-/* $Cambridge: exim/src/src/verify.c,v 1.5 2004/11/12 16:54:55 ph10 Exp $ */
+/* $Cambridge: exim/src/src/verify.c,v 1.15 2005/02/17 11:58:26 ph10 Exp $ */
/*************************************************
* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2004 */
+/* Copyright (c) University of Cambridge 1995 - 2005 */
/* See the file NOTICE for conditions of use and distribution. */
/* Functions concerned with verifying things. The original code for callout
static int
do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
- int callout, int callout_overall, int callout_connect, int options,
+ int callout, int callout_overall, int callout_connect, int options,
uschar *se_mailfrom, uschar *pm_mailfrom)
{
BOOL is_recipient = (options & vopt_is_recipient) != 0;
uschar *address_key;
uschar *from_address;
uschar *random_local_part = NULL;
-uschar **failure_ptr = is_recipient?
+uschar **failure_ptr = is_recipient?
&recipient_verify_failure : &sender_verify_failure;
open_db dbblock;
open_db *dbm_file = NULL;
setflag(addr, af_verify_nsfail);
addr->user_message = US"(result of an earlier callout reused).";
yield = FAIL;
- *failure_ptr = US"mail";
+ *failure_ptr = US"mail";
goto END_CALLOUT;
}
debug_printf("callout cache: domain does not accept "
"RCPT TO:<postmaster@domain>\n");
yield = FAIL;
- *failure_ptr = US"postmaster";
+ *failure_ptr = US"postmaster";
setflag(addr, af_verify_pmfail);
addr->user_message = US"(result of earlier verification reused).";
goto END_CALLOUT;
HDEBUG(D_verify)
debug_printf("callout cache: address record is negative\n");
addr->user_message = US"Previous (cached) callout verification failure";
- *failure_ptr = US"recipient";
+ *failure_ptr = US"recipient";
yield = FAIL;
}
goto END_CALLOUT;
smtp_outblock outblock;
int host_af;
int port = 25;
+ BOOL send_quit = TRUE;
uschar *helo = US"HELO";
uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
uschar inbuffer[4096];
if (!done)
{
- *failure_ptr = US"mail";
+ *failure_ptr = US"mail";
if (errno == 0 && responsebuffer[0] == '5')
{
setflag(addr, af_verify_nsfail);
new_address_record.result = ccache_accept;
else if (errno == 0 && responsebuffer[0] == '5')
{
- *failure_ptr = US"recipient";
+ *failure_ptr = US"recipient";
new_address_record.result = ccache_reject;
- }
+ }
/* Do postmaster check if requested */
new_domain_record.postmaster_result = ccache_accept;
else if (errno == 0 && responsebuffer[0] == '5')
{
- *failure_ptr = US"postmaster";
+ *failure_ptr = US"postmaster";
setflag(addr, af_verify_pmfail);
new_domain_record.postmaster_result = ccache_reject;
}
if (errno == ETIMEDOUT)
{
HDEBUG(D_verify) debug_printf("SMTP timeout\n");
+ send_quit = FALSE;
}
else if (errno == 0)
{
/* End the SMTP conversation and close the connection. */
- (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
+ if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
close(inblock.sock);
} /* Loop through all hosts, while !done */
for individual commands
callout_overall if > 0, gives overall timeout for the callout function;
if < 0, a default is used (see do_callout())
- callout_connect the connection timeout for callouts
+ callout_connect the connection timeout for callouts
se_mailfrom when callout is requested to verify a sender, use this
in MAIL FROM; NULL => ""
pm_mailfrom when callout is requested, if non-NULL, do the postmaster
int
verify_address(address_item *vaddr, FILE *f, int options, int callout,
- int callout_overall, int callout_connect, uschar *se_mailfrom,
+ int callout_overall, int callout_connect, uschar *se_mailfrom,
uschar *pm_mailfrom, BOOL *routed)
{
BOOL allok = TRUE;
address_item *addr_remote = NULL;
address_item *addr_local = NULL;
address_item *addr_succeed = NULL;
-uschar **failure_ptr = is_recipient?
+uschar **failure_ptr = is_recipient?
&recipient_verify_failure : &sender_verify_failure;
uschar *ko_prefix, *cr;
uschar *address = vaddr->address;
if (f != NULL)
fprintf(f, "%sA domain is required for \"%s\"%s\n", ko_prefix, address,
cr);
- *failure_ptr = US"qualify";
+ *failure_ptr = US"qualify";
return FAIL;
}
address = rewrite_address_qualify(address, is_recipient);
host_build_hostlist(&host_list, s, tf.hosts_randomize);
/* Just ignore failures to find a host address. If we don't manage
- to find any addresses, the callout will defer. Note that more than
- one address may be found for a single host, which will result in
- additional host items being inserted into the chain. Hence we must
+ to find any addresses, the callout will defer. Note that more than
+ one address may be found for a single host, which will result in
+ additional host items being inserted into the chain. Hence we must
save the next host first. */
for (host = host_list; host != NULL; host = nexthost)
{
nexthost = host->next;
- if (tf.gethostbyname || string_is_ip_address(host->name, NULL))
+ if (tf.gethostbyname ||
+ string_is_ip_address(host->name, NULL) > 0)
(void)host_find_byname(host, NULL, &canonical_name, TRUE);
else
{
}
}
- /* Can only do a callout if we have at least one host! If the callout
+ /* Can only do a callout if we have at least one host! If the callout
fails, it will have set ${sender,recipient}_verify_failure. */
if (host_list != NULL)
}
}
}
-
+
/* Otherwise, any failure is a routing failure */
-
- else *failure_ptr = US"route";
+
+ else *failure_ptr = US"route";
/* A router may return REROUTED if it has set up a child address as a result
of a change of domain name (typically from widening). In this case we always
}
}
-/* Will be DEFER or FAIL if any one address has, only for full_info (which is
+/* Will be DEFER or FAIL if any one address has, only for full_info (which is
the -bv or -bt case). */
-return yield;
+return yield;
}
log_msgptr points to where to put a log error message
callout timeout for callout check (passed to verify_address())
callout_overall overall callout timeout (ditto)
- callout_connect connect callout timeout (ditto)
+ callout_connect connect callout timeout (ditto)
se_mailfrom mailfrom for verify; NULL => ""
pm_mailfrom sender for pm callout check (passed to verify_address())
options callout options (passed to verify_address())
+ verrno where to put the address basic_errno
If log_msgptr is set to something without setting user_msgptr, the caller
normally uses log_msgptr for both things.
int
verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
- int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
- uschar *pm_mailfrom, int options)
+ int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
+ uschar *pm_mailfrom, int options, int *verrno)
{
static int header_types[] = { htype_sender, htype_reply_to, htype_from };
int yield = FAIL;
}
}
- /* Else go ahead with the sender verification. But is isn't *the*
+ /* Else go ahead with the sender verification. But it isn't *the*
sender of the message, so set vopt_fake_sender to stop sender_address
being replaced after rewriting or qualification. */
{
vaddr = deliver_make_addr(address, FALSE);
new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
- callout, callout_overall, callout_connect, se_mailfrom,
+ callout, callout_overall, callout_connect, se_mailfrom,
pm_mailfrom, NULL);
}
}
last of these will be returned to the user if all three fail. We do not
set a log message - the generic one below will be used. */
- if (new_ok != OK && smtp_return_error_details)
+ if (new_ok != OK)
{
- *user_msgptr = string_sprintf("Rejected after DATA: "
- "could not verify \"%.*s\" header address\n%s: %s",
- endname - h->text, h->text, vaddr->address, vaddr->message);
+ *verrno = vaddr->basic_errno;
+ if (smtp_return_error_details)
+ {
+ *user_msgptr = string_sprintf("Rejected after DATA: "
+ "could not verify \"%.*s\" header address\n%s: %s",
+ endname - h->text, h->text, vaddr->address, vaddr->message);
+ }
}
/* Success or defer */
/* If the pattern is an IP address, optionally followed by a bitmask count, do
a (possibly masked) comparision with the current IP address. */
-if (string_is_ip_address(ss, &maskoffset))
+if (string_is_ip_address(ss, &maskoffset) > 0)
return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
/* If the item is of the form net[n]-lookup;<file|query> then it is a lookup on
/* Adjust parameters for the type of lookup. For a query-style
lookup, there is no file name, and the "key" is just the query. For
a single-key lookup, the key is the current IP address, masked
- appropriately, and reconverted to text form, with the mask appended. */
+ appropriately, and reconverted to text form, with the mask appended.
+ For IPv6 addresses, specify dot separators instead of colons. */
if (mac_islookup(search_type, lookup_querystyle))
{
{
insize = host_aton(cb->host_address, incoming);
host_mask(insize, incoming, mlen);
- (void)host_nmtoa(insize, incoming, mlen, buffer);
+ (void)host_nmtoa(insize, incoming, mlen, buffer, '.');
key = buffer;
filename = semicolon + 1;
}
cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
host_address + 7 : host_address;
-/* During the running of the check, put the IP address into $host_address. In
-the case of calls from the smtp transport, it will already be there. However,
-in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
+/* During the running of the check, put the IP address into $host_address. In
+the case of calls from the smtp transport, it will already be there. However,
+in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
the safe side, any existing setting is preserved, though as I write this
(November 2004) I can't see any cases where it is actually needed. */
check_host, /* function for testing */
&cb, /* argument for function */
MCL_HOST, /* type of check */
- (host_address == sender_host_address)?
+ (host_address == sender_host_address)?
US"host" : host_address, /* text for debugging */
valueptr); /* where to pass back data */
deliver_host_address = save_host_address;
-return rc;
+return rc;
}
+/*************************************************
+* Perform a single dnsbl lookup *
+*************************************************/
+
+/* This function is called from verify_check_dnsbl() below.
+
+Arguments:
+ domain the outer dnsbl domain (for debug message)
+ keydomain the current keydomain (for debug message)
+ query the domain to be looked up
+ iplist the list of matching IP addresses
+ bitmask true if bitmask matching is wanted
+ invert_result true if result to be inverted
+ defer_return what to return for a defer
+
+Returns: OK if lookup succeeded
+ FAIL if not
+*/
+
+static int
+one_check_dnsbl(uschar *domain, uschar *keydomain, uschar *query,
+ uschar *iplist, BOOL bitmask, BOOL invert_result, int defer_return)
+{
+dns_answer dnsa;
+dns_scan dnss;
+tree_node *t;
+dnsbl_cache_block *cb;
+int old_pool = store_pool;
+
+/* Look for this query in the cache. */
+
+t = tree_search(dnsbl_cache, query);
+
+/* If not cached from a previous lookup, we must do a DNS lookup, and
+cache the result in permanent memory. */
+
+if (t == NULL)
+ {
+ store_pool = POOL_PERM;
+
+ /* Set up a tree entry to cache the lookup */
+
+ t = store_get(sizeof(tree_node) + Ustrlen(query));
+ Ustrcpy(t->name, query);
+ t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
+ (void)tree_insertnode(&dnsbl_cache, t);
+
+ /* Do the DNS loopup . */
+
+ HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
+ cb->rc = dns_basic_lookup(&dnsa, query, T_A);
+ cb->text_set = FALSE;
+ cb->text = NULL;
+ cb->rhs = NULL;
+
+ /* If the lookup succeeded, cache the RHS address. The code allows for
+ more than one address - this was for complete generality and the possible
+ use of A6 records. However, A6 records have been reduced to experimental
+ status (August 2001) and may die out. So they may never get used at all,
+ let alone in dnsbl records. However, leave the code here, just in case.
+
+ Quite apart from one A6 RR generating multiple addresses, there are DNS
+ lists that return more than one A record, so we must handle multiple
+ addresses generated in that way as well. */
+
+ if (cb->rc == DNS_SUCCEED)
+ {
+ dns_record *rr;
+ dns_address **addrp = &(cb->rhs);
+ for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
+ rr != NULL;
+ rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
+ {
+ if (rr->type == T_A)
+ {
+ dns_address *da = dns_address_from_rr(&dnsa, rr);
+ if (da != NULL)
+ {
+ *addrp = da;
+ while (da->next != NULL) da = da->next;
+ addrp = &(da->next);
+ }
+ }
+ }
+
+ /* If we didn't find any A records, change the return code. This can
+ happen when there is a CNAME record but there are no A records for what
+ it points to. */
+
+ if (cb->rhs == NULL) cb->rc = DNS_NODATA;
+ }
+
+ store_pool = old_pool;
+ }
+
+/* Previous lookup was cached */
+
+else
+ {
+ HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
+ cb = t->data.ptr;
+ }
+
+/* We now have the result of the DNS lookup, either newly done, or cached
+from a previous call. If the lookup succeeded, check against the address
+list if there is one. This may be a positive equality list (introduced by
+"="), a negative equality list (introduced by "!="), a positive bitmask
+list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
+
+if (cb->rc == DNS_SUCCEED)
+ {
+ dns_address *da = NULL;
+ uschar *addlist = cb->rhs->address;
+
+ /* For A and AAAA records, there may be multiple addresses from multiple
+ records. For A6 records (currently not expected to be used) there may be
+ multiple addresses from a single record. */
+
+ for (da = cb->rhs->next; da != NULL; da = da->next)
+ addlist = string_sprintf("%s, %s", addlist, da->address);
+
+ HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
+ query, addlist);
+
+ /* Address list check; this can be either for equality, or via a bitmask.
+ In the latter case, all the bits must match. */
+
+ if (iplist != NULL)
+ {
+ int ipsep = ',';
+ uschar ip[46];
+ uschar *ptr = iplist;
+
+ while (string_nextinlist(&ptr, &ipsep, ip, sizeof(ip)) != NULL)
+ {
+ /* Handle exact matching */
+ if (!bitmask)
+ {
+ for (da = cb->rhs; da != NULL; da = da->next)
+ {
+ if (Ustrcmp(CS da->address, ip) == 0) break;
+ }
+ }
+ /* Handle bitmask matching */
+ else
+ {
+ int address[4];
+ int mask = 0;
+
+ /* At present, all known DNS blocking lists use A records, with
+ IPv4 addresses on the RHS encoding the information they return. I
+ wonder if this will linger on as the last vestige of IPv4 when IPv6
+ is ubiquitous? Anyway, for now we use paranoia code to completely
+ ignore IPv6 addresses. The default mask is 0, which always matches.
+ We change this only for IPv4 addresses in the list. */
+
+ if (host_aton(ip, address) == 1) mask = address[0];
+
+ /* Scan the returned addresses, skipping any that are IPv6 */
+
+ for (da = cb->rhs; da != NULL; da = da->next)
+ {
+ if (host_aton(da->address, address) != 1) continue;
+ if ((address[0] & mask) == mask) break;
+ }
+ }
+
+ /* Break out if a match has been found */
+
+ if (da != NULL) break;
+ }
+
+ /* If either
+
+ (a) No IP address in a positive list matched, or
+ (b) An IP address in a negative list did match
+
+ then behave as if the DNSBL lookup had not succeeded, i.e. the host is
+ not on the list. */
+
+ if (invert_result != (da == NULL))
+ {
+ HDEBUG(D_dnsbl)
+ {
+ debug_printf("=> but we are not accepting this block class because\n");
+ debug_printf("=> there was %s match for %c%s\n",
+ invert_result? "an exclude":"no", bitmask? '&' : '=', iplist);
+ }
+ return FAIL;
+ }
+ }
+
+ /* Either there was no IP list, or the record matched. Look up a TXT record
+ if it hasn't previously been done. */
+
+ if (!cb->text_set)
+ {
+ cb->text_set = TRUE;
+ if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
+ {
+ dns_record *rr;
+ for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
+ rr != NULL;
+ rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
+ if (rr->type == T_TXT) break;
+ if (rr != NULL)
+ {
+ int len = (rr->data)[0];
+ if (len > 511) len = 127;
+ store_pool = POOL_PERM;
+ cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
+ store_pool = old_pool;
+ }
+ }
+ }
+
+ dnslist_value = addlist;
+ dnslist_text = cb->text;
+ return OK;
+ }
+
+/* There was a problem with the DNS lookup */
+
+if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
+ {
+ log_write(L_dnslist_defer, LOG_MAIN,
+ "DNS list lookup defer (probably timeout) for %s: %s", query,
+ (defer_return == OK)? US"assumed in list" :
+ (defer_return == FAIL)? US"assumed not in list" :
+ US"returned DEFER");
+ return defer_return;
+ }
+
+/* No entry was found in the DNS; continue for next domain */
+
+HDEBUG(D_dnsbl)
+ {
+ debug_printf("DNS lookup for %s failed\n", query);
+ debug_printf("=> that means %s is not listed at %s\n",
+ keydomain, domain);
+ }
+
+return FAIL;
+}
+
+
+
+
/*************************************************
* Check host against DNS black lists *
*************************************************/
{
int sep = 0;
int defer_return = FAIL;
-int old_pool = store_pool;
BOOL invert_result = FALSE;
uschar *list = *listptr;
uschar *domain;
revadd[0] = 0;
+/* In case this is the first time the DNS resolver is being used. */
+
+dns_init(FALSE, FALSE);
+
/* Loop through all the domains supplied, until something matches */
while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
{
+ int rc;
BOOL frc;
BOOL bitmask = FALSE;
- dns_answer dnsa;
- dns_scan dnss;
uschar *iplist;
uschar *key;
- tree_node *t;
- dnsbl_cache_block *cb;
HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
}
}
- /* Construct the query by adding the domain onto either the sending host
- address, or the given key string. */
+ /* If there is no key string, construct the query by adding the domain name
+ onto the inverted host address, and perform a single DNS lookup. */
if (key == NULL)
{
if (sender_host_address == NULL) return FAIL; /* can never match */
if (revadd[0] == 0) invert_address(revadd, sender_host_address);
frc = string_format(query, sizeof(query), "%s%s", revadd, domain);
- }
- else
- {
- frc = string_format(query, sizeof(query), "%s.%s", key, domain);
- }
-
- if (!frc)
- {
- log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
- "(ignored): %s...", query);
- continue;
- }
-
- /* Look for this query in the cache. */
-
- t = tree_search(dnsbl_cache, query);
-
- /* If not cached from a previous lookup, we must do a DNS lookup, and
- cache the result in permanent memory. */
-
- if (t == NULL)
- {
- store_pool = POOL_PERM;
-
- /* In case this is the first time the DNS resolver is being used. */
-
- dns_init(FALSE, FALSE);
-
- /* Set up a tree entry to cache the lookup */
-
- t = store_get(sizeof(tree_node) + Ustrlen(query));
- Ustrcpy(t->name, query);
- t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
- (void)tree_insertnode(&dnsbl_cache, t);
-
- /* Do the DNS loopup . */
-
- HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
- cb->rc = dns_basic_lookup(&dnsa, query, T_A);
- cb->text_set = FALSE;
- cb->text = NULL;
- cb->rhs = NULL;
-
- /* If the lookup succeeded, cache the RHS address. The code allows for
- more than one address - this was for complete generality and the possible
- use of A6 records. However, A6 records have been reduced to experimental
- status (August 2001) and may die out. So they may never get used at all,
- let alone in dnsbl records. However, leave the code here, just in case.
- Quite apart from one A6 RR generating multiple addresses, there are DNS
- lists that return more than one A record, so we must handle multiple
- addresses generated in that way as well. */
-
- if (cb->rc == DNS_SUCCEED)
+ if (!frc)
{
- dns_record *rr;
- dns_address **addrp = &(cb->rhs);
- for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
- rr != NULL;
- rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
- {
- if (rr->type == T_A)
- {
- dns_address *da = dns_address_from_rr(&dnsa, rr);
- if (da != NULL)
- {
- *addrp = da;
- while (da->next != NULL) da = da->next;
- addrp = &(da->next);
- }
- }
- }
+ log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
+ "(ignored): %s...", query);
+ continue;
+ }
- /* If we didn't find any A records, change the return code. This can
- happen when there is a CNAME record but there are no A records for what
- it points to. */
+ rc = one_check_dnsbl(domain, sender_host_address, query, iplist, bitmask,
+ invert_result, defer_return);
- if (cb->rhs == NULL) cb->rc = DNS_NODATA;
+ if (rc == OK)
+ {
+ dnslist_domain = string_copy(domain);
+ HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
+ sender_host_address, domain);
}
- store_pool = old_pool;
+ if (rc != FAIL) return rc; /* OK or DEFER */
}
- /* Previous lookup was cached */
+ /* If there is a key string, it can be a list of domains or IP addresses to
+ be concatenated with the main domain. */
else
{
- HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
- cb = t->data.ptr;
- }
-
- /* We now have the result of the DNS lookup, either newly done, or cached
- from a previous call. If the lookup succeeded, check against the address
- list if there is one. This may be a positive equality list (introduced by
- "="), a negative equality list (introduced by "!="), a positive bitmask
- list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
-
- if (cb->rc == DNS_SUCCEED)
- {
- dns_address *da = NULL;
- uschar *addlist = cb->rhs->address;
-
- /* For A and AAAA records, there may be multiple addresses from multiple
- records. For A6 records (currently not expected to be used) there may be
- multiple addresses from a single record. */
+ int keysep = 0;
+ BOOL defer = FALSE;
+ uschar *keydomain;
+ uschar keybuffer[256];
- for (da = cb->rhs->next; da != NULL; da = da->next)
- addlist = string_sprintf("%s, %s", addlist, da->address);
-
- HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
- query, addlist);
-
- /* Address list check; this can be either for equality, or via a bitmask.
- In the latter case, all the bits must match. */
-
- if (iplist != NULL)
+ while ((keydomain = string_nextinlist(&key, &keysep, keybuffer,
+ sizeof(keybuffer))) != NULL)
{
- int ipsep = ',';
- uschar ip[46];
- uschar *ptr = iplist;
-
- while (string_nextinlist(&ptr, &ipsep, ip, sizeof(ip)) != NULL)
+ if (string_is_ip_address(keydomain, NULL) > 0)
{
- /* Handle exact matching */
- if (!bitmask)
- {
- for (da = cb->rhs; da != NULL; da = da->next)
- {
- if (Ustrcmp(CS da->address, ip) == 0) break;
- }
- }
- /* Handle bitmask matching */
- else
- {
- int address[4];
- int mask = 0;
-
- /* At present, all known DNS blocking lists use A records, with
- IPv4 addresses on the RHS encoding the information they return. I
- wonder if this will linger on as the last vestige of IPv4 when IPv6
- is ubiquitous? Anyway, for now we use paranoia code to completely
- ignore IPv6 addresses. The default mask is 0, which always matches.
- We change this only for IPv4 addresses in the list. */
-
- if (host_aton(ip, address) == 1) mask = address[0];
-
- /* Scan the returned addresses, skipping any that are IPv6 */
-
- for (da = cb->rhs; da != NULL; da = da->next)
- {
- if (host_aton(da->address, address) != 1) continue;
- if ((address[0] & mask) == mask) break;
- }
- }
-
- /* Break out if a match has been found */
-
- if (da != NULL) break;
+ uschar keyrevadd[128];
+ invert_address(keyrevadd, keydomain);
+ frc = string_format(query, sizeof(query), "%s%s", keyrevadd, domain);
}
-
- /* If either
-
- (a) No IP address in a positive list matched, or
- (b) An IP address in a negative list did match
-
- then behave as if the DNSBL lookup had not succeeded, i.e. the host is
- not on the list. */
-
- if (invert_result != (da == NULL))
+ else
{
- HDEBUG(D_dnsbl)
- {
- debug_printf("=> but we are not accepting this block class because\n");
- debug_printf("=> there was %s match for %c%s\n",
- invert_result? "an exclude":"no", bitmask? '&' : '=', iplist);
- }
- continue; /* With next DNSBL domain */
+ frc = string_format(query, sizeof(query), "%s.%s", keydomain, domain);
}
- }
-
- /* Either there was no IP list, or the record matched. Look up a TXT record
- if it hasn't previously been done. */
- if (!cb->text_set)
- {
- cb->text_set = TRUE;
- if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
+ if (!frc)
{
- dns_record *rr;
- for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
- rr != NULL;
- rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
- if (rr->type == T_TXT) break;
- if (rr != NULL)
- {
- int len = (rr->data)[0];
- if (len > 511) len = 127;
- store_pool = POOL_PERM;
- cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
- store_pool = old_pool;
- }
+ log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
+ "(ignored): %s...", query);
+ continue;
}
- }
-
- HDEBUG(D_dnsbl)
- {
- debug_printf("=> that means %s is listed at %s\n",
- (key == NULL)? sender_host_address : key, domain);
- }
- dnslist_domain = string_copy(domain);
- dnslist_value = addlist;
- dnslist_text = cb->text;
- return OK;
- }
+ rc = one_check_dnsbl(domain, keydomain, query, iplist, bitmask,
+ invert_result, defer_return);
- /* There was a problem with the DNS lookup */
+ if (rc == OK)
+ {
+ dnslist_domain = string_copy(domain);
+ HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
+ keydomain, domain);
+ return OK;
+ }
- if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
- {
- log_write(L_dnslist_defer, LOG_MAIN,
- "DNS list lookup defer (probably timeout) for %s: %s", query,
- (defer_return == OK)? US"assumed in list" :
- (defer_return == FAIL)? US"assumed not in list" :
- US"returned DEFER");
- return defer_return;
- }
+ /* If the lookup deferred, remember this fact. We keep trying the rest
+ of the list to see if we get a useful result, and if we don't, we return
+ DEFER at the end. */
- /* No entry was found in the DNS; continue for next domain */
+ if (rc == DEFER) defer = TRUE;
+ } /* continue with next keystring domain/address */
- HDEBUG(D_dnsbl)
- {
- debug_printf("DNS lookup for %s failed\n", query);
- debug_printf("=> that means %s is not listed at %s\n",
- (key == NULL)? sender_host_address : key, domain);
+ if (defer) return DEFER;
}
- } /* Continue with next domain */
+ } /* continue with next dnsdb outer domain */
return FAIL;
}
git://git.exim.org / exim.git / blobdiff