xref: /freebsd/usr.bin/finger/finger.c (revision cc68614da8232d8baaca0ae0d0dd8f890f06623e)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Tony Nardo of the Johns Hopkins University/Applied Physics Lab.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 /*
36  * Luke Mewburn <lm@rmit.edu.au> added the following on 940622:
37  *    - mail status ("No Mail", "Mail read:...", or "New Mail ...,
38  *	Unread since ...".)
39  *    - 4 digit phone extensions (3210 is printed as x3210.)
40  *    - host/office toggling in short format with -h & -o.
41  *    - short day names (`Tue' printed instead of `Jun 21' if the
42  *	login time is < 6 days.
43  */
44 
45 #ifndef lint
46 static const char copyright[] =
47 "@(#) Copyright (c) 1989, 1993\n\
48 	The Regents of the University of California.  All rights reserved.\n";
49 #endif /* not lint */
50 
51 #if 0
52 #ifndef lint
53 static char sccsid[] = "@(#)finger.c	8.5 (Berkeley) 5/4/95";
54 #endif
55 #endif
56 
57 #include <sys/cdefs.h>
58 __FBSDID("$FreeBSD$");
59 
60 /*
61  * Finger prints out information about users.  It is not portable since
62  * certain fields (e.g. the full user name, office, and phone numbers) are
63  * extracted from the gecos field of the passwd file which other UNIXes
64  * may not have or may use for other things.
65  *
66  * There are currently two output formats; the short format is one line
67  * per user and displays login name, tty, login time, real name, idle time,
68  * and either remote host information (default) or office location/phone
69  * number, depending on if -h or -o is used respectively.
70  * The long format gives the same information (in a more legible format) as
71  * well as home directory, shell, mail info, and .plan/.project files.
72  */
73 
74 #include <sys/types.h>
75 #include <sys/socket.h>
76 #include <db.h>
77 #include <err.h>
78 #include <pwd.h>
79 #include <stdio.h>
80 #include <stdlib.h>
81 #include <string.h>
82 #include <time.h>
83 #include <unistd.h>
84 #include <utmpx.h>
85 #include <locale.h>
86 
87 #include "finger.h"
88 #include "pathnames.h"
89 
90 DB *db;
91 time_t now;
92 static int kflag, mflag, sflag;
93 int entries, gflag, lflag, pplan, oflag;
94 sa_family_t family = PF_UNSPEC;
95 int d_first = -1;
96 char tbuf[1024];
97 int invoker_root = 0;
98 
99 static void loginlist(void);
100 static int option(int, char **);
101 static void usage(void);
102 static void userlist(int, char **);
103 
104 static int
105 option(int argc, char **argv)
106 {
107 	int ch;
108 
109 	optind = 1;		/* reset getopt */
110 
111 	while ((ch = getopt(argc, argv, "46gklmpsho")) != -1)
112 		switch(ch) {
113 		case '4':
114 			family = AF_INET;
115 			break;
116 		case '6':
117 			family = AF_INET6;
118 			break;
119 		case 'g':
120 			gflag = 1;
121 			break;
122 		case 'k':
123 			kflag = 1;		/* keep going without utmp */
124 			break;
125 		case 'l':
126 			lflag = 1;		/* long format */
127 			break;
128 		case 'm':
129 			mflag = 1;		/* force exact match of names */
130 			break;
131 		case 'p':
132 			pplan = 1;		/* don't show .plan/.project */
133 			break;
134 		case 's':
135 			sflag = 1;		/* short format */
136 			break;
137 		case 'h':
138 			oflag = 0;		/* remote host info */
139 			break;
140 		case 'o':
141 			oflag = 1;		/* office info */
142 			break;
143 		case '?':
144 		default:
145 			usage();
146 		}
147 
148 	return optind;
149 }
150 
151 static void
152 usage(void)
153 {
154 	(void)fprintf(stderr,
155 	    "usage: finger [-46gklmpsho] [user ...] [user@host ...]\n");
156 	exit(1);
157 }
158 
159 int
160 main(int argc, char **argv)
161 {
162 	int envargc, argcnt;
163 	char *envargv[3];
164 	struct passwd *pw;
165 	static char myname[] = "finger";
166 
167 	if (getuid() == 0 || geteuid() == 0) {
168 		invoker_root = 1;
169 		if ((pw = getpwnam(UNPRIV_NAME)) && pw->pw_uid > 0) {
170 			if (setgid(pw->pw_gid) != 0)
171 				err(1, "setgid()");
172 			if (setuid(pw->pw_uid) != 0)
173 				err(1, "setuid()");
174 		} else {
175 			if (setgid(UNPRIV_UGID) != 0)
176 				err(1, "setgid()");
177 			if (setuid(UNPRIV_UGID) != 0)
178 				err(1, "setuid()");
179 		}
180 	}
181 
182 	(void) setlocale(LC_ALL, "");
183 
184 				/* remove this line to get remote host */
185 	oflag = 1;		/* default to old "office" behavior */
186 
187 	/*
188 	 * Process environment variables followed by command line arguments.
189 	 */
190 	if ((envargv[1] = getenv("FINGER"))) {
191 		envargc = 2;
192 		envargv[0] = myname;
193 		envargv[2] = NULL;
194 		(void) option(envargc, envargv);
195 	}
196 
197 	argcnt = option(argc, argv);
198 	argc -= argcnt;
199 	argv += argcnt;
200 
201 	(void)time(&now);
202 	setpassent(1);
203 	if (!*argv) {
204 		/*
205 		 * Assign explicit "small" format if no names given and -l
206 		 * not selected.  Force the -s BEFORE we get names so proper
207 		 * screening will be done.
208 		 */
209 		if (!lflag)
210 			sflag = 1;	/* if -l not explicit, force -s */
211 		loginlist();
212 		if (entries == 0)
213 			(void)printf("No one logged on.\n");
214 	} else {
215 		userlist(argc, argv);
216 		/*
217 		 * Assign explicit "large" format if names given and -s not
218 		 * explicitly stated.  Force the -l AFTER we get names so any
219 		 * remote finger attempts specified won't be mishandled.
220 		 */
221 		if (!sflag)
222 			lflag = 1;	/* if -s not explicit, force -l */
223 	}
224 	if (entries) {
225 		if (lflag)
226 			lflag_print();
227 		else
228 			sflag_print();
229 	}
230 	return (0);
231 }
232 
233 static void
234 loginlist(void)
235 {
236 	PERSON *pn;
237 	DBT data, key;
238 	struct passwd *pw;
239 	struct utmpx *user;
240 	int r, sflag1;
241 
242 	if (kflag)
243 		errx(1, "can't list logins without reading utmp");
244 
245 	setutxent();
246 	while ((user = getutxent()) != NULL) {
247 		if (user->ut_type != USER_PROCESS)
248 			continue;
249 		if ((pn = find_person(user->ut_user)) == NULL) {
250 			if ((pw = getpwnam(user->ut_user)) == NULL)
251 				continue;
252 			if (hide(pw))
253 				continue;
254 			pn = enter_person(pw);
255 		}
256 		enter_where(user, pn);
257 	}
258 	endutxent();
259 	if (db && lflag)
260 		for (sflag1 = R_FIRST;; sflag1 = R_NEXT) {
261 			PERSON *tmp;
262 
263 			r = (*db->seq)(db, &key, &data, sflag1);
264 			if (r == -1)
265 				err(1, "db seq");
266 			if (r == 1)
267 				break;
268 			memmove(&tmp, data.data, sizeof tmp);
269 			enter_lastlog(tmp);
270 		}
271 }
272 
273 static void
274 userlist(int argc, char **argv)
275 {
276 	PERSON *pn;
277 	DBT data, key;
278 	struct utmpx *user;
279 	struct passwd *pw;
280 	int r, sflag1, *used, *ip;
281 	char **ap, **nargv, **np, **p;
282 	FILE *conf_fp;
283 	char conf_alias[LINE_MAX];
284 	char *conf_realname;
285 	int conf_length;
286 
287 	if ((nargv = malloc((argc+1) * sizeof(char *))) == NULL ||
288 	    (used = calloc(argc, sizeof(int))) == NULL)
289 		err(1, NULL);
290 
291 	/* Pull out all network requests. */
292 	for (ap = p = argv, np = nargv; *p; ++p)
293 		if (strchr(*p, '@'))
294 			*np++ = *p;
295 		else
296 			*ap++ = *p;
297 
298 	*np++ = NULL;
299 	*ap++ = NULL;
300 
301 	if (!*argv)
302 		goto net;
303 
304 	/*
305 	 * Mark any arguments beginning with '/' as invalid so that we
306 	 * don't accidentally confuse them with expansions from finger.conf
307 	 */
308 	for (p = argv, ip = used; *p; ++p, ++ip)
309 	    if (**p == '/') {
310 		*ip = 1;
311 		warnx("%s: no such user", *p);
312 	    }
313 
314 	/*
315 	 * Traverse the finger alias configuration file of the form
316 	 * alias:(user|alias), ignoring comment lines beginning '#'.
317 	 */
318 	if ((conf_fp = fopen(_PATH_FINGERCONF, "r")) != NULL) {
319 	    while(fgets(conf_alias, sizeof(conf_alias), conf_fp) != NULL) {
320 		conf_length = strlen(conf_alias);
321 		if (*conf_alias == '#' || conf_alias[--conf_length] != '\n')
322 		    continue;
323 		conf_alias[conf_length] = '\0';      /* Remove trailing LF */
324 		if ((conf_realname = strchr(conf_alias, ':')) == NULL)
325 		    continue;
326 		*conf_realname = '\0';               /* Replace : with NUL */
327 		for (p = argv; *p; ++p) {
328 		    if (strcmp(*p, conf_alias) == 0) {
329 			if ((*p = strdup(conf_realname+1)) == NULL) {
330 			    err(1, NULL);
331 			}
332 		    }
333 		}
334 	    }
335 	    (void)fclose(conf_fp);
336 	}
337 
338 	/*
339 	 * Traverse the list of possible login names and check the login name
340 	 * and real name against the name specified by the user. If the name
341 	 * begins with a '/', try to read the file of that name instead of
342 	 * gathering the traditional finger information.
343 	 */
344 	if (mflag)
345 		for (p = argv, ip = used; *p; ++p, ++ip) {
346 			if (**p != '/' || *ip == 1 || !show_text("", *p, "")) {
347 				if (((pw = getpwnam(*p)) != NULL) && !hide(pw))
348 					enter_person(pw);
349 				else if (!*ip)
350 					warnx("%s: no such user", *p);
351 			}
352 		}
353 	else {
354 		while ((pw = getpwent()) != NULL) {
355 			for (p = argv, ip = used; *p; ++p, ++ip)
356 				if (**p == '/' && *ip != 1
357 				    && show_text("", *p, ""))
358 					*ip = 1;
359 				else if (match(pw, *p) && !hide(pw)) {
360 					enter_person(pw);
361 					*ip = 1;
362 				}
363 		}
364 		for (p = argv, ip = used; *p; ++p, ++ip)
365 			if (!*ip)
366 				warnx("%s: no such user", *p);
367 	}
368 
369 	/* Handle network requests. */
370 net:	for (p = nargv; *p;) {
371 		netfinger(*p++);
372 		if (*p || entries)
373 		    printf("\n");
374 	}
375 
376 	free(nargv);
377 	free(used);
378 	if (entries == 0)
379 		return;
380 
381 	if (kflag)
382 		return;
383 
384 	/*
385 	 * Scan thru the list of users currently logged in, saving
386 	 * appropriate data whenever a match occurs.
387 	 */
388 	setutxent();
389 	while ((user = getutxent()) != NULL) {
390 		if (user->ut_type != USER_PROCESS)
391 			continue;
392 		if ((pn = find_person(user->ut_user)) == NULL)
393 			continue;
394 		enter_where(user, pn);
395 	}
396 	endutxent();
397 	if (db)
398 		for (sflag1 = R_FIRST;; sflag1 = R_NEXT) {
399 			PERSON *tmp;
400 
401 			r = (*db->seq)(db, &key, &data, sflag1);
402 			if (r == -1)
403 				err(1, "db seq");
404 			if (r == 1)
405 				break;
406 			memmove(&tmp, data.data, sizeof tmp);
407 			enter_lastlog(tmp);
408 		}
409 }
410