/*      $OpenBSD: unfdpass.c,v 1.25 2024/11/06 17:43:53 claudio 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 file descriptors over Unix domain sockets and socketpairs.
 */

#include <sys/socket.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <sys/un.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, int);
void    catch_sigchld(int);

int
main(int argc, char *argv[])
{
        struct msghdr msg;
        int sock, pfd[2], fd, i;
        int listensock = -1;
        char fname[16], buf[64];
        struct cmsghdr *cmp;
        int *files = NULL;
        struct sockaddr_un sun, csun;
        int csunlen;
        pid_t pid;
        union {
                struct cmsghdr hdr;
                char buf[CMSG_SPACE(sizeof(int) * 3)];
        } cmsgbuf;
        int pflag, oflag, rflag;
        int type = SOCK_STREAM;
        extern char *__progname;

        pflag = 0;
        oflag = 0;
        rflag = 0;
        while ((i = getopt(argc, argv, "opqr")) != -1) {
                switch (i) {
                case 'o':
                        oflag = 1;
                        break;
                case 'p':
                        pflag = 1;
                        break;
                case 'q':
                        type = SOCK_SEQPACKET;
                        break;
                case 'r':
                        rflag = 1;
                        break;
                default:
                        fprintf(stderr, "usage: %s [-opqr]\n", __progname);
                        exit(1);
                }
        }

        /*
         * Create the test files.
         */
        for (i = 0; i < 5; i++) {
                (void) snprintf(fname, sizeof fname, "file%d", i + 1);
                if ((fd = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666)) == -1)
                        err(1, "open %s", fname);
                (void) snprintf(buf, sizeof buf, "This is file %d.\n", i + 1);
                if (write(fd, buf, strlen(buf)) != (ssize_t) strlen(buf))
                        err(1, "write %s", fname);
                (void) close(fd);
        }

        if (pflag) {
                /*
                 * Create the socketpair
                 */
                if (socketpair(PF_LOCAL, type, 0, pfd) == -1)
                        err(1, "socketpair");
        } else {
                /*
                 * Create the listen socket.
                 */
                if ((listensock = socket(PF_LOCAL, type, 0)) == -1)
                        err(1, "socket");

                (void) unlink(SOCK_NAME);
                (void) memset(&sun, 0, sizeof(sun));
                sun.sun_family = AF_LOCAL;
                (void) strlcpy(sun.sun_path, SOCK_NAME, sizeof sun.sun_path);

                if (bind(listensock, (struct sockaddr *)&sun, sizeof(sun)) == -1)
                        err(1, "bind");

                if (listen(listensock, 1) == -1)
                        err(1, "listen");
                pfd[0] = pfd[1] = -1;
        }

        /*
         * 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], type, oflag);
                /* NOTREACHED */
        }

        if (pfd[0] != -1) {
                close(pfd[1]);
                sock = pfd[0];
        } else {
                /*
                 * Wait for the sender to connect.
                 */
                if ((sock = accept(listensock, (struct sockaddr *)&csun,
                    &csunlen)) == -1)
                err(1, "accept");
        }

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

        if (rflag) {
                if (read(sock, buf, sizeof(buf)) < 0)
                        err(1, "read");
                printf("read successfully returned\n");
                exit(0);
        }

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

        if (recvmsg(sock, &msg, 0) < 0) {
                if (errno == EMSGSIZE) {
                        printf("recvmsg returned EMSGSIZE\n");
                        exit(0);
                } else
                        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) * 3))
                                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)
                warnx("didn't get fd control message");
        else {
                for (i = 0; i < 3; i++) {
                        (void) memset(buf, 0, sizeof(buf));
                        if (read(files[i], buf, sizeof(buf)) <= 0)
                                err(1, "read file %d (%d)", i + 1, files[i]);
                        printf("%s", buf);
                }
        }

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

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

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

void
child(int sock, int type, int oflag)
{
        struct msghdr msg;
        char fname[16];
        struct cmsghdr *cmp;
        int i, fd, nfds = 3;
        struct sockaddr_un sun;
        size_t len;
        char *cmsgbuf;
        int *files;

        /*
         * Create socket if needed and connect to the receiver.
         */
        if (sock == -1) {
                if ((sock = socket(PF_LOCAL, type, 0)) == -1)
                        err(1, "child socket");

                (void) memset(&sun, 0, sizeof(sun));
                sun.sun_family = AF_LOCAL;
                (void) strlcpy(sun.sun_path, SOCK_NAME, sizeof sun.sun_path);

                if (connect(sock, (struct sockaddr *)&sun, sizeof(sun)) == -1)
                        err(1, "child connect");
        }

        if (oflag)
                nfds = 5;
        len = CMSG_SPACE(sizeof(int) * nfds);
        if ((cmsgbuf = malloc(len)) == NULL)
                err(1, "child");

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

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

        /*
         * Open the files again, and pass them to the parent over the socket.
         */
        files = (int *)CMSG_DATA(cmp);
        for (i = 0; i < nfds; i++) {
                (void) snprintf(fname, sizeof fname, "file%d", i + 1);
                if ((fd = open(fname, O_RDONLY)) == -1)
                        err(1, "child open %s", fname);
                files[i] = fd;
        }

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

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