xref: /freebsd/lib/libcompat/4.3/rexec.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 __FBSDID("$FreeBSD$");
34 __SCCSID("@(#)rexec.c	8.1 (Berkeley) 6/4/93");
35 
36 #include <sys/types.h>
37 #include <sys/uio.h>
38 #include <sys/socket.h>
39 #include <sys/param.h>
40 #include <sys/stat.h>
41 
42 #include <netinet/in.h>
43 
44 #include <stdio.h>
45 #include <unistd.h>
46 #include <string.h>
47 #include <netdb.h>
48 #include <errno.h>
49 #include <ctype.h>
50 #include <err.h>
51 #include <stdlib.h>
52 #include <unistd.h>
53 
54 int	rexecoptions;
55 char	*getpass(), *getlogin();
56 
57 /*
58  * Options and other state info.
59  */
60 struct macel {
61 	char mac_name[9];	/* macro name */
62 	char *mac_start;	/* start of macro in macbuf */
63 	char *mac_end;		/* end of macro in macbuf */
64 };
65 
66 int macnum;			/* number of defined macros */
67 struct macel macros[16];
68 char macbuf[4096];
69 
70 static	FILE *cfile;
71 
72 #define	DEFAULT	1
73 #define	LOGIN	2
74 #define	PASSWD	3
75 #define	ACCOUNT 4
76 #define MACDEF  5
77 #define	ID	10
78 #define	MACH	11
79 
80 static char tokval[100];
81 
82 static struct toktab {
83 	char *tokstr;
84 	int tval;
85 } toktab[]= {
86 	{ "default",	DEFAULT },
87 	{ "login",	LOGIN },
88 	{ "password",	PASSWD },
89 	{ "passwd",	PASSWD },
90 	{ "account",	ACCOUNT },
91 	{ "machine",	MACH },
92 	{ "macdef",	MACDEF },
93 	{ NULL,		0 }
94 };
95 
96 static int
97 token()
98 {
99 	char *cp;
100 	int c;
101 	struct toktab *t;
102 
103 	if (feof(cfile) || ferror(cfile))
104 		return (0);
105 	while ((c = getc(cfile)) != EOF &&
106 	    (c == '\n' || c == '\t' || c == ' ' || c == ','))
107 		continue;
108 	if (c == EOF)
109 		return (0);
110 	cp = tokval;
111 	if (c == '"') {
112 		while ((c = getc(cfile)) != EOF && c != '"') {
113 			if (c == '\\')
114 				c = getc(cfile);
115 			*cp++ = c;
116 		}
117 	} else {
118 		*cp++ = c;
119 		while ((c = getc(cfile)) != EOF
120 		    && c != '\n' && c != '\t' && c != ' ' && c != ',') {
121 			if (c == '\\')
122 				c = getc(cfile);
123 			*cp++ = c;
124 		}
125 	}
126 	*cp = 0;
127 	if (tokval[0] == 0)
128 		return (0);
129 	for (t = toktab; t->tokstr; t++)
130 		if (!strcmp(t->tokstr, tokval))
131 			return (t->tval);
132 	return (ID);
133 }
134 
135 static int
136 ruserpass(host, aname, apass, aacct)
137 	char *host, **aname, **apass, **aacct;
138 {
139 	char *hdir, buf[BUFSIZ], *tmp;
140 	char myname[MAXHOSTNAMELEN], *mydomain;
141 	int t, i, c, usedefault = 0;
142 	struct stat stb;
143 
144 	hdir = getenv("HOME");
145 	if (hdir == NULL)
146 		hdir = ".";
147 	if (strlen(hdir) + 8 > sizeof(buf))
148 		return (0);
149 	(void) sprintf(buf, "%s/.netrc", hdir);
150 	cfile = fopen(buf, "r");
151 	if (cfile == NULL) {
152 		if (errno != ENOENT)
153 			warn("%s", buf);
154 		return (0);
155 	}
156 	if (gethostname(myname, sizeof(myname)) < 0)
157 		myname[0] = '\0';
158 	if ((mydomain = strchr(myname, '.')) == NULL)
159 		mydomain = "";
160 next:
161 	while ((t = token())) switch(t) {
162 
163 	case DEFAULT:
164 		usedefault = 1;
165 		/* FALL THROUGH */
166 
167 	case MACH:
168 		if (!usedefault) {
169 			if (token() != ID)
170 				continue;
171 			/*
172 			 * Allow match either for user's input host name
173 			 * or official hostname.  Also allow match of
174 			 * incompletely-specified host in local domain.
175 			 */
176 			if (strcasecmp(host, tokval) == 0)
177 				goto match;
178 			if ((tmp = strchr(host, '.')) != NULL &&
179 			    strcasecmp(tmp, mydomain) == 0 &&
180 			    strncasecmp(host, tokval, tmp - host) == 0 &&
181 			    tokval[tmp - host] == '\0')
182 				goto match;
183 			continue;
184 		}
185 	match:
186 		while ((t = token()) && t != MACH && t != DEFAULT) switch(t) {
187 
188 		case LOGIN:
189 			if (token())
190 				if (*aname == NULL) {
191 					*aname = malloc((unsigned) strlen(tokval) + 1);
192 					(void) strcpy(*aname, tokval);
193 				} else {
194 					if (strcmp(*aname, tokval))
195 						goto next;
196 				}
197 			break;
198 		case PASSWD:
199 			if ((*aname == NULL || strcmp(*aname, "anonymous")) &&
200 			    fstat(fileno(cfile), &stb) >= 0 &&
201 			    (stb.st_mode & 077) != 0) {
202 	warnx("Error: .netrc file is readable by others.");
203 	warnx("Remove password or make file unreadable by others.");
204 				goto bad;
205 			}
206 			if (token() && *apass == NULL) {
207 				*apass = malloc((unsigned) strlen(tokval) + 1);
208 				(void) strcpy(*apass, tokval);
209 			}
210 			break;
211 		case ACCOUNT:
212 			if (fstat(fileno(cfile), &stb) >= 0
213 			    && (stb.st_mode & 077) != 0) {
214 	warnx("Error: .netrc file is readable by others.");
215 	warnx("Remove account or make file unreadable by others.");
216 				goto bad;
217 			}
218 			if (token() && *aacct == NULL) {
219 				*aacct = malloc((unsigned) strlen(tokval) + 1);
220 				(void) strcpy(*aacct, tokval);
221 			}
222 			break;
223 		case MACDEF:
224 			while ((c=getc(cfile)) != EOF &&
225 						(c == ' ' || c == '\t'))
226 				;
227 			if (c == EOF || c == '\n') {
228 				printf("Missing macdef name argument.\n");
229 				goto bad;
230 			}
231 			if (macnum == 16) {
232 				printf("Limit of 16 macros have already been defined\n");
233 				goto bad;
234 			}
235 			tmp = macros[macnum].mac_name;
236 			*tmp++ = c;
237 			for (i=0; i < 8 && (c=getc(cfile)) != EOF &&
238 			    !isspace(c); ++i) {
239 				*tmp++ = c;
240 			}
241 			if (c == EOF) {
242 				printf("Macro definition missing null line terminator.\n");
243 				goto bad;
244 			}
245 			*tmp = '\0';
246 			if (c != '\n') {
247 				while ((c=getc(cfile)) != EOF && c != '\n');
248 			}
249 			if (c == EOF) {
250 				printf("Macro definition missing null line terminator.\n");
251 				goto bad;
252 			}
253 			if (macnum == 0) {
254 				macros[macnum].mac_start = macbuf;
255 			}
256 			else {
257 				macros[macnum].mac_start = macros[macnum-1].mac_end + 1;
258 			}
259 			tmp = macros[macnum].mac_start;
260 			while (tmp != macbuf + 4096) {
261 				if ((c=getc(cfile)) == EOF) {
262 				printf("Macro definition missing null line terminator.\n");
263 					goto bad;
264 				}
265 				*tmp = c;
266 				if (*tmp == '\n') {
267 					if (*(tmp-1) == '\0') {
268 					   macros[macnum++].mac_end = tmp - 1;
269 					   break;
270 					}
271 					*tmp = '\0';
272 				}
273 				tmp++;
274 			}
275 			if (tmp == macbuf + 4096) {
276 				printf("4K macro buffer exceeded\n");
277 				goto bad;
278 			}
279 			break;
280 		default:
281 			warnx("Unknown .netrc keyword %s", tokval);
282 			break;
283 		}
284 		goto done;
285 	}
286 done:
287 	(void) fclose(cfile);
288 	return (0);
289 bad:
290 	(void) fclose(cfile);
291 	return (-1);
292 }
293 
294 int
295 rexec(ahost, rport, name, pass, cmd, fd2p)
296 	char **ahost;
297 	int rport;
298 	char *name, *pass, *cmd;
299 	int *fd2p;
300 {
301 	struct sockaddr_in sin, sin2, from;
302 	struct hostent *hp;
303 	u_short port;
304 	int s, timo = 1, s3;
305 	char c, *acct;
306 
307 	hp = gethostbyname(*ahost);
308 	if (hp == NULL) {
309 		herror(*ahost);
310 		return (-1);
311 	}
312 	*ahost = hp->h_name;
313 	acct = NULL;
314 	ruserpass(hp->h_name, &name, &pass, &acct);
315 	free(acct);
316 retry:
317 	s = socket(AF_INET, SOCK_STREAM, 0);
318 	if (s < 0) {
319 		perror("rexec: socket");
320 		return (-1);
321 	}
322 	sin.sin_family = hp->h_addrtype;
323 	sin.sin_port = rport;
324 	bcopy(hp->h_addr, (caddr_t)&sin.sin_addr, hp->h_length);
325 	if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
326 		if (errno == ECONNREFUSED && timo <= 16) {
327 			(void) close(s);
328 			sleep(timo);
329 			timo *= 2;
330 			goto retry;
331 		}
332 		perror(hp->h_name);
333 		(void) close(s);
334 		return (-1);
335 	}
336 	port = 0;
337 	if (fd2p == 0)
338 		(void) write(s, "", 1);
339 	else {
340 		char num[8];
341 		int s2, sin2len;
342 
343 		s2 = socket(AF_INET, SOCK_STREAM, 0);
344 		if (s2 < 0) {
345 			(void) close(s);
346 			return (-1);
347 		}
348 		listen(s2, 1);
349 		sin2len = sizeof (sin2);
350 		if (getsockname(s2, (struct sockaddr *)&sin2, &sin2len) < 0 ||
351 		  sin2len != sizeof (sin2)) {
352 			perror("getsockname");
353 			(void) close(s2);
354 			goto bad;
355 		}
356 		port = ntohs((u_short)sin2.sin_port);
357 		(void) sprintf(num, "%hu", port);
358 		(void) write(s, num, strlen(num)+1);
359 		{ int len = sizeof (from);
360 		  s3 = accept(s2, (struct sockaddr *)&from, &len);
361 		  close(s2);
362 		  if (s3 < 0) {
363 			perror("accept");
364 			port = 0;
365 			goto bad;
366 		  }
367 		}
368 		*fd2p = s3;
369 	}
370 	(void) write(s, name, strlen(name) + 1);
371 	/* should public key encypt the password here */
372 	(void) write(s, pass, strlen(pass) + 1);
373 	(void) write(s, cmd, strlen(cmd) + 1);
374 	if (read(s, &c, 1) != 1) {
375 		perror(*ahost);
376 		goto bad;
377 	}
378 	if (c != 0) {
379 		while (read(s, &c, 1) == 1) {
380 			(void) write(2, &c, 1);
381 			if (c == '\n')
382 				break;
383 		}
384 		goto bad;
385 	}
386 	return (s);
387 bad:
388 	if (port)
389 		(void) close(*fd2p);
390 	(void) close(s);
391 	return (-1);
392 }
393