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 <assert.h> 43 #include <err.h> 44 #include <errno.h> 45 #include <fcntl.h> 46 #include <paths.h> 47 #include <pwd.h> 48 #include <stdio.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <syslog.h> 52 #include <unistd.h> 53 #include <netdb.h> 54 55 #include "nlm_prot.h" 56 #include <nfs/nfsproto.h> 57 #include <nfs/nfs_lock.h> 58 59 #include "lockd.h" 60 #include "lockd_lock.h" 61 #include <nfsclient/nfs.h> 62 63 #define DAEMON_USERNAME "daemon" 64 65 /* Lock request owner. */ 66 typedef struct __owner { 67 pid_t pid; /* Process ID. */ 68 time_t tod; /* Time-of-day. */ 69 } OWNER; 70 static OWNER owner; 71 72 static char hostname[MAXHOSTNAMELEN + 1]; /* Hostname. */ 73 static int devfd; 74 75 static void client_cleanup(void); 76 static const char *from_addr(struct sockaddr *); 77 int lock_request(LOCKD_MSG *); 78 static void set_auth(CLIENT *cl, struct xucred *ucred); 79 void show(LOCKD_MSG *); 80 int test_request(LOCKD_MSG *); 81 int unlock_request(LOCKD_MSG *); 82 83 static int 84 nfslockdans(int vers, struct lockd_ans *ansp) 85 { 86 87 ansp->la_vers = vers; 88 return (write(devfd, ansp, sizeof *ansp) <= 0); 89 } 90 91 /* 92 * will break because fifo needs to be repopened when EOF'd 93 */ 94 #define lockd_seteuid(uid) seteuid(uid) 95 96 #define d_calls (debug_level > 1) 97 #define d_args (debug_level > 2) 98 99 static const char * 100 from_addr(struct sockaddr *saddr) 101 { 102 static char inet_buf[INET6_ADDRSTRLEN]; 103 104 if (getnameinfo(saddr, saddr->sa_len, inet_buf, sizeof(inet_buf), 105 NULL, 0, NI_NUMERICHOST) == 0) 106 return inet_buf; 107 return "???"; 108 } 109 110 void 111 client_cleanup(void) 112 { 113 (void)lockd_seteuid(0); 114 exit(-1); 115 } 116 117 /* 118 * client_request -- 119 * Loop around messages from the kernel, forwarding them off to 120 * NLM servers. 121 */ 122 pid_t 123 client_request(void) 124 { 125 LOCKD_MSG msg; 126 int nr, ret; 127 pid_t child; 128 uid_t daemon_uid; 129 struct passwd *pw; 130 131 /* Open the dev . */ 132 devfd = open(_PATH_DEV _PATH_NFSLCKDEV, O_RDWR | O_NONBLOCK); 133 if (devfd < 0) { 134 syslog(LOG_ERR, "open: %s: %m", _PATH_NFSLCKDEV); 135 goto err; 136 } 137 138 signal(SIGPIPE, SIG_IGN); 139 140 /* 141 * Create a separate process, the client code is really a separate 142 * daemon that shares a lot of code. 143 */ 144 switch (child = fork()) { 145 case -1: 146 err(1, "fork"); 147 case 0: 148 setproctitle("client"); 149 break; 150 default: 151 setproctitle("server"); 152 return (child); 153 } 154 155 signal(SIGHUP, (sig_t)client_cleanup); 156 signal(SIGTERM, (sig_t)client_cleanup); 157 158 /* Setup. */ 159 (void)time(&owner.tod); 160 owner.pid = getpid(); 161 (void)gethostname(hostname, sizeof(hostname) - 1); 162 163 pw = getpwnam(DAEMON_USERNAME); 164 if (pw == NULL) { 165 syslog(LOG_ERR, "getpwnam: %s: %m", DAEMON_USERNAME); 166 goto err; 167 } 168 daemon_uid = pw->pw_uid; 169 /* drop our root privileges */ 170 (void)lockd_seteuid(daemon_uid); 171 172 for (;;) { 173 /* Read the fixed length message. */ 174 if ((nr = read(devfd, &msg, sizeof(msg))) == sizeof(msg)) { 175 if (d_args) 176 show(&msg); 177 178 if (msg.lm_version != LOCKD_MSG_VERSION) { 179 syslog(LOG_ERR, 180 "unknown msg type: %d", msg.lm_version); 181 } 182 /* 183 * Send it to the NLM server and don't grant the lock 184 * if we fail for any reason. 185 */ 186 switch (msg.lm_fl.l_type) { 187 case F_RDLCK: 188 case F_WRLCK: 189 if (msg.lm_getlk) 190 ret = test_request(&msg); 191 else 192 ret = lock_request(&msg); 193 break; 194 case F_UNLCK: 195 ret = unlock_request(&msg); 196 break; 197 default: 198 ret = 1; 199 syslog(LOG_ERR, 200 "unknown lock type: %d", msg.lm_fl.l_type); 201 break; 202 } 203 if (ret) { 204 struct lockd_ans ans; 205 206 ans.la_msg_ident = msg.lm_msg_ident; 207 ans.la_errno = EHOSTUNREACH; 208 209 if (nfslockdans(LOCKD_ANS_VERSION, &ans)) { 210 syslog((errno == EPIPE ? LOG_INFO : 211 LOG_ERR), "process %lu: %m", 212 (u_long)msg.lm_msg_ident.pid); 213 } 214 } 215 } else if (nr == -1) { 216 if (errno != EAGAIN) { 217 syslog(LOG_ERR, "read: %s: %m", _PATH_NFSLCKDEV); 218 goto err; 219 } 220 } else if (nr != 0) { 221 syslog(LOG_ERR, 222 "%s: discard %d bytes", _PATH_NFSLCKDEV, nr); 223 } 224 } 225 226 /* Reached only on error. */ 227 err: 228 (void)lockd_seteuid(0); 229 _exit (1); 230 } 231 232 void 233 set_auth(CLIENT *cl, struct xucred *xucred) 234 { 235 int ngroups; 236 gid_t *groups; 237 238 /* 239 * Exclude the first element if it is actually the egid, but account for 240 * the possibility that we could eventually exclude the egid from the 241 * exported group list some day. 242 */ 243 ngroups = xucred->cr_ngroups; 244 groups = &xucred->cr_groups[0]; 245 if (groups == &xucred->cr_gid) { 246 assert(ngroups > 0); 247 ngroups--; 248 groups++; 249 } 250 if (ngroups > NGRPS) 251 ngroups = NGRPS; 252 if (cl->cl_auth != NULL) 253 cl->cl_auth->ah_ops->ah_destroy(cl->cl_auth); 254 cl->cl_auth = authunix_create(hostname, 255 xucred->cr_uid, 256 xucred->cr_gid, 257 ngroups, 258 groups); 259 } 260 261 262 /* 263 * test_request -- 264 * Convert a lock LOCKD_MSG into an NLM request, and send it off. 265 */ 266 int 267 test_request(LOCKD_MSG *msg) 268 { 269 CLIENT *cli; 270 struct timeval timeout = {0, 0}; /* No timeout, no response. */ 271 char dummy; 272 273 if (d_calls) 274 syslog(LOG_DEBUG, "test request: %s: %s to %s", 275 msg->lm_nfsv3 ? "V4" : "V1/3", 276 msg->lm_fl.l_type == F_WRLCK ? "write" : "read", 277 from_addr((struct sockaddr *)&msg->lm_addr)); 278 279 if (msg->lm_nfsv3) { 280 struct nlm4_testargs arg4; 281 282 arg4.cookie.n_bytes = (char *)&msg->lm_msg_ident; 283 arg4.cookie.n_len = sizeof(msg->lm_msg_ident); 284 arg4.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0; 285 arg4.alock.caller_name = hostname; 286 arg4.alock.fh.n_bytes = (char *)&msg->lm_fh; 287 arg4.alock.fh.n_len = msg->lm_fh_len; 288 arg4.alock.oh.n_bytes = (char *)&owner; 289 arg4.alock.oh.n_len = sizeof(owner); 290 arg4.alock.svid = msg->lm_msg_ident.pid; 291 arg4.alock.l_offset = msg->lm_fl.l_start; 292 arg4.alock.l_len = msg->lm_fl.l_len; 293 294 if ((cli = get_client( 295 (struct sockaddr *)&msg->lm_addr, 296 NLM_VERS4)) == NULL) 297 return (1); 298 299 set_auth(cli, &msg->lm_cred); 300 (void)clnt_call(cli, NLM_TEST_MSG, 301 (xdrproc_t)xdr_nlm4_testargs, &arg4, 302 (xdrproc_t)xdr_void, &dummy, timeout); 303 } else { 304 struct nlm_testargs arg; 305 306 arg.cookie.n_bytes = (char *)&msg->lm_msg_ident; 307 arg.cookie.n_len = sizeof(msg->lm_msg_ident); 308 arg.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0; 309 arg.alock.caller_name = hostname; 310 arg.alock.fh.n_bytes = (char *)&msg->lm_fh; 311 arg.alock.fh.n_len = msg->lm_fh_len; 312 arg.alock.oh.n_bytes = (char *)&owner; 313 arg.alock.oh.n_len = sizeof(owner); 314 arg.alock.svid = msg->lm_msg_ident.pid; 315 arg.alock.l_offset = msg->lm_fl.l_start; 316 arg.alock.l_len = msg->lm_fl.l_len; 317 318 if ((cli = get_client( 319 (struct sockaddr *)&msg->lm_addr, 320 NLM_VERS)) == NULL) 321 return (1); 322 323 set_auth(cli, &msg->lm_cred); 324 (void)clnt_call(cli, NLM_TEST_MSG, 325 (xdrproc_t)xdr_nlm_testargs, &arg, 326 (xdrproc_t)xdr_void, &dummy, timeout); 327 } 328 return (0); 329 } 330 331 /* 332 * lock_request -- 333 * Convert a lock LOCKD_MSG into an NLM request, and send it off. 334 */ 335 int 336 lock_request(LOCKD_MSG *msg) 337 { 338 CLIENT *cli; 339 struct nlm4_lockargs arg4; 340 struct nlm_lockargs arg; 341 struct timeval timeout = {0, 0}; /* No timeout, no response. */ 342 char dummy; 343 344 if (d_calls) 345 syslog(LOG_DEBUG, "lock request: %s: %s to %s", 346 msg->lm_nfsv3 ? "V4" : "V1/3", 347 msg->lm_fl.l_type == F_WRLCK ? "write" : "read", 348 from_addr((struct sockaddr *)&msg->lm_addr)); 349 350 if (msg->lm_nfsv3) { 351 arg4.cookie.n_bytes = (char *)&msg->lm_msg_ident; 352 arg4.cookie.n_len = sizeof(msg->lm_msg_ident); 353 arg4.block = msg->lm_wait ? 1 : 0; 354 arg4.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0; 355 arg4.alock.caller_name = hostname; 356 arg4.alock.fh.n_bytes = (char *)&msg->lm_fh; 357 arg4.alock.fh.n_len = msg->lm_fh_len; 358 arg4.alock.oh.n_bytes = (char *)&owner; 359 arg4.alock.oh.n_len = sizeof(owner); 360 arg4.alock.svid = msg->lm_msg_ident.pid; 361 arg4.alock.l_offset = msg->lm_fl.l_start; 362 arg4.alock.l_len = msg->lm_fl.l_len; 363 arg4.reclaim = 0; 364 arg4.state = nsm_state; 365 366 if ((cli = get_client( 367 (struct sockaddr *)&msg->lm_addr, 368 NLM_VERS4)) == NULL) 369 return (1); 370 371 set_auth(cli, &msg->lm_cred); 372 (void)clnt_call(cli, NLM_LOCK_MSG, 373 (xdrproc_t)xdr_nlm4_lockargs, &arg4, 374 (xdrproc_t)xdr_void, &dummy, timeout); 375 } else { 376 arg.cookie.n_bytes = (char *)&msg->lm_msg_ident; 377 arg.cookie.n_len = sizeof(msg->lm_msg_ident); 378 arg.block = msg->lm_wait ? 1 : 0; 379 arg.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0; 380 arg.alock.caller_name = hostname; 381 arg.alock.fh.n_bytes = (char *)&msg->lm_fh; 382 arg.alock.fh.n_len = msg->lm_fh_len; 383 arg.alock.oh.n_bytes = (char *)&owner; 384 arg.alock.oh.n_len = sizeof(owner); 385 arg.alock.svid = msg->lm_msg_ident.pid; 386 arg.alock.l_offset = msg->lm_fl.l_start; 387 arg.alock.l_len = msg->lm_fl.l_len; 388 arg.reclaim = 0; 389 arg.state = nsm_state; 390 391 if ((cli = get_client( 392 (struct sockaddr *)&msg->lm_addr, 393 NLM_VERS)) == NULL) 394 return (1); 395 396 set_auth(cli, &msg->lm_cred); 397 (void)clnt_call(cli, NLM_LOCK_MSG, 398 (xdrproc_t)xdr_nlm_lockargs, &arg, 399 (xdrproc_t)xdr_void, &dummy, timeout); 400 } 401 return (0); 402 } 403 404 /* 405 * unlock_request -- 406 * Convert an unlock LOCKD_MSG into an NLM request, and send it off. 407 */ 408 int 409 unlock_request(LOCKD_MSG *msg) 410 { 411 CLIENT *cli; 412 struct nlm4_unlockargs arg4; 413 struct nlm_unlockargs arg; 414 struct timeval timeout = {0, 0}; /* No timeout, no response. */ 415 char dummy; 416 417 if (d_calls) 418 syslog(LOG_DEBUG, "unlock request: %s: to %s", 419 msg->lm_nfsv3 ? "V4" : "V1/3", 420 from_addr((struct sockaddr *)&msg->lm_addr)); 421 422 if (msg->lm_nfsv3) { 423 arg4.cookie.n_bytes = (char *)&msg->lm_msg_ident; 424 arg4.cookie.n_len = sizeof(msg->lm_msg_ident); 425 arg4.alock.caller_name = hostname; 426 arg4.alock.fh.n_bytes = (char *)&msg->lm_fh; 427 arg4.alock.fh.n_len = msg->lm_fh_len; 428 arg4.alock.oh.n_bytes = (char *)&owner; 429 arg4.alock.oh.n_len = sizeof(owner); 430 arg4.alock.svid = msg->lm_msg_ident.pid; 431 arg4.alock.l_offset = msg->lm_fl.l_start; 432 arg4.alock.l_len = msg->lm_fl.l_len; 433 434 if ((cli = get_client( 435 (struct sockaddr *)&msg->lm_addr, 436 NLM_VERS4)) == NULL) 437 return (1); 438 439 set_auth(cli, &msg->lm_cred); 440 (void)clnt_call(cli, NLM_UNLOCK_MSG, 441 (xdrproc_t)xdr_nlm4_unlockargs, &arg4, 442 (xdrproc_t)xdr_void, &dummy, timeout); 443 } else { 444 arg.cookie.n_bytes = (char *)&msg->lm_msg_ident; 445 arg.cookie.n_len = sizeof(msg->lm_msg_ident); 446 arg.alock.caller_name = hostname; 447 arg.alock.fh.n_bytes = (char *)&msg->lm_fh; 448 arg.alock.fh.n_len = msg->lm_fh_len; 449 arg.alock.oh.n_bytes = (char *)&owner; 450 arg.alock.oh.n_len = sizeof(owner); 451 arg.alock.svid = msg->lm_msg_ident.pid; 452 arg.alock.l_offset = msg->lm_fl.l_start; 453 arg.alock.l_len = msg->lm_fl.l_len; 454 455 if ((cli = get_client( 456 (struct sockaddr *)&msg->lm_addr, 457 NLM_VERS)) == NULL) 458 return (1); 459 460 set_auth(cli, &msg->lm_cred); 461 (void)clnt_call(cli, NLM_UNLOCK_MSG, 462 (xdrproc_t)xdr_nlm_unlockargs, &arg, 463 (xdrproc_t)xdr_void, &dummy, timeout); 464 } 465 466 return (0); 467 } 468 469 int 470 lock_answer(int pid, netobj *netcookie, int result, int *pid_p, int version) 471 { 472 struct lockd_ans ans; 473 474 if (netcookie->n_len != sizeof(ans.la_msg_ident)) { 475 if (pid == -1) { /* we're screwed */ 476 syslog(LOG_ERR, "inedible nlm cookie"); 477 return -1; 478 } 479 ans.la_msg_ident.pid = pid; 480 ans.la_msg_ident.msg_seq = -1; 481 } else { 482 memcpy(&ans.la_msg_ident, netcookie->n_bytes, 483 sizeof(ans.la_msg_ident)); 484 } 485 486 if (d_calls) 487 syslog(LOG_DEBUG, "lock answer: pid %lu: %s %d", 488 (unsigned long)ans.la_msg_ident.pid, 489 version == NLM_VERS4 ? "nlmv4" : "nlmv3", 490 result); 491 492 ans.la_set_getlk_pid = 0; 493 if (version == NLM_VERS4) 494 switch (result) { 495 case nlm4_granted: 496 ans.la_errno = 0; 497 break; 498 default: 499 ans.la_errno = EACCES; 500 break; 501 case nlm4_denied: 502 if (pid_p == NULL) 503 ans.la_errno = EAGAIN; 504 else { 505 /* this is an answer to a nlm_test msg */ 506 ans.la_set_getlk_pid = 1; 507 ans.la_getlk_pid = *pid_p; 508 ans.la_errno = 0; 509 } 510 break; 511 case nlm4_denied_nolocks: 512 ans.la_errno = EAGAIN; 513 break; 514 case nlm4_blocked: 515 return -1; 516 /* NOTREACHED */ 517 case nlm4_denied_grace_period: 518 ans.la_errno = EAGAIN; 519 break; 520 case nlm4_deadlck: 521 ans.la_errno = EDEADLK; 522 break; 523 case nlm4_rofs: 524 ans.la_errno = EROFS; 525 break; 526 case nlm4_stale_fh: 527 ans.la_errno = ESTALE; 528 break; 529 case nlm4_fbig: 530 ans.la_errno = EFBIG; 531 break; 532 case nlm4_failed: 533 ans.la_errno = EACCES; 534 break; 535 } 536 else 537 switch (result) { 538 case nlm_granted: 539 ans.la_errno = 0; 540 break; 541 default: 542 ans.la_errno = EACCES; 543 break; 544 case nlm_denied: 545 if (pid_p == NULL) 546 ans.la_errno = EAGAIN; 547 else { 548 /* this is an answer to a nlm_test msg */ 549 ans.la_set_getlk_pid = 1; 550 ans.la_getlk_pid = *pid_p; 551 ans.la_errno = 0; 552 } 553 break; 554 case nlm_denied_nolocks: 555 ans.la_errno = EAGAIN; 556 break; 557 case nlm_blocked: 558 return -1; 559 /* NOTREACHED */ 560 case nlm_denied_grace_period: 561 ans.la_errno = EAGAIN; 562 break; 563 case nlm_deadlck: 564 ans.la_errno = EDEADLK; 565 break; 566 } 567 568 if (nfslockdans(LOCKD_ANS_VERSION, &ans)) { 569 syslog(((errno == EPIPE || errno == ESRCH) ? 570 LOG_INFO : LOG_ERR), 571 "process %lu: %m", (u_long)ans.la_msg_ident.pid); 572 return -1; 573 } 574 return 0; 575 } 576 577 /* 578 * show -- 579 * Display the contents of a kernel LOCKD_MSG structure. 580 */ 581 void 582 show(LOCKD_MSG *mp) 583 { 584 static char hex[] = "0123456789abcdef"; 585 size_t len; 586 u_int8_t *p, *t, buf[NFS_SMALLFH*3+1]; 587 588 syslog(LOG_DEBUG, "process ID: %lu\n", (long)mp->lm_msg_ident.pid); 589 590 for (t = buf, p = (u_int8_t *)mp->lm_fh, 591 len = mp->lm_fh_len; 592 len > 0; ++p, --len) { 593 *t++ = '\\'; 594 *t++ = hex[(*p & 0xf0) >> 4]; 595 *t++ = hex[*p & 0x0f]; 596 } 597 *t = '\0'; 598 599 syslog(LOG_DEBUG, "fh_len %d, fh %s\n", (int)mp->lm_fh_len, buf); 600 601 /* Show flock structure. */ 602 syslog(LOG_DEBUG, "start %llu; len %llu; pid %lu; type %d; whence %d\n", 603 (unsigned long long)mp->lm_fl.l_start, 604 (unsigned long long)mp->lm_fl.l_len, (u_long)mp->lm_fl.l_pid, 605 mp->lm_fl.l_type, mp->lm_fl.l_whence); 606 607 /* Show wait flag. */ 608 syslog(LOG_DEBUG, "wait was %s\n", mp->lm_wait ? "set" : "not set"); 609 } 610