-/* $Cambridge: exim/src/src/verify.c,v 1.1 2004/10/07 10:39:01 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
portstring "port" option from transport, or NULL
protocolstring "protocol" option from transport, or NULL
callout the per-command callout timeout
- callout_overall the overall callout timeout (if < 0; use 4*callout)
+ callout_overall the overall callout timeout (if < 0 use 4*callout)
+ callout_connect the callout connection timeout (if < 0 use callout)
options the verification options - these bits are used:
vopt_is_recipient => this is a recipient address
vopt_callout_no_cache => don't use callout cache
static int
do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
- int callout, int callout_overall, int options, uschar *se_mailfrom,
- uschar *pm_mailfrom)
+ int callout, int callout_overall, int callout_connect, int options,
+ uschar *se_mailfrom, uschar *pm_mailfrom)
{
BOOL is_recipient = (options & vopt_is_recipient) != 0;
BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0;
uschar *address_key;
uschar *from_address;
uschar *random_local_part = NULL;
+uschar **failure_ptr = is_recipient?
+ &recipient_verify_failure : &sender_verify_failure;
open_db dbblock;
open_db *dbm_file = NULL;
dbdata_callout_cache new_domain_record;
setflag(addr, af_verify_nsfail);
addr->user_message = US"(result of an earlier callout reused).";
yield = FAIL;
+ *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";
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";
yield = FAIL;
}
goto END_CALLOUT;
"callout_random_local_part: %s", expand_string_message);
}
-/* Default the overall callout timeout if not set, and record the time we are
-starting so that we can enforce it. */
+/* Default the connect and overall callout timeouts if not set, and record the
+time we are starting so that we can enforce it. */
if (callout_overall < 0) callout_overall = 4 * callout;
+if (callout_connect < 0) callout_connect = callout;
callout_start_time = time(NULL);
/* Now make connections to the hosts and do real callouts. The list of hosts
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];
outblock.authenticating = FALSE;
/* Connect to the host; on failure, just loop for the next one, but we
- set the error for the last one. */
+ set the error for the last one. Use the callout_connect timeout. */
inblock.sock = outblock.sock =
- smtp_connect(host, host_af, port, interface, callout, TRUE);
+ smtp_connect(host, host_af, port, interface, callout_connect, TRUE);
if (inblock.sock < 0)
{
addr->message = string_sprintf("could not connect to %s [%s]: %s",
if (!done)
{
+ *failure_ptr = US"mail";
if (errno == 0 && responsebuffer[0] == '5')
{
setflag(addr, af_verify_nsfail);
if (done)
new_address_record.result = ccache_accept;
else if (errno == 0 && responsebuffer[0] == '5')
+ {
+ *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";
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 */
vopt_callout_recippmaster => use postmaster for recipient
callout if > 0, specifies that callout is required, and gives timeout
- for individual connections and commands
+ 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
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, uschar *se_mailfrom, uschar *pm_mailfrom, BOOL *routed)
+ int callout_overall, int callout_connect, uschar *se_mailfrom,
+ uschar *pm_mailfrom, BOOL *routed)
{
BOOL allok = TRUE;
BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
BOOL is_recipient = (options & vopt_is_recipient) != 0;
BOOL expn = (options & vopt_expn) != 0;
-
int i;
int yield = OK;
int verify_type = expn? v_expn :
address_item *addr_remote = NULL;
address_item *addr_local = NULL;
address_item *addr_succeed = NULL;
+uschar **failure_ptr = is_recipient?
+ &recipient_verify_failure : &sender_verify_failure;
uschar *ko_prefix, *cr;
uschar *address = vaddr->address;
uschar *save_sender;
uschar null_sender[] = { 0 }; /* Ensure writeable memory */
+/* Clear, just in case */
+
+*failure_ptr = NULL;
+
/* Set up a prefix and suffix for error message which allow us to use the same
output statements both in EXPN mode (where an SMTP response is needed) and when
debugging with an output file. */
if (f != NULL)
fprintf(f, "%sA domain is required for \"%s\"%s\n", ko_prefix, address,
cr);
+ *failure_ptr = US"qualify";
return FAIL;
}
address = rewrite_address_qualify(address, is_recipient);
else
{
uschar *canonical_name;
- host_item *host;
+ host_item *host, *nexthost;
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. */
+ 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 = host->next)
+ for (host = host_list; host != NULL; host = nexthost)
{
- if (tf.gethostbyname || string_is_ip_address(host->name, NULL))
+ nexthost = host->next;
+ 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! */
+ /* 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)
{
else
{
rc = do_callout(addr, host_list, &tf, callout, callout_overall,
- options, se_mailfrom, pm_mailfrom);
+ callout_connect, options, se_mailfrom, pm_mailfrom);
}
}
else
}
}
+ /* Otherwise, any failure is a routing failure */
+
+ 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
want to continue to verify the new child. */
}
}
-return yield; /* Will be DEFER or FAIL if any one address has */
+/* Will be DEFER or FAIL if any one address has, only for full_info (which is
+the -bv or -bt case). */
+
+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)
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, 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, se_mailfrom, pm_mailfrom, NULL);
+ 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;
}
verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
uschar *host_name, uschar *host_address, uschar **valueptr)
{
+int rc;
unsigned int *local_cache_bits = cache_bits;
+uschar *save_host_address = deliver_host_address;
check_host_block cb;
cb.host_name = host_name;
cb.host_address = host_address;
cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
host_address + 7 : host_address;
-return match_check_list(listptr, 0, &hostlist_anchor, &local_cache_bits,
- check_host, &cb, MCL_HOST,
- (host_address == sender_host_address)? US"host" : host_address, valueptr);
+/* 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. */
+
+deliver_host_address = host_address;
+rc = match_check_list(
+ listptr, /* the list */
+ 0, /* separator character */
+ &hostlist_anchor, /* anchor pointer */
+ &local_cache_bits, /* cache pointer */
+ check_host, /* function for testing */
+ &cb, /* argument for function */
+ MCL_HOST, /* type of check */
+ (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;
}
+/*************************************************
+* 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;
+ int keysep = 0;
+ BOOL defer = FALSE;
+ uschar *keydomain;
+ uschar keybuffer[256];
- /* 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)
+ 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