nis.subproj/yp_bind.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.1 (the "License").  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License.
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24 /*
  25  * Copyright (c) 1996 Theo de Raadt <deraadt@theos.com>
  26  * Copyright (c) 1992, 1993 Theo de Raadt <deraadt@theos.com>
  27  * All rights reserved.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. Redistributions in binary form must reproduce the above copyright
  35  *    notice, this list of conditions and the following disclaimer in the
  36  *    documentation and/or other materials provided with the distribution.
  37  * 3. All advertising materials mentioning features or use of this software
  38  *    must display the following acknowledgement:
  39  *      This product includes software developed by Theo de Raadt.
  40  * 4. The name of the author may not be used to endorse or promote products
  41  *    derived from this software without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
  44  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  45  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  46  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  47  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  53  * SUCH DAMAGE.
  54  */
  55
  56 #if defined(LIBC_SCCS) && !defined(lint)
  57 static char *rcsid = "$OpenBSD: yp_bind.c,v 1.9 1997/04/29 21:25:20 deraadt Exp $";
  58 #endif /* LIBC_SCCS and not lint */
  59
  60 #include <sys/param.h>
  61 #include <sys/types.h>
  62 #include <sys/socket.h>
  63 #include <sys/file.h>
  64 #include <sys/uio.h>
  65 #include <errno.h>
  66 #include <stdio.h>
  67 #include <stdlib.h>
  68 #include <string.h>
  69 #include <unistd.h>
  70 #include <rpc/rpc.h>
  71 #include <rpc/xdr.h>
  72 #include <rpcsvc/yp.h>
  73 #include <rpcsvc/ypclnt.h>
  74 #include "ypinternal.h"
  75
  76 struct dom_binding *_ypbindlist = NULL;
  77 char _yp_domain[MAXHOSTNAMELEN] = { '\0' };
  78
  79 int _yplib_timeout = 10;
  80
  81 int
  82 _yp_dobind(dom, ypdb)
  83         const char     *dom;
  84         struct dom_binding **ypdb;
  85 {
  86         static int      pid = -1;
  87         char            path[MAXPATHLEN];
  88         struct dom_binding *ysd, *ysd2;
  89         struct ypbind_resp ypbr;
  90         struct timeval  tv;
  91         struct sockaddr_in clnt_sin;
  92         struct ypbind_binding *bn;
  93         int             clnt_sock, fd, gpid;
  94         CLIENT         *client;
  95         int             new = 0, r;
  96         int             count = 0;
  97         u_short         port;
  98
  99         /*
 100          * test if YP is running or not
 101          */
 102         if ((fd = open(YPBINDLOCK, O_RDONLY)) == -1)
 103                 return YPERR_YPBIND;
 104         if (!(flock(fd, LOCK_EX | LOCK_NB) == -1 && errno == EWOULDBLOCK)) {
 105                 (void)close(fd);
 106                 return YPERR_YPBIND;
 107         }
 108         (void)close(fd);
 109
 110         gpid = getpid();
 111         if (!(pid == -1 || pid == gpid)) {
 112                 ysd = _ypbindlist;
 113                 while (ysd) {
 114                         if (ysd->dom_client)
 115                                 clnt_destroy(ysd->dom_client);
 116                         ysd2 = ysd->dom_pnext;
 117                         free(ysd);
 118                         ysd = ysd2;
 119                 }
 120                 _ypbindlist = NULL;
 121         }
 122         pid = gpid;
 123
 124         if (ypdb != NULL)
 125                 *ypdb = NULL;
 126
 127         if (dom == NULL || strlen(dom) == 0)
 128                 return YPERR_BADARGS;
 129
 130         for (ysd = _ypbindlist; ysd; ysd = ysd->dom_pnext)
 131                 if (strcmp(dom, ysd->dom_domain) == 0)
 132                         break;
 133         if (ysd == NULL) {
 134                 if ((ysd = malloc(sizeof *ysd)) == NULL)
 135                         return YPERR_YPERR;
 136                 (void)memset(ysd, 0, sizeof *ysd);
 137                 ysd->dom_socket = -1;
 138                 ysd->dom_vers = 0;
 139                 new = 1;
 140         }
 141 again:
 142         if (ysd->dom_vers == 0) {
 143                 (void) snprintf(path, sizeof(path), "%s/%s.%d",
 144                     BINDINGDIR, dom, 2);
 145                 if ((fd = open(path, O_RDONLY)) == -1) {
 146                         /*
 147                          * no binding file, YP is dead, or not yet fully
 148                          * alive.
 149                          */
 150                         goto trynet;
 151                 }
 152                 if (flock(fd, LOCK_EX | LOCK_NB) == -1 &&
 153                     errno == EWOULDBLOCK) {
 154                         struct iovec    iov[2];
 155                         u_short         ypb_port;
 156
 157                         /*
 158                          * we fetch the ypbind port number, but do
 159                          * nothing with it.
 160                          */
 161                         iov[0].iov_base = (caddr_t) &ypb_port;
 162                         iov[0].iov_len = sizeof ypb_port;
 163                         iov[1].iov_base = (caddr_t) &ypbr;
 164                         iov[1].iov_len = sizeof ypbr;
 165
 166                         r = readv(fd, iov, 2);
 167                         if (r != iov[0].iov_len + iov[1].iov_len) {
 168                                 (void)close(fd);
 169                                 ysd->dom_vers = -1;
 170                                 goto again;
 171                         }
 172                         (void)close(fd);
 173                         goto gotdata;
 174                 } else {
 175                         /* no lock on binding file, YP is dead. */
 176                         (void)close(fd);
 177                         if (new)
 178                                 free(ysd);
 179                         return YPERR_YPBIND;
 180                 }
 181         }
 182 trynet:
 183         if (ysd->dom_vers == -1 || ysd->dom_vers == 0) {
 184                 (void)memset(&clnt_sin, 0, sizeof clnt_sin);
 185                 clnt_sin.sin_len = sizeof(struct sockaddr_in);
 186                 clnt_sin.sin_family = AF_INET;
 187                 clnt_sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 188
 189                 clnt_sock = RPC_ANYSOCK;
 190                 client = clnttcp_create(&clnt_sin, YPBINDPROG, YPBINDVERS,
 191                     &clnt_sock, 0, 0);
 192                 if (client == NULL) {
 193                         clnt_pcreateerror("clnttcp_create");
 194                         if (new)
 195                                 free(ysd);
 196                         return YPERR_YPBIND;
 197                 }
 198                 if (ntohs(clnt_sin.sin_port) >= IPPORT_RESERVED ||
 199                     ntohs(clnt_sin.sin_port) == 20) {
 200                         /*
 201                          * YP was not running, but someone has registered
 202                          * ypbind with portmap -- this simply means YP is
 203                          * not running.
 204                          */
 205                         clnt_destroy(client);
 206                         if (new)
 207                                 free(ysd);
 208                         return YPERR_YPBIND;
 209                 }
 210                 tv.tv_sec = _yplib_timeout;
 211                 tv.tv_usec = 0;
 212                 r = clnt_call(client, YPBINDPROC_DOMAIN, xdr_domainname,
 213                     &dom, xdr_ypbind_resp, &ypbr, tv);
 214                 if (r != RPC_SUCCESS) {
 215                         if (new == 0 || count)
 216                                 fprintf(stderr,
 217                     "YP server for domain %s not responding, still trying\n",
 218                                     dom);
 219                         count++;
 220                         clnt_destroy(client);
 221                         ysd->dom_vers = -1;
 222                         goto again;
 223                 }
 224                 clnt_destroy(client);
 225 gotdata:
 226                 bn = &ypbr.ypbind_resp_u.ypbind_bindinfo;
 227                 memcpy(&port, &bn->ypbind_binding_port, sizeof port);
 228                 if (ntohs(port) >= IPPORT_RESERVED ||
 229                     ntohs(port) == 20) {
 230                         /*
 231                          * This is bogus -- the ypbind wants me to
 232                          * communicate to an insecure ypserv.  We are
 233                          * within rights to syslog this as an attack,
 234                          * but for now we'll simply ignore it; real YP
 235                          * is obviously not running.
 236                          */
 237                         if (new)
 238                                 free(ysd);
 239                         return YPERR_YPBIND;
 240                 }
 241                 (void)memset(&ysd->dom_server_addr, 0,
 242                     sizeof ysd->dom_server_addr);
 243                 ysd->dom_server_addr.sin_len = sizeof(struct sockaddr_in);
 244                 ysd->dom_server_addr.sin_family = AF_INET;
 245                 memcpy(&ysd->dom_server_addr.sin_port,
 246                     &bn->ypbind_binding_port,
 247                     sizeof(ysd->dom_server_addr.sin_port));
 248                 memcpy(&ysd->dom_server_addr.sin_addr.s_addr,
 249                     &bn->ypbind_binding_addr,
 250                     sizeof(ysd->dom_server_addr.sin_addr.s_addr));
 251                 ysd->dom_server_port = ysd->dom_server_addr.sin_port;
 252                 ysd->dom_vers = YPVERS;
 253                 (void)strncpy(ysd->dom_domain, dom, sizeof ysd->dom_domain-1);
 254                 ysd->dom_domain[sizeof ysd->dom_domain-1] = '\0';
 255         }
 256         tv.tv_sec = _yplib_timeout / 2;
 257         tv.tv_usec = 0;
 258         if (ysd->dom_client)
 259                 clnt_destroy(ysd->dom_client);
 260         ysd->dom_socket = RPC_ANYSOCK;
 261         ysd->dom_client = clntudp_create(&ysd->dom_server_addr,
 262             YPPROG, YPVERS, tv, &ysd->dom_socket);
 263         if (ysd->dom_client == NULL) {
 264                 clnt_pcreateerror("clntudp_create");
 265                 ysd->dom_vers = -1;
 266                 goto again;
 267         }
 268         if (fcntl(ysd->dom_socket, F_SETFD, 1) == -1)
 269                 perror("fcntl: F_SETFD");
 270
 271         if (new) {
 272                 ysd->dom_pnext = _ypbindlist;
 273                 _ypbindlist = ysd;
 274         }
 275         if (ypdb != NULL)
 276                 *ypdb = ysd;
 277         return 0;
 278 }
 279
 280 void
 281 _yp_unbind(ypb)
 282         struct dom_binding *ypb;
 283 {
 284         if (ypb->dom_client) clnt_destroy(ypb->dom_client);
 285         ypb->dom_client = NULL;
 286         ypb->dom_socket = -1;
 287 }
 288
 289 int
 290 yp_bind(dom)
 291         const char     *dom;
 292 {
 293         return _yp_dobind(dom, NULL);
 294 }
 295
 296 void
 297 yp_unbind(dom)
 298         const char     *dom;
 299 {
 300         struct dom_binding *ypb, *ypbp;
 301
 302         ypbp = NULL;
 303         for (ypb = _ypbindlist; ypb; ypb = ypb->dom_pnext) {
 304                 if (strcmp(dom, ypb->dom_domain) == 0) {
 305                         if (ypb->dom_client) clnt_destroy(ypb->dom_client);
 306                         if (ypbp)
 307                                 ypbp->dom_pnext = ypb->dom_pnext;
 308                         else
 309                                 _ypbindlist = ypb->dom_pnext;
 310                         free(ypb);
 311                         return;
 312                 }
 313                 ypbp = ypb;
 314         }
 315 }