Add expirevar support for lmdb

owasp-modsecurity · Oct 10, 2023 · 34809d8 · 34809d8
1 parent 118e1b3
commit 34809d8
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Showing 6 changed files with 363 additions and 24 deletions.
diff --git a/src/collection/backend/collection_data.cc b/src/collection/backend/collection_data.cc
@@ -35,6 +35,105 @@ void CollectionData::setExpiry(int32_t seconds_until_expiry) {
     m_hasExpiryTime = true;
 }
 
+std::string CollectionData::getSerialized() const {
+    std::string serialized;
+    if (hasValue()) {
+        serialized.reserve(30 + 10 + getValue().size());
+    } else {
+        serialized.reserve(16+10);
+    }
+
+    serialized.assign("{");
+
+    if (hasExpiry()) {
+        serialized.append("\"__expire_\":");
+        uint64_t expiryEpochSeconds = std::chrono::duration_cast<std::chrono::seconds>(m_expiryTime.time_since_epoch()).count();
+        serialized.append(std::to_string(expiryEpochSeconds));
+	if (hasValue()) {
+            serialized.append(",");
+	}
+    }
+    if (hasValue()) {
+        serialized.append("\"__value_\":\"");
+        serialized.append(getValue());
+        serialized.append("\"");
+    }
+
+    serialized.append("}");
+
+    return serialized;
+}
+
+void CollectionData::setFromSerialized(const char* serializedData, size_t length) {
+    const static std::string expiryPrefix("\"__expire_\":");
+    const static std::string valuePrefix("\"__value_\":\"");
+    m_hasValue = false;
+    m_hasExpiryTime = false;
+
+    std::string serializedString(serializedData, length);
+    if ((serializedString.find("{") == 0) && (serializedString.substr(serializedString.length()-1) == "}")) {
+        size_t currentPos = 1;
+        uint64_t expiryEpochSeconds = 0;
+        bool invalidSerializedFormat = false;
+        bool doneParsing = false;
+
+        // Extract the expiry time, if it exists
+        if (serializedString.find(expiryPrefix, currentPos) == currentPos) {
+            currentPos += expiryPrefix.length();
+            std::string expiryDigits = serializedString.substr(currentPos, 10);
+            if (expiryDigits.find_first_not_of("0123456789") == std::string::npos) {
+                expiryEpochSeconds = strtoll(expiryDigits.c_str(), NULL, 10);
+            } else {
+                invalidSerializedFormat = true;
+	    }
+            currentPos += 10;
+        }
+
+        if ((!invalidSerializedFormat) && (expiryEpochSeconds > 0)) {
+            if (serializedString.find(",", currentPos) == currentPos) {
+                currentPos++;
+            } else if (currentPos == serializedString.length()-1) {
+	        doneParsing = true;
+	    } else {
+                invalidSerializedFormat = true;
+	    }
+	}
+
+        if ((!invalidSerializedFormat) && (!doneParsing)) {
+            // Extract the value
+            if ((serializedString.find(valuePrefix, currentPos) == currentPos)) {
+                currentPos += valuePrefix.length();
+                size_t expectedCloseQuotePos = serializedString.length() - 2;
+                if ((serializedString.substr(expectedCloseQuotePos, 1) == "\"") && (expectedCloseQuotePos >= currentPos)) {
+                    m_value = serializedString.substr(currentPos);
+                    m_value.resize(m_value.length()-2);
+                    m_hasValue = true;
+                } else {
+                    invalidSerializedFormat = true;
+                }
+            } else {
+                invalidSerializedFormat = true;
+            }
+        }
+
+        // Set the object's expiry time, if we found one
+        if ((!invalidSerializedFormat) && (expiryEpochSeconds > 0)) {
+            std::chrono::seconds expiryDuration(expiryEpochSeconds);
+            std::chrono::system_clock::time_point expiryTimePoint(expiryDuration);
+            m_expiryTime = expiryTimePoint;
+            m_hasExpiryTime = true;
+	}
+        if (!invalidSerializedFormat) {
+            return;
+	}
+    }
+
+    // this is the residual case; the entire string is a simple value (not JSON-ish encoded)
+    // the foreseen case here is lmdb content from prior to the serialization support
+    m_value.assign(serializedData, length);
+    m_hasValue = true;
+    return;
+}
 
 }  // namespace backend
 }  // namespace collection

diff --git a/src/collection/backend/collection_data.h b/src/collection/backend/collection_data.h
@@ -16,13 +16,10 @@
 
 #ifdef __cplusplus
 #include <string>
-#include <memory>
 #include <chrono>
 #endif
 
 
-#include "modsecurity/collection/collection.h"
-
 #ifndef SRC_COLLECTION_DATA_H_
 #define SRC_COLLECTION_DATA_H_
 
@@ -53,6 +50,9 @@ class CollectionData {
     bool hasExpiry() const { return m_hasExpiryTime;}
     bool isExpired() const;
 
+    std::string getSerialized() const;
+    void setFromSerialized(const char* serializedData, size_t length);
+
 private:
     bool m_hasValue;
     bool m_hasExpiryTime;