nis.subproj/yp_bind.c

   1 /*
   2  * Copyright (c) 1999-2018 Apple 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 "libinfo_common.h"
  61
  62 #include <sys/param.h>
  63 #include <sys/types.h>
  64 #include <sys/socket.h>
  65 #include <sys/file.h>
  66 #include <sys/uio.h>
  67 #include <errno.h>
  68 #include <stdio.h>
  69 #include <stdlib.h>
  70 #include <string.h>
  71 #include <unistd.h>
  72 #include <rpc/rpc.h>
  73 #include <rpc/xdr.h>
  74 #include <rpcsvc/yp.h>
  75 #include <rpcsvc/ypclnt.h>
  76 #include <notify.h>
  77 #include <pthread.h>
  78 #include "ypinternal.h"
  79
  80 extern int notify_register_plain(char *, int *);
  81
  82 struct dom_binding *_ypbindlist = NULL;
  83 char _yp_domain[MAXHOSTNAMELEN] = { '\0' };
  84
  85 int _yplib_timeout = 10;
  86
  87 LIBINFO_EXPORT
  88 int
  89 _yp_dobind(dom, ypdb)
  90         const char     *dom;
  91         struct dom_binding **ypdb;
  92 {
  93         static int      pid = -1;
  94         struct dom_binding *ysd, *ysd2;
  95         struct ypbind_resp ypbr;
  96         struct timeval  tv;
  97         struct sockaddr_in clnt_sin;
  98         struct ypbind_binding *bn;
  99         int             clnt_sock, fd, gpid;
 100         CLIENT         *client;
 101         int             new = 0, r, proto;
 102         int             count = 0;
 103         u_short         port;
 104         int status, notify_token;
 105         uint64_t abort;
 106         char *notify_name;
 107
 108         /*
 109          * test if YP is running or not
 110          */
 111         if ((fd = open(YPBINDLOCK, O_RDONLY)) == -1) return YPERR_YPBIND;
 112
 113         if (!((flock(fd, LOCK_EX | LOCK_NB) == -1) && (errno == EWOULDBLOCK)))
 114         {
 115                 close(fd);
 116                 return YPERR_YPBIND;
 117         }
 118
 119         close(fd);
 120
 121         gpid = getpid();
 122         if (!((pid == -1) || (pid == gpid)))
 123         {
 124                 ysd = _ypbindlist;
 125                 while (ysd)
 126                 {
 127                         if (ysd->dom_client) clnt_destroy(ysd->dom_client);
 128                         ysd2 = ysd->dom_pnext;
 129                         free(ysd);
 130                         ysd = ysd2;
 131                 }
 132
 133                 _ypbindlist = NULL;
 134         }
 135
 136         pid = gpid;
 137
 138         if (ypdb != NULL) *ypdb = NULL;
 139
 140         if ((dom == NULL) || (strlen(dom) == 0)) return YPERR_BADARGS;
 141
 142         for (ysd = _ypbindlist; ysd; ysd = ysd->dom_pnext)
 143         {
 144                 if (strcmp(dom, ysd->dom_domain) == 0) break;
 145         }
 146
 147         if (ysd == NULL)
 148         {
 149                 ysd = calloc(1, sizeof(struct dom_binding));
 150                 if (ysd == NULL) return YPERR_YPERR;
 151                 ysd->dom_socket = -1;
 152                 ysd->dom_vers = 0;
 153                 new = 1;
 154         }
 155
 156         /*
 157          * Get notification token
 158          * we use a self-notification token to allow a caller
 159          * to signal the thread doing this bind call to quit.
 160          */
 161         notify_name = NULL;
 162         notify_token = -1;
 163
 164         asprintf(&notify_name, "self.thread.%lu", (unsigned long)pthread_self());
 165         if (notify_name != NULL)
 166         {
 167                 status = notify_register_plain(notify_name, &notify_token);
 168                 free(notify_name);
 169         }
 170
 171 again:
 172         if (notify_token != -1)
 173         {
 174                 abort = 0;
 175                 status = notify_get_state(notify_token, &abort);
 176                 if (abort == ThreadStateExitRequested)
 177                 {
 178                         if (new) free(ysd);
 179                         notify_cancel(notify_token);
 180                         return YPERR_YPBIND;
 181                 }
 182         }
 183
 184         proto = YP_BIND_UDP;
 185         if (ysd->dom_vers == YP_BIND_TCP) proto = YP_BIND_TCP;
 186
 187         if ((ysd->dom_vers == 0) || (ysd->dom_vers == YP_BIND_UDP) || (ysd->dom_vers == YP_BIND_TCP))
 188         {
 189                 memset(&clnt_sin, 0, sizeof clnt_sin);
 190                 clnt_sin.sin_len = sizeof(struct sockaddr_in);
 191                 clnt_sin.sin_family = AF_INET;
 192                 clnt_sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 193
 194                 clnt_sock = RPC_ANYSOCK;
 195                 client = clnttcp_create(&clnt_sin, YPBINDPROG, YPBINDVERS, &clnt_sock, 0, 0);
 196                 if (client == NULL)
 197                 {
 198                         clnt_pcreateerror("clnttcp_create");
 199                         if (new) free(ysd);
 200                         if (notify_token != -1) notify_cancel(notify_token);
 201                         return YPERR_YPBIND;
 202                 }
 203
 204                 if ((ntohs(clnt_sin.sin_port) >= IPPORT_RESERVED) || (ntohs(clnt_sin.sin_port) == 20))
 205                 {
 206                         /*
 207                          * YP was not running, but someone has registered
 208                          * ypbind with portmap -- this simply means YP is
 209                          * not running.
 210                          */
 211                         clnt_destroy(client);
 212                         if (new) free(ysd);
 213                         if (notify_token != -1) notify_cancel(notify_token);
 214                         return YPERR_YPBIND;
 215                 }
 216
 217                 tv.tv_sec = _yplib_timeout;
 218                 tv.tv_usec = 0;
 219
 220                 r = clnt_call(client, YPBINDPROC_DOMAIN, (xdrproc_t)xdr_domainname, &dom, (xdrproc_t)xdr_ypbind_resp, &ypbr, tv);
 221                 if (r != RPC_SUCCESS)
 222                 {
 223                         if (new == 0 || count) fprintf(stderr, "YP server for domain %s not responding, still trying\n", dom);
 224                         count++;
 225                         clnt_destroy(client);
 226                         ysd->dom_vers = proto;
 227                         goto again;
 228                 }
 229
 230                 clnt_destroy(client);
 231
 232                 bn = &ypbr.ypbind_resp_u.ypbind_bindinfo;
 233                 memcpy(&port, &bn->ypbind_binding_port, sizeof port);
 234                 if ((ntohs(port) >= IPPORT_RESERVED) || (ntohs(port) == 20))
 235                 {
 236                         /*
 237                          * This is bogus -- the ypbind wants me to
 238                          * communicate to an insecure ypserv.  We are
 239                          * within rights to syslog this as an attack,
 240                          * but for now we'll simply ignore it; real YP
 241                          * is obviously not running.
 242                          */
 243                         if (new) free(ysd);
 244                         if (notify_token != -1) notify_cancel(notify_token);
 245                         return YPERR_YPBIND;
 246                 }
 247
 248                 memset(&ysd->dom_server_addr, 0,  sizeof ysd->dom_server_addr);
 249                 ysd->dom_server_addr.sin_len = sizeof(struct sockaddr_in);
 250                 ysd->dom_server_addr.sin_family = AF_INET;
 251                 memcpy(&ysd->dom_server_addr.sin_port, &bn->ypbind_binding_port, sizeof(ysd->dom_server_addr.sin_port));
 252                 memcpy(&ysd->dom_server_addr.sin_addr.s_addr, &bn->ypbind_binding_addr, sizeof(ysd->dom_server_addr.sin_addr.s_addr));
 253                 ysd->dom_server_port = ysd->dom_server_addr.sin_port;
 254                 ysd->dom_vers = YPVERS;
 255                 strncpy(ysd->dom_domain, dom, sizeof ysd->dom_domain-1);
 256                 ysd->dom_domain[sizeof ysd->dom_domain-1] = '\0';
 257         }
 258
 259         tv.tv_sec = _yplib_timeout / 2;
 260         tv.tv_usec = 0;
 261
 262         if (ysd->dom_client) clnt_destroy(ysd->dom_client);
 263         ysd->dom_socket = RPC_ANYSOCK;
 264
 265         if (proto == YP_BIND_UDP) ysd->dom_client = clntudp_create(&ysd->dom_server_addr, YPPROG, YPVERS, tv, &ysd->dom_socket);
 266         else ysd->dom_client = clnttcp_create(&ysd->dom_server_addr, YPPROG, YPVERS, &ysd->dom_socket, 0, 0);
 267
 268         if (ysd->dom_client == NULL)
 269         {
 270                 if (proto == YP_BIND_UDP) clnt_pcreateerror("clntudp_create");
 271                 else clnt_pcreateerror("clnttcp_create");
 272                 ysd->dom_vers = proto;
 273                 goto again;
 274         }
 275
 276         if (notify_token != -1) notify_cancel(notify_token);
 277
 278         if (fcntl(ysd->dom_socket, F_SETFD, 1) == -1)
 279                 perror("fcntl: F_SETFD");
 280
 281         if (new != 0)
 282         {
 283                 ysd->dom_pnext = _ypbindlist;
 284                 _ypbindlist = ysd;
 285         }
 286
 287         if (ypdb != NULL) *ypdb = ysd;
 288         return 0;
 289 }
 290
 291 void
 292 _yp_unbind(ypb)
 293         struct dom_binding *ypb;
 294 {
 295         if (ypb->dom_client) clnt_destroy(ypb->dom_client);
 296         ypb->dom_client = NULL;
 297         ypb->dom_socket = -1;
 298 }
 299
 300 LIBINFO_EXPORT
 301 int
 302 yp_bind(dom)
 303         const char     *dom;
 304 {
 305         return _yp_dobind(dom, NULL);
 306 }
 307
 308 LIBINFO_EXPORT
 309 void
 310 yp_unbind(dom)
 311         const char     *dom;
 312 {
 313         struct dom_binding *ypb, *ypbp;
 314
 315         ypbp = NULL;
 316         for (ypb = _ypbindlist; ypb; ypb = ypb->dom_pnext) {
 317                 if (strcmp(dom, ypb->dom_domain) == 0) {
 318                         if (ypb->dom_client) clnt_destroy(ypb->dom_client);
 319                         if (ypbp)
 320                                 ypbp->dom_pnext = ypb->dom_pnext;
 321                         else
 322                                 _ypbindlist = ypb->dom_pnext;
 323                         free(ypb);
 324                         return;
 325                 }
 326                 ypbp = ypb;
 327         }
 328 }