/*-
 * Copyright (c) 2018 The FreeBSD Foundation
 *
 * This software was developed by Mark Johnston under sponsorship from
 * the FreeBSD Foundation.
 *
 * 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/event.h>
#include <sys/filio.h>
#include <sys/ioccom.h>
#include <sys/socket.h>

#include <netinet/in.h>
#include <netinet/tcp.h>

#include <err.h>
#include <errno.h>
#include <pthread.h>
#include <stdatomic.h>
#include <stdlib.h>
#include <unistd.h>

#include <atf-c.h>

/*
 * Given an array of non-blocking listening sockets configured in a LB group
 * for "addr", try connecting to "addr" in a loop and verify that connections
 * are roughly balanced across the sockets.
 */
static void
lb_simple_accept_loop(int domain, const struct sockaddr *addr, int sds[],
    size_t nsds, int nconns)
{
        size_t i;
        int *acceptcnt;
        int csd, error, excnt, sd;
        const struct linger lopt = { 1, 0 };

        /*
         * We expect each listening socket to accept roughly nconns/nsds
         * connections, but allow for some error.
         */
        excnt = nconns / nsds / 8;
        acceptcnt = calloc(nsds, sizeof(*acceptcnt));
        ATF_REQUIRE_MSG(acceptcnt != NULL, "calloc() failed: %s",
            strerror(errno));

        while (nconns-- > 0) {
                sd = socket(domain, SOCK_STREAM, 0);
                ATF_REQUIRE_MSG(sd >= 0, "socket() failed: %s",
                    strerror(errno));

                error = connect(sd, addr, addr->sa_len);
                ATF_REQUIRE_MSG(error == 0, "connect() failed: %s",
                    strerror(errno));

                error = setsockopt(sd, SOL_SOCKET, SO_LINGER, &lopt, sizeof(lopt));
                ATF_REQUIRE_MSG(error == 0, "Setting linger failed: %s",
                    strerror(errno));

                /*
                 * Poll the listening sockets.
                 */
                do {
                        for (i = 0; i < nsds; i++) {
                                csd = accept(sds[i], NULL, NULL);
                                if (csd < 0) {
                                        ATF_REQUIRE_MSG(errno == EWOULDBLOCK ||
                                            errno == EAGAIN,
                                            "accept() failed: %s",
                                            strerror(errno));
                                        continue;
                                }

                                error = close(csd);
                                ATF_REQUIRE_MSG(error == 0,
                                    "close() failed: %s", strerror(errno));

                                acceptcnt[i]++;
                                break;
                        }
                } while (i == nsds);

                error = close(sd);
                ATF_REQUIRE_MSG(error == 0, "close() failed: %s",
                    strerror(errno));
        }

        for (i = 0; i < nsds; i++)
                ATF_REQUIRE_MSG(acceptcnt[i] > excnt, "uneven balancing");
}

static int
lb_listen_socket(int domain, int flags)
{
        int one;
        int error, sd;

        sd = socket(domain, SOCK_STREAM | flags, 0);
        ATF_REQUIRE_MSG(sd >= 0, "socket() failed: %s", strerror(errno));

        one = 1;
        error = setsockopt(sd, SOL_SOCKET, SO_REUSEPORT_LB, &one, sizeof(one));
        ATF_REQUIRE_MSG(error == 0, "setsockopt(SO_REUSEPORT_LB) failed: %s",
            strerror(errno));

        return (sd);
}

ATF_TC_WITHOUT_HEAD(basic_ipv4);
ATF_TC_BODY(basic_ipv4, tc)
{
        struct sockaddr_in addr;
        socklen_t slen;
        size_t i;
        const int nconns = 16384;
        int error, sds[16];
        uint16_t port;

        sds[0] = lb_listen_socket(PF_INET, SOCK_NONBLOCK);

        memset(&addr, 0, sizeof(addr));
        addr.sin_len = sizeof(addr);
        addr.sin_family = AF_INET;
        addr.sin_port = htons(0);
        addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
        error = bind(sds[0], (const struct sockaddr *)&addr, sizeof(addr));
        ATF_REQUIRE_MSG(error == 0, "bind() failed: %s", strerror(errno));
        error = listen(sds[0], 1);
        ATF_REQUIRE_MSG(error == 0, "listen() failed: %s", strerror(errno));

        slen = sizeof(addr);
        error = getsockname(sds[0], (struct sockaddr *)&addr, &slen);
        ATF_REQUIRE_MSG(error == 0, "getsockname() failed: %s",
            strerror(errno));
        ATF_REQUIRE_MSG(slen == sizeof(addr), "sockaddr size changed");
        port = addr.sin_port;

        memset(&addr, 0, sizeof(addr));
        addr.sin_len = sizeof(addr);
        addr.sin_family = AF_INET;
        addr.sin_port = port;
        addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
        for (i = 1; i < nitems(sds); i++) {
                sds[i] = lb_listen_socket(PF_INET, SOCK_NONBLOCK);

                error = bind(sds[i], (const struct sockaddr *)&addr,
                    sizeof(addr));
                ATF_REQUIRE_MSG(error == 0, "bind() failed: %s",
                    strerror(errno));
                error = listen(sds[i], 1);
                ATF_REQUIRE_MSG(error == 0, "listen() failed: %s",
                    strerror(errno));
        }

        lb_simple_accept_loop(PF_INET, (struct sockaddr *)&addr, sds,
            nitems(sds), nconns);
        for (i = 0; i < nitems(sds); i++) {
                error = close(sds[i]);
                ATF_REQUIRE_MSG(error == 0, "close() failed: %s",
                    strerror(errno));
        }
}

ATF_TC_WITHOUT_HEAD(basic_ipv6);
ATF_TC_BODY(basic_ipv6, tc)
{
        const struct in6_addr loopback6 = IN6ADDR_LOOPBACK_INIT;
        struct sockaddr_in6 addr;
        socklen_t slen;
        size_t i;
        const int nconns = 16384;
        int error, sds[16];
        uint16_t port;

        sds[0] = lb_listen_socket(PF_INET6, SOCK_NONBLOCK);

        memset(&addr, 0, sizeof(addr));
        addr.sin6_len = sizeof(addr);
        addr.sin6_family = AF_INET6;
        addr.sin6_port = htons(0);
        addr.sin6_addr = loopback6;
        error = bind(sds[0], (const struct sockaddr *)&addr, sizeof(addr));
        ATF_REQUIRE_MSG(error == 0, "bind() failed: %s", strerror(errno));
        error = listen(sds[0], 1);
        ATF_REQUIRE_MSG(error == 0, "listen() failed: %s", strerror(errno));

        slen = sizeof(addr);
        error = getsockname(sds[0], (struct sockaddr *)&addr, &slen);
        ATF_REQUIRE_MSG(error == 0, "getsockname() failed: %s",
            strerror(errno));
        ATF_REQUIRE_MSG(slen == sizeof(addr), "sockaddr size changed");
        port = addr.sin6_port;

        memset(&addr, 0, sizeof(addr));
        addr.sin6_len = sizeof(addr);
        addr.sin6_family = AF_INET6;
        addr.sin6_port = port;
        addr.sin6_addr = loopback6;
        for (i = 1; i < nitems(sds); i++) {
                sds[i] = lb_listen_socket(PF_INET6, SOCK_NONBLOCK);

                error = bind(sds[i], (const struct sockaddr *)&addr,
                    sizeof(addr));
                ATF_REQUIRE_MSG(error == 0, "bind() failed: %s",
                    strerror(errno));
                error = listen(sds[i], 1);
                ATF_REQUIRE_MSG(error == 0, "listen() failed: %s",
                    strerror(errno));
        }

        lb_simple_accept_loop(PF_INET6, (struct sockaddr *)&addr, sds,
            nitems(sds), nconns);
        for (i = 0; i < nitems(sds); i++) {
                error = close(sds[i]);
                ATF_REQUIRE_MSG(error == 0, "close() failed: %s",
                    strerror(errno));
        }
}

struct concurrent_add_softc {
        struct sockaddr_storage ss;
        int socks[128];
        int kq;
};

static void *
listener(void *arg)
{
        for (struct concurrent_add_softc *sc = arg;;) {
                struct kevent kev;
                ssize_t n;
                int error, count, cs, s;
                uint8_t b;

                count = kevent(sc->kq, NULL, 0, &kev, 1, NULL);
                ATF_REQUIRE_MSG(count == 1,
                    "kevent() failed: %s", strerror(errno));

                s = (int)kev.ident;
                cs = accept(s, NULL, NULL);
                ATF_REQUIRE_MSG(cs >= 0,
                    "accept() failed: %s", strerror(errno));

                b = 'M';
                n = write(cs, &b, sizeof(b));
                ATF_REQUIRE_MSG(n >= 0, "write() failed: %s", strerror(errno));
                ATF_REQUIRE(n == 1);

                error = close(cs);
                ATF_REQUIRE_MSG(error == 0 || errno == ECONNRESET,
                    "close() failed: %s", strerror(errno));
        }
}

static void *
connector(void *arg)
{
        for (struct concurrent_add_softc *sc = arg;;) {
                ssize_t n;
                int error, s;
                uint8_t b;

                s = socket(sc->ss.ss_family, SOCK_STREAM, 0);
                ATF_REQUIRE_MSG(s >= 0, "socket() failed: %s", strerror(errno));

                error = setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (int[]){1},
                    sizeof(int));

                error = connect(s, (struct sockaddr *)&sc->ss, sc->ss.ss_len);
                ATF_REQUIRE_MSG(error == 0, "connect() failed: %s",
                    strerror(errno));

                n = read(s, &b, sizeof(b));
                ATF_REQUIRE_MSG(n >= 0, "read() failed: %s",
                    strerror(errno));
                ATF_REQUIRE(n == 1);
                ATF_REQUIRE(b == 'M');
                error = close(s);
                ATF_REQUIRE_MSG(error == 0,
                    "close() failed: %s", strerror(errno));
        }
}

/*
 * Run three threads.  One accepts connections from listening sockets on a
 * kqueue, while the other makes connections.  The third thread slowly adds
 * sockets to the LB group.  This is meant to help flush out race conditions.
 */
ATF_TC_WITHOUT_HEAD(concurrent_add);
ATF_TC_BODY(concurrent_add, tc)
{
        struct concurrent_add_softc sc;
        struct sockaddr_in *sin;
        pthread_t threads[4];
        int error;

        sc.kq = kqueue();
        ATF_REQUIRE_MSG(sc.kq >= 0, "kqueue() failed: %s", strerror(errno));

        error = pthread_create(&threads[0], NULL, listener, &sc);
        ATF_REQUIRE_MSG(error == 0, "pthread_create() failed: %s",
            strerror(error));

        sin = (struct sockaddr_in *)&sc.ss;
        memset(sin, 0, sizeof(*sin));
        sin->sin_len = sizeof(*sin);
        sin->sin_family = AF_INET;
        sin->sin_port = htons(0);
        sin->sin_addr.s_addr = htonl(INADDR_LOOPBACK);

        for (size_t i = 0; i < nitems(sc.socks); i++) {
                struct kevent kev;
                int s;

                sc.socks[i] = s = socket(AF_INET, SOCK_STREAM, 0);
                ATF_REQUIRE_MSG(s >= 0, "socket() failed: %s", strerror(errno));

                error = setsockopt(s, SOL_SOCKET, SO_REUSEPORT_LB, (int[]){1},
                    sizeof(int));
                ATF_REQUIRE_MSG(error == 0,
                    "setsockopt(SO_REUSEPORT_LB) failed: %s", strerror(errno));

                error = bind(s, (struct sockaddr *)sin, sizeof(*sin));
                ATF_REQUIRE_MSG(error == 0, "bind() failed: %s",
                    strerror(errno));

                error = listen(s, 5);
                ATF_REQUIRE_MSG(error == 0, "listen() failed: %s",
                    strerror(errno));

                EV_SET(&kev, s, EVFILT_READ, EV_ADD | EV_ENABLE, 0, 0, 0);
                error = kevent(sc.kq, &kev, 1, NULL, 0, NULL);
                ATF_REQUIRE_MSG(error == 0, "kevent() failed: %s",
                    strerror(errno));

                if (i == 0) {
                        socklen_t slen = sizeof(sc.ss);

                        error = getsockname(sc.socks[i],
                            (struct sockaddr *)&sc.ss, &slen);
                        ATF_REQUIRE_MSG(error == 0, "getsockname() failed: %s",
                            strerror(errno));
                        ATF_REQUIRE(sc.ss.ss_family == AF_INET);

                        for (size_t j = 1; j < nitems(threads); j++) {
                                error = pthread_create(&threads[j], NULL,
                                    connector, &sc);
                                ATF_REQUIRE_MSG(error == 0,
                                    "pthread_create() failed: %s",
                                    strerror(error));
                        }
                }

                usleep(20000);
        }

        for (size_t j = nitems(threads); j > 0; j--) {
                ATF_REQUIRE(pthread_cancel(threads[j - 1]) == 0);
                ATF_REQUIRE(pthread_join(threads[j - 1], NULL) == 0);
        }
}

/*
 * Try calling listen(2) twice on a socket with SO_REUSEPORT_LB set.
 */
ATF_TC_WITHOUT_HEAD(double_listen_ipv4);
ATF_TC_BODY(double_listen_ipv4, tc)
{
        struct sockaddr_in sin;
        int error, s;

        s = lb_listen_socket(PF_INET, 0);

        memset(&sin, 0, sizeof(sin));
        sin.sin_len = sizeof(sin);
        sin.sin_family = AF_INET;
        sin.sin_port = htons(0);
        sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
        error = bind(s, (struct sockaddr *)&sin, sizeof(sin));
        ATF_REQUIRE_MSG(error == 0, "bind() failed: %s", strerror(errno));

        error = listen(s, 1);
        ATF_REQUIRE_MSG(error == 0, "listen() failed: %s", strerror(errno));
        error = listen(s, 2);
        ATF_REQUIRE_MSG(error == 0, "listen() failed: %s", strerror(errno));

        error = close(s);
        ATF_REQUIRE_MSG(error == 0, "close() failed: %s", strerror(errno));
}

/*
 * Try calling listen(2) twice on a socket with SO_REUSEPORT_LB set.
 */
ATF_TC_WITHOUT_HEAD(double_listen_ipv6);
ATF_TC_BODY(double_listen_ipv6, tc)
{
        struct sockaddr_in6 sin6;
        int error, s;

        s = lb_listen_socket(PF_INET6, 0);

        memset(&sin6, 0, sizeof(sin6));
        sin6.sin6_len = sizeof(sin6);
        sin6.sin6_family = AF_INET6;
        sin6.sin6_port = htons(0);
        sin6.sin6_addr = in6addr_loopback;
        error = bind(s, (struct sockaddr *)&sin6, sizeof(sin6));
        ATF_REQUIRE_MSG(error == 0, "bind() failed: %s", strerror(errno));

        error = listen(s, 1);
        ATF_REQUIRE_MSG(error == 0, "listen() failed: %s", strerror(errno));
        error = listen(s, 2);
        ATF_REQUIRE_MSG(error == 0, "listen() failed: %s", strerror(errno));

        error = close(s);
        ATF_REQUIRE_MSG(error == 0, "close() failed: %s", strerror(errno));
}

/*
 * Try binding many sockets to the same lbgroup without calling listen(2) on
 * them.
 */
ATF_TC_WITHOUT_HEAD(bind_without_listen);
ATF_TC_BODY(bind_without_listen, tc)
{
        const int nsockets = 100;
        struct sockaddr_in sin;
        socklen_t socklen;
        int error, s, s2[nsockets];

        s = lb_listen_socket(PF_INET, 0);

        memset(&sin, 0, sizeof(sin));
        sin.sin_len = sizeof(sin);
        sin.sin_family = AF_INET;
        sin.sin_port = htons(0);
        sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
        error = bind(s, (struct sockaddr *)&sin, sizeof(sin));
        ATF_REQUIRE_MSG(error == 0, "bind() failed: %s", strerror(errno));

        socklen = sizeof(sin);
        error = getsockname(s, (struct sockaddr *)&sin, &socklen);
        ATF_REQUIRE_MSG(error == 0, "getsockname() failed: %s",
            strerror(errno));

        for (int i = 0; i < nsockets; i++) {
                s2[i] = lb_listen_socket(PF_INET, 0);
                error = bind(s2[i], (struct sockaddr *)&sin, sizeof(sin));
                ATF_REQUIRE_MSG(error == 0, "bind() failed: %s", strerror(errno));
        }
        for (int i = 0; i < nsockets; i++) {
                error = listen(s2[i], 1);
                ATF_REQUIRE_MSG(error == 0, "listen() failed: %s", strerror(errno));
        }
        for (int i = 0; i < nsockets; i++) {
                error = close(s2[i]);
                ATF_REQUIRE_MSG(error == 0, "close() failed: %s", strerror(errno));
        }

        error = close(s);
        ATF_REQUIRE_MSG(error == 0, "close() failed: %s", strerror(errno));
}

/*
 * Check that SO_REUSEPORT_LB doesn't mess with connect(2).
 * Two sockets:
 * 1) auxiliary peer socket 'p', where we connect to
 * 2) test socket 's', that sets SO_REUSEPORT_LB and then connect(2)s to 'p'
 */
ATF_TC_WITHOUT_HEAD(connect_not_bound);
ATF_TC_BODY(connect_not_bound, tc)
{
        struct sockaddr_in sin = {
                .sin_family = AF_INET,
                .sin_len = sizeof(sin),
                .sin_addr = { htonl(INADDR_LOOPBACK) },
        };
        socklen_t slen = sizeof(struct sockaddr_in);
        int p, s, rv;

        ATF_REQUIRE((p = socket(PF_INET, SOCK_STREAM, 0)) > 0);
        ATF_REQUIRE(bind(p, (struct sockaddr *)&sin, sizeof(sin)) == 0);
        ATF_REQUIRE(listen(p, 1) == 0);
        ATF_REQUIRE(getsockname(p, (struct sockaddr *)&sin, &slen) == 0);

        s = lb_listen_socket(PF_INET, 0);
        rv = connect(s, (struct sockaddr *)&sin, sizeof(sin));
        ATF_REQUIRE_MSG(rv == -1 && errno == EOPNOTSUPP,
            "Expected EOPNOTSUPP on connect(2) not met. Got %d, errno %d",
            rv, errno);
        rv = sendto(s, "test", 4, 0, (struct sockaddr *)&sin,
            sizeof(sin));
        ATF_REQUIRE_MSG(rv == -1 && errno == EOPNOTSUPP,
            "Expected EOPNOTSUPP on sendto(2) not met. Got %d, errno %d",
            rv, errno);

        close(p);
        close(s);
}

/*
 * Same as above, but we also bind(2) between setsockopt(2) of SO_REUSEPORT_LB
 * and the connect(2).
 */
ATF_TC_WITHOUT_HEAD(connect_bound);
ATF_TC_BODY(connect_bound, tc)
{
        struct sockaddr_in sin = {
                .sin_family = AF_INET,
                .sin_len = sizeof(sin),
                .sin_addr = { htonl(INADDR_LOOPBACK) },
        };
        socklen_t slen = sizeof(struct sockaddr_in);
        int p, s, rv;

        ATF_REQUIRE((p = socket(PF_INET, SOCK_STREAM, 0)) > 0);
        ATF_REQUIRE(bind(p, (struct sockaddr *)&sin, sizeof(sin)) == 0);
        ATF_REQUIRE(listen(p, 1) == 0);

        s = lb_listen_socket(PF_INET, 0);
        ATF_REQUIRE(bind(s, (struct sockaddr *)&sin, sizeof(sin)) == 0);
        ATF_REQUIRE(getsockname(p, (struct sockaddr *)&sin, &slen) == 0);
        rv = connect(s, (struct sockaddr *)&sin, sizeof(sin));
        ATF_REQUIRE_MSG(rv == -1 && errno == EOPNOTSUPP,
            "Expected EOPNOTSUPP on connect(2) not met. Got %d, errno %d",
            rv, errno);
        rv = sendto(s, "test", 4, 0, (struct sockaddr *)&sin,
            sizeof(sin));
        ATF_REQUIRE_MSG(rv == -1 && errno == EOPNOTSUPP,
            "Expected EOPNOTSUPP on sendto(2) not met. Got %d, errno %d",
            rv, errno);

        close(p);
        close(s);
}

/*
 * The kernel erroneously permits calling connect() on a UDP socket with
 * SO_REUSEPORT_LB set.  Verify that packets sent to the bound address are
 * dropped unless they come from the connected address.
 */
ATF_TC_WITHOUT_HEAD(connect_udp);
ATF_TC_BODY(connect_udp, tc)
{
        struct sockaddr_in sin = {
                .sin_family = AF_INET,
                .sin_len = sizeof(sin),
                .sin_addr = { htonl(INADDR_LOOPBACK) },
        };
        ssize_t n;
        int error, len, s1, s2, s3;
        char ch;

        s1 = socket(PF_INET, SOCK_DGRAM, 0);
        ATF_REQUIRE(s1 >= 0);
        s2 = socket(PF_INET, SOCK_DGRAM, 0);
        ATF_REQUIRE(s2 >= 0);
        s3 = socket(PF_INET, SOCK_DGRAM, 0);
        ATF_REQUIRE(s3 >= 0);

        error = setsockopt(s1, SOL_SOCKET, SO_REUSEPORT_LB, (int[]){1},
            sizeof(int));
        ATF_REQUIRE_MSG(error == 0,
            "setsockopt(SO_REUSEPORT_LB) failed: %s", strerror(errno));
        error = bind(s1, (struct sockaddr *)&sin, sizeof(sin));
        ATF_REQUIRE_MSG(error == 0, "bind() failed: %s", strerror(errno));

        error = bind(s2, (struct sockaddr *)&sin, sizeof(sin));
        ATF_REQUIRE_MSG(error == 0, "bind() failed: %s", strerror(errno));

        error = bind(s3, (struct sockaddr *)&sin, sizeof(sin));
        ATF_REQUIRE_MSG(error == 0, "bind() failed: %s", strerror(errno));

        /* Connect to an address not owned by s2. */
        error = getsockname(s3, (struct sockaddr *)&sin,
            (socklen_t[]){sizeof(sin)});
        ATF_REQUIRE(error == 0);
        error = connect(s1, (struct sockaddr *)&sin, sizeof(sin));
        ATF_REQUIRE_MSG(error == 0, "connect() failed: %s", strerror(errno));

        /* Try to send a packet to s1 from s2. */
        error = getsockname(s1, (struct sockaddr *)&sin,
            (socklen_t[]){sizeof(sin)});
        ATF_REQUIRE(error == 0);

        ch = 42;
        n = sendto(s2, &ch, sizeof(ch), 0, (struct sockaddr *)&sin,
            sizeof(sin));
        ATF_REQUIRE(n == 1);

        /* Give the packet some time to arrive. */
        usleep(100000);

        /* s1 is connected to s3 and shouldn't receive from s2. */
        error = ioctl(s1, FIONREAD, &len);
        ATF_REQUIRE(error == 0);
        ATF_REQUIRE_MSG(len == 0, "unexpected data available");

        /* ... but s3 can of course send to s1. */
        n = sendto(s3, &ch, sizeof(ch), 0, (struct sockaddr *)&sin,
            sizeof(sin));
        ATF_REQUIRE(n == 1);
        usleep(100000);
        error = ioctl(s1, FIONREAD, &len);
        ATF_REQUIRE(error == 0);
        ATF_REQUIRE_MSG(len == 1, "expected data available");
}

/*
 * The kernel erroneously permits calling connect() on a UDP socket with
 * SO_REUSEPORT_LB set.  Verify that packets sent to the bound address are
 * dropped unless they come from the connected address.
 */
ATF_TC_WITHOUT_HEAD(connect_udp6);
ATF_TC_BODY(connect_udp6, tc)
{
        struct sockaddr_in6 sin6 = {
                .sin6_family = AF_INET6,
                .sin6_len = sizeof(sin6),
                .sin6_addr = IN6ADDR_LOOPBACK_INIT,
        };
        ssize_t n;
        int error, len, s1, s2, s3;
        char ch;

        s1 = socket(PF_INET6, SOCK_DGRAM, 0);
        ATF_REQUIRE(s1 >= 0);
        s2 = socket(PF_INET6, SOCK_DGRAM, 0);
        ATF_REQUIRE(s2 >= 0);
        s3 = socket(PF_INET6, SOCK_DGRAM, 0);
        ATF_REQUIRE(s3 >= 0);

        error = setsockopt(s1, SOL_SOCKET, SO_REUSEPORT_LB, (int[]){1},
            sizeof(int));
        ATF_REQUIRE_MSG(error == 0,
            "setsockopt(SO_REUSEPORT_LB) failed: %s", strerror(errno));
        error = bind(s1, (struct sockaddr *)&sin6, sizeof(sin6));
        ATF_REQUIRE_MSG(error == 0, "bind() failed: %s", strerror(errno));

        error = bind(s2, (struct sockaddr *)&sin6, sizeof(sin6));
        ATF_REQUIRE_MSG(error == 0, "bind() failed: %s", strerror(errno));

        error = bind(s3, (struct sockaddr *)&sin6, sizeof(sin6));
        ATF_REQUIRE_MSG(error == 0, "bind() failed: %s", strerror(errno));

        /* Connect to an address not owned by s2. */
        error = getsockname(s3, (struct sockaddr *)&sin6,
            (socklen_t[]){sizeof(sin6)});
        ATF_REQUIRE(error == 0);
        error = connect(s1, (struct sockaddr *)&sin6, sizeof(sin6));
        ATF_REQUIRE_MSG(error == 0, "connect() failed: %s", strerror(errno));

        /* Try to send a packet to s1 from s2. */
        error = getsockname(s1, (struct sockaddr *)&sin6,
            (socklen_t[]){sizeof(sin6)});
        ATF_REQUIRE(error == 0);

        ch = 42;
        n = sendto(s2, &ch, sizeof(ch), 0, (struct sockaddr *)&sin6,
            sizeof(sin6));
        ATF_REQUIRE(n == 1);

        /* Give the packet some time to arrive. */
        usleep(100000);

        /* s1 is connected to s3 and shouldn't receive from s2. */
        error = ioctl(s1, FIONREAD, &len);
        ATF_REQUIRE(error == 0);
        ATF_REQUIRE_MSG(len == 0, "unexpected data available");

        /* ... but s3 can of course send to s1. */
        n = sendto(s3, &ch, sizeof(ch), 0, (struct sockaddr *)&sin6,
            sizeof(sin6));
        ATF_REQUIRE(n == 1);
        usleep(100000);
        error = ioctl(s1, FIONREAD, &len);
        ATF_REQUIRE(error == 0);
        ATF_REQUIRE_MSG(len == 1, "expected data available");
}

ATF_TP_ADD_TCS(tp)
{
        ATF_TP_ADD_TC(tp, basic_ipv4);
        ATF_TP_ADD_TC(tp, basic_ipv6);
        ATF_TP_ADD_TC(tp, concurrent_add);
        ATF_TP_ADD_TC(tp, double_listen_ipv4);
        ATF_TP_ADD_TC(tp, double_listen_ipv6);
        ATF_TP_ADD_TC(tp, bind_without_listen);
        ATF_TP_ADD_TC(tp, connect_not_bound);
        ATF_TP_ADD_TC(tp, connect_bound);
        ATF_TP_ADD_TC(tp, connect_udp);
        ATF_TP_ADD_TC(tp, connect_udp6);

        return (atf_no_error());
}