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