1 /* $NetBSD: yplib.c,v 1.37 2000/07/06 03:14:05 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1992, 1993 Theo de Raadt <deraadt@fsa.ca> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Theo de Raadt. 18 * 4. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 22 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 23 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 25 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <sys/cdefs.h> 35 #if defined(LIBC_SCCS) && !defined(lint) 36 __RCSID("$NetBSD: yplib.c,v 1.37 2000/07/06 03:14:05 christos Exp $"); 37 #endif 38 39 #include "namespace.h" 40 #include <sys/param.h> 41 #include <sys/socket.h> 42 #include <sys/file.h> 43 #include <sys/uio.h> 44 45 #include <arpa/nameser.h> 46 47 #include <assert.h> 48 #include <errno.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <unistd.h> 53 54 #include <rpc/rpc.h> 55 #include <rpc/xdr.h> 56 #include <rpcsvc/yp_prot.h> 57 #include <rpcsvc/ypclnt.h> 58 #include "local.h" 59 60 #define BINDINGDIR "/var/yp/binding" 61 #define YPBINDLOCK "/var/run/ypbind.lock" 62 63 struct dom_binding *_ypbindlist; 64 char _yp_domain[MAXHOSTNAMELEN]; 65 66 #define YPLIB_TIMEOUT 10 67 #define YPLIB_RPC_RETRIES 4 68 69 struct timeval _yplib_timeout = { YPLIB_TIMEOUT, 0 }; 70 struct timeval _yplib_rpc_timeout = { YPLIB_TIMEOUT / YPLIB_RPC_RETRIES, 71 1000000 * (YPLIB_TIMEOUT % YPLIB_RPC_RETRIES) / YPLIB_RPC_RETRIES }; 72 int _yplib_nerrs = 5; 73 74 #ifdef __weak_alias 75 __weak_alias(yp_bind, _yp_bind) 76 __weak_alias(yp_unbind, _yp_unbind) 77 __weak_alias(yp_get_default_domain, _yp_get_default_domain) 78 #endif 79 80 int 81 _yp_dobind(dom, ypdb) 82 const char *dom; 83 struct dom_binding **ypdb; 84 { 85 static int pid = -1; 86 char path[MAXPATHLEN]; 87 struct dom_binding *ysd, *ysd2; 88 struct ypbind_resp ypbr; 89 struct sockaddr_in clnt_sin; 90 int clnt_sock, fd, gpid; 91 CLIENT *client; 92 int new = 0, r; 93 int nerrs = 0; 94 95 if (dom == NULL || *dom == '\0') 96 return YPERR_BADARGS; 97 98 /* 99 * test if YP is running or not 100 */ 101 if ((fd = open(YPBINDLOCK, O_RDONLY)) == -1) 102 return YPERR_YPBIND; 103 if (!(flock(fd, LOCK_EX | LOCK_NB) == -1 && errno == EWOULDBLOCK)) { 104 (void)close(fd); 105 return YPERR_YPBIND; 106 } 107 (void)close(fd); 108 109 gpid = getpid(); 110 if (!(pid == -1 || pid == gpid)) { 111 ysd = _ypbindlist; 112 while (ysd) { 113 if (ysd->dom_client) 114 clnt_destroy(ysd->dom_client); 115 ysd2 = ysd->dom_pnext; 116 free(ysd); 117 ysd = ysd2; 118 } 119 _ypbindlist = NULL; 120 } 121 pid = gpid; 122 123 if (ypdb != NULL) 124 *ypdb = NULL; 125 126 for (ysd = _ypbindlist; ysd; ysd = ysd->dom_pnext) 127 if (strcmp(dom, ysd->dom_domain) == 0) 128 break; 129 if (ysd == NULL) { 130 if ((ysd = malloc(sizeof *ysd)) == NULL) 131 return YPERR_YPERR; 132 (void)memset(ysd, 0, sizeof *ysd); 133 ysd->dom_socket = -1; 134 ysd->dom_vers = 0; 135 new = 1; 136 } 137 again: 138 if (ysd->dom_vers == 0) { 139 (void) snprintf(path, sizeof(path), "%s/%s.%d", 140 BINDINGDIR, dom, 2); 141 if ((fd = open(path, O_RDONLY)) == -1) { 142 /* 143 * no binding file, YP is dead, or not yet fully 144 * alive. 145 */ 146 goto trynet; 147 } 148 if (flock(fd, LOCK_EX | LOCK_NB) == -1 && 149 errno == EWOULDBLOCK) { 150 struct iovec iov[2]; 151 struct ypbind_resp ybr; 152 u_short ypb_port; 153 struct ypbind_binding *bn; 154 155 iov[0].iov_base = &ypb_port; 156 iov[0].iov_len = sizeof ypb_port; 157 iov[1].iov_base = &ybr; 158 iov[1].iov_len = sizeof ybr; 159 160 r = readv(fd, iov, 2); 161 if (r != iov[0].iov_len + iov[1].iov_len) { 162 (void)close(fd); 163 ysd->dom_vers = -1; 164 goto again; 165 } 166 (void)memset(&ysd->dom_server_addr, 0, 167 sizeof ysd->dom_server_addr); 168 ysd->dom_server_addr.sin_len = 169 sizeof(struct sockaddr_in); 170 ysd->dom_server_addr.sin_family = AF_INET; 171 bn = &ybr.ypbind_respbody.ypbind_bindinfo; 172 ysd->dom_server_addr.sin_port = 173 bn->ypbind_binding_port; 174 175 ysd->dom_server_addr.sin_addr = 176 bn->ypbind_binding_addr; 177 178 ysd->dom_server_port = ysd->dom_server_addr.sin_port; 179 (void)close(fd); 180 goto gotit; 181 } else { 182 /* no lock on binding file, YP is dead. */ 183 (void)close(fd); 184 if (new) 185 free(ysd); 186 return YPERR_YPBIND; 187 } 188 } 189 trynet: 190 if (ysd->dom_vers == -1 || ysd->dom_vers == 0) { 191 struct ypbind_binding *bn; 192 (void)memset(&clnt_sin, 0, sizeof clnt_sin); 193 clnt_sin.sin_len = sizeof(struct sockaddr_in); 194 clnt_sin.sin_family = AF_INET; 195 clnt_sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK); 196 197 clnt_sock = RPC_ANYSOCK; 198 client = clnttcp_create(&clnt_sin, YPBINDPROG, YPBINDVERS, 199 &clnt_sock, 0, 0); 200 if (client == NULL) { 201 clnt_pcreateerror("clnttcp_create"); 202 if (new) 203 free(ysd); 204 return YPERR_YPBIND; 205 } 206 r = clnt_call(client, (rpcproc_t)YPBINDPROC_DOMAIN, 207 (xdrproc_t)xdr_ypdomain_wrap_string, &dom, 208 (xdrproc_t)xdr_ypbind_resp, &ypbr, _yplib_timeout); 209 if (r != RPC_SUCCESS) { 210 if (new == 0 && ++nerrs == _yplib_nerrs) { 211 nerrs = 0; 212 fprintf(stderr, 213 "YP server for domain %s not responding, still trying\n", 214 dom); 215 } 216 clnt_destroy(client); 217 ysd->dom_vers = -1; 218 goto again; 219 } 220 clnt_destroy(client); 221 222 (void)memset(&ysd->dom_server_addr, 0, 223 sizeof ysd->dom_server_addr); 224 ysd->dom_server_addr.sin_len = sizeof(struct sockaddr_in); 225 ysd->dom_server_addr.sin_family = AF_INET; 226 bn = &ypbr.ypbind_respbody.ypbind_bindinfo; 227 ysd->dom_server_addr.sin_port = 228 bn->ypbind_binding_port; 229 ysd->dom_server_addr.sin_addr.s_addr = 230 bn->ypbind_binding_addr.s_addr; 231 ysd->dom_server_port = 232 bn->ypbind_binding_port; 233 gotit: 234 ysd->dom_vers = YPVERS; 235 (void)strncpy(ysd->dom_domain, dom, sizeof(ysd->dom_domain)-1); 236 } 237 if (ysd->dom_client) 238 clnt_destroy(ysd->dom_client); 239 ysd->dom_socket = RPC_ANYSOCK; 240 ysd->dom_client = clntudp_create(&ysd->dom_server_addr, 241 YPPROG, YPVERS, _yplib_rpc_timeout, &ysd->dom_socket); 242 if (ysd->dom_client == NULL) { 243 clnt_pcreateerror("clntudp_create"); 244 ysd->dom_vers = -1; 245 goto again; 246 } 247 if (fcntl(ysd->dom_socket, F_SETFD, 1) == -1) 248 perror("fcntl: F_SETFD"); 249 250 if (new) { 251 ysd->dom_pnext = _ypbindlist; 252 _ypbindlist = ysd; 253 } 254 if (ypdb != NULL) 255 *ypdb = ysd; 256 return 0; 257 } 258 259 void 260 __yp_unbind(ypb) 261 struct dom_binding *ypb; 262 { 263 264 _DIAGASSERT(ypb != NULL); 265 266 clnt_destroy(ypb->dom_client); 267 ypb->dom_client = NULL; 268 ypb->dom_socket = -1; 269 } 270 271 int 272 yp_bind(dom) 273 const char *dom; 274 { 275 if (_yp_invalid_domain(dom)) 276 return YPERR_BADARGS; 277 278 return _yp_dobind(dom, NULL); 279 } 280 281 void 282 yp_unbind(dom) 283 const char *dom; 284 { 285 struct dom_binding *ypb, *ypbp; 286 287 if (_yp_invalid_domain(dom)) 288 return; 289 290 ypbp = NULL; 291 for (ypb = _ypbindlist; ypb; ypb = ypb->dom_pnext) { 292 if (strcmp(dom, ypb->dom_domain) == 0) { 293 clnt_destroy(ypb->dom_client); 294 if (ypbp) 295 ypbp->dom_pnext = ypb->dom_pnext; 296 else 297 _ypbindlist = ypb->dom_pnext; 298 free(ypb); 299 return; 300 } 301 ypbp = ypb; 302 } 303 return; 304 } 305 306 int 307 yp_get_default_domain(domp) 308 char **domp; 309 { 310 if (domp == NULL) 311 return YPERR_BADARGS; 312 *domp = NULL; 313 if (_yp_domain[0] == '\0') 314 if (getdomainname(_yp_domain, sizeof _yp_domain)) 315 return YPERR_NODOM; 316 *domp = _yp_domain; 317 return 0; 318 } 319 320 int 321 _yp_check(dom) 322 char **dom; 323 { 324 char *unused; 325 326 if (_yp_domain[0] == '\0') 327 if (yp_get_default_domain(&unused)) 328 return 0; 329 330 if (dom) 331 *dom = _yp_domain; 332 333 if (yp_bind(_yp_domain) == 0) 334 return 1; 335 return 0; 336 } 337 338 /* 339 * _yp_invalid_domain: check if given domainname isn't legal. 340 * returns non-zero if invalid 341 */ 342 int 343 _yp_invalid_domain(dom) 344 const char *dom; 345 { 346 if (dom == NULL || *dom == '\0') 347 return 1; 348 349 if (strlen(dom) > YPMAXDOMAIN) 350 return 1; 351 352 if (strchr(dom, '/') != NULL) 353 return 1; 354 355 return 0; 356 } 357