1 /* 2 * This file is part of the ZFS Event Daemon (ZED). 3 * 4 * Developed at Lawrence Livermore National Laboratory (LLNL-CODE-403049). 5 * Copyright (C) 2013-2014 Lawrence Livermore National Security, LLC. 6 * Refer to the OpenZFS git commit log for authoritative copyright attribution. 7 * 8 * The contents of this file are subject to the terms of the 9 * Common Development and Distribution License Version 1.0 (CDDL-1.0). 10 * You can obtain a copy of the license from the top-level file 11 * "OPENSOLARIS.LICENSE" or at <http://opensource.org/licenses/CDDL-1.0>. 12 * You may not use this file except in compliance with the license. 13 */ 14 15 #include <assert.h> 16 #include <ctype.h> 17 #include <errno.h> 18 #include <fcntl.h> 19 #include <stdlib.h> 20 #include <string.h> 21 #include <stddef.h> 22 #include <sys/avl.h> 23 #include <sys/resource.h> 24 #include <sys/stat.h> 25 #include <sys/wait.h> 26 #include <time.h> 27 #include <unistd.h> 28 #include <pthread.h> 29 #include <signal.h> 30 31 #include "zed_exec.h" 32 #include "zed_log.h" 33 #include "zed_strings.h" 34 35 #define ZEVENT_FILENO 3 36 37 struct launched_process_node { 38 avl_node_t node; 39 pid_t pid; 40 uint64_t eid; 41 char *name; 42 }; 43 44 static int 45 _launched_process_node_compare(const void *x1, const void *x2) 46 { 47 pid_t p1; 48 pid_t p2; 49 50 assert(x1 != NULL); 51 assert(x2 != NULL); 52 53 p1 = ((const struct launched_process_node *) x1)->pid; 54 p2 = ((const struct launched_process_node *) x2)->pid; 55 56 if (p1 < p2) 57 return (-1); 58 else if (p1 == p2) 59 return (0); 60 else 61 return (1); 62 } 63 64 static pthread_t _reap_children_tid = (pthread_t)-1; 65 static volatile boolean_t _reap_children_stop; 66 static avl_tree_t _launched_processes; 67 static pthread_mutex_t _launched_processes_lock = PTHREAD_MUTEX_INITIALIZER; 68 static int16_t _launched_processes_limit; 69 70 /* 71 * Create an environment string array for passing to execve() using the 72 * NAME=VALUE strings in container [zsp]. 73 * Return a newly-allocated environment, or NULL on error. 74 */ 75 static char ** 76 _zed_exec_create_env(zed_strings_t *zsp) 77 { 78 int num_ptrs; 79 int buflen; 80 char *buf; 81 char **pp; 82 char *p; 83 const char *q; 84 int i; 85 int len; 86 87 num_ptrs = zed_strings_count(zsp) + 1; 88 buflen = num_ptrs * sizeof (char *); 89 for (q = zed_strings_first(zsp); q; q = zed_strings_next(zsp)) 90 buflen += strlen(q) + 1; 91 92 buf = calloc(1, buflen); 93 if (!buf) 94 return (NULL); 95 96 pp = (char **)buf; 97 p = buf + (num_ptrs * sizeof (char *)); 98 i = 0; 99 for (q = zed_strings_first(zsp); q; q = zed_strings_next(zsp)) { 100 pp[i] = p; 101 len = strlen(q) + 1; 102 memcpy(p, q, len); 103 p += len; 104 i++; 105 } 106 pp[i] = NULL; 107 assert(buf + buflen == p); 108 return ((char **)buf); 109 } 110 111 /* 112 * Fork a child process to handle event [eid]. The program [prog] 113 * in directory [dir] is executed with the environment [env]. 114 * 115 * The file descriptor [zfd] is the zevent_fd used to track the 116 * current cursor location within the zevent nvlist. 117 */ 118 static void 119 _zed_exec_fork_child(uint64_t eid, const char *dir, const char *prog, 120 char *env[], int zfd, boolean_t in_foreground) 121 { 122 char path[PATH_MAX]; 123 int n; 124 pid_t pid; 125 int fd; 126 struct launched_process_node *node; 127 sigset_t mask; 128 struct timespec launch_timeout = 129 { .tv_sec = 0, .tv_nsec = 200 * 1000 * 1000, }; 130 131 assert(dir != NULL); 132 assert(prog != NULL); 133 assert(env != NULL); 134 assert(zfd >= 0); 135 136 while (__atomic_load_n(&_launched_processes_limit, 137 __ATOMIC_SEQ_CST) <= 0) 138 (void) nanosleep(&launch_timeout, NULL); 139 140 n = snprintf(path, sizeof (path), "%s/%s", dir, prog); 141 if ((n < 0) || (n >= sizeof (path))) { 142 zed_log_msg(LOG_WARNING, 143 "Failed to fork \"%s\" for eid=%llu: %s", 144 prog, eid, strerror(ENAMETOOLONG)); 145 return; 146 } 147 (void) pthread_mutex_lock(&_launched_processes_lock); 148 pid = fork(); 149 if (pid < 0) { 150 (void) pthread_mutex_unlock(&_launched_processes_lock); 151 zed_log_msg(LOG_WARNING, 152 "Failed to fork \"%s\" for eid=%llu: %s", 153 prog, eid, strerror(errno)); 154 return; 155 } else if (pid == 0) { 156 (void) sigemptyset(&mask); 157 (void) sigprocmask(SIG_SETMASK, &mask, NULL); 158 159 (void) umask(022); 160 if (in_foreground && /* we're already devnulled if daemonised */ 161 (fd = open("/dev/null", O_RDWR | O_CLOEXEC)) != -1) { 162 (void) dup2(fd, STDIN_FILENO); 163 (void) dup2(fd, STDOUT_FILENO); 164 (void) dup2(fd, STDERR_FILENO); 165 } 166 (void) dup2(zfd, ZEVENT_FILENO); 167 execle(path, prog, NULL, env); 168 _exit(127); 169 } 170 171 /* parent process */ 172 173 node = calloc(1, sizeof (*node)); 174 if (node) { 175 node->pid = pid; 176 node->eid = eid; 177 node->name = strdup(prog); 178 179 avl_add(&_launched_processes, node); 180 } 181 (void) pthread_mutex_unlock(&_launched_processes_lock); 182 183 __atomic_sub_fetch(&_launched_processes_limit, 1, __ATOMIC_SEQ_CST); 184 zed_log_msg(LOG_INFO, "Invoking \"%s\" eid=%llu pid=%d", 185 prog, eid, pid); 186 } 187 188 static void 189 _nop(int sig) 190 { 191 (void) sig; 192 } 193 194 static void * 195 _reap_children(void *arg) 196 { 197 (void) arg; 198 struct launched_process_node node, *pnode; 199 pid_t pid; 200 int status; 201 struct rusage usage; 202 struct sigaction sa = {}; 203 204 (void) sigfillset(&sa.sa_mask); 205 (void) sigdelset(&sa.sa_mask, SIGCHLD); 206 (void) pthread_sigmask(SIG_SETMASK, &sa.sa_mask, NULL); 207 208 (void) sigemptyset(&sa.sa_mask); 209 sa.sa_handler = _nop; 210 sa.sa_flags = SA_NOCLDSTOP; 211 (void) sigaction(SIGCHLD, &sa, NULL); 212 213 for (_reap_children_stop = B_FALSE; !_reap_children_stop; ) { 214 (void) pthread_mutex_lock(&_launched_processes_lock); 215 pid = wait4(0, &status, WNOHANG, &usage); 216 217 if (pid == 0 || pid == (pid_t)-1) { 218 (void) pthread_mutex_unlock(&_launched_processes_lock); 219 if (pid == 0 || errno == ECHILD) 220 pause(); 221 else if (errno != EINTR) 222 zed_log_msg(LOG_WARNING, 223 "Failed to wait for children: %s", 224 strerror(errno)); 225 } else { 226 memset(&node, 0, sizeof (node)); 227 node.pid = pid; 228 pnode = avl_find(&_launched_processes, &node, NULL); 229 if (pnode) { 230 memcpy(&node, pnode, sizeof (node)); 231 232 avl_remove(&_launched_processes, pnode); 233 free(pnode); 234 } 235 (void) pthread_mutex_unlock(&_launched_processes_lock); 236 __atomic_add_fetch(&_launched_processes_limit, 1, 237 __ATOMIC_SEQ_CST); 238 239 usage.ru_utime.tv_sec += usage.ru_stime.tv_sec; 240 usage.ru_utime.tv_usec += usage.ru_stime.tv_usec; 241 usage.ru_utime.tv_sec += 242 usage.ru_utime.tv_usec / (1000 * 1000); 243 usage.ru_utime.tv_usec %= 1000 * 1000; 244 245 if (WIFEXITED(status)) { 246 zed_log_msg(LOG_INFO, 247 "Finished \"%s\" eid=%llu pid=%d " 248 "time=%llu.%06us exit=%d", 249 node.name, node.eid, pid, 250 (unsigned long long) usage.ru_utime.tv_sec, 251 (unsigned int) usage.ru_utime.tv_usec, 252 WEXITSTATUS(status)); 253 } else if (WIFSIGNALED(status)) { 254 zed_log_msg(LOG_INFO, 255 "Finished \"%s\" eid=%llu pid=%d " 256 "time=%llu.%06us sig=%d/%s", 257 node.name, node.eid, pid, 258 (unsigned long long) usage.ru_utime.tv_sec, 259 (unsigned int) usage.ru_utime.tv_usec, 260 WTERMSIG(status), 261 strsignal(WTERMSIG(status))); 262 } else { 263 zed_log_msg(LOG_INFO, 264 "Finished \"%s\" eid=%llu pid=%d " 265 "time=%llu.%06us status=0x%X", 266 node.name, node.eid, 267 (unsigned long long) usage.ru_utime.tv_sec, 268 (unsigned int) usage.ru_utime.tv_usec, 269 (unsigned int) status); 270 } 271 272 free(node.name); 273 } 274 } 275 276 return (NULL); 277 } 278 279 void 280 zed_exec_fini(void) 281 { 282 struct launched_process_node *node; 283 void *ck = NULL; 284 285 if (_reap_children_tid == (pthread_t)-1) 286 return; 287 288 _reap_children_stop = B_TRUE; 289 (void) pthread_kill(_reap_children_tid, SIGCHLD); 290 (void) pthread_join(_reap_children_tid, NULL); 291 292 while ((node = avl_destroy_nodes(&_launched_processes, &ck)) != NULL) { 293 free(node->name); 294 free(node); 295 } 296 avl_destroy(&_launched_processes); 297 298 (void) pthread_mutex_destroy(&_launched_processes_lock); 299 (void) pthread_mutex_init(&_launched_processes_lock, NULL); 300 301 _reap_children_tid = (pthread_t)-1; 302 } 303 304 /* 305 * Process the event [eid] by synchronously invoking all zedlets with a 306 * matching class prefix. 307 * 308 * Each executable in [zcp->zedlets] from the directory [zcp->zedlet_dir] 309 * is matched against the event's [class], [subclass], and the "all" class 310 * (which matches all events). 311 * Every zedlet with a matching class prefix is invoked. 312 * The NAME=VALUE strings in [envs] will be passed to the zedlet as 313 * environment variables. 314 * 315 * The file descriptor [zcp->zevent_fd] is the zevent_fd used to track the 316 * current cursor location within the zevent nvlist. 317 * 318 * Return 0 on success, -1 on error. 319 */ 320 int 321 zed_exec_process(uint64_t eid, const char *class, const char *subclass, 322 struct zed_conf *zcp, zed_strings_t *envs) 323 { 324 const char *class_strings[4]; 325 const char *allclass = "all"; 326 const char **csp; 327 const char *z; 328 char **e; 329 int n; 330 331 if (!zcp->zedlet_dir || !zcp->zedlets || !envs || zcp->zevent_fd < 0) 332 return (-1); 333 334 if (_reap_children_tid == (pthread_t)-1) { 335 _launched_processes_limit = zcp->max_jobs; 336 337 if (pthread_create(&_reap_children_tid, NULL, 338 _reap_children, NULL) != 0) 339 return (-1); 340 pthread_setname_np(_reap_children_tid, "reap ZEDLETs"); 341 342 avl_create(&_launched_processes, _launched_process_node_compare, 343 sizeof (struct launched_process_node), 344 offsetof(struct launched_process_node, node)); 345 } 346 347 csp = class_strings; 348 349 if (class) 350 *csp++ = class; 351 352 if (subclass) 353 *csp++ = subclass; 354 355 if (allclass) 356 *csp++ = allclass; 357 358 *csp = NULL; 359 360 e = _zed_exec_create_env(envs); 361 362 for (z = zed_strings_first(zcp->zedlets); z; 363 z = zed_strings_next(zcp->zedlets)) { 364 for (csp = class_strings; *csp; csp++) { 365 n = strlen(*csp); 366 if ((strncmp(z, *csp, n) == 0) && !isalpha(z[n])) 367 _zed_exec_fork_child(eid, zcp->zedlet_dir, 368 z, e, zcp->zevent_fd, zcp->do_foreground); 369 } 370 } 371 free(e); 372 return (0); 373 } 374