Re-introduce alert functionality (#1470)

Re-introduce alert functionality removed from Bitcoin upstream

1 files changed, 112 insertions, 0 deletions

diff --git a/src/alert.h b/src/alert.h
new file mode 100644
index 000000000..7963fac11
--- /dev/null
+++ b/src/alert.h
@@ -0,0 +1,112 @@
+// Copyright (c) 2010 Satoshi Nakamoto
+// Copyright (c) 2009-2015 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_ALERT_H
+#define BITCOIN_ALERT_H
+
+#include "serialize.h"
+#include "sync.h"
+
+#include <map>
+#include <set>
+#include <stdint.h>
+#include <string>
+
+class CAlert;
+class CNode;
+class uint256;
+
+extern std::map<uint256, CAlert> mapAlerts;
+extern CCriticalSection cs_mapAlerts;
+
+/** Alerts are for notifying old versions if they become too obsolete and
+ * need to upgrade.  The message is displayed in the status bar.
+ * Alert messages are broadcast as a vector of signed data.  Unserializing may
+ * not read the entire buffer if the alert is for a newer version, but older
+ * versions can still relay the original data.
+ */
+class CUnsignedAlert
+{
+public:
+    int nVersion;
+    int64_t nRelayUntil;      // when newer nodes stop relaying to newer nodes
+    int64_t nExpiration;
+    int nID;
+    int nCancel;
+    std::set<int> setCancel;
+    int nMinVer;            // lowest version inclusive
+    int nMaxVer;            // highest version inclusive
+    std::set<std::string> setSubVer;  // empty matches all
+    int nPriority;
+
+    // Actions
+    std::string strComment;
+    std::string strStatusBar;
+    std::string strReserved;
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action) {
+        READWRITE(this->nVersion);
+        nVersion = this->nVersion;
+        READWRITE(nRelayUntil);
+        READWRITE(nExpiration);
+        READWRITE(nID);
+        READWRITE(nCancel);
+        READWRITE(setCancel);
+        READWRITE(nMinVer);
+        READWRITE(nMaxVer);
+        READWRITE(setSubVer);
+        READWRITE(nPriority);
+
+        READWRITE(LIMITED_STRING(strComment, 65536));
+        READWRITE(LIMITED_STRING(strStatusBar, 256));
+        READWRITE(LIMITED_STRING(strReserved, 256));
+    }
+
+    void SetNull();
+
+    std::string ToString() const;
+};
+
+/** An alert is a combination of a serialized CUnsignedAlert and a signature. */
+class CAlert : public CUnsignedAlert
+{
+public:
+    std::vector<unsigned char> vchMsg;
+    std::vector<unsigned char> vchSig;
+
+    CAlert()
+    {
+        SetNull();
+    }
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action) {
+        READWRITE(vchMsg);
+        READWRITE(vchSig);
+    }
+
+    void SetNull();
+    bool IsNull() const;
+    uint256 GetHash() const;
+    bool IsInEffect() const;
+    bool Cancels(const CAlert& alert) const;
+    bool AppliesTo(int nVersion, const std::string& strSubVerIn) const;
+    bool AppliesToMe() const;
+    bool CheckSignature(const std::vector<unsigned char>& alertKey) const;
+    bool ProcessAlert(const std::vector<unsigned char>& alertKey, bool fThread = true);
+    static void Notify(const std::string& strMessage, bool fThread = true);
+
+    /*
+     * Get copy of (active) alert object by hash. Returns a null alert if it is not found.
+     */
+    static CAlert getAlertByHash(const uint256 &hash);
+};
+
+#endif // BITCOIN_ALERT_H