/*-
 * Copyright (c) 2004 Robert N. M. Watson
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/socket.h>
#include <sys/wait.h>

#include <netinet/in.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define BIND_ATTEMPTS   10
#define LOOPS   500
#define NUM_ATTEMPTS    1000

static volatile int quit;

static void
child_died(int sig __unused)
{

        quit = 1;
}

/*
 * This test is intended to detect a leak of a file descriptor in the process
 * following a failed non-blocking accept.  It measures an available fd
 * baseline, then performs 1000 failing accepts, then checks to see what the
 * next fd is.  It relies on sequential fd allocation, and will test for it
 * briefly before beginning (not 100% reliable, but a good start).
 */
int
main(void)
{
        struct sockaddr_in sin;
        socklen_t size;
        pid_t child;
        int fd1, fd2, fd3, i, listen_port, s, status;

        printf("1..2\n");

        /*
         * Check for sequential fd allocation, and give up early if not.
         */
        fd1 = dup(STDIN_FILENO);
        fd2 = dup(STDIN_FILENO);
        if (fd2 != fd1 + 1)
                errx(-1, "Non-sequential fd allocation\n");

        s = socket(PF_INET, SOCK_STREAM, 0);
        if (s == -1)
                errx(-1, "socket: %s", strerror(errno));

        bzero(&sin, sizeof(sin));
        sin.sin_len = sizeof(sin);
        sin.sin_family = AF_INET;
        sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);

        srandomdev();

        for (i = 0; i < BIND_ATTEMPTS; i++) {
                /* Pick a random unprivileged port 1025-65535 */
                listen_port = MAX((int)random() % 65535, 1025);
                sin.sin_port = htons(listen_port);
                if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) == 0)
                        break;
                warn("bind with %d failed", listen_port);
                usleep(1000);
        }
        if (i >= BIND_ATTEMPTS) {
                printf("Bail out!\n");
                exit(1);
        }

        if (listen(s, -1) != 0)
                errx(-1, "listen: %s", strerror(errno));

        i = fcntl(s, F_GETFL);
        if (i == -1)
                errx(-1, "ioctl(F_GETFL): %s", strerror(errno));
        i |= O_NONBLOCK;
        if (fcntl(s, F_SETFL, i) != 0)
                errx(-1, "ioctl(F_SETFL): %s", strerror(errno));
        i = fcntl(s, F_GETFL);
        if (i == -1)
                errx(-1, "ioctl(F_GETFL): %s", strerror(errno));
        if ((i & O_NONBLOCK) != O_NONBLOCK)
                errx(-1, "Failed to set O_NONBLOCK (i=0x%x)\n", i);

        for (i = 0; i < LOOPS; i++) {
                size = sizeof(sin);
                if (accept(s, (struct sockaddr *)&sin, &size) != -1)
                        errx(-1, "accept succeeded\n");
                if (errno != EAGAIN)
                        errx(-1, "accept: %s", strerror(errno));
        }

        /*
         * Allocate a file descriptor and make sure it's fd2+2.  2 because
         * we allocate an fd for the socket.
         */
        fd3 = dup(STDIN_FILENO);
        if (fd3 != fd2 + 2)
                printf("not ok 1 - (%d, %d, %d)\n", fd1, fd2, fd3);
        else
                printf("ok 1\n");

        /*
         * Try failing accept's w/o non-blocking where the destination
         * address pointer is invalid.
         */
        close(fd3);
        signal(SIGCHLD, child_died);
        child = fork();
        if (child < 0)
                errx(-1, "fork: %s", strerror(errno));

        /*
         * Child process does `NUM_ATTEMPTS` connects.
         */
        if (child == 0) {
                close(fd1);
                close(fd2);
                close(s);

                bzero(&sin, sizeof(sin));
                sin.sin_len = sizeof(sin);
                sin.sin_family = AF_INET;
                sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
                sin.sin_port = htons(listen_port);

                for (i = 0; i < NUM_ATTEMPTS; i++) {
                        s = socket(PF_INET, SOCK_STREAM, 0);
                        if (s == -1)
                                errx(-1, "socket: %s", strerror(errno));
                        if (connect(s, (struct sockaddr *)&sin,
                            sizeof(sin)) < 0)
                                errx(-1, "connect: %s", strerror(errno));
                        close(s);
                }
                _exit(0);
        }

        /* Reset back to a blocking socket. */
        i = fcntl(s, F_GETFL);
        if (i == -1)
                errx(-1, "ioctl(F_GETFL): %s", strerror(errno));
        i &= ~O_NONBLOCK;
        if (fcntl(s, F_SETFL, i) != 0)
                errx(-1, "ioctl(F_SETFL): %s", strerror(errno));
        i = fcntl(s, F_GETFL);
        if (i == -1)
                errx(-1, "ioctl(F_GETFL): %s", strerror(errno));
        if (i & O_NONBLOCK)
                errx(-1, "Failed to clear O_NONBLOCK (i=0x%x)\n", i);

        /* Do `NUM_ATTEMPTS` accepts with an invalid pointer. */
        for (i = 0; !quit && i < NUM_ATTEMPTS; i++) {
                size = sizeof(sin);
                if (accept(s, (struct sockaddr *)(uintptr_t)(0x100),
                    &size) != -1)
                        errx(-1, "accept succeeded\n");
                if (errno != EFAULT)
                        errx(-1, "accept: %s", strerror(errno));
        }

        if (waitpid(child, &status, 0) < 0)
                errx(-1, "waitpid: %s", strerror(errno));
        if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
                warnx("child process died");

        /*
         * Allocate a file descriptor and make sure it's fd2+2.  2 because
         * we allocate an fd for the socket.
         */
        fd3 = dup(STDIN_FILENO);
        if (fd3 != fd2 + 2)
                printf("not ok 2 - (%d, %d, %d)\n", fd1, fd2, fd3);
        else
                printf("ok 2\n");

        return (0);
}