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 #ifdef HAVE_CONFIG_H
   8 #include <config.h>
   9 #endif
  10
  11 #include <sys/types.h>
  12 #include <sys/socket.h>
  13 #include <sys/stat.h>
  14 #include <sys/poll.h>
  15 #include <sys/param.h>
  16 #include <sys/syslog.h>
  17 #include <arpa/inet.h>
  18 #include <dirent.h>
  19 #include <time.h>
  20 #include <stdio.h>
  21 #include <getopt.h>
  22 #include <stdlib.h>
  23 #include <fcntl.h>
  24 #include <unistd.h>
  25 #include <string.h>
  26 #include <stdarg.h>
  27 #include <netdb.h>
  28 #include <errno.h>
  29 #include <grp.h>
  30
  31 #ifndef BASEDIR
  32 # ifdef NFS_STATEDIR
  33 #  define BASEDIR               NFS_STATEDIR
  34 # else
  35 #  define BASEDIR               "/var/lib/nfs"
  36 # endif
  37 #endif
  38
  39 #define DEFAULT_SM_STATE_PATH   BASEDIR "/state"
  40 #define DEFAULT_SM_DIR_PATH     BASEDIR "/sm"
  41 #define DEFAULT_SM_BAK_PATH     DEFAULT_SM_DIR_PATH ".bak"
  42
  43 char *_SM_BASE_PATH = BASEDIR;
  44 char *_SM_STATE_PATH = DEFAULT_SM_STATE_PATH;
  45 char *_SM_DIR_PATH = DEFAULT_SM_DIR_PATH;
  46 char *_SM_BAK_PATH = DEFAULT_SM_BAK_PATH;
  47
  48 #define NSM_PROG        100024
  49 #define NSM_PROGRAM     100024
  50 #define NSM_VERSION     1
  51 #define NSM_TIMEOUT     2
  52 #define NSM_NOTIFY      6
  53 #define NSM_MAX_TIMEOUT 120     /* don't make this too big */
  54 #define MAXMSGSIZE      256
  55
  56 struct nsm_host {
  57         struct nsm_host *       next;
  58         char *                  name;
  59         char *                  path;
  60         struct sockaddr_storage addr;
  61         struct addrinfo         *ai;
  62         time_t                  last_used;
  63         time_t                  send_next;
  64         unsigned int            timeout;
  65         unsigned int            retries;
  66         unsigned int            xid;
  67 };
  68
  69 static char             nsm_hostname[256];
  70 static uint32_t         nsm_state;
  71 static int              opt_debug = 0;
  72 static int              opt_quiet = 0;
  73 static int              opt_update_state = 1;
  74 static unsigned int     opt_max_retry = 15 * 60;
  75 static char *           opt_srcaddr = 0;
  76 static uint16_t         opt_srcport = 0;
  77 static int              log_syslog = 0;
  78
  79 static unsigned int     nsm_get_state(int);
  80 static void             notify(void);
  81 static int              notify_host(int, struct nsm_host *);
  82 static void             recv_reply(int);
  83 static void             backup_hosts(const char *, const char *);
  84 static void             get_hosts(const char *);
  85 static void             insert_host(struct nsm_host *);
  86 static struct nsm_host *find_host(uint32_t);
  87 static void             nsm_log(int fac, const char *fmt, ...);
  88 static int              record_pid(void);
  89 static void             drop_privs(void);
  90 static void             set_kernel_nsm_state(int state);
  91
  92 static struct nsm_host *        hosts = NULL;
  93
  94 /*
  95  * Address handling utilities
  96  */
  97
  98 static unsigned short smn_get_port(const struct sockaddr *sap)
  99 {
 100         switch (sap->sa_family) {
 101         case AF_INET:
 102                 return ntohs(((struct sockaddr_in *)sap)->sin_port);
 103         case AF_INET6:
 104                 return ntohs(((struct sockaddr_in6 *)sap)->sin6_port);
 105         }
 106         return 0;
 107 }
 108
 109 static void smn_set_port(struct sockaddr *sap, const unsigned short port)
 110 {
 111         switch (sap->sa_family) {
 112         case AF_INET:
 113                 ((struct sockaddr_in *)sap)->sin_port = htons(port);
 114                 break;
 115         case AF_INET6:
 116                 ((struct sockaddr_in6 *)sap)->sin6_port = htons(port);
 117                 break;
 118         }
 119 }
 120
 121 static struct addrinfo *smn_lookup(const sa_family_t family, const char *name)
 122 {
 123         struct addrinfo *ai, hint = {
 124                 .ai_family      = family,
 125                 .ai_protocol    = IPPROTO_UDP,
 126         };
 127
 128         if (getaddrinfo(name, NULL, &hint, &ai) != 0)
 129                 return NULL;
 130
 131         return ai;
 132 }
 133
 134 int
 135 main(int argc, char **argv)
 136 {
 137         int     c;
 138         int     force = 0;
 139
 140         while ((c = getopt(argc, argv, "dm:np:v:qP:f")) != -1) {
 141                 switch (c) {
 142                 case 'f':
 143                         force = 1;
 144                         break;
 145                 case 'd':
 146                         opt_debug++;
 147                         break;
 148                 case 'm':
 149                         opt_max_retry = atoi(optarg) * 60;
 150                         break;
 151                 case 'n':
 152                         opt_update_state = 0;
 153                         break;
 154                 case 'p':
 155                         opt_srcport = atoi(optarg);
 156                         break;
 157                 case 'v':
 158                         opt_srcaddr = optarg;
 159                         break;
 160                 case 'q':
 161                         opt_quiet = 1;
 162                         break;
 163                 case 'P':
 164                         _SM_BASE_PATH = strdup(optarg);
 165                         _SM_STATE_PATH = malloc(strlen(optarg)+1+sizeof("state"));
 166                         _SM_DIR_PATH = malloc(strlen(optarg)+1+sizeof("sm"));
 167                         _SM_BAK_PATH = malloc(strlen(optarg)+1+sizeof("sm.bak"));
 168                         if (_SM_BASE_PATH == NULL ||
 169                             _SM_STATE_PATH == NULL ||
 170                             _SM_DIR_PATH == NULL ||
 171                             _SM_BAK_PATH == NULL) {
 172                                 nsm_log(LOG_ERR, "unable to allocate memory");
 173                                 exit(1);
 174                         }
 175                         strcat(strcpy(_SM_STATE_PATH, _SM_BASE_PATH), "/state");
 176                         strcat(strcpy(_SM_DIR_PATH, _SM_BASE_PATH), "/sm");
 177                         strcat(strcpy(_SM_BAK_PATH, _SM_BASE_PATH), "/sm.bak");
 178                         break;
 179
 180                 default:
 181                         goto usage;
 182                 }
 183         }
 184
 185         if (optind < argc) {
 186 usage:          fprintf(stderr,
 187                         "Usage: sm-notify [-dfq] [-m max-retry-minutes] [-p srcport]\n"
 188                         "            [-P /path/to/state/directory] [-v my_host_name]\n");
 189                 exit(1);
 190         }
 191
 192         if (strcmp(_SM_BASE_PATH, BASEDIR) == 0) {
 193                 if (record_pid() == 0 && force == 0 && opt_update_state == 1)
 194                         /* already run, don't try again */
 195                         exit(0);
 196         }
 197
 198         if (opt_srcaddr) {
 199                 strncpy(nsm_hostname, opt_srcaddr, sizeof(nsm_hostname)-1);
 200         } else
 201         if (gethostname(nsm_hostname, sizeof(nsm_hostname)) < 0) {
 202                 nsm_log(LOG_ERR, "Failed to obtain name of local host: %s",
 203                         strerror(errno));
 204                 exit(1);
 205         }
 206
 207         backup_hosts(_SM_DIR_PATH, _SM_BAK_PATH);
 208         get_hosts(_SM_BAK_PATH);
 209
 210         /* Get and update the NSM state. This will call sync() */
 211         nsm_state = nsm_get_state(opt_update_state);
 212         set_kernel_nsm_state(nsm_state);
 213
 214         if (!opt_debug) {
 215                 if (!opt_quiet)
 216                         printf("Backgrounding to notify hosts...\n");
 217
 218                 openlog("sm-notify", LOG_PID, LOG_DAEMON);
 219                 log_syslog = 1;
 220
 221                 if (daemon(0, 0) < 0) {
 222                         nsm_log(LOG_ERR, "unable to background: %s",
 223                                         strerror(errno));
 224                         exit(1);
 225                 }
 226
 227                 close(0);
 228                 close(1);
 229                 close(2);
 230         }
 231
 232         notify();
 233
 234         if (hosts) {
 235                 struct nsm_host *hp;
 236
 237                 while ((hp = hosts) != 0) {
 238                         hosts = hp->next;
 239                         nsm_log(LOG_NOTICE,
 240                                 "Unable to notify %s, giving up",
 241                                 hp->name);
 242                 }
 243                 exit(1);
 244         }
 245
 246         exit(0);
 247 }
 248
 249 /*
 250  * Notify hosts
 251  */
 252 static void
 253 notify(void)
 254 {
 255         struct sockaddr_storage address;
 256         struct sockaddr *local_addr = (struct sockaddr *)&address;
 257         time_t  failtime = 0;
 258         int     sock = -1;
 259         int retry_cnt = 0;
 260
 261  retry:
 262         sock = socket(AF_INET, SOCK_DGRAM, 0);
 263         if (sock < 0) {
 264                 nsm_log(LOG_ERR, "Failed to create RPC socket: %s",
 265                         strerror(errno));
 266                 exit(1);
 267         }
 268         fcntl(sock, F_SETFL, O_NONBLOCK);
 269
 270         memset(&address, 0, sizeof(address));
 271         local_addr->sa_family = AF_INET;        /* Default to IPv4 */
 272
 273         /* Bind source IP if provided on command line */
 274         if (opt_srcaddr) {
 275                 struct addrinfo *ai = smn_lookup(AF_INET, opt_srcaddr);
 276                 if (!ai) {
 277                         nsm_log(LOG_ERR,
 278                                 "Not a valid hostname or address: \"%s\"",
 279                                 opt_srcaddr);
 280                         exit(1);
 281                 }
 282
 283                 /* We know it's IPv4 at this point */
 284                 memcpy(local_addr, ai->ai_addr, ai->ai_addrlen);
 285
 286                 freeaddrinfo(ai);
 287         }
 288
 289         /* Use source port if provided on the command line,
 290          * otherwise use bindresvport */
 291         if (opt_srcport) {
 292                 smn_set_port(local_addr, opt_srcport);
 293                 if (bind(sock, local_addr, sizeof(struct sockaddr_in)) < 0) {
 294                         nsm_log(LOG_ERR, "Failed to bind RPC socket: %s",
 295                                 strerror(errno));
 296                         exit(1);
 297                 }
 298         } else {
 299                 struct servent *se;
 300                 struct sockaddr_in *sin = (struct sockaddr_in *)local_addr;
 301                 (void) bindresvport(sock, sin);
 302                 /* try to avoid known ports */
 303                 se = getservbyport(sin->sin_port, "udp");
 304                 if (se && retry_cnt < 100) {
 305                         retry_cnt++;
 306                         close(sock);
 307                         goto retry;
 308                 }
 309         }
 310
 311         if (opt_max_retry)
 312                 failtime = time(NULL) + opt_max_retry;
 313
 314         drop_privs();
 315
 316         while (hosts) {
 317                 struct pollfd   pfd;
 318                 time_t          now = time(NULL);
 319                 unsigned int    sent = 0;
 320                 struct nsm_host *hp;
 321                 long            wait;
 322
 323                 if (failtime && now >= failtime)
 324                         break;
 325
 326                 while (hosts && ((wait = hosts->send_next - now) <= 0)) {
 327                         /* Never send more than 10 packets at once */
 328                         if (sent++ >= 10)
 329                                 break;
 330
 331                         /* Remove queue head */
 332                         hp = hosts;
 333                         hosts = hp->next;
 334
 335                         if (notify_host(sock, hp)){
 336                                 unlink(hp->path);
 337                                 free(hp->name);
 338                                 free(hp->path);
 339                                 free(hp);
 340                                 continue;
 341                         }
 342
 343                         /* Set the timeout for this call, using an
 344                            exponential timeout strategy */
 345                         wait = hp->timeout;
 346                         if ((hp->timeout <<= 1) > NSM_MAX_TIMEOUT)
 347                                 hp->timeout = NSM_MAX_TIMEOUT;
 348                         hp->send_next = now + wait;
 349                         hp->retries++;
 350
 351                         insert_host(hp);
 352                 }
 353                 if (hosts == NULL)
 354                         return;
 355
 356                 nsm_log(LOG_DEBUG, "Host %s due in %ld seconds",
 357                                 hosts->name, wait);
 358
 359                 pfd.fd = sock;
 360                 pfd.events = POLLIN;
 361
 362                 wait *= 1000;
 363                 if (wait < 100)
 364                         wait = 100;
 365                 if (poll(&pfd, 1, wait) != 1)
 366                         continue;
 367
 368                 recv_reply(sock);
 369         }
 370 }
 371
 372 /*
 373  * Send notification to a single host
 374  */
 375 static int
 376 notify_host(int sock, struct nsm_host *host)
 377 {
 378         struct sockaddr_storage address;
 379         struct sockaddr *dest = (struct sockaddr *)&address;
 380         socklen_t destlen = sizeof(address);
 381         static unsigned int     xid = 0;
 382         uint32_t                msgbuf[MAXMSGSIZE], *p;
 383         unsigned int            len;
 384
 385         if (!xid)
 386                 xid = getpid() + time(NULL);
 387         if (!host->xid)
 388                 host->xid = xid++;
 389
 390         if (host->ai == NULL) {
 391                 host->ai = smn_lookup(AF_UNSPEC, host->name);
 392                 if (host->ai == NULL) {
 393                         nsm_log(LOG_WARNING,
 394                                 "%s doesn't seem to be a valid address,"
 395                                 " skipped", host->name);
 396                         return 1;
 397                 }
 398         }
 399
 400         memset(msgbuf, 0, sizeof(msgbuf));
 401         p = msgbuf;
 402         *p++ = htonl(host->xid);
 403         *p++ = 0;
 404         *p++ = htonl(2);
 405
 406         /* If we retransmitted 4 times, reset the port to force
 407          * a new portmap lookup (in case statd was restarted).
 408          * We also rotate through multiple IP addresses at this
 409          * point.
 410          */
 411         if (host->retries >= 4) {
 412                 struct addrinfo *first = host->ai;
 413                 struct addrinfo **next = &host->ai;
 414
 415                 /* remove the first entry from the list */
 416                 host->ai = first->ai_next;
 417                 first->ai_next = NULL;
 418                 /* find the end of the list */
 419                 next = &first->ai_next;
 420                 while ( *next )
 421                         next = & (*next)->ai_next;
 422                 /* put first entry at end */
 423                 *next = first;
 424                 memcpy(&host->addr, first->ai_addr, first->ai_addrlen);
 425                 smn_set_port((struct sockaddr *)&host->addr, 0);
 426                 host->retries = 0;
 427         }
 428
 429         memcpy(dest, &host->addr, destlen);
 430         if (smn_get_port(dest) == 0) {
 431                 /* Build a PMAP packet */
 432                 nsm_log(LOG_DEBUG, "Sending portmap query to %s", host->name);
 433
 434                 smn_set_port(dest, 111);
 435                 *p++ = htonl(100000);
 436                 *p++ = htonl(2);
 437                 *p++ = htonl(3);
 438
 439                 /* Auth and verf */
 440                 *p++ = 0; *p++ = 0;
 441                 *p++ = 0; *p++ = 0;
 442
 443                 *p++ = htonl(NSM_PROGRAM);
 444                 *p++ = htonl(NSM_VERSION);
 445                 *p++ = htonl(IPPROTO_UDP);
 446                 *p++ = 0;
 447         } else {
 448                 /* Build an SM_NOTIFY packet */
 449                 nsm_log(LOG_DEBUG, "Sending SM_NOTIFY to %s", host->name);
 450
 451                 *p++ = htonl(NSM_PROGRAM);
 452                 *p++ = htonl(NSM_VERSION);
 453                 *p++ = htonl(NSM_NOTIFY);
 454
 455                 /* Auth and verf */
 456                 *p++ = 0; *p++ = 0;
 457                 *p++ = 0; *p++ = 0;
 458
 459                 /* state change */
 460                 len = strlen(nsm_hostname);
 461                 *p++ = htonl(len);
 462                 memcpy(p, nsm_hostname, len);
 463                 p += (len + 3) >> 2;
 464                 *p++ = htonl(nsm_state);
 465         }
 466         len = (p - msgbuf) << 2;
 467
 468         if (sendto(sock, msgbuf, len, 0, dest, destlen) < 0)
 469                 nsm_log(LOG_WARNING, "Sending Reboot Notification to "
 470                         "'%s' failed: errno %d (%s)", host->name, errno, strerror(errno));
 471
 472         return 0;
 473 }
 474
 475 /*
 476  * Receive reply from remote host
 477  */
 478 static void
 479 recv_reply(int sock)
 480 {
 481         struct nsm_host *hp;
 482         struct sockaddr *sap;
 483         uint32_t        msgbuf[MAXMSGSIZE], *p, *end;
 484         uint32_t        xid;
 485         int             res;
 486
 487         res = recv(sock, msgbuf, sizeof(msgbuf), 0);
 488         if (res < 0)
 489                 return;
 490
 491         nsm_log(LOG_DEBUG, "Received packet...");
 492
 493         p = msgbuf;
 494         end = p + (res >> 2);
 495
 496         xid = ntohl(*p++);
 497         if (*p++ != htonl(1)    /* must be REPLY */
 498          || *p++ != htonl(0)    /* must be ACCEPTED */
 499          || *p++ != htonl(0)    /* must be NULL verifier */
 500          || *p++ != htonl(0)
 501          || *p++ != htonl(0))   /* must be SUCCESS */
 502                 return;
 503
 504         /* Before we look at the data, find the host struct for
 505            this reply */
 506         if ((hp = find_host(xid)) == NULL)
 507                 return;
 508         sap = (struct sockaddr *)&hp->addr;
 509
 510         if (smn_get_port(sap) == 0) {
 511                 /* This was a portmap request */
 512                 unsigned int    port;
 513
 514                 port = ntohl(*p++);
 515                 if (p > end)
 516                         goto fail;
 517
 518                 hp->send_next = time(NULL);
 519                 if (port == 0) {
 520                         /* No binding for statd. Delay the next
 521                          * portmap query for max timeout */
 522                         nsm_log(LOG_DEBUG, "No statd on %s", hp->name);
 523                         hp->timeout = NSM_MAX_TIMEOUT;
 524                         hp->send_next += NSM_MAX_TIMEOUT;
 525                 } else {
 526                         smn_set_port(sap, port);
 527                         if (hp->timeout >= NSM_MAX_TIMEOUT / 4)
 528                                 hp->timeout = NSM_MAX_TIMEOUT / 4;
 529                 }
 530                 hp->xid = 0;
 531         } else {
 532                 /* Successful NOTIFY call. Server returns void,
 533                  * so nothing we need to do here (except
 534                  * check that we didn't read past the end of the
 535                  * packet)
 536                  */
 537                 if (p <= end) {
 538                         nsm_log(LOG_DEBUG, "Host %s notified successfully",
 539                                         hp->name);
 540                         unlink(hp->path);
 541                         free(hp->name);
 542                         free(hp->path);
 543                         free(hp);
 544                         freeaddrinfo(hp->ai);
 545                         return;
 546                 }
 547         }
 548
 549 fail:   /* Re-insert the host */
 550         insert_host(hp);
 551 }
 552
 553 /*
 554  * Back up all hosts from the sm directory to sm.bak
 555  */
 556 static void
 557 backup_hosts(const char *dirname, const char *bakname)
 558 {
 559         struct dirent   *de;
 560         DIR             *dir;
 561
 562         if (!(dir = opendir(dirname))) {
 563                 nsm_log(LOG_WARNING,
 564                         "Failed to open %s: %s", dirname, strerror(errno));
 565                 return;
 566         }
 567
 568         while ((de = readdir(dir)) != NULL) {
 569                 char    src[1024], dst[1024];
 570
 571                 if (de->d_name[0] == '.')
 572                         continue;
 573
 574                 snprintf(src, sizeof(src), "%s/%s", dirname, de->d_name);
 575                 snprintf(dst, sizeof(dst), "%s/%s", bakname, de->d_name);
 576                 if (rename(src, dst) < 0) {
 577                         nsm_log(LOG_WARNING,
 578                                 "Failed to rename %s -> %s: %m",
 579                                 src, dst);
 580                 }
 581         }
 582         closedir(dir);
 583 }
 584
 585 /*
 586  * Get all entries from sm.bak and convert them to host entries
 587  */
 588 static void
 589 get_hosts(const char *dirname)
 590 {
 591         struct nsm_host *host;
 592         struct dirent   *de;
 593         DIR             *dir;
 594
 595         if (!(dir = opendir(dirname))) {
 596                 nsm_log(LOG_WARNING,
 597                         "Failed to open %s: %s", dirname, strerror(errno));
 598                 return;
 599         }
 600
 601         host = NULL;
 602         while ((de = readdir(dir)) != NULL) {
 603                 struct stat     stb;
 604                 char            path[1024];
 605
 606                 if (de->d_name[0] == '.')
 607                         continue;
 608                 if (host == NULL)
 609                         host = calloc(1, sizeof(*host));
 610                 if (host == NULL) {
 611                         nsm_log(LOG_WARNING, "Unable to allocate memory");
 612                         return;
 613                 }
 614
 615                 snprintf(path, sizeof(path), "%s/%s", dirname, de->d_name);
 616                 if (stat(path, &stb) < 0)
 617                         continue;
 618
 619                 host->last_used = stb.st_mtime;
 620                 host->timeout = NSM_TIMEOUT;
 621                 host->path = strdup(path);
 622                 host->name = strdup(de->d_name);
 623                 host->retries = 100; /* force address retry */
 624
 625                 insert_host(host);
 626                 host = NULL;
 627         }
 628         closedir(dir);
 629
 630         if (host)
 631                 free(host);
 632 }
 633
 634 /*
 635  * Insert host into sorted list
 636  */
 637 static void
 638 insert_host(struct nsm_host *host)
 639 {
 640         struct nsm_host **where, *p;
 641
 642         where = &hosts;
 643         while ((p = *where) != 0) {
 644                 /* Sort in ascending order of timeout */
 645                 if (host->send_next < p->send_next)
 646                         break;
 647                 /* If we have the same timeout, put the
 648                  * most recently used host first.
 649                  * This makes sure that "recent" hosts
 650                  * get notified first.
 651                  */
 652                 if (host->send_next == p->send_next
 653                  && host->last_used > p->last_used)
 654                         break;
 655                 where = &p->next;
 656         }
 657
 658         host->next = *where;
 659         *where = host;
 660 }
 661
 662 /*
 663  * Find host given the XID
 664  */
 665 static struct nsm_host *
 666 find_host(uint32_t xid)
 667 {
 668         struct nsm_host **where, *p;
 669
 670         where = &hosts;
 671         while ((p = *where) != 0) {
 672                 if (p->xid == xid) {
 673                         *where = p->next;
 674                         return p;
 675                 }
 676                 where = &p->next;
 677         }
 678         return NULL;
 679 }
 680
 681
 682 /*
 683  * Retrieve the current NSM state
 684  */
 685 static unsigned int
 686 nsm_get_state(int update)
 687 {
 688         char            newfile[PATH_MAX];
 689         int             fd, state;
 690
 691         if ((fd = open(_SM_STATE_PATH, O_RDONLY)) < 0) {
 692                 if (!opt_quiet) {
 693                         nsm_log(LOG_WARNING, "%s: %m", _SM_STATE_PATH);
 694                         nsm_log(LOG_WARNING, "Creating %s, set initial state 1",
 695                                 _SM_STATE_PATH);
 696                 }
 697                 state = 1;
 698                 update = 1;
 699         } else {
 700                 if (read(fd, &state, sizeof(state)) != sizeof(state)) {
 701                         nsm_log(LOG_WARNING,
 702                                 "%s: bad file size, setting state = 1",
 703                                 _SM_STATE_PATH);
 704                         state = 1;
 705                         update = 1;
 706                 } else {
 707                         if (!(state & 1))
 708                                 state += 1;
 709                 }
 710                 close(fd);
 711         }
 712
 713         if (update) {
 714                 state += 2;
 715                 snprintf(newfile, sizeof(newfile),
 716                                 "%s.new", _SM_STATE_PATH);
 717                 if ((fd = open(newfile, O_CREAT|O_WRONLY, 0644)) < 0) {
 718                         nsm_log(LOG_ERR, "Cannot create %s: %m", newfile);
 719                         exit(1);
 720                 }
 721                 if (write(fd, &state, sizeof(state)) != sizeof(state)) {
 722                         nsm_log(LOG_ERR,
 723                                 "Failed to write state to %s", newfile);
 724                         exit(1);
 725                 }
 726                 close(fd);
 727                 if (rename(newfile, _SM_STATE_PATH) < 0) {
 728                         nsm_log(LOG_ERR,
 729                                 "Cannot create %s: %m", _SM_STATE_PATH);
 730                         exit(1);
 731                 }
 732                 sync();
 733         }
 734
 735         return state;
 736 }
 737
 738 /*
 739  * Log a message
 740  */
 741 static void
 742 nsm_log(int fac, const char *fmt, ...)
 743 {
 744         va_list ap;
 745
 746         if (fac == LOG_DEBUG && !opt_debug)
 747                 return;
 748
 749         va_start(ap, fmt);
 750         if (log_syslog)
 751                 vsyslog(fac, fmt, ap);
 752         else {
 753                 vfprintf(stderr, fmt, ap);
 754                 fputs("\n", stderr);
 755         }
 756         va_end(ap);
 757 }
 758
 759 /*
 760  * Record pid in /var/run/sm-notify.pid
 761  * This file should remain until a reboot, even if the
 762  * program exits.
 763  * If file already exists, fail.
 764  */
 765 static int record_pid(void)
 766 {
 767         char pid[20];
 768         int fd;
 769
 770         snprintf(pid, 20, "%d\n", getpid());
 771         fd = open("/var/run/sm-notify.pid", O_CREAT|O_EXCL|O_WRONLY, 0600);
 772         if (fd < 0)
 773                 return 0;
 774         write(fd, pid, strlen(pid));
 775         close(fd);
 776         return 1;
 777 }
 778
 779 /* Drop privileges to match owner of state-directory
 780  * (in case a reply triggers some unknown bug).
 781  */
 782 static void drop_privs(void)
 783 {
 784         struct stat st;
 785
 786         if (stat(_SM_DIR_PATH, &st) == -1 &&
 787             stat(_SM_BASE_PATH, &st) == -1) {
 788                 st.st_uid = 0;
 789                 st.st_gid = 0;
 790         }
 791
 792         if (st.st_uid == 0) {
 793                 nsm_log(LOG_WARNING,
 794                         "sm-notify running as root. chown %s to choose different user",
 795                     _SM_DIR_PATH);
 796                 return;
 797         }
 798
 799         setgroups(0, NULL);
 800         if (setgid(st.st_gid) == -1
 801             || setuid(st.st_uid) == -1) {
 802                 nsm_log(LOG_ERR, "Fail to drop privileges");
 803                 exit(1);
 804         }
 805 }
 806
 807 static void set_kernel_nsm_state(int state)
 808 {
 809         int fd;
 810
 811         fd = open("/proc/sys/fs/nfs/nsm_local_state",O_WRONLY);
 812         if (fd >= 0) {
 813                 char buf[20];
 814                 snprintf(buf, sizeof(buf), "%d", state);
 815                 write(fd, buf, strlen(buf));
 816                 close(fd);
 817         }
 818 }