| File: | src/usr.bin/vacation/vacation.c |
| Warning: | line 465, column 6 Call to function 'vfork' is insecure as it can lead to denial of service situations in the parent process. Replace calls to vfork with calls to the safer 'posix_spawn' function |
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| 1 | /* $OpenBSD: vacation.c,v 1.38 2019/06/28 13:35:05 deraadt Exp $ */ |
| 2 | /* $NetBSD: vacation.c,v 1.7 1995/04/29 05:58:27 cgd Exp $ */ |
| 3 | |
| 4 | /* |
| 5 | * Copyright (c) 1983, 1987, 1993 |
| 6 | * The Regents of the University of California. All rights reserved. |
| 7 | * |
| 8 | * Redistribution and use in source and binary forms, with or without |
| 9 | * modification, are permitted provided that the following conditions |
| 10 | * are met: |
| 11 | * 1. Redistributions of source code must retain the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer. |
| 13 | * 2. Redistributions in binary form must reproduce the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer in the |
| 15 | * documentation and/or other materials provided with the distribution. |
| 16 | * 3. Neither the name of the University nor the names of its contributors |
| 17 | * may be used to endorse or promote products derived from this software |
| 18 | * without specific prior written permission. |
| 19 | * |
| 20 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 21 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 22 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 23 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 24 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 25 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 26 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 27 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 28 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 29 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 30 | * SUCH DAMAGE. |
| 31 | */ |
| 32 | |
| 33 | /* |
| 34 | ** Vacation |
| 35 | ** Copyright (c) 1983 Eric P. Allman |
| 36 | ** Berkeley, California |
| 37 | */ |
| 38 | |
| 39 | #include <sys/stat.h> |
| 40 | #include <fcntl.h> |
| 41 | #include <pwd.h> |
| 42 | #include <db.h> |
| 43 | #include <time.h> |
| 44 | #include <syslog.h> |
| 45 | #include <errno(*__errno()).h> |
| 46 | #include <unistd.h> |
| 47 | #include <stdio.h> |
| 48 | #include <ctype.h> |
| 49 | #include <stdlib.h> |
| 50 | #include <string.h> |
| 51 | #include <paths.h> |
| 52 | |
| 53 | /* |
| 54 | * VACATION -- return a message to the sender when on vacation. |
| 55 | * |
| 56 | * This program is invoked as a message receiver. It returns a |
| 57 | * message specified by the user to whomever sent the mail, taking |
| 58 | * care not to return a message too often to prevent "I am on |
| 59 | * vacation" loops. |
| 60 | */ |
| 61 | |
| 62 | #define MAXLINE1024 1024 /* max line from mail header */ |
| 63 | #define VDB".vacation.db" ".vacation.db" /* dbm's database */ |
| 64 | #define VMSG".vacation.msg" ".vacation.msg" /* vacation message */ |
| 65 | |
| 66 | typedef struct alias { |
| 67 | struct alias *next; |
| 68 | char *name; |
| 69 | } ALIAS; |
| 70 | ALIAS *names; |
| 71 | |
| 72 | DB *db; |
| 73 | char from[MAXLINE1024]; |
| 74 | char subj[MAXLINE1024]; |
| 75 | |
| 76 | int junkmail(void); |
| 77 | int nsearch(char *, char *); |
| 78 | void readheaders(void); |
| 79 | int recent(void); |
| 80 | void sendmessage(char *); |
| 81 | void setinterval(time_t); |
| 82 | void setreply(void); |
| 83 | void usage(void); |
| 84 | |
| 85 | #define SECSPERDAY(24 * 60 * 60) (24 * 60 * 60) |
| 86 | |
| 87 | int |
| 88 | main(int argc, char *argv[]) |
| 89 | { |
| 90 | int ch, iflag, flags; |
| 91 | struct passwd *pw; |
| 92 | time_t interval; |
| 93 | struct stat sb; |
| 94 | ALIAS *cur; |
| 95 | |
| 96 | opterr = iflag = 0; |
| 97 | interval = -1; |
| 98 | while ((ch = getopt(argc, argv, "a:Iir:")) != -1) |
| 99 | switch ((char)ch) { |
| 100 | case 'a': /* alias */ |
| 101 | if (!(cur = malloc(sizeof(ALIAS)))) |
| 102 | break; |
| 103 | cur->name = optarg; |
| 104 | cur->next = names; |
| 105 | names = cur; |
| 106 | break; |
| 107 | case 'I': /* backward compatible */ |
| 108 | case 'i': /* init the database */ |
| 109 | iflag = 1; |
| 110 | break; |
| 111 | case 'r': |
| 112 | if (isdigit((unsigned char)*optarg)) { |
| 113 | interval = atol(optarg) * SECSPERDAY(24 * 60 * 60); |
| 114 | if (interval < 0) |
| 115 | usage(); |
| 116 | } else |
| 117 | interval = 0; /* one time only */ |
| 118 | break; |
| 119 | default: |
| 120 | usage(); |
| 121 | } |
| 122 | argc -= optind; |
| 123 | argv += optind; |
| 124 | |
| 125 | if (argc != 1) { |
| 126 | if (!iflag) |
| 127 | usage(); |
| 128 | if (!(pw = getpwuid(getuid()))) { |
| 129 | syslog(LOG_ERR3, |
| 130 | "no such user uid %u.", getuid()); |
| 131 | exit(1); |
| 132 | } |
| 133 | } else if (!(pw = getpwnam(*argv))) { |
| 134 | syslog(LOG_ERR3, "no such user %s.", *argv); |
| 135 | exit(1); |
| 136 | } |
| 137 | if (chdir(pw->pw_dir)) { |
| 138 | syslog(LOG_NOTICE5, |
| 139 | "no such directory %s.", pw->pw_dir); |
| 140 | exit(1); |
| 141 | } |
| 142 | |
| 143 | /* |
| 144 | * dbopen(3) can not deal with a zero-length file w/o O_TRUNC. |
| 145 | */ |
| 146 | if (iflag == 1 || (stat(VDB".vacation.db", &sb) == 0 && sb.st_size == (off_t)0)) |
| 147 | flags = O_CREAT0x0200|O_RDWR0x0002|O_TRUNC0x0400; |
| 148 | else |
| 149 | flags = O_CREAT0x0200|O_RDWR0x0002; |
| 150 | |
| 151 | db = dbopen(VDB".vacation.db", flags, S_IRUSR0000400|S_IWUSR0000200, DB_HASH, NULL((void *)0)); |
| 152 | if (!db) { |
| 153 | syslog(LOG_NOTICE5, "%s: %m", VDB".vacation.db"); |
| 154 | exit(1); |
| 155 | } |
| 156 | |
| 157 | if (interval != -1) |
| 158 | setinterval(interval); |
| 159 | |
| 160 | if (iflag) { |
| 161 | (void)(db->close)(db); |
| 162 | exit(0); |
| 163 | } |
| 164 | |
| 165 | if (!(cur = malloc(sizeof(ALIAS)))) |
| 166 | exit(1); |
| 167 | cur->name = pw->pw_name; |
| 168 | cur->next = names; |
| 169 | names = cur; |
| 170 | |
| 171 | readheaders(); |
| 172 | if (!recent()) { |
| 173 | setreply(); |
| 174 | (void)(db->close)(db); |
| 175 | sendmessage(pw->pw_name); |
| 176 | } else |
| 177 | (void)(db->close)(db); |
| 178 | exit(0); |
| 179 | /* NOTREACHED */ |
| 180 | } |
| 181 | |
| 182 | /* |
| 183 | * readheaders -- |
| 184 | * read mail headers |
| 185 | */ |
| 186 | void |
| 187 | readheaders(void) |
| 188 | { |
| 189 | char buf[MAXLINE1024], *p; |
| 190 | int tome, cont; |
| 191 | ALIAS *cur; |
| 192 | |
| 193 | cont = tome = 0; |
| 194 | while (fgets(buf, sizeof(buf), stdin(&__sF[0])) && *buf != '\n') |
| 195 | switch (*buf) { |
| 196 | case 'A': /* "Auto-Submitted:" */ |
| 197 | case 'a': |
| 198 | cont = 0; |
| 199 | if (strncasecmp(buf, "Auto-Submitted:", 15)) |
| 200 | break; |
| 201 | for (p = buf + 15; isspace((unsigned char)*p); ++p) |
| 202 | ; |
| 203 | /* |
| 204 | * RFC 3834 section 2: |
| 205 | * Automatic responses SHOULD NOT be issued in response |
| 206 | * to any message which contains an Auto-Submitted |
| 207 | * header where the field has any value other than "no". |
| 208 | */ |
| 209 | if ((p[0] == 'n' || p[0] == 'N') && |
| 210 | (p[1] == 'o' || p[1] == 'O')) { |
| 211 | for (p += 2; isspace((unsigned char)*p); ++p) |
| 212 | ; |
| 213 | if (*p == '\0') |
| 214 | break; /* Auto-Submitted: no */ |
| 215 | } |
| 216 | exit(0); |
| 217 | case 'F': /* "From " */ |
| 218 | case 'f': |
| 219 | cont = 0; |
| 220 | if (!strncasecmp(buf, "From ", 5)) { |
| 221 | for (p = buf + 5; *p && *p != ' '; ++p) |
| 222 | ; |
| 223 | *p = '\0'; |
| 224 | (void)strlcpy(from, buf + 5, sizeof(from)); |
| 225 | from[strcspn(from, "\n")] = '\0'; |
| 226 | if (junkmail()) |
| 227 | exit(0); |
| 228 | } |
| 229 | break; |
| 230 | case 'L': /* "List-Id:" */ |
| 231 | case 'l': |
| 232 | cont = 0; |
| 233 | /* |
| 234 | * If present (with any value), message is coming from a |
| 235 | * mailing list, cf. RFC2919. |
| 236 | */ |
| 237 | if (strncasecmp(buf, "List-Id:", 8) == 0) |
| 238 | exit(0); |
| 239 | break; |
| 240 | case 'R': /* "Return-Path:" */ |
| 241 | case 'r': |
| 242 | cont = 0; |
| 243 | if (strncasecmp(buf, "Return-Path:", |
| 244 | sizeof("Return-Path:")-1) || |
| 245 | (buf[12] != ' ' && buf[12] != '\t')) |
| 246 | break; |
| 247 | for (p = buf + 12; isspace((unsigned char)*p); ++p) |
| 248 | ; |
| 249 | if (strlcpy(from, p, sizeof(from)) >= sizeof(from)) { |
| 250 | syslog(LOG_NOTICE5, |
| 251 | "Return-Path %s exceeds limits", p); |
| 252 | exit(1); |
| 253 | } |
| 254 | from[strcspn(from, "\n")] = '\0'; |
| 255 | if (junkmail()) |
| 256 | exit(0); |
| 257 | break; |
| 258 | case 'P': /* "Precedence:" */ |
| 259 | case 'p': |
| 260 | cont = 0; |
| 261 | if (strncasecmp(buf, "Precedence:", 11)) |
| 262 | break; |
| 263 | for (p = buf + 11; isspace((unsigned char)*p); ++p) |
| 264 | ; |
| 265 | if (!strncasecmp(p, "junk", 4) || |
| 266 | !strncasecmp(p, "bulk", 4) || |
| 267 | !strncasecmp(p, "list", 4)) |
| 268 | exit(0); |
| 269 | break; |
| 270 | case 'S': /* Subject: */ |
| 271 | case 's': |
| 272 | cont = 0; |
| 273 | if (strncasecmp(buf, "Subject:", |
| 274 | sizeof("Subject:")-1) || |
| 275 | (buf[8] != ' ' && buf[8] != '\t')) |
| 276 | break; |
| 277 | for (p = buf + 8; isspace((unsigned char)*p); ++p) |
| 278 | ; |
| 279 | if (strlcpy(subj, p, sizeof(subj)) >= sizeof(subj)) { |
| 280 | syslog(LOG_NOTICE5, |
| 281 | "Subject %s exceeds limits", p); |
| 282 | exit(1); |
| 283 | } |
| 284 | subj[strcspn(subj, "\n")] = '\0'; |
| 285 | break; |
| 286 | case 'C': /* "Cc:" */ |
| 287 | case 'c': |
| 288 | if (strncasecmp(buf, "Cc:", 3)) |
| 289 | break; |
| 290 | cont = 1; |
| 291 | goto findme; |
| 292 | case 'T': /* "To:" */ |
| 293 | case 't': |
| 294 | if (strncasecmp(buf, "To:", 3)) |
| 295 | break; |
| 296 | cont = 1; |
| 297 | goto findme; |
| 298 | default: |
| 299 | if (!isspace((unsigned char)*buf) || !cont || tome) { |
| 300 | cont = 0; |
| 301 | break; |
| 302 | } |
| 303 | findme: for (cur = names; !tome && cur; cur = cur->next) |
| 304 | tome += nsearch(cur->name, buf); |
| 305 | } |
| 306 | if (!tome) |
| 307 | exit(0); |
| 308 | if (!*from) { |
| 309 | syslog(LOG_NOTICE5, |
| 310 | "no initial \"From\" or \"Return-Path\"line."); |
| 311 | exit(1); |
| 312 | } |
| 313 | } |
| 314 | |
| 315 | /* |
| 316 | * nsearch -- |
| 317 | * do a nice, slow, search of a string for a substring. |
| 318 | */ |
| 319 | int |
| 320 | nsearch(char *name, char *str) |
| 321 | { |
| 322 | int len; |
| 323 | |
| 324 | for (len = strlen(name); *str; ++str) |
| 325 | if (!strncasecmp(name, str, len)) |
| 326 | return(1); |
| 327 | return(0); |
| 328 | } |
| 329 | |
| 330 | /* |
| 331 | * junkmail -- |
| 332 | * read the header and return if automagic/junk/bulk/list mail |
| 333 | */ |
| 334 | int |
| 335 | junkmail(void) |
| 336 | { |
| 337 | static struct ignore { |
| 338 | char *name; |
| 339 | int len; |
| 340 | } ignore[] = { |
| 341 | { "-request", 8 }, |
| 342 | { "postmaster", 10 }, |
| 343 | { "uucp", 4 }, |
| 344 | { "mailer-daemon", 13 }, |
| 345 | { "mailer", 6 }, |
| 346 | { "-relay", 6 }, |
| 347 | { NULL((void *)0), 0 } |
| 348 | }; |
| 349 | struct ignore *cur; |
| 350 | int len; |
| 351 | char *p; |
| 352 | |
| 353 | /* |
| 354 | * This is mildly amusing, and I'm not positive it's right; trying |
| 355 | * to find the "real" name of the sender, assuming that addresses |
| 356 | * will be some variant of: |
| 357 | * |
| 358 | * From site!site!SENDER%site.domain%site.domain@site.domain |
| 359 | */ |
| 360 | if (!(p = strchr(from, '%'))) { |
| 361 | if (!(p = strchr(from, '@'))) { |
| 362 | if ((p = strrchr(from, '!'))) |
| 363 | ++p; |
| 364 | else |
| 365 | p = from; |
| 366 | for (; *p; ++p) |
| 367 | ; |
| 368 | } |
| 369 | } |
| 370 | len = p - from; |
| 371 | for (cur = ignore; cur->name; ++cur) |
| 372 | if (len >= cur->len && |
| 373 | !strncasecmp(cur->name, p - cur->len, cur->len)) |
| 374 | return(1); |
| 375 | return(0); |
| 376 | } |
| 377 | |
| 378 | #define VIT"__VACATION__INTERVAL__TIMER__" "__VACATION__INTERVAL__TIMER__" |
| 379 | |
| 380 | /* |
| 381 | * recent -- |
| 382 | * find out if user has gotten a vacation message recently. |
| 383 | * use bcopy for machines with alignment restrictions |
| 384 | */ |
| 385 | int |
| 386 | recent(void) |
| 387 | { |
| 388 | time_t then, next; |
| 389 | DBT key, data; |
| 390 | |
| 391 | /* get interval time */ |
| 392 | key.data = VIT"__VACATION__INTERVAL__TIMER__"; |
| 393 | key.size = sizeof(VIT"__VACATION__INTERVAL__TIMER__"); |
| 394 | if ((db->get)(db, &key, &data, 0)) |
| 395 | next = SECSPERDAY(24 * 60 * 60) * 7; |
| 396 | else |
| 397 | bcopy(data.data, &next, sizeof(next)); |
| 398 | |
| 399 | /* get record for this address */ |
| 400 | key.data = from; |
| 401 | key.size = strlen(from); |
| 402 | if (!(db->get)(db, &key, &data, 0)) { |
| 403 | bcopy(data.data, &then, sizeof(then)); |
| 404 | if (next == 0 || |
| 405 | then + next > time(NULL((void *)0))) |
| 406 | return(1); |
| 407 | } |
| 408 | return(0); |
| 409 | } |
| 410 | |
| 411 | /* |
| 412 | * setinterval -- |
| 413 | * store the reply interval |
| 414 | */ |
| 415 | void |
| 416 | setinterval(time_t interval) |
| 417 | { |
| 418 | DBT key, data; |
| 419 | |
| 420 | key.data = VIT"__VACATION__INTERVAL__TIMER__"; |
| 421 | key.size = sizeof(VIT"__VACATION__INTERVAL__TIMER__"); |
| 422 | data.data = &interval; |
| 423 | data.size = sizeof(interval); |
| 424 | (void)(db->put)(db, &key, &data, 0); |
| 425 | } |
| 426 | |
| 427 | /* |
| 428 | * setreply -- |
| 429 | * store that this user knows about the vacation. |
| 430 | */ |
| 431 | void |
| 432 | setreply(void) |
| 433 | { |
| 434 | DBT key, data; |
| 435 | time_t now; |
| 436 | |
| 437 | key.data = from; |
| 438 | key.size = strlen(from); |
| 439 | (void)time(&now); |
| 440 | data.data = &now; |
| 441 | data.size = sizeof(now); |
| 442 | (void)(db->put)(db, &key, &data, 0); |
| 443 | } |
| 444 | |
| 445 | /* |
| 446 | * sendmessage -- |
| 447 | * exec sendmail to send the vacation file to sender |
| 448 | */ |
| 449 | void |
| 450 | sendmessage(char *myname) |
| 451 | { |
| 452 | char buf[MAXLINE1024]; |
| 453 | FILE *mfp, *sfp; |
| 454 | int pvect[2], i; |
| 455 | |
| 456 | mfp = fopen(VMSG".vacation.msg", "r"); |
| 457 | if (mfp == NULL((void *)0)) { |
| 458 | syslog(LOG_NOTICE5, "no ~%s/%s file.", myname, VMSG".vacation.msg"); |
| 459 | exit(1); |
| 460 | } |
| 461 | if (pipe(pvect) == -1) { |
| 462 | syslog(LOG_ERR3, "pipe: %m"); |
| 463 | exit(1); |
| 464 | } |
| 465 | i = vfork(); |
Call to function 'vfork' is insecure as it can lead to denial of service situations in the parent process. Replace calls to vfork with calls to the safer 'posix_spawn' function | |
| 466 | if (i == -1) { |
| 467 | syslog(LOG_ERR3, "fork: %m"); |
| 468 | exit(1); |
| 469 | } |
| 470 | if (i == 0) { |
| 471 | dup2(pvect[0], 0); |
| 472 | close(pvect[0]); |
| 473 | close(pvect[1]); |
| 474 | close(fileno(mfp)(!__isthreaded ? ((mfp)->_file) : (fileno)(mfp))); |
| 475 | execl(_PATH_SENDMAIL"/usr/sbin/sendmail", "sendmail", "-f", myname, "--", |
| 476 | from, (char *)NULL((void *)0)); |
| 477 | syslog(LOG_ERR3, "can't exec %s: %m", _PATH_SENDMAIL"/usr/sbin/sendmail"); |
| 478 | _exit(1); |
| 479 | } |
| 480 | close(pvect[0]); |
| 481 | sfp = fdopen(pvect[1], "w"); |
| 482 | if (sfp == NULL((void *)0)) { |
| 483 | /* XXX could not fdopen; likely out of memory */ |
| 484 | fclose(mfp); |
| 485 | close(pvect[1]); |
| 486 | return; |
| 487 | } |
| 488 | fprintf(sfp, "To: %s\n", from); |
| 489 | fputs("Auto-Submitted: auto-replied\n", sfp); |
| 490 | while (fgets(buf, sizeof buf, mfp)) { |
| 491 | char *s = strstr(buf, "$SUBJECT"); |
| 492 | |
| 493 | if (s) { |
| 494 | *s = 0; |
| 495 | fputs(buf, sfp); |
| 496 | fputs(subj, sfp); |
| 497 | fputs(s+8, sfp); |
| 498 | } else { |
| 499 | fputs(buf, sfp); |
| 500 | } |
| 501 | } |
| 502 | fclose(mfp); |
| 503 | fclose(sfp); |
| 504 | } |
| 505 | |
| 506 | void |
| 507 | usage(void) |
| 508 | { |
| 509 | syslog(LOG_NOTICE5, "uid %u: usage: vacation [-i] [-a alias] login", |
| 510 | getuid()); |
| 511 | exit(1); |
| 512 | } |