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