neobytes/src/httpserver.cpp
Pieter Wuille aff4b6d2c5 Merge #9243: Clean up mapArgs and mapMultiArgs Usage
c2f61be Add a ForceSetArg method for testing (Matt Corallo)
4e04814 Lock mapArgs/mapMultiArgs access in util (Matt Corallo)
4cd373a Un-expose mapArgs from utils.h (Matt Corallo)
71fde55 Get rid of mapArgs direct access in ZMQ construction (Matt Corallo)
0cf86a6 Introduce (and use) an IsArgSet accessor method (Matt Corallo)
2b5f085 Fix non-const mapMultiArgs[] access after init. (Matt Corallo)
c8042a4 Remove arguments to ParseConfigFile (Matt Corallo)
2018-01-18 07:31:23 +01:00

679 lines
21 KiB
C++

// Copyright (c) 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.
#include "httpserver.h"
#include "chainparamsbase.h"
#include "compat.h"
#include "util.h"
#include "netbase.h"
#include "rpc/protocol.h" // For HTTP status codes
#include "sync.h"
#include "ui_interface.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <signal.h>
#include <future>
#include <event2/event.h>
#include <event2/http.h>
#include <event2/thread.h>
#include <event2/buffer.h>
#include <event2/util.h>
#include <event2/keyvalq_struct.h>
#ifdef EVENT__HAVE_NETINET_IN_H
#include <netinet/in.h>
#ifdef _XOPEN_SOURCE_EXTENDED
#include <arpa/inet.h>
#endif
#endif
/** Maximum size of http request (request line + headers) */
static const size_t MAX_HEADERS_SIZE = 8192;
/** HTTP request work item */
class HTTPWorkItem : public HTTPClosure
{
public:
HTTPWorkItem(std::unique_ptr<HTTPRequest> _req, const std::string &_path, const HTTPRequestHandler& _func):
req(std::move(_req)), path(_path), func(_func)
{
}
void operator()()
{
func(req.get(), path);
}
std::unique_ptr<HTTPRequest> req;
private:
std::string path;
HTTPRequestHandler func;
};
/** Simple work queue for distributing work over multiple threads.
* Work items are simply callable objects.
*/
template <typename WorkItem>
class WorkQueue
{
private:
/** Mutex protects entire object */
std::mutex cs;
std::condition_variable cond;
std::deque<std::unique_ptr<WorkItem>> queue;
bool running;
size_t maxDepth;
int numThreads;
/** RAII object to keep track of number of running worker threads */
class ThreadCounter
{
public:
WorkQueue &wq;
ThreadCounter(WorkQueue &w): wq(w)
{
std::lock_guard<std::mutex> lock(wq.cs);
wq.numThreads += 1;
}
~ThreadCounter()
{
std::lock_guard<std::mutex> lock(wq.cs);
wq.numThreads -= 1;
wq.cond.notify_all();
}
};
public:
WorkQueue(size_t _maxDepth) : running(true),
maxDepth(_maxDepth),
numThreads(0)
{
}
/** Precondition: worker threads have all stopped
* (call WaitExit)
*/
~WorkQueue()
{
}
/** Enqueue a work item */
bool Enqueue(WorkItem* item)
{
std::unique_lock<std::mutex> lock(cs);
if (queue.size() >= maxDepth) {
return false;
}
queue.emplace_back(std::unique_ptr<WorkItem>(item));
cond.notify_one();
return true;
}
/** Thread function */
void Run()
{
ThreadCounter count(*this);
while (true) {
std::unique_ptr<WorkItem> i;
{
std::unique_lock<std::mutex> lock(cs);
while (running && queue.empty())
cond.wait(lock);
if (!running)
break;
i = std::move(queue.front());
queue.pop_front();
}
(*i)();
}
}
/** Interrupt and exit loops */
void Interrupt()
{
std::unique_lock<std::mutex> lock(cs);
running = false;
cond.notify_all();
}
/** Wait for worker threads to exit */
void WaitExit()
{
std::unique_lock<std::mutex> lock(cs);
while (numThreads > 0){
cond.wait(lock);
}
}
/** Return current depth of queue */
size_t Depth()
{
std::unique_lock<std::mutex> lock(cs);
return queue.size();
}
};
struct HTTPPathHandler
{
HTTPPathHandler() {}
HTTPPathHandler(std::string _prefix, bool _exactMatch, HTTPRequestHandler _handler):
prefix(_prefix), exactMatch(_exactMatch), handler(_handler)
{
}
std::string prefix;
bool exactMatch;
HTTPRequestHandler handler;
};
/** HTTP module state */
//! libevent event loop
static struct event_base* eventBase = 0;
//! HTTP server
struct evhttp* eventHTTP = 0;
//! List of subnets to allow RPC connections from
static std::vector<CSubNet> rpc_allow_subnets;
//! Work queue for handling longer requests off the event loop thread
static WorkQueue<HTTPClosure>* workQueue = 0;
//! Handlers for (sub)paths
std::vector<HTTPPathHandler> pathHandlers;
//! Bound listening sockets
std::vector<evhttp_bound_socket *> boundSockets;
/** Check if a network address is allowed to access the HTTP server */
static bool ClientAllowed(const CNetAddr& netaddr)
{
if (!netaddr.IsValid())
return false;
for(const CSubNet& subnet : rpc_allow_subnets)
if (subnet.Match(netaddr))
return true;
return false;
}
/** Initialize ACL list for HTTP server */
static bool InitHTTPAllowList()
{
rpc_allow_subnets.clear();
CNetAddr localv4;
CNetAddr localv6;
LookupHost("127.0.0.1", localv4, false);
LookupHost("::1", localv6, false);
rpc_allow_subnets.push_back(CSubNet(localv4, 8)); // always allow IPv4 local subnet
rpc_allow_subnets.push_back(CSubNet(localv6)); // always allow IPv6 localhost
if (mapMultiArgs.count("-rpcallowip")) {
const std::vector<std::string>& vAllow = mapMultiArgs.at("-rpcallowip");
for (std::string strAllow : vAllow) {
CSubNet subnet;
LookupSubNet(strAllow.c_str(), subnet);
if (!subnet.IsValid()) {
uiInterface.ThreadSafeMessageBox(
strprintf("Invalid -rpcallowip subnet specification: %s. Valid are a single IP (e.g. 1.2.3.4), a network/netmask (e.g. 1.2.3.4/255.255.255.0) or a network/CIDR (e.g. 1.2.3.4/24).", strAllow),
"", CClientUIInterface::MSG_ERROR);
return false;
}
rpc_allow_subnets.push_back(subnet);
}
}
std::string strAllowed;
for (const CSubNet& subnet : rpc_allow_subnets)
strAllowed += subnet.ToString() + " ";
LogPrint("http", "Allowing HTTP connections from: %s\n", strAllowed);
return true;
}
/** HTTP request method as string - use for logging only */
static std::string RequestMethodString(HTTPRequest::RequestMethod m)
{
switch (m) {
case HTTPRequest::GET:
return "GET";
break;
case HTTPRequest::POST:
return "POST";
break;
case HTTPRequest::HEAD:
return "HEAD";
break;
case HTTPRequest::PUT:
return "PUT";
break;
default:
return "unknown";
}
}
/** HTTP request callback */
static void http_request_cb(struct evhttp_request* req, void* arg)
{
std::unique_ptr<HTTPRequest> hreq(new HTTPRequest(req));
LogPrint("http", "Received a %s request for %s from %s\n",
RequestMethodString(hreq->GetRequestMethod()), hreq->GetURI(), hreq->GetPeer().ToString());
// Early address-based allow check
if (!ClientAllowed(hreq->GetPeer())) {
hreq->WriteReply(HTTP_FORBIDDEN);
return;
}
// Early reject unknown HTTP methods
if (hreq->GetRequestMethod() == HTTPRequest::UNKNOWN) {
hreq->WriteReply(HTTP_BADMETHOD);
return;
}
// Find registered handler for prefix
std::string strURI = hreq->GetURI();
std::string path;
std::vector<HTTPPathHandler>::const_iterator i = pathHandlers.begin();
std::vector<HTTPPathHandler>::const_iterator iend = pathHandlers.end();
for (; i != iend; ++i) {
bool match = false;
if (i->exactMatch)
match = (strURI == i->prefix);
else
match = (strURI.substr(0, i->prefix.size()) == i->prefix);
if (match) {
path = strURI.substr(i->prefix.size());
break;
}
}
// Dispatch to worker thread
if (i != iend) {
std::unique_ptr<HTTPWorkItem> item(new HTTPWorkItem(std::move(hreq), path, i->handler));
assert(workQueue);
if (workQueue->Enqueue(item.get()))
item.release(); /* if true, queue took ownership */
else {
LogPrintf("WARNING: request rejected because http work queue depth exceeded, it can be increased with the -rpcworkqueue= setting\n");
item->req->WriteReply(HTTP_INTERNAL, "Work queue depth exceeded");
}
} else {
hreq->WriteReply(HTTP_NOTFOUND);
}
}
/** Callback to reject HTTP requests after shutdown. */
static void http_reject_request_cb(struct evhttp_request* req, void*)
{
LogPrint("http", "Rejecting request while shutting down\n");
evhttp_send_error(req, HTTP_SERVUNAVAIL, NULL);
}
/** Event dispatcher thread */
static bool ThreadHTTP(struct event_base* base, struct evhttp* http)
{
RenameThread("dash-http");
LogPrint("http", "Entering http event loop\n");
event_base_dispatch(base);
// Event loop will be interrupted by InterruptHTTPServer()
LogPrint("http", "Exited http event loop\n");
return event_base_got_break(base) == 0;
}
/** Bind HTTP server to specified addresses */
static bool HTTPBindAddresses(struct evhttp* http)
{
int defaultPort = GetArg("-rpcport", BaseParams().RPCPort());
std::vector<std::pair<std::string, uint16_t> > endpoints;
// Determine what addresses to bind to
if (!IsArgSet("-rpcallowip")) { // Default to loopback if not allowing external IPs
endpoints.push_back(std::make_pair("::1", defaultPort));
endpoints.push_back(std::make_pair("127.0.0.1", defaultPort));
if (IsArgSet("-rpcbind")) {
LogPrintf("WARNING: option -rpcbind was ignored because -rpcallowip was not specified, refusing to allow everyone to connect\n");
}
} else if (mapMultiArgs.count("-rpcbind")) { // Specific bind address
const std::vector<std::string>& vbind = mapMultiArgs.at("-rpcbind");
for (std::vector<std::string>::const_iterator i = vbind.begin(); i != vbind.end(); ++i) {
int port = defaultPort;
std::string host;
SplitHostPort(*i, port, host);
endpoints.push_back(std::make_pair(host, port));
}
} else { // No specific bind address specified, bind to any
endpoints.push_back(std::make_pair("::", defaultPort));
endpoints.push_back(std::make_pair("0.0.0.0", defaultPort));
}
// Bind addresses
for (std::vector<std::pair<std::string, uint16_t> >::iterator i = endpoints.begin(); i != endpoints.end(); ++i) {
LogPrint("http", "Binding RPC on address %s port %i\n", i->first, i->second);
evhttp_bound_socket *bind_handle = evhttp_bind_socket_with_handle(http, i->first.empty() ? NULL : i->first.c_str(), i->second);
if (bind_handle) {
boundSockets.push_back(bind_handle);
} else {
LogPrintf("Binding RPC on address %s port %i failed.\n", i->first, i->second);
}
}
return !boundSockets.empty();
}
/** Simple wrapper to set thread name and run work queue */
static void HTTPWorkQueueRun(WorkQueue<HTTPClosure>* queue)
{
RenameThread("dash-httpworker");
queue->Run();
}
/** libevent event log callback */
static void libevent_log_cb(int severity, const char *msg)
{
#ifndef EVENT_LOG_WARN
// EVENT_LOG_WARN was added in 2.0.19; but before then _EVENT_LOG_WARN existed.
# define EVENT_LOG_WARN _EVENT_LOG_WARN
#endif
if (severity >= EVENT_LOG_WARN) // Log warn messages and higher without debug category
LogPrintf("libevent: %s\n", msg);
else
LogPrint("libevent", "libevent: %s\n", msg);
}
bool InitHTTPServer()
{
struct evhttp* http = 0;
struct event_base* base = 0;
if (!InitHTTPAllowList())
return false;
if (GetBoolArg("-rpcssl", false)) {
uiInterface.ThreadSafeMessageBox(
"SSL mode for RPC (-rpcssl) is no longer supported.",
"", CClientUIInterface::MSG_ERROR);
return false;
}
// Redirect libevent's logging to our own log
event_set_log_callback(&libevent_log_cb);
#if LIBEVENT_VERSION_NUMBER >= 0x02010100
// If -debug=libevent, set full libevent debugging.
// Otherwise, disable all libevent debugging.
if (LogAcceptCategory("libevent"))
event_enable_debug_logging(EVENT_DBG_ALL);
else
event_enable_debug_logging(EVENT_DBG_NONE);
#endif
#ifdef WIN32
evthread_use_windows_threads();
#else
evthread_use_pthreads();
#endif
base = event_base_new(); // XXX RAII
if (!base) {
LogPrintf("Couldn't create an event_base: exiting\n");
return false;
}
/* Create a new evhttp object to handle requests. */
http = evhttp_new(base); // XXX RAII
if (!http) {
LogPrintf("couldn't create evhttp. Exiting.\n");
event_base_free(base);
return false;
}
evhttp_set_timeout(http, GetArg("-rpcservertimeout", DEFAULT_HTTP_SERVER_TIMEOUT));
evhttp_set_max_headers_size(http, MAX_HEADERS_SIZE);
evhttp_set_max_body_size(http, MAX_SIZE);
evhttp_set_gencb(http, http_request_cb, NULL);
if (!HTTPBindAddresses(http)) {
LogPrintf("Unable to bind any endpoint for RPC server\n");
evhttp_free(http);
event_base_free(base);
return false;
}
LogPrint("http", "Initialized HTTP server\n");
int workQueueDepth = std::max((long)GetArg("-rpcworkqueue", DEFAULT_HTTP_WORKQUEUE), 1L);
LogPrintf("HTTP: creating work queue of depth %d\n", workQueueDepth);
workQueue = new WorkQueue<HTTPClosure>(workQueueDepth);
eventBase = base;
eventHTTP = http;
return true;
}
std::thread threadHTTP;
std::future<bool> threadResult;
bool StartHTTPServer()
{
LogPrint("http", "Starting HTTP server\n");
int rpcThreads = std::max((long)GetArg("-rpcthreads", DEFAULT_HTTP_THREADS), 1L);
LogPrintf("HTTP: starting %d worker threads\n", rpcThreads);
std::packaged_task<bool(event_base*, evhttp*)> task(ThreadHTTP);
threadResult = task.get_future();
threadHTTP = std::thread(std::move(task), eventBase, eventHTTP);
for (int i = 0; i < rpcThreads; i++) {
std::thread rpc_worker(HTTPWorkQueueRun, workQueue);
rpc_worker.detach();
}
return true;
}
void InterruptHTTPServer()
{
LogPrint("http", "Interrupting HTTP server\n");
if (eventHTTP) {
// Unlisten sockets
for (evhttp_bound_socket *socket : boundSockets) {
evhttp_del_accept_socket(eventHTTP, socket);
}
// Reject requests on current connections
evhttp_set_gencb(eventHTTP, http_reject_request_cb, NULL);
}
if (workQueue)
workQueue->Interrupt();
}
void StopHTTPServer()
{
LogPrint("http", "Stopping HTTP server\n");
if (workQueue) {
LogPrint("http", "Waiting for HTTP worker threads to exit\n");
#ifndef WIN32
// ToDo: Disabling WaitExit() for Windows platforms is an ugly workaround for the wallet not
// closing during a repair-restart. It doesn't hurt, though, because threadHTTP.timed_join
// below takes care of this and sends a loopbreak.
workQueue->WaitExit();
#endif
delete workQueue;
}
if (eventBase) {
LogPrint("http", "Waiting for HTTP event thread to exit\n");
// Give event loop a few seconds to exit (to send back last RPC responses), then break it
// Before this was solved with event_base_loopexit, but that didn't work as expected in
// at least libevent 2.0.21 and always introduced a delay. In libevent
// master that appears to be solved, so in the future that solution
// could be used again (if desirable).
// (see discussion in https://github.com/bitcoin/bitcoin/pull/6990)
if (threadResult.valid() && threadResult.wait_for(std::chrono::milliseconds(2000)) == std::future_status::timeout) {
LogPrintf("HTTP event loop did not exit within allotted time, sending loopbreak\n");
event_base_loopbreak(eventBase);
}
threadHTTP.join();
}
if (eventHTTP) {
evhttp_free(eventHTTP);
eventHTTP = 0;
}
if (eventBase) {
event_base_free(eventBase);
eventBase = 0;
}
LogPrint("http", "Stopped HTTP server\n");
}
struct event_base* EventBase()
{
return eventBase;
}
static void httpevent_callback_fn(evutil_socket_t, short, void* data)
{
// Static handler: simply call inner handler
HTTPEvent *self = ((HTTPEvent*)data);
self->handler();
if (self->deleteWhenTriggered)
delete self;
}
HTTPEvent::HTTPEvent(struct event_base* base, bool _deleteWhenTriggered, const std::function<void(void)>& _handler):
deleteWhenTriggered(_deleteWhenTriggered), handler(_handler)
{
ev = event_new(base, -1, 0, httpevent_callback_fn, this);
assert(ev);
}
HTTPEvent::~HTTPEvent()
{
event_free(ev);
}
void HTTPEvent::trigger(struct timeval* tv)
{
if (tv == NULL)
event_active(ev, 0, 0); // immediately trigger event in main thread
else
evtimer_add(ev, tv); // trigger after timeval passed
}
HTTPRequest::HTTPRequest(struct evhttp_request* _req) : req(_req),
replySent(false)
{
}
HTTPRequest::~HTTPRequest()
{
if (!replySent) {
// Keep track of whether reply was sent to avoid request leaks
LogPrintf("%s: Unhandled request\n", __func__);
WriteReply(HTTP_INTERNAL, "Unhandled request");
}
// evhttpd cleans up the request, as long as a reply was sent.
}
std::pair<bool, std::string> HTTPRequest::GetHeader(const std::string& hdr)
{
const struct evkeyvalq* headers = evhttp_request_get_input_headers(req);
assert(headers);
const char* val = evhttp_find_header(headers, hdr.c_str());
if (val)
return std::make_pair(true, val);
else
return std::make_pair(false, "");
}
std::string HTTPRequest::ReadBody()
{
struct evbuffer* buf = evhttp_request_get_input_buffer(req);
if (!buf)
return "";
size_t size = evbuffer_get_length(buf);
/** Trivial implementation: if this is ever a performance bottleneck,
* internal copying can be avoided in multi-segment buffers by using
* evbuffer_peek and an awkward loop. Though in that case, it'd be even
* better to not copy into an intermediate string but use a stream
* abstraction to consume the evbuffer on the fly in the parsing algorithm.
*/
const char* data = (const char*)evbuffer_pullup(buf, size);
if (!data) // returns NULL in case of empty buffer
return "";
std::string rv(data, size);
evbuffer_drain(buf, size);
return rv;
}
void HTTPRequest::WriteHeader(const std::string& hdr, const std::string& value)
{
struct evkeyvalq* headers = evhttp_request_get_output_headers(req);
assert(headers);
evhttp_add_header(headers, hdr.c_str(), value.c_str());
}
/** Closure sent to main thread to request a reply to be sent to
* a HTTP request.
* Replies must be sent in the main loop in the main http thread,
* this cannot be done from worker threads.
*/
void HTTPRequest::WriteReply(int nStatus, const std::string& strReply)
{
assert(!replySent && req);
// Send event to main http thread to send reply message
struct evbuffer* evb = evhttp_request_get_output_buffer(req);
assert(evb);
evbuffer_add(evb, strReply.data(), strReply.size());
HTTPEvent* ev = new HTTPEvent(eventBase, true,
std::bind(evhttp_send_reply, req, nStatus, (const char*)NULL, (struct evbuffer *)NULL));
ev->trigger(0);
replySent = true;
req = 0; // transferred back to main thread
}
CService HTTPRequest::GetPeer()
{
evhttp_connection* con = evhttp_request_get_connection(req);
CService peer;
if (con) {
// evhttp retains ownership over returned address string
const char* address = "";
uint16_t port = 0;
evhttp_connection_get_peer(con, (char**)&address, &port);
peer = LookupNumeric(address, port);
}
return peer;
}
std::string HTTPRequest::GetURI()
{
return evhttp_request_get_uri(req);
}
HTTPRequest::RequestMethod HTTPRequest::GetRequestMethod()
{
switch (evhttp_request_get_command(req)) {
case EVHTTP_REQ_GET:
return GET;
break;
case EVHTTP_REQ_POST:
return POST;
break;
case EVHTTP_REQ_HEAD:
return HEAD;
break;
case EVHTTP_REQ_PUT:
return PUT;
break;
default:
return UNKNOWN;
break;
}
}
void RegisterHTTPHandler(const std::string &prefix, bool exactMatch, const HTTPRequestHandler &handler)
{
LogPrint("http", "Registering HTTP handler for %s (exactmatch %d)\n", prefix, exactMatch);
pathHandlers.push_back(HTTPPathHandler(prefix, exactMatch, handler));
}
void UnregisterHTTPHandler(const std::string &prefix, bool exactMatch)
{
std::vector<HTTPPathHandler>::iterator i = pathHandlers.begin();
std::vector<HTTPPathHandler>::iterator iend = pathHandlers.end();
for (; i != iend; ++i)
if (i->prefix == prefix && i->exactMatch == exactMatch)
break;
if (i != iend)
{
LogPrint("http", "Unregistering HTTP handler for %s (exactmatch %d)\n", prefix, exactMatch);
pathHandlers.erase(i);
}
}