xref: /freebsd/usr.bin/finger/finger.c (revision 5b31cc94b10d4bb7109c6b27940a0fc76a44a331)
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 #endif
53 
54 #include <sys/cdefs.h>
55 /*
56  * Finger prints out information about users.  It is not portable since
57  * certain fields (e.g. the full user name, office, and phone numbers) are
58  * extracted from the gecos field of the passwd file which other UNIXes
59  * may not have or may use for other things.
60  *
61  * There are currently two output formats; the short format is one line
62  * per user and displays login name, tty, login time, real name, idle time,
63  * and either remote host information (default) or office location/phone
64  * number, depending on if -h or -o is used respectively.
65  * The long format gives the same information (in a more legible format) as
66  * well as home directory, shell, mail info, and .plan/.project files.
67  */
68 
69 #include <sys/types.h>
70 #include <sys/socket.h>
71 #include <db.h>
72 #include <err.h>
73 #include <pwd.h>
74 #include <stdio.h>
75 #include <stdlib.h>
76 #include <string.h>
77 #include <time.h>
78 #include <unistd.h>
79 #include <utmpx.h>
80 #include <locale.h>
81 
82 #include "finger.h"
83 #include "pathnames.h"
84 
85 DB *db;
86 time_t now;
87 static int kflag, mflag, sflag;
88 int entries, gflag, lflag, pplan, oflag;
89 sa_family_t family = PF_UNSPEC;
90 int d_first = -1;
91 char tbuf[1024];
92 int invoker_root = 0;
93 
94 static void loginlist(void);
95 static int option(int, char **);
96 static void usage(void) __dead2;
97 static void userlist(int, char **);
98 
99 static int
100 option(int argc, char **argv)
101 {
102 	int ch;
103 
104 	optind = 1;		/* reset getopt */
105 
106 	while ((ch = getopt(argc, argv, "46gklmpsho")) != -1)
107 		switch(ch) {
108 		case '4':
109 			family = AF_INET;
110 			break;
111 		case '6':
112 			family = AF_INET6;
113 			break;
114 		case 'g':
115 			gflag = 1;
116 			break;
117 		case 'k':
118 			kflag = 1;		/* keep going without utmp */
119 			break;
120 		case 'l':
121 			lflag = 1;		/* long format */
122 			break;
123 		case 'm':
124 			mflag = 1;		/* force exact match of names */
125 			break;
126 		case 'p':
127 			pplan = 1;		/* don't show .plan/.project */
128 			break;
129 		case 's':
130 			sflag = 1;		/* short format */
131 			break;
132 		case 'h':
133 			oflag = 0;		/* remote host info */
134 			break;
135 		case 'o':
136 			oflag = 1;		/* office info */
137 			break;
138 		case '?':
139 		default:
140 			usage();
141 		}
142 
143 	return optind;
144 }
145 
146 static void
147 usage(void)
148 {
149 	(void)fprintf(stderr,
150 	    "usage: finger [-46gklmpsho] [user ...] [user@host ...]\n");
151 	exit(1);
152 }
153 
154 int
155 main(int argc, char **argv)
156 {
157 	int envargc, argcnt;
158 	char *envargv[3];
159 	struct passwd *pw;
160 	static char myname[] = "finger";
161 
162 	if (getuid() == 0 || geteuid() == 0) {
163 		invoker_root = 1;
164 		if ((pw = getpwnam(UNPRIV_NAME)) && pw->pw_uid > 0) {
165 			if (setgid(pw->pw_gid) != 0)
166 				err(1, "setgid()");
167 			if (setuid(pw->pw_uid) != 0)
168 				err(1, "setuid()");
169 		} else {
170 			if (setgid(UNPRIV_UGID) != 0)
171 				err(1, "setgid()");
172 			if (setuid(UNPRIV_UGID) != 0)
173 				err(1, "setuid()");
174 		}
175 	}
176 
177 	(void) setlocale(LC_ALL, "");
178 
179 				/* remove this line to get remote host */
180 	oflag = 1;		/* default to old "office" behavior */
181 
182 	/*
183 	 * Process environment variables followed by command line arguments.
184 	 */
185 	if ((envargv[1] = getenv("FINGER"))) {
186 		envargc = 2;
187 		envargv[0] = myname;
188 		envargv[2] = NULL;
189 		(void) option(envargc, envargv);
190 	}
191 
192 	argcnt = option(argc, argv);
193 	argc -= argcnt;
194 	argv += argcnt;
195 
196 	(void)time(&now);
197 	setpassent(1);
198 	if (!*argv) {
199 		/*
200 		 * Assign explicit "small" format if no names given and -l
201 		 * not selected.  Force the -s BEFORE we get names so proper
202 		 * screening will be done.
203 		 */
204 		if (!lflag)
205 			sflag = 1;	/* if -l not explicit, force -s */
206 		loginlist();
207 		if (entries == 0)
208 			(void)printf("No one logged on.\n");
209 	} else {
210 		userlist(argc, argv);
211 		/*
212 		 * Assign explicit "large" format if names given and -s not
213 		 * explicitly stated.  Force the -l AFTER we get names so any
214 		 * remote finger attempts specified won't be mishandled.
215 		 */
216 		if (!sflag)
217 			lflag = 1;	/* if -s not explicit, force -l */
218 	}
219 	if (entries) {
220 		if (lflag)
221 			lflag_print();
222 		else
223 			sflag_print();
224 	}
225 	return (0);
226 }
227 
228 static void
229 loginlist(void)
230 {
231 	PERSON *pn;
232 	DBT data, key;
233 	struct passwd *pw;
234 	struct utmpx *user;
235 	int r, sflag1;
236 
237 	if (kflag)
238 		errx(1, "can't list logins without reading utmp");
239 
240 	setutxent();
241 	while ((user = getutxent()) != NULL) {
242 		if (user->ut_type != USER_PROCESS)
243 			continue;
244 		if ((pn = find_person(user->ut_user)) == NULL) {
245 			if ((pw = getpwnam(user->ut_user)) == NULL)
246 				continue;
247 			if (hide(pw))
248 				continue;
249 			pn = enter_person(pw);
250 		}
251 		enter_where(user, pn);
252 	}
253 	endutxent();
254 	if (db && lflag)
255 		for (sflag1 = R_FIRST;; sflag1 = R_NEXT) {
256 			PERSON *tmp;
257 
258 			r = (*db->seq)(db, &key, &data, sflag1);
259 			if (r == -1)
260 				err(1, "db seq");
261 			if (r == 1)
262 				break;
263 			memmove(&tmp, data.data, sizeof tmp);
264 			enter_lastlog(tmp);
265 		}
266 }
267 
268 static void
269 userlist(int argc, char **argv)
270 {
271 	PERSON *pn;
272 	DBT data, key;
273 	struct utmpx *user;
274 	struct passwd *pw;
275 	int r, sflag1, *used, *ip;
276 	char **ap, **nargv, **np, **p;
277 	FILE *conf_fp;
278 	char conf_alias[LINE_MAX];
279 	char *conf_realname;
280 	int conf_length;
281 
282 	if ((nargv = malloc((argc+1) * sizeof(char *))) == NULL ||
283 	    (used = calloc(argc, sizeof(int))) == NULL)
284 		err(1, NULL);
285 
286 	/* Pull out all network requests. */
287 	for (ap = p = argv, np = nargv; *p; ++p)
288 		if (strchr(*p, '@'))
289 			*np++ = *p;
290 		else
291 			*ap++ = *p;
292 
293 	*np++ = NULL;
294 	*ap++ = NULL;
295 
296 	if (!*argv)
297 		goto net;
298 
299 	/*
300 	 * Mark any arguments beginning with '/' as invalid so that we
301 	 * don't accidentally confuse them with expansions from finger.conf
302 	 */
303 	for (p = argv, ip = used; *p; ++p, ++ip)
304 	    if (**p == '/') {
305 		*ip = 1;
306 		warnx("%s: no such user", *p);
307 	    }
308 
309 	/*
310 	 * Traverse the finger alias configuration file of the form
311 	 * alias:(user|alias), ignoring comment lines beginning '#'.
312 	 */
313 	if ((conf_fp = fopen(_PATH_FINGERCONF, "r")) != NULL) {
314 	    while(fgets(conf_alias, sizeof(conf_alias), conf_fp) != NULL) {
315 		conf_length = strlen(conf_alias);
316 		if (*conf_alias == '#' || conf_alias[--conf_length] != '\n')
317 		    continue;
318 		conf_alias[conf_length] = '\0';      /* Remove trailing LF */
319 		if ((conf_realname = strchr(conf_alias, ':')) == NULL)
320 		    continue;
321 		*conf_realname = '\0';               /* Replace : with NUL */
322 		for (p = argv; *p; ++p) {
323 		    if (strcmp(*p, conf_alias) == 0) {
324 			if ((*p = strdup(conf_realname+1)) == NULL) {
325 			    err(1, NULL);
326 			}
327 		    }
328 		}
329 	    }
330 	    (void)fclose(conf_fp);
331 	}
332 
333 	/*
334 	 * Traverse the list of possible login names and check the login name
335 	 * and real name against the name specified by the user. If the name
336 	 * begins with a '/', try to read the file of that name instead of
337 	 * gathering the traditional finger information.
338 	 */
339 	if (mflag)
340 		for (p = argv, ip = used; *p; ++p, ++ip) {
341 			if (**p != '/' || *ip == 1 || !show_text("", *p, "")) {
342 				if (((pw = getpwnam(*p)) != NULL) && !hide(pw))
343 					enter_person(pw);
344 				else if (!*ip)
345 					warnx("%s: no such user", *p);
346 			}
347 		}
348 	else {
349 		while ((pw = getpwent()) != NULL) {
350 			for (p = argv, ip = used; *p; ++p, ++ip)
351 				if (**p == '/' && *ip != 1
352 				    && show_text("", *p, ""))
353 					*ip = 1;
354 				else if (match(pw, *p) && !hide(pw)) {
355 					enter_person(pw);
356 					*ip = 1;
357 				}
358 		}
359 		for (p = argv, ip = used; *p; ++p, ++ip)
360 			if (!*ip)
361 				warnx("%s: no such user", *p);
362 	}
363 
364 	/* Handle network requests. */
365 net:	for (p = nargv; *p;) {
366 		netfinger(*p++);
367 		if (*p || entries)
368 		    printf("\n");
369 	}
370 
371 	free(nargv);
372 	free(used);
373 	if (entries == 0)
374 		return;
375 
376 	if (kflag)
377 		return;
378 
379 	/*
380 	 * Scan thru the list of users currently logged in, saving
381 	 * appropriate data whenever a match occurs.
382 	 */
383 	setutxent();
384 	while ((user = getutxent()) != NULL) {
385 		if (user->ut_type != USER_PROCESS)
386 			continue;
387 		if ((pn = find_person(user->ut_user)) == NULL)
388 			continue;
389 		enter_where(user, pn);
390 	}
391 	endutxent();
392 	if (db)
393 		for (sflag1 = R_FIRST;; sflag1 = R_NEXT) {
394 			PERSON *tmp;
395 
396 			r = (*db->seq)(db, &key, &data, sflag1);
397 			if (r == -1)
398 				err(1, "db seq");
399 			if (r == 1)
400 				break;
401 			memmove(&tmp, data.data, sizeof tmp);
402 			enter_lastlog(tmp);
403 		}
404 }
405