vacation.c revision 1.27
1 /* $NetBSD: vacation.c,v 1.27 2004/04/04 01:19:35 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1983, 1987, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 34 #ifndef lint 35 __COPYRIGHT("@(#) Copyright (c) 1983, 1987, 1993\n\ 36 The Regents of the University of California. All rights reserved.\n"); 37 #endif /* not lint */ 38 39 #ifndef lint 40 #if 0 41 static char sccsid[] = "@(#)vacation.c 8.2 (Berkeley) 1/26/94"; 42 #endif 43 __RCSID("$NetBSD: vacation.c,v 1.27 2004/04/04 01:19:35 christos Exp $"); 44 #endif /* not lint */ 45 46 /* 47 ** Vacation 48 ** Copyright (c) 1983 Eric P. Allman 49 ** Berkeley, California 50 */ 51 52 #include <sys/param.h> 53 #include <sys/stat.h> 54 55 #include <ctype.h> 56 #include <db.h> 57 #include <err.h> 58 #include <errno.h> 59 #include <fcntl.h> 60 #include <paths.h> 61 #include <pwd.h> 62 #include <stdio.h> 63 #include <stdlib.h> 64 #include <string.h> 65 #include <syslog.h> 66 #include <time.h> 67 #include <tzfile.h> 68 #include <unistd.h> 69 70 /* 71 * VACATION -- return a message to the sender when on vacation. 72 * 73 * This program is invoked as a message receiver. It returns a 74 * message specified by the user to whomever sent the mail, taking 75 * care not to return a message too often to prevent "I am on 76 * vacation" loops. 77 */ 78 79 #define MAXLINE 1024 /* max line from mail header */ 80 #define VDB ".vacation.db" /* dbm's database */ 81 #define VMSG ".vacation.msg" /* vacation message */ 82 83 typedef struct alias { 84 struct alias *next; 85 const char *name; 86 } alias_t; 87 alias_t *names; 88 89 DB *db; 90 char from[MAXLINE]; 91 static int tflag = 0; 92 #define APPARENTLY_TO 1 93 #define DELIVERED_TO 2 94 static int fflag = 0; 95 #define FROM_FROM 1 96 #define RETURN_PATH_FROM 2 97 #define SENDER_FROM 4 98 static int debug = 0; 99 100 int main(int, char **); 101 int junkmail(void); 102 int nsearch(const char *, const char *); 103 int readheaders(void); 104 int recent(void); 105 void getfrom(char *); 106 void sendmessage(const char *); 107 void setinterval(time_t); 108 void setreply(void); 109 void usage(void); 110 111 int 112 main(int argc, char **argv) 113 { 114 struct passwd *pw; 115 alias_t *cur; 116 time_t interval; 117 int ch, iflag, rv; 118 char *p; 119 120 opterr = iflag = 0; 121 interval = -1; 122 openlog(getprogname(), 0, LOG_USER); 123 while ((ch = getopt(argc, argv, "a:df:Iir:t:")) != -1) 124 switch((char)ch) { 125 case 'a': /* alias */ 126 if (!(cur = (alias_t *)malloc((size_t)sizeof(alias_t)))) 127 break; 128 cur->name = optarg; 129 cur->next = names; 130 names = cur; 131 break; 132 case 'd': 133 debug++; 134 break; 135 case 'f': 136 for (p = optarg; *p; p++) 137 switch (*p) { 138 case 'F': 139 fflag |= FROM_FROM; 140 break; 141 case 'R': 142 fflag |= RETURN_PATH_FROM; 143 break; 144 case 'S': 145 fflag |= SENDER_FROM; 146 break; 147 default: 148 errx(1, "Unknown -f option `%c'", *p); 149 } 150 break; 151 case 'I': /* backward compatible */ 152 case 'i': /* init the database */ 153 iflag = 1; 154 break; 155 case 'r': 156 if (isdigit((unsigned char)*optarg)) { 157 interval = atol(optarg) * SECSPERDAY; 158 if (interval < 0) 159 usage(); 160 } 161 else 162 interval = (time_t)LONG_MAX; /* XXX */ 163 break; 164 case 't': 165 for (p = optarg; *p; p++) 166 switch (*p) { 167 case 'A': 168 tflag |= APPARENTLY_TO; 169 break; 170 case 'D': 171 tflag |= DELIVERED_TO; 172 break; 173 default: 174 errx(1, "Unknown -t option `%c'", *p); 175 } 176 break; 177 case '?': 178 default: 179 usage(); 180 } 181 argc -= optind; 182 argv += optind; 183 184 if (argc != 1) { 185 if (!iflag) 186 usage(); 187 if (!(pw = getpwuid(getuid()))) { 188 syslog(LOG_ERR, "%s: no such user uid %u.", 189 getprogname(), getuid()); 190 exit(1); 191 } 192 } 193 else if (!(pw = getpwnam(*argv))) { 194 syslog(LOG_ERR, "%s: no such user %s.", 195 getprogname(), *argv); 196 exit(1); 197 } 198 if (chdir(pw->pw_dir)) { 199 syslog(LOG_ERR, "%s: no such directory %s.", 200 getprogname(), pw->pw_dir); 201 exit(1); 202 } 203 204 db = dbopen(VDB, O_CREAT|O_RDWR | (iflag ? O_TRUNC : 0), 205 S_IRUSR|S_IWUSR, DB_HASH, NULL); 206 if (!db) { 207 syslog(LOG_ERR, "%s: %s: %m", getprogname(), VDB); 208 exit(1); 209 } 210 211 if (interval != -1) 212 setinterval(interval); 213 214 if (iflag) { 215 (void)(db->close)(db); 216 exit(0); 217 } 218 219 if (!(cur = malloc((size_t)sizeof(alias_t)))) { 220 syslog(LOG_ERR, "%s: %m", getprogname()); 221 (void)(db->close)(db); 222 exit(1); 223 } 224 cur->name = pw->pw_name; 225 cur->next = names; 226 names = cur; 227 228 if ((rv = readheaders()) != -1) { 229 (void)(db->close)(db); 230 exit(rv); 231 } 232 233 if (!recent()) { 234 setreply(); 235 (void)(db->close)(db); 236 sendmessage(pw->pw_name); 237 } 238 else 239 (void)(db->close)(db); 240 exit(0); 241 /* NOTREACHED */ 242 } 243 244 /* 245 * readheaders -- 246 * read mail headers 247 */ 248 int 249 readheaders(void) 250 { 251 alias_t *cur; 252 char *p; 253 int tome, cont; 254 char buf[MAXLINE]; 255 256 cont = tome = 0; 257 while (fgets(buf, sizeof(buf), stdin) && *buf != '\n') 258 switch(*buf) { 259 case 'F': /* "From " or "From:" */ 260 cont = 0; 261 if (!strncmp(buf, "From ", 5)) 262 getfrom(buf + 5); 263 if ((fflag & FROM_FROM) != 0 && 264 strncmp(buf, "From:", 5) == 0) 265 getfrom(buf + 5); 266 break; 267 case 'P': /* "Precedence:" */ 268 cont = 0; 269 if (strncasecmp(buf, "Precedence", 10) || 270 (buf[10] != ':' && buf[10] != ' ' && 271 buf[10] != '\t')) 272 break; 273 if (!(p = strchr(buf, ':'))) 274 break; 275 while (*++p && isspace((unsigned char)*p)) 276 continue; 277 if (!*p) 278 break; 279 if (!strncasecmp(p, "junk", 4) || 280 !strncasecmp(p, "bulk", 4) || 281 !strncasecmp(p, "list", 4)) 282 exit(0); 283 break; 284 case 'C': /* "Cc:" */ 285 if (strncmp(buf, "Cc:", 3)) 286 break; 287 cont = 1; 288 goto findme; 289 case 'T': /* "To:" */ 290 if (strncmp(buf, "To:", 3)) 291 break; 292 cont = 1; 293 goto findme; 294 case 'A': /* "Apparently-To:" */ 295 if ((tflag & APPARENTLY_TO) == 0 || 296 strncmp(buf, "Apparently-To:", 14)) 297 break; 298 cont = 1; 299 goto findme; 300 case 'D': /* "Delivered-To:" */ 301 if ((tflag & DELIVERED_TO) == 0 || 302 strncmp(buf, "Delivered-To:", 13)) 303 break; 304 cont = 1; 305 goto findme; 306 case 'R': /* "Return-Path:" */ 307 cont = 0; 308 if ((fflag & RETURN_PATH_FROM) != 0 && 309 strncmp(buf, "Return-Path:", 12) == 0) 310 getfrom(buf + 12); 311 break; 312 case 'S': /* "Sender:" */ 313 cont = 0; 314 if ((fflag & SENDER_FROM) != 0 && 315 strncmp(buf, "Sender:", 7) == 0) 316 getfrom(buf + 7); 317 break; 318 default: 319 if (!isspace((unsigned char)*buf) || !cont || tome) { 320 cont = 0; 321 break; 322 } 323 findme: for (cur = names; !tome && cur; cur = cur->next) 324 tome += nsearch(cur->name, buf); 325 } 326 if (!tome) 327 return 0; 328 if (!*from) { 329 syslog(LOG_ERR, "%s: no initial \"From\" line.", 330 getprogname()); 331 return 1; 332 } 333 return -1; 334 } 335 336 /* 337 * nsearch -- 338 * do a nice, slow, search of a string for a substring. 339 */ 340 int 341 nsearch(const char *name, const char *str) 342 { 343 size_t len; 344 345 for (len = strlen(name); *str; ++str) 346 if (!strncasecmp(name, str, len)) 347 return(1); 348 return(0); 349 } 350 351 /* 352 * getfrom -- 353 * return the first string in the buffer, stripping leading and trailing 354 * blanks and <>. 355 */ 356 void 357 getfrom(char *buf) 358 { 359 char *s, *p; 360 361 if ((s = strchr(buf, '<')) != NULL) 362 s++; 363 else 364 s = buf; 365 366 for (; *s && isspace((unsigned char)*s); s++) 367 continue; 368 for (p = s; *p && !isspace((unsigned char)*p); p++) 369 continue; 370 if (*--p == '>') 371 *p = '\0'; 372 else 373 *++p = '\0'; 374 (void)strlcpy(from, s, sizeof(from)); 375 if (junkmail()) 376 exit(0); 377 } 378 379 /* 380 * junkmail -- 381 * read the header and return if automagic/junk/bulk/list mail 382 */ 383 int 384 junkmail(void) 385 { 386 static struct ignore { 387 char *name; 388 int len; 389 } ignore[] = { 390 { "-request", 8 }, 391 { "postmaster", 10 }, 392 { "uucp", 4 }, 393 { "mailer-daemon", 13 }, 394 { "mailer", 6 }, 395 { "-relay", 6 }, 396 {NULL, 0 } 397 }; 398 struct ignore *cur; 399 int len; 400 char *p; 401 402 /* 403 * This is mildly amusing, and I'm not positive it's right; trying 404 * to find the "real" name of the sender, assuming that addresses 405 * will be some variant of: 406 * 407 * From site!site!SENDER%site.domain%site.domain (at) site.domain 408 */ 409 if (!(p = strchr(from, '%'))) 410 if (!(p = strchr(from, '@'))) { 411 if ((p = strrchr(from, '!'))) 412 ++p; 413 else 414 p = from; 415 for (; *p; ++p); 416 } 417 len = p - from; 418 for (cur = ignore; cur->name; ++cur) 419 if (len >= cur->len && 420 !strncasecmp(cur->name, p - cur->len, cur->len)) 421 return(1); 422 return(0); 423 } 424 425 #define VIT "__VACATION__INTERVAL__TIMER__" 426 427 /* 428 * recent -- 429 * find out if user has gotten a vacation message recently. 430 * use memmove for machines with alignment restrictions 431 */ 432 int 433 recent(void) 434 { 435 DBT key, data; 436 time_t then, next; 437 438 /* get interval time */ 439 key.data = VIT; 440 key.size = sizeof(VIT); 441 if ((db->get)(db, &key, &data, 0)) 442 next = SECSPERDAY * DAYSPERWEEK; 443 else 444 memmove(&next, data.data, sizeof(next)); 445 446 /* get record for this address */ 447 key.data = from; 448 key.size = strlen(from); 449 if (!(db->get)(db, &key, &data, 0)) { 450 memmove(&then, data.data, sizeof(then)); 451 if (next == (time_t)LONG_MAX || /* XXX */ 452 then + next > time(NULL)) 453 return(1); 454 } 455 return(0); 456 } 457 458 /* 459 * setinterval -- 460 * store the reply interval 461 */ 462 void 463 setinterval(time_t interval) 464 { 465 DBT key, data; 466 467 key.data = VIT; 468 key.size = sizeof(VIT); 469 data.data = &interval; 470 data.size = sizeof(interval); 471 (void)(db->put)(db, &key, &data, 0); 472 } 473 474 /* 475 * setreply -- 476 * store that this user knows about the vacation. 477 */ 478 void 479 setreply(void) 480 { 481 DBT key, data; 482 time_t now; 483 484 key.data = from; 485 key.size = strlen(from); 486 (void)time(&now); 487 data.data = &now; 488 data.size = sizeof(now); 489 (void)(db->put)(db, &key, &data, 0); 490 } 491 492 /* 493 * sendmessage -- 494 * exec sendmail to send the vacation file to sender 495 */ 496 void 497 sendmessage(const char *myname) 498 { 499 FILE *mfp, *sfp; 500 int i; 501 int pvect[2]; 502 char buf[MAXLINE]; 503 504 mfp = fopen(VMSG, "r"); 505 if (mfp == NULL) { 506 syslog(LOG_ERR, "%s: no ~%s/%s file.", getprogname(), 507 myname, VMSG); 508 exit(1); 509 } 510 511 if (debug) { 512 sfp = stdout; 513 } else { 514 if (pipe(pvect) < 0) { 515 syslog(LOG_ERR, "%s: pipe: %m", getprogname()); 516 exit(1); 517 } 518 i = vfork(); 519 if (i < 0) { 520 syslog(LOG_ERR, "%s: fork: %m", getprogname()); 521 exit(1); 522 } 523 if (i == 0) { 524 dup2(pvect[0], 0); 525 close(pvect[0]); 526 close(pvect[1]); 527 close(fileno(mfp)); 528 execl(_PATH_SENDMAIL, "sendmail", "-f", myname, 529 "--", from, NULL); 530 syslog(LOG_ERR, "%s: can't exec %s: %m", 531 getprogname(), _PATH_SENDMAIL); 532 _exit(1); 533 } 534 (void)close(pvect[0]); 535 sfp = fdopen(pvect[1], "w"); 536 } 537 fprintf(sfp, "To: %s\n", from); 538 while (fgets(buf, sizeof buf, mfp)) 539 fputs(buf, sfp); 540 (void)fclose(mfp); 541 if (sfp != stdout) 542 (void)fclose(sfp); 543 } 544 545 void 546 usage(void) 547 { 548 549 syslog(LOG_ERR, "uid %u: Usage: %s [-id] [-a alias] [-t A|D] [-f F|R|S]" 550 " login", getuid(), getprogname()); 551 exit(1); 552 } 553
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