xref: /freebsd/usr.bin/finger/finger.c (revision ad30f8e79bd1007cc2476e491bd21b4f5e389e0a)
1 /*
2  * Copyright (c) 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Tony Nardo of the Johns Hopkins University/Applied Physics Lab.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 4. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * Luke Mewburn <lm@rmit.edu.au> added the following on 940622:
35  *    - mail status ("No Mail", "Mail read:...", or "New Mail ...,
36  *	Unread since ...".)
37  *    - 4 digit phone extensions (3210 is printed as x3210.)
38  *    - host/office toggling in short format with -h & -o.
39  *    - short day names (`Tue' printed instead of `Jun 21' if the
40  *	login time is < 6 days.
41  */
42 
43 #ifndef lint
44 static const char copyright[] =
45 "@(#) Copyright (c) 1989, 1993\n\
46 	The Regents of the University of California.  All rights reserved.\n";
47 #endif /* not lint */
48 
49 #if 0
50 #ifndef lint
51 static char sccsid[] = "@(#)finger.c	8.5 (Berkeley) 5/4/95";
52 #endif
53 #endif
54 
55 #include <sys/cdefs.h>
56 __FBSDID("$FreeBSD$");
57 
58 /*
59  * Finger prints out information about users.  It is not portable since
60  * certain fields (e.g. the full user name, office, and phone numbers) are
61  * extracted from the gecos field of the passwd file which other UNIXes
62  * may not have or may use for other things.
63  *
64  * There are currently two output formats; the short format is one line
65  * per user and displays login name, tty, login time, real name, idle time,
66  * and either remote host information (default) or office location/phone
67  * number, depending on if -h or -o is used respectively.
68  * The long format gives the same information (in a more legible format) as
69  * well as home directory, shell, mail info, and .plan/.project files.
70  */
71 
72 #include <sys/types.h>
73 #include <sys/socket.h>
74 #include <db.h>
75 #include <err.h>
76 #include <pwd.h>
77 #include <stdio.h>
78 #include <stdlib.h>
79 #include <string.h>
80 #include <time.h>
81 #include <unistd.h>
82 #include <utmpx.h>
83 #include <locale.h>
84 
85 #include "finger.h"
86 #include "pathnames.h"
87 
88 DB *db;
89 time_t now;
90 int entries, gflag, kflag, lflag, mflag, pplan, sflag, oflag;
91 sa_family_t family = PF_UNSPEC;
92 int d_first = -1;
93 char tbuf[1024];
94 int invoker_root = 0;
95 
96 static void loginlist(void);
97 static int option(int, char **);
98 static void usage(void);
99 static void userlist(int, char **);
100 
101 static int
102 option(int argc, char **argv)
103 {
104 	int ch;
105 
106 	optind = 1;		/* reset getopt */
107 
108 	while ((ch = getopt(argc, argv, "46gklmpsho")) != -1)
109 		switch(ch) {
110 		case '4':
111 			family = AF_INET;
112 			break;
113 		case '6':
114 			family = AF_INET6;
115 			break;
116 		case 'g':
117 			gflag = 1;
118 			break;
119 		case 'k':
120 			kflag = 1;		/* keep going without utmp */
121 			break;
122 		case 'l':
123 			lflag = 1;		/* long format */
124 			break;
125 		case 'm':
126 			mflag = 1;		/* force exact match of names */
127 			break;
128 		case 'p':
129 			pplan = 1;		/* don't show .plan/.project */
130 			break;
131 		case 's':
132 			sflag = 1;		/* short format */
133 			break;
134 		case 'h':
135 			oflag = 0;		/* remote host info */
136 			break;
137 		case 'o':
138 			oflag = 1;		/* office info */
139 			break;
140 		case '?':
141 		default:
142 			usage();
143 		}
144 
145 	return optind;
146 }
147 
148 static void
149 usage(void)
150 {
151 	(void)fprintf(stderr,
152 	    "usage: finger [-46gklmpsho] [user ...] [user@host ...]\n");
153 	exit(1);
154 }
155 
156 int
157 main(int argc, char **argv)
158 {
159 	int envargc, argcnt;
160 	char *envargv[3];
161 	struct passwd *pw;
162 	static char myname[] = "finger";
163 
164 	if (getuid() == 0 || geteuid() == 0) {
165 		invoker_root = 1;
166 		if ((pw = getpwnam(UNPRIV_NAME)) && pw->pw_uid > 0) {
167 			 setgid(pw->pw_gid);
168 			 setuid(pw->pw_uid);
169 		} else {
170 			 setgid(UNPRIV_UGID);
171 			 setuid(UNPRIV_UGID);
172 		}
173 	}
174 
175 	(void) setlocale(LC_ALL, "");
176 
177 				/* remove this line to get remote host */
178 	oflag = 1;		/* default to old "office" behavior */
179 
180 	/*
181 	 * Process environment variables followed by command line arguments.
182 	 */
183 	if ((envargv[1] = getenv("FINGER"))) {
184 		envargc = 2;
185 		envargv[0] = myname;
186 		envargv[2] = NULL;
187 		(void) option(envargc, envargv);
188 	}
189 
190 	argcnt = option(argc, argv);
191 	argc -= argcnt;
192 	argv += argcnt;
193 
194 	(void)time(&now);
195 	setpassent(1);
196 	if (!*argv) {
197 		/*
198 		 * Assign explicit "small" format if no names given and -l
199 		 * not selected.  Force the -s BEFORE we get names so proper
200 		 * screening will be done.
201 		 */
202 		if (!lflag)
203 			sflag = 1;	/* if -l not explicit, force -s */
204 		loginlist();
205 		if (entries == 0)
206 			(void)printf("No one logged on.\n");
207 	} else {
208 		userlist(argc, argv);
209 		/*
210 		 * Assign explicit "large" format if names given and -s not
211 		 * explicitly stated.  Force the -l AFTER we get names so any
212 		 * remote finger attempts specified won't be mishandled.
213 		 */
214 		if (!sflag)
215 			lflag = 1;	/* if -s not explicit, force -l */
216 	}
217 	if (entries) {
218 		if (lflag)
219 			lflag_print();
220 		else
221 			sflag_print();
222 	}
223 	return (0);
224 }
225 
226 static void
227 loginlist(void)
228 {
229 	PERSON *pn;
230 	DBT data, key;
231 	struct passwd *pw;
232 	struct utmpx *user;
233 	int r, sflag1;
234 
235 	if (kflag)
236 		errx(1, "can't list logins without reading utmp");
237 
238 	setutxent();
239 	while ((user = getutxent()) != NULL) {
240 		if (user->ut_type != USER_PROCESS)
241 			continue;
242 		if ((pn = find_person(user->ut_user)) == NULL) {
243 			if ((pw = getpwnam(user->ut_user)) == NULL)
244 				continue;
245 			if (hide(pw))
246 				continue;
247 			pn = enter_person(pw);
248 		}
249 		enter_where(user, pn);
250 	}
251 	endutxent();
252 	if (db && lflag)
253 		for (sflag1 = R_FIRST;; sflag1 = R_NEXT) {
254 			PERSON *tmp;
255 
256 			r = (*db->seq)(db, &key, &data, sflag1);
257 			if (r == -1)
258 				err(1, "db seq");
259 			if (r == 1)
260 				break;
261 			memmove(&tmp, data.data, sizeof tmp);
262 			enter_lastlog(tmp);
263 		}
264 }
265 
266 static void
267 userlist(int argc, char **argv)
268 {
269 	PERSON *pn;
270 	DBT data, key;
271 	struct utmpx *user;
272 	struct passwd *pw;
273 	int r, sflag1, *used, *ip;
274 	char **ap, **nargv, **np, **p;
275 	FILE *conf_fp;
276 	char conf_alias[LINE_MAX];
277 	char *conf_realname;
278 	int conf_length;
279 
280 	if ((nargv = malloc((argc+1) * sizeof(char *))) == NULL ||
281 	    (used = calloc(argc, sizeof(int))) == NULL)
282 		err(1, NULL);
283 
284 	/* Pull out all network requests. */
285 	for (ap = p = argv, np = nargv; *p; ++p)
286 		if (index(*p, '@'))
287 			*np++ = *p;
288 		else
289 			*ap++ = *p;
290 
291 	*np++ = NULL;
292 	*ap++ = NULL;
293 
294 	if (!*argv)
295 		goto net;
296 
297 	/*
298 	 * Mark any arguments beginning with '/' as invalid so that we
299 	 * don't accidently confuse them with expansions from finger.conf
300 	 */
301 	for (p = argv, ip = used; *p; ++p, ++ip)
302 	    if (**p == '/') {
303 		*ip = 1;
304 		warnx("%s: no such user", *p);
305 	    }
306 
307 	/*
308 	 * Traverse the finger alias configuration file of the form
309 	 * alias:(user|alias), ignoring comment lines beginning '#'.
310 	 */
311 	if ((conf_fp = fopen(_PATH_FINGERCONF, "r")) != NULL) {
312 	    while(fgets(conf_alias, sizeof(conf_alias), conf_fp) != NULL) {
313 		conf_length = strlen(conf_alias);
314 		if (*conf_alias == '#' || conf_alias[--conf_length] != '\n')
315 		    continue;
316 		conf_alias[conf_length] = '\0';      /* Remove trailing LF */
317 		if ((conf_realname = strchr(conf_alias, ':')) == NULL)
318 		    continue;
319 		*conf_realname = '\0';               /* Replace : with NUL */
320 		for (p = argv; *p; ++p) {
321 		    if (strcmp(*p, conf_alias) == 0) {
322 			if ((*p = strdup(conf_realname+1)) == NULL) {
323 			    err(1, NULL);
324 			}
325 		    }
326 		}
327 	    }
328 	    (void)fclose(conf_fp);
329 	}
330 
331 	/*
332 	 * Traverse the list of possible login names and check the login name
333 	 * and real name against the name specified by the user. If the name
334 	 * begins with a '/', try to read the file of that name instead of
335 	 * gathering the traditional finger information.
336 	 */
337 	if (mflag)
338 		for (p = argv, ip = used; *p; ++p, ++ip) {
339 			if (**p != '/' || *ip == 1 || !show_text("", *p, "")) {
340 				if (((pw = getpwnam(*p)) != NULL) && !hide(pw))
341 					enter_person(pw);
342 				else if (!*ip)
343 					warnx("%s: no such user", *p);
344 			}
345 		}
346 	else {
347 		while ((pw = getpwent()) != NULL) {
348 			for (p = argv, ip = used; *p; ++p, ++ip)
349 				if (**p == '/' && *ip != 1
350 				    && show_text("", *p, ""))
351 					*ip = 1;
352 				else if (match(pw, *p) && !hide(pw)) {
353 					enter_person(pw);
354 					*ip = 1;
355 				}
356 		}
357 		for (p = argv, ip = used; *p; ++p, ++ip)
358 			if (!*ip)
359 				warnx("%s: no such user", *p);
360 	}
361 
362 	/* Handle network requests. */
363 net:	for (p = nargv; *p;) {
364 		netfinger(*p++);
365 		if (*p || entries)
366 		    printf("\n");
367 	}
368 
369 	free(used);
370 	if (entries == 0)
371 		return;
372 
373 	if (kflag)
374 		return;
375 
376 	/*
377 	 * Scan thru the list of users currently logged in, saving
378 	 * appropriate data whenever a match occurs.
379 	 */
380 	setutxent();
381 	while ((user = getutxent()) != NULL) {
382 		if (user->ut_type != USER_PROCESS)
383 			continue;
384 		if ((pn = find_person(user->ut_user)) == NULL)
385 			continue;
386 		enter_where(user, pn);
387 	}
388 	endutxent();
389 	if (db)
390 		for (sflag1 = R_FIRST;; sflag1 = R_NEXT) {
391 			PERSON *tmp;
392 
393 			r = (*db->seq)(db, &key, &data, sflag1);
394 			if (r == -1)
395 				err(1, "db seq");
396 			if (r == 1)
397 				break;
398 			memmove(&tmp, data.data, sizeof tmp);
399 			enter_lastlog(tmp);
400 		}
401 }
402