rexec.c revision 17141 
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/uio.h>
40#include <sys/socket.h>
41#include <sys/param.h>
42#include <sys/stat.h>
43
44#include <netinet/in.h>
45
46#include <stdio.h>
47#include <unistd.h>
48#include <string.h>
49#include <netdb.h>
50#include <errno.h>
51#include <ctype.h>
52#include <err.h>
53#include <stdlib.h>
54#include <unistd.h>
55
56int	rexecoptions;
57char	*getpass(), *getlogin();
58
59/*
60 * Options and other state info.
61 */
62struct macel {
63	char mac_name[9];	/* macro name */
64	char *mac_start;	/* start of macro in macbuf */
65	char *mac_end;		/* end of macro in macbuf */
66};
67
68int macnum;			/* number of defined macros */
69struct macel macros[16];
70char macbuf[4096];
71
72static	FILE *cfile;
73
74#define	DEFAULT	1
75#define	LOGIN	2
76#define	PASSWD	3
77#define	ACCOUNT 4
78#define MACDEF  5
79#define	ID	10
80#define	MACH	11
81
82static char tokval[100];
83
84static struct toktab {
85	char *tokstr;
86	int tval;
87} toktab[]= {
88	{ "default",	DEFAULT },
89	{ "login",	LOGIN },
90	{ "password",	PASSWD },
91	{ "passwd",	PASSWD },
92	{ "account",	ACCOUNT },
93	{ "machine",	MACH },
94	{ "macdef",	MACDEF },
95	{ NULL,		0 }
96};
97
98static int
99token()
100{
101	char *cp;
102	int c;
103	struct toktab *t;
104
105	if (feof(cfile) || ferror(cfile))
106		return (0);
107	while ((c = getc(cfile)) != EOF &&
108	    (c == '\n' || c == '\t' || c == ' ' || c == ','))
109		continue;
110	if (c == EOF)
111		return (0);
112	cp = tokval;
113	if (c == '"') {
114		while ((c = getc(cfile)) != EOF && c != '"') {
115			if (c == '\\')
116				c = getc(cfile);
117			*cp++ = c;
118		}
119	} else {
120		*cp++ = c;
121		while ((c = getc(cfile)) != EOF
122		    && c != '\n' && c != '\t' && c != ' ' && c != ',') {
123			if (c == '\\')
124				c = getc(cfile);
125			*cp++ = c;
126		}
127	}
128	*cp = 0;
129	if (tokval[0] == 0)
130		return (0);
131	for (t = toktab; t->tokstr; t++)
132		if (!strcmp(t->tokstr, tokval))
133			return (t->tval);
134	return (ID);
135}
136
137static int
138ruserpass(host, aname, apass, aacct)
139	char *host, **aname, **apass, **aacct;
140{
141	char *hdir, buf[BUFSIZ], *tmp;
142	char myname[MAXHOSTNAMELEN], *mydomain;
143	int t, i, c, usedefault = 0;
144	struct stat stb;
145
146	hdir = getenv("HOME");
147	if (hdir == NULL)
148		hdir = ".";
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 = "";
160next:
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 == 0) {
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 == 0 || 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 == 0) {
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 == 0) {
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	}
286done:
287	(void) fclose(cfile);
288	return (0);
289bad:
290	(void) fclose(cfile);
291	return (-1);
292}
293
294int
295rexec(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;
306
307	hp = gethostbyname(*ahost);
308	if (hp == 0) {
309		herror(*ahost);
310		return (-1);
311	}
312	*ahost = hp->h_name;
313	ruserpass(hp->h_name, &name, &pass);
314retry:
315	s = socket(AF_INET, SOCK_STREAM, 0);
316	if (s < 0) {
317		perror("rexec: socket");
318		return (-1);
319	}
320	sin.sin_family = hp->h_addrtype;
321	sin.sin_port = rport;
322	bcopy(hp->h_addr, (caddr_t)&sin.sin_addr, hp->h_length);
323	if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
324		if (errno == ECONNREFUSED && timo <= 16) {
325			(void) close(s);
326			sleep(timo);
327			timo *= 2;
328			goto retry;
329		}
330		perror(hp->h_name);
331		return (-1);
332	}
333	if (fd2p == 0) {
334		(void) write(s, "", 1);
335		port = 0;
336	} else {
337		char num[8];
338		int s2, sin2len;
339
340		s2 = socket(AF_INET, SOCK_STREAM, 0);
341		if (s2 < 0) {
342			(void) close(s);
343			return (-1);
344		}
345		listen(s2, 1);
346		sin2len = sizeof (sin2);
347		if (getsockname(s2, (struct sockaddr *)&sin2, &sin2len) < 0 ||
348		  sin2len != sizeof (sin2)) {
349			perror("getsockname");
350			(void) close(s2);
351			goto bad;
352		}
353		port = ntohs((u_short)sin2.sin_port);
354		(void) sprintf(num, "%u", port);
355		(void) write(s, num, strlen(num)+1);
356		{ int len = sizeof (from);
357		  s3 = accept(s2, (struct sockaddr *)&from, &len);
358		  close(s2);
359		  if (s3 < 0) {
360			perror("accept");
361			port = 0;
362			goto bad;
363		  }
364		}
365		*fd2p = s3;
366	}
367	(void) write(s, name, strlen(name) + 1);
368	/* should public key encypt the password here */
369	(void) write(s, pass, strlen(pass) + 1);
370	(void) write(s, cmd, strlen(cmd) + 1);
371	if (read(s, &c, 1) != 1) {
372		perror(*ahost);
373		goto bad;
374	}
375	if (c != 0) {
376		while (read(s, &c, 1) == 1) {
377			(void) write(2, &c, 1);
378			if (c == '\n')
379				break;
380		}
381		goto bad;
382	}
383	return (s);
384bad:
385	if (port)
386		(void) close(*fd2p);
387	(void) close(s);
388	return (-1);
389}
390