xref: /freebsd/lib/libcompat/4.3/rexec.c (revision a64729f5077d77e13b9497cb33ecb3c82e606ee8)
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 
33 #include <sys/types.h>
34 #include <sys/uio.h>
35 #include <sys/socket.h>
36 #include <sys/param.h>
37 #include <sys/stat.h>
38 
39 #include <netinet/in.h>
40 
41 #include <stdio.h>
42 #include <unistd.h>
43 #include <string.h>
44 #include <netdb.h>
45 #include <errno.h>
46 #include <ctype.h>
47 #include <err.h>
48 #include <stdlib.h>
49 #include <unistd.h>
50 
51 int	rexecoptions;
52 
53 /*
54  * Options and other state info.
55  */
56 struct macel {
57 	char mac_name[9];	/* macro name */
58 	char *mac_start;	/* start of macro in macbuf */
59 	char *mac_end;		/* end of macro in macbuf */
60 };
61 
62 int macnum;			/* number of defined macros */
63 struct macel macros[16];
64 char macbuf[4096];
65 
66 static	FILE *cfile;
67 
68 #define	DEFAULT	1
69 #define	LOGIN	2
70 #define	PASSWD	3
71 #define	ACCOUNT 4
72 #define MACDEF  5
73 #define	ID	10
74 #define	MACH	11
75 
76 static char tokval[100];
77 
78 static struct toktab {
79 	char *tokstr;
80 	int tval;
81 } toktab[]= {
82 	{ "default",	DEFAULT },
83 	{ "login",	LOGIN },
84 	{ "password",	PASSWD },
85 	{ "passwd",	PASSWD },
86 	{ "account",	ACCOUNT },
87 	{ "machine",	MACH },
88 	{ "macdef",	MACDEF },
89 	{ NULL,		0 }
90 };
91 
92 static int
93 token()
94 {
95 	char *cp;
96 	int c;
97 	struct toktab *t;
98 
99 	if (feof(cfile) || ferror(cfile))
100 		return (0);
101 	while ((c = getc(cfile)) != EOF &&
102 	    (c == '\n' || c == '\t' || c == ' ' || c == ','))
103 		continue;
104 	if (c == EOF)
105 		return (0);
106 	cp = tokval;
107 	if (c == '"') {
108 		while ((c = getc(cfile)) != EOF && c != '"') {
109 			if (c == '\\')
110 				c = getc(cfile);
111 			*cp++ = c;
112 		}
113 	} else {
114 		*cp++ = c;
115 		while ((c = getc(cfile)) != EOF
116 		    && c != '\n' && c != '\t' && c != ' ' && c != ',') {
117 			if (c == '\\')
118 				c = getc(cfile);
119 			*cp++ = c;
120 		}
121 	}
122 	*cp = 0;
123 	if (tokval[0] == 0)
124 		return (0);
125 	for (t = toktab; t->tokstr; t++)
126 		if (!strcmp(t->tokstr, tokval))
127 			return (t->tval);
128 	return (ID);
129 }
130 
131 static int
132 ruserpass(char *host, char **aname, char **apass, char **aacct)
133 {
134 	char *hdir, buf[BUFSIZ], *tmp;
135 	char myname[MAXHOSTNAMELEN], *mydomain;
136 	int t, i, c, usedefault = 0;
137 	struct stat stb;
138 
139 	hdir = getenv("HOME");
140 	if (hdir == NULL)
141 		hdir = ".";
142 	if (strlen(hdir) + 8 > sizeof(buf))
143 		return (0);
144 	(void) sprintf(buf, "%s/.netrc", hdir);
145 	cfile = fopen(buf, "r");
146 	if (cfile == NULL) {
147 		if (errno != ENOENT)
148 			warn("%s", buf);
149 		return (0);
150 	}
151 	if (gethostname(myname, sizeof(myname)) < 0)
152 		myname[0] = '\0';
153 	if ((mydomain = strchr(myname, '.')) == NULL)
154 		mydomain = "";
155 next:
156 	while ((t = token())) switch(t) {
157 
158 	case DEFAULT:
159 		usedefault = 1;
160 		/* FALL THROUGH */
161 
162 	case MACH:
163 		if (!usedefault) {
164 			if (token() != ID)
165 				continue;
166 			/*
167 			 * Allow match either for user's input host name
168 			 * or official hostname.  Also allow match of
169 			 * incompletely-specified host in local domain.
170 			 */
171 			if (strcasecmp(host, tokval) == 0)
172 				goto match;
173 			if ((tmp = strchr(host, '.')) != NULL &&
174 			    strcasecmp(tmp, mydomain) == 0 &&
175 			    strncasecmp(host, tokval, tmp - host) == 0 &&
176 			    tokval[tmp - host] == '\0')
177 				goto match;
178 			continue;
179 		}
180 	match:
181 		while ((t = token()) && t != MACH && t != DEFAULT) switch(t) {
182 
183 		case LOGIN:
184 			if (token())
185 				if (*aname == NULL) {
186 					*aname = malloc((unsigned) strlen(tokval) + 1);
187 					(void) strcpy(*aname, tokval);
188 				} else {
189 					if (strcmp(*aname, tokval))
190 						goto next;
191 				}
192 			break;
193 		case PASSWD:
194 			if ((*aname == NULL || strcmp(*aname, "anonymous")) &&
195 			    fstat(fileno(cfile), &stb) >= 0 &&
196 			    (stb.st_mode & 077) != 0) {
197 	warnx("Error: .netrc file is readable by others.");
198 	warnx("Remove password or make file unreadable by others.");
199 				goto bad;
200 			}
201 			if (token() && *apass == NULL) {
202 				*apass = malloc((unsigned) strlen(tokval) + 1);
203 				(void) strcpy(*apass, tokval);
204 			}
205 			break;
206 		case ACCOUNT:
207 			if (fstat(fileno(cfile), &stb) >= 0
208 			    && (stb.st_mode & 077) != 0) {
209 	warnx("Error: .netrc file is readable by others.");
210 	warnx("Remove account or make file unreadable by others.");
211 				goto bad;
212 			}
213 			if (token() && *aacct == NULL) {
214 				*aacct = malloc((unsigned) strlen(tokval) + 1);
215 				(void) strcpy(*aacct, tokval);
216 			}
217 			break;
218 		case MACDEF:
219 			while ((c=getc(cfile)) != EOF &&
220 						(c == ' ' || c == '\t'))
221 				;
222 			if (c == EOF || c == '\n') {
223 				printf("Missing macdef name argument.\n");
224 				goto bad;
225 			}
226 			if (macnum == 16) {
227 				printf("Limit of 16 macros have already been defined\n");
228 				goto bad;
229 			}
230 			tmp = macros[macnum].mac_name;
231 			*tmp++ = c;
232 			for (i=0; i < 8 && (c=getc(cfile)) != EOF &&
233 			    !isspace(c); ++i) {
234 				*tmp++ = c;
235 			}
236 			if (c == EOF) {
237 				printf("Macro definition missing null line terminator.\n");
238 				goto bad;
239 			}
240 			*tmp = '\0';
241 			if (c != '\n') {
242 				while ((c=getc(cfile)) != EOF && c != '\n');
243 			}
244 			if (c == EOF) {
245 				printf("Macro definition missing null line terminator.\n");
246 				goto bad;
247 			}
248 			if (macnum == 0) {
249 				macros[macnum].mac_start = macbuf;
250 			}
251 			else {
252 				macros[macnum].mac_start = macros[macnum-1].mac_end + 1;
253 			}
254 			tmp = macros[macnum].mac_start;
255 			while (tmp != macbuf + 4096) {
256 				if ((c=getc(cfile)) == EOF) {
257 				printf("Macro definition missing null line terminator.\n");
258 					goto bad;
259 				}
260 				*tmp = c;
261 				if (*tmp == '\n') {
262 					if (*(tmp-1) == '\0') {
263 					   macros[macnum++].mac_end = tmp - 1;
264 					   break;
265 					}
266 					*tmp = '\0';
267 				}
268 				tmp++;
269 			}
270 			if (tmp == macbuf + 4096) {
271 				printf("4K macro buffer exceeded\n");
272 				goto bad;
273 			}
274 			break;
275 		default:
276 			warnx("Unknown .netrc keyword %s", tokval);
277 			break;
278 		}
279 		goto done;
280 	}
281 done:
282 	(void) fclose(cfile);
283 	return (0);
284 bad:
285 	(void) fclose(cfile);
286 	return (-1);
287 }
288 
289 int
290 rexec(char **ahost, int rport, char *name, char *pass, char *cmd, int *fd2p)
291 {
292 	struct sockaddr_in sin, sin2, from;
293 	struct hostent *hp;
294 	u_short port;
295 	int s, timo = 1, s3;
296 	char c, *acct;
297 
298 	hp = gethostbyname(*ahost);
299 	if (hp == NULL) {
300 		herror(*ahost);
301 		return (-1);
302 	}
303 	*ahost = hp->h_name;
304 	acct = NULL;
305 	ruserpass(hp->h_name, &name, &pass, &acct);
306 	free(acct);
307 retry:
308 	s = socket(AF_INET, SOCK_STREAM, 0);
309 	if (s < 0) {
310 		perror("rexec: socket");
311 		return (-1);
312 	}
313 	sin.sin_family = hp->h_addrtype;
314 	sin.sin_port = rport;
315 	bcopy(hp->h_addr, (caddr_t)&sin.sin_addr, hp->h_length);
316 	if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
317 		if (errno == ECONNREFUSED && timo <= 16) {
318 			(void) close(s);
319 			sleep(timo);
320 			timo *= 2;
321 			goto retry;
322 		}
323 		perror(hp->h_name);
324 		(void) close(s);
325 		return (-1);
326 	}
327 	port = 0;
328 	if (fd2p == 0)
329 		(void) write(s, "", 1);
330 	else {
331 		char num[8];
332 		int s2, sin2len;
333 
334 		s2 = socket(AF_INET, SOCK_STREAM, 0);
335 		if (s2 < 0) {
336 			(void) close(s);
337 			return (-1);
338 		}
339 		listen(s2, 1);
340 		sin2len = sizeof (sin2);
341 		if (getsockname(s2, (struct sockaddr *)&sin2, &sin2len) < 0 ||
342 		  sin2len != sizeof (sin2)) {
343 			perror("getsockname");
344 			(void) close(s2);
345 			goto bad;
346 		}
347 		port = ntohs((u_short)sin2.sin_port);
348 		(void) sprintf(num, "%hu", port);
349 		(void) write(s, num, strlen(num)+1);
350 		{ int len = sizeof (from);
351 		  s3 = accept(s2, (struct sockaddr *)&from, &len);
352 		  close(s2);
353 		  if (s3 < 0) {
354 			perror("accept");
355 			port = 0;
356 			goto bad;
357 		  }
358 		}
359 		*fd2p = s3;
360 	}
361 	(void) write(s, name, strlen(name) + 1);
362 	/* should public key encypt the password here */
363 	(void) write(s, pass, strlen(pass) + 1);
364 	(void) write(s, cmd, strlen(cmd) + 1);
365 	if (read(s, &c, 1) != 1) {
366 		perror(*ahost);
367 		goto bad;
368 	}
369 	if (c != 0) {
370 		while (read(s, &c, 1) == 1) {
371 			(void) write(2, &c, 1);
372 			if (c == '\n')
373 				break;
374 		}
375 		goto bad;
376 	}
377 	return (s);
378 bad:
379 	if (port)
380 		(void) close(*fd2p);
381 	(void) close(s);
382 	return (-1);
383 }
384