/*-
 * Copyright (c) 2005 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/types.h>
#include <sys/socket.h>

#include <netinet/in.h>

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

/*
 * This regression test is intended to verify whether or not SIGPIPE is
 * properly generated in several simple test cases, as well as testing
 * whether SO_NOSIGPIPE disables SIGPIPE, if available on the system.
 * SIGPIPE is generated if a write or send is attempted on a socket that has
 * been shutdown for write.  This test runs several test cases with UNIX
 * domain sockets and TCP sockets to confirm that either EPIPE or SIGPIPE is
 * properly returned.
 *
 * For the purposes of testing TCP, an unused port number must be specified.
 */
static void
usage(void)
{

        errx(-1, "usage: sigpipe tcpport");
}

/*
 * Signal catcher.  Set a global flag that can be tested by the caller.
 */
static int signaled;
static int
got_signal(void)
{

        return (signaled);
}

static void
signal_handler(int signum __unused)
{

        signaled = 1;
}

static void
signal_setup(const char *testname)
{

        signaled = 0;
        if (signal(SIGPIPE, signal_handler) == SIG_ERR)
                err(-1, "%s: signal(SIGPIPE)", testname);
}

static void
test_send(const char *testname, int sock)
{
        ssize_t len;
        char ch;

        ch = 0;
        len = send(sock, &ch, sizeof(ch), 0);
        if (len < 0) {
                if (errno == EPIPE)
                        return;
                err(-1, "%s: send", testname);
        }
        errx(-1, "%s: send: returned %zd", testname, len);
}

static void
test_write(const char *testname, int sock)
{
        ssize_t len;
        char ch;

        ch = 0;
        len = write(sock, &ch, sizeof(ch));
        if (len < 0) {
                if (errno == EPIPE)
                        return;
                err(-1, "%s: write", testname);
        }
        errx(-1, "%s: write: returned %zd", testname, len);
}

static void
test_send_wantsignal(const char *testname, int sock1, int sock2)
{

        if (shutdown(sock2, SHUT_WR) < 0)
                err(-1, "%s: shutdown", testname);
        signal_setup(testname);
        test_send(testname, sock2);
        if (!got_signal())
                errx(-1, "%s: send: didn't receive SIGPIPE", testname);
        close(sock1);
        close(sock2);
}

#ifdef SO_NOSIGPIPE
static void
test_send_dontsignal(const char *testname, int sock1, int sock2)
{
        int i;

        i = 1;
        if (setsockopt(sock2, SOL_SOCKET, SO_NOSIGPIPE, &i, sizeof(i)) < 0)
                err(-1, "%s: setsockopt(SOL_SOCKET, SO_NOSIGPIPE)", testname);
        if (shutdown(sock2, SHUT_WR) < 0)
                err(-1, "%s: shutdown", testname);
        signal_setup(testname);
        test_send(testname, sock2);
        if (got_signal())
                errx(-1, "%s: send: got SIGPIPE", testname);
        close(sock1);
        close(sock2);
}
#endif

static void
test_write_wantsignal(const char *testname, int sock1, int sock2)
{

        if (shutdown(sock2, SHUT_WR) < 0)
                err(-1, "%s: shutdown", testname);
        signal_setup(testname);
        test_write(testname, sock2);
        if (!got_signal())
                errx(-1, "%s: write: didn't receive SIGPIPE", testname);
        close(sock1);
        close(sock2);
}

#ifdef SO_NOSIGPIPE
static void
test_write_dontsignal(const char *testname, int sock1, int sock2)
{
        int i;

        i = 1;
        if (setsockopt(sock2, SOL_SOCKET, SO_NOSIGPIPE, &i, sizeof(i)) < 0)
                err(-1, "%s: setsockopt(SOL_SOCKET, SO_NOSIGPIPE)", testname);
        if (shutdown(sock2, SHUT_WR) < 0)
                err(-1, "%s: shutdown", testname);
        signal_setup(testname);
        test_write(testname, sock2);
        if (got_signal())
                errx(-1, "%s: write: got SIGPIPE", testname);
        close(sock1);
        close(sock2);
}
#endif

static int listen_sock;
static void
tcp_setup(u_short port)
{
        struct sockaddr_in sin;

        listen_sock = socket(PF_INET, SOCK_STREAM, 0);
        if (listen_sock < 0)
                err(-1, "tcp_setup: listen");

        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(port);

        if (bind(listen_sock, (struct sockaddr *)&sin, sizeof(sin)) < 0)
                err(-1, "tcp_setup: bind");

        if (listen(listen_sock, -1) < 0)
                err(-1, "tcp_setup: listen");
}

static void
tcp_teardown(void)
{

        close(listen_sock);
}

static void
tcp_pair(u_short port, int sock[2])
{
        int accept_sock, connect_sock;
        struct sockaddr_in sin;
        socklen_t len;

        connect_sock = socket(PF_INET, SOCK_STREAM, 0);
        if (connect_sock < 0)
                err(-1, "tcp_pair: socket");

        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(port);

        if (connect(connect_sock, (struct sockaddr *)&sin, sizeof(sin)) < 0)
                err(-1, "tcp_pair: connect");

        sleep(1);                               /* Time for TCP to settle. */

        len = sizeof(sin);
        accept_sock = accept(listen_sock, (struct sockaddr *)&sin, &len);
        if (accept_sock < 0)
                err(-1, "tcp_pair: accept");

        sleep(1);                               /* Time for TCP to settle. */

        sock[0] = accept_sock;
        sock[1] = connect_sock;
}

int
main(int argc, char *argv[])
{
        char *dummy;
        int sock[2];
        long port;

        if (argc != 2)
                usage();

        port = strtol(argv[1], &dummy, 10);
        if (port < 0 || port > 65535 || *dummy != '\0')
                usage();

#ifndef SO_NOSIGPIPE
        warnx("sigpipe: SO_NOSIGPIPE not defined, skipping some tests");
#endif

        /*
         * UNIX domain socketpair().
         */
        if (socketpair(PF_LOCAL, SOCK_STREAM, 0, sock) < 0)
                err(-1, "socketpair(PF_LOCAL, SOCK_STREAM)");
        test_send_wantsignal("test_send_wantsignal(PF_LOCAL)", sock[0],
            sock[1]);

#ifdef SO_NOSIGPIPE
        if (socketpair(PF_LOCAL, SOCK_STREAM, 0, sock) < 0)
                err(-1, "socketpair(PF_LOCAL, SOCK_STREAM)");
        test_send_dontsignal("test_send_dontsignal(PF_LOCAL)", sock[0],
            sock[1]);
#endif

        if (socketpair(PF_LOCAL, SOCK_STREAM, 0, sock) < 0)
                err(-1, "socketpair(PF_LOCAL, SOCK_STREAM)");
        test_write_wantsignal("test_write_wantsignal(PF_LOCAL)", sock[0],
            sock[1]);

#ifdef SO_NOSIGPIPE
        if (socketpair(PF_LOCAL, SOCK_STREAM, 0, sock) < 0)
                err(-1, "socketpair(PF_LOCAL, SOCK_STREAM)");
        test_write_dontsignal("test_write_dontsignal(PF_LOCAL)", sock[0],
            sock[1]);
#endif

        /*
         * TCP.
         */
        tcp_setup(port);
        tcp_pair(port, sock);
        test_send_wantsignal("test_send_wantsignal(PF_INET)", sock[0],
            sock[1]);

#ifdef SO_NOSIGPIPE
        tcp_pair(port, sock);
        test_send_dontsignal("test_send_dontsignal(PF_INET)", sock[0],
            sock[1]);
#endif

        tcp_pair(port, sock);
        test_write_wantsignal("test_write_wantsignal(PF_INET)", sock[0],
            sock[1]);

#ifdef SO_NOSIGPIPE
        tcp_pair(port, sock);
        test_write_dontsignal("test_write_dontsignal(PF_INET)", sock[0],
            sock[1]);
#endif
        tcp_teardown();

        fprintf(stderr, "PASS\n");
        return (0);
}