1 /* $NetBSD: rexec.c,v 1.16 2003/08/07 16:44:16 agc Exp $ */
2
3 /*
4 * Copyright (c) 1980, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 #if 0
35 static char sccsid[] = "@(#)rexec.c 8.1 (Berkeley) 6/4/93";
36 #else
37 __RCSID("$NetBSD: rexec.c,v 1.16 2003/08/07 16:44:16 agc Exp $");
38 #endif
39 #endif /* LIBC_SCCS and not lint */
40
41 #include <sys/types.h>
42 #include <sys/socket.h>
43
44 #include <netinet/in.h>
45
46 #include <assert.h>
47 #include <err.h>
48 #include <errno.h>
49 #include <netdb.h>
50 #include <stdio.h>
51 #include <string.h>
52 #include <unistd.h>
53
54 int rexecoptions;
55
56 int ruserpass __P((const char *, char **, char **));
57 int rexec __P((char **, int, char *, char *, char *, int *));
58
59 int
rexec(ahost,rport,name,pass,cmd,fd2p)60 rexec(ahost, rport, name, pass, cmd, fd2p)
61 char **ahost;
62 int rport;
63 char *name, *pass, *cmd;
64 int *fd2p;
65 {
66 struct sockaddr_in rsin, from;
67 socklen_t fromlen;
68 struct hostent *hp;
69 u_short port;
70 size_t len;
71 unsigned int timo = 1;
72 int s, s3;
73 char c;
74
75 _DIAGASSERT(ahost != NULL);
76 _DIAGASSERT(name != NULL);
77 _DIAGASSERT(pass != NULL);
78 _DIAGASSERT(cmd != NULL);
79 /* fd2p may be NULL */
80
81 hp = gethostbyname(*ahost);
82 if (hp == 0) {
83 warnx("Error resolving %s (%s)", *ahost, hstrerror(h_errno));
84 return -1;
85 }
86 *ahost = hp->h_name;
87 (void)ruserpass(hp->h_name, &name, &pass);
88 retry:
89 if ((s = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
90 warn("Cannot create socket");
91 return (-1);
92 }
93 rsin.sin_family = hp->h_addrtype;
94 rsin.sin_len = sizeof(rsin);
95 rsin.sin_port = rport;
96 /* Avoid data corruption from bogus DNS results */
97 if (hp->h_length > (int) sizeof(rsin.sin_addr))
98 len = sizeof(rsin.sin_addr);
99 else
100 len = hp->h_length;
101 memcpy(&rsin.sin_addr, hp->h_addr, len);
102 if (connect(s, (struct sockaddr *)(void *)&rsin, sizeof(rsin)) == -1) {
103 if (errno == ECONNREFUSED && timo <= 16) {
104 (void)close(s);
105 sleep(timo);
106 timo *= 2;
107 goto retry;
108 }
109 warn("Cannot connect to %s", hp->h_name);
110 return -1;
111 }
112 port = 0;
113 if (fd2p == 0) {
114 (void)write(s, "", 1);
115 } else {
116 char num[8];
117 int s2;
118 struct sockaddr_in sin2;
119 socklen_t sin2len;
120
121 s2 = socket(AF_INET, SOCK_STREAM, 0);
122 if (s2 == -1) {
123 warn("Error creating socket");
124 (void)close(s);
125 return -1;
126 }
127 listen(s2, 1);
128 sin2len = sizeof(sin2);
129 if (getsockname(s2, (struct sockaddr *)(void *)&sin2,
130 &sin2len) == -1 || sin2len != sizeof(sin2)) {
131 warn("Failed to get socket name");
132 (void)close(s2);
133 goto bad;
134 }
135 port = ntohs((u_short)sin2.sin_port);
136 (void)snprintf(num, sizeof(num), "%u", port);
137 (void)write(s, num, strlen(num)+1);
138
139 fromlen = sizeof(from);
140 s3 = accept(s2, (struct sockaddr *)(void *)&from, &fromlen);
141 (void)close(s2);
142 if (s3 == -1) {
143 warn("Error accepting connection");
144 port = 0;
145 goto bad;
146 }
147 *fd2p = s3;
148 }
149 (void)write(s, name, strlen(name) + 1);
150 /* should public key encypt the password here */
151 (void)write(s, pass, strlen(pass) + 1);
152 (void)write(s, cmd, strlen(cmd) + 1);
153 if (read(s, &c, 1) != 1) {
154 warn("Error reading from %s", *ahost);
155 goto bad;
156 }
157 if (c != 0) {
158 while (read(s, &c, 1) == 1) {
159 (void) write(2, &c, 1);
160 if (c == '\n')
161 break;
162 }
163 goto bad;
164 }
165 return s;
166 bad:
167 if (port)
168 (void)close(*fd2p);
169 (void)close(s);
170 return -1;
171 }
172