/*      $NetBSD: rexec.c,v 1.17 2026/07/10 22:24:01 andvar Exp $        */

/*
 * Copyright (c) 1980, 1993
 *      The Regents of the University of California.  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.
 * 3. Neither the name of the University 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 REGENTS 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 REGENTS 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/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)rexec.c     8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: rexec.c,v 1.17 2026/07/10 22:24:01 andvar Exp $");
#endif
#endif /* LIBC_SCCS and not lint */

#include <sys/types.h>
#include <sys/socket.h>

#include <netinet/in.h>

#include <assert.h>
#include <err.h>
#include <errno.h>
#include <netdb.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

int     rexecoptions;

int     ruserpass __P((const char *, char **, char **));
int     rexec __P((char **, int, char *, char *, char *, int *));

int
rexec(ahost, rport, name, pass, cmd, fd2p)
        char **ahost;
        int rport;
        char *name, *pass, *cmd;
        int *fd2p;
{
        struct sockaddr_in rsin, from;
        socklen_t fromlen;
        struct hostent *hp;
        u_short port;
        size_t len;
        unsigned int timo = 1;
        int s, s3;
        char c;

        _DIAGASSERT(ahost != NULL);
        _DIAGASSERT(name != NULL);
        _DIAGASSERT(pass != NULL);
        _DIAGASSERT(cmd != NULL);
        /* fd2p may be NULL */

        hp = gethostbyname(*ahost);
        if (hp == 0) {
                warnx("Error resolving %s (%s)", *ahost, hstrerror(h_errno));
                return -1;
        }
        *ahost = hp->h_name;
        (void)ruserpass(hp->h_name, &name, &pass);
retry:
        if ((s = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
                warn("Cannot create socket");
                return (-1);
        }
        rsin.sin_family = hp->h_addrtype;
        rsin.sin_len = sizeof(rsin);
        rsin.sin_port = rport;
        /* Avoid data corruption from bogus DNS results */
        if (hp->h_length > (int) sizeof(rsin.sin_addr))
                len = sizeof(rsin.sin_addr);
        else
                len = hp->h_length;
        memcpy(&rsin.sin_addr, hp->h_addr, len);
        if (connect(s, (struct sockaddr *)(void *)&rsin, sizeof(rsin)) == -1) {
                if (errno == ECONNREFUSED && timo <= 16) {
                        (void)close(s);
                        sleep(timo);
                        timo *= 2;
                        goto retry;
                }
                warn("Cannot connect to %s", hp->h_name);
                return -1;
        }
        port = 0;
        if (fd2p == 0) {
                (void)write(s, "", 1);
        } else {
                char num[8];
                int s2;
                struct sockaddr_in sin2;
                socklen_t sin2len;

                s2 = socket(AF_INET, SOCK_STREAM, 0);
                if (s2 == -1) {
                        warn("Error creating socket");
                        (void)close(s);
                        return -1;
                }
                listen(s2, 1);
                sin2len = sizeof(sin2);
                if (getsockname(s2, (struct sockaddr *)(void *)&sin2,
                    &sin2len) == -1 || sin2len != sizeof(sin2)) {
                        warn("Failed to get socket name");
                        (void)close(s2);
                        goto bad;
                }
                port = ntohs((u_short)sin2.sin_port);
                (void)snprintf(num, sizeof(num), "%u", port);
                (void)write(s, num, strlen(num)+1);

                fromlen = sizeof(from);
                s3 = accept(s2, (struct sockaddr *)(void *)&from, &fromlen);
                (void)close(s2);
                if (s3 == -1) {
                        warn("Error accepting connection");
                        port = 0;
                        goto bad;
                }
                *fd2p = s3;
        }
        (void)write(s, name, strlen(name) + 1);
        /* should public key encrypt the password here */
        (void)write(s, pass, strlen(pass) + 1);
        (void)write(s, cmd, strlen(cmd) + 1);
        if (read(s, &c, 1) != 1) {
                warn("Error reading from %s", *ahost);
                goto bad;
        }
        if (c != 0) {
                while (read(s, &c, 1) == 1) {
                        (void) write(2, &c, 1);
                        if (c == '\n')
                                break;
                }
                goto bad;
        }
        return s;
bad:
        if (port)
                (void)close(*fd2p);
        (void)close(s);
        return -1;
}