make CMessageHeader a dumb storage class

It shouldn't know or care about bitcoind's chain param selection

src/chainparams.h

@@ -14,8 +14,6 @@
 
 #include <vector>
 
-typedef unsigned char MessageStartChars[MESSAGE_START_SIZE];
-
 struct CDNSSeedData {
     std::string name, host;
     CDNSSeedData(const std::string &strName, const std::string &strHost) : name(strName), host(strHost) {}
@@ -42,7 +40,7 @@ public:
     };
 
     const uint256& HashGenesisBlock() const { return hashGenesisBlock; }
-    const MessageStartChars& MessageStart() const { return pchMessageStart; }
+    const CMessageHeader::MessageStartChars& MessageStart() const { return pchMessageStart; }
     const std::vector<unsigned char>& AlertKey() const { return vAlertPubKey; }
     int GetDefaultPort() const { return nDefaultPort; }
     const arith_uint256& ProofOfWorkLimit() const { return bnProofOfWorkLimit; }
@@ -83,7 +81,7 @@ protected:
     CChainParams() {}
 
     uint256 hashGenesisBlock;
-    MessageStartChars pchMessageStart;
+    CMessageHeader::MessageStartChars pchMessageStart;
     //! Raw pub key bytes for the broadcast alert signing key.
     std::vector<unsigned char> vAlertPubKey;
     int nDefaultPort;

src/main.cpp

@@ -4307,7 +4307,7 @@ bool ProcessMessages(CNode* pfrom)
 
         // Read header
         CMessageHeader& hdr = msg.hdr;
-        if (!hdr.IsValid())
+        if (!hdr.IsValid(Params().MessageStart()))
         {
             LogPrintf("PROCESSMESSAGE: ERRORS IN HEADER %s peer=%d\n", SanitizeString(hdr.GetCommand()), pfrom->id);
             continue;

src/net.cpp

@@ -509,7 +509,7 @@ bool CNode::ReceiveMsgBytes(const char *pch, unsigned int nBytes)
         // get current incomplete message, or create a new one
         if (vRecvMsg.empty() ||
             vRecvMsg.back().complete())
-            vRecvMsg.push_back(CNetMessage(SER_NETWORK, nRecvVersion));
+            vRecvMsg.push_back(CNetMessage(Params().MessageStart(), SER_NETWORK, nRecvVersion));
 
         CNetMessage& msg = vRecvMsg.back();
 
@@ -1970,7 +1970,7 @@ void CNode::BeginMessage(const char* pszCommand) EXCLUSIVE_LOCK_FUNCTION(cs_vSen
 {
     ENTER_CRITICAL_SECTION(cs_vSend);
     assert(ssSend.size() == 0);
-    ssSend << CMessageHeader(pszCommand, 0);
+    ssSend << CMessageHeader(Params().MessageStart(), pszCommand, 0);
     LogPrint("net", "sending: %s ", SanitizeString(pszCommand));
 }
 

src/net.h

@@ -183,7 +183,7 @@ public:
 
     int64_t nTime;                  // time (in microseconds) of message receipt.
 
-    CNetMessage(int nTypeIn, int nVersionIn) : hdrbuf(nTypeIn, nVersionIn), vRecv(nTypeIn, nVersionIn) {
+    CNetMessage(const CMessageHeader::MessageStartChars& pchMessageStartIn, int nTypeIn, int nVersionIn) : hdrbuf(nTypeIn, nVersionIn), hdr(pchMessageStartIn), vRecv(nTypeIn, nVersionIn) {
         hdrbuf.resize(24);
         in_data = false;
         nHdrPos = 0;

src/protocol.cpp

@@ -5,7 +5,6 @@
 
 #include "protocol.h"
 
-#include "chainparams.h"
 #include "util.h"
 #include "utilstrencodings.h"
 
@@ -21,17 +20,17 @@ static const char* ppszTypeName[] =
     "filtered block"
 };
 
-CMessageHeader::CMessageHeader()
+CMessageHeader::CMessageHeader(const MessageStartChars& pchMessageStartIn)
 {
-    memcpy(pchMessageStart, Params().MessageStart(), MESSAGE_START_SIZE);
+    memcpy(pchMessageStart, pchMessageStartIn, MESSAGE_START_SIZE);
     memset(pchCommand, 0, sizeof(pchCommand));
     nMessageSize = -1;
     nChecksum = 0;
 }
 
-CMessageHeader::CMessageHeader(const char* pszCommand, unsigned int nMessageSizeIn)
+CMessageHeader::CMessageHeader(const MessageStartChars& pchMessageStartIn, const char* pszCommand, unsigned int nMessageSizeIn)
 {
-    memcpy(pchMessageStart, Params().MessageStart(), MESSAGE_START_SIZE);
+    memcpy(pchMessageStart, pchMessageStartIn, MESSAGE_START_SIZE);
     memset(pchCommand, 0, sizeof(pchCommand));
     strncpy(pchCommand, pszCommand, COMMAND_SIZE);
     nMessageSize = nMessageSizeIn;
@@ -43,10 +42,10 @@ std::string CMessageHeader::GetCommand() const
     return std::string(pchCommand, pchCommand + strnlen(pchCommand, COMMAND_SIZE));
 }
 
-bool CMessageHeader::IsValid() const
+bool CMessageHeader::IsValid(const MessageStartChars& pchMessageStartIn) const
 {
     // Check start string
-    if (memcmp(pchMessageStart, Params().MessageStart(), MESSAGE_START_SIZE) != 0)
+    if (memcmp(pchMessageStart, pchMessageStartIn, MESSAGE_START_SIZE) != 0)
         return false;
 
     // Check the command string for errors

src/protocol.h

@@ -29,11 +29,13 @@
 class CMessageHeader
 {
 public:
-    CMessageHeader();
+    typedef unsigned char MessageStartChars[MESSAGE_START_SIZE];
-    CMessageHeader(const char* pszCommand, unsigned int nMessageSizeIn);
+
+    CMessageHeader(const MessageStartChars& pchMessageStartIn);
+    CMessageHeader(const MessageStartChars& pchMessageStartIn, const char* pszCommand, unsigned int nMessageSizeIn);
 
     std::string GetCommand() const;
-    bool IsValid() const;
+    bool IsValid(const MessageStartChars& messageStart) const;
 
     ADD_SERIALIZE_METHODS;