xref: /netbsd/usr.bin/id/id.c (revision 6550d01e) 
1 /*-
2  * Copyright (c) 1991, 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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 #ifndef lint
32 __COPYRIGHT("@(#) Copyright (c) 1991, 1993\
33  The Regents of the University of California.  All rights reserved.");
34 #endif /* not lint */
35 
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)id.c	8.3 (Berkeley) 4/28/95";
39 #else
40 __RCSID("$NetBSD: id.c,v 1.31 2009/04/12 10:51:38 lukem Exp $");
41 #endif
42 #endif /* not lint */
43 
44 #include <sys/param.h>
45 
46 #include <err.h>
47 #include <errno.h>
48 #include <grp.h>
49 #include <pwd.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54 
55 static void current(void);
56 static void pretty(struct passwd *);
57 static void group(struct passwd *, int);
58 static void usage(void);
59 static void user(struct passwd *);
60 static struct passwd *who(char *);
61 
62 static int maxgroups;
63 static gid_t *groups;
64 
65 int
66 main(int argc, char *argv[])
67 {
68 	struct group *gr;
69 	struct passwd *pw;
70 	int ch, id;
71 	int Gflag, gflag, nflag, pflag, rflag, uflag;
72 	const char *opts;
73 
74 	Gflag = gflag = nflag = pflag = rflag = uflag = 0;
75 
76 	if (strcmp(getprogname(), "groups") == 0) {
77 		Gflag = 1;
78 		nflag = 1;
79 		opts = "";
80 		if (argc > 2)
81 			usage();
82 	} else if (strcmp(getprogname(), "whoami") == 0) {
83 		uflag = 1;
84 		nflag = 1;
85 		opts = "";
86 		if (argc > 1)
87 			usage();
88 	} else
89 		opts = "Ggnpru";
90 
91 	while ((ch = getopt(argc, argv, opts)) != -1)
92 		switch (ch) {
93 		case 'G':
94 			Gflag = 1;
95 			break;
96 		case 'g':
97 			gflag = 1;
98 			break;
99 		case 'n':
100 			nflag = 1;
101 			break;
102 		case 'p':
103 			pflag = 1;
104 			break;
105 		case 'r':
106 			rflag = 1;
107 			break;
108 		case 'u':
109 			uflag = 1;
110 			break;
111 		case '?':
112 		default:
113 			usage();
114 		}
115 	argc -= optind;
116 	argv += optind;
117 
118 	switch (Gflag + gflag + pflag + uflag) {
119 	case 1:
120 		break;
121 	case 0:
122 		if (!nflag && !rflag)
123 			break;
124 		/* FALLTHROUGH */
125 	default:
126 		usage();
127 	}
128 
129 	if (strcmp(opts, "") != 0 && argc > 1)
130 		usage();
131 
132 	pw = *argv ? who(*argv) : NULL;
133 
134 	maxgroups = sysconf(_SC_NGROUPS_MAX);
135 	if ((groups = malloc((maxgroups + 1) * sizeof(gid_t))) == NULL)
136 		err(1, NULL);
137 
138 	if (gflag) {
139 		id = pw ? pw->pw_gid : rflag ? getgid() : getegid();
140 		if (nflag && (gr = getgrgid(id)))
141 			(void)printf("%s\n", gr->gr_name);
142 		else
143 			(void)printf("%u\n", id);
144 		goto done;
145 	}
146 
147 	if (uflag) {
148 		id = pw ? pw->pw_uid : rflag ? getuid() : geteuid();
149 		if (nflag && (pw = getpwuid(id)))
150 			(void)printf("%s\n", pw->pw_name);
151 		else
152 			(void)printf("%u\n", id);
153 		goto done;
154 	}
155 
156 	if (Gflag) {
157 		group(pw, nflag);
158 		goto done;
159 	}
160 
161 	if (pflag) {
162 		pretty(pw);
163 		goto done;
164 	}
165 
166 	if (pw)
167 		user(pw);
168 	else
169 		current();
170 done:
171 	free(groups);
172 
173 	return 0;
174 }
175 
176 static void
177 pretty(struct passwd *pw)
178 {
179 	struct group *gr;
180 	u_int eid, rid;
181 	char *login;
182 
183 	if (pw) {
184 		(void)printf("uid\t%s\n", pw->pw_name);
185 		(void)printf("groups\t");
186 		group(pw, 1);
187 	} else {
188 		if ((login = getlogin()) == NULL)
189 			err(1, "getlogin");
190 
191 		pw = getpwuid(rid = getuid());
192 		if (pw == NULL || strcmp(login, pw->pw_name))
193 			(void)printf("login\t%s\n", login);
194 		if (pw)
195 			(void)printf("uid\t%s\n", pw->pw_name);
196 		else
197 			(void)printf("uid\t%u\n", rid);
198 
199 		if ((eid = geteuid()) != rid) {
200 			if ((pw = getpwuid(eid)) != NULL)
201 				(void)printf("euid\t%s\n", pw->pw_name);
202 			else
203 				(void)printf("euid\t%u\n", eid);
204 		}
205 		if ((rid = getgid()) != (eid = getegid())) {
206 			if ((gr = getgrgid(rid)) != NULL)
207 				(void)printf("rgid\t%s\n", gr->gr_name);
208 			else
209 				(void)printf("rgid\t%u\n", rid);
210 		}
211 		(void)printf("groups\t");
212 		group(NULL, 1);
213 	}
214 }
215 
216 static void
217 current(void)
218 {
219 	struct group *gr;
220 	struct passwd *pw;
221 	gid_t gid, egid, lastid;
222 	uid_t uid, euid;
223 	int cnt, ngroups;
224 	const char *fmt;
225 
226 	uid = getuid();
227 	(void)printf("uid=%ju", (uintmax_t)uid);
228 	if ((pw = getpwuid(uid)) != NULL)
229 		(void)printf("(%s)", pw->pw_name);
230 	gid = getgid();
231 	(void)printf(" gid=%ju", (uintmax_t)gid);
232 	if ((gr = getgrgid(gid)) != NULL)
233 		(void)printf("(%s)", gr->gr_name);
234 	if ((euid = geteuid()) != uid) {
235 		(void)printf(" euid=%ju", (uintmax_t)euid);
236 		if ((pw = getpwuid(euid)) != NULL)
237 			(void)printf("(%s)", pw->pw_name);
238 	}
239 	if ((egid = getegid()) != gid) {
240 		(void)printf(" egid=%ju", (uintmax_t)egid);
241 		if ((gr = getgrgid(egid)) != NULL)
242 			(void)printf("(%s)", gr->gr_name);
243 	}
244 	if ((ngroups = getgroups(maxgroups, groups)) != 0) {
245 		for (fmt = " groups=%ju", lastid = -1, cnt = 0; cnt < ngroups;
246 		    fmt = ",%ju", lastid = gid, cnt++) {
247 			gid = groups[cnt];
248 			if (lastid == gid)
249 				continue;
250 			(void)printf(fmt, (uintmax_t)gid);
251 			if ((gr = getgrgid(gid)) != NULL)
252 				(void)printf("(%s)", gr->gr_name);
253 		}
254 	}
255 	(void)printf("\n");
256 }
257 
258 static void
259 user(struct passwd *pw)
260 {
261 	struct group *gr;
262 	const char *fmt;
263 	int cnt, id, lastid, ngroups;
264 	gid_t *glist = groups;
265 
266 	id = pw->pw_uid;
267 	(void)printf("uid=%u(%s)", id, pw->pw_name);
268 	(void)printf(" gid=%lu", (u_long)pw->pw_gid);
269 	if ((gr = getgrgid(pw->pw_gid)) != NULL)
270 		(void)printf("(%s)", gr->gr_name);
271 	ngroups = maxgroups + 1;
272 	if (getgrouplist(pw->pw_name, pw->pw_gid, glist, &ngroups) == -1) {
273 		glist = malloc(ngroups * sizeof(gid_t));
274 		(void) getgrouplist(pw->pw_name, pw->pw_gid, glist, &ngroups);
275 	}
276 	for (fmt = " groups=%u", lastid = -1, cnt = 0; cnt < ngroups;
277 	    fmt=",%u", lastid = id, cnt++) {
278 		id = glist[cnt];
279 		if (lastid == id)
280 			continue;
281 		(void)printf(fmt, id);
282 		if ((gr = getgrgid(id)) != NULL)
283 			(void)printf("(%s)", gr->gr_name);
284 	}
285 	(void)printf("\n");
286 	if (glist != groups)
287 		free(glist);
288 }
289 
290 static void
291 group(struct passwd *pw, int nflag)
292 {
293 	struct group *gr;
294 	int cnt, ngroups;
295 	gid_t id, lastid;
296 	const char *fmt;
297 	gid_t *glist = groups;
298 
299 	if (pw) {
300 		ngroups = maxgroups;
301 		if (getgrouplist(pw->pw_name, pw->pw_gid, glist, &ngroups)
302 		    == -1) {
303 			glist = malloc(ngroups * sizeof(gid_t));
304 			(void) getgrouplist(pw->pw_name, pw->pw_gid, glist,
305 					    &ngroups);
306 		}
307 	} else {
308 		glist[0] = getgid();
309 		ngroups = getgroups(maxgroups, glist + 1) + 1;
310 	}
311 	fmt = nflag ? "%s" : "%u";
312 	for (lastid = -1, cnt = 0; cnt < ngroups; ++cnt) {
313 		if (lastid == (id = glist[cnt]) || (cnt && id == glist[0]))
314 			continue;
315 		if (nflag) {
316 			if ((gr = getgrgid(id)) != NULL)
317 				(void)printf(fmt, gr->gr_name);
318 			else
319 				(void)printf(*fmt == ' ' ? " %u" : "%u",
320 				    id);
321 			fmt = " %s";
322 		} else {
323 			(void)printf(fmt, id);
324 			fmt = " %u";
325 		}
326 		lastid = id;
327 	}
328 	(void)printf("\n");
329 	if (glist != groups)
330 		free(glist);
331 }
332 
333 static struct passwd *
334 who(char *u)
335 {
336 	struct passwd *pw;
337 	long id;
338 	char *ep;
339 
340 	/*
341 	 * Translate user argument into a pw pointer.  First, try to
342 	 * get it as specified.  If that fails, try it as a number.
343 	 */
344 	if ((pw = getpwnam(u)) != NULL)
345 		return pw;
346 	id = strtol(u, &ep, 10);
347 	if (*u && !*ep && (pw = getpwuid(id)))
348 		return pw;
349 	errx(1, "%s: No such user", u);
350 	/* NOTREACHED */
351 	return NULL;
352 }
353 
354 static void
355 usage(void)
356 {
357 
358 	if (strcmp(getprogname(), "groups") == 0) {
359 		(void)fprintf(stderr, "usage: groups [user]\n");
360 	} else if (strcmp(getprogname(), "whoami") == 0) {
361 		(void)fprintf(stderr, "usage: whoami\n");
362 	} else {
363 		(void)fprintf(stderr, "usage: id [user]\n");
364 		(void)fprintf(stderr, "       id -G [-n] [user]\n");
365 		(void)fprintf(stderr, "       id -g [-nr] [user]\n");
366 		(void)fprintf(stderr, "       id -p [user]\n");
367 		(void)fprintf(stderr, "       id -u [-nr] [user]\n");
368 	}
369 	exit(1);
370 }
371