usr.bin/id/id.c

   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 }