* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2012 */
+/* Copyright (c) University of Cambridge 1995 - 2015 */
/* See the file NOTICE for conditions of use and distribution. */
#include "../exim.h"
#define T_SPF 99
#endif
+/* New TLSA record for DANE */
+#ifndef T_TLSA
+#define T_TLSA 52
+#endif
+
/* Table of recognized DNS record types and their integer values. */
static const char *type_names[] = {
#if HAVE_IPV6
"a+",
"aaaa",
- #ifdef SUPPORT_A6
- "a6",
- #endif
#endif
"cname",
"csa",
"mxh",
"ns",
"ptr",
+ "soa",
"spf",
"srv",
+ "tlsa",
"txt",
"zns"
};
static int type_values[] = {
T_A,
#if HAVE_IPV6
- T_APL, /* Private type for AAAA + A */
+ T_ADDRESSES, /* Private type for AAAA + A */
T_AAAA,
- #ifdef SUPPORT_A6
- T_A6,
- #endif
#endif
T_CNAME,
T_CSA, /* Private type for "Client SMTP Authorization". */
T_MXH, /* Private type for "MX hostnames" */
T_NS,
T_PTR,
+ T_SOA,
T_SPF,
T_SRV,
+ T_TLSA,
T_TXT,
T_ZNS /* Private type for "zone nameservers" */
};
is output. Similarly for "SPF" records, but the default for joining multiple
items in one SPF record is the empty string, for direct concatenation.
-(c) If the next sequence of characters is 'defer_FOO' followed by a comma,
-the defer behaviour is set to FOO. The possible behaviours are: 'strict', where
-any defer causes the whole lookup to defer; 'lax', where a defer causes the
-whole lookup to defer only if none of the DNS queries succeeds; and 'never',
-where all defers are as if the lookup failed. The default is 'lax'.
+(c) Options, all comma-terminated, in any order. Any unrecognised option
+terminates option processing. Recognised options are:
+
+- 'defer_FOO': set the defer behaviour to FOO. The possible behaviours are:
+'strict', where any defer causes the whole lookup to defer; 'lax', where a defer
+causes the whole lookup to defer only if none of the DNS queries succeeds; and
+'never', where all defers are as if the lookup failed. The default is 'lax'.
+
+- 'dnssec_FOO', with 'strict', 'lax' and 'never' (default). The meanings are
+require, try and don't-try dnssec respectively.
+
+- 'retrans_VAL', set the timeout value. VAL is an Exim time specification
+(eg "5s"). The default is set by the main configuration option 'dns_retrans'.
+
+- 'retry_VAL', set the retry count on timeouts. VAL is an integer. The
+default is set by the main configuration option "dns_retry".
(d) If the next sequence of characters is a sequence of letters and digits
followed by '=', it is interpreted as the name of the DNS record type. The
separator, as always, is colon. */
static int
-dnsdb_find(void *handle, uschar *filename, uschar *keystring, int length,
- uschar **result, uschar **errmsg, BOOL *do_cache)
+dnsdb_find(void *handle, uschar *filename, const uschar *keystring, int length,
+ uschar **result, uschar **errmsg, uint *do_cache)
{
int rc;
int size = 256;
int ptr = 0;
int sep = 0;
int defer_mode = PASS;
+int dnssec_mode = OK;
+int save_retrans = dns_retrans;
+int save_retry = dns_retry;
int type;
int failrc = FAIL;
-uschar *outsep = US"\n";
-uschar *outsep2 = NULL;
+const uschar *outsep = CUS"\n";
+const uschar *outsep2 = NULL;
uschar *equals, *domain, *found;
-uschar buffer[256];
/* Because we're the working in the search pool, we try to reclaim as much
store as possible later, so we preallocate the result here */
while (isspace(*keystring)) keystring++;
}
-/* Check for a defer behaviour keyword. */
+/* Check for a modifier keyword. */
-if (strncmpic(keystring, US"defer_", 6) == 0)
+for (;;)
{
- keystring += 6;
- if (strncmpic(keystring, US"strict", 6) == 0)
+ if (strncmpic(keystring, US"defer_", 6) == 0)
{
- defer_mode = DEFER;
keystring += 6;
+ if (strncmpic(keystring, US"strict", 6) == 0)
+ { defer_mode = DEFER; keystring += 6; }
+ else if (strncmpic(keystring, US"lax", 3) == 0)
+ { defer_mode = PASS; keystring += 3; }
+ else if (strncmpic(keystring, US"never", 5) == 0)
+ { defer_mode = OK; keystring += 5; }
+ else
+ {
+ *errmsg = US"unsupported dnsdb defer behaviour";
+ return DEFER;
+ }
}
- else if (strncmpic(keystring, US"lax", 3) == 0)
+ else if (strncmpic(keystring, US"dnssec_", 7) == 0)
{
- defer_mode = PASS;
- keystring += 3;
+ keystring += 7;
+ if (strncmpic(keystring, US"strict", 6) == 0)
+ { dnssec_mode = DEFER; keystring += 6; }
+ else if (strncmpic(keystring, US"lax", 3) == 0)
+ { dnssec_mode = PASS; keystring += 3; }
+ else if (strncmpic(keystring, US"never", 5) == 0)
+ { dnssec_mode = OK; keystring += 5; }
+ else
+ {
+ *errmsg = US"unsupported dnsdb dnssec behaviour";
+ return DEFER;
+ }
}
- else if (strncmpic(keystring, US"never", 5) == 0)
+ else if (strncmpic(keystring, US"retrans_", 8) == 0)
{
- defer_mode = OK;
- keystring += 5;
+ int timeout_sec;
+ if ((timeout_sec = readconf_readtime(keystring += 8, ',', FALSE)) <= 0)
+ {
+ *errmsg = US"unsupported dnsdb timeout value";
+ return DEFER;
+ }
+ dns_retrans = timeout_sec;
+ while (*keystring != ',') keystring++;
}
- else
+ else if (strncmpic(keystring, US"retry_", 6) == 0)
{
- *errmsg = US"unsupported dnsdb defer behaviour";
- return DEFER;
+ int retries;
+ if ((retries = (int)strtol(CCS keystring + 6, CSS &keystring, 0)) < 0)
+ {
+ *errmsg = US"unsupported dnsdb retry count";
+ return DEFER;
+ }
+ dns_retry = retries;
}
+ else
+ break;
+
while (isspace(*keystring)) keystring++;
if (*keystring++ != ',')
{
- *errmsg = US"dnsdb defer behaviour syntax error";
+ *errmsg = US"dnsdb modifier syntax error";
return DEFER;
}
while (isspace(*keystring)) keystring++;
while (tend > keystring && isspace(tend[-1])) tend--;
len = tend - keystring;
- for (i = 0; i < sizeof(type_names)/sizeof(uschar *); i++)
- {
+ for (i = 0; i < nelem(type_names); i++)
if (len == Ustrlen(type_names[i]) &&
strncmpic(keystring, US type_names[i], len) == 0)
{
type = type_values[i];
break;
}
- }
- if (i >= sizeof(type_names)/sizeof(uschar *))
+ if (i >= nelem(type_names))
{
*errmsg = US"unsupported DNS record type";
return DEFER;
/* Initialize the resolver in case this is the first time it has been used. */
-dns_init(FALSE, FALSE);
+dns_init(FALSE, FALSE, dnssec_mode != OK);
/* The remainder of the string must be a list of domains. As long as the lookup
for at least one of them succeeds, we return success. Failure means that none
/* SPF strings should be concatenated without a separator, thus make
it the default if not defined (see RFC 4408 section 3.1.3).
Multiple SPF records are forbidden (section 3.1.2) but are currently
-not handled specially, thus they are concatenated with \n by default. */
+not handled specially, thus they are concatenated with \n by default.
+MX priority and value are space-separated by default.
+SRV and TLSA record parts are space-separated by default. */
-if (type == T_SPF && outsep2 == NULL)
- outsep2 = US"";
+if (!outsep2) switch(type)
+ {
+ case T_SPF: outsep2 = US""; break;
+ case T_SRV: case T_MX: case T_TLSA: outsep2 = US" "; break;
+ }
/* Now scan the list and do a lookup for each item */
-while ((domain = string_nextinlist(&keystring, &sep, buffer, sizeof(buffer)))
- != NULL)
+while ((domain = string_nextinlist(&keystring, &sep, NULL, 0)))
{
uschar rbuffer[256];
int searchtype = (type == T_CSA)? T_SRV : /* record type we want */
DEBUG(D_lookup) debug_printf("dnsdb key: %s\n", domain);
/* Do the lookup and sort out the result. There are four special types that
- are handled specially: T_CSA, T_ZNS, T_APL and T_MXH.
+ are handled specially: T_CSA, T_ZNS, T_ADDRESSES and T_MXH.
The first two are handled in a special lookup function so that the facility
- could be used from other parts of the Exim code. T_APL is handled by looping
+ could be used from other parts of the Exim code. T_ADDRESSES is handled by looping
over the types of A lookup. T_MXH affects only what happens later on in
this function, but for tidiness it is handled by the "special". If the
lookup fails, continue with the next domain. In the case of DEFER, adjust
found = domain;
#if HAVE_IPV6
- if (type == T_APL) /* NB cannot happen unless HAVE_IPV6 */
+ if (type == T_ADDRESSES) /* NB cannot happen unless HAVE_IPV6 */
{
- if (searchtype == T_APL)
-# if defined(SUPPORT_A6)
- searchtype = T_A6;
-# else
- searchtype = T_AAAA;
-# endif
- else if (searchtype == T_A6) searchtype = T_AAAA;
+ if (searchtype == T_ADDRESSES) searchtype = T_AAAA;
else if (searchtype == T_AAAA) searchtype = T_A;
- rc = dns_special_lookup(&dnsa, domain, searchtype, &found);
+ rc = dns_special_lookup(&dnsa, domain, searchtype, CUSS &found);
}
else
#endif
- rc = dns_special_lookup(&dnsa, domain, type, &found);
+ rc = dns_special_lookup(&dnsa, domain, type, CUSS &found);
+
+ lookup_dnssec_authenticated = dnssec_mode==OK ? NULL
+ : dns_is_secure(&dnsa) ? US"yes" : US"no";
if (rc == DNS_NOMATCH || rc == DNS_NODATA) continue;
- if (rc != DNS_SUCCEED)
+ if ( rc != DNS_SUCCEED
+ || (dnssec_mode == DEFER && !dns_is_secure(&dnsa))
+ )
{
- if (defer_mode == DEFER) return DEFER; /* always defer */
+ if (defer_mode == DEFER)
+ {
+ dns_retrans = save_retrans;
+ dns_retry = save_retry;
+ dns_init(FALSE, FALSE, FALSE); /* clr dnssec bit */
+ return DEFER; /* always defer */
+ }
if (defer_mode == PASS) failrc = DEFER; /* defer only if all do */
continue; /* treat defer as fail */
}
+
/* Search the returned records */
for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
{
if (rr->type != searchtype) continue;
- /* There may be several addresses from an A6 record. Put the configured
- separator between them, just as for between several records. However, A6
- support is not normally configured these days. */
+ if (*do_cache > rr->ttl)
+ *do_cache = rr->ttl;
- if (type == T_A ||
- #ifdef SUPPORT_A6
- type == T_A6 ||
- #endif
- type == T_AAAA ||
- type == T_APL)
+ if (type == T_A || type == T_AAAA || type == T_ADDRESSES)
{
dns_address *da;
- for (da = dns_address_from_rr(&dnsa, rr); da != NULL; da = da->next)
+ for (da = dns_address_from_rr(&dnsa, rr); da; da = da->next)
{
- if (ptr != 0) yield = string_cat(yield, &size, &ptr, outsep, 1);
- yield = string_cat(yield, &size, &ptr, da->address,
- Ustrlen(da->address));
+ if (ptr != 0) yield = string_catn(yield, &size, &ptr, outsep, 1);
+ yield = string_cat(yield, &size, &ptr, da->address);
}
continue;
}
/* Other kinds of record just have one piece of data each, but there may be
several of them, of course. */
- if (ptr != 0) yield = string_cat(yield, &size, &ptr, outsep, 1);
+ if (ptr != 0) yield = string_catn(yield, &size, &ptr, outsep, 1);
if (type == T_TXT || type == T_SPF)
{
if (outsep2 == NULL)
{
/* output only the first item of data */
- yield = string_cat(yield, &size, &ptr, (uschar *)(rr->data+1),
+ yield = string_catn(yield, &size, &ptr, (uschar *)(rr->data+1),
(rr->data)[0]);
}
else
{
uschar chunk_len = (rr->data)[data_offset++];
if (outsep2[0] != '\0' && data_offset != 1)
- yield = string_cat(yield, &size, &ptr, outsep2, 1);
- yield = string_cat(yield, &size, &ptr,
- (uschar *)((rr->data)+data_offset), chunk_len);
+ yield = string_catn(yield, &size, &ptr, outsep2, 1);
+ yield = string_catn(yield, &size, &ptr,
+ US ((rr->data)+data_offset), chunk_len);
data_offset += chunk_len;
}
}
}
- else /* T_CNAME, T_CSA, T_MX, T_MXH, T_NS, T_PTR, T_SRV */
+ else if (type == T_TLSA)
+ {
+ uint8_t usage, selector, matching_type;
+ uint16_t i, payload_length;
+ uschar s[MAX_TLSA_EXPANDED_SIZE];
+ uschar * sp = s;
+ uschar * p = US rr->data;
+
+ usage = *p++;
+ selector = *p++;
+ matching_type = *p++;
+ /* What's left after removing the first 3 bytes above */
+ payload_length = rr->size - 3;
+ sp += sprintf(CS s, "%d%c%d%c%d%c", usage, *outsep2,
+ selector, *outsep2, matching_type, *outsep2);
+ /* Now append the cert/identifier, one hex char at a time */
+ for (i=0;
+ i < payload_length && sp-s < (MAX_TLSA_EXPANDED_SIZE - 4);
+ i++)
+ sp += sprintf(CS sp, "%02x", (unsigned char)p[i]);
+
+ yield = string_cat(yield, &size, &ptr, s);
+ }
+ else /* T_CNAME, T_CSA, T_MX, T_MXH, T_NS, T_PTR, T_SOA, T_SRV */
{
int priority, weight, port;
uschar s[264];
- uschar *p = (uschar *)(rr->data);
-
- if (type == T_MXH)
- {
- /* mxh ignores the priority number and includes only the hostnames */
- GETSHORT(priority, p);
- }
- else if (type == T_MX)
- {
- GETSHORT(priority, p);
- sprintf(CS s, "%d ", priority);
- yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
- }
- else if (type == T_SRV)
- {
- GETSHORT(priority, p);
- GETSHORT(weight, p);
- GETSHORT(port, p);
- sprintf(CS s, "%d %d %d ", priority, weight, port);
- yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
- }
- else if (type == T_CSA)
- {
- /* See acl_verify_csa() for more comments about CSA. */
-
- GETSHORT(priority, p);
- GETSHORT(weight, p);
- GETSHORT(port, p);
-
- if (priority != 1) continue; /* CSA version must be 1 */
-
- /* If the CSA record we found is not the one we asked for, analyse
- the subdomain assertions in the port field, else analyse the direct
- authorization status in the weight field. */
-
- if (found != domain)
- {
- if (port & 1) *s = 'X'; /* explicit authorization required */
- else *s = '?'; /* no subdomain assertions here */
- }
- else
- {
- if (weight < 2) *s = 'N'; /* not authorized */
- else if (weight == 2) *s = 'Y'; /* authorized */
- else if (weight == 3) *s = '?'; /* unauthorizable */
- else continue; /* invalid */
- }
-
- s[1] = ' ';
- yield = string_cat(yield, &size, &ptr, s, 2);
- }
+ uschar * p = US rr->data;
+
+ switch (type)
+ {
+ case T_MXH:
+ /* mxh ignores the priority number and includes only the hostnames */
+ GETSHORT(priority, p);
+ break;
+
+ case T_MX:
+ GETSHORT(priority, p);
+ sprintf(CS s, "%d%c", priority, *outsep2);
+ yield = string_cat(yield, &size, &ptr, s);
+ break;
+
+ case T_SRV:
+ GETSHORT(priority, p);
+ GETSHORT(weight, p);
+ GETSHORT(port, p);
+ sprintf(CS s, "%d%c%d%c%d%c", priority, *outsep2,
+ weight, *outsep2, port, *outsep2);
+ yield = string_cat(yield, &size, &ptr, s);
+ break;
+
+ case T_CSA:
+ /* See acl_verify_csa() for more comments about CSA. */
+ GETSHORT(priority, p);
+ GETSHORT(weight, p);
+ GETSHORT(port, p);
+
+ if (priority != 1) continue; /* CSA version must be 1 */
+
+ /* If the CSA record we found is not the one we asked for, analyse
+ the subdomain assertions in the port field, else analyse the direct
+ authorization status in the weight field. */
+
+ if (Ustrcmp(found, domain) != 0)
+ {
+ if (port & 1) *s = 'X'; /* explicit authorization required */
+ else *s = '?'; /* no subdomain assertions here */
+ }
+ else
+ {
+ if (weight < 2) *s = 'N'; /* not authorized */
+ else if (weight == 2) *s = 'Y'; /* authorized */
+ else if (weight == 3) *s = '?'; /* unauthorizable */
+ else continue; /* invalid */
+ }
+
+ s[1] = ' ';
+ yield = string_catn(yield, &size, &ptr, s, 2);
+ break;
+
+ default:
+ break;
+ }
/* GETSHORT() has advanced the pointer to the target domain. */
rc = dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, p,
- (DN_EXPAND_ARG4_TYPE)(s), sizeof(s));
+ (DN_EXPAND_ARG4_TYPE)s, sizeof(s));
/* If an overlong response was received, the data will have been
truncated and dn_expand may fail. */
"domain=%s", dns_text_type(type), domain);
break;
}
- else yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
+ else yield = string_cat(yield, &size, &ptr, s);
+
+ if (type == T_SOA && outsep2 != NULL)
+ {
+ unsigned long serial, refresh, retry, expire, minimum;
+
+ p += rc;
+ yield = string_catn(yield, &size, &ptr, outsep2, 1);
+
+ rc = dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, p,
+ (DN_EXPAND_ARG4_TYPE)s, sizeof(s));
+ if (rc < 0)
+ {
+ log_write(0, LOG_MAIN, "responsible-mailbox truncated: type=%s "
+ "domain=%s", dns_text_type(type), domain);
+ break;
+ }
+ else yield = string_cat(yield, &size, &ptr, s);
+
+ p += rc;
+ GETLONG(serial, p); GETLONG(refresh, p);
+ GETLONG(retry, p); GETLONG(expire, p); GETLONG(minimum, p);
+ sprintf(CS s, "%c%lu%c%lu%c%lu%c%lu%c%lu",
+ *outsep2, serial, *outsep2, refresh,
+ *outsep2, retry, *outsep2, expire, *outsep2, minimum);
+ yield = string_cat(yield, &size, &ptr, s);
+ }
}
} /* Loop for list of returned records */
- /* Loop for set of A-lookupu types */
- } while (type == T_APL && searchtype != T_A);
+ /* Loop for set of A-lookup types */
+ } while (type == T_ADDRESSES && searchtype != T_A);
} /* Loop for list of domains */
/* If ptr == 0 we have not found anything. Otherwise, insert the terminating
zero and return the result. */
+dns_retrans = save_retrans;
+dns_retry = save_retry;
+dns_init(FALSE, FALSE, FALSE); /* clear the dnssec bit for getaddrbyname */
+
if (ptr == 0) return failrc;
yield[ptr] = 0;
*result = yield;
static lookup_info *_lookup_list[] = { &_lookup_info };
lookup_module_info dnsdb_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };
+/* vi: aw ai sw=2
+*/
/* End of lookups/dnsdb.c */
git://git.exim.org / exim.git / blobdiff