1 /* Copyright 1988,1990,1993,1994 by Paul Vixie 2 * All rights reserved 3 * 4 * Distribute freely, except: don't remove my name from the source or 5 * documentation (don't take credit for my work), mark your changes (don't 6 * get me blamed for your possible bugs), don't alter or remove this 7 * notice. May be sold if buildable source is provided to buyer. No 8 * warrantee of any kind, express or implied, is included with this 9 * software; use at your own risk, responsibility for damages (if any) to 10 * anyone resulting from the use of this software rests entirely with the 11 * user. 12 * 13 * Send bug reports, bug fixes, enhancements, requests, flames, etc., and 14 * I'll try to keep a version up to date. I can be reached as follows: 15 * Paul Vixie <paul@vix.com> uunet!decwrl!vixie!paul 16 */ 17 18 #if !defined(lint) && !defined(LINT) 19 static const char rcsid[] = 20 "$FreeBSD$"; 21 #endif 22 23 /* vix 26jan87 [RCS has the log] 24 */ 25 26 27 #include "cron.h" 28 #include <fcntl.h> 29 #include <sys/stat.h> 30 #include <sys/file.h> 31 32 33 #define TMAX(a,b) ((a)>(b)?(a):(b)) 34 35 36 static void process_crontab(char *, char *, char *, 37 struct stat *, 38 cron_db *, cron_db *); 39 40 41 void 42 load_database(old_db) 43 cron_db *old_db; 44 { 45 DIR *dir; 46 struct stat statbuf; 47 struct stat syscron_stat, st; 48 time_t maxmtime; 49 DIR_T *dp; 50 cron_db new_db; 51 user *u, *nu; 52 struct { 53 const char *name; 54 struct stat st; 55 } syscrontabs [] = { 56 { SYSCRONTABS }, 57 { LOCALSYSCRONTABS } 58 }; 59 int i, ret; 60 61 Debug(DLOAD, ("[%d] load_database()\n", getpid())) 62 63 /* before we start loading any data, do a stat on SPOOL_DIR 64 * so that if anything changes as of this moment (i.e., before we've 65 * cached any of the database), we'll see the changes next time. 66 */ 67 if (stat(SPOOL_DIR, &statbuf) < OK) { 68 log_it("CRON", getpid(), "STAT FAILED", SPOOL_DIR); 69 (void) exit(ERROR_EXIT); 70 } 71 72 /* track system crontab file 73 */ 74 if (stat(SYSCRONTAB, &syscron_stat) < OK) 75 syscron_stat.st_mtime = 0; 76 77 maxmtime = TMAX(statbuf.st_mtime, syscron_stat.st_mtime); 78 79 for (i = 0; i < nitems(syscrontabs); i++) { 80 if (stat(syscrontabs[i].name, &syscrontabs[i].st) != -1) { 81 maxmtime = TMAX(syscrontabs[i].st.st_mtime, maxmtime); 82 /* Traverse into directory */ 83 if (!(dir = opendir(syscrontabs[i].name))) 84 continue; 85 while (NULL != (dp = readdir(dir))) { 86 if (dp->d_name[0] == '.') 87 continue; 88 ret = fstatat(dirfd(dir), dp->d_name, &st, 0); 89 if (ret != 0 || !S_ISREG(st.st_mode)) 90 continue; 91 maxmtime = TMAX(st.st_mtime, maxmtime); 92 } 93 closedir(dir); 94 } else { 95 syscrontabs[i].st.st_mtime = 0; 96 } 97 } 98 99 /* if spooldir's mtime has not changed, we don't need to fiddle with 100 * the database. 101 * 102 * Note that old_db->mtime is initialized to 0 in main(), and 103 * so is guaranteed to be different than the stat() mtime the first 104 * time this function is called. 105 */ 106 if (old_db->mtime == maxmtime) { 107 Debug(DLOAD, ("[%d] spool dir mtime unch, no load needed.\n", 108 getpid())) 109 return; 110 } 111 112 /* something's different. make a new database, moving unchanged 113 * elements from the old database, reloading elements that have 114 * actually changed. Whatever is left in the old database when 115 * we're done is chaff -- crontabs that disappeared. 116 */ 117 new_db.mtime = maxmtime; 118 new_db.head = new_db.tail = NULL; 119 120 if (syscron_stat.st_mtime) { 121 process_crontab("root", SYS_NAME, 122 SYSCRONTAB, &syscron_stat, 123 &new_db, old_db); 124 } 125 126 for (i = 0; i < nitems(syscrontabs); i++) { 127 char tabname[MAXPATHLEN]; 128 if (syscrontabs[i].st.st_mtime == 0) 129 continue; 130 if (!(dir = opendir(syscrontabs[i].name))) { 131 log_it("CRON", getpid(), "OPENDIR FAILED", 132 syscrontabs[i].name); 133 (void) exit(ERROR_EXIT); 134 } 135 136 while (NULL != (dp = readdir(dir))) { 137 if (dp->d_name[0] == '.') 138 continue; 139 if (fstatat(dirfd(dir), dp->d_name, &st, 0) == 0 && 140 !S_ISREG(st.st_mode)) 141 continue; 142 snprintf(tabname, sizeof(tabname), "%s/%s", 143 syscrontabs[i].name, dp->d_name); 144 process_crontab("root", SYS_NAME, tabname, 145 &syscrontabs[i].st, &new_db, old_db); 146 } 147 closedir(dir); 148 } 149 150 /* we used to keep this dir open all the time, for the sake of 151 * efficiency. however, we need to close it in every fork, and 152 * we fork a lot more often than the mtime of the dir changes. 153 */ 154 if (!(dir = opendir(SPOOL_DIR))) { 155 log_it("CRON", getpid(), "OPENDIR FAILED", SPOOL_DIR); 156 (void) exit(ERROR_EXIT); 157 } 158 159 while (NULL != (dp = readdir(dir))) { 160 char fname[MAXNAMLEN+1], 161 tabname[MAXNAMLEN+1]; 162 163 /* avoid file names beginning with ".". this is good 164 * because we would otherwise waste two guaranteed calls 165 * to getpwnam() for . and .., and also because user names 166 * starting with a period are just too nasty to consider. 167 */ 168 if (dp->d_name[0] == '.') 169 continue; 170 171 (void) strncpy(fname, dp->d_name, sizeof(fname)); 172 fname[sizeof(fname)-1] = '\0'; 173 (void) snprintf(tabname, sizeof tabname, CRON_TAB(fname)); 174 175 process_crontab(fname, fname, tabname, 176 &statbuf, &new_db, old_db); 177 } 178 closedir(dir); 179 180 /* if we don't do this, then when our children eventually call 181 * getpwnam() in do_command.c's child_process to verify MAILTO=, 182 * they will screw us up (and v-v). 183 */ 184 endpwent(); 185 186 /* whatever's left in the old database is now junk. 187 */ 188 Debug(DLOAD, ("unlinking old database:\n")) 189 for (u = old_db->head; u != NULL; u = nu) { 190 Debug(DLOAD, ("\t%s\n", u->name)) 191 nu = u->next; 192 unlink_user(old_db, u); 193 free_user(u); 194 } 195 196 /* overwrite the database control block with the new one. 197 */ 198 *old_db = new_db; 199 Debug(DLOAD, ("load_database is done\n")) 200 } 201 202 203 void 204 link_user(db, u) 205 cron_db *db; 206 user *u; 207 { 208 if (db->head == NULL) 209 db->head = u; 210 if (db->tail) 211 db->tail->next = u; 212 u->prev = db->tail; 213 u->next = NULL; 214 db->tail = u; 215 } 216 217 218 void 219 unlink_user(db, u) 220 cron_db *db; 221 user *u; 222 { 223 if (u->prev == NULL) 224 db->head = u->next; 225 else 226 u->prev->next = u->next; 227 228 if (u->next == NULL) 229 db->tail = u->prev; 230 else 231 u->next->prev = u->prev; 232 } 233 234 235 user * 236 find_user(db, name) 237 cron_db *db; 238 char *name; 239 { 240 char *env_get(); 241 user *u; 242 243 for (u = db->head; u != NULL; u = u->next) 244 if (!strcmp(u->name, name)) 245 break; 246 return u; 247 } 248 249 250 static void 251 process_crontab(uname, fname, tabname, statbuf, new_db, old_db) 252 char *uname; 253 char *fname; 254 char *tabname; 255 struct stat *statbuf; 256 cron_db *new_db; 257 cron_db *old_db; 258 { 259 struct passwd *pw = NULL; 260 int crontab_fd = OK - 1; 261 user *u; 262 263 if (strcmp(fname, SYS_NAME) && !(pw = getpwnam(uname))) { 264 /* file doesn't have a user in passwd file. 265 */ 266 log_it(fname, getpid(), "ORPHAN", "no passwd entry"); 267 goto next_crontab; 268 } 269 270 if ((crontab_fd = open(tabname, O_RDONLY, 0)) < OK) { 271 /* crontab not accessible? 272 */ 273 log_it(fname, getpid(), "CAN'T OPEN", tabname); 274 goto next_crontab; 275 } 276 277 if (fstat(crontab_fd, statbuf) < OK) { 278 log_it(fname, getpid(), "FSTAT FAILED", tabname); 279 goto next_crontab; 280 } 281 282 Debug(DLOAD, ("\t%s:", fname)) 283 u = find_user(old_db, fname); 284 if (u != NULL) { 285 /* if crontab has not changed since we last read it 286 * in, then we can just use our existing entry. 287 */ 288 if (u->mtime == statbuf->st_mtime) { 289 Debug(DLOAD, (" [no change, using old data]")) 290 unlink_user(old_db, u); 291 link_user(new_db, u); 292 goto next_crontab; 293 } 294 295 /* before we fall through to the code that will reload 296 * the user, let's deallocate and unlink the user in 297 * the old database. This is more a point of memory 298 * efficiency than anything else, since all leftover 299 * users will be deleted from the old database when 300 * we finish with the crontab... 301 */ 302 Debug(DLOAD, (" [delete old data]")) 303 unlink_user(old_db, u); 304 free_user(u); 305 log_it(fname, getpid(), "RELOAD", tabname); 306 } 307 u = load_user(crontab_fd, pw, fname); 308 if (u != NULL) { 309 u->mtime = statbuf->st_mtime; 310 link_user(new_db, u); 311 } 312 313 next_crontab: 314 if (crontab_fd >= OK) { 315 Debug(DLOAD, (" [done]\n")) 316 close(crontab_fd); 317 } 318 } 319