ESQL: TO_IP can handle leading zeros (elastic#126532)

Modifies TO_IP so it can handle leading `0`s in ipv4s. Here's how it
works now:
```
ROW ip = TO_IP("192.168.0.1") // OK!
ROW ip = TO_IP("192.168.010.1") // Fails
```

This adds
```
ROW ip = TO_IP("192.168.010.1", {"leading_zeros": "octal"})
ROW ip = TO_IP("192.168.010.1", {"leading_zeros": "decimal"})
```

We do this because there isn't a consensus on how to parse leading zeros
in ipv4s. The standard unix tools like `ping` and `ftp` interpret
leading zeros as octal. Java's built in ip parsing interprets them as
decimal. Because folks are using this for security rules we need to
support all the choices.

Closes elastic#125460

Author: nik9000

docs/changelog/126532.yaml

@@ -0,0 +1,6 @@
+pr: 126532
+summary: TO_IP can handle leading zeros
+area: ES|QL
+type: bug
+issues:
+ - 125460

x-pack/plugin/esql/qa/testFixtures/src/main/java/org/elasticsearch/xpack/esql/CsvTestsDataLoader.java

@@ -120,6 +120,7 @@ public class CsvTestsDataLoader {
     private static final TestDataset ADDRESSES = new TestDataset("addresses");
     private static final TestDataset BOOKS = new TestDataset("books").withSetting("books-settings.json");
     private static final TestDataset SEMANTIC_TEXT = new TestDataset("semantic_text").withInferenceEndpoint(true);
+    private static final TestDataset LOGS = new TestDataset("logs");
     private static final TestDataset MV_TEXT = new TestDataset("mv_text");
     private static final TestDataset DENSE_VECTOR = new TestDataset("dense_vector");
     private static final TestDataset COLORS = new TestDataset("colors");
@@ -172,6 +173,7 @@ public class CsvTestsDataLoader {
         Map.entry(ADDRESSES.indexName, ADDRESSES),
         Map.entry(BOOKS.indexName, BOOKS),
         Map.entry(SEMANTIC_TEXT.indexName, SEMANTIC_TEXT),
+        Map.entry(LOGS.indexName, LOGS),
         Map.entry(MV_TEXT.indexName, MV_TEXT),
         Map.entry(DENSE_VECTOR.indexName, DENSE_VECTOR),
         Map.entry(COLORS.indexName, COLORS)

x-pack/plugin/esql/qa/testFixtures/src/main/resources/data/logs.csv

@@ -0,0 +1,5 @@
+@timestamp:date         ,system:keyword,message:keyword
+2023-10-23T13:55:01.543Z,          ping,Pinging 192.168.86.046
+2023-10-23T13:55:01.544Z,          cron,Running cats
+2023-10-23T13:55:01.545Z,          java,Doing java stuff for 192.168.86.038
+2023-10-23T13:55:01.546Z,          java,More java stuff

x-pack/plugin/esql/qa/testFixtures/src/main/resources/ip.csv-spec

@@ -282,6 +282,86 @@ str1:keyword |str2:keyword |ip1:ip  |ip2:ip
 // end::to_ip-result[]
 ;
 
+convertFromStringLeadingZerosDecimal
+required_capability: to_ip_leading_zeros
+// tag::to_ip_leading_zeros_decimal[]
+ROW s = "1.1.010.1" | EVAL ip = TO_IP(s, {"leading_zeros":"decimal"})
+// end::to_ip_leading_zeros_decimal[]
+;
+
+// tag::to_ip_leading_zeros_decimal-result[]
+s:keyword | ip:ip
+1.1.010.1 | 1.1.10.1
+// end::to_ip_leading_zeros_decimal-result[]
+;
+
+convertFromStringLeadingZerosOctal
+required_capability: to_ip_leading_zeros
+// tag::to_ip_leading_zeros_octal[]
+ROW s = "1.1.010.1" | EVAL ip = TO_IP(s, {"leading_zeros":"octal"})
+// end::to_ip_leading_zeros_octal[]
+;
+
+// tag::to_ip_leading_zeros_octal-result[]
+s:keyword | ip:ip
+1.1.010.1 | 1.1.8.1
+// end::to_ip_leading_zeros_octal-result[]
+;
+
+convertFromStringFancy
+required_capability: to_ip_leading_zeros
+FROM logs
+| KEEP @timestamp, system, message
+| EVAL client = CASE(
+    system == "ping",
+        TO_IP(REPLACE(message, "Pinging ", ""), {"leading_zeros": "octal"}),
+    system == "java" AND STARTS_WITH(message, "Doing java stuff for "),
+        TO_IP(REPLACE(message, "Doing java stuff for ", ""), {"leading_zeros": "decimal"}))
+| SORT @timestamp
+| LIMIT 4
+;
+
+@timestamp:date         |system:keyword|message:keyword                    |client:ip
+2023-10-23T13:55:01.543Z|          ping|Pinging 192.168.86.046             |192.168.86.38
+2023-10-23T13:55:01.544Z|          cron|Running cats                       |null
+2023-10-23T13:55:01.545Z|          java|Doing java stuff for 192.168.86.038|192.168.86.38
+2023-10-23T13:55:01.546Z|          java|More java stuff                    |null
+;
+
+toIpInAgg
+ROW s = "1.1.1.1" | STATS COUNT(*) BY ip = TO_IP(s)
+;
+
+COUNT(*):long | ip:ip
+            1 | 1.1.1.1
+;
+
+toIpInSort
+ROW s = "1.1.1.1" | SORT TO_IP(s)
+;
+
+s:keyword
+1.1.1.1
+;
+
+toIpInAggOctal
+required_capability: to_ip_leading_zeros
+ROW s = "1.1.010.1" | STATS COUNT(*) BY ip = TO_IP(s, {"leading_zeros":"octal"})
+;
+
+COUNT(*):long | ip:ip
+            1 | 1.1.8.1
+;
+
+toIpInSortOctal
+required_capability: to_ip_leading_zeros
+ROW s = "1.1.010.1" | SORT TO_IP(s, {"leading_zeros":"octal"})
+;
+
+s:keyword
+1.1.010.1
+;
+
 cdirMatchOrsIPs
 required_capability: combine_disjunctive_cidrmatches
 

x-pack/plugin/esql/qa/testFixtures/src/main/resources/mapping-logs.json

@@ -0,0 +1,13 @@
+{
+    "properties" : {
+        "@timestamp" : {
+            "type" : "date"
+        },
+        "system" : {
+          "type" : "keyword"
+        },
+        "message" : {
+            "type" : "keyword"
+        }
+    }
+}

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/action/EsqlCapabilities.java

@@ -887,6 +887,11 @@ public enum Cap {
          */
         TO_LOWER_MV,
 
+        /**
+         * Support for the {@code leading_zeros} named parameter.
+         */
+        TO_IP_LEADING_ZEROS,
+
         /**
          * Resolve groupings before resolving references to groupings in the aggregations.
          */

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/analysis/Analyzer.java

@@ -56,6 +56,7 @@
 import org.elasticsearch.xpack.esql.expression.function.scalar.conditional.Greatest;
 import org.elasticsearch.xpack.esql.expression.function.scalar.conditional.Least;
 import org.elasticsearch.xpack.esql.expression.function.scalar.convert.AbstractConvertFunction;
+import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ConvertFunction;
 import org.elasticsearch.xpack.esql.expression.function.scalar.convert.FoldablesConvertFunction;
 import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToDateNanos;
 import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToDouble;
@@ -70,6 +71,7 @@
 import org.elasticsearch.xpack.esql.index.EsIndex;
 import org.elasticsearch.xpack.esql.index.IndexResolution;
 import org.elasticsearch.xpack.esql.inference.ResolvedInference;
+import org.elasticsearch.xpack.esql.optimizer.rules.logical.SubstituteSurrogateExpressions;
 import org.elasticsearch.xpack.esql.parser.ParsingException;
 import org.elasticsearch.xpack.esql.plan.IndexPattern;
 import org.elasticsearch.xpack.esql.plan.logical.Aggregate;
@@ -1450,10 +1452,12 @@ private LogicalPlan doRule(LogicalPlan plan) {
             int alreadyAddedUnionFieldAttributes = unionFieldAttributes.size();
             // See if the eval function has an unresolved MultiTypeEsField field
             // Replace the entire convert function with a new FieldAttribute (containing type conversion knowledge)
-            plan = plan.transformExpressionsOnly(
-                AbstractConvertFunction.class,
-                convert -> resolveConvertFunction(convert, unionFieldAttributes)
-            );
+            plan = plan.transformExpressionsOnly(e -> {
+                if (e instanceof ConvertFunction convert) {
+                    return resolveConvertFunction(convert, unionFieldAttributes);
+                }
+                return e;
+            });
             // If no union fields were generated, return the plan as is
             if (unionFieldAttributes.size() == alreadyAddedUnionFieldAttributes) {
                 return plan;
@@ -1484,7 +1488,8 @@ private LogicalPlan doRule(LogicalPlan plan) {
             return plan;
         }
 
-        private Expression resolveConvertFunction(AbstractConvertFunction convert, List<FieldAttribute> unionFieldAttributes) {
+        private Expression resolveConvertFunction(ConvertFunction convert, List<FieldAttribute> unionFieldAttributes) {
+            Expression convertExpression = (Expression) convert;
             if (convert.field() instanceof FieldAttribute fa && fa.field() instanceof InvalidMappedField imf) {
                 HashMap<TypeResolutionKey, Expression> typeResolutions = new HashMap<>();
                 Set<DataType> supportedTypes = convert.supportedTypes();
@@ -1517,7 +1522,7 @@ private Expression resolveConvertFunction(AbstractConvertFunction convert, List<
                     // example, an expression like multiTypeEsField(synthetic=false, date_nanos)::date_nanos::datetime is rewritten to
                     // multiTypeEsField(synthetic=true, date_nanos)::datetime, the implicit casting is overwritten by explicit casting and
                     // the multiTypeEsField is not casted to datetime directly.
-                    if (convert.dataType() == mtf.getDataType()) {
+                    if (((Expression) convert).dataType() == mtf.getDataType()) {
                         return createIfDoesNotAlreadyExist(fa, mtf, unionFieldAttributes);
                     }
 
@@ -1531,21 +1536,23 @@ private Expression resolveConvertFunction(AbstractConvertFunction convert, List<
                             String indexName = entry.getKey();
                             AbstractConvertFunction originalConversionFunction = (AbstractConvertFunction) entry.getValue();
                             Expression originalField = originalConversionFunction.field();
-                            Expression newConvertFunction = convert.replaceChildren(Collections.singletonList(originalField));
+                            Expression newConvertFunction = convertExpression.replaceChildren(Collections.singletonList(originalField));
                             indexToConversionExpressions.put(indexName, newConvertFunction);
                         }
                         MultiTypeEsField multiTypeEsField = new MultiTypeEsField(
                             fa.fieldName().string(),
-                            convert.dataType(),
+                            convertExpression.dataType(),
                             false,
                             indexToConversionExpressions
                         );
                         return createIfDoesNotAlreadyExist(fa, multiTypeEsField, unionFieldAttributes);
                     }
                 } else if (convert.field() instanceof AbstractConvertFunction subConvert) {
-                    return convert.replaceChildren(Collections.singletonList(resolveConvertFunction(subConvert, unionFieldAttributes)));
+                    return convertExpression.replaceChildren(
+                        Collections.singletonList(resolveConvertFunction(subConvert, unionFieldAttributes))
+                    );
                 }
-            return convert;
+            return convertExpression;
         }
 
         private Expression createIfDoesNotAlreadyExist(
@@ -1594,12 +1601,7 @@ private static boolean canConvertOriginalTypes(MultiTypeEsField multiTypeEsField
                 );
         }
 
-        private static Expression typeSpecificConvert(
-            AbstractConvertFunction convert,
-            Source source,
-            DataType type,
-            InvalidMappedField mtf
-        ) {
+        private static Expression typeSpecificConvert(ConvertFunction convert, Source source, DataType type, InvalidMappedField mtf) {
             EsField field = new EsField(mtf.getName(), type, mtf.getProperties(), mtf.isAggregatable());
             FieldAttribute originalFieldAttr = (FieldAttribute) convert.field();
             FieldAttribute resolvedAttr = new FieldAttribute(
@@ -1611,7 +1613,13 @@ private static Expression typeSpecificConvert(
                 originalFieldAttr.id(),
                 true
             );
-            return convert.replaceChildren(Collections.singletonList(resolvedAttr));
+            Expression e = ((Expression) convert).replaceChildren(Collections.singletonList(resolvedAttr));
+            /*
+             * Resolve surrogates immediately because these type specific conversions are serialized
+             * and SurrogateExpressions are expected to be resolved on the coordinating node. At least,
+             * TO_IP is expected to be resolved there.
+             */
+            return SubstituteSurrogateExpressions.rule(e);
         }
     }
 
@@ -1696,7 +1704,7 @@ public LogicalPlan apply(LogicalPlan plan) {
 
     private static void typeResolutions(
         FieldAttribute fieldAttribute,
-        AbstractConvertFunction convert,
+        ConvertFunction convert,
         DataType type,
         InvalidMappedField imf,
         HashMap<ResolveUnionTypes.TypeResolutionKey, Expression> typeResolutions

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/ExpressionWritables.java

@@ -26,8 +26,10 @@
 import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToDouble;
 import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToGeoPoint;
 import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToGeoShape;
-import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToIP;
 import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToInteger;
+import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToIpLeadingZerosDecimal;
+import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToIpLeadingZerosOctal;
+import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToIpLeadingZerosRejected;
 import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToLong;
 import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToRadians;
 import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToString;
@@ -207,7 +209,9 @@ public static List<NamedWriteableRegistry.Entry> unaryScalars() {
         entries.add(ToGeoShape.ENTRY);
         entries.add(ToCartesianShape.ENTRY);
         entries.add(ToGeoPoint.ENTRY);
-        entries.add(ToIP.ENTRY);
+        entries.add(ToIpLeadingZerosDecimal.ENTRY);
+        entries.add(ToIpLeadingZerosOctal.ENTRY);
+        entries.add(ToIpLeadingZerosRejected.ENTRY);
         entries.add(ToInteger.ENTRY);
         entries.add(ToLong.ENTRY);
         entries.add(ToRadians.ENTRY);

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/EsqlFunctionRegistry.java

@@ -16,6 +16,7 @@
 import org.elasticsearch.xpack.esql.core.tree.Source;
 import org.elasticsearch.xpack.esql.core.type.DataType;
 import org.elasticsearch.xpack.esql.core.util.Check;
+import org.elasticsearch.xpack.esql.expression.SurrogateExpression;
 import org.elasticsearch.xpack.esql.expression.function.aggregate.Avg;
 import org.elasticsearch.xpack.esql.expression.function.aggregate.Count;
 import org.elasticsearch.xpack.esql.expression.function.aggregate.CountDistinct;
@@ -55,8 +56,11 @@
 import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToDouble;
 import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToGeoPoint;
 import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToGeoShape;
-import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToIP;
 import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToInteger;
+import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToIp;
+import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToIpLeadingZerosDecimal;
+import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToIpLeadingZerosOctal;
+import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToIpLeadingZerosRejected;
 import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToLong;
 import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToRadians;
 import org.elasticsearch.xpack.esql.expression.function.scalar.convert.ToString;
@@ -241,6 +245,7 @@ public class EsqlFunctionRegistry {
     public EsqlFunctionRegistry() {
         register(functions());
         buildDataTypesForStringLiteralConversion(functions());
+        nameSurrogates();
     }
 
     EsqlFunctionRegistry(FunctionDefinition... functions) {
@@ -413,7 +418,7 @@ private static FunctionDefinition[][] functions() {
                 def(ToDouble.class, ToDouble::new, "to_double", "to_dbl"),
                 def(ToGeoPoint.class, ToGeoPoint::new, "to_geopoint"),
                 def(ToGeoShape.class, ToGeoShape::new, "to_geoshape"),
-                def(ToIP.class, ToIP::new, "to_ip"),
+                def(ToIp.class, ToIp::new, "to_ip"),
                 def(ToInteger.class, ToInteger::new, "to_integer", "to_int"),
                 def(ToLong.class, ToLong::new, "to_long"),
                 def(ToRadians.class, ToRadians::new, "to_radians"),
@@ -808,6 +813,15 @@ protected void buildDataTypesForStringLiteralConversion(FunctionDefinition[]...
         }
     }
 
+    /**
+     * Add {@link #names} entries for functions that are not registered, but we rewrite to using {@link SurrogateExpression}.
+     */
+    private void nameSurrogates() {
+        names.put(ToIpLeadingZerosRejected.class, "TO_IP");
+        names.put(ToIpLeadingZerosDecimal.class, "TO_IP");
+        names.put(ToIpLeadingZerosOctal.class, "TO_IP");
+    }
+
     protected interface FunctionBuilder {
         Function build(Source source, List<Expression> children, Configuration cfg);
     }

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/scalar/convert/AbstractConvertFunction.java

@@ -43,7 +43,7 @@
  *     {@link org.elasticsearch.xpack.esql.expression.function.scalar}.
  * </p>
  */
-public abstract class AbstractConvertFunction extends UnaryScalarFunction {
+public abstract class AbstractConvertFunction extends UnaryScalarFunction implements ConvertFunction {
 
     // the numeric types convert functions need to handle; the other numeric types are converted upstream to one of these
     private static final List<DataType> NUMERIC_TYPES = List.of(DataType.INTEGER, DataType.LONG, DataType.UNSIGNED_LONG, DataType.DOUBLE);
@@ -76,11 +76,12 @@ protected TypeResolution resolveType() {
         return isTypeOrUnionType(field(), factories()::containsKey, sourceText(), null, supportedTypesNames(supportedTypes()));
     }
 
+    @Override
     public Set<DataType> supportedTypes() {
         return factories().keySet();
     }
 
-    private static String supportedTypesNames(Set<DataType> types) {
+    static String supportedTypesNames(Set<DataType> types) {
         List<String> supportedTypesNames = new ArrayList<>(types.size());
         HashSet<DataType> supportTypes = new HashSet<>(types);
         if (supportTypes.containsAll(NUMERIC_TYPES)) {