/*
* 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>
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;
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;
seteuid(0);
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) {
fprintf(stderr, "Must pass a valid queue name\n\n");
fprintf(stderr, usage, argv[0]);
exit(1);
}
/*
* 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) {
fprintf(stderr, "Not running as root, but almost all tests "
"require root in order to modify\nsystem settings. "
"Exiting.\n");
exit(1);
}
/* 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%d\n", saved_limits.rlim_cur);
printf("\tRLIMIT_MSGQUEUE(hard):\t\t%d\n", 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%d\n", cur_limits.rlim_cur);
printf("\tRLIMIT_MSGQUEUE(hard):\t\t%d\n", 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");
seteuid(99);
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);
}