Changeset 59159 in vbox for trunk/src/VBox

Timestamp:

Dec 16, 2015 4:23:53 PM (9 years ago)

Author:

vboxsync

Message:

NAT: Host resolver - handle CNAME queries. When ANY query is received
for a CNAME, respond with just the CNAME, without A records, as per
RFC1034 section 3.6.2.

File:

• trunk/src/VBox/Devices/Network/slirp/hostres.c (modified) (3 diffs)

trunk/src/VBox/Devices/Network/slirp/hostres.c

@@ -399 +399 @@
 
     if (   qtype != Type_A
+        && qtype != Type_CNAME
         && qtype != Type_ANY)
     {
@@ -441 +442 @@
 #endif
 
+    /*
+     * Emit CNAME record if canonical name differs from the qname.
+     */
     if (   h->h_name != NULL
         && RTStrICmp(h->h_name, name) != 0)
@@ -462 +466 @@
             }
         }
+
+        /*
+         * rfc1034#section-3.6.2 - ... a type CNAME or * query should
+         * return just the CNAME.
+         */
+        if (qtype == Type_CNAME || qtype == Type_ANY)
+            goto out;
+    }
+    else if (qtype == Type_CNAME)
+    {
+        LogErr(("NAT: hostres: %s is already canonical\n", name));
+        goto out; /* NB: RCode_NoError without an answer, not RCode_NXDomain */
     }
 
     /*
-     * XXX: TODO: rfc1034#section-3.6.2
-     *
-     * If the query is Type_ANY and the name is CNAME, we should only
-     * return the CNAME, but not the A RRs.
+     * Emit A records.
      */
     for (i = 0; h->h_addr_list[i] != NULL; ++i)