utils/statd/sm-notify.c

   1 /*
   2  * Send NSM notify calls to all hosts listed in /var/lib/sm
   3  *
   4  * Copyright (C) 2004-2006 Olaf Kirch <okir@suse.de>
   5  */
   6
   7 #include <sys/types.h>
   8 #include <sys/socket.h>
   9 #include <sys/stat.h>
  10 #include <sys/poll.h>
  11 #include <sys/param.h>
  12 #include <sys/syslog.h>
  13 #include <arpa/inet.h>
  14 #include <dirent.h>
  15 #include <time.h>
  16 #include <stdio.h>
  17 #include <getopt.h>
  18 #include <stdlib.h>
  19 #include <fcntl.h>
  20 #include <unistd.h>
  21 #include <string.h>
  22 #include <stdarg.h>
  23 #include <netdb.h>
  24 #include <errno.h>
  25
  26 #ifndef BASEDIR
  27 #define BASEDIR         "/var/lib/nfs"
  28 #endif
  29
  30 #define DEFAULT_SM_STATE_PATH   BASEDIR "/state"
  31 #define DEFAULT_SM_DIR_PATH     BASEDIR "/sm"
  32 #define DEFAULT_SM_BAK_PATH     DEFAULT_SM_DIR_PATH ".bak"
  33
  34 char *_SM_BASE_PATH = BASEDIR;
  35 char *_SM_STATE_PATH = DEFAULT_SM_STATE_PATH;
  36 char *_SM_DIR_PATH = DEFAULT_SM_DIR_PATH;
  37 char *_SM_BAK_PATH = DEFAULT_SM_BAK_PATH;
  38
  39 #define NSM_PROG        100024
  40 #define NSM_PROGRAM     100024
  41 #define NSM_VERSION     1
  42 #define NSM_TIMEOUT     2
  43 #define NSM_NOTIFY      6
  44 #define NSM_MAX_TIMEOUT 120     /* don't make this too big */
  45 #define MAXMSGSIZE      256
  46
  47 typedef struct sockaddr_storage nsm_address;
  48
  49 struct nsm_host {
  50         struct nsm_host *       next;
  51         char *                  name;
  52         char *                  path;
  53         nsm_address             addr;
  54         time_t                  last_used;
  55         time_t                  send_next;
  56         unsigned int            timeout;
  57         unsigned int            retries;
  58         unsigned int            xid;
  59 };
  60
  61 static char             nsm_hostname[256];
  62 static uint32_t         nsm_state;
  63 static int              opt_debug = 0;
  64 static int              opt_quiet = 0;
  65 static int              opt_update_state = 1;
  66 static unsigned int     opt_max_retry = 15 * 60;
  67 static char *           opt_srcaddr = 0;
  68 static uint16_t         opt_srcport = 0;
  69 static int              log_syslog = 0;
  70
  71 static unsigned int     nsm_get_state(int);
  72 static void             notify(void);
  73 static void             notify_host(int, struct nsm_host *);
  74 static void             recv_reply(int);
  75 static void             backup_hosts(const char *, const char *);
  76 static void             get_hosts(const char *);
  77 static void             insert_host(struct nsm_host *);
  78 struct nsm_host *       find_host(uint32_t);
  79 static int              addr_get_port(nsm_address *);
  80 static void             addr_set_port(nsm_address *, int);
  81 static int              host_lookup(int, const char *, nsm_address *);
  82 void                    nsm_log(int fac, const char *fmt, ...);
  83 static int              record_pid();
  84 static void             drop_privs(void);
  85
  86 static struct nsm_host *        hosts = NULL;
  87
  88 int
  89 main(int argc, char **argv)
  90 {
  91         int     c;
  92         int     force = 0;
  93
  94         while ((c = getopt(argc, argv, "dm:np:v:qP:f")) != -1) {
  95                 switch (c) {
  96                 case 'f':
  97                         force = 1;
  98                         break;
  99                 case 'd':
 100                         opt_debug++;
 101                         break;
 102                 case 'm':
 103                         opt_max_retry = atoi(optarg) * 60;
 104                         break;
 105                 case 'n':
 106                         opt_update_state = 0;
 107                         break;
 108                 case 'p':
 109                         opt_srcport = atoi(optarg);
 110                         break;
 111                 case 'v':
 112                         opt_srcaddr = optarg;
 113                         break;
 114                 case 'q':
 115                         opt_quiet = 1;
 116                         break;
 117                 case 'P':
 118                         _SM_BASE_PATH = strdup(optarg);
 119                         _SM_STATE_PATH = malloc(strlen(optarg)+1+sizeof("state"));
 120                         _SM_DIR_PATH = malloc(strlen(optarg)+1+sizeof("sm"));
 121                         _SM_BAK_PATH = malloc(strlen(optarg)+1+sizeof("sm.bak"));
 122                         if (_SM_BASE_PATH == NULL ||
 123                             _SM_STATE_PATH == NULL ||
 124                             _SM_DIR_PATH == NULL ||
 125                             _SM_BAK_PATH == NULL) {
 126                                 nsm_log(LOG_WARNING, "unable to allocate memory");
 127                                 exit(1);
 128                         }
 129                         strcat(strcpy(_SM_STATE_PATH, _SM_BASE_PATH), "/state");
 130                         strcat(strcpy(_SM_DIR_PATH, _SM_BASE_PATH), "/sm");
 131                         strcat(strcpy(_SM_BAK_PATH, _SM_BASE_PATH), "/sm.bak");
 132                         break;
 133
 134                 default:
 135                         goto usage;
 136                 }
 137         }
 138
 139         if (optind < argc) {
 140 usage:          fprintf(stderr,
 141                         "Usage: sm-notify [-dfq] [-m max-retry-minutes] [-p srcport]\n"
 142                         "            [-P /path/to/state/directory] [-N my_host_name\n");
 143                 return 1;
 144         }
 145
 146         if (strcmp(_SM_BASE_PATH, BASEDIR) == 0) {
 147                 if (record_pid() == 0 && force == 0 && opt_update_state == 0)
 148                         /* already run, don't try again */
 149                         exit(0);
 150         }
 151
 152         if (opt_srcaddr) {
 153                 strncpy(nsm_hostname, opt_srcaddr, sizeof(nsm_hostname)-1);
 154         } else
 155         if (gethostname(nsm_hostname, sizeof(nsm_hostname)) < 0) {
 156                 perror("gethostname");
 157                 return 1;
 158         }
 159
 160         backup_hosts(_SM_DIR_PATH, _SM_BAK_PATH);
 161         get_hosts(_SM_BAK_PATH);
 162
 163         if (!opt_debug) {
 164                 if (!opt_quiet)
 165                         printf("Backgrounding to notify hosts...\n");
 166
 167                 openlog("sm-notify", LOG_PID, LOG_DAEMON);
 168                 log_syslog = 1;
 169
 170                 if (daemon(0, 0) < 0) {
 171                         nsm_log(LOG_WARNING, "unable to background: %s",
 172                                         strerror(errno));
 173                         return 1;
 174                 }
 175
 176                 close(0);
 177                 close(1);
 178                 close(2);
 179         }
 180
 181         /* Get and update the NSM state. This will call sync() */
 182         nsm_state = nsm_get_state(opt_update_state);
 183
 184         notify();
 185
 186         if (hosts) {
 187                 struct nsm_host *hp;
 188
 189                 while ((hp = hosts) != 0) {
 190                         hosts = hp->next;
 191                         nsm_log(LOG_NOTICE,
 192                                 "Unable to notify %s, giving up",
 193                                 hp->name);
 194                 }
 195                 return 1;
 196         }
 197
 198         return 0;
 199 }
 200
 201 /*
 202  * Notify hosts
 203  */
 204 void
 205 notify(void)
 206 {
 207         nsm_address local_addr;
 208         time_t  failtime = 0;
 209         int     sock = -1;
 210
 211         sock = socket(AF_INET, SOCK_DGRAM, 0);
 212         if (sock < 0) {
 213                 perror("socket");
 214                 exit(1);
 215         }
 216         fcntl(sock, F_SETFL, O_NONBLOCK);
 217
 218         memset(&local_addr, 0, sizeof(local_addr));
 219         local_addr.ss_family = AF_INET; /* Default to IPv4 */
 220
 221         /* Bind source IP if provided on command line */
 222         if (opt_srcaddr) {
 223                 if (!host_lookup(AF_INET, opt_srcaddr, &local_addr)) {
 224                         nsm_log(LOG_WARNING,
 225                                 "Not a valid hostname or address: \"%s\"\n",
 226                                 opt_srcaddr);
 227                         exit(1);
 228                 }
 229                 /* We know it's IPv4 at this point */
 230         }
 231
 232         /* Use source port if provided on the command line,
 233          * otherwise use bindresvport */
 234         if (opt_srcport) {
 235                 addr_set_port(&local_addr, opt_srcport);
 236                 if (bind(sock, (struct sockaddr *) &local_addr, sizeof(local_addr)) < 0) {
 237                         perror("bind");
 238                         exit(1);
 239                 }
 240         } else {
 241                 (void) bindresvport(sock, (struct sockaddr_in *) &local_addr);
 242         }
 243
 244         if (opt_max_retry)
 245                 failtime = time(NULL) + opt_max_retry;
 246
 247         drop_privs();
 248
 249         while (hosts) {
 250                 struct pollfd   pfd;
 251                 time_t          now = time(NULL);
 252                 unsigned int    sent = 0;
 253                 struct nsm_host *hp;
 254                 long            wait;
 255
 256                 if (failtime && now >= failtime)
 257                         break;
 258
 259                 while ((wait = hosts->send_next - now) <= 0) {
 260                         /* Never send more than 10 packets at once */
 261                         if (sent++ >= 10)
 262                                 break;
 263
 264                         /* Remove queue head */
 265                         hp = hosts;
 266                         hosts = hp->next;
 267
 268                         notify_host(sock, hp);
 269
 270                         /* Set the timeout for this call, using an
 271                            exponential timeout strategy */
 272                         wait = hp->timeout;
 273                         if ((hp->timeout <<= 1) > NSM_MAX_TIMEOUT)
 274                                 hp->timeout = NSM_MAX_TIMEOUT;
 275                         hp->send_next = now + wait;
 276                         hp->retries++;
 277
 278                         insert_host(hp);
 279                 }
 280
 281                 nsm_log(LOG_DEBUG, "Host %s due in %ld seconds",
 282                                 hosts->name, wait);
 283
 284                 pfd.fd = sock;
 285                 pfd.events = POLLIN;
 286
 287                 wait *= 1000;
 288                 if (wait < 100)
 289                         wait = 100;
 290                 if (poll(&pfd, 1, wait) != 1)
 291                         continue;
 292
 293                 recv_reply(sock);
 294         }
 295 }
 296
 297 /*
 298  * Send notification to a single host
 299  */
 300 void
 301 notify_host(int sock, struct nsm_host *host)
 302 {
 303         static unsigned int     xid = 0;
 304         nsm_address             dest;
 305         uint32_t                msgbuf[MAXMSGSIZE], *p;
 306         unsigned int            len;
 307
 308         if (!xid)
 309                 xid = getpid() + time(NULL);
 310         if (!host->xid)
 311                 host->xid = xid++;
 312
 313         memset(msgbuf, 0, sizeof(msgbuf));
 314         p = msgbuf;
 315         *p++ = htonl(host->xid);
 316         *p++ = 0;
 317         *p++ = htonl(2);
 318
 319         /* If we retransmitted 4 times, reset the port to force
 320          * a new portmap lookup (in case statd was restarted)
 321          */
 322         if (host->retries >= 4) {
 323                 addr_set_port(&host->addr, 0);
 324                 host->retries = 0;
 325         }
 326
 327         dest = host->addr;
 328         if (addr_get_port(&dest) == 0) {
 329                 /* Build a PMAP packet */
 330                 nsm_log(LOG_DEBUG, "Sending portmap query to %s", host->name);
 331
 332                 addr_set_port(&dest, 111);
 333                 *p++ = htonl(100000);
 334                 *p++ = htonl(2);
 335                 *p++ = htonl(3);
 336
 337                 /* Auth and verf */
 338                 *p++ = 0; *p++ = 0;
 339                 *p++ = 0; *p++ = 0;
 340
 341                 *p++ = htonl(NSM_PROGRAM);
 342                 *p++ = htonl(NSM_VERSION);
 343                 *p++ = htonl(IPPROTO_UDP);
 344                 *p++ = 0;
 345         } else {
 346                 /* Build an SM_NOTIFY packet */
 347                 nsm_log(LOG_DEBUG, "Sending SM_NOTIFY to %s", host->name);
 348
 349                 *p++ = htonl(NSM_PROGRAM);
 350                 *p++ = htonl(NSM_VERSION);
 351                 *p++ = htonl(NSM_NOTIFY);
 352
 353                 /* Auth and verf */
 354                 *p++ = 0; *p++ = 0;
 355                 *p++ = 0; *p++ = 0;
 356
 357                 /* state change */
 358                 len = strlen(nsm_hostname);
 359                 *p++ = htonl(len);
 360                 memcpy(p, nsm_hostname, len);
 361                 p += (len + 3) >> 2;
 362                 *p++ = htonl(nsm_state);
 363         }
 364         len = (p - msgbuf) << 2;
 365
 366         sendto(sock, msgbuf, len, 0, (struct sockaddr *) &dest, sizeof(dest));
 367 }
 368
 369 /*
 370  * Receive reply from remote host
 371  */
 372 void
 373 recv_reply(int sock)
 374 {
 375         struct nsm_host *hp;
 376         uint32_t        msgbuf[MAXMSGSIZE], *p, *end;
 377         uint32_t        xid;
 378         int             res;
 379
 380         res = recv(sock, msgbuf, sizeof(msgbuf), 0);
 381         if (res < 0)
 382                 return;
 383
 384         nsm_log(LOG_DEBUG, "Received packet...");
 385
 386         p = msgbuf;
 387         end = p + (res >> 2);
 388
 389         xid = ntohl(*p++);
 390         if (*p++ != htonl(1)    /* must be REPLY */
 391          || *p++ != htonl(0)    /* must be ACCEPTED */
 392          || *p++ != htonl(0)    /* must be NULL verifier */
 393          || *p++ != htonl(0)
 394          || *p++ != htonl(0))   /* must be SUCCESS */
 395                 return;
 396
 397         /* Before we look at the data, find the host struct for
 398            this reply */
 399         if ((hp = find_host(xid)) == NULL)
 400                 return;
 401
 402         if (addr_get_port(&hp->addr) == 0) {
 403                 /* This was a portmap request */
 404                 unsigned int    port;
 405
 406                 port = ntohl(*p++);
 407                 if (p > end)
 408                         goto fail;
 409
 410                 hp->send_next = time(NULL);
 411                 if (port == 0) {
 412                         /* No binding for statd. Delay the next
 413                          * portmap query for max timeout */
 414                         nsm_log(LOG_DEBUG, "No statd on %s", hp->name);
 415                         hp->timeout = NSM_MAX_TIMEOUT;
 416                         hp->send_next += NSM_MAX_TIMEOUT;
 417                 } else {
 418                         addr_set_port(&hp->addr, port);
 419                         if (hp->timeout >= NSM_MAX_TIMEOUT / 4)
 420                                 hp->timeout = NSM_MAX_TIMEOUT / 4;
 421                 }
 422                 hp->xid = 0;
 423         } else {
 424                 /* Successful NOTIFY call. Server returns void,
 425                  * so nothing we need to do here (except
 426                  * check that we didn't read past the end of the
 427                  * packet)
 428                  */
 429                 if (p <= end) {
 430                         nsm_log(LOG_DEBUG, "Host %s notified successfully", hp->name);
 431                         unlink(hp->path);
 432                         free(hp->name);
 433                         free(hp->path);
 434                         free(hp);
 435                         return;
 436                 }
 437         }
 438
 439 fail:   /* Re-insert the host */
 440         insert_host(hp);
 441 }
 442
 443 /*
 444  * Back up all hosts from the sm directory to sm.bak
 445  */
 446 static void
 447 backup_hosts(const char *dirname, const char *bakname)
 448 {
 449         struct dirent   *de;
 450         DIR             *dir;
 451
 452         if (!(dir = opendir(dirname))) {
 453                 perror(dirname);
 454                 return;
 455         }
 456
 457         while ((de = readdir(dir)) != NULL) {
 458                 char    src[1024], dst[1024];
 459
 460                 if (de->d_name[0] == '.')
 461                         continue;
 462
 463                 snprintf(src, sizeof(src), "%s/%s", dirname, de->d_name);
 464                 snprintf(dst, sizeof(dst), "%s/%s", bakname, de->d_name);
 465                 if (rename(src, dst) < 0) {
 466                         nsm_log(LOG_WARNING,
 467                                 "Failed to rename %s -> %s: %m",
 468                                 src, dst);
 469                 }
 470         }
 471         closedir(dir);
 472 }
 473
 474 /*
 475  * Get all entries from sm.bak and convert them to host names
 476  */
 477 static void
 478 get_hosts(const char *dirname)
 479 {
 480         struct nsm_host *host;
 481         struct dirent   *de;
 482         DIR             *dir;
 483
 484         if (!(dir = opendir(dirname))) {
 485                 perror(dirname);
 486                 return;
 487         }
 488
 489         host = NULL;
 490         while ((de = readdir(dir)) != NULL) {
 491                 struct stat     stb;
 492                 char            path[1024];
 493
 494                 if (de->d_name[0] == '.')
 495                         continue;
 496                 if (host == NULL)
 497                         host = calloc(1, sizeof(*host));
 498
 499                 snprintf(path, sizeof(path), "%s/%s", dirname, de->d_name);
 500                 if (!host_lookup(AF_UNSPEC, de->d_name, &host->addr)) {
 501                         nsm_log(LOG_WARNING,
 502                                 "%s doesn't seem to be a valid address, skipped",
 503                                 de->d_name);
 504                         unlink(path);
 505                         continue;
 506                 }
 507
 508                 if (stat(path, &stb) < 0)
 509                         continue;
 510                 host->last_used = stb.st_mtime;
 511                 host->timeout = NSM_TIMEOUT;
 512                 host->path = strdup(path);
 513                 host->name = strdup(de->d_name);
 514
 515                 insert_host(host);
 516                 host = NULL;
 517         }
 518         closedir(dir);
 519
 520         if (host)
 521                 free(host);
 522 }
 523
 524 /*
 525  * Insert host into sorted list
 526  */
 527 void
 528 insert_host(struct nsm_host *host)
 529 {
 530         struct nsm_host **where, *p;
 531
 532         where = &hosts;
 533         while ((p = *where) != 0) {
 534                 /* Sort in ascending order of timeout */
 535                 if (host->send_next < p->send_next)
 536                         break;
 537                 /* If we have the same timeout, put the
 538                  * most recently used host first.
 539                  * This makes sure that "recent" hosts
 540                  * get notified first.
 541                  */
 542                 if (host->send_next == p->send_next
 543                  && host->last_used > p->last_used)
 544                         break;
 545                 where = &p->next;
 546         }
 547
 548         host->next = *where;
 549         *where = host;
 550 }
 551
 552 /*
 553  * Find host given the XID
 554  */
 555 struct nsm_host *
 556 find_host(uint32_t xid)
 557 {
 558         struct nsm_host **where, *p;
 559
 560         where = &hosts;
 561         while ((p = *where) != 0) {
 562                 if (p->xid == xid) {
 563                         *where = p->next;
 564                         return p;
 565                 }
 566                 where = &p->next;
 567         }
 568         return NULL;
 569 }
 570
 571
 572 /*
 573  * Retrieve the current NSM state
 574  */
 575 unsigned int
 576 nsm_get_state(int update)
 577 {
 578         char            newfile[PATH_MAX];
 579         int             fd, state;
 580
 581         if ((fd = open(_SM_STATE_PATH, O_RDONLY)) < 0) {
 582                 if (!opt_quiet) {
 583                         nsm_log(LOG_WARNING, "%s: %m", _SM_STATE_PATH);
 584                         nsm_log(LOG_WARNING, "Creating %s, set initial state 1",
 585                                 _SM_STATE_PATH);
 586                 }
 587                 state = 1;
 588                 update = 1;
 589         } else {
 590                 if (read(fd, &state, sizeof(state)) != sizeof(state)) {
 591                         nsm_log(LOG_WARNING,
 592                                 "%s: bad file size, setting state = 1",
 593                                 _SM_STATE_PATH);
 594                         state = 1;
 595                         update = 1;
 596                 } else {
 597                         if (!(state & 1))
 598                                 state += 1;
 599                 }
 600                 close(fd);
 601         }
 602
 603         if (update) {
 604                 state += 2;
 605                 snprintf(newfile, sizeof(newfile),
 606                                 "%s.new", _SM_STATE_PATH);
 607                 if ((fd = open(newfile, O_CREAT|O_WRONLY, 0644)) < 0) {
 608                         nsm_log(LOG_WARNING, "Cannot create %s: %m", newfile);
 609                         exit(1);
 610                 }
 611                 if (write(fd, &state, sizeof(state)) != sizeof(state)) {
 612                         nsm_log(LOG_WARNING,
 613                                 "Failed to write state to %s", newfile);
 614                         exit(1);
 615                 }
 616                 close(fd);
 617                 if (rename(newfile, _SM_STATE_PATH) < 0) {
 618                         nsm_log(LOG_WARNING,
 619                                 "Cannot create %s: %m", _SM_STATE_PATH);
 620                         exit(1);
 621                 }
 622                 sync();
 623         }
 624
 625         return state;
 626 }
 627
 628 /*
 629  * Address handling utilities
 630  */
 631
 632 int
 633 addr_get_port(nsm_address *addr)
 634 {
 635         switch (((struct sockaddr *) addr)->sa_family) {
 636         case AF_INET:
 637                 return ntohs(((struct sockaddr_in *) addr)->sin_port);
 638         case AF_INET6:
 639                 return ntohs(((struct sockaddr_in6 *) addr)->sin6_port);
 640         }
 641         return 0;
 642 }
 643
 644 static void
 645 addr_set_port(nsm_address *addr, int port)
 646 {
 647         switch (((struct sockaddr *) addr)->sa_family) {
 648         case AF_INET:
 649                 ((struct sockaddr_in *) addr)->sin_port = htons(port);
 650                 break;
 651         case AF_INET6:
 652                 ((struct sockaddr_in6 *) addr)->sin6_port = htons(port);
 653         }
 654 }
 655
 656 static int
 657 host_lookup(int af, const char *name, nsm_address *addr)
 658 {
 659         struct addrinfo hints, *ai;
 660         int okay = 0;
 661
 662         memset(&hints, 0, sizeof(hints));
 663         hints.ai_family = af;
 664
 665         if (getaddrinfo(name, NULL, &hints, &ai) != 0)
 666                 return 0;
 667
 668         if (ai->ai_addrlen < sizeof(*addr)) {
 669                 memcpy(addr, ai->ai_addr, ai->ai_addrlen);
 670                 okay = 1;
 671         }
 672
 673         freeaddrinfo(ai);
 674         return okay;
 675 }
 676
 677 /*
 678  * Log a message
 679  */
 680 void
 681 nsm_log(int fac, const char *fmt, ...)
 682 {
 683         va_list ap;
 684
 685         if (fac == LOG_DEBUG && !opt_debug)
 686                 return;
 687
 688         va_start(ap, fmt);
 689         if (log_syslog)
 690                 vsyslog(fac, fmt, ap);
 691         else {
 692                 vfprintf(stderr, fmt, ap);
 693                 fputs("\n", stderr);
 694         }
 695         va_end(ap);
 696 }
 697
 698 /*
 699  * Record pid in /var/run/sm-notify.pid
 700  * This file should remain until a reboot, even if the
 701  * program exits.
 702  * If file already exists, fail.
 703  */
 704 static int record_pid()
 705 {
 706         char pid[20];
 707         int fd;
 708
 709         snprintf(pid, 20, "%d\n", getpid());
 710         fd = open("/var/run/sm-notify.pid", O_CREAT|O_EXCL|O_WRONLY, 0600);
 711         if (!fd)
 712                 return 0;
 713         write(fd, pid, strlen(pid));
 714         close(fd);
 715         return 1;
 716 }
 717
 718 /* Drop privileges to match owner of state-directory
 719  * (in case a reply triggers some unknown bug).
 720  */
 721 static void drop_privs(void)
 722 {
 723         struct stat st;
 724
 725         if (stat(_SM_DIR_PATH, &st) == -1 &&
 726             stat(_SM_BASE_PATH, &st) == -1) {
 727                 st.st_uid = 0;
 728                 st.st_gid = 0;
 729         }
 730
 731         if (st.st_uid == 0) {
 732                 nsm_log(LOG_WARNING,
 733                         "sm-notify running as root. chown %s to choose different user\n",
 734                     _SM_DIR_PATH);
 735                 return;
 736         }
 737
 738         setgroups(0, NULL);
 739         if (setgid(st.st_gid) == -1
 740             || setuid(st.st_uid) == -1) {
 741                 nsm_log(LOG_ERR, "Fail to drop privileges");
 742                 exit(1);
 743         }
 744 }