/**
* Looks up Records in the Zone. This follows CNAMEs and wildcards.
*
* @param name The name to look up
* @param type The type to look up
* @return A SetResponse object
* @see SetResponse
*/
public SetResponse findRecords(Name name, short type) {
SetResponse zr = null;
Object o = findSets(name, type);
if (o == null) {
/* The name does not exist */
if (name.isWild()) return SetResponse.ofType(SetResponse.NXDOMAIN);
int labels = name.labels() - origin.labels();
if (labels == 0) return SetResponse.ofType(SetResponse.NXDOMAIN);
if (hasWild) {
SetResponse sr;
Name tname = name;
do {
sr = findRecords(tname.wild(1), type);
if (!sr.isNXDOMAIN()) return sr;
tname = new Name(tname, 1);
} while (labels-- >= 1);
return sr;
} else return SetResponse.ofType(SetResponse.NXDOMAIN);
}
if (o instanceof TypeMap) {
/* The name exists but the type does not. */
return SetResponse.ofType(SetResponse.NXRRSET);
}
Object[] objects;
RRset rrset;
if (o instanceof RRset) {
objects = null;
rrset = (RRset) o;
} else {
objects = (Object[]) o;
rrset = (RRset) objects[0];
}
if (name.equals(rrset.getName())) {
if (type != Type.CNAME && type != Type.ANY && rrset.getType() == Type.CNAME)
zr = new SetResponse(SetResponse.CNAME, rrset);
else if (rrset.getType() == Type.NS && !name.equals(origin))
zr = new SetResponse(SetResponse.DELEGATION, rrset);
else {
zr = new SetResponse(SetResponse.SUCCESSFUL);
zr.addRRset(rrset);
if (objects != null) {
for (int i = 1; i < objects.length; i++) zr.addRRset((RRset) objects[i]);
}
}
} else {
if (rrset.getType() == Type.CNAME) return SetResponse.ofType(SetResponse.NXDOMAIN);
else if (rrset.getType() == Type.DNAME) {
zr = new SetResponse(SetResponse.DNAME, rrset);
} else if (rrset.getType() == Type.NS) {
zr = new SetResponse(SetResponse.DELEGATION, rrset);
}
}
return zr;
}
/**
* Looks up Records in the Cache. This follows CNAMEs and handles negatively cached data.
*
* @param name The name to look up
* @param type The type to look up
* @param minCred The minimum acceptable credibility
* @return A SetResponse object
* @see SetResponse
* @see Credibility
*/
public SetResponse lookupRecords(Name name, short type, byte minCred) {
SetResponse cr = null;
boolean verbose = Options.check("verbosecache");
Object o = lookup(name, type);
if (verbose) logLookup(name, type, "Starting");
if (o == null || o == NXRRSET) {
/*
* The name exists, but the type was not found. Or, the
* name does not exist and no parent does either. Punt.
*/
if (verbose) logLookup(name, type, "no information found");
return SetResponse.ofType(SetResponse.UNKNOWN);
}
Object[] objects;
if (o instanceof Element) objects = new Object[] {o};
else objects = (Object[]) o;
int nelements = 0;
for (int i = 0; i < objects.length; i++) {
Element element = (Element) objects[i];
if (element.expired()) {
if (verbose) {
logLookup(name, type, element.toString());
logLookup(name, type, "expired: ignoring");
}
removeSet(name, type, element);
objects[i] = null;
} else if (element.credibility < minCred) {
if (verbose) {
logLookup(name, type, element.toString());
logLookup(name, type, "not credible: ignoring");
}
objects[i] = null;
} else {
nelements++;
}
}
if (nelements == 0) {
/* We have data, but can't use it. Punt. */
if (verbose) logLookup(name, type, "no useful data found");
return SetResponse.ofType(SetResponse.UNKNOWN);
}
/*
* We have something at the name. It could be the answer,
* a CNAME, DNAME, or NS, or a negative cache entry.
*
* Ignore wildcards, since it's pretty unlikely that any will be
* cached. The occasional extra query is easily balanced by the
* reduced number of lookups.
*/
for (int i = 0; i < objects.length; i++) {
if (objects[i] == null) continue;
Element element = (Element) objects[i];
if (verbose) logLookup(name, type, element.toString());
RRset rrset = null;
if (element instanceof PositiveElement) rrset = ((PositiveElement) element).rrset;
/* Is this a negatively cached entry? */
if (rrset == null) {
/*
* If this is an NXDOMAIN entry, return NXDOMAIN.
*/
if (element.getType() == 0) {
if (verbose) logLookup(name, type, "NXDOMAIN");
return SetResponse.ofType(SetResponse.NXDOMAIN);
}
/*
* If we're not looking for type ANY, return NXRRSET.
* Otherwise ignore this.
*/
if (type != Type.ANY) {
if (verbose) logLookup(name, type, "NXRRSET");
return SetResponse.ofType(SetResponse.NXRRSET);
} else {
if (verbose) logLookup(name, type, "ANY query; " + "ignoring NXRRSET");
continue;
}
}
short rtype = rrset.getType();
Name rname = rrset.getName();
if (name.equals(rname)) {
if (type != Type.CNAME && type != Type.ANY && rtype == Type.CNAME) {
if (verbose) logLookup(name, type, "cname");
return new SetResponse(SetResponse.CNAME, rrset);
} else if (type != Type.NS && type != Type.ANY && rtype == Type.NS) {
if (verbose) logLookup(name, type, "exact delegation");
return new SetResponse(SetResponse.DELEGATION, rrset);
} else {
if (verbose) logLookup(name, type, "exact match");
if (cr == null) cr = new SetResponse(SetResponse.SUCCESSFUL);
cr.addRRset(rrset);
}
} else if (name.subdomain(rname)) {
if (rtype == Type.DNAME) {
if (verbose) logLookup(name, type, "dname");
return new SetResponse(SetResponse.DNAME, rrset);
} else if (rtype == Type.NS) {
if (verbose) logLookup(name, type, "parent delegation");
return new SetResponse(SetResponse.DELEGATION, rrset);
} else {
if (verbose)
logLookup(name, type, "ignoring rrset (" + rname + " " + Type.string(rtype) + ")");
}
} else {
if (verbose)
logLookup(name, type, "ignoring rrset (" + rname + " " + Type.string(rtype) + ")");
}
}
/*
* As far as I can tell, the only legitimate time cr will be null is
* if we queried for ANY and only saw negative responses, but not an
* NXDOMAIN. Return UNKNOWN.
*/
if (cr == null && type == Type.ANY) return SetResponse.ofType(SetResponse.UNKNOWN);
else if (cr == null)
throw new IllegalStateException(
"looking up (" + name + " " + Type.string(type) + "): " + "cr == null.");
return cr;
}
private RRset[] findRecords(Name name, short type, byte minCred) {
SetResponse cr = lookupRecords(name, type, minCred);
if (cr.isSuccessful()) return cr.answers();
else return null;
}
private synchronized SetResponse lookup(Name name, int type) {
int labels;
int olabels;
int tlabels;
RRset rrset;
Name tname;
Object types;
SetResponse sr;
if (!name.subdomain(origin)) return SetResponse.ofType(SetResponse.NXDOMAIN);
labels = name.labels();
olabels = origin.labels();
for (tlabels = olabels; tlabels <= labels; tlabels++) {
boolean isOrigin = (tlabels == olabels);
boolean isExact = (tlabels == labels);
if (isOrigin) tname = origin;
else if (isExact) tname = name;
else tname = new Name(name, labels - tlabels);
types = exactName(tname);
if (types == null) continue;
/* If this is a delegation, return that. */
if (!isOrigin) {
RRset ns = oneRRset(types, Type.NS);
if (ns != null) return new SetResponse(SetResponse.DELEGATION, ns);
}
/* If this is an ANY lookup, return everything. */
if (isExact && type == Type.ANY) {
sr = new SetResponse(SetResponse.SUCCESSFUL);
RRset[] sets = allRRsets(types);
for (int i = 0; i < sets.length; i++) sr.addRRset(sets[i]);
return sr;
}
/*
* If this is the name, look for the actual type or a CNAME.
* Otherwise, look for a DNAME.
*/
if (isExact) {
rrset = oneRRset(types, type);
if (rrset != null) {
sr = new SetResponse(SetResponse.SUCCESSFUL);
sr.addRRset(rrset);
return sr;
}
rrset = oneRRset(types, Type.CNAME);
if (rrset != null) return new SetResponse(SetResponse.CNAME, rrset);
} else {
rrset = oneRRset(types, Type.DNAME);
if (rrset != null) return new SetResponse(SetResponse.DNAME, rrset);
}
/* We found the name, but not the type. */
if (isExact) return SetResponse.ofType(SetResponse.NXRRSET);
}
if (hasWild) {
for (int i = 0; i < labels - olabels; i++) {
tname = name.wild(i + 1);
types = exactName(tname);
if (types == null) continue;
rrset = oneRRset(types, type);
if (rrset != null) {
sr = new SetResponse(SetResponse.SUCCESSFUL);
sr.addRRset(rrset);
return sr;
}
}
}
return SetResponse.ofType(SetResponse.NXDOMAIN);
}