* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2012 */
+/* Copyright (c) University of Cambridge 1995 - 2014 */
/* See the file NOTICE for conditions of use and distribution. */
/* Functions for interfacing with the DNS. */
*/
static int
-fakens_search(uschar *domain, int type, uschar *answerptr, int size)
+fakens_search(const uschar *domain, int type, uschar *answerptr, int size)
{
int len = Ustrlen(domain);
int asize = size; /* Locally modified */
Arguments:
qualify_single TRUE to set the RES_DEFNAMES option
search_parents TRUE to set the RES_DNSRCH option
+ use_dnssec TRUE to set the RES_USE_DNSSEC option
Returns: nothing
*/
void
-dns_init(BOOL qualify_single, BOOL search_parents)
+dns_init(BOOL qualify_single, BOOL search_parents, BOOL use_dnssec)
{
res_state resp = os_get_dns_resolver_res();
# ifndef RES_USE_EDNS0
# error Have RES_USE_DNSSEC but not RES_USE_EDNS0? Something hinky ...
# endif
-if (dns_use_dnssec >= 0)
+if (use_dnssec)
+ resp->options |= RES_USE_DNSSEC;
+if (dns_dnssec_ok >= 0)
{
- if (dns_use_edns0 == 0 && dns_use_dnssec != 0)
+ if (dns_use_edns0 == 0 && dns_dnssec_ok != 0)
{
DEBUG(D_resolver)
- debug_printf("CONFLICT: dns_use_edns0 forced false, dns_use_dnssec forced true!\n");
+ debug_printf("CONFLICT: dns_use_edns0 forced false, dns_dnssec_ok forced true, ignoring latter!\n");
}
else
{
- if (dns_use_dnssec)
+ if (dns_dnssec_ok)
resp->options |= RES_USE_DNSSEC;
else
resp->options &= ~RES_USE_DNSSEC;
DEBUG(D_resolver) debug_printf("Coerced resolver DNSSEC support %s.\n",
- dns_use_dnssec ? "on" : "off");
+ dns_dnssec_ok ? "on" : "off");
}
}
# else
-if (dns_use_dnssec >= 0)
+if (dns_dnssec_ok >= 0)
DEBUG(D_resolver)
debug_printf("Unable to %sset DNSSEC without resolver support.\n",
- dns_use_dnssec ? "" : "un");
+ dns_dnssec_ok ? "" : "un");
+if (use_dnssec)
+ DEBUG(D_resolver)
+ debug_printf("Unable to set DNSSEC without resolver support.\n");
# endif
#endif /* DISABLE_DNSSEC */
*/
BOOL
-dns_is_secure(dns_answer *dnsa)
+dns_is_secure(const dns_answer * dnsa)
{
#ifdef DISABLE_DNSSEC
DEBUG(D_dns)
#endif
}
+static void
+dns_set_insecure(dns_answer * dnsa)
+{
+HEADER * h = (HEADER *)dnsa->answer;
+h->ad = 0;
+}
+
case T_SRV: return US"SRV";
case T_NS: return US"NS";
case T_CNAME: return US"CNAME";
+ case T_TLSA: return US"TLSA";
default: return US"?";
}
}
*/
static int
-dns_return(uschar *name, int type, int rc)
+dns_return(const uschar * name, int type, int rc)
{
res_state resp = os_get_dns_resolver_res();
tree_node *node = store_get_perm(sizeof(tree_node) + 290);
*/
int
-dns_basic_lookup(dns_answer *dnsa, uschar *name, int type)
+dns_basic_lookup(dns_answer *dnsa, const uschar *name, int type)
{
#ifndef STAND_ALONE
int rc = -1;
if (check_dns_names_pattern[0] != 0 && type != T_PTR && type != T_TXT)
{
- uschar *checkname = name;
+ const uschar *checkname = name;
int ovector[3*(EXPAND_MAXN+1)];
- if (regex_check_dns_names == NULL)
- regex_check_dns_names =
- regex_must_compile(check_dns_names_pattern, FALSE, TRUE);
+ dns_pattern_init();
/* For an SRV lookup, skip over the first two components (the service and
protocol names, which both start with an underscore). */
- if (type == T_SRV)
+ if (type == T_SRV || type == T_TLSA)
{
while (*checkname++ != '.');
while (*checkname++ != '.');
}
- if (pcre_exec(regex_check_dns_names, NULL, CS checkname, Ustrlen(checkname),
+ if (pcre_exec(regex_check_dns_names, NULL, CCS checkname, Ustrlen(checkname),
0, PCRE_EOPT, ovector, sizeof(ovector)/sizeof(int)) < 0)
{
DEBUG(D_dns)
if (running_in_test_harness)
dnsa->answerlen = fakens_search(name, type, dnsa->answer, MAXPACKET);
else
- dnsa->answerlen = res_search(CS name, C_IN, type, dnsa->answer, MAXPACKET);
+ dnsa->answerlen = res_search(CCS name, C_IN, type, dnsa->answer, MAXPACKET);
if (dnsa->answerlen > MAXPACKET)
{
name, dns_text_type(type));
/* Cut this out for various test programs */
- #ifndef STAND_ALONE
+#ifndef STAND_ALONE
save = deliver_domain;
- deliver_domain = name; /* set $domain */
+ deliver_domain = string_copy(name); /* set $domain */
rc = match_isinlist(name, &dns_again_means_nonexist, 0, NULL, NULL,
MCL_DOMAIN, TRUE, NULL);
deliver_domain = save;
"DNS_NOMATCH\n", name);
return dns_return(name, type, DNS_NOMATCH);
- #else /* For stand-alone tests */
+#else /* For stand-alone tests */
return dns_return(name, type, DNS_AGAIN);
- #endif
+#endif
case NO_RECOVERY:
DEBUG(D_dns) debug_printf("DNS lookup of %s (%s) gave NO_RECOVERY\n"
*/
int
-dns_lookup(dns_answer *dnsa, uschar *name, int type, uschar **fully_qualified_name)
+dns_lookup(dns_answer *dnsa, const uschar *name, int type,
+ uschar **fully_qualified_name)
{
int i;
-uschar *orig_name = name;
+const uschar *orig_name = name;
+BOOL secure_so_far = TRUE;
/* Loop to follow CNAME chains so far, but no further... */
/* If any data records of the correct type were found, we are done. */
- if (type_rr.data != NULL) return DNS_SUCCEED;
+ if (type_rr.data != NULL)
+ {
+ if (!secure_so_far) /* mark insecure if any element of CNAME chain was */
+ dns_set_insecure(dnsa);
+ return DNS_SUCCEED;
+ }
/* If there are no data records, we need to re-scan the DNS using the
domain given in the CNAME record, which should exist (otherwise we should
if (cname_rr.data == NULL) return DNS_FAIL;
datalen = dn_expand(dnsa->answer, dnsa->answer + dnsa->answerlen,
- cname_rr.data, (DN_EXPAND_ARG4_TYPE)data, 256);
+ cname_rr.data, (DN_EXPAND_ARG4_TYPE)data, sizeof(data));
if (datalen < 0) return DNS_FAIL;
name = data;
+ if (!dns_is_secure(dnsa))
+ secure_so_far = FALSE;
+
DEBUG(D_dns) debug_printf("CNAME found: change to %s\n", name);
} /* Loop back to do another lookup */
*/
int
-dns_special_lookup(dns_answer *dnsa, uschar *name, int type,
+dns_special_lookup(dns_answer *dnsa, const uschar *name, int type,
uschar **fully_qualified_name)
{
if (type >= 0) return dns_lookup(dnsa, name, type, fully_qualified_name);
if (type == T_ZNS)
{
- uschar *d = name;
+ const uschar *d = name;
while (d != 0)
{
int rc = dns_lookup(dnsa, d, T_NS, fully_qualified_name);
rc = dns_lookup(dnsa, srvname, T_SRV, NULL);
if (rc == DNS_SUCCEED || rc == DNS_AGAIN)
{
- if (rc == DNS_SUCCEED) *fully_qualified_name = name;
+ if (rc == DNS_SUCCEED) *fully_qualified_name = string_copy(name);
return rc;
}
/* Extract the numerical SRV fields (p is incremented) */
p = rr->data;
GETSHORT(priority, p);
- GETSHORT(weight, p);
+ GETSHORT(weight, p); weight = weight; /* compiler quietening */
GETSHORT(port, p);
/* Check the CSA version number */
return yield;
}
+
+
+void
+dns_pattern_init(void)
+{
+if (check_dns_names_pattern[0] != 0 && !regex_check_dns_names)
+ regex_check_dns_names =
+ regex_must_compile(check_dns_names_pattern, FALSE, TRUE);
+}
+
+/* vi: aw ai sw=2
+*/
/* End of dns.c */
git://git.exim.org / users / jgh / exim.git / blobdiff