-/* $Cambridge: exim/src/src/lookups/dnsdb.c,v 1.8 2005/01/04 10:00:44 ph10 Exp $ */
+/* $Cambridge: exim/src/src/lookups/dnsdb.c,v 1.17.2.1 2009/04/30 08:21:30 tom Exp $ */
/*************************************************
* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2005 */
+/* Copyright (c) University of Cambridge 1995 - 2007 */
/* See the file NOTICE for conditions of use and distribution. */
#include "../exim.h"
#endif
#endif
"cname",
+ "csa",
"mx",
"mxh",
"ns",
"ptr",
"srv",
"txt",
- "zns"
+ "zns"
};
static int type_values[] = {
#endif
#endif
T_CNAME,
+ T_CSA, /* Private type for "Client SMTP Authorization". */
T_MX,
T_MXH, /* Private type for "MX hostnames" */
T_NS,
/* See local README for interface description. The query in the "keystring" may
consist of a number of parts.
-(a) If the first significant character is '>' then the next character is the
-separator character that is used when multiple records are found. The default
+(a) If the first significant character is '>' then the next character is the
+separator character that is used when multiple records are found. The default
separator is newline.
(b) If the next sequence of characters is 'defer_FOO' followed by a comma,
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) 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
+(c) 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
default is "TXT".
-(d) Then there follows list of domain names. This is a generalized Exim list,
-which may start with '<' in order to set a specific separator. The default
+(d) Then there follows list of domain names. This is a generalized Exim list,
+which may start with '<' in order to set a specific separator. The default
separator, as always, is colon. */
int
int type = T_TXT;
int failrc = FAIL;
uschar *outsep = US"\n";
-uschar *equals, *domain;
+uschar *equals, *domain, *found;
uschar buffer[256];
/* Because we're the working in the search pool, we try to reclaim as much
if (*keystring == '>')
{
outsep = keystring + 1;
- keystring += 2;
+ keystring += 2;
while (isspace(*keystring)) keystring++;
- }
+ }
/* Check for a defer behaviour keyword. */
{
int i, len;
uschar *tend = equals;
-
- while (tend > keystring && isspace(tend[-1])) tend--;
- len = tend - keystring;
-
+
+ while (tend > keystring && isspace(tend[-1])) tend--;
+ len = tend - keystring;
+
for (i = 0; i < sizeof(type_names)/sizeof(uschar *); i++)
{
if (len == Ustrlen(type_names[i]) &&
break;
}
}
-
+
if (i >= sizeof(type_names)/sizeof(uschar *))
{
*errmsg = US"unsupported DNS record type";
return DEFER;
}
-
+
keystring = equals + 1;
while (isspace(*keystring)) keystring++;
}
-
+
/* Initialize the resolver in case this is the first time it has been used. */
dns_init(FALSE, FALSE);
-/* 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
-of them were found.
+/* 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
+of them were found.
-The original implementation did not support a list of domains. Adding the list
-feature is compatible, except in one case: when PTR records are being looked up
-for a single IPv6 address. Fortunately, we can hack in a compatibility feature
-here: If the type is PTR and no list separator is specified, and the entire
-remaining string is valid as an IP address, set an impossible separator so that
+The original implementation did not support a list of domains. Adding the list
+feature is compatible, except in one case: when PTR records are being looked up
+for a single IPv6 address. Fortunately, we can hack in a compatibility feature
+here: If the type is PTR and no list separator is specified, and the entire
+remaining string is valid as an IP address, set an impossible separator so that
it is treated as one item. */
if (type == T_PTR && keystring[0] != '<' &&
- string_is_ip_address(keystring, NULL) > 0)
+ string_is_ip_address(keystring, NULL) != 0)
sep = -1;
/* Now scan the list and do a lookup for each item */
-while ((domain = string_nextinlist(&keystring, &sep, buffer, sizeof(buffer)))
+while ((domain = string_nextinlist(&keystring, &sep, buffer, sizeof(buffer)))
!= NULL)
- {
+ {
uschar rbuffer[256];
- int searchtype = (type == T_ZNS)? T_NS : /* record type we want */
- (type == T_MXH)? T_MX : type;
-
- /* If the type is PTR, we have to construct the relevant magic lookup key if
- the original is an IP address (some experimental protocols are using PTR
- records for different purposes where the key string is a host name). This
- code for doing the reversal is now in a separate function. */
-
- if (type == T_PTR && string_is_ip_address(domain, NULL))
+ int searchtype = (type == T_CSA)? T_SRV : /* record type we want */
+ (type == T_MXH)? T_MX :
+ (type == T_ZNS)? T_NS : type;
+
+ /* If the type is PTR or CSA, we have to construct the relevant magic lookup
+ key if the original is an IP address (some experimental protocols are using
+ PTR records for different purposes where the key string is a host name, and
+ Exim's extended CSA can be keyed by domains or IP addresses). This code for
+ doing the reversal is now in a separate function. */
+
+ if ((type == T_PTR || type == T_CSA) &&
+ string_is_ip_address(domain, NULL) != 0)
{
dns_build_reverse(domain, rbuffer);
domain = rbuffer;
}
-
+
DEBUG(D_lookup) debug_printf("dnsdb key: %s\n", domain);
-
- /* Do the lookup and sort out the result. There are two special types that
- are handled specially: T_ZNS and T_MXH. The former is handled in a special
- lookup function so that the facility could be used from other parts of the
- Exim code. The latter affects only what happens later on in this function,
- but for tidiness it is handled in a similar way. If the lookup fails,
- continue with the next domain. In the case of DEFER, adjust the final
- "nothing found" result, but carry on to the next domain. */
-
- rc = dns_special_lookup(&dnsa, domain, type, NULL);
-
+
+ /* Do the lookup and sort out the result. There are three special types that
+ are handled specially: T_CSA, T_ZNS and T_MXH. The former two are handled in
+ a special lookup function so that the facility could be used from other
+ parts of the Exim code. The latter affects only what happens later on in
+ this function, but for tidiness it is handled in a similar way. If the
+ lookup fails, continue with the next domain. In the case of DEFER, adjust
+ the final "nothing found" result, but carry on to the next domain. */
+
+ found = domain;
+ rc = dns_special_lookup(&dnsa, domain, type, &found);
+
if (rc == DNS_NOMATCH || rc == DNS_NODATA) continue;
if (rc != DNS_SUCCEED)
{
else 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);
rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
{
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
+
+ /* 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 (type == T_A ||
#ifdef SUPPORT_A6
type == T_A6 ||
for (da = dns_address_from_rr(&dnsa, rr); da != NULL; da = da->next)
{
if (ptr != 0) yield = string_cat(yield, &size, &ptr, outsep, 1);
- yield = string_cat(yield, &size, &ptr, da->address,
+ yield = string_cat(yield, &size, &ptr, da->address,
Ustrlen(da->address));
}
continue;
}
-
- /* Other kinds of record just have one piece of data each, but there may be
+
+ /* 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 (type == T_TXT)
{
- yield = string_cat(yield, &size, &ptr, (uschar *)(rr->data+1),
- (rr->data)[0]);
+ int data_offset = 0;
+ while (data_offset < rr->size)
+ {
+ uschar chunk_len = (rr->data)[data_offset++];
+ yield = string_cat(yield, &size, &ptr,
+ (uschar *)((rr->data)+data_offset), chunk_len);
+ data_offset += chunk_len;
+ }
}
- else /* T_CNAME, T_MX, T_MXH, T_NS, T_SRV, T_PTR */
+ else /* T_CNAME, T_CSA, T_MX, T_MXH, T_NS, T_PTR, T_SRV */
{
- int num;
+ 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(num, p); /* pointer is advanced */
+ GETSHORT(priority, p);
}
else if (type == T_MX)
{
- GETSHORT(num, p); /* pointer is advanced */
- sprintf(CS s, "%d ", num);
+ GETSHORT(priority, p);
+ sprintf(CS s, "%d ", priority);
yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
}
else if (type == T_SRV)
{
- int weight, port;
- GETSHORT(num, p); /* pointer is advanced */
+ GETSHORT(priority, p);
GETSHORT(weight, p);
GETSHORT(port, p);
- sprintf(CS s, "%d %d %d ", num, weight, port);
+ 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);
+ }
+
+ /* 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));
-
+
/* If an overlong response was received, the data will have been
truncated and dn_expand may fail. */
-
+
if (rc < 0)
{
log_write(0, LOG_MAIN, "host name alias list truncated: type=%s "
store_reset(yield + ptr + 1);
-/* If ptr == 0 we have not found anything. Otherwise, insert the terminating
+/* If ptr == 0 we have not found anything. Otherwise, insert the terminating
zero and return the result. */
if (ptr == 0) return failrc;