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Diffstat (limited to 'src/acl.c')
| -rw-r--r-- | src/acl.c | 4896 |
1 files changed, 4896 insertions, 0 deletions
diff --git a/src/acl.c b/src/acl.c new file mode 100644 index 0000000..fb78a7b --- /dev/null +++ b/src/acl.c @@ -0,0 +1,4896 @@ +/************************************************* +* Exim - an Internet mail transport agent * +*************************************************/ + +/* Copyright (c) The Exim Maintainers 2020 - 2022 */ +/* Copyright (c) University of Cambridge 1995 - 2018 */ +/* See the file NOTICE for conditions of use and distribution. */ + +/* Code for handling Access Control Lists (ACLs) */ + +#include "exim.h" + +#ifndef MACRO_PREDEF + +/* Default callout timeout */ + +#define CALLOUT_TIMEOUT_DEFAULT 30 + +/* Default quota cache TTLs */ + +#define QUOTA_POS_DEFAULT (5*60) +#define QUOTA_NEG_DEFAULT (60*60) + + +/* 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[] = { + [ACL_ACCEPT] = US"accept", + [ACL_DEFER] = US"defer", + [ACL_DENY] = US"deny", + [ACL_DISCARD] = US"discard", + [ACL_DROP] = US"drop", + [ACL_REQUIRE] = US"require", + [ACL_WARN] = US"warn" +}; + +/* For each verb, the conditions for which "message" or "log_message" are used +are held as a bitmap. This is to avoid expanding the strings unnecessarily. For +"accept", the FAIL case is used only after "endpass", but that is selected in +the code. */ + +static int msgcond[] = { + [ACL_ACCEPT] = BIT(OK) | BIT(FAIL) | BIT(FAIL_DROP), + [ACL_DEFER] = BIT(OK), + [ACL_DENY] = BIT(OK), + [ACL_DISCARD] = BIT(OK) | BIT(FAIL) | BIT(FAIL_DROP), + [ACL_DROP] = BIT(OK), + [ACL_REQUIRE] = BIT(FAIL) | BIT(FAIL_DROP), + [ACL_WARN] = BIT(OK) + }; + +#endif + +/* ACL condition and modifier codes - keep in step with the table that +follows. +down. */ + +enum { ACLC_ACL, + ACLC_ADD_HEADER, + ACLC_AUTHENTICATED, +#ifdef EXPERIMENTAL_BRIGHTMAIL + ACLC_BMI_OPTIN, +#endif + ACLC_CONDITION, + ACLC_CONTINUE, + ACLC_CONTROL, +#ifdef EXPERIMENTAL_DCC + ACLC_DCC, +#endif +#ifdef WITH_CONTENT_SCAN + ACLC_DECODE, +#endif + ACLC_DELAY, +#ifndef DISABLE_DKIM + ACLC_DKIM_SIGNER, + ACLC_DKIM_STATUS, +#endif +#ifdef SUPPORT_DMARC + ACLC_DMARC_STATUS, +#endif + ACLC_DNSLISTS, + ACLC_DOMAINS, + ACLC_ENCRYPTED, + ACLC_ENDPASS, + ACLC_HOSTS, + ACLC_LOCAL_PARTS, + ACLC_LOG_MESSAGE, + ACLC_LOG_REJECT_TARGET, + ACLC_LOGWRITE, +#ifdef WITH_CONTENT_SCAN + ACLC_MALWARE, +#endif + ACLC_MESSAGE, +#ifdef WITH_CONTENT_SCAN + ACLC_MIME_REGEX, +#endif + ACLC_QUEUE, + ACLC_RATELIMIT, + ACLC_RECIPIENTS, +#ifdef WITH_CONTENT_SCAN + ACLC_REGEX, +#endif + ACLC_REMOVE_HEADER, + ACLC_SEEN, + ACLC_SENDER_DOMAINS, + ACLC_SENDERS, + ACLC_SET, +#ifdef WITH_CONTENT_SCAN + ACLC_SPAM, +#endif +#ifdef SUPPORT_SPF + ACLC_SPF, + ACLC_SPF_GUESS, +#endif + ACLC_UDPSEND, + ACLC_VERIFY }; + +/* ACL conditions/modifiers: "delay", "control", "continue", "endpass", +"message", "log_message", "log_reject_target", "logwrite", "queue" and "set" are +modifiers that look like conditions but always return TRUE. They are used for +their side effects. Do not invent new modifier names that result in one name +being the prefix of another; the binary-search in the list will go wrong. */ + +typedef struct condition_def { + uschar *name; + +/* Flag to indicate the condition/modifier has a string expansion done +at the outer level. In the other cases, expansion already occurs in the +checking functions. */ + BOOL expand_at_top:1; + + BOOL is_modifier:1; + +/* Bit map vector of which conditions and modifiers are not allowed at certain +times. For each condition and modifier, there's a bitmap of dis-allowed times. +For some, it is easier to specify the negation of a small number of allowed +times. */ + unsigned forbids; + +} condition_def; + +static condition_def conditions[] = { + [ACLC_ACL] = { US"acl", FALSE, FALSE, 0 }, + + [ACLC_ADD_HEADER] = { US"add_header", TRUE, TRUE, + (unsigned int) + ~(ACL_BIT_MAIL | ACL_BIT_RCPT | + ACL_BIT_PREDATA | ACL_BIT_DATA | +#ifndef DISABLE_PRDR + ACL_BIT_PRDR | +#endif + ACL_BIT_MIME | ACL_BIT_NOTSMTP | + ACL_BIT_DKIM | + ACL_BIT_NOTSMTP_START), + }, + + [ACLC_AUTHENTICATED] = { US"authenticated", FALSE, FALSE, + ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START | + ACL_BIT_CONNECT | ACL_BIT_HELO, + }, +#ifdef EXPERIMENTAL_BRIGHTMAIL + [ACLC_BMI_OPTIN] = { US"bmi_optin", TRUE, TRUE, + ACL_BIT_AUTH | + ACL_BIT_CONNECT | ACL_BIT_HELO | + ACL_BIT_DATA | ACL_BIT_MIME | +# ifndef DISABLE_PRDR + ACL_BIT_PRDR | +# endif + ACL_BIT_ETRN | ACL_BIT_EXPN | + ACL_BIT_MAILAUTH | + ACL_BIT_MAIL | ACL_BIT_STARTTLS | + ACL_BIT_VRFY | ACL_BIT_PREDATA | + ACL_BIT_NOTSMTP_START, + }, +#endif + [ACLC_CONDITION] = { US"condition", TRUE, FALSE, 0 }, + [ACLC_CONTINUE] = { US"continue", TRUE, TRUE, 0 }, + + /* Certain types of control are always allowed, so we let it through + always and check in the control processing itself. */ + [ACLC_CONTROL] = { US"control", TRUE, TRUE, 0 }, + +#ifdef EXPERIMENTAL_DCC + [ACLC_DCC] = { US"dcc", TRUE, FALSE, + (unsigned int) + ~(ACL_BIT_DATA | +# ifndef DISABLE_PRDR + ACL_BIT_PRDR | +# endif + ACL_BIT_NOTSMTP), + }, +#endif +#ifdef WITH_CONTENT_SCAN + [ACLC_DECODE] = { US"decode", TRUE, FALSE, (unsigned int) ~ACL_BIT_MIME }, + +#endif + [ACLC_DELAY] = { US"delay", TRUE, TRUE, ACL_BIT_NOTQUIT }, +#ifndef DISABLE_DKIM + [ACLC_DKIM_SIGNER] = { US"dkim_signers", TRUE, FALSE, (unsigned int) ~ACL_BIT_DKIM }, + [ACLC_DKIM_STATUS] = { US"dkim_status", TRUE, FALSE, (unsigned int) ~ACL_BIT_DKIM }, +#endif +#ifdef SUPPORT_DMARC + [ACLC_DMARC_STATUS] = { US"dmarc_status", TRUE, FALSE, (unsigned int) ~ACL_BIT_DATA }, +#endif + + /* Explicit key lookups can be made in non-smtp ACLs so pass + always and check in the verify processing itself. */ + [ACLC_DNSLISTS] = { US"dnslists", TRUE, FALSE, 0 }, + + [ACLC_DOMAINS] = { US"domains", FALSE, FALSE, + (unsigned int) + ~(ACL_BIT_RCPT | ACL_BIT_VRFY +#ifndef DISABLE_PRDR + |ACL_BIT_PRDR +#endif + ), + }, + [ACLC_ENCRYPTED] = { US"encrypted", FALSE, FALSE, + ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START | + ACL_BIT_HELO, + }, + + [ACLC_ENDPASS] = { US"endpass", TRUE, TRUE, 0 }, + + [ACLC_HOSTS] = { US"hosts", FALSE, FALSE, + ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START, + }, + [ACLC_LOCAL_PARTS] = { US"local_parts", FALSE, FALSE, + (unsigned int) + ~(ACL_BIT_RCPT | ACL_BIT_VRFY +#ifndef DISABLE_PRDR + | ACL_BIT_PRDR +#endif + ), + }, + + [ACLC_LOG_MESSAGE] = { US"log_message", TRUE, TRUE, 0 }, + [ACLC_LOG_REJECT_TARGET] = { US"log_reject_target", TRUE, TRUE, 0 }, + [ACLC_LOGWRITE] = { US"logwrite", TRUE, TRUE, 0 }, + +#ifdef WITH_CONTENT_SCAN + [ACLC_MALWARE] = { US"malware", TRUE, FALSE, + (unsigned int) + ~(ACL_BIT_DATA | +# ifndef DISABLE_PRDR + ACL_BIT_PRDR | +# endif + ACL_BIT_NOTSMTP), + }, +#endif + + [ACLC_MESSAGE] = { US"message", TRUE, TRUE, 0 }, +#ifdef WITH_CONTENT_SCAN + [ACLC_MIME_REGEX] = { US"mime_regex", TRUE, FALSE, (unsigned int) ~ACL_BIT_MIME }, +#endif + + [ACLC_QUEUE] = { US"queue", TRUE, TRUE, + ACL_BIT_NOTSMTP | +#ifndef DISABLE_PRDR + ACL_BIT_PRDR | +#endif + ACL_BIT_DATA, + }, + + [ACLC_RATELIMIT] = { US"ratelimit", TRUE, FALSE, 0 }, + [ACLC_RECIPIENTS] = { US"recipients", FALSE, FALSE, (unsigned int) ~ACL_BIT_RCPT }, + +#ifdef WITH_CONTENT_SCAN + [ACLC_REGEX] = { US"regex", TRUE, FALSE, + (unsigned int) + ~(ACL_BIT_DATA | +# ifndef DISABLE_PRDR + ACL_BIT_PRDR | +# endif + ACL_BIT_NOTSMTP | + ACL_BIT_MIME), + }, + +#endif + [ACLC_REMOVE_HEADER] = { US"remove_header", TRUE, TRUE, + (unsigned int) + ~(ACL_BIT_MAIL|ACL_BIT_RCPT | + ACL_BIT_PREDATA | ACL_BIT_DATA | +#ifndef DISABLE_PRDR + ACL_BIT_PRDR | +#endif + ACL_BIT_MIME | ACL_BIT_NOTSMTP | + ACL_BIT_NOTSMTP_START), + }, + [ACLC_SEEN] = { US"seen", TRUE, FALSE, 0 }, + [ACLC_SENDER_DOMAINS] = { US"sender_domains", FALSE, FALSE, + ACL_BIT_AUTH | ACL_BIT_CONNECT | + ACL_BIT_HELO | + ACL_BIT_MAILAUTH | ACL_BIT_QUIT | + ACL_BIT_ETRN | ACL_BIT_EXPN | + ACL_BIT_STARTTLS | ACL_BIT_VRFY, + }, + [ACLC_SENDERS] = { US"senders", FALSE, FALSE, + ACL_BIT_AUTH | ACL_BIT_CONNECT | + ACL_BIT_HELO | + ACL_BIT_MAILAUTH | ACL_BIT_QUIT | + ACL_BIT_ETRN | ACL_BIT_EXPN | + ACL_BIT_STARTTLS | ACL_BIT_VRFY, + }, + + [ACLC_SET] = { US"set", TRUE, TRUE, 0 }, + +#ifdef WITH_CONTENT_SCAN + [ACLC_SPAM] = { US"spam", TRUE, FALSE, + (unsigned int) ~(ACL_BIT_DATA | +# ifndef DISABLE_PRDR + ACL_BIT_PRDR | +# endif + ACL_BIT_NOTSMTP), + }, +#endif +#ifdef SUPPORT_SPF + [ACLC_SPF] = { US"spf", TRUE, FALSE, + ACL_BIT_AUTH | ACL_BIT_CONNECT | + ACL_BIT_HELO | ACL_BIT_MAILAUTH | + ACL_BIT_ETRN | ACL_BIT_EXPN | + ACL_BIT_STARTTLS | ACL_BIT_VRFY | + ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START, + }, + [ACLC_SPF_GUESS] = { US"spf_guess", TRUE, FALSE, + ACL_BIT_AUTH | ACL_BIT_CONNECT | + ACL_BIT_HELO | ACL_BIT_MAILAUTH | + ACL_BIT_ETRN | ACL_BIT_EXPN | + ACL_BIT_STARTTLS | ACL_BIT_VRFY | + ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START, + }, +#endif + [ACLC_UDPSEND] = { US"udpsend", TRUE, TRUE, 0 }, + + /* Certain types of verify are always allowed, so we let it through + always and check in the verify function itself */ + [ACLC_VERIFY] = { US"verify", TRUE, FALSE, 0 }, +}; + + +#ifdef MACRO_PREDEF +# include "macro_predef.h" +void +features_acl(void) +{ +for (condition_def * c = conditions; c < conditions + nelem(conditions); c++) + { + uschar buf[64], * p, * s; + int n = sprintf(CS buf, "_ACL_%s_", c->is_modifier ? "MOD" : "COND"); + for (p = buf + n, s = c->name; *s; s++) *p++ = toupper(*s); + *p = '\0'; + builtin_macro_create(buf); + } +} +#endif + + +#ifndef MACRO_PREDEF + +/* Return values from decode_control(); used as index so keep in step +with the controls_list table that follows! */ + +enum { + CONTROL_AUTH_UNADVERTISED, +#ifdef EXPERIMENTAL_BRIGHTMAIL + CONTROL_BMI_RUN, +#endif + CONTROL_CASEFUL_LOCAL_PART, + CONTROL_CASELOWER_LOCAL_PART, + CONTROL_CUTTHROUGH_DELIVERY, + CONTROL_DEBUG, +#ifndef DISABLE_DKIM + CONTROL_DKIM_VERIFY, +#endif +#ifdef SUPPORT_DMARC + CONTROL_DMARC_VERIFY, + CONTROL_DMARC_FORENSIC, +#endif + CONTROL_DSCP, + CONTROL_ENFORCE_SYNC, + CONTROL_ERROR, /* pseudo-value for decode errors */ + CONTROL_FAKEDEFER, + CONTROL_FAKEREJECT, + CONTROL_FREEZE, + + CONTROL_NO_CALLOUT_FLUSH, + CONTROL_NO_DELAY_FLUSH, + CONTROL_NO_ENFORCE_SYNC, +#ifdef WITH_CONTENT_SCAN + CONTROL_NO_MBOX_UNSPOOL, +#endif + CONTROL_NO_MULTILINE, + CONTROL_NO_PIPELINING, + + CONTROL_QUEUE, + CONTROL_SUBMISSION, + CONTROL_SUPPRESS_LOCAL_FIXUPS, +#ifdef SUPPORT_I18N + CONTROL_UTF8_DOWNCONVERT, +#endif +}; + + + +/* Structure listing various control arguments, with their characteristics. +For each control, there's a bitmap of dis-allowed times. For some, it is easier +to specify the negation of a small number of allowed times. */ + +typedef struct control_def { + uschar *name; + BOOL has_option; /* Has /option(s) following */ + unsigned forbids; /* bitmap of dis-allowed times */ +} control_def; + +static control_def controls_list[] = { + /* name has_option forbids */ +[CONTROL_AUTH_UNADVERTISED] = + { US"allow_auth_unadvertised", FALSE, + (unsigned) + ~(ACL_BIT_CONNECT | ACL_BIT_HELO) + }, +#ifdef EXPERIMENTAL_BRIGHTMAIL +[CONTROL_BMI_RUN] = + { US"bmi_run", FALSE, 0 }, +#endif +[CONTROL_CASEFUL_LOCAL_PART] = + { US"caseful_local_part", FALSE, (unsigned) ~ACL_BIT_RCPT }, +[CONTROL_CASELOWER_LOCAL_PART] = + { US"caselower_local_part", FALSE, (unsigned) ~ACL_BIT_RCPT }, +[CONTROL_CUTTHROUGH_DELIVERY] = + { US"cutthrough_delivery", TRUE, 0 }, +[CONTROL_DEBUG] = + { US"debug", TRUE, 0 }, + +#ifndef DISABLE_DKIM +[CONTROL_DKIM_VERIFY] = + { US"dkim_disable_verify", FALSE, + ACL_BIT_DATA | ACL_BIT_NOTSMTP | +# ifndef DISABLE_PRDR + ACL_BIT_PRDR | +# endif + ACL_BIT_NOTSMTP_START + }, +#endif + +#ifdef SUPPORT_DMARC +[CONTROL_DMARC_VERIFY] = + { US"dmarc_disable_verify", FALSE, + ACL_BIT_DATA | ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START + }, +[CONTROL_DMARC_FORENSIC] = + { US"dmarc_enable_forensic", FALSE, + ACL_BIT_DATA | ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START + }, +#endif + +[CONTROL_DSCP] = + { US"dscp", TRUE, + ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START | ACL_BIT_NOTQUIT + }, +[CONTROL_ENFORCE_SYNC] = + { US"enforce_sync", FALSE, + ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START + }, + + /* Pseudo-value for decode errors */ +[CONTROL_ERROR] = + { US"error", FALSE, 0 }, + +[CONTROL_FAKEDEFER] = + { US"fakedefer", TRUE, + (unsigned) + ~(ACL_BIT_MAIL | ACL_BIT_RCPT | + ACL_BIT_PREDATA | ACL_BIT_DATA | +#ifndef DISABLE_PRDR + ACL_BIT_PRDR | +#endif + ACL_BIT_MIME) + }, +[CONTROL_FAKEREJECT] = + { US"fakereject", TRUE, + (unsigned) + ~(ACL_BIT_MAIL | ACL_BIT_RCPT | + ACL_BIT_PREDATA | ACL_BIT_DATA | +#ifndef DISABLE_PRDR + ACL_BIT_PRDR | +#endif + ACL_BIT_MIME) + }, +[CONTROL_FREEZE] = + { US"freeze", TRUE, + (unsigned) + ~(ACL_BIT_MAIL | ACL_BIT_RCPT | + ACL_BIT_PREDATA | ACL_BIT_DATA | + // ACL_BIT_PRDR| /* Not allow one user to freeze for all */ + ACL_BIT_NOTSMTP | ACL_BIT_MIME) + }, + +[CONTROL_NO_CALLOUT_FLUSH] = + { US"no_callout_flush", FALSE, + ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START + }, +[CONTROL_NO_DELAY_FLUSH] = + { US"no_delay_flush", FALSE, + ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START + }, + +[CONTROL_NO_ENFORCE_SYNC] = + { US"no_enforce_sync", FALSE, + ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START + }, +#ifdef WITH_CONTENT_SCAN +[CONTROL_NO_MBOX_UNSPOOL] = + { US"no_mbox_unspool", FALSE, + (unsigned) + ~(ACL_BIT_MAIL | ACL_BIT_RCPT | + ACL_BIT_PREDATA | ACL_BIT_DATA | + // ACL_BIT_PRDR| /* Not allow one user to freeze for all */ + ACL_BIT_MIME) + }, +#endif +[CONTROL_NO_MULTILINE] = + { US"no_multiline_responses", FALSE, + ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START + }, +[CONTROL_NO_PIPELINING] = + { US"no_pipelining", FALSE, + ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START + }, + +[CONTROL_QUEUE] = + { US"queue", TRUE, + (unsigned) + ~(ACL_BIT_MAIL | ACL_BIT_RCPT | + ACL_BIT_PREDATA | ACL_BIT_DATA | + // ACL_BIT_PRDR| /* Not allow one user to freeze for all */ + ACL_BIT_NOTSMTP | ACL_BIT_MIME) + }, + +[CONTROL_SUBMISSION] = + { US"submission", TRUE, + (unsigned) + ~(ACL_BIT_MAIL | ACL_BIT_RCPT | ACL_BIT_PREDATA) + }, +[CONTROL_SUPPRESS_LOCAL_FIXUPS] = + { US"suppress_local_fixups", FALSE, + (unsigned) + ~(ACL_BIT_MAIL | ACL_BIT_RCPT | ACL_BIT_PREDATA | + ACL_BIT_NOTSMTP_START) + }, +#ifdef SUPPORT_I18N +[CONTROL_UTF8_DOWNCONVERT] = + { US"utf8_downconvert", TRUE, (unsigned) ~(ACL_BIT_RCPT | ACL_BIT_VRFY) + } +#endif +}; + +/* Support data structures for Client SMTP Authorization. acl_verify_csa() +caches its result in a tree to avoid repeated DNS queries. The result is an +integer code which is used as an index into the following tables of +explanatory strings and verification return codes. */ + +static tree_node *csa_cache = NULL; + +enum { CSA_UNKNOWN, CSA_OK, CSA_DEFER_SRV, CSA_DEFER_ADDR, + CSA_FAIL_EXPLICIT, CSA_FAIL_DOMAIN, CSA_FAIL_NOADDR, CSA_FAIL_MISMATCH }; + +/* The acl_verify_csa() return code is translated into an acl_verify() return +code using the following table. It is OK unless the client is definitely not +authorized. This is because CSA is supposed to be optional for sending sites, +so recipients should not be too strict about checking it - especially because +DNS problems are quite likely to occur. It's possible to use $csa_status in +further ACL conditions to distinguish ok, unknown, and defer if required, but +the aim is to make the usual configuration simple. */ + +static int csa_return_code[] = { + [CSA_UNKNOWN] = OK, + [CSA_OK] = OK, + [CSA_DEFER_SRV] = OK, + [CSA_DEFER_ADDR] = OK, + [CSA_FAIL_EXPLICIT] = FAIL, + [CSA_FAIL_DOMAIN] = FAIL, + [CSA_FAIL_NOADDR] = FAIL, + [CSA_FAIL_MISMATCH] = FAIL +}; + +static uschar *csa_status_string[] = { + [CSA_UNKNOWN] = US"unknown", + [CSA_OK] = US"ok", + [CSA_DEFER_SRV] = US"defer", + [CSA_DEFER_ADDR] = US"defer", + [CSA_FAIL_EXPLICIT] = US"fail", + [CSA_FAIL_DOMAIN] = US"fail", + [CSA_FAIL_NOADDR] = US"fail", + [CSA_FAIL_MISMATCH] = US"fail" +}; + +static uschar *csa_reason_string[] = { + [CSA_UNKNOWN] = US"unknown", + [CSA_OK] = US"ok", + [CSA_DEFER_SRV] = US"deferred (SRV lookup failed)", + [CSA_DEFER_ADDR] = US"deferred (target address lookup failed)", + [CSA_FAIL_EXPLICIT] = US"failed (explicit authorization required)", + [CSA_FAIL_DOMAIN] = US"failed (host name not authorized)", + [CSA_FAIL_NOADDR] = US"failed (no authorized addresses)", + [CSA_FAIL_MISMATCH] = US"failed (client address mismatch)" +}; + +/* Options for the ratelimit condition. Note that there are two variants of +the per_rcpt option, depending on the ACL that is used to measure the rate. +However any ACL must be able to look up per_rcpt rates in /noupdate mode, +so the two variants must have the same internal representation as well as +the same configuration string. */ + +enum { + RATE_PER_WHAT, RATE_PER_CLASH, RATE_PER_ADDR, RATE_PER_BYTE, RATE_PER_CMD, + RATE_PER_CONN, RATE_PER_MAIL, RATE_PER_RCPT, RATE_PER_ALLRCPTS +}; + +#define RATE_SET(var,new) \ + (((var) == RATE_PER_WHAT) ? ((var) = RATE_##new) : ((var) = RATE_PER_CLASH)) + +static uschar *ratelimit_option_string[] = { + [RATE_PER_WHAT] = US"?", + [RATE_PER_CLASH] = US"!", + [RATE_PER_ADDR] = US"per_addr", + [RATE_PER_BYTE] = US"per_byte", + [RATE_PER_CMD] = US"per_cmd", + [RATE_PER_CONN] = US"per_conn", + [RATE_PER_MAIL] = US"per_mail", + [RATE_PER_RCPT] = US"per_rcpt", + [RATE_PER_ALLRCPTS] = US"per_rcpt" +}; + +/* Enable recursion between acl_check_internal() and acl_check_condition() */ + +static int acl_check_wargs(int, address_item *, const uschar *, uschar **, + uschar **); + +static acl_block * acl_current = NULL; + + +/************************************************* +* Find control in list * +*************************************************/ + +/* The lists are always in order, so binary chop can be used. + +Arguments: + name the control name to search for + ol the first entry in the control list + last one more than the offset of the last entry in the control list + +Returns: index of a control entry, or -1 if not found +*/ + +static int +find_control(const uschar * name, control_def * ol, int last) +{ +for (int first = 0; last > first; ) + { + int middle = (first + last)/2; + uschar * s = ol[middle].name; + int c = Ustrncmp(name, s, Ustrlen(s)); + if (c == 0) return middle; + else if (c > 0) first = middle + 1; + else last = middle; + } +return -1; +} + + + +/************************************************* +* Pick out condition from list * +*************************************************/ + +/* Use a binary chop method + +Arguments: + name name to find + list list of conditions + end size of list + +Returns: offset in list, or -1 if not found +*/ + +static int +acl_checkcondition(uschar * name, condition_def * list, int end) +{ +for (int start = 0; start < end; ) + { + int mid = (start + end)/2; + int c = Ustrcmp(name, list[mid].name); + if (c == 0) return mid; + if (c < 0) end = mid; + else start = mid + 1; + } +return -1; +} + + +/************************************************* +* Pick out name from list * +*************************************************/ + +/* Use a binary chop method + +Arguments: + name name to find + list list of names + end size of list + +Returns: offset in list, or -1 if not found +*/ + +static int +acl_checkname(uschar *name, uschar **list, int end) +{ +for (int start = 0; start < end; ) + { + int mid = (start + end)/2; + int c = Ustrcmp(name, list[mid]); + if (c == 0) return mid; + if (c < 0) end = mid; else start = mid + 1; + } + +return -1; +} + + +/************************************************* +* Read and parse one ACL * +*************************************************/ + +/* This function is called both from readconf in order to parse the ACLs in the +configuration file, and also when an ACL is encountered dynamically (e.g. as +the result of an expansion). It is given a function to call in order to +retrieve the lines of the ACL. This function handles skipping comments and +blank lines (where relevant). + +Arguments: + func function to get next line of ACL + error where to put an error message + +Returns: pointer to ACL, or NULL + NULL can be legal (empty ACL); in this case error will be NULL +*/ + +acl_block * +acl_read(uschar *(*func)(void), uschar **error) +{ +acl_block *yield = NULL; +acl_block **lastp = &yield; +acl_block *this = NULL; +acl_condition_block *cond; +acl_condition_block **condp = NULL; +uschar * s; + +*error = NULL; + +while ((s = (*func)())) + { + int v, c; + BOOL negated = FALSE; + uschar *saveline = s; + uschar name[EXIM_DRIVERNAME_MAX]; + + /* Conditions (but not verbs) are allowed to be negated by an initial + exclamation mark. */ + + if (Uskip_whitespace(&s) == '!') + { + negated = TRUE; + s++; + } + + /* Read the name of a verb or a condition, or the start of a new ACL, which + can be started by a name, or by a macro definition. */ + + s = readconf_readname(name, sizeof(name), s); + if (*s == ':' || (isupper(name[0]) && *s == '=')) return yield; + + /* If a verb is unrecognized, it may be another condition or modifier that + continues the previous verb. */ + + if ((v = acl_checkname(name, verbs, nelem(verbs))) < 0) + { + if (!this) + { + *error = string_sprintf("unknown ACL verb \"%s\" in \"%s\"", name, + saveline); + return NULL; + } + } + + /* New verb */ + + else + { + if (negated) + { + *error = string_sprintf("malformed ACL line \"%s\"", saveline); + return NULL; + } + this = store_get(sizeof(acl_block), GET_UNTAINTED); + *lastp = this; + lastp = &(this->next); + this->next = NULL; + this->condition = NULL; + this->verb = v; + this->srcline = config_lineno; /* for debug output */ + this->srcfile = config_filename; /**/ + 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. */ + + if ((c = acl_checkcondition(name, conditions, nelem(conditions))) < 0) + { + *error = string_sprintf("unknown ACL condition/modifier in \"%s\"", + saveline); + return NULL; + } + + /* The modifiers may not be negated */ + + if (negated && conditions[c].is_modifier) + { + *error = string_sprintf("ACL error: negation is not allowed with " + "\"%s\"", conditions[c].name); + 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].name, verbs[this->verb]); + return NULL; + } + + cond = store_get(sizeof(acl_condition_block), GET_UNTAINTED); + 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 name to insert into the data block. The original ACL + variable names were acl_c0 ... acl_c9 and acl_m0 ... acl_m9. This was + extended to 20 of each type, but after that people successfully argued for + arbitrary names. In the new scheme, the names must start with acl_c or acl_m. + After that, we allow alphanumerics and underscores, but the first character + after c or m must be a digit or an underscore. This retains backwards + compatibility. */ + + if (c == ACLC_SET) +#ifndef DISABLE_DKIM + if ( Ustrncmp(s, "dkim_verify_status", 18) == 0 + || Ustrncmp(s, "dkim_verify_reason", 18) == 0) + { + uschar * endptr = s+18; + + if (isalnum(*endptr)) + { + *error = string_sprintf("invalid variable name after \"set\" in ACL " + "modifier \"set %s\" " + "(only \"dkim_verify_status\" or \"dkim_verify_reason\" permitted)", + s); + return NULL; + } + cond->u.varname = string_copyn(s, 18); + s = endptr; + Uskip_whitespace(&s); + } + else +#endif + { + uschar *endptr; + + if (Ustrncmp(s, "acl_c", 5) != 0 && Ustrncmp(s, "acl_m", 5) != 0) + { + *error = string_sprintf("invalid variable name after \"set\" in ACL " + "modifier \"set %s\" (must start \"acl_c\" or \"acl_m\")", s); + return NULL; + } + + endptr = s + 5; + if (!isdigit(*endptr) && *endptr != '_') + { + *error = string_sprintf("invalid variable name after \"set\" in ACL " + "modifier \"set %s\" (digit or underscore must follow acl_c or acl_m)", + s); + return NULL; + } + + while (*endptr && *endptr != '=' && !isspace(*endptr)) + { + if (!isalnum(*endptr) && *endptr != '_') + { + *error = string_sprintf("invalid character \"%c\" in variable name " + "in ACL modifier \"set %s\"", *endptr, s); + return NULL; + } + endptr++; + } + + cond->u.varname = string_copyn(s + 4, endptr - s - 4); + s = endptr; + Uskip_whitespace(&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, + conditions[c].is_modifier ? US"modifier" : US"condition"); + return NULL; + } + Uskip_whitespace(&s); + cond->arg = string_copy(s); + } + } + +return yield; +} + + + +/************************************************* +* Set up added header line(s) * +*************************************************/ + +/* This function is called by the add_header modifier, and also from acl_warn() +to implement the now-deprecated way of adding header lines using "message" on a +"warn" verb. The argument is treated as a sequence of header lines which are +added to a chain, provided there isn't an identical one already there. + +Argument: string of header lines +Returns: nothing +*/ + +static void +setup_header(const uschar *hstring) +{ +const uschar *p, *q; +int hlen = Ustrlen(hstring); + +/* Ignore any leading newlines */ +while (*hstring == '\n') hstring++, hlen--; + +/* An empty string does nothing; ensure exactly one final newline. */ +if (hlen <= 0) return; +if (hstring[--hlen] != '\n') /* no newline */ + q = string_sprintf("%s\n", hstring); +else if (hstring[hlen-1] == '\n') /* double newline */ + { + uschar * s = string_copy(hstring); + while(s[--hlen] == '\n') + s[hlen+1] = '\0'; + q = s; + } +else + q = hstring; + +/* Loop for multiple header lines, taking care about continuations */ + +for (p = q; *p; p = q) + { + const uschar *s; + uschar * hdr; + int newtype = htype_add_bot; + header_line **hptr = &acl_added_headers; + + /* Find next header line within the string */ + + for (;;) + { + q = Ustrchr(q, '\n'); /* we know there was a newline */ + 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; + + hdr = string_sprintf("%s%.*s", *s == ':' ? "" : "X-ACL-Warn: ", (int) (q - p), p); + hlen = Ustrlen(hdr); + + /* See if this line has already been added */ + + while (*hptr) + { + if (Ustrncmp((*hptr)->text, hdr, hlen) == 0) break; + hptr = &(*hptr)->next; + } + + /* Add if not previously present */ + + if (!*hptr) + { + /* The header_line struct itself is not tainted, though it points to + possibly tainted data. */ + header_line * h = store_get(sizeof(header_line), GET_UNTAINTED); + h->text = hdr; + h->next = NULL; + h->type = newtype; + h->slen = hlen; + *hptr = h; + hptr = &h->next; + } + } +} + + + +/************************************************* +* List the added header lines * +*************************************************/ +uschar * +fn_hdrs_added(void) +{ +gstring * g = NULL; + +for (header_line * h = acl_added_headers; h; h = h->next) + { + int i = h->slen; + if (h->text[i-1] == '\n') i--; + g = string_append_listele_n(g, '\n', h->text, i); + } + +return g ? g->s : NULL; +} + + +/************************************************* +* Set up removed header line(s) * +*************************************************/ + +/* This function is called by the remove_header modifier. The argument is +treated as a sequence of header names which are added to a colon separated +list, provided there isn't an identical one already there. + +Argument: string of header names +Returns: nothing +*/ + +static void +setup_remove_header(const uschar *hnames) +{ +if (*hnames) + acl_removed_headers = acl_removed_headers + ? string_sprintf("%s : %s", acl_removed_headers, hnames) + : string_copy(hnames); +} + + + +/************************************************* +* 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). + +** NOTE: The header adding action using the "message" setting is historic, and +its use is now deprecated. The new add_header modifier should be used instead. + +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) +{ +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; logged = logged->next) + if (Ustrcmp(logged->text, text) == 0) break; + + if (!logged) + { + int length = Ustrlen(text) + 1; + log_write(0, LOG_MAIN, "%s", text); + logged = store_malloc(sizeof(string_item) + length); + logged->text = US 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) 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; + } + +/* The code for setting up header lines is now abstracted into a separate +function so that it can be used for the add_header modifier as well. */ + +setup_header(user_message); +} + + + +/************************************************* +* 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; + +/* Previous success */ + +if (sender_host_name) 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_indent("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; +} + + + +/************************************************* +* Check client IP address matches CSA target * +*************************************************/ + +/* Called from acl_verify_csa() below. This routine scans a section of a DNS +response for address records belonging to the CSA target hostname. The section +is specified by the reset argument, either RESET_ADDITIONAL or RESET_ANSWERS. +If one of the addresses matches the client's IP address, then the client is +authorized by CSA. If there are target IP addresses but none of them match +then the client is using an unauthorized IP address. If there are no target IP +addresses then the client cannot be using an authorized IP address. (This is +an odd configuration - why didn't the SRV record have a weight of 1 instead?) + +Arguments: + dnsa the DNS answer block + dnss a DNS scan block for us to use + reset option specifying what portion to scan, as described above + target the target hostname to use for matching RR names + +Returns: CSA_OK successfully authorized + CSA_FAIL_MISMATCH addresses found but none matched + CSA_FAIL_NOADDR no target addresses found +*/ + +static int +acl_verify_csa_address(dns_answer *dnsa, dns_scan *dnss, int reset, + uschar *target) +{ +int rc = CSA_FAIL_NOADDR; + +for (dns_record * rr = dns_next_rr(dnsa, dnss, reset); + rr; + rr = dns_next_rr(dnsa, dnss, RESET_NEXT)) + { + /* Check this is an address RR for the target hostname. */ + + if (rr->type != T_A + #if HAVE_IPV6 + && rr->type != T_AAAA + #endif + ) continue; + + if (strcmpic(target, rr->name) != 0) continue; + + rc = CSA_FAIL_MISMATCH; + + /* Turn the target address RR into a list of textual IP addresses and scan + the list. There may be more than one if it is an A6 RR. */ + + for (dns_address * da = dns_address_from_rr(dnsa, rr); da; da = da->next) + { + /* If the client IP address matches the target IP address, it's good! */ + + DEBUG(D_acl) debug_printf_indent("CSA target address is %s\n", da->address); + + if (strcmpic(sender_host_address, da->address) == 0) return CSA_OK; + } + } + +/* If we found some target addresses but none of them matched, the client is +using an unauthorized IP address, otherwise the target has no authorized IP +addresses. */ + +return rc; +} + + + +/************************************************* +* Verify Client SMTP Authorization * +*************************************************/ + +/* Called from acl_verify() below. This routine calls dns_lookup_special() +to find the CSA SRV record corresponding to the domain argument, or +$sender_helo_name if no argument is provided. It then checks that the +client is authorized, and that its IP address corresponds to the SRV +target's address by calling acl_verify_csa_address() above. The address +should have been returned in the DNS response's ADDITIONAL section, but if +not we perform another DNS lookup to get it. + +Arguments: + domain pointer to optional parameter following verify = csa + +Returns: CSA_UNKNOWN no valid CSA record found + CSA_OK successfully authorized + CSA_FAIL_* client is definitely not authorized + CSA_DEFER_* there was a DNS problem +*/ + +static int +acl_verify_csa(const uschar *domain) +{ +tree_node *t; +const uschar *found; +int priority, weight, port; +dns_answer * dnsa; +dns_scan dnss; +dns_record *rr; +int rc, type, yield; +#define TARGET_SIZE 256 +uschar * target = store_get(TARGET_SIZE, GET_TAINTED); + +/* Work out the domain we are using for the CSA lookup. The default is the +client's HELO domain. If the client has not said HELO, use its IP address +instead. If it's a local client (exim -bs), CSA isn't applicable. */ + +while (isspace(*domain) && *domain != '\0') ++domain; +if (*domain == '\0') domain = sender_helo_name; +if (!domain) domain = sender_host_address; +if (!sender_host_address) return CSA_UNKNOWN; + +/* If we have an address literal, strip off the framing ready for turning it +into a domain. The framing consists of matched square brackets possibly +containing a keyword and a colon before the actual IP address. */ + +if (domain[0] == '[') + { + const uschar *start = Ustrchr(domain, ':'); + if (start == NULL) start = domain; + domain = string_copyn(start + 1, Ustrlen(start) - 2); + } + +/* Turn domains that look like bare IP addresses into domains in the reverse +DNS. This code also deals with address literals and $sender_host_address. It's +not quite kosher to treat bare domains such as EHLO 192.0.2.57 the same as +address literals, but it's probably the most friendly thing to do. This is an +extension to CSA, so we allow it to be turned off for proper conformance. */ + +if (string_is_ip_address(domain, NULL) != 0) + { + if (!dns_csa_use_reverse) return CSA_UNKNOWN; + domain = dns_build_reverse(domain); + } + +/* Find out if we've already done the CSA check for this domain. If we have, +return the same result again. Otherwise build a new cached result structure +for this domain. The name is filled in now, and the value is filled in when +we return from this function. */ + +if ((t = tree_search(csa_cache, domain))) + return t->data.val; + +t = store_get_perm(sizeof(tree_node) + Ustrlen(domain), domain); +Ustrcpy(t->name, domain); +(void)tree_insertnode(&csa_cache, t); + +/* Now we are ready to do the actual DNS lookup(s). */ + +found = domain; +dnsa = store_get_dns_answer(); +switch (dns_special_lookup(dnsa, domain, T_CSA, &found)) + { + /* If something bad happened (most commonly DNS_AGAIN), defer. */ + + default: + yield = CSA_DEFER_SRV; + goto out; + + /* If we found nothing, the client's authorization is unknown. */ + + case DNS_NOMATCH: + case DNS_NODATA: + yield = CSA_UNKNOWN; + goto out; + + /* We got something! Go on to look at the reply in more detail. */ + + case DNS_SUCCEED: + break; + } + +/* Scan the reply for well-formed CSA SRV records. */ + +for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); + rr; + rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) if (rr->type == T_SRV) + { + const uschar * p = rr->data; + + /* Extract the numerical SRV fields (p is incremented) */ + + GETSHORT(priority, p); + GETSHORT(weight, p); + GETSHORT(port, p); + + DEBUG(D_acl) + debug_printf_indent("CSA priority=%d weight=%d port=%d\n", priority, weight, port); + + /* Check the CSA version number */ + + if (priority != 1) continue; + + /* If the domain does not have a CSA SRV record of its own (i.e. the domain + found by dns_special_lookup() is a parent of the one we asked for), we check + the subdomain assertions in the port field. At the moment there's only one + assertion: legitimate SMTP clients are all explicitly authorized with CSA + SRV records of their own. */ + + if (Ustrcmp(found, domain) != 0) + { + yield = port & 1 ? CSA_FAIL_EXPLICIT : CSA_UNKNOWN; + goto out; + } + + /* This CSA SRV record refers directly to our domain, so we check the value + in the weight field to work out the domain's authorization. 0 and 1 are + unauthorized; 3 means the client is authorized but we can't check the IP + address in order to authenticate it, so we treat it as unknown; values + greater than 3 are undefined. */ + + if (weight < 2) + { + yield = CSA_FAIL_DOMAIN; + goto out; + } + + if (weight > 2) continue; + + /* Weight == 2, which means the domain is authorized. We must check that the + client's IP address is listed as one of the SRV target addresses. Save the + target hostname then break to scan the additional data for its addresses. */ + + (void)dn_expand(dnsa->answer, dnsa->answer + dnsa->answerlen, p, + (DN_EXPAND_ARG4_TYPE)target, TARGET_SIZE); + + DEBUG(D_acl) debug_printf_indent("CSA target is %s\n", target); + + break; + } + +/* If we didn't break the loop then no appropriate records were found. */ + +if (!rr) + { + yield = CSA_UNKNOWN; + goto out; + } + +/* Do not check addresses if the target is ".", in accordance with RFC 2782. +A target of "." indicates there are no valid addresses, so the client cannot +be authorized. (This is an odd configuration because weight=2 target=. is +equivalent to weight=1, but we check for it in order to keep load off the +root name servers.) Note that dn_expand() turns "." into "". */ + +if (Ustrcmp(target, "") == 0) + { + yield = CSA_FAIL_NOADDR; + goto out; + } + +/* Scan the additional section of the CSA SRV reply for addresses belonging +to the target. If the name server didn't return any additional data (e.g. +because it does not fully support SRV records), we need to do another lookup +to obtain the target addresses; otherwise we have a definitive result. */ + +rc = acl_verify_csa_address(dnsa, &dnss, RESET_ADDITIONAL, target); +if (rc != CSA_FAIL_NOADDR) + { + yield = rc; + goto out; + } + +/* The DNS lookup type corresponds to the IP version used by the client. */ + +#if HAVE_IPV6 +if (Ustrchr(sender_host_address, ':') != NULL) + type = T_AAAA; +else +#endif /* HAVE_IPV6 */ + type = T_A; + + +lookup_dnssec_authenticated = NULL; +switch (dns_lookup(dnsa, target, type, NULL)) + { + /* If something bad happened (most commonly DNS_AGAIN), defer. */ + + default: + yield = CSA_DEFER_ADDR; + break; + + /* If the query succeeded, scan the addresses and return the result. */ + + case DNS_SUCCEED: + rc = acl_verify_csa_address(dnsa, &dnss, RESET_ANSWERS, target); + if (rc != CSA_FAIL_NOADDR) + { + yield = rc; + break; + } + /* else fall through */ + + /* If the target has no IP addresses, the client cannot have an authorized + IP address. However, if the target site uses A6 records (not AAAA records) + we have to do yet another lookup in order to check them. */ + + case DNS_NOMATCH: + case DNS_NODATA: + yield = CSA_FAIL_NOADDR; + break; + } + +out: + +store_free_dns_answer(dnsa); +return t->data.val = yield; +} + + + +/************************************************* +* Handle verification (address & other) * +*************************************************/ + +enum { VERIFY_REV_HOST_LKUP, VERIFY_CERT, VERIFY_HELO, VERIFY_CSA, VERIFY_HDR_SYNTAX, + VERIFY_NOT_BLIND, VERIFY_HDR_SNDR, VERIFY_SNDR, VERIFY_RCPT, + VERIFY_HDR_NAMES_ASCII, VERIFY_ARC + }; +typedef struct { + uschar * name; + int value; + unsigned where_allowed; /* bitmap */ + BOOL no_options; /* Never has /option(s) following */ + unsigned alt_opt_sep; /* >0 Non-/ option separator (custom parser) */ + } verify_type_t; +static verify_type_t verify_type_list[] = { + /* name value where no-opt opt-sep */ + { US"reverse_host_lookup", VERIFY_REV_HOST_LKUP, (unsigned)~0, FALSE, 0 }, + { US"certificate", VERIFY_CERT, (unsigned)~0, TRUE, 0 }, + { US"helo", VERIFY_HELO, (unsigned)~0, TRUE, 0 }, + { US"csa", VERIFY_CSA, (unsigned)~0, FALSE, 0 }, + { US"header_syntax", VERIFY_HDR_SYNTAX, ACL_BITS_HAVEDATA, TRUE, 0 }, + { US"not_blind", VERIFY_NOT_BLIND, ACL_BITS_HAVEDATA, FALSE, 0 }, + { US"header_sender", VERIFY_HDR_SNDR, ACL_BITS_HAVEDATA, FALSE, 0 }, + { US"sender", VERIFY_SNDR, ACL_BIT_MAIL | ACL_BIT_RCPT + | ACL_BIT_PREDATA | ACL_BIT_DATA | ACL_BIT_NOTSMTP, + FALSE, 6 }, + { US"recipient", VERIFY_RCPT, ACL_BIT_RCPT, FALSE, 0 }, + { US"header_names_ascii", VERIFY_HDR_NAMES_ASCII, ACL_BITS_HAVEDATA, TRUE, 0 }, +#ifdef EXPERIMENTAL_ARC + { US"arc", VERIFY_ARC, ACL_BIT_DATA, FALSE , 0 }, +#endif + }; + + +enum { CALLOUT_DEFER_OK, CALLOUT_NOCACHE, CALLOUT_RANDOM, CALLOUT_USE_SENDER, + CALLOUT_USE_POSTMASTER, CALLOUT_POSTMASTER, CALLOUT_FULLPOSTMASTER, + CALLOUT_MAILFROM, CALLOUT_POSTMASTER_MAILFROM, CALLOUT_MAXWAIT, CALLOUT_CONNECT, + CALLOUT_HOLD, CALLOUT_TIME /* TIME must be last */ + }; +typedef struct { + uschar * name; + int value; + int flag; + BOOL has_option; /* Has =option(s) following */ + BOOL timeval; /* Has a time value */ + } callout_opt_t; +static callout_opt_t callout_opt_list[] = { + /* name value flag has-opt has-time */ + { US"defer_ok", CALLOUT_DEFER_OK, 0, FALSE, FALSE }, + { US"no_cache", CALLOUT_NOCACHE, vopt_callout_no_cache, FALSE, FALSE }, + { US"random", CALLOUT_RANDOM, vopt_callout_random, FALSE, FALSE }, + { US"use_sender", CALLOUT_USE_SENDER, vopt_callout_recipsender, FALSE, FALSE }, + { US"use_postmaster", CALLOUT_USE_POSTMASTER,vopt_callout_recippmaster, FALSE, FALSE }, + { US"postmaster_mailfrom",CALLOUT_POSTMASTER_MAILFROM,0, TRUE, FALSE }, + { US"postmaster", CALLOUT_POSTMASTER, 0, FALSE, FALSE }, + { US"fullpostmaster", CALLOUT_FULLPOSTMASTER,vopt_callout_fullpm, FALSE, FALSE }, + { US"mailfrom", CALLOUT_MAILFROM, 0, TRUE, FALSE }, + { US"maxwait", CALLOUT_MAXWAIT, 0, TRUE, TRUE }, + { US"connect", CALLOUT_CONNECT, 0, TRUE, TRUE }, + { US"hold", CALLOUT_HOLD, vopt_callout_hold, FALSE, FALSE }, + { NULL, CALLOUT_TIME, 0, FALSE, TRUE } + }; + + + +static int +v_period(const uschar * s, const uschar * arg, uschar ** log_msgptr) +{ +int period; +if ((period = readconf_readtime(s, 0, FALSE)) < 0) + { + *log_msgptr = string_sprintf("bad time value in ACL condition " + "\"verify %s\"", arg); + } +return period; +} + + + +/* 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, const 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; +BOOL success_on_redirect = FALSE; +BOOL quota = FALSE; +int quota_pos_cache = QUOTA_POS_DEFAULT, quota_neg_cache = QUOTA_NEG_DEFAULT; +address_item *sender_vaddr = NULL; +uschar *verify_sender_address = NULL; +uschar *pm_mailfrom = NULL; +uschar *se_mailfrom = NULL; + +/* Some of the verify items have slash-separated options; some do not. Diagnose +an error if options are given for items that don't expect them. +*/ + +uschar *slash = Ustrchr(arg, '/'); +const uschar *list = arg; +uschar *ss = string_nextinlist(&list, &sep, NULL, 0); +verify_type_t * vp; + +if (!ss) goto BAD_VERIFY; + +/* Handle name/address consistency verification in a separate function. */ + +for (vp = verify_type_list; + CS vp < CS verify_type_list + sizeof(verify_type_list); + vp++ + ) + if (vp->alt_opt_sep ? strncmpic(ss, vp->name, vp->alt_opt_sep) == 0 + : strcmpic (ss, vp->name) == 0) + break; +if (CS vp >= CS verify_type_list + sizeof(verify_type_list)) + goto BAD_VERIFY; + +if (vp->no_options && slash) + { + *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" " + "(this verify item has no options)", arg); + return ERROR; + } +if (!(vp->where_allowed & BIT(where))) + { + *log_msgptr = string_sprintf("cannot verify %s in ACL for %s", + vp->name, acl_wherenames[where]); + return ERROR; + } +switch(vp->value) + { + case VERIFY_REV_HOST_LKUP: + if (!sender_host_address) return OK; + if ((rc = acl_verify_reverse(user_msgptr, log_msgptr)) == DEFER) + while ((ss = string_nextinlist(&list, &sep, NULL, 0))) + if (strcmpic(ss, US"defer_ok") == 0) + return OK; + return rc; + + case VERIFY_CERT: + /* 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 (tls_in.certificate_verified) return OK; + *user_msgptr = US"no verified certificate"; + return FAIL; + + case VERIFY_HELO: + /* We can test the result of optional HELO verification that might have + occurred earlier. If not, we can attempt the verification now. */ + + if (!f.helo_verified && !f.helo_verify_failed) smtp_verify_helo(); + return f.helo_verified ? OK : FAIL; + + case VERIFY_CSA: + /* Do Client SMTP Authorization checks in a separate function, and turn the + result code into user-friendly strings. */ + + rc = acl_verify_csa(list); + *log_msgptr = *user_msgptr = string_sprintf("client SMTP authorization %s", + csa_reason_string[rc]); + csa_status = csa_status_string[rc]; + DEBUG(D_acl) debug_printf_indent("CSA result %s\n", csa_status); + return csa_return_code[rc]; + +#ifdef EXPERIMENTAL_ARC + case VERIFY_ARC: + { /* Do Authenticated Received Chain checks in a separate function. */ + const uschar * condlist = CUS string_nextinlist(&list, &sep, NULL, 0); + int csep = 0; + uschar * cond; + + if (!(arc_state = acl_verify_arc())) return DEFER; + DEBUG(D_acl) debug_printf_indent("ARC verify result %s %s%s%s\n", arc_state, + arc_state_reason ? "(":"", arc_state_reason, arc_state_reason ? ")":""); + + if (!condlist) condlist = US"none:pass"; + while ((cond = string_nextinlist(&condlist, &csep, NULL, 0))) + if (Ustrcmp(arc_state, cond) == 0) return OK; + return FAIL; + } +#endif + + case VERIFY_HDR_SYNTAX: + /* Check that all relevant header lines have the correct 5322-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). */ + + rc = verify_check_headers(log_msgptr); + if (rc != OK && *log_msgptr) + if (smtp_return_error_details) + *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr); + else + acl_verify_message = *log_msgptr; + return rc; + + case VERIFY_HDR_NAMES_ASCII: + /* Check that all header names are true 7 bit strings + See RFC 5322, 2.2. and RFC 6532, 3. */ + + rc = verify_check_header_names_ascii(log_msgptr); + if (rc != OK && smtp_return_error_details && *log_msgptr) + *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr); + return rc; + + case VERIFY_NOT_BLIND: + /* Check that no recipient of this message is "blind", that is, every envelope + recipient must be mentioned in either To: or Cc:. */ + { + BOOL case_sensitive = TRUE; + + while ((ss = string_nextinlist(&list, &sep, NULL, 0))) + if (strcmpic(ss, US"case_insensitive") == 0) + case_sensitive = FALSE; + else + { + *log_msgptr = string_sprintf("unknown option \"%s\" in ACL " + "condition \"verify %s\"", ss, arg); + return ERROR; + } + + if ((rc = verify_check_notblind(case_sensitive)) != OK) + { + *log_msgptr = US"bcc recipient detected"; + if (smtp_return_error_details) + *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr); + } + return rc; + } + + /* The remaining verification tests check recipient and sender addresses, + either from the envelope or from the header. There are a number of + slash-separated options that are common to all of them. */ + + case VERIFY_HDR_SNDR: + verify_header_sender = TRUE; + break; + + case VERIFY_SNDR: + /* 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). */ + { + uschar *s = ss + 6; + if (!*s) + 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); + } + } + break; + + case VERIFY_RCPT: + break; + } + + + +/* Remaining items are optional; they apply to sender and recipient +verification, including "header sender" verification. */ + +while ((ss = string_nextinlist(&list, &sep, NULL, 0))) + { + if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE; + else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE; + else if (strcmpic(ss, US"success_on_redirect") == 0) success_on_redirect = 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; + if (*(ss += 7)) + { + while (isspace(*ss)) ss++; + if (*ss++ == '=') + { + const uschar * sublist = ss; + int optsep = ','; + + while (isspace(*sublist)) sublist++; + for (uschar * opt; opt = string_nextinlist(&sublist, &optsep, NULL, 0); ) + { + callout_opt_t * op; + double period = 1.0F; + + for (op= callout_opt_list; op->name; op++) + if (strncmpic(opt, op->name, Ustrlen(op->name)) == 0) + break; + + verify_options |= op->flag; + if (op->has_option) + { + opt += Ustrlen(op->name); + while (isspace(*opt)) opt++; + if (*opt++ != '=') + { + *log_msgptr = string_sprintf("'=' expected after " + "\"%s\" in ACL verify condition \"%s\"", op->name, arg); + return ERROR; + } + while (isspace(*opt)) opt++; + } + if (op->timeval && (period = v_period(opt, arg, log_msgptr)) < 0) + return ERROR; + + switch(op->value) + { + case CALLOUT_DEFER_OK: callout_defer_ok = TRUE; break; + case CALLOUT_POSTMASTER: pm_mailfrom = US""; break; + case CALLOUT_FULLPOSTMASTER: pm_mailfrom = US""; break; + case CALLOUT_MAILFROM: + 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; + } + se_mailfrom = string_copy(opt); + break; + case CALLOUT_POSTMASTER_MAILFROM: pm_mailfrom = string_copy(opt); break; + case CALLOUT_MAXWAIT: callout_overall = period; break; + case CALLOUT_CONNECT: callout_connect = period; break; + case CALLOUT_TIME: callout = period; break; + } + } + } + else + { + *log_msgptr = string_sprintf("'=' expected after \"callout\" in " + "ACL condition \"%s\"", arg); + return ERROR; + } + } + } + + /* The quota option has sub-options, comma-separated */ + + else if (strncmpic(ss, US"quota", 5) == 0) + { + quota = TRUE; + if (*(ss += 5)) + { + while (isspace(*ss)) ss++; + if (*ss++ == '=') + { + const uschar * sublist = ss; + int optsep = ','; + int period; + + while (isspace(*sublist)) sublist++; + for (uschar * opt; opt = string_nextinlist(&sublist, &optsep, NULL, 0); ) + if (Ustrncmp(opt, "cachepos=", 9) == 0) + if ((period = v_period(opt += 9, arg, log_msgptr)) < 0) + return ERROR; + else + quota_pos_cache = period; + else if (Ustrncmp(opt, "cacheneg=", 9) == 0) + if ((period = v_period(opt += 9, arg, log_msgptr)) < 0) + return ERROR; + else + quota_neg_cache = period; + else if (Ustrcmp(opt, "no_cache") == 0) + quota_pos_cache = quota_neg_cache = 0; + } + } + } + + /* 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 quota verification */ +if (quota) + { + if (vp->value != VERIFY_RCPT) + { + *log_msgptr = US"can only verify quota of recipient"; + return ERROR; + } + + if ((rc = verify_quota_call(addr->address, + quota_pos_cache, quota_neg_cache, log_msgptr)) != OK) + { + *basic_errno = errno; + if (smtp_return_error_details) + { + if (!*user_msgptr && *log_msgptr) + *user_msgptr = string_sprintf("Rejected after %s: %s", + smtp_names[smtp_connection_had[SMTP_HBUFF_PREV(smtp_ch_index)]], + *log_msgptr); + if (rc == DEFER) f.acl_temp_details = TRUE; + } + } + + return rc; + } + +/* Handle sender-in-header verification. Default the user message to the log +message if giving out verification details. */ + +if (verify_header_sender) + { + int verrno; + + if ((rc = verify_check_header_address(user_msgptr, log_msgptr, callout, + callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options, + &verrno)) != OK) + { + *basic_errno = verrno; + if (smtp_return_error_details) + { + if (!*user_msgptr && *log_msgptr) + *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr); + if (rc == DEFER) f.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) + { + if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster))) + { + *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 /* 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_indent("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); +#ifdef SUPPORT_I18N + if ((sender_vaddr->prop.utf8_msg = message_smtputf8)) + { + sender_vaddr->prop.utf8_downcvt = message_utf8_downconvert == 1; + sender_vaddr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1; + } +#endif + 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; + + if (success_on_redirect) + verify_options |= vopt_success_on_redirect; + + /* 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_indent("----------- end verify ------------\n"); + + if (rc != OK) + *basic_errno = sender_vaddr->basic_errno; + else + DEBUG(D_acl) + if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0) + debug_printf_indent("sender %s verified ok as %s\n", + verify_sender_address, sender_vaddr->address); + else + debug_printf_indent("sender %s verified ok\n", + verify_sender_address); + } + 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->prop.address_data; + } + +/* A recipient address just gets a straightforward verify; again we must handle +the DEFER overrides. */ + +else + { + address_item addr2; + + if (success_on_redirect) + verify_options |= vopt_success_on_redirect; + + /* 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_indent("----------- end verify ------------\n"); + + *basic_errno = addr2.basic_errno; + *log_msgptr = addr2.message; + *user_msgptr = addr2.user_message ? addr2.user_message : addr2.message; + + /* Allow details for temporary error if the address is so flagged. */ + if (testflag((&addr2), af_pass_message)) f.acl_temp_details = TRUE; + + /* Make $address_data visible */ + deliver_address_data = addr2.prop.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_indent("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) + { + 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) + { + 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\", " + "\"helo\", \"header_syntax\", \"header_sender\", \"header_names_ascii\" " + "or \"reverse_host_lookup\" at start of ACL condition " + "\"verify %s\"", arg); +return ERROR; +} + + + + +/************************************************* +* Check argument for control= modifier * +*************************************************/ + +/* Called from acl_check_condition() below. +To handle the case "queue_only" we accept an _ in the +initial / option-switch position. + +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(const uschar *arg, const uschar **pptr, int where, uschar **log_msgptr) +{ +int idx, len; +control_def * d; +uschar c; + +if ( (idx = find_control(arg, controls_list, nelem(controls_list))) < 0 + || ( (c = arg[len = Ustrlen((d = controls_list+idx)->name)]) != 0 + && (!d->has_option || c != '/' && c != '_') + ) ) + { + *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg); + return CONTROL_ERROR; + } + +*pptr = arg + len; +return idx; +} + + + + +/************************************************* +* Return a ratelimit error * +*************************************************/ + +/* Called from acl_ratelimit() below + +Arguments: + log_msgptr for error messages + format format string + ... supplementary arguments + +Returns: ERROR +*/ + +static int +ratelimit_error(uschar **log_msgptr, const char *format, ...) +{ +va_list ap; +gstring * g = + string_cat(NULL, US"error in arguments to \"ratelimit\" condition: "); + +va_start(ap, format); +g = string_vformat(g, SVFMT_EXTEND|SVFMT_REBUFFER, format, ap); +va_end(ap); + +gstring_release_unused(g); +*log_msgptr = string_from_gstring(g); +return ERROR; +} + + + + +/************************************************* +* Handle rate limiting * +*************************************************/ + +/* Called by acl_check_condition() below to calculate the result +of the ACL ratelimit condition. + +Note that the return value might be slightly unexpected: if the +sender's rate is above the limit then the result is OK. This is +similar to the dnslists condition, and is so that you can write +ACL clauses like: defer ratelimit = 15 / 1h + +Arguments: + arg the option string for ratelimit= + where ACL_WHERE_xxxx indicating which ACL this is + log_msgptr for error messages + +Returns: OK - Sender's rate is above limit + FAIL - Sender's rate is below limit + DEFER - Problem opening ratelimit database + ERROR - Syntax error in options. +*/ + +static int +acl_ratelimit(const uschar *arg, int where, uschar **log_msgptr) +{ +double limit, period, count; +uschar *ss; +uschar *key = NULL; +uschar *unique = NULL; +int sep = '/'; +BOOL leaky = FALSE, strict = FALSE, readonly = FALSE; +BOOL noupdate = FALSE, badacl = FALSE; +int mode = RATE_PER_WHAT; +int old_pool, rc; +tree_node **anchor, *t; +open_db dbblock, *dbm; +int dbdb_size; +dbdata_ratelimit *dbd; +dbdata_ratelimit_unique *dbdb; +struct timeval tv; + +/* Parse the first two options and record their values in expansion +variables. These variables allow the configuration to have informative +error messages based on rate limits obtained from a table lookup. */ + +/* First is the maximum number of messages per period / maximum burst +size, which must be greater than or equal to zero. Zero is useful for +rate measurement as opposed to rate limiting. */ + +if (!(sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0))) + return ratelimit_error(log_msgptr, "sender rate limit not set"); + +limit = Ustrtod(sender_rate_limit, &ss); +if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; } +else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; } +else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; } + +if (limit < 0.0 || *ss != '\0') + return ratelimit_error(log_msgptr, + "\"%s\" is not a positive number", sender_rate_limit); + +/* Second is the rate measurement period / exponential smoothing time +constant. This must be strictly greater than zero, because zero leads to +run-time division errors. */ + +period = !(sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0)) + ? -1.0 : readconf_readtime(sender_rate_period, 0, FALSE); +if (period <= 0.0) + return ratelimit_error(log_msgptr, + "\"%s\" is not a time value", sender_rate_period); + +/* By default we are counting one of something, but the per_rcpt, +per_byte, and count options can change this. */ + +count = 1.0; + +/* Parse the other options. */ + +while ((ss = string_nextinlist(&arg, &sep, NULL, 0))) + { + if (strcmpic(ss, US"leaky") == 0) leaky = TRUE; + else if (strcmpic(ss, US"strict") == 0) strict = TRUE; + else if (strcmpic(ss, US"noupdate") == 0) noupdate = TRUE; + else if (strcmpic(ss, US"readonly") == 0) readonly = TRUE; + else if (strcmpic(ss, US"per_cmd") == 0) RATE_SET(mode, PER_CMD); + else if (strcmpic(ss, US"per_conn") == 0) + { + RATE_SET(mode, PER_CONN); + if (where == ACL_WHERE_NOTSMTP || where == ACL_WHERE_NOTSMTP_START) + badacl = TRUE; + } + else if (strcmpic(ss, US"per_mail") == 0) + { + RATE_SET(mode, PER_MAIL); + if (where > ACL_WHERE_NOTSMTP) badacl = TRUE; + } + else if (strcmpic(ss, US"per_rcpt") == 0) + { + /* If we are running in the RCPT ACL, then we'll count the recipients + one by one, but if we are running when we have accumulated the whole + list then we'll add them all in one batch. */ + if (where == ACL_WHERE_RCPT) + RATE_SET(mode, PER_RCPT); + else if (where >= ACL_WHERE_PREDATA && where <= ACL_WHERE_NOTSMTP) + RATE_SET(mode, PER_ALLRCPTS), count = (double)recipients_count; + else if (where == ACL_WHERE_MAIL || where > ACL_WHERE_NOTSMTP) + RATE_SET(mode, PER_RCPT), badacl = TRUE; + } + else if (strcmpic(ss, US"per_byte") == 0) + { + /* If we have not yet received the message data and there was no SIZE + declaration on the MAIL command, then it's safe to just use a value of + zero and let the recorded rate decay as if nothing happened. */ + RATE_SET(mode, PER_MAIL); + if (where > ACL_WHERE_NOTSMTP) badacl = TRUE; + else count = message_size < 0 ? 0.0 : (double)message_size; + } + else if (strcmpic(ss, US"per_addr") == 0) + { + RATE_SET(mode, PER_RCPT); + if (where != ACL_WHERE_RCPT) badacl = TRUE, unique = US"*"; + else unique = string_sprintf("%s@%s", deliver_localpart, deliver_domain); + } + else if (strncmpic(ss, US"count=", 6) == 0) + { + uschar *e; + count = Ustrtod(ss+6, &e); + if (count < 0.0 || *e != '\0') + return ratelimit_error(log_msgptr, "\"%s\" is not a positive number", ss); + } + else if (strncmpic(ss, US"unique=", 7) == 0) + unique = string_copy(ss + 7); + else if (!key) + key = string_copy(ss); + else + key = string_sprintf("%s/%s", key, ss); + } + +/* Sanity check. When the badacl flag is set the update mode must either +be readonly (which is the default if it is omitted) or, for backwards +compatibility, a combination of noupdate and strict or leaky. */ + +if (mode == RATE_PER_CLASH) + return ratelimit_error(log_msgptr, "conflicting per_* options"); +if (leaky + strict + readonly > 1) + return ratelimit_error(log_msgptr, "conflicting update modes"); +if (badacl && (leaky || strict) && !noupdate) + return ratelimit_error(log_msgptr, + "\"%s\" must not have /leaky or /strict option, or cannot be used in %s ACL", + ratelimit_option_string[mode], acl_wherenames[where]); + +/* Set the default values of any unset options. In readonly mode we +perform the rate computation without any increment so that its value +decays to eventually allow over-limit senders through. */ + +if (noupdate) readonly = TRUE, leaky = strict = FALSE; +if (badacl) readonly = TRUE; +if (readonly) count = 0.0; +if (!strict && !readonly) leaky = TRUE; +if (mode == RATE_PER_WHAT) mode = RATE_PER_MAIL; + +/* Create the lookup key. If there is no explicit key, use sender_host_address. +If there is no sender_host_address (e.g. -bs or acl_not_smtp) then we simply +omit it. The smoothing constant (sender_rate_period) and the per_xxx options +are added to the key because they alter the meaning of the stored data. */ + +if (!key) + key = !sender_host_address ? US"" : sender_host_address; + +key = string_sprintf("%s/%s/%s%s", + sender_rate_period, + ratelimit_option_string[mode], + unique == NULL ? "" : "unique/", + key); + +HDEBUG(D_acl) + debug_printf_indent("ratelimit condition count=%.0f %.1f/%s\n", count, limit, key); + +/* See if we have already computed the rate by looking in the relevant tree. +For per-connection rate limiting, store tree nodes and dbdata in the permanent +pool so that they survive across resets. In readonly mode we only remember the +result for the rest of this command in case a later command changes it. After +this bit of logic the code is independent of the per_* mode. */ + +old_pool = store_pool; + +if (readonly) + anchor = &ratelimiters_cmd; +else switch(mode) + { + case RATE_PER_CONN: + anchor = &ratelimiters_conn; + store_pool = POOL_PERM; + break; + case RATE_PER_BYTE: + case RATE_PER_MAIL: + case RATE_PER_ALLRCPTS: + anchor = &ratelimiters_mail; + break; + case RATE_PER_ADDR: + case RATE_PER_CMD: + case RATE_PER_RCPT: + anchor = &ratelimiters_cmd; + break; + default: + anchor = NULL; /* silence an "unused" complaint */ + log_write(0, LOG_MAIN|LOG_PANIC_DIE, + "internal ACL error: unknown ratelimit mode %d", mode); + break; + } + +if ((t = tree_search(*anchor, key))) + { + dbd = t->data.ptr; + /* The following few lines duplicate some of the code below. */ + rc = (dbd->rate < limit)? FAIL : OK; + store_pool = old_pool; + sender_rate = string_sprintf("%.1f", dbd->rate); + HDEBUG(D_acl) + debug_printf_indent("ratelimit found pre-computed rate %s\n", sender_rate); + return rc; + } + +/* We aren't using a pre-computed rate, so get a previously recorded rate +from the database, which will be updated and written back if required. */ + +if (!(dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE, TRUE))) + { + store_pool = old_pool; + sender_rate = NULL; + HDEBUG(D_acl) debug_printf_indent("ratelimit database not available\n"); + *log_msgptr = US"ratelimit database not available"; + return DEFER; + } +dbdb = dbfn_read_with_length(dbm, key, &dbdb_size); +dbd = NULL; + +gettimeofday(&tv, NULL); + +if (dbdb) + { + /* Locate the basic ratelimit block inside the DB data. */ + HDEBUG(D_acl) debug_printf_indent("ratelimit found key in database\n"); + dbd = &dbdb->dbd; + + /* Forget the old Bloom filter if it is too old, so that we count each + repeating event once per period. We don't simply clear and re-use the old + filter because we want its size to change if the limit changes. Note that + we keep the dbd pointer for copying the rate into the new data block. */ + + if(unique && tv.tv_sec > dbdb->bloom_epoch + period) + { + HDEBUG(D_acl) debug_printf_indent("ratelimit discarding old Bloom filter\n"); + dbdb = NULL; + } + + /* Sanity check. */ + + if(unique && dbdb_size < sizeof(*dbdb)) + { + HDEBUG(D_acl) debug_printf_indent("ratelimit discarding undersize Bloom filter\n"); + dbdb = NULL; + } + } + +/* Allocate a new data block if the database lookup failed +or the Bloom filter passed its age limit. */ + +if (!dbdb) + { + if (!unique) + { + /* No Bloom filter. This basic ratelimit block is initialized below. */ + HDEBUG(D_acl) debug_printf_indent("ratelimit creating new rate data block\n"); + dbdb_size = sizeof(*dbd); + dbdb = store_get(dbdb_size, GET_UNTAINTED); + } + else + { + int extra; + HDEBUG(D_acl) debug_printf_indent("ratelimit creating new Bloom filter\n"); + + /* See the long comment below for an explanation of the magic number 2. + The filter has a minimum size in case the rate limit is very small; + this is determined by the definition of dbdata_ratelimit_unique. */ + + extra = (int)limit * 2 - sizeof(dbdb->bloom); + if (extra < 0) extra = 0; + dbdb_size = sizeof(*dbdb) + extra; + dbdb = store_get(dbdb_size, GET_UNTAINTED); + dbdb->bloom_epoch = tv.tv_sec; + dbdb->bloom_size = sizeof(dbdb->bloom) + extra; + memset(dbdb->bloom, 0, dbdb->bloom_size); + + /* Preserve any basic ratelimit data (which is our longer-term memory) + by copying it from the discarded block. */ + + if (dbd) + { + dbdb->dbd = *dbd; + dbd = &dbdb->dbd; + } + } + } + +/* If we are counting unique events, find out if this event is new or not. +If the client repeats the event during the current period then it should be +counted. We skip this code in readonly mode for efficiency, because any +changes to the filter will be discarded and because count is already set to +zero. */ + +if (unique && !readonly) + { + /* We identify unique events using a Bloom filter. (You can find my + notes on Bloom filters at http://fanf.livejournal.com/81696.html) + With the per_addr option, an "event" is a recipient address, though the + user can use the unique option to define their own events. We only count + an event if we have not seen it before. + + We size the filter according to the rate limit, which (in leaky mode) + is the limit on the population of the filter. We allow 16 bits of space + per entry (see the construction code above) and we set (up to) 8 of them + when inserting an element (see the loop below). The probability of a false + positive (an event we have not seen before but which we fail to count) is + + size = limit * 16 + numhash = 8 + allzero = exp(-numhash * pop / size) + = exp(-0.5 * pop / limit) + fpr = pow(1 - allzero, numhash) + + For senders at the limit the fpr is 0.06% or 1 in 1700 + and for senders at half the limit it is 0.0006% or 1 in 170000 + + In strict mode the Bloom filter can fill up beyond the normal limit, in + which case the false positive rate will rise. This means that the + measured rate for very fast senders can bogusly drop off after a while. + + At twice the limit, the fpr is 2.5% or 1 in 40 + At four times the limit, it is 31% or 1 in 3.2 + + It takes ln(pop/limit) periods for an over-limit burst of pop events to + decay below the limit, and if this is more than one then the Bloom filter + will be discarded before the decay gets that far. The false positive rate + at this threshold is 9.3% or 1 in 10.7. */ + + BOOL seen; + unsigned n, hash, hinc; + uschar md5sum[16]; + md5 md5info; + + /* Instead of using eight independent hash values, we combine two values + using the formula h1 + n * h2. This does not harm the Bloom filter's + performance, and means the amount of hash we need is independent of the + number of bits we set in the filter. */ + + md5_start(&md5info); + md5_end(&md5info, unique, Ustrlen(unique), md5sum); + hash = md5sum[0] | md5sum[1] << 8 | md5sum[2] << 16 | md5sum[3] << 24; + hinc = md5sum[4] | md5sum[5] << 8 | md5sum[6] << 16 | md5sum[7] << 24; + + /* Scan the bits corresponding to this event. A zero bit means we have + not seen it before. Ensure all bits are set to record this event. */ + + HDEBUG(D_acl) debug_printf_indent("ratelimit checking uniqueness of %s\n", unique); + + seen = TRUE; + for (n = 0; n < 8; n++, hash += hinc) + { + int bit = 1 << (hash % 8); + int byte = (hash / 8) % dbdb->bloom_size; + if ((dbdb->bloom[byte] & bit) == 0) + { + dbdb->bloom[byte] |= bit; + seen = FALSE; + } + } + + /* If this event has occurred before, do not count it. */ + + if (seen) + { + HDEBUG(D_acl) debug_printf_indent("ratelimit event found in Bloom filter\n"); + count = 0.0; + } + else + HDEBUG(D_acl) debug_printf_indent("ratelimit event added to Bloom filter\n"); + } + +/* If there was no previous ratelimit data block for this key, initialize +the new one, otherwise update the block from the database. The initial rate +is what would be computed by the code below for an infinite interval. */ + +if (!dbd) + { + HDEBUG(D_acl) debug_printf_indent("ratelimit initializing new key's rate data\n"); + dbd = &dbdb->dbd; + dbd->time_stamp = tv.tv_sec; + dbd->time_usec = tv.tv_usec; + dbd->rate = count; + } +else + { + /* The smoothed rate is computed using an exponentially weighted moving + average adjusted for variable sampling intervals. The standard EWMA for + a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1) + where f() is the measured value and f'() is the smoothed value. + + Old data decays out of the smoothed value exponentially, such that data n + samples old is multiplied by a^n. The exponential decay time constant p + is defined such that data p samples old is multiplied by 1/e, which means + that a = exp(-1/p). We can maintain the same time constant for a variable + sampling interval i by using a = exp(-i/p). + + The rate we are measuring is messages per period, suitable for directly + comparing with the limit. The average rate between now and the previous + message is period / interval, which we feed into the EWMA as the sample. + + It turns out that the number of messages required for the smoothed rate + to reach the limit when they are sent in a burst is equal to the limit. + This can be seen by analysing the value of the smoothed rate after N + messages sent at even intervals. Let k = (1 - a) * p/i + + rate_1 = (1 - a) * p/i + a * rate_0 + = k + a * rate_0 + rate_2 = k + a * rate_1 + = k + a * k + a^2 * rate_0 + rate_3 = k + a * k + a^2 * k + a^3 * rate_0 + rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x) + = rate_0 * a^N + k * (1 - a^N) / (1 - a) + = rate_0 * a^N + p/i * (1 - a^N) + + When N is large, a^N -> 0 so rate_N -> p/i as desired. + + rate_N = p/i + (rate_0 - p/i) * a^N + a^N = (rate_N - p/i) / (rate_0 - p/i) + N * -i/p = log((rate_N - p/i) / (rate_0 - p/i)) + N = p/i * log((rate_0 - p/i) / (rate_N - p/i)) + + Numerical analysis of the above equation, setting the computed rate to + increase from rate_0 = 0 to rate_N = limit, shows that for large sending + rates, p/i, the number of messages N = limit. So limit serves as both the + maximum rate measured in messages per period, and the maximum number of + messages that can be sent in a fast burst. */ + + double this_time = (double)tv.tv_sec + + (double)tv.tv_usec / 1000000.0; + double prev_time = (double)dbd->time_stamp + + (double)dbd->time_usec / 1000000.0; + + /* We must avoid division by zero, and deal gracefully with the clock going + backwards. If we blunder ahead when time is in reverse then the computed + rate will be bogus. To be safe we clamp interval to a very small number. */ + + double interval = this_time - prev_time <= 0.0 ? 1e-9 + : this_time - prev_time; + + double i_over_p = interval / period; + double a = exp(-i_over_p); + + /* Combine the instantaneous rate (period / interval) with the previous rate + using the smoothing factor a. In order to measure sized events, multiply the + instantaneous rate by the count of bytes or recipients etc. */ + + dbd->time_stamp = tv.tv_sec; + dbd->time_usec = tv.tv_usec; + dbd->rate = (1 - a) * count / i_over_p + a * dbd->rate; + + /* When events are very widely spaced the computed rate tends towards zero. + Although this is accurate it turns out not to be useful for our purposes, + especially when the first event after a long silence is the start of a spam + run. A more useful model is that the rate for an isolated event should be the + size of the event per the period size, ignoring the lack of events outside + the current period and regardless of where the event falls in the period. So, + if the interval was so long that the calculated rate is unhelpfully small, we + re-initialize the rate. In the absence of higher-rate bursts, the condition + below is true if the interval is greater than the period. */ + + if (dbd->rate < count) dbd->rate = count; + } + +/* Clients sending at the limit are considered to be over the limit. +This matters for edge cases such as a limit of zero, when the client +should be completely blocked. */ + +rc = dbd->rate < limit ? FAIL : OK; + +/* Update the state if the rate is low or if we are being strict. If we +are in leaky mode and the sender's rate is too high, we do not update +the recorded rate in order to avoid an over-aggressive sender's retry +rate preventing them from getting any email through. If readonly is set, +neither leaky nor strict are set, so we do not do any updates. */ + +if ((rc == FAIL && leaky) || strict) + { + dbfn_write(dbm, key, dbdb, dbdb_size); + HDEBUG(D_acl) debug_printf_indent("ratelimit db updated\n"); + } +else + { + HDEBUG(D_acl) debug_printf_indent("ratelimit db not updated: %s\n", + readonly? "readonly mode" : "over the limit, but leaky"); + } + +dbfn_close(dbm); + +/* Store the result in the tree for future reference. Take the taint status +from the key for consistency even though it's unlikely we'll ever expand this. */ + +t = store_get(sizeof(tree_node) + Ustrlen(key), key); +t->data.ptr = dbd; +Ustrcpy(t->name, key); +(void)tree_insertnode(anchor, t); + +/* We create the formatted version of the sender's rate very late in +order to ensure that it is done using the correct storage pool. */ + +store_pool = old_pool; +sender_rate = string_sprintf("%.1f", dbd->rate); + +HDEBUG(D_acl) + debug_printf_indent("ratelimit computed rate %s\n", sender_rate); + +return rc; +} + + + +/************************************************* +* Handle a check for previously-seen * +*************************************************/ + +/* +ACL clauses like: seen = -5m / key=$foo / readonly + +Return is true for condition-true - but the semantics +depend heavily on the actual use-case. + +Negative times test for seen-before, positive for seen-more-recently-than +(the given interval before current time). + +All are subject to history not having been cleaned from the DB. + +Default for seen-before is to create if not present, and to +update if older than 10d (with the seen-test time). +Default for seen-since is to always create or update. + +Options: + key=value. Default key is $sender_host_address + readonly + write + refresh=<interval>: update an existing DB entry older than given + amount. Default refresh lacking this option is 10d. + The update sets the record timestamp to the seen-test time. + +XXX do we need separate nocreate, noupdate controls? + +Arguments: + arg the option string for seen= + where ACL_WHERE_xxxx indicating which ACL this is + log_msgptr for error messages + +Returns: OK - Condition is true + FAIL - Condition is false + DEFER - Problem opening history database + ERROR - Syntax error in options +*/ + +static int +acl_seen(const uschar * arg, int where, uschar ** log_msgptr) +{ +enum { SEEN_DEFAULT, SEEN_READONLY, SEEN_WRITE }; + +const uschar * list = arg; +int slash = '/', interval, mode = SEEN_DEFAULT, yield = FAIL; +BOOL before; +int refresh = 10 * 24 * 60 * 60; /* 10 days */ +const uschar * ele, * key = sender_host_address; +open_db dbblock, * dbm; +dbdata_seen * dbd; +time_t now; + +/* Parse the first element, the time-relation. */ + +if (!(ele = string_nextinlist(&list, &slash, NULL, 0))) + goto badparse; +if ((before = *ele == '-')) + ele++; +if ((interval = readconf_readtime(ele, 0, FALSE)) < 0) + goto badparse; + +/* Remaining elements are options */ + +while ((ele = string_nextinlist(&list, &slash, NULL, 0))) + if (Ustrncmp(ele, "key=", 4) == 0) + key = ele + 4; + else if (Ustrcmp(ele, "readonly") == 0) + mode = SEEN_READONLY; + else if (Ustrcmp(ele, "write") == 0) + mode = SEEN_WRITE; + else if (Ustrncmp(ele, "refresh=", 8) == 0) + { + if ((refresh = readconf_readtime(ele + 8, 0, FALSE)) < 0) + goto badparse; + } + else + goto badopt; + +if (!(dbm = dbfn_open(US"seen", O_RDWR, &dbblock, TRUE, TRUE))) + { + HDEBUG(D_acl) debug_printf_indent("database for 'seen' not available\n"); + *log_msgptr = US"database for 'seen' not available"; + return DEFER; + } + +dbd = dbfn_read_with_length(dbm, key, NULL); +now = time(NULL); +if (dbd) /* an existing record */ + { + time_t diff = now - dbd->time_stamp; /* time since the record was written */ + + if (before ? diff >= interval : diff < interval) + yield = OK; + + if (mode == SEEN_READONLY) + { HDEBUG(D_acl) debug_printf_indent("seen db not written (readonly)\n"); } + else if (mode == SEEN_WRITE || !before) + { + dbd->time_stamp = now; + dbfn_write(dbm, key, dbd, sizeof(*dbd)); + HDEBUG(D_acl) debug_printf_indent("seen db written (update)\n"); + } + else if (diff >= refresh) + { + dbd->time_stamp = now - interval; + dbfn_write(dbm, key, dbd, sizeof(*dbd)); + HDEBUG(D_acl) debug_printf_indent("seen db written (refresh)\n"); + } + } +else + { /* No record found, yield always FAIL */ + if (mode != SEEN_READONLY) + { + dbdata_seen d = {.time_stamp = now}; + dbfn_write(dbm, key, &d, sizeof(*dbd)); + HDEBUG(D_acl) debug_printf_indent("seen db written (create)\n"); + } + else + HDEBUG(D_acl) debug_printf_indent("seen db not written (readonly)\n"); + } + +dbfn_close(dbm); +return yield; + + +badparse: + *log_msgptr = string_sprintf("failed to parse '%s'", arg); + return ERROR; +badopt: + *log_msgptr = string_sprintf("unrecognised option '%s' in '%s'", ele, arg); + return ERROR; +} + + + +/************************************************* +* The udpsend ACL modifier * +*************************************************/ + +/* Called by acl_check_condition() below. + +Arguments: + arg the option string for udpsend= + log_msgptr for error messages + +Returns: OK - Completed. + DEFER - Problem with DNS lookup. + ERROR - Syntax error in options. +*/ + +static int +acl_udpsend(const uschar *arg, uschar **log_msgptr) +{ +int sep = 0; +uschar *hostname; +uschar *portstr; +uschar *portend; +host_item *h; +int portnum; +int len; +int r, s; +uschar * errstr; + +hostname = string_nextinlist(&arg, &sep, NULL, 0); +portstr = string_nextinlist(&arg, &sep, NULL, 0); + +if (!hostname) + { + *log_msgptr = US"missing destination host in \"udpsend\" modifier"; + return ERROR; + } +if (!portstr) + { + *log_msgptr = US"missing destination port in \"udpsend\" modifier"; + return ERROR; + } +if (!arg) + { + *log_msgptr = US"missing datagram payload in \"udpsend\" modifier"; + return ERROR; + } +portnum = Ustrtol(portstr, &portend, 10); +if (*portend != '\0') + { + *log_msgptr = US"bad destination port in \"udpsend\" modifier"; + return ERROR; + } + +/* Make a single-item host list. */ +h = store_get(sizeof(host_item), GET_UNTAINTED); +memset(h, 0, sizeof(host_item)); +h->name = hostname; +h->port = portnum; +h->mx = MX_NONE; + +if (string_is_ip_address(hostname, NULL)) + h->address = hostname, r = HOST_FOUND; +else + r = host_find_byname(h, NULL, 0, NULL, FALSE); +if (r == HOST_FIND_FAILED || r == HOST_FIND_AGAIN) + { + *log_msgptr = US"DNS lookup failed in \"udpsend\" modifier"; + return DEFER; + } + +HDEBUG(D_acl) + debug_printf_indent("udpsend [%s]:%d %s\n", h->address, portnum, arg); + +/*XXX this could better use sendto */ +r = s = ip_connectedsocket(SOCK_DGRAM, h->address, portnum, portnum, + 1, NULL, &errstr, NULL); +if (r < 0) goto defer; +len = Ustrlen(arg); +r = send(s, arg, len, 0); +if (r < 0) + { + errstr = US strerror(errno); + close(s); + goto defer; + } +close(s); +if (r < len) + { + *log_msgptr = + string_sprintf("\"udpsend\" truncated from %d to %d octets", len, r); + return DEFER; + } + +HDEBUG(D_acl) + debug_printf_indent("udpsend %d bytes\n", r); + +return OK; + +defer: +*log_msgptr = string_sprintf("\"udpsend\" failed: %s", errstr); +return DEFER; +} + + + +/************************************************* +* 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; +int rc = OK; +#ifdef WITH_CONTENT_SCAN +int sep = -'/'; +#endif + +for (; cb; cb = cb->next) + { + const 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) + { + HDEBUG(D_acl) debug_printf_indent(" message: %s\n", cb->arg); + user_message = cb->arg; + continue; + } + + if (cb->type == ACLC_LOG_MESSAGE) + { + HDEBUG(D_acl) debug_printf_indent("l_message: %s\n", cb->arg); + 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 (!conditions[cb->type].expand_at_top) + arg = cb->arg; + else if (!(arg = expand_string(cb->arg))) + { + if (f.expand_string_forcedfail) continue; + *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", + cb->arg, expand_string_message); + return f.search_find_defer ? DEFER : ERROR; + } + + /* Show condition, and expanded condition if it's different */ + + HDEBUG(D_acl) + { + int lhswidth = 0; + debug_printf_indent("check %s%s %n", + (!conditions[cb->type].is_modifier && cb->u.negated)? "!":"", + conditions[cb->type].name, &lhswidth); + + if (cb->type == ACLC_SET) + { +#ifndef DISABLE_DKIM + if ( Ustrcmp(cb->u.varname, "dkim_verify_status") == 0 + || Ustrcmp(cb->u.varname, "dkim_verify_reason") == 0) + { + debug_printf("%s ", cb->u.varname); + lhswidth += 19; + } + else +#endif + { + debug_printf("acl_%s ", cb->u.varname); + lhswidth += 5 + Ustrlen(cb->u.varname); + } + } + + 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 ((conditions[cb->type].forbids & (1 << where)) != 0) + { + *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL", + conditions[cb->type].is_modifier ? "use" : "test", + conditions[cb->type].name, acl_wherenames[where]); + return ERROR; + } + + /* Run the appropriate test for each condition, or take the appropriate + action for the remaining modifiers. */ + + switch(cb->type) + { + case ACLC_ADD_HEADER: + setup_header(arg); + break; + + /* A nested ACL that returns "discard" makes sense only for an "accept" or + "discard" verb. */ + + case ACLC_ACL: + rc = acl_check_wargs(where, addr, arg, 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 ? match_isinlist(sender_host_authenticated, + &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL) : FAIL; + 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: + /* The true/false parsing here should be kept in sync with that used in + expand.c when dealing with ECOND_BOOL so that we don't have too many + different definitions of what can be a boolean. */ + if (*arg == '-' + ? Ustrspn(arg+1, "0123456789") == Ustrlen(arg+1) /* Negative number */ + : 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_CONTINUE: /* Always succeeds */ + break; + + case ACLC_CONTROL: + { + const uschar *p = NULL; + control_type = decode_control(arg, &p, where, log_msgptr); + + /* Check if this control makes sense at this time */ + + if (controls_list[control_type].forbids & (1 << where)) + { + *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL", + controls_list[control_type].name, acl_wherenames[where]); + return ERROR; + } + + switch(control_type) + { + case CONTROL_AUTH_UNADVERTISED: + f.allow_auth_unadvertised = TRUE; + break; + +#ifdef EXPERIMENTAL_BRIGHTMAIL + case CONTROL_BMI_RUN: + bmi_run = 1; + break; +#endif + +#ifndef DISABLE_DKIM + case CONTROL_DKIM_VERIFY: + f.dkim_disable_verify = TRUE; +# ifdef SUPPORT_DMARC + /* Since DKIM was blocked, skip DMARC too */ + f.dmarc_disable_verify = TRUE; + f.dmarc_enable_forensic = FALSE; +# endif + break; +#endif + +#ifdef SUPPORT_DMARC + case CONTROL_DMARC_VERIFY: + f.dmarc_disable_verify = TRUE; + break; + + case CONTROL_DMARC_FORENSIC: + f.dmarc_enable_forensic = TRUE; + break; +#endif + + case CONTROL_DSCP: + if (*p == '/') + { + int fd, af, level, optname, value; + /* If we are acting on stdin, the setsockopt may fail if stdin is not + a socket; we can accept that, we'll just debug-log failures anyway. */ + fd = fileno(smtp_in); + if ((af = ip_get_address_family(fd)) < 0) + { + HDEBUG(D_acl) + debug_printf_indent("smtp input is probably not a socket [%s], not setting DSCP\n", + strerror(errno)); + break; + } + if (dscp_lookup(p+1, af, &level, &optname, &value)) + if (setsockopt(fd, level, optname, &value, sizeof(value)) < 0) + { + HDEBUG(D_acl) debug_printf_indent("failed to set input DSCP[%s]: %s\n", + p+1, strerror(errno)); + } + else + { + HDEBUG(D_acl) debug_printf_indent("set input DSCP to \"%s\"\n", p+1); + } + else + { + *log_msgptr = string_sprintf("unrecognised DSCP value in \"control=%s\"", arg); + return ERROR; + } + } + else + { + *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg); + return ERROR; + } + break; + + 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: + f.no_mbox_unspool = TRUE; + break; +#endif + + case CONTROL_NO_MULTILINE: + f.no_multiline_responses = TRUE; + break; + + case CONTROL_NO_PIPELINING: + f.pipelining_enable = FALSE; + break; + + case CONTROL_NO_DELAY_FLUSH: + f.disable_delay_flush = TRUE; + break; + + case CONTROL_NO_CALLOUT_FLUSH: + f.disable_callout_flush = TRUE; + break; + + case CONTROL_FAKEREJECT: + cancel_cutthrough_connection(TRUE, US"fakereject"); + case CONTROL_FAKEDEFER: + fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL; + if (*p == '/') + { + const uschar *pp = p + 1; + while (*pp) pp++; + /* The entire control= line was expanded at top so no need to expand + the part after the / */ + fake_response_text = string_copyn(p+1, pp-p-1); + p = pp; + } + else /* Explicitly reset to default string */ + 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)."; + break; + + case CONTROL_FREEZE: + f.deliver_freeze = TRUE; + deliver_frozen_at = time(NULL); + freeze_tell = freeze_tell_config; /* Reset to configured value */ + if (Ustrncmp(p, "/no_tell", 8) == 0) + { + p += 8; + freeze_tell = NULL; + } + if (*p) + { + *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg); + return ERROR; + } + cancel_cutthrough_connection(TRUE, US"item frozen"); + break; + + case CONTROL_QUEUE: + f.queue_only_policy = TRUE; + if (Ustrcmp(p, "_only") == 0) + p += 5; + else while (*p == '/') + if (Ustrncmp(p, "/only", 5) == 0) + { p += 5; f.queue_smtp = FALSE; } + else if (Ustrncmp(p, "/first_pass_route", 17) == 0) + { p += 17; f.queue_smtp = TRUE; } + else + break; + cancel_cutthrough_connection(TRUE, US"queueing forced"); + break; + + case CONTROL_SUBMISSION: + originator_name = US""; + f.submission_mode = TRUE; + while (*p == '/') + { + if (Ustrncmp(p, "/sender_retain", 14) == 0) + { + p += 14; + f.active_local_sender_retain = TRUE; + f.active_local_from_check = FALSE; + } + else if (Ustrncmp(p, "/domain=", 8) == 0) + { + const uschar *pp = p + 8; + while (*pp && *pp != '/') pp++; + submission_domain = string_copyn(p+8, pp-p-8); + p = pp; + } + /* The name= option must be last, because it swallows the rest of + the string. */ + else if (Ustrncmp(p, "/name=", 6) == 0) + { + const uschar *pp = p + 6; + while (*pp) pp++; + submission_name = parse_fix_phrase(p+6, pp-p-6); + p = pp; + } + else break; + } + if (*p) + { + *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg); + return ERROR; + } + break; + + case CONTROL_DEBUG: + { + uschar * debug_tag = NULL, * debug_opts = NULL; + BOOL kill = FALSE, stop = FALSE; + + while (*p == '/') + { + const uschar * pp = p+1; + if (Ustrncmp(pp, "tag=", 4) == 0) + { + for (pp += 4; *pp && *pp != '/';) pp++; + debug_tag = string_copyn(p+5, pp-p-5); + } + else if (Ustrncmp(pp, "opts=", 5) == 0) + { + for (pp += 5; *pp && *pp != '/';) pp++; + debug_opts = string_copyn(p+6, pp-p-6); + } + else if (Ustrncmp(pp, "kill", 4) == 0) + { + pp += 4; + kill = TRUE; + } + else if (Ustrncmp(pp, "stop", 4) == 0) + { + pp += 4; + stop = TRUE; + } + else if (Ustrncmp(pp, "pretrigger=", 11) == 0) + debug_pretrigger_setup(pp+11); + else if (Ustrncmp(pp, "trigger=", 8) == 0) + { + if (Ustrncmp(pp += 8, "now", 3) == 0) + { + pp += 3; + debug_trigger_fire(); + } + else if (Ustrncmp(pp, "paniclog", 8) == 0) + { + pp += 8; + dtrigger_selector |= BIT(DTi_panictrigger); + } + } + while (*pp && *pp != '/') pp++; + p = pp; + } + + if (kill) + debug_logging_stop(TRUE); + else if (stop) + debug_logging_stop(FALSE); + else if (debug_tag || debug_opts) + debug_logging_activate(debug_tag, debug_opts); + break; + } + + case CONTROL_SUPPRESS_LOCAL_FIXUPS: + f.suppress_local_fixups = TRUE; + break; + + case CONTROL_CUTTHROUGH_DELIVERY: + { + uschar * ignored = NULL; +#ifndef DISABLE_PRDR + if (prdr_requested) +#else + if (0) +#endif + /* Too hard to think about for now. We might in future cutthrough + the case where both sides handle prdr and this-node prdr acl + is "accept" */ + ignored = US"PRDR active"; + else if (f.deliver_freeze) + ignored = US"frozen"; + else if (f.queue_only_policy) + ignored = US"queue-only"; + else if (fake_response == FAIL) + ignored = US"fakereject"; + else if (rcpt_count != 1) + ignored = US"nonfirst rcpt"; + else if (cutthrough.delivery) + ignored = US"repeated"; + else if (cutthrough.callout_hold_only) + { + DEBUG(D_acl) + debug_printf_indent(" cutthrough request upgrades callout hold\n"); + cutthrough.callout_hold_only = FALSE; + cutthrough.delivery = TRUE; /* control accepted */ + } + else + { + cutthrough.delivery = TRUE; /* control accepted */ + while (*p == '/') + { + const uschar * pp = p+1; + if (Ustrncmp(pp, "defer=", 6) == 0) + { + pp += 6; + if (Ustrncmp(pp, "pass", 4) == 0) cutthrough.defer_pass = TRUE; + /* else if (Ustrncmp(pp, "spool") == 0) ; default */ + } + else + while (*pp && *pp != '/') pp++; + p = pp; + } + } + + DEBUG(D_acl) if (ignored) + debug_printf(" cutthrough request ignored on %s item\n", ignored); + } + break; + +#ifdef SUPPORT_I18N + case CONTROL_UTF8_DOWNCONVERT: + if (*p == '/') + { + if (p[1] == '1') + { + message_utf8_downconvert = 1; + addr->prop.utf8_downcvt = TRUE; + addr->prop.utf8_downcvt_maybe = FALSE; + p += 2; + break; + } + if (p[1] == '0') + { + message_utf8_downconvert = 0; + addr->prop.utf8_downcvt = FALSE; + addr->prop.utf8_downcvt_maybe = FALSE; + p += 2; + break; + } + if (p[1] == '-' && p[2] == '1') + { + message_utf8_downconvert = -1; + addr->prop.utf8_downcvt = FALSE; + addr->prop.utf8_downcvt_maybe = TRUE; + p += 3; + break; + } + *log_msgptr = US"bad option value for control=utf8_downconvert"; + } + else + { + message_utf8_downconvert = 1; + addr->prop.utf8_downcvt = TRUE; + addr->prop.utf8_downcvt_maybe = FALSE; + break; + } + return ERROR; +#endif + + } + break; + } + + #ifdef EXPERIMENTAL_DCC + case ACLC_DCC: + { + /* Separate the regular expression and any optional parameters. */ + const uschar * list = arg; + uschar *ss = string_nextinlist(&list, &sep, NULL, 0); + /* Run the dcc backend. */ + rc = dcc_process(&ss); + /* Modify return code based upon the existence of options. */ + while ((ss = string_nextinlist(&list, &sep, NULL, 0))) + if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER) + rc = FAIL; /* FAIL so that the message is passed to the next ACL */ + } + break; + #endif + + #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_indent("delay modifier requests %d-second delay\n", + delay); + if (host_checking) + { + HDEBUG(D_acl) + debug_printf_indent("delay skipped in -bh checking mode\n"); + } + + /* NOTE 1: Remember that we may be + dealing with stdin/stdout here, in addition to TCP/IP connections. + Also, delays may be specified for non-SMTP input, where smtp_out and + smtp_in will be NULL. Whatever is done must work in all cases. + + NOTE 2: The added feature of flushing the output before a delay must + apply only to SMTP input. Hence the test for smtp_out being non-NULL. + */ + + else + { + if (smtp_out && !f.disable_delay_flush) + mac_smtp_fflush(); + +#if !defined(NO_POLL_H) && defined (POLLRDHUP) + { + struct pollfd p; + nfds_t n = 0; + if (smtp_out) + { + p.fd = fileno(smtp_out); + p.events = POLLRDHUP; + n = 1; + } + if (poll(&p, n, delay*1000) > 0) + HDEBUG(D_acl) debug_printf_indent("delay cancelled by peer close\n"); + } +#else + /* Lacking POLLRDHUP it appears to be impossible to detect that a + TCP/IP connection has gone away without reading from it. This means + that we cannot shorten the delay below if the client goes away, + because we cannot discover that the client has closed its end of the + connection. (The connection is actually in a half-closed state, + waiting for the server to close its end.) It would be nice to be able + to detect this state, so that the Exim process is not held up + unnecessarily. However, it seems that we can't. The poll() function + does not do the right thing, and in any case it is not always + available. */ + + while (delay > 0) delay = sleep(delay); +#endif + } + } + } + break; + +#ifndef DISABLE_DKIM + case ACLC_DKIM_SIGNER: + if (dkim_cur_signer) + rc = match_isinlist(dkim_cur_signer, + &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL); + else + rc = FAIL; + break; + + case ACLC_DKIM_STATUS: + rc = match_isinlist(dkim_verify_status, + &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL); + break; +#endif + +#ifdef SUPPORT_DMARC + case ACLC_DMARC_STATUS: + if (!f.dmarc_has_been_checked) + dmarc_process(); + f.dmarc_has_been_checked = TRUE; + /* used long way of dmarc_exim_expand_query() in case we need more + * view into the process in the future. */ + rc = match_isinlist(dmarc_exim_expand_query(DMARC_VERIFY_STATUS), + &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL); + break; +#endif + + case ACLC_DNSLISTS: + rc = verify_check_dnsbl(where, &arg, log_msgptr); + break; + + case ACLC_DOMAINS: + rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor, + addr->domain_cache, MCL_DOMAIN, TRUE, CUSS &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_in.cipher == NULL) rc = FAIL; else + { + uschar *endcipher = NULL; + uschar *cipher = Ustrchr(tls_in.cipher, ':'); + if (!cipher) cipher = tls_in.cipher; else + { + endcipher = Ustrchr(++cipher, ':'); + if (endcipher) *endcipher = 0; + } + rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL); + if (endcipher) *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 ? sender_host_address : US"", CUSS &host_data); + if (rc == DEFER) *log_msgptr = search_error_message; + if (host_data) host_data = string_copy_perm(host_data, TRUE); + break; + + case ACLC_LOCAL_PARTS: + rc = match_isinlist(addr->cc_local_part, &arg, 0, + &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE, + CUSS &deliver_localpart_data); + break; + + case ACLC_LOG_REJECT_TARGET: + { + int logbits = 0; + int sep = 0; + const uschar *s = arg; + uschar * ss; + while ((ss = string_nextinlist(&s, &sep, NULL, 0))) + { + if (Ustrcmp(ss, "main") == 0) logbits |= LOG_MAIN; + else if (Ustrcmp(ss, "panic") == 0) logbits |= LOG_PANIC; + else if (Ustrcmp(ss, "reject") == 0) logbits |= LOG_REJECT; + else + { + logbits |= LOG_MAIN|LOG_REJECT; + log_write(0, LOG_MAIN|LOG_PANIC, "unknown log name \"%s\" in " + "\"log_reject_target\" in %s ACL", ss, acl_wherenames[where]); + } + } + log_reject_target = logbits; + } + break; + + case ACLC_LOGWRITE: + { + int logbits = 0; + const 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: /* Run the malware backend. */ + { + /* Separate the regular expression and any optional parameters. */ + const uschar * list = arg; + uschar * ss = string_nextinlist(&list, &sep, NULL, 0); + uschar * opt; + BOOL defer_ok = FALSE; + int timeout = 0; + + while ((opt = string_nextinlist(&list, &sep, NULL, 0))) + if (strcmpic(opt, US"defer_ok") == 0) + defer_ok = TRUE; + else if ( strncmpic(opt, US"tmo=", 4) == 0 + && (timeout = readconf_readtime(opt+4, '\0', FALSE)) < 0 + ) + { + *log_msgptr = string_sprintf("bad timeout value in '%s'", opt); + return ERROR; + } + + rc = malware(ss, timeout); + if (rc == DEFER && defer_ok) + rc = FAIL; /* FAIL so that the message is passed to the next ACL */ + } + break; + + case ACLC_MIME_REGEX: + rc = mime_regex(&arg); + break; + #endif + + case ACLC_QUEUE: + if (is_tainted(arg)) + { + *log_msgptr = string_sprintf("Tainted name '%s' for queue not permitted", + arg); + return ERROR; + } + if (Ustrchr(arg, '/')) + { + *log_msgptr = string_sprintf( + "Directory separator not permitted in queue name: '%s'", arg); + return ERROR; + } + queue_name = string_copy_perm(arg, FALSE); + break; + + case ACLC_RATELIMIT: + rc = acl_ratelimit(arg, where, log_msgptr); + break; + + case ACLC_RECIPIENTS: + rc = match_address_list(CUS addr->address, TRUE, TRUE, &arg, NULL, -1, 0, + CUSS &recipient_data); + break; + + #ifdef WITH_CONTENT_SCAN + case ACLC_REGEX: + rc = regex(&arg); + break; + #endif + + case ACLC_REMOVE_HEADER: + setup_remove_header(arg); + break; + + case ACLC_SEEN: + rc = acl_seen(arg, where, log_msgptr); + break; + + case ACLC_SENDER_DOMAINS: + { + uschar *sdomain; + sdomain = Ustrrchr(sender_address, '@'); + sdomain = sdomain ? sdomain + 1 : US""; + rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor, + sender_domain_cache, MCL_DOMAIN, TRUE, NULL); + } + break; + + case ACLC_SENDERS: + rc = match_address_list(CUS sender_address, TRUE, TRUE, &arg, + sender_address_cache, -1, 0, CUSS &sender_data); + break; + + /* Connection variables must persist forever; message variables not */ + + case ACLC_SET: + { + int old_pool = store_pool; + if ( cb->u.varname[0] != 'm' +#ifndef DISABLE_EVENT + || event_name /* An event is being delivered */ +#endif + ) + store_pool = POOL_PERM; +#ifndef DISABLE_DKIM /* Overwriteable dkim result variables */ + if (Ustrcmp(cb->u.varname, "dkim_verify_status") == 0) + dkim_verify_status = string_copy(arg); + else if (Ustrcmp(cb->u.varname, "dkim_verify_reason") == 0) + dkim_verify_reason = string_copy(arg); + else +#endif + acl_var_create(cb->u.varname)->data.ptr = string_copy(arg); + store_pool = old_pool; + } + break; + +#ifdef WITH_CONTENT_SCAN + case ACLC_SPAM: + { + /* Separate the regular expression and any optional parameters. */ + const uschar * list = arg; + uschar *ss = string_nextinlist(&list, &sep, NULL, 0); + + rc = spam(CUSS &ss); + /* Modify return code based upon the existence of options. */ + while ((ss = string_nextinlist(&list, &sep, NULL, 0))) + if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER) + rc = FAIL; /* FAIL so that the message is passed to the next ACL */ + } + break; +#endif + +#ifdef SUPPORT_SPF + case ACLC_SPF: + rc = spf_process(&arg, sender_address, SPF_PROCESS_NORMAL); + break; + case ACLC_SPF_GUESS: + rc = spf_process(&arg, sender_address, SPF_PROCESS_GUESS); + break; +#endif + + case ACLC_UDPSEND: + rc = acl_udpsend(arg, log_msgptr); + break; + + /* 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. However, put the user message into + $acl_verify_message so it can be used in subsequent conditions or modifiers + (until something changes it). */ + + case ACLC_VERIFY: + rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno); + if (*user_msgptr) + acl_verify_message = *user_msgptr; + 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 (!conditions[cb->type].is_modifier && 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 modifiers. If there isn't a log message set, we make +it the same as the user message. + +"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. + +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. For "accept", the message is used in the OK case if there is no +"endpass", but (for backwards compatibility) in the FAIL case if "endpass" is +present. */ + +if (*epp && rc == OK) user_message = NULL; + +if ((BIT(rc) & msgcond[verb]) != 0) + { + uschar *expmessage; + uschar *old_user_msgptr = *user_msgptr; + uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr; + + /* If the verb is "warn", messages generated by conditions (verification or + nested ACLs) are always discarded. This also happens for acceptance verbs + when they actually do accept. Only messages specified at this level are used. + However, the value of an existing message is available in $acl_verify_message + during expansions. */ + + if (verb == ACL_WARN || + (rc == OK && (verb == ACL_ACCEPT || verb == ACL_DISCARD))) + *log_msgptr = *user_msgptr = NULL; + + if (user_message) + { + acl_verify_message = old_user_msgptr; + expmessage = expand_string(user_message); + if (!expmessage) + { + if (!f.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) + { + acl_verify_message = old_log_msgptr; + expmessage = expand_string(log_message); + if (!expmessage) + { + if (!f.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) *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(;;) + { + Uskip_whitespace(&acl_text); /* Leading spaces/empty lines */ + if (!*acl_text) return NULL; /* No more data */ + yield = acl_text; /* Potential data line */ + + while (*acl_text && *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) 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 */ +} + + + + + +/************************************************/ +/* For error messages, a string describing the config location +associated with current processing. NULL if not in an ACL. */ + +uschar * +acl_current_verb(void) +{ +if (acl_current) return string_sprintf(" (ACL %s, %s %d)", + verbs[acl_current->verb], acl_current->srcfile, acl_current->srcline); +return NULL; +} + +/************************************************* +* 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 + 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, + 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 (acl_level > 20) + { + *log_msgptr = US"ACL nested too deep: possible loop"; + return ERROR; + } + +if (!s) + { + HDEBUG(D_acl) debug_printf_indent("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 (acl_level == 0) + { + if (!(ss = expand_string(s))) + { + if (f.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; + +if (is_tainted(acl_text) && !f.running_in_test_harness) + { + log_write(0, LOG_MAIN|LOG_PANIC, + "attempt to use tainted ACL text \"%s\"", acl_text); + /* Avoid leaking info to an attacker */ + *log_msgptr = US"internal configuration error"; + return ERROR; + } + +/* 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) + { + if (!(acl = (acl_block *)(t->data.ptr))) + { + HDEBUG(D_acl) debug_printf_indent("ACL \"%s\" is empty: implicit DENY\n", ss); + return FAIL; + } + acl_name = string_sprintf("ACL \"%s\"", ss); + HDEBUG(D_acl) debug_printf_indent("using ACL \"%s\"\n", ss); + } + + else if (*ss == '/') + { + struct stat statbuf; + if ((fd = Uopen(ss, O_RDONLY, 0)) < 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; + } + + /* If the string being used as a filename is tainted, so is the file content */ + acl_text = store_get(statbuf.st_size + 1, ss); + 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; + (void)close(fd); + + acl_name = string_sprintf("ACL \"%s\"", ss); + HDEBUG(D_acl) debug_printf_indent("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) + { + 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 && *log_msgptr) return ERROR; + if (fd >= 0) + { + tree_node * t = store_get_perm(sizeof(tree_node) + Ustrlen(ss), 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_current = acl)) + { + int cond; + int basic_errno = 0; + BOOL endpass_seen = FALSE; + BOOL acl_quit_check = acl_level == 0 + && (where == ACL_WHERE_QUIT || where == ACL_WHERE_NOTQUIT); + + *log_msgptr = *user_msgptr = NULL; + f.acl_temp_details = FALSE; + + HDEBUG(D_acl) debug_printf_indent("processing \"%s\" (%s %d)\n", + verbs[acl->verb], acl->srcfile, acl->srcline); + + /* 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, acl_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_indent("%s: condition test deferred in %s\n", + verbs[acl->verb], acl_name); + if (basic_errno != ERRNO_CALLOUTDEFER) + { + if (search_error_message != NULL && *search_error_message != 0) + *log_msgptr = search_error_message; + if (smtp_return_error_details) f.acl_temp_details = TRUE; + } + else + f.acl_temp_details = TRUE; + if (acl->verb != ACL_WARN) return DEFER; + break; + + default: /* Paranoia */ + case ERROR: + HDEBUG(D_acl) debug_printf_indent("%s: condition test error in %s\n", + verbs[acl->verb], acl_name); + return ERROR; + + case OK: + HDEBUG(D_acl) debug_printf_indent("%s: condition test succeeded in %s\n", + verbs[acl->verb], acl_name); + break; + + case FAIL: + HDEBUG(D_acl) debug_printf_indent("%s: condition test failed in %s\n", + verbs[acl->verb], acl_name); + 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_indent("%s: condition test yielded \"discard\" in %s\n", + verbs[acl->verb], acl_name); + break; + + case FAIL_DROP: + HDEBUG(D_acl) debug_printf_indent("%s: condition test yielded \"drop\" in %s\n", + verbs[acl->verb], acl_name); + 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) + { + HDEBUG(D_acl) debug_printf_indent("end of %s: ACCEPT\n", acl_name); + return cond; + } + if (endpass_seen) + { + HDEBUG(D_acl) debug_printf_indent("accept: endpass encountered - denying access\n"); + return cond; + } + break; + + case ACL_DEFER: + if (cond == OK) + { + HDEBUG(D_acl) debug_printf_indent("end of %s: DEFER\n", acl_name); + if (acl_quit_check) goto badquit; + f.acl_temp_details = TRUE; + return DEFER; + } + break; + + case ACL_DENY: + if (cond == OK) + { + HDEBUG(D_acl) debug_printf_indent("end of %s: DENY\n", acl_name); + if (acl_quit_check) goto badquit; + return FAIL; + } + break; + + case ACL_DISCARD: + if (cond == OK || cond == DISCARD) + { + HDEBUG(D_acl) debug_printf_indent("end of %s: DISCARD\n", acl_name); + if (acl_quit_check) goto badquit; + return DISCARD; + } + if (endpass_seen) + { + HDEBUG(D_acl) + debug_printf_indent("discard: endpass encountered - denying access\n"); + return cond; + } + break; + + case ACL_DROP: + if (cond == OK) + { + HDEBUG(D_acl) debug_printf_indent("end of %s: DROP\n", acl_name); + if (acl_quit_check) goto badquit; + return FAIL_DROP; + } + break; + + case ACL_REQUIRE: + if (cond != OK) + { + HDEBUG(D_acl) debug_printf_indent("end of %s: not OK\n", acl_name); + if (acl_quit_check) goto badquit; + return cond; + } + break; + + case ACL_WARN: + if (cond == OK) + acl_warn(where, *user_msgptr, *log_msgptr); + else if (cond == DEFER && LOGGING(acl_warn_skipped)) + log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: " + "condition test deferred%s%s", host_and_ident(TRUE), + *log_msgptr ? US": " : US"", + *log_msgptr ? *log_msgptr : US""); + *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_indent("end of %s: implicit DENY\n", acl_name); +return FAIL; + +badquit: + *log_msgptr = string_sprintf("QUIT or not-QUIT toplevel ACL may not fail " + "('%s' verb used incorrectly)", verbs[acl->verb]); + return ERROR; +} + + + + +/* Same args as acl_check_internal() above, but the string s is +the name of an ACL followed optionally by up to 9 space-separated arguments. +The name and args are separately expanded. Args go into $acl_arg globals. */ +static int +acl_check_wargs(int where, address_item *addr, const uschar *s, + uschar **user_msgptr, uschar **log_msgptr) +{ +uschar * tmp; +uschar * tmp_arg[9]; /* must match acl_arg[] */ +uschar * sav_arg[9]; /* must match acl_arg[] */ +int sav_narg; +uschar * name; +int i; +int ret; + +if (!(tmp = string_dequote(&s)) || !(name = expand_string(tmp))) + goto bad; + +for (i = 0; i < 9; i++) + { + while (*s && isspace(*s)) s++; + if (!*s) break; + if (!(tmp = string_dequote(&s)) || !(tmp_arg[i] = expand_string(tmp))) + { + tmp = name; + goto bad; + } + } + +sav_narg = acl_narg; +acl_narg = i; +for (i = 0; i < acl_narg; i++) + { + sav_arg[i] = acl_arg[i]; + acl_arg[i] = tmp_arg[i]; + } +while (i < 9) + { + sav_arg[i] = acl_arg[i]; + acl_arg[i++] = NULL; + } + +acl_level++; +ret = acl_check_internal(where, addr, name, user_msgptr, log_msgptr); +acl_level--; + +acl_narg = sav_narg; +for (i = 0; i < 9; i++) acl_arg[i] = sav_arg[i]; +return ret; + +bad: +if (f.expand_string_forcedfail) return ERROR; +*log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", + tmp, expand_string_message); +return f.search_find_defer ? DEFER : ERROR; +} + + + +/************************************************* +* Check access using an ACL * +*************************************************/ + +/* Alternate interface for ACL, used by expansions */ +int +acl_eval(int where, uschar *s, uschar **user_msgptr, uschar **log_msgptr) +{ +address_item adb; +address_item *addr = NULL; +int rc; + +*user_msgptr = *log_msgptr = NULL; +sender_verified_failed = NULL; +ratelimiters_cmd = NULL; +log_reject_target = LOG_MAIN|LOG_REJECT; + +if (where == ACL_WHERE_RCPT) + { + adb = address_defaults; + addr = &adb; + addr->address = expand_string(US"$local_part@$domain"); + addr->domain = deliver_domain; + addr->local_part = deliver_localpart; + addr->cc_local_part = deliver_localpart; + addr->lc_local_part = deliver_localpart; + } + +acl_level++; +rc = acl_check_internal(where, addr, s, user_msgptr, log_msgptr); +acl_level--; +return rc; +} + + + +/* 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 + recipient RCPT address for RCPT check, else 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_where = ACL_WHERE_UNKNOWN; + +int +acl_check(int where, uschar *recipient, uschar *s, uschar **user_msgptr, + uschar **log_msgptr) +{ +int rc; +address_item adb; +address_item *addr = NULL; + +*user_msgptr = *log_msgptr = NULL; +sender_verified_failed = NULL; +ratelimiters_cmd = NULL; +log_reject_target = LOG_MAIN|LOG_REJECT; + +#ifndef DISABLE_PRDR +if (where==ACL_WHERE_RCPT || where==ACL_WHERE_VRFY || where==ACL_WHERE_PRDR) +#else +if (where==ACL_WHERE_RCPT || where==ACL_WHERE_VRFY) +#endif + { + adb = address_defaults; + addr = &adb; + addr->address = recipient; + if (deliver_split_address(addr) == DEFER) + { + *log_msgptr = US"defer in percent_hack_domains check"; + return DEFER; + } +#ifdef SUPPORT_I18N + if ((addr->prop.utf8_msg = message_smtputf8)) + { + addr->prop.utf8_downcvt = message_utf8_downconvert == 1; + addr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1; + } +#endif + deliver_domain = addr->domain; + deliver_localpart = addr->local_part; + } + +acl_where = where; +acl_level = 0; +rc = acl_check_internal(where, addr, s, user_msgptr, log_msgptr); +acl_level = 0; +acl_where = ACL_WHERE_UNKNOWN; + +/* Cutthrough - if requested, +and WHERE_RCPT and not yet opened conn as result of recipient-verify, +and rcpt acl returned accept, +and first recipient (cancel on any subsequents) +open one now and run it up to RCPT acceptance. +A failed verify should cancel cutthrough request, +and will pass the fail to the originator. +Initial implementation: dual-write to spool. +Assume the rxd datastream is now being copied byte-for-byte to an open cutthrough connection. + +Cease cutthrough copy on rxd final dot; do not send one. + +On a data acl, if not accept and a cutthrough conn is open, hard-close it (no SMTP niceness). + +On data acl accept, terminate the dataphase on an open cutthrough conn. If accepted or +perm-rejected, reflect that to the original sender - and dump the spooled copy. +If temp-reject, close the conn (and keep the spooled copy). +If conn-failure, no action (and keep the spooled copy). +*/ +switch (where) + { + case ACL_WHERE_RCPT: +#ifndef DISABLE_PRDR + case ACL_WHERE_PRDR: +#endif + + if (f.host_checking_callout) /* -bhc mode */ + cancel_cutthrough_connection(TRUE, US"host-checking mode"); + + else if ( rc == OK + && cutthrough.delivery + && rcpt_count > cutthrough.nrcpt + ) + { + if ((rc = open_cutthrough_connection(addr)) == DEFER) + if (cutthrough.defer_pass) + { + uschar * s = addr->message; + /* Horrid kludge to recover target's SMTP message */ + while (*s) s++; + do --s; while (!isdigit(*s)); + if (*--s && isdigit(*s) && *--s && isdigit(*s)) *user_msgptr = s; + f.acl_temp_details = TRUE; + } + else + { + HDEBUG(D_acl) debug_printf_indent("cutthrough defer; will spool\n"); + rc = OK; + } + } + else HDEBUG(D_acl) if (cutthrough.delivery) + if (rcpt_count <= cutthrough.nrcpt) + debug_printf_indent("ignore cutthrough request; nonfirst message\n"); + else if (rc != OK) + debug_printf_indent("ignore cutthrough request; ACL did not accept\n"); + break; + + case ACL_WHERE_PREDATA: + if (rc == OK) + cutthrough_predata(); + else + cancel_cutthrough_connection(TRUE, US"predata acl not ok"); + break; + + case ACL_WHERE_QUIT: + case ACL_WHERE_NOTQUIT: + /* Drop cutthrough conns, and drop heldopen verify conns if + the previous was not DATA */ + { + uschar prev = + smtp_connection_had[SMTP_HBUFF_PREV(SMTP_HBUFF_PREV(smtp_ch_index))]; + BOOL dropverify = !(prev == SCH_DATA || prev == SCH_BDAT); + + cancel_cutthrough_connection(dropverify, US"quit or conndrop"); + break; + } + + default: + break; + } + +deliver_domain = deliver_localpart = deliver_address_data = + deliver_domain_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 a response, take a look at the length of any user message, and +split it up into multiple lines if possible. */ + +*user_msgptr = string_split_message(*user_msgptr); +if (fake_response != OK) + fake_response_text = string_split_message(fake_response_text); + +return rc; +} + + +/************************************************* +* Create ACL variable * +*************************************************/ + +/* Create an ACL variable or reuse an existing one. ACL variables are in a +binary tree (see tree.c) with acl_var_c and acl_var_m as root nodes. + +Argument: + name pointer to the variable's name, starting with c or m + +Returns the pointer to variable's tree node +*/ + +tree_node * +acl_var_create(uschar * name) +{ +tree_node * node, ** root = name[0] == 'c' ? &acl_var_c : &acl_var_m; +if (!(node = tree_search(*root, name))) + { + node = store_get(sizeof(tree_node) + Ustrlen(name), name); + Ustrcpy(node->name, name); + (void)tree_insertnode(root, node); + } +node->data.ptr = NULL; +return node; +} + + + +/************************************************* +* Write an ACL variable in spool format * +*************************************************/ + +/* This function is used as a callback for tree_walk when writing variables to +the spool file. To retain spool file compatibility, what is written is -aclc or +-aclm followed by the rest of the name and the data length, space separated, +then the value itself, starting on a new line, and terminated by an additional +newline. When we had only numbered ACL variables, the first line might look +like this: "-aclc 5 20". Now it might be "-aclc foo 20" for the variable called +acl_cfoo. + +Arguments: + name of the variable + value of the variable + ctx FILE pointer (as a void pointer) + +Returns: nothing +*/ + +void +acl_var_write(uschar * name, uschar * value, void * ctx) +{ +FILE * f = (FILE *)ctx; +putc('-', f); +if (is_tainted(value)) + { + int q = quoter_for_address(value); + putc('-', f); + if (is_real_quoter(q)) fprintf(f, "(%s)", lookup_list[q]->name); + } +fprintf(f, "acl%c %s %d\n%s\n", name[0], name+1, Ustrlen(value), value); +} + +#endif /* !MACRO_PREDEF */ +/* vi: aw ai sw=2 +*/ +/* End of acl.c */ |