utils/showmount/showmount.c

   1 /*
   2  * showmount.c -- show mount information for an NFS server
   3  * Copyright (C) 1993 Rick Sladkey <jrs@world.std.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2, or (at your option)
   8  * any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #ifdef HAVE_CONFIG_H
  17 #include <config.h>
  18 #endif
  19
  20 #include <stdio.h>
  21 #include <rpc/rpc.h>
  22 #include <rpc/pmap_prot.h>
  23 #include <sys/socket.h>
  24 #include <netinet/in.h>
  25 #include <sys/time.h>
  26 #include <string.h>
  27 #include <sys/types.h>
  28 #include <unistd.h>
  29 #include <memory.h>
  30 #include <stdlib.h>
  31 #include <fcntl.h>
  32
  33 #include <netdb.h>
  34 #include <arpa/inet.h>
  35 #include <errno.h>
  36 #include <getopt.h>
  37 #include <mount.h>
  38 #include <unistd.h>
  39
  40 #define TIMEOUT_UDP     3
  41 #define TIMEOUT_TCP     10
  42 #define TOTAL_TIMEOUT   20
  43
  44 static char *   version = "showmount for " VERSION;
  45 static char *   program_name;
  46 static int      headers = 1;
  47 static int      hflag = 0;
  48 static int      aflag = 0;
  49 static int      dflag = 0;
  50 static int      eflag = 0;
  51
  52 static struct option longopts[] =
  53 {
  54         { "all", 0, 0, 'a' },
  55         { "directories", 0, 0, 'd' },
  56         { "exports", 0, 0, 'e' },
  57         { "no-headers", 0, &headers, 0 },
  58         { "version", 0, 0, 'v' },
  59         { "help", 0, 0, 'h' },
  60         { NULL, 0, 0, 0 }
  61 };
  62
  63 #define MAXHOSTLEN 256
  64
  65 static int dump_cmp(const void *pv, const void *qv)
  66 {
  67         const char **p = (const char **)pv;
  68         const char **q = (const char **)qv;
  69         return strcmp(*p, *q);
  70 }
  71
  72 static void usage(FILE *fp, int n)
  73 {
  74         fprintf(fp, "Usage: %s [-adehv]\n", program_name);
  75         fprintf(fp, "       [--all] [--directories] [--exports]\n");
  76         fprintf(fp, "       [--no-headers] [--help] [--version] [host]\n");
  77         exit(n);
  78 }
  79
  80 /*
  81  *  Perform a non-blocking connect on the socket fd.
  82  *
  83  *  tout contains the timeout.  It will be modified to contain the time
  84  *  remaining (i.e. time provided - time elasped).
  85  *
  86  *  Returns zero on success; otherwise, -1 is returned and errno is set
  87  *  to reflect the nature of the error.
  88  */
  89 static int connect_nb(int fd, struct sockaddr_in *addr, struct timeval *tout)
  90 {
  91         int flags, ret;
  92         socklen_t len;
  93         fd_set rset;
  94
  95         flags = fcntl(fd, F_GETFL, 0);
  96         if (flags < 0)
  97                 return -1;
  98
  99         ret = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
 100         if (ret < 0)
 101                 return -1;
 102
 103         /*
 104          * From here on subsequent sys calls could change errno so
 105          * we set ret = -errno to capture it in case we decide to
 106          * use it later.
 107          */
 108         len = sizeof(struct sockaddr);
 109         ret = connect(fd, (struct sockaddr *)addr, len);
 110         if (ret < 0 && errno != EINPROGRESS) {
 111                 ret = -1;
 112                 goto done;
 113         }
 114
 115         if (ret == 0)
 116                 goto done;
 117
 118         /* now wait */
 119         FD_ZERO(&rset);
 120         FD_SET(fd, &rset);
 121
 122         ret = select(fd + 1, NULL, &rset, NULL, tout);
 123         if (ret <= 0) {
 124                 if (ret == 0)
 125                         errno = ETIMEDOUT;
 126                 ret = -1;
 127                 goto done;
 128         }
 129
 130         if (FD_ISSET(fd, &rset)) {
 131                 int status;
 132
 133                 len = sizeof(ret);
 134                 status = getsockopt(fd, SOL_SOCKET, SO_ERROR, &ret, &len);
 135                 if (status < 0) {
 136                         ret = -1;
 137                         goto done;
 138                 }
 139
 140                 /* Oops - something wrong with connect */
 141                 if (ret != 0) {
 142                         errno = ret;
 143                         ret = -1;
 144                 }
 145         }
 146
 147 done:
 148         fcntl(fd, F_SETFL, flags);
 149         return ret;
 150 }
 151
 152 static unsigned short getport(struct sockaddr_in *addr,
 153                          unsigned long prog, unsigned long vers, int prot)
 154 {
 155         CLIENT *client;
 156         enum clnt_stat status;
 157         struct pmap parms;
 158         int ret, sock;
 159         struct sockaddr_in laddr, saddr;
 160         struct timeval tout = {0, 0};
 161         socklen_t len;
 162         unsigned int send_sz = 0;
 163         unsigned int recv_sz = 0;
 164         unsigned short port;
 165
 166         memset(&laddr, 0, sizeof(laddr));
 167         memset(&saddr, 0, sizeof(saddr));
 168         memset(&parms, 0, sizeof(parms));
 169
 170         memcpy(&saddr, addr, sizeof(saddr));
 171         saddr.sin_port = htons(PMAPPORT);
 172
 173         if (prot == IPPROTO_TCP) {
 174                 sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
 175                 if (sock == -1) {
 176                         rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 177                         rpc_createerr.cf_error.re_errno = errno;
 178                         return 0;
 179                 }
 180
 181                 tout.tv_sec = TIMEOUT_TCP;
 182
 183                 ret = connect_nb(sock, &saddr, &tout);
 184                 if (ret != 0) {
 185                         rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 186                         rpc_createerr.cf_error.re_errno = errno;
 187                         close(sock);
 188                         return 0;
 189                 }
 190                 client = clnttcp_create(&saddr,
 191                                         PMAPPROG, PMAPVERS, &sock,
 192                                         0, 0);
 193         } else {
 194                 /*
 195                  * bind to any unused port.  If we left this up to the rpc
 196                  * layer, it would bind to a reserved port, which has been shown
 197                  * to exhaust the reserved port range in some situations.
 198                  */
 199                 sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
 200                 if (sock == -1) {
 201                         rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 202                         rpc_createerr.cf_error.re_errno = errno;
 203                         return 0;
 204                 }
 205
 206                 laddr.sin_family = AF_INET;
 207                 laddr.sin_port = 0;
 208                 laddr.sin_addr.s_addr = htonl(INADDR_ANY);
 209
 210                 tout.tv_sec = TIMEOUT_UDP;
 211
 212                 send_sz = RPCSMALLMSGSIZE;
 213                 recv_sz = RPCSMALLMSGSIZE;
 214
 215                 len = sizeof(struct sockaddr_in);
 216                 if (bind(sock, (struct sockaddr *)&laddr, len) < 0) {
 217                         close(sock);
 218                         sock = RPC_ANYSOCK;
 219                         /* FALLTHROUGH */
 220                 }
 221                 client = clntudp_bufcreate(&saddr, PMAPPROG, PMAPVERS,
 222                                            tout, &sock, send_sz, recv_sz);
 223         }
 224
 225         if (!client) {
 226                 close(sock);
 227                 rpc_createerr.cf_stat = RPC_RPCBFAILURE;
 228                 return 0;
 229         }
 230
 231         clnt_control(client, CLSET_FD_CLOSE, NULL);
 232
 233         parms.pm_prog = prog;
 234         parms.pm_vers = vers;
 235         parms.pm_prot = prot;
 236
 237         status = clnt_call(client, PMAPPROC_GETPORT,
 238                            (xdrproc_t) xdr_pmap, (caddr_t) &parms,
 239                            (xdrproc_t) xdr_u_short, (caddr_t) &port,
 240                            tout);
 241
 242         if (status != RPC_SUCCESS) {
 243                 clnt_geterr(client, &rpc_createerr.cf_error);
 244                 rpc_createerr.cf_stat = status;
 245                 clnt_destroy(client);
 246                 return 0;
 247         } else if (port == 0) {
 248                 rpc_createerr.cf_stat = RPC_PROGNOTREGISTERED;
 249         }
 250
 251         clnt_destroy(client);
 252
 253         return htons(port);
 254 }
 255
 256 int main(int argc, char **argv)
 257 {
 258         char hostname_buf[MAXHOSTLEN];
 259         char *hostname;
 260         enum clnt_stat clnt_stat;
 261         struct hostent *hp;
 262         struct sockaddr_in server_addr;
 263         int ret, msock;
 264         struct timeval total_timeout;
 265         struct timeval pertry_timeout;
 266         int c;
 267         CLIENT *mclient;
 268         groups grouplist;
 269         exports exportlist, exl;
 270         mountlist dumplist;
 271         mountlist list;
 272         int i;
 273         int n;
 274         int maxlen;
 275         char **dumpv;
 276
 277         program_name = argv[0];
 278         while ((c = getopt_long(argc, argv, "adehv", longopts, NULL)) != EOF) {
 279                 switch (c) {
 280                 case 'a':
 281                         aflag = 1;
 282                         break;
 283                 case 'd':
 284                         dflag = 1;
 285                         break;
 286                 case 'e':
 287                         eflag = 1;
 288                         break;
 289                 case 'h':
 290                         usage(stdout, 0);
 291                         break;
 292                 case 'v':
 293                         printf("%s\n", version);
 294                         exit(0);
 295                 case 0:
 296                         break;
 297                 case '?':
 298                 default:
 299                         usage(stderr, 1);
 300                         break;
 301                 }
 302         }
 303         argc -= optind;
 304         argv += optind;
 305
 306         switch (aflag + dflag + eflag) {
 307         case 0:
 308                 hflag = 1;
 309                 break;
 310         case 1:
 311                 break;
 312         default:
 313                 fprintf(stderr, "%s: only one of -a, -d or -e is allowed\n",
 314                         program_name);
 315                 exit(1);
 316                 break;
 317         }
 318
 319         switch (argc) {
 320         case 0:
 321                 if (gethostname(hostname_buf, MAXHOSTLEN) < 0) {
 322                         perror("getting hostname");
 323                         exit(1);
 324                 }
 325                 hostname = hostname_buf;
 326                 break;
 327         case 1:
 328                 hostname = argv[0];
 329                 break;
 330         default:
 331                 fprintf(stderr, "%s: only one hostname is allowed\n",
 332                         program_name);
 333                 exit(1);
 334                 break;
 335         }
 336
 337         if (inet_aton(hostname, &server_addr.sin_addr)) {
 338                 server_addr.sin_family = AF_INET;
 339         }
 340         else {
 341                 if ((hp = gethostbyname(hostname)) == NULL) {
 342                         fprintf(stderr, "%s: can't get address for %s\n",
 343                                 program_name, hostname);
 344                         exit(1);
 345                 }
 346                 server_addr.sin_family = AF_INET;
 347                 memcpy(&server_addr.sin_addr, hp->h_addr, hp->h_length);
 348         }
 349
 350         /* create mount deamon client */
 351
 352         mclient = NULL;
 353         msock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
 354         if (msock != -1) {
 355                 server_addr.sin_port = getport(&server_addr,
 356                                          MOUNTPROG, MOUNTVERS, IPPROTO_TCP);
 357                 if (server_addr.sin_port) {
 358                         ret = connect_nb(msock, &server_addr, 0);
 359                         if (ret == 0) /* success */
 360                                 mclient = clnttcp_create(&server_addr,
 361                                                 MOUNTPROG, MOUNTVERS, &msock,
 362                                                 0, 0);
 363                         else
 364                                 close(msock);
 365                 } else
 366                         close(msock);
 367         }
 368
 369         if (!mclient) {
 370                 server_addr.sin_port = getport(&server_addr,
 371                                          MOUNTPROG, MOUNTVERS, IPPROTO_UDP);
 372                 if (!server_addr.sin_port) {
 373                         clnt_pcreateerror("showmount");
 374                         exit(1);
 375                 }
 376                 msock = RPC_ANYSOCK;
 377                 pertry_timeout.tv_sec = TIMEOUT_UDP;
 378                 pertry_timeout.tv_usec = 0;
 379                 if ((mclient = clntudp_create(&server_addr,
 380                     MOUNTPROG, MOUNTVERS, pertry_timeout, &msock)) == NULL) {
 381                         clnt_pcreateerror("mount clntudp_create");
 382                         exit(1);
 383                 }
 384         }
 385         mclient->cl_auth = authunix_create_default();
 386         total_timeout.tv_sec = TOTAL_TIMEOUT;
 387         total_timeout.tv_usec = 0;
 388
 389         if (eflag) {
 390                 memset(&exportlist, '\0', sizeof(exportlist));
 391
 392                 clnt_stat = clnt_call(mclient, MOUNTPROC_EXPORT,
 393                         (xdrproc_t) xdr_void, NULL,
 394                         (xdrproc_t) xdr_exports, (caddr_t) &exportlist,
 395                         total_timeout);
 396                 if (clnt_stat != RPC_SUCCESS) {
 397                         clnt_perror(mclient, "rpc mount export");
 398                         clnt_destroy(mclient);
 399                         exit(1);
 400                 }
 401                 if (headers)
 402                         printf("Export list for %s:\n", hostname);
 403                 maxlen = 0;
 404                 for (exl = exportlist; exl; exl = exl->ex_next) {
 405                         if ((n = strlen(exl->ex_dir)) > maxlen)
 406                                 maxlen = n;
 407                 }
 408                 while (exportlist) {
 409                         printf("%-*s ", maxlen, exportlist->ex_dir);
 410                         grouplist = exportlist->ex_groups;
 411                         if (grouplist)
 412                                 while (grouplist) {
 413                                         printf("%s%s", grouplist->gr_name,
 414                                                 grouplist->gr_next ? "," : "");
 415                                         grouplist = grouplist->gr_next;
 416                                 }
 417                         else
 418                                 printf("(everyone)");
 419                         printf("\n");
 420                         exportlist = exportlist->ex_next;
 421                 }
 422                 clnt_destroy(mclient);
 423                 exit(0);
 424         }
 425
 426         memset(&dumplist, '\0', sizeof(dumplist));
 427         clnt_stat = clnt_call(mclient, MOUNTPROC_DUMP,
 428                 (xdrproc_t) xdr_void, NULL,
 429                 (xdrproc_t) xdr_mountlist, (caddr_t) &dumplist,
 430                 total_timeout);
 431         if (clnt_stat != RPC_SUCCESS) {
 432                 clnt_perror(mclient, "rpc mount dump");
 433                 clnt_destroy(mclient);
 434                 exit(1);
 435         }
 436         clnt_destroy(mclient);
 437
 438         n = 0;
 439         for (list = dumplist; list; list = list->ml_next)
 440                 n++;
 441         dumpv = (char **) calloc(n, sizeof (char *));
 442         if (n && !dumpv) {
 443                 fprintf(stderr, "%s: out of memory\n", program_name);
 444                 exit(1);
 445         }
 446         i = 0;
 447
 448         if (hflag) {
 449                 if (headers)
 450                         printf("Hosts on %s:\n", hostname);
 451                 while (dumplist) {
 452                         dumpv[i++] = dumplist->ml_hostname;
 453                         dumplist = dumplist->ml_next;
 454                 }
 455         }
 456         else if (aflag) {
 457                 if (headers)
 458                         printf("All mount points on %s:\n", hostname);
 459                 while (dumplist) {
 460                         char *t;
 461
 462                         t=malloc(strlen(dumplist->ml_hostname)+strlen(dumplist->ml_directory)+2);
 463                         if (!t)
 464                         {
 465                                 fprintf(stderr, "%s: out of memory\n", program_name);
 466                                 exit(1);
 467                         }
 468                         sprintf(t, "%s:%s", dumplist->ml_hostname, dumplist->ml_directory);
 469                         dumpv[i++] = t;
 470                         dumplist = dumplist->ml_next;
 471                 }
 472         }
 473         else if (dflag) {
 474                 if (headers)
 475                         printf("Directories on %s:\n", hostname);
 476                 while (dumplist) {
 477                         dumpv[i++] = dumplist->ml_directory;
 478                         dumplist = dumplist->ml_next;
 479                 }
 480         }
 481
 482         qsort(dumpv, n, sizeof (char *), dump_cmp);
 483
 484         for (i = 0; i < n; i++) {
 485                 if (i == 0 || strcmp(dumpv[i], dumpv[i - 1]) != 0)
 486                         printf("%s\n", dumpv[i]);
 487         }
 488         exit(0);
 489 }
 490