fixed infinite loop bug when Sqlite3DataSrc::findClosest() failed

(a regression of rev1222).

refactored findClosest() to avoid having a character-by-character loop,
which is error prone.  this may make the code a bit slower, but IMO accuracy
and better understandability are more important in this stage.

added a test case that rev1222 seemingly tried to address.


git-svn-id: svn://bind10.isc.org/svn/bind10/trunk@1228 e5f2f494-b856-4b98-b285-d166d9295462

src/lib/auth/data_source_sqlite3.cc

@@ -185,10 +185,15 @@ Sqlite3DataSrc::findRecords(const Name& name, const RRType& rdtype,
                             RRsetList& target, const Name* zonename,
                             const Mode mode, uint32_t& flags) const
 {
-    const string s_name = name.toText();
-    const char* const c_name = s_name.c_str();
-    sqlite3_stmt* query;
+    flags = 0;
+    int zone_id = (zonename == NULL) ? findClosest(name, NULL) :
+        findClosest(*zonename, NULL);
+    if (zone_id < 0) {
+        flags = NO_SUCH_ZONE;
+        return (0);
+    }
 
+    sqlite3_stmt* query;
     switch (mode) {
     case ADDRESS:
         query = q_addrs;
@@ -204,15 +209,6 @@ Sqlite3DataSrc::findRecords(const Name& name, const RRType& rdtype,
         }
         break;
     }
-
-    flags = 0;
-
-    int zone_id = (zonename == NULL) ? findClosest(c_name, NULL) :
-        findClosest(zonename->toText().c_str(), NULL);
-    if (zone_id < 0) {
-        flags = NO_SUCH_ZONE;
-        return (0);
-    }
     
     sqlite3_reset(query);
     sqlite3_clear_bindings(query);
@@ -222,7 +218,8 @@ Sqlite3DataSrc::findRecords(const Name& name, const RRType& rdtype,
     if (rc != SQLITE_OK) {
         throw("Could not bind 1 (query)");
     }
-    rc = sqlite3_bind_text(query, 2, c_name, -1, SQLITE_STATIC);
+    const string s_name = name.toText();
+    rc = sqlite3_bind_text(query, 2, s_name.c_str(), -1, SQLITE_STATIC);
     if (rc != SQLITE_OK) {
         throw("Could not bind 2 (query)");
     }
@@ -282,30 +279,23 @@ Sqlite3DataSrc::findRecords(const Name& name, const RRType& rdtype,
 //  longest match found.
 //
 int
-Sqlite3DataSrc::findClosest(const char* const name,
-                            const char** position) const
-{
-    const char* current = name;
-
-    while (*current != 0) {
-        const int rc = hasExactZone(current);
+Sqlite3DataSrc::findClosest(const Name& name, unsigned int* position) const {
+    const unsigned int nlabels = name.getLabelCount();
+    for (unsigned int i = 0; i < nlabels; ++i) {
+        Name matchname(name.split(i, nlabels - i));
+        const int rc = hasExactZone(matchname.toText().c_str());
         if (rc >= 0) {
             if (position != NULL) {
-                *position = current;
+                *position = i;
             }
             return (rc);
         }
-        while (*current != '.' && *current != 0) {
-            ++current;
-        }
-        if (*current == '.' && *(current + 1) != '\0') {
-            ++current;
-        }
     }
 
     return (-1);
 }
 
+
 void
 Sqlite3DataSrc::loadVersion(void) {
     sqlite3_stmt* prepared = prepare("SELECT version FROM schema_version");
@@ -498,18 +488,20 @@ Sqlite3DataSrc::init(const isc::data::ElementPtr config) {
 
 void
 Sqlite3DataSrc::findClosestEnclosure(NameMatch& match,
-                                     const RRClass& qclass) const {
-    const char* position = NULL;
-    
+                                     const RRClass& qclass) const
+{
     if (qclass != getClass()) {
         return;
     }
 
-    if (findClosest(match.qname().toText().c_str(), &position) == -1) {
+    unsigned int position;
+    if (findClosest(match.qname(), &position) == -1) {
         return;
     }
 
-    match.update(*this, Name(position));
+    match.update(*this, match.qname().split(position,
+                                            match.qname().getLabelCount() -
+                                            position));
 }
 
 DataSrc::Result
@@ -519,8 +511,8 @@ Sqlite3DataSrc::findPreviousName(const Query& q,
                                  const Name* zonename) const
 {
     int zone_id = (zonename == NULL) ?
-        findClosest(qname.toText().c_str(), NULL) :
-        findClosest(zonename->toText().c_str(), NULL);
+        findClosest(qname, NULL) :
+        findClosest(*zonename, NULL);
 
     if (zone_id < 0) {
         return (ERROR);
@@ -557,7 +549,7 @@ Sqlite3DataSrc::findCoveringNSEC3(const Query& q,
                                   string& hashstr,
                                   RRsetList& target) const
 {
-    int zone_id = findClosest(zonename.toText().c_str(), NULL);
+    int zone_id = findClosest(zonename, NULL);
     if (zone_id < 0) {
         return (ERROR);
     }

src/lib/auth/data_source_sqlite3.h

@@ -121,7 +121,7 @@ private:
     int findRecords(const isc::dns::Name& name, const isc::dns::RRType& rdtype,
                     isc::dns::RRsetList& target, const isc::dns::Name* zonename,
                     const Mode mode, uint32_t& flags) const;
-    int findClosest(const char *name, const char **position) const;
+    int findClosest(const isc::dns::Name& name, unsigned int* position) const;
     void loadVersion(void);
     void setupPreparedStatements(void);
     void execSetupQuery(const char *query);

src/lib/auth/data_source_sqlite3_unittest.cc

@@ -46,7 +46,9 @@ static ElementPtr SQLITE_DBFILE_EXAMPLE = Element::createFromString(
                      "{ \"database_file\": \"testdata/test.sqlite3\"}");
 static ElementPtr SQLITE_DBFILE_EXAMPLE2 = Element::createFromString(
                      "{ \"database_file\": \"testdata/test2.sqlite3\"}");
-// The following file must be non existent and mutt be "creatable";
+static ElementPtr SQLITE_DBFILE_EXAMPLE_ROOT = Element::createFromString(
+                     "{ \"database_file\": \"testdata/test-root.sqlite3\"}");
+// The following file must be non existent and must be non"creatable";
 // the sqlite3 library will try to create a new DB file if it doesn't exist,
 // so to test a failure case the create operation should also fail.
 // The "nodir", a non existent directory, is inserted for this purpose.
@@ -342,9 +344,9 @@ checkFind(FindMode mode, const Sqlite3DataSrc& data_source, const Query& query,
     answers.push_back(&expected_data);
     signatures.push_back(expected_sig_data);
 
-    checkFind(mode, data_source, query, expected_name, zone_name, expected_class,
-              expected_type, ttls, expected_flags, types, answers,
-              signatures);
+    checkFind(mode, data_source, query, expected_name, zone_name,
+              expected_class, expected_type, ttls, expected_flags, types,
+              answers, signatures);
 }
 
 TEST_F(Sqlite3DataSourceTest, close) {
@@ -355,7 +357,6 @@ TEST_F(Sqlite3DataSourceTest, reOpen) {
     // Replace the data with a totally different zone.  This should succeed,
     // and shouldn't match any names in the previously managed domains.
     EXPECT_EQ(DataSrc::SUCCESS, data_source.close());
-
     EXPECT_EQ(DataSrc::SUCCESS, data_source.init(SQLITE_DBFILE_EXAMPLE2));
 
     NameMatch name_match(www_name);
@@ -371,23 +372,33 @@ TEST_F(Sqlite3DataSourceTest, openFail) {
 
 TEST_F(Sqlite3DataSourceTest, findClosestEnclosure) {
     NameMatch name_match(www_name);
-    data_source.findClosestEnclosure(name_match, RRClass::IN());
+    data_source.findClosestEnclosure(name_match, rrclass);
     EXPECT_EQ(zone_name, *name_match.closestName());
     EXPECT_EQ(&data_source, name_match.bestDataSrc());
 }
 
+TEST_F(Sqlite3DataSourceTest, findClosestEnclosureMatchRoot) {
+    EXPECT_EQ(DataSrc::SUCCESS, data_source.close());
+    EXPECT_EQ(DataSrc::SUCCESS, data_source.init(SQLITE_DBFILE_EXAMPLE_ROOT));
+
+    NameMatch name_match(Name("org."));
+    data_source.findClosestEnclosure(name_match, rrclass);
+    EXPECT_EQ(Name("."), *name_match.closestName());
+    EXPECT_EQ(&data_source, name_match.bestDataSrc());
+}
+
 TEST_F(Sqlite3DataSourceTest, findClosestEnclosureAtDelegation) {
     // The search name exists both in the parent and child zones, but
     // child has a better match.
     NameMatch name_match(child_name);
-    data_source.findClosestEnclosure(name_match, RRClass::IN());
+    data_source.findClosestEnclosure(name_match, rrclass);
     EXPECT_EQ(child_name, *name_match.closestName());
     EXPECT_EQ(&data_source, name_match.bestDataSrc());
 }
 
 TEST_F(Sqlite3DataSourceTest, findClosestEnclosureNoMatch) {
     NameMatch name_match(nomatch_name);
-    data_source.findClosestEnclosure(name_match, RRClass::IN());
+    data_source.findClosestEnclosure(name_match, rrclass);
     EXPECT_EQ(NULL, name_match.closestName());
     EXPECT_EQ(NULL, name_match.bestDataSrc());
 }

src/lib/auth/testdata/root.zone

@@ -0,0 +1,36 @@
+.			86400	IN	SOA	a.root-servers.net. nstld.verisign-grs.com. 2010030802 1800 900 604800 86400
+
+.			518400	IN	NS	a.root-servers.net.
+.			518400	IN	NS	e.root-servers.net.
+.			518400	IN	NS	g.root-servers.net.
+.			518400	IN	NS	l.root-servers.net.
+.			518400	IN	NS	f.root-servers.net.
+.			518400	IN	NS	k.root-servers.net.
+.			518400	IN	NS	m.root-servers.net.
+.			518400	IN	NS	d.root-servers.net.
+.			518400	IN	NS	h.root-servers.net.
+.			518400	IN	NS	c.root-servers.net.
+.			518400	IN	NS	b.root-servers.net.
+.			518400	IN	NS	i.root-servers.net.
+.			518400	IN	NS	j.root-servers.net.
+
+a.root-servers.net.	3600000	IN	A	198.41.0.4
+a.root-servers.net.	3600000	IN	AAAA	2001:503:ba3e::2:30
+b.root-servers.net.	3600000	IN	A	192.228.79.201
+c.root-servers.net.	3600000	IN	A	192.33.4.12
+d.root-servers.net.	3600000	IN	A	128.8.10.90
+e.root-servers.net.	3600000	IN	A	192.203.230.10
+f.root-servers.net.	3600000	IN	A	192.5.5.241
+f.root-servers.net.	3600000	IN	AAAA	2001:500:2f::f
+g.root-servers.net.	3600000	IN	A	192.112.36.4
+h.root-servers.net.	3600000	IN	A	128.63.2.53
+h.root-servers.net.	3600000	IN	AAAA	2001:500:1::803f:235
+i.root-servers.net.	3600000	IN	A	192.36.148.17
+j.root-servers.net.	3600000	IN	A	192.58.128.30
+j.root-servers.net.	3600000	IN	AAAA	2001:503:c27::2:30
+k.root-servers.net.	3600000	IN	A	193.0.14.129
+k.root-servers.net.	3600000	IN	AAAA	2001:7fd::1
+l.root-servers.net.	3600000	IN	A	199.7.83.42
+l.root-servers.net.	3600000	IN	AAAA	2001:500:3::42
+m.root-servers.net.	3600000	IN	A	202.12.27.33
+m.root-servers.net.	3600000	IN	AAAA	2001:dc3::35