/*      $OpenBSD: unfdpass.c,v 1.4 2023/03/08 04:43:06 guenther Exp $   */
/*      $NetBSD: unfdpass.c,v 1.3 1998/06/24 23:51:30 thorpej Exp $     */

/*-
 * Copyright (c) 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
 * NASA Ames Research Center.
 *
 * 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 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.
 */

/*
 * Test passing of a /dev/pf file descriptors over socketpair,
 * and of passing a fd opened before the first pledge call that
 * is then used for ioctl()
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <sys/un.h>
#include <net/if.h>
#include <net/pfvar.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 SOCK_NAME       "test-sock"

int     main(int, char *[]);
void    child(int, int);
void    catch_sigchld(int);

int
main(int argc, char *argv[])
{
        struct msghdr msg;
        int sock, pfd[2], i;
        struct cmsghdr *cmp;
        int *files = NULL;
        int fdpf_prepledge, fdpf_postpledge;
        pid_t pid;
        union {
                struct cmsghdr hdr;
                char buf[CMSG_SPACE(sizeof(int))];
        } cmsgbuf;
        int type = SOCK_STREAM;
        int fail = 0;
        struct pf_status status;
        extern char *__progname;

        if ((fdpf_prepledge = open("/dev/pf", O_RDWR)) == -1) {
                err(1, "%s: cannot open pf socket", __func__);
        }

        if (pledge("stdio rpath wpath sendfd recvfd proc pf", NULL)
            == -1)
                err(1, "pledge");

        if ((fdpf_postpledge = open("/dev/pf", O_RDWR)) == -1) {
                err(1, "%s: cannot open pf socket", __func__);
        }

        while ((i = getopt(argc, argv, "f")) != -1) {
                switch (i) {
                case 'f':
                        fail = 1;
                        break;
                default:
                        fprintf(stderr, "usage: %s [-f]\n", __progname);
                        exit(1);
                }
        }

        if (socketpair(PF_LOCAL, type, 0, pfd) == -1)
                err(1, "socketpair");

        /*
         * Create the sender.
         */
        (void) signal(SIGCHLD, catch_sigchld);
        pid = fork();
        switch (pid) {
        case -1:
                err(1, "fork");
                /* NOTREACHED */

        case 0:
                if (pfd[0] != -1)
                        close(pfd[0]);
                child(pfd[1], (fail ? fdpf_postpledge : fdpf_prepledge));
                /* NOTREACHED */
        }

        if (pfd[0] != -1) {
                close(pfd[1]);
                sock = pfd[0];
        } else {
                err(1, "should not happen");
        }

        if (pledge("stdio recvfd pf", NULL) == -1)
                err(1, "pledge");

        /*
         * Give sender a chance to run.  We will get going again
         * once the SIGCHLD arrives.
         */
        (void) sleep(10);

        /*
         * Grab the descriptors passed to us.
         */
        (void) memset(&msg, 0, sizeof(msg));
        msg.msg_control = &cmsgbuf.buf;
        msg.msg_controllen = sizeof(cmsgbuf.buf);

        if (recvmsg(sock, &msg, 0) < 0)
                err(1, "recvmsg");

        (void) close(sock);

        if (msg.msg_controllen == 0)
                errx(1, "no control messages received");

        if (msg.msg_flags & MSG_CTRUNC)
                errx(1, "lost control message data");

        for (cmp = CMSG_FIRSTHDR(&msg); cmp != NULL;
            cmp = CMSG_NXTHDR(&msg, cmp)) {
                if (cmp->cmsg_level != SOL_SOCKET)
                        errx(1, "bad control message level %d",
                            cmp->cmsg_level);

                switch (cmp->cmsg_type) {
                case SCM_RIGHTS:
                        if (cmp->cmsg_len != CMSG_LEN(sizeof(int)))
                                errx(1, "bad fd control message length %d",
                                    cmp->cmsg_len);

                        files = (int *)CMSG_DATA(cmp);
                        break;

                default:
                        errx(1, "unexpected control message");
                        /* NOTREACHED */
                }
        }

        /*
         * Read the files and print their contents.
         */
        if (files == NULL)
                errx(1, "didn't get fd control message");

        if (ioctl(files[0], DIOCGETSTATUS, &status) == -1)
                err(1, "%s: DIOCGETSTATUS", __func__);
        if (!status.running)
                warnx("%s: pf is disabled", __func__);

        /*
         * All done!
         */
        return 0;
}

void
catch_sigchld(sig)
        int sig;
{
        int save_errno = errno;
        int status;

        (void) wait(&status);
        errno = save_errno;
}

void
child(int sock, int fdpf)
{
        struct msghdr msg;
        struct cmsghdr *cmp;
        union {
                struct cmsghdr hdr;
                char buf[CMSG_SPACE(sizeof(int))];
        } cmsgbuf;
        int *files;

        (void) memset(&msg, 0, sizeof(msg));
        msg.msg_control = &cmsgbuf.buf;
        msg.msg_controllen = sizeof(cmsgbuf.buf);

        cmp = CMSG_FIRSTHDR(&msg);
        cmp->cmsg_len = CMSG_LEN(sizeof(int));
        cmp->cmsg_level = SOL_SOCKET;
        cmp->cmsg_type = SCM_RIGHTS;

        files = (int *)CMSG_DATA(cmp);
        files[0] = fdpf;

        if (pledge("stdio sendfd", NULL) == -1)
                errx(1, "pledge");

        if (sendmsg(sock, &msg, 0))
                err(1, "child sendmsg");

        /*
         * All done!
         */
        _exit(0);
}