| 1 | /************************************************* |
| 2 | * Exim - an Internet mail transport agent * |
| 3 | *************************************************/ |
| 4 | |
| 5 | /* Copyright (c) University of Cambridge 1995 - 2009 */ |
| 6 | /* See the file NOTICE for conditions of use and distribution. */ |
| 7 | |
| 8 | |
| 9 | #include "../exim.h" |
| 10 | #include "appendfile.h" |
| 11 | |
| 12 | #ifdef SUPPORT_MAILDIR |
| 13 | #include "tf_maildir.h" |
| 14 | #endif |
| 15 | |
| 16 | |
| 17 | /* Encodings for mailbox formats, and their names. MBX format is actually |
| 18 | supported only if SUPPORT_MBX is set. */ |
| 19 | |
| 20 | enum { mbf_unix, mbf_mbx, mbf_smail, mbf_maildir, mbf_mailstore }; |
| 21 | |
| 22 | static const char *mailbox_formats[] = { |
| 23 | "unix", "mbx", "smail", "maildir", "mailstore" }; |
| 24 | |
| 25 | |
| 26 | /* Check warn threshold only if quota size set or not a percentage threshold |
| 27 | percentage check should only be done if quota > 0 */ |
| 28 | |
| 29 | #define THRESHOLD_CHECK (ob->quota_warn_threshold_value > 0 && \ |
| 30 | (!ob->quota_warn_threshold_is_percent || ob->quota_value > 0)) |
| 31 | |
| 32 | |
| 33 | /* Options specific to the appendfile transport. They must be in alphabetic |
| 34 | order (note that "_" comes before the lower case letters). Some of them are |
| 35 | stored in the publicly visible instance block - these are flagged with the |
| 36 | opt_public flag. */ |
| 37 | |
| 38 | optionlist appendfile_transport_options[] = { |
| 39 | #ifdef SUPPORT_MAILDIR |
| 40 | { "*expand_maildir_use_size_file", opt_stringptr, |
| 41 | (void *)offsetof(appendfile_transport_options_block, expand_maildir_use_size_file) }, |
| 42 | #endif |
| 43 | { "*set_use_fcntl_lock",opt_bool | opt_hidden, |
| 44 | (void *)offsetof(appendfile_transport_options_block, set_use_fcntl) }, |
| 45 | { "*set_use_flock_lock",opt_bool | opt_hidden, |
| 46 | (void *)offsetof(appendfile_transport_options_block, set_use_flock) }, |
| 47 | { "*set_use_lockfile", opt_bool | opt_hidden, |
| 48 | (void *)offsetof(appendfile_transport_options_block, set_use_lockfile) }, |
| 49 | #ifdef SUPPORT_MBX |
| 50 | { "*set_use_mbx_lock", opt_bool | opt_hidden, |
| 51 | (void *)offsetof(appendfile_transport_options_block, set_use_mbx_lock) }, |
| 52 | #endif |
| 53 | { "allow_fifo", opt_bool, |
| 54 | (void *)offsetof(appendfile_transport_options_block, allow_fifo) }, |
| 55 | { "allow_symlink", opt_bool, |
| 56 | (void *)offsetof(appendfile_transport_options_block, allow_symlink) }, |
| 57 | { "batch_id", opt_stringptr | opt_public, |
| 58 | (void *)offsetof(transport_instance, batch_id) }, |
| 59 | { "batch_max", opt_int | opt_public, |
| 60 | (void *)offsetof(transport_instance, batch_max) }, |
| 61 | { "check_group", opt_bool, |
| 62 | (void *)offsetof(appendfile_transport_options_block, check_group) }, |
| 63 | { "check_owner", opt_bool, |
| 64 | (void *)offsetof(appendfile_transport_options_block, check_owner) }, |
| 65 | { "check_string", opt_stringptr, |
| 66 | (void *)offsetof(appendfile_transport_options_block, check_string) }, |
| 67 | { "create_directory", opt_bool, |
| 68 | (void *)offsetof(appendfile_transport_options_block, create_directory) }, |
| 69 | { "create_file", opt_stringptr, |
| 70 | (void *)offsetof(appendfile_transport_options_block, create_file_string) }, |
| 71 | { "directory", opt_stringptr, |
| 72 | (void *)offsetof(appendfile_transport_options_block, dirname) }, |
| 73 | { "directory_file", opt_stringptr, |
| 74 | (void *)offsetof(appendfile_transport_options_block, dirfilename) }, |
| 75 | { "directory_mode", opt_octint, |
| 76 | (void *)offsetof(appendfile_transport_options_block, dirmode) }, |
| 77 | { "escape_string", opt_stringptr, |
| 78 | (void *)offsetof(appendfile_transport_options_block, escape_string) }, |
| 79 | { "file", opt_stringptr, |
| 80 | (void *)offsetof(appendfile_transport_options_block, filename) }, |
| 81 | { "file_format", opt_stringptr, |
| 82 | (void *)offsetof(appendfile_transport_options_block, file_format) }, |
| 83 | { "file_must_exist", opt_bool, |
| 84 | (void *)offsetof(appendfile_transport_options_block, file_must_exist) }, |
| 85 | { "lock_fcntl_timeout", opt_time, |
| 86 | (void *)offsetof(appendfile_transport_options_block, lock_fcntl_timeout) }, |
| 87 | { "lock_flock_timeout", opt_time, |
| 88 | (void *)offsetof(appendfile_transport_options_block, lock_flock_timeout) }, |
| 89 | { "lock_interval", opt_time, |
| 90 | (void *)offsetof(appendfile_transport_options_block, lock_interval) }, |
| 91 | { "lock_retries", opt_int, |
| 92 | (void *)offsetof(appendfile_transport_options_block, lock_retries) }, |
| 93 | { "lockfile_mode", opt_octint, |
| 94 | (void *)offsetof(appendfile_transport_options_block, lockfile_mode) }, |
| 95 | { "lockfile_timeout", opt_time, |
| 96 | (void *)offsetof(appendfile_transport_options_block, lockfile_timeout) }, |
| 97 | { "mailbox_filecount", opt_stringptr, |
| 98 | (void *)offsetof(appendfile_transport_options_block, mailbox_filecount_string) }, |
| 99 | { "mailbox_size", opt_stringptr, |
| 100 | (void *)offsetof(appendfile_transport_options_block, mailbox_size_string) }, |
| 101 | #ifdef SUPPORT_MAILDIR |
| 102 | { "maildir_format", opt_bool, |
| 103 | (void *)offsetof(appendfile_transport_options_block, maildir_format ) } , |
| 104 | { "maildir_quota_directory_regex", opt_stringptr, |
| 105 | (void *)offsetof(appendfile_transport_options_block, maildir_dir_regex) }, |
| 106 | { "maildir_retries", opt_int, |
| 107 | (void *)offsetof(appendfile_transport_options_block, maildir_retries) }, |
| 108 | { "maildir_tag", opt_stringptr, |
| 109 | (void *)offsetof(appendfile_transport_options_block, maildir_tag) }, |
| 110 | { "maildir_use_size_file", opt_expand_bool, |
| 111 | (void *)offsetof(appendfile_transport_options_block, maildir_use_size_file ) } , |
| 112 | { "maildirfolder_create_regex", opt_stringptr, |
| 113 | (void *)offsetof(appendfile_transport_options_block, maildirfolder_create_regex ) }, |
| 114 | #endif /* SUPPORT_MAILDIR */ |
| 115 | #ifdef SUPPORT_MAILSTORE |
| 116 | { "mailstore_format", opt_bool, |
| 117 | (void *)offsetof(appendfile_transport_options_block, mailstore_format ) }, |
| 118 | { "mailstore_prefix", opt_stringptr, |
| 119 | (void *)offsetof(appendfile_transport_options_block, mailstore_prefix ) }, |
| 120 | { "mailstore_suffix", opt_stringptr, |
| 121 | (void *)offsetof(appendfile_transport_options_block, mailstore_suffix ) }, |
| 122 | #endif /* SUPPORT_MAILSTORE */ |
| 123 | #ifdef SUPPORT_MBX |
| 124 | { "mbx_format", opt_bool, |
| 125 | (void *)offsetof(appendfile_transport_options_block, mbx_format ) } , |
| 126 | #endif /* SUPPORT_MBX */ |
| 127 | { "message_prefix", opt_stringptr, |
| 128 | (void *)offsetof(appendfile_transport_options_block, message_prefix) }, |
| 129 | { "message_suffix", opt_stringptr, |
| 130 | (void *)offsetof(appendfile_transport_options_block, message_suffix) }, |
| 131 | { "mode", opt_octint, |
| 132 | (void *)offsetof(appendfile_transport_options_block, mode) }, |
| 133 | { "mode_fail_narrower",opt_bool, |
| 134 | (void *)offsetof(appendfile_transport_options_block, mode_fail_narrower) }, |
| 135 | { "notify_comsat", opt_bool, |
| 136 | (void *)offsetof(appendfile_transport_options_block, notify_comsat) }, |
| 137 | { "quota", opt_stringptr, |
| 138 | (void *)offsetof(appendfile_transport_options_block, quota) }, |
| 139 | { "quota_directory", opt_stringptr, |
| 140 | (void *)offsetof(appendfile_transport_options_block, quota_directory) }, |
| 141 | { "quota_filecount", opt_stringptr, |
| 142 | (void *)offsetof(appendfile_transport_options_block, quota_filecount) }, |
| 143 | { "quota_is_inclusive", opt_bool, |
| 144 | (void *)offsetof(appendfile_transport_options_block, quota_is_inclusive) }, |
| 145 | { "quota_size_regex", opt_stringptr, |
| 146 | (void *)offsetof(appendfile_transport_options_block, quota_size_regex) }, |
| 147 | { "quota_warn_message", opt_stringptr | opt_public, |
| 148 | (void *)offsetof(transport_instance, warn_message) }, |
| 149 | { "quota_warn_threshold", opt_stringptr, |
| 150 | (void *)offsetof(appendfile_transport_options_block, quota_warn_threshold) }, |
| 151 | { "use_bsmtp", opt_bool, |
| 152 | (void *)offsetof(appendfile_transport_options_block, use_bsmtp) }, |
| 153 | { "use_crlf", opt_bool, |
| 154 | (void *)offsetof(appendfile_transport_options_block, use_crlf) }, |
| 155 | { "use_fcntl_lock", opt_bool_set, |
| 156 | (void *)offsetof(appendfile_transport_options_block, use_fcntl) }, |
| 157 | { "use_flock_lock", opt_bool_set, |
| 158 | (void *)offsetof(appendfile_transport_options_block, use_flock) }, |
| 159 | { "use_lockfile", opt_bool_set, |
| 160 | (void *)offsetof(appendfile_transport_options_block, use_lockfile) }, |
| 161 | #ifdef SUPPORT_MBX |
| 162 | { "use_mbx_lock", opt_bool_set, |
| 163 | (void *)offsetof(appendfile_transport_options_block, use_mbx_lock) }, |
| 164 | #endif /* SUPPORT_MBX */ |
| 165 | }; |
| 166 | |
| 167 | /* Size of the options list. An extern variable has to be used so that its |
| 168 | address can appear in the tables drtables.c. */ |
| 169 | |
| 170 | int appendfile_transport_options_count = |
| 171 | sizeof(appendfile_transport_options)/sizeof(optionlist); |
| 172 | |
| 173 | /* Default private options block for the appendfile transport. */ |
| 174 | |
| 175 | appendfile_transport_options_block appendfile_transport_option_defaults = { |
| 176 | NULL, /* filename */ |
| 177 | NULL, /* dirname */ |
| 178 | US"q${base62:$tod_epoch}-$inode", /* dirfilename */ |
| 179 | NULL, /* message_prefix (default reset in init if not bsmtp) */ |
| 180 | NULL, /* message_suffix (ditto) */ |
| 181 | US"anywhere", /* create_file_string (string value for create_file) */ |
| 182 | NULL, /* quota */ |
| 183 | NULL, /* quota_directory */ |
| 184 | NULL, /* quota_filecount */ |
| 185 | NULL, /* quota_size_regex */ |
| 186 | NULL, /* quota_warn_threshold */ |
| 187 | NULL, /* mailbox_size_string */ |
| 188 | NULL, /* mailbox_filecount_string */ |
| 189 | NULL, /* expand_maildir_use_size_file */ |
| 190 | US"^(?:cur|new|\\..*)$", /* maildir_dir_regex */ |
| 191 | NULL, /* maildir_tag */ |
| 192 | NULL, /* maildirfolder_create_regex */ |
| 193 | NULL, /* mailstore_prefix */ |
| 194 | NULL, /* mailstore_suffix */ |
| 195 | NULL, /* check_string (default changed for non-bsmtp file)*/ |
| 196 | NULL, /* escape_string (ditto) */ |
| 197 | NULL, /* file_format */ |
| 198 | 0, /* quota_value */ |
| 199 | 0, /* quota_warn_threshold_value */ |
| 200 | -1, /* mailbox_size_value */ |
| 201 | -1, /* mailbox_filecount_value */ |
| 202 | 0, /* quota_filecount_value */ |
| 203 | APPENDFILE_MODE, /* mode */ |
| 204 | APPENDFILE_DIRECTORY_MODE, /* dirmode */ |
| 205 | APPENDFILE_LOCKFILE_MODE, /* lockfile_mode */ |
| 206 | 30*60, /* lockfile_timeout */ |
| 207 | 0, /* lock_fcntl_timeout */ |
| 208 | 0, /* lock_flock_timeout */ |
| 209 | 10, /* lock_retries */ |
| 210 | 3, /* lock_interval */ |
| 211 | 10, /* maildir_retries */ |
| 212 | create_anywhere,/* create_file */ |
| 213 | 0, /* options */ |
| 214 | FALSE, /* allow_fifo */ |
| 215 | FALSE, /* allow_symlink */ |
| 216 | FALSE, /* check_group */ |
| 217 | TRUE, /* check_owner */ |
| 218 | TRUE, /* create_directory */ |
| 219 | FALSE, /* notify_comsat */ |
| 220 | TRUE, /* use_lockfile */ |
| 221 | FALSE, /* set_use_lockfile */ |
| 222 | TRUE, /* use_fcntl */ |
| 223 | FALSE, /* set_use_fcntl */ |
| 224 | FALSE, /* use_flock */ |
| 225 | FALSE, /* set_use_flock */ |
| 226 | FALSE, /* use_mbx_lock */ |
| 227 | FALSE, /* set_use_mbx_lock */ |
| 228 | FALSE, /* use_bsmtp */ |
| 229 | FALSE, /* use_crlf */ |
| 230 | FALSE, /* file_must_exist */ |
| 231 | TRUE, /* mode_fail_narrower */ |
| 232 | FALSE, /* maildir_format */ |
| 233 | FALSE, /* maildir_use_size_file */ |
| 234 | FALSE, /* mailstore_format */ |
| 235 | FALSE, /* mbx_format */ |
| 236 | FALSE, /* quota_warn_threshold_is_percent */ |
| 237 | TRUE /* quota_is_inclusive */ |
| 238 | }; |
| 239 | |
| 240 | |
| 241 | |
| 242 | /************************************************* |
| 243 | * Setup entry point * |
| 244 | *************************************************/ |
| 245 | |
| 246 | /* Called for each delivery in the privileged state, just before the uid/gid |
| 247 | are changed and the main entry point is called. We use this function to |
| 248 | expand any quota settings, so that it can access files that may not be readable |
| 249 | by the user. It is also used to pick up external mailbox size information, if |
| 250 | set. |
| 251 | |
| 252 | Arguments: |
| 253 | tblock points to the transport instance |
| 254 | addrlist addresses about to be delivered (not used) |
| 255 | dummy not used (doesn't pass back data) |
| 256 | uid the uid that will be set (not used) |
| 257 | gid the gid that will be set (not used) |
| 258 | errmsg where to put an error message |
| 259 | |
| 260 | Returns: OK, FAIL, or DEFER |
| 261 | */ |
| 262 | |
| 263 | static int |
| 264 | appendfile_transport_setup(transport_instance *tblock, address_item *addrlist, |
| 265 | transport_feedback *dummy, uid_t uid, gid_t gid, uschar **errmsg) |
| 266 | { |
| 267 | appendfile_transport_options_block *ob = |
| 268 | (appendfile_transport_options_block *)(tblock->options_block); |
| 269 | uschar *q = ob->quota; |
| 270 | double default_value = 0.0; |
| 271 | int i; |
| 272 | |
| 273 | addrlist = addrlist; /* Keep picky compilers happy */ |
| 274 | dummy = dummy; |
| 275 | uid = uid; |
| 276 | gid = gid; |
| 277 | |
| 278 | if (ob->expand_maildir_use_size_file) |
| 279 | ob->maildir_use_size_file = expand_check_condition(ob->expand_maildir_use_size_file, |
| 280 | US"`maildir_use_size_file` in transport", tblock->name); |
| 281 | |
| 282 | /* Loop for quota, quota_filecount, quota_warn_threshold, mailbox_size, |
| 283 | mailbox_filecount */ |
| 284 | |
| 285 | for (i = 0; i < 5; i++) |
| 286 | { |
| 287 | double d; |
| 288 | uschar *which = NULL; |
| 289 | |
| 290 | if (q == NULL) d = default_value; else |
| 291 | { |
| 292 | uschar *rest; |
| 293 | uschar *s = expand_string(q); |
| 294 | |
| 295 | if (s == NULL) |
| 296 | { |
| 297 | *errmsg = string_sprintf("Expansion of \"%s\" in %s transport failed: " |
| 298 | "%s", q, tblock->name, expand_string_message); |
| 299 | return search_find_defer? DEFER : FAIL; |
| 300 | } |
| 301 | |
| 302 | d = Ustrtod(s, &rest); |
| 303 | |
| 304 | /* Handle following characters K, M, G, %, the latter being permitted |
| 305 | for quota_warn_threshold only. A threshold with no quota setting is |
| 306 | just ignored. */ |
| 307 | |
| 308 | if (tolower(*rest) == 'k') { d *= 1024.0; rest++; } |
| 309 | else if (tolower(*rest) == 'm') { d *= 1024.0*1024.0; rest++; } |
| 310 | else if (tolower(*rest) == 'g') { d *= 1024.0*1024.0*1024.0; rest++; } |
| 311 | else if (*rest == '%' && i == 2) |
| 312 | { |
| 313 | if (ob->quota_value <= 0 && !ob->maildir_use_size_file) d = 0; |
| 314 | else if ((int)d < 0 || (int)d > 100) |
| 315 | { |
| 316 | *errmsg = string_sprintf("Invalid quota_warn_threshold percentage (%d)" |
| 317 | " for %s transport", (int)d, tblock->name); |
| 318 | return FAIL; |
| 319 | } |
| 320 | ob->quota_warn_threshold_is_percent = TRUE; |
| 321 | rest++; |
| 322 | } |
| 323 | |
| 324 | while (isspace(*rest)) rest++; |
| 325 | |
| 326 | if (*rest != 0) |
| 327 | { |
| 328 | *errmsg = string_sprintf("Malformed value \"%s\" (expansion of \"%s\") " |
| 329 | "in %s transport", s, q, tblock->name); |
| 330 | return FAIL; |
| 331 | } |
| 332 | } |
| 333 | |
| 334 | /* Set each value, checking for possible overflow. */ |
| 335 | |
| 336 | switch (i) |
| 337 | { |
| 338 | case 0: |
| 339 | if (d >= 2.0*1024.0*1024.0*1024.0 && sizeof(off_t) <= 4) which = US"quota"; |
| 340 | ob->quota_value = (off_t)d; |
| 341 | q = ob->quota_filecount; |
| 342 | break; |
| 343 | |
| 344 | case 1: |
| 345 | if (d >= 2.0*1024.0*1024.0*1024.0) which = US"quota_filecount"; |
| 346 | ob->quota_filecount_value = (int)d; |
| 347 | q = ob->quota_warn_threshold; |
| 348 | break; |
| 349 | |
| 350 | case 2: |
| 351 | if (d >= 2.0*1024.0*1024.0*1024.0 && sizeof(off_t) <= 4) |
| 352 | which = US"quota_warn_threshold"; |
| 353 | ob->quota_warn_threshold_value = (off_t)d; |
| 354 | q = ob->mailbox_size_string; |
| 355 | default_value = -1.0; |
| 356 | break; |
| 357 | |
| 358 | case 3: |
| 359 | if (d >= 2.0*1024.0*1024.0*1024.0 && sizeof(off_t) <= 4) |
| 360 | which = US"mailbox_size";; |
| 361 | ob->mailbox_size_value = (off_t)d; |
| 362 | q = ob->mailbox_filecount_string; |
| 363 | break; |
| 364 | |
| 365 | case 4: |
| 366 | if (d >= 2.0*1024.0*1024.0*1024.0) which = US"mailbox_filecount"; |
| 367 | ob->mailbox_filecount_value = (int)d; |
| 368 | break; |
| 369 | } |
| 370 | |
| 371 | if (which != NULL) |
| 372 | { |
| 373 | *errmsg = string_sprintf("%s value %.10g is too large (overflow) in " |
| 374 | "%s transport", which, d, tblock->name); |
| 375 | return FAIL; |
| 376 | } |
| 377 | } |
| 378 | |
| 379 | return OK; |
| 380 | } |
| 381 | |
| 382 | |
| 383 | |
| 384 | /************************************************* |
| 385 | * Initialization entry point * |
| 386 | *************************************************/ |
| 387 | |
| 388 | /* Called for each instance, after its options have been read, to |
| 389 | enable consistency checks to be done, or anything else that needs |
| 390 | to be set up. */ |
| 391 | |
| 392 | void |
| 393 | appendfile_transport_init(transport_instance *tblock) |
| 394 | { |
| 395 | appendfile_transport_options_block *ob = |
| 396 | (appendfile_transport_options_block *)(tblock->options_block); |
| 397 | |
| 398 | /* Set up the setup entry point, to be called in the privileged state */ |
| 399 | |
| 400 | tblock->setup = appendfile_transport_setup; |
| 401 | |
| 402 | /* Lock_retries must be greater than zero */ |
| 403 | |
| 404 | if (ob->lock_retries == 0) ob->lock_retries = 1; |
| 405 | |
| 406 | /* Only one of a file name or directory name must be given. */ |
| 407 | |
| 408 | if (ob->filename != NULL && ob->dirname != NULL) |
| 409 | log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s transport:\n " |
| 410 | "only one of \"file\" or \"directory\" can be specified", tblock->name); |
| 411 | |
| 412 | /* If a file name was specified, neither quota_filecount nor quota_directory |
| 413 | must be given. */ |
| 414 | |
| 415 | if (ob->filename != NULL) |
| 416 | { |
| 417 | if (ob->quota_filecount != NULL) |
| 418 | log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s transport:\n " |
| 419 | "quota_filecount must not be set without \"directory\"", tblock->name); |
| 420 | if (ob->quota_directory != NULL) |
| 421 | log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s transport:\n " |
| 422 | "quota_directory must not be set without \"directory\"", tblock->name); |
| 423 | } |
| 424 | |
| 425 | /* The default locking depends on whether MBX is set or not. Change the |
| 426 | built-in default if none of the lock options has been explicitly set. At least |
| 427 | one form of locking is required in all cases, but mbx locking changes the |
| 428 | meaning of fcntl and flock locking. */ |
| 429 | |
| 430 | /* Not all operating systems provide flock(). For those that do, if flock is |
| 431 | requested, the default for fcntl is FALSE. */ |
| 432 | |
| 433 | if (ob->use_flock) |
| 434 | { |
| 435 | #ifdef NO_FLOCK |
| 436 | log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s transport:\n " |
| 437 | "flock() support was not available in the operating system when this " |
| 438 | "binary was built", tblock->name); |
| 439 | #endif /* NO_FLOCK */ |
| 440 | if (!ob->set_use_fcntl) ob->use_fcntl = FALSE; |
| 441 | } |
| 442 | |
| 443 | #ifdef SUPPORT_MBX |
| 444 | if (ob->mbx_format) |
| 445 | { |
| 446 | if (!ob->set_use_lockfile && !ob->set_use_fcntl && !ob->set_use_flock && |
| 447 | !ob->set_use_mbx_lock) |
| 448 | { |
| 449 | ob->use_lockfile = ob->use_flock = FALSE; |
| 450 | ob->use_mbx_lock = ob->use_fcntl = TRUE; |
| 451 | } |
| 452 | else if (ob->use_mbx_lock) |
| 453 | { |
| 454 | if (!ob->set_use_lockfile) ob->use_lockfile = FALSE; |
| 455 | if (!ob->set_use_fcntl) ob->use_fcntl = FALSE; |
| 456 | if (!ob->set_use_flock) ob->use_flock = FALSE; |
| 457 | if (!ob->use_fcntl && !ob->use_flock) ob->use_fcntl = TRUE; |
| 458 | } |
| 459 | } |
| 460 | #endif /* SUPPORT_MBX */ |
| 461 | |
| 462 | if (!ob->use_fcntl && !ob->use_flock && !ob->use_lockfile && !ob->use_mbx_lock) |
| 463 | log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s transport:\n " |
| 464 | "no locking configured", tblock->name); |
| 465 | |
| 466 | /* Unset timeouts for non-used locking types */ |
| 467 | |
| 468 | if (!ob->use_fcntl) ob->lock_fcntl_timeout = 0; |
| 469 | if (!ob->use_flock) ob->lock_flock_timeout = 0; |
| 470 | |
| 471 | /* If a directory name was specified, only one of maildir or mailstore may be |
| 472 | specified, and if quota_filecount or quota_directory is given, quota must |
| 473 | be set. */ |
| 474 | |
| 475 | if (ob->dirname != NULL) |
| 476 | { |
| 477 | if (ob->maildir_format && ob->mailstore_format) |
| 478 | log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s transport:\n " |
| 479 | "only one of maildir and mailstore may be specified", tblock->name); |
| 480 | if (ob->quota_filecount != NULL && ob->quota == NULL) |
| 481 | log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s transport:\n " |
| 482 | "quota must be set if quota_filecount is set", tblock->name); |
| 483 | if (ob->quota_directory != NULL && ob->quota == NULL) |
| 484 | log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s transport:\n " |
| 485 | "quota must be set if quota_directory is set", tblock->name); |
| 486 | } |
| 487 | |
| 488 | /* If a fixed uid field is set, then a gid field must also be set. */ |
| 489 | |
| 490 | if (tblock->uid_set && !tblock->gid_set && tblock->expand_gid == NULL) |
| 491 | log_write(0, LOG_PANIC_DIE|LOG_CONFIG, |
| 492 | "user set without group for the %s transport", tblock->name); |
| 493 | |
| 494 | /* If "create_file" is set, check that a valid option is given, and set the |
| 495 | integer variable. */ |
| 496 | |
| 497 | if (ob->create_file_string != NULL) |
| 498 | { |
| 499 | int value = 0; |
| 500 | if (Ustrcmp(ob->create_file_string, "anywhere") == 0) value = create_anywhere; |
| 501 | else if (Ustrcmp(ob->create_file_string, "belowhome") == 0) value = |
| 502 | create_belowhome; |
| 503 | else if (Ustrcmp(ob->create_file_string, "inhome") == 0) |
| 504 | value = create_inhome; |
| 505 | else |
| 506 | log_write(0, LOG_PANIC_DIE|LOG_CONFIG, |
| 507 | "invalid value given for \"file_create\" for the %s transport: %s", |
| 508 | tblock->name, ob->create_file_string); |
| 509 | ob->create_file = value; |
| 510 | } |
| 511 | |
| 512 | /* If quota_warn_threshold is set, set up default for warn_message. It may |
| 513 | not be used if the actual threshold for a given delivery ends up as zero, |
| 514 | of if it's given as a percentage and there's no quota setting. */ |
| 515 | |
| 516 | if (ob->quota_warn_threshold != NULL) |
| 517 | { |
| 518 | if (tblock->warn_message == NULL) tblock->warn_message = US |
| 519 | "To: $local_part@$domain\n" |
| 520 | "Subject: Your mailbox\n\n" |
| 521 | "This message is automatically created by mail delivery software (Exim).\n\n" |
| 522 | "The size of your mailbox has exceeded a warning threshold that is\n" |
| 523 | "set by the system administrator.\n"; |
| 524 | } |
| 525 | |
| 526 | /* If batch SMTP is set, force the check and escape strings, and arrange that |
| 527 | headers are also escaped. */ |
| 528 | |
| 529 | if (ob->use_bsmtp) |
| 530 | { |
| 531 | ob->check_string = US"."; |
| 532 | ob->escape_string = US".."; |
| 533 | ob->options |= topt_escape_headers; |
| 534 | } |
| 535 | |
| 536 | /* If not batch SMTP, not maildir, not mailstore, and directory is not set, |
| 537 | insert default values for for the affixes and the check/escape strings. */ |
| 538 | |
| 539 | else if (ob->dirname == NULL && !ob->maildir_format && !ob->mailstore_format) |
| 540 | { |
| 541 | if (ob->message_prefix == NULL) ob->message_prefix = |
| 542 | US"From ${if def:return_path{$return_path}{MAILER-DAEMON}} ${tod_bsdinbox}\n"; |
| 543 | if (ob->message_suffix == NULL) ob->message_suffix = US"\n"; |
| 544 | if (ob->check_string == NULL) ob->check_string = US"From "; |
| 545 | if (ob->escape_string == NULL) ob->escape_string = US">From "; |
| 546 | |
| 547 | } |
| 548 | |
| 549 | /* Set up the bitwise options for transport_write_message from the various |
| 550 | driver options. Only one of body_only and headers_only can be set. */ |
| 551 | |
| 552 | ob->options |= |
| 553 | (tblock->body_only? topt_no_headers : 0) | |
| 554 | (tblock->headers_only? topt_no_body : 0) | |
| 555 | (tblock->return_path_add? topt_add_return_path : 0) | |
| 556 | (tblock->delivery_date_add? topt_add_delivery_date : 0) | |
| 557 | (tblock->envelope_to_add? topt_add_envelope_to : 0) | |
| 558 | ((ob->use_crlf || ob->mbx_format)? topt_use_crlf : 0); |
| 559 | } |
| 560 | |
| 561 | |
| 562 | |
| 563 | /************************************************* |
| 564 | * Notify comsat * |
| 565 | *************************************************/ |
| 566 | |
| 567 | /* The comsat daemon is the thing that provides asynchronous notification of |
| 568 | the arrival of local messages, if requested by the user by "biff y". It is a |
| 569 | BSD thing that uses a TCP/IP protocol for communication. A message consisting |
| 570 | of the text "user@offset" must be sent, where offset is the place in the |
| 571 | mailbox where new mail starts. There is no scope for telling it which file to |
| 572 | look at, which makes it a less than useful if mail is being delivered into a |
| 573 | non-standard place such as the user's home directory. In fact, it doesn't seem |
| 574 | to pay much attention to the offset. |
| 575 | |
| 576 | Arguments: |
| 577 | user user name |
| 578 | offset offset in mailbox |
| 579 | |
| 580 | Returns: nothing |
| 581 | */ |
| 582 | |
| 583 | static void |
| 584 | notify_comsat(uschar *user, off_t offset) |
| 585 | { |
| 586 | struct servent *sp; |
| 587 | host_item host; |
| 588 | host_item *h; |
| 589 | uschar buffer[256]; |
| 590 | |
| 591 | DEBUG(D_transport) debug_printf("notify_comsat called\n"); |
| 592 | |
| 593 | sprintf(CS buffer, "%.200s@" OFF_T_FMT "\n", user, offset); |
| 594 | |
| 595 | if ((sp = getservbyname("biff", "udp")) == NULL) |
| 596 | { |
| 597 | DEBUG(D_transport) debug_printf("biff/udp is an unknown service"); |
| 598 | return; |
| 599 | } |
| 600 | |
| 601 | host.name = US"localhost"; |
| 602 | host.next = NULL; |
| 603 | |
| 604 | |
| 605 | /* This code is all set up to look up "localhost" and use all its addresses |
| 606 | until one succeeds. However, it appears that at least on some systems, comsat |
| 607 | doesn't listen on the ::1 address. So for the moment, just force the address to |
| 608 | be 127.0.0.1. At some future stage, when IPv6 really is superseding IPv4, this |
| 609 | can be changed. (But actually, comsat is probably dying out anyway.) */ |
| 610 | |
| 611 | /****** |
| 612 | if (host_find_byname(&host, NULL, 0, NULL, FALSE) == HOST_FIND_FAILED) |
| 613 | { |
| 614 | DEBUG(D_transport) debug_printf("\"localhost\" unknown\n"); |
| 615 | return; |
| 616 | } |
| 617 | ******/ |
| 618 | |
| 619 | host.address = US"127.0.0.1"; |
| 620 | |
| 621 | |
| 622 | for (h = &host; h != NULL; h = h->next) |
| 623 | { |
| 624 | int sock, rc; |
| 625 | int host_af = (Ustrchr(h->address, ':') != NULL)? AF_INET6 : AF_INET; |
| 626 | |
| 627 | DEBUG(D_transport) debug_printf("calling comsat on %s\n", h->address); |
| 628 | |
| 629 | sock = ip_socket(SOCK_DGRAM, host_af); |
| 630 | if (sock < 0) continue; |
| 631 | |
| 632 | /* Connect never fails for a UDP socket, so don't set a timeout. */ |
| 633 | |
| 634 | (void)ip_connect(sock, host_af, h->address, ntohs(sp->s_port), 0); |
| 635 | rc = send(sock, buffer, Ustrlen(buffer) + 1, 0); |
| 636 | (void)close(sock); |
| 637 | |
| 638 | if (rc >= 0) break; |
| 639 | DEBUG(D_transport) |
| 640 | debug_printf("send to comsat failed for %s: %s\n", strerror(errno), |
| 641 | h->address); |
| 642 | } |
| 643 | } |
| 644 | |
| 645 | |
| 646 | |
| 647 | /************************************************* |
| 648 | * Check the format of a file * |
| 649 | *************************************************/ |
| 650 | |
| 651 | /* This function is called when file_format is set, to check that an existing |
| 652 | file has the right format. The format string contains text/transport pairs. The |
| 653 | string matching is literal. we just read big_buffer_size bytes, because this is |
| 654 | all about the first few bytes of a file. |
| 655 | |
| 656 | Arguments: |
| 657 | cfd the open file |
| 658 | tblock the transport block |
| 659 | addr the address block - for inserting error data |
| 660 | |
| 661 | Returns: pointer to the required transport, or NULL |
| 662 | */ |
| 663 | |
| 664 | transport_instance * |
| 665 | check_file_format(int cfd, transport_instance *tblock, address_item *addr) |
| 666 | { |
| 667 | uschar *format = |
| 668 | ((appendfile_transport_options_block *)(tblock->options_block))->file_format; |
| 669 | uschar data[256]; |
| 670 | int len = read(cfd, data, sizeof(data)); |
| 671 | int sep = 0; |
| 672 | uschar *s; |
| 673 | |
| 674 | DEBUG(D_transport) debug_printf("checking file format\n"); |
| 675 | |
| 676 | /* An empty file matches the current transport */ |
| 677 | |
| 678 | if (len == 0) return tblock; |
| 679 | |
| 680 | /* Search the formats for a match */ |
| 681 | |
| 682 | while ((s = string_nextinlist(&format,&sep,big_buffer,big_buffer_size))!= NULL) |
| 683 | { |
| 684 | int slen = Ustrlen(s); |
| 685 | BOOL match = len >= slen && Ustrncmp(data, s, slen) == 0; |
| 686 | uschar *tp = string_nextinlist(&format, &sep, big_buffer, big_buffer_size); |
| 687 | if (match) |
| 688 | { |
| 689 | transport_instance *tt; |
| 690 | for (tt = transports; tt != NULL; tt = tt->next) |
| 691 | if (Ustrcmp(tp, tt->name) == 0) |
| 692 | { |
| 693 | DEBUG(D_transport) |
| 694 | debug_printf("file format -> %s transport\n", tt->name); |
| 695 | return tt; |
| 696 | } |
| 697 | addr->basic_errno = ERRNO_BADTRANSPORT; |
| 698 | addr->message = string_sprintf("%s transport (for %.*s format) not found", |
| 699 | tp, slen, data); |
| 700 | return NULL; |
| 701 | } |
| 702 | } |
| 703 | |
| 704 | /* Failed to find a match */ |
| 705 | |
| 706 | addr->basic_errno = ERRNO_FORMATUNKNOWN; |
| 707 | addr->message = US"mailbox file format unrecognized"; |
| 708 | return NULL; |
| 709 | } |
| 710 | |
| 711 | |
| 712 | |
| 713 | |
| 714 | /************************************************* |
| 715 | * Check directory's files for quota * |
| 716 | *************************************************/ |
| 717 | |
| 718 | /* This function is called if quota is set for one of the delivery modes that |
| 719 | delivers into a specific directory. It scans the directory and stats all the |
| 720 | files in order to get a total size and count. This is an expensive thing to do, |
| 721 | but some people are prepared to bear the cost. Alternatively, if size_regex is |
| 722 | set, it is used as a regex to try to extract the size from the file name, a |
| 723 | strategy that some people use on maildir files on systems where the users have |
| 724 | no shell access. |
| 725 | |
| 726 | The function is global, because it is also called from tf_maildir.c for maildir |
| 727 | folders (which should contain only regular files). |
| 728 | |
| 729 | Note: Any problems can be written to debugging output, but cannot be written to |
| 730 | the log, because we are running as an unprivileged user here. |
| 731 | |
| 732 | Arguments: |
| 733 | dirname the name of the directory |
| 734 | countptr where to add the file count (because this function recurses) |
| 735 | regex a compiled regex to get the size from a name |
| 736 | |
| 737 | Returns: the sum of the sizes of the stattable files |
| 738 | zero if the directory cannot be opened |
| 739 | */ |
| 740 | |
| 741 | off_t |
| 742 | check_dir_size(uschar *dirname, int *countptr, const pcre *regex) |
| 743 | { |
| 744 | DIR *dir; |
| 745 | off_t sum = 0; |
| 746 | int count = *countptr; |
| 747 | struct dirent *ent; |
| 748 | struct stat statbuf; |
| 749 | |
| 750 | dir = opendir(CS dirname); |
| 751 | if (dir == NULL) return 0; |
| 752 | |
| 753 | while ((ent = readdir(dir)) != NULL) |
| 754 | { |
| 755 | uschar *name = US ent->d_name; |
| 756 | uschar buffer[1024]; |
| 757 | |
| 758 | if (Ustrcmp(name, ".") == 0 || Ustrcmp(name, "..") == 0) continue; |
| 759 | |
| 760 | count++; |
| 761 | |
| 762 | /* If there's a regex, try to find the size using it */ |
| 763 | |
| 764 | if (regex != NULL) |
| 765 | { |
| 766 | int ovector[6]; |
| 767 | if (pcre_exec(regex, NULL, CS name, Ustrlen(name), 0, 0, ovector,6) >= 2) |
| 768 | { |
| 769 | uschar *endptr; |
| 770 | off_t size = (off_t)Ustrtod(name + ovector[2], &endptr); |
| 771 | if (endptr == name + ovector[3]) |
| 772 | { |
| 773 | sum += size; |
| 774 | DEBUG(D_transport) |
| 775 | debug_printf("check_dir_size: size from %s is " OFF_T_FMT "\n", name, |
| 776 | size); |
| 777 | continue; |
| 778 | } |
| 779 | } |
| 780 | DEBUG(D_transport) |
| 781 | debug_printf("check_dir_size: regex did not match %s\n", name); |
| 782 | } |
| 783 | |
| 784 | /* No regex or no match for the regex, or captured non-digits */ |
| 785 | |
| 786 | if (!string_format(buffer, sizeof(buffer), "%s/%s", dirname, name)) |
| 787 | { |
| 788 | DEBUG(D_transport) |
| 789 | debug_printf("check_dir_size: name too long: dir=%s name=%s\n", dirname, |
| 790 | name); |
| 791 | continue; |
| 792 | } |
| 793 | |
| 794 | if (Ustat(buffer, &statbuf) < 0) |
| 795 | { |
| 796 | DEBUG(D_transport) |
| 797 | debug_printf("check_dir_size: stat error %d for %s: %s\n", errno, buffer, |
| 798 | strerror(errno)); |
| 799 | continue; |
| 800 | } |
| 801 | |
| 802 | if ((statbuf.st_mode & S_IFMT) == S_IFREG) |
| 803 | sum += statbuf.st_size; |
| 804 | else if ((statbuf.st_mode & S_IFMT) == S_IFDIR) |
| 805 | sum += check_dir_size(buffer, &count, regex); |
| 806 | } |
| 807 | |
| 808 | closedir(dir); |
| 809 | DEBUG(D_transport) |
| 810 | debug_printf("check_dir_size: dir=%s sum=" OFF_T_FMT " count=%d\n", dirname, |
| 811 | sum, count); |
| 812 | |
| 813 | *countptr = count; |
| 814 | return sum; |
| 815 | } |
| 816 | |
| 817 | |
| 818 | |
| 819 | |
| 820 | /************************************************* |
| 821 | * Apply a lock to a file descriptor * |
| 822 | *************************************************/ |
| 823 | |
| 824 | /* This function applies a lock to a file descriptor, using a blocking or |
| 825 | non-blocking lock, depending on the timeout value. It can apply either or |
| 826 | both of a fcntl() and a flock() lock. However, not all OS support flock(); |
| 827 | for those that don't, the use_flock option cannot be set. |
| 828 | |
| 829 | Arguments: |
| 830 | fd the file descriptor |
| 831 | fcntltype type of lock, specified as F_WRLCK or F_RDLCK (that is, in |
| 832 | fcntl() format); the flock() type is deduced if needed |
| 833 | dofcntl do fcntl() locking |
| 834 | fcntltime non-zero to use blocking fcntl() |
| 835 | doflock do flock() locking |
| 836 | flocktime non-zero to use blocking flock() |
| 837 | |
| 838 | Returns: yield of the fcntl() or flock() call, with errno preserved; |
| 839 | sigalrm_seen set if there has been a timeout |
| 840 | */ |
| 841 | |
| 842 | static int |
| 843 | apply_lock(int fd, int fcntltype, BOOL dofcntl, int fcntltime, BOOL doflock, |
| 844 | int flocktime) |
| 845 | { |
| 846 | int yield = 0; |
| 847 | int save_errno; |
| 848 | struct flock lock_data; |
| 849 | lock_data.l_type = fcntltype; |
| 850 | lock_data.l_whence = lock_data.l_start = lock_data.l_len = 0; |
| 851 | |
| 852 | sigalrm_seen = FALSE; |
| 853 | |
| 854 | if (dofcntl) |
| 855 | { |
| 856 | if (fcntltime > 0) |
| 857 | { |
| 858 | alarm(fcntltime); |
| 859 | yield = fcntl(fd, F_SETLKW, &lock_data); |
| 860 | save_errno = errno; |
| 861 | alarm(0); |
| 862 | errno = save_errno; |
| 863 | } |
| 864 | else yield = fcntl(fd, F_SETLK, &lock_data); |
| 865 | } |
| 866 | |
| 867 | #ifndef NO_FLOCK |
| 868 | if (doflock && (yield >= 0)) |
| 869 | { |
| 870 | int flocktype = (fcntltype == F_WRLCK)? LOCK_EX : LOCK_SH; |
| 871 | if (flocktime > 0) |
| 872 | { |
| 873 | alarm(flocktime); |
| 874 | yield = flock(fd, flocktype); |
| 875 | save_errno = errno; |
| 876 | alarm(0); |
| 877 | errno = save_errno; |
| 878 | } |
| 879 | else yield = flock(fd, flocktype | LOCK_NB); |
| 880 | } |
| 881 | #endif /* NO_FLOCK */ |
| 882 | |
| 883 | return yield; |
| 884 | } |
| 885 | |
| 886 | |
| 887 | |
| 888 | |
| 889 | #ifdef SUPPORT_MBX |
| 890 | /************************************************* |
| 891 | * Copy message into MBX mailbox * |
| 892 | *************************************************/ |
| 893 | |
| 894 | /* This function is called when a message intended for a MBX mailbox has been |
| 895 | written to a temporary file. We can now get the size of the message and then |
| 896 | copy it in MBX format to the mailbox. |
| 897 | |
| 898 | Arguments: |
| 899 | to_fd fd to write to (the real mailbox) |
| 900 | from_fd fd to read from (the temporary file) |
| 901 | saved_size current size of mailbox |
| 902 | |
| 903 | Returns: OK if all went well, DEFER otherwise, with errno preserved |
| 904 | the number of bytes written are added to transport_count |
| 905 | by virtue of calling transport_write_block() |
| 906 | */ |
| 907 | |
| 908 | /* Values taken from c-client */ |
| 909 | |
| 910 | #define MBX_HDRSIZE 2048 |
| 911 | #define MBX_NUSERFLAGS 30 |
| 912 | |
| 913 | static int |
| 914 | copy_mbx_message(int to_fd, int from_fd, off_t saved_size) |
| 915 | { |
| 916 | int used; |
| 917 | off_t size; |
| 918 | struct stat statbuf; |
| 919 | |
| 920 | /* If the current mailbox size is zero, write a header block */ |
| 921 | |
| 922 | if (saved_size == 0) |
| 923 | { |
| 924 | int i; |
| 925 | uschar *s; |
| 926 | memset (deliver_out_buffer, '\0', MBX_HDRSIZE); |
| 927 | sprintf(CS(s = deliver_out_buffer), "*mbx*\015\012%08lx00000000\015\012", |
| 928 | (long int)time(NULL)); |
| 929 | for (i = 0; i < MBX_NUSERFLAGS; i++) |
| 930 | sprintf (CS(s += Ustrlen(s)), "\015\012"); |
| 931 | if (!transport_write_block (to_fd, deliver_out_buffer, MBX_HDRSIZE)) |
| 932 | return DEFER; |
| 933 | } |
| 934 | |
| 935 | DEBUG(D_transport) debug_printf("copying MBX message from temporary file\n"); |
| 936 | |
| 937 | /* Now construct the message's header from the time and the RFC822 file |
| 938 | size, including CRLFs, which is the size of the input (temporary) file. */ |
| 939 | |
| 940 | if (fstat(from_fd, &statbuf) < 0) return DEFER; |
| 941 | size = statbuf.st_size; |
| 942 | |
| 943 | sprintf (CS deliver_out_buffer, "%s," OFF_T_FMT ";%08lx%04x-%08x\015\012", |
| 944 | tod_stamp(tod_mbx), size, 0L, 0, 0); |
| 945 | used = Ustrlen(deliver_out_buffer); |
| 946 | |
| 947 | /* Rewind the temporary file, and copy it over in chunks. */ |
| 948 | |
| 949 | lseek(from_fd, 0 , SEEK_SET); |
| 950 | |
| 951 | while (size > 0) |
| 952 | { |
| 953 | int len = read(from_fd, deliver_out_buffer + used, |
| 954 | DELIVER_OUT_BUFFER_SIZE - used); |
| 955 | if (len <= 0) |
| 956 | { |
| 957 | if (len == 0) errno = ERRNO_MBXLENGTH; |
| 958 | return DEFER; |
| 959 | } |
| 960 | if (!transport_write_block(to_fd, deliver_out_buffer, used + len)) |
| 961 | return DEFER; |
| 962 | size -= len; |
| 963 | used = 0; |
| 964 | } |
| 965 | |
| 966 | return OK; |
| 967 | } |
| 968 | #endif /* SUPPORT_MBX */ |
| 969 | |
| 970 | |
| 971 | |
| 972 | /************************************************* |
| 973 | * Check creation is permitted * |
| 974 | *************************************************/ |
| 975 | |
| 976 | /* This function checks whether a given file name is permitted to be created, |
| 977 | as controlled by the create_file option. If no home directory is set, however, |
| 978 | we can't do any tests. |
| 979 | |
| 980 | Arguments: |
| 981 | filename the file name |
| 982 | create_file the ob->create_file option |
| 983 | |
| 984 | Returns: TRUE if creation is permitted |
| 985 | */ |
| 986 | |
| 987 | static BOOL |
| 988 | check_creation(uschar *filename, int create_file) |
| 989 | { |
| 990 | BOOL yield = TRUE; |
| 991 | |
| 992 | if (deliver_home != NULL && create_file != create_anywhere) |
| 993 | { |
| 994 | int len = Ustrlen(deliver_home); |
| 995 | uschar *file = filename; |
| 996 | |
| 997 | while (file[0] == '/' && file[1] == '/') file++; |
| 998 | if (Ustrncmp(file, deliver_home, len) != 0 || file[len] != '/' || |
| 999 | ( Ustrchr(file+len+2, '/') != NULL && |
| 1000 | ( |
| 1001 | create_file != create_belowhome || |
| 1002 | Ustrstr(file+len, "/../") != NULL |
| 1003 | ) |
| 1004 | ) |
| 1005 | ) yield = FALSE; |
| 1006 | |
| 1007 | /* If yield is TRUE, the file name starts with the home directory, and does |
| 1008 | not contain any instances of "/../" in the "belowhome" case. However, it may |
| 1009 | still contain symbolic links. We can check for this by making use of |
| 1010 | realpath(), which most Unixes seem to have (but make it possible to cut this |
| 1011 | out). We can't just use realpath() on the whole file name, because we know |
| 1012 | the file itself doesn't exist, and intermediate directories may also not |
| 1013 | exist. What we want to know is the real path of the longest existing part of |
| 1014 | the path. That must match the home directory's beginning, whichever is the |
| 1015 | shorter. */ |
| 1016 | |
| 1017 | #ifndef NO_REALPATH |
| 1018 | if (yield && create_file == create_belowhome) |
| 1019 | { |
| 1020 | uschar *slash, *next; |
| 1021 | uschar *rp = NULL; |
| 1022 | for (slash = Ustrrchr(file, '/'); /* There is known to be one */ |
| 1023 | rp == NULL && slash > file; /* Stop if reached beginning */ |
| 1024 | slash = next) |
| 1025 | { |
| 1026 | *slash = 0; |
| 1027 | rp = US realpath(CS file, CS big_buffer); |
| 1028 | next = Ustrrchr(file, '/'); |
| 1029 | *slash = '/'; |
| 1030 | } |
| 1031 | |
| 1032 | /* If rp == NULL it means that none of the relevant directories exist. |
| 1033 | This is not a problem here - it means that no symbolic links can exist, |
| 1034 | which is all we are worried about. Otherwise, we must compare it |
| 1035 | against the start of the home directory. However, that may itself |
| 1036 | contain symbolic links, so we have to "realpath" it as well, if |
| 1037 | possible. */ |
| 1038 | |
| 1039 | if (rp != NULL) |
| 1040 | { |
| 1041 | uschar hdbuffer[PATH_MAX+1]; |
| 1042 | uschar *rph = deliver_home; |
| 1043 | int rlen = Ustrlen(big_buffer); |
| 1044 | |
| 1045 | rp = US realpath(CS deliver_home, CS hdbuffer); |
| 1046 | if (rp != NULL) |
| 1047 | { |
| 1048 | rph = hdbuffer; |
| 1049 | len = Ustrlen(rph); |
| 1050 | } |
| 1051 | |
| 1052 | if (rlen > len) rlen = len; |
| 1053 | if (Ustrncmp(rph, big_buffer, rlen) != 0) |
| 1054 | { |
| 1055 | yield = FALSE; |
| 1056 | DEBUG(D_transport) debug_printf("Real path \"%s\" does not match \"%s\"\n", |
| 1057 | big_buffer, deliver_home); |
| 1058 | } |
| 1059 | } |
| 1060 | } |
| 1061 | #endif /* NO_REALPATH */ |
| 1062 | } |
| 1063 | |
| 1064 | return yield; |
| 1065 | } |
| 1066 | |
| 1067 | |
| 1068 | |
| 1069 | /************************************************* |
| 1070 | * Main entry point * |
| 1071 | *************************************************/ |
| 1072 | |
| 1073 | /* See local README for general interface details. This transport always |
| 1074 | returns FALSE, indicating that the status which has been placed in the first |
| 1075 | address should be copied to any other addresses in a batch. |
| 1076 | |
| 1077 | Appendfile delivery is tricky and has led to various security problems in other |
| 1078 | mailers. The logic used here is therefore laid out in some detail. When this |
| 1079 | function is called, we are running in a subprocess which has had its gid and |
| 1080 | uid set to the appropriate values. Therefore, we cannot write directly to the |
| 1081 | exim logs. Any errors must be handled by setting appropriate return codes. |
| 1082 | Note that the default setting for addr->transport_return is DEFER, so it need |
| 1083 | not be set unless some other value is required. |
| 1084 | |
| 1085 | The code below calls geteuid() rather than getuid() to get the current uid |
| 1086 | because in weird configurations not running setuid root there may be a |
| 1087 | difference. In the standard configuration, where setuid() has been used in the |
| 1088 | delivery process, there will be no difference between the uid and the euid. |
| 1089 | |
| 1090 | (1) If the af_file flag is set, this is a delivery to a file after .forward or |
| 1091 | alias expansion. Otherwise, there must be a configured file name or |
| 1092 | directory name. |
| 1093 | |
| 1094 | The following items apply in the case when a file name (as opposed to a |
| 1095 | directory name) is given, that is, when appending to a single file: |
| 1096 | |
| 1097 | (2f) Expand the file name. |
| 1098 | |
| 1099 | (3f) If the file name is /dev/null, return success (optimization). |
| 1100 | |
| 1101 | (4f) If the file_format options is set, open the file for reading, and check |
| 1102 | that the bytes at the start of the file match one of the given strings. |
| 1103 | If the check indicates a transport other than the current one should be |
| 1104 | used, pass control to that other transport. Otherwise continue. An empty |
| 1105 | or non-existent file matches the current transport. The file is closed |
| 1106 | after the check. |
| 1107 | |
| 1108 | (5f) If a lock file is required, create it (see extensive separate comments |
| 1109 | below about the algorithm for doing this). It is important to do this |
| 1110 | before opening the mailbox if NFS is in use. |
| 1111 | |
| 1112 | (6f) Stat the file, using lstat() rather than stat(), in order to pick up |
| 1113 | details of any symbolic link. |
| 1114 | |
| 1115 | (7f) If the file already exists: |
| 1116 | |
| 1117 | Check the owner and group if necessary, and defer if they are wrong. |
| 1118 | |
| 1119 | If it is a symbolic link AND the allow_symlink option is set (NOT the |
| 1120 | default), go back to (6f) but this time use stat() instead of lstat(). |
| 1121 | |
| 1122 | If it's not a regular file (or FIFO when permitted), defer delivery. |
| 1123 | |
| 1124 | Check permissions. If the required permissions are *less* than the |
| 1125 | existing ones, or supplied by the address (often by the user via filter), |
| 1126 | chmod() the file. Otherwise, defer. |
| 1127 | |
| 1128 | Save the inode number. |
| 1129 | |
| 1130 | Open with O_RDRW + O_APPEND, thus failing if the file has vanished. |
| 1131 | |
| 1132 | If open fails because the file does not exist, go to (6f); on any other |
| 1133 | failure, defer. |
| 1134 | |
| 1135 | Check the inode number hasn't changed - I realize this isn't perfect (an |
| 1136 | inode can be reused) but it's cheap and will catch some of the races. |
| 1137 | |
| 1138 | Check it's still a regular file (or FIFO if permitted). |
| 1139 | |
| 1140 | Check that the owner and permissions haven't changed. |
| 1141 | |
| 1142 | If file_format is set, check that the file still matches the format for |
| 1143 | the current transport. If not, defer delivery. |
| 1144 | |
| 1145 | (8f) If file does not exist initially: |
| 1146 | |
| 1147 | Open with O_WRONLY + O_EXCL + O_CREAT with configured mode, unless we know |
| 1148 | this is via a symbolic link (only possible if allow_symlinks is set), in |
| 1149 | which case don't use O_EXCL, as it dosn't work. |
| 1150 | |
| 1151 | If open fails because the file already exists, go to (6f). To avoid |
| 1152 | looping for ever in a situation where the file is continuously being |
| 1153 | created and deleted, all of this happens inside a loop that operates |
| 1154 | lock_retries times and includes the fcntl and flock locking. If the |
| 1155 | loop completes without the file getting opened, defer and request |
| 1156 | freezing, because something really weird is happening. |
| 1157 | |
| 1158 | If open fails for any other reason, defer for subsequent delivery except |
| 1159 | when this is a file delivery resulting from an alias or forward expansion |
| 1160 | and the error is EPERM or ENOENT or EACCES, in which case FAIL as this is |
| 1161 | most likely a user rather than a configuration error. |
| 1162 | |
| 1163 | (9f) We now have the file checked and open for writing. If so configured, lock |
| 1164 | it using fcntl, flock, or MBX locking rules. If this fails, close the file |
| 1165 | and goto (6f), up to lock_retries times, after sleeping for a while. If it |
| 1166 | still fails, give up and defer delivery. |
| 1167 | |
| 1168 | (10f)Save the access time (for subsequent restoration) and the size of the |
| 1169 | file, for comsat and for re-setting if delivery fails in the middle - |
| 1170 | e.g. for quota exceeded. |
| 1171 | |
| 1172 | The following items apply in the case when a directory name is given: |
| 1173 | |
| 1174 | (2d) Create a new file in the directory using a temporary name, by opening for |
| 1175 | writing and with O_CREAT. If maildir format is being used, the file |
| 1176 | is created in a temporary subdirectory with a prescribed name. If |
| 1177 | mailstore format is being used, the envelope file is first created with a |
| 1178 | temporary name, then the data file. |
| 1179 | |
| 1180 | The following items apply in all cases: |
| 1181 | |
| 1182 | (11) We now have the file open for writing, and locked if it was given as a |
| 1183 | file name. Write the message and flush the file, unless there is a setting |
| 1184 | of the local quota option, in which case we can check for its excession |
| 1185 | without doing any writing. |
| 1186 | |
| 1187 | In the case of MBX format mailboxes, the message is first written to a |
| 1188 | temporary file, in order to get its correct length. This is then copied to |
| 1189 | the real file, preceded by an MBX header. |
| 1190 | |
| 1191 | If there is a quota error on writing, defer the address. Timeout logic |
| 1192 | will determine for how long retries are attempted. We restore the mailbox |
| 1193 | to its original length if it's a single file. There doesn't seem to be a |
| 1194 | uniform error code for quota excession (it even differs between SunOS4 |
| 1195 | and some versions of SunOS5) so a system-dependent macro called |
| 1196 | ERRNO_QUOTA is used for it, and the value gets put into errno_quota at |
| 1197 | compile time. |
| 1198 | |
| 1199 | For any other error (most commonly disk full), do the same. |
| 1200 | |
| 1201 | The following applies after appending to a file: |
| 1202 | |
| 1203 | (12f)Restore the atime; notify_comsat if required; close the file (which |
| 1204 | unlocks it if it was locked). Delete the lock file if it exists. |
| 1205 | |
| 1206 | The following applies after writing a unique file in a directory: |
| 1207 | |
| 1208 | (12d)For maildir format, rename the file into the new directory. For mailstore |
| 1209 | format, rename the envelope file to its correct name. Otherwise, generate |
| 1210 | a unique name from the directory_file option, and rename to that, possibly |
| 1211 | trying a few times if the file exists and re-expanding the name gives a |
| 1212 | different string. |
| 1213 | |
| 1214 | This transport yields FAIL only when a file name is generated by an alias or |
| 1215 | forwarding operation and attempting to open it gives EPERM, ENOENT, or EACCES. |
| 1216 | All other failures return DEFER (in addr->transport_return). */ |
| 1217 | |
| 1218 | |
| 1219 | BOOL |
| 1220 | appendfile_transport_entry( |
| 1221 | transport_instance *tblock, /* data for this instantiation */ |
| 1222 | address_item *addr) /* address we are working on */ |
| 1223 | { |
| 1224 | appendfile_transport_options_block *ob = |
| 1225 | (appendfile_transport_options_block *)(tblock->options_block); |
| 1226 | struct stat statbuf; |
| 1227 | uschar *fdname = NULL; |
| 1228 | uschar *filename = NULL; |
| 1229 | uschar *hitchname = NULL; |
| 1230 | uschar *dataname = NULL; |
| 1231 | uschar *lockname = NULL; |
| 1232 | uschar *newname = NULL; |
| 1233 | uschar *nametag = NULL; |
| 1234 | uschar *cr = US""; |
| 1235 | uschar *filecount_msg = US""; |
| 1236 | uschar *path; |
| 1237 | struct utimbuf times; |
| 1238 | struct timeval msg_tv; |
| 1239 | BOOL disable_quota = FALSE; |
| 1240 | BOOL isdirectory = FALSE; |
| 1241 | BOOL isfifo = FALSE; |
| 1242 | BOOL wait_for_tick = FALSE; |
| 1243 | uid_t uid = geteuid(); /* See note above */ |
| 1244 | gid_t gid = getegid(); |
| 1245 | int mbformat; |
| 1246 | int mode = (addr->mode > 0)? addr->mode : ob->mode; |
| 1247 | off_t saved_size = -1; |
| 1248 | off_t mailbox_size = ob->mailbox_size_value; |
| 1249 | int mailbox_filecount = ob->mailbox_filecount_value; |
| 1250 | int hd = -1; |
| 1251 | int fd = -1; |
| 1252 | int yield = FAIL; |
| 1253 | int i; |
| 1254 | |
| 1255 | #ifdef SUPPORT_MBX |
| 1256 | int save_fd = 0; |
| 1257 | int mbx_lockfd = -1; |
| 1258 | uschar mbx_lockname[40]; |
| 1259 | FILE *temp_file = NULL; |
| 1260 | #endif /* SUPPORT_MBX */ |
| 1261 | |
| 1262 | #ifdef SUPPORT_MAILDIR |
| 1263 | int maildirsize_fd = -1; /* fd for maildirsize file */ |
| 1264 | int maildir_save_errno; |
| 1265 | #endif |
| 1266 | |
| 1267 | |
| 1268 | DEBUG(D_transport) debug_printf("appendfile transport entered\n"); |
| 1269 | |
| 1270 | /* An "address_file" or "address_directory" transport is used to deliver to |
| 1271 | files specified via .forward or an alias file. Prior to release 4.20, the |
| 1272 | "file" and "directory" options were ignored in this case. This has been changed |
| 1273 | to allow the redirection data to specify what is in effect a folder, whose |
| 1274 | location is determined by the options on the transport. |
| 1275 | |
| 1276 | Compatibility with the case when neither option is set is retained by forcing a |
| 1277 | value for the file or directory name. A directory delivery is assumed if the |
| 1278 | last character of the path from the router is '/'. |
| 1279 | |
| 1280 | The file path is in the local part of the address, but not in the $local_part |
| 1281 | variable (that holds the parent local part). It is, however, in the |
| 1282 | $address_file variable. Below, we update the local part in the address if it |
| 1283 | changes by expansion, so that the final path ends up in the log. */ |
| 1284 | |
| 1285 | if (testflag(addr, af_file) && |
| 1286 | ob->filename == NULL && |
| 1287 | ob->dirname == NULL) |
| 1288 | { |
| 1289 | fdname = US"$address_file"; |
| 1290 | if (address_file[Ustrlen(address_file)-1] == '/' || |
| 1291 | ob->maildir_format || |
| 1292 | ob->mailstore_format) |
| 1293 | isdirectory = TRUE; |
| 1294 | } |
| 1295 | |
| 1296 | /* Handle (a) an "address file" delivery where "file" or "directory" is |
| 1297 | explicitly set and (b) a non-address_file delivery, where one of "file" or |
| 1298 | "directory" must be set; initialization ensures that they are not both set. */ |
| 1299 | |
| 1300 | if (fdname == NULL) |
| 1301 | { |
| 1302 | fdname = ob->filename; |
| 1303 | if (fdname == NULL) |
| 1304 | { |
| 1305 | fdname = ob->dirname; |
| 1306 | isdirectory = TRUE; |
| 1307 | } |
| 1308 | if (fdname == NULL) |
| 1309 | { |
| 1310 | addr->transport_return = PANIC; |
| 1311 | addr->message = string_sprintf("Mandatory file or directory option " |
| 1312 | "missing from %s transport", tblock->name); |
| 1313 | return FALSE; |
| 1314 | } |
| 1315 | } |
| 1316 | |
| 1317 | /* Maildir and mailstore require a directory */ |
| 1318 | |
| 1319 | if ((ob->maildir_format || ob->mailstore_format) && !isdirectory) |
| 1320 | { |
| 1321 | addr->transport_return = PANIC; |
| 1322 | addr->message = string_sprintf("mail%s_format requires \"directory\" " |
| 1323 | "to be specified for the %s transport", |
| 1324 | ob->maildir_format? "dir" : "store", tblock->name); |
| 1325 | return FALSE; |
| 1326 | } |
| 1327 | |
| 1328 | path = expand_string(fdname); |
| 1329 | |
| 1330 | if (path == NULL) |
| 1331 | { |
| 1332 | addr->transport_return = PANIC; |
| 1333 | addr->message = string_sprintf("Expansion of \"%s\" (file or directory " |
| 1334 | "name for %s transport) failed: %s", fdname, tblock->name, |
| 1335 | expand_string_message); |
| 1336 | return FALSE; |
| 1337 | } |
| 1338 | |
| 1339 | if (path[0] != '/') |
| 1340 | { |
| 1341 | addr->message = string_sprintf("appendfile: file or directory name " |
| 1342 | "\"%s\" is not absolute", path); |
| 1343 | addr->basic_errno = ERRNO_NOTABSOLUTE; |
| 1344 | return FALSE; |
| 1345 | } |
| 1346 | |
| 1347 | /* For a file delivery, make sure the local part in the address(es) is updated |
| 1348 | to the true local part. */ |
| 1349 | |
| 1350 | if (testflag(addr, af_file)) |
| 1351 | { |
| 1352 | address_item *addr2; |
| 1353 | for (addr2 = addr; addr2 != NULL; addr2 = addr2->next) |
| 1354 | addr2->local_part = string_copy(path); |
| 1355 | } |
| 1356 | |
| 1357 | /* The available mailbox formats depend on whether it is a directory or a file |
| 1358 | delivery. */ |
| 1359 | |
| 1360 | if (isdirectory) |
| 1361 | { |
| 1362 | mbformat = |
| 1363 | #ifdef SUPPORT_MAILDIR |
| 1364 | (ob->maildir_format)? mbf_maildir : |
| 1365 | #endif |
| 1366 | #ifdef SUPPORT_MAILSTORE |
| 1367 | (ob->mailstore_format)? mbf_mailstore : |
| 1368 | #endif |
| 1369 | mbf_smail; |
| 1370 | } |
| 1371 | else |
| 1372 | { |
| 1373 | mbformat = |
| 1374 | #ifdef SUPPORT_MBX |
| 1375 | (ob->mbx_format)? mbf_mbx : |
| 1376 | #endif |
| 1377 | mbf_unix; |
| 1378 | } |
| 1379 | |
| 1380 | DEBUG(D_transport) |
| 1381 | { |
| 1382 | debug_printf("appendfile: mode=%o notify_comsat=%d quota=" OFF_T_FMT |
| 1383 | " warning=" OFF_T_FMT "%s\n" |
| 1384 | " %s=%s format=%s\n message_prefix=%s\n message_suffix=%s\n " |
| 1385 | "maildir_use_size_file=%s\n", |
| 1386 | mode, ob->notify_comsat, ob->quota_value, |
| 1387 | ob->quota_warn_threshold_value, |
| 1388 | ob->quota_warn_threshold_is_percent? "%" : "", |
| 1389 | isdirectory? "directory" : "file", |
| 1390 | path, mailbox_formats[mbformat], |
| 1391 | (ob->message_prefix == NULL)? US"null" : string_printing(ob->message_prefix), |
| 1392 | (ob->message_suffix == NULL)? US"null" : string_printing(ob->message_suffix), |
| 1393 | (ob->maildir_use_size_file)? "yes" : "no"); |
| 1394 | |
| 1395 | if (!isdirectory) debug_printf(" locking by %s%s%s%s%s\n", |
| 1396 | ob->use_lockfile? "lockfile " : "", |
| 1397 | ob->use_mbx_lock? "mbx locking (" : "", |
| 1398 | ob->use_fcntl? "fcntl " : "", |
| 1399 | ob->use_flock? "flock" : "", |
| 1400 | ob->use_mbx_lock? ")" : ""); |
| 1401 | } |
| 1402 | |
| 1403 | /* If the -N option is set, can't do any more. */ |
| 1404 | |
| 1405 | if (dont_deliver) |
| 1406 | { |
| 1407 | DEBUG(D_transport) |
| 1408 | debug_printf("*** delivery by %s transport bypassed by -N option\n", |
| 1409 | tblock->name); |
| 1410 | addr->transport_return = OK; |
| 1411 | return FALSE; |
| 1412 | } |
| 1413 | |
| 1414 | /* Handle the case of a file name. If the file name is /dev/null, we can save |
| 1415 | ourselves some effort and just give a success return right away. */ |
| 1416 | |
| 1417 | if (!isdirectory) |
| 1418 | { |
| 1419 | BOOL use_lstat = TRUE; |
| 1420 | BOOL file_opened = FALSE; |
| 1421 | BOOL allow_creation_here = TRUE; |
| 1422 | |
| 1423 | if (Ustrcmp(path, "/dev/null") == 0) |
| 1424 | { |
| 1425 | addr->transport_return = OK; |
| 1426 | return FALSE; |
| 1427 | } |
| 1428 | |
| 1429 | /* Set the name of the file to be opened, and the file to which the data |
| 1430 | is written, and find out if we are permitted to create a non-existent file. */ |
| 1431 | |
| 1432 | dataname = filename = path; |
| 1433 | allow_creation_here = check_creation(filename, ob->create_file); |
| 1434 | |
| 1435 | /* If ob->create_directory is set, attempt to create the directories in |
| 1436 | which this mailbox lives, but only if we are permitted to create the file |
| 1437 | itself. We know we are dealing with an absolute path, because this was |
| 1438 | checked above. */ |
| 1439 | |
| 1440 | if (ob->create_directory && allow_creation_here) |
| 1441 | { |
| 1442 | uschar *p = Ustrrchr(path, '/'); |
| 1443 | *p = '\0'; |
| 1444 | if (!directory_make(NULL, path, ob->dirmode, FALSE)) |
| 1445 | { |
| 1446 | addr->basic_errno = errno; |
| 1447 | addr->message = |
| 1448 | string_sprintf("failed to create directories for %s: %s", path, |
| 1449 | strerror(errno)); |
| 1450 | DEBUG(D_transport) debug_printf("%s transport: %s\n", tblock->name, path); |
| 1451 | return FALSE; |
| 1452 | } |
| 1453 | *p = '/'; |
| 1454 | } |
| 1455 | |
| 1456 | /* If file_format is set we must check that any existing file matches one of |
| 1457 | the configured formats by checking the bytes it starts with. A match then |
| 1458 | indicates a specific transport - if it is not this one, pass control to it. |
| 1459 | Otherwise carry on here. An empty or non-existent file matches the current |
| 1460 | transport. We don't need to distinguish between non-existence and other open |
| 1461 | failures because if an existing file fails to open here, it will also fail |
| 1462 | again later when O_RDWR is used. */ |
| 1463 | |
| 1464 | if (ob->file_format != NULL) |
| 1465 | { |
| 1466 | int cfd = Uopen(path, O_RDONLY, 0); |
| 1467 | if (cfd >= 0) |
| 1468 | { |
| 1469 | transport_instance *tt = check_file_format(cfd, tblock, addr); |
| 1470 | (void)close(cfd); |
| 1471 | |
| 1472 | /* If another transport is indicated, call it and return; if no transport |
| 1473 | was found, just return - the error data will have been set up.*/ |
| 1474 | |
| 1475 | if (tt != tblock) |
| 1476 | { |
| 1477 | if (tt != NULL) |
| 1478 | { |
| 1479 | set_process_info("delivering %s to %s using %s", message_id, |
| 1480 | addr->local_part, tt->name); |
| 1481 | debug_print_string(tt->debug_string); |
| 1482 | addr->transport = tt; |
| 1483 | (tt->info->code)(tt, addr); |
| 1484 | } |
| 1485 | return FALSE; |
| 1486 | } |
| 1487 | } |
| 1488 | } |
| 1489 | |
| 1490 | /* The locking of mailbox files is worse than the naming of cats, which is |
| 1491 | known to be "a difficult matter" (T.S. Eliot) and just as cats must have |
| 1492 | three different names, so several different styles of locking are used. |
| 1493 | |
| 1494 | Research in other programs that lock mailboxes shows that there is no |
| 1495 | universally standard method. Having mailboxes NFS-mounted on the system that |
| 1496 | is delivering mail is not the best thing, but people do run like this, |
| 1497 | and so the code must do its best to cope. |
| 1498 | |
| 1499 | Three different locking mechanisms are supported. The initialization function |
| 1500 | checks that at least one is configured. |
| 1501 | |
| 1502 | LOCK FILES |
| 1503 | |
| 1504 | Unless no_use_lockfile is set, we attempt to build a lock file in a way that |
| 1505 | will work over NFS. Only after that is done do we actually open the mailbox |
| 1506 | and apply locks to it (if configured). |
| 1507 | |
| 1508 | Originally, Exim got the file opened before doing anything about locking. |
| 1509 | However, a very occasional problem was observed on Solaris 2 when delivering |
| 1510 | over NFS. It is seems that when a file is opened with O_APPEND, the file size |
| 1511 | gets remembered at open time. If another process on another host (that's |
| 1512 | important) has the file open and locked and writes to it and then releases |
| 1513 | the lock while the first process is waiting to get the lock, the first |
| 1514 | process may fail to write at the new end point of the file - despite the very |
| 1515 | definite statement about O_APPEND in the man page for write(). Experiments |
| 1516 | have reproduced this problem, but I do not know any way of forcing a host to |
| 1517 | update its attribute cache for an open NFS file. It would be nice if it did |
| 1518 | so when a lock was taken out, but this does not seem to happen. Anyway, to |
| 1519 | reduce the risk of this problem happening, we now create the lock file |
| 1520 | (if configured) *before* opening the mailbox. That will prevent two different |
| 1521 | Exims opening the file simultaneously. It may not prevent clashes with MUAs, |
| 1522 | however, but Pine at least seems to operate in the same way. |
| 1523 | |
| 1524 | Lockfiles should normally be used when NFS is involved, because of the above |
| 1525 | problem. |
| 1526 | |
| 1527 | The logic for creating the lock file is: |
| 1528 | |
| 1529 | . The name of the lock file is <mailbox-name>.lock |
| 1530 | |
| 1531 | . First, create a "hitching post" name by adding the primary host name, |
| 1532 | current time and pid to the lock file name. This should be unique. |
| 1533 | |
| 1534 | . Create the hitching post file using WRONLY + CREAT + EXCL. |
| 1535 | |
| 1536 | . If that fails EACCES, we assume it means that the user is unable to create |
| 1537 | files in the mail spool directory. Some installations might operate in this |
| 1538 | manner, so there is a configuration option to allow this state not to be an |
| 1539 | error - we proceed to lock using fcntl only, after the file is open. |
| 1540 | |
| 1541 | . Otherwise, an error causes a deferment of the address. |
| 1542 | |
| 1543 | . Hard link the hitching post to the lock file name. |
| 1544 | |
| 1545 | . If the link succeeds, we have successfully created the lock file. Simply |
| 1546 | close and unlink the hitching post file. |
| 1547 | |
| 1548 | . If the link does not succeed, proceed as follows: |
| 1549 | |
| 1550 | o Fstat the hitching post file, and then close and unlink it. |
| 1551 | |
| 1552 | o Now examine the stat data. If the number of links to the file is exactly |
| 1553 | 2, the linking succeeded but for some reason, e.g. an NFS server crash, |
| 1554 | the return never made it back, so the link() function gave a failure |
| 1555 | return. |
| 1556 | |
| 1557 | . This method allows for the lock file to be created by some other process |
| 1558 | right up to the moment of the attempt to hard link it, and is also robust |
| 1559 | against NFS server crash-reboots, which would probably result in timeouts |
| 1560 | in the middle of link(). |
| 1561 | |
| 1562 | . System crashes may cause lock files to get left lying around, and some means |
| 1563 | of flushing them is required. The approach of writing a pid (used by smail |
| 1564 | and by elm) into the file isn't useful when NFS may be in use. Pine uses a |
| 1565 | timeout, which seems a better approach. Since any program that writes to a |
| 1566 | mailbox using a lock file should complete its task very quickly, Pine |
| 1567 | removes lock files that are older than 5 minutes. We allow the value to be |
| 1568 | configurable on the transport. |
| 1569 | |
| 1570 | FCNTL LOCKING |
| 1571 | |
| 1572 | If use_fcntl_lock is set, then Exim gets an exclusive fcntl() lock on the |
| 1573 | mailbox once it is open. This is done by default with a non-blocking lock. |
| 1574 | Failures to lock cause retries after a sleep, but only for a certain number |
| 1575 | of tries. A blocking lock is deliberately not used so that we don't hold the |
| 1576 | mailbox open. This minimizes the possibility of the NFS problem described |
| 1577 | under LOCK FILES above, if for some reason NFS deliveries are happening |
| 1578 | without lock files. However, the use of a non-blocking lock and sleep, though |
| 1579 | the safest approach, does not give the best performance on very busy systems. |
| 1580 | A blocking lock plus timeout does better. Therefore Exim has an option to |
| 1581 | allow it to work this way. If lock_fcntl_timeout is set greater than zero, it |
| 1582 | enables the use of blocking fcntl() calls. |
| 1583 | |
| 1584 | FLOCK LOCKING |
| 1585 | |
| 1586 | If use_flock_lock is set, then Exim gets an exclusive flock() lock in the |
| 1587 | same manner as for fcntl locking above. No-blocking/timeout is also set as |
| 1588 | above in lock_flock_timeout. Not all operating systems provide or support |
| 1589 | flock(). For those that don't (as determined by the definition of LOCK_SH in |
| 1590 | /usr/include/sys/file.h), use_flock_lock may not be set. For some OS, flock() |
| 1591 | is implemented (not precisely) on top of fcntl(), which means there's no |
| 1592 | point in actually using it. |
| 1593 | |
| 1594 | MBX LOCKING |
| 1595 | |
| 1596 | If use_mbx_lock is set (this is supported only if SUPPORT_MBX is defined) |
| 1597 | then the rules used for locking in c-client are used. Exim takes out a shared |
| 1598 | lock on the mailbox file, and an exclusive lock on the file whose name is |
| 1599 | /tmp/.<device-number>.<inode-number>. The shared lock on the mailbox stops |
| 1600 | any other MBX client from getting an exclusive lock on it and expunging it. |
| 1601 | It also stops any other MBX client from unlinking the /tmp lock when it has |
| 1602 | finished with it. |
| 1603 | |
| 1604 | The exclusive lock on the /tmp file prevents any other MBX client from |
| 1605 | updating the mailbox in any way. When writing is finished, if an exclusive |
| 1606 | lock on the mailbox can be obtained, indicating there are no current sharers, |
| 1607 | the /tmp file is unlinked. |
| 1608 | |
| 1609 | MBX locking can use either fcntl() or flock() locking. If neither |
| 1610 | use_fcntl_lock or use_flock_lock is set, it defaults to using fcntl() only. |
| 1611 | The calls for getting these locks are by default non-blocking, as for non-mbx |
| 1612 | locking, but can be made blocking by setting lock_fcntl_timeout and/or |
| 1613 | lock_flock_timeout as appropriate. As MBX delivery doesn't work over NFS, it |
| 1614 | probably makes sense to set timeouts for any MBX deliveries. */ |
| 1615 | |
| 1616 | |
| 1617 | /* Build a lock file if configured to do so - the existence of a lock |
| 1618 | file is subsequently checked by looking for a non-negative value of the |
| 1619 | file descriptor hd - even though the file is no longer open. */ |
| 1620 | |
| 1621 | if (ob->use_lockfile) |
| 1622 | { |
| 1623 | /* cf. exim_lock.c */ |
| 1624 | lockname = string_sprintf("%s.lock", filename); |
| 1625 | hitchname = string_sprintf( "%s.%s.%08x.%08x", lockname, primary_hostname, |
| 1626 | (unsigned int)(time(NULL)), (unsigned int)getpid()); |
| 1627 | |
| 1628 | DEBUG(D_transport) debug_printf("lock name: %s\nhitch name: %s\n", lockname, |
| 1629 | hitchname); |
| 1630 | |
| 1631 | /* Lock file creation retry loop */ |
| 1632 | |
| 1633 | for (i = 0; i < ob->lock_retries; sleep(ob->lock_interval), i++) |
| 1634 | { |
| 1635 | int rc; |
| 1636 | hd = Uopen(hitchname, O_WRONLY | O_CREAT | O_EXCL, ob->lockfile_mode); |
| 1637 | |
| 1638 | if (hd < 0) |
| 1639 | { |
| 1640 | addr->basic_errno = errno; |
| 1641 | addr->message = |
| 1642 | string_sprintf("creating lock file hitching post %s " |
| 1643 | "(euid=%ld egid=%ld)", hitchname, (long int)geteuid(), |
| 1644 | (long int)getegid()); |
| 1645 | return FALSE; |
| 1646 | } |
| 1647 | |
| 1648 | /* Attempt to hitch the hitching post to the lock file. If link() |
| 1649 | succeeds (the common case, we hope) all is well. Otherwise, fstat the |
| 1650 | file, and get rid of the hitching post. If the number of links was 2, |
| 1651 | the link was created, despite the failure of link(). If the hitch was |
| 1652 | not successful, try again, having unlinked the lock file if it is too |
| 1653 | old. |
| 1654 | |
| 1655 | There's a version of Linux (2.0.27) which doesn't update its local cache |
| 1656 | of the inode after link() by default - which many think is a bug - but |
| 1657 | if the link succeeds, this code will be OK. It just won't work in the |
| 1658 | case when link() fails after having actually created the link. The Linux |
| 1659 | NFS person is fixing this; a temporary patch is available if anyone is |
| 1660 | sufficiently worried. */ |
| 1661 | |
| 1662 | if ((rc = Ulink(hitchname, lockname)) != 0) fstat(hd, &statbuf); |
| 1663 | (void)close(hd); |
| 1664 | Uunlink(hitchname); |
| 1665 | if (rc != 0 && statbuf.st_nlink != 2) |
| 1666 | { |
| 1667 | if (ob->lockfile_timeout > 0 && Ustat(lockname, &statbuf) == 0 && |
| 1668 | time(NULL) - statbuf.st_ctime > ob->lockfile_timeout) |
| 1669 | { |
| 1670 | DEBUG(D_transport) debug_printf("unlinking timed-out lock file\n"); |
| 1671 | Uunlink(lockname); |
| 1672 | } |
| 1673 | DEBUG(D_transport) debug_printf("link of hitching post failed - retrying\n"); |
| 1674 | continue; |
| 1675 | } |
| 1676 | |
| 1677 | DEBUG(D_transport) debug_printf("lock file created\n"); |
| 1678 | break; |
| 1679 | } |
| 1680 | |
| 1681 | /* Check for too many tries at creating the lock file */ |
| 1682 | |
| 1683 | if (i >= ob->lock_retries) |
| 1684 | { |
| 1685 | addr->basic_errno = ERRNO_LOCKFAILED; |
| 1686 | addr->message = string_sprintf("failed to lock mailbox %s (lock file)", |
| 1687 | filename); |
| 1688 | return FALSE; |
| 1689 | } |
| 1690 | } |
| 1691 | |
| 1692 | |
| 1693 | /* We now have to get the file open. First, stat() it and act on existence or |
| 1694 | non-existence. This is in a loop to handle the case of a file's being created |
| 1695 | or deleted as we watch, and also to handle retries when the locking fails. |
| 1696 | Rather than holding the file open while waiting for the fcntl() and/or |
| 1697 | flock() lock, we close and do the whole thing again. This should be safer, |
| 1698 | especially for NFS files, which might get altered from other hosts, making |
| 1699 | their cached sizes incorrect. |
| 1700 | |
| 1701 | With the default settings, no symlinks are permitted, but there is an option |
| 1702 | to permit symlinks for those sysadmins that know what they are doing. |
| 1703 | Shudder. However, insist that the initial symlink is owned by the right user. |
| 1704 | Thus lstat() is used initially; if a symlink is discovered, the loop is |
| 1705 | repeated such that stat() is used, to look at the end file. */ |
| 1706 | |
| 1707 | for (i = 0; i < ob->lock_retries; i++) |
| 1708 | { |
| 1709 | int sleep_before_retry = TRUE; |
| 1710 | file_opened = FALSE; |
| 1711 | |
| 1712 | if((use_lstat? Ulstat(filename, &statbuf) : Ustat(filename, &statbuf)) != 0) |
| 1713 | { |
| 1714 | /* Let's hope that failure to stat (other than non-existence) is a |
| 1715 | rare event. */ |
| 1716 | |
| 1717 | if (errno != ENOENT) |
| 1718 | { |
| 1719 | addr->basic_errno = errno; |
| 1720 | addr->message = string_sprintf("attempting to stat mailbox %s", |
| 1721 | filename); |
| 1722 | goto RETURN; |
| 1723 | } |
| 1724 | |
| 1725 | /* File does not exist. If it is required to pre-exist this state is an |
| 1726 | error. */ |
| 1727 | |
| 1728 | if (ob->file_must_exist) |
| 1729 | { |
| 1730 | addr->basic_errno = errno; |
| 1731 | addr->message = string_sprintf("mailbox %s does not exist, " |
| 1732 | "but file_must_exist is set", filename); |
| 1733 | goto RETURN; |
| 1734 | } |
| 1735 | |
| 1736 | /* If not permitted to create this file because it isn't in or below |
| 1737 | the home directory, generate an error. */ |
| 1738 | |
| 1739 | if (!allow_creation_here) |
| 1740 | { |
| 1741 | addr->basic_errno = ERRNO_BADCREATE; |
| 1742 | addr->message = string_sprintf("mailbox %s does not exist, " |
| 1743 | "but creation outside the home directory is not permitted", |
| 1744 | filename); |
| 1745 | goto RETURN; |
| 1746 | } |
| 1747 | |
| 1748 | /* Attempt to create and open the file. If open fails because of |
| 1749 | pre-existence, go round the loop again. For any other error, defer the |
| 1750 | address, except for an alias or forward generated file name with EPERM, |
| 1751 | ENOENT, or EACCES, as those are most likely to be user errors rather |
| 1752 | than Exim config errors. When a symbolic link is permitted and points |
| 1753 | to a non-existent file, we get here with use_lstat = FALSE. In this case |
| 1754 | we mustn't use O_EXCL, since it doesn't work. The file is opened RDRW for |
| 1755 | consistency and because MBX locking requires it in order to be able to |
| 1756 | get a shared lock. */ |
| 1757 | |
| 1758 | fd = Uopen(filename, O_RDWR | O_APPEND | O_CREAT | |
| 1759 | (use_lstat? O_EXCL : 0), mode); |
| 1760 | if (fd < 0) |
| 1761 | { |
| 1762 | if (errno == EEXIST) continue; |
| 1763 | addr->basic_errno = errno; |
| 1764 | addr->message = string_sprintf("while creating mailbox %s", |
| 1765 | filename); |
| 1766 | if (testflag(addr, af_file) && |
| 1767 | (errno == EPERM || errno == ENOENT || errno == EACCES)) |
| 1768 | addr->transport_return = FAIL; |
| 1769 | goto RETURN; |
| 1770 | } |
| 1771 | |
| 1772 | /* We have successfully created and opened the file. Ensure that the group |
| 1773 | and the mode are correct. */ |
| 1774 | |
| 1775 | if(Uchown(filename, uid, gid) || Uchmod(filename, mode)) |
| 1776 | { |
| 1777 | addr->basic_errno = errno; |
| 1778 | addr->message = string_sprintf("while setting perms on mailbox %s", |
| 1779 | filename); |
| 1780 | addr->transport_return = FAIL; |
| 1781 | goto RETURN; |
| 1782 | } |
| 1783 | } |
| 1784 | |
| 1785 | |
| 1786 | /* The file already exists. Test its type, ownership, and permissions, and |
| 1787 | save the inode for checking later. If symlinks are permitted (not the |
| 1788 | default or recommended state) it may be a symlink that already exists. |
| 1789 | Check its ownership and then look for the file at the end of the link(s). |
| 1790 | This at least prevents one user creating a symlink for another user in |
| 1791 | a sticky directory. */ |
| 1792 | |
| 1793 | else |
| 1794 | { |
| 1795 | int oldmode = (int)statbuf.st_mode; |
| 1796 | ino_t inode = statbuf.st_ino; |
| 1797 | BOOL islink = (oldmode & S_IFMT) == S_IFLNK; |
| 1798 | |
| 1799 | isfifo = FALSE; /* In case things are changing */ |
| 1800 | |
| 1801 | /* Check owner if required - the default. */ |
| 1802 | |
| 1803 | if (ob->check_owner && statbuf.st_uid != uid) |
| 1804 | { |
| 1805 | addr->basic_errno = ERRNO_BADUGID; |
| 1806 | addr->message = string_sprintf("mailbox %s%s has wrong uid " |
| 1807 | "(%ld != %ld)", filename, |
| 1808 | islink? " (symlink)" : "", |
| 1809 | (long int)(statbuf.st_uid), (long int)uid); |
| 1810 | goto RETURN; |
| 1811 | } |
| 1812 | |
| 1813 | /* Group is checked only if check_group is set. */ |
| 1814 | |
| 1815 | if (ob->check_group && statbuf.st_gid != gid) |
| 1816 | { |
| 1817 | addr->basic_errno = ERRNO_BADUGID; |
| 1818 | addr->message = string_sprintf("mailbox %s%s has wrong gid (%d != %d)", |
| 1819 | filename, islink? " (symlink)" : "", statbuf.st_gid, gid); |
| 1820 | goto RETURN; |
| 1821 | } |
| 1822 | |
| 1823 | /* Just in case this is a sticky-bit mail directory, we don't want |
| 1824 | users to be able to create hard links to other users' files. */ |
| 1825 | |
| 1826 | if (statbuf.st_nlink != 1) |
| 1827 | { |
| 1828 | addr->basic_errno = ERRNO_NOTREGULAR; |
| 1829 | addr->message = string_sprintf("mailbox %s%s has too many links (%d)", |
| 1830 | filename, islink? " (symlink)" : "", statbuf.st_nlink); |
| 1831 | goto RETURN; |
| 1832 | |
| 1833 | } |
| 1834 | |
| 1835 | /* If symlinks are permitted (not recommended), the lstat() above will |
| 1836 | have found the symlink. Its ownership has just been checked; go round |
| 1837 | the loop again, using stat() instead of lstat(). That will never yield a |
| 1838 | mode of S_IFLNK. */ |
| 1839 | |
| 1840 | if (islink && ob->allow_symlink) |
| 1841 | { |
| 1842 | use_lstat = FALSE; |
| 1843 | i--; /* Don't count this time round */ |
| 1844 | continue; |
| 1845 | } |
| 1846 | |
| 1847 | /* An actual file exists. Check that it is a regular file, or FIFO |
| 1848 | if permitted. */ |
| 1849 | |
| 1850 | if (ob->allow_fifo && (oldmode & S_IFMT) == S_IFIFO) isfifo = TRUE; |
| 1851 | |
| 1852 | else if ((oldmode & S_IFMT) != S_IFREG) |
| 1853 | { |
| 1854 | addr->basic_errno = ERRNO_NOTREGULAR; |
| 1855 | addr->message = string_sprintf("mailbox %s is not a regular file%s", |
| 1856 | filename, ob->allow_fifo? " or named pipe" : ""); |
| 1857 | goto RETURN; |
| 1858 | } |
| 1859 | |
| 1860 | /* If the mode is not what it would be for a newly created file, change |
| 1861 | the permissions if the mode is supplied for the address. Otherwise, |
| 1862 | reduce but do not extend the permissions. If the newly created |
| 1863 | permissions are greater than the existing permissions, don't change |
| 1864 | things when the mode is not from the address. */ |
| 1865 | |
| 1866 | if ((oldmode = (oldmode & 07777)) != mode) |
| 1867 | { |
| 1868 | int diffs = oldmode ^ mode; |
| 1869 | if (addr->mode > 0 || (diffs & oldmode) == diffs) |
| 1870 | { |
| 1871 | DEBUG(D_transport) debug_printf("chmod %o %s\n", mode, filename); |
| 1872 | if (Uchmod(filename, mode) < 0) |
| 1873 | { |
| 1874 | addr->basic_errno = errno; |
| 1875 | addr->message = string_sprintf("attempting to chmod mailbox %s", |
| 1876 | filename); |
| 1877 | goto RETURN; |
| 1878 | } |
| 1879 | oldmode = mode; |
| 1880 | } |
| 1881 | |
| 1882 | /* Mode not from address, and newly-created permissions are greater |
| 1883 | than existing permissions. Default is to complain, but it can be |
| 1884 | configured to go ahead and try to deliver anyway if that's what |
| 1885 | the administration wants. */ |
| 1886 | |
| 1887 | else if (ob->mode_fail_narrower) |
| 1888 | { |
| 1889 | addr->basic_errno = ERRNO_BADMODE; |
| 1890 | addr->message = string_sprintf("mailbox %s has the wrong mode %o " |
| 1891 | "(%o expected)", filename, oldmode, mode); |
| 1892 | goto RETURN; |
| 1893 | } |
| 1894 | } |
| 1895 | |
| 1896 | /* We are happy with the existing file. Open it, and then do further |
| 1897 | tests to ensure that it is the same file that we were just looking at. |
| 1898 | If the file does not now exist, restart this loop, going back to using |
| 1899 | lstat again. For an NFS error, just defer; other opening errors are |
| 1900 | more serious. The file is opened RDWR so that its format can be checked, |
| 1901 | and also MBX locking requires the use of a shared (read) lock. However, |
| 1902 | a FIFO is opened WRONLY + NDELAY so that it fails if there is no process |
| 1903 | reading the pipe. */ |
| 1904 | |
| 1905 | fd = Uopen(filename, isfifo? (O_WRONLY|O_NDELAY) : (O_RDWR|O_APPEND), |
| 1906 | mode); |
| 1907 | if (fd < 0) |
| 1908 | { |
| 1909 | if (errno == ENOENT) |
| 1910 | { |
| 1911 | use_lstat = TRUE; |
| 1912 | continue; |
| 1913 | } |
| 1914 | addr->basic_errno = errno; |
| 1915 | if (isfifo) |
| 1916 | { |
| 1917 | addr->message = string_sprintf("while opening named pipe %s " |
| 1918 | "(could mean no process is reading it)", filename); |
| 1919 | } |
| 1920 | else if (errno != EWOULDBLOCK) |
| 1921 | { |
| 1922 | addr->message = string_sprintf("while opening mailbox %s", filename); |
| 1923 | } |
| 1924 | goto RETURN; |
| 1925 | } |
| 1926 | |
| 1927 | /* This fstat really shouldn't fail, as we have an open file! There's a |
| 1928 | dilemma here. We use fstat in order to be sure we are peering at the file |
| 1929 | we have got open. However, that won't tell us if the file was reached |
| 1930 | via a symbolic link. We checked this above, but there is a race exposure |
| 1931 | if the link was created between the previous lstat and the open. However, |
| 1932 | it would have to be created with the same inode in order to pass the |
| 1933 | check below. If ob->allow_symlink is set, causing the use of stat rather |
| 1934 | than lstat above, symbolic links may be there anyway, and the checking is |
| 1935 | weaker. */ |
| 1936 | |
| 1937 | if (fstat(fd, &statbuf) < 0) |
| 1938 | { |
| 1939 | addr->basic_errno = errno; |
| 1940 | addr->message = string_sprintf("attempting to stat open mailbox %s", |
| 1941 | filename); |
| 1942 | goto RETURN; |
| 1943 | } |
| 1944 | |
| 1945 | /* Check the inode; this is isn't a perfect check, but gives some |
| 1946 | confidence. */ |
| 1947 | |
| 1948 | if (inode != statbuf.st_ino) |
| 1949 | { |
| 1950 | addr->basic_errno = ERRNO_INODECHANGED; |
| 1951 | addr->message = string_sprintf("opened mailbox %s inode number changed " |
| 1952 | "from %d to %ld", filename, inode, statbuf.st_ino); |
| 1953 | addr->special_action = SPECIAL_FREEZE; |
| 1954 | goto RETURN; |
| 1955 | } |
| 1956 | |
| 1957 | /* Check it's still a regular file or FIFO, and the uid, gid, and |
| 1958 | permissions have not changed. */ |
| 1959 | |
| 1960 | if ((!isfifo && (statbuf.st_mode & S_IFMT) != S_IFREG) || |
| 1961 | (isfifo && (statbuf.st_mode & S_IFMT) != S_IFIFO)) |
| 1962 | { |
| 1963 | addr->basic_errno = ERRNO_NOTREGULAR; |
| 1964 | addr->message = |
| 1965 | string_sprintf("opened mailbox %s is no longer a %s", filename, |
| 1966 | isfifo? "named pipe" : "regular file"); |
| 1967 | addr->special_action = SPECIAL_FREEZE; |
| 1968 | goto RETURN; |
| 1969 | } |
| 1970 | |
| 1971 | if ((ob->check_owner && statbuf.st_uid != uid) || |
| 1972 | (ob->check_group && statbuf.st_gid != gid)) |
| 1973 | { |
| 1974 | addr->basic_errno = ERRNO_BADUGID; |
| 1975 | addr->message = |
| 1976 | string_sprintf("opened mailbox %s has wrong uid or gid", filename); |
| 1977 | addr->special_action = SPECIAL_FREEZE; |
| 1978 | goto RETURN; |
| 1979 | } |
| 1980 | |
| 1981 | if ((statbuf.st_mode & 07777) != oldmode) |
| 1982 | { |
| 1983 | addr->basic_errno = ERRNO_BADMODE; |
| 1984 | addr->message = string_sprintf("opened mailbox %s has wrong mode %o " |
| 1985 | "(%o expected)", filename, statbuf.st_mode & 07777, mode); |
| 1986 | addr->special_action = SPECIAL_FREEZE; |
| 1987 | goto RETURN; |
| 1988 | } |
| 1989 | |
| 1990 | /* If file_format is set, check that the format of the file has not |
| 1991 | changed. Error data is set by the testing function. */ |
| 1992 | |
| 1993 | if (ob->file_format != NULL && |
| 1994 | check_file_format(fd, tblock, addr) != tblock) |
| 1995 | { |
| 1996 | addr->message = US"open mailbox has changed format"; |
| 1997 | goto RETURN; |
| 1998 | } |
| 1999 | |
| 2000 | /* The file is OK. Carry on to do the locking. */ |
| 2001 | } |
| 2002 | |
| 2003 | /* We now have an open file, and must lock it using fcntl(), flock() or MBX |
| 2004 | locking rules if configured to do so. If a lock file is also required, it |
| 2005 | was created above and hd was left >= 0. At least one form of locking is |
| 2006 | required by the initialization function. If locking fails here, close the |
| 2007 | file and go round the loop all over again, after waiting for a bit, unless |
| 2008 | blocking locking was used. */ |
| 2009 | |
| 2010 | file_opened = TRUE; |
| 2011 | if ((ob->lock_fcntl_timeout > 0) || (ob->lock_flock_timeout > 0)) |
| 2012 | sleep_before_retry = FALSE; |
| 2013 | |
| 2014 | /* Simple fcntl() and/or flock() locking */ |
| 2015 | |
| 2016 | if (!ob->use_mbx_lock && (ob->use_fcntl || ob->use_flock)) |
| 2017 | { |
| 2018 | if (apply_lock(fd, F_WRLCK, ob->use_fcntl, ob->lock_fcntl_timeout, |
| 2019 | ob->use_flock, ob->lock_flock_timeout) >= 0) break; |
| 2020 | } |
| 2021 | |
| 2022 | /* MBX locking rules */ |
| 2023 | |
| 2024 | #ifdef SUPPORT_MBX |
| 2025 | else if (ob->use_mbx_lock) |
| 2026 | { |
| 2027 | int mbx_tmp_oflags; |
| 2028 | struct stat lstatbuf, statbuf2; |
| 2029 | if (apply_lock(fd, F_RDLCK, ob->use_fcntl, ob->lock_fcntl_timeout, |
| 2030 | ob->use_flock, ob->lock_flock_timeout) >= 0 && |
| 2031 | fstat(fd, &statbuf) >= 0) |
| 2032 | { |
| 2033 | sprintf(CS mbx_lockname, "/tmp/.%lx.%lx", (long)statbuf.st_dev, |
| 2034 | (long)statbuf.st_ino); |
| 2035 | |
| 2036 | /* |
| 2037 | * 2010-05-29: SECURITY |
| 2038 | * Dan Rosenberg reported the presence of a race-condition in the |
| 2039 | * original code here. Beware that many systems still allow symlinks |
| 2040 | * to be followed in /tmp so an attacker can create a symlink pointing |
| 2041 | * elsewhere between a stat and an open, which we should avoid |
| 2042 | * following. |
| 2043 | * |
| 2044 | * It's unfortunate that we can't just use all the heavily debugged |
| 2045 | * locking from above. |
| 2046 | * |
| 2047 | * Also: remember to mirror changes into exim_lock.c */ |
| 2048 | |
| 2049 | /* first leave the old pre-check in place, it provides better |
| 2050 | * diagnostics for common cases */ |
| 2051 | if (Ulstat(mbx_lockname, &statbuf) >= 0) |
| 2052 | { |
| 2053 | if ((statbuf.st_mode & S_IFMT) == S_IFLNK) |
| 2054 | { |
| 2055 | addr->basic_errno = ERRNO_LOCKFAILED; |
| 2056 | addr->message = string_sprintf("symbolic link on MBX lock file %s", |
| 2057 | mbx_lockname); |
| 2058 | goto RETURN; |
| 2059 | } |
| 2060 | if (statbuf.st_nlink > 1) |
| 2061 | { |
| 2062 | addr->basic_errno = ERRNO_LOCKFAILED; |
| 2063 | addr->message = string_sprintf("hard link to MBX lock file %s", |
| 2064 | mbx_lockname); |
| 2065 | goto RETURN; |
| 2066 | } |
| 2067 | } |
| 2068 | |
| 2069 | /* If we could just declare "we must be the ones who create this |
| 2070 | * file" then a hitching post in a subdir would work, since a |
| 2071 | * subdir directly in /tmp/ which we create wouldn't follow links |
| 2072 | * but this isn't our locking logic, so we can't safely change the |
| 2073 | * file existence rules. */ |
| 2074 | |
| 2075 | /* On systems which support O_NOFOLLOW, it's the easiest and most |
| 2076 | * obviously correct security fix */ |
| 2077 | mbx_tmp_oflags = O_RDWR | O_CREAT; |
| 2078 | #ifdef O_NOFOLLOW |
| 2079 | mbx_tmp_oflags |= O_NOFOLLOW; |
| 2080 | #endif |
| 2081 | mbx_lockfd = Uopen(mbx_lockname, mbx_tmp_oflags, ob->lockfile_mode); |
| 2082 | if (mbx_lockfd < 0) |
| 2083 | { |
| 2084 | addr->basic_errno = ERRNO_LOCKFAILED; |
| 2085 | addr->message = string_sprintf("failed to open MBX lock file %s :%s", |
| 2086 | mbx_lockname, strerror(errno)); |
| 2087 | goto RETURN; |
| 2088 | } |
| 2089 | |
| 2090 | if (Ulstat(mbx_lockname, &lstatbuf) < 0) |
| 2091 | { |
| 2092 | addr->basic_errno = ERRNO_LOCKFAILED; |
| 2093 | addr->message = string_sprintf("attempting to lstat open MBX " |
| 2094 | "lock file %s: %s", mbx_lockname, strerror(errno)); |
| 2095 | goto RETURN; |
| 2096 | } |
| 2097 | if (fstat(mbx_lockfd, &statbuf2) < 0) |
| 2098 | { |
| 2099 | addr->basic_errno = ERRNO_LOCKFAILED; |
| 2100 | addr->message = string_sprintf("attempting to stat fd of open MBX " |
| 2101 | "lock file %s: %s", mbx_lockname, strerror(errno)); |
| 2102 | goto RETURN; |
| 2103 | } |
| 2104 | |
| 2105 | /* |
| 2106 | * At this point: |
| 2107 | * statbuf: if exists, is file which existed prior to opening the |
| 2108 | * lockfile, might have been replaced since then |
| 2109 | * statbuf2: result of stat'ing the open fd, is what was actually |
| 2110 | * opened |
| 2111 | * lstatbuf: result of lstat'ing the filename immediately after |
| 2112 | * the open but there's a race condition again between |
| 2113 | * those two steps: before open, symlink to foo, after |
| 2114 | * open but before lstat have one of: |
| 2115 | * * was no symlink, so is the opened file |
| 2116 | * (we created it, no messing possible after that point) |
| 2117 | * * hardlink to foo |
| 2118 | * * symlink elsewhere |
| 2119 | * * hardlink elsewhere |
| 2120 | * * new file/other |
| 2121 | * Don't want to compare to device of /tmp because some modern systems |
| 2122 | * have regressed to having /tmp be the safe actual filesystem as |
| 2123 | * valuable data, so is mostly worthless, unless we assume that *only* |
| 2124 | * Linux systems do this and that all Linux has O_NOFOLLOW. Something |
| 2125 | * for further consideration. |
| 2126 | * No point in doing a readlink on the lockfile as that will always be |
| 2127 | * at a different point in time from when we open it, so tells us |
| 2128 | * nothing; attempts to clean up and delete after ourselves would risk |
| 2129 | * deleting a *third* filename. |
| 2130 | */ |
| 2131 | if ((statbuf2.st_nlink > 1) || |
| 2132 | (lstatbuf.st_nlink > 1) || |
| 2133 | (!S_ISREG(lstatbuf.st_mode)) || |
| 2134 | (lstatbuf.st_dev != statbuf2.st_dev) || |
| 2135 | (lstatbuf.st_ino != statbuf2.st_ino)) |
| 2136 | { |
| 2137 | addr->basic_errno = ERRNO_LOCKFAILED; |
| 2138 | addr->message = string_sprintf("RACE CONDITION detected: " |
| 2139 | "mismatch post-initial-checks between \"%s\" and opened " |
| 2140 | "fd lead us to abort!", mbx_lockname); |
| 2141 | goto RETURN; |
| 2142 | } |
| 2143 | |
| 2144 | (void)Uchmod(mbx_lockname, ob->lockfile_mode); |
| 2145 | |
| 2146 | if (apply_lock(mbx_lockfd, F_WRLCK, ob->use_fcntl, |
| 2147 | ob->lock_fcntl_timeout, ob->use_flock, ob->lock_flock_timeout) >= 0) |
| 2148 | { |
| 2149 | struct stat ostatbuf; |
| 2150 | |
| 2151 | /* This tests for a specific race condition. Ensure that we still |
| 2152 | have the same file. */ |
| 2153 | |
| 2154 | if (Ulstat(mbx_lockname, &statbuf) == 0 && |
| 2155 | fstat(mbx_lockfd, &ostatbuf) == 0 && |
| 2156 | statbuf.st_dev == ostatbuf.st_dev && |
| 2157 | statbuf.st_ino == ostatbuf.st_ino) |
| 2158 | break; |
| 2159 | DEBUG(D_transport) debug_printf("MBX lockfile %s changed " |
| 2160 | "between creation and locking\n", mbx_lockname); |
| 2161 | } |
| 2162 | |
| 2163 | DEBUG(D_transport) debug_printf("failed to lock %s: %s\n", mbx_lockname, |
| 2164 | strerror(errno)); |
| 2165 | (void)close(mbx_lockfd); |
| 2166 | mbx_lockfd = -1; |
| 2167 | } |
| 2168 | else |
| 2169 | { |
| 2170 | DEBUG(D_transport) debug_printf("failed to fstat or get read lock on %s: %s\n", |
| 2171 | filename, strerror(errno)); |
| 2172 | } |
| 2173 | } |
| 2174 | #endif /* SUPPORT_MBX */ |
| 2175 | |
| 2176 | else break; /* No on-file locking required; break the open/lock loop */ |
| 2177 | |
| 2178 | DEBUG(D_transport) |
| 2179 | debug_printf("fcntl(), flock(), or MBX locking failed - retrying\n"); |
| 2180 | |
| 2181 | (void)close(fd); |
| 2182 | fd = -1; |
| 2183 | use_lstat = TRUE; /* Reset to use lstat first */ |
| 2184 | |
| 2185 | |
| 2186 | /* If a blocking call timed out, break the retry loop if the total time |
| 2187 | so far is not less than than retries * interval. Use the larger of the |
| 2188 | flock() and fcntl() timeouts. */ |
| 2189 | |
| 2190 | if (sigalrm_seen && |
| 2191 | (i+1) * ((ob->lock_fcntl_timeout > ob->lock_flock_timeout)? |
| 2192 | ob->lock_fcntl_timeout : ob->lock_flock_timeout) >= |
| 2193 | ob->lock_retries * ob->lock_interval) |
| 2194 | i = ob->lock_retries; |
| 2195 | |
| 2196 | /* Wait a bit before retrying, except when it was a blocked fcntl() or |
| 2197 | flock() that caused the problem. */ |
| 2198 | |
| 2199 | if (i < ob->lock_retries && sleep_before_retry) sleep(ob->lock_interval); |
| 2200 | } |
| 2201 | |
| 2202 | /* Test for exceeding the maximum number of tries. Either the file remains |
| 2203 | locked, or, if we haven't got it open, something is terribly wrong... */ |
| 2204 | |
| 2205 | if (i >= ob->lock_retries) |
| 2206 | { |
| 2207 | if (!file_opened) |
| 2208 | { |
| 2209 | addr->basic_errno = ERRNO_EXISTRACE; |
| 2210 | addr->message = string_sprintf("mailbox %s: existence unclear", filename); |
| 2211 | addr->special_action = SPECIAL_FREEZE; |
| 2212 | } |
| 2213 | else |
| 2214 | { |
| 2215 | addr->basic_errno = ERRNO_LOCKFAILED; |
| 2216 | addr->message = string_sprintf("failed to lock mailbox %s (fcntl/flock)", |
| 2217 | filename); |
| 2218 | } |
| 2219 | goto RETURN; |
| 2220 | } |
| 2221 | |
| 2222 | DEBUG(D_transport) debug_printf("mailbox %s is locked\n", filename); |
| 2223 | |
| 2224 | /* Save access time (for subsequent restoration), modification time (for |
| 2225 | restoration if updating fails), size of file (for comsat and for re-setting if |
| 2226 | delivery fails in the middle - e.g. for quota exceeded). */ |
| 2227 | |
| 2228 | if (fstat(fd, &statbuf) < 0) |
| 2229 | { |
| 2230 | addr->basic_errno = errno; |
| 2231 | addr->message = string_sprintf("while fstatting opened mailbox %s", |
| 2232 | filename); |
| 2233 | goto RETURN; |
| 2234 | } |
| 2235 | |
| 2236 | times.actime = statbuf.st_atime; |
| 2237 | times.modtime = statbuf.st_mtime; |
| 2238 | saved_size = statbuf.st_size; |
| 2239 | if (mailbox_size < 0) mailbox_size = saved_size; |
| 2240 | mailbox_filecount = 0; /* Not actually relevant for single-file mailbox */ |
| 2241 | } |
| 2242 | |
| 2243 | /* Prepare for writing to a new file (as opposed to appending to an old one). |
| 2244 | There are several different formats, but there is preliminary stuff concerned |
| 2245 | with quotas that applies to all of them. Finding the current size by directory |
| 2246 | scanning is expensive; for maildirs some fudges have been invented: |
| 2247 | |
| 2248 | (1) A regex can be used to extract a file size from its name; |
| 2249 | (2) If maildir_use_size is set, a maildirsize file is used to cache the |
| 2250 | mailbox size. |
| 2251 | */ |
| 2252 | |
| 2253 | else |
| 2254 | { |
| 2255 | uschar *check_path = path; /* Default quota check path */ |
| 2256 | const pcre *regex = NULL; /* Regex for file size from file name */ |
| 2257 | |
| 2258 | if (!check_creation(string_sprintf("%s/any", path), ob->create_file)) |
| 2259 | { |
| 2260 | addr->basic_errno = ERRNO_BADCREATE; |
| 2261 | addr->message = string_sprintf("tried to create file in %s, but " |
| 2262 | "file creation outside the home directory is not permitted", path); |
| 2263 | goto RETURN; |
| 2264 | } |
| 2265 | |
| 2266 | #ifdef SUPPORT_MAILDIR |
| 2267 | /* For a maildir delivery, ensure that all the relevant directories exist, |
| 2268 | and a maildirfolder file if necessary. */ |
| 2269 | |
| 2270 | if (mbformat == mbf_maildir && !maildir_ensure_directories(path, addr, |
| 2271 | ob->create_directory, ob->dirmode, ob->maildirfolder_create_regex)) |
| 2272 | return FALSE; |
| 2273 | #endif /* SUPPORT_MAILDIR */ |
| 2274 | |
| 2275 | /* If we are going to do a quota check, of if maildir_use_size_file is set |
| 2276 | for a maildir delivery, compile the regular expression if there is one. We |
| 2277 | may also need to adjust the path that is used. We need to do this for |
| 2278 | maildir_use_size_file even if the quota is unset, because we still want to |
| 2279 | create the file. When maildir support is not compiled, |
| 2280 | ob->maildir_use_size_file is always FALSE. */ |
| 2281 | |
| 2282 | if (ob->quota_value > 0 || THRESHOLD_CHECK || ob->maildir_use_size_file) |
| 2283 | { |
| 2284 | const uschar *error; |
| 2285 | int offset; |
| 2286 | |
| 2287 | /* Compile the regex if there is one. */ |
| 2288 | |
| 2289 | if (ob->quota_size_regex != NULL) |
| 2290 | { |
| 2291 | regex = pcre_compile(CS ob->quota_size_regex, PCRE_COPT, |
| 2292 | (const char **)&error, &offset, NULL); |
| 2293 | if (regex == NULL) |
| 2294 | { |
| 2295 | addr->message = string_sprintf("appendfile: regular expression " |
| 2296 | "error: %s at offset %d while compiling %s", error, offset, |
| 2297 | ob->quota_size_regex); |
| 2298 | return FALSE; |
| 2299 | } |
| 2300 | DEBUG(D_transport) debug_printf("using regex for file sizes: %s\n", |
| 2301 | ob->quota_size_regex); |
| 2302 | } |
| 2303 | |
| 2304 | /* Use an explicitly configured directory if set */ |
| 2305 | |
| 2306 | if (ob->quota_directory != NULL) |
| 2307 | { |
| 2308 | check_path = expand_string(ob->quota_directory); |
| 2309 | if (check_path == NULL) |
| 2310 | { |
| 2311 | addr->transport_return = PANIC; |
| 2312 | addr->message = string_sprintf("Expansion of \"%s\" (quota_directory " |
| 2313 | "name for %s transport) failed: %s", ob->quota_directory, |
| 2314 | tblock->name, expand_string_message); |
| 2315 | return FALSE; |
| 2316 | } |
| 2317 | |
| 2318 | if (check_path[0] != '/') |
| 2319 | { |
| 2320 | addr->message = string_sprintf("appendfile: quota_directory name " |
| 2321 | "\"%s\" is not absolute", check_path); |
| 2322 | addr->basic_errno = ERRNO_NOTABSOLUTE; |
| 2323 | return FALSE; |
| 2324 | } |
| 2325 | } |
| 2326 | |
| 2327 | #ifdef SUPPORT_MAILDIR |
| 2328 | /* Otherwise, if we are handling a maildir delivery, and the directory |
| 2329 | contains a file called maildirfolder, this is a maildir++ feature telling |
| 2330 | us that this is a sub-directory of the real inbox. We should therefore do |
| 2331 | the quota check on the parent directory. Beware of the special case when |
| 2332 | the directory name itself ends in a slash. */ |
| 2333 | |
| 2334 | else if (mbformat == mbf_maildir) |
| 2335 | { |
| 2336 | struct stat statbuf; |
| 2337 | if (Ustat(string_sprintf("%s/maildirfolder", path), &statbuf) >= 0) |
| 2338 | { |
| 2339 | uschar *new_check_path = string_copy(check_path); |
| 2340 | uschar *slash = Ustrrchr(new_check_path, '/'); |
| 2341 | if (slash != NULL) |
| 2342 | { |
| 2343 | if (slash[1] == 0) |
| 2344 | { |
| 2345 | *slash = 0; |
| 2346 | slash = Ustrrchr(new_check_path, '/'); |
| 2347 | } |
| 2348 | if (slash != NULL) |
| 2349 | { |
| 2350 | *slash = 0; |
| 2351 | check_path = new_check_path; |
| 2352 | DEBUG(D_transport) debug_printf("maildirfolder file exists: " |
| 2353 | "quota check directory changed to %s\n", check_path); |
| 2354 | } |
| 2355 | } |
| 2356 | } |
| 2357 | } |
| 2358 | #endif /* SUPPORT_MAILDIR */ |
| 2359 | } |
| 2360 | |
| 2361 | /* If we are using maildirsize files, we need to ensure that such a file |
| 2362 | exists and, if necessary, recalculate its contents. As a byproduct of this, |
| 2363 | we obtain the current size of the maildir. If no quota is to be enforced |
| 2364 | (ob->quota_value == 0), we still need the size if a threshold check will |
| 2365 | happen later. |
| 2366 | |
| 2367 | Another regular expression is used to determine which directories inside the |
| 2368 | maildir are going to be counted. */ |
| 2369 | |
| 2370 | #ifdef SUPPORT_MAILDIR |
| 2371 | if (ob->maildir_use_size_file) |
| 2372 | { |
| 2373 | const pcre *dir_regex = NULL; |
| 2374 | const uschar *error; |
| 2375 | int offset; |
| 2376 | |
| 2377 | if (ob->maildir_dir_regex != NULL) |
| 2378 | { |
| 2379 | int check_path_len = Ustrlen(check_path); |
| 2380 | |
| 2381 | dir_regex = pcre_compile(CS ob->maildir_dir_regex, PCRE_COPT, |
| 2382 | (const char **)&error, &offset, NULL); |
| 2383 | if (dir_regex == NULL) |
| 2384 | { |
| 2385 | addr->message = string_sprintf("appendfile: regular expression " |
| 2386 | "error: %s at offset %d while compiling %s", error, offset, |
| 2387 | ob->maildir_dir_regex); |
| 2388 | return FALSE; |
| 2389 | } |
| 2390 | |
| 2391 | DEBUG(D_transport) |
| 2392 | debug_printf("using regex for maildir directory selection: %s\n", |
| 2393 | ob->maildir_dir_regex); |
| 2394 | |
| 2395 | /* Check to see if we are delivering into an ignored directory, that is, |
| 2396 | if the delivery path starts with the quota check path, and the rest |
| 2397 | of the deliver path matches the regex; if so, set a flag to disable quota |
| 2398 | checking and maildirsize updating. */ |
| 2399 | |
| 2400 | if (Ustrncmp(path, check_path, check_path_len) == 0) |
| 2401 | { |
| 2402 | uschar *s = path + check_path_len; |
| 2403 | while (*s == '/') s++; |
| 2404 | s = (*s == 0)? US "new" : string_sprintf("%s/new", s); |
| 2405 | if (pcre_exec(dir_regex, NULL, CS s, Ustrlen(s), 0, 0, NULL, 0) < 0) |
| 2406 | { |
| 2407 | disable_quota = TRUE; |
| 2408 | DEBUG(D_transport) debug_printf("delivery directory does not match " |
| 2409 | "maildir_quota_directory_regex: disabling quota\n"); |
| 2410 | } |
| 2411 | } |
| 2412 | } |
| 2413 | |
| 2414 | /* Quota enforcement; create and check the file. There is some discussion |
| 2415 | about whether this should happen if the quota is unset. At present, Exim |
| 2416 | always creates the file. If we ever want to change this, uncomment |
| 2417 | appropriate lines below, possibly doing a check on some option. */ |
| 2418 | |
| 2419 | /* if (???? || ob->quota_value > 0) */ |
| 2420 | |
| 2421 | if (!disable_quota) |
| 2422 | { |
| 2423 | off_t size; |
| 2424 | int filecount; |
| 2425 | |
| 2426 | maildirsize_fd = maildir_ensure_sizefile(check_path, ob, regex, dir_regex, |
| 2427 | &size, &filecount); |
| 2428 | |
| 2429 | if (maildirsize_fd == -1) |
| 2430 | { |
| 2431 | addr->basic_errno = errno; |
| 2432 | addr->message = string_sprintf("while opening or reading " |
| 2433 | "%s/maildirsize", check_path); |
| 2434 | return FALSE; |
| 2435 | } |
| 2436 | /* can also return -2, which means that the file was removed because of |
| 2437 | raciness; but in this case, the size & filecount will still have been |
| 2438 | updated. */ |
| 2439 | |
| 2440 | if (mailbox_size < 0) mailbox_size = size; |
| 2441 | if (mailbox_filecount < 0) mailbox_filecount = filecount; |
| 2442 | } |
| 2443 | |
| 2444 | /* No quota enforcement; ensure file does *not* exist; calculate size if |
| 2445 | needed. */ |
| 2446 | |
| 2447 | /* else |
| 2448 | * { |
| 2449 | * time_t old_latest; |
| 2450 | * (void)unlink(CS string_sprintf("%s/maildirsize", check_path)); |
| 2451 | * if (THRESHOLD_CHECK) |
| 2452 | * mailbox_size = maildir_compute_size(check_path, &mailbox_filecount, &old_latest, |
| 2453 | * regex, dir_regex, FALSE); |
| 2454 | * } |
| 2455 | */ |
| 2456 | |
| 2457 | } |
| 2458 | #endif /* SUPPORT_MAILDIR */ |
| 2459 | |
| 2460 | /* Otherwise if we are going to do a quota check later on, and the mailbox |
| 2461 | size is not set, find the current size of the mailbox. Ditto for the file |
| 2462 | count. Note that ob->quota_filecount_value cannot be set without |
| 2463 | ob->quota_value being set. */ |
| 2464 | |
| 2465 | if (!disable_quota && |
| 2466 | (ob->quota_value > 0 || THRESHOLD_CHECK) && |
| 2467 | (mailbox_size < 0 || |
| 2468 | (mailbox_filecount < 0 && ob->quota_filecount_value > 0))) |
| 2469 | { |
| 2470 | off_t size; |
| 2471 | int filecount = 0; |
| 2472 | DEBUG(D_transport) |
| 2473 | debug_printf("quota checks on directory %s\n", check_path); |
| 2474 | size = check_dir_size(check_path, &filecount, regex); |
| 2475 | if (mailbox_size < 0) mailbox_size = size; |
| 2476 | if (mailbox_filecount < 0) mailbox_filecount = filecount; |
| 2477 | } |
| 2478 | |
| 2479 | /* Handle the case of creating a unique file in a given directory (not in |
| 2480 | maildir or mailstore format - this is how smail did it). A temporary name is |
| 2481 | used to create the file. Later, when it is written, the name is changed to a |
| 2482 | unique one. There is no need to lock the file. An attempt is made to create |
| 2483 | the directory if it does not exist. */ |
| 2484 | |
| 2485 | if (mbformat == mbf_smail) |
| 2486 | { |
| 2487 | DEBUG(D_transport) |
| 2488 | debug_printf("delivering to new file in %s\n", path); |
| 2489 | filename = dataname = |
| 2490 | string_sprintf("%s/temp.%d.%s", path, (int)getpid(), primary_hostname); |
| 2491 | fd = Uopen(filename, O_WRONLY|O_CREAT, mode); |
| 2492 | if (fd < 0 && /* failed to open, and */ |
| 2493 | (errno != ENOENT || /* either not non-exist */ |
| 2494 | !ob->create_directory || /* or not allowed to make */ |
| 2495 | !directory_make(NULL, path, ob->dirmode, FALSE) || /* or failed to create dir */ |
| 2496 | (fd = Uopen(filename, O_WRONLY|O_CREAT|O_EXCL, mode)) < 0)) /* or then failed to open */ |
| 2497 | { |
| 2498 | addr->basic_errno = errno; |
| 2499 | addr->message = string_sprintf("while creating file %s", filename); |
| 2500 | return FALSE; |
| 2501 | } |
| 2502 | } |
| 2503 | |
| 2504 | #ifdef SUPPORT_MAILDIR |
| 2505 | |
| 2506 | /* Handle the case of a unique file in maildir format. The file is written to |
| 2507 | the tmp subdirectory, with a prescribed form of name. */ |
| 2508 | |
| 2509 | else if (mbformat == mbf_maildir) |
| 2510 | { |
| 2511 | DEBUG(D_transport) |
| 2512 | debug_printf("delivering in maildir format in %s\n", path); |
| 2513 | |
| 2514 | nametag = ob->maildir_tag; |
| 2515 | |
| 2516 | /* Check that nametag expands successfully; a hard failure causes a panic |
| 2517 | return. The actual expansion for use happens again later, when |
| 2518 | $message_size is accurately known. */ |
| 2519 | |
| 2520 | if (nametag != NULL && expand_string(nametag) == NULL && |
| 2521 | !expand_string_forcedfail) |
| 2522 | { |
| 2523 | addr->transport_return = PANIC; |
| 2524 | addr->message = string_sprintf("Expansion of \"%s\" (maildir_tag " |
| 2525 | "for %s transport) failed: %s", nametag, tblock->name, |
| 2526 | expand_string_message); |
| 2527 | return FALSE; |
| 2528 | } |
| 2529 | |
| 2530 | /* We ensured the existence of all the relevant directories above. Attempt |
| 2531 | to open the temporary file a limited number of times. I think this rather |
| 2532 | scary-looking for statement is actually OK. If open succeeds, the loop is |
| 2533 | broken; if not, there is a test on the value of i. Get the time again |
| 2534 | afresh each time round the loop. Its value goes into a variable that is |
| 2535 | checked at the end, to make sure we don't release this process until the |
| 2536 | clock has ticked. */ |
| 2537 | |
| 2538 | for (i = 1;; i++) |
| 2539 | { |
| 2540 | uschar *basename; |
| 2541 | |
| 2542 | (void)gettimeofday(&msg_tv, NULL); |
| 2543 | basename = string_sprintf("%lu.H%luP%lu.%s", msg_tv.tv_sec, |
| 2544 | msg_tv.tv_usec, getpid(), primary_hostname); |
| 2545 | |
| 2546 | filename = dataname = string_sprintf("tmp/%s", basename); |
| 2547 | newname = string_sprintf("new/%s", basename); |
| 2548 | |
| 2549 | if (Ustat(filename, &statbuf) == 0) |
| 2550 | errno = EEXIST; |
| 2551 | else if (errno == ENOENT) |
| 2552 | { |
| 2553 | fd = Uopen(filename, O_WRONLY | O_CREAT | O_EXCL, mode); |
| 2554 | if (fd >= 0) break; |
| 2555 | DEBUG (D_transport) debug_printf ("open failed for %s: %s\n", |
| 2556 | filename, strerror(errno)); |
| 2557 | } |
| 2558 | |
| 2559 | /* Too many retries - give up */ |
| 2560 | |
| 2561 | if (i >= ob->maildir_retries) |
| 2562 | { |
| 2563 | addr->message = string_sprintf ("failed to open %s (%d tr%s)", |
| 2564 | filename, i, (i == 1)? "y" : "ies"); |
| 2565 | addr->basic_errno = errno; |
| 2566 | if (errno == errno_quota || errno == ENOSPC) |
| 2567 | addr->user_message = US"mailbox is full"; |
| 2568 | return FALSE; |
| 2569 | } |
| 2570 | |
| 2571 | /* Open or stat failed but we haven't tried too many times yet. */ |
| 2572 | |
| 2573 | sleep(2); |
| 2574 | } |
| 2575 | |
| 2576 | /* Note that we have to ensure the clock has ticked before leaving */ |
| 2577 | |
| 2578 | wait_for_tick = TRUE; |
| 2579 | |
| 2580 | /* Why are these here? Put in because they are present in the non-maildir |
| 2581 | directory case above. */ |
| 2582 | |
| 2583 | if(Uchown(filename, uid, gid) || Uchmod(filename, mode)) |
| 2584 | { |
| 2585 | addr->basic_errno = errno; |
| 2586 | addr->message = string_sprintf("while setting perms on maildir %s", |
| 2587 | filename); |
| 2588 | return FALSE; |
| 2589 | } |
| 2590 | } |
| 2591 | |
| 2592 | #endif /* SUPPORT_MAILDIR */ |
| 2593 | |
| 2594 | #ifdef SUPPORT_MAILSTORE |
| 2595 | |
| 2596 | /* Handle the case of a unique file in mailstore format. First write the |
| 2597 | envelope to a temporary file, then open the main file. The unique base name |
| 2598 | for the files consists of the message id plus the pid of this delivery |
| 2599 | process. */ |
| 2600 | |
| 2601 | else |
| 2602 | { |
| 2603 | FILE *env_file; |
| 2604 | address_item *taddr; |
| 2605 | mailstore_basename = string_sprintf("%s/%s-%s", path, message_id, |
| 2606 | string_base62((long int)getpid())); |
| 2607 | |
| 2608 | DEBUG(D_transport) |
| 2609 | debug_printf("delivering in mailstore format in %s\n", path); |
| 2610 | |
| 2611 | filename = string_sprintf("%s.tmp", mailstore_basename); |
| 2612 | newname = string_sprintf("%s.env", mailstore_basename); |
| 2613 | dataname = string_sprintf("%s.msg", mailstore_basename); |
| 2614 | |
| 2615 | fd = Uopen(filename, O_WRONLY|O_CREAT|O_EXCL, mode); |
| 2616 | if (fd < 0 && /* failed to open, and */ |
| 2617 | (errno != ENOENT || /* either not non-exist */ |
| 2618 | !ob->create_directory || /* or not allowed to make */ |
| 2619 | !directory_make(NULL, path, ob->dirmode, FALSE) || /* or failed to create dir */ |
| 2620 | (fd = Uopen(filename, O_WRONLY|O_CREAT|O_EXCL, mode)) < 0)) /* or then failed to open */ |
| 2621 | { |
| 2622 | addr->basic_errno = errno; |
| 2623 | addr->message = string_sprintf("while creating file %s", filename); |
| 2624 | return FALSE; |
| 2625 | } |
| 2626 | |
| 2627 | /* Why are these here? Put in because they are present in the non-maildir |
| 2628 | directory case above. */ |
| 2629 | |
| 2630 | if(Uchown(filename, uid, gid) || Uchmod(filename, mode)) |
| 2631 | { |
| 2632 | addr->basic_errno = errno; |
| 2633 | addr->message = string_sprintf("while setting perms on file %s", |
| 2634 | filename); |
| 2635 | return FALSE; |
| 2636 | } |
| 2637 | |
| 2638 | /* Built a C stream from the open file descriptor. */ |
| 2639 | |
| 2640 | if ((env_file = fdopen(fd, "wb")) == NULL) |
| 2641 | { |
| 2642 | addr->basic_errno = errno; |
| 2643 | addr->transport_return = PANIC; |
| 2644 | addr->message = string_sprintf("fdopen of %s (" |
| 2645 | "for %s transport) failed", filename, tblock->name); |
| 2646 | (void)close(fd); |
| 2647 | Uunlink(filename); |
| 2648 | return FALSE; |
| 2649 | } |
| 2650 | |
| 2651 | /* Write the envelope file, then close it. */ |
| 2652 | |
| 2653 | if (ob->mailstore_prefix != NULL) |
| 2654 | { |
| 2655 | uschar *s = expand_string(ob->mailstore_prefix); |
| 2656 | if (s == NULL) |
| 2657 | { |
| 2658 | if (!expand_string_forcedfail) |
| 2659 | { |
| 2660 | addr->transport_return = PANIC; |
| 2661 | addr->message = string_sprintf("Expansion of \"%s\" (mailstore " |
| 2662 | "prefix for %s transport) failed: %s", ob->mailstore_prefix, |
| 2663 | tblock->name, expand_string_message); |
| 2664 | (void)fclose(env_file); |
| 2665 | Uunlink(filename); |
| 2666 | return FALSE; |
| 2667 | } |
| 2668 | } |
| 2669 | else |
| 2670 | { |
| 2671 | int n = Ustrlen(s); |
| 2672 | fprintf(env_file, "%s", CS s); |
| 2673 | if (n == 0 || s[n-1] != '\n') fprintf(env_file, "\n"); |
| 2674 | } |
| 2675 | } |
| 2676 | |
| 2677 | fprintf(env_file, "%s\n", sender_address); |
| 2678 | |
| 2679 | for (taddr = addr; taddr!= NULL; taddr = taddr->next) |
| 2680 | fprintf(env_file, "%s@%s\n", taddr->local_part, taddr->domain); |
| 2681 | |
| 2682 | if (ob->mailstore_suffix != NULL) |
| 2683 | { |
| 2684 | uschar *s = expand_string(ob->mailstore_suffix); |
| 2685 | if (s == NULL) |
| 2686 | { |
| 2687 | if (!expand_string_forcedfail) |
| 2688 | { |
| 2689 | addr->transport_return = PANIC; |
| 2690 | addr->message = string_sprintf("Expansion of \"%s\" (mailstore " |
| 2691 | "suffix for %s transport) failed: %s", ob->mailstore_suffix, |
| 2692 | tblock->name, expand_string_message); |
| 2693 | (void)fclose(env_file); |
| 2694 | Uunlink(filename); |
| 2695 | return FALSE; |
| 2696 | } |
| 2697 | } |
| 2698 | else |
| 2699 | { |
| 2700 | int n = Ustrlen(s); |
| 2701 | fprintf(env_file, "%s", CS s); |
| 2702 | if (n == 0 || s[n-1] != '\n') fprintf(env_file, "\n"); |
| 2703 | } |
| 2704 | } |
| 2705 | |
| 2706 | if (fclose(env_file) != 0) |
| 2707 | { |
| 2708 | addr->basic_errno = errno; |
| 2709 | addr->message = string_sprintf("while closing %s", filename); |
| 2710 | Uunlink(filename); |
| 2711 | return FALSE; |
| 2712 | } |
| 2713 | |
| 2714 | DEBUG(D_transport) debug_printf("Envelope file %s written\n", filename); |
| 2715 | |
| 2716 | /* Now open the data file, and ensure that it has the correct ownership and |
| 2717 | mode. */ |
| 2718 | |
| 2719 | fd = Uopen(dataname, O_WRONLY|O_CREAT|O_EXCL, mode); |
| 2720 | if (fd < 0) |
| 2721 | { |
| 2722 | addr->basic_errno = errno; |
| 2723 | addr->message = string_sprintf("while creating file %s", dataname); |
| 2724 | Uunlink(filename); |
| 2725 | return FALSE; |
| 2726 | } |
| 2727 | if(Uchown(dataname, uid, gid) || Uchmod(dataname, mode)) |
| 2728 | { |
| 2729 | addr->basic_errno = errno; |
| 2730 | addr->message = string_sprintf("while setting perms on file %s", |
| 2731 | dataname); |
| 2732 | return FALSE; |
| 2733 | } |
| 2734 | } |
| 2735 | |
| 2736 | #endif /* SUPPORT_MAILSTORE */ |
| 2737 | |
| 2738 | |
| 2739 | /* In all cases of writing to a new file, ensure that the file which is |
| 2740 | going to be renamed has the correct ownership and mode. */ |
| 2741 | |
| 2742 | if(Uchown(filename, uid, gid) || Uchmod(filename, mode)) |
| 2743 | { |
| 2744 | addr->basic_errno = errno; |
| 2745 | addr->message = string_sprintf("while setting perms on file %s", |
| 2746 | filename); |
| 2747 | return FALSE; |
| 2748 | } |
| 2749 | } |
| 2750 | |
| 2751 | |
| 2752 | /* At last we can write the message to the file, preceded by any configured |
| 2753 | prefix line, and followed by any configured suffix line. If there are any |
| 2754 | writing errors, we must defer. */ |
| 2755 | |
| 2756 | DEBUG(D_transport) debug_printf("writing to file %s\n", dataname); |
| 2757 | |
| 2758 | yield = OK; |
| 2759 | errno = 0; |
| 2760 | |
| 2761 | /* If there is a local quota setting, check that we are not going to exceed it |
| 2762 | with this message if quota_is_inclusive is set; if it is not set, the check |
| 2763 | is for the mailbox already being over quota (i.e. the current message is not |
| 2764 | included in the check). */ |
| 2765 | |
| 2766 | if (!disable_quota && ob->quota_value > 0) |
| 2767 | { |
| 2768 | DEBUG(D_transport) |
| 2769 | { |
| 2770 | debug_printf("Exim quota = " OFF_T_FMT " old size = " OFF_T_FMT |
| 2771 | " this message = %d (%sincluded)\n", |
| 2772 | ob->quota_value, mailbox_size, message_size, |
| 2773 | ob->quota_is_inclusive? "" : "not "); |
| 2774 | debug_printf(" file count quota = %d count = %d\n", |
| 2775 | ob->quota_filecount_value, mailbox_filecount); |
| 2776 | } |
| 2777 | if (mailbox_size + (ob->quota_is_inclusive? message_size:0) > ob->quota_value) |
| 2778 | { |
| 2779 | DEBUG(D_transport) debug_printf("mailbox quota exceeded\n"); |
| 2780 | yield = DEFER; |
| 2781 | errno = ERRNO_EXIMQUOTA; |
| 2782 | } |
| 2783 | else if (ob->quota_filecount_value > 0 && |
| 2784 | mailbox_filecount + (ob->quota_is_inclusive ? 1:0) > |
| 2785 | ob->quota_filecount_value) |
| 2786 | { |
| 2787 | DEBUG(D_transport) debug_printf("mailbox file count quota exceeded\n"); |
| 2788 | yield = DEFER; |
| 2789 | errno = ERRNO_EXIMQUOTA; |
| 2790 | filecount_msg = US" filecount"; |
| 2791 | } |
| 2792 | } |
| 2793 | |
| 2794 | /* If we are writing in MBX format, what we actually do is to write the message |
| 2795 | to a temporary file, and then copy it to the real file once we know its size. |
| 2796 | This is the most straightforward way of getting the correct length in the |
| 2797 | separator line. So, what we do here is to save the real file descriptor, and |
| 2798 | replace it with one for a temporary file. The temporary file gets unlinked once |
| 2799 | opened, so that it goes away on closure. */ |
| 2800 | |
| 2801 | #ifdef SUPPORT_MBX |
| 2802 | if (yield == OK && ob->mbx_format) |
| 2803 | { |
| 2804 | temp_file = tmpfile(); |
| 2805 | if (temp_file == NULL) |
| 2806 | { |
| 2807 | addr->basic_errno = errno; |
| 2808 | addr->message = US"while setting up temporary file"; |
| 2809 | yield = DEFER; |
| 2810 | goto RETURN; |
| 2811 | } |
| 2812 | save_fd = fd; |
| 2813 | fd = fileno(temp_file); |
| 2814 | DEBUG(D_transport) debug_printf("writing to temporary file\n"); |
| 2815 | } |
| 2816 | #endif /* SUPPORT_MBX */ |
| 2817 | |
| 2818 | /* Zero the count of bytes written. It is incremented by the transport_xxx() |
| 2819 | functions. */ |
| 2820 | |
| 2821 | transport_count = 0; |
| 2822 | transport_newlines = 0; |
| 2823 | |
| 2824 | /* Write any configured prefix text first */ |
| 2825 | |
| 2826 | if (yield == OK && ob->message_prefix != NULL && ob->message_prefix[0] != 0) |
| 2827 | { |
| 2828 | uschar *prefix = expand_string(ob->message_prefix); |
| 2829 | if (prefix == NULL) |
| 2830 | { |
| 2831 | errno = ERRNO_EXPANDFAIL; |
| 2832 | addr->transport_return = PANIC; |
| 2833 | addr->message = string_sprintf("Expansion of \"%s\" (prefix for %s " |
| 2834 | "transport) failed", ob->message_prefix, tblock->name); |
| 2835 | yield = DEFER; |
| 2836 | } |
| 2837 | else if (!transport_write_string(fd, "%s", prefix)) yield = DEFER; |
| 2838 | } |
| 2839 | |
| 2840 | /* If the use_bsmtp option is on, we need to write SMTP prefix information. The |
| 2841 | various different values for batching are handled outside; if there is more |
| 2842 | than one address available here, all must be included. If any address is a |
| 2843 | file, use its parent in the RCPT TO. */ |
| 2844 | |
| 2845 | if (yield == OK && ob->use_bsmtp) |
| 2846 | { |
| 2847 | transport_count = 0; |
| 2848 | transport_newlines = 0; |
| 2849 | if (ob->use_crlf) cr = US"\r"; |
| 2850 | if (!transport_write_string(fd, "MAIL FROM:<%s>%s\n", return_path, cr)) |
| 2851 | yield = DEFER; |
| 2852 | else |
| 2853 | { |
| 2854 | address_item *a; |
| 2855 | transport_newlines++; |
| 2856 | for (a = addr; a != NULL; a = a->next) |
| 2857 | { |
| 2858 | address_item *b = testflag(a, af_pfr)? a->parent: a; |
| 2859 | if (!transport_write_string(fd, "RCPT TO:<%s>%s\n", |
| 2860 | transport_rcpt_address(b, tblock->rcpt_include_affixes), cr)) |
| 2861 | { yield = DEFER; break; } |
| 2862 | transport_newlines++; |
| 2863 | } |
| 2864 | if (yield == OK && !transport_write_string(fd, "DATA%s\n", cr)) |
| 2865 | yield = DEFER; |
| 2866 | else |
| 2867 | transport_newlines++; |
| 2868 | } |
| 2869 | } |
| 2870 | |
| 2871 | /* Now the message itself. The options for transport_write_message were set up |
| 2872 | at initialization time. */ |
| 2873 | |
| 2874 | if (yield == OK) |
| 2875 | { |
| 2876 | if (!transport_write_message(addr, fd, ob->options, 0, tblock->add_headers, |
| 2877 | tblock->remove_headers, ob->check_string, ob->escape_string, |
| 2878 | tblock->rewrite_rules, tblock->rewrite_existflags)) |
| 2879 | yield = DEFER; |
| 2880 | } |
| 2881 | |
| 2882 | /* Now a configured suffix. */ |
| 2883 | |
| 2884 | if (yield == OK && ob->message_suffix != NULL && ob->message_suffix[0] != 0) |
| 2885 | { |
| 2886 | uschar *suffix = expand_string(ob->message_suffix); |
| 2887 | if (suffix == NULL) |
| 2888 | { |
| 2889 | errno = ERRNO_EXPANDFAIL; |
| 2890 | addr->transport_return = PANIC; |
| 2891 | addr->message = string_sprintf("Expansion of \"%s\" (suffix for %s " |
| 2892 | "transport) failed", ob->message_suffix, tblock->name); |
| 2893 | yield = DEFER; |
| 2894 | } |
| 2895 | else if (!transport_write_string(fd, "%s", suffix)) yield = DEFER; |
| 2896 | } |
| 2897 | |
| 2898 | /* If batch smtp, write the terminating dot. */ |
| 2899 | |
| 2900 | if (yield == OK && ob->use_bsmtp ) { |
| 2901 | if(!transport_write_string(fd, ".%s\n", cr)) yield = DEFER; |
| 2902 | else transport_newlines++; |
| 2903 | } |
| 2904 | |
| 2905 | /* If MBX format is being used, all that writing was to the temporary file. |
| 2906 | However, if there was an earlier failure (Exim quota exceeded, for example), |
| 2907 | the temporary file won't have got opened - and no writing will have been done. |
| 2908 | If writing was OK, we restore the fd, and call a function that copies the |
| 2909 | message in MBX format into the real file. Otherwise use the temporary name in |
| 2910 | any messages. */ |
| 2911 | |
| 2912 | #ifdef SUPPORT_MBX |
| 2913 | if (temp_file != NULL && ob->mbx_format) |
| 2914 | { |
| 2915 | int mbx_save_errno; |
| 2916 | fd = save_fd; |
| 2917 | |
| 2918 | if (yield == OK) |
| 2919 | { |
| 2920 | transport_count = 0; /* Reset transport count for actual write */ |
| 2921 | /* No need to reset transport_newlines as we're just using a block copy |
| 2922 | * routine so the number won't be affected */ |
| 2923 | yield = copy_mbx_message(fd, fileno(temp_file), saved_size); |
| 2924 | } |
| 2925 | else if (errno >= 0) dataname = US"temporary file"; |
| 2926 | |
| 2927 | /* Preserve errno while closing the temporary file. */ |
| 2928 | |
| 2929 | mbx_save_errno = errno; |
| 2930 | (void)fclose(temp_file); |
| 2931 | errno = mbx_save_errno; |
| 2932 | } |
| 2933 | #endif /* SUPPORT_MBX */ |
| 2934 | |
| 2935 | /* Force out the remaining data to check for any errors; some OS don't allow |
| 2936 | fsync() to be called for a FIFO. */ |
| 2937 | |
| 2938 | if (yield == OK && !isfifo && EXIMfsync(fd) < 0) yield = DEFER; |
| 2939 | |
| 2940 | /* Update message_size and message_linecount to the accurate count of bytes |
| 2941 | written, including added headers. Note; we subtract 1 from message_linecount as |
| 2942 | this variable doesn't count the new line between the header and the body of the |
| 2943 | message. */ |
| 2944 | |
| 2945 | message_size = transport_count; |
| 2946 | message_linecount = transport_newlines - 1; |
| 2947 | |
| 2948 | /* If using a maildir++ quota file, add this message's size to it, and |
| 2949 | close the file descriptor, except when the quota has been disabled because we |
| 2950 | are delivering into an uncounted folder. */ |
| 2951 | |
| 2952 | #ifdef SUPPORT_MAILDIR |
| 2953 | if (!disable_quota) |
| 2954 | { |
| 2955 | if (yield == OK && maildirsize_fd >= 0) |
| 2956 | maildir_record_length(maildirsize_fd, message_size); |
| 2957 | maildir_save_errno = errno; /* Preserve errno while closing the file */ |
| 2958 | if (maildirsize_fd >= 0) |
| 2959 | (void)close(maildirsize_fd); |
| 2960 | errno = maildir_save_errno; |
| 2961 | } |
| 2962 | #endif /* SUPPORT_MAILDIR */ |
| 2963 | |
| 2964 | /* If there is a quota warning threshold and we are have crossed it with this |
| 2965 | message, set the SPECIAL_WARN flag in the address, to cause a warning message |
| 2966 | to be sent. */ |
| 2967 | |
| 2968 | if (!disable_quota && THRESHOLD_CHECK) |
| 2969 | { |
| 2970 | off_t threshold = ob->quota_warn_threshold_value; |
| 2971 | if (ob->quota_warn_threshold_is_percent) |
| 2972 | threshold = (off_t)(((double)ob->quota_value * threshold) / 100); |
| 2973 | DEBUG(D_transport) |
| 2974 | debug_printf("quota = " OFF_T_FMT |
| 2975 | " threshold = " OFF_T_FMT |
| 2976 | " old size = " OFF_T_FMT |
| 2977 | " message size = %d\n", |
| 2978 | ob->quota_value, threshold, mailbox_size, |
| 2979 | message_size); |
| 2980 | if (mailbox_size <= threshold && mailbox_size + message_size > threshold) |
| 2981 | addr->special_action = SPECIAL_WARN; |
| 2982 | |
| 2983 | /******* You might think that the test ought to be this: |
| 2984 | * |
| 2985 | * if (ob->quota_value > 0 && threshold > 0 && mailbox_size > 0 && |
| 2986 | * mailbox_size <= threshold && mailbox_size + message_size > threshold) |
| 2987 | * |
| 2988 | * (indeed, I was sent a patch with that in). However, it is possible to |
| 2989 | * have a warning threshold without actually imposing a quota, and I have |
| 2990 | * therefore kept Exim backwards compatible. |
| 2991 | ********/ |
| 2992 | |
| 2993 | } |
| 2994 | |
| 2995 | /* Handle error while writing the file. Control should come here directly after |
| 2996 | the error, with the reason in errno. In the case of expansion failure in prefix |
| 2997 | or suffix, it will be ERRNO_EXPANDFAIL. */ |
| 2998 | |
| 2999 | if (yield != OK) |
| 3000 | { |
| 3001 | addr->special_action = SPECIAL_NONE; /* Cancel any quota warning */ |
| 3002 | |
| 3003 | /* Save the error number. If positive, it will ultimately cause a strerror() |
| 3004 | call to generate some text. */ |
| 3005 | |
| 3006 | addr->basic_errno = errno; |
| 3007 | |
| 3008 | /* For system or Exim quota excession, or disk full, set more_errno to the |
| 3009 | time since the file was last read. If delivery was into a directory, the |
| 3010 | time since last read logic is not relevant, in general. However, for maildir |
| 3011 | deliveries we can approximate it by looking at the last modified time of the |
| 3012 | "new" subdirectory. Since Exim won't be adding new messages, a change to the |
| 3013 | "new" subdirectory implies that an MUA has moved a message from there to the |
| 3014 | "cur" directory. */ |
| 3015 | |
| 3016 | if (errno == errno_quota || errno == ERRNO_EXIMQUOTA || errno == ENOSPC) |
| 3017 | { |
| 3018 | addr->more_errno = 0; |
| 3019 | if (!isdirectory) addr->more_errno = (int)(time(NULL) - times.actime); |
| 3020 | |
| 3021 | #ifdef SUPPORT_MAILDIR |
| 3022 | else if (mbformat == mbf_maildir) |
| 3023 | { |
| 3024 | struct stat statbuf; |
| 3025 | if (Ustat("new", &statbuf) < 0) |
| 3026 | { |
| 3027 | DEBUG(D_transport) debug_printf("maildir quota exceeded: " |
| 3028 | "stat error %d for \"new\": %s\n", errno, strerror(errno)); |
| 3029 | } |
| 3030 | else /* Want a repeatable time when in test harness */ |
| 3031 | { |
| 3032 | addr->more_errno = running_in_test_harness? 10 : |
| 3033 | (int)time(NULL) - statbuf.st_mtime; |
| 3034 | } |
| 3035 | DEBUG(D_transport) |
| 3036 | debug_printf("maildir: time since \"new\" directory modified = %s\n", |
| 3037 | readconf_printtime(addr->more_errno)); |
| 3038 | } |
| 3039 | #endif /* SUPPORT_MAILDIR */ |
| 3040 | } |
| 3041 | |
| 3042 | /* Handle system quota excession. Add an explanatory phrase for the error |
| 3043 | message, since some systems don't have special quota-excession errors, |
| 3044 | and on those that do, "quota" doesn't always mean anything to the user. */ |
| 3045 | |
| 3046 | if (errno == errno_quota) |
| 3047 | { |
| 3048 | #ifndef EDQUOT |
| 3049 | addr->message = string_sprintf("mailbox is full " |
| 3050 | "(quota exceeded while writing to file %s)", filename); |
| 3051 | #else |
| 3052 | addr->message = string_sprintf("mailbox is full"); |
| 3053 | #endif /* EDQUOT */ |
| 3054 | addr->user_message = US"mailbox is full"; |
| 3055 | DEBUG(D_transport) debug_printf("System quota exceeded for %s%s%s\n", |
| 3056 | dataname, |
| 3057 | isdirectory? US"" : US": time since file read = ", |
| 3058 | isdirectory? US"" : readconf_printtime(addr->more_errno)); |
| 3059 | } |
| 3060 | |
| 3061 | /* Handle Exim's own quota-imposition */ |
| 3062 | |
| 3063 | else if (errno == ERRNO_EXIMQUOTA) |
| 3064 | { |
| 3065 | addr->message = string_sprintf("mailbox is full " |
| 3066 | "(MTA-imposed%s quota exceeded while writing to %s)", filecount_msg, |
| 3067 | dataname); |
| 3068 | addr->user_message = US"mailbox is full"; |
| 3069 | DEBUG(D_transport) debug_printf("Exim%s quota exceeded for %s%s%s\n", |
| 3070 | filecount_msg, dataname, |
| 3071 | isdirectory? US"" : US": time since file read = ", |
| 3072 | isdirectory? US"" : readconf_printtime(addr->more_errno)); |
| 3073 | } |
| 3074 | |
| 3075 | /* Handle a process failure while writing via a filter; the return |
| 3076 | from child_close() is in more_errno. */ |
| 3077 | |
| 3078 | else if (errno == ERRNO_FILTER_FAIL) |
| 3079 | { |
| 3080 | yield = PANIC; |
| 3081 | addr->message = string_sprintf("transport filter process failed (%d) " |
| 3082 | "while writing to %s%s", addr->more_errno, dataname, |
| 3083 | (addr->more_errno == EX_EXECFAILED)? ": unable to execute command" : ""); |
| 3084 | } |
| 3085 | |
| 3086 | /* Handle failure to expand header changes */ |
| 3087 | |
| 3088 | else if (errno == ERRNO_CHHEADER_FAIL) |
| 3089 | { |
| 3090 | yield = PANIC; |
| 3091 | addr->message = |
| 3092 | string_sprintf("failed to expand headers_add or headers_remove while " |
| 3093 | "writing to %s: %s", dataname, expand_string_message); |
| 3094 | } |
| 3095 | |
| 3096 | /* Handle failure to complete writing of a data block */ |
| 3097 | |
| 3098 | else if (errno == ERRNO_WRITEINCOMPLETE) |
| 3099 | { |
| 3100 | addr->message = string_sprintf("failed to write data block while " |
| 3101 | "writing to %s", dataname); |
| 3102 | } |
| 3103 | |
| 3104 | /* Handle length mismatch on MBX copying */ |
| 3105 | |
| 3106 | #ifdef SUPPORT_MBX |
| 3107 | else if (errno == ERRNO_MBXLENGTH) |
| 3108 | { |
| 3109 | addr->message = string_sprintf("length mismatch while copying MBX " |
| 3110 | "temporary file to %s", dataname); |
| 3111 | } |
| 3112 | #endif /* SUPPORT_MBX */ |
| 3113 | |
| 3114 | /* For other errors, a general-purpose explanation, if the message is |
| 3115 | not already set. */ |
| 3116 | |
| 3117 | else if (addr->message == NULL) |
| 3118 | addr->message = string_sprintf("error while writing to %s", dataname); |
| 3119 | |
| 3120 | /* For a file, reset the file size to what it was before we started, leaving |
| 3121 | the last modification time unchanged, so it will get reset also. All systems |
| 3122 | investigated so far have ftruncate(), whereas not all have the F_FREESP |
| 3123 | fcntl() call (BSDI & FreeBSD do not). */ |
| 3124 | |
| 3125 | if (!isdirectory && ftruncate(fd, saved_size)) |
| 3126 | DEBUG(D_transport) debug_printf("Error restting file size\n"); |
| 3127 | } |
| 3128 | |
| 3129 | /* Handle successful writing - we want the modification time to be now for |
| 3130 | appended files. Remove the default backstop error number. For a directory, now |
| 3131 | is the time to rename the file with a unique name. As soon as such a name |
| 3132 | appears it may get used by another process, so we close the file first and |
| 3133 | check that all is well. */ |
| 3134 | |
| 3135 | else |
| 3136 | { |
| 3137 | times.modtime = time(NULL); |
| 3138 | addr->basic_errno = 0; |
| 3139 | |
| 3140 | /* Handle the case of writing to a new file in a directory. This applies |
| 3141 | to all single-file formats - maildir, mailstore, and "smail format". */ |
| 3142 | |
| 3143 | if (isdirectory) |
| 3144 | { |
| 3145 | if (fstat(fd, &statbuf) < 0) |
| 3146 | { |
| 3147 | addr->basic_errno = errno; |
| 3148 | addr->message = string_sprintf("while fstatting opened message file %s", |
| 3149 | filename); |
| 3150 | yield = DEFER; |
| 3151 | } |
| 3152 | |
| 3153 | else if (close(fd) < 0) |
| 3154 | { |
| 3155 | addr->basic_errno = errno; |
| 3156 | addr->message = string_sprintf("close() error for %s", |
| 3157 | (ob->mailstore_format)? dataname : filename); |
| 3158 | yield = DEFER; |
| 3159 | } |
| 3160 | |
| 3161 | /* File is successfully written and closed. Arrange to rename it. For the |
| 3162 | different kinds of single-file delivery, some games can be played with the |
| 3163 | name. The message size is by this time set to the accurate value so that |
| 3164 | its value can be used in expansions. */ |
| 3165 | |
| 3166 | else |
| 3167 | { |
| 3168 | uschar *renamename = newname; |
| 3169 | fd = -1; |
| 3170 | |
| 3171 | DEBUG(D_transport) debug_printf("renaming temporary file\n"); |
| 3172 | |
| 3173 | /* If there is no rename name set, we are in a non-maildir, non-mailstore |
| 3174 | situation. The name is built by expanding the directory_file option, and |
| 3175 | we make the inode number available for use in this. The expansion was |
| 3176 | checked for syntactic validity above, before we wrote the file. |
| 3177 | |
| 3178 | We have to be careful here, in case the file name exists. (In the other |
| 3179 | cases, the names used are constructed to be unique.) The rename() |
| 3180 | function just replaces an existing file - we don't want that! So instead |
| 3181 | of calling rename(), we must use link() and unlink(). |
| 3182 | |
| 3183 | In this case, if the link fails because of an existing file, we wait |
| 3184 | for one second and try the expansion again, to see if it produces a |
| 3185 | different value. Do this up to 5 times unless the name stops changing. |
| 3186 | This makes it possible to build values that are based on the time, and |
| 3187 | still cope with races from multiple simultaneous deliveries. */ |
| 3188 | |
| 3189 | if (newname == NULL) |
| 3190 | { |
| 3191 | int i; |
| 3192 | uschar *renameleaf; |
| 3193 | uschar *old_renameleaf = US""; |
| 3194 | |
| 3195 | for (i = 0; ; sleep(1), i++) |
| 3196 | { |
| 3197 | deliver_inode = statbuf.st_ino; |
| 3198 | renameleaf = expand_string(ob->dirfilename); |
| 3199 | deliver_inode = 0; |
| 3200 | |
| 3201 | if (renameleaf == NULL) |
| 3202 | { |
| 3203 | addr->transport_return = PANIC; |
| 3204 | addr->message = string_sprintf("Expansion of \"%s\" " |
| 3205 | "(directory_file for %s transport) failed: %s", |
| 3206 | ob->dirfilename, tblock->name, expand_string_message); |
| 3207 | goto RETURN; |
| 3208 | } |
| 3209 | |
| 3210 | renamename = string_sprintf("%s/%s", path, renameleaf); |
| 3211 | if (Ulink(filename, renamename) < 0) |
| 3212 | { |
| 3213 | DEBUG(D_transport) debug_printf("link failed: %s\n", |
| 3214 | strerror(errno)); |
| 3215 | if (errno != EEXIST || i >= 4 || |
| 3216 | Ustrcmp(renameleaf, old_renameleaf) == 0) |
| 3217 | { |
| 3218 | addr->basic_errno = errno; |
| 3219 | addr->message = string_sprintf("while renaming %s as %s", |
| 3220 | filename, renamename); |
| 3221 | yield = DEFER; |
| 3222 | break; |
| 3223 | } |
| 3224 | old_renameleaf = renameleaf; |
| 3225 | DEBUG(D_transport) debug_printf("%s exists - trying again\n", |
| 3226 | renamename); |
| 3227 | } |
| 3228 | else |
| 3229 | { |
| 3230 | Uunlink(filename); |
| 3231 | filename = NULL; |
| 3232 | break; |
| 3233 | } |
| 3234 | } /* re-expand loop */ |
| 3235 | } /* not mailstore or maildir */ |
| 3236 | |
| 3237 | /* For maildir and mailstore formats, the new name was created earlier, |
| 3238 | except that for maildir, there is the possibility of adding a "tag" on |
| 3239 | the end of the name by expanding the value of nametag. This usually |
| 3240 | includes a reference to the message size. The expansion of nametag was |
| 3241 | checked above, before the file was opened. It either succeeded, or |
| 3242 | provoked a soft failure. So any failure here can be treated as soft. |
| 3243 | Ignore non-printing characters and / and put a colon at the start if the |
| 3244 | first character is alphanumeric. */ |
| 3245 | |
| 3246 | else |
| 3247 | { |
| 3248 | if (nametag != NULL) |
| 3249 | { |
| 3250 | uschar *iptr = expand_string(nametag); |
| 3251 | if (iptr != NULL) |
| 3252 | { |
| 3253 | uschar *etag = store_get(Ustrlen(iptr) + 2); |
| 3254 | uschar *optr = etag; |
| 3255 | while (*iptr != 0) |
| 3256 | { |
| 3257 | if (mac_isgraph(*iptr) && *iptr != '/') |
| 3258 | { |
| 3259 | if (optr == etag && isalnum(*iptr)) *optr++ = ':'; |
| 3260 | *optr++ = *iptr; |
| 3261 | } |
| 3262 | iptr++; |
| 3263 | } |
| 3264 | *optr = 0; |
| 3265 | renamename = string_sprintf("%s%s", newname, etag); |
| 3266 | } |
| 3267 | } |
| 3268 | |
| 3269 | /* Do the rename. If the name is too long and a tag exists, try again |
| 3270 | without the tag. */ |
| 3271 | |
| 3272 | if (Urename(filename, renamename) < 0 && |
| 3273 | (nametag == NULL || errno != ENAMETOOLONG || |
| 3274 | (renamename = newname, Urename(filename, renamename) < 0))) |
| 3275 | { |
| 3276 | addr->basic_errno = errno; |
| 3277 | addr->message = string_sprintf("while renaming %s as %s", |
| 3278 | filename, renamename); |
| 3279 | yield = DEFER; |
| 3280 | } |
| 3281 | |
| 3282 | /* Rename succeeded */ |
| 3283 | |
| 3284 | else |
| 3285 | { |
| 3286 | DEBUG(D_transport) debug_printf("renamed %s as %s\n", filename, |
| 3287 | renamename); |
| 3288 | filename = dataname = NULL; /* Prevents attempt to unlink at end */ |
| 3289 | } |
| 3290 | } /* maildir or mailstore */ |
| 3291 | } /* successful write + close */ |
| 3292 | } /* isdirectory */ |
| 3293 | } /* write success */ |
| 3294 | |
| 3295 | |
| 3296 | /* For a file, restore the last access time (atime), and set the modification |
| 3297 | time as required - changed if write succeeded, unchanged if not. */ |
| 3298 | |
| 3299 | if (!isdirectory) utime(CS filename, ×); |
| 3300 | |
| 3301 | /* Notify comsat if configured to do so. It only makes sense if the configured |
| 3302 | file is the one that the comsat daemon knows about. */ |
| 3303 | |
| 3304 | if (ob->notify_comsat && yield == OK && deliver_localpart != NULL) |
| 3305 | notify_comsat(deliver_localpart, saved_size); |
| 3306 | |
| 3307 | /* Pass back the final return code in the address structure */ |
| 3308 | |
| 3309 | DEBUG(D_transport) |
| 3310 | debug_printf("appendfile yields %d with errno=%d more_errno=%d\n", |
| 3311 | yield, addr->basic_errno, addr->more_errno); |
| 3312 | |
| 3313 | addr->transport_return = yield; |
| 3314 | |
| 3315 | /* Close the file, which will release the fcntl lock. For a directory write it |
| 3316 | is closed above, except in cases of error which goto RETURN, when we also need |
| 3317 | to remove the original file(s). For MBX locking, if all has gone well, before |
| 3318 | closing the file, see if we can get an exclusive lock on it, in which case we |
| 3319 | can unlink the /tmp lock file before closing it. This is always a non-blocking |
| 3320 | lock; there's no need to wait if we can't get it. If everything has gone right |
| 3321 | but close fails, defer the message. Then unlink the lock file, if present. This |
| 3322 | point in the code is jumped to from a number of places when errors are |
| 3323 | detected, in order to get the file closed and the lock file tidied away. */ |
| 3324 | |
| 3325 | RETURN: |
| 3326 | |
| 3327 | #ifdef SUPPORT_MBX |
| 3328 | if (mbx_lockfd >= 0) |
| 3329 | { |
| 3330 | if (yield == OK && apply_lock(fd, F_WRLCK, ob->use_fcntl, 0, |
| 3331 | ob->use_flock, 0) >= 0) |
| 3332 | { |
| 3333 | DEBUG(D_transport) |
| 3334 | debug_printf("unlinking MBX lock file %s\n", mbx_lockname); |
| 3335 | Uunlink(mbx_lockname); |
| 3336 | } |
| 3337 | (void)close(mbx_lockfd); |
| 3338 | } |
| 3339 | #endif /* SUPPORT_MBX */ |
| 3340 | |
| 3341 | if (fd >= 0 && close(fd) < 0 && yield == OK) |
| 3342 | { |
| 3343 | addr->basic_errno = errno; |
| 3344 | addr->message = string_sprintf("while closing %s", filename); |
| 3345 | addr->transport_return = DEFER; |
| 3346 | } |
| 3347 | |
| 3348 | if (hd >= 0) Uunlink(lockname); |
| 3349 | |
| 3350 | /* We get here with isdirectory and filename set only in error situations. */ |
| 3351 | |
| 3352 | if (isdirectory && filename != NULL) |
| 3353 | { |
| 3354 | Uunlink(filename); |
| 3355 | if (dataname != filename) Uunlink(dataname); |
| 3356 | } |
| 3357 | |
| 3358 | /* If wait_for_tick is TRUE, we have done a delivery where the uniqueness of a |
| 3359 | file name relies on time + pid. We must not allow the process to finish until |
| 3360 | the clock has move on by at least one microsecond. Usually we expect this |
| 3361 | already to be the case, but machines keep getting faster... */ |
| 3362 | |
| 3363 | if (wait_for_tick) exim_wait_tick(&msg_tv, 1); |
| 3364 | |
| 3365 | /* A return of FALSE means that if there was an error, a common error was |
| 3366 | put in the first address of a batch. */ |
| 3367 | |
| 3368 | return FALSE; |
| 3369 | } |
| 3370 | |
| 3371 | /* End of transport/appendfile.c */ |