);
 if (!max_msgsize)
  shutdown(2, "Failed to open msgsize_max", __LINE__);
 if (def_msgs || def_msgsize)
  default_settings = 1;

 /* Load up the current system values for everything we can */
 getr(RLIMIT_MSGQUEUE, &saved_limits);
 cur_limits = saved_limits;
 if (default_settings) {
  saved_def_msgs = cur_def_msgs = get(def_msgs);
  saved_def_msgsize = cur_def_msgsize = get(def_msgsize);
 }
 saved_max_msgs = cur_max_msgs = get(max_msgs);
 saved_max_msgsize = cur_max_msgsize = get(max_msgsize);

 /* Tell the user our initial state */
 printf("\nInitial system state:\n");
 printf("\tUsing queue path:\t\t%s\n", queue_path);
 printf("\tRLIMIT_MSGQUEUE(soft):\t\t%ld\n",
  (long) saved_limits.rlim_cur);
 printf("\tRLIMIT_MSGQUEUE(hard):\t\t%ld\n",
  (long) saved_limits.rlim_max);
 printf("\tMaximum Message Size:\t\t%d\n", saved_max_msgsize);
 printf("\tMaximum Queue Size:\t\t%d\n", saved_max_msgs);
 if (default_settings) {
  printf("\tDefault Message Size:\t\t%d\n", saved_def_msgsize);
  printf("\tDefault Queue Size:\t\t%d\n", saved_def_msgs);
 } else {
  printf("\tDefault Message Size:\t\tNot Supported\n");
  printf("\tDefault Queue Size:\t\tNot Supported\n");
 }
 printf("\n");

 validate_current_settings();

 printf("Adjusted system state for testing:\n");
 printf("\tRLIMIT_MSGQUEUE(soft):\t\t%ld\n", (long) cur_limits.rlim_cur);
 printf("\tRLIMIT_MSGQUEUE(hard):\t\t%ld\n", (long) cur_limits.rlim_max);
 printf("\tMaximum Message Size:\t\t%d\n", cur_max_msgsize);
 printf("\tMaximum Queue Size:\t\t%d\n", cur_max_msgs);
 if (default_settings) {
  printf("\tDefault Message Size:\t\t%d\n", cur_def_msgsize);
  printf("\tDefault Queue Size:\t\t%d\n", cur_def_msgs);
 }

 printf("\n\nTest series 1, behavior when no attr struct "
        "passed to mq_open:\n");
 if (!default_settings) {
  test_queue(NULL, &result);
  printf("Given sane system settings, mq_open without an attr "
         "struct succeeds:\tPASS\n");
  if (result.mq_maxmsg != cur_max_msgs ||
      result.mq_msgsize != cur_max_msgsize) {
   printf("Kernel does not support setting the default "
          "mq attributes,\nbut also doesn't tie the "
          "defaults to the maximums:\t\t\tPASS\n");
  } else {
   set(max_msgs, ++cur_max_msgs);
   set(max_msgsize, ++cur_max_msgsize);
   test_queue(NULL, &result);
   if (result.mq_maxmsg == cur_max_msgs &&
       result.mq_msgsize == cur_max_msgsize)
    printf("Kernel does not support setting the "
           "default mq attributes and\n"
           "also ties system wide defaults to "
           "the system wide maximums:\t\t"
           "FAIL\n");
   else
    printf("Kernel does not support setting the "
           "default mq attributes,\n"
           "but also doesn't tie the defaults to "
           "the maximums:\t\t\tPASS\n");
  }
 } else {
  printf("Kernel supports setting defaults separately from "
         "maximums:\t\tPASS\n");
  /*
 * While we are here, go ahead and test that the kernel
 * properly follows the default settings
 */
  test_queue(NULL, &result);
  printf("Given sane values, mq_open without an attr struct "
         "succeeds:\t\tPASS\n");
  if (result.mq_maxmsg != cur_def_msgs ||
      result.mq_msgsize != cur_def_msgsize)
   printf("Kernel supports setting defaults, but does "
          "not actually honor them:\tFAIL\n\n");
  else {
   set(def_msgs, ++cur_def_msgs);
   set(def_msgsize, ++cur_def_msgsize);
   /* In case max was the same as the default */
   set(max_msgs, ++cur_max_msgs);
   set(max_msgsize, ++cur_max_msgsize);
   test_queue(NULL, &result);
   if (result.mq_maxmsg != cur_def_msgs ||
       result.mq_msgsize != cur_def_msgsize)
    printf("Kernel supports setting defaults, but "
           "does not actually honor them:\t"
           "FAIL\n");
   else
    printf("Kernel properly honors default setting "
           "knobs:\t\t\t\tPASS\n");
  }
  set(def_msgs, cur_max_msgs + 1);
  cur_def_msgs = cur_max_msgs + 1;
  set(def_msgsize, cur_max_msgsize + 1);
  cur_def_msgsize = cur_max_msgsize + 1;
  if (cur_def_msgs * (cur_def_msgsize + 2 * sizeof(void *)) >=
      cur_limits.rlim_cur) {
   cur_limits.rlim_cur = (cur_def_msgs + 2) *
    (cur_def_msgsize + 2 * sizeof(void *));
   cur_limits.rlim_max = 2 * cur_limits.rlim_cur;
   setr(RLIMIT_MSGQUEUE, &cur_limits);
  }
  if (test_queue_fail(NULL, &result)) {
   if (result.mq_maxmsg == cur_max_msgs &&
       result.mq_msgsize == cur_max_msgsize)
    printf("Kernel properly limits default values "
           "to lesser of default/max:\t\tPASS\n");
   else
    printf("Kernel does not properly set default "
           "queue parameters when\ndefaults > "
           "max:\t\t\t\t\t\t\t\tFAIL\n");
  } else
   printf("Kernel fails to open mq because defaults are "
          "greater than maximums:\tFAIL\n");
  set(def_msgs, --cur_def_msgs);
  set(def_msgsize, --cur_def_msgsize);
  cur_limits.rlim_cur = cur_limits.rlim_max = cur_def_msgs *
   cur_def_msgsize;
  setr(RLIMIT_MSGQUEUE, &cur_limits);
  if (test_queue_fail(NULL, &result))
   printf("Kernel creates queue even though defaults "
          "would exceed\nrlimit setting:"
          "\t\t\t\t\t\t\t\tFAIL\n");
  else
   printf("Kernel properly fails to create queue when "
          "defaults would\nexceed rlimit:"
          "\t\t\t\t\t\t\t\tPASS\n");
 }

 /*
 * Test #2 - open with an attr struct that exceeds rlimit
 */
 printf("\n\nTest series 2, behavior when attr struct is "
        "passed to mq_open:\n");
 cur_max_msgs = 32;
 cur_max_msgsize = cur_limits.rlim_max >> 4;
 set(max_msgs, cur_max_msgs);
 set(max_msgsize, cur_max_msgsize);
 attr.mq_maxmsg = cur_max_msgs;
 attr.mq_msgsize = cur_max_msgsize;
 if (test_queue_fail(&attr, &result))
  printf("Queue open in excess of rlimit max when euid = 0 "
         "succeeded:\t\tFAIL\n");
 else
  printf("Queue open in excess of rlimit max when euid = 0 "
         "failed:\t\tPASS\n");
 attr.mq_maxmsg = cur_max_msgs + 1;
 attr.mq_msgsize = 10;
 if (test_queue_fail(&attr, &result))
  printf("Queue open with mq_maxmsg > limit when euid = 0 "
         "succeeded:\t\tPASS\n");
 else
  printf("Queue open with mq_maxmsg > limit when euid = 0 "
         "failed:\t\tFAIL\n");
 attr.mq_maxmsg = 1;
 attr.mq_msgsize = cur_max_msgsize + 1;
 if (test_queue_fail(&attr, &result))
  printf("Queue open with mq_msgsize > limit when euid = 0 "
         "succeeded:\t\tPASS\n");
 else
  printf("Queue open with mq_msgsize > limit when euid = 0 "
         "failed:\t\tFAIL\n");
 attr.mq_maxmsg = 65536;
 attr.mq_msgsize = 65536;
 if (test_queue_fail(&attr, &result))
  printf("Queue open with total size > 2GB when euid = 0 "
         "succeeded:\t\tFAIL\n");
 else
  printf("Queue open with total size > 2GB when euid = 0 "
         "failed:\t\t\tPASS\n");

 if (seteuid(99) == -1) {
  perror("seteuid() failed");
  exit(1);
 }

 attr.mq_maxmsg = cur_max_msgs;
 attr.mq_msgsize = cur_max_msgsize;
 if (test_queue_fail(&attr, &result))
  printf("Queue open in excess of rlimit max when euid = 99 "
         "succeeded:\t\tFAIL\n");
 else
  printf("Queue open in excess of rlimit max when euid = 99 "
         "failed:\t\tPASS\n");
 attr.mq_maxmsg = cur_max_msgs + 1;
 attr.mq_msgsize = 10;
 if (test_queue_fail(&attr, &result))
  printf("Queue open with mq_maxmsg > limit when euid = 99 "
         "succeeded:\t\tFAIL\n");
 else
  printf("Queue open with mq_maxmsg > limit when euid = 99 "
         "failed:\t\tPASS\n");
 attr.mq_maxmsg = 1;
 attr.mq_msgsize = cur_max_msgsize + 1;
 if (test_queue_fail(&attr, &result))
  printf("Queue open with mq_msgsize > limit when euid = 99 "
         "succeeded:\t\tFAIL\n");
 else
  printf("Queue open with mq_msgsize > limit when euid = 99 "
         "failed:\t\tPASS\n");
 attr.mq_maxmsg = 65536;
 attr.mq_msgsize = 65536;
 if (test_queue_fail(&attr, &result))
  printf("Queue open with total size > 2GB when euid = 99 "
         "succeeded:\t\tFAIL\n");
 else
  printf("Queue open with total size > 2GB when euid = 99 "
         "failed:\t\t\tPASS\n");

 shutdown(0,"",0);
}