rexec.c revision 7151 
1/*
2 * Copyright (c) 1980, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#if defined(LIBC_SCCS) && !defined(lint)
35static char sccsid[] = "@(#)rexec.c	8.1 (Berkeley) 6/4/93";
36#endif /* LIBC_SCCS and not lint */
37
38#include <sys/types.h>
39#include <sys/uio.h>
40#include <sys/socket.h>
41
42#include <netinet/in.h>
43
44#include <stdio.h>
45#include <unistd.h>
46#include <netdb.h>
47#include <errno.h>
48
49extern	errno;
50char	*index();
51int	rexecoptions;
52char	*getpass(), *getlogin();
53
54rexec(ahost, rport, name, pass, cmd, fd2p)
55	char **ahost;
56	int rport;
57	char *name, *pass, *cmd;
58	int *fd2p;
59{
60	struct sockaddr_in sin, sin2, from;
61	struct hostent *hp;
62	u_short port;
63	int s, timo = 1, s3;
64	char c;
65
66	hp = gethostbyname(*ahost);
67	if (hp == 0) {
68		herror(*ahost);
69		return (-1);
70	}
71	*ahost = hp->h_name;
72	ruserpass(hp->h_name, &name, &pass);
73retry:
74	s = socket(AF_INET, SOCK_STREAM, 0);
75	if (s < 0) {
76		perror("rexec: socket");
77		return (-1);
78	}
79	sin.sin_family = hp->h_addrtype;
80	sin.sin_port = rport;
81	bcopy(hp->h_addr, (caddr_t)&sin.sin_addr, hp->h_length);
82	if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
83		if (errno == ECONNREFUSED && timo <= 16) {
84			(void) close(s);
85			sleep(timo);
86			timo *= 2;
87			goto retry;
88		}
89		perror(hp->h_name);
90		return (-1);
91	}
92	if (fd2p == 0) {
93		(void) write(s, "", 1);
94		port = 0;
95	} else {
96		char num[8];
97		int s2, sin2len;
98
99		s2 = socket(AF_INET, SOCK_STREAM, 0);
100		if (s2 < 0) {
101			(void) close(s);
102			return (-1);
103		}
104		listen(s2, 1);
105		sin2len = sizeof (sin2);
106		if (getsockname(s2, (struct sockaddr *)&sin2, &sin2len) < 0 ||
107		  sin2len != sizeof (sin2)) {
108			perror("getsockname");
109			(void) close(s2);
110			goto bad;
111		}
112		port = ntohs((u_short)sin2.sin_port);
113		(void) sprintf(num, "%u", port);
114		(void) write(s, num, strlen(num)+1);
115		{ int len = sizeof (from);
116		  s3 = accept(s2, (struct sockaddr *)&from, &len);
117		  close(s2);
118		  if (s3 < 0) {
119			perror("accept");
120			port = 0;
121			goto bad;
122		  }
123		}
124		*fd2p = s3;
125	}
126	(void) write(s, name, strlen(name) + 1);
127	/* should public key encypt the password here */
128	(void) write(s, pass, strlen(pass) + 1);
129	(void) write(s, cmd, strlen(cmd) + 1);
130	if (read(s, &c, 1) != 1) {
131		perror(*ahost);
132		goto bad;
133	}
134	if (c != 0) {
135		while (read(s, &c, 1) == 1) {
136			(void) write(2, &c, 1);
137			if (c == '\n')
138				break;
139		}
140		goto bad;
141	}
142	return (s);
143bad:
144	if (port)
145		(void) close(*fd2p);
146	(void) close(s);
147	return (-1);
148}
149