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/*************************************************
* Exim - an Internet mail transport agent *
*************************************************/
/* 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"
/* Default callout timeout */
#define CALLOUT_TIMEOUT_DEFAULT 30
/* ACL verb codes - keep in step with the table of verbs that follows */
enum { ACL_ACCEPT, ACL_DEFER, ACL_DENY, ACL_DISCARD, ACL_DROP, ACL_REQUIRE,
ACL_WARN };
/* ACL verbs */
static uschar *verbs[] = {
[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)
};
/* 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 EXPERIMENTAL_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_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. */
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 EXPERIMENTAL_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_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 },
};
/* 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 EXPERIMENTAL_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_ONLY,
#if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_REQUIRETLS)
CONTROL_REQUIRETLS,
#endif
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 EXPERIMENTAL_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_ONLY] =
{ US"queue_only", 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_NOTSMTP | ACL_BIT_MIME)
},
#if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_REQUIRETLS)
[CONTROL_REQUIRETLS] =
{ US"requiretls", FALSE,
(unsigned)
~(ACL_BIT_MAIL | ACL_BIT_RCPT | ACL_BIT_PREDATA |
ACL_BIT_DATA | ACL_BIT_MIME |
ACL_BIT_NOTSMTP)
},
#endif
[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 **);
/*************************************************
* 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)
{
int first = 0;
while (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)
{
int start = 0;
while (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)
{
int start = 0;
while (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)()) != NULL)
{
int v, c;
BOOL negated = FALSE;
uschar *saveline = s;
uschar name[64];
/* Conditions (but not verbs) are allowed to be negated by an initial
exclamation mark. */
while (isspace(*s)) s++;
if (*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 == NULL)
{
*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));
*lastp = this;
lastp = &(this->next);
this->next = NULL;
this->verb = v;
this->condition = NULL;
condp = &(this->condition);
if (*s == 0) continue; /* No condition on this line */
if (*s == '!')
{
negated = TRUE;
s++;
}
s = readconf_readname(name, sizeof(name), s); /* Condition name */
}
/* Handle a condition or modifier. */
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));
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;
while (isspace(*s)) 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 != 0 && *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;
while (isspace(*s)) s++;
}
/* For "set", we are now positioned for the data. For the others, only
"endpass" has no data */
if (c != ACLC_ENDPASS)
{
if (*s++ != '=')
{
*error = string_sprintf("\"=\" missing after ACL \"%s\" %s", name,
conditions[c].is_modifier ? US"modifier" : US"condition");
return NULL;
}
while (isspace(*s)) 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)
{
header_line *h = store_get(sizeof(header_line));
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;
header_line * h;
for (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 != NULL; logged = logged->next)
if (Ustrcmp(logged->text, text) == 0) break;
if (logged == NULL)
{
int length = Ustrlen(text) + 1;
log_write(0, LOG_MAIN, "%s", text);
logged = store_malloc(sizeof(string_item) + length);
logged->text = 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 == NULL) return;
/* If this isn't a message ACL, we can't do anything with a user message.
Log an error. */
if (where > ACL_WHERE_NOTSMTP)
{
log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting "
"found in a non-message (%s) ACL: cannot specify header lines here: "
"message ignored", acl_wherenames[where]);
return;
}
/* 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;
user_msgptr = user_msgptr; /* stop compiler warning */
/* Previous success */
if (sender_host_name != NULL) return OK;
/* Previous failure */
if (host_lookup_failed)
{
*log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg);
return FAIL;
}
/* Need to do a lookup */
HDEBUG(D_acl)
debug_printf_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)
{
dns_record *rr;
dns_address *da;
BOOL target_found = FALSE;
for (rr = dns_next_rr(dnsa, dnss, reset);
rr != NULL;
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;
target_found = TRUE;
/* 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 (da = dns_address_from_rr(dnsa, rr); da != NULL; 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. */
if (target_found) return CSA_FAIL_MISMATCH;
else return CSA_FAIL_NOADDR;
}
/*************************************************
* 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;
uschar target[256];
/* 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 == NULL) domain = sender_host_address;
if (sender_host_address == NULL) 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;
dns_build_reverse(domain, target);
domain = target;
}
/* 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. */
t = tree_search(csa_cache, domain);
if (t != NULL) return t->data.val;
t = store_get_perm(sizeof(tree_node) + Ustrlen(domain));
Ustrcpy(t->name, domain);
(void)tree_insertnode(&csa_cache, t);
/* Now we are ready to do the actual DNS lookup(s). */
found = domain;
switch (dns_special_lookup(&dnsa, domain, T_CSA, &found))
{
/* If something bad happened (most commonly DNS_AGAIN), defer. */
default:
return t->data.val = CSA_DEFER_SRV;
/* If we found nothing, the client's authorization is unknown. */
case DNS_NOMATCH:
case DNS_NODATA:
return t->data.val = CSA_UNKNOWN;
/* 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)
return t->data.val = port & 1 ? CSA_FAIL_EXPLICIT : CSA_UNKNOWN;
/* 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) return t->data.val = CSA_FAIL_DOMAIN;
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, sizeof(target));
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 == NULL) return t->data.val = CSA_UNKNOWN;
/* 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) return t->data.val = CSA_FAIL_NOADDR;
/* 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) return t->data.val = rc;
/* 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:
return t->data.val = CSA_DEFER_ADDR;
/* 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) return t->data.val = rc;
/* 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:
return t->data.val = CSA_FAIL_NOADDR;
}
}
/*************************************************
* 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, ~0, FALSE, 0 },
{ US"certificate", VERIFY_CERT, ~0, TRUE, 0 },
{ US"helo", VERIFY_HELO, ~0, TRUE, 0 },
{ US"csa", VERIFY_CSA, ~0, FALSE, 0 },
{ US"header_syntax", VERIFY_HDR_SYNTAX, ACL_BIT_DATA | ACL_BIT_NOTSMTP, TRUE, 0 },
{ US"not_blind", VERIFY_NOT_BLIND, ACL_BIT_DATA | ACL_BIT_NOTSMTP, TRUE, 0 },
{ US"header_sender", VERIFY_HDR_SNDR, ACL_BIT_DATA | ACL_BIT_NOTSMTP, 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_BIT_DATA | ACL_BIT_NOTSMTP, 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 }
};
/* 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;
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, big_buffer, big_buffer_size);
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:. */
if ((rc = verify_check_notblind()) != OK)
{
*log_msgptr = string_sprintf("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 == 0)
verify_sender_address = sender_address;
else
{
while (isspace(*s)) s++;
if (*s++ != '=') goto BAD_VERIFY;
while (isspace(*s)) s++;
verify_sender_address = string_copy(s);
}
}
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, big_buffer, big_buffer_size))
!= NULL)
{
if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE;
else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE;
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;
ss += 7;
if (*ss != 0)
{
while (isspace(*ss)) ss++;
if (*ss++ == '=')
{
const uschar * sublist = ss;
int optsep = ',';
uschar *opt;
uschar buffer[256];
while (isspace(*sublist)) sublist++;
while ((opt = string_nextinlist(&sublist, &optsep, buffer, sizeof(buffer))))
{
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 = readconf_readtime(opt, 0, FALSE)) < 0)
{
*log_msgptr = string_sprintf("bad time value in ACL condition "
"\"verify %s\"", arg);
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;
}
}
}
/* Option not recognized */
else
{
*log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
"condition \"verify %s\"", ss, arg);
return ERROR;
}
}
if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
(vopt_callout_recipsender|vopt_callout_recippmaster))
{
*log_msgptr = US"only one of use_sender and use_postmaster can be set "
"for a recipient callout";
return ERROR;
}
/* Handle sender-in-header verification. Default the user message to the log
message if giving out verification details. */
if (verify_header_sender)
{
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 != NULL && /* Previously checked */
callout <= 0) /* No callout needed this time */
{
/* If the "routed" flag is set, it means that routing worked before, so
this check can give OK (the saved return code value, if set, belongs to a
callout that was done previously). If the "routed" flag is not set, routing
must have failed, so we use the saved return code. */
if (testflag(sender_vaddr, af_verify_routed))
rc = OK;
else
{
rc = sender_vaddr->special_action;
*basic_errno = sender_vaddr->basic_errno;
}
HDEBUG(D_acl) debug_printf_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 != NULL)?
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 != NULL)
{
if (rc != DEFER)
*log_msgptr = *user_msgptr = US"Sender verify failed";
else if (*basic_errno != ERRNO_CALLOUTDEFER)
*log_msgptr = *user_msgptr = US"Could not complete sender verify";
else
{
*log_msgptr = US"Could not complete sender verify callout";
*user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
*log_msgptr;
}
sender_verified_failed = sender_vaddr;
}
/* Verifying an address messes up the values of $domain and $local_part,
so reset them before returning if this is a RCPT ACL. */
if (addr != NULL)
{
deliver_domain = addr->domain;
deliver_localpart = addr->local_part;
}
return rc;
/* Syntax errors in the verify argument come here. */
BAD_VERIFY:
*log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
"\"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
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;
if ( (idx = find_control(arg, controls_list, nelem(controls_list))) < 0
|| ( arg[len = Ustrlen((d = controls_list+idx)->name)] != 0
&& (!d->has_option || arg[len] != '/')
) )
{
*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
ss ratelimit option name
where ACL_WHERE_xxxx indicating which ACL this is
Returns: ERROR
*/
static int
ratelimit_error(uschar **log_msgptr, const char *format, ...)
{
va_list ap;
uschar buffer[STRING_SPRINTF_BUFFER_SIZE];
va_start(ap, format);
if (!string_vformat(buffer, sizeof(buffer), format, ap))
log_write(0, LOG_MAIN|LOG_PANIC_DIE,
"string_sprintf expansion was longer than " SIZE_T_FMT, sizeof(buffer));
va_end(ap);
*log_msgptr = string_sprintf(
"error in arguments to \"ratelimit\" condition: %s", buffer);
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, big_buffer, big_buffer_size)))
{
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)))
{
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);
}
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);
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. */
t = store_get(sizeof(tree_node) + Ustrlen(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;
}
/*************************************************
* 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));
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 EXPERIMENTAL_DMARC
/* Since DKIM was blocked, skip DMARC too */
f.dmarc_disable_verify = TRUE;
f.dmarc_enable_forensic = FALSE;
#endif
break;
#endif
#ifdef EXPERIMENTAL_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);
af = ip_get_address_family(fd);
if (af < 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 != 0) pp++;
fake_response_text = expand_string(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 != 0)
{
*log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
return ERROR;
}
cancel_cutthrough_connection(TRUE, US"item frozen");
break;
case CONTROL_QUEUE_ONLY:
f.queue_only_policy = TRUE;
cancel_cutthrough_connection(TRUE, US"queueing forced");
break;
#if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_REQUIRETLS)
case CONTROL_REQUIRETLS:
tls_requiretls |= REQUIRETLS_MSG;
break;
#endif
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 != 0 && *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 != 0) pp++;
submission_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
big_buffer, big_buffer_size));
p = pp;
}
else break;
}
if (*p != 0)
{
*log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
return ERROR;
}
break;
case CONTROL_DEBUG:
{
uschar * debug_tag = NULL;
uschar * debug_opts = NULL;
BOOL kill = 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)
{
for (pp += 4; *pp && *pp != '/';) pp++;
kill = TRUE;
}
else
while (*pp && *pp != '/') pp++;
p = pp;
}
if (kill)
debug_logging_stop();
else
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)
{
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;
}
}
else
ignored = US"nonfirst rcpt";
}
}
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, big_buffer, big_buffer_size);
/* Run the dcc backend. */
rc = dcc_process(&ss);
/* Modify return code based upon the existence of options. */
while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
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 != NULL && !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
/* 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 EXPERIMENTAL_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 == NULL) cipher = tls_in.cipher; else
{
endcipher = Ustrchr(++cipher, ':');
if (endcipher != NULL) *endcipher = 0;
}
rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
if (endcipher != NULL) *endcipher = ':';
}
break;
/* Use verify_check_this_host() instead of verify_check_host() so that
we can pass over &host_data to catch any looked up data. Once it has been
set, it retains its value so that it's still there if another ACL verb
comes through here and uses the cache. However, we must put it into
permanent store in case it is also expected to be used in a subsequent
message in the same SMTP connection. */
case ACLC_HOSTS:
rc = verify_check_this_host(&arg, sender_host_cache, NULL,
(sender_host_address == NULL)? US"" : sender_host_address,
CUSS &host_data);
if (rc == DEFER) *log_msgptr = search_error_message;
if (host_data) host_data = string_copy_malloc(host_data);
break;
case ACLC_LOCAL_PARTS:
rc = match_isinlist(addr->cc_local_part, &arg, 0,
&localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
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, big_buffer, big_buffer_size)))
{
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, big_buffer, big_buffer_size);
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 (Ustrchr(arg, '/'))
{
*log_msgptr = string_sprintf(
"Directory separator not permitted in queue name: '%s'", arg);
return ERROR;
}
queue_name = string_copy_malloc(arg);
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_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);