/*      $NetBSD: t_unix.c,v 1.28 2025/03/27 11:01:07 riastradh Exp $    */

/*-
 * Copyright (c) 2011 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Christos Zoulas.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *        This product includes software developed by the NetBSD
 *        Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

#define _GNU_SOURCE
#include <sys/cdefs.h>
#ifdef __RCSID
__RCSID("$Id: t_unix.c,v 1.28 2025/03/27 11:01:07 riastradh Exp $");
#else
#define getprogname() argv[0]
#endif

#ifdef __linux__
#define LX -1
#else
#define LX
#endif

#include <sys/param.h>

#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <sys/wait.h>

#include <err.h>
#include <errno.h>
#include <poll.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "test.h"

#define UID 666
#define GID 999

uid_t srvruid, clntuid;
gid_t srvrgid, clntgid;

#define OF offsetof(struct sockaddr_un, sun_path)

static void
print(const char *msg, struct sockaddr_un *addr, socklen_t len)
{
        size_t i;

        printf("%s: client socket length: %zu\n", msg, (size_t)len);
        printf("%s: client family %d\n", msg, addr->sun_family);
#ifdef BSD4_4
        printf("%s: client len %d\n", msg, addr->sun_len);
#endif
        printf("%s: socket name: ", msg);
        for (i = 0; i < len - OF; i++) {
                int ch = addr->sun_path[i];
                if (ch < ' ' || '~' < ch)
                        printf("\\x%02x", ch);
                else
                        printf("%c", ch);
        }
        printf("\n");
}

static int
acc(int s)
{
        char guard1;
        struct sockaddr_un sun;
        char guard2;
        socklen_t len;

        guard1 = guard2 = 's';

        memset(&sun, 0, sizeof(sun));
        len = sizeof(sun);
        if ((s = accept(s, (struct sockaddr *)&sun, &len)) == -1)
                FAIL("accept");
        if (guard1 != 's')
                FAIL("guard1 = '%c'", guard1);
        if (guard2 != 's')
                FAIL("guard2 = '%c'", guard2);
#ifdef DEBUG
        print("accept", &sun, len);
#endif
        if (len != 2)
                FAIL("len %d != 2", len);
        if (sun.sun_family != AF_UNIX)
                FAIL("sun->sun_family %d != AF_UNIX", sun.sun_family);
#ifdef BSD4_4
        if (sun.sun_len != 2)
                FAIL("sun->sun_len %d != 2", sun.sun_len);
#endif
        for (size_t i = 0; i < sizeof(sun.sun_path); i++)
                if (sun.sun_path[i])
                        FAIL("sun.sun_path[%zu] %d != NULL", i,
                            sun.sun_path[i]);
        return s;
fail:
        if (s != -1)
                close(s);
        return -1;
}

static int
peercred(int s, uid_t *euid, gid_t *egid, pid_t *pid)
{
#ifdef SO_PEERCRED
        /* Linux */
# define unpcbid ucred
# define unp_euid uid
# define unp_egid gid
# define unp_pid pid
# define LOCAL_PEEREID SO_PEERCRED
# define LEVEL SOL_SOCKET
#else
# define LEVEL SOL_LOCAL
#endif

#ifdef LOCAL_PEEREID
        /* NetBSD */
        struct unpcbid cred;
        socklen_t crl;
        crl = sizeof(cred);
        if (getsockopt(s, LEVEL, LOCAL_PEEREID, &cred, &crl) == -1)
                return -1;
        *euid = cred.unp_euid;
        *egid = cred.unp_egid;
        *pid = cred.unp_pid;
        return 0;
#else
        /* FreeBSD */
        *pid = -1;
        return getpeereid(s, euid, egid);
#endif
}

static int
check_cred(int fd, bool statit, pid_t checkpid, pid_t otherpid, const char *s)
{
        pid_t pid;
        uid_t euid, uid;
        gid_t egid, gid;

        if (statit) {
                struct stat st;
                if (fstat(fd, &st) == -1)
                        FAIL("fstat (%s)", s);
                euid = st.st_uid;
                egid = st.st_gid;
                pid = checkpid;
        } else {
                if (peercred(fd, &euid, &egid, &pid) == -1)
                        FAIL("peercred (%s)", s);
        }
        printf("%s(%s) euid=%jd egid=%jd pid=%jd\n",
            statit ? "fstat" : "peercred", s,
            (intmax_t)euid, (intmax_t)egid, (intmax_t)pid);

        if (statit) {
                if (strcmp(s, "server") == 0) {
                        uid = srvruid;
                        gid = srvrgid;
                } else {
                        uid = clntuid;
                        gid = clntgid;
                }
        } else {
                if (checkpid != otherpid && strcmp(s, "server") == 0) {
                        uid = clntuid;
                        gid = clntgid;
                } else {
                        uid = srvruid;
                        gid = srvrgid;
                }
        }
        fflush(stdout);

        CHECK_EQUAL(euid, uid, s);
        CHECK_EQUAL(egid, gid, s);
        CHECK_EQUAL(pid, checkpid, s);
        return 0;
fail:
        return -1;
}

static int
test(bool forkit, bool closeit, bool statit, size_t len)
{
        size_t slen;
        socklen_t sl;
        int srvr = -1, clnt = -1, acpt = -1;
        pid_t srvrpid, clntpid;
        struct sockaddr_un *sock_addr = NULL, *sun = NULL;
        socklen_t sock_addrlen;
        socklen_t peer_addrlen;
        struct sockaddr_un peer_addr;

        srvruid = geteuid();
        srvrgid = getegid();
        srvrpid = clntpid = getpid();
        srvr = socket(AF_UNIX, SOCK_STREAM, 0);
        if (srvr == -1)
                FAIL("socket(server)");

        slen = len + OF + 1;

        if ((sun = calloc(1, slen)) == NULL)
                FAIL("calloc");

        if (mkdir("sock", 0777) == -1)
                FAIL("mkdir");

        if (chdir("sock") == -1)
                FAIL("chdir");

        memset(sun->sun_path, 'a', len);
        sun->sun_path[len] = '\0';
        (void)unlink(sun->sun_path);

        sl = SUN_LEN(sun);
#ifdef BSD4_4
        sun->sun_len = sl;
#endif
        sun->sun_family = AF_UNIX;

        unlink(sun->sun_path);

        if (bind(srvr, (struct sockaddr *)sun, sl) == -1) {
                if (errno == EINVAL && sl >= 256) {
                        close(srvr);
                        return -1;
                }
                FAIL("bind");
        }
        if (chmod(sun->sun_path, 0777) == -1)
                FAIL("chmod `%s'", sun->sun_path);

        if (listen(srvr, SOMAXCONN) == -1)
                FAIL("listen");

        if (forkit) {
                switch (clntpid = fork()) {
                case 0: /* child */
                        srvrpid = getppid();
                        clntpid = getpid();
                        if (srvruid == 0) {
                                setgid(clntgid = GID);
                                setuid(clntuid = UID);
                        } else {
                                clntgid = srvrgid;
                                clntuid = srvruid;
                        }
                        break;
                case -1:
                        FAIL("fork");
                default:
                        if (srvruid == 0) {
                                clntgid = GID;
                                clntuid = UID;
                        }
                        break;
                }
        }

        if (clntpid == getpid()) {
                clnt = socket(AF_UNIX, SOCK_STREAM, 0);
                if (clnt == -1)
                        FAIL("socket(client)");

                if (connect(clnt, (const struct sockaddr *)sun, sl) == -1)
                        FAIL("connect");
                check_cred(clnt, statit, srvrpid, clntpid, "client");

        }

        if (srvrpid == getpid()) {
                acpt = acc(srvr);
                peer_addrlen = sizeof(peer_addr);
                memset(&peer_addr, 0, sizeof(peer_addr));
                if (getpeername(acpt, (struct sockaddr *)&peer_addr,
                    &peer_addrlen) == -1)
                        FAIL("getpeername");
                print("peer", &peer_addr, peer_addrlen);
        }

        if (clntpid == getpid()) {
                if (closeit) {
                        if (close(clnt) == -1)
                                FAIL("close");
                        clnt = -1;
                }
        }

        if (srvrpid == getpid()) {
                check_cred(acpt, statit, clntpid, srvrpid, "server");
                if ((sock_addr = calloc(1, slen)) == NULL)
                        FAIL("calloc");
                sock_addrlen = slen;
                if (getsockname(srvr, (struct sockaddr *)sock_addr,
                    &sock_addrlen) == -1)
                        FAIL("getsockname");
                print("sock", sock_addr, sock_addrlen);

                if (sock_addr->sun_family != AF_UNIX)
                        FAIL("sock_addr->sun_family %d != AF_UNIX",
                            sock_addr->sun_family);

                len += OF;
                if (sock_addrlen LX != len)
                        FAIL("sock_addr_len %zu != %zu", (size_t)sock_addrlen,
                            len);
#ifdef BSD4_4
                if (sock_addr->sun_len != sl)
                        FAIL("sock_addr.sun_len %d != %zu", sock_addr->sun_len,
                            (size_t)sl);
#endif
                for (size_t i = 0; i < slen - OF; i++)
                        if (sock_addr->sun_path[i] != sun->sun_path[i])
                                FAIL("sock_addr.sun_path[%zu] %d != "
                                    "sun->sun_path[%zu] %d\n", i,
                                    sock_addr->sun_path[i], i,
                                    sun->sun_path[i]);

                if (acpt != -1)
                        (void)close(acpt);
                if (srvr != -1)
                        (void)close(srvr);
                free(sock_addr);
                sock_addr = NULL;
                if (forkit && waitpid(clntpid, NULL, 0) == -1)
                        FAIL("waitpid");
        }
        if (clnt != -1 && !closeit)
                (void)close(clnt);

        free(sock_addr);
        free(sun);
        if (forkit && clntpid == getpid())
                _exit(0);
        return 0;
fail:
        if (srvrpid == getpid()) {
                if (acpt != -1)
                        (void)close(acpt);
                if (srvr != -1)
                        (void)close(srvr);
        }
        if (clntpid == getpid()) {
                if (clnt != -1 && !closeit)
                        (void)close(clnt);
        }
        free(sock_addr);
        free(sun);
        if (forkit && clntpid == getpid())
                _exit(0);
        return -1;
}

#ifndef TEST

#include "h_macros.h"

ATF_TC(sockaddr_un_len_exceed);
ATF_TC_HEAD(sockaddr_un_len_exceed, tc)
{

        atf_tc_set_md_var(tc, "descr", "Check that exceeding the size of "
            "unix domain sockets does not trash memory or kernel when "
            "exceeding the size of the fixed sun_path");
}

ATF_TC_BODY(sockaddr_un_len_exceed, tc)
{
        ATF_REQUIRE_MSG(test(false, false, false, 254) == -1,
            "test(false, false, false, 254): %s", strerror(errno));
}

ATF_TC(sockaddr_un_len_max);
ATF_TC_HEAD(sockaddr_un_len_max, tc)
{

        atf_tc_set_md_var(tc, "descr", "Check that we can use the maximum "
            "unix domain socket pathlen (253): 255 - sizeof(sun_len) - "
            "sizeof(sun_family)");
}

ATF_TC_BODY(sockaddr_un_len_max, tc)
{
        ATF_REQUIRE_MSG(test(false, false, false, 253) == 0,
            "test(false, false, false, 253): %s", strerror(errno));
}

ATF_TC(sockaddr_un_closed);
ATF_TC_HEAD(sockaddr_un_closed, tc)
{

        atf_tc_set_md_var(tc, "descr", "Check that we can use the accepted "
            "address of unix domain socket when closed");
}

ATF_TC_BODY(sockaddr_un_closed, tc)
{
        ATF_REQUIRE_MSG(test(false, true, false, 100) == 0,
            "test(false, true, false, 100): %s", strerror(errno));
}

ATF_TC(sockaddr_un_local_connwait);
ATF_TC_HEAD(sockaddr_un_local_connwait, tc)
{

        atf_tc_set_md_var(tc, "descr", "Check that LOCAL_CONNWAIT works");
}

ATF_TC_BODY(sockaddr_un_local_connwait, tc)
{
        /* too annoying to fit this into the test(...) framework above */
        struct sockaddr_un sun = {.sun_family = AF_UNIX, .sun_path = "sock"};
        int listener, conn, acc;
        const int one = 1;
        struct pollfd pfd;
        int nfd, error;
        socklen_t errorlen = sizeof(error);

        /*
         * Create and bind a listening socket.
         */
        RL(listener = socket(PF_LOCAL, SOCK_STREAM|SOCK_NONBLOCK, 0));
        RL(bind(listener, (const struct sockaddr *)&sun, sizeof(sun)));
        RL(listen(listener, 5));

        /*
         * Nobody's trying to connect, so accept would block.
         */
        ATF_REQUIRE_ERRNO(EAGAIN, accept(listener, NULL, NULL) == -1);

        /*
         * Connect should succeed immediately even though nobody is
         * waiting to accept on the other end yet.
         */
        RL(conn = socket(PF_LOCAL, SOCK_STREAM|SOCK_NONBLOCK, 0));
        RL(connect(conn, (const struct sockaddr *)&sun, sizeof(sun)));

        /*
         * Accept should succeed now that a client connected.  Close
         * both sides; we're done with this connection and will try
         * again with LOCAL_CONNWAIT next.
         */
        RL(acc = accept(listener, NULL, NULL));
        RL(close(acc));
        RL(close(conn));

        /*
         * If we set LOCAL_CONNWAIT, connect should fail, but with
         * EINPROGRESS -- note: not EAGAIN, because it has changed
         * state.  If we try to connect again, it should fail with
         * EALREADY because the connection is already pending.
         */
        RL(conn = socket(PF_LOCAL, SOCK_STREAM|SOCK_NONBLOCK, 0));
        RL(setsockopt(conn, SOL_LOCAL, LOCAL_CONNWAIT, &one, sizeof(one)));
        ATF_REQUIRE_ERRNO(EINPROGRESS,
            connect(conn, (const struct sockaddr *)&sun, sizeof(sun)) == -1);
        ATF_REQUIRE_ERRNO(EALREADY,
            connect(conn, (const struct sockaddr *)&sun, sizeof(sun)) == -1);

        /*
         * Accept should succeed immediately now.
         */
        RL(acc = accept(listener, NULL, NULL));

        /*
         * Verify via poll(2) that the pending connect(2) has finished
         * -- it will report POLLOUT when that happens.  And then
         * verify that there was no error.
         */
        pfd = (struct pollfd){.fd = conn, .events = POLLOUT};
        RL(nfd = poll(&pfd, 1, 0));
        ATF_REQUIRE_MSG(pfd.revents & POLLOUT, "revents=0x%x", pfd.revents);
        RL(getsockopt(conn, SOL_SOCKET, SO_ERROR, &error, &errorlen));
        ATF_REQUIRE_MSG(errorlen == sizeof(error), "errorlen=%d", errorlen);
        ATF_REQUIRE_MSG(error == 0, "error=%d", error);

        RL(close(acc));
        RL(close(conn));
        RL(close(listener));
}

ATF_TC(sockaddr_un_local_peereid);
ATF_TC_HEAD(sockaddr_un_local_peereid, tc)
{

        atf_tc_set_md_var(tc, "descr", "Check that we get the right information"
            " from LOCAL_PEEREID");
}

ATF_TC_BODY(sockaddr_un_local_peereid, tc)
{
        ATF_REQUIRE_MSG(test(true, true, false, 100) == 0,
            "test(true, true, false, 100): %s", strerror(errno));
}

ATF_TC(sockaddr_un_fstat);
ATF_TC_HEAD(sockaddr_un_fstat, tc)
{

        atf_tc_set_md_var(tc, "descr", "Check that we get the right information"
            " from fstat");
}

ATF_TC_BODY(sockaddr_un_fstat, tc)
{
        ATF_REQUIRE_MSG(test(true, true, true, 100) == 0,
            "test(true, true, true, 100): %s", strerror(errno));
}

ATF_TP_ADD_TCS(tp)
{

        ATF_TP_ADD_TC(tp, sockaddr_un_len_exceed);
        ATF_TP_ADD_TC(tp, sockaddr_un_len_max);
        ATF_TP_ADD_TC(tp, sockaddr_un_closed);
        ATF_TP_ADD_TC(tp, sockaddr_un_local_connwait);
        ATF_TP_ADD_TC(tp, sockaddr_un_local_peereid);
        ATF_TP_ADD_TC(tp, sockaddr_un_fstat);
        return atf_no_error();
}
#else
int
main(int argc, char *argv[])
{
        size_t len;

        if (argc == 1) {
                fprintf(stderr, "Usage: %s <len>\n", getprogname());
                return EXIT_FAILURE;
        }
        test(false, false, false, atoi(argv[1]));
        test(false, true, false, atoi(argv[1]));
        test(true, false, false, atoi(argv[1]));
        test(true, true, false, atoi(argv[1]));
        test(true, true, true, atoi(argv[1]));
}
#endif