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 static int connect_nb(int fd, struct sockaddr_in *addr, struct timeval *tout)
  87 {
  88         int flags, ret;
  89         socklen_t len;
  90         fd_set rset;
  91
  92         flags = fcntl(fd, F_GETFL, 0);
  93         if (flags < 0)
  94                 return -1;
  95
  96         ret = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
  97         if (ret < 0)
  98                 return -1;
  99
 100         /*
 101          * From here on subsequent sys calls could change errno so
 102          * we set ret = -errno to capture it in case we decide to
 103          * use it later.
 104          */
 105         len = sizeof(struct sockaddr);
 106         ret = connect(fd, (struct sockaddr *)addr, len);
 107         if (ret < 0 && errno != EINPROGRESS) {
 108                 ret = -errno;
 109                 goto done;
 110         }
 111
 112         if (ret == 0)
 113                 goto done;
 114
 115         /* now wait */
 116         FD_ZERO(&rset);
 117         FD_SET(fd, &rset);
 118
 119         ret = select(fd + 1, NULL, &rset, NULL, tout);
 120         if (ret <= 0) {
 121                 if (ret == 0)
 122                         ret = -ETIMEDOUT;
 123                 else
 124                         ret = -errno;
 125                 goto done;
 126         }
 127
 128         if (FD_ISSET(fd, &rset)) {
 129                 int status;
 130
 131                 len = sizeof(ret);
 132                 status = getsockopt(fd, SOL_SOCKET, SO_ERROR, &ret, &len);
 133                 if (status < 0) {
 134                         ret = -errno;
 135                         goto done;
 136                 }
 137
 138                 /* Oops - something wrong with connect */
 139                 if (ret)
 140                         ret = -ret;
 141         }
 142
 143 done:
 144         fcntl(fd, F_SETFL, flags);
 145         return ret;
 146 }
 147
 148 static unsigned short getport(struct sockaddr_in *addr,
 149                          unsigned long prog, unsigned long vers, int prot)
 150 {
 151         CLIENT *client;
 152         enum clnt_stat status;
 153         struct pmap parms;
 154         int ret, sock;
 155         struct sockaddr_in laddr, saddr;
 156         struct timeval tout = {0, 0};
 157         socklen_t len;
 158         unsigned int send_sz = 0;
 159         unsigned int recv_sz = 0;
 160         unsigned short port;
 161
 162         memset(&laddr, 0, sizeof(laddr));
 163         memset(&saddr, 0, sizeof(saddr));
 164         memset(&parms, 0, sizeof(parms));
 165
 166         memcpy(&saddr, addr, sizeof(saddr));
 167         saddr.sin_port = htons(PMAPPORT);
 168
 169         if (prot == IPPROTO_TCP) {
 170                 sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
 171                 if (sock == -1) {
 172                         rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 173                         rpc_createerr.cf_error.re_errno = errno;
 174                         return 0;
 175                 }
 176
 177                 tout.tv_sec = TIMEOUT_TCP;
 178
 179                 ret = connect_nb(sock, &saddr, &tout);
 180                 if (ret == -1) {
 181                         close(sock);
 182                         rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 183                         rpc_createerr.cf_error.re_errno = errno;
 184                         return 0;
 185                 }
 186                 client = clnttcp_create(&saddr,
 187                                         PMAPPROG, PMAPVERS, &sock,
 188                                         0, 0);
 189         } else {
 190                 /*
 191                  * bind to any unused port.  If we left this up to the rpc
 192                  * layer, it would bind to a reserved port, which has been shown
 193                  * to exhaust the reserved port range in some situations.
 194                  */
 195                 sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
 196                 if (sock == -1) {
 197                         rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 198                         rpc_createerr.cf_error.re_errno = errno;
 199                         return 0;
 200                 }
 201
 202                 laddr.sin_family = AF_INET;
 203                 laddr.sin_port = 0;
 204                 laddr.sin_addr.s_addr = htonl(INADDR_ANY);
 205
 206                 tout.tv_sec = TIMEOUT_UDP;
 207
 208                 send_sz = RPCSMALLMSGSIZE;
 209                 recv_sz = RPCSMALLMSGSIZE;
 210
 211                 len = sizeof(struct sockaddr_in);
 212                 if (bind(sock, (struct sockaddr *)&laddr, len) < 0) {
 213                         close(sock);
 214                         sock = RPC_ANYSOCK;
 215                         /* FALLTHROUGH */
 216                 }
 217                 client = clntudp_bufcreate(&saddr, PMAPPROG, PMAPVERS,
 218                                            tout, &sock, send_sz, recv_sz);
 219         }
 220
 221         if (!client) {
 222                 close(sock);
 223                 rpc_createerr.cf_stat = RPC_RPCBFAILURE;
 224                 return 0;
 225         }
 226
 227         clnt_control(client, CLSET_FD_CLOSE, NULL);
 228
 229         parms.pm_prog = prog;
 230         parms.pm_vers = vers;
 231         parms.pm_prot = prot;
 232
 233         status = clnt_call(client, PMAPPROC_GETPORT,
 234                            (xdrproc_t) xdr_pmap, (caddr_t) &parms,
 235                            (xdrproc_t) xdr_u_short, (caddr_t) &port,
 236                            tout);
 237
 238         if (status != RPC_SUCCESS) {
 239                 clnt_geterr(client, &rpc_createerr.cf_error);
 240                 rpc_createerr.cf_stat = status;
 241                 clnt_destroy(client);
 242                 return 0;
 243         }
 244
 245         clnt_destroy(client);
 246
 247         return htons(port);
 248 }
 249
 250 int main(int argc, char **argv)
 251 {
 252         char hostname_buf[MAXHOSTLEN];
 253         char *hostname;
 254         enum clnt_stat clnt_stat;
 255         struct hostent *hp;
 256         struct sockaddr_in server_addr;
 257         int ret, msock;
 258         struct timeval total_timeout;
 259         struct timeval pertry_timeout;
 260         int c;
 261         CLIENT *mclient;
 262         groups grouplist;
 263         exports exportlist, exl;
 264         mountlist dumplist;
 265         mountlist list;
 266         int i;
 267         int n;
 268         int maxlen;
 269         char **dumpv;
 270
 271         program_name = argv[0];
 272         while ((c = getopt_long(argc, argv, "adehv", longopts, NULL)) != EOF) {
 273                 switch (c) {
 274                 case 'a':
 275                         aflag = 1;
 276                         break;
 277                 case 'd':
 278                         dflag = 1;
 279                         break;
 280                 case 'e':
 281                         eflag = 1;
 282                         break;
 283                 case 'h':
 284                         usage(stdout, 0);
 285                         break;
 286                 case 'v':
 287                         printf("%s\n", version);
 288                         exit(0);
 289                 case 0:
 290                         break;
 291                 case '?':
 292                 default:
 293                         usage(stderr, 1);
 294                         break;
 295                 }
 296         }
 297         argc -= optind;
 298         argv += optind;
 299
 300         switch (aflag + dflag + eflag) {
 301         case 0:
 302                 hflag = 1;
 303                 break;
 304         case 1:
 305                 break;
 306         default:
 307                 fprintf(stderr, "%s: only one of -a, -d or -e is allowed\n",
 308                         program_name);
 309                 exit(1);
 310                 break;
 311         }
 312
 313         switch (argc) {
 314         case 0:
 315                 if (gethostname(hostname_buf, MAXHOSTLEN) < 0) {
 316                         perror("getting hostname");
 317                         exit(1);
 318                 }
 319                 hostname = hostname_buf;
 320                 break;
 321         case 1:
 322                 hostname = argv[0];
 323                 break;
 324         default:
 325                 fprintf(stderr, "%s: only one hostname is allowed\n",
 326                         program_name);
 327                 exit(1);
 328                 break;
 329         }
 330
 331         if (inet_aton(hostname, &server_addr.sin_addr)) {
 332                 server_addr.sin_family = AF_INET;
 333         }
 334         else {
 335                 if ((hp = gethostbyname(hostname)) == NULL) {
 336                         fprintf(stderr, "%s: can't get address for %s\n",
 337                                 program_name, hostname);
 338                         exit(1);
 339                 }
 340                 server_addr.sin_family = AF_INET;
 341                 memcpy(&server_addr.sin_addr, hp->h_addr, hp->h_length);
 342         }
 343
 344         /* create mount deamon client */
 345
 346         mclient = NULL;
 347         msock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
 348         if (msock != -1) {
 349                 server_addr.sin_port = getport(&server_addr,
 350                                          MOUNTPROG, MOUNTVERS, IPPROTO_TCP);
 351                 if (server_addr.sin_port) {
 352                         ret = connect_nb(msock, &server_addr, 0);
 353                         if (ret != -1)
 354                                 mclient = clnttcp_create(&server_addr,
 355                                                 MOUNTPROG, MOUNTVERS, &msock,
 356                                                 0, 0);
 357                         else
 358                                 close(msock);
 359                 } else
 360                         close(msock);
 361         }
 362
 363         if (!mclient) {
 364                 server_addr.sin_port = getport(&server_addr,
 365                                          MOUNTPROG, MOUNTVERS, IPPROTO_UDP);
 366                 if (!server_addr.sin_port) {
 367                         clnt_pcreateerror("portmap getport");
 368                         exit(1);
 369                 }
 370                 msock = RPC_ANYSOCK;
 371                 pertry_timeout.tv_sec = TIMEOUT_UDP;
 372                 pertry_timeout.tv_usec = 0;
 373                 if ((mclient = clntudp_create(&server_addr,
 374                     MOUNTPROG, MOUNTVERS, pertry_timeout, &msock)) == NULL) {
 375                         clnt_pcreateerror("mount clntudp_create");
 376                         exit(1);
 377                 }
 378         }
 379         mclient->cl_auth = authunix_create_default();
 380         total_timeout.tv_sec = TOTAL_TIMEOUT;
 381         total_timeout.tv_usec = 0;
 382
 383         if (eflag) {
 384                 memset(&exportlist, '\0', sizeof(exportlist));
 385
 386                 clnt_stat = clnt_call(mclient, MOUNTPROC_EXPORT,
 387                         (xdrproc_t) xdr_void, NULL,
 388                         (xdrproc_t) xdr_exports, (caddr_t) &exportlist,
 389                         total_timeout);
 390                 if (clnt_stat != RPC_SUCCESS) {
 391                         clnt_perror(mclient, "rpc mount export");
 392                         exit(1);
 393                 }
 394                 if (headers)
 395                         printf("Export list for %s:\n", hostname);
 396                 maxlen = 0;
 397                 for (exl = exportlist; exl; exl = exl->ex_next) {
 398                         if ((n = strlen(exl->ex_dir)) > maxlen)
 399                                 maxlen = n;
 400                 }
 401                 while (exportlist) {
 402                         printf("%-*s ", maxlen, exportlist->ex_dir);
 403                         grouplist = exportlist->ex_groups;
 404                         if (grouplist)
 405                                 while (grouplist) {
 406                                         printf("%s%s", grouplist->gr_name,
 407                                                 grouplist->gr_next ? "," : "");
 408                                         grouplist = grouplist->gr_next;
 409                                 }
 410                         else
 411                                 printf("(everyone)");
 412                         printf("\n");
 413                         exportlist = exportlist->ex_next;
 414                 }
 415                 exit(0);
 416         }
 417
 418         memset(&dumplist, '\0', sizeof(dumplist));
 419         clnt_stat = clnt_call(mclient, MOUNTPROC_DUMP,
 420                 (xdrproc_t) xdr_void, NULL,
 421                 (xdrproc_t) xdr_mountlist, (caddr_t) &dumplist,
 422                 total_timeout);
 423         if (clnt_stat != RPC_SUCCESS) {
 424                 clnt_perror(mclient, "rpc mount dump");
 425                 exit(1);
 426         }
 427
 428         n = 0;
 429         for (list = dumplist; list; list = list->ml_next)
 430                 n++;
 431         dumpv = (char **) calloc(n, sizeof (char *));
 432         if (n && !dumpv) {
 433                 fprintf(stderr, "%s: out of memory\n", program_name);
 434                 exit(1);
 435         }
 436         i = 0;
 437
 438         if (hflag) {
 439                 if (headers)
 440                         printf("Hosts on %s:\n", hostname);
 441                 while (dumplist) {
 442                         dumpv[i++] = dumplist->ml_hostname;
 443                         dumplist = dumplist->ml_next;
 444                 }
 445         }
 446         else if (aflag) {
 447                 if (headers)
 448                         printf("All mount points on %s:\n", hostname);
 449                 while (dumplist) {
 450                         char *t;
 451
 452                         t=malloc(strlen(dumplist->ml_hostname)+strlen(dumplist->ml_directory)+2);
 453                         if (!t)
 454                         {
 455                                 fprintf(stderr, "%s: out of memory\n", program_name);
 456                                 exit(1);
 457                         }
 458                         sprintf(t, "%s:%s", dumplist->ml_hostname, dumplist->ml_directory);
 459                         dumpv[i++] = t;
 460                         dumplist = dumplist->ml_next;
 461                 }
 462         }
 463         else if (dflag) {
 464                 if (headers)
 465                         printf("Directories on %s:\n", hostname);
 466                 while (dumplist) {
 467                         dumpv[i++] = dumplist->ml_directory;
 468                         dumplist = dumplist->ml_next;
 469                 }
 470         }
 471
 472         qsort(dumpv, n, sizeof (char *), dump_cmp);
 473
 474         for (i = 0; i < n; i++) {
 475                 if (i == 0 || strcmp(dumpv[i], dumpv[i - 1]) != 0)
 476                         printf("%s\n", dumpv[i]);
 477         }
 478         exit(0);
 479 }
 480