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 2008 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/param.h> 52 #include <sys/stat.h> 53 #include <unistd.h> 54 #include <libdladm_impl.h> 55 #include <libdlmgmt.h> 56 #include "dlmgmt_impl.h" 57 58 const char *progname; 59 boolean_t debug; 60 static int pfds[2]; 61 /* 62 * This file descriptor to DLMGMT_DOOR cannot be in the libdladm 63 * handle because the door isn't created when the handle is created. 64 */ 65 static int dlmgmt_door_fd = -1; 66 67 /* 68 * This libdladm handle is global so that dlmgmt_upcall_linkprop_init() 69 * can pass to libdladm. The handle is opened during dlmgmt_init_privileges() 70 * with "ALL" privileges. It is not able to open DLMGMT_DOOR at that time as 71 * it hasn't been created yet. This door in the handle is opened in the first 72 * call to dladm_door_fd(). 73 */ 74 dladm_handle_t dld_handle = NULL; 75 76 static void dlmgmtd_exit(int); 77 static int dlmgmt_init(); 78 static void dlmgmt_fini(); 79 static int dlmgmt_init_privileges(); 80 static void dlmgmt_fini_privileges(); 81 82 static int 83 dlmgmt_set_doorfd(boolean_t start) 84 { 85 dld_ioc_door_t did; 86 int err = 0; 87 88 assert(dld_handle != NULL); 89 90 did.did_start_door = start; 91 92 if (ioctl(dladm_dld_fd(dld_handle), DLDIOC_DOORSERVER, &did) == -1) 93 err = errno; 94 95 return (err); 96 } 97 98 static int 99 dlmgmt_door_init() 100 { 101 int fd; 102 int err; 103 104 /* 105 * Create the door file for dlmgmtd. 106 */ 107 if ((fd = open(DLMGMT_DOOR, O_CREAT|O_RDONLY, 0644)) == -1) { 108 err = errno; 109 dlmgmt_log(LOG_ERR, "open(%s) failed: %s", 110 DLMGMT_DOOR, strerror(err)); 111 return (err); 112 } 113 (void) close(fd); 114 115 if ((dlmgmt_door_fd = door_create(dlmgmt_handler, NULL, 116 DOOR_REFUSE_DESC | DOOR_NO_CANCEL)) == -1) { 117 err = errno; 118 dlmgmt_log(LOG_ERR, "door_create() failed: %s", 119 strerror(err)); 120 return (err); 121 } 122 if (fattach(dlmgmt_door_fd, DLMGMT_DOOR) != 0) { 123 err = errno; 124 dlmgmt_log(LOG_ERR, "fattach(%s) failed: %s", 125 DLMGMT_DOOR, strerror(err)); 126 goto fail; 127 } 128 if ((err = dlmgmt_set_doorfd(B_TRUE)) != 0) { 129 dlmgmt_log(LOG_ERR, "cannot set kernel doorfd: %s", 130 strerror(err)); 131 (void) fdetach(DLMGMT_DOOR); 132 goto fail; 133 } 134 135 return (0); 136 fail: 137 (void) door_revoke(dlmgmt_door_fd); 138 dlmgmt_door_fd = -1; 139 return (err); 140 } 141 142 static void 143 dlmgmt_door_fini() 144 { 145 if (dlmgmt_door_fd == -1) 146 return; 147 148 if (door_revoke(dlmgmt_door_fd) == -1) { 149 dlmgmt_log(LOG_WARNING, "door_revoke(%s) failed: %s", 150 DLMGMT_DOOR, strerror(errno)); 151 } 152 153 (void) fdetach(DLMGMT_DOOR); 154 (void) dlmgmt_set_doorfd(B_FALSE); 155 } 156 157 static int 158 dlmgmt_init() 159 { 160 int err; 161 162 if (signal(SIGTERM, dlmgmtd_exit) == SIG_ERR || 163 signal(SIGINT, dlmgmtd_exit) == SIG_ERR) { 164 err = errno; 165 dlmgmt_log(LOG_ERR, "signal() for SIGTERM/INT failed: %s", 166 strerror(err)); 167 return (err); 168 } 169 170 if ((err = dlmgmt_linktable_init()) != 0) 171 return (err); 172 173 if ((err = dlmgmt_db_init()) != 0 || (err = dlmgmt_door_init()) != 0) 174 dlmgmt_linktable_fini(); 175 176 return (err); 177 } 178 179 static void 180 dlmgmt_fini() 181 { 182 dlmgmt_door_fini(); 183 dlmgmt_linktable_fini(); 184 } 185 186 /* 187 * This is called by the child process to inform the parent process to 188 * exit with the given return value. 189 */ 190 static void 191 dlmgmt_inform_parent_exit(int rv) 192 { 193 if (debug) 194 return; 195 196 if (write(pfds[1], &rv, sizeof (int)) != sizeof (int)) { 197 dlmgmt_log(LOG_WARNING, 198 "dlmgmt_inform_parent_exit() failed: %s", strerror(errno)); 199 (void) close(pfds[1]); 200 exit(EXIT_FAILURE); 201 } 202 (void) close(pfds[1]); 203 } 204 205 /*ARGSUSED*/ 206 static void 207 dlmgmtd_exit(int signo) 208 { 209 (void) close(pfds[1]); 210 dlmgmt_fini(); 211 dlmgmt_fini_privileges(); 212 exit(EXIT_FAILURE); 213 } 214 215 static void 216 usage(void) 217 { 218 (void) fprintf(stderr, "Usage: %s [-d]\n", progname); 219 exit(EXIT_FAILURE); 220 } 221 222 /* 223 * Set the uid of this daemon to the "dladm" user. Finish the following 224 * operations before setuid() because they need root privileges: 225 * 226 * - create the /etc/svc/volatile/dladm directory; 227 * - change its uid/gid to "dladm"/"sys"; 228 * - open the dld control node 229 */ 230 static int 231 dlmgmt_init_privileges() 232 { 233 struct stat statbuf; 234 235 /* 236 * Create the DLMGMT_TMPFS_DIR directory. 237 */ 238 if (stat(DLMGMT_TMPFS_DIR, &statbuf) < 0) { 239 if (mkdir(DLMGMT_TMPFS_DIR, (mode_t)0755) < 0) 240 return (errno); 241 } else { 242 if ((statbuf.st_mode & S_IFMT) != S_IFDIR) 243 return (ENOTDIR); 244 } 245 246 if ((chmod(DLMGMT_TMPFS_DIR, 0755) < 0) || 247 (chown(DLMGMT_TMPFS_DIR, UID_DLADM, GID_SYS) < 0)) { 248 return (EPERM); 249 } 250 251 /* 252 * When dlmgmtd is started at boot, "ALL" privilege is required 253 * to open the dld control node. The door isn't created yet. 254 */ 255 if (dladm_open(&dld_handle) != DLADM_STATUS_OK) { 256 dlmgmt_log(LOG_ERR, "dladm_open() failed"); 257 return (EPERM); 258 } 259 260 /* 261 * We need PRIV_SYS_DL_CONFIG for the DLDIOC_DOORSERVER ioctl, 262 * and PRIV_SYS_CONFIG to post sysevents. 263 */ 264 if (__init_daemon_priv(PU_RESETGROUPS|PU_CLEARLIMITSET, UID_DLADM, 265 GID_SYS, PRIV_SYS_DL_CONFIG, PRIV_SYS_CONFIG, NULL) == -1) { 266 dladm_close(dld_handle); 267 dld_handle = NULL; 268 return (EPERM); 269 } 270 271 272 return (0); 273 } 274 275 static void 276 dlmgmt_fini_privileges() 277 { 278 if (dld_handle != NULL) { 279 dladm_close(dld_handle); 280 dld_handle = NULL; 281 } 282 } 283 284 /* 285 * Keep the pfds fd open, close other fds. 286 */ 287 /*ARGSUSED*/ 288 static int 289 closefunc(void *arg, int fd) 290 { 291 if (fd != pfds[1]) 292 (void) close(fd); 293 return (0); 294 } 295 296 static boolean_t 297 dlmgmt_daemonize(void) 298 { 299 pid_t pid; 300 int rv; 301 302 if (pipe(pfds) < 0) { 303 (void) fprintf(stderr, "%s: pipe() failed: %s\n", 304 progname, strerror(errno)); 305 exit(EXIT_FAILURE); 306 } 307 308 if ((pid = fork()) == -1) { 309 (void) fprintf(stderr, "%s: fork() failed: %s\n", 310 progname, strerror(errno)); 311 exit(EXIT_FAILURE); 312 } else if (pid > 0) { /* Parent */ 313 (void) close(pfds[1]); 314 315 /* 316 * Read the child process's return value from the pfds. 317 * If the child process exits unexpected, read() returns -1. 318 */ 319 if (read(pfds[0], &rv, sizeof (int)) != sizeof (int)) { 320 (void) kill(pid, SIGKILL); 321 rv = EXIT_FAILURE; 322 } 323 324 (void) close(pfds[0]); 325 exit(rv); 326 } 327 328 /* Child */ 329 (void) close(pfds[0]); 330 (void) setsid(); 331 332 /* 333 * Close all files except pfds[1]. 334 */ 335 (void) fdwalk(closefunc, NULL); 336 (void) chdir("/"); 337 openlog(progname, LOG_PID, LOG_DAEMON); 338 return (B_TRUE); 339 } 340 341 int 342 main(int argc, char *argv[]) 343 { 344 int opt; 345 346 progname = strrchr(argv[0], '/'); 347 if (progname != NULL) 348 progname++; 349 else 350 progname = argv[0]; 351 352 /* 353 * Process options. 354 */ 355 while ((opt = getopt(argc, argv, "d")) != EOF) { 356 switch (opt) { 357 case 'd': 358 debug = B_TRUE; 359 break; 360 default: 361 usage(); 362 } 363 } 364 365 if (!debug && !dlmgmt_daemonize()) 366 return (EXIT_FAILURE); 367 368 if ((errno = dlmgmt_init_privileges()) != 0) { 369 dlmgmt_log(LOG_ERR, "dlmgmt_init_privileges() failed: %s", 370 strerror(errno)); 371 goto child_out; 372 } 373 374 if (dlmgmt_init() != 0) { 375 dlmgmt_fini_privileges(); 376 goto child_out; 377 } 378 379 /* 380 * Inform the parent process that it can successfully exit. 381 */ 382 dlmgmt_inform_parent_exit(EXIT_SUCCESS); 383 384 for (;;) 385 (void) pause(); 386 387 child_out: 388 /* return from main() forcibly exits an MT process */ 389 dlmgmt_inform_parent_exit(EXIT_FAILURE); 390 return (EXIT_FAILURE); 391 } 392