Force modifyRule command handler to fail if an incompatible old fastjson found (#1377)

* Note that this is only a temporary solution.

sentinel-core/src/main/java/com/alibaba/csp/sentinel/util/VersionUtil.java

@@ -36,4 +36,69 @@ public final class VersionUtil {
     }
 
     private VersionUtil() {}
+    
+    private static int parseInt(String str) {
+        if (str == null || str.length() < 1) {
+            return 0;
+        }
+        int num = 0;
+        for (int i = 0; i < str.length(); i ++) {
+            char ch = str.charAt(i);
+            if (ch < '0' || ch > '9') {
+                break;
+            }
+            num = num * 10 + (ch - '0');
+        }
+        return num;
+    }
+
+    /**
+     * Convert version in string like x.y.z or x.y.z.b into number<br />
+     * Each segment has one byte space(unsigned)<br />
+     * eg.<br />
+     * <pre>
+     * 1.2.3.4 => 01 02 03 04
+     * 1.2.3   => 01 02 03 00
+     * 1.2     => 01 02 00 00
+     * 1       => 01 00 00 00
+     * </pre>
+     * 
+     * @return
+     */
+    public static int fromVersionString(String verStr) {
+        if (verStr == null || verStr.length() < 1) {
+            return 0;
+        }
+        int[] versions = new int[] {0, 0, 0, 0};
+        int index = 0;
+        String segment;
+        int cur = 0;
+        int pos;
+        do {
+            if (index >= versions.length) {
+                // More dots than "x.y.z.b" contains
+                return 0;
+            }
+            pos = verStr.indexOf('.', cur);
+            if (pos == -1) {
+                segment = verStr.substring(cur);
+            } else if (cur < pos) {
+                segment = verStr.substring(cur, pos);
+            } else {
+                // Illegal format
+                return 0;
+            }
+            versions[index] = parseInt(segment);
+            if (versions[index] < 0 || versions[index] > 255) {
+                // Out of range [0, 255]
+                return 0;
+            }
+            cur = pos + 1;
+            index ++;
+        } while (pos > 0);
+        return ((versions[0] & 0xff) << 24)
+             | ((versions[1] & 0xff) << 16)
+             | ((versions[2] & 0xff) << 8)
+              | (versions[3] & 0xff);
+    }
 }

sentinel-core/src/test/java/com/alibaba/csp/sentinel/util/VersionUtilTest.java

@@ -15,6 +15,8 @@
  */
 package com.alibaba.csp.sentinel.util;
 
+import static org.junit.Assert.*;
+
 import org.junit.Assert;
 import org.junit.Test;
 
@@ -27,4 +29,21 @@ public class VersionUtilTest {
         // Manifest cannot be load before package.
         Assert.assertEquals(defaultVersion, version);
     }
+    
+    @Test
+    public void testFromVersionString() {
+        assertEquals(0x01020300, VersionUtil.fromVersionString("1.2.3"));
+        assertEquals(0x01020304, VersionUtil.fromVersionString("1.2.3.4"));
+        assertEquals(0x0102ff04, VersionUtil.fromVersionString("1.2.255.4"));
+        assertEquals(0xffffffff, VersionUtil.fromVersionString("255.255.255.255"));
+        assertEquals(0, VersionUtil.fromVersionString("1.255.256.0"));
+        assertEquals(0x01020000, VersionUtil.fromVersionString("1.2."));
+        assertEquals(0x01000000, VersionUtil.fromVersionString("1"));
+        assertEquals(0x01020000, VersionUtil.fromVersionString("1.2"));
+        assertEquals(0, VersionUtil.fromVersionString("test"));
+        assertEquals(0x01020300, VersionUtil.fromVersionString("1.2.3-"));
+        assertEquals(0x01020300, VersionUtil.fromVersionString("1.2.3b"));
+        assertEquals(0x01023c00, VersionUtil.fromVersionString("1.2.60.sec9"));
+        assertEquals(0x01023c00, VersionUtil.fromVersionString("1.2.60-internal"));
+    }
 }

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/ModifyRulesCommandHandler.java

@@ -25,6 +25,7 @@ import com.alibaba.csp.sentinel.command.annotation.CommandMapping;
 import com.alibaba.csp.sentinel.datasource.WritableDataSource;
 import com.alibaba.csp.sentinel.log.RecordLog;
 import com.alibaba.csp.sentinel.util.StringUtil;
+import com.alibaba.csp.sentinel.util.VersionUtil;
 import com.alibaba.csp.sentinel.slots.block.authority.AuthorityRule;
 import com.alibaba.csp.sentinel.slots.block.authority.AuthorityRuleManager;
 import com.alibaba.csp.sentinel.slots.block.degrade.DegradeRule;
@@ -33,6 +34,7 @@ import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
 import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;
 import com.alibaba.csp.sentinel.slots.system.SystemRuleManager;
 import com.alibaba.csp.sentinel.slots.system.SystemRule;
+import com.alibaba.fastjson.JSON;
 import com.alibaba.fastjson.JSONArray;
 
 import static com.alibaba.csp.sentinel.transport.util.WritableDataSourceRegistry.*;
@@ -43,9 +45,17 @@ import static com.alibaba.csp.sentinel.transport.util.WritableDataSourceRegistry
  */
 @CommandMapping(name = "setRules", desc = "modify the rules, accept param: type={ruleType}&data={ruleJson}")
 public class ModifyRulesCommandHandler implements CommandHandler<String> {
+    private static final int FASTJSON_MINIMAL_VER = 0x01020C00;
 
     @Override
     public CommandResponse<String> handle(CommandRequest request) {
+        // XXX from 1.7.2, force to fail when fastjson is older than 1.2.12
+        // We may need a better solution on this.
+        if (VersionUtil.fromVersionString(JSON.VERSION) < FASTJSON_MINIMAL_VER) {
+            // fastjson too old
+            return CommandResponse.ofFailure(new RuntimeException("The \"fastjson-" + JSON.VERSION
+                    + "\" introduced in application is too old, you need fastjson-1.2.12 at least."));
+        }
         String type = request.getParam("type");
         // rule data in get parameter
         String data = request.getParam("data");
@@ -58,7 +68,7 @@ public class ModifyRulesCommandHandler implements CommandHandler<String> {
             }
         }
 
-        RecordLog.info(String.format("Receiving rule change (type: %s): %s", type, data));
+        RecordLog.info("Receiving rule change (type: {}): {}", type, data);
 
         String result = "success";