Support expirevar for in-memory collection

Author: martinhsv

Makefile.am

@@ -103,6 +103,7 @@ TESTS+=test/test-cases/regression/action-ctl_rule_remove_target_by_id.json
 TESTS+=test/test-cases/regression/action-ctl_rule_remove_target_by_tag.json
 TESTS+=test/test-cases/regression/action-disruptive.json
 TESTS+=test/test-cases/regression/action-exec.json
+TESTS+=test/test-cases/regression/action-expirevar.json
 TESTS+=test/test-cases/regression/action-id.json
 TESTS+=test/test-cases/regression/action-initcol.json
 TESTS+=test/test-cases/regression/action-msg.json

headers/modsecurity/collection/collection.h

@@ -1,6 +1,6 @@
 /*
  * ModSecurity, http://www.modsecurity.org/
- * Copyright (c) 2015 - 2021 Trustwave Holdings, Inc. (http://www.trustwave.com/)
+ * Copyright (c) 2015 - 2023 Trustwave Holdings, Inc. (http://www.trustwave.com/)
  *
  * You may not use this file except in compliance with
  * the License.  You may obtain a copy of the License at
@@ -16,7 +16,6 @@
 
 #ifdef __cplusplus
 #include <string>
-#include <iostream>
 #include <unordered_map>
 #include <list>
 #include <vector>
@@ -56,6 +55,8 @@ class Collection {
 
     virtual void del(const std::string& key) = 0;
 
+    virtual void setExpiry(const std::string& key, int32_t expiry_seconds) = 0;
+
     virtual std::unique_ptr<std::string> resolveFirst(
         const std::string& var) = 0;
 
@@ -129,6 +130,21 @@ class Collection {
     }
 
 
+    /* setExpiry */
+    virtual void setExpiry(const std::string& key, std::string compartment,
+        int32_t expiry_seconds) {
+        std::string nkey = compartment + "::" + key;
+        setExpiry(nkey, expiry_seconds);
+    }
+
+
+    virtual void setExpiry(const std::string& key, std::string compartment,
+        std::string compartment2, int32_t expiry_seconds) {
+        std::string nkey = compartment + "::" + compartment2 + "::" + key;
+        setExpiry(nkey, expiry_seconds);
+    }
+
+
     /* resolveFirst */
     virtual std::unique_ptr<std::string> resolveFirst(const std::string& var,
         std::string compartment) {

src/Makefile.am

@@ -134,6 +134,7 @@ ACTIONS = \
 	actions/disruptive/redirect.cc \
 	actions/disruptive/pass.cc \
 	actions/exec.cc \
+	actions/expire_var.cc \
 	actions/init_col.cc \
 	actions/log.cc \
 	actions/log_data.cc \
@@ -259,6 +260,7 @@ UTILS = \
 
 COLLECTION = \
 	collection/collections.cc \
+	collection/backend/collection_data.cc \
 	collection/backend/in_memory-per_process.cc \
 	collection/backend/lmdb.cc
 

src/actions/expire_var.cc

@@ -0,0 +1,95 @@
+/*
+ * ModSecurity, http://www.modsecurity.org/
+ * Copyright (c) 2023 Trustwave Holdings, Inc. (http://www.trustwave.com/)
+ *
+ * You may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * If any of the files related to licensing are missing or if you have any
+ * other questions related to licensing please contact Trustwave Holdings, Inc.
+ * directly using the email address [email protected].
+ *
+ */
+
+#include "src/actions/expire_var.h"
+
+#include <string>
+
+#include "modsecurity/rules_set.h"
+#include "modsecurity/transaction.h"
+#include "modsecurity/rule.h"
+#include "src/utils/string.h"
+#include "src/variables/global.h"
+#include "src/variables/ip.h"
+#include "src/variables/resource.h"
+#include "src/variables/session.h"
+#include "src/variables/user.h"
+#include "src/variables/variable.h"
+
+namespace modsecurity {
+namespace actions {
+
+
+bool ExpireVar::init(std::string *error) {
+    return true;
+}
+
+
+bool ExpireVar::evaluate(RuleWithActions *rule, Transaction *t) {
+
+    std::string expireExpressionExpanded(m_string->evaluate(t));
+
+    std::string fully_qualified_var;
+    int expirySeconds = 0;
+    size_t posEquals = expireExpressionExpanded.find("=");
+    if (posEquals == std::string::npos) {
+        fully_qualified_var = expireExpressionExpanded;
+    } else {
+        fully_qualified_var = expireExpressionExpanded.substr(0, posEquals);
+	std::string expiry = expireExpressionExpanded.substr(posEquals+1);
+	if (expiry.find_first_not_of("0123456789") == std::string::npos) {
+            expirySeconds = atoi(expiry.c_str());
+	} else {
+            ms_dbg_a(t, 5, "Non-numeric expiry seconds found in expirevar expression.");
+            return true;
+	}
+    }
+
+    size_t posDot = fully_qualified_var.find(".");
+    if (posDot == std::string::npos) {
+        ms_dbg_a(t, 5, "No collection found in expirevar expression.");
+	return true;
+    }
+
+    std::string collection = fully_qualified_var.substr(0, posDot);
+    std::string variable_name = fully_qualified_var.substr(posDot+1);
+    std::unique_ptr<RunTimeString> runTimeString(new RunTimeString());
+    runTimeString->appendText(fully_qualified_var);
+
+    if (collection == "ip") {
+        std::unique_ptr<modsecurity::variables::Ip_DynamicElement> ip_dynamicElement(new modsecurity::variables::Ip_DynamicElement(std::move(runTimeString)));
+        ip_dynamicElement->setExpiry(t, variable_name, expirySeconds);
+    } else if (collection == "global") {
+        std::unique_ptr<modsecurity::variables::Global_DynamicElement> global_dynamicElement(new modsecurity::variables::Global_DynamicElement(std::move(runTimeString)));
+        global_dynamicElement->setExpiry(t, variable_name, expirySeconds);
+    } else if (collection == "resource") {
+        std::unique_ptr<modsecurity::variables::Resource_DynamicElement> resource_dynamicElement(new modsecurity::variables::Resource_DynamicElement(std::move(runTimeString)));
+        resource_dynamicElement->setExpiry(t, variable_name, expirySeconds);
+    } else if (collection == "session") {
+        std::unique_ptr<modsecurity::variables::Session_DynamicElement> session_dynamicElement(new modsecurity::variables::Session_DynamicElement(std::move(runTimeString)));
+        session_dynamicElement->setExpiry(t, variable_name, expirySeconds);
+    } else if (collection == "user") {
+        std::unique_ptr<modsecurity::variables::User_DynamicElement> user_dynamicElement(new modsecurity::variables::User_DynamicElement(std::move(runTimeString)));
+        user_dynamicElement->setExpiry(t, variable_name, expirySeconds);
+    } else {
+        ms_dbg_a(t, 5, "Invalid collection found in expirevar expression: collection must be `ip', `global', `resource', `user' or `session'");
+    }
+    ms_dbg_a(t, 9, "Setting variable `" + variable_name + "' to expire in " + std::to_string(expirySeconds) + " seconds.");
+
+    return true;
+}
+
+}  // namespace actions
+}  // namespace modsecurity

src/actions/expire_var.h

@@ -0,0 +1,54 @@
+/*
+ * ModSecurity, http://www.modsecurity.org/
+ * Copyright (c) 2023 Trustwave Holdings, Inc. (http://www.trustwave.com/)
+ *
+ * You may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * If any of the files related to licensing are missing or if you have any
+ * other questions related to licensing please contact Trustwave Holdings, Inc.
+ * directly using the email address [email protected].
+ *
+ */
+
+#include <memory>
+#include <string>
+#include <utility>
+
+#include "modsecurity/actions/action.h"
+#include "src/run_time_string.h"
+
+#ifndef SRC_ACTIONS_EXPIRE_VAR_H_
+#define SRC_ACTIONS_EXPIRE_VAR_H_
+
+class Transaction;
+
+namespace modsecurity {
+class Transaction;
+class RuleWithOperator;
+
+namespace actions {
+
+class ExpireVar : public Action {
+ public:
+    explicit ExpireVar(const std::string &action) : Action(action) { }
+
+    explicit ExpireVar(std::unique_ptr<RunTimeString> z)
+        : Action("expirevar", RunTimeOnlyIfMatchKind),
+            m_string(std::move(z)) { }
+
+    bool evaluate(RuleWithActions *rule, Transaction *transaction) override;
+    bool init(std::string *error) override;
+
+ private:
+
+    std::unique_ptr<RunTimeString> m_string;
+};
+
+}  // namespace actions
+}  // namespace modsecurity
+
+
+#endif  // SRC_ACTIONS_EXPIRE_VAR_H_

src/collection/backend/collection_data.cc

@@ -0,0 +1,41 @@
+/*
+ * ModSecurity, http://www.modsecurity.org/
+ * Copyright (c) 2023 Trustwave Holdings, Inc. (http://www.trustwave.com/)
+ *
+ * You may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * If any of the files related to licensing are missing or if you have any
+ * other questions related to licensing please contact Trustwave Holdings, Inc.
+ * directly using the email address [email protected].
+ *
+ */
+
+#include "src/collection/backend/collection_data.h"
+
+
+namespace modsecurity {
+namespace collection {
+namespace backend {
+
+
+bool CollectionData::isExpired() const {
+    if (m_hasExpiryTime == false) {
+        return false;
+    }
+    auto now = std::chrono::system_clock::now();
+    return (now >= m_expiryTime);
+}
+
+
+void CollectionData::setExpiry(int32_t seconds_until_expiry) {
+    m_expiryTime = std::chrono::system_clock::now() + std::chrono::seconds(seconds_until_expiry);
+    m_hasExpiryTime = true;
+}
+
+
+}  // namespace backend
+}  // namespace collection
+}  // namespace modsecurity

src/collection/backend/collection_data.h

@@ -0,0 +1,68 @@
+/*
+ * ModSecurity, http://www.modsecurity.org/
+ * Copyright (c) 2023 Trustwave Holdings, Inc. (http://www.trustwave.com/)
+ *
+ * You may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * If any of the files related to licensing are missing or if you have any
+ * other questions related to licensing please contact Trustwave Holdings, Inc.
+ * directly using the email address [email protected].
+ *
+ */
+
+
+#ifdef __cplusplus
+#include <string>
+#include <memory>
+#include <chrono>
+#endif
+
+
+#include "modsecurity/collection/collection.h"
+
+#ifndef SRC_COLLECTION_DATA_H_
+#define SRC_COLLECTION_DATA_H_
+
+#ifdef __cplusplus
+namespace modsecurity {
+namespace collection {
+namespace backend {
+
+class CollectionData {
+public:
+    CollectionData() :
+        m_hasValue(false),
+	m_hasExpiryTime(false) { }
+
+    CollectionData(const std::string &value) :
+        m_hasValue(true),
+	m_hasExpiryTime(false),
+	m_value(value) { }
+
+    void setValue(const std::string &value) {
+        m_value = value;
+        m_hasValue = true;
+    }
+    bool hasValue() const { return m_hasValue;}
+    const std::string& getValue() const { return m_value;}
+
+    void setExpiry(int32_t seconds_until_expiry);
+    bool hasExpiry() const { return m_hasExpiryTime;}
+    bool isExpired() const;
+
+private:
+    bool m_hasValue;
+    bool m_hasExpiryTime;
+    std::string m_value;
+    std::chrono::system_clock::time_point m_expiryTime;
+};
+
+}  // namespace backend
+}  // namespace collection
+}  // namespace modsecurity
+#endif
+
+#endif  // SRC_COLLECTION_DATA_H_