utils/mount/network.c

   1 /*
   2  * network.c -- Provide common network functions for NFS mount/umount
   3  *
   4  * Copyright (C) 2007 Oracle.  All rights reserved.
   5  * Copyright (C) 2007 Chuck Lever <chuck.lever@oracle.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public
  18  * License along with this program; if not, write to the
  19  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20  * Boston, MA 021110-1307, USA.
  21  *
  22  */
  23
  24 #include <ctype.h>
  25 #include <unistd.h>
  26 #include <stdio.h>
  27 #include <string.h>
  28 #include <stdlib.h>
  29 #include <errno.h>
  30 #include <netdb.h>
  31 #include <time.h>
  32 #include <rpc/rpc.h>
  33 #include <rpc/pmap_prot.h>
  34 #include <rpc/pmap_clnt.h>
  35 #include <sys/socket.h>
  36
  37 #include "conn.h"
  38 #include "xcommon.h"
  39 #include "mount.h"
  40 #include "nls.h"
  41 #include "nfsumount.h"
  42 #include "nfs_mount.h"
  43 #include "mount_constants.h"
  44 #include "network.h"
  45
  46 #ifdef HAVE_RPCSVC_NFS_PROT_H
  47 #include <rpcsvc/nfs_prot.h>
  48 #else
  49 #include <linux/nfs.h>
  50 #define nfsstat nfs_stat
  51 #endif
  52
  53 #ifndef NFS_PORT
  54 #define NFS_PORT 2049
  55 #endif
  56
  57 extern int nfs_mount_data_version;
  58 extern char *progname;
  59 extern int verbose;
  60
  61 static const unsigned int probe_udp_only[] = {
  62         IPPROTO_UDP,
  63         0,
  64 };
  65
  66 static const unsigned int probe_udp_first[] = {
  67         IPPROTO_UDP,
  68         IPPROTO_TCP,
  69         0,
  70 };
  71
  72 static const unsigned int probe_tcp_first[] = {
  73         IPPROTO_TCP,
  74         IPPROTO_UDP,
  75         0,
  76 };
  77
  78 static const unsigned long probe_nfs2_only[] = {
  79         2,
  80         0,
  81 };
  82
  83 static const unsigned long probe_nfs3_first[] = {
  84         3,
  85         2,
  86         0,
  87 };
  88
  89 static const unsigned long probe_mnt1_first[] = {
  90         1,
  91         2,
  92         0,
  93 };
  94
  95 static const unsigned long probe_mnt3_first[] = {
  96         3,
  97         1,
  98         2,
  99         0,
 100 };
 101
 102 int nfs_gethostbyname(const char *hostname, struct sockaddr_in *saddr)
 103 {
 104         struct hostent *hp;
 105
 106         saddr->sin_family = AF_INET;
 107         if (!inet_aton(hostname, &saddr->sin_addr)) {
 108                 if ((hp = gethostbyname(hostname)) == NULL) {
 109                         nfs_error(_("mount: can't get address for %s\n"),
 110                                 hostname);
 111                         return 0;
 112                 } else {
 113                         if (hp->h_length > sizeof(*saddr)) {
 114                                 nfs_error(_("mount: got bad hp->h_length\n"));
 115                                 hp->h_length = sizeof(*saddr);
 116                         }
 117                         memcpy(&saddr->sin_addr, hp->h_addr, hp->h_length);
 118                 }
 119         }
 120         return 1;
 121 }
 122
 123 /*
 124  * getport() is very similar to pmap_getport() with
 125  * the exception this version uses a non-reserve ports
 126  * instead of reserve ports since reserve ports
 127  * are not needed for pmap requests.
 128  */
 129 unsigned short getport(struct sockaddr_in *saddr, unsigned long prog,
 130                         unsigned long vers, unsigned int prot)
 131 {
 132         unsigned short port = 0;
 133         int socket;
 134         CLIENT *clnt = NULL;
 135         struct pmap parms;
 136         enum clnt_stat stat;
 137
 138         saddr->sin_port = htons (PMAPPORT);
 139         socket = get_socket(saddr, prot, FALSE, FALSE);
 140
 141         switch (prot) {
 142         case IPPROTO_UDP:
 143                 clnt = clntudp_bufcreate(saddr,
 144                                          PMAPPROG, PMAPVERS, TIMEOUT, &socket,
 145                                          UDPMSGSIZE, UDPMSGSIZE);
 146                 break;
 147         case IPPROTO_TCP:
 148                 clnt = clnttcp_create(saddr,
 149                         PMAPPROG, PMAPVERS, &socket, 50, 500);
 150                 break;
 151         }
 152         if (clnt != NULL) {
 153                 parms.pm_prog = prog;
 154                 parms.pm_vers = vers;
 155                 parms.pm_prot = prot;
 156                 parms.pm_port = 0;    /* not needed or used */
 157
 158                 stat = clnt_call(clnt, PMAPPROC_GETPORT, (xdrproc_t)xdr_pmap,
 159                         (caddr_t)&parms, (xdrproc_t)xdr_u_short, (caddr_t)&port, TIMEOUT);
 160                 if (stat) {
 161                         clnt_geterr(clnt, &rpc_createerr.cf_error);
 162                         rpc_createerr.cf_stat = stat;
 163                 }
 164                 clnt_destroy(clnt);
 165                 if (stat != RPC_SUCCESS)
 166                         port = 0;
 167                 else if (port == 0)
 168                         rpc_createerr.cf_stat = RPC_PROGNOTREGISTERED;
 169         }
 170         if (socket != 1)
 171                 close(socket);
 172
 173         return port;
 174 }
 175
 176 /*
 177  * Use the portmapper to discover whether or not the service we want is
 178  * available. The lists 'versions' and 'protos' define ordered sequences
 179  * of service versions and udp/tcp protocols to probe for.
 180  */
 181 static int probe_port(clnt_addr_t *server, const unsigned long *versions,
 182                         const unsigned int *protos)
 183 {
 184         struct sockaddr_in *saddr = &server->saddr;
 185         struct pmap *pmap = &server->pmap;
 186         const unsigned long prog = pmap->pm_prog, *p_vers;
 187         const unsigned int prot = (u_int)pmap->pm_prot, *p_prot;
 188         const u_short port = (u_short) pmap->pm_port;
 189         unsigned long vers = pmap->pm_vers;
 190         unsigned short p_port;
 191
 192         p_prot = prot ? &prot : protos;
 193         p_vers = vers ? &vers : versions;
 194         rpc_createerr.cf_stat = 0;
 195         for (;;) {
 196                 saddr->sin_port = htons(PMAPPORT);
 197                 p_port = getport(saddr, prog, *p_vers, *p_prot);
 198                 if (p_port) {
 199                         if (!port || port == p_port) {
 200                                 saddr->sin_port = htons(p_port);
 201                                 if (verbose) {
 202                                         printf(_("%s: trying %s prog %ld vers "
 203                                                 "%ld prot %s port %d\n"),
 204                                                 progname,
 205                                                 inet_ntoa(saddr->sin_addr),
 206                                                 prog, *p_vers,
 207                                                 *p_prot == IPPROTO_UDP ?
 208                                                         "udp" : "tcp",
 209                                                 p_port);
 210                                 }
 211                                 if (clnt_ping(saddr, prog, *p_vers, *p_prot, NULL))
 212                                         goto out_ok;
 213                                 if (rpc_createerr.cf_stat == RPC_TIMEDOUT)
 214                                         goto out_bad;
 215                         }
 216                 }
 217                 if (rpc_createerr.cf_stat != RPC_PROGNOTREGISTERED)
 218                         goto out_bad;
 219
 220                 if (!prot) {
 221                         if (*++p_prot)
 222                                 continue;
 223                         p_prot = protos;
 224                 }
 225                 if (vers == pmap->pm_vers) {
 226                         p_vers = versions;
 227                         vers = 0;
 228                 }
 229                 if (vers || !*++p_vers)
 230                         break;
 231         }
 232
 233 out_bad:
 234         return 0;
 235
 236 out_ok:
 237         if (!vers)
 238                 pmap->pm_vers = *p_vers;
 239         if (!prot)
 240                 pmap->pm_prot = *p_prot;
 241         if (!port)
 242                 pmap->pm_port = p_port;
 243         rpc_createerr.cf_stat = 0;
 244         return 1;
 245 }
 246
 247 int probe_nfsport(clnt_addr_t *nfs_server)
 248 {
 249         struct pmap *pmap = &nfs_server->pmap;
 250
 251         if (pmap->pm_vers && pmap->pm_prot && pmap->pm_port)
 252                 return 1;
 253
 254         if (nfs_mount_data_version >= 4)
 255                 return probe_port(nfs_server, probe_nfs3_first, probe_tcp_first);
 256         else
 257                 return probe_port(nfs_server, probe_nfs2_only, probe_udp_only);
 258 }
 259
 260 int probe_mntport(clnt_addr_t *mnt_server)
 261 {
 262         struct pmap *pmap = &mnt_server->pmap;
 263
 264         if (pmap->pm_vers && pmap->pm_prot && pmap->pm_port)
 265                 return 1;
 266
 267         if (nfs_mount_data_version >= 4)
 268                 return probe_port(mnt_server, probe_mnt3_first, probe_udp_first);
 269         else
 270                 return probe_port(mnt_server, probe_mnt1_first, probe_udp_only);
 271 }
 272
 273 int probe_bothports(clnt_addr_t *mnt_server, clnt_addr_t *nfs_server)
 274 {
 275         struct pmap *nfs_pmap = &nfs_server->pmap;
 276         struct pmap *mnt_pmap = &mnt_server->pmap;
 277         struct pmap save_nfs, save_mnt;
 278         int res;
 279         const unsigned long *probe_vers;
 280
 281         if (mnt_pmap->pm_vers && !nfs_pmap->pm_vers)
 282                 nfs_pmap->pm_vers = mntvers_to_nfs(mnt_pmap->pm_vers);
 283         else if (nfs_pmap->pm_vers && !mnt_pmap->pm_vers)
 284                 mnt_pmap->pm_vers = nfsvers_to_mnt(nfs_pmap->pm_vers);
 285         if (nfs_pmap->pm_vers)
 286                 goto version_fixed;
 287
 288         memcpy(&save_nfs, nfs_pmap, sizeof(save_nfs));
 289         memcpy(&save_mnt, mnt_pmap, sizeof(save_mnt));
 290         probe_vers = (nfs_mount_data_version >= 4) ?
 291                         probe_mnt3_first : probe_mnt1_first;
 292
 293         for (; *probe_vers; probe_vers++) {
 294                 nfs_pmap->pm_vers = mntvers_to_nfs(*probe_vers);
 295                 if ((res = probe_nfsport(nfs_server) != 0)) {
 296                         mnt_pmap->pm_vers = nfsvers_to_mnt(nfs_pmap->pm_vers);
 297                         if ((res = probe_mntport(mnt_server)) != 0)
 298                                 return 1;
 299                         memcpy(mnt_pmap, &save_mnt, sizeof(*mnt_pmap));
 300                 }
 301                 switch (rpc_createerr.cf_stat) {
 302                 case RPC_PROGVERSMISMATCH:
 303                 case RPC_PROGNOTREGISTERED:
 304                         break;
 305                 default:
 306                         goto out_bad;
 307                 }
 308                 memcpy(nfs_pmap, &save_nfs, sizeof(*nfs_pmap));
 309         }
 310
 311 out_bad:
 312         return 0;
 313
 314 version_fixed:
 315         if (!probe_nfsport(nfs_server))
 316                 goto out_bad;
 317         return probe_mntport(mnt_server);
 318 }