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      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 1.32 2011/09/16 15:39:26 joerg 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 __dead 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