thehub/hub/server/rest.cpp

/*
 * This file is part of the Flowee project
 * Copyright (c) 2009-2010 Satoshi Nakamoto
 * Copyright (c) 2009-2015 The Bitcoin Core developers
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "chain.h"
#include "chainparams.h"
#include "primitives/MutableBlock.h"
#include "primitives/transaction.h"
#include "primitives/Block.h"
#include "primitives/Tx.h"
#include "main.h"
#include "httpserver.h"
#include "rpcserver.h"
#include "streaming/streams.h"
#include "sync.h"
#include "BlocksDB.h"
#include "txmempool.h"
#include "utilstrencodings.h"
#include "UnspentOutputData.h"
#include <txmempool.h>
#include <utxo/UnspentOutputDatabase.h>
#include <Application.h>
#include <BitcoinVersion.h>

#include <boost/algorithm/string.hpp>
#include <boost/dynamic_bitset.hpp>
#include <boost/foreach.hpp>

#include <univalue.h>

static const size_t MAX_GETUTXOS_OUTPOINTS = 15; //allow a max of 15 outpoints to be queried at once

enum RetFormat {
    RF_UNDEF,
    RF_BINARY,
    RF_HEX,
    RF_JSON,
};

static const struct {
    enum RetFormat rf;
    const char* name;
} rf_names[] = {
      {RF_UNDEF, ""},
      {RF_BINARY, "bin"},
      {RF_HEX, "hex"},
      {RF_JSON, "json"},
};

struct CCoin {
    uint32_t nTxVer; // Don't call this nVersion, that name has a special meaning inside IMPLEMENT_SERIALIZE
    uint32_t nHeight;
    CTxOut out;

    ADD_SERIALIZE_METHODS

    template <typename Stream, typename Operation>
    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion)
    {
        READWRITE(nTxVer);
        READWRITE(nHeight);
        READWRITE(out);
    }
};

extern void TxToJSON(const CTransaction& tx, const uint256 hashBlock, UniValue& entry);
extern UniValue blockToJSON(const MutableBlock& block, const CBlockIndex* blockindex, bool txDetails = false);
extern UniValue mempoolInfoToJSON();
extern UniValue mempoolToJSON(bool fVerbose = false);
extern void ScriptPubKeyToJSON(const CScript& scriptPubKey, UniValue& out, bool fIncludeHex);
extern UniValue blockheaderToJSON(const CBlockIndex* blockindex);

static bool RESTERR(HTTPRequest* req, enum HTTPStatusCode status, std::string message)
{
    req->WriteHeader("Content-Type", "text/plain");
    req->WriteReply(status, message + "\r\n");
    return false;
}

static enum RetFormat ParseDataFormat(std::string& param, const std::string& strReq)
{
    const std::string::size_type pos = strReq.rfind('.');
    if (pos == std::string::npos)
    {
        param = strReq;
        return rf_names[0].rf;
    }

    param = strReq.substr(0, pos);
    const std::string suff(strReq, pos + 1);

    for (unsigned int i = 0; i < ARRAYLEN(rf_names); i++)
        if (suff == rf_names[i].name)
            return rf_names[i].rf;

    /* If no suffix is found, return original string.  */
    param = strReq;
    return rf_names[0].rf;
}

static std::string AvailableDataFormatsString()
{
    std::string formats = "";
    for (unsigned int i = 0; i < ARRAYLEN(rf_names); i++)
        if (strlen(rf_names[i].name) > 0) {
            formats.append(".");
            formats.append(rf_names[i].name);
            formats.append(", ");
        }

    if (formats.length() > 0)
        return formats.substr(0, formats.length() - 2);

    return formats;
}

static bool ParseHashStr(const std::string& strReq, uint256& v)
{
    if (!IsHex(strReq) || (strReq.size() != 64))
        return false;

    v.SetHex(strReq);
    return true;
}

static bool CheckWarmup(HTTPRequest* req)
{
    std::string statusmessage;
    if (RPCIsInWarmup(&statusmessage))
         return RESTERR(req, HTTP_SERVICE_UNAVAILABLE, "Service temporarily unavailable: " + statusmessage);
    return true;
}

static bool rest_headers(HTTPRequest* req,
                         const std::string& strURIPart)
{
    if (!CheckWarmup(req))
        return false;
    std::string param;
    const RetFormat rf = ParseDataFormat(param, strURIPart);
    std::vector<std::string> path;
    boost::split(path, param, boost::is_any_of("/"));

    if (path.size() != 2)
        return RESTERR(req, HTTP_BAD_REQUEST, "No header count specified. Use /rest/headers/<count>/<hash>.<ext>.");

    long count = strtol(path[0].c_str(), NULL, 10);
    if (count < 1 || count > 2000)
        return RESTERR(req, HTTP_BAD_REQUEST, "Header count out of range: " + path[0]);

    std::string hashStr = path[1];
    uint256 hash;
    if (!ParseHashStr(hashStr, hash))
        return RESTERR(req, HTTP_BAD_REQUEST, "Invalid hash: " + hashStr);

    std::vector<const CBlockIndex *> headers;
    headers.reserve(count);
    {
        LOCK(cs_main);
        const CBlockIndex *pindex = Blocks::Index::get(hash);
        while (pindex != NULL && chainActive.Contains(pindex)) {
            headers.push_back(pindex);
            if (headers.size() == (unsigned long)count)
                break;
            pindex = chainActive.Next(pindex);
        }
    }

    CDataStream ssHeader(SER_NETWORK, PROTOCOL_VERSION);
    BOOST_FOREACH(const CBlockIndex *pindex, headers) {
        ssHeader << pindex->GetBlockHeader();
    }

    switch (rf) {
    case RF_BINARY: {
        std::string binaryHeader = ssHeader.str();
        req->WriteHeader("Content-Type", "application/octet-stream");
        req->WriteReply(HTTP_OK, binaryHeader);
        return true;
    }

    case RF_HEX: {
        std::string strHex = HexStr(ssHeader.begin(), ssHeader.end()) + "\n";
        req->WriteHeader("Content-Type", "text/plain");
        req->WriteReply(HTTP_OK, strHex);
        return true;
    }
    case RF_JSON: {
        UniValue jsonHeaders(UniValue::VARR);
        BOOST_FOREACH(const CBlockIndex *pindex, headers) {
            jsonHeaders.push_back(blockheaderToJSON(pindex));
        }
        std::string strJSON = jsonHeaders.write() + "\n";
        req->WriteHeader("Content-Type", "application/json");
        req->WriteReply(HTTP_OK, strJSON);
        return true;
    }
    default: {
        return RESTERR(req, HTTP_NOT_FOUND, "output format not found (available: .bin, .hex)");
    }
    }

    // not reached
    return true; // continue to process further HTTP reqs on this cxn
}

static bool rest_block(HTTPRequest* req,
                       const std::string& strURIPart,
                       bool showTxDetails)
{
    if (!CheckWarmup(req))
        return false;
    std::string hashStr;
    const RetFormat rf = ParseDataFormat(hashStr, strURIPart);

    uint256 hash;
    if (!ParseHashStr(hashStr, hash))
        return RESTERR(req, HTTP_BAD_REQUEST, "Invalid hash: " + hashStr);

    MutableBlock block;
    CBlockIndex* pblockindex = NULL;
    {
        LOCK(cs_main);
        if (!Blocks::Index::exists(hash))
            return RESTERR(req, HTTP_NOT_FOUND, hashStr + " not found");

        pblockindex = Blocks::Index::get(hash);
        if (!ReadBlockFromDisk(block, pblockindex, Params().GetConsensus()))
            return RESTERR(req, HTTP_NOT_FOUND, hashStr + " not found");
    }

    CDataStream ssBlock(SER_NETWORK, PROTOCOL_VERSION);
    ssBlock << block;

    switch (rf) {
    case RF_BINARY: {
        std::string binaryBlock = ssBlock.str();
        req->WriteHeader("Content-Type", "application/octet-stream");
        req->WriteReply(HTTP_OK, binaryBlock);
        return true;
    }

    case RF_HEX: {
        std::string strHex = HexStr(ssBlock.begin(), ssBlock.end()) + "\n";
        req->WriteHeader("Content-Type", "text/plain");
        req->WriteReply(HTTP_OK, strHex);
        return true;
    }

    case RF_JSON: {
        UniValue objBlock = blockToJSON(block, pblockindex, showTxDetails);
        std::string strJSON = objBlock.write() + "\n";
        req->WriteHeader("Content-Type", "application/json");
        req->WriteReply(HTTP_OK, strJSON);
        return true;
    }

    default: {
        return RESTERR(req, HTTP_NOT_FOUND, "output format not found (available: " + AvailableDataFormatsString() + ")");
    }
    }

    // not reached
    return true; // continue to process further HTTP reqs on this cxn
}

static bool rest_block_extended(HTTPRequest* req, const std::string& strURIPart)
{
    return rest_block(req, strURIPart, true);
}

static bool rest_block_notxdetails(HTTPRequest* req, const std::string& strURIPart)
{
    return rest_block(req, strURIPart, false);
}

static bool rest_chaininfo(HTTPRequest* req, const std::string& strURIPart)
{
    if (!CheckWarmup(req))
        return false;
    std::string param;
    const RetFormat rf = ParseDataFormat(param, strURIPart);

    switch (rf) {
    case RF_JSON: {
        UniValue rpcParams(UniValue::VARR);
        UniValue chainInfoObject = getblockchaininfo(rpcParams, false);
        std::string strJSON = chainInfoObject.write() + "\n";
        req->WriteHeader("Content-Type", "application/json");
        req->WriteReply(HTTP_OK, strJSON);
        return true;
    }
    default: {
        return RESTERR(req, HTTP_NOT_FOUND, "output format not found (available: json)");
    }
    }

    // not reached
    return true; // continue to process further HTTP reqs on this cxn
}

static bool rest_mempool_info(HTTPRequest* req, const std::string& strURIPart)
{
    if (!CheckWarmup(req))
        return false;
    std::string param;
    const RetFormat rf = ParseDataFormat(param, strURIPart);

    switch (rf) {
    case RF_JSON: {
        UniValue mempoolInfoObject = mempoolInfoToJSON();

        std::string strJSON = mempoolInfoObject.write() + "\n";
        req->WriteHeader("Content-Type", "application/json");
        req->WriteReply(HTTP_OK, strJSON);
        return true;
    }
    default: {
        return RESTERR(req, HTTP_NOT_FOUND, "output format not found (available: json)");
    }
    }

    // not reached
    return true; // continue to process further HTTP reqs on this cxn
}

static bool rest_mempool_contents(HTTPRequest* req, const std::string& strURIPart)
{
    if (!CheckWarmup(req))
        return false;
    std::string param;
    const RetFormat rf = ParseDataFormat(param, strURIPart);

    switch (rf) {
    case RF_JSON: {
        UniValue mempoolObject = mempoolToJSON(true);

        std::string strJSON = mempoolObject.write() + "\n";
        req->WriteHeader("Content-Type", "application/json");
        req->WriteReply(HTTP_OK, strJSON);
        return true;
    }
    default: {
        return RESTERR(req, HTTP_NOT_FOUND, "output format not found (available: json)");
    }
    }

    // not reached
    return true; // continue to process further HTTP reqs on this cxn
}

static bool rest_tx(HTTPRequest* req, const std::string& strURIPart)
{
    if (!CheckWarmup(req))
        return false;
    std::string hashStr;
    const RetFormat rf = ParseDataFormat(hashStr, strURIPart);

    uint256 hash;
    if (!ParseHashStr(hashStr, hash))
        return RESTERR(req, HTTP_BAD_REQUEST, "Invalid hash: " + hashStr);

    CTransaction tx;
    if (!flApp->mempool()->lookup(hash, tx))
        return RESTERR(req, HTTP_NOT_FOUND, hashStr + " not found");

    CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
    ssTx << tx;

    switch (rf) {
    case RF_BINARY: {
        std::string binaryTx = ssTx.str();
        req->WriteHeader("Content-Type", "application/octet-stream");
        req->WriteReply(HTTP_OK, binaryTx);
        return true;
    }

    case RF_HEX: {
        std::string strHex = HexStr(ssTx.begin(), ssTx.end()) + "\n";
        req->WriteHeader("Content-Type", "text/plain");
        req->WriteReply(HTTP_OK, strHex);
        return true;
    }

    case RF_JSON: {
        UniValue objTx(UniValue::VOBJ);
        uint256 hashBlock;
        TxToJSON(tx, hashBlock, objTx);
        std::string strJSON = objTx.write() + "\n";
        req->WriteHeader("Content-Type", "application/json");
        req->WriteReply(HTTP_OK, strJSON);
        return true;
    }

    default: {
        return RESTERR(req, HTTP_NOT_FOUND, "output format not found (available: " + AvailableDataFormatsString() + ")");
    }
    }

    // not reached
    return true; // continue to process further HTTP reqs on this cxn
}

static bool rest_getutxos(HTTPRequest* req, const std::string& strURIPart)
{
    if (!CheckWarmup(req))
        return false;
    std::string param;
    const RetFormat rf = ParseDataFormat(param, strURIPart);

    std::vector<std::string> uriParts;
    if (param.length() > 1)
    {
        std::string strUriParams = param.substr(1);
        boost::split(uriParts, strUriParams, boost::is_any_of("/"));
    }

    // throw exception in case of a empty request
    std::string strRequestMutable = req->ReadBody();
    if (strRequestMutable.length() == 0 && uriParts.size() == 0)
        return RESTERR(req, HTTP_INTERNAL_SERVER_ERROR, "Error: empty request");

    bool fInputParsed = false;
    bool fCheckMemPool = false;
    std::vector<COutPoint> vOutPoints;

    // parse/deserialize input
    // input-format = output-format, rest/getutxos/bin requires binary input, gives binary output, ...

    if (uriParts.size() > 0)
    {

        //inputs is sent over URI scheme (/rest/getutxos/checkmempool/txid1-n/txid2-n/...)
        if (uriParts.size() > 0 && uriParts[0] == "checkmempool")
            fCheckMemPool = true;

        for (size_t i = (fCheckMemPool) ? 1 : 0; i < uriParts.size(); i++)
        {
            uint256 txid;
            int32_t nOutput;
            std::string strTxid = uriParts[i].substr(0, uriParts[i].find("-"));
            std::string strOutput = uriParts[i].substr(uriParts[i].find("-")+1);

            if (!ParseInt32(strOutput, &nOutput) || !IsHex(strTxid))
                return RESTERR(req, HTTP_INTERNAL_SERVER_ERROR, "Parse error");

            txid.SetHex(strTxid);
            vOutPoints.push_back(COutPoint(txid, (uint32_t)nOutput));
        }

        if (vOutPoints.size() > 0)
            fInputParsed = true;
        else
            return RESTERR(req, HTTP_INTERNAL_SERVER_ERROR, "Error: empty request");
    }

    switch (rf) {
    case RF_HEX: {
        // convert hex to bin, continue then with bin part
        std::vector<unsigned char> strRequestV = ParseHex(strRequestMutable);
        strRequestMutable.assign(strRequestV.begin(), strRequestV.end());
    }

    case RF_BINARY: {
        try {
            //deserialize only if user sent a request
            if (strRequestMutable.size() > 0)
            {
                if (fInputParsed) //don't allow sending input over URI and HTTP RAW DATA
                    return RESTERR(req, HTTP_INTERNAL_SERVER_ERROR, "Combination of URI scheme inputs and raw post data is not allowed");

                CDataStream oss(SER_NETWORK, PROTOCOL_VERSION);
                oss << strRequestMutable;
                oss >> fCheckMemPool;
                oss >> vOutPoints;
            }
        } catch (const std::ios_base::failure& e) {
            // abort in case of unreadable binary data
            return RESTERR(req, HTTP_INTERNAL_SERVER_ERROR, "Parse error");
        }
        break;
    }

    case RF_JSON: {
        if (!fInputParsed)
            return RESTERR(req, HTTP_INTERNAL_SERVER_ERROR, "Error: empty request");
        break;
    }
    default: {
        return RESTERR(req, HTTP_NOT_FOUND, "output format not found (available: " + AvailableDataFormatsString() + ")");
    }
    }

    // limit max outpoints
    if (vOutPoints.size() > MAX_GETUTXOS_OUTPOINTS)
        return RESTERR(req, HTTP_INTERNAL_SERVER_ERROR, strprintf("Error: max outpoints exceeded (max: %d, tried: %d)", MAX_GETUTXOS_OUTPOINTS, vOutPoints.size()));

    // check spentness and form a bitmap (as well as a JSON capable human-readable string representation)
    std::vector<unsigned char> bitmap;
    std::vector<CCoin> outs;
    std::string bitmapStringRepresentation;
    boost::dynamic_bitset<unsigned char> hits(vOutPoints.size());
    {
        LOCK(mempool.cs);
        Blocks::DB *blockDb = Blocks::DB::instance();

        int i = 0;
        for (auto op : vOutPoints) {
            bool found = false;
            if (fCheckMemPool) {
                CTransaction tx;
                if (mempool.lookup(op.hash, tx) && tx.vout.size() > op.n) { // found it!
                    found = true;
                    CCoin coin;
                    coin.nTxVer = tx.nVersion;
                    coin.nHeight = MEMPOOL_HEIGHT;
                    coin.out = tx.vout.at(op.n);
                    assert(!coin.out.IsNull());
                    outs.push_back(coin);
                }
            }

            if (!found) { // Try UTXO
                auto utxo = g_utxo->find(op.hash, op.n);
                if (utxo.isValid()) { // Found it!
                    UnspentOutputData result= UnspentOutputData::fromUtxoDB(utxo);
                    assert(utxo.isValid()); // if it didn't the UTXO would point to a non-existing output...
                    if (utxo.isValid()) {
                        CCoin coin;
                        coin.nHeight = result.blockHeight;
                        coin.nTxVer = result.prevTxVersion;
                        coin.out.nValue = result.outputValue;
                        coin.out.scriptPubKey = result.outputScript();
                        assert(!coin.out.IsNull());
                        outs.push_back(coin);
                    }
                }
            }
            hits[i++] = found;
            bitmapStringRepresentation.append(found ? "1" : "0"); // form a binary string representation (human-readable for json output)
        }
    }
    boost::to_block_range(hits, std::back_inserter(bitmap));

    switch (rf) {
    case RF_BINARY: {
        // serialize data
        // use exact same output as mentioned in Bip64
        CDataStream ssGetUTXOResponse(SER_NETWORK, PROTOCOL_VERSION);
        ssGetUTXOResponse << chainActive.Height() << chainActive.Tip()->GetBlockHash() << bitmap << outs;
        std::string ssGetUTXOResponseString = ssGetUTXOResponse.str();

        req->WriteHeader("Content-Type", "application/octet-stream");
        req->WriteReply(HTTP_OK, ssGetUTXOResponseString);
        return true;
    }

    case RF_HEX: {
        CDataStream ssGetUTXOResponse(SER_NETWORK, PROTOCOL_VERSION);
        ssGetUTXOResponse << chainActive.Height() << chainActive.Tip()->GetBlockHash() << bitmap << outs;
        std::string strHex = HexStr(ssGetUTXOResponse.begin(), ssGetUTXOResponse.end()) + "\n";

        req->WriteHeader("Content-Type", "text/plain");
        req->WriteReply(HTTP_OK, strHex);
        return true;
    }

    case RF_JSON: {
        UniValue objGetUTXOResponse(UniValue::VOBJ);

        // pack in some essentials
        // use more or less the same output as mentioned in Bip64
        objGetUTXOResponse.push_back(Pair("chainHeight", chainActive.Height()));
        objGetUTXOResponse.push_back(Pair("chaintipHash", chainActive.Tip()->GetBlockHash().GetHex()));
        objGetUTXOResponse.push_back(Pair("bitmap", bitmapStringRepresentation));

        UniValue utxos(UniValue::VARR);
        BOOST_FOREACH (const CCoin& coin, outs) {
            UniValue utxo(UniValue::VOBJ);
            utxo.push_back(Pair("txvers", (int32_t)coin.nTxVer));
            utxo.push_back(Pair("height", (int32_t)coin.nHeight));
            utxo.push_back(Pair("value", ValueFromAmount(coin.out.nValue)));

            // include the script in a json output
            UniValue o(UniValue::VOBJ);
            ScriptPubKeyToJSON(coin.out.scriptPubKey, o, true);
            utxo.push_back(Pair("scriptPubKey", o));
            utxos.push_back(utxo);
        }
        objGetUTXOResponse.push_back(Pair("utxos", utxos));

        // return json string
        std::string strJSON = objGetUTXOResponse.write() + "\n";
        req->WriteHeader("Content-Type", "application/json");
        req->WriteReply(HTTP_OK, strJSON);
        return true;
    }
    default: {
        return RESTERR(req, HTTP_NOT_FOUND, "output format not found (available: " + AvailableDataFormatsString() + ")");
    }
    }

    // not reached
    return true; // continue to process further HTTP reqs on this cxn
}

static const struct {
    const char* prefix;
    bool (*handler)(HTTPRequest* req, const std::string& strReq);
} uri_prefixes[] = {
      {"/rest/tx/", rest_tx},
      {"/rest/block/notxdetails/", rest_block_notxdetails},
      {"/rest/block/", rest_block_extended},
      {"/rest/chaininfo", rest_chaininfo},
      {"/rest/mempool/info", rest_mempool_info},
      {"/rest/mempool/contents", rest_mempool_contents},
      {"/rest/headers/", rest_headers},
      {"/rest/getutxos", rest_getutxos},
};

void StartREST()
{
    for (unsigned int i = 0; i < ARRAYLEN(uri_prefixes); i++)
        RegisterHTTPHandler(uri_prefixes[i].prefix, false, uri_prefixes[i].handler);
}

void StopREST()
{
    for (unsigned int i = 0; i < ARRAYLEN(uri_prefixes); i++)
        UnregisterHTTPHandler(uri_prefixes[i].prefix, false);
}