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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char sccsid[] = "@(#)rexec.c	8.1 (Berkeley) 6/4/93";
32 #endif /* LIBC_SCCS and not lint */
33 
34 #include <sys/types.h>
35 #include <sys/socket.h>
36 
37 #include <netinet/in.h>
38 
39 #include <alloca.h>
40 #include <stdio.h>
41 #include <netdb.h>
42 #include <errno.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 #include <sys/uio.h>
47 #include "libc-symbols.h"
48 
49 int	rexecoptions;
50 libc_freeres_ptr (static char *ahostbuf);
51 
52 int
rexec_af(ahost,rport,name,pass,cmd,fd2p,af)53 rexec_af(ahost, rport, name, pass, cmd, fd2p, af)
54 	char **ahost;
55 	int rport;
56 	const char *name, *pass, *cmd;
57 	int *fd2p;
58 	sa_family_t af;
59 {
60 	struct sockaddr_storage sa2, from;
61 	struct addrinfo hints, *res0;
62 	const char *orig_name = name;
63 	const char *orig_pass = pass;
64 	u_short port = 0;
65 	int s, timo = 1, s3;
66 	char c;
67 	int gai;
68 	char servbuff[NI_MAXSERV];
69 
70 	snprintf(servbuff, sizeof(servbuff), "%d", ntohs(rport));
71 	servbuff[sizeof(servbuff) - 1] = '\0';
72 
73 	memset(&hints, '\0', sizeof(hints));
74 	hints.ai_family = af;
75 	hints.ai_socktype = SOCK_STREAM;
76 	hints.ai_flags = AI_CANONNAME;
77 	gai = getaddrinfo(*ahost, servbuff, &hints, &res0);
78 	if (gai){
79 		/* XXX: set errno? */
80 		return -1;
81 	}
82 
83 	if (res0->ai_canonname){
84 		free (ahostbuf);
85 		ahostbuf = strdup (res0->ai_canonname);
86 		if (ahostbuf == NULL) {
87 			perror ("rexec: strdup");
88 			return (-1);
89 		}
90 		*ahost = ahostbuf;
91 	} else
92 		*ahost = NULL;
93 	ruserpass(res0->ai_canonname, &name, &pass);
94 retry:
95 	s = socket(res0->ai_family, res0->ai_socktype, 0);
96 	if (s < 0) {
97 		perror("rexec: socket");
98 		return (-1);
99 	}
100 	if (connect(s, res0->ai_addr, res0->ai_addrlen) < 0) {
101 		if (errno == ECONNREFUSED && timo <= 16) {
102 			(void) __close(s);
103 			sleep(timo);
104 			timo *= 2;
105 			goto retry;
106 		}
107 		perror(res0->ai_canonname);
108 		return (-1);
109 	}
110 	if (fd2p == 0) {
111 		(void) write(s, "", 1);
112 		port = 0;
113 	} else {
114 		char num[32];
115 		int s2, sa2len;
116 
117 		s2 = socket(res0->ai_family, res0->ai_socktype, 0);
118 		if (s2 < 0) {
119 			(void) __close(s);
120 			return (-1);
121 		}
122 		listen(s2, 1);
123 		sa2len = sizeof (sa2);
124 		if (getsockname(s2, (struct sockaddr *)&sa2, &sa2len) < 0) {
125 			perror("getsockname");
126 			(void) __close(s2);
127 			goto bad;
128 #ifdef SA_LEN
129 		} else if (sa2len != SA_LEN((struct sockaddr *)&sa2)) {
130 			__set_errno(EINVAL);
131 			(void) __close(s2);
132 			goto bad;
133 #endif
134 		}
135 		port = 0;
136 		if (!getnameinfo((struct sockaddr *)&sa2, sa2len,
137 				 NULL, 0, servbuff, sizeof(servbuff),
138 				 NI_NUMERICSERV))
139 			port = atoi(servbuff);
140 		(void) sprintf(num, "%u", port);
141 		(void) __write(s, num, strlen(num)+1);
142 		{ int len = sizeof (from);
143 		  s3 = TEMP_FAILURE_RETRY (accept(s2, (struct sockaddr *)&from,
144 						  &len));
145 		  __close(s2);
146 		  if (s3 < 0) {
147 			perror("accept");
148 			port = 0;
149 			goto bad;
150 		  }
151 		}
152 		*fd2p = s3;
153 	}
154 
155 	struct iovec iov[3] =
156 	  {
157 	    [0] = { .iov_base = (void *) name, .iov_len = strlen (name) + 1 },
158 	    /* should public key encypt the password here */
159 	    [1] = { .iov_base = (void *) pass, .iov_len = strlen (pass) + 1 },
160 	    [2] = { .iov_base = (void *) cmd, .iov_len = strlen (cmd) + 1 }
161 	  };
162 	(void) TEMP_FAILURE_RETRY (writev (s, iov, 3));
163 
164 	/* We don't need the memory allocated for the name and the password
165 	   in ruserpass anymore.  */
166 	if (name != orig_name)
167 	  free ((char *) name);
168 	if (pass != orig_pass)
169 	  free ((char *) pass);
170 
171 	if (__read(s, &c, 1) != 1) {
172 		perror(*ahost);
173 		goto bad;
174 	}
175 	if (c != 0) {
176 		while (__read(s, &c, 1) == 1) {
177 			(void) __write(2, &c, 1);
178 			if (c == '\n')
179 				break;
180 		}
181 		goto bad;
182 	}
183 	freeaddrinfo(res0);
184 	return (s);
185 bad:
186 	if (port)
187 		(void) __close(*fd2p);
188 	(void) __close(s);
189 	freeaddrinfo(res0);
190 	return (-1);
191 }
192 libc_hidden_def (rexec_af)
193 
194 int
195 rexec(ahost, rport, name, pass, cmd, fd2p)
196 	char **ahost;
197 	int rport;
198 	const char *name, *pass, *cmd;
199 	int *fd2p;
200 {
201 	return rexec_af(ahost, rport, name, pass, cmd, fd2p, AF_INET);
202 }
203