/* $Cambridge: exim/src/src/acl.c,v 1.12 2005/01/04 11:01:33 ph10 Exp $ */ /************************************************* * Exim - an Internet mail transport agent * *************************************************/ /* Copyright (c) University of Cambridge 1995 - 2005 */ /* See the file NOTICE for conditions of use and distribution. */ /* Code for handling Access Control Lists (ACLs) */ #include "exim.h" /* Default callout timeout */ #define CALLOUT_TIMEOUT_DEFAULT 30 /* ACL verb codes - keep in step with the table of verbs that follows */ enum { ACL_ACCEPT, ACL_DEFER, ACL_DENY, ACL_DISCARD, ACL_DROP, ACL_REQUIRE, ACL_WARN }; /* ACL verbs */ static uschar *verbs[] = { US"accept", US"defer", US"deny", US"discard", US"drop", US"require", US"warn" }; /* For each verb, the condition for which "message" is used */ static int msgcond[] = { FAIL, OK, OK, FAIL, OK, FAIL, OK }; /* ACL condition and modifier codes - keep in step with the table that follows. */ enum { ACLC_ACL, ACLC_AUTHENTICATED, #ifdef EXPERIMENTAL_BRIGHTMAIL ACLC_BMI_OPTIN, #endif ACLC_CONDITION, ACLC_CONTROL, #ifdef WITH_CONTENT_SCAN ACLC_DECODE, #endif ACLC_DELAY, #ifdef WITH_OLD_DEMIME ACLC_DEMIME, #endif ACLC_DNSLISTS, ACLC_DOMAINS, ACLC_ENCRYPTED, ACLC_ENDPASS, ACLC_HOSTS, ACLC_LOCAL_PARTS, ACLC_LOG_MESSAGE, ACLC_LOGWRITE, #ifdef WITH_CONTENT_SCAN ACLC_MALWARE, #endif ACLC_MESSAGE, #ifdef WITH_CONTENT_SCAN ACLC_MIME_REGEX, #endif ACLC_RECIPIENTS, #ifdef WITH_CONTENT_SCAN ACLC_REGEX, #endif ACLC_SENDER_DOMAINS, ACLC_SENDERS, ACLC_SET, #ifdef WITH_CONTENT_SCAN ACLC_SPAM, #endif #ifdef EXPERIMENTAL_SPF ACLC_SPF, #endif ACLC_VERIFY }; /* ACL conditions/modifiers: "delay", "control", "endpass", "message", "log_message", "logwrite", and "set" are modifiers that look like conditions but always return TRUE. They are used for their side effects. */ static uschar *conditions[] = { US"acl", US"authenticated", #ifdef EXPERIMENTAL_BRIGHTMAIL US"bmi_optin", #endif US"condition", US"control", #ifdef WITH_CONTENT_SCAN US"decode", #endif US"delay", #ifdef WITH_OLD_DEMIME US"demime", #endif US"dnslists", US"domains", US"encrypted", US"endpass", US"hosts", US"local_parts", US"log_message", US"logwrite", #ifdef WITH_CONTENT_SCAN US"malware", #endif US"message", #ifdef WITH_CONTENT_SCAN US"mime_regex", #endif US"recipients", #ifdef WITH_CONTENT_SCAN US"regex", #endif US"sender_domains", US"senders", US"set", #ifdef WITH_CONTENT_SCAN US"spam", #endif #ifdef EXPERIMENTAL_SPF US"spf", #endif US"verify" }; /* ACL control names */ static uschar *controls[] = { US"error", US"caseful_local_part", US"caselower_local_part", US"enforce_sync", US"no_enforce_sync", US"freeze", US"queue_only", US"submission", US"no_multiline"}; /* Flags to indicate for which conditions /modifiers a string expansion is done at the outer level. In the other cases, expansion already occurs in the checking functions. */ static uschar cond_expand_at_top[] = { TRUE, /* acl */ FALSE, /* authenticated */ #ifdef EXPERIMENTAL_BRIGHTMAIL TRUE, /* bmi_optin */ #endif TRUE, /* condition */ TRUE, /* control */ #ifdef WITH_CONTENT_SCAN TRUE, /* decode */ #endif TRUE, /* delay */ #ifdef WITH_OLD_DEMIME TRUE, /* demime */ #endif TRUE, /* dnslists */ FALSE, /* domains */ FALSE, /* encrypted */ TRUE, /* endpass */ FALSE, /* hosts */ FALSE, /* local_parts */ TRUE, /* log_message */ TRUE, /* logwrite */ #ifdef WITH_CONTENT_SCAN TRUE, /* malware */ #endif TRUE, /* message */ #ifdef WITH_CONTENT_SCAN TRUE, /* mime_regex */ #endif FALSE, /* recipients */ #ifdef WITH_CONTENT_SCAN TRUE, /* regex */ #endif FALSE, /* sender_domains */ FALSE, /* senders */ TRUE, /* set */ #ifdef WITH_CONTENT_SCAN TRUE, /* spam */ #endif #ifdef EXPERIMENTAL_SPF TRUE, /* spf */ #endif TRUE /* verify */ }; /* Flags to identify the modifiers */ static uschar cond_modifiers[] = { FALSE, /* acl */ FALSE, /* authenticated */ #ifdef EXPERIMENTAL_BRIGHTMAIL TRUE, /* bmi_optin */ #endif FALSE, /* condition */ TRUE, /* control */ #ifdef WITH_CONTENT_SCAN FALSE, /* decode */ #endif TRUE, /* delay */ #ifdef WITH_OLD_DEMIME FALSE, /* demime */ #endif FALSE, /* dnslists */ FALSE, /* domains */ FALSE, /* encrypted */ TRUE, /* endpass */ FALSE, /* hosts */ FALSE, /* local_parts */ TRUE, /* log_message */ TRUE, /* logwrite */ #ifdef WITH_CONTENT_SCAN FALSE, /* malware */ #endif TRUE, /* message */ #ifdef WITH_CONTENT_SCAN FALSE, /* mime_regex */ #endif FALSE, /* recipients */ #ifdef WITH_CONTENT_SCAN FALSE, /* regex */ #endif FALSE, /* sender_domains */ FALSE, /* senders */ TRUE, /* set */ #ifdef WITH_CONTENT_SCAN FALSE, /* spam */ #endif #ifdef EXPERIMENTAL_SPF FALSE, /* spf */ #endif FALSE /* verify */ }; /* Bit map vector of which conditions are not allowed at certain times. For each condition, there's a bitmap of dis-allowed times. */ static unsigned int cond_forbids[] = { 0, /* acl */ (1<next); this->next = NULL; this->verb = v; this->condition = NULL; condp = &(this->condition); if (*s == 0) continue; /* No condition on this line */ if (*s == '!') { negated = TRUE; s++; } s = readconf_readname(name, sizeof(name), s); /* Condition name */ } /* Handle a condition or modifier. */ c = acl_checkname(name, conditions, sizeof(conditions)/sizeof(char *)); if (c < 0) { *error = string_sprintf("unknown ACL condition/modifier in \"%s\"", saveline); return NULL; } /* The modifiers may not be negated */ if (negated && cond_modifiers[c]) { *error = string_sprintf("ACL error: negation is not allowed with " "\"%s\"", conditions[c]); return NULL; } /* ENDPASS may occur only with ACCEPT or DISCARD. */ if (c == ACLC_ENDPASS && this->verb != ACL_ACCEPT && this->verb != ACL_DISCARD) { *error = string_sprintf("ACL error: \"%s\" is not allowed with \"%s\"", conditions[c], verbs[this->verb]); return NULL; } cond = store_get(sizeof(acl_condition_block)); cond->next = NULL; cond->type = c; cond->u.negated = negated; *condp = cond; condp = &(cond->next); /* The "set" modifier is different in that its argument is "name=value" rather than just a value, and we can check the validity of the name, which gives us a variable number to insert into the data block. */ if (c == ACLC_SET) { if (Ustrncmp(s, "acl_", 4) != 0 || (s[4] != 'c' && s[4] != 'm') || !isdigit(s[5]) || (!isspace(s[6]) && s[6] != '=')) { *error = string_sprintf("unrecognized name after \"set\" in ACL " "modifier \"set %s\"", s); return NULL; } cond->u.varnumber = s[5] - '0'; if (s[4] == 'm') cond->u.varnumber += ACL_C_MAX; s += 6; while (isspace(*s)) s++; } /* For "set", we are now positioned for the data. For the others, only "endpass" has no data */ if (c != ACLC_ENDPASS) { if (*s++ != '=') { *error = string_sprintf("\"=\" missing after ACL \"%s\" %s", name, cond_modifiers[c]? US"modifier" : US"condition"); return NULL; } while (isspace(*s)) s++; cond->arg = string_copy(s); } } return yield; } /************************************************* * Handle warnings * *************************************************/ /* This function is called when a WARN verb's conditions are true. It adds to the message's headers, and/or writes information to the log. In each case, this only happens once (per message for headers, per connection for log). Arguments: where ACL_WHERE_xxxx indicating which ACL this is user_message message for adding to headers log_message message for logging, if different Returns: nothing */ static void acl_warn(int where, uschar *user_message, uschar *log_message) { int hlen; if (log_message != NULL && log_message != user_message) { uschar *text; string_item *logged; text = string_sprintf("%s Warning: %s", host_and_ident(TRUE), string_printing(log_message)); /* If a sender verification has failed, and the log message is "sender verify failed", add the failure message. */ if (sender_verified_failed != NULL && sender_verified_failed->message != NULL && strcmpic(log_message, US"sender verify failed") == 0) text = string_sprintf("%s: %s", text, sender_verified_failed->message); /* Search previously logged warnings. They are kept in malloc store so they can be freed at the start of a new message. */ for (logged = acl_warn_logged; logged != NULL; logged = logged->next) if (Ustrcmp(logged->text, text) == 0) break; if (logged == NULL) { int length = Ustrlen(text) + 1; log_write(0, LOG_MAIN, "%s", text); logged = store_malloc(sizeof(string_item) + length); logged->text = (uschar *)logged + sizeof(string_item); memcpy(logged->text, text, length); logged->next = acl_warn_logged; acl_warn_logged = logged; } } /* If there's no user message, we are done. */ if (user_message == NULL) return; /* If this isn't a message ACL, we can't do anything with a user message. Log an error. */ if (where > ACL_WHERE_NOTSMTP) { log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting " "found in a non-message (%s) ACL: cannot specify header lines here: " "message ignored", acl_wherenames[where]); return; } /* Treat the user message as a sequence of one or more header lines. */ hlen = Ustrlen(user_message); if (hlen > 0) { uschar *text, *p, *q; /* Add a final newline if not present */ text = ((user_message)[hlen-1] == '\n')? user_message : string_sprintf("%s\n", user_message); /* Loop for multiple header lines, taking care about continuations */ for (p = q = text; *p != 0; ) { uschar *s; int newtype = htype_add_bot; header_line **hptr = &acl_warn_headers; /* Find next header line within the string */ for (;;) { q = Ustrchr(q, '\n'); if (*(++q) != ' ' && *q != '\t') break; } /* If the line starts with a colon, interpret the instruction for where to add it. This temporarily sets up a new type. */ if (*p == ':') { if (strncmpic(p, US":after_received:", 16) == 0) { newtype = htype_add_rec; p += 16; } else if (strncmpic(p, US":at_start_rfc:", 14) == 0) { newtype = htype_add_rfc; p += 14; } else if (strncmpic(p, US":at_start:", 10) == 0) { newtype = htype_add_top; p += 10; } else if (strncmpic(p, US":at_end:", 8) == 0) { newtype = htype_add_bot; p += 8; } while (*p == ' ' || *p == '\t') p++; } /* See if this line starts with a header name, and if not, add X-ACL-Warn: to the front of it. */ for (s = p; s < q - 1; s++) { if (*s == ':' || !isgraph(*s)) break; } s = string_sprintf("%s%.*s", (*s == ':')? "" : "X-ACL-Warn: ", q - p, p); hlen = Ustrlen(s); /* See if this line has already been added */ while (*hptr != NULL) { if (Ustrncmp((*hptr)->text, s, hlen) == 0) break; hptr = &((*hptr)->next); } /* Add if not previously present */ if (*hptr == NULL) { header_line *h = store_get(sizeof(header_line)); h->text = s; h->next = NULL; h->type = newtype; h->slen = hlen; *hptr = h; hptr = &(h->next); } /* Advance for next header line within the string */ p = q; } } } /************************************************* * Verify and check reverse DNS * *************************************************/ /* Called from acl_verify() below. We look up the host name(s) of the client IP address if this has not yet been done. The host_name_lookup() function checks that one of these names resolves to an address list that contains the client IP address, so we don't actually have to do the check here. Arguments: user_msgptr pointer for user message log_msgptr pointer for log message Returns: OK verification condition succeeded FAIL verification failed DEFER there was a problem verifying */ static int acl_verify_reverse(uschar **user_msgptr, uschar **log_msgptr) { int rc; user_msgptr = user_msgptr; /* stop compiler warning */ /* Previous success */ if (sender_host_name != NULL) return OK; /* Previous failure */ if (host_lookup_failed) { *log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg); return FAIL; } /* Need to do a lookup */ HDEBUG(D_acl) debug_printf("looking up host name to force name/address consistency check\n"); if ((rc = host_name_lookup()) != OK) { *log_msgptr = (rc == DEFER)? US"host lookup deferred for reverse lookup check" : string_sprintf("host lookup failed for reverse lookup check%s", host_lookup_msg); return rc; /* DEFER or FAIL */ } host_build_sender_fullhost(); return OK; } /************************************************* * Handle verification (address & other) * *************************************************/ /* This function implements the "verify" condition. It is called when encountered in any ACL, because some tests are almost always permitted. Some just don't make sense, and always fail (for example, an attempt to test a host lookup for a non-TCP/IP message). Others are restricted to certain ACLs. Arguments: where where called from addr the recipient address that the ACL is handling, or NULL arg the argument of "verify" user_msgptr pointer for user message log_msgptr pointer for log message basic_errno where to put verify errno Returns: OK verification condition succeeded FAIL verification failed DEFER there was a problem verifying ERROR syntax error */ static int acl_verify(int where, address_item *addr, uschar *arg, uschar **user_msgptr, uschar **log_msgptr, int *basic_errno) { int sep = '/'; int callout = -1; int callout_overall = -1; int callout_connect = -1; int verify_options = 0; int rc; BOOL verify_header_sender = FALSE; BOOL defer_ok = FALSE; BOOL callout_defer_ok = FALSE; BOOL no_details = FALSE; address_item *sender_vaddr = NULL; uschar *verify_sender_address = NULL; uschar *pm_mailfrom = NULL; uschar *se_mailfrom = NULL; uschar *list = arg; uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size); if (ss == NULL) goto BAD_VERIFY; /* Handle name/address consistency verification in a separate function. */ if (strcmpic(ss, US"reverse_host_lookup") == 0) { if (sender_host_address == NULL) return OK; return acl_verify_reverse(user_msgptr, log_msgptr); } /* TLS certificate verification is done at STARTTLS time; here we just test whether it was successful or not. (This is for optional verification; for mandatory verification, the connection doesn't last this long.) */ if (strcmpic(ss, US"certificate") == 0) { if (tls_certificate_verified) return OK; *user_msgptr = US"no verified certificate"; return FAIL; } /* We can test the result of optional HELO verification */ if (strcmpic(ss, US"helo") == 0) return helo_verified? OK : FAIL; /* Handle header verification options - permitted only after DATA or a non-SMTP message. */ if (strncmpic(ss, US"header_", 7) == 0) { if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP) { *log_msgptr = string_sprintf("cannot check header contents in ACL for %s " "(only possible in ACL for DATA)", acl_wherenames[where]); return ERROR; } /* Check that all relevant header lines have the correct syntax. If there is a syntax error, we return details of the error to the sender if configured to send out full details. (But a "message" setting on the ACL can override, as always). */ if (strcmpic(ss+7, US"syntax") == 0) { int rc = verify_check_headers(log_msgptr); if (rc != OK && smtp_return_error_details && *log_msgptr != NULL) *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr); return rc; } /* Check that there is at least one verifiable sender address in the relevant header lines. This can be followed by callout and defer options, just like sender and recipient. */ else if (strcmpic(ss+7, US"sender") == 0) verify_header_sender = TRUE; /* Unknown verify argument starting with "header_" */ else goto BAD_VERIFY; } /* Otherwise, first item in verify argument must be "sender" or "recipient". In the case of a sender, this can optionally be followed by an address to use in place of the actual sender (rare special-case requirement). */ else if (strncmpic(ss, US"sender", 6) == 0) { uschar *s = ss + 6; if (where > ACL_WHERE_NOTSMTP) { *log_msgptr = string_sprintf("cannot verify sender in ACL for %s " "(only possible for MAIL, RCPT, PREDATA, or DATA)", acl_wherenames[where]); return ERROR; } if (*s == 0) verify_sender_address = sender_address; else { while (isspace(*s)) s++; if (*s++ != '=') goto BAD_VERIFY; while (isspace(*s)) s++; verify_sender_address = string_copy(s); } } else { if (strcmpic(ss, US"recipient") != 0) goto BAD_VERIFY; if (addr == NULL) { *log_msgptr = string_sprintf("cannot verify recipient in ACL for %s " "(only possible for RCPT)", acl_wherenames[where]); return ERROR; } } /* Remaining items are optional */ while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)) != NULL) { if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE; else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE; /* These two old options are left for backwards compatibility */ else if (strcmpic(ss, US"callout_defer_ok") == 0) { callout_defer_ok = TRUE; if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT; } else if (strcmpic(ss, US"check_postmaster") == 0) { pm_mailfrom = US""; if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT; } /* The callout option has a number of sub-options, comma separated */ else if (strncmpic(ss, US"callout", 7) == 0) { callout = CALLOUT_TIMEOUT_DEFAULT; ss += 7; if (*ss != 0) { while (isspace(*ss)) ss++; if (*ss++ == '=') { int optsep = ','; uschar *opt; uschar buffer[256]; while (isspace(*ss)) ss++; /* This callout option handling code has become a mess as new options have been added in an ad hoc manner. It should be tidied up into some kind of table-driven thing. */ while ((opt = string_nextinlist(&ss, &optsep, buffer, sizeof(buffer))) != NULL) { if (strcmpic(opt, US"defer_ok") == 0) callout_defer_ok = TRUE; else if (strcmpic(opt, US"no_cache") == 0) verify_options |= vopt_callout_no_cache; else if (strcmpic(opt, US"random") == 0) verify_options |= vopt_callout_random; else if (strcmpic(opt, US"use_sender") == 0) verify_options |= vopt_callout_recipsender; else if (strcmpic(opt, US"use_postmaster") == 0) verify_options |= vopt_callout_recippmaster; else if (strcmpic(opt, US"postmaster") == 0) pm_mailfrom = US""; else if (strncmpic(opt, US"mailfrom", 8) == 0) { if (!verify_header_sender) { *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a " "callout option only for verify=header_sender (detected in ACL " "condition \"%s\")", arg); return ERROR; } opt += 8; while (isspace(*opt)) opt++; if (*opt++ != '=') { *log_msgptr = string_sprintf("'=' expected after " "\"mailfrom\" in ACL condition \"%s\"", arg); return ERROR; } while (isspace(*opt)) opt++; se_mailfrom = string_copy(opt); } else if (strncmpic(opt, US"postmaster_mailfrom", 19) == 0) { opt += 19; while (isspace(*opt)) opt++; if (*opt++ != '=') { *log_msgptr = string_sprintf("'=' expected after " "\"postmaster_mailfrom\" in ACL condition \"%s\"", arg); return ERROR; } while (isspace(*opt)) opt++; pm_mailfrom = string_copy(opt); } else if (strncmpic(opt, US"maxwait", 7) == 0) { opt += 7; while (isspace(*opt)) opt++; if (*opt++ != '=') { *log_msgptr = string_sprintf("'=' expected after \"maxwait\" in " "ACL condition \"%s\"", arg); return ERROR; } while (isspace(*opt)) opt++; callout_overall = readconf_readtime(opt, 0, FALSE); if (callout_overall < 0) { *log_msgptr = string_sprintf("bad time value in ACL condition " "\"verify %s\"", arg); return ERROR; } } else if (strncmpic(opt, US"connect", 7) == 0) { opt += 7; while (isspace(*opt)) opt++; if (*opt++ != '=') { *log_msgptr = string_sprintf("'=' expected after " "\"callout_overaall\" in ACL condition \"%s\"", arg); return ERROR; } while (isspace(*opt)) opt++; callout_connect = readconf_readtime(opt, 0, FALSE); if (callout_connect < 0) { *log_msgptr = string_sprintf("bad time value in ACL condition " "\"verify %s\"", arg); return ERROR; } } else /* Plain time is callout connect/command timeout */ { callout = readconf_readtime(opt, 0, FALSE); if (callout < 0) { *log_msgptr = string_sprintf("bad time value in ACL condition " "\"verify %s\"", arg); return ERROR; } } } } else { *log_msgptr = string_sprintf("'=' expected after \"callout\" in " "ACL condition \"%s\"", arg); return ERROR; } } } /* Option not recognized */ else { *log_msgptr = string_sprintf("unknown option \"%s\" in ACL " "condition \"verify %s\"", ss, arg); return ERROR; } } if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == (vopt_callout_recipsender|vopt_callout_recippmaster)) { *log_msgptr = US"only one of use_sender and use_postmaster can be set " "for a recipient callout"; return ERROR; } /* Handle sender-in-header verification. Default the user message to the log message if giving out verification details. */ if (verify_header_sender) { rc = verify_check_header_address(user_msgptr, log_msgptr, callout, callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options); if (smtp_return_error_details) { if (*user_msgptr == NULL && *log_msgptr != NULL) *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr); if (rc == DEFER) acl_temp_details = TRUE; } } /* Handle a sender address. The default is to verify *the* sender address, but optionally a different address can be given, for special requirements. If the address is empty, we are dealing with a bounce message that has no sender, so we cannot do any checking. If the real sender address gets rewritten during verification (e.g. DNS widening), set the flag to stop it being rewritten again during message reception. A list of verified "sender" addresses is kept to try to avoid doing to much work repetitively when there are multiple recipients in a message and they all require sender verification. However, when callouts are involved, it gets too complicated because different recipients may require different callout options. Therefore, we always do a full sender verify when any kind of callout is specified. Caching elsewhere, for instance in the DNS resolver and in the callout handling, should ensure that this is not terribly inefficient. */ else if (verify_sender_address != NULL) { if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) != 0) { *log_msgptr = US"use_sender or use_postmaster cannot be used for a " "sender verify callout"; return ERROR; } sender_vaddr = verify_checked_sender(verify_sender_address); if (sender_vaddr != NULL && /* Previously checked */ callout <= 0) /* No callout needed this time */ { /* If the "routed" flag is set, it means that routing worked before, so this check can give OK (the saved return code value, if set, belongs to a callout that was done previously). If the "routed" flag is not set, routing must have failed, so we use the saved return code. */ if (testflag(sender_vaddr, af_verify_routed)) rc = OK; else { rc = sender_vaddr->special_action; *basic_errno = sender_vaddr->basic_errno; } HDEBUG(D_acl) debug_printf("using cached sender verify result\n"); } /* Do a new verification, and cache the result. The cache is used to avoid verifying the sender multiple times for multiple RCPTs when callouts are not specified (see comments above). The cache is also used on failure to give details in response to the first RCPT that gets bounced for this reason. However, this can be suppressed by the no_details option, which sets the flag that says "this detail has already been sent". The cache normally contains just one address, but there may be more in esoteric circumstances. */ else { BOOL routed = TRUE; uschar *save_address_data = deliver_address_data; sender_vaddr = deliver_make_addr(verify_sender_address, TRUE); if (no_details) setflag(sender_vaddr, af_sverify_told); if (verify_sender_address[0] != 0) { /* If this is the real sender address, save the unrewritten version for use later in receive. Otherwise, set a flag so that rewriting the sender in verify_address() does not update sender_address. */ if (verify_sender_address == sender_address) sender_address_unrewritten = sender_address; else verify_options |= vopt_fake_sender; /* The recipient, qualify, and expn options are never set in verify_options. */ rc = verify_address(sender_vaddr, NULL, verify_options, callout, callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed); HDEBUG(D_acl) debug_printf("----------- end verify ------------\n"); if (rc == OK) { if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0) { DEBUG(D_acl) debug_printf("sender %s verified ok as %s\n", verify_sender_address, sender_vaddr->address); } else { DEBUG(D_acl) debug_printf("sender %s verified ok\n", verify_sender_address); } } else *basic_errno = sender_vaddr->basic_errno; } else rc = OK; /* Null sender */ /* Cache the result code */ if (routed) setflag(sender_vaddr, af_verify_routed); if (callout > 0) setflag(sender_vaddr, af_verify_callout); sender_vaddr->special_action = rc; sender_vaddr->next = sender_verified_list; sender_verified_list = sender_vaddr; /* Restore the recipient address data, which might have been clobbered by the sender verification. */ deliver_address_data = save_address_data; } /* Put the sender address_data value into $sender_address_data */ sender_address_data = sender_vaddr->p.address_data; } /* A recipient address just gets a straightforward verify; again we must handle the DEFER overrides. */ else { address_item addr2; /* We must use a copy of the address for verification, because it might get rewritten. */ addr2 = *addr; rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout, callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL); HDEBUG(D_acl) debug_printf("----------- end verify ------------\n"); *log_msgptr = addr2.message; *user_msgptr = addr2.user_message; *basic_errno = addr2.basic_errno; /* Make $address_data visible */ deliver_address_data = addr2.p.address_data; } /* We have a result from the relevant test. Handle defer overrides first. */ if (rc == DEFER && (defer_ok || (callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER))) { HDEBUG(D_acl) debug_printf("verify defer overridden by %s\n", defer_ok? "defer_ok" : "callout_defer_ok"); rc = OK; } /* If we've failed a sender, set up a recipient message, and point sender_verified_failed to the address item that actually failed. */ if (rc != OK && verify_sender_address != NULL) { if (rc != DEFER) { *log_msgptr = *user_msgptr = US"Sender verify failed"; } else if (*basic_errno != ERRNO_CALLOUTDEFER) { *log_msgptr = *user_msgptr = US"Could not complete sender verify"; } else { *log_msgptr = US"Could not complete sender verify callout"; *user_msgptr = smtp_return_error_details? sender_vaddr->user_message : *log_msgptr; } sender_verified_failed = sender_vaddr; } /* Verifying an address messes up the values of $domain and $local_part, so reset them before returning if this is a RCPT ACL. */ if (addr != NULL) { deliver_domain = addr->domain; deliver_localpart = addr->local_part; } return rc; /* Syntax errors in the verify argument come here. */ BAD_VERIFY: *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", " "\"header_syntax\" or \"header_sender\" at start of ACL condition " "\"verify %s\"", arg); return ERROR; } /************************************************* * Check argument for control= modifier * *************************************************/ /* Called from acl_check_condition() below Arguments: arg the argument string for control= pptr set to point to the terminating character where which ACL we are in log_msgptr for error messages Returns: CONTROL_xxx value */ static int decode_control(uschar *arg, uschar **pptr, int where, uschar **log_msgptr) { int len; control_def *d; for (d = controls_list; d < controls_list + sizeof(controls_list)/sizeof(control_def); d++) { len = Ustrlen(d->name); if (Ustrncmp(d->name, arg, len) == 0) break; } if (d >= controls_list + sizeof(controls_list)/sizeof(control_def) || (arg[len] != 0 && (!d->has_option || arg[len] != '/'))) { *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg); return CONTROL_ERROR; } *pptr = arg + len; return d->value; } /************************************************* * Handle conditions/modifiers on an ACL item * *************************************************/ /* Called from acl_check() below. Arguments: verb ACL verb cb ACL condition block - if NULL, result is OK where where called from addr the address being checked for RCPT, or NULL level the nesting level epp pointer to pass back TRUE if "endpass" encountered (applies only to "accept" and "discard") user_msgptr user message pointer log_msgptr log message pointer basic_errno pointer to where to put verify error Returns: OK - all conditions are met DISCARD - an "acl" condition returned DISCARD - only allowed for "accept" or "discard" verbs FAIL - at least one condition fails FAIL_DROP - an "acl" condition returned FAIL_DROP DEFER - can't tell at the moment (typically, lookup defer, but can be temporary callout problem) ERROR - ERROR from nested ACL or expansion failure or other error */ static int acl_check_condition(int verb, acl_condition_block *cb, int where, address_item *addr, int level, BOOL *epp, uschar **user_msgptr, uschar **log_msgptr, int *basic_errno) { uschar *user_message = NULL; uschar *log_message = NULL; uschar *p; int rc = OK; #ifdef WITH_CONTENT_SCAN int sep = '/'; #endif for (; cb != NULL; cb = cb->next) { uschar *arg; int control_type; /* The message and log_message items set up messages to be used in case of rejection. They are expanded later. */ if (cb->type == ACLC_MESSAGE) { user_message = cb->arg; continue; } if (cb->type == ACLC_LOG_MESSAGE) { log_message = cb->arg; continue; } /* The endpass "condition" just sets a flag to show it occurred. This is checked at compile time to be on an "accept" or "discard" item. */ if (cb->type == ACLC_ENDPASS) { *epp = TRUE; continue; } /* For other conditions and modifiers, the argument is expanded now for some of them, but not for all, because expansion happens down in some lower level checking functions in some cases. */ if (cond_expand_at_top[cb->type]) { arg = expand_string(cb->arg); if (arg == NULL) { if (expand_string_forcedfail) continue; *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", cb->arg, expand_string_message); return search_find_defer? DEFER : ERROR; } } else arg = cb->arg; /* Show condition, and expanded condition if it's different */ HDEBUG(D_acl) { int lhswidth = 0; debug_printf("check %s%s %n", (!cond_modifiers[cb->type] && cb->u.negated)? "!":"", conditions[cb->type], &lhswidth); if (cb->type == ACLC_SET) { int n = cb->u.varnumber; int t = (n < ACL_C_MAX)? 'c' : 'm'; if (n >= ACL_C_MAX) n -= ACL_C_MAX; debug_printf("acl_%c%d ", t, n); lhswidth += 7; } debug_printf("= %s\n", cb->arg); if (arg != cb->arg) debug_printf("%.*s= %s\n", lhswidth, US" ", CS arg); } /* Check that this condition makes sense at this time */ if ((cond_forbids[cb->type] & (1 << where)) != 0) { *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL", cond_modifiers[cb->type]? "use" : "test", conditions[cb->type], acl_wherenames[where]); return ERROR; } /* Run the appropriate test for each condition, or take the appropriate action for the remaining modifiers. */ switch(cb->type) { /* A nested ACL that returns "discard" makes sense only for an "accept" or "discard" verb. */ case ACLC_ACL: rc = acl_check_internal(where, addr, arg, level+1, user_msgptr, log_msgptr); if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD) { *log_msgptr = string_sprintf("nested ACL returned \"discard\" for " "\"%s\" command (only allowed with \"accept\" or \"discard\")", verbs[verb]); return ERROR; } break; case ACLC_AUTHENTICATED: rc = (sender_host_authenticated == NULL)? FAIL : match_isinlist(sender_host_authenticated, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL); break; #ifdef EXPERIMENTAL_BRIGHTMAIL case ACLC_BMI_OPTIN: { int old_pool = store_pool; store_pool = POOL_PERM; bmi_current_optin = string_copy(arg); store_pool = old_pool; } break; #endif case ACLC_CONDITION: if (Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */ rc = (Uatoi(arg) == 0)? FAIL : OK; else rc = (strcmpic(arg, US"no") == 0 || strcmpic(arg, US"false") == 0)? FAIL : (strcmpic(arg, US"yes") == 0 || strcmpic(arg, US"true") == 0)? OK : DEFER; if (rc == DEFER) *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg); break; case ACLC_CONTROL: control_type = decode_control(arg, &p, where, log_msgptr); /* Check if this control makes sense at this time */ if ((control_forbids[control_type] & (1 << where)) != 0) { *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL", controls[control_type], acl_wherenames[where]); return ERROR; } switch(control_type) { #ifdef EXPERIMENTAL_BRIGHTMAIL case CONTROL_BMI_RUN: bmi_run = 1; break; #endif case CONTROL_ERROR: return ERROR; case CONTROL_CASEFUL_LOCAL_PART: deliver_localpart = addr->cc_local_part; break; case CONTROL_CASELOWER_LOCAL_PART: deliver_localpart = addr->lc_local_part; break; case CONTROL_ENFORCE_SYNC: smtp_enforce_sync = TRUE; break; case CONTROL_NO_ENFORCE_SYNC: smtp_enforce_sync = FALSE; break; #ifdef WITH_CONTENT_SCAN case CONTROL_NO_MBOX_UNSPOOL: no_mbox_unspool = TRUE; break; #endif case CONTROL_NO_MULTILINE: no_multiline_responses = TRUE; break; case CONTROL_FAKEREJECT: fake_reject = TRUE; if (*p == '/') { uschar *pp = p + 1; while (*pp != 0) pp++; fake_reject_text = expand_string(string_copyn(p+1, pp-p)); p = pp; } else { /* Explicitly reset to default string */ fake_reject_text = US"Your message has been rejected but is being kept for evaluation.\nIf it was a legit message, it may still be delivered to the target recipient(s)."; } break; case CONTROL_FREEZE: deliver_freeze = TRUE; deliver_frozen_at = time(NULL); break; case CONTROL_QUEUE_ONLY: queue_only_policy = TRUE; break; case CONTROL_SUBMISSION: submission_mode = TRUE; while (*p == '/') { if (Ustrncmp(p, "/sender_retain", 14) == 0) { p += 14; active_local_sender_retain = TRUE; active_local_from_check = FALSE; } else if (Ustrncmp(p, "/domain=", 8) == 0) { uschar *pp = p + 8; while (*pp != 0 && *pp != '/') pp++; submission_domain = string_copyn(p+8, pp-p); p = pp; } else break; } if (*p != 0) { *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg); return ERROR; } break; } break; #ifdef WITH_CONTENT_SCAN case ACLC_DECODE: rc = mime_decode(&arg); break; #endif case ACLC_DELAY: { int delay = readconf_readtime(arg, 0, FALSE); if (delay < 0) { *log_msgptr = string_sprintf("syntax error in argument for \"delay\" " "modifier: \"%s\" is not a time value", arg); return ERROR; } else { HDEBUG(D_acl) debug_printf("delay modifier requests %d-second delay\n", delay); if (host_checking) { HDEBUG(D_acl) debug_printf("delay skipped in -bh checking mode\n"); } else { while (delay > 0) delay = sleep(delay); } } } break; #ifdef WITH_OLD_DEMIME case ACLC_DEMIME: rc = demime(&arg); break; #endif case ACLC_DNSLISTS: rc = verify_check_dnsbl(&arg); break; case ACLC_DOMAINS: rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor, addr->domain_cache, MCL_DOMAIN, TRUE, &deliver_domain_data); break; /* The value in tls_cipher is the full cipher name, for example, TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the cipher names such as DES-CBC3-SHA. But program defensively. We don't know what may in practice come out of the SSL library - which at the time of writing is poorly documented. */ case ACLC_ENCRYPTED: if (tls_cipher == NULL) rc = FAIL; else { uschar *endcipher = NULL; uschar *cipher = Ustrchr(tls_cipher, ':'); if (cipher == NULL) cipher = tls_cipher; else { endcipher = Ustrchr(++cipher, ':'); if (endcipher != NULL) *endcipher = 0; } rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL); if (endcipher != NULL) *endcipher = ':'; } break; /* Use verify_check_this_host() instead of verify_check_host() so that we can pass over &host_data to catch any looked up data. Once it has been set, it retains its value so that it's still there if another ACL verb comes through here and uses the cache. However, we must put it into permanent store in case it is also expected to be used in a subsequent message in the same SMTP connection. */ case ACLC_HOSTS: rc = verify_check_this_host(&arg, sender_host_cache, NULL, (sender_host_address == NULL)? US"" : sender_host_address, &host_data); if (host_data != NULL) host_data = string_copy_malloc(host_data); break; case ACLC_LOCAL_PARTS: rc = match_isinlist(addr->cc_local_part, &arg, 0, &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE, &deliver_localpart_data); break; case ACLC_LOGWRITE: { int logbits = 0; uschar *s = arg; if (*s == ':') { s++; while (*s != ':') { if (Ustrncmp(s, "main", 4) == 0) { logbits |= LOG_MAIN; s += 4; } else if (Ustrncmp(s, "panic", 5) == 0) { logbits |= LOG_PANIC; s += 5; } else if (Ustrncmp(s, "reject", 6) == 0) { logbits |= LOG_REJECT; s += 6; } else { logbits = LOG_MAIN|LOG_PANIC; s = string_sprintf(":unknown log name in \"%s\" in " "\"logwrite\" in %s ACL", arg, acl_wherenames[where]); } if (*s == ',') s++; } s++; } while (isspace(*s)) s++; if (logbits == 0) logbits = LOG_MAIN; log_write(0, logbits, "%s", string_printing(s)); } break; #ifdef WITH_CONTENT_SCAN case ACLC_MALWARE: { /* Seperate the regular expression and any optional parameters. */ uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size); /* Run the malware backend. */ rc = malware(&ss); /* Modify return code based upon the existance of options. */ while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size)) != NULL) { if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER) { /* FAIL so that the message is passed to the next ACL */ rc = FAIL; } } } break; case ACLC_MIME_REGEX: rc = mime_regex(&arg); break; #endif case ACLC_RECIPIENTS: rc = match_address_list(addr->address, TRUE, TRUE, &arg, NULL, -1, 0, &recipient_data); break; #ifdef WITH_CONTENT_SCAN case ACLC_REGEX: rc = regex(&arg); break; #endif case ACLC_SENDER_DOMAINS: { uschar *sdomain; sdomain = Ustrrchr(sender_address, '@'); sdomain = (sdomain == NULL)? US"" : sdomain + 1; rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor, sender_domain_cache, MCL_DOMAIN, TRUE, NULL); } break; case ACLC_SENDERS: rc = match_address_list(sender_address, TRUE, TRUE, &arg, sender_address_cache, -1, 0, &sender_data); break; /* Connection variables must persist forever */ case ACLC_SET: { int old_pool = store_pool; if (cb->u.varnumber < ACL_C_MAX) store_pool = POOL_PERM; acl_var[cb->u.varnumber] = string_copy(arg); store_pool = old_pool; } break; #ifdef WITH_CONTENT_SCAN case ACLC_SPAM: { /* Seperate the regular expression and any optional parameters. */ uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size); /* Run the spam backend. */ rc = spam(&ss); /* Modify return code based upon the existance of options. */ while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size)) != NULL) { if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER) { /* FAIL so that the message is passed to the next ACL */ rc = FAIL; } } } break; #endif #ifdef EXPERIMENTAL_SPF case ACLC_SPF: rc = spf_process(&arg, sender_address); break; #endif /* If the verb is WARN, discard any user message from verification, because such messages are SMTP responses, not header additions. The latter come only from explicit "message" modifiers. */ case ACLC_VERIFY: rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno); if (verb == ACL_WARN) *user_msgptr = NULL; break; default: log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown " "condition %d", cb->type); break; } /* If a condition was negated, invert OK/FAIL. */ if (!cond_modifiers[cb->type] && cb->u.negated) { if (rc == OK) rc = FAIL; else if (rc == FAIL || rc == FAIL_DROP) rc = OK; } if (rc != OK) break; /* Conditions loop */ } /* If the result is the one for which "message" and/or "log_message" are used, handle the values of these options. Most verbs have but a single return for which the messages are relevant, but for "discard", it's useful to have the log message both when it succeeds and when it fails. Also, for an "accept" that appears in a QUIT ACL, we want to handle the user message. Since only "accept" and "warn" are permitted in that ACL, we don't need to test the verb. These modifiers act in different ways: "message" is a user message that will be included in an SMTP response. Unless it is empty, it overrides any previously set user message. "log_message" is a non-user message, and it adds to any existing non-user message that is already set. If there isn't a log message set, we make it the same as the user message. */ if (((rc == FAIL_DROP)? FAIL : rc) == msgcond[verb] || (verb == ACL_DISCARD && rc == OK) || (where == ACL_WHERE_QUIT)) { uschar *expmessage; /* If the verb is "warn", messages generated by conditions (verification or nested ACLs) are discarded. Only messages specified at this level are used. However, the value of an existing message is available in $acl_verify_message during expansions. */ uschar *old_user_msgptr = *user_msgptr; uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr; if (verb == ACL_WARN) *log_msgptr = *user_msgptr = NULL; if (user_message != NULL) { acl_verify_message = old_user_msgptr; expmessage = expand_string(user_message); if (expmessage == NULL) { if (!expand_string_forcedfail) log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s", user_message, expand_string_message); } else if (expmessage[0] != 0) *user_msgptr = expmessage; } if (log_message != NULL) { acl_verify_message = old_log_msgptr; expmessage = expand_string(log_message); if (expmessage == NULL) { if (!expand_string_forcedfail) log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s", log_message, expand_string_message); } else if (expmessage[0] != 0) { *log_msgptr = (*log_msgptr == NULL)? expmessage : string_sprintf("%s: %s", expmessage, *log_msgptr); } } /* If no log message, default it to the user message */ if (*log_msgptr == NULL) *log_msgptr = *user_msgptr; } acl_verify_message = NULL; return rc; } /************************************************* * Get line from a literal ACL * *************************************************/ /* This function is passed to acl_read() in order to extract individual lines of a literal ACL, which we access via static pointers. We can destroy the contents because this is called only once (the compiled ACL is remembered). This code is intended to treat the data in the same way as lines in the main Exim configuration file. That is: . Leading spaces are ignored. . A \ at the end of a line is a continuation - trailing spaces after the \ are permitted (this is because I don't believe in making invisible things significant). Leading spaces on the continued part of a line are ignored. . Physical lines starting (significantly) with # are totally ignored, and may appear within a sequence of backslash-continued lines. . Blank lines are ignored, but will end a sequence of continuations. Arguments: none Returns: a pointer to the next line */ static uschar *acl_text; /* Current pointer in the text */ static uschar *acl_text_end; /* Points one past the terminating '0' */ static uschar * acl_getline(void) { uschar *yield; /* This loop handles leading blank lines and comments. */ for(;;) { while (isspace(*acl_text)) acl_text++; /* Leading spaces/empty lines */ if (*acl_text == 0) return NULL; /* No more data */ yield = acl_text; /* Potential data line */ while (*acl_text != 0 && *acl_text != '\n') acl_text++; /* If we hit the end before a newline, we have the whole logical line. If it's a comment, there's no more data to be given. Otherwise, yield it. */ if (*acl_text == 0) return (*yield == '#')? NULL : yield; /* After reaching a newline, end this loop if the physical line does not start with '#'. If it does, it's a comment, and the loop continues. */ if (*yield != '#') break; } /* This loop handles continuations. We know we have some real data, ending in newline. See if there is a continuation marker at the end (ignoring trailing white space). We know that *yield is not white space, so no need to test for cont > yield in the backwards scanning loop. */ for(;;) { uschar *cont; for (cont = acl_text - 1; isspace(*cont); cont--); /* If no continuation follows, we are done. Mark the end of the line and return it. */ if (*cont != '\\') { *acl_text++ = 0; return yield; } /* We have encountered a continuation. Skip over whitespace at the start of the next line, and indeed the whole of the next line or lines if they are comment lines. */ for (;;) { while (*(++acl_text) == ' ' || *acl_text == '\t'); if (*acl_text != '#') break; while (*(++acl_text) != 0 && *acl_text != '\n'); } /* We have the start of a continuation line. Move all the rest of the data to join onto the previous line, and then find its end. If the end is not a newline, we are done. Otherwise loop to look for another continuation. */ memmove(cont, acl_text, acl_text_end - acl_text); acl_text_end -= acl_text - cont; acl_text = cont; while (*acl_text != 0 && *acl_text != '\n') acl_text++; if (*acl_text == 0) return yield; } /* Control does not reach here */ } /************************************************* * Check access using an ACL * *************************************************/ /* This function is called from address_check. It may recurse via acl_check_condition() - hence the use of a level to stop looping. The ACL is passed as a string which is expanded. A forced failure implies no access check is required. If the result is a single word, it is taken as the name of an ACL which is sought in the global ACL tree. Otherwise, it is taken as literal ACL text, complete with newlines, and parsed as such. In both cases, the ACL check is then run. This function uses an auxiliary function for acl_read() to call for reading individual lines of a literal ACL. This is acl_getline(), which appears immediately above. Arguments: where where called from addr address item when called from RCPT; otherwise NULL s the input string; NULL is the same as an empty ACL => DENY level the nesting level user_msgptr where to put a user error (for SMTP response) log_msgptr where to put a logging message (not for SMTP response) Returns: OK access is granted DISCARD access is apparently granted... FAIL access is denied FAIL_DROP access is denied; drop the connection DEFER can't tell at the moment ERROR disaster */ static int acl_check_internal(int where, address_item *addr, uschar *s, int level, uschar **user_msgptr, uschar **log_msgptr) { int fd = -1; acl_block *acl = NULL; uschar *acl_name = US"inline ACL"; uschar *ss; /* Catch configuration loops */ if (level > 20) { *log_msgptr = US"ACL nested too deep: possible loop"; return ERROR; } if (s == NULL) { HDEBUG(D_acl) debug_printf("ACL is NULL: implicit DENY\n"); return FAIL; } /* At top level, we expand the incoming string. At lower levels, it has already been expanded as part of condition processing. */ if (level == 0) { ss = expand_string(s); if (ss == NULL) { if (expand_string_forcedfail) return OK; *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s, expand_string_message); return ERROR; } } else ss = s; while (isspace(*ss))ss++; /* If we can't find a named ACL, the default is to parse it as an inline one. (Unless it begins with a slash; non-existent files give rise to an error.) */ acl_text = ss; /* Handle the case of a string that does not contain any spaces. Look for a named ACL among those read from the configuration, or a previously read file. It is possible that the pointer to the ACL is NULL if the configuration contains a name with no data. If not found, and the text begins with '/', read an ACL from a file, and save it so it can be re-used. */ if (Ustrchr(ss, ' ') == NULL) { tree_node *t = tree_search(acl_anchor, ss); if (t != NULL) { acl = (acl_block *)(t->data.ptr); if (acl == NULL) { HDEBUG(D_acl) debug_printf("ACL \"%s\" is empty: implicit DENY\n", ss); return FAIL; } acl_name = string_sprintf("ACL \"%s\"", ss); HDEBUG(D_acl) debug_printf("using ACL \"%s\"\n", ss); } else if (*ss == '/') { struct stat statbuf; fd = Uopen(ss, O_RDONLY, 0); if (fd < 0) { *log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss, strerror(errno)); return ERROR; } if (fstat(fd, &statbuf) != 0) { *log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss, strerror(errno)); return ERROR; } acl_text = store_get(statbuf.st_size + 1); acl_text_end = acl_text + statbuf.st_size + 1; if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size) { *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s", ss, strerror(errno)); return ERROR; } acl_text[statbuf.st_size] = 0; close(fd); acl_name = string_sprintf("ACL \"%s\"", ss); HDEBUG(D_acl) debug_printf("read ACL from file %s\n", ss); } } /* Parse an ACL that is still in text form. If it came from a file, remember it in the ACL tree, having read it into the POOL_PERM store pool so that it persists between multiple messages. */ if (acl == NULL) { int old_pool = store_pool; if (fd >= 0) store_pool = POOL_PERM; acl = acl_read(acl_getline, log_msgptr); store_pool = old_pool; if (acl == NULL && *log_msgptr != NULL) return ERROR; if (fd >= 0) { tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss)); Ustrcpy(t->name, ss); t->data.ptr = acl; (void)tree_insertnode(&acl_anchor, t); } } /* Now we have an ACL to use. It's possible it may be NULL. */ while (acl != NULL) { int cond; int basic_errno = 0; BOOL endpass_seen = FALSE; *log_msgptr = *user_msgptr = NULL; acl_temp_details = FALSE; if (where == ACL_WHERE_QUIT && acl->verb != ACL_ACCEPT && acl->verb != ACL_WARN) { *log_msgptr = string_sprintf("\"%s\" is not allowed in a QUIT ACL", verbs[acl->verb]); return ERROR; } HDEBUG(D_acl) debug_printf("processing \"%s\"\n", verbs[acl->verb]); /* Clear out any search error message from a previous check before testing this condition. */ search_error_message = NULL; cond = acl_check_condition(acl->verb, acl->condition, where, addr, level, &endpass_seen, user_msgptr, log_msgptr, &basic_errno); /* Handle special returns: DEFER causes a return except on a WARN verb; ERROR always causes a return. */ switch (cond) { case DEFER: HDEBUG(D_acl) debug_printf("%s: condition test deferred\n", verbs[acl->verb]); if (basic_errno != ERRNO_CALLOUTDEFER) { if (search_error_message != NULL && *search_error_message != 0) *log_msgptr = search_error_message; if (smtp_return_error_details) acl_temp_details = TRUE; } else { acl_temp_details = TRUE; } if (acl->verb != ACL_WARN) return DEFER; break; default: /* Paranoia */ case ERROR: HDEBUG(D_acl) debug_printf("%s: condition test error\n", verbs[acl->verb]); return ERROR; case OK: HDEBUG(D_acl) debug_printf("%s: condition test succeeded\n", verbs[acl->verb]); break; case FAIL: HDEBUG(D_acl) debug_printf("%s: condition test failed\n", verbs[acl->verb]); break; /* DISCARD and DROP can happen only from a nested ACL condition, and DISCARD can happen only for an "accept" or "discard" verb. */ case DISCARD: HDEBUG(D_acl) debug_printf("%s: condition test yielded \"discard\"\n", verbs[acl->verb]); break; case FAIL_DROP: HDEBUG(D_acl) debug_printf("%s: condition test yielded \"drop\"\n", verbs[acl->verb]); break; } /* At this point, cond for most verbs is either OK or FAIL or (as a result of a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */ switch(acl->verb) { case ACL_ACCEPT: if (cond == OK || cond == DISCARD) return cond; if (endpass_seen) { HDEBUG(D_acl) debug_printf("accept: endpass encountered - denying access\n"); return cond; } break; case ACL_DEFER: if (cond == OK) { acl_temp_details = TRUE; return DEFER; } break; case ACL_DENY: if (cond == OK) return FAIL; break; case ACL_DISCARD: if (cond == OK || cond == DISCARD) return DISCARD; if (endpass_seen) { HDEBUG(D_acl) debug_printf("discard: endpass encountered - denying access\n"); return cond; } break; case ACL_DROP: if (cond == OK) return FAIL_DROP; break; case ACL_REQUIRE: if (cond != OK) return cond; break; case ACL_WARN: if (cond == OK) acl_warn(where, *user_msgptr, *log_msgptr); else if (cond == DEFER) acl_warn(where, NULL, string_sprintf("ACL \"warn\" statement skipped: " "condition test deferred: %s", (*log_msgptr == NULL)? US"" : *log_msgptr)); *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */ break; default: log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d", acl->verb); break; } /* Pass to the next ACL item */ acl = acl->next; } /* We have reached the end of the ACL. This is an implicit DENY. */ HDEBUG(D_acl) debug_printf("end of %s: implicit DENY\n", acl_name); return FAIL; } /************************************************* * Check access using an ACL * *************************************************/ /* This is the external interface for ACL checks. It sets up an address and the expansions for $domain and $local_part when called after RCPT, then calls acl_check_internal() to do the actual work. Arguments: where ACL_WHERE_xxxx indicating where called from data_string RCPT address, or SMTP command argument, or NULL s the input string; NULL is the same as an empty ACL => DENY user_msgptr where to put a user error (for SMTP response) log_msgptr where to put a logging message (not for SMTP response) Returns: OK access is granted by an ACCEPT verb DISCARD access is granted by a DISCARD verb FAIL access is denied FAIL_DROP access is denied; drop the connection DEFER can't tell at the moment ERROR disaster */ int acl_check(int where, uschar *data_string, uschar *s, uschar **user_msgptr, uschar **log_msgptr) { int rc; address_item adb; address_item *addr; *user_msgptr = *log_msgptr = NULL; sender_verified_failed = NULL; if (where == ACL_WHERE_RCPT) { adb = address_defaults; addr = &adb; addr->address = data_string; if (deliver_split_address(addr) == DEFER) { *log_msgptr = US"defer in percent_hack_domains check"; return DEFER; } deliver_domain = addr->domain; deliver_localpart = addr->local_part; } else { addr = NULL; smtp_command_argument = data_string; } rc = acl_check_internal(where, addr, s, 0, user_msgptr, log_msgptr); smtp_command_argument = deliver_domain = deliver_localpart = deliver_address_data = sender_address_data = NULL; /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA ACL, which is really in the middle of an SMTP command. */ if (rc == DISCARD) { if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA) { log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s " "ACL", acl_wherenames[where]); return ERROR; } return DISCARD; } /* A DROP response is not permitted from MAILAUTH */ if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH) { log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s " "ACL", acl_wherenames[where]); return ERROR; } /* Before giving an error response, take a look at the length of any user message, and split it up into multiple lines if possible. */ if (rc != OK && *user_msgptr != NULL && Ustrlen(*user_msgptr) > 75) { uschar *s = *user_msgptr = string_copy(*user_msgptr); uschar *ss = s; for (;;) { int i = 0; while (i < 75 && *ss != 0 && *ss != '\n') ss++, i++; if (*ss == 0) break; if (*ss == '\n') s = ++ss; else { uschar *t = ss + 1; uschar *tt = NULL; while (--t > s + 35) { if (*t == ' ') { if (t[-1] == ':') { tt = t; break; } if (tt == NULL) tt = t; } } if (tt == NULL) /* Can't split behind - try ahead */ { t = ss + 1; while (*t != 0) { if (*t == ' ' || *t == '\n') { tt = t; break; } t++; } } if (tt == NULL) break; /* Can't find anywhere to split */ *tt = '\n'; s = ss = tt+1; } } } return rc; } /* End of acl.c */