minetest/src/httpfetch.cpp
rubenwardy 87ad4d8e7f
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Replaces mods and texture pack tabs with a single content tab
2018-04-19 20:14:53 +01:00

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C++

/*
Minetest
Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "httpfetch.h"
#include "porting.h" // for sleep_ms(), get_sysinfo(), secure_rand_fill_buf()
#include <iostream>
#include <sstream>
#include <list>
#include <map>
#include <cerrno>
#include <mutex>
#include "network/socket.h" // for select()
#include "threading/event.h"
#include "config.h"
#include "exceptions.h"
#include "debug.h"
#include "log.h"
#include "util/container.h"
#include "util/thread.h"
#include "version.h"
#include "settings.h"
#include "noise.h"
std::mutex g_httpfetch_mutex;
std::map<unsigned long, std::queue<HTTPFetchResult> > g_httpfetch_results;
PcgRandom g_callerid_randomness;
HTTPFetchRequest::HTTPFetchRequest() :
timeout(g_settings->getS32("curl_timeout")),
connect_timeout(timeout),
useragent(std::string(PROJECT_NAME_C "/") + g_version_hash + " (" + porting::get_sysinfo() + ")")
{
}
static void httpfetch_deliver_result(const HTTPFetchResult &fetch_result)
{
unsigned long caller = fetch_result.caller;
if (caller != HTTPFETCH_DISCARD) {
MutexAutoLock lock(g_httpfetch_mutex);
g_httpfetch_results[caller].push(fetch_result);
}
}
static void httpfetch_request_clear(unsigned long caller);
unsigned long httpfetch_caller_alloc()
{
MutexAutoLock lock(g_httpfetch_mutex);
// Check each caller ID except HTTPFETCH_DISCARD
const unsigned long discard = HTTPFETCH_DISCARD;
for (unsigned long caller = discard + 1; caller != discard; ++caller) {
std::map<unsigned long, std::queue<HTTPFetchResult> >::iterator
it = g_httpfetch_results.find(caller);
if (it == g_httpfetch_results.end()) {
verbosestream << "httpfetch_caller_alloc: allocating "
<< caller << std::endl;
// Access element to create it
g_httpfetch_results[caller];
return caller;
}
}
FATAL_ERROR("httpfetch_caller_alloc: ran out of caller IDs");
return discard;
}
unsigned long httpfetch_caller_alloc_secure()
{
MutexAutoLock lock(g_httpfetch_mutex);
// Generate random caller IDs and make sure they're not
// already used or equal to HTTPFETCH_DISCARD
// Give up after 100 tries to prevent infinite loop
u8 tries = 100;
unsigned long caller;
do {
caller = (((u64) g_callerid_randomness.next()) << 32) |
g_callerid_randomness.next();
if (--tries < 1) {
FATAL_ERROR("httpfetch_caller_alloc_secure: ran out of caller IDs");
return HTTPFETCH_DISCARD;
}
} while (g_httpfetch_results.find(caller) != g_httpfetch_results.end());
verbosestream << "httpfetch_caller_alloc_secure: allocating "
<< caller << std::endl;
// Access element to create it
g_httpfetch_results[caller];
return caller;
}
void httpfetch_caller_free(unsigned long caller)
{
verbosestream<<"httpfetch_caller_free: freeing "
<<caller<<std::endl;
httpfetch_request_clear(caller);
if (caller != HTTPFETCH_DISCARD) {
MutexAutoLock lock(g_httpfetch_mutex);
g_httpfetch_results.erase(caller);
}
}
bool httpfetch_async_get(unsigned long caller, HTTPFetchResult &fetch_result)
{
MutexAutoLock lock(g_httpfetch_mutex);
// Check that caller exists
std::map<unsigned long, std::queue<HTTPFetchResult> >::iterator
it = g_httpfetch_results.find(caller);
if (it == g_httpfetch_results.end())
return false;
// Check that result queue is nonempty
std::queue<HTTPFetchResult> &caller_results = it->second;
if (caller_results.empty())
return false;
// Pop first result
fetch_result = caller_results.front();
caller_results.pop();
return true;
}
#if USE_CURL
#include <curl/curl.h>
/*
USE_CURL is on: use cURL based httpfetch implementation
*/
static size_t httpfetch_writefunction(
char *ptr, size_t size, size_t nmemb, void *userdata)
{
std::ostringstream *stream = (std::ostringstream*)userdata;
size_t count = size * nmemb;
stream->write(ptr, count);
return count;
}
static size_t httpfetch_discardfunction(
char *ptr, size_t size, size_t nmemb, void *userdata)
{
return size * nmemb;
}
class CurlHandlePool
{
std::list<CURL*> handles;
public:
CurlHandlePool() = default;
~CurlHandlePool()
{
for (std::list<CURL*>::iterator it = handles.begin();
it != handles.end(); ++it) {
curl_easy_cleanup(*it);
}
}
CURL * alloc()
{
CURL *curl;
if (handles.empty()) {
curl = curl_easy_init();
if (curl == NULL) {
errorstream<<"curl_easy_init returned NULL"<<std::endl;
}
}
else {
curl = handles.front();
handles.pop_front();
}
return curl;
}
void free(CURL *handle)
{
if (handle)
handles.push_back(handle);
}
};
class HTTPFetchOngoing
{
public:
HTTPFetchOngoing(const HTTPFetchRequest &request, CurlHandlePool *pool);
~HTTPFetchOngoing();
CURLcode start(CURLM *multi);
const HTTPFetchResult * complete(CURLcode res);
const HTTPFetchRequest &getRequest() const { return request; };
const CURL *getEasyHandle() const { return curl; };
private:
CurlHandlePool *pool;
CURL *curl;
CURLM *multi;
HTTPFetchRequest request;
HTTPFetchResult result;
std::ostringstream oss;
struct curl_slist *http_header;
curl_httppost *post;
};
HTTPFetchOngoing::HTTPFetchOngoing(const HTTPFetchRequest &request_,
CurlHandlePool *pool_):
pool(pool_),
curl(NULL),
multi(NULL),
request(request_),
result(request_),
oss(std::ios::binary),
http_header(NULL),
post(NULL)
{
curl = pool->alloc();
if (curl == NULL) {
return;
}
// Set static cURL options
curl_easy_setopt(curl, CURLOPT_NOSIGNAL, 1);
curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1);
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
curl_easy_setopt(curl, CURLOPT_MAXREDIRS, 3);
curl_easy_setopt(curl, CURLOPT_ENCODING, "gzip");
std::string bind_address = g_settings->get("bind_address");
if (!bind_address.empty()) {
curl_easy_setopt(curl, CURLOPT_INTERFACE, bind_address.c_str());
}
#if LIBCURL_VERSION_NUM >= 0x071304
// Restrict protocols so that curl vulnerabilities in
// other protocols don't affect us.
// These settings were introduced in curl 7.19.4.
long protocols =
CURLPROTO_HTTP |
CURLPROTO_HTTPS |
CURLPROTO_FTP |
CURLPROTO_FTPS;
curl_easy_setopt(curl, CURLOPT_PROTOCOLS, protocols);
curl_easy_setopt(curl, CURLOPT_REDIR_PROTOCOLS, protocols);
#endif
// Set cURL options based on HTTPFetchRequest
curl_easy_setopt(curl, CURLOPT_URL,
request.url.c_str());
curl_easy_setopt(curl, CURLOPT_TIMEOUT_MS,
request.timeout);
curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT_MS,
request.connect_timeout);
if (!request.useragent.empty())
curl_easy_setopt(curl, CURLOPT_USERAGENT, request.useragent.c_str());
// Set up a write callback that writes to the
// ostringstream ongoing->oss, unless the data
// is to be discarded
if (request.caller == HTTPFETCH_DISCARD) {
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
httpfetch_discardfunction);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
} else {
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
httpfetch_writefunction);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, &oss);
}
// Set POST (or GET) data
if (request.post_fields.empty() && request.post_data.empty()) {
curl_easy_setopt(curl, CURLOPT_HTTPGET, 1);
} else if (request.multipart) {
curl_httppost *last = NULL;
for (StringMap::iterator it = request.post_fields.begin();
it != request.post_fields.end(); ++it) {
curl_formadd(&post, &last,
CURLFORM_NAMELENGTH, it->first.size(),
CURLFORM_PTRNAME, it->first.c_str(),
CURLFORM_CONTENTSLENGTH, it->second.size(),
CURLFORM_PTRCONTENTS, it->second.c_str(),
CURLFORM_END);
}
curl_easy_setopt(curl, CURLOPT_HTTPPOST, post);
// request.post_fields must now *never* be
// modified until CURLOPT_HTTPPOST is cleared
} else if (request.post_data.empty()) {
curl_easy_setopt(curl, CURLOPT_POST, 1);
std::string str;
for (auto &post_field : request.post_fields) {
if (!str.empty())
str += "&";
str += urlencode(post_field.first);
str += "=";
str += urlencode(post_field.second);
}
curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE,
str.size());
curl_easy_setopt(curl, CURLOPT_COPYPOSTFIELDS,
str.c_str());
} else {
curl_easy_setopt(curl, CURLOPT_POST, 1);
curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE,
request.post_data.size());
curl_easy_setopt(curl, CURLOPT_POSTFIELDS,
request.post_data.c_str());
// request.post_data must now *never* be
// modified until CURLOPT_POSTFIELDS is cleared
}
// Set additional HTTP headers
for (const std::string &extra_header : request.extra_headers) {
http_header = curl_slist_append(http_header, extra_header.c_str());
}
curl_easy_setopt(curl, CURLOPT_HTTPHEADER, http_header);
if (!g_settings->getBool("curl_verify_cert")) {
curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, false);
}
}
CURLcode HTTPFetchOngoing::start(CURLM *multi_)
{
if (!curl)
return CURLE_FAILED_INIT;
if (!multi_) {
// Easy interface (sync)
return curl_easy_perform(curl);
}
// Multi interface (async)
CURLMcode mres = curl_multi_add_handle(multi_, curl);
if (mres != CURLM_OK) {
errorstream << "curl_multi_add_handle"
<< " returned error code " << mres
<< std::endl;
return CURLE_FAILED_INIT;
}
multi = multi_; // store for curl_multi_remove_handle
return CURLE_OK;
}
const HTTPFetchResult * HTTPFetchOngoing::complete(CURLcode res)
{
result.succeeded = (res == CURLE_OK);
result.timeout = (res == CURLE_OPERATION_TIMEDOUT);
result.data = oss.str();
// Get HTTP/FTP response code
result.response_code = 0;
if (curl && (curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE,
&result.response_code) != CURLE_OK)) {
// We failed to get a return code, make sure it is still 0
result.response_code = 0;
}
if (res != CURLE_OK) {
errorstream << request.url << " not found ("
<< curl_easy_strerror(res) << ")"
<< " (response code " << result.response_code << ")"
<< std::endl;
}
return &result;
}
HTTPFetchOngoing::~HTTPFetchOngoing()
{
if (multi) {
CURLMcode mres = curl_multi_remove_handle(multi, curl);
if (mres != CURLM_OK) {
errorstream << "curl_multi_remove_handle"
<< " returned error code " << mres
<< std::endl;
}
}
// Set safe options for the reusable cURL handle
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
httpfetch_discardfunction);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
curl_easy_setopt(curl, CURLOPT_POSTFIELDS, NULL);
if (http_header) {
curl_easy_setopt(curl, CURLOPT_HTTPHEADER, NULL);
curl_slist_free_all(http_header);
}
if (post) {
curl_easy_setopt(curl, CURLOPT_HTTPPOST, NULL);
curl_formfree(post);
}
// Store the cURL handle for reuse
pool->free(curl);
}
class CurlFetchThread : public Thread
{
protected:
enum RequestType {
RT_FETCH,
RT_CLEAR,
RT_WAKEUP,
};
struct Request {
RequestType type;
HTTPFetchRequest fetch_request;
Event *event;
};
CURLM *m_multi;
MutexedQueue<Request> m_requests;
size_t m_parallel_limit;
// Variables exclusively used within thread
std::vector<HTTPFetchOngoing*> m_all_ongoing;
std::list<HTTPFetchRequest> m_queued_fetches;
public:
CurlFetchThread(int parallel_limit) :
Thread("CurlFetch")
{
if (parallel_limit >= 1)
m_parallel_limit = parallel_limit;
else
m_parallel_limit = 1;
}
void requestFetch(const HTTPFetchRequest &fetch_request)
{
Request req;
req.type = RT_FETCH;
req.fetch_request = fetch_request;
req.event = NULL;
m_requests.push_back(req);
}
void requestClear(unsigned long caller, Event *event)
{
Request req;
req.type = RT_CLEAR;
req.fetch_request.caller = caller;
req.event = event;
m_requests.push_back(req);
}
void requestWakeUp()
{
Request req;
req.type = RT_WAKEUP;
req.event = NULL;
m_requests.push_back(req);
}
protected:
// Handle a request from some other thread
// E.g. new fetch; clear fetches for one caller; wake up
void processRequest(const Request &req)
{
if (req.type == RT_FETCH) {
// New fetch, queue until there are less
// than m_parallel_limit ongoing fetches
m_queued_fetches.push_back(req.fetch_request);
// see processQueued() for what happens next
}
else if (req.type == RT_CLEAR) {
unsigned long caller = req.fetch_request.caller;
// Abort all ongoing fetches for the caller
for (std::vector<HTTPFetchOngoing*>::iterator
it = m_all_ongoing.begin();
it != m_all_ongoing.end();) {
if ((*it)->getRequest().caller == caller) {
delete (*it);
it = m_all_ongoing.erase(it);
} else {
++it;
}
}
// Also abort all queued fetches for the caller
for (std::list<HTTPFetchRequest>::iterator
it = m_queued_fetches.begin();
it != m_queued_fetches.end();) {
if ((*it).caller == caller)
it = m_queued_fetches.erase(it);
else
++it;
}
}
else if (req.type == RT_WAKEUP) {
// Wakeup: Nothing to do, thread is awake at this point
}
if (req.event != NULL)
req.event->signal();
}
// Start new ongoing fetches if m_parallel_limit allows
void processQueued(CurlHandlePool *pool)
{
while (m_all_ongoing.size() < m_parallel_limit &&
!m_queued_fetches.empty()) {
HTTPFetchRequest request = m_queued_fetches.front();
m_queued_fetches.pop_front();
// Create ongoing fetch data and make a cURL handle
// Set cURL options based on HTTPFetchRequest
HTTPFetchOngoing *ongoing =
new HTTPFetchOngoing(request, pool);
// Initiate the connection (curl_multi_add_handle)
CURLcode res = ongoing->start(m_multi);
if (res == CURLE_OK) {
m_all_ongoing.push_back(ongoing);
}
else {
httpfetch_deliver_result(*ongoing->complete(res));
delete ongoing;
}
}
}
// Process CURLMsg (indicates completion of a fetch)
void processCurlMessage(CURLMsg *msg)
{
// Determine which ongoing fetch the message pertains to
size_t i = 0;
bool found = false;
for (i = 0; i < m_all_ongoing.size(); ++i) {
if (m_all_ongoing[i]->getEasyHandle() == msg->easy_handle) {
found = true;
break;
}
}
if (msg->msg == CURLMSG_DONE && found) {
// m_all_ongoing[i] succeeded or failed.
HTTPFetchOngoing *ongoing = m_all_ongoing[i];
httpfetch_deliver_result(*ongoing->complete(msg->data.result));
delete ongoing;
m_all_ongoing.erase(m_all_ongoing.begin() + i);
}
}
// Wait for a request from another thread, or timeout elapses
void waitForRequest(long timeout)
{
if (m_queued_fetches.empty()) {
try {
Request req = m_requests.pop_front(timeout);
processRequest(req);
}
catch (ItemNotFoundException &e) {}
}
}
// Wait until some IO happens, or timeout elapses
void waitForIO(long timeout)
{
fd_set read_fd_set;
fd_set write_fd_set;
fd_set exc_fd_set;
int max_fd;
long select_timeout = -1;
struct timeval select_tv;
CURLMcode mres;
FD_ZERO(&read_fd_set);
FD_ZERO(&write_fd_set);
FD_ZERO(&exc_fd_set);
mres = curl_multi_fdset(m_multi, &read_fd_set,
&write_fd_set, &exc_fd_set, &max_fd);
if (mres != CURLM_OK) {
errorstream<<"curl_multi_fdset"
<<" returned error code "<<mres
<<std::endl;
select_timeout = 0;
}
mres = curl_multi_timeout(m_multi, &select_timeout);
if (mres != CURLM_OK) {
errorstream<<"curl_multi_timeout"
<<" returned error code "<<mres
<<std::endl;
select_timeout = 0;
}
// Limit timeout so new requests get through
if (select_timeout < 0 || select_timeout > timeout)
select_timeout = timeout;
if (select_timeout > 0) {
// in Winsock it is forbidden to pass three empty
// fd_sets to select(), so in that case use sleep_ms
if (max_fd != -1) {
select_tv.tv_sec = select_timeout / 1000;
select_tv.tv_usec = (select_timeout % 1000) * 1000;
int retval = select(max_fd + 1, &read_fd_set,
&write_fd_set, &exc_fd_set,
&select_tv);
if (retval == -1) {
#ifdef _WIN32
errorstream<<"select returned error code "
<<WSAGetLastError()<<std::endl;
#else
errorstream<<"select returned error code "
<<errno<<std::endl;
#endif
}
}
else {
sleep_ms(select_timeout);
}
}
}
void *run()
{
CurlHandlePool pool;
m_multi = curl_multi_init();
if (m_multi == NULL) {
errorstream<<"curl_multi_init returned NULL\n";
return NULL;
}
FATAL_ERROR_IF(!m_all_ongoing.empty(), "Expected empty");
while (!stopRequested()) {
BEGIN_DEBUG_EXCEPTION_HANDLER
/*
Handle new async requests
*/
while (!m_requests.empty()) {
Request req = m_requests.pop_frontNoEx();
processRequest(req);
}
processQueued(&pool);
/*
Handle ongoing async requests
*/
int still_ongoing = 0;
while (curl_multi_perform(m_multi, &still_ongoing) ==
CURLM_CALL_MULTI_PERFORM)
/* noop */;
/*
Handle completed async requests
*/
if (still_ongoing < (int) m_all_ongoing.size()) {
CURLMsg *msg;
int msgs_in_queue;
msg = curl_multi_info_read(m_multi, &msgs_in_queue);
while (msg != NULL) {
processCurlMessage(msg);
msg = curl_multi_info_read(m_multi, &msgs_in_queue);
}
}
/*
If there are ongoing requests, wait for data
(with a timeout of 100ms so that new requests
can be processed).
If no ongoing requests, wait for a new request.
(Possibly an empty request that signals
that the thread should be stopped.)
*/
if (m_all_ongoing.empty())
waitForRequest(100000000);
else
waitForIO(100);
END_DEBUG_EXCEPTION_HANDLER
}
// Call curl_multi_remove_handle and cleanup easy handles
for (HTTPFetchOngoing *i : m_all_ongoing) {
delete i;
}
m_all_ongoing.clear();
m_queued_fetches.clear();
CURLMcode mres = curl_multi_cleanup(m_multi);
if (mres != CURLM_OK) {
errorstream<<"curl_multi_cleanup"
<<" returned error code "<<mres
<<std::endl;
}
return NULL;
}
};
CurlFetchThread *g_httpfetch_thread = NULL;
void httpfetch_init(int parallel_limit)
{
verbosestream<<"httpfetch_init: parallel_limit="<<parallel_limit
<<std::endl;
CURLcode res = curl_global_init(CURL_GLOBAL_DEFAULT);
FATAL_ERROR_IF(res != CURLE_OK, "CURL init failed");
g_httpfetch_thread = new CurlFetchThread(parallel_limit);
// Initialize g_callerid_randomness for httpfetch_caller_alloc_secure
u64 randbuf[2];
porting::secure_rand_fill_buf(randbuf, sizeof(u64) * 2);
g_callerid_randomness = PcgRandom(randbuf[0], randbuf[1]);
}
void httpfetch_cleanup()
{
verbosestream<<"httpfetch_cleanup: cleaning up"<<std::endl;
g_httpfetch_thread->stop();
g_httpfetch_thread->requestWakeUp();
g_httpfetch_thread->wait();
delete g_httpfetch_thread;
curl_global_cleanup();
}
void httpfetch_async(const HTTPFetchRequest &fetch_request)
{
g_httpfetch_thread->requestFetch(fetch_request);
if (!g_httpfetch_thread->isRunning())
g_httpfetch_thread->start();
}
static void httpfetch_request_clear(unsigned long caller)
{
if (g_httpfetch_thread->isRunning()) {
Event event;
g_httpfetch_thread->requestClear(caller, &event);
event.wait();
} else {
g_httpfetch_thread->requestClear(caller, NULL);
}
}
void httpfetch_sync(const HTTPFetchRequest &fetch_request,
HTTPFetchResult &fetch_result)
{
// Create ongoing fetch data and make a cURL handle
// Set cURL options based on HTTPFetchRequest
CurlHandlePool pool;
HTTPFetchOngoing ongoing(fetch_request, &pool);
// Do the fetch (curl_easy_perform)
CURLcode res = ongoing.start(NULL);
// Update fetch result
fetch_result = *ongoing.complete(res);
}
#else // USE_CURL
/*
USE_CURL is off:
Dummy httpfetch implementation that always returns an error.
*/
void httpfetch_init(int parallel_limit)
{
}
void httpfetch_cleanup()
{
}
void httpfetch_async(const HTTPFetchRequest &fetch_request)
{
errorstream << "httpfetch_async: unable to fetch " << fetch_request.url
<< " because USE_CURL=0" << std::endl;
HTTPFetchResult fetch_result(fetch_request); // sets succeeded = false etc.
httpfetch_deliver_result(fetch_result);
}
static void httpfetch_request_clear(unsigned long caller)
{
}
void httpfetch_sync(const HTTPFetchRequest &fetch_request,
HTTPFetchResult &fetch_result)
{
errorstream << "httpfetch_sync: unable to fetch " << fetch_request.url
<< " because USE_CURL=0" << std::endl;
fetch_result = HTTPFetchResult(fetch_request); // sets succeeded = false etc.
}
#endif // USE_CURL