Fix RULE lookup in chained rules.

Author: Felipe Zimmerle

headers/modsecurity/rule.h

@@ -140,7 +140,8 @@ class Rule {
     int m_phase;
     modsecurity::Variables::Variables *m_variables;
     operators::Operator *m_op;
-    Rule *m_chainedRule;
+    Rule *m_chainedRuleChild;
+    Rule *m_chainedRuleParent;
     std::string m_fileName;
     std::string m_marker;
     std::string m_rev;

src/parser/driver.cc

@@ -78,22 +78,24 @@ int Driver::addSecRule(Rule *rule) {
     }
 
     if (lastRule && lastRule->m_chained) {
-        if (lastRule->m_chainedRule == NULL) {
+        if (lastRule->m_chainedRuleChild == NULL) {
             rule->m_phase = lastRule->m_phase;
-            lastRule->m_chainedRule = rule;
+            lastRule->m_chainedRuleChild = rule;
+            rule->m_chainedRuleParent = lastRule;
             if (rule->m_theDisruptiveAction) {
                 m_parserError << "Disruptive actions can only be specified by";
                 m_parserError << " chain starter rules.";
                 return false;
             }
             return true;
         } else {
-            Rule *a = lastRule->m_chainedRule;
-            while (a->m_chained && a->m_chainedRule != NULL) {
-                a = a->m_chainedRule;
+            Rule *a = lastRule->m_chainedRuleChild;
+            while (a->m_chained && a->m_chainedRuleChild != NULL) {
+                a = a->m_chainedRuleChild;
             }
-            if (a->m_chained && a->m_chainedRule == NULL) {
-                a->m_chainedRule = rule;
+            if (a->m_chained && a->m_chainedRuleChild == NULL) {
+                a->m_chainedRuleChild = rule;
+                rule->m_chainedRuleParent = a;
                 if (a->m_theDisruptiveAction) {
                     m_parserError << "Disruptive actions can only be ";
                     m_parserError << "specified by chain starter rules.";

src/rule.cc

@@ -57,7 +57,7 @@ Rule::Rule(std::string marker)
     m_actionsSetVar(),
     m_actionsTag(),
     m_chained(false),
-    m_chainedRule(NULL),
+    m_chainedRuleChild(NULL),
     m_fileName(""),
     m_lineNumber(0),
     m_marker(marker),
@@ -91,7 +91,8 @@ Rule::Rule(Operator *_op,
     m_actionsSetVar(),
     m_actionsTag(),
     m_chained(false),
-    m_chainedRule(NULL),
+    m_chainedRuleChild(NULL),
+    m_chainedRuleParent(NULL),
     m_fileName(fileName),
     m_lineNumber(lineNumber),
     m_marker(""),
@@ -146,8 +147,8 @@ Rule::~Rule() {
         delete m_variables;
     }
 
-    if (m_chainedRule != NULL) {
-        delete m_chainedRule;
+    if (m_chainedRuleChild != NULL) {
+        delete m_chainedRuleChild;
     }
 }
 
@@ -793,7 +794,7 @@ bool Rule::evaluate(Transaction *trans,
         goto end_exec;
     }
 
-    if (this->m_chainedRule == NULL) {
+    if (this->m_chainedRuleChild == NULL) {
 #ifndef NO_LOGS
         trans->debug(4, "Rule is marked as chained but there " \
             "isn't a subsequent rule.");
@@ -804,7 +805,7 @@ bool Rule::evaluate(Transaction *trans,
 #ifndef NO_LOGS
     trans->debug(4, "Executing chained rule.");
 #endif
-    recursiveGlobalRet = this->m_chainedRule->evaluate(trans, ruleMessage);
+    recursiveGlobalRet = this->m_chainedRuleChild->evaluate(trans, ruleMessage);
 
     if (recursiveGlobalRet == true) {
         goto end_exec;

src/variables/rule.h

@@ -40,11 +40,17 @@ class Rule_DictElement : public VariableDictElement { \
     static void id(Transaction *t,
         Rule *rule,
         std::vector<const VariableValue *> *l) {
-        if (!rule) {
+        Rule *r = rule;
+
+        while (r && r->m_ruleId == 0) {
+            r = r->m_chainedRuleParent;
+        }
+
+        if (!r || r->m_ruleId == 0) {
             return;
         }
         std::unique_ptr<VariableOrigin> origin(new VariableOrigin());
-        std::string *a = new std::string(std::to_string(rule->m_ruleId));
+        std::string *a = new std::string(std::to_string(r->m_ruleId));
         VariableValue *var = new VariableValue(
             std::make_shared<std::string>("RULE:id"),
             a
@@ -60,11 +66,18 @@ class Rule_DictElement : public VariableDictElement { \
     static void rev(Transaction *t,
         Rule *rule,
         std::vector<const VariableValue *> *l) {
-        if (!rule) {
+        Rule *r = rule;
+
+        while (r && r->m_rev.empty()) {
+            r = r->m_chainedRuleParent;
+        }
+
+        if (!r) {
             return;
         }
+
         std::unique_ptr<VariableOrigin> origin(new VariableOrigin());
-        std::string *a = new std::string(rule->m_rev);
+        std::string *a = new std::string(r->m_rev);
         VariableValue *var = new VariableValue(
             std::make_shared<std::string>("RULE:rev"),
             a
@@ -80,9 +93,15 @@ class Rule_DictElement : public VariableDictElement { \
     static void severity(Transaction *t,
         Rule *rule,
         std::vector<const VariableValue *> *l) {
-        if (rule && rule->m_severity) {
+        Rule *r = rule;
+
+        while (r && !r->m_severity) {
+            r = r->m_chainedRuleParent;
+        }
+
+        if (r && r->m_severity) {
             std::unique_ptr<VariableOrigin> origin(new VariableOrigin());
-            std::string *a = new std::string(std::to_string(rule->m_severity->m_severity));
+            std::string *a = new std::string(std::to_string(r->m_severity->m_severity));
             VariableValue *var = new VariableValue(
                 std::make_shared<std::string>("RULE:severity"),
                 a
@@ -99,9 +118,15 @@ class Rule_DictElement : public VariableDictElement { \
     static void logData(Transaction *t,
         Rule *rule,
         std::vector<const VariableValue *> *l) {
-        if (rule && rule->m_logData) {
+        Rule *r = rule;
+
+        while (r && !r->m_logData) {
+            r = r->m_chainedRuleParent;
+        }
+
+        if (r && r->m_logData) {
             std::unique_ptr<VariableOrigin> origin(new VariableOrigin());
-            std::string *a = new std::string(rule->m_logData->data(t));
+            std::string *a = new std::string(r->m_logData->data(t));
             VariableValue *var = new VariableValue(
                 std::make_shared<std::string>("RULE:logdata"),
                 a
@@ -117,9 +142,15 @@ class Rule_DictElement : public VariableDictElement { \
     static void msg(Transaction *t,
         Rule *rule,
         std::vector<const VariableValue *> *l) {
-        if (rule && rule->m_msg) {
+        Rule *r = rule;
+
+        while (r && !r->m_msg) {
+            r = r->m_chainedRuleParent;
+        }
+
+        if (r && r->m_msg) {
             std::unique_ptr<VariableOrigin> origin(new VariableOrigin());
-            std::string *a = new std::string(rule->m_msg->data(t));
+            std::string *a = new std::string(r->m_msg->data(t));
             VariableValue *var = new VariableValue(
                 std::make_shared<std::string>("RULE:msg"),
                 a