1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2010 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* 28 * The dlmgmtd daemon is started by the datalink-management SMF service. 29 * This daemon is used to manage <link name, linkid> mapping and the 30 * persistent datalink configuration. 31 * 32 * Today, the <link name, linkid> mapping and the persistent configuration 33 * of datalinks is kept in /etc/dladm/datalink.conf, and the daemon keeps 34 * a copy of the datalinks in the memory (see dlmgmt_id_avl and 35 * dlmgmt_name_avl). The active <link name, linkid> mapping is kept in 36 * /etc/svc/volatile/dladm cache file, so that the mapping can be recovered 37 * when dlmgmtd exits for some reason (e.g., when dlmgmtd is accidentally 38 * killed). 39 */ 40 41 #include <assert.h> 42 #include <errno.h> 43 #include <fcntl.h> 44 #include <priv.h> 45 #include <signal.h> 46 #include <stdlib.h> 47 #include <stdio.h> 48 #include <strings.h> 49 #include <syslog.h> 50 #include <zone.h> 51 #include <sys/dld.h> 52 #include <sys/dld_ioc.h> 53 #include <sys/param.h> 54 #include <sys/stat.h> 55 #include <unistd.h> 56 #include <libdladm_impl.h> 57 #include <libdlmgmt.h> 58 #include "dlmgmt_impl.h" 59 60 const char *progname; 61 boolean_t debug; 62 static int pfds[2]; 63 /* 64 * This file descriptor to DLMGMT_DOOR cannot be in the libdladm 65 * handle because the door isn't created when the handle is created. 66 */ 67 static int dlmgmt_door_fd = -1; 68 69 /* 70 * This libdladm handle is global so that dlmgmt_upcall_linkprop_init() can 71 * pass to libdladm. The handle is opened with "ALL" privileges, before 72 * privileges are dropped in dlmgmt_drop_privileges(). It is not able to open 73 * DLMGMT_DOOR at that time as it hasn't been created yet. This door in the 74 * handle is opened in the first call to dladm_door_fd(). 75 */ 76 dladm_handle_t dld_handle = NULL; 77 78 static void dlmgmtd_exit(int); 79 static int dlmgmt_init(); 80 static void dlmgmt_fini(); 81 static int dlmgmt_set_privileges(); 82 83 static int 84 dlmgmt_set_doorfd(boolean_t start) 85 { 86 dld_ioc_door_t did; 87 int err = 0; 88 89 assert(dld_handle != NULL); 90 91 did.did_start_door = start; 92 93 if (ioctl(dladm_dld_fd(dld_handle), DLDIOC_DOORSERVER, &did) == -1) 94 err = errno; 95 96 return (err); 97 } 98 99 static int 100 dlmgmt_door_init(void) 101 { 102 int err = 0; 103 104 if ((dlmgmt_door_fd = door_create(dlmgmt_handler, NULL, 105 DOOR_REFUSE_DESC | DOOR_NO_CANCEL)) == -1) { 106 err = errno; 107 dlmgmt_log(LOG_ERR, "door_create() failed: %s", 108 strerror(err)); 109 return (err); 110 } 111 return (err); 112 } 113 114 static void 115 dlmgmt_door_fini(void) 116 { 117 if (dlmgmt_door_fd == -1) 118 return; 119 120 if (door_revoke(dlmgmt_door_fd) == -1) { 121 dlmgmt_log(LOG_WARNING, "door_revoke(%s) failed: %s", 122 DLMGMT_DOOR, strerror(errno)); 123 } 124 (void) dlmgmt_set_doorfd(B_FALSE); 125 dlmgmt_door_fd = -1; 126 } 127 128 int 129 dlmgmt_door_attach(zoneid_t zoneid, char *rootdir) 130 { 131 int fd; 132 int err = 0; 133 char doorpath[MAXPATHLEN]; 134 135 (void) snprintf(doorpath, sizeof (doorpath), "%s%s", rootdir, 136 DLMGMT_DOOR); 137 138 /* 139 * Create the door file for dlmgmtd. 140 */ 141 if ((fd = open(doorpath, O_CREAT|O_RDONLY, 0644)) == -1) { 142 err = errno; 143 dlmgmt_log(LOG_ERR, "open(%s) failed: %s", doorpath, 144 strerror(err)); 145 return (err); 146 } 147 (void) close(fd); 148 if (chown(doorpath, UID_DLADM, GID_NETADM) == -1) 149 return (errno); 150 151 /* 152 * fdetach first in case a previous daemon instance exited 153 * ungracefully. 154 */ 155 (void) fdetach(doorpath); 156 if (fattach(dlmgmt_door_fd, doorpath) != 0) { 157 err = errno; 158 dlmgmt_log(LOG_ERR, "fattach(%s) failed: %s", doorpath, 159 strerror(err)); 160 } else if (zoneid == GLOBAL_ZONEID) { 161 if ((err = dlmgmt_set_doorfd(B_TRUE)) != 0) { 162 dlmgmt_log(LOG_ERR, "cannot set kernel doorfd: %s", 163 strerror(err)); 164 } 165 } 166 167 return (err); 168 } 169 170 /* 171 * Create the /etc/svc/volatile/dladm/ directory if it doesn't exist, load the 172 * datalink.conf data for this zone, and create/attach the door rendezvous 173 * file. 174 */ 175 int 176 dlmgmt_zone_init(zoneid_t zoneid) 177 { 178 char rootdir[MAXPATHLEN], tmpfsdir[MAXPATHLEN]; 179 int err; 180 struct stat statbuf; 181 182 if (zoneid == GLOBAL_ZONEID) { 183 rootdir[0] = '\0'; 184 } else if (zone_getattr(zoneid, ZONE_ATTR_ROOT, rootdir, 185 sizeof (rootdir)) < 0) { 186 return (errno); 187 } 188 189 /* 190 * Create the DLMGMT_TMPFS_DIR directory. 191 */ 192 (void) snprintf(tmpfsdir, sizeof (tmpfsdir), "%s%s", rootdir, 193 DLMGMT_TMPFS_DIR); 194 if (stat(tmpfsdir, &statbuf) < 0) { 195 if (mkdir(tmpfsdir, (mode_t)0755) < 0) 196 return (errno); 197 } else if ((statbuf.st_mode & S_IFMT) != S_IFDIR) { 198 return (ENOTDIR); 199 } 200 201 if ((chmod(tmpfsdir, 0755) < 0) || 202 (chown(tmpfsdir, UID_DLADM, GID_NETADM) < 0)) { 203 return (EPERM); 204 } 205 206 if ((err = dlmgmt_db_init(zoneid)) != 0) 207 return (err); 208 return (dlmgmt_door_attach(zoneid, rootdir)); 209 } 210 211 /* 212 * Initialize each running zone. 213 */ 214 static int 215 dlmgmt_allzones_init(void) 216 { 217 int err, i; 218 zoneid_t *zids = NULL; 219 uint_t nzids, nzids_saved; 220 221 if (zone_list(NULL, &nzids) != 0) 222 return (errno); 223 again: 224 nzids *= 2; 225 if ((zids = malloc(nzids * sizeof (zoneid_t))) == NULL) 226 return (errno); 227 nzids_saved = nzids; 228 if (zone_list(zids, &nzids) != 0) { 229 free(zids); 230 return (errno); 231 } 232 if (nzids > nzids_saved) { 233 free(zids); 234 goto again; 235 } 236 237 for (i = 0; i < nzids; i++) { 238 if ((err = dlmgmt_zone_init(zids[i])) != 0) 239 break; 240 } 241 free(zids); 242 return (err); 243 } 244 245 static int 246 dlmgmt_init(void) 247 { 248 int err; 249 char *fmri, *c; 250 char filename[MAXPATHLEN]; 251 252 if (dladm_open(&dld_handle) != DLADM_STATUS_OK) { 253 dlmgmt_log(LOG_ERR, "dladm_open() failed"); 254 return (EPERM); 255 } 256 257 if (signal(SIGTERM, dlmgmtd_exit) == SIG_ERR || 258 signal(SIGINT, dlmgmtd_exit) == SIG_ERR) { 259 err = errno; 260 dlmgmt_log(LOG_ERR, "signal() for SIGTERM/INT failed: %s", 261 strerror(err)); 262 return (err); 263 } 264 265 /* 266 * First derive the name of the cache file from the FMRI name. This 267 * cache name is used to keep active datalink configuration. 268 */ 269 if (debug) { 270 (void) snprintf(cachefile, MAXPATHLEN, "%s/%s%s", 271 DLMGMT_TMPFS_DIR, progname, ".debug.cache"); 272 } else { 273 if ((fmri = getenv("SMF_FMRI")) == NULL) { 274 dlmgmt_log(LOG_ERR, "dlmgmtd is an smf(5) managed " 275 "service and should not be run from the command " 276 "line."); 277 return (EINVAL); 278 } 279 280 /* 281 * The FMRI name is in the form of 282 * svc:/service/service:instance. We need to remove the 283 * prefix "svc:/" and replace '/' with '-'. The cache file 284 * name is in the form of "service:instance.cache". 285 */ 286 if ((c = strchr(fmri, '/')) != NULL) 287 c++; 288 else 289 c = fmri; 290 (void) snprintf(filename, MAXPATHLEN, "%s.cache", c); 291 c = filename; 292 while ((c = strchr(c, '/')) != NULL) 293 *c = '-'; 294 295 (void) snprintf(cachefile, MAXPATHLEN, "%s/%s", 296 DLMGMT_TMPFS_DIR, filename); 297 } 298 299 dlmgmt_linktable_init(); 300 if ((err = dlmgmt_door_init()) != 0) 301 goto done; 302 303 /* 304 * Load datalink configuration and create dlmgmtd door files for all 305 * currently running zones. 306 */ 307 if ((err = dlmgmt_allzones_init()) != 0) 308 dlmgmt_door_fini(); 309 310 done: 311 if (err != 0) 312 dlmgmt_linktable_fini(); 313 return (err); 314 } 315 316 static void 317 dlmgmt_fini(void) 318 { 319 dlmgmt_door_fini(); 320 dlmgmt_linktable_fini(); 321 if (dld_handle != NULL) { 322 dladm_close(dld_handle); 323 dld_handle = NULL; 324 } 325 } 326 327 /* 328 * This is called by the child process to inform the parent process to 329 * exit with the given return value. 330 */ 331 static void 332 dlmgmt_inform_parent_exit(int rv) 333 { 334 if (debug) 335 return; 336 337 if (write(pfds[1], &rv, sizeof (int)) != sizeof (int)) { 338 dlmgmt_log(LOG_WARNING, 339 "dlmgmt_inform_parent_exit() failed: %s", strerror(errno)); 340 (void) close(pfds[1]); 341 exit(EXIT_FAILURE); 342 } 343 (void) close(pfds[1]); 344 } 345 346 /*ARGSUSED*/ 347 static void 348 dlmgmtd_exit(int signo) 349 { 350 (void) close(pfds[1]); 351 dlmgmt_fini(); 352 exit(EXIT_FAILURE); 353 } 354 355 static void 356 usage(void) 357 { 358 (void) fprintf(stderr, "Usage: %s [-d]\n", progname); 359 exit(EXIT_FAILURE); 360 } 361 362 /* 363 * Restrict privileges to only those needed. 364 */ 365 int 366 dlmgmt_drop_privileges(void) 367 { 368 priv_set_t *pset; 369 priv_ptype_t ptype; 370 zoneid_t zoneid = getzoneid(); 371 int err = 0; 372 373 if ((pset = priv_allocset()) == NULL) 374 return (errno); 375 376 /* 377 * The global zone needs PRIV_PROC_FORK so that it can fork() when it 378 * issues db ops in non-global zones, PRIV_SYS_CONFIG to post 379 * sysevents, and PRIV_SYS_DL_CONFIG to initialize link properties in 380 * dlmgmt_upcall_linkprop_init(). 381 * 382 * We remove non-basic privileges from the permitted (and thus 383 * effective) set. When executing in a non-global zone, dlmgmtd 384 * only needs to read and write to files that it already owns. 385 */ 386 priv_basicset(pset); 387 (void) priv_delset(pset, PRIV_PROC_EXEC); 388 (void) priv_delset(pset, PRIV_PROC_INFO); 389 (void) priv_delset(pset, PRIV_PROC_SESSION); 390 (void) priv_delset(pset, PRIV_FILE_LINK_ANY); 391 if (zoneid == GLOBAL_ZONEID) { 392 ptype = PRIV_EFFECTIVE; 393 if (priv_addset(pset, PRIV_SYS_CONFIG) == -1 || 394 priv_addset(pset, PRIV_SYS_DL_CONFIG) == -1) 395 err = errno; 396 } else { 397 (void) priv_delset(pset, PRIV_PROC_FORK); 398 ptype = PRIV_PERMITTED; 399 } 400 if (err == 0 && setppriv(PRIV_SET, ptype, pset) == -1) 401 err = errno; 402 done: 403 priv_freeset(pset); 404 return (err); 405 } 406 407 int 408 dlmgmt_elevate_privileges(void) 409 { 410 priv_set_t *privset; 411 int err = 0; 412 413 if ((privset = priv_str_to_set("zone", ",", NULL)) == NULL) 414 return (errno); 415 if (setppriv(PRIV_SET, PRIV_EFFECTIVE, privset) == -1) 416 err = errno; 417 priv_freeset(privset); 418 return (err); 419 } 420 421 /* 422 * Set the uid of this daemon to the "dladm" user and drop privileges to only 423 * those needed. 424 */ 425 static int 426 dlmgmt_set_privileges(void) 427 { 428 int err; 429 430 (void) setgroups(0, NULL); 431 if (setegid(GID_NETADM) == -1 || seteuid(UID_DLADM) == -1) 432 err = errno; 433 else 434 err = dlmgmt_drop_privileges(); 435 done: 436 return (err); 437 } 438 439 /* 440 * Keep the pfds fd open, close other fds. 441 */ 442 /*ARGSUSED*/ 443 static int 444 closefunc(void *arg, int fd) 445 { 446 if (fd != pfds[1]) 447 (void) close(fd); 448 return (0); 449 } 450 451 static boolean_t 452 dlmgmt_daemonize(void) 453 { 454 pid_t pid; 455 int rv; 456 457 if (pipe(pfds) < 0) { 458 (void) fprintf(stderr, "%s: pipe() failed: %s\n", 459 progname, strerror(errno)); 460 exit(EXIT_FAILURE); 461 } 462 463 if ((pid = fork()) == -1) { 464 (void) fprintf(stderr, "%s: fork() failed: %s\n", 465 progname, strerror(errno)); 466 exit(EXIT_FAILURE); 467 } else if (pid > 0) { /* Parent */ 468 (void) close(pfds[1]); 469 470 /* 471 * Read the child process's return value from the pfds. 472 * If the child process exits unexpected, read() returns -1. 473 */ 474 if (read(pfds[0], &rv, sizeof (int)) != sizeof (int)) { 475 (void) kill(pid, SIGKILL); 476 rv = EXIT_FAILURE; 477 } 478 479 (void) close(pfds[0]); 480 exit(rv); 481 } 482 483 /* Child */ 484 (void) close(pfds[0]); 485 (void) setsid(); 486 487 /* 488 * Close all files except pfds[1]. 489 */ 490 (void) fdwalk(closefunc, NULL); 491 (void) chdir("/"); 492 openlog(progname, LOG_PID, LOG_DAEMON); 493 return (B_TRUE); 494 } 495 496 int 497 main(int argc, char *argv[]) 498 { 499 int opt, err; 500 501 progname = strrchr(argv[0], '/'); 502 if (progname != NULL) 503 progname++; 504 else 505 progname = argv[0]; 506 507 /* 508 * Process options. 509 */ 510 while ((opt = getopt(argc, argv, "d")) != EOF) { 511 switch (opt) { 512 case 'd': 513 debug = B_TRUE; 514 break; 515 default: 516 usage(); 517 } 518 } 519 520 if (!debug && !dlmgmt_daemonize()) 521 return (EXIT_FAILURE); 522 523 if ((err = dlmgmt_init()) != 0) { 524 dlmgmt_log(LOG_ERR, "unable to initialize daemon: %s", 525 strerror(err)); 526 goto child_out; 527 } else if ((err = dlmgmt_set_privileges()) != 0) { 528 dlmgmt_log(LOG_ERR, "unable to set daemon privileges: %s", 529 strerror(err)); 530 dlmgmt_fini(); 531 goto child_out; 532 } 533 534 /* 535 * Inform the parent process that it can successfully exit. 536 */ 537 dlmgmt_inform_parent_exit(EXIT_SUCCESS); 538 539 for (;;) 540 (void) pause(); 541 542 child_out: 543 /* return from main() forcibly exits an MT process */ 544 dlmgmt_inform_parent_exit(EXIT_FAILURE); 545 return (EXIT_FAILURE); 546 } 547