/* Previous lookup was cached */
{
- HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
+ HDEBUG(D_dnsbl) debug_printf("dnslists: using result of previous lookup\n");
}
/* If not cached from a previous lookup, we must do a DNS lookup, and
else
{
- uint ttl = 3600;
+ uint ttl = 3600; /* max TTL for positive cache entries */
store_pool = POOL_PERM;
addresses generated in that way as well.
Mark the cache entry with the "now" plus the minimum of the address TTLs,
- or some suitably far-future time if none were found. */
+ or the RFC 2308 negative-cache value from the SOA if none were found. */
- if (cb->rc == DNS_SUCCEED)
+ switch (cb->rc)
{
- dns_address ** addrp = &(cb->rhs);
- for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr;
- rr = dns_next_rr(dnsa, &dnss, RESET_NEXT))
- if (rr->type == T_A)
- {
- dns_address *da = dns_address_from_rr(dnsa, rr);
- if (da)
- {
- *addrp = da;
- while (da->next) da = da->next;
- addrp = &da->next;
+ case DNS_SUCCEED:
+ {
+ dns_address ** addrp = &cb->rhs;
+ dns_address * da;
+ for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr;
+ rr = dns_next_rr(dnsa, &dnss, RESET_NEXT))
+ if (rr->type == T_A && (da = dns_address_from_rr(dnsa, rr)))
+ {
+ *addrp = da;
+ while (da->next) da = da->next;
+ addrp = &da->next;
if (ttl > rr->ttl) ttl = rr->ttl;
- }
- }
+ }
+
+ if (cb->rhs)
+ {
+ cb->expiry = time(NULL) + ttl;
+ break;
+ }
+
+ /* 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. */
+
+ cb->rc = DNS_NODATA;
+ }
+ /*FALLTHROUGH*/
- /* 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. */
+ case DNS_NOMATCH:
+ case DNS_NODATA:
+ {
+ /* Although there already is a neg-cache layer maintained by
+ dns_basic_lookup(), we have a dnslist cache entry allocated and
+ tree-inserted. So we may as well use it. */
- if (!cb->rhs) cb->rc = DNS_NODATA;
+ time_t soa_negttl = dns_expire_from_soa(dnsa);
+ cb->expiry = soa_negttl ? soa_negttl : time(NULL) + ttl;
+ break;
+ }
+
+ default:
+ cb->expiry = time(NULL) + ttl;
+ break;
}
- cb->expiry = time(NULL)+ttl;
store_pool = old_pool;
+ HDEBUG(D_dnsbl) debug_printf("dnslists: wrote cache entry, ttl=%d\n",
+ (int)(cb->expiry - time(NULL)));
}
/* We now have the result of the DNS lookup, either newly done, or cached
if (cb->rc == DNS_SUCCEED)
{
- dns_address *da = NULL;
+ dns_address * da = NULL;
uschar *addlist = cb->rhs->address;
/* For A and AAAA records, there may be multiple addresses from multiple
/* Loop through all the domains supplied, until something matches */
-while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
+while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))))
{
int rc;
BOOL bitmask = FALSE;
uschar *iplist;
uschar *key;
- HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
+ HDEBUG(D_dnsbl) debug_printf("dnslists check: %s\n", domain);
/* Deal with special values that change the behaviour on defer */
set domain_txt == domain. */
domain_txt = domain;
- comma = Ustrchr(domain, ',');
- if (comma != NULL)
+ if ((comma = Ustrchr(domain, ',')))
{
*comma++ = 0;
domain = comma;
acl_wherenames[where]);
return ERROR;
}
- if (sender_host_address == NULL) return FAIL; /* can never match */
+ if (!sender_host_address) return FAIL; /* can never match */
if (revadd[0] == 0) invert_address(revadd, sender_host_address);
rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
iplist, bitmask, match_type, defer_return);
int keysep = 0;
BOOL defer = FALSE;
uschar *keydomain;
- uschar keybuffer[256];
uschar keyrevadd[128];
- while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer,
- sizeof(keybuffer))) != NULL)
+ while ((keydomain = string_nextinlist(CUSS &key, &keysep, NULL, 0)))
{
uschar *prepend = keydomain;
rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
bitmask, match_type, defer_return);
-
if (rc == OK)
{
dnslist_domain = string_copy(domain_txt);