/* $Cambridge: exim/exim-src/src/acl.c,v 1.80 2007/09/28 12:21:57 tom Exp $ */
/*************************************************
* Exim - an Internet mail transport agent *
*************************************************/
/* Copyright (c) University of Cambridge 1995 - 2007 */
/* See the file NOTICE for conditions of use and distribution. */
/* Code for handling Access Control Lists (ACLs) */
#include "exim.h"
/* Default callout timeout */
#define CALLOUT_TIMEOUT_DEFAULT 30
/* ACL verb codes - keep in step with the table of verbs that follows */
enum { ACL_ACCEPT, ACL_DEFER, ACL_DENY, ACL_DISCARD, ACL_DROP, ACL_REQUIRE,
ACL_WARN };
/* ACL verbs */
static uschar *verbs[] =
{ US"accept", US"defer", US"deny", US"discard", US"drop", US"require",
US"warn" };
/* For each verb, the 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[] = {
(1<<OK) | (1<<FAIL) | (1<<FAIL_DROP), /* accept */
(1<<OK), /* defer */
(1<<OK), /* deny */
(1<<OK) | (1<<FAIL) | (1<<FAIL_DROP), /* discard */
(1<<OK), /* drop */
(1<<FAIL) | (1<<FAIL_DROP), /* require */
(1<<OK) /* warn */
};
/* ACL condition and modifier codes - keep in step with the table that
follows, and the cond_expand_at_top and uschar cond_modifiers tables lower
down. */
enum { ACLC_ACL,
ACLC_ADD_HEADER,
ACLC_AUTHENTICATED,
#ifdef EXPERIMENTAL_BRIGHTMAIL
ACLC_BMI_OPTIN,
#endif
ACLC_CONDITION,
ACLC_CONTINUE,
ACLC_CONTROL,
#ifdef WITH_CONTENT_SCAN
ACLC_DECODE,
#endif
ACLC_DELAY,
#ifdef WITH_OLD_DEMIME
ACLC_DEMIME,
#endif
#ifdef EXPERIMENTAL_DOMAINKEYS
ACLC_DK_DOMAIN_SOURCE,
ACLC_DK_POLICY,
ACLC_DK_SENDER_DOMAINS,
ACLC_DK_SENDER_LOCAL_PARTS,
ACLC_DK_SENDERS,
ACLC_DK_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_RATELIMIT,
ACLC_RECIPIENTS,
#ifdef WITH_CONTENT_SCAN
ACLC_REGEX,
#endif
ACLC_SENDER_DOMAINS,
ACLC_SENDERS,
ACLC_SET,
#ifdef WITH_CONTENT_SCAN
ACLC_SPAM,
#endif
#ifdef EXPERIMENTAL_SPF
ACLC_SPF,
#endif
ACLC_VERIFY };
/* ACL conditions/modifiers: "delay", "control", "continue", "endpass",
"message", "log_message", "log_reject_target", "logwrite", and "set" are
modifiers that look like conditions but always return TRUE. They are used for
their side effects. */
static uschar *conditions[] = {
US"acl",
US"add_header",
US"authenticated",
#ifdef EXPERIMENTAL_BRIGHTMAIL
US"bmi_optin",
#endif
US"condition",
US"continue",
US"control",
#ifdef WITH_CONTENT_SCAN
US"decode",
#endif
US"delay",
#ifdef WITH_OLD_DEMIME
US"demime",
#endif
#ifdef EXPERIMENTAL_DOMAINKEYS
US"dk_domain_source",
US"dk_policy",
US"dk_sender_domains",
US"dk_sender_local_parts",
US"dk_senders",
US"dk_status",
#endif
US"dnslists",
US"domains",
US"encrypted",
US"endpass",
US"hosts",
US"local_parts",
US"log_message",
US"log_reject_target",
US"logwrite",
#ifdef WITH_CONTENT_SCAN
US"malware",
#endif
US"message",
#ifdef WITH_CONTENT_SCAN
US"mime_regex",
#endif
US"ratelimit",
US"recipients",
#ifdef WITH_CONTENT_SCAN
US"regex",
#endif
US"sender_domains", US"senders", US"set",
#ifdef WITH_CONTENT_SCAN
US"spam",
#endif
#ifdef EXPERIMENTAL_SPF
US"spf",
#endif
US"verify" };
/* Return values from decode_control(); keep in step with the table of names
that follows! */
enum {
CONTROL_AUTH_UNADVERTISED,
#ifdef EXPERIMENTAL_BRIGHTMAIL
CONTROL_BMI_RUN,
#endif
#ifdef EXPERIMENTAL_DOMAINKEYS
CONTROL_DK_VERIFY,
#endif
#ifdef EXPERIMENTAL_DKIM
CONTROL_DKIM_VERIFY,
#endif
CONTROL_ERROR,
CONTROL_CASEFUL_LOCAL_PART,
CONTROL_CASELOWER_LOCAL_PART,
CONTROL_ENFORCE_SYNC,
CONTROL_NO_ENFORCE_SYNC,
CONTROL_FREEZE,
CONTROL_QUEUE_ONLY,
CONTROL_SUBMISSION,
CONTROL_SUPPRESS_LOCAL_FIXUPS,
#ifdef WITH_CONTENT_SCAN
CONTROL_NO_MBOX_UNSPOOL,
#endif
CONTROL_FAKEDEFER,
CONTROL_FAKEREJECT,
CONTROL_NO_MULTILINE,
CONTROL_NO_PIPELINING,
CONTROL_NO_DELAY_FLUSH,
CONTROL_NO_CALLOUT_FLUSH
};
/* ACL control names; keep in step with the table above! This list is used for
turning ids into names. The actual list of recognized names is in the variable
control_def controls_list[] below. The fact that there are two lists is a mess
and should be tidied up. */
static uschar *controls[] = {
US"allow_auth_unadvertised",
#ifdef EXPERIMENTAL_BRIGHTMAIL
US"bmi_run",
#endif
#ifdef EXPERIMENTAL_DOMAINKEYS
US"dk_verify",
#endif
#ifdef EXPERIMENTAL_DKIM
US"dkim_verify",
#endif
US"error",
US"caseful_local_part",
US"caselower_local_part",
US"enforce_sync",
US"no_enforce_sync",
US"freeze",
US"queue_only",
US"submission",
US"suppress_local_fixups",
#ifdef WITH_CONTENT_SCAN
US"no_mbox_unspool",
#endif
US"fakedefer",
US"fakereject",
US"no_multiline_responses",
US"no_pipelining",
US"no_delay_flush",
US"no_callout_flush"
};
/* Flags to indicate for which conditions/modifiers a string expansion is done
at the outer level. In the other cases, expansion already occurs in the
checking functions. */
static uschar cond_expand_at_top[] = {
TRUE, /* acl */
TRUE, /* add_header */
FALSE, /* authenticated */
#ifdef EXPERIMENTAL_BRIGHTMAIL
TRUE, /* bmi_optin */
#endif
TRUE, /* condition */
TRUE, /* continue */
TRUE, /* control */
#ifdef WITH_CONTENT_SCAN
TRUE, /* decode */
#endif
TRUE, /* delay */
#ifdef WITH_OLD_DEMIME
TRUE, /* demime */
#endif
#ifdef EXPERIMENTAL_DOMAINKEYS
TRUE, /* dk_domain_source */
TRUE, /* dk_policy */
TRUE, /* dk_sender_domains */
TRUE, /* dk_sender_local_parts */
TRUE, /* dk_senders */
TRUE, /* dk_status */
#endif
TRUE, /* dnslists */
FALSE, /* domains */
FALSE, /* encrypted */
TRUE, /* endpass */
FALSE, /* hosts */
FALSE, /* local_parts */
TRUE, /* log_message */
TRUE, /* log_reject_target */
TRUE, /* logwrite */
#ifdef WITH_CONTENT_SCAN
TRUE, /* malware */
#endif
TRUE, /* message */
#ifdef WITH_CONTENT_SCAN
TRUE, /* mime_regex */
#endif
TRUE, /* ratelimit */
FALSE, /* recipients */
#ifdef WITH_CONTENT_SCAN
TRUE, /* regex */
#endif
FALSE, /* sender_domains */
FALSE, /* senders */
TRUE, /* set */
#ifdef WITH_CONTENT_SCAN
TRUE, /* spam */
#endif
#ifdef EXPERIMENTAL_SPF
TRUE, /* spf */
#endif
TRUE /* verify */
};
/* Flags to identify the modifiers */
static uschar cond_modifiers[] = {
FALSE, /* acl */
TRUE, /* add_header */
FALSE, /* authenticated */
#ifdef EXPERIMENTAL_BRIGHTMAIL
TRUE, /* bmi_optin */
#endif
FALSE, /* condition */
TRUE, /* continue */
TRUE, /* control */
#ifdef WITH_CONTENT_SCAN
FALSE, /* decode */
#endif
TRUE, /* delay */
#ifdef WITH_OLD_DEMIME
FALSE, /* demime */
#endif
#ifdef EXPERIMENTAL_DOMAINKEYS
FALSE, /* dk_domain_source */
FALSE, /* dk_policy */
FALSE, /* dk_sender_domains */
FALSE, /* dk_sender_local_parts */
FALSE, /* dk_senders */
FALSE, /* dk_status */
#endif
FALSE, /* dnslists */
FALSE, /* domains */
FALSE, /* encrypted */
TRUE, /* endpass */
FALSE, /* hosts */
FALSE, /* local_parts */
TRUE, /* log_message */
TRUE, /* log_reject_target */
TRUE, /* logwrite */
#ifdef WITH_CONTENT_SCAN
FALSE, /* malware */
#endif
TRUE, /* message */
#ifdef WITH_CONTENT_SCAN
FALSE, /* mime_regex */
#endif
FALSE, /* ratelimit */
FALSE, /* recipients */
#ifdef WITH_CONTENT_SCAN
FALSE, /* regex */
#endif
FALSE, /* sender_domains */
FALSE, /* senders */
TRUE, /* set */
#ifdef WITH_CONTENT_SCAN
FALSE, /* spam */
#endif
#ifdef EXPERIMENTAL_SPF
FALSE, /* spf */
#endif
FALSE /* verify */
};
/* Bit map vector of which conditions 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. */
static unsigned int cond_forbids[] = {
0, /* acl */
(unsigned int)
~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* add_header */
(1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
(1<<ACL_WHERE_MIME)|(1<<ACL_WHERE_NOTSMTP)|
(1<<ACL_WHERE_NOTSMTP_START)),
(1<<ACL_WHERE_NOTSMTP)| /* authenticated */
(1<<ACL_WHERE_NOTSMTP_START)|
(1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO),
#ifdef EXPERIMENTAL_BRIGHTMAIL
(1<<ACL_WHERE_AUTH)| /* bmi_optin */
(1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
(1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_MIME)|
(1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
(1<<ACL_WHERE_MAILAUTH)|
(1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
(1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_PREDATA)|
(1<<ACL_WHERE_NOTSMTP_START),
#endif
0, /* condition */
0, /* continue */
/* Certain types of control are always allowed, so we let it through
always and check in the control processing itself. */
0, /* control */
#ifdef WITH_CONTENT_SCAN
(unsigned int)
~(1<<ACL_WHERE_MIME), /* decode */
#endif
(1<<ACL_WHERE_NOTQUIT), /* delay */
#ifdef WITH_OLD_DEMIME
(unsigned int)
~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* demime */
#endif
#ifdef EXPERIMENTAL_DOMAINKEYS
(1<<ACL_WHERE_AUTH)| /* dk_domain_source */
(1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
(1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
(1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
(1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
(1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
(1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_NOTSMTP_START),
(1<<ACL_WHERE_AUTH)| /* dk_policy */
(1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
(1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
(1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
(1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
(1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
(1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_NOTSMTP_START),
(1<<ACL_WHERE_AUTH)| /* dk_sender_domains */
(1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
(1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
(1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
(1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
(1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
(1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_NOTSMTP_START),
(1<<ACL_WHERE_AUTH)| /* dk_sender_local_parts */
(1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
(1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
(1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
(1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
(1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
(1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_NOTSMTP_START),
(1<<ACL_WHERE_AUTH)| /* dk_senders */
(1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
(1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
(1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
(1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
(1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
(1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_NOTSMTP_START),
(1<<ACL_WHERE_AUTH)| /* dk_status */
(1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
(1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
(1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
(1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
(1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
(1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_NOTSMTP_START),
#endif
(1<<ACL_WHERE_NOTSMTP)| /* dnslists */
(1<<ACL_WHERE_NOTSMTP_START),
(unsigned int)
~(1<<ACL_WHERE_RCPT), /* domains */
(1<<ACL_WHERE_NOTSMTP)| /* encrypted */
(1<<ACL_WHERE_CONNECT)|
(1<<ACL_WHERE_NOTSMTP_START)|
(1<<ACL_WHERE_HELO),
0, /* endpass */
(1<<ACL_WHERE_NOTSMTP)| /* hosts */
(1<<ACL_WHERE_NOTSMTP_START),
(unsigned int)
~(1<<ACL_WHERE_RCPT), /* local_parts */
0, /* log_message */
0, /* log_reject_target */
0, /* logwrite */
#ifdef WITH_CONTENT_SCAN
(unsigned int)
~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* malware */
#endif
0, /* message */
#ifdef WITH_CONTENT_SCAN
(unsigned int)
~(1<<ACL_WHERE_MIME), /* mime_regex */
#endif
0, /* ratelimit */
(unsigned int)
~(1<<ACL_WHERE_RCPT), /* recipients */
#ifdef WITH_CONTENT_SCAN
(unsigned int)
~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* regex */
(1<<ACL_WHERE_MIME)),
#endif
(1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* sender_domains */
(1<<ACL_WHERE_HELO)|
(1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
(1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
(1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
(1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* senders */
(1<<ACL_WHERE_HELO)|
(1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
(1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
(1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
0, /* set */
#ifdef WITH_CONTENT_SCAN
(unsigned int)
~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* spam */
#endif
#ifdef EXPERIMENTAL_SPF
(1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* spf */
(1<<ACL_WHERE_HELO)|
(1<<ACL_WHERE_MAILAUTH)|
(1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
(1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY)|
(1<<ACL_WHERE_NOTSMTP)|
(1<<ACL_WHERE_NOTSMTP_START),
#endif
/* Certain types of verify are always allowed, so we let it through
always and check in the verify function itself */
0 /* verify */
};
/* Bit map vector of which controls are not allowed at certain times. 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. */
static unsigned int control_forbids[] = {
(unsigned int)
~((1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)), /* allow_auth_unadvertised */
#ifdef EXPERIMENTAL_BRIGHTMAIL
0, /* bmi_run */
#endif
#ifdef EXPERIMENTAL_DOMAINKEYS
(1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* dk_verify */
(1<<ACL_WHERE_NOTSMTP_START),
#endif
#ifdef EXPERIMENTAL_DKIM
(1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* dkim_verify */
(1<<ACL_WHERE_NOTSMTP_START),
#endif
0, /* error */
(unsigned int)
~(1<<ACL_WHERE_RCPT), /* caseful_local_part */
(unsigned int)
~(1<<ACL_WHERE_RCPT), /* caselower_local_part */
(1<<ACL_WHERE_NOTSMTP)| /* enforce_sync */
(1<<ACL_WHERE_NOTSMTP_START),
(1<<ACL_WHERE_NOTSMTP)| /* no_enforce_sync */
(1<<ACL_WHERE_NOTSMTP_START),
(unsigned int)
~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* freeze */
(1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
(1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME)),
(unsigned int)
~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* queue_only */
(1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
(1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME)),
(unsigned int)
~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* submission */
(1<<ACL_WHERE_PREDATA)),
(unsigned int)
~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* suppress_local_fixups */
(1<<ACL_WHERE_PREDATA)|
(1<<ACL_WHERE_NOTSMTP_START)),
#ifdef WITH_CONTENT_SCAN
(unsigned int)
~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* no_mbox_unspool */
(1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
(1<<ACL_WHERE_MIME)),
#endif
(unsigned int)
~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* fakedefer */
(1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
(1<<ACL_WHERE_MIME)),
(unsigned int)
~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* fakereject */
(1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
(1<<ACL_WHERE_MIME)),
(1<<ACL_WHERE_NOTSMTP)| /* no_multiline */
(1<<ACL_WHERE_NOTSMTP_START),
(1<<ACL_WHERE_NOTSMTP)| /* no_pipelining */
(1<<ACL_WHERE_NOTSMTP_START),
(1<<ACL_WHERE_NOTSMTP)| /* no_delay_flush */
(1<<ACL_WHERE_NOTSMTP_START),
(1<<ACL_WHERE_NOTSMTP)| /* no_callout_flush */
(1<<ACL_WHERE_NOTSMTP_START)
};
/* Structure listing various control arguments, with their characteristics. */
typedef struct control_def {
uschar *name;
int value; /* CONTROL_xxx value */
BOOL has_option; /* Has /option(s) following */
} control_def;
static control_def controls_list[] = {
{ US"allow_auth_unadvertised", CONTROL_AUTH_UNADVERTISED, FALSE },
#ifdef EXPERIMENTAL_BRIGHTMAIL
{ US"bmi_run", CONTROL_BMI_RUN, FALSE },
#endif
#ifdef EXPERIMENTAL_DOMAINKEYS
{ US"dk_verify", CONTROL_DK_VERIFY, FALSE },
#endif
#ifdef EXPERIMENTAL_DKIM
{ US"dkim_verify", CONTROL_DKIM_VERIFY, FALSE },
#endif
{ US"caseful_local_part", CONTROL_CASEFUL_LOCAL_PART, FALSE },
{ US"caselower_local_part", CONTROL_CASELOWER_LOCAL_PART, FALSE },
{ US"enforce_sync", CONTROL_ENFORCE_SYNC, FALSE },
{ US"freeze", CONTROL_FREEZE, TRUE },
{ US"no_callout_flush", CONTROL_NO_CALLOUT_FLUSH, FALSE },
{ US"no_delay_flush", CONTROL_NO_DELAY_FLUSH, FALSE },
{ US"no_enforce_sync", CONTROL_NO_ENFORCE_SYNC, FALSE },
{ US"no_multiline_responses", CONTROL_NO_MULTILINE, FALSE },
{ US"no_pipelining", CONTROL_NO_PIPELINING, FALSE },
{ US"queue_only", CONTROL_QUEUE_ONLY, FALSE },
#ifdef WITH_CONTENT_SCAN
{ US"no_mbox_unspool", CONTROL_NO_MBOX_UNSPOOL, FALSE },
#endif
{ US"fakedefer", CONTROL_FAKEDEFER, TRUE },
{ US"fakereject", CONTROL_FAKEREJECT, TRUE },
{ US"submission", CONTROL_SUBMISSION, TRUE },
{ US"suppress_local_fixups", CONTROL_SUPPRESS_LOCAL_FIXUPS, FALSE }
};
/* 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[] = {
OK, OK, OK, OK,
FAIL, FAIL, FAIL, FAIL
};
static uschar *csa_status_string[] = {
US"unknown", US"ok", US"defer", US"defer",
US"fail", US"fail", US"fail", US"fail"
};
static uschar *csa_reason_string[] = {
US"unknown",
US"ok",
US"deferred (SRV lookup failed)",
US"deferred (target address lookup failed)",
US"failed (explicit authorization required)",
US"failed (host name not authorized)",
US"failed (no authorized addresses)",
US"failed (client address mismatch)"
};
/* Enable recursion between acl_check_internal() and acl_check_condition() */
static int acl_check_internal(int, address_item *, uschar *, int, uschar **,
uschar **);
/*************************************************
* 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. */
v = acl_checkname(name, verbs, sizeof(verbs)/sizeof(char *));
if (v < 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. */
c = acl_checkname(name, conditions, sizeof(conditions)/sizeof(char *));
if (c < 0)
{
*error = string_sprintf("unknown ACL condition/modifier in \"%s\"",
saveline);
return NULL;
}
/* The modifiers may not be negated */
if (negated && cond_modifiers[c])
{
*error = string_sprintf("ACL error: negation is not allowed with "
"\"%s\"", conditions[c]);
return NULL;
}
/* ENDPASS may occur only with ACCEPT or DISCARD. */
if (c == ACLC_ENDPASS &&
this->verb != ACL_ACCEPT &&
this->verb != ACL_DISCARD)
{
*error = string_sprintf("ACL error: \"%s\" is not allowed with \"%s\"",
conditions[c], verbs[this->verb]);
return NULL;
}
cond = store_get(sizeof(acl_condition_block));
cond->next = NULL;
cond->type = c;
cond->u.negated = negated;
*condp = cond;
condp = &(cond->next);
/* The "set" modifier is different in that its argument is "name=value"
rather than just a value, and we can check the validity of the name, which
gives us a variable 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)
{
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,
cond_modifiers[c]? 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(uschar *hstring)
{
uschar *p, *q;
int hlen = Ustrlen(hstring);
/* An empty string does nothing; otherwise add a final newline if necessary. */
if (hlen <= 0) return;
if (hstring[hlen-1] != '\n') hstring = string_sprintf("%s\n", hstring);
/* Loop for multiple header lines, taking care about continuations */
for (p = q = hstring; *p != 0; )
{
uschar *s;
int newtype = htype_add_bot;
header_line **hptr = &acl_added_headers;
/* Find next header line within the string */
for (;;)
{
q = Ustrchr(q, '\n');
if (*(++q) != ' ' && *q != '\t') break;
}
/* If the line starts with a colon, interpret the instruction for where to
add it. This temporarily sets up a new type. */
if (*p == ':')
{
if (strncmpic(p, US":after_received:", 16) == 0)
{
newtype = htype_add_rec;
p += 16;
}
else if (strncmpic(p, US":at_start_rfc:", 14) == 0)
{
newtype = htype_add_rfc;
p += 14;
}
else if (strncmpic(p, US":at_start:", 10) == 0)
{
newtype = htype_add_top;
p += 10;
}
else if (strncmpic(p, US":at_end:", 8) == 0)
{
newtype = htype_add_bot;
p += 8;
}
while (*p == ' ' || *p == '\t') p++;
}
/* See if this line starts with a header name, and if not, add X-ACL-Warn:
to the front of it. */
for (s = p; s < q - 1; s++)
{
if (*s == ':' || !isgraph(*s)) break;
}
s = string_sprintf("%s%.*s", (*s == ':')? "" : "X-ACL-Warn: ", q - p, p);
hlen = Ustrlen(s);
/* See if this line has already been added */
while (*hptr != NULL)
{
if (Ustrncmp((*hptr)->text, s, hlen) == 0) break;
hptr = &((*hptr)->next);
}
/* Add if not previously present */
if (*hptr == NULL)
{
header_line *h = store_get(sizeof(header_line));
h->text = s;
h->next = NULL;
h->type = newtype;
h->slen = hlen;
*hptr = h;
hptr = &(h->next);
}
/* Advance for next header line within the string */
p = q;
}
}
/*************************************************
* 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 = (uschar *)logged + sizeof(string_item);
memcpy(logged->text, text, length);
logged->next = acl_warn_logged;
acl_warn_logged = logged;
}
}
/* If there's no user message, we are done. */
if (user_message == NULL) return;
/* If this isn't a message ACL, we can't do anything with a user message.
Log an error. */
if (where > ACL_WHERE_NOTSMTP)
{
log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting "
"found in a non-message (%s) ACL: cannot specify header lines here: "
"message ignored", acl_wherenames[where]);
return;
}
/* 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("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 specifing 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
#ifdef SUPPORT_A6
&& rr->type != T_A6
#endif
#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("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(uschar *domain)
{
tree_node *t;
uschar *found, *p;
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] == '[')
{
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 != NULL;
rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
{
if (rr->type != T_SRV) continue;
/* Extract the numerical SRV fields (p is incremented) */
p = rr->data;
GETSHORT(priority, p);
GETSHORT(weight, p);
GETSHORT(port, p);
DEBUG(D_acl)
debug_printf("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 (found != domain)
{
if (port & 1)
return t->data.val = CSA_FAIL_EXPLICIT;
else
return t->data.val = 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("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;
#if HAVE_IPV6 && defined(SUPPORT_A6)
DNS_LOOKUP_AGAIN:
#endif
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:
#if HAVE_IPV6 && defined(SUPPORT_A6)
if (type == T_AAAA) { type = T_A6; goto DNS_LOOKUP_AGAIN; }
#endif
return t->data.val = CSA_FAIL_NOADDR;
}
}
/*************************************************
* Handle verification (address & other) *
*************************************************/
/* This function implements the "verify" condition. It is called when
encountered in any ACL, because some tests are almost always permitted. Some
just don't make sense, and always fail (for example, an attempt to test a host
lookup for a non-TCP/IP message). Others are restricted to certain ACLs.
Arguments:
where where called from
addr the recipient address that the ACL is handling, or NULL
arg the argument of "verify"
user_msgptr pointer for user message
log_msgptr pointer for log message
basic_errno where to put verify errno
Returns: OK verification condition succeeded
FAIL verification failed
DEFER there was a problem verifying
ERROR syntax error
*/
static int
acl_verify(int where, address_item *addr, uschar *arg,
uschar **user_msgptr, uschar **log_msgptr, int *basic_errno)
{
int sep = '/';
int callout = -1;
int callout_overall = -1;
int callout_connect = -1;
int verify_options = 0;
int rc;
BOOL verify_header_sender = FALSE;
BOOL defer_ok = FALSE;
BOOL callout_defer_ok = FALSE;
BOOL no_details = FALSE;
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. This code has
now got very message. Refactoring to use a table would be a good idea one day.
*/
uschar *slash = Ustrchr(arg, '/');
uschar *list = arg;
uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
if (ss == NULL) goto BAD_VERIFY;
/* Handle name/address consistency verification in a separate function. */
if (strcmpic(ss, US"reverse_host_lookup") == 0)
{
if (slash != NULL) goto NO_OPTIONS;
if (sender_host_address == NULL) return OK;
return acl_verify_reverse(user_msgptr, log_msgptr);
}
/* TLS certificate verification is done at STARTTLS time; here we just
test whether it was successful or not. (This is for optional verification; for
mandatory verification, the connection doesn't last this long.) */
if (strcmpic(ss, US"certificate") == 0)
{
if (slash != NULL) goto NO_OPTIONS;
if (tls_certificate_verified) return OK;
*user_msgptr = US"no verified certificate";
return FAIL;
}
/* We can test the result of optional HELO verification that might have
occurred earlier. If not, we can attempt the verification now. */
if (strcmpic(ss, US"helo") == 0)
{
if (slash != NULL) goto NO_OPTIONS;
if (!helo_verified && !helo_verify_failed) smtp_verify_helo();
return helo_verified? OK : FAIL;
}
/* Do Client SMTP Authorization checks in a separate function, and turn the
result code into user-friendly strings. */
if (strcmpic(ss, US"csa") == 0)
{
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("CSA result %s\n", csa_status);
return csa_return_code[rc];
}
/* Check that all relevant header lines have the correct syntax. If there is
a syntax error, we return details of the error to the sender if configured to
send out full details. (But a "message" setting on the ACL can override, as
always). */
if (strcmpic(ss, US"header_syntax") == 0)
{
if (slash != NULL) goto NO_OPTIONS;
if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP) goto WRONG_ACL;
rc = verify_check_headers(log_msgptr);
if (rc != OK && smtp_return_error_details && *log_msgptr != NULL)
*user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
return rc;
}
/* Check that no recipient of this message is "blind", that is, every envelope
recipient must be mentioned in either To: or Cc:. */
if (strcmpic(ss, US"not_blind") == 0)
{
if (slash != NULL) goto NO_OPTIONS;
if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP) goto WRONG_ACL;
rc = verify_check_notblind();
if (rc != 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. */
/* Check that there is at least one verifiable sender address in the relevant
header lines. This can be followed by callout and defer options, just like
sender and recipient. */
if (strcmpic(ss, US"header_sender") == 0)
{
if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP) goto WRONG_ACL;
verify_header_sender = TRUE;
}
/* Otherwise, first item in verify argument must be "sender" or "recipient".
In the case of a sender, this can optionally be followed by an address to use
in place of the actual sender (rare special-case requirement). */
else if (strncmpic(ss, US"sender", 6) == 0)
{
uschar *s = ss + 6;
if (where > ACL_WHERE_NOTSMTP)
{
*log_msgptr = string_sprintf("cannot verify sender in ACL for %s "
"(only possible for MAIL, RCPT, PREDATA, or DATA)",
acl_wherenames[where]);
return ERROR;
}
if (*s == 0)
verify_sender_address = sender_address;
else
{
while (isspace(*s)) s++;
if (*s++ != '=') goto BAD_VERIFY;
while (isspace(*s)) s++;
verify_sender_address = string_copy(s);
}
}
else
{
if (strcmpic(ss, US"recipient") != 0) goto BAD_VERIFY;
if (addr == NULL)
{
*log_msgptr = string_sprintf("cannot verify recipient in ACL for %s "
"(only possible for RCPT)", acl_wherenames[where]);
return ERROR;
}
}
/* Remaining items are optional; 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++ == '=')
{
int optsep = ',';
uschar *opt;
uschar buffer[256];
while (isspace(*ss)) ss++;
/* This callout option handling code has become a mess as new options
have been added in an ad hoc manner. It should be tidied up into some
kind of table-driven thing. */
while ((opt = string_nextinlist(&ss, &optsep, buffer, sizeof(buffer)))
!= NULL)
{
if (strcmpic(opt, US"defer_ok") == 0) callout_defer_ok = TRUE;
else if (strcmpic(opt, US"no_cache") == 0)
verify_options |= vopt_callout_no_cache;
else if (strcmpic(opt, US"random") == 0)
verify_options |= vopt_callout_random;
else if (strcmpic(opt, US"use_sender") == 0)
verify_options |= vopt_callout_recipsender;
else if (strcmpic(opt, US"use_postmaster") == 0)
verify_options |= vopt_callout_recippmaster;
else if (strcmpic(opt, US"postmaster") == 0) pm_mailfrom = US"";
else if (strcmpic(opt, US"fullpostmaster") == 0)
{
pm_mailfrom = US"";
verify_options |= vopt_callout_fullpm;
}
else if (strncmpic(opt, US"mailfrom", 8) == 0)
{
if (!verify_header_sender)
{
*log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
"callout option only for verify=header_sender (detected in ACL "
"condition \"%s\")", arg);
return ERROR;
}
opt += 8;
while (isspace(*opt)) opt++;
if (*opt++ != '=')
{
*log_msgptr = string_sprintf("'=' expected after "
"\"mailfrom\" in ACL condition \"%s\"", arg);
return ERROR;
}
while (isspace(*opt)) opt++;
se_mailfrom = string_copy(opt);
}
else if (strncmpic(opt, US"postmaster_mailfrom", 19) == 0)
{
opt += 19;
while (isspace(*opt)) opt++;
if (*opt++ != '=')
{
*log_msgptr = string_sprintf("'=' expected after "
"\"postmaster_mailfrom\" in ACL condition \"%s\"", arg);
return ERROR;
}
while (isspace(*opt)) opt++;
pm_mailfrom = string_copy(opt);
}
else if (strncmpic(opt, US"maxwait", 7) == 0)
{
opt += 7;
while (isspace(*opt)) opt++;
if (*opt++ != '=')
{
*log_msgptr = string_sprintf("'=' expected after \"maxwait\" in "
"ACL condition \"%s\"", arg);
return ERROR;
}
while (isspace(*opt)) opt++;
callout_overall = readconf_readtime(opt, 0, FALSE);
if (callout_overall < 0)
{
*log_msgptr = string_sprintf("bad time value in ACL condition "
"\"verify %s\"", arg);
return ERROR;
}
}
else if (strncmpic(opt, US"connect", 7) == 0)
{
opt += 7;
while (isspace(*opt)) opt++;
if (*opt++ != '=')
{
*log_msgptr = string_sprintf("'=' expected after "
"\"callout_overaall\" in ACL condition \"%s\"", arg);
return ERROR;
}
while (isspace(*opt)) opt++;
callout_connect = readconf_readtime(opt, 0, FALSE);
if (callout_connect < 0)
{
*log_msgptr = string_sprintf("bad time value in ACL condition "
"\"verify %s\"", arg);
return ERROR;
}
}
else /* Plain time is callout connect/command timeout */
{
callout = readconf_readtime(opt, 0, FALSE);
if (callout < 0)
{
*log_msgptr = string_sprintf("bad time value in ACL condition "
"\"verify %s\"", arg);
return ERROR;
}
}
}
}
else
{
*log_msgptr = string_sprintf("'=' expected after \"callout\" in "
"ACL condition \"%s\"", arg);
return ERROR;
}
}
}
/* Option not recognized */
else
{
*log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
"condition \"verify %s\"", ss, arg);
return ERROR;
}
}
if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
(vopt_callout_recipsender|vopt_callout_recippmaster))
{
*log_msgptr = US"only one of use_sender and use_postmaster can be set "
"for a recipient callout";
return ERROR;
}
/* Handle sender-in-header verification. Default the user message to the log
message if giving out verification details. */
if (verify_header_sender)
{
int verrno;
rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
&verrno);
if (rc != OK)
{
*basic_errno = verrno;
if (smtp_return_error_details)
{
if (*user_msgptr == NULL && *log_msgptr != NULL)
*user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
if (rc == DEFER) acl_temp_details = TRUE;
}
}
}
/* Handle a sender address. The default is to verify *the* sender address, but
optionally a different address can be given, for special requirements. If the
address is empty, we are dealing with a bounce message that has no sender, so
we cannot do any checking. If the real sender address gets rewritten during
verification (e.g. DNS widening), set the flag to stop it being rewritten again
during message reception.
A list of verified "sender" addresses is kept to try to avoid doing to much
work repetitively when there are multiple recipients in a message and they all
require sender verification. However, when callouts are involved, it gets too
complicated because different recipients may require different callout options.
Therefore, we always do a full sender verify when any kind of callout is
specified. Caching elsewhere, for instance in the DNS resolver and in the
callout handling, should ensure that this is not terribly inefficient. */
else if (verify_sender_address != NULL)
{
if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster))
!= 0)
{
*log_msgptr = US"use_sender or use_postmaster cannot be used for a "
"sender verify callout";
return ERROR;
}
sender_vaddr = verify_checked_sender(verify_sender_address);
if (sender_vaddr != NULL && /* Previously checked */
callout <= 0) /* No callout needed this time */
{
/* If the "routed" flag is set, it means that routing worked before, so
this check can give OK (the saved return code value, if set, belongs to a
callout that was done previously). If the "routed" flag is not set, routing
must have failed, so we use the saved return code. */
if (testflag(sender_vaddr, af_verify_routed)) rc = OK; else
{
rc = sender_vaddr->special_action;
*basic_errno = sender_vaddr->basic_errno;
}
HDEBUG(D_acl) debug_printf("using cached sender verify result\n");
}
/* Do a new verification, and cache the result. The cache is used to avoid
verifying the sender multiple times for multiple RCPTs when callouts are not
specified (see comments above).
The cache is also used on failure to give details in response to the first
RCPT that gets bounced for this reason. However, this can be suppressed by
the no_details option, which sets the flag that says "this detail has already
been sent". The cache normally contains just one address, but there may be
more in esoteric circumstances. */
else
{
BOOL routed = TRUE;
uschar *save_address_data = deliver_address_data;
sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
if (no_details) setflag(sender_vaddr, af_sverify_told);
if (verify_sender_address[0] != 0)
{
/* If this is the real sender address, save the unrewritten version
for use later in receive. Otherwise, set a flag so that rewriting the
sender in verify_address() does not update sender_address. */
if (verify_sender_address == sender_address)
sender_address_unrewritten = sender_address;
else
verify_options |= vopt_fake_sender;
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("----------- end verify ------------\n");
if (rc == OK)
{
if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
{
DEBUG(D_acl) debug_printf("sender %s verified ok as %s\n",
verify_sender_address, sender_vaddr->address);
}
else
{
DEBUG(D_acl) debug_printf("sender %s verified ok\n",
verify_sender_address);
}
}
else *basic_errno = sender_vaddr->basic_errno;
}
else rc = OK; /* Null sender */
/* Cache the result code */
if (routed) setflag(sender_vaddr, af_verify_routed);
if (callout > 0) setflag(sender_vaddr, af_verify_callout);
sender_vaddr->special_action = rc;
sender_vaddr->next = sender_verified_list;
sender_verified_list = sender_vaddr;
/* Restore the recipient address data, which might have been clobbered by
the sender verification. */
deliver_address_data = save_address_data;
}
/* Put the sender address_data value into $sender_address_data */
sender_address_data = sender_vaddr->p.address_data;
}
/* A recipient address just gets a straightforward verify; again we must handle
the DEFER overrides. */
else
{
address_item addr2;
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("----------- 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)) acl_temp_details = TRUE;
/* Make $address_data visible */
deliver_address_data = addr2.p.address_data;
}
/* We have a result from the relevant test. Handle defer overrides first. */
if (rc == DEFER && (defer_ok ||
(callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER)))
{
HDEBUG(D_acl) debug_printf("verify defer overridden by %s\n",
defer_ok? "defer_ok" : "callout_defer_ok");
rc = OK;
}
/* If we've failed a sender, set up a recipient message, and point
sender_verified_failed to the address item that actually failed. */
if (rc != OK && verify_sender_address != NULL)
{
if (rc != DEFER)
{
*log_msgptr = *user_msgptr = US"Sender verify failed";
}
else if (*basic_errno != ERRNO_CALLOUTDEFER)
{
*log_msgptr = *user_msgptr = US"Could not complete sender verify";
}
else
{
*log_msgptr = US"Could not complete sender verify callout";
*user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
*log_msgptr;
}
sender_verified_failed = sender_vaddr;
}
/* Verifying an address messes up the values of $domain and $local_part,
so reset them before returning if this is a RCPT ACL. */
if (addr != NULL)
{
deliver_domain = addr->domain;
deliver_localpart = addr->local_part;
}
return rc;
/* Syntax errors in the verify argument come here. */
BAD_VERIFY:
*log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
"\"helo\", \"header_syntax\", \"header_sender\" or "
"\"reverse_host_lookup\" at start of ACL condition "
"\"verify %s\"", arg);
return ERROR;
/* Options supplied when not allowed come here */
NO_OPTIONS:
*log_msgptr = string_sprintf("unexpected '/' found in \"%s\" "
"(this verify item has no options)", arg);
return ERROR;
/* Calls in the wrong ACL come here */
WRONG_ACL:
*log_msgptr = string_sprintf("cannot check header contents in ACL for %s "
"(only possible in ACL for DATA)", acl_wherenames[where]);
return ERROR;
}
/*************************************************
* Check argument for control= modifier *
*************************************************/
/* Called from acl_check_condition() below
Arguments:
arg the argument string for control=
pptr set to point to the terminating character
where which ACL we are in
log_msgptr for error messages
Returns: CONTROL_xxx value
*/
static int
decode_control(uschar *arg, uschar **pptr, int where, uschar **log_msgptr)
{
int len;
control_def *d;
for (d = controls_list;
d < controls_list + sizeof(controls_list)/sizeof(control_def);
d++)
{
len = Ustrlen(d->name);
if (Ustrncmp(d->name, arg, len) == 0) break;
}
if (d >= controls_list + sizeof(controls_list)/sizeof(control_def) ||
(arg[len] != 0 && (!d->has_option || arg[len] != '/')))
{
*log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
return CONTROL_ERROR;
}
*pptr = arg + len;
return d->value;
}
/*************************************************
* Handle 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(uschar *arg, int where, uschar **log_msgptr)
{
double limit, period;
uschar *ss;
uschar *key = NULL;
int sep = '/';
BOOL leaky = FALSE, strict = FALSE, noupdate = FALSE;
BOOL per_byte = FALSE, per_cmd = FALSE, per_conn = FALSE, per_mail = FALSE;
int old_pool, rc;
tree_node **anchor, *t;
open_db dbblock, *dbm;
dbdata_ratelimit *dbd;
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 and maximum burst
size, which must be greater than or equal to zero. Zero is useful for
rate measurement as opposed to rate limiting. */
sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0);
if (sender_rate_limit == NULL)
limit = -1.0;
else
{
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)
{
*log_msgptr = string_sprintf("syntax error in argument for "
"\"ratelimit\" condition: \"%s\" is not a positive number",
sender_rate_limit);
return ERROR;
}
/* Second is the rate measurement period and exponential smoothing time
constant. This must be strictly greater than zero, because zero leads to
run-time division errors. */
sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0);
if (sender_rate_period == NULL) period = -1.0;
else period = readconf_readtime(sender_rate_period, 0, FALSE);
if (period <= 0.0)
{
*log_msgptr = string_sprintf("syntax error in argument for "
"\"ratelimit\" condition: \"%s\" is not a time value",
sender_rate_period);
return ERROR;
}
/* Parse the other options. Should we check if the per_* options are being
used in ACLs where they don't make sense, e.g. per_mail in the connect ACL? */
while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
!= NULL)
{
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"per_byte") == 0) per_byte = TRUE;
else if (strcmpic(ss, US"per_cmd") == 0) per_cmd = TRUE;
else if (strcmpic(ss, US"per_rcpt") == 0) per_cmd = TRUE; /* alias */
else if (strcmpic(ss, US"per_conn") == 0) per_conn = TRUE;
else if (strcmpic(ss, US"per_mail") == 0) per_mail = TRUE;
else key = string_sprintf("%s", ss);
}
if (leaky + strict > 1 || per_byte + per_cmd + per_conn + per_mail > 1)
{
*log_msgptr = US"conflicting options for \"ratelimit\" condition";
return ERROR;
}
/* Default option values */
if (!strict) leaky = TRUE;
if (!per_byte && !per_cmd && !per_conn) per_mail = TRUE;
/* 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 == NULL)
key = (sender_host_address == NULL)? US"" : sender_host_address;
key = string_sprintf("%s/%s/%s/%s",
sender_rate_period,
per_byte? US"per_byte" :
per_cmd? US"per_cmd" :
per_mail? US"per_mail" : US"per_conn",
strict? US"strict" : US"leaky",
key);
HDEBUG(D_acl) debug_printf("ratelimit condition limit=%.0f period=%.0f key=%s\n",
limit, period, 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. */
anchor = NULL;
old_pool = store_pool;
if (per_conn)
{
anchor = &ratelimiters_conn;
store_pool = POOL_PERM;
}
else if (per_mail || per_byte)
anchor = &ratelimiters_mail;
else if (per_cmd)
anchor = &ratelimiters_cmd;
if (anchor != NULL && (t = tree_search(*anchor, key)) != NULL)
{
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("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, update it, and write it back when required. If there's
no previous rate for this key, create one. */
dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE);
if (dbm == NULL)
{
store_pool = old_pool;
sender_rate = NULL;
HDEBUG(D_acl) debug_printf("ratelimit database not available\n");
*log_msgptr = US"ratelimit database not available";
return DEFER;
}
dbd = dbfn_read(dbm, key);
gettimeofday(&tv, NULL);
if (dbd == NULL)
{
HDEBUG(D_acl) debug_printf("ratelimit initializing new key's data\n");
dbd = store_get(sizeof(dbdata_ratelimit));
dbd->time_stamp = tv.tv_sec;
dbd->time_usec = tv.tv_usec;
dbd->rate = 0.0;
}
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);
dbd->time_stamp = tv.tv_sec;
dbd->time_usec = tv.tv_usec;
/* If we are measuring the rate in bytes per period, multiply the
measured rate by the message size. If we don't know the message size
then it's safe to just use a value of zero and let the recorded rate
decay as if nothing happened. */
if (per_byte)
dbd->rate = (message_size < 0 ? 0.0 : (double)message_size)
* (1 - a) / i_over_p + a * dbd->rate;
else if (per_cmd && where == ACL_WHERE_NOTSMTP)
dbd->rate = (double)recipients_count
* (1 - a) / i_over_p + a * dbd->rate;
else
dbd->rate = (1 - a) / i_over_p + a * dbd->rate;
}
/* Clients sending at the limit are considered to be over the limit. This
matters for edge cases such the first message sent by a client (which gets
the initial rate of 0.0) when the rate limit is zero (i.e. 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 noupdate is set,
do not do any updates. */
if ((rc == FAIL || !leaky) && !noupdate)
{
dbfn_write(dbm, key, dbd, sizeof(dbdata_ratelimit));
HDEBUG(D_acl) debug_printf("ratelimit db updated\n");
}
else
{
HDEBUG(D_acl) debug_printf("ratelimit db not updated: %s\n",
noupdate? "noupdate set" : "over the limit, but leaky");
}
dbfn_close(dbm);
/* Store the result in the tree for future reference, if necessary. */
if (anchor != NULL && !noupdate)
{
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("ratelimit computed rate %s\n", sender_rate);
return rc;
}
/*************************************************
* Handle conditions/modifiers on an ACL item *
*************************************************/
/* Called from acl_check() below.
Arguments:
verb ACL verb
cb ACL condition block - if NULL, result is OK
where where called from
addr the address being checked for RCPT, or NULL
level the nesting level
epp pointer to pass back TRUE if "endpass" encountered
(applies only to "accept" and "discard")
user_msgptr user message pointer
log_msgptr log message pointer
basic_errno pointer to where to put verify error
Returns: OK - all conditions are met
DISCARD - an "acl" condition returned DISCARD - only allowed
for "accept" or "discard" verbs
FAIL - at least one condition fails
FAIL_DROP - an "acl" condition returned FAIL_DROP
DEFER - can't tell at the moment (typically, lookup defer,
but can be temporary callout problem)
ERROR - ERROR from nested ACL or expansion failure or other
error
*/
static int
acl_check_condition(int verb, acl_condition_block *cb, int where,
address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
uschar **log_msgptr, int *basic_errno)
{
uschar *user_message = NULL;
uschar *log_message = NULL;
uschar *p = NULL;
int rc = OK;
#ifdef WITH_CONTENT_SCAN
int sep = '/';
#endif
for (; cb != NULL; cb = cb->next)
{
uschar *arg;
int control_type;
/* The message and log_message items set up messages to be used in
case of rejection. They are expanded later. */
if (cb->type == ACLC_MESSAGE)
{
user_message = cb->arg;
continue;
}
if (cb->type == ACLC_LOG_MESSAGE)
{
log_message = cb->arg;
continue;
}
/* The endpass "condition" just sets a flag to show it occurred. This is
checked at compile time to be on an "accept" or "discard" item. */
if (cb->type == ACLC_ENDPASS)
{
*epp = TRUE;
continue;
}
/* For other conditions and modifiers, the argument is expanded now for some
of them, but not for all, because expansion happens down in some lower level
checking functions in some cases. */
if (cond_expand_at_top[cb->type])
{
arg = expand_string(cb->arg);
if (arg == NULL)
{
if (expand_string_forcedfail) continue;
*log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
cb->arg, expand_string_message);
return search_find_defer? DEFER : ERROR;
}
}
else arg = cb->arg;
/* Show condition, and expanded condition if it's different */
HDEBUG(D_acl)
{
int lhswidth = 0;
debug_printf("check %s%s %n",
(!cond_modifiers[cb->type] && cb->u.negated)? "!":"",
conditions[cb->type], &lhswidth);
if (cb->type == ACLC_SET)
{
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 ((cond_forbids[cb->type] & (1 << where)) != 0)
{
*log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
cond_modifiers[cb->type]? "use" : "test",
conditions[cb->type], acl_wherenames[where]);
return ERROR;
}
/* Run the appropriate test for each condition, or take the appropriate
action for the remaining modifiers. */
switch(cb->type)
{
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_internal(where, addr, arg, level+1, user_msgptr, log_msgptr);
if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
{
*log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
"\"%s\" command (only allowed with \"accept\" or \"discard\")",
verbs[verb]);
return ERROR;
}
break;
case ACLC_AUTHENTICATED:
rc = (sender_host_authenticated == NULL)? FAIL :
match_isinlist(sender_host_authenticated, &arg, 0, NULL, NULL, MCL_STRING,
TRUE, NULL);
break;
#ifdef EXPERIMENTAL_BRIGHTMAIL
case ACLC_BMI_OPTIN:
{
int old_pool = store_pool;
store_pool = POOL_PERM;
bmi_current_optin = string_copy(arg);
store_pool = old_pool;
}
break;
#endif
case ACLC_CONDITION:
if (Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
rc = (Uatoi(arg) == 0)? FAIL : OK;
else
rc = (strcmpic(arg, US"no") == 0 ||
strcmpic(arg, US"false") == 0)? FAIL :
(strcmpic(arg, US"yes") == 0 ||
strcmpic(arg, US"true") == 0)? OK : DEFER;
if (rc == DEFER)
*log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
break;
case ACLC_CONTINUE: /* Always succeeds */
break;
case ACLC_CONTROL:
control_type = decode_control(arg, &p, where, log_msgptr);
/* Check if this control makes sense at this time */
if ((control_forbids[control_type] & (1 << where)) != 0)
{
*log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
controls[control_type], acl_wherenames[where]);
return ERROR;
}
switch(control_type)
{
case CONTROL_AUTH_UNADVERTISED:
allow_auth_unadvertised = TRUE;
break;
#ifdef EXPERIMENTAL_BRIGHTMAIL
case CONTROL_BMI_RUN:
bmi_run = 1;
break;
#endif
#ifdef EXPERIMENTAL_DOMAINKEYS
case CONTROL_DK_VERIFY:
dk_do_verify = 1;
break;
#endif
#ifdef EXPERIMENTAL_DKIM
case CONTROL_DKIM_VERIFY:
dkim_do_verify = 1;
break;
#endif
case CONTROL_ERROR:
return ERROR;
case CONTROL_CASEFUL_LOCAL_PART:
deliver_localpart = addr->cc_local_part;
break;
case CONTROL_CASELOWER_LOCAL_PART:
deliver_localpart = addr->lc_local_part;
break;
case CONTROL_ENFORCE_SYNC:
smtp_enforce_sync = TRUE;
break;
case CONTROL_NO_ENFORCE_SYNC:
smtp_enforce_sync = FALSE;
break;
#ifdef WITH_CONTENT_SCAN
case CONTROL_NO_MBOX_UNSPOOL:
no_mbox_unspool = TRUE;
break;
#endif
case CONTROL_NO_MULTILINE:
no_multiline_responses = TRUE;
break;
case CONTROL_NO_PIPELINING:
pipelining_enable = FALSE;
break;
case CONTROL_NO_DELAY_FLUSH:
disable_delay_flush = TRUE;
break;
case CONTROL_NO_CALLOUT_FLUSH:
disable_callout_flush = TRUE;
break;
case CONTROL_FAKEDEFER:
case CONTROL_FAKEREJECT:
fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
if (*p == '/')
{
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:
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;
}
break;
case CONTROL_QUEUE_ONLY:
queue_only_policy = TRUE;
break;
case CONTROL_SUBMISSION:
originator_name = US"";
submission_mode = TRUE;
while (*p == '/')
{
if (Ustrncmp(p, "/sender_retain", 14) == 0)
{
p += 14;
active_local_sender_retain = TRUE;
active_local_from_check = FALSE;
}
else if (Ustrncmp(p, "/domain=", 8) == 0)
{
uschar *pp = p + 8;
while (*pp != 0 && *pp != '/') pp++;
submission_domain = string_copyn(p+8, pp-p-8);
p = pp;
}
/* The name= option must be last, because it swallows the rest of
the string. */
else if (Ustrncmp(p, "/name=", 6) == 0)
{
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_SUPPRESS_LOCAL_FIXUPS:
suppress_local_fixups = TRUE;
break;
}
break;
#ifdef WITH_CONTENT_SCAN
case ACLC_DECODE:
rc = mime_decode(&arg);
break;
#endif
case ACLC_DELAY:
{
int delay = readconf_readtime(arg, 0, FALSE);
if (delay < 0)
{
*log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
"modifier: \"%s\" is not a time value", arg);
return ERROR;
}
else
{
HDEBUG(D_acl) debug_printf("delay modifier requests %d-second delay\n",
delay);
if (host_checking)
{
HDEBUG(D_acl)
debug_printf("delay skipped in -bh checking mode\n");
}
/* 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.
NOTE 1: If ever this state of affairs changes, 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 && !disable_delay_flush) mac_smtp_fflush();
while (delay > 0) delay = sleep(delay);
}
}
}
break;
#ifdef WITH_OLD_DEMIME
case ACLC_DEMIME:
rc = demime(&arg);
break;
#endif
#ifdef EXPERIMENTAL_DOMAINKEYS
case ACLC_DK_DOMAIN_SOURCE:
if (dk_verify_block == NULL) { rc = FAIL; break; };
/* check header source of domain against given string */
switch (dk_verify_block->address_source) {
case DK_EXIM_ADDRESS_FROM_FROM:
rc = match_isinlist(US"from", &arg, 0, NULL,
NULL, MCL_STRING, TRUE, NULL);
break;
case DK_EXIM_ADDRESS_FROM_SENDER:
rc = match_isinlist(US"sender", &arg, 0, NULL,
NULL, MCL_STRING, TRUE, NULL);
break;
case DK_EXIM_ADDRESS_NONE:
rc = match_isinlist(US"none", &arg, 0, NULL,
NULL, MCL_STRING, TRUE, NULL);
break;
}
break;
case ACLC_DK_POLICY:
if (dk_verify_block == NULL) { rc = FAIL; break; };
/* check policy against given string, default FAIL */
rc = FAIL;
if (dk_verify_block->signsall)
rc = match_isinlist(US"signsall", &arg, 0, NULL,
NULL, MCL_STRING, TRUE, NULL);
if (dk_verify_block->testing)
rc = match_isinlist(US"testing", &arg, 0, NULL,
NULL, MCL_STRING, TRUE, NULL);
break;
case ACLC_DK_SENDER_DOMAINS:
if (dk_verify_block == NULL) { rc = FAIL; break; };
if (dk_verify_block->domain != NULL)
rc = match_isinlist(dk_verify_block->domain, &arg, 0, &domainlist_anchor,
NULL, MCL_DOMAIN, TRUE, NULL);
else rc = FAIL;
break;
case ACLC_DK_SENDER_LOCAL_PARTS:
if (dk_verify_block == NULL) { rc = FAIL; break; };
if (dk_verify_block->local_part != NULL)
rc = match_isinlist(dk_verify_block->local_part, &arg, 0, &localpartlist_anchor,
NULL, MCL_LOCALPART, TRUE, NULL);
else rc = FAIL;
break;
case ACLC_DK_SENDERS:
if (dk_verify_block == NULL) { rc = FAIL; break; };
if (dk_verify_block->address != NULL)
rc = match_address_list(dk_verify_block->address, TRUE, TRUE, &arg, NULL, -1, 0, NULL);
else rc = FAIL;
break;
case ACLC_DK_STATUS:
if (dk_verify_block == NULL) { rc = FAIL; break; };
if (dk_verify_block->result > 0) {
switch(dk_verify_block->result) {
case DK_EXIM_RESULT_BAD_FORMAT:
rc = match_isinlist(US"bad format", &arg, 0, NULL,
NULL, MCL_STRING, TRUE, NULL);
break;
case DK_EXIM_RESULT_NO_KEY:
rc = match_isinlist(US"no key", &arg, 0, NULL,
NULL, MCL_STRING, TRUE, NULL);
break;
case DK_EXIM_RESULT_NO_SIGNATURE:
rc = match_isinlist(US"no signature", &arg, 0, NULL,
NULL, MCL_STRING, TRUE, NULL);
break;
case DK_EXIM_RESULT_REVOKED:
rc = match_isinlist(US"revoked", &arg, 0, NULL,
NULL, MCL_STRING, TRUE, NULL);
break;
case DK_EXIM_RESULT_NON_PARTICIPANT:
rc = match_isinlist(US"non-participant", &arg, 0, NULL,
NULL, MCL_STRING, TRUE, NULL);
break;
case DK_EXIM_RESULT_GOOD:
rc = match_isinlist(US"good", &arg, 0, NULL,
NULL, MCL_STRING, TRUE, NULL);
break;
case DK_EXIM_RESULT_BAD:
rc = match_isinlist(US"bad", &arg, 0, NULL,
NULL, MCL_STRING, TRUE, NULL);
break;
}
}
break;
#endif
case ACLC_DNSLISTS:
rc = verify_check_dnsbl(&arg);
break;
case ACLC_DOMAINS:
rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
addr->domain_cache, MCL_DOMAIN, TRUE, &deliver_domain_data);
break;
/* The value in tls_cipher is the full cipher name, for example,
TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
cipher names such as DES-CBC3-SHA. But program defensively. We don't know
what may in practice come out of the SSL library - which at the time of
writing is poorly documented. */
case ACLC_ENCRYPTED:
if (tls_cipher == NULL) rc = FAIL; else
{
uschar *endcipher = NULL;
uschar *cipher = Ustrchr(tls_cipher, ':');
if (cipher == NULL) cipher = tls_cipher; else
{
endcipher = Ustrchr(++cipher, ':');
if (endcipher != NULL) *endcipher = 0;
}
rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
if (endcipher != NULL) *endcipher = ':';
}
break;
/* Use verify_check_this_host() instead of verify_check_host() so that
we can pass over &host_data to catch any looked up data. Once it has been
set, it retains its value so that it's still there if another ACL verb
comes through here and uses the cache. However, we must put it into
permanent store in case it is also expected to be used in a subsequent
message in the same SMTP connection. */
case ACLC_HOSTS:
rc = verify_check_this_host(&arg, sender_host_cache, NULL,
(sender_host_address == NULL)? US"" : sender_host_address, &host_data);
if (host_data != NULL) host_data = string_copy_malloc(host_data);
break;
case ACLC_LOCAL_PARTS:
rc = match_isinlist(addr->cc_local_part, &arg, 0,
&localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
&deliver_localpart_data);
break;
case ACLC_LOG_REJECT_TARGET:
{
int logbits = 0;
int sep = 0;
uschar *s = arg;
uschar *ss;
while ((ss = string_nextinlist(&s, &sep, big_buffer, big_buffer_size))
!= NULL)
{
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;
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:
{
/* Separate the regular expression and any optional parameters. */
uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
/* Run the malware backend. */
rc = malware(&ss);
/* Modify return code based upon the existance of options. */
while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
!= NULL) {
if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
{
/* FAIL so that the message is passed to the next ACL */
rc = FAIL;
}
}
}
break;
case ACLC_MIME_REGEX:
rc = mime_regex(&arg);
break;
#endif
case ACLC_RATELIMIT:
rc = acl_ratelimit(arg, where, log_msgptr);
break;
case ACLC_RECIPIENTS:
rc = match_address_list(addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
&recipient_data);
break;
#ifdef WITH_CONTENT_SCAN
case ACLC_REGEX:
rc = regex(&arg);
break;
#endif
case ACLC_SENDER_DOMAINS:
{
uschar *sdomain;
sdomain = Ustrrchr(sender_address, '@');
sdomain = (sdomain == NULL)? US"" : sdomain + 1;
rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
}
break;
case ACLC_SENDERS:
rc = match_address_list(sender_address, TRUE, TRUE, &arg,
sender_address_cache, -1, 0, &sender_data);
break;
/* Connection variables must persist forever */
case ACLC_SET:
{
int old_pool = store_pool;
if (cb->u.varname[0] == 'c') store_pool = POOL_PERM;
acl_var_create(cb->u.varname)->data.ptr = string_copy(arg);
store_pool = old_pool;
}
break;
#ifdef WITH_CONTENT_SCAN
case ACLC_SPAM:
{
/* Seperate the regular expression and any optional parameters. */
uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
/* Run the spam backend. */
rc = spam(&ss);
/* Modify return code based upon the existance of options. */
while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
!= NULL) {
if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
{
/* FAIL so that the message is passed to the next ACL */
rc = FAIL;
}
}
}
break;
#endif
#ifdef EXPERIMENTAL_SPF
case ACLC_SPF:
rc = spf_process(&arg, sender_address);
break;
#endif
/* If the verb is WARN, discard any user message from verification, because
such messages are SMTP responses, not header additions. The latter come
only from explicit "message" modifiers. However, put the user message into
$acl_verify_message so it can be used in subsequent conditions or modifiers
(until something changes it). */
case ACLC_VERIFY:
rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
acl_verify_message = *user_msgptr;
if (verb == ACL_WARN) *user_msgptr = NULL;
break;
default:
log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
"condition %d", cb->type);
break;
}
/* If a condition was negated, invert OK/FAIL. */
if (!cond_modifiers[cb->type] && cb->u.negated)
{
if (rc == OK) rc = FAIL;
else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
}
if (rc != OK) break; /* Conditions loop */
}
/* If the result is the one for which "message" and/or "log_message" are used,
handle the values of these modifiers. If there isn't a log message set, we make
it the same as the user message.
"message" is a user message that will be included in an SMTP response. Unless
it is empty, it overrides any previously set user message.
"log_message" is a non-user message, and it adds to any existing non-user
message that is already set.
Most verbs have but a single return for which the messages are relevant, but
for "discard", it's useful to have the log message both when it succeeds and
when it fails. For "accept", the message is used in the OK case if there is no
"endpass", but (for backwards compatibility) in the FAIL case if "endpass" is
present. */
if (*epp && rc == OK) user_message = NULL;
if (((1<<rc) & msgcond[verb]) != 0)
{
uschar *expmessage;
uschar *old_user_msgptr = *user_msgptr;
uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
/* If the verb is "warn", messages generated by conditions (verification or
nested ACLs) are always discarded. This also happens for acceptance verbs
when they actually do accept. Only messages specified at this level are used.
However, the value of an existing message is available in $acl_verify_message
during expansions. */
if (verb == ACL_WARN ||
(rc == OK && (verb == ACL_ACCEPT || verb == ACL_DISCARD)))
*log_msgptr = *user_msgptr = NULL;
if (user_message != NULL)
{
acl_verify_message = old_user_msgptr;
expmessage = expand_string(user_message);
if (expmessage == NULL)
{
if (!expand_string_forcedfail)
log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
user_message, expand_string_message);
}
else if (expmessage[0] != 0) *user_msgptr = expmessage;
}
if (log_message != NULL)
{
acl_verify_message = old_log_msgptr;
expmessage = expand_string(log_message);
if (expmessage == NULL)
{
if (!expand_string_forcedfail)
log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
log_message, expand_string_message);
}
else if (expmessage[0] != 0)
{
*log_msgptr = (*log_msgptr == NULL)? expmessage :
string_sprintf("%s: %s", expmessage, *log_msgptr);
}
}
/* If no log message, default it to the user message */
if (*log_msgptr == NULL) *log_msgptr = *user_msgptr;
}
acl_verify_message = NULL;
return rc;
}
/*************************************************
* Get line from a literal ACL *
*************************************************/
/* This function is passed to acl_read() in order to extract individual lines
of a literal ACL, which we access via static pointers. We can destroy the
contents because this is called only once (the compiled ACL is remembered).
This code is intended to treat the data in the same way as lines in the main
Exim configuration file. That is:
. Leading spaces are ignored.
. A \ at the end of a line is a continuation - trailing spaces after the \
are permitted (this is because I don't believe in making invisible things
significant). Leading spaces on the continued part of a line are ignored.
. Physical lines starting (significantly) with # are totally ignored, and
may appear within a sequence of backslash-continued lines.
. Blank lines are ignored, but will end a sequence of continuations.
Arguments: none
Returns: a pointer to the next line
*/
static uschar *acl_text; /* Current pointer in the text */
static uschar *acl_text_end; /* Points one past the terminating '0' */
static uschar *
acl_getline(void)
{
uschar *yield;
/* This loop handles leading blank lines and comments. */
for(;;)
{
while (isspace(*acl_text)) acl_text++; /* Leading spaces/empty lines */
if (*acl_text == 0) return NULL; /* No more data */
yield = acl_text; /* Potential data line */
while (*acl_text != 0 && *acl_text != '\n') acl_text++;
/* If we hit the end before a newline, we have the whole logical line. If
it's a comment, there's no more data to be given. Otherwise, yield it. */
if (*acl_text == 0) return (*yield == '#')? NULL : yield;
/* After reaching a newline, end this loop if the physical line does not
start with '#'. If it does, it's a comment, and the loop continues. */
if (*yield != '#') break;
}
/* This loop handles continuations. We know we have some real data, ending in
newline. See if there is a continuation marker at the end (ignoring trailing
white space). We know that *yield is not white space, so no need to test for
cont > yield in the backwards scanning loop. */
for(;;)
{
uschar *cont;
for (cont = acl_text - 1; isspace(*cont); cont--);
/* If no continuation follows, we are done. Mark the end of the line and
return it. */
if (*cont != '\\')
{
*acl_text++ = 0;
return yield;
}
/* We have encountered a continuation. Skip over whitespace at the start of
the next line, and indeed the whole of the next line or lines if they are
comment lines. */
for (;;)
{
while (*(++acl_text) == ' ' || *acl_text == '\t');
if (*acl_text != '#') break;
while (*(++acl_text) != 0 && *acl_text != '\n');
}
/* We have the start of a continuation line. Move all the rest of the data
to join onto the previous line, and then find its end. If the end is not a
newline, we are done. Otherwise loop to look for another continuation. */
memmove(cont, acl_text, acl_text_end - acl_text);
acl_text_end -= acl_text - cont;
acl_text = cont;
while (*acl_text != 0 && *acl_text != '\n') acl_text++;
if (*acl_text == 0) return yield;
}
/* Control does not reach here */
}
/*************************************************
* Check access using an ACL *
*************************************************/
/* This function is called from address_check. It may recurse via
acl_check_condition() - hence the use of a level to stop looping. The ACL is
passed as a string which is expanded. A forced failure implies no access check
is required. If the result is a single word, it is taken as the name of an ACL
which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
text, complete with newlines, and parsed as such. In both cases, the ACL check
is then run. This function uses an auxiliary function for acl_read() to call
for reading individual lines of a literal ACL. This is acl_getline(), which
appears immediately above.
Arguments:
where where called from
addr address item when called from RCPT; otherwise NULL
s the input string; NULL is the same as an empty ACL => DENY
level the nesting level
user_msgptr where to put a user error (for SMTP response)
log_msgptr where to put a logging message (not for SMTP response)
Returns: OK access is granted
DISCARD access is apparently granted...
FAIL access is denied
FAIL_DROP access is denied; drop the connection
DEFER can't tell at the moment
ERROR disaster
*/
static int
acl_check_internal(int where, address_item *addr, uschar *s, int level,
uschar **user_msgptr, uschar **log_msgptr)
{
int fd = -1;
acl_block *acl = NULL;
uschar *acl_name = US"inline ACL";
uschar *ss;
/* Catch configuration loops */
if (level > 20)
{
*log_msgptr = US"ACL nested too deep: possible loop";
return ERROR;
}
if (s == NULL)
{
HDEBUG(D_acl) debug_printf("ACL is NULL: implicit DENY\n");
return FAIL;
}
/* At top level, we expand the incoming string. At lower levels, it has already
been expanded as part of condition processing. */
if (level == 0)
{
ss = expand_string(s);
if (ss == NULL)
{
if (expand_string_forcedfail) return OK;
*log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
expand_string_message);
return ERROR;
}
}
else ss = s;
while (isspace(*ss))ss++;
/* If we can't find a named ACL, the default is to parse it as an inline one.
(Unless it begins with a slash; non-existent files give rise to an error.) */
acl_text = ss;
/* Handle the case of a string that does not contain any spaces. Look for a
named ACL among those read from the configuration, or a previously read file.
It is possible that the pointer to the ACL is NULL if the configuration
contains a name with no data. If not found, and the text begins with '/',
read an ACL from a file, and save it so it can be re-used. */
if (Ustrchr(ss, ' ') == NULL)
{
tree_node *t = tree_search(acl_anchor, ss);
if (t != NULL)
{
acl = (acl_block *)(t->data.ptr);
if (acl == NULL)
{
HDEBUG(D_acl) debug_printf("ACL \"%s\" is empty: implicit DENY\n", ss);
return FAIL;
}
acl_name = string_sprintf("ACL \"%s\"", ss);
HDEBUG(D_acl) debug_printf("using ACL \"%s\"\n", ss);
}
else if (*ss == '/')
{
struct stat statbuf;
fd = Uopen(ss, O_RDONLY, 0);
if (fd < 0)
{
*log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss,
strerror(errno));
return ERROR;
}
if (fstat(fd, &statbuf) != 0)
{
*log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss,
strerror(errno));
return ERROR;
}
acl_text = store_get(statbuf.st_size + 1);
acl_text_end = acl_text + statbuf.st_size + 1;
if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size)
{
*log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s",
ss, strerror(errno));
return ERROR;
}
acl_text[statbuf.st_size] = 0;
(void)close(fd);
acl_name = string_sprintf("ACL \"%s\"", ss);
HDEBUG(D_acl) debug_printf("read ACL from file %s\n", ss);
}
}
/* Parse an ACL that is still in text form. If it came from a file, remember it
in the ACL tree, having read it into the POOL_PERM store pool so that it
persists between multiple messages. */
if (acl == NULL)
{
int old_pool = store_pool;
if (fd >= 0) store_pool = POOL_PERM;
acl = acl_read(acl_getline, log_msgptr);
store_pool = old_pool;
if (acl == NULL && *log_msgptr != NULL) return ERROR;
if (fd >= 0)
{
tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss));
Ustrcpy(t->name, ss);
t->data.ptr = acl;
(void)tree_insertnode(&acl_anchor, t);
}
}
/* Now we have an ACL to use. It's possible it may be NULL. */
while (acl != NULL)
{
int cond;
int basic_errno = 0;
BOOL endpass_seen = FALSE;
*log_msgptr = *user_msgptr = NULL;
acl_temp_details = FALSE;
if ((where == ACL_WHERE_QUIT || where == ACL_WHERE_NOTQUIT) &&
acl->verb != ACL_ACCEPT &&
acl->verb != ACL_WARN)
{
*log_msgptr = string_sprintf("\"%s\" is not allowed in a QUIT or not-QUIT ACL",
verbs[acl->verb]);
return ERROR;
}
HDEBUG(D_acl) debug_printf("processing \"%s\"\n", verbs[acl->verb]);
/* Clear out any search error message from a previous check before testing
this condition. */
search_error_message = NULL;
cond = acl_check_condition(acl->verb, acl->condition, where, addr, level,
&endpass_seen, user_msgptr, log_msgptr, &basic_errno);
/* Handle special returns: DEFER causes a return except on a WARN verb;
ERROR always causes a return. */
switch (cond)
{
case DEFER:
HDEBUG(D_acl) debug_printf("%s: condition test deferred\n", verbs[acl->verb]);
if (basic_errno != ERRNO_CALLOUTDEFER)
{
if (search_error_message != NULL && *search_error_message != 0)
*log_msgptr = search_error_message;
if (smtp_return_error_details) acl_temp_details = TRUE;
}
else
{
acl_temp_details = TRUE;
}
if (acl->verb != ACL_WARN) return DEFER;
break;
default: /* Paranoia */
case ERROR:
HDEBUG(D_acl) debug_printf("%s: condition test error\n", verbs[acl->verb]);
return ERROR;
case OK:
HDEBUG(D_acl) debug_printf("%s: condition test succeeded\n",
verbs[acl->verb]);
break;
case FAIL:
HDEBUG(D_acl) debug_printf("%s: condition test failed\n", verbs[acl->verb]);
break;
/* DISCARD and DROP can happen only from a nested ACL condition, and
DISCARD can happen only for an "accept" or "discard" verb. */
case DISCARD:
HDEBUG(D_acl) debug_printf("%s: condition test yielded \"discard\"\n",
verbs[acl->verb]);
break;
case FAIL_DROP:
HDEBUG(D_acl) debug_printf("%s: condition test yielded \"drop\"\n",
verbs[acl->verb]);
break;
}
/* At this point, cond for most verbs is either OK or FAIL or (as a result of
a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and
for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */
switch(acl->verb)
{
case ACL_ACCEPT:
if (cond == OK || cond == DISCARD) return cond;
if (endpass_seen)
{
HDEBUG(D_acl) debug_printf("accept: endpass encountered - denying access\n");
return cond;
}
break;
case ACL_DEFER:
if (cond == OK)
{
acl_temp_details = TRUE;
return DEFER;
}
break;
case ACL_DENY:
if (cond == OK) return FAIL;
break;
case ACL_DISCARD:
if (cond == OK || cond == DISCARD) return DISCARD;
if (endpass_seen)
{
HDEBUG(D_acl) debug_printf("discard: endpass encountered - denying access\n");
return cond;
}
break;
case ACL_DROP:
if (cond == OK) return FAIL_DROP;
break;
case ACL_REQUIRE:
if (cond != OK) return cond;
break;
case ACL_WARN:
if (cond == OK)
acl_warn(where, *user_msgptr, *log_msgptr);
else if (cond == DEFER && (log_extra_selector & LX_acl_warn_skipped) != 0)
log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: "
"condition test deferred%s%s", host_and_ident(TRUE),
(*log_msgptr == NULL)? US"" : US": ",
(*log_msgptr == NULL)? US"" : *log_msgptr);
*log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */
break;
default:
log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d",
acl->verb);
break;
}
/* Pass to the next ACL item */
acl = acl->next;
}
/* We have reached the end of the ACL. This is an implicit DENY. */
HDEBUG(D_acl) debug_printf("end of %s: implicit DENY\n", acl_name);
return FAIL;
}
/*************************************************
* Check access using an ACL *
*************************************************/
/* This is the external interface for ACL checks. It sets up an address and the
expansions for $domain and $local_part when called after RCPT, then calls
acl_check_internal() to do the actual work.
Arguments:
where ACL_WHERE_xxxx indicating where called from
recipient RCPT address for RCPT check, else NULL
s the input string; NULL is the same as an empty ACL => DENY
user_msgptr where to put a user error (for SMTP response)
log_msgptr where to put a logging message (not for SMTP response)
Returns: OK access is granted by an ACCEPT verb
DISCARD access is granted by a DISCARD verb
FAIL access is denied
FAIL_DROP access is denied; drop the connection
DEFER can't tell at the moment
ERROR disaster
*/
int
acl_check(int where, uschar *recipient, uschar *s, uschar **user_msgptr,
uschar **log_msgptr)
{
int rc;
address_item adb;
address_item *addr = NULL;
*user_msgptr = *log_msgptr = NULL;
sender_verified_failed = NULL;
ratelimiters_cmd = NULL;
log_reject_target = LOG_MAIN|LOG_REJECT;
if (where == ACL_WHERE_RCPT)
{
adb = address_defaults;
addr = &adb;
addr->address = recipient;
if (deliver_split_address(addr) == DEFER)
{
*log_msgptr = US"defer in percent_hack_domains check";
return DEFER;
}
deliver_domain = addr->domain;
deliver_localpart = addr->local_part;
}
rc = acl_check_internal(where, addr, s, 0, user_msgptr, log_msgptr);
deliver_domain = deliver_localpart = deliver_address_data =
sender_address_data = NULL;
/* A DISCARD response is permitted only for message ACLs, excluding the PREDATA
ACL, which is really in the middle of an SMTP command. */
if (rc == DISCARD)
{
if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA)
{
log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s "
"ACL", acl_wherenames[where]);
return ERROR;
}
return DISCARD;
}
/* A DROP response is not permitted from MAILAUTH */
if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH)
{
log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s "
"ACL", acl_wherenames[where]);
return ERROR;
}
/* Before giving a response, take a look at the length of any user message, and
split it up into multiple lines if possible. */
*user_msgptr = string_split_message(*user_msgptr);
if (fake_response != OK)
fake_response_text = string_split_message(fake_response_text);
return rc;
}
/*************************************************
* Create ACL variable *
*************************************************/
/* Create an ACL variable or reuse an existing one. ACL variables are in a
binary tree (see tree.c) with acl_var_c and acl_var_m as root nodes.
Argument:
name pointer to the variable's name, starting with c or m
Returns the pointer to variable's tree node
*/
tree_node *
acl_var_create(uschar *name)
{
tree_node *node, **root;
root = (name[0] == 'c')? &acl_var_c : &acl_var_m;
node = tree_search(*root, name);
if (node == NULL)
{
node = store_get(sizeof(tree_node) + Ustrlen(name));
Ustrcpy(node->name, name);
(void)tree_insertnode(root, node);
}
node->data.ptr = NULL;
return node;
}
/*************************************************
* Write an ACL variable in spool format *
*************************************************/
/* This function is used as a callback for tree_walk when writing variables to
the spool file. To retain spool file compatibility, what is written is -aclc or
-aclm followed by the rest of the name and the data length, space separated,
then the value itself, starting on a new line, and terminated by an additional
newline. When we had only numbered ACL variables, the first line might look
like this: "-aclc 5 20". Now it might be "-aclc foo 20" for the variable called
acl_cfoo.
Arguments:
name of the variable
value of the variable
ctx FILE pointer (as a void pointer)
Returns: nothing
*/
void
acl_var_write(uschar *name, uschar *value, void *ctx)
{
FILE *f = (FILE *)ctx;
fprintf(f, "-acl%c %s %d\n%s\n", name[0], name+1, Ustrlen(value), value);
}
/* End of acl.c */
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