ph10 2004/11/19 09:45:54 GMT
Modified files:
exim-doc/doc-txt ChangeLog NewStuff
exim-src/src dns.c exim.h functions.h
exim-src/src/lookups dnsdb.c
exim-test-orig/AutoTest/scripts 082
exim-test-orig/AutoTest/stdout 082 353
Log:
Implement the pseudo dns lookup type "zns" for ${dnsdb lookups.
Revision Changes Path
1.34 +10 -0 exim/exim-doc/doc-txt/ChangeLog
1.12 +21 -0 exim/exim-doc/doc-txt/NewStuff
1.2 +64 -8 exim/exim-src/src/dns.c
1.2 +5 -0 exim/exim-src/src/exim.h
1.5 +1 -0 exim/exim-src/src/functions.h
1.2 +11 -3 exim/exim-src/src/lookups/dnsdb.c
1.5 +1 -0 exim/exim-test-orig/AutoTest/scripts/082
1.5 +1 -0 exim/exim-test-orig/AutoTest/stdout/082
1.2 +2 -2 exim/exim-test-orig/AutoTest/stdout/353
Index: ChangeLog
===================================================================
RCS file: /home/cvs/exim/exim-doc/doc-txt/ChangeLog,v
retrieving revision 1.33
retrieving revision 1.34
diff -u -r1.33 -r1.34
--- ChangeLog 18 Nov 2004 11:17:33 -0000 1.33
+++ ChangeLog 19 Nov 2004 09:45:54 -0000 1.34
@@ -1,4 +1,4 @@
-$Cambridge: exim/exim-doc/doc-txt/ChangeLog,v 1.33 2004/11/18 11:17:33 ph10 Exp $
+$Cambridge: exim/exim-doc/doc-txt/ChangeLog,v 1.34 2004/11/19 09:45:54 ph10 Exp $
Change log file for Exim from version 4.21
-------------------------------------------
@@ -141,6 +141,16 @@
35. If an IPv6 address is given for -bh or -bhc, it is now converted to the
canonical form (fully expanded) before being placed in
$sender_host_address.
+
+36. The table in the code that translates DNS record types into text (T_A to
+ "A" for instance) was missing entries for NS and CNAME. It is just possible
+ that this could have caused confusion if both these types were looked up
+ for the same domain, because the text type is used as part of Exim's
+ per-process caching. But the chance of anyone hitting this buglet seems
+ very small.
+
+37. The dnsdb lookup has a new type, "zns", which walks up the domain tree
+ until it finds some nameserver records. It should be used with care.
Exim version 4.43
Index: NewStuff
===================================================================
RCS file: /home/cvs/exim/exim-doc/doc-txt/NewStuff,v
retrieving revision 1.11
retrieving revision 1.12
diff -u -r1.11 -r1.12
--- NewStuff 17 Nov 2004 16:12:26 -0000 1.11
+++ NewStuff 19 Nov 2004 09:45:54 -0000 1.12
@@ -1,4 +1,4 @@
-$Cambridge: exim/exim-doc/doc-txt/NewStuff,v 1.11 2004/11/17 16:12:26 ph10 Exp $
+$Cambridge: exim/exim-doc/doc-txt/NewStuff,v 1.12 2004/11/19 09:45:54 ph10 Exp $
New Features in Exim
--------------------
@@ -107,6 +107,27 @@
condition = ${if eq {$acl_m4}{1}}
Previously this was a syntax error.
+
+12. There is now a new "record type" that can be specified in dnsdb lookups. It
+ is "zns" (for "zone NS"). It performs a lookup for NS records on the given
+ domain, but if none are found, it removes the first component of the domain
+ name, and tries again. This process continues until NS records are found
+ or there are no more components left (or there's a DNS error). In other
+ words, it may return the name servers for a top-level domain, but it never
+ returns the root name servers. If there are no NS records for the top-level
+ domain, the lookup fails.
+
+ For example, ${lookup dnsdb{zns=xxx.quercite.com}} returns the name
+ servers for quercite.com, whereas ${lookup dnsdb{zns=xxx.edu}} returns
+ the name servers for edu, assuming in each case that there are no NS
+ records for the full domain name.
+
+ You should be careful about how you use this lookup because, unless the
+ top-level domain does not exist, the lookup will always return some host
+ names. The sort of use to which this might be put is for seeing if the name
+ servers for a given domain are on a blacklist. You can probably assume that
+ the name servers for the high-level domains such as .com or .co.uk are not
+ going to be on such a list.
Version 4.43
Index: dns.c
===================================================================
RCS file: /home/cvs/exim/exim-src/src/dns.c,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- dns.c 7 Oct 2004 10:39:01 -0000 1.1
+++ dns.c 19 Nov 2004 09:45:54 -0000 1.2
@@ -1,4 +1,4 @@
-/* $Cambridge: exim/exim-src/src/dns.c,v 1.1 2004/10/07 10:39:01 ph10 Exp $ */
+/* $Cambridge: exim/exim-src/src/dns.c,v 1.2 2004/11/19 09:45:54 ph10 Exp $ */
/*************************************************
* Exim - an Internet mail transport agent *
@@ -258,14 +258,16 @@
{
switch(t)
{
- case T_A: return US"A";
- case T_MX: return US"MX";
- case T_AAAA: return US"AAAA";
- case T_A6: return US"A6";
- case T_TXT: return US"TXT";
- case T_PTR: return US"PTR";
- case T_SRV: return US"SRV";
- default: return US"?";
+ case T_A: return US"A";
+ case T_MX: return US"MX";
+ case T_AAAA: return US"AAAA";
+ case T_A6: return US"A6";
+ case T_TXT: return US"TXT";
+ case T_PTR: return US"PTR";
+ case T_SRV: return US"SRV";
+ case T_NS: return US"NS";
+ case T_CNAME: return US"CNAME";
+ default: return US"?";
}
}
@@ -612,6 +614,60 @@
right... */
log_write(0, LOG_MAIN, "CNAME loop for %s encountered", orig_name);
+return DNS_FAIL;
+}
+
+
+
+
+
+
+/************************************************
+* Do a DNS lookup and handle virtual types *
+************************************************/
+
+/* This function handles some invented "lookup types" that synthesize feature
+not available in the basic types. The special types all have negative values.
+Positive type values are passed straight on to dns_lookup().
+
+Arguments:
+ dnsa pointer to dns_answer structure
+ name domain name to look up
+ type DNS record type (T_A, T_MX, etc or a "special")
+ fully_qualified_name if not NULL, return the returned name here if its
+ contents are different (i.e. it must be preset)
+
+Returns: DNS_SUCCEED successful lookup
+ DNS_NOMATCH name not found
+ DNS_NODATA no data found
+ DNS_AGAIN soft failure, try again later
+ DNS_FAIL DNS failure
+*/
+
+int
+dns_special_lookup(dns_answer *dnsa, uschar *name, int type,
+ uschar **fully_qualified_name)
+{
+if (type >= 0) return dns_lookup(dnsa, name, type, fully_qualified_name);
+
+/* Find nameservers for the domain or the nearest enclosing zone, excluding the
+root servers. */
+
+if (type == T_ZNS)
+ {
+ uschar *d = name;
+ while (d != 0)
+ {
+ int rc = dns_lookup(dnsa, d, T_NS, fully_qualified_name);
+ if (rc != DNS_NOMATCH && rc != DNS_NODATA) return rc;
+ while (*d != 0 && *d != '.') d++;
+ if (*d++ == 0) break;
+ }
+ return DNS_NOMATCH;
+ }
+
+/* Control should never reach here */
+
return DNS_FAIL;
}
Index: exim.h
===================================================================
RCS file: /home/cvs/exim/exim-src/src/exim.h,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- exim.h 7 Oct 2004 10:39:01 -0000 1.1
+++ exim.h 19 Nov 2004 09:45:54 -0000 1.2
@@ -1,4 +1,4 @@
-/* $Cambridge: exim/exim-src/src/exim.h,v 1.1 2004/10/07 10:39:01 ph10 Exp $ */
+/* $Cambridge: exim/exim-src/src/exim.h,v 1.2 2004/11/19 09:45:54 ph10 Exp $ */
/*************************************************
* Exim - an Internet mail transport agent *
@@ -277,6 +277,11 @@
#ifndef T_SRV
#define T_SRV 33
#endif
+
+/* We use the private type T_ZNS for retrieving the nameservers for the
+enclosing zone of a domain. */
+
+#define T_ZNS (-1)
/* The resolv.h header defines __P(x) on some Solaris 2.5.1 systems (without
checking that it is already defined, in fact). This conflicts with other
Index: functions.h
===================================================================
RCS file: /home/cvs/exim/exim-src/src/functions.h,v
retrieving revision 1.4
retrieving revision 1.5
diff -u -r1.4 -r1.5
--- functions.h 18 Nov 2004 11:17:33 -0000 1.4
+++ functions.h 19 Nov 2004 09:45:54 -0000 1.5
@@ -1,4 +1,4 @@
-/* $Cambridge: exim/exim-src/src/functions.h,v 1.4 2004/11/18 11:17:33 ph10 Exp $ */
+/* $Cambridge: exim/exim-src/src/functions.h,v 1.5 2004/11/19 09:45:54 ph10 Exp $ */
/*************************************************
* Exim - an Internet mail transport agent *
@@ -74,6 +74,7 @@
extern void dns_init(BOOL, BOOL);
extern int dns_basic_lookup(dns_answer *, uschar *, int);
extern int dns_lookup(dns_answer *, uschar *, int, uschar **);
+extern int dns_special_lookup(dns_answer *, uschar *, int, uschar **);
extern dns_record *dns_next_rr(dns_answer *, dns_scan *, int);
extern uschar *dns_text_type(int);
Index: dnsdb.c
===================================================================
RCS file: /home/cvs/exim/exim-src/src/lookups/dnsdb.c,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- dnsdb.c 7 Oct 2004 13:10:01 -0000 1.1
+++ dnsdb.c 19 Nov 2004 09:45:54 -0000 1.2
@@ -1,4 +1,4 @@
-/* $Cambridge: exim/exim-src/src/lookups/dnsdb.c,v 1.1 2004/10/07 13:10:01 ph10 Exp $ */
+/* $Cambridge: exim/exim-src/src/lookups/dnsdb.c,v 1.2 2004/11/19 09:45:54 ph10 Exp $ */
/*************************************************
* Exim - an Internet mail transport agent *
@@ -35,7 +35,9 @@
"ns",
"ptr",
"srv",
- "txt" };
+ "txt",
+ "zns"
+};
static int type_values[] = {
T_A,
@@ -50,7 +52,9 @@
T_NS,
T_PTR,
T_SRV,
- T_TXT };
+ T_TXT,
+ T_ZNS /* Private type for "zone nameservers" */
+};
/*************************************************
@@ -139,11 +143,15 @@
in this run. Then do the lookup and sort out the result. */
dns_init(FALSE, FALSE);
-rc = dns_lookup(&dnsa, keystring, type, NULL);
+rc = dns_special_lookup(&dnsa, keystring, type, NULL);
if (rc == DNS_NOMATCH || rc == DNS_NODATA) return FAIL;
if (rc != DNS_SUCCEED) return DEFER;
+/* If the lookup was a pseudo-type, change it to the correct type for searching
+the returned records; then search for them. */
+
+if (type == T_ZNS) type = T_NS;
for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
rr != NULL;
rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
Index: 082
===================================================================
RCS file: /home/cvs/exim/exim-test-orig/AutoTest/scripts/082,v
retrieving revision 1.4
retrieving revision 1.5
diff -u -r1.4 -r1.5
--- 082 17 Nov 2004 16:12:26 -0000 1.4
+++ 082 19 Nov 2004 09:45:54 -0000 1.5
@@ -436,6 +436,7 @@
a=localhost.test.ex ${lookup dnsdb{a=localhost.test.ex}{$value}fail}
cname=alias-xoanon.test.ex ${lookup dnsdb{cname=alias-xoanon.test.ex}{$value}fail}
ns=test.ex ${lookup dnsdb{ns=test.ex}{$value}fail}
+zns=x.y.z.test.ex ${lookup dnsdb{zns=x.y.z.test.ex}{$value}fail}
mx=mxt1.test.ex ${lookup dnsdb{mx=mxt1.test.ex}{$value}fail}
ptr=131.111.10.206 ${lookup dnsdb{ptr=131.111.10.206}{$value}fail}
a6=xoanon.ipv6.test.ex ${lookup dnsdb {a6=xoanon.ipv6.test.ex}{$value}{fail}}
Index: 082
===================================================================
RCS file: /home/cvs/exim/exim-test-orig/AutoTest/stdout/082,v
retrieving revision 1.4
retrieving revision 1.5
diff -u -r1.4 -r1.5
--- 082 17 Nov 2004 16:12:26 -0000 1.4
+++ 082 19 Nov 2004 09:45:54 -0000 1.5
@@ -432,6 +432,7 @@
> a=localhost.test.ex 127.0.0.1
> cname=alias-xoanon.test.ex xoanon.test.ex
> ns=test.ex xoanon.csi.cam.ac.uk
+> zns=x.y.z.test.ex xoanon.csi.cam.ac.uk
> mx=mxt1.test.ex 5 xoanon.csi.cam.ac.uk
> ptr=131.111.10.206 xoanon.csi.cam.ac.uk
> Failed: lookup of "a6=xoanon.ipv6.test.ex" gave DEFER: unsupported DNS record type
Index: 353
===================================================================
RCS file: /home/cvs/exim/exim-test-orig/AutoTest/stdout/353,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- 353 8 Oct 2004 14:50:13 -0000 1.1
+++ 353 19 Nov 2004 09:45:54 -0000 1.2
@@ -26,12 +26,12 @@
250 myhost.test.ex Hello rhubarb.custard [10.0.0.1]
221 myhost.test.ex closing connection
-**** SMTP testing session as if from host 2002:c1ed:8229:10:202:2dff:fe07:a42a
+**** SMTP testing session as if from host 2002:c1ed:8229:0010:0202:2dff:fe07:a42a
**** but without any ident (RFC 1413) callback.
**** This is not for real!
220 myhost.test.ex ESMTP Exim x.yz Tue, 2 Mar 1999 09:44:33 +0000
-250-myhost.test.ex Hello [IPV6:2002:c1ed:8229:10:202:2dff:fe07:a42a] [2002:c1ed:8229:10:202:2dff:fe07:a42a]
+250-myhost.test.ex Hello [IPV6:2002:c1ed:8229:10:202:2dff:fe07:a42a] [2002:c1ed:8229:0010:0202:2dff:fe07:a42a]
250-SIZE 52428800
250-PIPELINING
250 HELP
