evhttpd implementation

- *Replace usage of boost::asio with [libevent2](http://libevent.org/)*.
boost::asio is not part of C++11, so unlike other boost there is no
forwards-compatibility reason to stick with it. Together with #4738 (convert
json_spirit to UniValue), this rids Bitcoin Core of the worst offenders with
regard to compile-time slowness.

- *Replace spit-and-duct-tape http server with evhttp*. Front-end http handling
is handled by libevent, a work queue (with configurable depth and parallelism)
is used to handle application requests.

- *Wrap HTTP request in C++ class*; this makes the application code mostly
HTTP-server-neutral

- *Refactor RPC to move all http-specific code to a separate file*.
Theoreticaly this can allow building without HTTP server but with another RPC
backend, e.g. Qt's debug console (currently not implemented) or future RPC
mechanisms people may want to use.

- *HTTP dispatch mechanism*; services (e.g., RPC, REST) register which URL
paths they want to handle.

By using a proven, high-performance asynchronous networking library (also used
by Tor) and HTTP server, problems such as #5674, #5655, #344 should be avoided.

What works? bitcoind, bitcoin-cli, bitcoin-qt. Unit tests and RPC/REST tests
pass. The aim for now is everything but SSL support.

Configuration options:

- `-rpcthreads`: repurposed as "number of  work handler threads". Still
defaults to 4.

- `-rpcworkqueue`: maximum depth of work queue. When this is reached, new
requests will return a 500 Internal Error.

- `-rpctimeout`: inactivity time, in seconds, after which to disconnect a
client.

- `-debug=http`: low-level http activity logging
This commit is contained in:
Wladimir J. van der Laan
2015-01-23 07:53:17 +01:00
parent ee2a42b447
commit 40b556d374
15 changed files with 1297 additions and 1047 deletions

View File

@@ -11,6 +11,12 @@
#include "utilstrencodings.h"
#include <boost/filesystem/operations.hpp>
#include <stdio.h>
#include <event2/event.h>
#include <event2/http.h>
#include <event2/buffer.h>
#include <event2/keyvalq_struct.h>
#include "univalue/univalue.h"
@@ -32,9 +38,6 @@ std::string HelpMessageCli()
strUsage += HelpMessageOpt("-rpcuser=<user>", _("Username for JSON-RPC connections"));
strUsage += HelpMessageOpt("-rpcpassword=<pw>", _("Password for JSON-RPC connections"));
strUsage += HelpMessageGroup(_("SSL options: (see the Bitcoin Wiki for SSL setup instructions)"));
strUsage += HelpMessageOpt("-rpcssl", _("Use OpenSSL (https) for JSON-RPC connections"));
return strUsage;
}
@@ -92,32 +95,75 @@ static bool AppInitRPC(int argc, char* argv[])
fprintf(stderr, "Error: Invalid combination of -regtest and -testnet.\n");
return false;
}
if (GetBoolArg("-rpcssl", false))
{
fprintf(stderr, "Error: SSL mode for RPC (-rpcssl) is no longer supported.\n");
return false;
}
return true;
}
/** Reply structure for request_done to fill in */
struct HTTPReply
{
int status;
std::string body;
};
static void http_request_done(struct evhttp_request *req, void *ctx)
{
HTTPReply *reply = static_cast<HTTPReply*>(ctx);
if (req == NULL) {
/* If req is NULL, it means an error occurred while connecting, but
* I'm not sure how to find out which one. We also don't really care.
*/
reply->status = 0;
return;
}
reply->status = evhttp_request_get_response_code(req);
struct evbuffer *buf = evhttp_request_get_input_buffer(req);
if (buf)
{
size_t size = evbuffer_get_length(buf);
const char *data = (const char*)evbuffer_pullup(buf, size);
if (data)
reply->body = std::string(data, size);
evbuffer_drain(buf, size);
}
}
UniValue CallRPC(const string& strMethod, const UniValue& params)
{
// Connect to localhost
bool fUseSSL = GetBoolArg("-rpcssl", false);
boost::asio::io_service io_service;
boost::asio::ssl::context context(io_service, boost::asio::ssl::context::sslv23);
context.set_options(boost::asio::ssl::context::no_sslv2 | boost::asio::ssl::context::no_sslv3);
boost::asio::ssl::stream<boost::asio::ip::tcp::socket> sslStream(io_service, context);
SSLIOStreamDevice<boost::asio::ip::tcp> d(sslStream, fUseSSL);
boost::iostreams::stream< SSLIOStreamDevice<boost::asio::ip::tcp> > stream(d);
std::string host = GetArg("-rpcconnect", "127.0.0.1");
int port = GetArg("-rpcport", BaseParams().RPCPort());
const bool fConnected = d.connect(GetArg("-rpcconnect", "127.0.0.1"), GetArg("-rpcport", itostr(BaseParams().RPCPort())));
if (!fConnected)
throw CConnectionFailed("couldn't connect to server");
// Create event base
struct event_base *base = event_base_new(); // TODO RAII
if (!base)
throw runtime_error("cannot create event_base");
// Find credentials to use
// Synchronously look up hostname
struct evhttp_connection *evcon = evhttp_connection_base_new(base, NULL, host.c_str(), port); // TODO RAII
if (evcon == NULL)
throw runtime_error("create connection failed");
evhttp_connection_set_timeout(evcon, GetArg("-rpctimeout", 30));
HTTPReply response;
struct evhttp_request *req = evhttp_request_new(http_request_done, (void*)&response); // TODO RAII
if (req == NULL)
throw runtime_error("create http request failed");
// Get credentials
std::string strRPCUserColonPass;
if (mapArgs["-rpcpassword"] == "") {
// Try fall back to cookie-based authentication if no password is provided
if (!GetAuthCookie(&strRPCUserColonPass)) {
throw runtime_error(strprintf(
_("You must set rpcpassword=<password> in the configuration file:\n%s\n"
"If the file does not exist, create it with owner-readable-only file permissions."),
_("Could not locate RPC credentials. No authentication cookie could be found, and no rpcpassword is set in the configuration file (%s)"),
GetConfigFile().string().c_str()));
}
@@ -125,34 +171,41 @@ UniValue CallRPC(const string& strMethod, const UniValue& params)
strRPCUserColonPass = mapArgs["-rpcuser"] + ":" + mapArgs["-rpcpassword"];
}
// HTTP basic authentication
map<string, string> mapRequestHeaders;
mapRequestHeaders["Authorization"] = string("Basic ") + EncodeBase64(strRPCUserColonPass);
struct evkeyvalq *output_headers = evhttp_request_get_output_headers(req);
assert(output_headers);
evhttp_add_header(output_headers, "Host", host.c_str());
evhttp_add_header(output_headers, "Connection", "close");
evhttp_add_header(output_headers, "Authorization", (std::string("Basic ") + EncodeBase64(strRPCUserColonPass)).c_str());
// Send request
string strRequest = JSONRPCRequest(strMethod, params, 1);
string strPost = HTTPPost(strRequest, mapRequestHeaders);
stream << strPost << std::flush;
// Attach request data
std::string strRequest = JSONRPCRequest(strMethod, params, 1);
struct evbuffer * output_buffer = evhttp_request_get_output_buffer(req);
assert(output_buffer);
evbuffer_add(output_buffer, strRequest.data(), strRequest.size());
// Receive HTTP reply status
int nProto = 0;
int nStatus = ReadHTTPStatus(stream, nProto);
int r = evhttp_make_request(evcon, req, EVHTTP_REQ_POST, "/");
if (r != 0) {
evhttp_connection_free(evcon);
event_base_free(base);
throw CConnectionFailed("send http request failed");
}
// Receive HTTP reply message headers and body
map<string, string> mapHeaders;
string strReply;
ReadHTTPMessage(stream, mapHeaders, strReply, nProto, std::numeric_limits<size_t>::max());
event_base_dispatch(base);
evhttp_connection_free(evcon);
event_base_free(base);
if (nStatus == HTTP_UNAUTHORIZED)
if (response.status == 0)
throw CConnectionFailed("couldn't connect to server");
else if (response.status == HTTP_UNAUTHORIZED)
throw runtime_error("incorrect rpcuser or rpcpassword (authorization failed)");
else if (nStatus >= 400 && nStatus != HTTP_BAD_REQUEST && nStatus != HTTP_NOT_FOUND && nStatus != HTTP_INTERNAL_SERVER_ERROR)
throw runtime_error(strprintf("server returned HTTP error %d", nStatus));
else if (strReply.empty())
else if (response.status >= 400 && response.status != HTTP_BAD_REQUEST && response.status != HTTP_NOT_FOUND && response.status != HTTP_INTERNAL_SERVER_ERROR)
throw runtime_error(strprintf("server returned HTTP error %d", response.status));
else if (response.body.empty())
throw runtime_error("no response from server");
// Parse reply
UniValue valReply(UniValue::VSTR);
if (!valReply.read(strReply))
if (!valReply.read(response.body))
throw runtime_error("couldn't parse reply from server");
const UniValue& reply = valReply.get_obj();
if (reply.empty())