selftests: add mq_open_tests

Add a directory to house POSIX message queue subsystem specific tests.
Add first test which checks the operation of mq_open() under various
corner conditions.

Signed-off-by: Doug Ledford <dledford@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Joe Korty <joe.korty@ccur.com>
Cc: Amerigo Wang <amwang@redhat.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 501 insertions, 1 deletions

diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 28bc57ee757c..14972017a43e 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -1,4 +1,4 @@
-TARGETS = breakpoints vm
+TARGETS = breakpoints mqueue vm
 
 all:
         for TARGET in $(TARGETS); do \
diff --git a/tools/testing/selftests/mqueue/Makefile b/tools/testing/selftests/mqueue/Makefile
new file mode 100644
index 000000000000..bd74142a173f
--- /dev/null
+++ b/tools/testing/selftests/mqueue/Makefile
@@ -0,0 +1,8 @@
+all:
+        gcc -O2 -lrt mq_open_tests.c -o mq_open_tests
+
+run_tests:
+        ./mq_open_tests /test1
+
+clean:
+        rm -f mq_open_tests
diff --git a/tools/testing/selftests/mqueue/mq_open_tests.c b/tools/testing/selftests/mqueue/mq_open_tests.c
new file mode 100644
index 000000000000..711cc2923047
--- /dev/null
+++ b/tools/testing/selftests/mqueue/mq_open_tests.c
@@ -0,0 +1,492 @@
+/*
+ * 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);
+}