misc/uuidd.c

   1 /*
   2  * uuidd.c --- UUID-generation daemon
   3  *
   4  * Copyright (C) 2007  Theodore Ts'o
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the GNU Public
   8  * License.
   9  * %End-Header%
  10  */
  11
  12 #define _GNU_SOURCE /* for setres[ug]id() */
  13
  14 #include <stdio.h>
  15 #ifdef HAVE_STDLIB_H
  16 #include <stdlib.h>
  17 #endif
  18 #include <unistd.h>
  19 #include <inttypes.h>
  20 #include <errno.h>
  21 #include <sys/types.h>
  22 #include <sys/stat.h>
  23 #include <sys/socket.h>
  24 #include <sys/un.h>
  25 #include <fcntl.h>
  26 #include <signal.h>
  27 #include <string.h>
  28 #ifdef HAVE_GETOPT_H
  29 #include <getopt.h>
  30 #else
  31 extern int getopt(int argc, char * const argv[], const char *optstring);
  32 extern char *optarg;
  33 extern int optind;
  34 #endif
  35 #include "uuid/uuid.h"
  36 #include "uuid/uuidd.h"
  37 #include "nls-enable.h"
  38
  39 #ifdef __GNUC__
  40 #define CODE_ATTR(x) __attribute__(x)
  41 #else
  42 #define CODE_ATTR(x)
  43 #endif
  44
  45 static void usage(const char *progname)
  46 {
  47         fprintf(stderr, _("Usage: %s [-d] [-p pidfile] [-s socketpath] "
  48                           "[-T timeout]\n"), progname);
  49         fprintf(stderr, _("       %s [-r|t] [-n num] [-s socketpath]\n"),
  50                 progname);
  51         fprintf(stderr, _("       %s -k\n"), progname);
  52         exit(1);
  53 }
  54
  55 static void die(const char *msg)
  56 {
  57         perror(msg);
  58         exit(1);
  59 }
  60
  61 static void create_daemon(void)
  62 {
  63         pid_t pid;
  64         uid_t euid;
  65
  66         pid = fork();
  67         if (pid == -1) {
  68                 perror("fork");
  69                 exit(1);
  70         } else if (pid != 0) {
  71             exit(0);
  72         }
  73
  74         close(0);
  75         close(1);
  76         close(2);
  77         open("/dev/null", O_RDWR);
  78         open("/dev/null", O_RDWR);
  79         open("/dev/null", O_RDWR);
  80
  81         if (chdir("/")) {}      /* Silence warn_unused_result warning */
  82         (void) setsid();
  83         euid = geteuid();
  84         if (setreuid(euid, euid) < 0)
  85                 die("setreuid");
  86 }
  87
  88 static ssize_t read_all(int fd, char *buf, size_t count)
  89 {
  90         ssize_t ret;
  91         ssize_t c = 0;
  92         int tries = 0;
  93
  94         memset(buf, 0, count);
  95         while (count > 0) {
  96                 ret = read(fd, buf, count);
  97                 if (ret <= 0) {
  98                         if ((errno == EAGAIN || errno == EINTR || ret == 0) &&
  99                             (tries++ < 5))
 100                                 continue;
 101                         return c ? c : -1;
 102                 }
 103                 if (ret > 0)
 104                         tries = 0;
 105                 count -= ret;
 106                 buf += ret;
 107                 c += ret;
 108         }
 109         return c;
 110 }
 111
 112 static int write_all(int fd, char *buf, size_t count)
 113 {
 114         ssize_t ret;
 115         int c = 0;
 116
 117         while (count > 0) {
 118                 ret = write(fd, buf, count);
 119                 if (ret < 0) {
 120                         if ((errno == EAGAIN) || (errno == EINTR))
 121                                 continue;
 122                         return -1;
 123                 }
 124                 count -= ret;
 125                 buf += ret;
 126                 c += ret;
 127         }
 128         return c;
 129 }
 130
 131 static const char *cleanup_pidfile, *cleanup_socket;
 132
 133 static void terminate_intr(int signo CODE_ATTR((unused)))
 134 {
 135         (void) unlink(cleanup_pidfile);
 136         if (cleanup_socket)
 137                 (void) unlink(cleanup_socket);
 138         exit(0);
 139 }
 140
 141 static int call_daemon(const char *socket_path, int op, char *buf,
 142                        int buflen, int *num, const char **err_context)
 143 {
 144         char op_buf[8];
 145         int op_len;
 146         int s;
 147         ssize_t ret;
 148         int32_t reply_len = 0;
 149         struct sockaddr_un srv_addr;
 150
 151         if (((op == 4) || (op == 5)) && !num) {
 152                 if (err_context)
 153                         *err_context = _("bad arguments");
 154                 errno = EINVAL;
 155                 return -1;
 156         }
 157
 158         if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
 159                 if (err_context)
 160                         *err_context = _("socket");
 161                 return -1;
 162         }
 163
 164         srv_addr.sun_family = AF_UNIX;
 165         strncpy(srv_addr.sun_path, socket_path, sizeof(srv_addr.sun_path));
 166         srv_addr.sun_path[sizeof(srv_addr.sun_path)-1] = '\0';
 167
 168         if (connect(s, (const struct sockaddr *) &srv_addr,
 169                     sizeof(struct sockaddr_un)) < 0) {
 170                 if (err_context)
 171                         *err_context = _("connect");
 172                 close(s);
 173                 return -1;
 174         }
 175
 176         if (op == 5) {
 177                 if ((*num)*16 > buflen-4)
 178                         *num = (buflen-4) / 16;
 179         }
 180         op_buf[0] = op;
 181         op_len = 1;
 182         if ((op == 4) || (op == 5)) {
 183                 memcpy(op_buf+1, num, sizeof(int));
 184                 op_len += sizeof(int);
 185         }
 186
 187         ret = write_all(s, op_buf, op_len);
 188         if (ret < op_len) {
 189                 if (err_context)
 190                         *err_context = _("write");
 191                 close(s);
 192                 return -1;
 193         }
 194
 195         ret = read_all(s, (char *) &reply_len, sizeof(reply_len));
 196         if (ret < 0) {
 197                 if (err_context)
 198                         *err_context = _("read count");
 199                 close(s);
 200                 return -1;
 201         }
 202         if (reply_len < 0 || reply_len > buflen) {
 203                 if (err_context)
 204                         *err_context = _("bad response length");
 205                 close(s);
 206                 return -1;
 207         }
 208         ret = read_all(s, (char *) buf, reply_len);
 209
 210         if ((ret > 0) && (op == 4)) {
 211                 if (reply_len >= (int) (16+sizeof(int)))
 212                         memcpy(buf+16, num, sizeof(int));
 213                 else
 214                         *num = -1;
 215         }
 216         if ((ret > 0) && (op == 5)) {
 217                 if (*num >= (int) sizeof(int))
 218                         memcpy(buf, num, sizeof(int));
 219                 else
 220                         *num = -1;
 221         }
 222
 223         close(s);
 224
 225         return ret;
 226 }
 227
 228 static void server_loop(const char *socket_path, const char *pidfile_path,
 229                         int debug, int timeout, int quiet)
 230 {
 231         struct sockaddr_un      my_addr, from_addr;
 232         struct flock            fl;
 233         socklen_t               fromlen;
 234         int32_t                 reply_len = 0;
 235         uuid_t                  uu;
 236         mode_t                  save_umask;
 237         char                    reply_buf[1024], *cp;
 238         char                    op, str[37];
 239         int                     i, s, ns, len, num;
 240         int                     fd_pidfile, ret;
 241
 242         fd_pidfile = open(pidfile_path, O_CREAT | O_RDWR, 0664);
 243         if (fd_pidfile < 0) {
 244                 if (!quiet)
 245                         fprintf(stderr, "Failed to open/create %s: %s\n",
 246                                 pidfile_path, strerror(errno));
 247                 exit(1);
 248         }
 249         cleanup_pidfile = pidfile_path;
 250         cleanup_socket = 0;
 251         signal(SIGALRM, terminate_intr);
 252         alarm(30);
 253         fl.l_type = F_WRLCK;
 254         fl.l_whence = SEEK_SET;
 255         fl.l_start = 0;
 256         fl.l_len = 0;
 257         fl.l_pid = 0;
 258         while (fcntl(fd_pidfile, F_SETLKW, &fl) < 0) {
 259                 if ((errno == EAGAIN) || (errno == EINTR))
 260                         continue;
 261                 if (!quiet)
 262                         fprintf(stderr, "Failed to lock %s: %s\n",
 263                                 pidfile_path, strerror(errno));
 264                 exit(1);
 265         }
 266         ret = call_daemon(socket_path, 0, reply_buf, sizeof(reply_buf), 0, 0);
 267         if (ret > 0) {
 268                 if (!quiet)
 269                         printf(_("uuidd daemon already running at pid %s\n"),
 270                                reply_buf);
 271                 exit(1);
 272         }
 273         alarm(0);
 274
 275         if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
 276                 if (!quiet)
 277                         fprintf(stderr, _("Couldn't create unix stream "
 278                                           "socket: %s"), strerror(errno));
 279                 exit(1);
 280         }
 281
 282         /*
 283          * Make sure the socket isn't using fd numbers 0-2 to avoid it
 284          * getting closed by create_daemon()
 285          */
 286         while (!debug && s <= 2) {
 287                 s = dup(s);
 288                 if (s < 0) {
 289                         perror("dup");
 290                         exit(1);
 291                 }
 292         }
 293
 294         /*
 295          * Create the address we will be binding to.
 296          */
 297         my_addr.sun_family = AF_UNIX;
 298         strncpy(my_addr.sun_path, socket_path, sizeof(my_addr.sun_path));
 299         my_addr.sun_path[sizeof(my_addr.sun_path)-1] = '\0';
 300         (void) unlink(socket_path);
 301         save_umask = umask(0);
 302         if (bind(s, (const struct sockaddr *) &my_addr,
 303                  sizeof(struct sockaddr_un)) < 0) {
 304                 if (!quiet)
 305                         fprintf(stderr,
 306                                 _("Couldn't bind unix socket %s: %s\n"),
 307                                 socket_path, strerror(errno));
 308                 exit(1);
 309         }
 310         (void) umask(save_umask);
 311
 312         if (listen(s, 5) < 0) {
 313                 if (!quiet)
 314                         fprintf(stderr, _("Couldn't listen on unix "
 315                                           "socket %s: %s\n"), socket_path,
 316                                 strerror(errno));
 317                 exit(1);
 318         }
 319
 320         cleanup_socket = socket_path;
 321         if (!debug)
 322                 create_daemon();
 323         signal(SIGHUP, terminate_intr);
 324         signal(SIGINT, terminate_intr);
 325         signal(SIGTERM, terminate_intr);
 326         signal(SIGALRM, terminate_intr);
 327         signal(SIGPIPE, SIG_IGN);
 328
 329         sprintf(reply_buf, "%8d\n", getpid());
 330         if (ftruncate(fd_pidfile, 0)) {} /* Silence warn_unused_result */
 331         write_all(fd_pidfile, reply_buf, strlen(reply_buf));
 332         if (fd_pidfile > 1)
 333                 close(fd_pidfile); /* Unlock the pid file */
 334
 335         while (1) {
 336                 fromlen = sizeof(from_addr);
 337                 if (timeout > 0)
 338                         alarm(timeout);
 339                 ns = accept(s, (struct sockaddr *) &from_addr, &fromlen);
 340                 alarm(0);
 341                 if (ns < 0) {
 342                         if ((errno == EAGAIN) || (errno == EINTR))
 343                                 continue;
 344                         perror("accept");
 345                         exit(1);
 346                 }
 347                 len = read(ns, &op, 1);
 348                 if (len != 1) {
 349                         if (len < 0)
 350                                 perror("read");
 351                         else
 352                                 printf(_("Error reading from client, "
 353                                          "len = %d\n"), len);
 354                         goto shutdown_socket;
 355                 }
 356                 if ((op == 4) || (op == 5)) {
 357                         if (read_all(ns, (char *) &num, sizeof(num)) != 4)
 358                                 goto shutdown_socket;
 359                         if (debug)
 360                                 printf(_("operation %d, incoming num = %d\n"),
 361                                        op, num);
 362                 } else if (debug)
 363                         printf("operation %d\n", op);
 364
 365                 switch(op) {
 366                 case UUIDD_OP_GETPID:
 367                         sprintf(reply_buf, "%d", getpid());
 368                         reply_len = strlen(reply_buf)+1;
 369                         break;
 370                 case UUIDD_OP_GET_MAXOP:
 371                         sprintf(reply_buf, "%d", UUIDD_MAX_OP);
 372                         reply_len = strlen(reply_buf)+1;
 373                         break;
 374                 case UUIDD_OP_TIME_UUID:
 375                         num = 1;
 376                         uuid__generate_time(uu, &num);
 377                         if (debug) {
 378                                 uuid_unparse(uu, str);
 379                                 printf(_("Generated time UUID: %s\n"), str);
 380                         }
 381                         memcpy(reply_buf, uu, sizeof(uu));
 382                         reply_len = sizeof(uu);
 383                         break;
 384                 case UUIDD_OP_RANDOM_UUID:
 385                         num = 1;
 386                         uuid__generate_random(uu, &num);
 387                         if (debug) {
 388                                 uuid_unparse(uu, str);
 389                                 printf(_("Generated random UUID: %s\n"), str);
 390                         }
 391                         memcpy(reply_buf, uu, sizeof(uu));
 392                         reply_len = sizeof(uu);
 393                         break;
 394                 case UUIDD_OP_BULK_TIME_UUID:
 395                         uuid__generate_time(uu, &num);
 396                         if (debug) {
 397                                 uuid_unparse(uu, str);
 398                                 printf(_("Generated time UUID %s and %d "
 399                                          "following\n"), str, num);
 400                         }
 401                         memcpy(reply_buf, uu, sizeof(uu));
 402                         reply_len = sizeof(uu);
 403                         memcpy(reply_buf+reply_len, &num, sizeof(num));
 404                         reply_len += sizeof(num);
 405                         break;
 406                 case UUIDD_OP_BULK_RANDOM_UUID:
 407                         if (num < 0)
 408                                 num = 1;
 409                         if (num > 1000)
 410                                 num = 1000;
 411                         if (num*16 > (int) (sizeof(reply_buf)-sizeof(num)))
 412                                 num = (sizeof(reply_buf)-sizeof(num)) / 16;
 413                         uuid__generate_random((unsigned char *) reply_buf +
 414                                               sizeof(num), &num);
 415                         if (debug) {
 416                                 printf(_("Generated %d UUID's:\n"), num);
 417                                 for (i=0, cp=reply_buf+sizeof(num);
 418                                      i < num; i++, cp+=16) {
 419                                         uuid_unparse((unsigned char *)cp, str);
 420                                         printf("\t%s\n", str);
 421                                 }
 422                         }
 423                         reply_len = (num*16) + sizeof(num);
 424                         memcpy(reply_buf, &num, sizeof(num));
 425                         break;
 426                 default:
 427                         if (debug)
 428                                 printf(_("Invalid operation %d\n"), op);
 429                         goto shutdown_socket;
 430                 }
 431                 write_all(ns, (char *) &reply_len, sizeof(reply_len));
 432                 write_all(ns, reply_buf, reply_len);
 433         shutdown_socket:
 434                 close(ns);
 435         }
 436 }
 437
 438 int main(int argc, char **argv)
 439 {
 440         const char      *socket_path = UUIDD_SOCKET_PATH;
 441         const char      *pidfile_path = UUIDD_PIDFILE_PATH;
 442         const char      *err_context;
 443         char            buf[1024], *cp;
 444         char            str[37], *tmp;
 445         uuid_t          uu;
 446         uid_t           uid;
 447         gid_t           gid;
 448         int             i, c, ret;
 449         int             debug = 0, do_type = 0, do_kill = 0, num = 0;
 450         int             timeout = 0, quiet = 0, drop_privs = 0;
 451
 452 #ifdef ENABLE_NLS
 453         setlocale(LC_MESSAGES, "");
 454         setlocale(LC_CTYPE, "");
 455         bindtextdomain(NLS_CAT_NAME, LOCALEDIR);
 456         textdomain(NLS_CAT_NAME);
 457 #endif
 458
 459         while ((c = getopt (argc, argv, "dkn:qp:s:tT:r")) != EOF) {
 460                 switch (c) {
 461                 case 'd':
 462                         debug++;
 463                         drop_privs = 1;
 464                         break;
 465                 case 'k':
 466                         do_kill++;
 467                         drop_privs = 1;
 468                         break;
 469                 case 'n':
 470                         num = strtol(optarg, &tmp, 0);
 471                         if ((num < 0) || *tmp) {
 472                                 fprintf(stderr, _("Bad number: %s\n"), optarg);
 473                                 exit(1);
 474                         }
 475                 case 'p':
 476                         pidfile_path = optarg;
 477                         drop_privs = 1;
 478                         break;
 479                 case 'q':
 480                         quiet++;
 481                         break;
 482                 case 's':
 483                         socket_path = optarg;
 484                         drop_privs = 1;
 485                         break;
 486                 case 't':
 487                         do_type = UUIDD_OP_TIME_UUID;
 488                         drop_privs = 1;
 489                         break;
 490                 case 'T':
 491                         timeout = strtol(optarg, &tmp, 0);
 492                         if ((timeout < 0) || *tmp) {
 493                                 fprintf(stderr, _("Bad number: %s\n"), optarg);
 494                                 exit(1);
 495                         }
 496                         break;
 497                 case 'r':
 498                         do_type = UUIDD_OP_RANDOM_UUID;
 499                         drop_privs = 1;
 500                         break;
 501                 default:
 502                         usage(argv[0]);
 503                 }
 504         }
 505         uid = getuid();
 506         if (uid && drop_privs) {
 507                 gid = getgid();
 508 #ifdef HAVE_SETRESGID
 509                 if (setresgid(gid, gid, gid) < 0)
 510                         die("setresgid");
 511 #else
 512                 if (setregid(gid, gid) < 0)
 513                         die("setregid");
 514 #endif
 515
 516 #ifdef HAVE_SETRESUID
 517                 if (setresuid(uid, uid, uid) < 0)
 518                         die("setresuid");
 519 #else
 520                 if (setreuid(uid, uid) < 0)
 521                         die("setreuid");
 522 #endif
 523         }
 524         if (num && do_type) {
 525                 ret = call_daemon(socket_path, do_type+2, buf,
 526                                   sizeof(buf), &num, &err_context);
 527                 if (ret < 0) {
 528                         printf(_("Error calling uuidd daemon (%s): %s\n"),
 529                                err_context, strerror(errno));
 530                         exit(1);
 531                 }
 532                 if (do_type == UUIDD_OP_TIME_UUID) {
 533                         if (ret != sizeof(uu) + sizeof(num))
 534                                 goto unexpected_size;
 535
 536                         uuid_unparse((unsigned char *) buf, str);
 537
 538                         printf(_("%s and subsequent %d UUID's\n"), str, num);
 539                 } else {
 540                         printf(_("List of UUID's:\n"));
 541                         cp = buf + 4;
 542                         if (ret != (int) (sizeof(num) + num*sizeof(uu)))
 543                                 goto unexpected_size;
 544                         for (i=0; i < num; i++, cp+=16) {
 545                                 uuid_unparse((unsigned char *) cp, str);
 546                                 printf("\t%s\n", str);
 547                         }
 548                 }
 549                 exit(0);
 550         }
 551         if (do_type) {
 552                 ret = call_daemon(socket_path, do_type, (char *) &uu,
 553                                   sizeof(uu), 0, &err_context);
 554                 if (ret < 0) {
 555                         printf(_("Error calling uuidd daemon (%s): %s\n"),
 556                                err_context, strerror(errno));
 557                         exit(1);
 558                 }
 559                 if (ret != sizeof(uu)) {
 560                 unexpected_size:
 561                         printf(_("Unexpected reply length from server %d\n"),
 562                                ret);
 563                         exit(1);
 564                 }
 565                 uuid_unparse(uu, str);
 566
 567                 printf("%s\n", str);
 568                 exit(0);
 569         }
 570
 571         if (do_kill) {
 572                 ret = call_daemon(socket_path, 0, buf, sizeof(buf), 0, 0);
 573                 if ((ret > 0) && ((do_kill = atoi((char *) buf)) > 0)) {
 574                         ret = kill(do_kill, SIGTERM);
 575                         if (ret < 0) {
 576                                 if (!quiet)
 577                                         fprintf(stderr,
 578                                                 _("Couldn't kill uuidd running "
 579                                                   "at pid %d: %s\n"), do_kill,
 580                                                 strerror(errno));
 581                                 exit(1);
 582                         }
 583                         if (!quiet)
 584                                 printf(_("Killed uuidd running at pid %d\n"),
 585                                        do_kill);
 586                 }
 587                 exit(0);
 588         }
 589
 590         server_loop(socket_path, pidfile_path, debug, timeout, quiet);
 591         return 0;
 592 }