| 1 | /* $Cambridge: exim/src/src/rda.c,v 1.13 2006/09/05 14:05:43 ph10 Exp $ */ |
| 2 | |
| 3 | /************************************************* |
| 4 | * Exim - an Internet mail transport agent * |
| 5 | *************************************************/ |
| 6 | |
| 7 | /* Copyright (c) University of Cambridge 1995 - 2006 */ |
| 8 | /* See the file NOTICE for conditions of use and distribution. */ |
| 9 | |
| 10 | /* This module contains code for extracting addresses from a forwarding list |
| 11 | (from an alias or forward file) or by running the filter interpreter. It may do |
| 12 | this in a sub-process if a uid/gid are supplied. */ |
| 13 | |
| 14 | |
| 15 | #include "exim.h" |
| 16 | |
| 17 | enum { FILE_EXIST, FILE_NOT_EXIST, FILE_EXIST_UNCLEAR }; |
| 18 | |
| 19 | #define REPLY_EXISTS 0x01 |
| 20 | #define REPLY_EXPAND 0x02 |
| 21 | #define REPLY_RETURN 0x04 |
| 22 | |
| 23 | |
| 24 | /************************************************* |
| 25 | * Check string for filter program * |
| 26 | *************************************************/ |
| 27 | |
| 28 | /* This function checks whether a string is actually a filter program. The rule |
| 29 | is that it must start with "# Exim filter ..." (any capitalization, spaces |
| 30 | optional). It is envisaged that in future, other kinds of filter may be |
| 31 | implemented. That's why it is implemented the way it is. The function is global |
| 32 | because it is also called from filter.c when checking filters. |
| 33 | |
| 34 | Argument: the string |
| 35 | |
| 36 | Returns: FILTER_EXIM if it starts with "# Exim filter" |
| 37 | FILTER_SIEVE if it starts with "# Sieve filter" |
| 38 | FILTER_FORWARD otherwise |
| 39 | */ |
| 40 | |
| 41 | /* This is an auxiliary function for matching a tag. */ |
| 42 | |
| 43 | static BOOL |
| 44 | match_tag(const uschar *s, const uschar *tag) |
| 45 | { |
| 46 | for (; *tag != 0; s++, tag++) |
| 47 | { |
| 48 | if (*tag == ' ') |
| 49 | { |
| 50 | while (*s == ' ' || *s == '\t') s++; |
| 51 | s--; |
| 52 | } |
| 53 | else if (tolower(*s) != tolower(*tag)) break; |
| 54 | } |
| 55 | return (*tag == 0); |
| 56 | } |
| 57 | |
| 58 | /* This is the real function. It should be easy to add checking different |
| 59 | tags for other types of filter. */ |
| 60 | |
| 61 | int |
| 62 | rda_is_filter(const uschar *s) |
| 63 | { |
| 64 | while (isspace(*s)) s++; /* Skips initial blank lines */ |
| 65 | if (match_tag(s, CUS"# exim filter")) return FILTER_EXIM; |
| 66 | else if (match_tag(s, CUS"# sieve filter")) return FILTER_SIEVE; |
| 67 | else return FILTER_FORWARD; |
| 68 | } |
| 69 | |
| 70 | |
| 71 | |
| 72 | |
| 73 | /************************************************* |
| 74 | * Check for existence of file * |
| 75 | *************************************************/ |
| 76 | |
| 77 | /* First of all, we stat the file. If this fails, we try to stat the enclosing |
| 78 | directory, because a file in an unmounted NFS directory will look the same as a |
| 79 | non-existent file. It seems that in Solaris 2.6, statting an entry in an |
| 80 | indirect map that is currently unmounted does not cause the mount to happen. |
| 81 | Instead, dummy data is returned, which defeats the whole point of this test. |
| 82 | However, if a stat() is done on some object inside the directory, such as the |
| 83 | "." back reference to itself, then the mount does occur. If an NFS host is |
| 84 | taken offline, it is possible for the stat() to get stuck until it comes back. |
| 85 | To guard against this, stick a timer round it. If we can't access the "." |
| 86 | inside the directory, try the plain directory, just in case that helps. |
| 87 | |
| 88 | Argument: |
| 89 | filename the file name |
| 90 | error for message on error |
| 91 | |
| 92 | Returns: FILE_EXIST the file exists |
| 93 | FILE_NOT_EXIST the file does not exist |
| 94 | FILE_EXIST_UNCLEAR cannot determine existence |
| 95 | */ |
| 96 | |
| 97 | static int |
| 98 | rda_exists(uschar *filename, uschar **error) |
| 99 | { |
| 100 | int rc, saved_errno; |
| 101 | uschar *slash; |
| 102 | struct stat statbuf; |
| 103 | |
| 104 | if ((rc = Ustat(filename, &statbuf)) >= 0) return FILE_EXIST; |
| 105 | saved_errno = errno; |
| 106 | |
| 107 | Ustrncpy(big_buffer, filename, big_buffer_size - 3); |
| 108 | sigalrm_seen = FALSE; |
| 109 | |
| 110 | if (saved_errno == ENOENT) |
| 111 | { |
| 112 | slash = Ustrrchr(big_buffer, '/'); |
| 113 | Ustrcpy(slash+1, "."); |
| 114 | |
| 115 | alarm(30); |
| 116 | rc = Ustat(big_buffer, &statbuf); |
| 117 | if (rc != 0 && errno == EACCES && !sigalrm_seen) |
| 118 | { |
| 119 | *slash = 0; |
| 120 | rc = Ustat(big_buffer, &statbuf); |
| 121 | } |
| 122 | saved_errno = errno; |
| 123 | alarm(0); |
| 124 | |
| 125 | DEBUG(D_route) debug_printf("stat(%s)=%d\n", big_buffer, rc); |
| 126 | } |
| 127 | |
| 128 | if (sigalrm_seen || rc != 0) |
| 129 | { |
| 130 | *error = string_sprintf("failed to stat %s (%s)", big_buffer, |
| 131 | sigalrm_seen? "timeout" : strerror(saved_errno)); |
| 132 | return FILE_EXIST_UNCLEAR; |
| 133 | } |
| 134 | |
| 135 | *error = string_sprintf("%s does not exist", filename); |
| 136 | DEBUG(D_route) debug_printf("%s\n", *error); |
| 137 | return FILE_NOT_EXIST; |
| 138 | } |
| 139 | |
| 140 | |
| 141 | |
| 142 | /************************************************* |
| 143 | * Get forwarding list from a file * |
| 144 | *************************************************/ |
| 145 | |
| 146 | /* Open a file and read its entire contents into a block of memory. Certain |
| 147 | opening errors are optionally treated the same as "file does not exist". |
| 148 | |
| 149 | ENOTDIR means that something along the line is not a directory: there are |
| 150 | installations that set home directories to be /dev/null for non-login accounts |
| 151 | but in normal circumstances this indicates some kind of configuration error. |
| 152 | |
| 153 | EACCES means there's a permissions failure. Some users turn off read permission |
| 154 | on a .forward file to suspend forwarding, but this is probably an error in any |
| 155 | kind of mailing list processing. |
| 156 | |
| 157 | The redirect block that contains the file name also contains constraints such |
| 158 | as who may own the file, and mode bits that must not be set. This function is |
| 159 | |
| 160 | Arguments: |
| 161 | rdata rdirect block, containing file name and constraints |
| 162 | options for the RDO_ENOTDIR and RDO_EACCES options |
| 163 | error where to put an error message |
| 164 | yield what to return from rda_interpret on error |
| 165 | |
| 166 | Returns: pointer to string in store; NULL on error |
| 167 | */ |
| 168 | |
| 169 | static uschar * |
| 170 | rda_get_file_contents(redirect_block *rdata, int options, uschar **error, |
| 171 | int *yield) |
| 172 | { |
| 173 | FILE *fwd; |
| 174 | uschar *filebuf; |
| 175 | uschar *filename = rdata->string; |
| 176 | BOOL uid_ok = !rdata->check_owner; |
| 177 | BOOL gid_ok = !rdata->check_group; |
| 178 | struct stat statbuf; |
| 179 | |
| 180 | /* Attempt to open the file. If it appears not to exist, check up on the |
| 181 | containing directory by statting it. If the directory does not exist, we treat |
| 182 | this situation as an error (which will cause delivery to defer); otherwise we |
| 183 | pass back FF_NONEXIST, which causes the redirect router to decline. |
| 184 | |
| 185 | However, if the ignore_enotdir option is set (to ignore "something on the |
| 186 | path is not a directory" errors), the right behaviour seems to be not to do the |
| 187 | directory test. */ |
| 188 | |
| 189 | fwd = Ufopen(filename, "rb"); |
| 190 | if (fwd == NULL) |
| 191 | { |
| 192 | switch(errno) |
| 193 | { |
| 194 | case ENOENT: /* File does not exist */ |
| 195 | DEBUG(D_route) debug_printf("%s does not exist\n%schecking parent directory\n", |
| 196 | filename, |
| 197 | ((options & RDO_ENOTDIR) != 0)? "ignore_enotdir set => skip " : ""); |
| 198 | *yield = (((options & RDO_ENOTDIR) != 0) || |
| 199 | rda_exists(filename, error) == FILE_NOT_EXIST)? |
| 200 | FF_NONEXIST : FF_ERROR; |
| 201 | return NULL; |
| 202 | |
| 203 | case ENOTDIR: /* Something on the path isn't a directory */ |
| 204 | if ((options & RDO_ENOTDIR) == 0) goto DEFAULT_ERROR; |
| 205 | DEBUG(D_route) debug_printf("non-directory on path %s: file assumed not to " |
| 206 | "exist\n", filename); |
| 207 | *yield = FF_NONEXIST; |
| 208 | return NULL; |
| 209 | |
| 210 | case EACCES: /* Permission denied */ |
| 211 | if ((options & RDO_EACCES) == 0) goto DEFAULT_ERROR; |
| 212 | DEBUG(D_route) debug_printf("permission denied for %s: file assumed not to " |
| 213 | "exist\n", filename); |
| 214 | *yield = FF_NONEXIST; |
| 215 | return NULL; |
| 216 | |
| 217 | DEFAULT_ERROR: |
| 218 | default: |
| 219 | *error = string_open_failed(errno, "%s", filename); |
| 220 | *yield = FF_ERROR; |
| 221 | return NULL; |
| 222 | } |
| 223 | } |
| 224 | |
| 225 | /* Check that we have a regular file. */ |
| 226 | |
| 227 | if (fstat(fileno(fwd), &statbuf) != 0) |
| 228 | { |
| 229 | *error = string_sprintf("failed to stat %s: %s", filename, strerror(errno)); |
| 230 | goto ERROR_RETURN; |
| 231 | } |
| 232 | |
| 233 | if ((statbuf.st_mode & S_IFMT) != S_IFREG) |
| 234 | { |
| 235 | *error = string_sprintf("%s is not a regular file", filename); |
| 236 | goto ERROR_RETURN; |
| 237 | } |
| 238 | |
| 239 | /* Check for unwanted mode bits */ |
| 240 | |
| 241 | if ((statbuf.st_mode & rdata->modemask) != 0) |
| 242 | { |
| 243 | *error = string_sprintf("bad mode (0%o) for %s: 0%o bit(s) unexpected", |
| 244 | statbuf.st_mode, filename, statbuf.st_mode & rdata->modemask); |
| 245 | goto ERROR_RETURN; |
| 246 | } |
| 247 | |
| 248 | /* Check the file owner and file group if required to do so. */ |
| 249 | |
| 250 | if (!uid_ok) |
| 251 | { |
| 252 | if (rdata->pw != NULL && statbuf.st_uid == rdata->pw->pw_uid) |
| 253 | uid_ok = TRUE; |
| 254 | else if (rdata->owners != NULL) |
| 255 | { |
| 256 | int i; |
| 257 | for (i = 1; i <= (int)(rdata->owners[0]); i++) |
| 258 | if (rdata->owners[i] == statbuf.st_uid) { uid_ok = TRUE; break; } |
| 259 | } |
| 260 | } |
| 261 | |
| 262 | if (!gid_ok) |
| 263 | { |
| 264 | if (rdata->pw != NULL && statbuf.st_gid == rdata->pw->pw_gid) |
| 265 | gid_ok = TRUE; |
| 266 | else if (rdata->owngroups != NULL) |
| 267 | { |
| 268 | int i; |
| 269 | for (i = 1; i <= (int)(rdata->owngroups[0]); i++) |
| 270 | if (rdata->owngroups[i] == statbuf.st_gid) { gid_ok = TRUE; break; } |
| 271 | } |
| 272 | } |
| 273 | |
| 274 | if (!uid_ok || !gid_ok) |
| 275 | { |
| 276 | *error = string_sprintf("bad %s for %s", uid_ok? "group" : "owner", filename); |
| 277 | goto ERROR_RETURN; |
| 278 | } |
| 279 | |
| 280 | /* Put an upper limit on the size of the file, just to stop silly people |
| 281 | feeding in ridiculously large files, which can easily be created by making |
| 282 | files that have holes in them. */ |
| 283 | |
| 284 | if (statbuf.st_size > MAX_FILTER_SIZE) |
| 285 | { |
| 286 | *error = string_sprintf("%s is too big (max %d)", filename, MAX_FILTER_SIZE); |
| 287 | goto ERROR_RETURN; |
| 288 | } |
| 289 | |
| 290 | /* Read the file in one go in order to minimize the time we have it open. */ |
| 291 | |
| 292 | filebuf = store_get(statbuf.st_size + 1); |
| 293 | |
| 294 | if (fread(filebuf, 1, statbuf.st_size, fwd) != statbuf.st_size) |
| 295 | { |
| 296 | *error = string_sprintf("error while reading %s: %s", |
| 297 | filename, strerror(errno)); |
| 298 | goto ERROR_RETURN; |
| 299 | } |
| 300 | filebuf[statbuf.st_size] = 0; |
| 301 | |
| 302 | DEBUG(D_route) |
| 303 | debug_printf(OFF_T_FMT " bytes read from %s\n", statbuf.st_size, filename); |
| 304 | |
| 305 | (void)fclose(fwd); |
| 306 | return filebuf; |
| 307 | |
| 308 | /* Return an error: the string is already set up. */ |
| 309 | |
| 310 | ERROR_RETURN: |
| 311 | *yield = FF_ERROR; |
| 312 | (void)fclose(fwd); |
| 313 | return NULL; |
| 314 | } |
| 315 | |
| 316 | |
| 317 | |
| 318 | /************************************************* |
| 319 | * Extract info from list or filter * |
| 320 | *************************************************/ |
| 321 | |
| 322 | /* This function calls the appropriate function to extract addresses from a |
| 323 | forwarding list, or to run a filter file and get addresses from there. |
| 324 | |
| 325 | Arguments: |
| 326 | rdata the redirection block |
| 327 | options the options bits |
| 328 | include_directory restrain to this directory |
| 329 | sieve_vacation_directory passed to sieve_interpret |
| 330 | sieve_useraddress passed to sieve_interpret |
| 331 | sieve_subaddress passed to sieve_interpret |
| 332 | generated where to hang generated addresses |
| 333 | error for error messages |
| 334 | eblockp for details of skipped syntax errors |
| 335 | (NULL => no skip) |
| 336 | filtertype set to the filter type: |
| 337 | FILTER_FORWARD => a traditional .forward file |
| 338 | FILTER_EXIM => an Exim filter file |
| 339 | FILTER_SIEVE => a Sieve filter file |
| 340 | a system filter is always forced to be FILTER_EXIM |
| 341 | |
| 342 | Returns: a suitable return for rda_interpret() |
| 343 | */ |
| 344 | |
| 345 | static int |
| 346 | rda_extract(redirect_block *rdata, int options, uschar *include_directory, |
| 347 | uschar *sieve_vacation_directory, uschar *sieve_useraddress, |
| 348 | uschar *sieve_subaddress, address_item **generated, uschar **error, |
| 349 | error_block **eblockp, int *filtertype) |
| 350 | { |
| 351 | uschar *data; |
| 352 | |
| 353 | if (rdata->isfile) |
| 354 | { |
| 355 | int yield = 0; |
| 356 | data = rda_get_file_contents(rdata, options, error, &yield); |
| 357 | if (data == NULL) return yield; |
| 358 | } |
| 359 | else data = rdata->string; |
| 360 | |
| 361 | *filtertype = system_filtering? FILTER_EXIM : rda_is_filter(data); |
| 362 | |
| 363 | /* Filter interpretation is done by a general function that is also called from |
| 364 | the filter testing option (-bf). There are two versions: one for Exim filtering |
| 365 | and one for Sieve filtering. Several features of string expansion may be locked |
| 366 | out at sites that don't trust users. This is done by setting flags in |
| 367 | expand_forbid that the expander inspects. */ |
| 368 | |
| 369 | if (*filtertype != FILTER_FORWARD) |
| 370 | { |
| 371 | int frc; |
| 372 | int old_expand_forbid = expand_forbid; |
| 373 | |
| 374 | DEBUG(D_route) debug_printf("data is %s filter program\n", |
| 375 | (*filtertype == FILTER_EXIM)? "an Exim" : "a Sieve"); |
| 376 | |
| 377 | /* RDO_FILTER is an "allow" bit */ |
| 378 | |
| 379 | if ((options & RDO_FILTER) == 0) |
| 380 | { |
| 381 | *error = US"filtering not enabled"; |
| 382 | return FF_ERROR; |
| 383 | } |
| 384 | |
| 385 | expand_forbid = |
| 386 | (expand_forbid & ~RDO_FILTER_EXPANSIONS) | |
| 387 | (options & RDO_FILTER_EXPANSIONS); |
| 388 | |
| 389 | /* RDO_{EXIM,SIEVE}_FILTER are forbid bits */ |
| 390 | |
| 391 | if (*filtertype == FILTER_EXIM) |
| 392 | { |
| 393 | if ((options & RDO_EXIM_FILTER) != 0) |
| 394 | { |
| 395 | *error = US"Exim filtering not enabled"; |
| 396 | return FF_ERROR; |
| 397 | } |
| 398 | frc = filter_interpret(data, options, generated, error); |
| 399 | } |
| 400 | else |
| 401 | { |
| 402 | if ((options & RDO_SIEVE_FILTER) != 0) |
| 403 | { |
| 404 | *error = US"Sieve filtering not enabled"; |
| 405 | return FF_ERROR; |
| 406 | } |
| 407 | frc = sieve_interpret(data, options, sieve_vacation_directory, |
| 408 | sieve_useraddress, sieve_subaddress, generated, error); |
| 409 | } |
| 410 | |
| 411 | expand_forbid = old_expand_forbid; |
| 412 | return frc; |
| 413 | } |
| 414 | |
| 415 | /* Not a filter script */ |
| 416 | |
| 417 | DEBUG(D_route) debug_printf("file is not a filter file\n"); |
| 418 | |
| 419 | return parse_forward_list(data, |
| 420 | options, /* specials that are allowed */ |
| 421 | generated, /* where to hang them */ |
| 422 | error, /* for errors */ |
| 423 | deliver_domain, /* to qualify \name */ |
| 424 | include_directory, /* restrain to directory */ |
| 425 | eblockp); /* for skipped syntax errors */ |
| 426 | } |
| 427 | |
| 428 | |
| 429 | |
| 430 | |
| 431 | /************************************************* |
| 432 | * Write string down pipe * |
| 433 | *************************************************/ |
| 434 | |
| 435 | /* This function is used for tranferring a string down a pipe between |
| 436 | processes. If the pointer is NULL, a length of zero is written. |
| 437 | |
| 438 | Arguments: |
| 439 | fd the pipe |
| 440 | s the string |
| 441 | |
| 442 | Returns: nothing |
| 443 | */ |
| 444 | |
| 445 | static void |
| 446 | rda_write_string(int fd, uschar *s) |
| 447 | { |
| 448 | int len = (s == NULL)? 0 : Ustrlen(s) + 1; |
| 449 | (void)write(fd, &len, sizeof(int)); |
| 450 | if (s != NULL) (void)write(fd, s, len); |
| 451 | } |
| 452 | |
| 453 | |
| 454 | |
| 455 | /************************************************* |
| 456 | * Read string from pipe * |
| 457 | *************************************************/ |
| 458 | |
| 459 | /* This function is used for receiving a string from a pipe. |
| 460 | |
| 461 | Arguments: |
| 462 | fd the pipe |
| 463 | sp where to put the string |
| 464 | |
| 465 | Returns: FALSE if data missing |
| 466 | */ |
| 467 | |
| 468 | static BOOL |
| 469 | rda_read_string(int fd, uschar **sp) |
| 470 | { |
| 471 | int len; |
| 472 | |
| 473 | if (read(fd, &len, sizeof(int)) != sizeof(int)) return FALSE; |
| 474 | if (len == 0) *sp = NULL; else |
| 475 | { |
| 476 | *sp = store_get(len); |
| 477 | if (read(fd, *sp, len) != len) return FALSE; |
| 478 | } |
| 479 | return TRUE; |
| 480 | } |
| 481 | |
| 482 | |
| 483 | |
| 484 | /************************************************* |
| 485 | * Interpret forward list or filter * |
| 486 | *************************************************/ |
| 487 | |
| 488 | /* This function is passed a forward list string (unexpanded) or the name of a |
| 489 | file (unexpanded) whose contents are the forwarding list. The list may in fact |
| 490 | be a filter program if it starts with "#Exim filter" or "#Sieve filter". Other |
| 491 | types of filter, with different inital tag strings, may be introduced in due |
| 492 | course. |
| 493 | |
| 494 | The job of the function is to process the forwarding list or filter. It is |
| 495 | pulled out into this separate function, because it is used for system filter |
| 496 | files as well as from the redirect router. |
| 497 | |
| 498 | If the function is given a uid/gid, it runs a subprocess that passes the |
| 499 | results back via a pipe. This provides security for things like :include:s in |
| 500 | users' .forward files, and "logwrite" calls in users' filter files. A |
| 501 | sub-process is NOT used when: |
| 502 | |
| 503 | . No uid/gid is provided |
| 504 | . The input is a string which is not a filter string, and does not contain |
| 505 | :include: |
| 506 | . The input is a file whose non-existence can be detected in the main |
| 507 | process (which is usually running as root). |
| 508 | |
| 509 | Arguments: |
| 510 | rdata redirect data (file + constraints, or data string) |
| 511 | options options to pass to the extraction functions, |
| 512 | plus ENOTDIR and EACCES handling bits |
| 513 | include_directory restrain :include: to this directory |
| 514 | sieve_vacation_directory directory passed to sieve_interpret() |
| 515 | sieve_useraddress passed to sieve_interpret |
| 516 | sieve_subaddress passed to sieve_interpret |
| 517 | ugid uid/gid to run under - if NULL, no change |
| 518 | generated where to hang generated addresses, initially NULL |
| 519 | error pointer for error message |
| 520 | eblockp for skipped syntax errors; NULL if no skipping |
| 521 | filtertype set to the type of file: |
| 522 | FILTER_FORWARD => traditional .forward file |
| 523 | FILTER_EXIM => an Exim filter file |
| 524 | FILTER_SIEVE => a Sieve filter file |
| 525 | a system filter is always forced to be FILTER_EXIM |
| 526 | rname router name for error messages in the format |
| 527 | "xxx router" or "system filter" |
| 528 | |
| 529 | Returns: values from extraction function, or FF_NONEXIST: |
| 530 | FF_DELIVERED success, a significant action was taken |
| 531 | FF_NOTDELIVERED success, no significant action |
| 532 | FF_BLACKHOLE :blackhole: |
| 533 | FF_DEFER defer requested |
| 534 | FF_FAIL fail requested |
| 535 | FF_INCLUDEFAIL some problem with :include: |
| 536 | FF_FREEZE freeze requested |
| 537 | FF_ERROR there was a problem |
| 538 | FF_NONEXIST the file does not exist |
| 539 | */ |
| 540 | |
| 541 | int |
| 542 | rda_interpret(redirect_block *rdata, int options, uschar *include_directory, |
| 543 | uschar *sieve_vacation_directory, uschar *sieve_useraddress, |
| 544 | uschar *sieve_subaddress, ugid_block *ugid, address_item **generated, |
| 545 | uschar **error, error_block **eblockp, int *filtertype, uschar *rname) |
| 546 | { |
| 547 | int fd, rc, pfd[2]; |
| 548 | int yield, status; |
| 549 | BOOL had_disaster = FALSE; |
| 550 | pid_t pid; |
| 551 | uschar *data; |
| 552 | uschar *readerror = US""; |
| 553 | void (*oldsignal)(int); |
| 554 | |
| 555 | DEBUG(D_route) debug_printf("rda_interpret (%s): %s\n", |
| 556 | (rdata->isfile)? "file" : "string", rdata->string); |
| 557 | |
| 558 | /* Do the expansions of the file name or data first, while still privileged. */ |
| 559 | |
| 560 | data = expand_string(rdata->string); |
| 561 | if (data == NULL) |
| 562 | { |
| 563 | if (expand_string_forcedfail) return FF_NOTDELIVERED; |
| 564 | *error = string_sprintf("failed to expand \"%s\": %s", rdata->string, |
| 565 | expand_string_message); |
| 566 | return FF_ERROR; |
| 567 | } |
| 568 | rdata->string = data; |
| 569 | |
| 570 | DEBUG(D_route) debug_printf("expanded: %s\n", data); |
| 571 | |
| 572 | if (rdata->isfile && data[0] != '/') |
| 573 | { |
| 574 | *error = string_sprintf("\"%s\" is not an absolute path", data); |
| 575 | return FF_ERROR; |
| 576 | } |
| 577 | |
| 578 | /* If no uid/gid are supplied, or if we have a data string which does not start |
| 579 | with #Exim filter or #Sieve filter, and does not contain :include:, do all the |
| 580 | work in this process. Note that for a system filter, we always have a file, so |
| 581 | the work is done in this process only if no user is supplied. */ |
| 582 | |
| 583 | if (!ugid->uid_set || /* Either there's no uid, or */ |
| 584 | (!rdata->isfile && /* We've got the data, and */ |
| 585 | rda_is_filter(data) == FILTER_FORWARD && /* It's not a filter script, */ |
| 586 | Ustrstr(data, ":include:") == NULL)) /* and there's no :include: */ |
| 587 | { |
| 588 | return rda_extract(rdata, options, include_directory, |
| 589 | sieve_vacation_directory, sieve_useraddress, sieve_subaddress, |
| 590 | generated, error, eblockp, filtertype); |
| 591 | } |
| 592 | |
| 593 | /* We need to run the processing code in a sub-process. However, if we can |
| 594 | determine the non-existence of a file first, we can decline without having to |
| 595 | create the sub-process. */ |
| 596 | |
| 597 | if (rdata->isfile && rda_exists(data, error) == FILE_NOT_EXIST) |
| 598 | return FF_NONEXIST; |
| 599 | |
| 600 | /* If the file does exist, or we can't tell (non-root mounted NFS directory) |
| 601 | we have to create the subprocess to do everything as the given user. The |
| 602 | results of processing are passed back via a pipe. */ |
| 603 | |
| 604 | if (pipe(pfd) != 0) |
| 605 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "creation of pipe for filter or " |
| 606 | ":include: failed for %s: %s", rname, strerror(errno)); |
| 607 | |
| 608 | /* Ensure that SIGCHLD is set to SIG_DFL before forking, so that the child |
| 609 | process can be waited for. We sometimes get here with it set otherwise. Save |
| 610 | the old state for resetting on the wait. Ensure that all cached resources are |
| 611 | freed so that the subprocess starts with a clean slate and doesn't interfere |
| 612 | with the parent process. */ |
| 613 | |
| 614 | oldsignal = signal(SIGCHLD, SIG_DFL); |
| 615 | search_tidyup(); |
| 616 | |
| 617 | if ((pid = fork()) == 0) |
| 618 | { |
| 619 | header_line *waslast = header_last; /* Save last header */ |
| 620 | |
| 621 | fd = pfd[pipe_write]; |
| 622 | (void)close(pfd[pipe_read]); |
| 623 | exim_setugid(ugid->uid, ugid->gid, FALSE, rname); |
| 624 | |
| 625 | /* Addresses can get rewritten in filters; if we are not root or the exim |
| 626 | user (and we probably are not), turn off rewrite logging, because we cannot |
| 627 | write to the log now. */ |
| 628 | |
| 629 | if (ugid->uid != root_uid && ugid->uid != exim_uid) |
| 630 | { |
| 631 | DEBUG(D_rewrite) debug_printf("turned off address rewrite logging (not " |
| 632 | "root or exim in this process)\n"); |
| 633 | log_write_selector &= ~L_address_rewrite; |
| 634 | } |
| 635 | |
| 636 | /* Now do the business */ |
| 637 | |
| 638 | yield = rda_extract(rdata, options, include_directory, |
| 639 | sieve_vacation_directory, sieve_useraddress, sieve_subaddress, generated, |
| 640 | error, eblockp, filtertype); |
| 641 | |
| 642 | /* Pass back whether it was a filter, and the return code and any overall |
| 643 | error text via the pipe. */ |
| 644 | |
| 645 | (void)write(fd, filtertype, sizeof(int)); |
| 646 | (void)write(fd, &yield, sizeof(int)); |
| 647 | rda_write_string(fd, *error); |
| 648 | |
| 649 | /* Pass back the contents of any syntax error blocks if we have a pointer */ |
| 650 | |
| 651 | if (eblockp != NULL) |
| 652 | { |
| 653 | error_block *ep; |
| 654 | for (ep = *eblockp; ep != NULL; ep = ep->next) |
| 655 | { |
| 656 | rda_write_string(fd, ep->text1); |
| 657 | rda_write_string(fd, ep->text2); |
| 658 | } |
| 659 | rda_write_string(fd, NULL); /* Indicates end of eblocks */ |
| 660 | } |
| 661 | |
| 662 | /* If this is a system filter, we have to pass back the numbers of any |
| 663 | original header lines that were removed, and then any header lines that were |
| 664 | added but not subsequently removed. */ |
| 665 | |
| 666 | if (system_filtering) |
| 667 | { |
| 668 | int i = 0; |
| 669 | header_line *h; |
| 670 | for (h = header_list; h != waslast->next; i++, h = h->next) |
| 671 | { |
| 672 | if (h->type == htype_old) (void)write(fd, &i, sizeof(i)); |
| 673 | } |
| 674 | i = -1; |
| 675 | (void)write(fd, &i, sizeof(i)); |
| 676 | |
| 677 | while (waslast != header_last) |
| 678 | { |
| 679 | waslast = waslast->next; |
| 680 | if (waslast->type != htype_old) |
| 681 | { |
| 682 | rda_write_string(fd, waslast->text); |
| 683 | (void)write(fd, &(waslast->type), sizeof(waslast->type)); |
| 684 | } |
| 685 | } |
| 686 | rda_write_string(fd, NULL); /* Indicates end of added headers */ |
| 687 | } |
| 688 | |
| 689 | /* Write the contents of the $n variables */ |
| 690 | |
| 691 | (void)write(fd, filter_n, sizeof(filter_n)); |
| 692 | |
| 693 | /* If the result was DELIVERED or NOTDELIVERED, we pass back the generated |
| 694 | addresses, and their associated information, through the pipe. This is |
| 695 | just tedious, but it seems to be the only safe way. We do this also for |
| 696 | FAIL and FREEZE, because a filter is allowed to set up deliveries that |
| 697 | are honoured before freezing or failing. */ |
| 698 | |
| 699 | if (yield == FF_DELIVERED || yield == FF_NOTDELIVERED || |
| 700 | yield == FF_FAIL || yield == FF_FREEZE) |
| 701 | { |
| 702 | address_item *addr; |
| 703 | for (addr = *generated; addr != NULL; addr = addr->next) |
| 704 | { |
| 705 | int reply_options = 0; |
| 706 | |
| 707 | rda_write_string(fd, addr->address); |
| 708 | (void)write(fd, &(addr->mode), sizeof(addr->mode)); |
| 709 | (void)write(fd, &(addr->flags), sizeof(addr->flags)); |
| 710 | rda_write_string(fd, addr->p.errors_address); |
| 711 | |
| 712 | if (addr->pipe_expandn != NULL) |
| 713 | { |
| 714 | uschar **pp; |
| 715 | for (pp = addr->pipe_expandn; *pp != NULL; pp++) |
| 716 | rda_write_string(fd, *pp); |
| 717 | } |
| 718 | rda_write_string(fd, NULL); |
| 719 | |
| 720 | if (addr->reply == NULL) |
| 721 | (void)write(fd, &reply_options, sizeof(int)); /* 0 means no reply */ |
| 722 | else |
| 723 | { |
| 724 | reply_options |= REPLY_EXISTS; |
| 725 | if (addr->reply->file_expand) reply_options |= REPLY_EXPAND; |
| 726 | if (addr->reply->return_message) reply_options |= REPLY_RETURN; |
| 727 | (void)write(fd, &reply_options, sizeof(int)); |
| 728 | (void)write(fd, &(addr->reply->expand_forbid), sizeof(int)); |
| 729 | (void)write(fd, &(addr->reply->once_repeat), sizeof(time_t)); |
| 730 | rda_write_string(fd, addr->reply->to); |
| 731 | rda_write_string(fd, addr->reply->cc); |
| 732 | rda_write_string(fd, addr->reply->bcc); |
| 733 | rda_write_string(fd, addr->reply->from); |
| 734 | rda_write_string(fd, addr->reply->reply_to); |
| 735 | rda_write_string(fd, addr->reply->subject); |
| 736 | rda_write_string(fd, addr->reply->headers); |
| 737 | rda_write_string(fd, addr->reply->text); |
| 738 | rda_write_string(fd, addr->reply->file); |
| 739 | rda_write_string(fd, addr->reply->logfile); |
| 740 | rda_write_string(fd, addr->reply->oncelog); |
| 741 | } |
| 742 | } |
| 743 | |
| 744 | rda_write_string(fd, NULL); /* Marks end of addresses */ |
| 745 | } |
| 746 | |
| 747 | /* OK, this process is now done. Free any cached resources. Must use _exit() |
| 748 | and not exit() !! */ |
| 749 | |
| 750 | (void)close(fd); |
| 751 | search_tidyup(); |
| 752 | _exit(0); |
| 753 | } |
| 754 | |
| 755 | /* Back in the main process: panic if the fork did not succeed. */ |
| 756 | |
| 757 | if (pid < 0) |
| 758 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "fork failed for %s", rname); |
| 759 | |
| 760 | /* Read the pipe to get the data from the filter/forward. Our copy of the |
| 761 | writing end must be closed first, as otherwise read() won't return zero on an |
| 762 | empty pipe. Afterwards, close the reading end. */ |
| 763 | |
| 764 | (void)close(pfd[pipe_write]); |
| 765 | |
| 766 | /* Read initial data, including yield and contents of *error */ |
| 767 | |
| 768 | fd = pfd[pipe_read]; |
| 769 | if (read(fd, filtertype, sizeof(int)) != sizeof(int) || |
| 770 | read(fd, &yield, sizeof(int)) != sizeof(int) || |
| 771 | !rda_read_string(fd, error)) goto DISASTER; |
| 772 | |
| 773 | /* Read the contents of any syntax error blocks if we have a pointer */ |
| 774 | |
| 775 | if (eblockp != NULL) |
| 776 | { |
| 777 | uschar *s; |
| 778 | error_block *e; |
| 779 | error_block **p = eblockp; |
| 780 | for (;;) |
| 781 | { |
| 782 | if (!rda_read_string(fd, &s)) goto DISASTER; |
| 783 | if (s == NULL) break; |
| 784 | e = store_get(sizeof(error_block)); |
| 785 | e->next = NULL; |
| 786 | e->text1 = s; |
| 787 | if (!rda_read_string(fd, &s)) goto DISASTER; |
| 788 | e->text2 = s; |
| 789 | *p = e; |
| 790 | p = &(e->next); |
| 791 | } |
| 792 | } |
| 793 | |
| 794 | /* If this is a system filter, read the identify of any original header lines |
| 795 | that were removed, and then read data for any new ones that were added. */ |
| 796 | |
| 797 | if (system_filtering) |
| 798 | { |
| 799 | int hn = 0; |
| 800 | header_line *h = header_list; |
| 801 | |
| 802 | for (;;) |
| 803 | { |
| 804 | int n; |
| 805 | if (read(fd, &n, sizeof(int)) != sizeof(int)) goto DISASTER; |
| 806 | if (n < 0) break; |
| 807 | while (hn < n) |
| 808 | { |
| 809 | hn++; |
| 810 | h = h->next; |
| 811 | if (h == NULL) goto DISASTER_NO_HEADER; |
| 812 | } |
| 813 | h->type = htype_old; |
| 814 | } |
| 815 | |
| 816 | for (;;) |
| 817 | { |
| 818 | uschar *s; |
| 819 | int type; |
| 820 | if (!rda_read_string(fd, &s)) goto DISASTER; |
| 821 | if (s == NULL) break; |
| 822 | if (read(fd, &type, sizeof(type)) != sizeof(type)) goto DISASTER; |
| 823 | header_add(type, "%s", s); |
| 824 | } |
| 825 | } |
| 826 | |
| 827 | /* Read the values of the $n variables */ |
| 828 | |
| 829 | if (read(fd, filter_n, sizeof(filter_n)) != sizeof(filter_n)) goto DISASTER; |
| 830 | |
| 831 | /* If the yield is DELIVERED, NOTDELIVERED, FAIL, or FREEZE there may follow |
| 832 | addresses and data to go with them. Keep them in the same order in the |
| 833 | generated chain. */ |
| 834 | |
| 835 | if (yield == FF_DELIVERED || yield == FF_NOTDELIVERED || |
| 836 | yield == FF_FAIL || yield == FF_FREEZE) |
| 837 | { |
| 838 | address_item **nextp = generated; |
| 839 | |
| 840 | for (;;) |
| 841 | { |
| 842 | int i, reply_options; |
| 843 | address_item *addr; |
| 844 | uschar *recipient; |
| 845 | uschar *expandn[EXPAND_MAXN + 2]; |
| 846 | |
| 847 | /* First string is the address; NULL => end of addresses */ |
| 848 | |
| 849 | if (!rda_read_string(fd, &recipient)) goto DISASTER; |
| 850 | if (recipient == NULL) break; |
| 851 | |
| 852 | /* Hang on the end of the chain */ |
| 853 | |
| 854 | addr = deliver_make_addr(recipient, FALSE); |
| 855 | *nextp = addr; |
| 856 | nextp = &(addr->next); |
| 857 | |
| 858 | /* Next comes the mode and the flags fields */ |
| 859 | |
| 860 | if (read(fd, &(addr->mode), sizeof(addr->mode)) != sizeof(addr->mode) || |
| 861 | read(fd, &(addr->flags), sizeof(addr->flags)) != sizeof(addr->flags) || |
| 862 | !rda_read_string(fd, &(addr->p.errors_address))) goto DISASTER; |
| 863 | |
| 864 | /* Next comes a possible setting for $thisaddress and any numerical |
| 865 | variables for pipe expansion, terminated by a NULL string. The maximum |
| 866 | number of numericals is EXPAND_MAXN. Note that we put filter_thisaddress |
| 867 | into the zeroth item in the vector - this is sorted out inside the pipe |
| 868 | transport. */ |
| 869 | |
| 870 | for (i = 0; i < EXPAND_MAXN + 1; i++) |
| 871 | { |
| 872 | uschar *temp; |
| 873 | if (!rda_read_string(fd, &temp)) goto DISASTER; |
| 874 | if (i == 0) filter_thisaddress = temp; /* Just in case */ |
| 875 | expandn[i] = temp; |
| 876 | if (temp == NULL) break; |
| 877 | } |
| 878 | |
| 879 | if (i > 0) |
| 880 | { |
| 881 | addr->pipe_expandn = store_get((i+1) * sizeof(uschar **)); |
| 882 | addr->pipe_expandn[i] = NULL; |
| 883 | while (--i >= 0) addr->pipe_expandn[i] = expandn[i]; |
| 884 | } |
| 885 | |
| 886 | /* Then an int containing reply options; zero => no reply data. */ |
| 887 | |
| 888 | if (read(fd, &reply_options, sizeof(int)) != sizeof(int)) goto DISASTER; |
| 889 | if ((reply_options & REPLY_EXISTS) != 0) |
| 890 | { |
| 891 | addr->reply = store_get(sizeof(reply_item)); |
| 892 | |
| 893 | addr->reply->file_expand = (reply_options & REPLY_EXPAND) != 0; |
| 894 | addr->reply->return_message = (reply_options & REPLY_RETURN) != 0; |
| 895 | |
| 896 | if (read(fd,&(addr->reply->expand_forbid),sizeof(int)) != |
| 897 | sizeof(int) || |
| 898 | read(fd,&(addr->reply->once_repeat),sizeof(time_t)) != |
| 899 | sizeof(time_t) || |
| 900 | !rda_read_string(fd, &(addr->reply->to)) || |
| 901 | !rda_read_string(fd, &(addr->reply->cc)) || |
| 902 | !rda_read_string(fd, &(addr->reply->bcc)) || |
| 903 | !rda_read_string(fd, &(addr->reply->from)) || |
| 904 | !rda_read_string(fd, &(addr->reply->reply_to)) || |
| 905 | !rda_read_string(fd, &(addr->reply->subject)) || |
| 906 | !rda_read_string(fd, &(addr->reply->headers)) || |
| 907 | !rda_read_string(fd, &(addr->reply->text)) || |
| 908 | !rda_read_string(fd, &(addr->reply->file)) || |
| 909 | !rda_read_string(fd, &(addr->reply->logfile)) || |
| 910 | !rda_read_string(fd, &(addr->reply->oncelog))) |
| 911 | goto DISASTER; |
| 912 | } |
| 913 | } |
| 914 | } |
| 915 | |
| 916 | /* All data has been transferred from the sub-process. Reap it, close the |
| 917 | reading end of the pipe, and we are done. */ |
| 918 | |
| 919 | WAIT_EXIT: |
| 920 | while ((rc = wait(&status)) != pid) |
| 921 | { |
| 922 | if (rc < 0 && errno == ECHILD) /* Process has vanished */ |
| 923 | { |
| 924 | log_write(0, LOG_MAIN, "redirection process %d vanished unexpectedly", pid); |
| 925 | goto FINAL_EXIT; |
| 926 | } |
| 927 | } |
| 928 | |
| 929 | DEBUG(D_route) |
| 930 | debug_printf("rda_interpret: subprocess yield=%d error=%s\n", yield, *error); |
| 931 | |
| 932 | if (had_disaster) |
| 933 | { |
| 934 | *error = string_sprintf("internal problem in %s: failure to transfer " |
| 935 | "data from subprocess: status=%04x%s%s%s", rname, |
| 936 | status, readerror, |
| 937 | (*error == NULL)? US"" : US": error=", |
| 938 | (*error == NULL)? US"" : *error); |
| 939 | log_write(0, LOG_MAIN|LOG_PANIC, "%s", *error); |
| 940 | } |
| 941 | else if (status != 0) |
| 942 | { |
| 943 | log_write(0, LOG_MAIN|LOG_PANIC, "internal problem in %s: unexpected status " |
| 944 | "%04x from redirect subprocess (but data correctly received)", rname, |
| 945 | status); |
| 946 | } |
| 947 | |
| 948 | FINAL_EXIT: |
| 949 | (void)close(fd); |
| 950 | signal(SIGCHLD, oldsignal); /* restore */ |
| 951 | return yield; |
| 952 | |
| 953 | |
| 954 | /* Come here if the data indicates removal of a header that we can't find */ |
| 955 | |
| 956 | DISASTER_NO_HEADER: |
| 957 | readerror = US" readerror=bad header identifier"; |
| 958 | had_disaster = TRUE; |
| 959 | yield = FF_ERROR; |
| 960 | goto WAIT_EXIT; |
| 961 | |
| 962 | /* Come here is there's a shambles in transferring the data over the pipe. The |
| 963 | value of errno should still be set. */ |
| 964 | |
| 965 | DISASTER: |
| 966 | readerror = string_sprintf(" readerror='%s'", strerror(errno)); |
| 967 | had_disaster = TRUE; |
| 968 | yield = FF_ERROR; |
| 969 | goto WAIT_EXIT; |
| 970 | } |
| 971 | |
| 972 | /* End of rda.c */ |