commands/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
  32 #include <sys/param.h>
  33
  34 #include <err.h>
  35 #include <errno.h>
  36 #include <grp.h>
  37 #include <pwd.h>
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <string.h>
  41 #include <unistd.h>
  42
  43 static void current(void);
  44 static void pretty(struct passwd *);
  45 static void group(struct passwd *, int);
  46 static void usage(void);
  47 static void user(struct passwd *);
  48 static struct passwd *who(char *);
  49
  50 static int maxgroups;
  51 static gid_t *groups;
  52
  53 int
  54 main(int argc, char *argv[])
  55 {
  56         struct group *gr;
  57         struct passwd *pw;
  58         int ch, id;
  59         int Gflag, gflag, nflag, pflag, rflag, uflag;
  60         const char *opts;
  61
  62         Gflag = gflag = nflag = pflag = rflag = uflag = 0;
  63
  64         if (strcmp(getprogname(), "groups") == 0) {
  65                 Gflag = 1;
  66                 nflag = 1;
  67                 opts = "";
  68                 if (argc > 2)
  69                         usage();
  70         } else if (strcmp(getprogname(), "whoami") == 0) {
  71                 uflag = 1;
  72                 nflag = 1;
  73                 opts = "";
  74                 if (argc > 1)
  75                         usage();
  76         } else
  77                 opts = "Ggnpru";
  78
  79         while ((ch = getopt(argc, argv, opts)) != -1)
  80                 switch (ch) {
  81                 case 'G':
  82                         Gflag = 1;
  83                         break;
  84                 case 'g':
  85                         gflag = 1;
  86                         break;
  87                 case 'n':
  88                         nflag = 1;
  89                         break;
  90                 case 'p':
  91                         pflag = 1;
  92                         break;
  93                 case 'r':
  94                         rflag = 1;
  95                         break;
  96                 case 'u':
  97                         uflag = 1;
  98                         break;
  99                 case '?':
 100                 default:
 101                         usage();
 102                 }
 103         argc -= optind;
 104         argv += optind;
 105
 106         switch (Gflag + gflag + pflag + uflag) {
 107         case 1:
 108                 break;
 109         case 0:
 110                 if (!nflag && !rflag)
 111                         break;
 112                 /* FALLTHROUGH */
 113         default:
 114                 usage();
 115         }
 116
 117         if (strcmp(opts, "") != 0 && argc > 1)
 118                 usage();
 119
 120         pw = *argv ? who(*argv) : NULL;
 121
 122         maxgroups = sysconf(_SC_NGROUPS_MAX);
 123         if ((groups = malloc((maxgroups + 1) * sizeof(gid_t))) == NULL)
 124                 err(1, NULL);
 125
 126         if (gflag) {
 127                 id = pw ? pw->pw_gid : rflag ? getgid() : getegid();
 128                 if (nflag && (gr = getgrgid(id)))
 129                         (void)printf("%s\n", gr->gr_name);
 130                 else
 131                         (void)printf("%u\n", id);
 132                 goto done;
 133         }
 134
 135         if (uflag) {
 136                 id = pw ? pw->pw_uid : rflag ? getuid() : geteuid();
 137                 if (nflag && (pw = getpwuid(id)))
 138                         (void)printf("%s\n", pw->pw_name);
 139                 else
 140                         (void)printf("%u\n", id);
 141                 goto done;
 142         }
 143
 144         if (Gflag) {
 145                 group(pw, nflag);
 146                 goto done;
 147         }
 148
 149         if (pflag) {
 150                 pretty(pw);
 151                 goto done;
 152         }
 153
 154         if (pw)
 155                 user(pw);
 156         else
 157                 current();
 158 done:
 159         free(groups);
 160
 161         return 0;
 162 }
 163
 164 static void
 165 pretty(struct passwd *pw)
 166 {
 167         struct group *gr;
 168         u_int eid, rid;
 169         char *login;
 170
 171         if (pw) {
 172                 (void)printf("uid\t%s\n", pw->pw_name);
 173                 (void)printf("groups\t");
 174                 group(pw, 1);
 175         } else {
 176                 if ((login = getlogin()) == NULL)
 177                         err(1, "getlogin");
 178
 179                 pw = getpwuid(rid = getuid());
 180                 if (pw == NULL || strcmp(login, pw->pw_name))
 181                         (void)printf("login\t%s\n", login);
 182                 if (pw)
 183                         (void)printf("uid\t%s\n", pw->pw_name);
 184                 else
 185                         (void)printf("uid\t%u\n", rid);
 186
 187                 if ((eid = geteuid()) != rid) {
 188                         if ((pw = getpwuid(eid)) != NULL)
 189                                 (void)printf("euid\t%s\n", pw->pw_name);
 190                         else
 191                                 (void)printf("euid\t%u\n", eid);
 192                 }
 193                 if ((rid = getgid()) != (eid = getegid())) {
 194                         if ((gr = getgrgid(rid)) != NULL)
 195                                 (void)printf("rgid\t%s\n", gr->gr_name);
 196                         else
 197                                 (void)printf("rgid\t%u\n", rid);
 198                 }
 199                 (void)printf("groups\t");
 200                 group(NULL, 1);
 201         }
 202 }
 203
 204 static void
 205 current(void)
 206 {
 207         struct group *gr;
 208         struct passwd *pw;
 209         gid_t gid, egid, lastid;
 210         uid_t uid, euid;
 211         int cnt, ngroups;
 212         const char *fmt;
 213
 214         uid = getuid();
 215         (void)printf("uid=%ju", (uintmax_t)uid);
 216         if ((pw = getpwuid(uid)) != NULL)
 217                 (void)printf("(%s)", pw->pw_name);
 218         gid = getgid();
 219         (void)printf(" gid=%ju", (uintmax_t)gid);
 220         if ((gr = getgrgid(gid)) != NULL)
 221                 (void)printf("(%s)", gr->gr_name);
 222         if ((euid = geteuid()) != uid) {
 223                 (void)printf(" euid=%ju", (uintmax_t)euid);
 224                 if ((pw = getpwuid(euid)) != NULL)
 225                         (void)printf("(%s)", pw->pw_name);
 226         }
 227         if ((egid = getegid()) != gid) {
 228                 (void)printf(" egid=%ju", (uintmax_t)egid);
 229                 if ((gr = getgrgid(egid)) != NULL)
 230                         (void)printf("(%s)", gr->gr_name);
 231         }
 232 #ifndef __minix
 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 #endif
 245         (void)printf("\n");
 246 }
 247
 248 static void
 249 user(struct passwd *pw)
 250 {
 251         struct group *gr;
 252         const char *fmt;
 253         int cnt, id, lastid, ngroups;
 254         gid_t *glist = groups;
 255
 256         id = pw->pw_uid;
 257         (void)printf("uid=%u(%s)", id, pw->pw_name);
 258         (void)printf(" gid=%lu", (u_long)pw->pw_gid);
 259         if ((gr = getgrgid(pw->pw_gid)) != NULL)
 260                 (void)printf("(%s)", gr->gr_name);
 261         ngroups = maxgroups + 1;
 262 #ifndef __minix
 263         if (getgrouplist(pw->pw_name, pw->pw_gid, glist, &ngroups) == -1) {
 264                 glist = malloc(ngroups * sizeof(gid_t));
 265                 (void) getgrouplist(pw->pw_name, pw->pw_gid, glist, &ngroups);
 266         }
 267 #endif
 268         for (fmt = " groups=%u", lastid = -1, cnt = 0; cnt < ngroups;
 269             fmt=",%u", lastid = id, cnt++) {
 270                 id = glist[cnt];
 271                 if (lastid == id)
 272                         continue;
 273                 (void)printf(fmt, id);
 274                 if ((gr = getgrgid(id)) != NULL)
 275                         (void)printf("(%s)", gr->gr_name);
 276         }
 277         (void)printf("\n");
 278         if (glist != groups)
 279                 free(glist);
 280 }
 281
 282 static void
 283 group(struct passwd *pw, int nflag)
 284 {
 285         struct group *gr;
 286         int cnt, id, lastid, ngroups;
 287         const char *fmt;
 288         gid_t *glist = groups;
 289
 290         if (pw) {
 291                 ngroups = maxgroups;
 292 #ifndef __minix
 293                 if (getgrouplist(pw->pw_name, pw->pw_gid, glist, &ngroups)
 294                     == -1) {
 295                         glist = malloc(ngroups * sizeof(gid_t));
 296                         (void) getgrouplist(pw->pw_name, pw->pw_gid, glist,
 297                                             &ngroups);
 298
 299                 }
 300 #endif
 301         } else {
 302                 glist[0] = getgid();
 303                 ngroups = getgroups(maxgroups, glist + 1) + 1;
 304         }
 305         fmt = nflag ? "%s" : "%u";
 306         for (lastid = -1, cnt = 0; cnt < ngroups; ++cnt) {
 307                 if (lastid == (id = glist[cnt]) || (cnt && id == glist[0]))
 308                         continue;
 309                 if (nflag) {
 310                         if ((gr = getgrgid(id)) != NULL)
 311                                 (void)printf(fmt, gr->gr_name);
 312                         else
 313                                 (void)printf(*fmt == ' ' ? " %u" : "%u",
 314                                     id);
 315                         fmt = " %s";
 316                 } else {
 317                         (void)printf(fmt, id);
 318                         fmt = " %u";
 319                 }
 320                 lastid = id;
 321         }
 322         (void)printf("\n");
 323         if (glist != groups)
 324                 free(glist);
 325 }
 326
 327 static struct passwd *
 328 who(char *u)
 329 {
 330         struct passwd *pw;
 331         long id;
 332         char *ep;
 333
 334         /*
 335          * Translate user argument into a pw pointer.  First, try to
 336          * get it as specified.  If that fails, try it as a number.
 337          */
 338         if ((pw = getpwnam(u)) != NULL)
 339                 return pw;
 340         id = strtol(u, &ep, 10);
 341         if (*u && !*ep && (pw = getpwuid(id)))
 342                 return pw;
 343         errx(1, "%s: No such user", u);
 344         /* NOTREACHED */
 345         return NULL;
 346 }
 347
 348 static void
 349 usage(void)
 350 {
 351
 352         if (strcmp(getprogname(), "groups") == 0) {
 353                 (void)fprintf(stderr, "usage: groups [user]\n");
 354         } else if (strcmp(getprogname(), "whoami") == 0) {
 355                 (void)fprintf(stderr, "usage: whoami\n");
 356         } else {
 357                 (void)fprintf(stderr, "usage: id [user]\n");
 358                 (void)fprintf(stderr, "       id -G [-n] [user]\n");
 359                 (void)fprintf(stderr, "       id -g [-nr] [user]\n");
 360                 (void)fprintf(stderr, "       id -p [user]\n");
 361                 (void)fprintf(stderr, "       id -u [-nr] [user]\n");
 362         }
 363         exit(1);
 364 }