| 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 | /* Code for handling Access Control Lists (ACLs) */ |
| 9 | |
| 10 | #include "exim.h" |
| 11 | |
| 12 | |
| 13 | /* Default callout timeout */ |
| 14 | |
| 15 | #define CALLOUT_TIMEOUT_DEFAULT 30 |
| 16 | |
| 17 | /* ACL verb codes - keep in step with the table of verbs that follows */ |
| 18 | |
| 19 | enum { ACL_ACCEPT, ACL_DEFER, ACL_DENY, ACL_DISCARD, ACL_DROP, ACL_REQUIRE, |
| 20 | ACL_WARN }; |
| 21 | |
| 22 | /* ACL verbs */ |
| 23 | |
| 24 | static uschar *verbs[] = |
| 25 | { US"accept", US"defer", US"deny", US"discard", US"drop", US"require", |
| 26 | US"warn" }; |
| 27 | |
| 28 | /* For each verb, the conditions for which "message" or "log_message" are used |
| 29 | are held as a bitmap. This is to avoid expanding the strings unnecessarily. For |
| 30 | "accept", the FAIL case is used only after "endpass", but that is selected in |
| 31 | the code. */ |
| 32 | |
| 33 | static int msgcond[] = { |
| 34 | (1<<OK) | (1<<FAIL) | (1<<FAIL_DROP), /* accept */ |
| 35 | (1<<OK), /* defer */ |
| 36 | (1<<OK), /* deny */ |
| 37 | (1<<OK) | (1<<FAIL) | (1<<FAIL_DROP), /* discard */ |
| 38 | (1<<OK), /* drop */ |
| 39 | (1<<FAIL) | (1<<FAIL_DROP), /* require */ |
| 40 | (1<<OK) /* warn */ |
| 41 | }; |
| 42 | |
| 43 | /* ACL condition and modifier codes - keep in step with the table that |
| 44 | follows, and the cond_expand_at_top and uschar cond_modifiers tables lower |
| 45 | down. */ |
| 46 | |
| 47 | enum { ACLC_ACL, |
| 48 | ACLC_ADD_HEADER, |
| 49 | ACLC_AUTHENTICATED, |
| 50 | #ifdef EXPERIMENTAL_BRIGHTMAIL |
| 51 | ACLC_BMI_OPTIN, |
| 52 | #endif |
| 53 | ACLC_CONDITION, |
| 54 | ACLC_CONTINUE, |
| 55 | ACLC_CONTROL, |
| 56 | #ifdef EXPERIMENTAL_DCC |
| 57 | ACLC_DCC, |
| 58 | #endif |
| 59 | #ifdef WITH_CONTENT_SCAN |
| 60 | ACLC_DECODE, |
| 61 | #endif |
| 62 | ACLC_DELAY, |
| 63 | #ifdef WITH_OLD_DEMIME |
| 64 | ACLC_DEMIME, |
| 65 | #endif |
| 66 | #ifndef DISABLE_DKIM |
| 67 | ACLC_DKIM_SIGNER, |
| 68 | ACLC_DKIM_STATUS, |
| 69 | #endif |
| 70 | ACLC_DNSLISTS, |
| 71 | ACLC_DOMAINS, |
| 72 | ACLC_ENCRYPTED, |
| 73 | ACLC_ENDPASS, |
| 74 | ACLC_HOSTS, |
| 75 | ACLC_LOCAL_PARTS, |
| 76 | ACLC_LOG_MESSAGE, |
| 77 | ACLC_LOG_REJECT_TARGET, |
| 78 | ACLC_LOGWRITE, |
| 79 | #ifdef WITH_CONTENT_SCAN |
| 80 | ACLC_MALWARE, |
| 81 | #endif |
| 82 | ACLC_MESSAGE, |
| 83 | #ifdef WITH_CONTENT_SCAN |
| 84 | ACLC_MIME_REGEX, |
| 85 | #endif |
| 86 | ACLC_RATELIMIT, |
| 87 | ACLC_RECIPIENTS, |
| 88 | #ifdef WITH_CONTENT_SCAN |
| 89 | ACLC_REGEX, |
| 90 | #endif |
| 91 | ACLC_SENDER_DOMAINS, |
| 92 | ACLC_SENDERS, |
| 93 | ACLC_SET, |
| 94 | #ifdef WITH_CONTENT_SCAN |
| 95 | ACLC_SPAM, |
| 96 | #endif |
| 97 | #ifdef EXPERIMENTAL_SPF |
| 98 | ACLC_SPF, |
| 99 | ACLC_SPF_GUESS, |
| 100 | #endif |
| 101 | ACLC_VERIFY }; |
| 102 | |
| 103 | /* ACL conditions/modifiers: "delay", "control", "continue", "endpass", |
| 104 | "message", "log_message", "log_reject_target", "logwrite", and "set" are |
| 105 | modifiers that look like conditions but always return TRUE. They are used for |
| 106 | their side effects. */ |
| 107 | |
| 108 | static uschar *conditions[] = { |
| 109 | US"acl", |
| 110 | US"add_header", |
| 111 | US"authenticated", |
| 112 | #ifdef EXPERIMENTAL_BRIGHTMAIL |
| 113 | US"bmi_optin", |
| 114 | #endif |
| 115 | US"condition", |
| 116 | US"continue", |
| 117 | US"control", |
| 118 | #ifdef EXPERIMENTAL_DCC |
| 119 | US"dcc", |
| 120 | #endif |
| 121 | #ifdef WITH_CONTENT_SCAN |
| 122 | US"decode", |
| 123 | #endif |
| 124 | US"delay", |
| 125 | #ifdef WITH_OLD_DEMIME |
| 126 | US"demime", |
| 127 | #endif |
| 128 | #ifndef DISABLE_DKIM |
| 129 | US"dkim_signers", |
| 130 | US"dkim_status", |
| 131 | #endif |
| 132 | US"dnslists", |
| 133 | US"domains", |
| 134 | US"encrypted", |
| 135 | US"endpass", |
| 136 | US"hosts", |
| 137 | US"local_parts", |
| 138 | US"log_message", |
| 139 | US"log_reject_target", |
| 140 | US"logwrite", |
| 141 | #ifdef WITH_CONTENT_SCAN |
| 142 | US"malware", |
| 143 | #endif |
| 144 | US"message", |
| 145 | #ifdef WITH_CONTENT_SCAN |
| 146 | US"mime_regex", |
| 147 | #endif |
| 148 | US"ratelimit", |
| 149 | US"recipients", |
| 150 | #ifdef WITH_CONTENT_SCAN |
| 151 | US"regex", |
| 152 | #endif |
| 153 | US"sender_domains", US"senders", US"set", |
| 154 | #ifdef WITH_CONTENT_SCAN |
| 155 | US"spam", |
| 156 | #endif |
| 157 | #ifdef EXPERIMENTAL_SPF |
| 158 | US"spf", |
| 159 | US"spf_guess", |
| 160 | #endif |
| 161 | US"verify" }; |
| 162 | |
| 163 | |
| 164 | /* Return values from decode_control(); keep in step with the table of names |
| 165 | that follows! */ |
| 166 | |
| 167 | enum { |
| 168 | CONTROL_AUTH_UNADVERTISED, |
| 169 | #ifdef EXPERIMENTAL_BRIGHTMAIL |
| 170 | CONTROL_BMI_RUN, |
| 171 | #endif |
| 172 | CONTROL_DEBUG, |
| 173 | #ifndef DISABLE_DKIM |
| 174 | CONTROL_DKIM_VERIFY, |
| 175 | #endif |
| 176 | CONTROL_ERROR, |
| 177 | CONTROL_CASEFUL_LOCAL_PART, |
| 178 | CONTROL_CASELOWER_LOCAL_PART, |
| 179 | CONTROL_ENFORCE_SYNC, |
| 180 | CONTROL_NO_ENFORCE_SYNC, |
| 181 | CONTROL_FREEZE, |
| 182 | CONTROL_QUEUE_ONLY, |
| 183 | CONTROL_SUBMISSION, |
| 184 | CONTROL_SUPPRESS_LOCAL_FIXUPS, |
| 185 | #ifdef WITH_CONTENT_SCAN |
| 186 | CONTROL_NO_MBOX_UNSPOOL, |
| 187 | #endif |
| 188 | CONTROL_FAKEDEFER, |
| 189 | CONTROL_FAKEREJECT, |
| 190 | CONTROL_NO_MULTILINE, |
| 191 | CONTROL_NO_PIPELINING, |
| 192 | CONTROL_NO_DELAY_FLUSH, |
| 193 | CONTROL_NO_CALLOUT_FLUSH |
| 194 | }; |
| 195 | |
| 196 | /* ACL control names; keep in step with the table above! This list is used for |
| 197 | turning ids into names. The actual list of recognized names is in the variable |
| 198 | control_def controls_list[] below. The fact that there are two lists is a mess |
| 199 | and should be tidied up. */ |
| 200 | |
| 201 | static uschar *controls[] = { |
| 202 | US"allow_auth_unadvertised", |
| 203 | #ifdef EXPERIMENTAL_BRIGHTMAIL |
| 204 | US"bmi_run", |
| 205 | #endif |
| 206 | US"debug", |
| 207 | #ifndef DISABLE_DKIM |
| 208 | US"dkim_disable_verify", |
| 209 | #endif |
| 210 | US"error", |
| 211 | US"caseful_local_part", |
| 212 | US"caselower_local_part", |
| 213 | US"enforce_sync", |
| 214 | US"no_enforce_sync", |
| 215 | US"freeze", |
| 216 | US"queue_only", |
| 217 | US"submission", |
| 218 | US"suppress_local_fixups", |
| 219 | #ifdef WITH_CONTENT_SCAN |
| 220 | US"no_mbox_unspool", |
| 221 | #endif |
| 222 | US"fakedefer", |
| 223 | US"fakereject", |
| 224 | US"no_multiline_responses", |
| 225 | US"no_pipelining", |
| 226 | US"no_delay_flush", |
| 227 | US"no_callout_flush" |
| 228 | }; |
| 229 | |
| 230 | /* Flags to indicate for which conditions/modifiers a string expansion is done |
| 231 | at the outer level. In the other cases, expansion already occurs in the |
| 232 | checking functions. */ |
| 233 | |
| 234 | static uschar cond_expand_at_top[] = { |
| 235 | TRUE, /* acl */ |
| 236 | TRUE, /* add_header */ |
| 237 | FALSE, /* authenticated */ |
| 238 | #ifdef EXPERIMENTAL_BRIGHTMAIL |
| 239 | TRUE, /* bmi_optin */ |
| 240 | #endif |
| 241 | TRUE, /* condition */ |
| 242 | TRUE, /* continue */ |
| 243 | TRUE, /* control */ |
| 244 | #ifdef EXPERIMENTAL_DCC |
| 245 | TRUE, /* dcc */ |
| 246 | #endif |
| 247 | #ifdef WITH_CONTENT_SCAN |
| 248 | TRUE, /* decode */ |
| 249 | #endif |
| 250 | TRUE, /* delay */ |
| 251 | #ifdef WITH_OLD_DEMIME |
| 252 | TRUE, /* demime */ |
| 253 | #endif |
| 254 | #ifndef DISABLE_DKIM |
| 255 | TRUE, /* dkim_signers */ |
| 256 | TRUE, /* dkim_status */ |
| 257 | #endif |
| 258 | TRUE, /* dnslists */ |
| 259 | FALSE, /* domains */ |
| 260 | FALSE, /* encrypted */ |
| 261 | TRUE, /* endpass */ |
| 262 | FALSE, /* hosts */ |
| 263 | FALSE, /* local_parts */ |
| 264 | TRUE, /* log_message */ |
| 265 | TRUE, /* log_reject_target */ |
| 266 | TRUE, /* logwrite */ |
| 267 | #ifdef WITH_CONTENT_SCAN |
| 268 | TRUE, /* malware */ |
| 269 | #endif |
| 270 | TRUE, /* message */ |
| 271 | #ifdef WITH_CONTENT_SCAN |
| 272 | TRUE, /* mime_regex */ |
| 273 | #endif |
| 274 | TRUE, /* ratelimit */ |
| 275 | FALSE, /* recipients */ |
| 276 | #ifdef WITH_CONTENT_SCAN |
| 277 | TRUE, /* regex */ |
| 278 | #endif |
| 279 | FALSE, /* sender_domains */ |
| 280 | FALSE, /* senders */ |
| 281 | TRUE, /* set */ |
| 282 | #ifdef WITH_CONTENT_SCAN |
| 283 | TRUE, /* spam */ |
| 284 | #endif |
| 285 | #ifdef EXPERIMENTAL_SPF |
| 286 | TRUE, /* spf */ |
| 287 | TRUE, /* spf_guess */ |
| 288 | #endif |
| 289 | TRUE /* verify */ |
| 290 | }; |
| 291 | |
| 292 | /* Flags to identify the modifiers */ |
| 293 | |
| 294 | static uschar cond_modifiers[] = { |
| 295 | FALSE, /* acl */ |
| 296 | TRUE, /* add_header */ |
| 297 | FALSE, /* authenticated */ |
| 298 | #ifdef EXPERIMENTAL_BRIGHTMAIL |
| 299 | TRUE, /* bmi_optin */ |
| 300 | #endif |
| 301 | FALSE, /* condition */ |
| 302 | TRUE, /* continue */ |
| 303 | TRUE, /* control */ |
| 304 | #ifdef EXPERIMENTAL_DCC |
| 305 | FALSE, /* dcc */ |
| 306 | #endif |
| 307 | #ifdef WITH_CONTENT_SCAN |
| 308 | FALSE, /* decode */ |
| 309 | #endif |
| 310 | TRUE, /* delay */ |
| 311 | #ifdef WITH_OLD_DEMIME |
| 312 | FALSE, /* demime */ |
| 313 | #endif |
| 314 | #ifndef DISABLE_DKIM |
| 315 | FALSE, /* dkim_signers */ |
| 316 | FALSE, /* dkim_status */ |
| 317 | #endif |
| 318 | FALSE, /* dnslists */ |
| 319 | FALSE, /* domains */ |
| 320 | FALSE, /* encrypted */ |
| 321 | TRUE, /* endpass */ |
| 322 | FALSE, /* hosts */ |
| 323 | FALSE, /* local_parts */ |
| 324 | TRUE, /* log_message */ |
| 325 | TRUE, /* log_reject_target */ |
| 326 | TRUE, /* logwrite */ |
| 327 | #ifdef WITH_CONTENT_SCAN |
| 328 | FALSE, /* malware */ |
| 329 | #endif |
| 330 | TRUE, /* message */ |
| 331 | #ifdef WITH_CONTENT_SCAN |
| 332 | FALSE, /* mime_regex */ |
| 333 | #endif |
| 334 | FALSE, /* ratelimit */ |
| 335 | FALSE, /* recipients */ |
| 336 | #ifdef WITH_CONTENT_SCAN |
| 337 | FALSE, /* regex */ |
| 338 | #endif |
| 339 | FALSE, /* sender_domains */ |
| 340 | FALSE, /* senders */ |
| 341 | TRUE, /* set */ |
| 342 | #ifdef WITH_CONTENT_SCAN |
| 343 | FALSE, /* spam */ |
| 344 | #endif |
| 345 | #ifdef EXPERIMENTAL_SPF |
| 346 | FALSE, /* spf */ |
| 347 | FALSE, /* spf_guess */ |
| 348 | #endif |
| 349 | FALSE /* verify */ |
| 350 | }; |
| 351 | |
| 352 | /* Bit map vector of which conditions and modifiers are not allowed at certain |
| 353 | times. For each condition and modifier, there's a bitmap of dis-allowed times. |
| 354 | For some, it is easier to specify the negation of a small number of allowed |
| 355 | times. */ |
| 356 | |
| 357 | static unsigned int cond_forbids[] = { |
| 358 | 0, /* acl */ |
| 359 | |
| 360 | (unsigned int) |
| 361 | ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* add_header */ |
| 362 | (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)| |
| 363 | (1<<ACL_WHERE_MIME)|(1<<ACL_WHERE_NOTSMTP)| |
| 364 | (1<<ACL_WHERE_DKIM)| |
| 365 | (1<<ACL_WHERE_NOTSMTP_START)), |
| 366 | |
| 367 | (1<<ACL_WHERE_NOTSMTP)| /* authenticated */ |
| 368 | (1<<ACL_WHERE_NOTSMTP_START)| |
| 369 | (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO), |
| 370 | |
| 371 | #ifdef EXPERIMENTAL_BRIGHTMAIL |
| 372 | (1<<ACL_WHERE_AUTH)| /* bmi_optin */ |
| 373 | (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)| |
| 374 | (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_MIME)| |
| 375 | (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)| |
| 376 | (1<<ACL_WHERE_MAILAUTH)| |
| 377 | (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)| |
| 378 | (1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_PREDATA)| |
| 379 | (1<<ACL_WHERE_NOTSMTP_START), |
| 380 | #endif |
| 381 | |
| 382 | 0, /* condition */ |
| 383 | |
| 384 | 0, /* continue */ |
| 385 | |
| 386 | /* Certain types of control are always allowed, so we let it through |
| 387 | always and check in the control processing itself. */ |
| 388 | |
| 389 | 0, /* control */ |
| 390 | |
| 391 | #ifdef EXPERIMENTAL_DCC |
| 392 | (unsigned int) |
| 393 | ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* dcc */ |
| 394 | #endif |
| 395 | |
| 396 | #ifdef WITH_CONTENT_SCAN |
| 397 | (unsigned int) |
| 398 | ~(1<<ACL_WHERE_MIME), /* decode */ |
| 399 | #endif |
| 400 | |
| 401 | (1<<ACL_WHERE_NOTQUIT), /* delay */ |
| 402 | |
| 403 | #ifdef WITH_OLD_DEMIME |
| 404 | (unsigned int) |
| 405 | ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* demime */ |
| 406 | #endif |
| 407 | |
| 408 | #ifndef DISABLE_DKIM |
| 409 | (unsigned int) |
| 410 | ~(1<<ACL_WHERE_DKIM), /* dkim_signers */ |
| 411 | |
| 412 | (unsigned int) |
| 413 | ~(1<<ACL_WHERE_DKIM), /* dkim_status */ |
| 414 | #endif |
| 415 | |
| 416 | (1<<ACL_WHERE_NOTSMTP)| /* dnslists */ |
| 417 | (1<<ACL_WHERE_NOTSMTP_START), |
| 418 | |
| 419 | (unsigned int) |
| 420 | ~(1<<ACL_WHERE_RCPT), /* domains */ |
| 421 | |
| 422 | (1<<ACL_WHERE_NOTSMTP)| /* encrypted */ |
| 423 | (1<<ACL_WHERE_CONNECT)| |
| 424 | (1<<ACL_WHERE_NOTSMTP_START)| |
| 425 | (1<<ACL_WHERE_HELO), |
| 426 | |
| 427 | 0, /* endpass */ |
| 428 | |
| 429 | (1<<ACL_WHERE_NOTSMTP)| /* hosts */ |
| 430 | (1<<ACL_WHERE_NOTSMTP_START), |
| 431 | |
| 432 | (unsigned int) |
| 433 | ~(1<<ACL_WHERE_RCPT), /* local_parts */ |
| 434 | |
| 435 | 0, /* log_message */ |
| 436 | |
| 437 | 0, /* log_reject_target */ |
| 438 | |
| 439 | 0, /* logwrite */ |
| 440 | |
| 441 | #ifdef WITH_CONTENT_SCAN |
| 442 | (unsigned int) |
| 443 | ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* malware */ |
| 444 | #endif |
| 445 | |
| 446 | 0, /* message */ |
| 447 | |
| 448 | #ifdef WITH_CONTENT_SCAN |
| 449 | (unsigned int) |
| 450 | ~(1<<ACL_WHERE_MIME), /* mime_regex */ |
| 451 | #endif |
| 452 | |
| 453 | 0, /* ratelimit */ |
| 454 | |
| 455 | (unsigned int) |
| 456 | ~(1<<ACL_WHERE_RCPT), /* recipients */ |
| 457 | |
| 458 | #ifdef WITH_CONTENT_SCAN |
| 459 | (unsigned int) |
| 460 | ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* regex */ |
| 461 | (1<<ACL_WHERE_MIME)), |
| 462 | #endif |
| 463 | |
| 464 | (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* sender_domains */ |
| 465 | (1<<ACL_WHERE_HELO)| |
| 466 | (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)| |
| 467 | (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)| |
| 468 | (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY), |
| 469 | |
| 470 | (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* senders */ |
| 471 | (1<<ACL_WHERE_HELO)| |
| 472 | (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)| |
| 473 | (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)| |
| 474 | (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY), |
| 475 | |
| 476 | 0, /* set */ |
| 477 | |
| 478 | #ifdef WITH_CONTENT_SCAN |
| 479 | (unsigned int) |
| 480 | ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* spam */ |
| 481 | #endif |
| 482 | |
| 483 | #ifdef EXPERIMENTAL_SPF |
| 484 | (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* spf */ |
| 485 | (1<<ACL_WHERE_HELO)| |
| 486 | (1<<ACL_WHERE_MAILAUTH)| |
| 487 | (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)| |
| 488 | (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY)| |
| 489 | (1<<ACL_WHERE_NOTSMTP)| |
| 490 | (1<<ACL_WHERE_NOTSMTP_START), |
| 491 | |
| 492 | (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* spf_guess */ |
| 493 | (1<<ACL_WHERE_HELO)| |
| 494 | (1<<ACL_WHERE_MAILAUTH)| |
| 495 | (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)| |
| 496 | (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY)| |
| 497 | (1<<ACL_WHERE_NOTSMTP)| |
| 498 | (1<<ACL_WHERE_NOTSMTP_START), |
| 499 | #endif |
| 500 | |
| 501 | /* Certain types of verify are always allowed, so we let it through |
| 502 | always and check in the verify function itself */ |
| 503 | |
| 504 | 0 /* verify */ |
| 505 | }; |
| 506 | |
| 507 | |
| 508 | /* Bit map vector of which controls are not allowed at certain times. For |
| 509 | each control, there's a bitmap of dis-allowed times. For some, it is easier to |
| 510 | specify the negation of a small number of allowed times. */ |
| 511 | |
| 512 | static unsigned int control_forbids[] = { |
| 513 | (unsigned int) |
| 514 | ~((1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)), /* allow_auth_unadvertised */ |
| 515 | |
| 516 | #ifdef EXPERIMENTAL_BRIGHTMAIL |
| 517 | 0, /* bmi_run */ |
| 518 | #endif |
| 519 | |
| 520 | 0, /* debug */ |
| 521 | |
| 522 | #ifndef DISABLE_DKIM |
| 523 | (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* dkim_disable_verify */ |
| 524 | (1<<ACL_WHERE_NOTSMTP_START), |
| 525 | #endif |
| 526 | |
| 527 | 0, /* error */ |
| 528 | |
| 529 | (unsigned int) |
| 530 | ~(1<<ACL_WHERE_RCPT), /* caseful_local_part */ |
| 531 | |
| 532 | (unsigned int) |
| 533 | ~(1<<ACL_WHERE_RCPT), /* caselower_local_part */ |
| 534 | |
| 535 | (1<<ACL_WHERE_NOTSMTP)| /* enforce_sync */ |
| 536 | (1<<ACL_WHERE_NOTSMTP_START), |
| 537 | |
| 538 | (1<<ACL_WHERE_NOTSMTP)| /* no_enforce_sync */ |
| 539 | (1<<ACL_WHERE_NOTSMTP_START), |
| 540 | |
| 541 | (unsigned int) |
| 542 | ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* freeze */ |
| 543 | (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)| |
| 544 | (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME)), |
| 545 | |
| 546 | (unsigned int) |
| 547 | ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* queue_only */ |
| 548 | (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)| |
| 549 | (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME)), |
| 550 | |
| 551 | (unsigned int) |
| 552 | ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* submission */ |
| 553 | (1<<ACL_WHERE_PREDATA)), |
| 554 | |
| 555 | (unsigned int) |
| 556 | ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* suppress_local_fixups */ |
| 557 | (1<<ACL_WHERE_PREDATA)| |
| 558 | (1<<ACL_WHERE_NOTSMTP_START)), |
| 559 | |
| 560 | #ifdef WITH_CONTENT_SCAN |
| 561 | (unsigned int) |
| 562 | ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* no_mbox_unspool */ |
| 563 | (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)| |
| 564 | (1<<ACL_WHERE_MIME)), |
| 565 | #endif |
| 566 | |
| 567 | (unsigned int) |
| 568 | ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* fakedefer */ |
| 569 | (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)| |
| 570 | (1<<ACL_WHERE_MIME)), |
| 571 | |
| 572 | (unsigned int) |
| 573 | ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* fakereject */ |
| 574 | (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)| |
| 575 | (1<<ACL_WHERE_MIME)), |
| 576 | |
| 577 | (1<<ACL_WHERE_NOTSMTP)| /* no_multiline */ |
| 578 | (1<<ACL_WHERE_NOTSMTP_START), |
| 579 | |
| 580 | (1<<ACL_WHERE_NOTSMTP)| /* no_pipelining */ |
| 581 | (1<<ACL_WHERE_NOTSMTP_START), |
| 582 | |
| 583 | (1<<ACL_WHERE_NOTSMTP)| /* no_delay_flush */ |
| 584 | (1<<ACL_WHERE_NOTSMTP_START), |
| 585 | |
| 586 | (1<<ACL_WHERE_NOTSMTP)| /* no_callout_flush */ |
| 587 | (1<<ACL_WHERE_NOTSMTP_START) |
| 588 | }; |
| 589 | |
| 590 | /* Structure listing various control arguments, with their characteristics. */ |
| 591 | |
| 592 | typedef struct control_def { |
| 593 | uschar *name; |
| 594 | int value; /* CONTROL_xxx value */ |
| 595 | BOOL has_option; /* Has /option(s) following */ |
| 596 | } control_def; |
| 597 | |
| 598 | static control_def controls_list[] = { |
| 599 | { US"allow_auth_unadvertised", CONTROL_AUTH_UNADVERTISED, FALSE }, |
| 600 | #ifdef EXPERIMENTAL_BRIGHTMAIL |
| 601 | { US"bmi_run", CONTROL_BMI_RUN, FALSE }, |
| 602 | #endif |
| 603 | { US"debug", CONTROL_DEBUG, TRUE }, |
| 604 | #ifndef DISABLE_DKIM |
| 605 | { US"dkim_disable_verify", CONTROL_DKIM_VERIFY, FALSE }, |
| 606 | #endif |
| 607 | { US"caseful_local_part", CONTROL_CASEFUL_LOCAL_PART, FALSE }, |
| 608 | { US"caselower_local_part", CONTROL_CASELOWER_LOCAL_PART, FALSE }, |
| 609 | { US"enforce_sync", CONTROL_ENFORCE_SYNC, FALSE }, |
| 610 | { US"freeze", CONTROL_FREEZE, TRUE }, |
| 611 | { US"no_callout_flush", CONTROL_NO_CALLOUT_FLUSH, FALSE }, |
| 612 | { US"no_delay_flush", CONTROL_NO_DELAY_FLUSH, FALSE }, |
| 613 | { US"no_enforce_sync", CONTROL_NO_ENFORCE_SYNC, FALSE }, |
| 614 | { US"no_multiline_responses", CONTROL_NO_MULTILINE, FALSE }, |
| 615 | { US"no_pipelining", CONTROL_NO_PIPELINING, FALSE }, |
| 616 | { US"queue_only", CONTROL_QUEUE_ONLY, FALSE }, |
| 617 | #ifdef WITH_CONTENT_SCAN |
| 618 | { US"no_mbox_unspool", CONTROL_NO_MBOX_UNSPOOL, FALSE }, |
| 619 | #endif |
| 620 | { US"fakedefer", CONTROL_FAKEDEFER, TRUE }, |
| 621 | { US"fakereject", CONTROL_FAKEREJECT, TRUE }, |
| 622 | { US"submission", CONTROL_SUBMISSION, TRUE }, |
| 623 | { US"suppress_local_fixups", CONTROL_SUPPRESS_LOCAL_FIXUPS, FALSE } |
| 624 | }; |
| 625 | |
| 626 | /* Support data structures for Client SMTP Authorization. acl_verify_csa() |
| 627 | caches its result in a tree to avoid repeated DNS queries. The result is an |
| 628 | integer code which is used as an index into the following tables of |
| 629 | explanatory strings and verification return codes. */ |
| 630 | |
| 631 | static tree_node *csa_cache = NULL; |
| 632 | |
| 633 | enum { CSA_UNKNOWN, CSA_OK, CSA_DEFER_SRV, CSA_DEFER_ADDR, |
| 634 | CSA_FAIL_EXPLICIT, CSA_FAIL_DOMAIN, CSA_FAIL_NOADDR, CSA_FAIL_MISMATCH }; |
| 635 | |
| 636 | /* The acl_verify_csa() return code is translated into an acl_verify() return |
| 637 | code using the following table. It is OK unless the client is definitely not |
| 638 | authorized. This is because CSA is supposed to be optional for sending sites, |
| 639 | so recipients should not be too strict about checking it - especially because |
| 640 | DNS problems are quite likely to occur. It's possible to use $csa_status in |
| 641 | further ACL conditions to distinguish ok, unknown, and defer if required, but |
| 642 | the aim is to make the usual configuration simple. */ |
| 643 | |
| 644 | static int csa_return_code[] = { |
| 645 | OK, OK, OK, OK, |
| 646 | FAIL, FAIL, FAIL, FAIL |
| 647 | }; |
| 648 | |
| 649 | static uschar *csa_status_string[] = { |
| 650 | US"unknown", US"ok", US"defer", US"defer", |
| 651 | US"fail", US"fail", US"fail", US"fail" |
| 652 | }; |
| 653 | |
| 654 | static uschar *csa_reason_string[] = { |
| 655 | US"unknown", |
| 656 | US"ok", |
| 657 | US"deferred (SRV lookup failed)", |
| 658 | US"deferred (target address lookup failed)", |
| 659 | US"failed (explicit authorization required)", |
| 660 | US"failed (host name not authorized)", |
| 661 | US"failed (no authorized addresses)", |
| 662 | US"failed (client address mismatch)" |
| 663 | }; |
| 664 | |
| 665 | /* Options for the ratelimit condition. Note that there are two variants of |
| 666 | the per_rcpt option, depending on the ACL that is used to measure the rate. |
| 667 | However any ACL must be able to look up per_rcpt rates in /noupdate mode, |
| 668 | so the two variants must have the same internal representation as well as |
| 669 | the same configuration string. */ |
| 670 | |
| 671 | enum { |
| 672 | RATE_PER_WHAT, RATE_PER_CLASH, RATE_PER_ADDR, RATE_PER_BYTE, RATE_PER_CMD, |
| 673 | RATE_PER_CONN, RATE_PER_MAIL, RATE_PER_RCPT, RATE_PER_ALLRCPTS |
| 674 | }; |
| 675 | |
| 676 | #define RATE_SET(var,new) \ |
| 677 | (((var) == RATE_PER_WHAT) ? ((var) = RATE_##new) : ((var) = RATE_PER_CLASH)) |
| 678 | |
| 679 | static uschar *ratelimit_option_string[] = { |
| 680 | US"?", US"!", US"per_addr", US"per_byte", US"per_cmd", |
| 681 | US"per_conn", US"per_mail", US"per_rcpt", US"per_rcpt" |
| 682 | }; |
| 683 | |
| 684 | /* Enable recursion between acl_check_internal() and acl_check_condition() */ |
| 685 | |
| 686 | static int acl_check_internal(int, address_item *, uschar *, int, uschar **, |
| 687 | uschar **); |
| 688 | |
| 689 | |
| 690 | /************************************************* |
| 691 | * Pick out name from list * |
| 692 | *************************************************/ |
| 693 | |
| 694 | /* Use a binary chop method |
| 695 | |
| 696 | Arguments: |
| 697 | name name to find |
| 698 | list list of names |
| 699 | end size of list |
| 700 | |
| 701 | Returns: offset in list, or -1 if not found |
| 702 | */ |
| 703 | |
| 704 | static int |
| 705 | acl_checkname(uschar *name, uschar **list, int end) |
| 706 | { |
| 707 | int start = 0; |
| 708 | |
| 709 | while (start < end) |
| 710 | { |
| 711 | int mid = (start + end)/2; |
| 712 | int c = Ustrcmp(name, list[mid]); |
| 713 | if (c == 0) return mid; |
| 714 | if (c < 0) end = mid; else start = mid + 1; |
| 715 | } |
| 716 | |
| 717 | return -1; |
| 718 | } |
| 719 | |
| 720 | |
| 721 | /************************************************* |
| 722 | * Read and parse one ACL * |
| 723 | *************************************************/ |
| 724 | |
| 725 | /* This function is called both from readconf in order to parse the ACLs in the |
| 726 | configuration file, and also when an ACL is encountered dynamically (e.g. as |
| 727 | the result of an expansion). It is given a function to call in order to |
| 728 | retrieve the lines of the ACL. This function handles skipping comments and |
| 729 | blank lines (where relevant). |
| 730 | |
| 731 | Arguments: |
| 732 | func function to get next line of ACL |
| 733 | error where to put an error message |
| 734 | |
| 735 | Returns: pointer to ACL, or NULL |
| 736 | NULL can be legal (empty ACL); in this case error will be NULL |
| 737 | */ |
| 738 | |
| 739 | acl_block * |
| 740 | acl_read(uschar *(*func)(void), uschar **error) |
| 741 | { |
| 742 | acl_block *yield = NULL; |
| 743 | acl_block **lastp = &yield; |
| 744 | acl_block *this = NULL; |
| 745 | acl_condition_block *cond; |
| 746 | acl_condition_block **condp = NULL; |
| 747 | uschar *s; |
| 748 | |
| 749 | *error = NULL; |
| 750 | |
| 751 | while ((s = (*func)()) != NULL) |
| 752 | { |
| 753 | int v, c; |
| 754 | BOOL negated = FALSE; |
| 755 | uschar *saveline = s; |
| 756 | uschar name[64]; |
| 757 | |
| 758 | /* Conditions (but not verbs) are allowed to be negated by an initial |
| 759 | exclamation mark. */ |
| 760 | |
| 761 | while (isspace(*s)) s++; |
| 762 | if (*s == '!') |
| 763 | { |
| 764 | negated = TRUE; |
| 765 | s++; |
| 766 | } |
| 767 | |
| 768 | /* Read the name of a verb or a condition, or the start of a new ACL, which |
| 769 | can be started by a name, or by a macro definition. */ |
| 770 | |
| 771 | s = readconf_readname(name, sizeof(name), s); |
| 772 | if (*s == ':' || (isupper(name[0]) && *s == '=')) return yield; |
| 773 | |
| 774 | /* If a verb is unrecognized, it may be another condition or modifier that |
| 775 | continues the previous verb. */ |
| 776 | |
| 777 | v = acl_checkname(name, verbs, sizeof(verbs)/sizeof(char *)); |
| 778 | if (v < 0) |
| 779 | { |
| 780 | if (this == NULL) |
| 781 | { |
| 782 | *error = string_sprintf("unknown ACL verb \"%s\" in \"%s\"", name, |
| 783 | saveline); |
| 784 | return NULL; |
| 785 | } |
| 786 | } |
| 787 | |
| 788 | /* New verb */ |
| 789 | |
| 790 | else |
| 791 | { |
| 792 | if (negated) |
| 793 | { |
| 794 | *error = string_sprintf("malformed ACL line \"%s\"", saveline); |
| 795 | return NULL; |
| 796 | } |
| 797 | this = store_get(sizeof(acl_block)); |
| 798 | *lastp = this; |
| 799 | lastp = &(this->next); |
| 800 | this->next = NULL; |
| 801 | this->verb = v; |
| 802 | this->condition = NULL; |
| 803 | condp = &(this->condition); |
| 804 | if (*s == 0) continue; /* No condition on this line */ |
| 805 | if (*s == '!') |
| 806 | { |
| 807 | negated = TRUE; |
| 808 | s++; |
| 809 | } |
| 810 | s = readconf_readname(name, sizeof(name), s); /* Condition name */ |
| 811 | } |
| 812 | |
| 813 | /* Handle a condition or modifier. */ |
| 814 | |
| 815 | c = acl_checkname(name, conditions, sizeof(conditions)/sizeof(char *)); |
| 816 | if (c < 0) |
| 817 | { |
| 818 | *error = string_sprintf("unknown ACL condition/modifier in \"%s\"", |
| 819 | saveline); |
| 820 | return NULL; |
| 821 | } |
| 822 | |
| 823 | /* The modifiers may not be negated */ |
| 824 | |
| 825 | if (negated && cond_modifiers[c]) |
| 826 | { |
| 827 | *error = string_sprintf("ACL error: negation is not allowed with " |
| 828 | "\"%s\"", conditions[c]); |
| 829 | return NULL; |
| 830 | } |
| 831 | |
| 832 | /* ENDPASS may occur only with ACCEPT or DISCARD. */ |
| 833 | |
| 834 | if (c == ACLC_ENDPASS && |
| 835 | this->verb != ACL_ACCEPT && |
| 836 | this->verb != ACL_DISCARD) |
| 837 | { |
| 838 | *error = string_sprintf("ACL error: \"%s\" is not allowed with \"%s\"", |
| 839 | conditions[c], verbs[this->verb]); |
| 840 | return NULL; |
| 841 | } |
| 842 | |
| 843 | cond = store_get(sizeof(acl_condition_block)); |
| 844 | cond->next = NULL; |
| 845 | cond->type = c; |
| 846 | cond->u.negated = negated; |
| 847 | |
| 848 | *condp = cond; |
| 849 | condp = &(cond->next); |
| 850 | |
| 851 | /* The "set" modifier is different in that its argument is "name=value" |
| 852 | rather than just a value, and we can check the validity of the name, which |
| 853 | gives us a variable name to insert into the data block. The original ACL |
| 854 | variable names were acl_c0 ... acl_c9 and acl_m0 ... acl_m9. This was |
| 855 | extended to 20 of each type, but after that people successfully argued for |
| 856 | arbitrary names. In the new scheme, the names must start with acl_c or acl_m. |
| 857 | After that, we allow alphanumerics and underscores, but the first character |
| 858 | after c or m must be a digit or an underscore. This retains backwards |
| 859 | compatibility. */ |
| 860 | |
| 861 | if (c == ACLC_SET) |
| 862 | { |
| 863 | uschar *endptr; |
| 864 | |
| 865 | if (Ustrncmp(s, "acl_c", 5) != 0 && |
| 866 | Ustrncmp(s, "acl_m", 5) != 0) |
| 867 | { |
| 868 | *error = string_sprintf("invalid variable name after \"set\" in ACL " |
| 869 | "modifier \"set %s\" (must start \"acl_c\" or \"acl_m\")", s); |
| 870 | return NULL; |
| 871 | } |
| 872 | |
| 873 | endptr = s + 5; |
| 874 | if (!isdigit(*endptr) && *endptr != '_') |
| 875 | { |
| 876 | *error = string_sprintf("invalid variable name after \"set\" in ACL " |
| 877 | "modifier \"set %s\" (digit or underscore must follow acl_c or acl_m)", |
| 878 | s); |
| 879 | return NULL; |
| 880 | } |
| 881 | |
| 882 | while (*endptr != 0 && *endptr != '=' && !isspace(*endptr)) |
| 883 | { |
| 884 | if (!isalnum(*endptr) && *endptr != '_') |
| 885 | { |
| 886 | *error = string_sprintf("invalid character \"%c\" in variable name " |
| 887 | "in ACL modifier \"set %s\"", *endptr, s); |
| 888 | return NULL; |
| 889 | } |
| 890 | endptr++; |
| 891 | } |
| 892 | |
| 893 | cond->u.varname = string_copyn(s + 4, endptr - s - 4); |
| 894 | s = endptr; |
| 895 | while (isspace(*s)) s++; |
| 896 | } |
| 897 | |
| 898 | /* For "set", we are now positioned for the data. For the others, only |
| 899 | "endpass" has no data */ |
| 900 | |
| 901 | if (c != ACLC_ENDPASS) |
| 902 | { |
| 903 | if (*s++ != '=') |
| 904 | { |
| 905 | *error = string_sprintf("\"=\" missing after ACL \"%s\" %s", name, |
| 906 | cond_modifiers[c]? US"modifier" : US"condition"); |
| 907 | return NULL; |
| 908 | } |
| 909 | while (isspace(*s)) s++; |
| 910 | cond->arg = string_copy(s); |
| 911 | } |
| 912 | } |
| 913 | |
| 914 | return yield; |
| 915 | } |
| 916 | |
| 917 | |
| 918 | |
| 919 | /************************************************* |
| 920 | * Set up added header line(s) * |
| 921 | *************************************************/ |
| 922 | |
| 923 | /* This function is called by the add_header modifier, and also from acl_warn() |
| 924 | to implement the now-deprecated way of adding header lines using "message" on a |
| 925 | "warn" verb. The argument is treated as a sequence of header lines which are |
| 926 | added to a chain, provided there isn't an identical one already there. |
| 927 | |
| 928 | Argument: string of header lines |
| 929 | Returns: nothing |
| 930 | */ |
| 931 | |
| 932 | static void |
| 933 | setup_header(uschar *hstring) |
| 934 | { |
| 935 | uschar *p, *q; |
| 936 | int hlen = Ustrlen(hstring); |
| 937 | |
| 938 | /* An empty string does nothing; otherwise add a final newline if necessary. */ |
| 939 | |
| 940 | if (hlen <= 0) return; |
| 941 | if (hstring[hlen-1] != '\n') hstring = string_sprintf("%s\n", hstring); |
| 942 | |
| 943 | /* Loop for multiple header lines, taking care about continuations */ |
| 944 | |
| 945 | for (p = q = hstring; *p != 0; ) |
| 946 | { |
| 947 | uschar *s; |
| 948 | int newtype = htype_add_bot; |
| 949 | header_line **hptr = &acl_added_headers; |
| 950 | |
| 951 | /* Find next header line within the string */ |
| 952 | |
| 953 | for (;;) |
| 954 | { |
| 955 | q = Ustrchr(q, '\n'); |
| 956 | if (*(++q) != ' ' && *q != '\t') break; |
| 957 | } |
| 958 | |
| 959 | /* If the line starts with a colon, interpret the instruction for where to |
| 960 | add it. This temporarily sets up a new type. */ |
| 961 | |
| 962 | if (*p == ':') |
| 963 | { |
| 964 | if (strncmpic(p, US":after_received:", 16) == 0) |
| 965 | { |
| 966 | newtype = htype_add_rec; |
| 967 | p += 16; |
| 968 | } |
| 969 | else if (strncmpic(p, US":at_start_rfc:", 14) == 0) |
| 970 | { |
| 971 | newtype = htype_add_rfc; |
| 972 | p += 14; |
| 973 | } |
| 974 | else if (strncmpic(p, US":at_start:", 10) == 0) |
| 975 | { |
| 976 | newtype = htype_add_top; |
| 977 | p += 10; |
| 978 | } |
| 979 | else if (strncmpic(p, US":at_end:", 8) == 0) |
| 980 | { |
| 981 | newtype = htype_add_bot; |
| 982 | p += 8; |
| 983 | } |
| 984 | while (*p == ' ' || *p == '\t') p++; |
| 985 | } |
| 986 | |
| 987 | /* See if this line starts with a header name, and if not, add X-ACL-Warn: |
| 988 | to the front of it. */ |
| 989 | |
| 990 | for (s = p; s < q - 1; s++) |
| 991 | { |
| 992 | if (*s == ':' || !isgraph(*s)) break; |
| 993 | } |
| 994 | |
| 995 | s = string_sprintf("%s%.*s", (*s == ':')? "" : "X-ACL-Warn: ", q - p, p); |
| 996 | hlen = Ustrlen(s); |
| 997 | |
| 998 | /* See if this line has already been added */ |
| 999 | |
| 1000 | while (*hptr != NULL) |
| 1001 | { |
| 1002 | if (Ustrncmp((*hptr)->text, s, hlen) == 0) break; |
| 1003 | hptr = &((*hptr)->next); |
| 1004 | } |
| 1005 | |
| 1006 | /* Add if not previously present */ |
| 1007 | |
| 1008 | if (*hptr == NULL) |
| 1009 | { |
| 1010 | header_line *h = store_get(sizeof(header_line)); |
| 1011 | h->text = s; |
| 1012 | h->next = NULL; |
| 1013 | h->type = newtype; |
| 1014 | h->slen = hlen; |
| 1015 | *hptr = h; |
| 1016 | hptr = &(h->next); |
| 1017 | } |
| 1018 | |
| 1019 | /* Advance for next header line within the string */ |
| 1020 | |
| 1021 | p = q; |
| 1022 | } |
| 1023 | } |
| 1024 | |
| 1025 | |
| 1026 | |
| 1027 | |
| 1028 | /************************************************* |
| 1029 | * Handle warnings * |
| 1030 | *************************************************/ |
| 1031 | |
| 1032 | /* This function is called when a WARN verb's conditions are true. It adds to |
| 1033 | the message's headers, and/or writes information to the log. In each case, this |
| 1034 | only happens once (per message for headers, per connection for log). |
| 1035 | |
| 1036 | ** NOTE: The header adding action using the "message" setting is historic, and |
| 1037 | its use is now deprecated. The new add_header modifier should be used instead. |
| 1038 | |
| 1039 | Arguments: |
| 1040 | where ACL_WHERE_xxxx indicating which ACL this is |
| 1041 | user_message message for adding to headers |
| 1042 | log_message message for logging, if different |
| 1043 | |
| 1044 | Returns: nothing |
| 1045 | */ |
| 1046 | |
| 1047 | static void |
| 1048 | acl_warn(int where, uschar *user_message, uschar *log_message) |
| 1049 | { |
| 1050 | if (log_message != NULL && log_message != user_message) |
| 1051 | { |
| 1052 | uschar *text; |
| 1053 | string_item *logged; |
| 1054 | |
| 1055 | text = string_sprintf("%s Warning: %s", host_and_ident(TRUE), |
| 1056 | string_printing(log_message)); |
| 1057 | |
| 1058 | /* If a sender verification has failed, and the log message is "sender verify |
| 1059 | failed", add the failure message. */ |
| 1060 | |
| 1061 | if (sender_verified_failed != NULL && |
| 1062 | sender_verified_failed->message != NULL && |
| 1063 | strcmpic(log_message, US"sender verify failed") == 0) |
| 1064 | text = string_sprintf("%s: %s", text, sender_verified_failed->message); |
| 1065 | |
| 1066 | /* Search previously logged warnings. They are kept in malloc |
| 1067 | store so they can be freed at the start of a new message. */ |
| 1068 | |
| 1069 | for (logged = acl_warn_logged; logged != NULL; logged = logged->next) |
| 1070 | if (Ustrcmp(logged->text, text) == 0) break; |
| 1071 | |
| 1072 | if (logged == NULL) |
| 1073 | { |
| 1074 | int length = Ustrlen(text) + 1; |
| 1075 | log_write(0, LOG_MAIN, "%s", text); |
| 1076 | logged = store_malloc(sizeof(string_item) + length); |
| 1077 | logged->text = (uschar *)logged + sizeof(string_item); |
| 1078 | memcpy(logged->text, text, length); |
| 1079 | logged->next = acl_warn_logged; |
| 1080 | acl_warn_logged = logged; |
| 1081 | } |
| 1082 | } |
| 1083 | |
| 1084 | /* If there's no user message, we are done. */ |
| 1085 | |
| 1086 | if (user_message == NULL) return; |
| 1087 | |
| 1088 | /* If this isn't a message ACL, we can't do anything with a user message. |
| 1089 | Log an error. */ |
| 1090 | |
| 1091 | if (where > ACL_WHERE_NOTSMTP) |
| 1092 | { |
| 1093 | log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting " |
| 1094 | "found in a non-message (%s) ACL: cannot specify header lines here: " |
| 1095 | "message ignored", acl_wherenames[where]); |
| 1096 | return; |
| 1097 | } |
| 1098 | |
| 1099 | /* The code for setting up header lines is now abstracted into a separate |
| 1100 | function so that it can be used for the add_header modifier as well. */ |
| 1101 | |
| 1102 | setup_header(user_message); |
| 1103 | } |
| 1104 | |
| 1105 | |
| 1106 | |
| 1107 | /************************************************* |
| 1108 | * Verify and check reverse DNS * |
| 1109 | *************************************************/ |
| 1110 | |
| 1111 | /* Called from acl_verify() below. We look up the host name(s) of the client IP |
| 1112 | address if this has not yet been done. The host_name_lookup() function checks |
| 1113 | that one of these names resolves to an address list that contains the client IP |
| 1114 | address, so we don't actually have to do the check here. |
| 1115 | |
| 1116 | Arguments: |
| 1117 | user_msgptr pointer for user message |
| 1118 | log_msgptr pointer for log message |
| 1119 | |
| 1120 | Returns: OK verification condition succeeded |
| 1121 | FAIL verification failed |
| 1122 | DEFER there was a problem verifying |
| 1123 | */ |
| 1124 | |
| 1125 | static int |
| 1126 | acl_verify_reverse(uschar **user_msgptr, uschar **log_msgptr) |
| 1127 | { |
| 1128 | int rc; |
| 1129 | |
| 1130 | user_msgptr = user_msgptr; /* stop compiler warning */ |
| 1131 | |
| 1132 | /* Previous success */ |
| 1133 | |
| 1134 | if (sender_host_name != NULL) return OK; |
| 1135 | |
| 1136 | /* Previous failure */ |
| 1137 | |
| 1138 | if (host_lookup_failed) |
| 1139 | { |
| 1140 | *log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg); |
| 1141 | return FAIL; |
| 1142 | } |
| 1143 | |
| 1144 | /* Need to do a lookup */ |
| 1145 | |
| 1146 | HDEBUG(D_acl) |
| 1147 | debug_printf("looking up host name to force name/address consistency check\n"); |
| 1148 | |
| 1149 | if ((rc = host_name_lookup()) != OK) |
| 1150 | { |
| 1151 | *log_msgptr = (rc == DEFER)? |
| 1152 | US"host lookup deferred for reverse lookup check" |
| 1153 | : |
| 1154 | string_sprintf("host lookup failed for reverse lookup check%s", |
| 1155 | host_lookup_msg); |
| 1156 | return rc; /* DEFER or FAIL */ |
| 1157 | } |
| 1158 | |
| 1159 | host_build_sender_fullhost(); |
| 1160 | return OK; |
| 1161 | } |
| 1162 | |
| 1163 | |
| 1164 | |
| 1165 | /************************************************* |
| 1166 | * Check client IP address matches CSA target * |
| 1167 | *************************************************/ |
| 1168 | |
| 1169 | /* Called from acl_verify_csa() below. This routine scans a section of a DNS |
| 1170 | response for address records belonging to the CSA target hostname. The section |
| 1171 | is specified by the reset argument, either RESET_ADDITIONAL or RESET_ANSWERS. |
| 1172 | If one of the addresses matches the client's IP address, then the client is |
| 1173 | authorized by CSA. If there are target IP addresses but none of them match |
| 1174 | then the client is using an unauthorized IP address. If there are no target IP |
| 1175 | addresses then the client cannot be using an authorized IP address. (This is |
| 1176 | an odd configuration - why didn't the SRV record have a weight of 1 instead?) |
| 1177 | |
| 1178 | Arguments: |
| 1179 | dnsa the DNS answer block |
| 1180 | dnss a DNS scan block for us to use |
| 1181 | reset option specifing what portion to scan, as described above |
| 1182 | target the target hostname to use for matching RR names |
| 1183 | |
| 1184 | Returns: CSA_OK successfully authorized |
| 1185 | CSA_FAIL_MISMATCH addresses found but none matched |
| 1186 | CSA_FAIL_NOADDR no target addresses found |
| 1187 | */ |
| 1188 | |
| 1189 | static int |
| 1190 | acl_verify_csa_address(dns_answer *dnsa, dns_scan *dnss, int reset, |
| 1191 | uschar *target) |
| 1192 | { |
| 1193 | dns_record *rr; |
| 1194 | dns_address *da; |
| 1195 | |
| 1196 | BOOL target_found = FALSE; |
| 1197 | |
| 1198 | for (rr = dns_next_rr(dnsa, dnss, reset); |
| 1199 | rr != NULL; |
| 1200 | rr = dns_next_rr(dnsa, dnss, RESET_NEXT)) |
| 1201 | { |
| 1202 | /* Check this is an address RR for the target hostname. */ |
| 1203 | |
| 1204 | if (rr->type != T_A |
| 1205 | #if HAVE_IPV6 |
| 1206 | && rr->type != T_AAAA |
| 1207 | #ifdef SUPPORT_A6 |
| 1208 | && rr->type != T_A6 |
| 1209 | #endif |
| 1210 | #endif |
| 1211 | ) continue; |
| 1212 | |
| 1213 | if (strcmpic(target, rr->name) != 0) continue; |
| 1214 | |
| 1215 | target_found = TRUE; |
| 1216 | |
| 1217 | /* Turn the target address RR into a list of textual IP addresses and scan |
| 1218 | the list. There may be more than one if it is an A6 RR. */ |
| 1219 | |
| 1220 | for (da = dns_address_from_rr(dnsa, rr); da != NULL; da = da->next) |
| 1221 | { |
| 1222 | /* If the client IP address matches the target IP address, it's good! */ |
| 1223 | |
| 1224 | DEBUG(D_acl) debug_printf("CSA target address is %s\n", da->address); |
| 1225 | |
| 1226 | if (strcmpic(sender_host_address, da->address) == 0) return CSA_OK; |
| 1227 | } |
| 1228 | } |
| 1229 | |
| 1230 | /* If we found some target addresses but none of them matched, the client is |
| 1231 | using an unauthorized IP address, otherwise the target has no authorized IP |
| 1232 | addresses. */ |
| 1233 | |
| 1234 | if (target_found) return CSA_FAIL_MISMATCH; |
| 1235 | else return CSA_FAIL_NOADDR; |
| 1236 | } |
| 1237 | |
| 1238 | |
| 1239 | |
| 1240 | /************************************************* |
| 1241 | * Verify Client SMTP Authorization * |
| 1242 | *************************************************/ |
| 1243 | |
| 1244 | /* Called from acl_verify() below. This routine calls dns_lookup_special() |
| 1245 | to find the CSA SRV record corresponding to the domain argument, or |
| 1246 | $sender_helo_name if no argument is provided. It then checks that the |
| 1247 | client is authorized, and that its IP address corresponds to the SRV |
| 1248 | target's address by calling acl_verify_csa_address() above. The address |
| 1249 | should have been returned in the DNS response's ADDITIONAL section, but if |
| 1250 | not we perform another DNS lookup to get it. |
| 1251 | |
| 1252 | Arguments: |
| 1253 | domain pointer to optional parameter following verify = csa |
| 1254 | |
| 1255 | Returns: CSA_UNKNOWN no valid CSA record found |
| 1256 | CSA_OK successfully authorized |
| 1257 | CSA_FAIL_* client is definitely not authorized |
| 1258 | CSA_DEFER_* there was a DNS problem |
| 1259 | */ |
| 1260 | |
| 1261 | static int |
| 1262 | acl_verify_csa(uschar *domain) |
| 1263 | { |
| 1264 | tree_node *t; |
| 1265 | uschar *found, *p; |
| 1266 | int priority, weight, port; |
| 1267 | dns_answer dnsa; |
| 1268 | dns_scan dnss; |
| 1269 | dns_record *rr; |
| 1270 | int rc, type; |
| 1271 | uschar target[256]; |
| 1272 | |
| 1273 | /* Work out the domain we are using for the CSA lookup. The default is the |
| 1274 | client's HELO domain. If the client has not said HELO, use its IP address |
| 1275 | instead. If it's a local client (exim -bs), CSA isn't applicable. */ |
| 1276 | |
| 1277 | while (isspace(*domain) && *domain != '\0') ++domain; |
| 1278 | if (*domain == '\0') domain = sender_helo_name; |
| 1279 | if (domain == NULL) domain = sender_host_address; |
| 1280 | if (sender_host_address == NULL) return CSA_UNKNOWN; |
| 1281 | |
| 1282 | /* If we have an address literal, strip off the framing ready for turning it |
| 1283 | into a domain. The framing consists of matched square brackets possibly |
| 1284 | containing a keyword and a colon before the actual IP address. */ |
| 1285 | |
| 1286 | if (domain[0] == '[') |
| 1287 | { |
| 1288 | uschar *start = Ustrchr(domain, ':'); |
| 1289 | if (start == NULL) start = domain; |
| 1290 | domain = string_copyn(start + 1, Ustrlen(start) - 2); |
| 1291 | } |
| 1292 | |
| 1293 | /* Turn domains that look like bare IP addresses into domains in the reverse |
| 1294 | DNS. This code also deals with address literals and $sender_host_address. It's |
| 1295 | not quite kosher to treat bare domains such as EHLO 192.0.2.57 the same as |
| 1296 | address literals, but it's probably the most friendly thing to do. This is an |
| 1297 | extension to CSA, so we allow it to be turned off for proper conformance. */ |
| 1298 | |
| 1299 | if (string_is_ip_address(domain, NULL) != 0) |
| 1300 | { |
| 1301 | if (!dns_csa_use_reverse) return CSA_UNKNOWN; |
| 1302 | dns_build_reverse(domain, target); |
| 1303 | domain = target; |
| 1304 | } |
| 1305 | |
| 1306 | /* Find out if we've already done the CSA check for this domain. If we have, |
| 1307 | return the same result again. Otherwise build a new cached result structure |
| 1308 | for this domain. The name is filled in now, and the value is filled in when |
| 1309 | we return from this function. */ |
| 1310 | |
| 1311 | t = tree_search(csa_cache, domain); |
| 1312 | if (t != NULL) return t->data.val; |
| 1313 | |
| 1314 | t = store_get_perm(sizeof(tree_node) + Ustrlen(domain)); |
| 1315 | Ustrcpy(t->name, domain); |
| 1316 | (void)tree_insertnode(&csa_cache, t); |
| 1317 | |
| 1318 | /* Now we are ready to do the actual DNS lookup(s). */ |
| 1319 | |
| 1320 | found = domain; |
| 1321 | switch (dns_special_lookup(&dnsa, domain, T_CSA, &found)) |
| 1322 | { |
| 1323 | /* If something bad happened (most commonly DNS_AGAIN), defer. */ |
| 1324 | |
| 1325 | default: |
| 1326 | return t->data.val = CSA_DEFER_SRV; |
| 1327 | |
| 1328 | /* If we found nothing, the client's authorization is unknown. */ |
| 1329 | |
| 1330 | case DNS_NOMATCH: |
| 1331 | case DNS_NODATA: |
| 1332 | return t->data.val = CSA_UNKNOWN; |
| 1333 | |
| 1334 | /* We got something! Go on to look at the reply in more detail. */ |
| 1335 | |
| 1336 | case DNS_SUCCEED: |
| 1337 | break; |
| 1338 | } |
| 1339 | |
| 1340 | /* Scan the reply for well-formed CSA SRV records. */ |
| 1341 | |
| 1342 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); |
| 1343 | rr != NULL; |
| 1344 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) |
| 1345 | { |
| 1346 | if (rr->type != T_SRV) continue; |
| 1347 | |
| 1348 | /* Extract the numerical SRV fields (p is incremented) */ |
| 1349 | |
| 1350 | p = rr->data; |
| 1351 | GETSHORT(priority, p); |
| 1352 | GETSHORT(weight, p); |
| 1353 | GETSHORT(port, p); |
| 1354 | |
| 1355 | DEBUG(D_acl) |
| 1356 | debug_printf("CSA priority=%d weight=%d port=%d\n", priority, weight, port); |
| 1357 | |
| 1358 | /* Check the CSA version number */ |
| 1359 | |
| 1360 | if (priority != 1) continue; |
| 1361 | |
| 1362 | /* If the domain does not have a CSA SRV record of its own (i.e. the domain |
| 1363 | found by dns_special_lookup() is a parent of the one we asked for), we check |
| 1364 | the subdomain assertions in the port field. At the moment there's only one |
| 1365 | assertion: legitimate SMTP clients are all explicitly authorized with CSA |
| 1366 | SRV records of their own. */ |
| 1367 | |
| 1368 | if (found != domain) |
| 1369 | { |
| 1370 | if (port & 1) |
| 1371 | return t->data.val = CSA_FAIL_EXPLICIT; |
| 1372 | else |
| 1373 | return t->data.val = CSA_UNKNOWN; |
| 1374 | } |
| 1375 | |
| 1376 | /* This CSA SRV record refers directly to our domain, so we check the value |
| 1377 | in the weight field to work out the domain's authorization. 0 and 1 are |
| 1378 | unauthorized; 3 means the client is authorized but we can't check the IP |
| 1379 | address in order to authenticate it, so we treat it as unknown; values |
| 1380 | greater than 3 are undefined. */ |
| 1381 | |
| 1382 | if (weight < 2) return t->data.val = CSA_FAIL_DOMAIN; |
| 1383 | |
| 1384 | if (weight > 2) continue; |
| 1385 | |
| 1386 | /* Weight == 2, which means the domain is authorized. We must check that the |
| 1387 | client's IP address is listed as one of the SRV target addresses. Save the |
| 1388 | target hostname then break to scan the additional data for its addresses. */ |
| 1389 | |
| 1390 | (void)dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, p, |
| 1391 | (DN_EXPAND_ARG4_TYPE)target, sizeof(target)); |
| 1392 | |
| 1393 | DEBUG(D_acl) debug_printf("CSA target is %s\n", target); |
| 1394 | |
| 1395 | break; |
| 1396 | } |
| 1397 | |
| 1398 | /* If we didn't break the loop then no appropriate records were found. */ |
| 1399 | |
| 1400 | if (rr == NULL) return t->data.val = CSA_UNKNOWN; |
| 1401 | |
| 1402 | /* Do not check addresses if the target is ".", in accordance with RFC 2782. |
| 1403 | A target of "." indicates there are no valid addresses, so the client cannot |
| 1404 | be authorized. (This is an odd configuration because weight=2 target=. is |
| 1405 | equivalent to weight=1, but we check for it in order to keep load off the |
| 1406 | root name servers.) Note that dn_expand() turns "." into "". */ |
| 1407 | |
| 1408 | if (Ustrcmp(target, "") == 0) return t->data.val = CSA_FAIL_NOADDR; |
| 1409 | |
| 1410 | /* Scan the additional section of the CSA SRV reply for addresses belonging |
| 1411 | to the target. If the name server didn't return any additional data (e.g. |
| 1412 | because it does not fully support SRV records), we need to do another lookup |
| 1413 | to obtain the target addresses; otherwise we have a definitive result. */ |
| 1414 | |
| 1415 | rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ADDITIONAL, target); |
| 1416 | if (rc != CSA_FAIL_NOADDR) return t->data.val = rc; |
| 1417 | |
| 1418 | /* The DNS lookup type corresponds to the IP version used by the client. */ |
| 1419 | |
| 1420 | #if HAVE_IPV6 |
| 1421 | if (Ustrchr(sender_host_address, ':') != NULL) |
| 1422 | type = T_AAAA; |
| 1423 | else |
| 1424 | #endif /* HAVE_IPV6 */ |
| 1425 | type = T_A; |
| 1426 | |
| 1427 | |
| 1428 | #if HAVE_IPV6 && defined(SUPPORT_A6) |
| 1429 | DNS_LOOKUP_AGAIN: |
| 1430 | #endif |
| 1431 | |
| 1432 | switch (dns_lookup(&dnsa, target, type, NULL)) |
| 1433 | { |
| 1434 | /* If something bad happened (most commonly DNS_AGAIN), defer. */ |
| 1435 | |
| 1436 | default: |
| 1437 | return t->data.val = CSA_DEFER_ADDR; |
| 1438 | |
| 1439 | /* If the query succeeded, scan the addresses and return the result. */ |
| 1440 | |
| 1441 | case DNS_SUCCEED: |
| 1442 | rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ANSWERS, target); |
| 1443 | if (rc != CSA_FAIL_NOADDR) return t->data.val = rc; |
| 1444 | /* else fall through */ |
| 1445 | |
| 1446 | /* If the target has no IP addresses, the client cannot have an authorized |
| 1447 | IP address. However, if the target site uses A6 records (not AAAA records) |
| 1448 | we have to do yet another lookup in order to check them. */ |
| 1449 | |
| 1450 | case DNS_NOMATCH: |
| 1451 | case DNS_NODATA: |
| 1452 | |
| 1453 | #if HAVE_IPV6 && defined(SUPPORT_A6) |
| 1454 | if (type == T_AAAA) { type = T_A6; goto DNS_LOOKUP_AGAIN; } |
| 1455 | #endif |
| 1456 | |
| 1457 | return t->data.val = CSA_FAIL_NOADDR; |
| 1458 | } |
| 1459 | } |
| 1460 | |
| 1461 | |
| 1462 | |
| 1463 | /************************************************* |
| 1464 | * Handle verification (address & other) * |
| 1465 | *************************************************/ |
| 1466 | |
| 1467 | /* This function implements the "verify" condition. It is called when |
| 1468 | encountered in any ACL, because some tests are almost always permitted. Some |
| 1469 | just don't make sense, and always fail (for example, an attempt to test a host |
| 1470 | lookup for a non-TCP/IP message). Others are restricted to certain ACLs. |
| 1471 | |
| 1472 | Arguments: |
| 1473 | where where called from |
| 1474 | addr the recipient address that the ACL is handling, or NULL |
| 1475 | arg the argument of "verify" |
| 1476 | user_msgptr pointer for user message |
| 1477 | log_msgptr pointer for log message |
| 1478 | basic_errno where to put verify errno |
| 1479 | |
| 1480 | Returns: OK verification condition succeeded |
| 1481 | FAIL verification failed |
| 1482 | DEFER there was a problem verifying |
| 1483 | ERROR syntax error |
| 1484 | */ |
| 1485 | |
| 1486 | static int |
| 1487 | acl_verify(int where, address_item *addr, uschar *arg, |
| 1488 | uschar **user_msgptr, uschar **log_msgptr, int *basic_errno) |
| 1489 | { |
| 1490 | int sep = '/'; |
| 1491 | int callout = -1; |
| 1492 | int callout_overall = -1; |
| 1493 | int callout_connect = -1; |
| 1494 | int verify_options = 0; |
| 1495 | int rc; |
| 1496 | BOOL verify_header_sender = FALSE; |
| 1497 | BOOL defer_ok = FALSE; |
| 1498 | BOOL callout_defer_ok = FALSE; |
| 1499 | BOOL no_details = FALSE; |
| 1500 | BOOL success_on_redirect = FALSE; |
| 1501 | address_item *sender_vaddr = NULL; |
| 1502 | uschar *verify_sender_address = NULL; |
| 1503 | uschar *pm_mailfrom = NULL; |
| 1504 | uschar *se_mailfrom = NULL; |
| 1505 | |
| 1506 | /* Some of the verify items have slash-separated options; some do not. Diagnose |
| 1507 | an error if options are given for items that don't expect them. This code has |
| 1508 | now got very message. Refactoring to use a table would be a good idea one day. |
| 1509 | */ |
| 1510 | |
| 1511 | uschar *slash = Ustrchr(arg, '/'); |
| 1512 | uschar *list = arg; |
| 1513 | uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size); |
| 1514 | |
| 1515 | if (ss == NULL) goto BAD_VERIFY; |
| 1516 | |
| 1517 | /* Handle name/address consistency verification in a separate function. */ |
| 1518 | |
| 1519 | if (strcmpic(ss, US"reverse_host_lookup") == 0) |
| 1520 | { |
| 1521 | if (slash != NULL) goto NO_OPTIONS; |
| 1522 | if (sender_host_address == NULL) return OK; |
| 1523 | return acl_verify_reverse(user_msgptr, log_msgptr); |
| 1524 | } |
| 1525 | |
| 1526 | /* TLS certificate verification is done at STARTTLS time; here we just |
| 1527 | test whether it was successful or not. (This is for optional verification; for |
| 1528 | mandatory verification, the connection doesn't last this long.) */ |
| 1529 | |
| 1530 | if (strcmpic(ss, US"certificate") == 0) |
| 1531 | { |
| 1532 | if (slash != NULL) goto NO_OPTIONS; |
| 1533 | if (tls_certificate_verified) return OK; |
| 1534 | *user_msgptr = US"no verified certificate"; |
| 1535 | return FAIL; |
| 1536 | } |
| 1537 | |
| 1538 | /* We can test the result of optional HELO verification that might have |
| 1539 | occurred earlier. If not, we can attempt the verification now. */ |
| 1540 | |
| 1541 | if (strcmpic(ss, US"helo") == 0) |
| 1542 | { |
| 1543 | if (slash != NULL) goto NO_OPTIONS; |
| 1544 | if (!helo_verified && !helo_verify_failed) smtp_verify_helo(); |
| 1545 | return helo_verified? OK : FAIL; |
| 1546 | } |
| 1547 | |
| 1548 | /* Do Client SMTP Authorization checks in a separate function, and turn the |
| 1549 | result code into user-friendly strings. */ |
| 1550 | |
| 1551 | if (strcmpic(ss, US"csa") == 0) |
| 1552 | { |
| 1553 | rc = acl_verify_csa(list); |
| 1554 | *log_msgptr = *user_msgptr = string_sprintf("client SMTP authorization %s", |
| 1555 | csa_reason_string[rc]); |
| 1556 | csa_status = csa_status_string[rc]; |
| 1557 | DEBUG(D_acl) debug_printf("CSA result %s\n", csa_status); |
| 1558 | return csa_return_code[rc]; |
| 1559 | } |
| 1560 | |
| 1561 | /* Check that all relevant header lines have the correct syntax. If there is |
| 1562 | a syntax error, we return details of the error to the sender if configured to |
| 1563 | send out full details. (But a "message" setting on the ACL can override, as |
| 1564 | always). */ |
| 1565 | |
| 1566 | if (strcmpic(ss, US"header_syntax") == 0) |
| 1567 | { |
| 1568 | if (slash != NULL) goto NO_OPTIONS; |
| 1569 | if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP) goto WRONG_ACL; |
| 1570 | rc = verify_check_headers(log_msgptr); |
| 1571 | if (rc != OK && smtp_return_error_details && *log_msgptr != NULL) |
| 1572 | *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr); |
| 1573 | return rc; |
| 1574 | } |
| 1575 | |
| 1576 | /* Check that no recipient of this message is "blind", that is, every envelope |
| 1577 | recipient must be mentioned in either To: or Cc:. */ |
| 1578 | |
| 1579 | if (strcmpic(ss, US"not_blind") == 0) |
| 1580 | { |
| 1581 | if (slash != NULL) goto NO_OPTIONS; |
| 1582 | if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP) goto WRONG_ACL; |
| 1583 | rc = verify_check_notblind(); |
| 1584 | if (rc != OK) |
| 1585 | { |
| 1586 | *log_msgptr = string_sprintf("bcc recipient detected"); |
| 1587 | if (smtp_return_error_details) |
| 1588 | *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr); |
| 1589 | } |
| 1590 | return rc; |
| 1591 | } |
| 1592 | |
| 1593 | /* The remaining verification tests check recipient and sender addresses, |
| 1594 | either from the envelope or from the header. There are a number of |
| 1595 | slash-separated options that are common to all of them. */ |
| 1596 | |
| 1597 | |
| 1598 | /* Check that there is at least one verifiable sender address in the relevant |
| 1599 | header lines. This can be followed by callout and defer options, just like |
| 1600 | sender and recipient. */ |
| 1601 | |
| 1602 | if (strcmpic(ss, US"header_sender") == 0) |
| 1603 | { |
| 1604 | if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP) goto WRONG_ACL; |
| 1605 | verify_header_sender = TRUE; |
| 1606 | } |
| 1607 | |
| 1608 | /* Otherwise, first item in verify argument must be "sender" or "recipient". |
| 1609 | In the case of a sender, this can optionally be followed by an address to use |
| 1610 | in place of the actual sender (rare special-case requirement). */ |
| 1611 | |
| 1612 | else if (strncmpic(ss, US"sender", 6) == 0) |
| 1613 | { |
| 1614 | uschar *s = ss + 6; |
| 1615 | if (where > ACL_WHERE_NOTSMTP) |
| 1616 | { |
| 1617 | *log_msgptr = string_sprintf("cannot verify sender in ACL for %s " |
| 1618 | "(only possible for MAIL, RCPT, PREDATA, or DATA)", |
| 1619 | acl_wherenames[where]); |
| 1620 | return ERROR; |
| 1621 | } |
| 1622 | if (*s == 0) |
| 1623 | verify_sender_address = sender_address; |
| 1624 | else |
| 1625 | { |
| 1626 | while (isspace(*s)) s++; |
| 1627 | if (*s++ != '=') goto BAD_VERIFY; |
| 1628 | while (isspace(*s)) s++; |
| 1629 | verify_sender_address = string_copy(s); |
| 1630 | } |
| 1631 | } |
| 1632 | else |
| 1633 | { |
| 1634 | if (strcmpic(ss, US"recipient") != 0) goto BAD_VERIFY; |
| 1635 | if (addr == NULL) |
| 1636 | { |
| 1637 | *log_msgptr = string_sprintf("cannot verify recipient in ACL for %s " |
| 1638 | "(only possible for RCPT)", acl_wherenames[where]); |
| 1639 | return ERROR; |
| 1640 | } |
| 1641 | } |
| 1642 | |
| 1643 | /* Remaining items are optional; they apply to sender and recipient |
| 1644 | verification, including "header sender" verification. */ |
| 1645 | |
| 1646 | while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)) |
| 1647 | != NULL) |
| 1648 | { |
| 1649 | if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE; |
| 1650 | else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE; |
| 1651 | else if (strcmpic(ss, US"success_on_redirect") == 0) success_on_redirect = TRUE; |
| 1652 | |
| 1653 | /* These two old options are left for backwards compatibility */ |
| 1654 | |
| 1655 | else if (strcmpic(ss, US"callout_defer_ok") == 0) |
| 1656 | { |
| 1657 | callout_defer_ok = TRUE; |
| 1658 | if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT; |
| 1659 | } |
| 1660 | |
| 1661 | else if (strcmpic(ss, US"check_postmaster") == 0) |
| 1662 | { |
| 1663 | pm_mailfrom = US""; |
| 1664 | if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT; |
| 1665 | } |
| 1666 | |
| 1667 | /* The callout option has a number of sub-options, comma separated */ |
| 1668 | |
| 1669 | else if (strncmpic(ss, US"callout", 7) == 0) |
| 1670 | { |
| 1671 | callout = CALLOUT_TIMEOUT_DEFAULT; |
| 1672 | ss += 7; |
| 1673 | if (*ss != 0) |
| 1674 | { |
| 1675 | while (isspace(*ss)) ss++; |
| 1676 | if (*ss++ == '=') |
| 1677 | { |
| 1678 | int optsep = ','; |
| 1679 | uschar *opt; |
| 1680 | uschar buffer[256]; |
| 1681 | while (isspace(*ss)) ss++; |
| 1682 | |
| 1683 | /* This callout option handling code has become a mess as new options |
| 1684 | have been added in an ad hoc manner. It should be tidied up into some |
| 1685 | kind of table-driven thing. */ |
| 1686 | |
| 1687 | while ((opt = string_nextinlist(&ss, &optsep, buffer, sizeof(buffer))) |
| 1688 | != NULL) |
| 1689 | { |
| 1690 | if (strcmpic(opt, US"defer_ok") == 0) callout_defer_ok = TRUE; |
| 1691 | else if (strcmpic(opt, US"no_cache") == 0) |
| 1692 | verify_options |= vopt_callout_no_cache; |
| 1693 | else if (strcmpic(opt, US"random") == 0) |
| 1694 | verify_options |= vopt_callout_random; |
| 1695 | else if (strcmpic(opt, US"use_sender") == 0) |
| 1696 | verify_options |= vopt_callout_recipsender; |
| 1697 | else if (strcmpic(opt, US"use_postmaster") == 0) |
| 1698 | verify_options |= vopt_callout_recippmaster; |
| 1699 | else if (strcmpic(opt, US"postmaster") == 0) pm_mailfrom = US""; |
| 1700 | else if (strcmpic(opt, US"fullpostmaster") == 0) |
| 1701 | { |
| 1702 | pm_mailfrom = US""; |
| 1703 | verify_options |= vopt_callout_fullpm; |
| 1704 | } |
| 1705 | |
| 1706 | else if (strncmpic(opt, US"mailfrom", 8) == 0) |
| 1707 | { |
| 1708 | if (!verify_header_sender) |
| 1709 | { |
| 1710 | *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a " |
| 1711 | "callout option only for verify=header_sender (detected in ACL " |
| 1712 | "condition \"%s\")", arg); |
| 1713 | return ERROR; |
| 1714 | } |
| 1715 | opt += 8; |
| 1716 | while (isspace(*opt)) opt++; |
| 1717 | if (*opt++ != '=') |
| 1718 | { |
| 1719 | *log_msgptr = string_sprintf("'=' expected after " |
| 1720 | "\"mailfrom\" in ACL condition \"%s\"", arg); |
| 1721 | return ERROR; |
| 1722 | } |
| 1723 | while (isspace(*opt)) opt++; |
| 1724 | se_mailfrom = string_copy(opt); |
| 1725 | } |
| 1726 | |
| 1727 | else if (strncmpic(opt, US"postmaster_mailfrom", 19) == 0) |
| 1728 | { |
| 1729 | opt += 19; |
| 1730 | while (isspace(*opt)) opt++; |
| 1731 | if (*opt++ != '=') |
| 1732 | { |
| 1733 | *log_msgptr = string_sprintf("'=' expected after " |
| 1734 | "\"postmaster_mailfrom\" in ACL condition \"%s\"", arg); |
| 1735 | return ERROR; |
| 1736 | } |
| 1737 | while (isspace(*opt)) opt++; |
| 1738 | pm_mailfrom = string_copy(opt); |
| 1739 | } |
| 1740 | |
| 1741 | else if (strncmpic(opt, US"maxwait", 7) == 0) |
| 1742 | { |
| 1743 | opt += 7; |
| 1744 | while (isspace(*opt)) opt++; |
| 1745 | if (*opt++ != '=') |
| 1746 | { |
| 1747 | *log_msgptr = string_sprintf("'=' expected after \"maxwait\" in " |
| 1748 | "ACL condition \"%s\"", arg); |
| 1749 | return ERROR; |
| 1750 | } |
| 1751 | while (isspace(*opt)) opt++; |
| 1752 | callout_overall = readconf_readtime(opt, 0, FALSE); |
| 1753 | if (callout_overall < 0) |
| 1754 | { |
| 1755 | *log_msgptr = string_sprintf("bad time value in ACL condition " |
| 1756 | "\"verify %s\"", arg); |
| 1757 | return ERROR; |
| 1758 | } |
| 1759 | } |
| 1760 | else if (strncmpic(opt, US"connect", 7) == 0) |
| 1761 | { |
| 1762 | opt += 7; |
| 1763 | while (isspace(*opt)) opt++; |
| 1764 | if (*opt++ != '=') |
| 1765 | { |
| 1766 | *log_msgptr = string_sprintf("'=' expected after " |
| 1767 | "\"callout_overaall\" in ACL condition \"%s\"", arg); |
| 1768 | return ERROR; |
| 1769 | } |
| 1770 | while (isspace(*opt)) opt++; |
| 1771 | callout_connect = readconf_readtime(opt, 0, FALSE); |
| 1772 | if (callout_connect < 0) |
| 1773 | { |
| 1774 | *log_msgptr = string_sprintf("bad time value in ACL condition " |
| 1775 | "\"verify %s\"", arg); |
| 1776 | return ERROR; |
| 1777 | } |
| 1778 | } |
| 1779 | else /* Plain time is callout connect/command timeout */ |
| 1780 | { |
| 1781 | callout = readconf_readtime(opt, 0, FALSE); |
| 1782 | if (callout < 0) |
| 1783 | { |
| 1784 | *log_msgptr = string_sprintf("bad time value in ACL condition " |
| 1785 | "\"verify %s\"", arg); |
| 1786 | return ERROR; |
| 1787 | } |
| 1788 | } |
| 1789 | } |
| 1790 | } |
| 1791 | else |
| 1792 | { |
| 1793 | *log_msgptr = string_sprintf("'=' expected after \"callout\" in " |
| 1794 | "ACL condition \"%s\"", arg); |
| 1795 | return ERROR; |
| 1796 | } |
| 1797 | } |
| 1798 | } |
| 1799 | |
| 1800 | /* Option not recognized */ |
| 1801 | |
| 1802 | else |
| 1803 | { |
| 1804 | *log_msgptr = string_sprintf("unknown option \"%s\" in ACL " |
| 1805 | "condition \"verify %s\"", ss, arg); |
| 1806 | return ERROR; |
| 1807 | } |
| 1808 | } |
| 1809 | |
| 1810 | if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == |
| 1811 | (vopt_callout_recipsender|vopt_callout_recippmaster)) |
| 1812 | { |
| 1813 | *log_msgptr = US"only one of use_sender and use_postmaster can be set " |
| 1814 | "for a recipient callout"; |
| 1815 | return ERROR; |
| 1816 | } |
| 1817 | |
| 1818 | /* Handle sender-in-header verification. Default the user message to the log |
| 1819 | message if giving out verification details. */ |
| 1820 | |
| 1821 | if (verify_header_sender) |
| 1822 | { |
| 1823 | int verrno; |
| 1824 | rc = verify_check_header_address(user_msgptr, log_msgptr, callout, |
| 1825 | callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options, |
| 1826 | &verrno); |
| 1827 | if (rc != OK) |
| 1828 | { |
| 1829 | *basic_errno = verrno; |
| 1830 | if (smtp_return_error_details) |
| 1831 | { |
| 1832 | if (*user_msgptr == NULL && *log_msgptr != NULL) |
| 1833 | *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr); |
| 1834 | if (rc == DEFER) acl_temp_details = TRUE; |
| 1835 | } |
| 1836 | } |
| 1837 | } |
| 1838 | |
| 1839 | /* Handle a sender address. The default is to verify *the* sender address, but |
| 1840 | optionally a different address can be given, for special requirements. If the |
| 1841 | address is empty, we are dealing with a bounce message that has no sender, so |
| 1842 | we cannot do any checking. If the real sender address gets rewritten during |
| 1843 | verification (e.g. DNS widening), set the flag to stop it being rewritten again |
| 1844 | during message reception. |
| 1845 | |
| 1846 | A list of verified "sender" addresses is kept to try to avoid doing to much |
| 1847 | work repetitively when there are multiple recipients in a message and they all |
| 1848 | require sender verification. However, when callouts are involved, it gets too |
| 1849 | complicated because different recipients may require different callout options. |
| 1850 | Therefore, we always do a full sender verify when any kind of callout is |
| 1851 | specified. Caching elsewhere, for instance in the DNS resolver and in the |
| 1852 | callout handling, should ensure that this is not terribly inefficient. */ |
| 1853 | |
| 1854 | else if (verify_sender_address != NULL) |
| 1855 | { |
| 1856 | if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) |
| 1857 | != 0) |
| 1858 | { |
| 1859 | *log_msgptr = US"use_sender or use_postmaster cannot be used for a " |
| 1860 | "sender verify callout"; |
| 1861 | return ERROR; |
| 1862 | } |
| 1863 | |
| 1864 | sender_vaddr = verify_checked_sender(verify_sender_address); |
| 1865 | if (sender_vaddr != NULL && /* Previously checked */ |
| 1866 | callout <= 0) /* No callout needed this time */ |
| 1867 | { |
| 1868 | /* If the "routed" flag is set, it means that routing worked before, so |
| 1869 | this check can give OK (the saved return code value, if set, belongs to a |
| 1870 | callout that was done previously). If the "routed" flag is not set, routing |
| 1871 | must have failed, so we use the saved return code. */ |
| 1872 | |
| 1873 | if (testflag(sender_vaddr, af_verify_routed)) rc = OK; else |
| 1874 | { |
| 1875 | rc = sender_vaddr->special_action; |
| 1876 | *basic_errno = sender_vaddr->basic_errno; |
| 1877 | } |
| 1878 | HDEBUG(D_acl) debug_printf("using cached sender verify result\n"); |
| 1879 | } |
| 1880 | |
| 1881 | /* Do a new verification, and cache the result. The cache is used to avoid |
| 1882 | verifying the sender multiple times for multiple RCPTs when callouts are not |
| 1883 | specified (see comments above). |
| 1884 | |
| 1885 | The cache is also used on failure to give details in response to the first |
| 1886 | RCPT that gets bounced for this reason. However, this can be suppressed by |
| 1887 | the no_details option, which sets the flag that says "this detail has already |
| 1888 | been sent". The cache normally contains just one address, but there may be |
| 1889 | more in esoteric circumstances. */ |
| 1890 | |
| 1891 | else |
| 1892 | { |
| 1893 | BOOL routed = TRUE; |
| 1894 | uschar *save_address_data = deliver_address_data; |
| 1895 | |
| 1896 | sender_vaddr = deliver_make_addr(verify_sender_address, TRUE); |
| 1897 | if (no_details) setflag(sender_vaddr, af_sverify_told); |
| 1898 | if (verify_sender_address[0] != 0) |
| 1899 | { |
| 1900 | /* If this is the real sender address, save the unrewritten version |
| 1901 | for use later in receive. Otherwise, set a flag so that rewriting the |
| 1902 | sender in verify_address() does not update sender_address. */ |
| 1903 | |
| 1904 | if (verify_sender_address == sender_address) |
| 1905 | sender_address_unrewritten = sender_address; |
| 1906 | else |
| 1907 | verify_options |= vopt_fake_sender; |
| 1908 | |
| 1909 | if (success_on_redirect) |
| 1910 | verify_options |= vopt_success_on_redirect; |
| 1911 | |
| 1912 | /* The recipient, qualify, and expn options are never set in |
| 1913 | verify_options. */ |
| 1914 | |
| 1915 | rc = verify_address(sender_vaddr, NULL, verify_options, callout, |
| 1916 | callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed); |
| 1917 | |
| 1918 | HDEBUG(D_acl) debug_printf("----------- end verify ------------\n"); |
| 1919 | |
| 1920 | if (rc == OK) |
| 1921 | { |
| 1922 | if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0) |
| 1923 | { |
| 1924 | DEBUG(D_acl) debug_printf("sender %s verified ok as %s\n", |
| 1925 | verify_sender_address, sender_vaddr->address); |
| 1926 | } |
| 1927 | else |
| 1928 | { |
| 1929 | DEBUG(D_acl) debug_printf("sender %s verified ok\n", |
| 1930 | verify_sender_address); |
| 1931 | } |
| 1932 | } |
| 1933 | else *basic_errno = sender_vaddr->basic_errno; |
| 1934 | } |
| 1935 | else rc = OK; /* Null sender */ |
| 1936 | |
| 1937 | /* Cache the result code */ |
| 1938 | |
| 1939 | if (routed) setflag(sender_vaddr, af_verify_routed); |
| 1940 | if (callout > 0) setflag(sender_vaddr, af_verify_callout); |
| 1941 | sender_vaddr->special_action = rc; |
| 1942 | sender_vaddr->next = sender_verified_list; |
| 1943 | sender_verified_list = sender_vaddr; |
| 1944 | |
| 1945 | /* Restore the recipient address data, which might have been clobbered by |
| 1946 | the sender verification. */ |
| 1947 | |
| 1948 | deliver_address_data = save_address_data; |
| 1949 | } |
| 1950 | |
| 1951 | /* Put the sender address_data value into $sender_address_data */ |
| 1952 | |
| 1953 | sender_address_data = sender_vaddr->p.address_data; |
| 1954 | } |
| 1955 | |
| 1956 | /* A recipient address just gets a straightforward verify; again we must handle |
| 1957 | the DEFER overrides. */ |
| 1958 | |
| 1959 | else |
| 1960 | { |
| 1961 | address_item addr2; |
| 1962 | |
| 1963 | if (success_on_redirect) |
| 1964 | verify_options |= vopt_success_on_redirect; |
| 1965 | |
| 1966 | /* We must use a copy of the address for verification, because it might |
| 1967 | get rewritten. */ |
| 1968 | |
| 1969 | addr2 = *addr; |
| 1970 | rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout, |
| 1971 | callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL); |
| 1972 | HDEBUG(D_acl) debug_printf("----------- end verify ------------\n"); |
| 1973 | |
| 1974 | *basic_errno = addr2.basic_errno; |
| 1975 | *log_msgptr = addr2.message; |
| 1976 | *user_msgptr = (addr2.user_message != NULL)? |
| 1977 | addr2.user_message : addr2.message; |
| 1978 | |
| 1979 | /* Allow details for temporary error if the address is so flagged. */ |
| 1980 | if (testflag((&addr2), af_pass_message)) acl_temp_details = TRUE; |
| 1981 | |
| 1982 | /* Make $address_data visible */ |
| 1983 | deliver_address_data = addr2.p.address_data; |
| 1984 | } |
| 1985 | |
| 1986 | /* We have a result from the relevant test. Handle defer overrides first. */ |
| 1987 | |
| 1988 | if (rc == DEFER && (defer_ok || |
| 1989 | (callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER))) |
| 1990 | { |
| 1991 | HDEBUG(D_acl) debug_printf("verify defer overridden by %s\n", |
| 1992 | defer_ok? "defer_ok" : "callout_defer_ok"); |
| 1993 | rc = OK; |
| 1994 | } |
| 1995 | |
| 1996 | /* If we've failed a sender, set up a recipient message, and point |
| 1997 | sender_verified_failed to the address item that actually failed. */ |
| 1998 | |
| 1999 | if (rc != OK && verify_sender_address != NULL) |
| 2000 | { |
| 2001 | if (rc != DEFER) |
| 2002 | { |
| 2003 | *log_msgptr = *user_msgptr = US"Sender verify failed"; |
| 2004 | } |
| 2005 | else if (*basic_errno != ERRNO_CALLOUTDEFER) |
| 2006 | { |
| 2007 | *log_msgptr = *user_msgptr = US"Could not complete sender verify"; |
| 2008 | } |
| 2009 | else |
| 2010 | { |
| 2011 | *log_msgptr = US"Could not complete sender verify callout"; |
| 2012 | *user_msgptr = smtp_return_error_details? sender_vaddr->user_message : |
| 2013 | *log_msgptr; |
| 2014 | } |
| 2015 | |
| 2016 | sender_verified_failed = sender_vaddr; |
| 2017 | } |
| 2018 | |
| 2019 | /* Verifying an address messes up the values of $domain and $local_part, |
| 2020 | so reset them before returning if this is a RCPT ACL. */ |
| 2021 | |
| 2022 | if (addr != NULL) |
| 2023 | { |
| 2024 | deliver_domain = addr->domain; |
| 2025 | deliver_localpart = addr->local_part; |
| 2026 | } |
| 2027 | return rc; |
| 2028 | |
| 2029 | /* Syntax errors in the verify argument come here. */ |
| 2030 | |
| 2031 | BAD_VERIFY: |
| 2032 | *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", " |
| 2033 | "\"helo\", \"header_syntax\", \"header_sender\" or " |
| 2034 | "\"reverse_host_lookup\" at start of ACL condition " |
| 2035 | "\"verify %s\"", arg); |
| 2036 | return ERROR; |
| 2037 | |
| 2038 | /* Options supplied when not allowed come here */ |
| 2039 | |
| 2040 | NO_OPTIONS: |
| 2041 | *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" " |
| 2042 | "(this verify item has no options)", arg); |
| 2043 | return ERROR; |
| 2044 | |
| 2045 | /* Calls in the wrong ACL come here */ |
| 2046 | |
| 2047 | WRONG_ACL: |
| 2048 | *log_msgptr = string_sprintf("cannot check header contents in ACL for %s " |
| 2049 | "(only possible in ACL for DATA)", acl_wherenames[where]); |
| 2050 | return ERROR; |
| 2051 | } |
| 2052 | |
| 2053 | |
| 2054 | |
| 2055 | |
| 2056 | /************************************************* |
| 2057 | * Check argument for control= modifier * |
| 2058 | *************************************************/ |
| 2059 | |
| 2060 | /* Called from acl_check_condition() below |
| 2061 | |
| 2062 | Arguments: |
| 2063 | arg the argument string for control= |
| 2064 | pptr set to point to the terminating character |
| 2065 | where which ACL we are in |
| 2066 | log_msgptr for error messages |
| 2067 | |
| 2068 | Returns: CONTROL_xxx value |
| 2069 | */ |
| 2070 | |
| 2071 | static int |
| 2072 | decode_control(uschar *arg, uschar **pptr, int where, uschar **log_msgptr) |
| 2073 | { |
| 2074 | int len; |
| 2075 | control_def *d; |
| 2076 | |
| 2077 | for (d = controls_list; |
| 2078 | d < controls_list + sizeof(controls_list)/sizeof(control_def); |
| 2079 | d++) |
| 2080 | { |
| 2081 | len = Ustrlen(d->name); |
| 2082 | if (Ustrncmp(d->name, arg, len) == 0) break; |
| 2083 | } |
| 2084 | |
| 2085 | if (d >= controls_list + sizeof(controls_list)/sizeof(control_def) || |
| 2086 | (arg[len] != 0 && (!d->has_option || arg[len] != '/'))) |
| 2087 | { |
| 2088 | *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg); |
| 2089 | return CONTROL_ERROR; |
| 2090 | } |
| 2091 | |
| 2092 | *pptr = arg + len; |
| 2093 | return d->value; |
| 2094 | } |
| 2095 | |
| 2096 | |
| 2097 | |
| 2098 | |
| 2099 | /************************************************* |
| 2100 | * Return a ratelimit error * |
| 2101 | *************************************************/ |
| 2102 | |
| 2103 | /* Called from acl_ratelimit() below |
| 2104 | |
| 2105 | Arguments: |
| 2106 | log_msgptr for error messages |
| 2107 | format format string |
| 2108 | ... supplementary arguments |
| 2109 | ss ratelimit option name |
| 2110 | where ACL_WHERE_xxxx indicating which ACL this is |
| 2111 | |
| 2112 | Returns: ERROR |
| 2113 | */ |
| 2114 | |
| 2115 | static int |
| 2116 | ratelimit_error(uschar **log_msgptr, const char *format, ...) |
| 2117 | { |
| 2118 | va_list ap; |
| 2119 | uschar buffer[STRING_SPRINTF_BUFFER_SIZE]; |
| 2120 | va_start(ap, format); |
| 2121 | if (!string_vformat(buffer, sizeof(buffer), format, ap)) |
| 2122 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, |
| 2123 | "string_sprintf expansion was longer than %d", sizeof(buffer)); |
| 2124 | va_end(ap); |
| 2125 | *log_msgptr = string_sprintf( |
| 2126 | "error in arguments to \"ratelimit\" condition: %s", buffer); |
| 2127 | return ERROR; |
| 2128 | } |
| 2129 | |
| 2130 | |
| 2131 | |
| 2132 | |
| 2133 | /************************************************* |
| 2134 | * Handle rate limiting * |
| 2135 | *************************************************/ |
| 2136 | |
| 2137 | /* Called by acl_check_condition() below to calculate the result |
| 2138 | of the ACL ratelimit condition. |
| 2139 | |
| 2140 | Note that the return value might be slightly unexpected: if the |
| 2141 | sender's rate is above the limit then the result is OK. This is |
| 2142 | similar to the dnslists condition, and is so that you can write |
| 2143 | ACL clauses like: defer ratelimit = 15 / 1h |
| 2144 | |
| 2145 | Arguments: |
| 2146 | arg the option string for ratelimit= |
| 2147 | where ACL_WHERE_xxxx indicating which ACL this is |
| 2148 | log_msgptr for error messages |
| 2149 | |
| 2150 | Returns: OK - Sender's rate is above limit |
| 2151 | FAIL - Sender's rate is below limit |
| 2152 | DEFER - Problem opening ratelimit database |
| 2153 | ERROR - Syntax error in options. |
| 2154 | */ |
| 2155 | |
| 2156 | static int |
| 2157 | acl_ratelimit(uschar *arg, int where, uschar **log_msgptr) |
| 2158 | { |
| 2159 | double limit, period, count; |
| 2160 | uschar *ss; |
| 2161 | uschar *key = NULL; |
| 2162 | uschar *unique = NULL; |
| 2163 | int sep = '/'; |
| 2164 | BOOL leaky = FALSE, strict = FALSE, readonly = FALSE; |
| 2165 | BOOL noupdate = FALSE, badacl = FALSE; |
| 2166 | int mode = RATE_PER_WHAT; |
| 2167 | int old_pool, rc; |
| 2168 | tree_node **anchor, *t; |
| 2169 | open_db dbblock, *dbm; |
| 2170 | int dbdb_size; |
| 2171 | dbdata_ratelimit *dbd; |
| 2172 | dbdata_ratelimit_unique *dbdb; |
| 2173 | struct timeval tv; |
| 2174 | |
| 2175 | /* Parse the first two options and record their values in expansion |
| 2176 | variables. These variables allow the configuration to have informative |
| 2177 | error messages based on rate limits obtained from a table lookup. */ |
| 2178 | |
| 2179 | /* First is the maximum number of messages per period / maximum burst |
| 2180 | size, which must be greater than or equal to zero. Zero is useful for |
| 2181 | rate measurement as opposed to rate limiting. */ |
| 2182 | |
| 2183 | sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0); |
| 2184 | if (sender_rate_limit == NULL) |
| 2185 | limit = -1.0; |
| 2186 | else |
| 2187 | { |
| 2188 | limit = Ustrtod(sender_rate_limit, &ss); |
| 2189 | if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; } |
| 2190 | else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; } |
| 2191 | else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; } |
| 2192 | } |
| 2193 | if (limit < 0.0 || *ss != '\0') |
| 2194 | return ratelimit_error(log_msgptr, |
| 2195 | "\"%s\" is not a positive number", sender_rate_limit); |
| 2196 | |
| 2197 | /* Second is the rate measurement period / exponential smoothing time |
| 2198 | constant. This must be strictly greater than zero, because zero leads to |
| 2199 | run-time division errors. */ |
| 2200 | |
| 2201 | sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0); |
| 2202 | if (sender_rate_period == NULL) period = -1.0; |
| 2203 | else period = readconf_readtime(sender_rate_period, 0, FALSE); |
| 2204 | if (period <= 0.0) |
| 2205 | return ratelimit_error(log_msgptr, |
| 2206 | "\"%s\" is not a time value", sender_rate_period); |
| 2207 | |
| 2208 | /* By default we are counting one of something, but the per_rcpt, |
| 2209 | per_byte, and count options can change this. */ |
| 2210 | |
| 2211 | count = 1.0; |
| 2212 | |
| 2213 | /* Parse the other options. */ |
| 2214 | |
| 2215 | while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size)) |
| 2216 | != NULL) |
| 2217 | { |
| 2218 | if (strcmpic(ss, US"leaky") == 0) leaky = TRUE; |
| 2219 | else if (strcmpic(ss, US"strict") == 0) strict = TRUE; |
| 2220 | else if (strcmpic(ss, US"noupdate") == 0) noupdate = TRUE; |
| 2221 | else if (strcmpic(ss, US"readonly") == 0) readonly = TRUE; |
| 2222 | else if (strcmpic(ss, US"per_cmd") == 0) RATE_SET(mode, PER_CMD); |
| 2223 | else if (strcmpic(ss, US"per_conn") == 0) |
| 2224 | { |
| 2225 | RATE_SET(mode, PER_CONN); |
| 2226 | if (where == ACL_WHERE_NOTSMTP || where == ACL_WHERE_NOTSMTP_START) |
| 2227 | badacl = TRUE; |
| 2228 | } |
| 2229 | else if (strcmpic(ss, US"per_mail") == 0) |
| 2230 | { |
| 2231 | RATE_SET(mode, PER_MAIL); |
| 2232 | if (where > ACL_WHERE_NOTSMTP) badacl = TRUE; |
| 2233 | } |
| 2234 | else if (strcmpic(ss, US"per_rcpt") == 0) |
| 2235 | { |
| 2236 | /* If we are running in the RCPT ACL, then we'll count the recipients |
| 2237 | one by one, but if we are running when we have accumulated the whole |
| 2238 | list then we'll add them all in one batch. */ |
| 2239 | if (where == ACL_WHERE_RCPT) |
| 2240 | RATE_SET(mode, PER_RCPT); |
| 2241 | else if (where >= ACL_WHERE_PREDATA && where <= ACL_WHERE_NOTSMTP) |
| 2242 | RATE_SET(mode, PER_ALLRCPTS), count = (double)recipients_count; |
| 2243 | else if (where == ACL_WHERE_MAIL || where > ACL_WHERE_NOTSMTP) |
| 2244 | RATE_SET(mode, PER_RCPT), badacl = TRUE; |
| 2245 | } |
| 2246 | else if (strcmpic(ss, US"per_byte") == 0) |
| 2247 | { |
| 2248 | /* If we have not yet received the message data and there was no SIZE |
| 2249 | declaration on the MAIL comand, then it's safe to just use a value of |
| 2250 | zero and let the recorded rate decay as if nothing happened. */ |
| 2251 | RATE_SET(mode, PER_MAIL); |
| 2252 | if (where > ACL_WHERE_NOTSMTP) badacl = TRUE; |
| 2253 | else count = message_size < 0 ? 0.0 : (double)message_size; |
| 2254 | } |
| 2255 | else if (strcmpic(ss, US"per_addr") == 0) |
| 2256 | { |
| 2257 | RATE_SET(mode, PER_RCPT); |
| 2258 | if (where != ACL_WHERE_RCPT) badacl = TRUE, unique = "*"; |
| 2259 | else unique = string_sprintf("%s@%s", deliver_localpart, deliver_domain); |
| 2260 | } |
| 2261 | else if (strncmpic(ss, US"count=", 6) == 0) |
| 2262 | { |
| 2263 | uschar *e; |
| 2264 | count = Ustrtod(ss+6, &e); |
| 2265 | if (count < 0.0 || *e != '\0') |
| 2266 | return ratelimit_error(log_msgptr, |
| 2267 | "\"%s\" is not a positive number", ss); |
| 2268 | } |
| 2269 | else if (strncmpic(ss, US"unique=", 7) == 0) |
| 2270 | unique = string_copy(ss + 7); |
| 2271 | else if (key == NULL) |
| 2272 | key = string_copy(ss); |
| 2273 | else |
| 2274 | key = string_sprintf("%s/%s", key, ss); |
| 2275 | } |
| 2276 | |
| 2277 | /* Sanity check. When the badacl flag is set the update mode must either |
| 2278 | be readonly (which is the default if it is omitted) or, for backwards |
| 2279 | compatibility, a combination of noupdate and strict or leaky. */ |
| 2280 | |
| 2281 | if (mode == RATE_PER_CLASH) |
| 2282 | return ratelimit_error(log_msgptr, "conflicting per_* options"); |
| 2283 | if (leaky + strict + readonly > 1) |
| 2284 | return ratelimit_error(log_msgptr, "conflicting update modes"); |
| 2285 | if (badacl && (leaky || strict) && !noupdate) |
| 2286 | return ratelimit_error(log_msgptr, |
| 2287 | "\"%s\" must not have /leaky or /strict option in %s ACL", |
| 2288 | ratelimit_option_string[mode], acl_wherenames[where]); |
| 2289 | |
| 2290 | /* Set the default values of any unset options. In readonly mode we |
| 2291 | perform the rate computation without any increment so that its value |
| 2292 | decays to eventually allow over-limit senders through. */ |
| 2293 | |
| 2294 | if (noupdate) readonly = TRUE, leaky = strict = FALSE; |
| 2295 | if (badacl) readonly = TRUE; |
| 2296 | if (readonly) count = 0.0; |
| 2297 | if (!strict && !readonly) leaky = TRUE; |
| 2298 | if (mode == RATE_PER_WHAT) mode = RATE_PER_MAIL; |
| 2299 | |
| 2300 | /* Create the lookup key. If there is no explicit key, use sender_host_address. |
| 2301 | If there is no sender_host_address (e.g. -bs or acl_not_smtp) then we simply |
| 2302 | omit it. The smoothing constant (sender_rate_period) and the per_xxx options |
| 2303 | are added to the key because they alter the meaning of the stored data. */ |
| 2304 | |
| 2305 | if (key == NULL) |
| 2306 | key = (sender_host_address == NULL)? US"" : sender_host_address; |
| 2307 | |
| 2308 | key = string_sprintf("%s/%s/%s%s", |
| 2309 | sender_rate_period, |
| 2310 | ratelimit_option_string[mode], |
| 2311 | unique == NULL ? "" : "unique/", |
| 2312 | key); |
| 2313 | |
| 2314 | HDEBUG(D_acl) |
| 2315 | debug_printf("ratelimit condition count=%.0f %.1f/%s\n", count, limit, key); |
| 2316 | |
| 2317 | /* See if we have already computed the rate by looking in the relevant tree. |
| 2318 | For per-connection rate limiting, store tree nodes and dbdata in the permanent |
| 2319 | pool so that they survive across resets. In readonly mode we only remember the |
| 2320 | result for the rest of this command in case a later command changes it. After |
| 2321 | this bit of logic the code is independent of the per_* mode. */ |
| 2322 | |
| 2323 | old_pool = store_pool; |
| 2324 | |
| 2325 | if (readonly) |
| 2326 | anchor = &ratelimiters_cmd; |
| 2327 | else switch(mode) { |
| 2328 | case RATE_PER_CONN: |
| 2329 | anchor = &ratelimiters_conn; |
| 2330 | store_pool = POOL_PERM; |
| 2331 | break; |
| 2332 | case RATE_PER_BYTE: |
| 2333 | case RATE_PER_MAIL: |
| 2334 | case RATE_PER_ALLRCPTS: |
| 2335 | anchor = &ratelimiters_mail; |
| 2336 | break; |
| 2337 | case RATE_PER_ADDR: |
| 2338 | case RATE_PER_CMD: |
| 2339 | case RATE_PER_RCPT: |
| 2340 | anchor = &ratelimiters_cmd; |
| 2341 | break; |
| 2342 | default: |
| 2343 | anchor = NULL; /* silence an "unused" complaint */ |
| 2344 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, |
| 2345 | "internal ACL error: unknown ratelimit mode %d", mode); |
| 2346 | break; |
| 2347 | } |
| 2348 | |
| 2349 | t = tree_search(*anchor, key); |
| 2350 | if (t != NULL) |
| 2351 | { |
| 2352 | dbd = t->data.ptr; |
| 2353 | /* The following few lines duplicate some of the code below. */ |
| 2354 | rc = (dbd->rate < limit)? FAIL : OK; |
| 2355 | store_pool = old_pool; |
| 2356 | sender_rate = string_sprintf("%.1f", dbd->rate); |
| 2357 | HDEBUG(D_acl) |
| 2358 | debug_printf("ratelimit found pre-computed rate %s\n", sender_rate); |
| 2359 | return rc; |
| 2360 | } |
| 2361 | |
| 2362 | /* We aren't using a pre-computed rate, so get a previously recorded rate |
| 2363 | from the database, which will be updated and written back if required. */ |
| 2364 | |
| 2365 | dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE); |
| 2366 | if (dbm == NULL) |
| 2367 | { |
| 2368 | store_pool = old_pool; |
| 2369 | sender_rate = NULL; |
| 2370 | HDEBUG(D_acl) debug_printf("ratelimit database not available\n"); |
| 2371 | *log_msgptr = US"ratelimit database not available"; |
| 2372 | return DEFER; |
| 2373 | } |
| 2374 | dbdb = dbfn_read_with_length(dbm, key, &dbdb_size); |
| 2375 | dbd = NULL; |
| 2376 | |
| 2377 | gettimeofday(&tv, NULL); |
| 2378 | |
| 2379 | if (dbdb != NULL) |
| 2380 | { |
| 2381 | /* Locate the basic ratelimit block inside the DB data. */ |
| 2382 | HDEBUG(D_acl) debug_printf("ratelimit found key in database\n"); |
| 2383 | dbd = &dbdb->dbd; |
| 2384 | |
| 2385 | /* Forget the old Bloom filter if it is too old, so that we count each |
| 2386 | repeating event once per period. We don't simply clear and re-use the old |
| 2387 | filter because we want its size to change if the limit changes. Note that |
| 2388 | we keep the dbd pointer for copying the rate into the new data block. */ |
| 2389 | |
| 2390 | if(unique != NULL && tv.tv_sec > dbdb->bloom_epoch + period) |
| 2391 | { |
| 2392 | HDEBUG(D_acl) debug_printf("ratelimit discarding old Bloom filter\n"); |
| 2393 | dbdb = NULL; |
| 2394 | } |
| 2395 | |
| 2396 | /* Sanity check. */ |
| 2397 | |
| 2398 | if(unique != NULL && dbdb_size < sizeof(*dbdb)) |
| 2399 | { |
| 2400 | HDEBUG(D_acl) debug_printf("ratelimit discarding undersize Bloom filter\n"); |
| 2401 | dbdb = NULL; |
| 2402 | } |
| 2403 | } |
| 2404 | |
| 2405 | /* Allocate a new data block if the database lookup failed |
| 2406 | or the Bloom filter passed its age limit. */ |
| 2407 | |
| 2408 | if (dbdb == NULL) |
| 2409 | { |
| 2410 | if (unique == NULL) |
| 2411 | { |
| 2412 | /* No Bloom filter. This basic ratelimit block is initialized below. */ |
| 2413 | HDEBUG(D_acl) debug_printf("ratelimit creating new rate data block\n"); |
| 2414 | dbdb_size = sizeof(*dbd); |
| 2415 | dbdb = store_get(dbdb_size); |
| 2416 | } |
| 2417 | else |
| 2418 | { |
| 2419 | int extra; |
| 2420 | HDEBUG(D_acl) debug_printf("ratelimit creating new Bloom filter\n"); |
| 2421 | |
| 2422 | /* See the long comment below for an explanation of the magic number 2. |
| 2423 | The filter has a minimum size in case the rate limit is very small; |
| 2424 | this is determined by the definition of dbdata_ratelimit_unique. */ |
| 2425 | |
| 2426 | extra = (int)limit * 2 - sizeof(dbdb->bloom); |
| 2427 | if (extra < 0) extra = 0; |
| 2428 | dbdb_size = sizeof(*dbdb) + extra; |
| 2429 | dbdb = store_get(dbdb_size); |
| 2430 | dbdb->bloom_epoch = tv.tv_sec; |
| 2431 | dbdb->bloom_size = sizeof(dbdb->bloom) + extra; |
| 2432 | memset(dbdb->bloom, 0, dbdb->bloom_size); |
| 2433 | |
| 2434 | /* Preserve any basic ratelimit data (which is our longer-term memory) |
| 2435 | by copying it from the discarded block. */ |
| 2436 | |
| 2437 | if (dbd != NULL) |
| 2438 | { |
| 2439 | dbdb->dbd = *dbd; |
| 2440 | dbd = &dbdb->dbd; |
| 2441 | } |
| 2442 | } |
| 2443 | } |
| 2444 | |
| 2445 | /* If we are counting unique events, find out if this event is new or not. |
| 2446 | If the client repeats the event during the current period then it should be |
| 2447 | counted. We skip this code in readonly mode for efficiency, because any |
| 2448 | changes to the filter will be discarded and because count is already set to |
| 2449 | zero. */ |
| 2450 | |
| 2451 | if (unique != NULL && !readonly) |
| 2452 | { |
| 2453 | /* We identify unique events using a Bloom filter. (You can find my |
| 2454 | notes on Bloom filters at http://fanf.livejournal.com/81696.html) |
| 2455 | With the per_addr option, an "event" is a recipient address, though the |
| 2456 | user can use the unique option to define their own events. We only count |
| 2457 | an event if we have not seen it before. |
| 2458 | |
| 2459 | We size the filter according to the rate limit, which (in leaky mode) |
| 2460 | is the limit on the population of the filter. We allow 16 bits of space |
| 2461 | per entry (see the construction code above) and we set (up to) 8 of them |
| 2462 | when inserting an element (see the loop below). The probability of a false |
| 2463 | positive (an event we have not seen before but which we fail to count) is |
| 2464 | |
| 2465 | size = limit * 16 |
| 2466 | numhash = 8 |
| 2467 | allzero = exp(-numhash * pop / size) |
| 2468 | = exp(-0.5 * pop / limit) |
| 2469 | fpr = pow(1 - allzero, numhash) |
| 2470 | |
| 2471 | For senders at the limit the fpr is 0.06% or 1 in 1700 |
| 2472 | and for senders at half the limit it is 0.0006% or 1 in 170000 |
| 2473 | |
| 2474 | In strict mode the Bloom filter can fill up beyond the normal limit, in |
| 2475 | which case the false positive rate will rise. This means that the |
| 2476 | measured rate for very fast senders can bogusly drop off after a while. |
| 2477 | |
| 2478 | At twice the limit, the fpr is 2.5% or 1 in 40 |
| 2479 | At four times the limit, it is 31% or 1 in 3.2 |
| 2480 | |
| 2481 | It takes ln(pop/limit) periods for an over-limit burst of pop events to |
| 2482 | decay below the limit, and if this is more than one then the Bloom filter |
| 2483 | will be discarded before the decay gets that far. The false positive rate |
| 2484 | at this threshold is 9.3% or 1 in 10.7. */ |
| 2485 | |
| 2486 | BOOL seen; |
| 2487 | unsigned n, hash, hinc; |
| 2488 | uschar md5sum[16]; |
| 2489 | md5 md5info; |
| 2490 | |
| 2491 | /* Instead of using eight independent hash values, we combine two values |
| 2492 | using the formula h1 + n * h2. This does not harm the Bloom filter's |
| 2493 | performance, and means the amount of hash we need is independent of the |
| 2494 | number of bits we set in the filter. */ |
| 2495 | |
| 2496 | md5_start(&md5info); |
| 2497 | md5_end(&md5info, unique, Ustrlen(unique), md5sum); |
| 2498 | hash = md5sum[0] | md5sum[1] << 8 | md5sum[2] << 16 | md5sum[3] << 24; |
| 2499 | hinc = md5sum[4] | md5sum[5] << 8 | md5sum[6] << 16 | md5sum[7] << 24; |
| 2500 | |
| 2501 | /* Scan the bits corresponding to this event. A zero bit means we have |
| 2502 | not seen it before. Ensure all bits are set to record this event. */ |
| 2503 | |
| 2504 | HDEBUG(D_acl) debug_printf("ratelimit checking uniqueness of %s\n", unique); |
| 2505 | |
| 2506 | seen = TRUE; |
| 2507 | for (n = 0; n < 8; n++, hash += hinc) |
| 2508 | { |
| 2509 | int bit = 1 << (hash % 8); |
| 2510 | int byte = (hash / 8) % dbdb->bloom_size; |
| 2511 | if ((dbdb->bloom[byte] & bit) == 0) |
| 2512 | { |
| 2513 | dbdb->bloom[byte] |= bit; |
| 2514 | seen = FALSE; |
| 2515 | } |
| 2516 | } |
| 2517 | |
| 2518 | /* If this event has occurred before, do not count it. */ |
| 2519 | |
| 2520 | if (seen) |
| 2521 | { |
| 2522 | HDEBUG(D_acl) debug_printf("ratelimit event found in Bloom filter\n"); |
| 2523 | count = 0.0; |
| 2524 | } |
| 2525 | else |
| 2526 | HDEBUG(D_acl) debug_printf("ratelimit event added to Bloom filter\n"); |
| 2527 | } |
| 2528 | |
| 2529 | /* If there was no previous ratelimit data block for this key, initialize |
| 2530 | the new one, otherwise update the block from the database. The initial rate |
| 2531 | is what would be computed by the code below for an infinite interval. */ |
| 2532 | |
| 2533 | if (dbd == NULL) |
| 2534 | { |
| 2535 | HDEBUG(D_acl) debug_printf("ratelimit initializing new key's rate data\n"); |
| 2536 | dbd = &dbdb->dbd; |
| 2537 | dbd->time_stamp = tv.tv_sec; |
| 2538 | dbd->time_usec = tv.tv_usec; |
| 2539 | dbd->rate = count; |
| 2540 | } |
| 2541 | else |
| 2542 | { |
| 2543 | /* The smoothed rate is computed using an exponentially weighted moving |
| 2544 | average adjusted for variable sampling intervals. The standard EWMA for |
| 2545 | a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1) |
| 2546 | where f() is the measured value and f'() is the smoothed value. |
| 2547 | |
| 2548 | Old data decays out of the smoothed value exponentially, such that data n |
| 2549 | samples old is multiplied by a^n. The exponential decay time constant p |
| 2550 | is defined such that data p samples old is multiplied by 1/e, which means |
| 2551 | that a = exp(-1/p). We can maintain the same time constant for a variable |
| 2552 | sampling interval i by using a = exp(-i/p). |
| 2553 | |
| 2554 | The rate we are measuring is messages per period, suitable for directly |
| 2555 | comparing with the limit. The average rate between now and the previous |
| 2556 | message is period / interval, which we feed into the EWMA as the sample. |
| 2557 | |
| 2558 | It turns out that the number of messages required for the smoothed rate |
| 2559 | to reach the limit when they are sent in a burst is equal to the limit. |
| 2560 | This can be seen by analysing the value of the smoothed rate after N |
| 2561 | messages sent at even intervals. Let k = (1 - a) * p/i |
| 2562 | |
| 2563 | rate_1 = (1 - a) * p/i + a * rate_0 |
| 2564 | = k + a * rate_0 |
| 2565 | rate_2 = k + a * rate_1 |
| 2566 | = k + a * k + a^2 * rate_0 |
| 2567 | rate_3 = k + a * k + a^2 * k + a^3 * rate_0 |
| 2568 | rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x) |
| 2569 | = rate_0 * a^N + k * (1 - a^N) / (1 - a) |
| 2570 | = rate_0 * a^N + p/i * (1 - a^N) |
| 2571 | |
| 2572 | When N is large, a^N -> 0 so rate_N -> p/i as desired. |
| 2573 | |
| 2574 | rate_N = p/i + (rate_0 - p/i) * a^N |
| 2575 | a^N = (rate_N - p/i) / (rate_0 - p/i) |
| 2576 | N * -i/p = log((rate_N - p/i) / (rate_0 - p/i)) |
| 2577 | N = p/i * log((rate_0 - p/i) / (rate_N - p/i)) |
| 2578 | |
| 2579 | Numerical analysis of the above equation, setting the computed rate to |
| 2580 | increase from rate_0 = 0 to rate_N = limit, shows that for large sending |
| 2581 | rates, p/i, the number of messages N = limit. So limit serves as both the |
| 2582 | maximum rate measured in messages per period, and the maximum number of |
| 2583 | messages that can be sent in a fast burst. */ |
| 2584 | |
| 2585 | double this_time = (double)tv.tv_sec |
| 2586 | + (double)tv.tv_usec / 1000000.0; |
| 2587 | double prev_time = (double)dbd->time_stamp |
| 2588 | + (double)dbd->time_usec / 1000000.0; |
| 2589 | |
| 2590 | /* We must avoid division by zero, and deal gracefully with the clock going |
| 2591 | backwards. If we blunder ahead when time is in reverse then the computed |
| 2592 | rate will be bogus. To be safe we clamp interval to a very small number. */ |
| 2593 | |
| 2594 | double interval = this_time - prev_time <= 0.0 ? 1e-9 |
| 2595 | : this_time - prev_time; |
| 2596 | |
| 2597 | double i_over_p = interval / period; |
| 2598 | double a = exp(-i_over_p); |
| 2599 | |
| 2600 | /* Combine the instantaneous rate (period / interval) with the previous rate |
| 2601 | using the smoothing factor a. In order to measure sized events, multiply the |
| 2602 | instantaneous rate by the count of bytes or recipients etc. */ |
| 2603 | |
| 2604 | dbd->time_stamp = tv.tv_sec; |
| 2605 | dbd->time_usec = tv.tv_usec; |
| 2606 | dbd->rate = (1 - a) * count / i_over_p + a * dbd->rate; |
| 2607 | |
| 2608 | /* When events are very widely spaced the computed rate tends towards zero. |
| 2609 | Although this is accurate it turns out not to be useful for our purposes, |
| 2610 | especially when the first event after a long silence is the start of a spam |
| 2611 | run. A more useful model is that the rate for an isolated event should be the |
| 2612 | size of the event per the period size, ignoring the lack of events outside |
| 2613 | the current period and regardless of where the event falls in the period. So, |
| 2614 | if the interval was so long that the calculated rate is unhelpfully small, we |
| 2615 | re-intialize the rate. In the absence of higher-rate bursts, the condition |
| 2616 | below is true if the interval is greater than the period. */ |
| 2617 | |
| 2618 | if (dbd->rate < count) dbd->rate = count; |
| 2619 | } |
| 2620 | |
| 2621 | /* Clients sending at the limit are considered to be over the limit. |
| 2622 | This matters for edge cases such as a limit of zero, when the client |
| 2623 | should be completely blocked. */ |
| 2624 | |
| 2625 | rc = (dbd->rate < limit)? FAIL : OK; |
| 2626 | |
| 2627 | /* Update the state if the rate is low or if we are being strict. If we |
| 2628 | are in leaky mode and the sender's rate is too high, we do not update |
| 2629 | the recorded rate in order to avoid an over-aggressive sender's retry |
| 2630 | rate preventing them from getting any email through. If readonly is set, |
| 2631 | neither leaky nor strict are set, so we do not do any updates. */ |
| 2632 | |
| 2633 | if ((rc == FAIL && leaky) || strict) |
| 2634 | { |
| 2635 | dbfn_write(dbm, key, dbdb, dbdb_size); |
| 2636 | HDEBUG(D_acl) debug_printf("ratelimit db updated\n"); |
| 2637 | } |
| 2638 | else |
| 2639 | { |
| 2640 | HDEBUG(D_acl) debug_printf("ratelimit db not updated: %s\n", |
| 2641 | readonly? "readonly mode" : "over the limit, but leaky"); |
| 2642 | } |
| 2643 | |
| 2644 | dbfn_close(dbm); |
| 2645 | |
| 2646 | /* Store the result in the tree for future reference. */ |
| 2647 | |
| 2648 | t = store_get(sizeof(tree_node) + Ustrlen(key)); |
| 2649 | t->data.ptr = dbd; |
| 2650 | Ustrcpy(t->name, key); |
| 2651 | (void)tree_insertnode(anchor, t); |
| 2652 | |
| 2653 | /* We create the formatted version of the sender's rate very late in |
| 2654 | order to ensure that it is done using the correct storage pool. */ |
| 2655 | |
| 2656 | store_pool = old_pool; |
| 2657 | sender_rate = string_sprintf("%.1f", dbd->rate); |
| 2658 | |
| 2659 | HDEBUG(D_acl) |
| 2660 | debug_printf("ratelimit computed rate %s\n", sender_rate); |
| 2661 | |
| 2662 | return rc; |
| 2663 | } |
| 2664 | |
| 2665 | |
| 2666 | |
| 2667 | /************************************************* |
| 2668 | * Handle conditions/modifiers on an ACL item * |
| 2669 | *************************************************/ |
| 2670 | |
| 2671 | /* Called from acl_check() below. |
| 2672 | |
| 2673 | Arguments: |
| 2674 | verb ACL verb |
| 2675 | cb ACL condition block - if NULL, result is OK |
| 2676 | where where called from |
| 2677 | addr the address being checked for RCPT, or NULL |
| 2678 | level the nesting level |
| 2679 | epp pointer to pass back TRUE if "endpass" encountered |
| 2680 | (applies only to "accept" and "discard") |
| 2681 | user_msgptr user message pointer |
| 2682 | log_msgptr log message pointer |
| 2683 | basic_errno pointer to where to put verify error |
| 2684 | |
| 2685 | Returns: OK - all conditions are met |
| 2686 | DISCARD - an "acl" condition returned DISCARD - only allowed |
| 2687 | for "accept" or "discard" verbs |
| 2688 | FAIL - at least one condition fails |
| 2689 | FAIL_DROP - an "acl" condition returned FAIL_DROP |
| 2690 | DEFER - can't tell at the moment (typically, lookup defer, |
| 2691 | but can be temporary callout problem) |
| 2692 | ERROR - ERROR from nested ACL or expansion failure or other |
| 2693 | error |
| 2694 | */ |
| 2695 | |
| 2696 | static int |
| 2697 | acl_check_condition(int verb, acl_condition_block *cb, int where, |
| 2698 | address_item *addr, int level, BOOL *epp, uschar **user_msgptr, |
| 2699 | uschar **log_msgptr, int *basic_errno) |
| 2700 | { |
| 2701 | uschar *user_message = NULL; |
| 2702 | uschar *log_message = NULL; |
| 2703 | uschar *debug_tag = NULL; |
| 2704 | uschar *debug_opts = NULL; |
| 2705 | uschar *p = NULL; |
| 2706 | int rc = OK; |
| 2707 | #ifdef WITH_CONTENT_SCAN |
| 2708 | int sep = '/'; |
| 2709 | #endif |
| 2710 | |
| 2711 | for (; cb != NULL; cb = cb->next) |
| 2712 | { |
| 2713 | uschar *arg; |
| 2714 | int control_type; |
| 2715 | |
| 2716 | /* The message and log_message items set up messages to be used in |
| 2717 | case of rejection. They are expanded later. */ |
| 2718 | |
| 2719 | if (cb->type == ACLC_MESSAGE) |
| 2720 | { |
| 2721 | user_message = cb->arg; |
| 2722 | continue; |
| 2723 | } |
| 2724 | |
| 2725 | if (cb->type == ACLC_LOG_MESSAGE) |
| 2726 | { |
| 2727 | log_message = cb->arg; |
| 2728 | continue; |
| 2729 | } |
| 2730 | |
| 2731 | /* The endpass "condition" just sets a flag to show it occurred. This is |
| 2732 | checked at compile time to be on an "accept" or "discard" item. */ |
| 2733 | |
| 2734 | if (cb->type == ACLC_ENDPASS) |
| 2735 | { |
| 2736 | *epp = TRUE; |
| 2737 | continue; |
| 2738 | } |
| 2739 | |
| 2740 | /* For other conditions and modifiers, the argument is expanded now for some |
| 2741 | of them, but not for all, because expansion happens down in some lower level |
| 2742 | checking functions in some cases. */ |
| 2743 | |
| 2744 | if (cond_expand_at_top[cb->type]) |
| 2745 | { |
| 2746 | arg = expand_string(cb->arg); |
| 2747 | if (arg == NULL) |
| 2748 | { |
| 2749 | if (expand_string_forcedfail) continue; |
| 2750 | *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", |
| 2751 | cb->arg, expand_string_message); |
| 2752 | return search_find_defer? DEFER : ERROR; |
| 2753 | } |
| 2754 | } |
| 2755 | else arg = cb->arg; |
| 2756 | |
| 2757 | /* Show condition, and expanded condition if it's different */ |
| 2758 | |
| 2759 | HDEBUG(D_acl) |
| 2760 | { |
| 2761 | int lhswidth = 0; |
| 2762 | debug_printf("check %s%s %n", |
| 2763 | (!cond_modifiers[cb->type] && cb->u.negated)? "!":"", |
| 2764 | conditions[cb->type], &lhswidth); |
| 2765 | |
| 2766 | if (cb->type == ACLC_SET) |
| 2767 | { |
| 2768 | debug_printf("acl_%s ", cb->u.varname); |
| 2769 | lhswidth += 5 + Ustrlen(cb->u.varname); |
| 2770 | } |
| 2771 | |
| 2772 | debug_printf("= %s\n", cb->arg); |
| 2773 | |
| 2774 | if (arg != cb->arg) |
| 2775 | debug_printf("%.*s= %s\n", lhswidth, |
| 2776 | US" ", CS arg); |
| 2777 | } |
| 2778 | |
| 2779 | /* Check that this condition makes sense at this time */ |
| 2780 | |
| 2781 | if ((cond_forbids[cb->type] & (1 << where)) != 0) |
| 2782 | { |
| 2783 | *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL", |
| 2784 | cond_modifiers[cb->type]? "use" : "test", |
| 2785 | conditions[cb->type], acl_wherenames[where]); |
| 2786 | return ERROR; |
| 2787 | } |
| 2788 | |
| 2789 | /* Run the appropriate test for each condition, or take the appropriate |
| 2790 | action for the remaining modifiers. */ |
| 2791 | |
| 2792 | switch(cb->type) |
| 2793 | { |
| 2794 | case ACLC_ADD_HEADER: |
| 2795 | setup_header(arg); |
| 2796 | break; |
| 2797 | |
| 2798 | /* A nested ACL that returns "discard" makes sense only for an "accept" or |
| 2799 | "discard" verb. */ |
| 2800 | |
| 2801 | case ACLC_ACL: |
| 2802 | rc = acl_check_internal(where, addr, arg, level+1, user_msgptr, log_msgptr); |
| 2803 | if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD) |
| 2804 | { |
| 2805 | *log_msgptr = string_sprintf("nested ACL returned \"discard\" for " |
| 2806 | "\"%s\" command (only allowed with \"accept\" or \"discard\")", |
| 2807 | verbs[verb]); |
| 2808 | return ERROR; |
| 2809 | } |
| 2810 | break; |
| 2811 | |
| 2812 | case ACLC_AUTHENTICATED: |
| 2813 | rc = (sender_host_authenticated == NULL)? FAIL : |
| 2814 | match_isinlist(sender_host_authenticated, &arg, 0, NULL, NULL, MCL_STRING, |
| 2815 | TRUE, NULL); |
| 2816 | break; |
| 2817 | |
| 2818 | #ifdef EXPERIMENTAL_BRIGHTMAIL |
| 2819 | case ACLC_BMI_OPTIN: |
| 2820 | { |
| 2821 | int old_pool = store_pool; |
| 2822 | store_pool = POOL_PERM; |
| 2823 | bmi_current_optin = string_copy(arg); |
| 2824 | store_pool = old_pool; |
| 2825 | } |
| 2826 | break; |
| 2827 | #endif |
| 2828 | |
| 2829 | case ACLC_CONDITION: |
| 2830 | /* The true/false parsing here should be kept in sync with that used in |
| 2831 | expand.c when dealing with ECOND_BOOL so that we don't have too many |
| 2832 | different definitions of what can be a boolean. */ |
| 2833 | if (Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */ |
| 2834 | rc = (Uatoi(arg) == 0)? FAIL : OK; |
| 2835 | else |
| 2836 | rc = (strcmpic(arg, US"no") == 0 || |
| 2837 | strcmpic(arg, US"false") == 0)? FAIL : |
| 2838 | (strcmpic(arg, US"yes") == 0 || |
| 2839 | strcmpic(arg, US"true") == 0)? OK : DEFER; |
| 2840 | if (rc == DEFER) |
| 2841 | *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg); |
| 2842 | break; |
| 2843 | |
| 2844 | case ACLC_CONTINUE: /* Always succeeds */ |
| 2845 | break; |
| 2846 | |
| 2847 | case ACLC_CONTROL: |
| 2848 | control_type = decode_control(arg, &p, where, log_msgptr); |
| 2849 | |
| 2850 | /* Check if this control makes sense at this time */ |
| 2851 | |
| 2852 | if ((control_forbids[control_type] & (1 << where)) != 0) |
| 2853 | { |
| 2854 | *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL", |
| 2855 | controls[control_type], acl_wherenames[where]); |
| 2856 | return ERROR; |
| 2857 | } |
| 2858 | |
| 2859 | switch(control_type) |
| 2860 | { |
| 2861 | case CONTROL_AUTH_UNADVERTISED: |
| 2862 | allow_auth_unadvertised = TRUE; |
| 2863 | break; |
| 2864 | |
| 2865 | #ifdef EXPERIMENTAL_BRIGHTMAIL |
| 2866 | case CONTROL_BMI_RUN: |
| 2867 | bmi_run = 1; |
| 2868 | break; |
| 2869 | #endif |
| 2870 | |
| 2871 | #ifndef DISABLE_DKIM |
| 2872 | case CONTROL_DKIM_VERIFY: |
| 2873 | dkim_disable_verify = TRUE; |
| 2874 | break; |
| 2875 | #endif |
| 2876 | |
| 2877 | case CONTROL_ERROR: |
| 2878 | return ERROR; |
| 2879 | |
| 2880 | case CONTROL_CASEFUL_LOCAL_PART: |
| 2881 | deliver_localpart = addr->cc_local_part; |
| 2882 | break; |
| 2883 | |
| 2884 | case CONTROL_CASELOWER_LOCAL_PART: |
| 2885 | deliver_localpart = addr->lc_local_part; |
| 2886 | break; |
| 2887 | |
| 2888 | case CONTROL_ENFORCE_SYNC: |
| 2889 | smtp_enforce_sync = TRUE; |
| 2890 | break; |
| 2891 | |
| 2892 | case CONTROL_NO_ENFORCE_SYNC: |
| 2893 | smtp_enforce_sync = FALSE; |
| 2894 | break; |
| 2895 | |
| 2896 | #ifdef WITH_CONTENT_SCAN |
| 2897 | case CONTROL_NO_MBOX_UNSPOOL: |
| 2898 | no_mbox_unspool = TRUE; |
| 2899 | break; |
| 2900 | #endif |
| 2901 | |
| 2902 | case CONTROL_NO_MULTILINE: |
| 2903 | no_multiline_responses = TRUE; |
| 2904 | break; |
| 2905 | |
| 2906 | case CONTROL_NO_PIPELINING: |
| 2907 | pipelining_enable = FALSE; |
| 2908 | break; |
| 2909 | |
| 2910 | case CONTROL_NO_DELAY_FLUSH: |
| 2911 | disable_delay_flush = TRUE; |
| 2912 | break; |
| 2913 | |
| 2914 | case CONTROL_NO_CALLOUT_FLUSH: |
| 2915 | disable_callout_flush = TRUE; |
| 2916 | break; |
| 2917 | |
| 2918 | case CONTROL_FAKEDEFER: |
| 2919 | case CONTROL_FAKEREJECT: |
| 2920 | fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL; |
| 2921 | if (*p == '/') |
| 2922 | { |
| 2923 | uschar *pp = p + 1; |
| 2924 | while (*pp != 0) pp++; |
| 2925 | fake_response_text = expand_string(string_copyn(p+1, pp-p-1)); |
| 2926 | p = pp; |
| 2927 | } |
| 2928 | else |
| 2929 | { |
| 2930 | /* Explicitly reset to default string */ |
| 2931 | fake_response_text = US"Your message has been rejected but is being kept for evaluation.\nIf it was a legitimate message, it may still be delivered to the target recipient(s)."; |
| 2932 | } |
| 2933 | break; |
| 2934 | |
| 2935 | case CONTROL_FREEZE: |
| 2936 | deliver_freeze = TRUE; |
| 2937 | deliver_frozen_at = time(NULL); |
| 2938 | freeze_tell = freeze_tell_config; /* Reset to configured value */ |
| 2939 | if (Ustrncmp(p, "/no_tell", 8) == 0) |
| 2940 | { |
| 2941 | p += 8; |
| 2942 | freeze_tell = NULL; |
| 2943 | } |
| 2944 | if (*p != 0) |
| 2945 | { |
| 2946 | *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg); |
| 2947 | return ERROR; |
| 2948 | } |
| 2949 | break; |
| 2950 | |
| 2951 | case CONTROL_QUEUE_ONLY: |
| 2952 | queue_only_policy = TRUE; |
| 2953 | break; |
| 2954 | |
| 2955 | case CONTROL_SUBMISSION: |
| 2956 | originator_name = US""; |
| 2957 | submission_mode = TRUE; |
| 2958 | while (*p == '/') |
| 2959 | { |
| 2960 | if (Ustrncmp(p, "/sender_retain", 14) == 0) |
| 2961 | { |
| 2962 | p += 14; |
| 2963 | active_local_sender_retain = TRUE; |
| 2964 | active_local_from_check = FALSE; |
| 2965 | } |
| 2966 | else if (Ustrncmp(p, "/domain=", 8) == 0) |
| 2967 | { |
| 2968 | uschar *pp = p + 8; |
| 2969 | while (*pp != 0 && *pp != '/') pp++; |
| 2970 | submission_domain = string_copyn(p+8, pp-p-8); |
| 2971 | p = pp; |
| 2972 | } |
| 2973 | /* The name= option must be last, because it swallows the rest of |
| 2974 | the string. */ |
| 2975 | else if (Ustrncmp(p, "/name=", 6) == 0) |
| 2976 | { |
| 2977 | uschar *pp = p + 6; |
| 2978 | while (*pp != 0) pp++; |
| 2979 | submission_name = string_copy(parse_fix_phrase(p+6, pp-p-6, |
| 2980 | big_buffer, big_buffer_size)); |
| 2981 | p = pp; |
| 2982 | } |
| 2983 | else break; |
| 2984 | } |
| 2985 | if (*p != 0) |
| 2986 | { |
| 2987 | *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg); |
| 2988 | return ERROR; |
| 2989 | } |
| 2990 | break; |
| 2991 | |
| 2992 | case CONTROL_DEBUG: |
| 2993 | while (*p == '/') |
| 2994 | { |
| 2995 | if (Ustrncmp(p, "/tag=", 5) == 0) |
| 2996 | { |
| 2997 | uschar *pp = p + 5; |
| 2998 | while (*pp != '\0' && *pp != '/') pp++; |
| 2999 | debug_tag = string_copyn(p+5, pp-p-5); |
| 3000 | p = pp; |
| 3001 | } |
| 3002 | else if (Ustrncmp(p, "/opts=", 6) == 0) |
| 3003 | { |
| 3004 | uschar *pp = p + 6; |
| 3005 | while (*pp != '\0' && *pp != '/') pp++; |
| 3006 | debug_opts = string_copyn(p+6, pp-p-6); |
| 3007 | p = pp; |
| 3008 | } |
| 3009 | } |
| 3010 | debug_logging_activate(debug_tag, debug_opts); |
| 3011 | break; |
| 3012 | |
| 3013 | case CONTROL_SUPPRESS_LOCAL_FIXUPS: |
| 3014 | suppress_local_fixups = TRUE; |
| 3015 | break; |
| 3016 | } |
| 3017 | break; |
| 3018 | |
| 3019 | #ifdef EXPERIMENTAL_DCC |
| 3020 | case ACLC_DCC: |
| 3021 | { |
| 3022 | /* Seperate the regular expression and any optional parameters. */ |
| 3023 | uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size); |
| 3024 | /* Run the dcc backend. */ |
| 3025 | rc = dcc_process(&ss); |
| 3026 | /* Modify return code based upon the existance of options. */ |
| 3027 | while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size)) |
| 3028 | != NULL) { |
| 3029 | if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER) |
| 3030 | { |
| 3031 | /* FAIL so that the message is passed to the next ACL */ |
| 3032 | rc = FAIL; |
| 3033 | } |
| 3034 | } |
| 3035 | } |
| 3036 | break; |
| 3037 | #endif |
| 3038 | |
| 3039 | #ifdef WITH_CONTENT_SCAN |
| 3040 | case ACLC_DECODE: |
| 3041 | rc = mime_decode(&arg); |
| 3042 | break; |
| 3043 | #endif |
| 3044 | |
| 3045 | case ACLC_DELAY: |
| 3046 | { |
| 3047 | int delay = readconf_readtime(arg, 0, FALSE); |
| 3048 | if (delay < 0) |
| 3049 | { |
| 3050 | *log_msgptr = string_sprintf("syntax error in argument for \"delay\" " |
| 3051 | "modifier: \"%s\" is not a time value", arg); |
| 3052 | return ERROR; |
| 3053 | } |
| 3054 | else |
| 3055 | { |
| 3056 | HDEBUG(D_acl) debug_printf("delay modifier requests %d-second delay\n", |
| 3057 | delay); |
| 3058 | if (host_checking) |
| 3059 | { |
| 3060 | HDEBUG(D_acl) |
| 3061 | debug_printf("delay skipped in -bh checking mode\n"); |
| 3062 | } |
| 3063 | |
| 3064 | /* It appears to be impossible to detect that a TCP/IP connection has |
| 3065 | gone away without reading from it. This means that we cannot shorten |
| 3066 | the delay below if the client goes away, because we cannot discover |
| 3067 | that the client has closed its end of the connection. (The connection |
| 3068 | is actually in a half-closed state, waiting for the server to close its |
| 3069 | end.) It would be nice to be able to detect this state, so that the |
| 3070 | Exim process is not held up unnecessarily. However, it seems that we |
| 3071 | can't. The poll() function does not do the right thing, and in any case |
| 3072 | it is not always available. |
| 3073 | |
| 3074 | NOTE 1: If ever this state of affairs changes, remember that we may be |
| 3075 | dealing with stdin/stdout here, in addition to TCP/IP connections. |
| 3076 | Also, delays may be specified for non-SMTP input, where smtp_out and |
| 3077 | smtp_in will be NULL. Whatever is done must work in all cases. |
| 3078 | |
| 3079 | NOTE 2: The added feature of flushing the output before a delay must |
| 3080 | apply only to SMTP input. Hence the test for smtp_out being non-NULL. |
| 3081 | */ |
| 3082 | |
| 3083 | else |
| 3084 | { |
| 3085 | if (smtp_out != NULL && !disable_delay_flush) mac_smtp_fflush(); |
| 3086 | while (delay > 0) delay = sleep(delay); |
| 3087 | } |
| 3088 | } |
| 3089 | } |
| 3090 | break; |
| 3091 | |
| 3092 | #ifdef WITH_OLD_DEMIME |
| 3093 | case ACLC_DEMIME: |
| 3094 | rc = demime(&arg); |
| 3095 | break; |
| 3096 | #endif |
| 3097 | |
| 3098 | #ifndef DISABLE_DKIM |
| 3099 | case ACLC_DKIM_SIGNER: |
| 3100 | if (dkim_cur_signer != NULL) |
| 3101 | rc = match_isinlist(dkim_cur_signer, |
| 3102 | &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL); |
| 3103 | else |
| 3104 | rc = FAIL; |
| 3105 | break; |
| 3106 | |
| 3107 | case ACLC_DKIM_STATUS: |
| 3108 | rc = match_isinlist(dkim_exim_expand_query(DKIM_VERIFY_STATUS), |
| 3109 | &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL); |
| 3110 | break; |
| 3111 | #endif |
| 3112 | |
| 3113 | case ACLC_DNSLISTS: |
| 3114 | rc = verify_check_dnsbl(&arg); |
| 3115 | break; |
| 3116 | |
| 3117 | case ACLC_DOMAINS: |
| 3118 | rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor, |
| 3119 | addr->domain_cache, MCL_DOMAIN, TRUE, &deliver_domain_data); |
| 3120 | break; |
| 3121 | |
| 3122 | /* The value in tls_cipher is the full cipher name, for example, |
| 3123 | TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the |
| 3124 | cipher names such as DES-CBC3-SHA. But program defensively. We don't know |
| 3125 | what may in practice come out of the SSL library - which at the time of |
| 3126 | writing is poorly documented. */ |
| 3127 | |
| 3128 | case ACLC_ENCRYPTED: |
| 3129 | if (tls_cipher == NULL) rc = FAIL; else |
| 3130 | { |
| 3131 | uschar *endcipher = NULL; |
| 3132 | uschar *cipher = Ustrchr(tls_cipher, ':'); |
| 3133 | if (cipher == NULL) cipher = tls_cipher; else |
| 3134 | { |
| 3135 | endcipher = Ustrchr(++cipher, ':'); |
| 3136 | if (endcipher != NULL) *endcipher = 0; |
| 3137 | } |
| 3138 | rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL); |
| 3139 | if (endcipher != NULL) *endcipher = ':'; |
| 3140 | } |
| 3141 | break; |
| 3142 | |
| 3143 | /* Use verify_check_this_host() instead of verify_check_host() so that |
| 3144 | we can pass over &host_data to catch any looked up data. Once it has been |
| 3145 | set, it retains its value so that it's still there if another ACL verb |
| 3146 | comes through here and uses the cache. However, we must put it into |
| 3147 | permanent store in case it is also expected to be used in a subsequent |
| 3148 | message in the same SMTP connection. */ |
| 3149 | |
| 3150 | case ACLC_HOSTS: |
| 3151 | rc = verify_check_this_host(&arg, sender_host_cache, NULL, |
| 3152 | (sender_host_address == NULL)? US"" : sender_host_address, &host_data); |
| 3153 | if (host_data != NULL) host_data = string_copy_malloc(host_data); |
| 3154 | break; |
| 3155 | |
| 3156 | case ACLC_LOCAL_PARTS: |
| 3157 | rc = match_isinlist(addr->cc_local_part, &arg, 0, |
| 3158 | &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE, |
| 3159 | &deliver_localpart_data); |
| 3160 | break; |
| 3161 | |
| 3162 | case ACLC_LOG_REJECT_TARGET: |
| 3163 | { |
| 3164 | int logbits = 0; |
| 3165 | int sep = 0; |
| 3166 | uschar *s = arg; |
| 3167 | uschar *ss; |
| 3168 | while ((ss = string_nextinlist(&s, &sep, big_buffer, big_buffer_size)) |
| 3169 | != NULL) |
| 3170 | { |
| 3171 | if (Ustrcmp(ss, "main") == 0) logbits |= LOG_MAIN; |
| 3172 | else if (Ustrcmp(ss, "panic") == 0) logbits |= LOG_PANIC; |
| 3173 | else if (Ustrcmp(ss, "reject") == 0) logbits |= LOG_REJECT; |
| 3174 | else |
| 3175 | { |
| 3176 | logbits |= LOG_MAIN|LOG_REJECT; |
| 3177 | log_write(0, LOG_MAIN|LOG_PANIC, "unknown log name \"%s\" in " |
| 3178 | "\"log_reject_target\" in %s ACL", ss, acl_wherenames[where]); |
| 3179 | } |
| 3180 | } |
| 3181 | log_reject_target = logbits; |
| 3182 | } |
| 3183 | break; |
| 3184 | |
| 3185 | case ACLC_LOGWRITE: |
| 3186 | { |
| 3187 | int logbits = 0; |
| 3188 | uschar *s = arg; |
| 3189 | if (*s == ':') |
| 3190 | { |
| 3191 | s++; |
| 3192 | while (*s != ':') |
| 3193 | { |
| 3194 | if (Ustrncmp(s, "main", 4) == 0) |
| 3195 | { logbits |= LOG_MAIN; s += 4; } |
| 3196 | else if (Ustrncmp(s, "panic", 5) == 0) |
| 3197 | { logbits |= LOG_PANIC; s += 5; } |
| 3198 | else if (Ustrncmp(s, "reject", 6) == 0) |
| 3199 | { logbits |= LOG_REJECT; s += 6; } |
| 3200 | else |
| 3201 | { |
| 3202 | logbits = LOG_MAIN|LOG_PANIC; |
| 3203 | s = string_sprintf(":unknown log name in \"%s\" in " |
| 3204 | "\"logwrite\" in %s ACL", arg, acl_wherenames[where]); |
| 3205 | } |
| 3206 | if (*s == ',') s++; |
| 3207 | } |
| 3208 | s++; |
| 3209 | } |
| 3210 | while (isspace(*s)) s++; |
| 3211 | |
| 3212 | |
| 3213 | if (logbits == 0) logbits = LOG_MAIN; |
| 3214 | log_write(0, logbits, "%s", string_printing(s)); |
| 3215 | } |
| 3216 | break; |
| 3217 | |
| 3218 | #ifdef WITH_CONTENT_SCAN |
| 3219 | case ACLC_MALWARE: |
| 3220 | { |
| 3221 | /* Separate the regular expression and any optional parameters. */ |
| 3222 | uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size); |
| 3223 | /* Run the malware backend. */ |
| 3224 | rc = malware(&ss); |
| 3225 | /* Modify return code based upon the existance of options. */ |
| 3226 | while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size)) |
| 3227 | != NULL) { |
| 3228 | if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER) |
| 3229 | { |
| 3230 | /* FAIL so that the message is passed to the next ACL */ |
| 3231 | rc = FAIL; |
| 3232 | } |
| 3233 | } |
| 3234 | } |
| 3235 | break; |
| 3236 | |
| 3237 | case ACLC_MIME_REGEX: |
| 3238 | rc = mime_regex(&arg); |
| 3239 | break; |
| 3240 | #endif |
| 3241 | |
| 3242 | case ACLC_RATELIMIT: |
| 3243 | rc = acl_ratelimit(arg, where, log_msgptr); |
| 3244 | break; |
| 3245 | |
| 3246 | case ACLC_RECIPIENTS: |
| 3247 | rc = match_address_list(addr->address, TRUE, TRUE, &arg, NULL, -1, 0, |
| 3248 | &recipient_data); |
| 3249 | break; |
| 3250 | |
| 3251 | #ifdef WITH_CONTENT_SCAN |
| 3252 | case ACLC_REGEX: |
| 3253 | rc = regex(&arg); |
| 3254 | break; |
| 3255 | #endif |
| 3256 | |
| 3257 | case ACLC_SENDER_DOMAINS: |
| 3258 | { |
| 3259 | uschar *sdomain; |
| 3260 | sdomain = Ustrrchr(sender_address, '@'); |
| 3261 | sdomain = (sdomain == NULL)? US"" : sdomain + 1; |
| 3262 | rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor, |
| 3263 | sender_domain_cache, MCL_DOMAIN, TRUE, NULL); |
| 3264 | } |
| 3265 | break; |
| 3266 | |
| 3267 | case ACLC_SENDERS: |
| 3268 | rc = match_address_list(sender_address, TRUE, TRUE, &arg, |
| 3269 | sender_address_cache, -1, 0, &sender_data); |
| 3270 | break; |
| 3271 | |
| 3272 | /* Connection variables must persist forever */ |
| 3273 | |
| 3274 | case ACLC_SET: |
| 3275 | { |
| 3276 | int old_pool = store_pool; |
| 3277 | if (cb->u.varname[0] == 'c') store_pool = POOL_PERM; |
| 3278 | acl_var_create(cb->u.varname)->data.ptr = string_copy(arg); |
| 3279 | store_pool = old_pool; |
| 3280 | } |
| 3281 | break; |
| 3282 | |
| 3283 | #ifdef WITH_CONTENT_SCAN |
| 3284 | case ACLC_SPAM: |
| 3285 | { |
| 3286 | /* Seperate the regular expression and any optional parameters. */ |
| 3287 | uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size); |
| 3288 | /* Run the spam backend. */ |
| 3289 | rc = spam(&ss); |
| 3290 | /* Modify return code based upon the existance of options. */ |
| 3291 | while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size)) |
| 3292 | != NULL) { |
| 3293 | if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER) |
| 3294 | { |
| 3295 | /* FAIL so that the message is passed to the next ACL */ |
| 3296 | rc = FAIL; |
| 3297 | } |
| 3298 | } |
| 3299 | } |
| 3300 | break; |
| 3301 | #endif |
| 3302 | |
| 3303 | #ifdef EXPERIMENTAL_SPF |
| 3304 | case ACLC_SPF: |
| 3305 | rc = spf_process(&arg, sender_address, SPF_PROCESS_NORMAL); |
| 3306 | break; |
| 3307 | case ACLC_SPF_GUESS: |
| 3308 | rc = spf_process(&arg, sender_address, SPF_PROCESS_GUESS); |
| 3309 | break; |
| 3310 | #endif |
| 3311 | |
| 3312 | /* If the verb is WARN, discard any user message from verification, because |
| 3313 | such messages are SMTP responses, not header additions. The latter come |
| 3314 | only from explicit "message" modifiers. However, put the user message into |
| 3315 | $acl_verify_message so it can be used in subsequent conditions or modifiers |
| 3316 | (until something changes it). */ |
| 3317 | |
| 3318 | case ACLC_VERIFY: |
| 3319 | rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno); |
| 3320 | acl_verify_message = *user_msgptr; |
| 3321 | if (verb == ACL_WARN) *user_msgptr = NULL; |
| 3322 | break; |
| 3323 | |
| 3324 | default: |
| 3325 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown " |
| 3326 | "condition %d", cb->type); |
| 3327 | break; |
| 3328 | } |
| 3329 | |
| 3330 | /* If a condition was negated, invert OK/FAIL. */ |
| 3331 | |
| 3332 | if (!cond_modifiers[cb->type] && cb->u.negated) |
| 3333 | { |
| 3334 | if (rc == OK) rc = FAIL; |
| 3335 | else if (rc == FAIL || rc == FAIL_DROP) rc = OK; |
| 3336 | } |
| 3337 | |
| 3338 | if (rc != OK) break; /* Conditions loop */ |
| 3339 | } |
| 3340 | |
| 3341 | |
| 3342 | /* If the result is the one for which "message" and/or "log_message" are used, |
| 3343 | handle the values of these modifiers. If there isn't a log message set, we make |
| 3344 | it the same as the user message. |
| 3345 | |
| 3346 | "message" is a user message that will be included in an SMTP response. Unless |
| 3347 | it is empty, it overrides any previously set user message. |
| 3348 | |
| 3349 | "log_message" is a non-user message, and it adds to any existing non-user |
| 3350 | message that is already set. |
| 3351 | |
| 3352 | Most verbs have but a single return for which the messages are relevant, but |
| 3353 | for "discard", it's useful to have the log message both when it succeeds and |
| 3354 | when it fails. For "accept", the message is used in the OK case if there is no |
| 3355 | "endpass", but (for backwards compatibility) in the FAIL case if "endpass" is |
| 3356 | present. */ |
| 3357 | |
| 3358 | if (*epp && rc == OK) user_message = NULL; |
| 3359 | |
| 3360 | if (((1<<rc) & msgcond[verb]) != 0) |
| 3361 | { |
| 3362 | uschar *expmessage; |
| 3363 | uschar *old_user_msgptr = *user_msgptr; |
| 3364 | uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr; |
| 3365 | |
| 3366 | /* If the verb is "warn", messages generated by conditions (verification or |
| 3367 | nested ACLs) are always discarded. This also happens for acceptance verbs |
| 3368 | when they actually do accept. Only messages specified at this level are used. |
| 3369 | However, the value of an existing message is available in $acl_verify_message |
| 3370 | during expansions. */ |
| 3371 | |
| 3372 | if (verb == ACL_WARN || |
| 3373 | (rc == OK && (verb == ACL_ACCEPT || verb == ACL_DISCARD))) |
| 3374 | *log_msgptr = *user_msgptr = NULL; |
| 3375 | |
| 3376 | if (user_message != NULL) |
| 3377 | { |
| 3378 | acl_verify_message = old_user_msgptr; |
| 3379 | expmessage = expand_string(user_message); |
| 3380 | if (expmessage == NULL) |
| 3381 | { |
| 3382 | if (!expand_string_forcedfail) |
| 3383 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s", |
| 3384 | user_message, expand_string_message); |
| 3385 | } |
| 3386 | else if (expmessage[0] != 0) *user_msgptr = expmessage; |
| 3387 | } |
| 3388 | |
| 3389 | if (log_message != NULL) |
| 3390 | { |
| 3391 | acl_verify_message = old_log_msgptr; |
| 3392 | expmessage = expand_string(log_message); |
| 3393 | if (expmessage == NULL) |
| 3394 | { |
| 3395 | if (!expand_string_forcedfail) |
| 3396 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s", |
| 3397 | log_message, expand_string_message); |
| 3398 | } |
| 3399 | else if (expmessage[0] != 0) |
| 3400 | { |
| 3401 | *log_msgptr = (*log_msgptr == NULL)? expmessage : |
| 3402 | string_sprintf("%s: %s", expmessage, *log_msgptr); |
| 3403 | } |
| 3404 | } |
| 3405 | |
| 3406 | /* If no log message, default it to the user message */ |
| 3407 | |
| 3408 | if (*log_msgptr == NULL) *log_msgptr = *user_msgptr; |
| 3409 | } |
| 3410 | |
| 3411 | acl_verify_message = NULL; |
| 3412 | return rc; |
| 3413 | } |
| 3414 | |
| 3415 | |
| 3416 | |
| 3417 | |
| 3418 | |
| 3419 | /************************************************* |
| 3420 | * Get line from a literal ACL * |
| 3421 | *************************************************/ |
| 3422 | |
| 3423 | /* This function is passed to acl_read() in order to extract individual lines |
| 3424 | of a literal ACL, which we access via static pointers. We can destroy the |
| 3425 | contents because this is called only once (the compiled ACL is remembered). |
| 3426 | |
| 3427 | This code is intended to treat the data in the same way as lines in the main |
| 3428 | Exim configuration file. That is: |
| 3429 | |
| 3430 | . Leading spaces are ignored. |
| 3431 | |
| 3432 | . A \ at the end of a line is a continuation - trailing spaces after the \ |
| 3433 | are permitted (this is because I don't believe in making invisible things |
| 3434 | significant). Leading spaces on the continued part of a line are ignored. |
| 3435 | |
| 3436 | . Physical lines starting (significantly) with # are totally ignored, and |
| 3437 | may appear within a sequence of backslash-continued lines. |
| 3438 | |
| 3439 | . Blank lines are ignored, but will end a sequence of continuations. |
| 3440 | |
| 3441 | Arguments: none |
| 3442 | Returns: a pointer to the next line |
| 3443 | */ |
| 3444 | |
| 3445 | |
| 3446 | static uschar *acl_text; /* Current pointer in the text */ |
| 3447 | static uschar *acl_text_end; /* Points one past the terminating '0' */ |
| 3448 | |
| 3449 | |
| 3450 | static uschar * |
| 3451 | acl_getline(void) |
| 3452 | { |
| 3453 | uschar *yield; |
| 3454 | |
| 3455 | /* This loop handles leading blank lines and comments. */ |
| 3456 | |
| 3457 | for(;;) |
| 3458 | { |
| 3459 | while (isspace(*acl_text)) acl_text++; /* Leading spaces/empty lines */ |
| 3460 | if (*acl_text == 0) return NULL; /* No more data */ |
| 3461 | yield = acl_text; /* Potential data line */ |
| 3462 | |
| 3463 | while (*acl_text != 0 && *acl_text != '\n') acl_text++; |
| 3464 | |
| 3465 | /* If we hit the end before a newline, we have the whole logical line. If |
| 3466 | it's a comment, there's no more data to be given. Otherwise, yield it. */ |
| 3467 | |
| 3468 | if (*acl_text == 0) return (*yield == '#')? NULL : yield; |
| 3469 | |
| 3470 | /* After reaching a newline, end this loop if the physical line does not |
| 3471 | start with '#'. If it does, it's a comment, and the loop continues. */ |
| 3472 | |
| 3473 | if (*yield != '#') break; |
| 3474 | } |
| 3475 | |
| 3476 | /* This loop handles continuations. We know we have some real data, ending in |
| 3477 | newline. See if there is a continuation marker at the end (ignoring trailing |
| 3478 | white space). We know that *yield is not white space, so no need to test for |
| 3479 | cont > yield in the backwards scanning loop. */ |
| 3480 | |
| 3481 | for(;;) |
| 3482 | { |
| 3483 | uschar *cont; |
| 3484 | for (cont = acl_text - 1; isspace(*cont); cont--); |
| 3485 | |
| 3486 | /* If no continuation follows, we are done. Mark the end of the line and |
| 3487 | return it. */ |
| 3488 | |
| 3489 | if (*cont != '\\') |
| 3490 | { |
| 3491 | *acl_text++ = 0; |
| 3492 | return yield; |
| 3493 | } |
| 3494 | |
| 3495 | /* We have encountered a continuation. Skip over whitespace at the start of |
| 3496 | the next line, and indeed the whole of the next line or lines if they are |
| 3497 | comment lines. */ |
| 3498 | |
| 3499 | for (;;) |
| 3500 | { |
| 3501 | while (*(++acl_text) == ' ' || *acl_text == '\t'); |
| 3502 | if (*acl_text != '#') break; |
| 3503 | while (*(++acl_text) != 0 && *acl_text != '\n'); |
| 3504 | } |
| 3505 | |
| 3506 | /* We have the start of a continuation line. Move all the rest of the data |
| 3507 | to join onto the previous line, and then find its end. If the end is not a |
| 3508 | newline, we are done. Otherwise loop to look for another continuation. */ |
| 3509 | |
| 3510 | memmove(cont, acl_text, acl_text_end - acl_text); |
| 3511 | acl_text_end -= acl_text - cont; |
| 3512 | acl_text = cont; |
| 3513 | while (*acl_text != 0 && *acl_text != '\n') acl_text++; |
| 3514 | if (*acl_text == 0) return yield; |
| 3515 | } |
| 3516 | |
| 3517 | /* Control does not reach here */ |
| 3518 | } |
| 3519 | |
| 3520 | |
| 3521 | |
| 3522 | |
| 3523 | |
| 3524 | /************************************************* |
| 3525 | * Check access using an ACL * |
| 3526 | *************************************************/ |
| 3527 | |
| 3528 | /* This function is called from address_check. It may recurse via |
| 3529 | acl_check_condition() - hence the use of a level to stop looping. The ACL is |
| 3530 | passed as a string which is expanded. A forced failure implies no access check |
| 3531 | is required. If the result is a single word, it is taken as the name of an ACL |
| 3532 | which is sought in the global ACL tree. Otherwise, it is taken as literal ACL |
| 3533 | text, complete with newlines, and parsed as such. In both cases, the ACL check |
| 3534 | is then run. This function uses an auxiliary function for acl_read() to call |
| 3535 | for reading individual lines of a literal ACL. This is acl_getline(), which |
| 3536 | appears immediately above. |
| 3537 | |
| 3538 | Arguments: |
| 3539 | where where called from |
| 3540 | addr address item when called from RCPT; otherwise NULL |
| 3541 | s the input string; NULL is the same as an empty ACL => DENY |
| 3542 | level the nesting level |
| 3543 | user_msgptr where to put a user error (for SMTP response) |
| 3544 | log_msgptr where to put a logging message (not for SMTP response) |
| 3545 | |
| 3546 | Returns: OK access is granted |
| 3547 | DISCARD access is apparently granted... |
| 3548 | FAIL access is denied |
| 3549 | FAIL_DROP access is denied; drop the connection |
| 3550 | DEFER can't tell at the moment |
| 3551 | ERROR disaster |
| 3552 | */ |
| 3553 | |
| 3554 | static int |
| 3555 | acl_check_internal(int where, address_item *addr, uschar *s, int level, |
| 3556 | uschar **user_msgptr, uschar **log_msgptr) |
| 3557 | { |
| 3558 | int fd = -1; |
| 3559 | acl_block *acl = NULL; |
| 3560 | uschar *acl_name = US"inline ACL"; |
| 3561 | uschar *ss; |
| 3562 | |
| 3563 | /* Catch configuration loops */ |
| 3564 | |
| 3565 | if (level > 20) |
| 3566 | { |
| 3567 | *log_msgptr = US"ACL nested too deep: possible loop"; |
| 3568 | return ERROR; |
| 3569 | } |
| 3570 | |
| 3571 | if (s == NULL) |
| 3572 | { |
| 3573 | HDEBUG(D_acl) debug_printf("ACL is NULL: implicit DENY\n"); |
| 3574 | return FAIL; |
| 3575 | } |
| 3576 | |
| 3577 | /* At top level, we expand the incoming string. At lower levels, it has already |
| 3578 | been expanded as part of condition processing. */ |
| 3579 | |
| 3580 | if (level == 0) |
| 3581 | { |
| 3582 | ss = expand_string(s); |
| 3583 | if (ss == NULL) |
| 3584 | { |
| 3585 | if (expand_string_forcedfail) return OK; |
| 3586 | *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s, |
| 3587 | expand_string_message); |
| 3588 | return ERROR; |
| 3589 | } |
| 3590 | } |
| 3591 | else ss = s; |
| 3592 | |
| 3593 | while (isspace(*ss))ss++; |
| 3594 | |
| 3595 | /* If we can't find a named ACL, the default is to parse it as an inline one. |
| 3596 | (Unless it begins with a slash; non-existent files give rise to an error.) */ |
| 3597 | |
| 3598 | acl_text = ss; |
| 3599 | |
| 3600 | /* Handle the case of a string that does not contain any spaces. Look for a |
| 3601 | named ACL among those read from the configuration, or a previously read file. |
| 3602 | It is possible that the pointer to the ACL is NULL if the configuration |
| 3603 | contains a name with no data. If not found, and the text begins with '/', |
| 3604 | read an ACL from a file, and save it so it can be re-used. */ |
| 3605 | |
| 3606 | if (Ustrchr(ss, ' ') == NULL) |
| 3607 | { |
| 3608 | tree_node *t = tree_search(acl_anchor, ss); |
| 3609 | if (t != NULL) |
| 3610 | { |
| 3611 | acl = (acl_block *)(t->data.ptr); |
| 3612 | if (acl == NULL) |
| 3613 | { |
| 3614 | HDEBUG(D_acl) debug_printf("ACL \"%s\" is empty: implicit DENY\n", ss); |
| 3615 | return FAIL; |
| 3616 | } |
| 3617 | acl_name = string_sprintf("ACL \"%s\"", ss); |
| 3618 | HDEBUG(D_acl) debug_printf("using ACL \"%s\"\n", ss); |
| 3619 | } |
| 3620 | |
| 3621 | else if (*ss == '/') |
| 3622 | { |
| 3623 | struct stat statbuf; |
| 3624 | fd = Uopen(ss, O_RDONLY, 0); |
| 3625 | if (fd < 0) |
| 3626 | { |
| 3627 | *log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss, |
| 3628 | strerror(errno)); |
| 3629 | return ERROR; |
| 3630 | } |
| 3631 | |
| 3632 | if (fstat(fd, &statbuf) != 0) |
| 3633 | { |
| 3634 | *log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss, |
| 3635 | strerror(errno)); |
| 3636 | return ERROR; |
| 3637 | } |
| 3638 | |
| 3639 | acl_text = store_get(statbuf.st_size + 1); |
| 3640 | acl_text_end = acl_text + statbuf.st_size + 1; |
| 3641 | |
| 3642 | if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size) |
| 3643 | { |
| 3644 | *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s", |
| 3645 | ss, strerror(errno)); |
| 3646 | return ERROR; |
| 3647 | } |
| 3648 | acl_text[statbuf.st_size] = 0; |
| 3649 | (void)close(fd); |
| 3650 | |
| 3651 | acl_name = string_sprintf("ACL \"%s\"", ss); |
| 3652 | HDEBUG(D_acl) debug_printf("read ACL from file %s\n", ss); |
| 3653 | } |
| 3654 | } |
| 3655 | |
| 3656 | /* Parse an ACL that is still in text form. If it came from a file, remember it |
| 3657 | in the ACL tree, having read it into the POOL_PERM store pool so that it |
| 3658 | persists between multiple messages. */ |
| 3659 | |
| 3660 | if (acl == NULL) |
| 3661 | { |
| 3662 | int old_pool = store_pool; |
| 3663 | if (fd >= 0) store_pool = POOL_PERM; |
| 3664 | acl = acl_read(acl_getline, log_msgptr); |
| 3665 | store_pool = old_pool; |
| 3666 | if (acl == NULL && *log_msgptr != NULL) return ERROR; |
| 3667 | if (fd >= 0) |
| 3668 | { |
| 3669 | tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss)); |
| 3670 | Ustrcpy(t->name, ss); |
| 3671 | t->data.ptr = acl; |
| 3672 | (void)tree_insertnode(&acl_anchor, t); |
| 3673 | } |
| 3674 | } |
| 3675 | |
| 3676 | /* Now we have an ACL to use. It's possible it may be NULL. */ |
| 3677 | |
| 3678 | while (acl != NULL) |
| 3679 | { |
| 3680 | int cond; |
| 3681 | int basic_errno = 0; |
| 3682 | BOOL endpass_seen = FALSE; |
| 3683 | |
| 3684 | *log_msgptr = *user_msgptr = NULL; |
| 3685 | acl_temp_details = FALSE; |
| 3686 | |
| 3687 | if ((where == ACL_WHERE_QUIT || where == ACL_WHERE_NOTQUIT) && |
| 3688 | acl->verb != ACL_ACCEPT && |
| 3689 | acl->verb != ACL_WARN) |
| 3690 | { |
| 3691 | *log_msgptr = string_sprintf("\"%s\" is not allowed in a QUIT or not-QUIT ACL", |
| 3692 | verbs[acl->verb]); |
| 3693 | return ERROR; |
| 3694 | } |
| 3695 | |
| 3696 | HDEBUG(D_acl) debug_printf("processing \"%s\"\n", verbs[acl->verb]); |
| 3697 | |
| 3698 | /* Clear out any search error message from a previous check before testing |
| 3699 | this condition. */ |
| 3700 | |
| 3701 | search_error_message = NULL; |
| 3702 | cond = acl_check_condition(acl->verb, acl->condition, where, addr, level, |
| 3703 | &endpass_seen, user_msgptr, log_msgptr, &basic_errno); |
| 3704 | |
| 3705 | /* Handle special returns: DEFER causes a return except on a WARN verb; |
| 3706 | ERROR always causes a return. */ |
| 3707 | |
| 3708 | switch (cond) |
| 3709 | { |
| 3710 | case DEFER: |
| 3711 | HDEBUG(D_acl) debug_printf("%s: condition test deferred in %s\n", verbs[acl->verb], acl_name); |
| 3712 | if (basic_errno != ERRNO_CALLOUTDEFER) |
| 3713 | { |
| 3714 | if (search_error_message != NULL && *search_error_message != 0) |
| 3715 | *log_msgptr = search_error_message; |
| 3716 | if (smtp_return_error_details) acl_temp_details = TRUE; |
| 3717 | } |
| 3718 | else |
| 3719 | { |
| 3720 | acl_temp_details = TRUE; |
| 3721 | } |
| 3722 | if (acl->verb != ACL_WARN) return DEFER; |
| 3723 | break; |
| 3724 | |
| 3725 | default: /* Paranoia */ |
| 3726 | case ERROR: |
| 3727 | HDEBUG(D_acl) debug_printf("%s: condition test error in %s\n", verbs[acl->verb], acl_name); |
| 3728 | return ERROR; |
| 3729 | |
| 3730 | case OK: |
| 3731 | HDEBUG(D_acl) debug_printf("%s: condition test succeeded in %s\n", |
| 3732 | verbs[acl->verb], acl_name); |
| 3733 | break; |
| 3734 | |
| 3735 | case FAIL: |
| 3736 | HDEBUG(D_acl) debug_printf("%s: condition test failed in %s\n", verbs[acl->verb], acl_name); |
| 3737 | break; |
| 3738 | |
| 3739 | /* DISCARD and DROP can happen only from a nested ACL condition, and |
| 3740 | DISCARD can happen only for an "accept" or "discard" verb. */ |
| 3741 | |
| 3742 | case DISCARD: |
| 3743 | HDEBUG(D_acl) debug_printf("%s: condition test yielded \"discard\" in %s\n", |
| 3744 | verbs[acl->verb], acl_name); |
| 3745 | break; |
| 3746 | |
| 3747 | case FAIL_DROP: |
| 3748 | HDEBUG(D_acl) debug_printf("%s: condition test yielded \"drop\" in %s\n", |
| 3749 | verbs[acl->verb], acl_name); |
| 3750 | break; |
| 3751 | } |
| 3752 | |
| 3753 | /* At this point, cond for most verbs is either OK or FAIL or (as a result of |
| 3754 | a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and |
| 3755 | for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */ |
| 3756 | |
| 3757 | switch(acl->verb) |
| 3758 | { |
| 3759 | case ACL_ACCEPT: |
| 3760 | if (cond == OK || cond == DISCARD) return cond; |
| 3761 | if (endpass_seen) |
| 3762 | { |
| 3763 | HDEBUG(D_acl) debug_printf("accept: endpass encountered - denying access\n"); |
| 3764 | return cond; |
| 3765 | } |
| 3766 | break; |
| 3767 | |
| 3768 | case ACL_DEFER: |
| 3769 | if (cond == OK) |
| 3770 | { |
| 3771 | acl_temp_details = TRUE; |
| 3772 | return DEFER; |
| 3773 | } |
| 3774 | break; |
| 3775 | |
| 3776 | case ACL_DENY: |
| 3777 | if (cond == OK) return FAIL; |
| 3778 | break; |
| 3779 | |
| 3780 | case ACL_DISCARD: |
| 3781 | if (cond == OK || cond == DISCARD) return DISCARD; |
| 3782 | if (endpass_seen) |
| 3783 | { |
| 3784 | HDEBUG(D_acl) debug_printf("discard: endpass encountered - denying access\n"); |
| 3785 | return cond; |
| 3786 | } |
| 3787 | break; |
| 3788 | |
| 3789 | case ACL_DROP: |
| 3790 | if (cond == OK) return FAIL_DROP; |
| 3791 | break; |
| 3792 | |
| 3793 | case ACL_REQUIRE: |
| 3794 | if (cond != OK) return cond; |
| 3795 | break; |
| 3796 | |
| 3797 | case ACL_WARN: |
| 3798 | if (cond == OK) |
| 3799 | acl_warn(where, *user_msgptr, *log_msgptr); |
| 3800 | else if (cond == DEFER && (log_extra_selector & LX_acl_warn_skipped) != 0) |
| 3801 | log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: " |
| 3802 | "condition test deferred%s%s", host_and_ident(TRUE), |
| 3803 | (*log_msgptr == NULL)? US"" : US": ", |
| 3804 | (*log_msgptr == NULL)? US"" : *log_msgptr); |
| 3805 | *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */ |
| 3806 | break; |
| 3807 | |
| 3808 | default: |
| 3809 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d", |
| 3810 | acl->verb); |
| 3811 | break; |
| 3812 | } |
| 3813 | |
| 3814 | /* Pass to the next ACL item */ |
| 3815 | |
| 3816 | acl = acl->next; |
| 3817 | } |
| 3818 | |
| 3819 | /* We have reached the end of the ACL. This is an implicit DENY. */ |
| 3820 | |
| 3821 | HDEBUG(D_acl) debug_printf("end of %s: implicit DENY\n", acl_name); |
| 3822 | return FAIL; |
| 3823 | } |
| 3824 | |
| 3825 | |
| 3826 | /************************************************* |
| 3827 | * Check access using an ACL * |
| 3828 | *************************************************/ |
| 3829 | |
| 3830 | /* This is the external interface for ACL checks. It sets up an address and the |
| 3831 | expansions for $domain and $local_part when called after RCPT, then calls |
| 3832 | acl_check_internal() to do the actual work. |
| 3833 | |
| 3834 | Arguments: |
| 3835 | where ACL_WHERE_xxxx indicating where called from |
| 3836 | recipient RCPT address for RCPT check, else NULL |
| 3837 | s the input string; NULL is the same as an empty ACL => DENY |
| 3838 | user_msgptr where to put a user error (for SMTP response) |
| 3839 | log_msgptr where to put a logging message (not for SMTP response) |
| 3840 | |
| 3841 | Returns: OK access is granted by an ACCEPT verb |
| 3842 | DISCARD access is granted by a DISCARD verb |
| 3843 | FAIL access is denied |
| 3844 | FAIL_DROP access is denied; drop the connection |
| 3845 | DEFER can't tell at the moment |
| 3846 | ERROR disaster |
| 3847 | */ |
| 3848 | |
| 3849 | int |
| 3850 | acl_check(int where, uschar *recipient, uschar *s, uschar **user_msgptr, |
| 3851 | uschar **log_msgptr) |
| 3852 | { |
| 3853 | int rc; |
| 3854 | address_item adb; |
| 3855 | address_item *addr = NULL; |
| 3856 | |
| 3857 | *user_msgptr = *log_msgptr = NULL; |
| 3858 | sender_verified_failed = NULL; |
| 3859 | ratelimiters_cmd = NULL; |
| 3860 | log_reject_target = LOG_MAIN|LOG_REJECT; |
| 3861 | |
| 3862 | if (where == ACL_WHERE_RCPT) |
| 3863 | { |
| 3864 | adb = address_defaults; |
| 3865 | addr = &adb; |
| 3866 | addr->address = recipient; |
| 3867 | if (deliver_split_address(addr) == DEFER) |
| 3868 | { |
| 3869 | *log_msgptr = US"defer in percent_hack_domains check"; |
| 3870 | return DEFER; |
| 3871 | } |
| 3872 | deliver_domain = addr->domain; |
| 3873 | deliver_localpart = addr->local_part; |
| 3874 | } |
| 3875 | |
| 3876 | rc = acl_check_internal(where, addr, s, 0, user_msgptr, log_msgptr); |
| 3877 | |
| 3878 | deliver_domain = deliver_localpart = deliver_address_data = |
| 3879 | sender_address_data = NULL; |
| 3880 | |
| 3881 | /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA |
| 3882 | ACL, which is really in the middle of an SMTP command. */ |
| 3883 | |
| 3884 | if (rc == DISCARD) |
| 3885 | { |
| 3886 | if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA) |
| 3887 | { |
| 3888 | log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s " |
| 3889 | "ACL", acl_wherenames[where]); |
| 3890 | return ERROR; |
| 3891 | } |
| 3892 | return DISCARD; |
| 3893 | } |
| 3894 | |
| 3895 | /* A DROP response is not permitted from MAILAUTH */ |
| 3896 | |
| 3897 | if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH) |
| 3898 | { |
| 3899 | log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s " |
| 3900 | "ACL", acl_wherenames[where]); |
| 3901 | return ERROR; |
| 3902 | } |
| 3903 | |
| 3904 | /* Before giving a response, take a look at the length of any user message, and |
| 3905 | split it up into multiple lines if possible. */ |
| 3906 | |
| 3907 | *user_msgptr = string_split_message(*user_msgptr); |
| 3908 | if (fake_response != OK) |
| 3909 | fake_response_text = string_split_message(fake_response_text); |
| 3910 | |
| 3911 | return rc; |
| 3912 | } |
| 3913 | |
| 3914 | |
| 3915 | |
| 3916 | /************************************************* |
| 3917 | * Create ACL variable * |
| 3918 | *************************************************/ |
| 3919 | |
| 3920 | /* Create an ACL variable or reuse an existing one. ACL variables are in a |
| 3921 | binary tree (see tree.c) with acl_var_c and acl_var_m as root nodes. |
| 3922 | |
| 3923 | Argument: |
| 3924 | name pointer to the variable's name, starting with c or m |
| 3925 | |
| 3926 | Returns the pointer to variable's tree node |
| 3927 | */ |
| 3928 | |
| 3929 | tree_node * |
| 3930 | acl_var_create(uschar *name) |
| 3931 | { |
| 3932 | tree_node *node, **root; |
| 3933 | root = (name[0] == 'c')? &acl_var_c : &acl_var_m; |
| 3934 | node = tree_search(*root, name); |
| 3935 | if (node == NULL) |
| 3936 | { |
| 3937 | node = store_get(sizeof(tree_node) + Ustrlen(name)); |
| 3938 | Ustrcpy(node->name, name); |
| 3939 | (void)tree_insertnode(root, node); |
| 3940 | } |
| 3941 | node->data.ptr = NULL; |
| 3942 | return node; |
| 3943 | } |
| 3944 | |
| 3945 | |
| 3946 | |
| 3947 | /************************************************* |
| 3948 | * Write an ACL variable in spool format * |
| 3949 | *************************************************/ |
| 3950 | |
| 3951 | /* This function is used as a callback for tree_walk when writing variables to |
| 3952 | the spool file. To retain spool file compatibility, what is written is -aclc or |
| 3953 | -aclm followed by the rest of the name and the data length, space separated, |
| 3954 | then the value itself, starting on a new line, and terminated by an additional |
| 3955 | newline. When we had only numbered ACL variables, the first line might look |
| 3956 | like this: "-aclc 5 20". Now it might be "-aclc foo 20" for the variable called |
| 3957 | acl_cfoo. |
| 3958 | |
| 3959 | Arguments: |
| 3960 | name of the variable |
| 3961 | value of the variable |
| 3962 | ctx FILE pointer (as a void pointer) |
| 3963 | |
| 3964 | Returns: nothing |
| 3965 | */ |
| 3966 | |
| 3967 | void |
| 3968 | acl_var_write(uschar *name, uschar *value, void *ctx) |
| 3969 | { |
| 3970 | FILE *f = (FILE *)ctx; |
| 3971 | fprintf(f, "-acl%c %s %d\n%s\n", name[0], name+1, Ustrlen(value), value); |
| 3972 | } |
| 3973 | |
| 3974 | /* End of acl.c */ |