/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2022 Oxide Computer Company
 */

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
#include <dirent.h>
#include <port.h>
#include <err.h>
#include <assert.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <sys/poll.h>

/*
 * Attempt to trigger the #15036 regression.  This depends on a subsequent
 * allocation in the same slab setting a bit at a specific offset, so reliable
 * detection of the issue is a challenge.  This test uses brute force in its
 * attempt, but cannot guarantee to trigger the behavior on a system affected by
 * the issue.
 */

/*
 * We need regular files on a regular filesystem for fs_poll to be called.
 * Assume that we can find some in our own tests dir.
 *
 * As for repetitions, this is not especially consistent, so really hammer
 * things out of brute force.
 */
#define FILE_SRC        "/opt/os-tests/tests"
#define FILE_COUNT      10
#define TEST_REPEAT     10000

static uint_t
find_test_files(const char *dir, uint_t count, int *result_fds)
{
        assert(count > 0);

        DIR *dirp;

        dirp = opendir(dir);
        if (dirp == NULL) {
                return (0);
        }

        dirent_t *de;
        uint_t nvalid = 0;
        while ((de = readdir(dirp)) != NULL) {
                char path[MAXPATHLEN];
                struct stat st;

                (void) snprintf(path, sizeof (path), "%s/%s", dir, de->d_name);
                if (lstat(path, &st) != 0 || (st.st_mode & S_IFREG) == 0) {
                        continue;
                }
                result_fds[nvalid] = open(path, O_RDONLY, 0);
                if (result_fds[nvalid] < 0) {
                        continue;
                }

                nvalid++;
                if (nvalid == count) {
                        break;
                }
        }

        (void) closedir(dirp);
        return (nvalid);
}

int
main(int argc, char *argv[])
{
        int poll_fds[FILE_COUNT];

        if (find_test_files(FILE_SRC, FILE_COUNT, poll_fds) != FILE_COUNT) {
                errx(EXIT_FAILURE, "FAIL - count not open test files to poll");
        }

        for (uint_t i = 0; i < TEST_REPEAT; i++) {
                int port_fds[FILE_COUNT];

                for (uint_t j = 0; j < FILE_COUNT; j++) {
                        port_fds[j] = port_create();
                        if (port_fds[j] < 0) {
                                err(EXIT_FAILURE, "FAIL - port_create()");
                        }

                        int res = port_associate(port_fds[j], PORT_SOURCE_FD,
                            (uintptr_t)poll_fds[j], POLLIN, NULL);
                        if (res != 0) {
                                err(EXIT_FAILURE, "FAIL - port_associate()");
                        }
                }

                for (uint_t j = 0; j < FILE_COUNT; j++) {
                        int res = port_dissociate(port_fds[j], PORT_SOURCE_FD,
                            (uintptr_t)poll_fds[j]);
                        if (res != 0) {
                                err(EXIT_FAILURE, "FAIL - port_dissociate()");
                        }
                        (void) close(port_fds[j]);
                }
        }

        (void) printf("PASS\n");
        return (EXIT_SUCCESS);
}