usr/src/usr.bin/rlogin/kcmd.c

/*
 * Copyright (c) 1983, 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. 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.
 */

#ifndef lint
static char Xsccsid[] = "derived from @(#)rcmd.c 5.17 (Berkeley) 6/27/88";
static char sccsid[] = "@(#)kcmd.c      8.2 (Berkeley) 8/19/93";
#endif /* not lint */

#include <sys/param.h>
#include <sys/file.h>
#include <sys/socket.h>
#include <sys/stat.h>

#include <netinet/in.h>
#include <arpa/inet.h>

#include <kerberosIV/des.h>
#include <kerberosIV/krb.h>
#include <kerberosIV/kparse.h>

#include <ctype.h>
#include <errno.h>
#include <netdb.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "krb.h"

#ifndef MAXHOSTNAMELEN
#define MAXHOSTNAMELEN 64
#endif

#define START_PORT      5120     /* arbitrary */

int     getport __P((int *));

int
kcmd(sock, ahost, rport, locuser, remuser, cmd, fd2p, ticket, service, realm,
    cred, schedule, msg_data, laddr, faddr, authopts)
        int *sock;
        char **ahost;
        u_short rport;
        char *locuser, *remuser, *cmd;
        int *fd2p;
        KTEXT ticket;
        char *service;
        char *realm;
        CREDENTIALS *cred;
        Key_schedule schedule;
        MSG_DAT *msg_data;
        struct sockaddr_in *laddr, *faddr;
        long authopts;
{
        int s, timo = 1, pid;
        long oldmask;
        struct sockaddr_in sin, from;
        char c;
#ifdef ATHENA_COMPAT
        int lport = IPPORT_RESERVED - 1;
#else
        int lport = START_PORT;
#endif
        struct hostent *hp;
        int rc;
        char *host_save;
        int status;

        pid = getpid();
        hp = gethostbyname(*ahost);
        if (hp == NULL) {
                /* fprintf(stderr, "%s: unknown host\n", *ahost); */
                return (-1);
        }

        host_save = malloc(strlen(hp->h_name) + 1);
        strcpy(host_save, hp->h_name);
        *ahost = host_save;

#ifdef KERBEROS
        /* If realm is null, look up from table */
        if (realm == NULL || realm[0] == '\0')
                realm = krb_realmofhost(host_save);
#endif /* KERBEROS */

        oldmask = sigblock(sigmask(SIGURG));
        for (;;) {
                s = getport(&lport);
                if (s < 0) {
                        if (errno == EAGAIN)
                                fprintf(stderr,
                                        "kcmd(socket): All ports in use\n");
                        else
                                perror("kcmd: socket");
                        sigsetmask(oldmask);
                        return (-1);
                }
                fcntl(s, F_SETOWN, pid);
                sin.sin_family = hp->h_addrtype;
#if defined(ultrix) || defined(sun)
                bcopy(hp->h_addr, (caddr_t)&sin.sin_addr, hp->h_length);
#else
                bcopy(hp->h_addr_list[0], (caddr_t)&sin.sin_addr, hp->h_length);
#endif
                sin.sin_port = rport;
                if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
                        break;
                (void) close(s);
                if (errno == EADDRINUSE) {
                        lport--;
                        continue;
                }
                /*
                 * don't wait very long for Kerberos rcmd.
                 */
                if (errno == ECONNREFUSED && timo <= 4) {
                        /* sleep(timo); don't wait at all here */
                        timo *= 2;
                        continue;
                }
#if !(defined(ultrix) || defined(sun))
                if (hp->h_addr_list[1] != NULL) {
                        int oerrno = errno;

                        fprintf(stderr,
                            "kcmd: connect to address %s: ",
                            inet_ntoa(sin.sin_addr));
                        errno = oerrno;
                        perror(NULL);
                        hp->h_addr_list++;
                        bcopy(hp->h_addr_list[0], (caddr_t)&sin.sin_addr,
                            hp->h_length);
                        fprintf(stderr, "Trying %s...\n",
                                inet_ntoa(sin.sin_addr));
                        continue;
                }
#endif /* !(defined(ultrix) || defined(sun)) */
                if (errno != ECONNREFUSED)
                        perror(hp->h_name);
                sigsetmask(oldmask);
                return (-1);
        }
        lport--;
        if (fd2p == 0) {
                write(s, "", 1);
                lport = 0;
        } else {
                char num[8];
                int s2 = getport(&lport), s3;
                int len = sizeof(from);

                if (s2 < 0) {
                        status = -1;
                        goto bad;
                }
                listen(s2, 1);
                (void) sprintf(num, "%d", lport);
                if (write(s, num, strlen(num) + 1) != strlen(num) + 1) {
                        perror("kcmd(write): setting up stderr");
                        (void) close(s2);
                        status = -1;
                        goto bad;
                }
                s3 = accept(s2, (struct sockaddr *)&from, &len);
                (void) close(s2);
                if (s3 < 0) {
                        perror("kcmd:accept");
                        lport = 0;
                        status = -1;
                        goto bad;
                }
                *fd2p = s3;
                from.sin_port = ntohs((u_short)from.sin_port);
                if (from.sin_family != AF_INET ||
                    from.sin_port >= IPPORT_RESERVED) {
                        fprintf(stderr,
                         "kcmd(socket): protocol failure in circuit setup.\n");
                        status = -1;
                        goto bad2;
                }
        }
        /*
         * Kerberos-authenticated service.  Don't have to send locuser,
         * since its already in the ticket, and we'll extract it on
         * the other side.
         */
        /* (void) write(s, locuser, strlen(locuser)+1); */

        /* set up the needed stuff for mutual auth, but only if necessary */
        if (authopts & KOPT_DO_MUTUAL) {
                int sin_len;
                *faddr = sin;

                sin_len = sizeof(struct sockaddr_in);
                if (getsockname(s, (struct sockaddr *)laddr, &sin_len) < 0) {
                        perror("kcmd(getsockname)");
                        status = -1;
                        goto bad2;
                }
        }
#ifdef KERBEROS
        if ((status = krb_sendauth(authopts, s, ticket, service, *ahost,
                               realm, (unsigned long) getpid(), msg_data,
                               cred, schedule,
                               laddr,
                               faddr,
                               "KCMDV0.1")) != KSUCCESS)
                goto bad2;
#endif /* KERBEROS */

        (void) write(s, remuser, strlen(remuser)+1);
        (void) write(s, cmd, strlen(cmd)+1);

        if ((rc = read(s, &c, 1)) != 1) {
                if (rc == -1)
                        perror(*ahost);
                else
                        fprintf(stderr,"kcmd: bad connection with remote host\n");
                status = -1;
                goto bad2;
        }
        if (c != '\0') {
                while (read(s, &c, 1) == 1) {
                        (void) write(2, &c, 1);
                        if (c == '\n')
                                break;
                }
                status = -1;
                goto bad2;
        }
        sigsetmask(oldmask);
        *sock = s;
        return (KSUCCESS);
bad2:
        if (lport)
                (void) close(*fd2p);
bad:
        (void) close(s);
        sigsetmask(oldmask);
        return (status);
}

int
getport(alport)
        int *alport;
{
        struct sockaddr_in sin;
        int s;

        sin.sin_family = AF_INET;
        sin.sin_addr.s_addr = INADDR_ANY;
        s = socket(AF_INET, SOCK_STREAM, 0);
        if (s < 0)
                return (-1);
        for (;;) {
                sin.sin_port = htons((u_short)*alport);
                if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
                        return (s);
                if (errno != EADDRINUSE) {
                        (void) close(s);
                        return (-1);
                }
                (*alport)--;
#ifdef ATHENA_COMPAT
                if (*alport == IPPORT_RESERVED/2) {
#else
                if (*alport == IPPORT_RESERVED) {
#endif
                        (void) close(s);
                        errno = EAGAIN;         /* close */
                        return (-1);
                }
        }
}