xref: /netbsd-src/usr.bin/id/id.c (revision fad4c9f71477ae11cea2ee75ec82151ac770a534)
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\n\
33 	The Regents of the University of California.  All rights reserved.\n");
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 1.27 2006/06/07 13:09:56 liamjfoy 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 
73 	Gflag = gflag = nflag = pflag = rflag = uflag = 0;
74 
75 	if (strcmp(getprogname(), "groups") == 0) {
76 		Gflag = 1;
77 		nflag = 1;
78 	} else if (strcmp(getprogname(), "whoami") == 0) {
79 		uflag = 1;
80 		nflag = 1;
81 	}
82 
83 	while ((ch = getopt(argc, argv, "Ggnpru")) != -1)
84 		switch (ch) {
85 		case 'G':
86 			Gflag = 1;
87 			break;
88 		case 'g':
89 			gflag = 1;
90 			break;
91 		case 'n':
92 			nflag = 1;
93 			break;
94 		case 'p':
95 			pflag = 1;
96 			break;
97 		case 'r':
98 			rflag = 1;
99 			break;
100 		case 'u':
101 			uflag = 1;
102 			break;
103 		case '?':
104 		default:
105 			usage();
106 		}
107 	argc -= optind;
108 	argv += optind;
109 
110 	switch (Gflag + gflag + pflag + uflag) {
111 	case 1:
112 		break;
113 	case 0:
114 		if (!nflag && !rflag)
115 			break;
116 		/* FALLTHROUGH */
117 	default:
118 		usage();
119 	}
120 
121 	pw = *argv ? who(*argv) : NULL;
122 
123 	maxgroups = sysconf(_SC_NGROUPS_MAX);
124 	if ((groups = malloc((maxgroups + 1) * sizeof(gid_t))) == NULL)
125 		err(1, NULL);
126 
127 	if (gflag) {
128 		id = pw ? pw->pw_gid : rflag ? getgid() : getegid();
129 		if (nflag && (gr = getgrgid(id)))
130 			(void)printf("%s\n", gr->gr_name);
131 		else
132 			(void)printf("%u\n", id);
133 		goto done;
134 	}
135 
136 	if (uflag) {
137 		id = pw ? pw->pw_uid : rflag ? getuid() : geteuid();
138 		if (nflag && (pw = getpwuid(id)))
139 			(void)printf("%s\n", pw->pw_name);
140 		else
141 			(void)printf("%u\n", id);
142 		goto done;
143 	}
144 
145 	if (Gflag) {
146 		group(pw, nflag);
147 		goto done;
148 	}
149 
150 	if (pflag) {
151 		pretty(pw);
152 		goto done;
153 	}
154 
155 	if (pw)
156 		user(pw);
157 	else
158 		current();
159 done:
160 	free(groups);
161 
162 	return 0;
163 }
164 
165 static void
166 pretty(struct passwd *pw)
167 {
168 	struct group *gr;
169 	u_int eid, rid;
170 	char *login;
171 
172 	if (pw) {
173 		(void)printf("uid\t%s\n", pw->pw_name);
174 		(void)printf("groups\t");
175 		group(pw, 1);
176 	} else {
177 		if ((login = getlogin()) == NULL)
178 			err(1, "getlogin");
179 
180 		pw = getpwuid(rid = getuid());
181 		if (pw == NULL || strcmp(login, pw->pw_name))
182 			(void)printf("login\t%s\n", login);
183 		if (pw)
184 			(void)printf("uid\t%s\n", pw->pw_name);
185 		else
186 			(void)printf("uid\t%u\n", rid);
187 
188 		if ((eid = geteuid()) != rid) {
189 			if ((pw = getpwuid(eid)) != NULL)
190 				(void)printf("euid\t%s\n", pw->pw_name);
191 			else
192 				(void)printf("euid\t%u\n", eid);
193 		}
194 		if ((rid = getgid()) != (eid = getegid())) {
195 			if ((gr = getgrgid(rid)) != NULL)
196 				(void)printf("rgid\t%s\n", gr->gr_name);
197 			else
198 				(void)printf("rgid\t%u\n", rid);
199 		}
200 		(void)printf("groups\t");
201 		group(NULL, 1);
202 	}
203 }
204 
205 static void
206 current(void)
207 {
208 	struct group *gr;
209 	struct passwd *pw;
210 	gid_t gid, egid, lastid;
211 	uid_t uid, euid;
212 	int cnt, ngroups;
213 	const char *fmt;
214 
215 	uid = getuid();
216 	(void)printf("uid=%ju", (uintmax_t)uid);
217 	if ((pw = getpwuid(uid)) != NULL)
218 		(void)printf("(%s)", pw->pw_name);
219 	gid = getgid();
220 	(void)printf(" gid=%ju", (uintmax_t)gid);
221 	if ((gr = getgrgid(gid)) != NULL)
222 		(void)printf("(%s)", gr->gr_name);
223 	if ((euid = geteuid()) != uid) {
224 		(void)printf(" euid=%ju", (uintmax_t)euid);
225 		if ((pw = getpwuid(euid)) != NULL)
226 			(void)printf("(%s)", pw->pw_name);
227 	}
228 	if ((egid = getegid()) != gid) {
229 		(void)printf(" egid=%ju", (uintmax_t)egid);
230 		if ((gr = getgrgid(egid)) != NULL)
231 			(void)printf("(%s)", gr->gr_name);
232 	}
233 	if ((ngroups = getgroups(maxgroups, groups)) != 0) {
234 		for (fmt = " groups=%ju", lastid = -1, cnt = 0; cnt < ngroups;
235 		    fmt = ",%ju", lastid = gid, cnt++) {
236 			gid = groups[cnt];
237 			if (lastid == gid)
238 				continue;
239 			(void)printf(fmt, (uintmax_t)gid);
240 			if ((gr = getgrgid(gid)) != NULL)
241 				(void)printf("(%s)", gr->gr_name);
242 		}
243 	}
244 	(void)printf("\n");
245 }
246 
247 static void
248 user(struct passwd *pw)
249 {
250 	struct group *gr;
251 	const char *fmt;
252 	int cnt, id, lastid, ngroups;
253 	gid_t *glist = groups;
254 
255 	id = pw->pw_uid;
256 	(void)printf("uid=%u(%s)", id, pw->pw_name);
257 	(void)printf(" gid=%lu", (u_long)pw->pw_gid);
258 	if ((gr = getgrgid(pw->pw_gid)) != NULL)
259 		(void)printf("(%s)", gr->gr_name);
260 	ngroups = maxgroups + 1;
261 	if (getgrouplist(pw->pw_name, pw->pw_gid, glist, &ngroups) == -1) {
262 		glist = malloc(ngroups * sizeof(gid_t));
263 		(void) getgrouplist(pw->pw_name, pw->pw_gid, glist, &ngroups);
264 	}
265 	for (fmt = " groups=%u", lastid = -1, cnt = 0; cnt < ngroups;
266 	    fmt=",%u", lastid = id, cnt++) {
267 		id = glist[cnt];
268 		if (lastid == id)
269 			continue;
270 		(void)printf(fmt, id);
271 		if ((gr = getgrgid(id)) != NULL)
272 			(void)printf("(%s)", gr->gr_name);
273 	}
274 	(void)printf("\n");
275 	if (glist != groups)
276 		free(glist);
277 }
278 
279 static void
280 group(struct passwd *pw, int nflag)
281 {
282 	struct group *gr;
283 	int cnt, id, lastid, ngroups;
284 	const char *fmt;
285 	gid_t *glist = groups;
286 
287 	if (pw) {
288 		ngroups = maxgroups;
289 		if (getgrouplist(pw->pw_name, pw->pw_gid, glist, &ngroups)
290 		    == -1) {
291 			glist = malloc(ngroups * sizeof(gid_t));
292 			(void) getgrouplist(pw->pw_name, pw->pw_gid, glist,
293 					    &ngroups);
294 		}
295 	} else {
296 		glist[0] = getgid();
297 		ngroups = getgroups(maxgroups, glist + 1) + 1;
298 	}
299 	fmt = nflag ? "%s" : "%u";
300 	for (lastid = -1, cnt = 0; cnt < ngroups; ++cnt) {
301 		if (lastid == (id = glist[cnt]) || (cnt && id == glist[0]))
302 			continue;
303 		if (nflag) {
304 			if ((gr = getgrgid(id)) != NULL)
305 				(void)printf(fmt, gr->gr_name);
306 			else
307 				(void)printf(*fmt == ' ' ? " %u" : "%u",
308 				    id);
309 			fmt = " %s";
310 		} else {
311 			(void)printf(fmt, id);
312 			fmt = " %u";
313 		}
314 		lastid = id;
315 	}
316 	(void)printf("\n");
317 	if (glist != groups)
318 		free(glist);
319 }
320 
321 static struct passwd *
322 who(char *u)
323 {
324 	struct passwd *pw;
325 	long id;
326 	char *ep;
327 
328 	/*
329 	 * Translate user argument into a pw pointer.  First, try to
330 	 * get it as specified.  If that fails, try it as a number.
331 	 */
332 	if ((pw = getpwnam(u)) != NULL)
333 		return pw;
334 	id = strtol(u, &ep, 10);
335 	if (*u && !*ep && (pw = getpwuid(id)))
336 		return pw;
337 	errx(1, "%s: No such user", u);
338 	/* NOTREACHED */
339 	return NULL;
340 }
341 
342 static void
343 usage(void)
344 {
345 
346 	if (strcmp(getprogname(), "groups") == 0) {
347 		(void)fprintf(stderr, "usage: groups [user]\n");
348 	} else if (strcmp(getprogname(), "whoami") == 0) {
349 		(void)fprintf(stderr, "usage: whoami\n");
350 	} else {
351 		(void)fprintf(stderr, "usage: id [user]\n");
352 		(void)fprintf(stderr, "       id -G [-n] [user]\n");
353 		(void)fprintf(stderr, "       id -g [-nr] [user]\n");
354 		(void)fprintf(stderr, "       id -p [user]\n");
355 		(void)fprintf(stderr, "       id -u [-nr] [user]\n");
356 	}
357 	exit(1);
358 }
359