1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Berkeley Software Design Inc's name may not be used to endorse or 15 * promote products derived from this software without specific prior 16 * written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 * from BSDI kern.c,v 1.2 1998/11/25 22:38:27 don Exp 31 */ 32 33 #include <sys/param.h> 34 #include <sys/mount.h> 35 #include <sys/queue.h> 36 #include <sys/socket.h> 37 #include <sys/stat.h> 38 39 #include <netinet/in.h> 40 #include <arpa/inet.h> 41 42 #include <err.h> 43 #include <errno.h> 44 #include <fcntl.h> 45 #include <paths.h> 46 #include <pwd.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <string.h> 50 #include <syslog.h> 51 #include <unistd.h> 52 #include <netdb.h> 53 54 #include "nlm_prot.h" 55 #include <nfs/nfsproto.h> 56 #include <nfs/nfs_lock.h> 57 58 #include "lockd.h" 59 #include "lockd_lock.h" 60 #include <nfsclient/nfs.h> 61 62 #define DAEMON_USERNAME "daemon" 63 64 /* Lock request owner. */ 65 typedef struct __owner { 66 pid_t pid; /* Process ID. */ 67 time_t tod; /* Time-of-day. */ 68 } OWNER; 69 static OWNER owner; 70 71 static char hostname[MAXHOSTNAMELEN + 1]; /* Hostname. */ 72 static int devfd; 73 74 static void client_cleanup(void); 75 static const char *from_addr(struct sockaddr *); 76 int lock_request(LOCKD_MSG *); 77 static void set_auth(CLIENT *cl, struct xucred *ucred); 78 void show(LOCKD_MSG *); 79 int test_request(LOCKD_MSG *); 80 int unlock_request(LOCKD_MSG *); 81 82 static int 83 nfslockdans(int vers, struct lockd_ans *ansp) 84 { 85 86 ansp->la_vers = vers; 87 return (write(devfd, ansp, sizeof *ansp) <= 0); 88 } 89 90 /* 91 * will break because fifo needs to be repopened when EOF'd 92 */ 93 #define lockd_seteuid(uid) seteuid(uid) 94 95 #define d_calls (debug_level > 1) 96 #define d_args (debug_level > 2) 97 98 static const char * 99 from_addr(struct sockaddr *saddr) 100 { 101 static char inet_buf[INET6_ADDRSTRLEN]; 102 103 if (getnameinfo(saddr, saddr->sa_len, inet_buf, sizeof(inet_buf), 104 NULL, 0, NI_NUMERICHOST) == 0) 105 return inet_buf; 106 return "???"; 107 } 108 109 void 110 client_cleanup(void) 111 { 112 (void)lockd_seteuid(0); 113 exit(-1); 114 } 115 116 /* 117 * client_request -- 118 * Loop around messages from the kernel, forwarding them off to 119 * NLM servers. 120 */ 121 pid_t 122 client_request(void) 123 { 124 LOCKD_MSG msg; 125 int nr, ret; 126 pid_t child; 127 uid_t daemon_uid; 128 struct passwd *pw; 129 130 /* Open the dev . */ 131 devfd = open(_PATH_DEV _PATH_NFSLCKDEV, O_RDWR | O_NONBLOCK); 132 if (devfd < 0) { 133 syslog(LOG_ERR, "open: %s: %m", _PATH_NFSLCKDEV); 134 goto err; 135 } 136 137 signal(SIGPIPE, SIG_IGN); 138 139 /* 140 * Create a separate process, the client code is really a separate 141 * daemon that shares a lot of code. 142 */ 143 switch (child = fork()) { 144 case -1: 145 err(1, "fork"); 146 case 0: 147 setproctitle("client"); 148 break; 149 default: 150 setproctitle("server"); 151 return (child); 152 } 153 154 signal(SIGHUP, (sig_t)client_cleanup); 155 signal(SIGTERM, (sig_t)client_cleanup); 156 157 /* Setup. */ 158 (void)time(&owner.tod); 159 owner.pid = getpid(); 160 (void)gethostname(hostname, sizeof(hostname) - 1); 161 162 pw = getpwnam(DAEMON_USERNAME); 163 if (pw == NULL) { 164 syslog(LOG_ERR, "getpwnam: %s: %m", DAEMON_USERNAME); 165 goto err; 166 } 167 daemon_uid = pw->pw_uid; 168 /* drop our root privileges */ 169 (void)lockd_seteuid(daemon_uid); 170 171 for (;;) { 172 /* Read the fixed length message. */ 173 if ((nr = read(devfd, &msg, sizeof(msg))) == sizeof(msg)) { 174 if (d_args) 175 show(&msg); 176 177 if (msg.lm_version != LOCKD_MSG_VERSION) { 178 syslog(LOG_ERR, 179 "unknown msg type: %d", msg.lm_version); 180 } 181 /* 182 * Send it to the NLM server and don't grant the lock 183 * if we fail for any reason. 184 */ 185 switch (msg.lm_fl.l_type) { 186 case F_RDLCK: 187 case F_WRLCK: 188 if (msg.lm_getlk) 189 ret = test_request(&msg); 190 else 191 ret = lock_request(&msg); 192 break; 193 case F_UNLCK: 194 ret = unlock_request(&msg); 195 break; 196 default: 197 ret = 1; 198 syslog(LOG_ERR, 199 "unknown lock type: %d", msg.lm_fl.l_type); 200 break; 201 } 202 if (ret) { 203 struct lockd_ans ans; 204 205 ans.la_msg_ident = msg.lm_msg_ident; 206 ans.la_errno = EHOSTUNREACH; 207 208 if (nfslockdans(LOCKD_ANS_VERSION, &ans)) { 209 syslog((errno == EPIPE ? LOG_INFO : 210 LOG_ERR), "process %lu: %m", 211 (u_long)msg.lm_msg_ident.pid); 212 } 213 } 214 } else if (nr == -1) { 215 if (errno != EAGAIN) { 216 syslog(LOG_ERR, "read: %s: %m", _PATH_NFSLCKDEV); 217 goto err; 218 } 219 } else if (nr != 0) { 220 syslog(LOG_ERR, 221 "%s: discard %d bytes", _PATH_NFSLCKDEV, nr); 222 } 223 } 224 225 /* Reached only on error. */ 226 err: 227 (void)lockd_seteuid(0); 228 _exit (1); 229 } 230 231 void 232 set_auth(CLIENT *cl, struct xucred *xucred) 233 { 234 int ngroups; 235 236 ngroups = xucred->cr_ngroups - 1; 237 if (ngroups > NGRPS) 238 ngroups = NGRPS; 239 if (cl->cl_auth != NULL) 240 cl->cl_auth->ah_ops->ah_destroy(cl->cl_auth); 241 cl->cl_auth = authunix_create(hostname, 242 xucred->cr_uid, 243 xucred->cr_groups[0], 244 ngroups, 245 &xucred->cr_groups[1]); 246 } 247 248 249 /* 250 * test_request -- 251 * Convert a lock LOCKD_MSG into an NLM request, and send it off. 252 */ 253 int 254 test_request(LOCKD_MSG *msg) 255 { 256 CLIENT *cli; 257 struct timeval timeout = {0, 0}; /* No timeout, no response. */ 258 char dummy; 259 260 if (d_calls) 261 syslog(LOG_DEBUG, "test request: %s: %s to %s", 262 msg->lm_nfsv3 ? "V4" : "V1/3", 263 msg->lm_fl.l_type == F_WRLCK ? "write" : "read", 264 from_addr((struct sockaddr *)&msg->lm_addr)); 265 266 if (msg->lm_nfsv3) { 267 struct nlm4_testargs arg4; 268 269 arg4.cookie.n_bytes = (char *)&msg->lm_msg_ident; 270 arg4.cookie.n_len = sizeof(msg->lm_msg_ident); 271 arg4.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0; 272 arg4.alock.caller_name = hostname; 273 arg4.alock.fh.n_bytes = (char *)&msg->lm_fh; 274 arg4.alock.fh.n_len = msg->lm_fh_len; 275 arg4.alock.oh.n_bytes = (char *)&owner; 276 arg4.alock.oh.n_len = sizeof(owner); 277 arg4.alock.svid = msg->lm_msg_ident.pid; 278 arg4.alock.l_offset = msg->lm_fl.l_start; 279 arg4.alock.l_len = msg->lm_fl.l_len; 280 281 if ((cli = get_client( 282 (struct sockaddr *)&msg->lm_addr, 283 NLM_VERS4)) == NULL) 284 return (1); 285 286 set_auth(cli, &msg->lm_cred); 287 (void)clnt_call(cli, NLM_TEST_MSG, 288 (xdrproc_t)xdr_nlm4_testargs, &arg4, 289 (xdrproc_t)xdr_void, &dummy, timeout); 290 } else { 291 struct nlm_testargs arg; 292 293 arg.cookie.n_bytes = (char *)&msg->lm_msg_ident; 294 arg.cookie.n_len = sizeof(msg->lm_msg_ident); 295 arg.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0; 296 arg.alock.caller_name = hostname; 297 arg.alock.fh.n_bytes = (char *)&msg->lm_fh; 298 arg.alock.fh.n_len = msg->lm_fh_len; 299 arg.alock.oh.n_bytes = (char *)&owner; 300 arg.alock.oh.n_len = sizeof(owner); 301 arg.alock.svid = msg->lm_msg_ident.pid; 302 arg.alock.l_offset = msg->lm_fl.l_start; 303 arg.alock.l_len = msg->lm_fl.l_len; 304 305 if ((cli = get_client( 306 (struct sockaddr *)&msg->lm_addr, 307 NLM_VERS)) == NULL) 308 return (1); 309 310 set_auth(cli, &msg->lm_cred); 311 (void)clnt_call(cli, NLM_TEST_MSG, 312 (xdrproc_t)xdr_nlm_testargs, &arg, 313 (xdrproc_t)xdr_void, &dummy, timeout); 314 } 315 return (0); 316 } 317 318 /* 319 * lock_request -- 320 * Convert a lock LOCKD_MSG into an NLM request, and send it off. 321 */ 322 int 323 lock_request(LOCKD_MSG *msg) 324 { 325 CLIENT *cli; 326 struct nlm4_lockargs arg4; 327 struct nlm_lockargs arg; 328 struct timeval timeout = {0, 0}; /* No timeout, no response. */ 329 char dummy; 330 331 if (d_calls) 332 syslog(LOG_DEBUG, "lock request: %s: %s to %s", 333 msg->lm_nfsv3 ? "V4" : "V1/3", 334 msg->lm_fl.l_type == F_WRLCK ? "write" : "read", 335 from_addr((struct sockaddr *)&msg->lm_addr)); 336 337 if (msg->lm_nfsv3) { 338 arg4.cookie.n_bytes = (char *)&msg->lm_msg_ident; 339 arg4.cookie.n_len = sizeof(msg->lm_msg_ident); 340 arg4.block = msg->lm_wait ? 1 : 0; 341 arg4.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0; 342 arg4.alock.caller_name = hostname; 343 arg4.alock.fh.n_bytes = (char *)&msg->lm_fh; 344 arg4.alock.fh.n_len = msg->lm_fh_len; 345 arg4.alock.oh.n_bytes = (char *)&owner; 346 arg4.alock.oh.n_len = sizeof(owner); 347 arg4.alock.svid = msg->lm_msg_ident.pid; 348 arg4.alock.l_offset = msg->lm_fl.l_start; 349 arg4.alock.l_len = msg->lm_fl.l_len; 350 arg4.reclaim = 0; 351 arg4.state = nsm_state; 352 353 if ((cli = get_client( 354 (struct sockaddr *)&msg->lm_addr, 355 NLM_VERS4)) == NULL) 356 return (1); 357 358 set_auth(cli, &msg->lm_cred); 359 (void)clnt_call(cli, NLM_LOCK_MSG, 360 (xdrproc_t)xdr_nlm4_lockargs, &arg4, 361 (xdrproc_t)xdr_void, &dummy, timeout); 362 } else { 363 arg.cookie.n_bytes = (char *)&msg->lm_msg_ident; 364 arg.cookie.n_len = sizeof(msg->lm_msg_ident); 365 arg.block = msg->lm_wait ? 1 : 0; 366 arg.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0; 367 arg.alock.caller_name = hostname; 368 arg.alock.fh.n_bytes = (char *)&msg->lm_fh; 369 arg.alock.fh.n_len = msg->lm_fh_len; 370 arg.alock.oh.n_bytes = (char *)&owner; 371 arg.alock.oh.n_len = sizeof(owner); 372 arg.alock.svid = msg->lm_msg_ident.pid; 373 arg.alock.l_offset = msg->lm_fl.l_start; 374 arg.alock.l_len = msg->lm_fl.l_len; 375 arg.reclaim = 0; 376 arg.state = nsm_state; 377 378 if ((cli = get_client( 379 (struct sockaddr *)&msg->lm_addr, 380 NLM_VERS)) == NULL) 381 return (1); 382 383 set_auth(cli, &msg->lm_cred); 384 (void)clnt_call(cli, NLM_LOCK_MSG, 385 (xdrproc_t)xdr_nlm_lockargs, &arg, 386 (xdrproc_t)xdr_void, &dummy, timeout); 387 } 388 return (0); 389 } 390 391 /* 392 * unlock_request -- 393 * Convert an unlock LOCKD_MSG into an NLM request, and send it off. 394 */ 395 int 396 unlock_request(LOCKD_MSG *msg) 397 { 398 CLIENT *cli; 399 struct nlm4_unlockargs arg4; 400 struct nlm_unlockargs arg; 401 struct timeval timeout = {0, 0}; /* No timeout, no response. */ 402 char dummy; 403 404 if (d_calls) 405 syslog(LOG_DEBUG, "unlock request: %s: to %s", 406 msg->lm_nfsv3 ? "V4" : "V1/3", 407 from_addr((struct sockaddr *)&msg->lm_addr)); 408 409 if (msg->lm_nfsv3) { 410 arg4.cookie.n_bytes = (char *)&msg->lm_msg_ident; 411 arg4.cookie.n_len = sizeof(msg->lm_msg_ident); 412 arg4.alock.caller_name = hostname; 413 arg4.alock.fh.n_bytes = (char *)&msg->lm_fh; 414 arg4.alock.fh.n_len = msg->lm_fh_len; 415 arg4.alock.oh.n_bytes = (char *)&owner; 416 arg4.alock.oh.n_len = sizeof(owner); 417 arg4.alock.svid = msg->lm_msg_ident.pid; 418 arg4.alock.l_offset = msg->lm_fl.l_start; 419 arg4.alock.l_len = msg->lm_fl.l_len; 420 421 if ((cli = get_client( 422 (struct sockaddr *)&msg->lm_addr, 423 NLM_VERS4)) == NULL) 424 return (1); 425 426 set_auth(cli, &msg->lm_cred); 427 (void)clnt_call(cli, NLM_UNLOCK_MSG, 428 (xdrproc_t)xdr_nlm4_unlockargs, &arg4, 429 (xdrproc_t)xdr_void, &dummy, timeout); 430 } else { 431 arg.cookie.n_bytes = (char *)&msg->lm_msg_ident; 432 arg.cookie.n_len = sizeof(msg->lm_msg_ident); 433 arg.alock.caller_name = hostname; 434 arg.alock.fh.n_bytes = (char *)&msg->lm_fh; 435 arg.alock.fh.n_len = msg->lm_fh_len; 436 arg.alock.oh.n_bytes = (char *)&owner; 437 arg.alock.oh.n_len = sizeof(owner); 438 arg.alock.svid = msg->lm_msg_ident.pid; 439 arg.alock.l_offset = msg->lm_fl.l_start; 440 arg.alock.l_len = msg->lm_fl.l_len; 441 442 if ((cli = get_client( 443 (struct sockaddr *)&msg->lm_addr, 444 NLM_VERS)) == NULL) 445 return (1); 446 447 set_auth(cli, &msg->lm_cred); 448 (void)clnt_call(cli, NLM_UNLOCK_MSG, 449 (xdrproc_t)xdr_nlm_unlockargs, &arg, 450 (xdrproc_t)xdr_void, &dummy, timeout); 451 } 452 453 return (0); 454 } 455 456 int 457 lock_answer(int pid, netobj *netcookie, int result, int *pid_p, int version) 458 { 459 struct lockd_ans ans; 460 461 if (netcookie->n_len != sizeof(ans.la_msg_ident)) { 462 if (pid == -1) { /* we're screwed */ 463 syslog(LOG_ERR, "inedible nlm cookie"); 464 return -1; 465 } 466 ans.la_msg_ident.pid = pid; 467 ans.la_msg_ident.msg_seq = -1; 468 } else { 469 memcpy(&ans.la_msg_ident, netcookie->n_bytes, 470 sizeof(ans.la_msg_ident)); 471 } 472 473 if (d_calls) 474 syslog(LOG_DEBUG, "lock answer: pid %lu: %s %d", 475 (unsigned long)ans.la_msg_ident.pid, 476 version == NLM_VERS4 ? "nlmv4" : "nlmv3", 477 result); 478 479 ans.la_set_getlk_pid = 0; 480 if (version == NLM_VERS4) 481 switch (result) { 482 case nlm4_granted: 483 ans.la_errno = 0; 484 break; 485 default: 486 ans.la_errno = EACCES; 487 break; 488 case nlm4_denied: 489 if (pid_p == NULL) 490 ans.la_errno = EAGAIN; 491 else { 492 /* this is an answer to a nlm_test msg */ 493 ans.la_set_getlk_pid = 1; 494 ans.la_getlk_pid = *pid_p; 495 ans.la_errno = 0; 496 } 497 break; 498 case nlm4_denied_nolocks: 499 ans.la_errno = EAGAIN; 500 break; 501 case nlm4_blocked: 502 return -1; 503 /* NOTREACHED */ 504 case nlm4_denied_grace_period: 505 ans.la_errno = EAGAIN; 506 break; 507 case nlm4_deadlck: 508 ans.la_errno = EDEADLK; 509 break; 510 case nlm4_rofs: 511 ans.la_errno = EROFS; 512 break; 513 case nlm4_stale_fh: 514 ans.la_errno = ESTALE; 515 break; 516 case nlm4_fbig: 517 ans.la_errno = EFBIG; 518 break; 519 case nlm4_failed: 520 ans.la_errno = EACCES; 521 break; 522 } 523 else 524 switch (result) { 525 case nlm_granted: 526 ans.la_errno = 0; 527 break; 528 default: 529 ans.la_errno = EACCES; 530 break; 531 case nlm_denied: 532 if (pid_p == NULL) 533 ans.la_errno = EAGAIN; 534 else { 535 /* this is an answer to a nlm_test msg */ 536 ans.la_set_getlk_pid = 1; 537 ans.la_getlk_pid = *pid_p; 538 ans.la_errno = 0; 539 } 540 break; 541 case nlm_denied_nolocks: 542 ans.la_errno = EAGAIN; 543 break; 544 case nlm_blocked: 545 return -1; 546 /* NOTREACHED */ 547 case nlm_denied_grace_period: 548 ans.la_errno = EAGAIN; 549 break; 550 case nlm_deadlck: 551 ans.la_errno = EDEADLK; 552 break; 553 } 554 555 if (nfslockdans(LOCKD_ANS_VERSION, &ans)) { 556 syslog(((errno == EPIPE || errno == ESRCH) ? 557 LOG_INFO : LOG_ERR), 558 "process %lu: %m", (u_long)ans.la_msg_ident.pid); 559 return -1; 560 } 561 return 0; 562 } 563 564 /* 565 * show -- 566 * Display the contents of a kernel LOCKD_MSG structure. 567 */ 568 void 569 show(LOCKD_MSG *mp) 570 { 571 static char hex[] = "0123456789abcdef"; 572 size_t len; 573 u_int8_t *p, *t, buf[NFS_SMALLFH*3+1]; 574 575 syslog(LOG_DEBUG, "process ID: %lu\n", (long)mp->lm_msg_ident.pid); 576 577 for (t = buf, p = (u_int8_t *)mp->lm_fh, 578 len = mp->lm_fh_len; 579 len > 0; ++p, --len) { 580 *t++ = '\\'; 581 *t++ = hex[(*p & 0xf0) >> 4]; 582 *t++ = hex[*p & 0x0f]; 583 } 584 *t = '\0'; 585 586 syslog(LOG_DEBUG, "fh_len %d, fh %s\n", (int)mp->lm_fh_len, buf); 587 588 /* Show flock structure. */ 589 syslog(LOG_DEBUG, "start %llu; len %llu; pid %lu; type %d; whence %d\n", 590 (unsigned long long)mp->lm_fl.l_start, 591 (unsigned long long)mp->lm_fl.l_len, (u_long)mp->lm_fl.l_pid, 592 mp->lm_fl.l_type, mp->lm_fl.l_whence); 593 594 /* Show wait flag. */ 595 syslog(LOG_DEBUG, "wait was %s\n", mp->lm_wait ? "set" : "not set"); 596 } 597