Support more than 1024 IP/masks with indexed field

CHANGELOG.md

@@ -36,6 +36,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Bump `Netty` from 4.1.114.Final to 4.1.115.Final ([#16661](https://github.com/opensearch-project/OpenSearch/pull/16661))
 
 ### Changed
+- Indexed IP field supports `terms_query` with more than 1025 IP masks [#16391](https://github.com/opensearch-project/OpenSearch/pull/16391)
 
 ### Deprecated
 

server/src/internalClusterTest/java/org/opensearch/search/fields/SearchIpFieldTermsIT.java

@@ -0,0 +1,249 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.search.fields;
+
+import org.apache.lucene.search.IndexSearcher;
+import org.opensearch.action.bulk.BulkRequestBuilder;
+import org.opensearch.action.search.SearchPhaseExecutionException;
+import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.network.InetAddresses;
+import org.opensearch.common.xcontent.XContentFactory;
+import org.opensearch.core.xcontent.XContentBuilder;
+import org.opensearch.index.query.BoolQueryBuilder;
+import org.opensearch.index.query.QueryBuilders;
+import org.opensearch.index.query.TermsQueryBuilder;
+import org.opensearch.test.OpenSearchSingleNodeTestCase;
+import org.hamcrest.MatcherAssert;
+
+import java.io.IOException;
+import java.net.InetAddress;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.function.Consumer;
+
+import static org.opensearch.action.support.WriteRequest.RefreshPolicy.IMMEDIATE;
+import static org.hamcrest.Matchers.equalTo;
+
+public class SearchIpFieldTermsIT extends OpenSearchSingleNodeTestCase {
+
+    /**
+     * @return number of expected matches
+     * */
+    private int createIndex(String indexName, int numberOfMasks, List<String> queryTermsSink) throws IOException {
+        XContentBuilder xcb = createMapping();
+        client().admin().indices().prepareCreate(indexName).setMapping(xcb).get();
+        ensureGreen();
+
+        BulkRequestBuilder bulkRequestBuilder = client().prepareBulk();
+
+        Set<String> dedupeCidrs = new HashSet<>();
+        int cidrs = 0;
+        int ips = 0;
+
+        for (int i = 0; ips <= 10240 && cidrs < numberOfMasks && i < 1000000; i++) {
+            String ip;
+            int prefix;
+            boolean mask;
+            do {
+                mask = ips > 0 && random().nextBoolean();
+                ip = generateRandomIPv4();
+                prefix = 24 + random().nextInt(8); // CIDR prefix for IPv4
+            } while (mask && !dedupeCidrs.add(getFirstThreeOctets(ip)));
+
+            bulkRequestBuilder.add(
+                client().prepareIndex(indexName).setSource(Map.of("addr", ip, "dummy_filter", randomSubsetOf(1, "1", "2", "3")))
+            );
+
+            final String termToQuery;
+            if (mask) {
+                termToQuery = ip + "/" + prefix;
+                cidrs++;
+            } else {
+                termToQuery = ip;
+                ips++;
+            }
+            queryTermsSink.add(termToQuery);
+        }
+        int addMatches = 0;
+        for (int i = 0; i < atLeast(100); i++) {
+            final String ip;
+            ip = generateRandomIPv4();
+            bulkRequestBuilder.add(
+                client().prepareIndex(indexName).setSource(Map.of("addr", ip, "dummy_filter", randomSubsetOf(1, "1", "2", "3")))
+            );
+            boolean match = false;
+            for (String termQ : queryTermsSink) {
+                boolean isCidr = termQ.contains("/");
+                if ((isCidr && isIPInCIDR(ip, termQ)) || (!isCidr && termQ.equals(ip))) {
+                    match = true;
+                    break;
+                }
+            }
+            if (match) {
+                addMatches++;
+            } else {
+                break; // single mismatch is enough.
+            }
+        }
+
+        bulkRequestBuilder.setRefreshPolicy(IMMEDIATE).get();
+        return ips + cidrs + addMatches;
+    }
+
+    public void testLessThanMaxClauses() throws IOException {
+        ArrayList<String> toQuery = new ArrayList<>();
+        String indexName = "small";
+        int expectMatches = createIndex(indexName, IndexSearcher.getMaxClauseCount() - 1, toQuery);
+
+        assertTermsHitCount(indexName, "addr", toQuery, expectMatches);
+        assertTermsHitCount(indexName, "addr.idx", toQuery, expectMatches);
+        assertTermsHitCount(indexName, "addr.dv", toQuery, expectMatches);
+        // passing dummy filter crushes on rewriting
+        try {
+            assertTermsHitCount(
+                indexName,
+                "addr.dv",
+                toQuery,
+                expectMatches,
+                (boolBuilder) -> boolBuilder.filter(QueryBuilders.termsQuery("dummy_filter", "1", "2", "3"))
+                    .filter(QueryBuilders.termsQuery("dummy_filter", "1", "2", "3", "4"))
+                    .filter(QueryBuilders.termsQuery("dummy_filter", "1", "2", "3", "4", "5"))
+            );
+            fail();
+        } catch (SearchPhaseExecutionException ose) {
+            assertTrue("exceeding on query rewrite", ose.shardFailures()[0].getCause() instanceof IndexSearcher.TooManyNestedClauses);
+        }
+    }
+
+    public void testExceedMaxClauses() throws IOException {
+        ArrayList<String> toQuery = new ArrayList<>();
+        String indexName = "larger";
+        int expectMatches = createIndex(indexName, IndexSearcher.getMaxClauseCount() + (rarely() ? 0 : atLeast(10)), toQuery);
+        assertTermsHitCount(indexName, "addr", toQuery, expectMatches);
+        assertTermsHitCount(indexName, "addr.idx", toQuery, expectMatches);
+        try { // error from mapper/parser
+            final SearchPhaseExecutionException ose = assertThrows(
+                SearchPhaseExecutionException.class,
+                () -> assertTermsHitCount(indexName, "addr.dv", toQuery, expectMatches)
+            );
+            assertTrue("exceeding on query building", ose.shardFailures()[0].getCause().getCause() instanceof IndexSearcher.TooManyClauses);
+            fail();
+        } catch (SearchPhaseExecutionException ose) {
+            assertTrue("exceeding on query building", ose.shardFailures()[0].getCause().getCause() instanceof IndexSearcher.TooManyClauses);
+        }
+    }
+
+    private static String getFirstThreeOctets(String ipAddress) {
+        // Split the IP address by the dot delimiter
+        String[] octets = ipAddress.split("\\.");
+
+        // Take the first three octets
+        String[] firstThreeOctets = new String[3];
+        System.arraycopy(octets, 0, firstThreeOctets, 0, 3);
+
+        // Join the first three octets back together with dots
+        return String.join(".", firstThreeOctets);
+    }
+
+    private void assertTermsHitCount(String indexName, String field, Collection<String> toQuery, long expectedMatches) {
+        assertTermsHitCount(indexName, field, toQuery, expectedMatches, (bqb) -> {});
+    }
+
+    private void assertTermsHitCount(
+        String indexName,
+        String field,
+        Collection<String> toQuery,
+        long expectedMatches,
+        Consumer<BoolQueryBuilder> addFilter
+    ) {
+        TermsQueryBuilder ipTerms = QueryBuilders.termsQuery(field, new ArrayList<>(toQuery));
+        BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
+        addFilter.accept(boolQueryBuilder);
+        SearchResponse result = client().prepareSearch(indexName).setQuery(boolQueryBuilder.must(ipTerms)
+        // .filter(QueryBuilders.termsQuery("dummy_filter", "a", "b"))
+        ).get();
+        long hitsFound = Objects.requireNonNull(result.getHits().getTotalHits()).value;
+        MatcherAssert.assertThat(field, hitsFound, equalTo(expectedMatches));
+    }
+
+    // Converts an IP string (either IPv4 or IPv6) to a byte array
+    private static byte[] ipToBytes(String ip) {
+        InetAddress inetAddress = InetAddresses.forString(ip);
+        return inetAddress.getAddress();
+    }
+
+    // Checks if an IP is within a given CIDR (works for both IPv4 and IPv6)
+    private static boolean isIPInCIDR(String ip, String cidr) {
+        String[] cidrParts = cidr.split("/");
+        String cidrIp = cidrParts[0];
+        int prefixLength = Integer.parseInt(cidrParts[1]);
+
+        byte[] ipBytes = ipToBytes(ip);
+        byte[] cidrIpBytes = ipToBytes(cidrIp);
+
+        // Calculate how many full bytes and how many bits are in the mask
+        int fullBytes = prefixLength / 8;
+        int extraBits = prefixLength % 8;
+
+        // Compare full bytes
+        for (int i = 0; i < fullBytes; i++) {
+            if (ipBytes[i] != cidrIpBytes[i]) {
+                return false;
+            }
+        }
+
+        // Compare extra bits (if any)
+        if (extraBits > 0) {
+            int mask = 0xFF << (8 - extraBits);
+            return (ipBytes[fullBytes] & mask) == (cidrIpBytes[fullBytes] & mask);
+        }
+
+        return true;
+    }
+
+    // Generate a random IPv4 address
+    private String generateRandomIPv4() {
+        return String.join(
+            ".",
+            String.valueOf(random().nextInt(256)),
+            String.valueOf(random().nextInt(256)),
+            String.valueOf(random().nextInt(256)),
+            String.valueOf(random().nextInt(256))
+        );
+    }
+
+    private XContentBuilder createMapping() throws IOException {
+        return XContentFactory.jsonBuilder()
+            .startObject()
+            .startObject("properties")
+            .startObject("addr")
+            .field("type", "ip")
+            .startObject("fields")
+            .startObject("idx")
+            .field("type", "ip")
+            .field("doc_values", false)
+            .endObject()
+            .startObject("dv")
+            .field("type", "ip")
+            .field("index", false)
+            .endObject()
+            .endObject()
+            .endObject()
+            .startObject("dummy_filter")
+            .field("type", "keyword")
+            .endObject()
+            .endObject()
+            .endObject();
+    }
+}