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 0 for success
  87  */
  88 static int connect_nb(int fd, struct sockaddr_in *addr, struct timeval *tout)
  89 {
  90         int flags, ret;
  91         socklen_t len;
  92         fd_set rset;
  93
  94         flags = fcntl(fd, F_GETFL, 0);
  95         if (flags < 0)
  96                 return -1;
  97
  98         ret = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
  99         if (ret < 0)
 100                 return -1;
 101
 102         /*
 103          * From here on subsequent sys calls could change errno so
 104          * we set ret = -errno to capture it in case we decide to
 105          * use it later.
 106          */
 107         len = sizeof(struct sockaddr);
 108         ret = connect(fd, (struct sockaddr *)addr, len);
 109         if (ret < 0 && errno != EINPROGRESS) {
 110                 ret = -errno;
 111                 goto done;
 112         }
 113
 114         if (ret == 0)
 115                 goto done;
 116
 117         /* now wait */
 118         FD_ZERO(&rset);
 119         FD_SET(fd, &rset);
 120
 121         ret = select(fd + 1, NULL, &rset, NULL, tout);
 122         if (ret <= 0) {
 123                 if (ret == 0)
 124                         ret = -ETIMEDOUT;
 125                 else
 126                         ret = -errno;
 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 = -errno;
 137                         goto done;
 138                 }
 139
 140                 /* Oops - something wrong with connect */
 141                 if (ret)
 142                         ret = -ret;
 143         }
 144
 145 done:
 146         fcntl(fd, F_SETFL, flags);
 147         return ret;
 148 }
 149
 150 static unsigned short getport(struct sockaddr_in *addr,
 151                          unsigned long prog, unsigned long vers, int prot)
 152 {
 153         CLIENT *client;
 154         enum clnt_stat status;
 155         struct pmap parms;
 156         int ret, sock;
 157         struct sockaddr_in laddr, saddr;
 158         struct timeval tout = {0, 0};
 159         socklen_t len;
 160         unsigned int send_sz = 0;
 161         unsigned int recv_sz = 0;
 162         unsigned short port;
 163
 164         memset(&laddr, 0, sizeof(laddr));
 165         memset(&saddr, 0, sizeof(saddr));
 166         memset(&parms, 0, sizeof(parms));
 167
 168         memcpy(&saddr, addr, sizeof(saddr));
 169         saddr.sin_port = htons(PMAPPORT);
 170
 171         if (prot == IPPROTO_TCP) {
 172                 sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
 173                 if (sock == -1) {
 174                         rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 175                         rpc_createerr.cf_error.re_errno = errno;
 176                         return 0;
 177                 }
 178
 179                 tout.tv_sec = TIMEOUT_TCP;
 180
 181                 ret = connect_nb(sock, &saddr, &tout);
 182                 if (ret < 0) {
 183                         close(sock);
 184                         rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 185                         rpc_createerr.cf_error.re_errno = errno;
 186                         return 0;
 187                 }
 188                 client = clnttcp_create(&saddr,
 189                                         PMAPPROG, PMAPVERS, &sock,
 190                                         0, 0);
 191         } else {
 192                 /*
 193                  * bind to any unused port.  If we left this up to the rpc
 194                  * layer, it would bind to a reserved port, which has been shown
 195                  * to exhaust the reserved port range in some situations.
 196                  */
 197                 sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
 198                 if (sock == -1) {
 199                         rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 200                         rpc_createerr.cf_error.re_errno = errno;
 201                         return 0;
 202                 }
 203
 204                 laddr.sin_family = AF_INET;
 205                 laddr.sin_port = 0;
 206                 laddr.sin_addr.s_addr = htonl(INADDR_ANY);
 207
 208                 tout.tv_sec = TIMEOUT_UDP;
 209
 210                 send_sz = RPCSMALLMSGSIZE;
 211                 recv_sz = RPCSMALLMSGSIZE;
 212
 213                 len = sizeof(struct sockaddr_in);
 214                 if (bind(sock, (struct sockaddr *)&laddr, len) < 0) {
 215                         close(sock);
 216                         sock = RPC_ANYSOCK;
 217                         /* FALLTHROUGH */
 218                 }
 219                 client = clntudp_bufcreate(&saddr, PMAPPROG, PMAPVERS,
 220                                            tout, &sock, send_sz, recv_sz);
 221         }
 222
 223         if (!client) {
 224                 close(sock);
 225                 rpc_createerr.cf_stat = RPC_RPCBFAILURE;
 226                 return 0;
 227         }
 228
 229         clnt_control(client, CLSET_FD_CLOSE, NULL);
 230
 231         parms.pm_prog = prog;
 232         parms.pm_vers = vers;
 233         parms.pm_prot = prot;
 234
 235         status = clnt_call(client, PMAPPROC_GETPORT,
 236                            (xdrproc_t) xdr_pmap, (caddr_t) &parms,
 237                            (xdrproc_t) xdr_u_short, (caddr_t) &port,
 238                            tout);
 239
 240         if (status != RPC_SUCCESS) {
 241                 clnt_geterr(client, &rpc_createerr.cf_error);
 242                 rpc_createerr.cf_stat = status;
 243                 clnt_destroy(client);
 244                 return 0;
 245         } else if (port == 0) {
 246                 rpc_createerr.cf_stat = RPC_PROGNOTREGISTERED;
 247         }
 248
 249         clnt_destroy(client);
 250
 251         return htons(port);
 252 }
 253
 254 int main(int argc, char **argv)
 255 {
 256         char hostname_buf[MAXHOSTLEN];
 257         char *hostname;
 258         enum clnt_stat clnt_stat;
 259         struct hostent *hp;
 260         struct sockaddr_in server_addr;
 261         int ret, msock;
 262         struct timeval total_timeout;
 263         struct timeval pertry_timeout;
 264         int c;
 265         CLIENT *mclient;
 266         groups grouplist;
 267         exports exportlist, exl;
 268         mountlist dumplist;
 269         mountlist list;
 270         int i;
 271         int n;
 272         int maxlen;
 273         char **dumpv;
 274
 275         program_name = argv[0];
 276         while ((c = getopt_long(argc, argv, "adehv", longopts, NULL)) != EOF) {
 277                 switch (c) {
 278                 case 'a':
 279                         aflag = 1;
 280                         break;
 281                 case 'd':
 282                         dflag = 1;
 283                         break;
 284                 case 'e':
 285                         eflag = 1;
 286                         break;
 287                 case 'h':
 288                         usage(stdout, 0);
 289                         break;
 290                 case 'v':
 291                         printf("%s\n", version);
 292                         exit(0);
 293                 case 0:
 294                         break;
 295                 case '?':
 296                 default:
 297                         usage(stderr, 1);
 298                         break;
 299                 }
 300         }
 301         argc -= optind;
 302         argv += optind;
 303
 304         switch (aflag + dflag + eflag) {
 305         case 0:
 306                 hflag = 1;
 307                 break;
 308         case 1:
 309                 break;
 310         default:
 311                 fprintf(stderr, "%s: only one of -a, -d or -e is allowed\n",
 312                         program_name);
 313                 exit(1);
 314                 break;
 315         }
 316
 317         switch (argc) {
 318         case 0:
 319                 if (gethostname(hostname_buf, MAXHOSTLEN) < 0) {
 320                         perror("getting hostname");
 321                         exit(1);
 322                 }
 323                 hostname = hostname_buf;
 324                 break;
 325         case 1:
 326                 hostname = argv[0];
 327                 break;
 328         default:
 329                 fprintf(stderr, "%s: only one hostname is allowed\n",
 330                         program_name);
 331                 exit(1);
 332                 break;
 333         }
 334
 335         if (inet_aton(hostname, &server_addr.sin_addr)) {
 336                 server_addr.sin_family = AF_INET;
 337         }
 338         else {
 339                 if ((hp = gethostbyname(hostname)) == NULL) {
 340                         fprintf(stderr, "%s: can't get address for %s\n",
 341                                 program_name, hostname);
 342                         exit(1);
 343                 }
 344                 server_addr.sin_family = AF_INET;
 345                 memcpy(&server_addr.sin_addr, hp->h_addr, hp->h_length);
 346         }
 347
 348         /* create mount deamon client */
 349
 350         mclient = NULL;
 351         msock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
 352         if (msock != -1) {
 353                 server_addr.sin_port = getport(&server_addr,
 354                                          MOUNTPROG, MOUNTVERS, IPPROTO_TCP);
 355                 if (server_addr.sin_port) {
 356                         ret = connect_nb(msock, &server_addr, 0);
 357                         if (ret == 0) /* success */
 358                                 mclient = clnttcp_create(&server_addr,
 359                                                 MOUNTPROG, MOUNTVERS, &msock,
 360                                                 0, 0);
 361                         else
 362                                 close(msock);
 363                 } else
 364                         close(msock);
 365         }
 366
 367         if (!mclient) {
 368                 server_addr.sin_port = getport(&server_addr,
 369                                          MOUNTPROG, MOUNTVERS, IPPROTO_UDP);
 370                 if (!server_addr.sin_port) {
 371                         clnt_pcreateerror("showmount");
 372                         exit(1);
 373                 }
 374                 msock = RPC_ANYSOCK;
 375                 pertry_timeout.tv_sec = TIMEOUT_UDP;
 376                 pertry_timeout.tv_usec = 0;
 377                 if ((mclient = clntudp_create(&server_addr,
 378                     MOUNTPROG, MOUNTVERS, pertry_timeout, &msock)) == NULL) {
 379                         clnt_pcreateerror("mount clntudp_create");
 380                         exit(1);
 381                 }
 382         }
 383         mclient->cl_auth = authunix_create_default();
 384         total_timeout.tv_sec = TOTAL_TIMEOUT;
 385         total_timeout.tv_usec = 0;
 386
 387         if (eflag) {
 388                 memset(&exportlist, '\0', sizeof(exportlist));
 389
 390                 clnt_stat = clnt_call(mclient, MOUNTPROC_EXPORT,
 391                         (xdrproc_t) xdr_void, NULL,
 392                         (xdrproc_t) xdr_exports, (caddr_t) &exportlist,
 393                         total_timeout);
 394                 if (clnt_stat != RPC_SUCCESS) {
 395                         clnt_perror(mclient, "rpc mount export");
 396                         exit(1);
 397                 }
 398                 if (headers)
 399                         printf("Export list for %s:\n", hostname);
 400                 maxlen = 0;
 401                 for (exl = exportlist; exl; exl = exl->ex_next) {
 402                         if ((n = strlen(exl->ex_dir)) > maxlen)
 403                                 maxlen = n;
 404                 }
 405                 while (exportlist) {
 406                         printf("%-*s ", maxlen, exportlist->ex_dir);
 407                         grouplist = exportlist->ex_groups;
 408                         if (grouplist)
 409                                 while (grouplist) {
 410                                         printf("%s%s", grouplist->gr_name,
 411                                                 grouplist->gr_next ? "," : "");
 412                                         grouplist = grouplist->gr_next;
 413                                 }
 414                         else
 415                                 printf("(everyone)");
 416                         printf("\n");
 417                         exportlist = exportlist->ex_next;
 418                 }
 419                 exit(0);
 420         }
 421
 422         memset(&dumplist, '\0', sizeof(dumplist));
 423         clnt_stat = clnt_call(mclient, MOUNTPROC_DUMP,
 424                 (xdrproc_t) xdr_void, NULL,
 425                 (xdrproc_t) xdr_mountlist, (caddr_t) &dumplist,
 426                 total_timeout);
 427         if (clnt_stat != RPC_SUCCESS) {
 428                 clnt_perror(mclient, "rpc mount dump");
 429                 exit(1);
 430         }
 431
 432         n = 0;
 433         for (list = dumplist; list; list = list->ml_next)
 434                 n++;
 435         dumpv = (char **) calloc(n, sizeof (char *));
 436         if (n && !dumpv) {
 437                 fprintf(stderr, "%s: out of memory\n", program_name);
 438                 exit(1);
 439         }
 440         i = 0;
 441
 442         if (hflag) {
 443                 if (headers)
 444                         printf("Hosts on %s:\n", hostname);
 445                 while (dumplist) {
 446                         dumpv[i++] = dumplist->ml_hostname;
 447                         dumplist = dumplist->ml_next;
 448                 }
 449         }
 450         else if (aflag) {
 451                 if (headers)
 452                         printf("All mount points on %s:\n", hostname);
 453                 while (dumplist) {
 454                         char *t;
 455
 456                         t=malloc(strlen(dumplist->ml_hostname)+strlen(dumplist->ml_directory)+2);
 457                         if (!t)
 458                         {
 459                                 fprintf(stderr, "%s: out of memory\n", program_name);
 460                                 exit(1);
 461                         }
 462                         sprintf(t, "%s:%s", dumplist->ml_hostname, dumplist->ml_directory);
 463                         dumpv[i++] = t;
 464                         dumplist = dumplist->ml_next;
 465                 }
 466         }
 467         else if (dflag) {
 468                 if (headers)
 469                         printf("Directories on %s:\n", hostname);
 470                 while (dumplist) {
 471                         dumpv[i++] = dumplist->ml_directory;
 472                         dumplist = dumplist->ml_next;
 473                 }
 474         }
 475
 476         qsort(dumpv, n, sizeof (char *), dump_cmp);
 477
 478         for (i = 0; i < n; i++) {
 479                 if (i == 0 || strcmp(dumpv[i], dumpv[i - 1]) != 0)
 480                         printf("%s\n", dumpv[i]);
 481         }
 482         exit(0);
 483 }
 484