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 2009 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_utils.h> 45 #include <signal.h> 46 #include <stdlib.h> 47 #include <stdio.h> 48 #include <strings.h> 49 #include <syslog.h> 50 #include <sys/dld.h> 51 #include <sys/dld_ioc.h> 52 #include <sys/param.h> 53 #include <sys/stat.h> 54 #include <unistd.h> 55 #include <libdladm_impl.h> 56 #include <libdlmgmt.h> 57 #include "dlmgmt_impl.h" 58 59 const char *progname; 60 boolean_t debug; 61 static int pfds[2]; 62 /* 63 * This file descriptor to DLMGMT_DOOR cannot be in the libdladm 64 * handle because the door isn't created when the handle is created. 65 */ 66 static int dlmgmt_door_fd = -1; 67 68 /* 69 * This libdladm handle is global so that dlmgmt_upcall_linkprop_init() 70 * can pass to libdladm. The handle is opened during dlmgmt_init_privileges() 71 * with "ALL" privileges. It is not able to open DLMGMT_DOOR at that time as 72 * it hasn't been created yet. This door in the handle is opened in the first 73 * call to dladm_door_fd(). 74 */ 75 dladm_handle_t dld_handle = NULL; 76 77 static void dlmgmtd_exit(int); 78 static int dlmgmt_init(); 79 static void dlmgmt_fini(); 80 static int dlmgmt_init_privileges(); 81 static void dlmgmt_fini_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() 101 { 102 int fd; 103 int err; 104 105 /* 106 * Create the door file for dlmgmtd. 107 */ 108 if ((fd = open(DLMGMT_DOOR, O_CREAT|O_RDONLY, 0644)) == -1) { 109 err = errno; 110 dlmgmt_log(LOG_ERR, "open(%s) failed: %s", 111 DLMGMT_DOOR, strerror(err)); 112 return (err); 113 } 114 (void) close(fd); 115 116 if ((dlmgmt_door_fd = door_create(dlmgmt_handler, NULL, 117 DOOR_REFUSE_DESC | DOOR_NO_CANCEL)) == -1) { 118 err = errno; 119 dlmgmt_log(LOG_ERR, "door_create() failed: %s", 120 strerror(err)); 121 return (err); 122 } 123 /* 124 * fdetach first in case a previous daemon instance exited 125 * ungracefully. 126 */ 127 (void) fdetach(DLMGMT_DOOR); 128 if (fattach(dlmgmt_door_fd, DLMGMT_DOOR) != 0) { 129 err = errno; 130 dlmgmt_log(LOG_ERR, "fattach(%s) failed: %s", 131 DLMGMT_DOOR, strerror(err)); 132 goto fail; 133 } 134 if ((err = dlmgmt_set_doorfd(B_TRUE)) != 0) { 135 dlmgmt_log(LOG_ERR, "cannot set kernel doorfd: %s", 136 strerror(err)); 137 (void) fdetach(DLMGMT_DOOR); 138 goto fail; 139 } 140 141 return (0); 142 fail: 143 (void) door_revoke(dlmgmt_door_fd); 144 dlmgmt_door_fd = -1; 145 return (err); 146 } 147 148 static void 149 dlmgmt_door_fini() 150 { 151 if (dlmgmt_door_fd == -1) 152 return; 153 154 if (door_revoke(dlmgmt_door_fd) == -1) { 155 dlmgmt_log(LOG_WARNING, "door_revoke(%s) failed: %s", 156 DLMGMT_DOOR, strerror(errno)); 157 } 158 159 (void) fdetach(DLMGMT_DOOR); 160 (void) dlmgmt_set_doorfd(B_FALSE); 161 } 162 163 static int 164 dlmgmt_init() 165 { 166 int err; 167 168 if (signal(SIGTERM, dlmgmtd_exit) == SIG_ERR || 169 signal(SIGINT, dlmgmtd_exit) == SIG_ERR) { 170 err = errno; 171 dlmgmt_log(LOG_ERR, "signal() for SIGTERM/INT failed: %s", 172 strerror(err)); 173 return (err); 174 } 175 176 if ((err = dlmgmt_linktable_init()) != 0) 177 return (err); 178 179 if ((err = dlmgmt_db_init()) != 0 || (err = dlmgmt_door_init()) != 0) 180 dlmgmt_linktable_fini(); 181 182 return (err); 183 } 184 185 static void 186 dlmgmt_fini() 187 { 188 dlmgmt_door_fini(); 189 dlmgmt_linktable_fini(); 190 } 191 192 /* 193 * This is called by the child process to inform the parent process to 194 * exit with the given return value. 195 */ 196 static void 197 dlmgmt_inform_parent_exit(int rv) 198 { 199 if (debug) 200 return; 201 202 if (write(pfds[1], &rv, sizeof (int)) != sizeof (int)) { 203 dlmgmt_log(LOG_WARNING, 204 "dlmgmt_inform_parent_exit() failed: %s", strerror(errno)); 205 (void) close(pfds[1]); 206 exit(EXIT_FAILURE); 207 } 208 (void) close(pfds[1]); 209 } 210 211 /*ARGSUSED*/ 212 static void 213 dlmgmtd_exit(int signo) 214 { 215 (void) close(pfds[1]); 216 dlmgmt_fini(); 217 dlmgmt_fini_privileges(); 218 exit(EXIT_FAILURE); 219 } 220 221 static void 222 usage(void) 223 { 224 (void) fprintf(stderr, "Usage: %s [-d]\n", progname); 225 exit(EXIT_FAILURE); 226 } 227 228 /* 229 * Set the uid of this daemon to the "dladm" user. Finish the following 230 * operations before setuid() because they need root privileges: 231 * 232 * - create the /etc/svc/volatile/dladm directory; 233 * - change its uid/gid to "dladm"/"sys"; 234 * - open the dld control node 235 */ 236 static int 237 dlmgmt_init_privileges() 238 { 239 struct stat statbuf; 240 241 /* 242 * Create the DLMGMT_TMPFS_DIR directory. 243 */ 244 if (stat(DLMGMT_TMPFS_DIR, &statbuf) < 0) { 245 if (mkdir(DLMGMT_TMPFS_DIR, (mode_t)0755) < 0) 246 return (errno); 247 } else { 248 if ((statbuf.st_mode & S_IFMT) != S_IFDIR) 249 return (ENOTDIR); 250 } 251 252 if ((chmod(DLMGMT_TMPFS_DIR, 0755) < 0) || 253 (chown(DLMGMT_TMPFS_DIR, UID_DLADM, GID_SYS) < 0)) { 254 return (EPERM); 255 } 256 257 /* 258 * When dlmgmtd is started at boot, "ALL" privilege is required 259 * to open the dld control node. The door isn't created yet. 260 */ 261 if (dladm_open(&dld_handle) != DLADM_STATUS_OK) { 262 dlmgmt_log(LOG_ERR, "dladm_open() failed"); 263 return (EPERM); 264 } 265 266 /* 267 * We need PRIV_SYS_DL_CONFIG for the DLDIOC_DOORSERVER ioctl, 268 * and PRIV_SYS_CONFIG to post sysevents. 269 */ 270 if (__init_daemon_priv(PU_RESETGROUPS|PU_CLEARLIMITSET, UID_DLADM, 271 GID_SYS, PRIV_SYS_DL_CONFIG, PRIV_SYS_CONFIG, NULL) == -1) { 272 dladm_close(dld_handle); 273 dld_handle = NULL; 274 return (EPERM); 275 } 276 277 278 return (0); 279 } 280 281 static void 282 dlmgmt_fini_privileges() 283 { 284 if (dld_handle != NULL) { 285 dladm_close(dld_handle); 286 dld_handle = NULL; 287 } 288 } 289 290 /* 291 * Keep the pfds fd open, close other fds. 292 */ 293 /*ARGSUSED*/ 294 static int 295 closefunc(void *arg, int fd) 296 { 297 if (fd != pfds[1]) 298 (void) close(fd); 299 return (0); 300 } 301 302 static boolean_t 303 dlmgmt_daemonize(void) 304 { 305 pid_t pid; 306 int rv; 307 308 if (pipe(pfds) < 0) { 309 (void) fprintf(stderr, "%s: pipe() failed: %s\n", 310 progname, strerror(errno)); 311 exit(EXIT_FAILURE); 312 } 313 314 if ((pid = fork()) == -1) { 315 (void) fprintf(stderr, "%s: fork() failed: %s\n", 316 progname, strerror(errno)); 317 exit(EXIT_FAILURE); 318 } else if (pid > 0) { /* Parent */ 319 (void) close(pfds[1]); 320 321 /* 322 * Read the child process's return value from the pfds. 323 * If the child process exits unexpected, read() returns -1. 324 */ 325 if (read(pfds[0], &rv, sizeof (int)) != sizeof (int)) { 326 (void) kill(pid, SIGKILL); 327 rv = EXIT_FAILURE; 328 } 329 330 (void) close(pfds[0]); 331 exit(rv); 332 } 333 334 /* Child */ 335 (void) close(pfds[0]); 336 (void) setsid(); 337 338 /* 339 * Close all files except pfds[1]. 340 */ 341 (void) fdwalk(closefunc, NULL); 342 (void) chdir("/"); 343 openlog(progname, LOG_PID, LOG_DAEMON); 344 return (B_TRUE); 345 } 346 347 int 348 main(int argc, char *argv[]) 349 { 350 int opt; 351 352 progname = strrchr(argv[0], '/'); 353 if (progname != NULL) 354 progname++; 355 else 356 progname = argv[0]; 357 358 /* 359 * Process options. 360 */ 361 while ((opt = getopt(argc, argv, "d")) != EOF) { 362 switch (opt) { 363 case 'd': 364 debug = B_TRUE; 365 break; 366 default: 367 usage(); 368 } 369 } 370 371 if (!debug && !dlmgmt_daemonize()) 372 return (EXIT_FAILURE); 373 374 if ((errno = dlmgmt_init_privileges()) != 0) { 375 dlmgmt_log(LOG_ERR, "dlmgmt_init_privileges() failed: %s", 376 strerror(errno)); 377 goto child_out; 378 } 379 380 if (dlmgmt_init() != 0) { 381 dlmgmt_fini_privileges(); 382 goto child_out; 383 } 384 385 /* 386 * Inform the parent process that it can successfully exit. 387 */ 388 dlmgmt_inform_parent_exit(EXIT_SUCCESS); 389 390 for (;;) 391 (void) pause(); 392 393 child_out: 394 /* return from main() forcibly exits an MT process */ 395 dlmgmt_inform_parent_exit(EXIT_FAILURE); 396 return (EXIT_FAILURE); 397 } 398