src/httpfetch.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as published by
   7 the Free Software Foundation; either version 2.1 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public License along
  16 with this program; if not, write to the Free Software Foundation, Inc.,
  17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include "httpfetch.h"
  21 #include "porting.h" // for sleep_ms(), get_sysinfo(), secure_rand_fill_buf()
  22 #include <iostream>
  23 #include <sstream>
  24 #include <list>
  25 #include <map>
  26 #include <cerrno>
  27 #include <mutex>
  28 #include "network/socket.h" // for select()
  29 #include "threading/event.h"
  30 #include "config.h"
  31 #include "exceptions.h"
  32 #include "debug.h"
  33 #include "log.h"
  34 #include "util/container.h"
  35 #include "util/thread.h"
  36 #include "version.h"
  37 #include "settings.h"
  38 #include "noise.h"
  39
  40 std::mutex g_httpfetch_mutex;
  41 std::map<unsigned long, std::queue<HTTPFetchResult> > g_httpfetch_results;
  42 PcgRandom g_callerid_randomness;
  43
  44 HTTPFetchRequest::HTTPFetchRequest() :
  45         timeout(g_settings->getS32("curl_timeout")),
  46         connect_timeout(timeout),
  47         useragent(std::string(PROJECT_NAME_C "/") + g_version_hash + " (" + porting::get_sysinfo() + ")")
  48 {
  49 }
  50
  51
  52 static void httpfetch_deliver_result(const HTTPFetchResult &fetch_result)
  53 {
  54         unsigned long caller = fetch_result.caller;
  55         if (caller != HTTPFETCH_DISCARD) {
  56                 MutexAutoLock lock(g_httpfetch_mutex);
  57                 g_httpfetch_results[caller].push(fetch_result);
  58         }
  59 }
  60
  61 static void httpfetch_request_clear(unsigned long caller);
  62
  63 unsigned long httpfetch_caller_alloc()
  64 {
  65         MutexAutoLock lock(g_httpfetch_mutex);
  66
  67         // Check each caller ID except HTTPFETCH_DISCARD
  68         const unsigned long discard = HTTPFETCH_DISCARD;
  69         for (unsigned long caller = discard + 1; caller != discard; ++caller) {
  70                 std::map<unsigned long, std::queue<HTTPFetchResult> >::iterator
  71                         it = g_httpfetch_results.find(caller);
  72                 if (it == g_httpfetch_results.end()) {
  73                         verbosestream << "httpfetch_caller_alloc: allocating "
  74                                         << caller << std::endl;
  75                         // Access element to create it
  76                         g_httpfetch_results[caller];
  77                         return caller;
  78                 }
  79         }
  80
  81         FATAL_ERROR("httpfetch_caller_alloc: ran out of caller IDs");
  82         return discard;
  83 }
  84
  85 unsigned long httpfetch_caller_alloc_secure()
  86 {
  87         MutexAutoLock lock(g_httpfetch_mutex);
  88
  89         // Generate random caller IDs and make sure they're not
  90         // already used or equal to HTTPFETCH_DISCARD
  91         // Give up after 100 tries to prevent infinite loop
  92         u8 tries = 100;
  93         unsigned long caller;
  94
  95         do {
  96                 caller = (((u64) g_callerid_randomness.next()) << 32) |
  97                                 g_callerid_randomness.next();
  98
  99                 if (--tries < 1) {
 100                         FATAL_ERROR("httpfetch_caller_alloc_secure: ran out of caller IDs");
 101                         return HTTPFETCH_DISCARD;
 102                 }
 103         } while (g_httpfetch_results.find(caller) != g_httpfetch_results.end());
 104
 105         verbosestream << "httpfetch_caller_alloc_secure: allocating "
 106                 << caller << std::endl;
 107
 108         // Access element to create it
 109         g_httpfetch_results[caller];
 110         return caller;
 111 }
 112
 113 void httpfetch_caller_free(unsigned long caller)
 114 {
 115         verbosestream<<"httpfetch_caller_free: freeing "
 116                         <<caller<<std::endl;
 117
 118         httpfetch_request_clear(caller);
 119         if (caller != HTTPFETCH_DISCARD) {
 120                 MutexAutoLock lock(g_httpfetch_mutex);
 121                 g_httpfetch_results.erase(caller);
 122         }
 123 }
 124
 125 bool httpfetch_async_get(unsigned long caller, HTTPFetchResult &fetch_result)
 126 {
 127         MutexAutoLock lock(g_httpfetch_mutex);
 128
 129         // Check that caller exists
 130         std::map<unsigned long, std::queue<HTTPFetchResult> >::iterator
 131                 it = g_httpfetch_results.find(caller);
 132         if (it == g_httpfetch_results.end())
 133                 return false;
 134
 135         // Check that result queue is nonempty
 136         std::queue<HTTPFetchResult> &caller_results = it->second;
 137         if (caller_results.empty())
 138                 return false;
 139
 140         // Pop first result
 141         fetch_result = caller_results.front();
 142         caller_results.pop();
 143         return true;
 144 }
 145
 146 #if USE_CURL
 147 #include <curl/curl.h>
 148
 149 /*
 150         USE_CURL is on: use cURL based httpfetch implementation
 151 */
 152
 153 static size_t httpfetch_writefunction(
 154                 char *ptr, size_t size, size_t nmemb, void *userdata)
 155 {
 156         std::ostringstream *stream = (std::ostringstream*)userdata;
 157         size_t count = size * nmemb;
 158         stream->write(ptr, count);
 159         return count;
 160 }
 161
 162 static size_t httpfetch_discardfunction(
 163                 char *ptr, size_t size, size_t nmemb, void *userdata)
 164 {
 165         return size * nmemb;
 166 }
 167
 168 class CurlHandlePool
 169 {
 170         std::list<CURL*> handles;
 171
 172 public:
 173         CurlHandlePool() = default;
 174
 175         ~CurlHandlePool()
 176         {
 177                 for (std::list<CURL*>::iterator it = handles.begin();
 178                                 it != handles.end(); ++it) {
 179                         curl_easy_cleanup(*it);
 180                 }
 181         }
 182         CURL * alloc()
 183         {
 184                 CURL *curl;
 185                 if (handles.empty()) {
 186                         curl = curl_easy_init();
 187                         if (curl == NULL) {
 188                                 errorstream<<"curl_easy_init returned NULL"<<std::endl;
 189                         }
 190                 }
 191                 else {
 192                         curl = handles.front();
 193                         handles.pop_front();
 194                 }
 195                 return curl;
 196         }
 197         void free(CURL *handle)
 198         {
 199                 if (handle)
 200                         handles.push_back(handle);
 201         }
 202 };
 203
 204 class HTTPFetchOngoing
 205 {
 206 public:
 207         HTTPFetchOngoing(const HTTPFetchRequest &request, CurlHandlePool *pool);
 208         ~HTTPFetchOngoing();
 209
 210         CURLcode start(CURLM *multi);
 211         const HTTPFetchResult * complete(CURLcode res);
 212
 213         const HTTPFetchRequest &getRequest()    const { return request; };
 214         const CURL             *getEasyHandle() const { return curl; };
 215
 216 private:
 217         CurlHandlePool *pool;
 218         CURL *curl;
 219         CURLM *multi;
 220         HTTPFetchRequest request;
 221         HTTPFetchResult result;
 222         std::ostringstream oss;
 223         struct curl_slist *http_header;
 224         curl_httppost *post;
 225 };
 226
 227
 228 HTTPFetchOngoing::HTTPFetchOngoing(const HTTPFetchRequest &request_,
 229                 CurlHandlePool *pool_):
 230         pool(pool_),
 231         curl(NULL),
 232         multi(NULL),
 233         request(request_),
 234         result(request_),
 235         oss(std::ios::binary),
 236         http_header(NULL),
 237         post(NULL)
 238 {
 239         curl = pool->alloc();
 240         if (curl == NULL) {
 241                 return;
 242         }
 243
 244         // Set static cURL options
 245         curl_easy_setopt(curl, CURLOPT_NOSIGNAL, 1);
 246         curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1);
 247         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 248         curl_easy_setopt(curl, CURLOPT_MAXREDIRS, 3);
 249         curl_easy_setopt(curl, CURLOPT_ENCODING, "gzip");
 250
 251         std::string bind_address = g_settings->get("bind_address");
 252         if (!bind_address.empty()) {
 253                 curl_easy_setopt(curl, CURLOPT_INTERFACE, bind_address.c_str());
 254         }
 255
 256         if (!g_settings->getBool("enable_ipv6")) {
 257                 curl_easy_setopt(curl, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4);
 258         }
 259
 260 #if LIBCURL_VERSION_NUM >= 0x071304
 261         // Restrict protocols so that curl vulnerabilities in
 262         // other protocols don't affect us.
 263         // These settings were introduced in curl 7.19.4.
 264         long protocols =
 265                 CURLPROTO_HTTP |
 266                 CURLPROTO_HTTPS |
 267                 CURLPROTO_FTP |
 268                 CURLPROTO_FTPS;
 269         curl_easy_setopt(curl, CURLOPT_PROTOCOLS, protocols);
 270         curl_easy_setopt(curl, CURLOPT_REDIR_PROTOCOLS, protocols);
 271 #endif
 272
 273         // Set cURL options based on HTTPFetchRequest
 274         curl_easy_setopt(curl, CURLOPT_URL,
 275                         request.url.c_str());
 276         curl_easy_setopt(curl, CURLOPT_TIMEOUT_MS,
 277                         request.timeout);
 278         curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT_MS,
 279                         request.connect_timeout);
 280
 281         if (!request.useragent.empty())
 282                 curl_easy_setopt(curl, CURLOPT_USERAGENT, request.useragent.c_str());
 283
 284         // Set up a write callback that writes to the
 285         // ostringstream ongoing->oss, unless the data
 286         // is to be discarded
 287         if (request.caller == HTTPFETCH_DISCARD) {
 288                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 289                                 httpfetch_discardfunction);
 290                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
 291         } else {
 292                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 293                                 httpfetch_writefunction);
 294                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, &oss);
 295         }
 296
 297         // Set POST (or GET) data
 298         if (request.post_fields.empty() && request.post_data.empty()) {
 299                 curl_easy_setopt(curl, CURLOPT_HTTPGET, 1);
 300         } else if (request.multipart) {
 301                 curl_httppost *last = NULL;
 302                 for (StringMap::iterator it = request.post_fields.begin();
 303                                 it != request.post_fields.end(); ++it) {
 304                         curl_formadd(&post, &last,
 305                                         CURLFORM_NAMELENGTH, it->first.size(),
 306                                         CURLFORM_PTRNAME, it->first.c_str(),
 307                                         CURLFORM_CONTENTSLENGTH, it->second.size(),
 308                                         CURLFORM_PTRCONTENTS, it->second.c_str(),
 309                                         CURLFORM_END);
 310                 }
 311                 curl_easy_setopt(curl, CURLOPT_HTTPPOST, post);
 312                 // request.post_fields must now *never* be
 313                 // modified until CURLOPT_HTTPPOST is cleared
 314         } else if (request.post_data.empty()) {
 315                 curl_easy_setopt(curl, CURLOPT_POST, 1);
 316                 std::string str;
 317                 for (auto &post_field : request.post_fields) {
 318                         if (!str.empty())
 319                                 str += "&";
 320                         str += urlencode(post_field.first);
 321                         str += "=";
 322                         str += urlencode(post_field.second);
 323                 }
 324                 curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE,
 325                                 str.size());
 326                 curl_easy_setopt(curl, CURLOPT_COPYPOSTFIELDS,
 327                                 str.c_str());
 328         } else {
 329                 curl_easy_setopt(curl, CURLOPT_POST, 1);
 330                 curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE,
 331                                 request.post_data.size());
 332                 curl_easy_setopt(curl, CURLOPT_POSTFIELDS,
 333                                 request.post_data.c_str());
 334                 // request.post_data must now *never* be
 335                 // modified until CURLOPT_POSTFIELDS is cleared
 336         }
 337         // Set additional HTTP headers
 338         for (const std::string &extra_header : request.extra_headers) {
 339                 http_header = curl_slist_append(http_header, extra_header.c_str());
 340         }
 341         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, http_header);
 342
 343         if (!g_settings->getBool("curl_verify_cert")) {
 344                 curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, false);
 345         }
 346 }
 347
 348 CURLcode HTTPFetchOngoing::start(CURLM *multi_)
 349 {
 350         if (!curl)
 351                 return CURLE_FAILED_INIT;
 352
 353         if (!multi_) {
 354                 // Easy interface (sync)
 355                 return curl_easy_perform(curl);
 356         }
 357
 358         // Multi interface (async)
 359         CURLMcode mres = curl_multi_add_handle(multi_, curl);
 360         if (mres != CURLM_OK) {
 361                 errorstream << "curl_multi_add_handle"
 362                         << " returned error code " << mres
 363                         << std::endl;
 364                 return CURLE_FAILED_INIT;
 365         }
 366         multi = multi_; // store for curl_multi_remove_handle
 367         return CURLE_OK;
 368 }
 369
 370 const HTTPFetchResult * HTTPFetchOngoing::complete(CURLcode res)
 371 {
 372         result.succeeded = (res == CURLE_OK);
 373         result.timeout = (res == CURLE_OPERATION_TIMEDOUT);
 374         result.data = oss.str();
 375
 376         // Get HTTP/FTP response code
 377         result.response_code = 0;
 378         if (curl && (curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE,
 379                                 &result.response_code) != CURLE_OK)) {
 380                 // We failed to get a return code, make sure it is still 0
 381                 result.response_code = 0;
 382         }
 383
 384         if (res != CURLE_OK) {
 385                 errorstream << request.url << " not found ("
 386                         << curl_easy_strerror(res) << ")"
 387                         << " (response code " << result.response_code << ")"
 388                         << std::endl;
 389         }
 390
 391         return &result;
 392 }
 393
 394 HTTPFetchOngoing::~HTTPFetchOngoing()
 395 {
 396         if (multi) {
 397                 CURLMcode mres = curl_multi_remove_handle(multi, curl);
 398                 if (mres != CURLM_OK) {
 399                         errorstream << "curl_multi_remove_handle"
 400                                 << " returned error code " << mres
 401                                 << std::endl;
 402                 }
 403         }
 404
 405         // Set safe options for the reusable cURL handle
 406         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 407                         httpfetch_discardfunction);
 408         curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
 409         curl_easy_setopt(curl, CURLOPT_POSTFIELDS, NULL);
 410         if (http_header) {
 411                 curl_easy_setopt(curl, CURLOPT_HTTPHEADER, NULL);
 412                 curl_slist_free_all(http_header);
 413         }
 414         if (post) {
 415                 curl_easy_setopt(curl, CURLOPT_HTTPPOST, NULL);
 416                 curl_formfree(post);
 417         }
 418
 419         // Store the cURL handle for reuse
 420         pool->free(curl);
 421 }
 422
 423
 424 class CurlFetchThread : public Thread
 425 {
 426 protected:
 427         enum RequestType {
 428                 RT_FETCH,
 429                 RT_CLEAR,
 430                 RT_WAKEUP,
 431         };
 432
 433         struct Request {
 434                 RequestType type;
 435                 HTTPFetchRequest fetch_request;
 436                 Event *event;
 437         };
 438
 439         CURLM *m_multi;
 440         MutexedQueue<Request> m_requests;
 441         size_t m_parallel_limit;
 442
 443         // Variables exclusively used within thread
 444         std::vector<HTTPFetchOngoing*> m_all_ongoing;
 445         std::list<HTTPFetchRequest> m_queued_fetches;
 446
 447 public:
 448         CurlFetchThread(int parallel_limit) :
 449                 Thread("CurlFetch")
 450         {
 451                 if (parallel_limit >= 1)
 452                         m_parallel_limit = parallel_limit;
 453                 else
 454                         m_parallel_limit = 1;
 455         }
 456
 457         void requestFetch(const HTTPFetchRequest &fetch_request)
 458         {
 459                 Request req;
 460                 req.type = RT_FETCH;
 461                 req.fetch_request = fetch_request;
 462                 req.event = NULL;
 463                 m_requests.push_back(req);
 464         }
 465
 466         void requestClear(unsigned long caller, Event *event)
 467         {
 468                 Request req;
 469                 req.type = RT_CLEAR;
 470                 req.fetch_request.caller = caller;
 471                 req.event = event;
 472                 m_requests.push_back(req);
 473         }
 474
 475         void requestWakeUp()
 476         {
 477                 Request req;
 478                 req.type = RT_WAKEUP;
 479                 req.event = NULL;
 480                 m_requests.push_back(req);
 481         }
 482
 483 protected:
 484         // Handle a request from some other thread
 485         // E.g. new fetch; clear fetches for one caller; wake up
 486         void processRequest(const Request &req)
 487         {
 488                 if (req.type == RT_FETCH) {
 489                         // New fetch, queue until there are less
 490                         // than m_parallel_limit ongoing fetches
 491                         m_queued_fetches.push_back(req.fetch_request);
 492
 493                         // see processQueued() for what happens next
 494
 495                 }
 496                 else if (req.type == RT_CLEAR) {
 497                         unsigned long caller = req.fetch_request.caller;
 498
 499                         // Abort all ongoing fetches for the caller
 500                         for (std::vector<HTTPFetchOngoing*>::iterator
 501                                         it = m_all_ongoing.begin();
 502                                         it != m_all_ongoing.end();) {
 503                                 if ((*it)->getRequest().caller == caller) {
 504                                         delete (*it);
 505                                         it = m_all_ongoing.erase(it);
 506                                 } else {
 507                                         ++it;
 508                                 }
 509                         }
 510
 511                         // Also abort all queued fetches for the caller
 512                         for (std::list<HTTPFetchRequest>::iterator
 513                                         it = m_queued_fetches.begin();
 514                                         it != m_queued_fetches.end();) {
 515                                 if ((*it).caller == caller)
 516                                         it = m_queued_fetches.erase(it);
 517                                 else
 518                                         ++it;
 519                         }
 520                 }
 521                 else if (req.type == RT_WAKEUP) {
 522                         // Wakeup: Nothing to do, thread is awake at this point
 523                 }
 524
 525                 if (req.event != NULL)
 526                         req.event->signal();
 527         }
 528
 529         // Start new ongoing fetches if m_parallel_limit allows
 530         void processQueued(CurlHandlePool *pool)
 531         {
 532                 while (m_all_ongoing.size() < m_parallel_limit &&
 533                                 !m_queued_fetches.empty()) {
 534                         HTTPFetchRequest request = m_queued_fetches.front();
 535                         m_queued_fetches.pop_front();
 536
 537                         // Create ongoing fetch data and make a cURL handle
 538                         // Set cURL options based on HTTPFetchRequest
 539                         HTTPFetchOngoing *ongoing =
 540                                 new HTTPFetchOngoing(request, pool);
 541
 542                         // Initiate the connection (curl_multi_add_handle)
 543                         CURLcode res = ongoing->start(m_multi);
 544                         if (res == CURLE_OK) {
 545                                 m_all_ongoing.push_back(ongoing);
 546                         }
 547                         else {
 548                                 httpfetch_deliver_result(*ongoing->complete(res));
 549                                 delete ongoing;
 550                         }
 551                 }
 552         }
 553
 554         // Process CURLMsg (indicates completion of a fetch)
 555         void processCurlMessage(CURLMsg *msg)
 556         {
 557                 // Determine which ongoing fetch the message pertains to
 558                 size_t i = 0;
 559                 bool found = false;
 560                 for (i = 0; i < m_all_ongoing.size(); ++i) {
 561                         if (m_all_ongoing[i]->getEasyHandle() == msg->easy_handle) {
 562                                 found = true;
 563                                 break;
 564                         }
 565                 }
 566                 if (msg->msg == CURLMSG_DONE && found) {
 567                         // m_all_ongoing[i] succeeded or failed.
 568                         HTTPFetchOngoing *ongoing = m_all_ongoing[i];
 569                         httpfetch_deliver_result(*ongoing->complete(msg->data.result));
 570                         delete ongoing;
 571                         m_all_ongoing.erase(m_all_ongoing.begin() + i);
 572                 }
 573         }
 574
 575         // Wait for a request from another thread, or timeout elapses
 576         void waitForRequest(long timeout)
 577         {
 578                 if (m_queued_fetches.empty()) {
 579                         try {
 580                                 Request req = m_requests.pop_front(timeout);
 581                                 processRequest(req);
 582                         }
 583                         catch (ItemNotFoundException &e) {}
 584                 }
 585         }
 586
 587         // Wait until some IO happens, or timeout elapses
 588         void waitForIO(long timeout)
 589         {
 590                 fd_set read_fd_set;
 591                 fd_set write_fd_set;
 592                 fd_set exc_fd_set;
 593                 int max_fd;
 594                 long select_timeout = -1;
 595                 struct timeval select_tv;
 596                 CURLMcode mres;
 597
 598                 FD_ZERO(&read_fd_set);
 599                 FD_ZERO(&write_fd_set);
 600                 FD_ZERO(&exc_fd_set);
 601
 602                 mres = curl_multi_fdset(m_multi, &read_fd_set,
 603                                 &write_fd_set, &exc_fd_set, &max_fd);
 604                 if (mres != CURLM_OK) {
 605                         errorstream<<"curl_multi_fdset"
 606                                 <<" returned error code "<<mres
 607                                 <<std::endl;
 608                         select_timeout = 0;
 609                 }
 610
 611                 mres = curl_multi_timeout(m_multi, &select_timeout);
 612                 if (mres != CURLM_OK) {
 613                         errorstream<<"curl_multi_timeout"
 614                                 <<" returned error code "<<mres
 615                                 <<std::endl;
 616                         select_timeout = 0;
 617                 }
 618
 619                 // Limit timeout so new requests get through
 620                 if (select_timeout < 0 || select_timeout > timeout)
 621                         select_timeout = timeout;
 622
 623                 if (select_timeout > 0) {
 624                         // in Winsock it is forbidden to pass three empty
 625                         // fd_sets to select(), so in that case use sleep_ms
 626                         if (max_fd != -1) {
 627                                 select_tv.tv_sec = select_timeout / 1000;
 628                                 select_tv.tv_usec = (select_timeout % 1000) * 1000;
 629                                 int retval = select(max_fd + 1, &read_fd_set,
 630                                                 &write_fd_set, &exc_fd_set,
 631                                                 &select_tv);
 632                                 if (retval == -1) {
 633                                         #ifdef _WIN32
 634                                         errorstream<<"select returned error code "
 635                                                 <<WSAGetLastError()<<std::endl;
 636                                         #else
 637                                         errorstream<<"select returned error code "
 638                                                 <<errno<<std::endl;
 639                                         #endif
 640                                 }
 641                         }
 642                         else {
 643                                 sleep_ms(select_timeout);
 644                         }
 645                 }
 646         }
 647
 648         void *run()
 649         {
 650                 CurlHandlePool pool;
 651
 652                 m_multi = curl_multi_init();
 653                 if (m_multi == NULL) {
 654                         errorstream<<"curl_multi_init returned NULL\n";
 655                         return NULL;
 656                 }
 657
 658                 FATAL_ERROR_IF(!m_all_ongoing.empty(), "Expected empty");
 659
 660                 while (!stopRequested()) {
 661                         BEGIN_DEBUG_EXCEPTION_HANDLER
 662
 663                         /*
 664                                 Handle new async requests
 665                         */
 666
 667                         while (!m_requests.empty()) {
 668                                 Request req = m_requests.pop_frontNoEx();
 669                                 processRequest(req);
 670                         }
 671                         processQueued(&pool);
 672
 673                         /*
 674                                 Handle ongoing async requests
 675                         */
 676
 677                         int still_ongoing = 0;
 678                         while (curl_multi_perform(m_multi, &still_ongoing) ==
 679                                         CURLM_CALL_MULTI_PERFORM)
 680                                 /* noop */;
 681
 682                         /*
 683                                 Handle completed async requests
 684                         */
 685                         if (still_ongoing < (int) m_all_ongoing.size()) {
 686                                 CURLMsg *msg;
 687                                 int msgs_in_queue;
 688                                 msg = curl_multi_info_read(m_multi, &msgs_in_queue);
 689                                 while (msg != NULL) {
 690                                         processCurlMessage(msg);
 691                                         msg = curl_multi_info_read(m_multi, &msgs_in_queue);
 692                                 }
 693                         }
 694
 695                         /*
 696                                 If there are ongoing requests, wait for data
 697                                 (with a timeout of 100ms so that new requests
 698                                 can be processed).
 699
 700                                 If no ongoing requests, wait for a new request.
 701                                 (Possibly an empty request that signals
 702                                 that the thread should be stopped.)
 703                         */
 704                         if (m_all_ongoing.empty())
 705                                 waitForRequest(100000000);
 706                         else
 707                                 waitForIO(100);
 708
 709                         END_DEBUG_EXCEPTION_HANDLER
 710                 }
 711
 712                 // Call curl_multi_remove_handle and cleanup easy handles
 713                 for (HTTPFetchOngoing *i : m_all_ongoing) {
 714                         delete i;
 715                 }
 716                 m_all_ongoing.clear();
 717
 718                 m_queued_fetches.clear();
 719
 720                 CURLMcode mres = curl_multi_cleanup(m_multi);
 721                 if (mres != CURLM_OK) {
 722                         errorstream<<"curl_multi_cleanup"
 723                                 <<" returned error code "<<mres
 724                                 <<std::endl;
 725                 }
 726
 727                 return NULL;
 728         }
 729 };
 730
 731 CurlFetchThread *g_httpfetch_thread = NULL;
 732
 733 void httpfetch_init(int parallel_limit)
 734 {
 735         verbosestream<<"httpfetch_init: parallel_limit="<<parallel_limit
 736                         <<std::endl;
 737
 738         CURLcode res = curl_global_init(CURL_GLOBAL_DEFAULT);
 739         FATAL_ERROR_IF(res != CURLE_OK, "CURL init failed");
 740
 741         g_httpfetch_thread = new CurlFetchThread(parallel_limit);
 742
 743         // Initialize g_callerid_randomness for httpfetch_caller_alloc_secure
 744         u64 randbuf[2];
 745         porting::secure_rand_fill_buf(randbuf, sizeof(u64) * 2);
 746         g_callerid_randomness = PcgRandom(randbuf[0], randbuf[1]);
 747 }
 748
 749 void httpfetch_cleanup()
 750 {
 751         verbosestream<<"httpfetch_cleanup: cleaning up"<<std::endl;
 752
 753         g_httpfetch_thread->stop();
 754         g_httpfetch_thread->requestWakeUp();
 755         g_httpfetch_thread->wait();
 756         delete g_httpfetch_thread;
 757
 758         curl_global_cleanup();
 759 }
 760
 761 void httpfetch_async(const HTTPFetchRequest &fetch_request)
 762 {
 763         g_httpfetch_thread->requestFetch(fetch_request);
 764         if (!g_httpfetch_thread->isRunning())
 765                 g_httpfetch_thread->start();
 766 }
 767
 768 static void httpfetch_request_clear(unsigned long caller)
 769 {
 770         if (g_httpfetch_thread->isRunning()) {
 771                 Event event;
 772                 g_httpfetch_thread->requestClear(caller, &event);
 773                 event.wait();
 774         } else {
 775                 g_httpfetch_thread->requestClear(caller, NULL);
 776         }
 777 }
 778
 779 void httpfetch_sync(const HTTPFetchRequest &fetch_request,
 780                 HTTPFetchResult &fetch_result)
 781 {
 782         // Create ongoing fetch data and make a cURL handle
 783         // Set cURL options based on HTTPFetchRequest
 784         CurlHandlePool pool;
 785         HTTPFetchOngoing ongoing(fetch_request, &pool);
 786         // Do the fetch (curl_easy_perform)
 787         CURLcode res = ongoing.start(NULL);
 788         // Update fetch result
 789         fetch_result = *ongoing.complete(res);
 790 }
 791
 792 #else  // USE_CURL
 793
 794 /*
 795         USE_CURL is off:
 796
 797         Dummy httpfetch implementation that always returns an error.
 798 */
 799
 800 void httpfetch_init(int parallel_limit)
 801 {
 802 }
 803
 804 void httpfetch_cleanup()
 805 {
 806 }
 807
 808 void httpfetch_async(const HTTPFetchRequest &fetch_request)
 809 {
 810         errorstream << "httpfetch_async: unable to fetch " << fetch_request.url
 811                         << " because USE_CURL=0" << std::endl;
 812
 813         HTTPFetchResult fetch_result(fetch_request); // sets succeeded = false etc.
 814         httpfetch_deliver_result(fetch_result);
 815 }
 816
 817 static void httpfetch_request_clear(unsigned long caller)
 818 {
 819 }
 820
 821 void httpfetch_sync(const HTTPFetchRequest &fetch_request,
 822                 HTTPFetchResult &fetch_result)
 823 {
 824         errorstream << "httpfetch_sync: unable to fetch " << fetch_request.url
 825                         << " because USE_CURL=0" << std::endl;
 826
 827         fetch_result = HTTPFetchResult(fetch_request); // sets succeeded = false etc.
 828 }
 829
 830 #endif  // USE_CURL