freebsd-dev/usr.bin/rlogin/kcmd.c
Justin T. Gibbs f4390542d7 Kerberos can now deal with multi-homed clients.
Kerberos obtains a network address for the local host from the routing
tables and uses it consistently for all Kerberos transactions.  This ensures
that packets only leave the *authenticated* interface.  Clients who open
and use their own sockets for encrypted or authenticated correspondance
to kerberos services should bind their sockets to the same address as that
used by kerberos.  krb_get_local_addr() and krb_bind_local_addr() allow
clients to obtain the local address or bind a socket to the local address
used by Kerberos respectively.

Reviewed by: Mark Murray <markm>, Garrett Wollman <wollman>
Obtained from: concept by Dieter Dworkin Muller <dworkin@village.org>
1995-10-05 21:30:21 +00:00

311 lines
7.6 KiB
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, retval;
s = socket(AF_INET, SOCK_STREAM, 0);
if ((retval = krb_get_local_addr(&sin)) != KSUCCESS) {
fprintf(stderr, "krb_get_local_addr: %s\n",krb_err_txt[retval]);
close(s);
return (-1);
}
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);
}
}
}