rexec.c revision 1573 
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/socket.h>
40
41#include <netinet/in.h>
42
43#include <stdio.h>
44#include <netdb.h>
45#include <errno.h>
46
47extern	errno;
48char	*index();
49int	rexecoptions;
50char	*getpass(), *getlogin();
51
52rexec(ahost, rport, name, pass, cmd, fd2p)
53	char **ahost;
54	int rport;
55	char *name, *pass, *cmd;
56	int *fd2p;
57{
58	struct sockaddr_in sin, sin2, from;
59	struct hostent *hp;
60	u_short port;
61	int s, timo = 1, s3;
62	char c;
63
64	hp = gethostbyname(*ahost);
65	if (hp == 0) {
66		herror(*ahost);
67		return (-1);
68	}
69	*ahost = hp->h_name;
70	ruserpass(hp->h_name, &name, &pass);
71retry:
72	s = socket(AF_INET, SOCK_STREAM, 0);
73	if (s < 0) {
74		perror("rexec: socket");
75		return (-1);
76	}
77	sin.sin_family = hp->h_addrtype;
78	sin.sin_port = rport;
79	bcopy(hp->h_addr, (caddr_t)&sin.sin_addr, hp->h_length);
80	if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
81		if (errno == ECONNREFUSED && timo <= 16) {
82			(void) close(s);
83			sleep(timo);
84			timo *= 2;
85			goto retry;
86		}
87		perror(hp->h_name);
88		return (-1);
89	}
90	if (fd2p == 0) {
91		(void) write(s, "", 1);
92		port = 0;
93	} else {
94		char num[8];
95		int s2, sin2len;
96
97		s2 = socket(AF_INET, SOCK_STREAM, 0);
98		if (s2 < 0) {
99			(void) close(s);
100			return (-1);
101		}
102		listen(s2, 1);
103		sin2len = sizeof (sin2);
104		if (getsockname(s2, (struct sockaddr *)&sin2, &sin2len) < 0 ||
105		  sin2len != sizeof (sin2)) {
106			perror("getsockname");
107			(void) close(s2);
108			goto bad;
109		}
110		port = ntohs((u_short)sin2.sin_port);
111		(void) sprintf(num, "%u", port);
112		(void) write(s, num, strlen(num)+1);
113		{ int len = sizeof (from);
114		  s3 = accept(s2, (struct sockaddr *)&from, &len);
115		  close(s2);
116		  if (s3 < 0) {
117			perror("accept");
118			port = 0;
119			goto bad;
120		  }
121		}
122		*fd2p = s3;
123	}
124	(void) write(s, name, strlen(name) + 1);
125	/* should public key encypt the password here */
126	(void) write(s, pass, strlen(pass) + 1);
127	(void) write(s, cmd, strlen(cmd) + 1);
128	if (read(s, &c, 1) != 1) {
129		perror(*ahost);
130		goto bad;
131	}
132	if (c != 0) {
133		while (read(s, &c, 1) == 1) {
134			(void) write(2, &c, 1);
135			if (c == '\n')
136				break;
137		}
138		goto bad;
139	}
140	return (s);
141bad:
142	if (port)
143		(void) close(*fd2p);
144	(void) close(s);
145	return (-1);
146}
147