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 <unordered_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 static std::mutex g_httpfetch_mutex;
  41 static std::unordered_map<unsigned long, std::queue<HTTPFetchResult>>
  42         g_httpfetch_results;
  43 static PcgRandom g_callerid_randomness;
  44
  45 HTTPFetchRequest::HTTPFetchRequest() :
  46         timeout(g_settings->getS32("curl_timeout")),
  47         connect_timeout(10 * 1000),
  48         useragent(std::string(PROJECT_NAME_C "/") + g_version_hash + " (" + porting::get_sysinfo() + ")")
  49 {
  50 }
  51
  52
  53 static void httpfetch_deliver_result(const HTTPFetchResult &fetch_result)
  54 {
  55         unsigned long caller = fetch_result.caller;
  56         if (caller != HTTPFETCH_DISCARD) {
  57                 MutexAutoLock lock(g_httpfetch_mutex);
  58                 g_httpfetch_results[caller].emplace(fetch_result);
  59         }
  60 }
  61
  62 static void httpfetch_request_clear(unsigned long caller);
  63
  64 unsigned long httpfetch_caller_alloc()
  65 {
  66         MutexAutoLock lock(g_httpfetch_mutex);
  67
  68         // Check each caller ID except HTTPFETCH_DISCARD
  69         const unsigned long discard = HTTPFETCH_DISCARD;
  70         for (unsigned long caller = discard + 1; caller != discard; ++caller) {
  71                 auto 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         auto it = g_httpfetch_results.find(caller);
 131         if (it == g_httpfetch_results.end())
 132                 return false;
 133
 134         // Check that result queue is nonempty
 135         std::queue<HTTPFetchResult> &caller_results = it->second;
 136         if (caller_results.empty())
 137                 return false;
 138
 139         // Pop first result
 140         fetch_result = std::move(caller_results.front());
 141         caller_results.pop();
 142         return true;
 143 }
 144
 145 #if USE_CURL
 146 #include <curl/curl.h>
 147
 148 /*
 149         USE_CURL is on: use cURL based httpfetch implementation
 150 */
 151
 152 static size_t httpfetch_writefunction(
 153                 char *ptr, size_t size, size_t nmemb, void *userdata)
 154 {
 155         std::ostringstream *stream = (std::ostringstream*)userdata;
 156         size_t count = size * nmemb;
 157         stream->write(ptr, count);
 158         return count;
 159 }
 160
 161 static size_t httpfetch_discardfunction(
 162                 char *ptr, size_t size, size_t nmemb, void *userdata)
 163 {
 164         return size * nmemb;
 165 }
 166
 167 class CurlHandlePool
 168 {
 169         std::list<CURL*> handles;
 170
 171 public:
 172         CurlHandlePool() = default;
 173
 174         ~CurlHandlePool()
 175         {
 176                 for (std::list<CURL*>::iterator it = handles.begin();
 177                                 it != handles.end(); ++it) {
 178                         curl_easy_cleanup(*it);
 179                 }
 180         }
 181         CURL * alloc()
 182         {
 183                 CURL *curl;
 184                 if (handles.empty()) {
 185                         curl = curl_easy_init();
 186                         if (curl == NULL) {
 187                                 errorstream<<"curl_easy_init returned NULL"<<std::endl;
 188                         }
 189                 }
 190                 else {
 191                         curl = handles.front();
 192                         handles.pop_front();
 193                 }
 194                 return curl;
 195         }
 196         void free(CURL *handle)
 197         {
 198                 if (handle)
 199                         handles.push_back(handle);
 200         }
 201 };
 202
 203 class HTTPFetchOngoing
 204 {
 205 public:
 206         HTTPFetchOngoing(const HTTPFetchRequest &request, CurlHandlePool *pool);
 207         ~HTTPFetchOngoing();
 208
 209         CURLcode start(CURLM *multi);
 210         const HTTPFetchResult * complete(CURLcode res);
 211
 212         const HTTPFetchRequest &getRequest()    const { return request; };
 213         const CURL             *getEasyHandle() const { return curl; };
 214
 215 private:
 216         CurlHandlePool *pool;
 217         CURL *curl;
 218         CURLM *multi;
 219         HTTPFetchRequest request;
 220         HTTPFetchResult result;
 221         std::ostringstream oss;
 222         struct curl_slist *http_header;
 223         curl_httppost *post;
 224 };
 225
 226
 227 HTTPFetchOngoing::HTTPFetchOngoing(const HTTPFetchRequest &request_,
 228                 CurlHandlePool *pool_):
 229         pool(pool_),
 230         curl(NULL),
 231         multi(NULL),
 232         request(request_),
 233         result(request_),
 234         oss(std::ios::binary),
 235         http_header(NULL),
 236         post(NULL)
 237 {
 238         curl = pool->alloc();
 239         if (curl == NULL) {
 240                 return;
 241         }
 242
 243         // Set static cURL options
 244         curl_easy_setopt(curl, CURLOPT_NOSIGNAL, 1);
 245         curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1);
 246         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 247         curl_easy_setopt(curl, CURLOPT_MAXREDIRS, 3);
 248         curl_easy_setopt(curl, CURLOPT_ENCODING, "gzip");
 249
 250         std::string bind_address = g_settings->get("bind_address");
 251         if (!bind_address.empty()) {
 252                 curl_easy_setopt(curl, CURLOPT_INTERFACE, bind_address.c_str());
 253         }
 254
 255         if (!g_settings->getBool("enable_ipv6")) {
 256                 curl_easy_setopt(curl, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4);
 257         }
 258
 259 #if LIBCURL_VERSION_NUM >= 0x071304
 260         // Restrict protocols so that curl vulnerabilities in
 261         // other protocols don't affect us.
 262         // These settings were introduced in curl 7.19.4.
 263         long protocols =
 264                 CURLPROTO_HTTP |
 265                 CURLPROTO_HTTPS |
 266                 CURLPROTO_FTP |
 267                 CURLPROTO_FTPS;
 268         curl_easy_setopt(curl, CURLOPT_PROTOCOLS, protocols);
 269         curl_easy_setopt(curl, CURLOPT_REDIR_PROTOCOLS, protocols);
 270 #endif
 271
 272         // Set cURL options based on HTTPFetchRequest
 273         curl_easy_setopt(curl, CURLOPT_URL,
 274                         request.url.c_str());
 275         curl_easy_setopt(curl, CURLOPT_TIMEOUT_MS,
 276                         request.timeout);
 277         curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT_MS,
 278                         request.connect_timeout);
 279
 280         if (!request.useragent.empty())
 281                 curl_easy_setopt(curl, CURLOPT_USERAGENT, request.useragent.c_str());
 282
 283         // Set up a write callback that writes to the
 284         // ostringstream ongoing->oss, unless the data
 285         // is to be discarded
 286         if (request.caller == HTTPFETCH_DISCARD) {
 287                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 288                                 httpfetch_discardfunction);
 289                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
 290         } else {
 291                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 292                                 httpfetch_writefunction);
 293                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, &oss);
 294         }
 295
 296         // Set data from fields or raw_data
 297         if (request.multipart) {
 298                 curl_httppost *last = NULL;
 299                 for (StringMap::iterator it = request.fields.begin();
 300                                 it != request.fields.end(); ++it) {
 301                         curl_formadd(&post, &last,
 302                                         CURLFORM_NAMELENGTH, it->first.size(),
 303                                         CURLFORM_PTRNAME, it->first.c_str(),
 304                                         CURLFORM_CONTENTSLENGTH, it->second.size(),
 305                                         CURLFORM_PTRCONTENTS, it->second.c_str(),
 306                                         CURLFORM_END);
 307                 }
 308                 curl_easy_setopt(curl, CURLOPT_HTTPPOST, post);
 309                 // request.post_fields must now *never* be
 310                 // modified until CURLOPT_HTTPPOST is cleared
 311         } else {
 312                 switch (request.method) {
 313                 case HTTP_GET:
 314                         curl_easy_setopt(curl, CURLOPT_HTTPGET, 1);
 315                         break;
 316                 case HTTP_POST:
 317                         curl_easy_setopt(curl, CURLOPT_POST, 1);
 318                         break;
 319                 case HTTP_PUT:
 320                         curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "PUT");
 321                         break;
 322                 case HTTP_DELETE:
 323                         curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "DELETE");
 324                         break;
 325                 }
 326                 if (request.method != HTTP_GET) {
 327                         if (!request.raw_data.empty()) {
 328                                 curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE,
 329                                                 request.raw_data.size());
 330                                 curl_easy_setopt(curl, CURLOPT_POSTFIELDS,
 331                                                 request.raw_data.c_str());
 332                         } else if (!request.fields.empty()) {
 333                                 std::string str;
 334                                 for (auto &field : request.fields) {
 335                                         if (!str.empty())
 336                                                 str += "&";
 337                                         str += urlencode(field.first);
 338                                         str += "=";
 339                                         str += urlencode(field.second);
 340                                 }
 341                                 curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE,
 342                                                 str.size());
 343                                 curl_easy_setopt(curl, CURLOPT_COPYPOSTFIELDS,
 344                                                 str.c_str());
 345                         }
 346                 }
 347         }
 348         // Set additional HTTP headers
 349         for (const std::string &extra_header : request.extra_headers) {
 350                 http_header = curl_slist_append(http_header, extra_header.c_str());
 351         }
 352         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, http_header);
 353
 354         if (!g_settings->getBool("curl_verify_cert")) {
 355                 curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, false);
 356         }
 357 }
 358
 359 CURLcode HTTPFetchOngoing::start(CURLM *multi_)
 360 {
 361         if (!curl)
 362                 return CURLE_FAILED_INIT;
 363
 364         if (!multi_) {
 365                 // Easy interface (sync)
 366                 return curl_easy_perform(curl);
 367         }
 368
 369         // Multi interface (async)
 370         CURLMcode mres = curl_multi_add_handle(multi_, curl);
 371         if (mres != CURLM_OK) {
 372                 errorstream << "curl_multi_add_handle"
 373                         << " returned error code " << mres
 374                         << std::endl;
 375                 return CURLE_FAILED_INIT;
 376         }
 377         multi = multi_; // store for curl_multi_remove_handle
 378         return CURLE_OK;
 379 }
 380
 381 const HTTPFetchResult * HTTPFetchOngoing::complete(CURLcode res)
 382 {
 383         result.succeeded = (res == CURLE_OK);
 384         result.timeout = (res == CURLE_OPERATION_TIMEDOUT);
 385         result.data = oss.str();
 386
 387         // Get HTTP/FTP response code
 388         result.response_code = 0;
 389         if (curl && (curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE,
 390                                 &result.response_code) != CURLE_OK)) {
 391                 // We failed to get a return code, make sure it is still 0
 392                 result.response_code = 0;
 393         }
 394
 395         if (res != CURLE_OK) {
 396                 errorstream << request.url << " not found ("
 397                         << curl_easy_strerror(res) << ")"
 398                         << " (response code " << result.response_code << ")"
 399                         << std::endl;
 400         }
 401
 402         return &result;
 403 }
 404
 405 HTTPFetchOngoing::~HTTPFetchOngoing()
 406 {
 407         if (multi) {
 408                 CURLMcode mres = curl_multi_remove_handle(multi, curl);
 409                 if (mres != CURLM_OK) {
 410                         errorstream << "curl_multi_remove_handle"
 411                                 << " returned error code " << mres
 412                                 << std::endl;
 413                 }
 414         }
 415
 416         // Set safe options for the reusable cURL handle
 417         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 418                         httpfetch_discardfunction);
 419         curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
 420         curl_easy_setopt(curl, CURLOPT_POSTFIELDS, NULL);
 421         if (http_header) {
 422                 curl_easy_setopt(curl, CURLOPT_HTTPHEADER, NULL);
 423                 curl_slist_free_all(http_header);
 424         }
 425         if (post) {
 426                 curl_easy_setopt(curl, CURLOPT_HTTPPOST, NULL);
 427                 curl_formfree(post);
 428         }
 429
 430         // Store the cURL handle for reuse
 431         pool->free(curl);
 432 }
 433
 434
 435 class CurlFetchThread : public Thread
 436 {
 437 protected:
 438         enum RequestType {
 439                 RT_FETCH,
 440                 RT_CLEAR,
 441                 RT_WAKEUP,
 442         };
 443
 444         struct Request {
 445                 RequestType type;
 446                 HTTPFetchRequest fetch_request;
 447                 Event *event;
 448         };
 449
 450         CURLM *m_multi;
 451         MutexedQueue<Request> m_requests;
 452         size_t m_parallel_limit;
 453
 454         // Variables exclusively used within thread
 455         std::vector<HTTPFetchOngoing*> m_all_ongoing;
 456         std::list<HTTPFetchRequest> m_queued_fetches;
 457
 458 public:
 459         CurlFetchThread(int parallel_limit) :
 460                 Thread("CurlFetch")
 461         {
 462                 if (parallel_limit >= 1)
 463                         m_parallel_limit = parallel_limit;
 464                 else
 465                         m_parallel_limit = 1;
 466         }
 467
 468         void requestFetch(const HTTPFetchRequest &fetch_request)
 469         {
 470                 Request req;
 471                 req.type = RT_FETCH;
 472                 req.fetch_request = fetch_request;
 473                 req.event = NULL;
 474                 m_requests.push_back(req);
 475         }
 476
 477         void requestClear(unsigned long caller, Event *event)
 478         {
 479                 Request req;
 480                 req.type = RT_CLEAR;
 481                 req.fetch_request.caller = caller;
 482                 req.event = event;
 483                 m_requests.push_back(req);
 484         }
 485
 486         void requestWakeUp()
 487         {
 488                 Request req;
 489                 req.type = RT_WAKEUP;
 490                 req.event = NULL;
 491                 m_requests.push_back(req);
 492         }
 493
 494 protected:
 495         // Handle a request from some other thread
 496         // E.g. new fetch; clear fetches for one caller; wake up
 497         void processRequest(const Request &req)
 498         {
 499                 if (req.type == RT_FETCH) {
 500                         // New fetch, queue until there are less
 501                         // than m_parallel_limit ongoing fetches
 502                         m_queued_fetches.push_back(req.fetch_request);
 503
 504                         // see processQueued() for what happens next
 505
 506                 }
 507                 else if (req.type == RT_CLEAR) {
 508                         unsigned long caller = req.fetch_request.caller;
 509
 510                         // Abort all ongoing fetches for the caller
 511                         for (std::vector<HTTPFetchOngoing*>::iterator
 512                                         it = m_all_ongoing.begin();
 513                                         it != m_all_ongoing.end();) {
 514                                 if ((*it)->getRequest().caller == caller) {
 515                                         delete (*it);
 516                                         it = m_all_ongoing.erase(it);
 517                                 } else {
 518                                         ++it;
 519                                 }
 520                         }
 521
 522                         // Also abort all queued fetches for the caller
 523                         for (std::list<HTTPFetchRequest>::iterator
 524                                         it = m_queued_fetches.begin();
 525                                         it != m_queued_fetches.end();) {
 526                                 if ((*it).caller == caller)
 527                                         it = m_queued_fetches.erase(it);
 528                                 else
 529                                         ++it;
 530                         }
 531                 }
 532                 else if (req.type == RT_WAKEUP) {
 533                         // Wakeup: Nothing to do, thread is awake at this point
 534                 }
 535
 536                 if (req.event != NULL)
 537                         req.event->signal();
 538         }
 539
 540         // Start new ongoing fetches if m_parallel_limit allows
 541         void processQueued(CurlHandlePool *pool)
 542         {
 543                 while (m_all_ongoing.size() < m_parallel_limit &&
 544                                 !m_queued_fetches.empty()) {
 545                         HTTPFetchRequest request = m_queued_fetches.front();
 546                         m_queued_fetches.pop_front();
 547
 548                         // Create ongoing fetch data and make a cURL handle
 549                         // Set cURL options based on HTTPFetchRequest
 550                         HTTPFetchOngoing *ongoing =
 551                                 new HTTPFetchOngoing(request, pool);
 552
 553                         // Initiate the connection (curl_multi_add_handle)
 554                         CURLcode res = ongoing->start(m_multi);
 555                         if (res == CURLE_OK) {
 556                                 m_all_ongoing.push_back(ongoing);
 557                         }
 558                         else {
 559                                 httpfetch_deliver_result(*ongoing->complete(res));
 560                                 delete ongoing;
 561                         }
 562                 }
 563         }
 564
 565         // Process CURLMsg (indicates completion of a fetch)
 566         void processCurlMessage(CURLMsg *msg)
 567         {
 568                 // Determine which ongoing fetch the message pertains to
 569                 size_t i = 0;
 570                 bool found = false;
 571                 for (i = 0; i < m_all_ongoing.size(); ++i) {
 572                         if (m_all_ongoing[i]->getEasyHandle() == msg->easy_handle) {
 573                                 found = true;
 574                                 break;
 575                         }
 576                 }
 577                 if (msg->msg == CURLMSG_DONE && found) {
 578                         // m_all_ongoing[i] succeeded or failed.
 579                         HTTPFetchOngoing *ongoing = m_all_ongoing[i];
 580                         httpfetch_deliver_result(*ongoing->complete(msg->data.result));
 581                         delete ongoing;
 582                         m_all_ongoing.erase(m_all_ongoing.begin() + i);
 583                 }
 584         }
 585
 586         // Wait for a request from another thread, or timeout elapses
 587         void waitForRequest(long timeout)
 588         {
 589                 if (m_queued_fetches.empty()) {
 590                         try {
 591                                 Request req = m_requests.pop_front(timeout);
 592                                 processRequest(req);
 593                         }
 594                         catch (ItemNotFoundException &e) {}
 595                 }
 596         }
 597
 598         // Wait until some IO happens, or timeout elapses
 599         void waitForIO(long timeout)
 600         {
 601                 fd_set read_fd_set;
 602                 fd_set write_fd_set;
 603                 fd_set exc_fd_set;
 604                 int max_fd;
 605                 long select_timeout = -1;
 606                 struct timeval select_tv;
 607                 CURLMcode mres;
 608
 609                 FD_ZERO(&read_fd_set);
 610                 FD_ZERO(&write_fd_set);
 611                 FD_ZERO(&exc_fd_set);
 612
 613                 mres = curl_multi_fdset(m_multi, &read_fd_set,
 614                                 &write_fd_set, &exc_fd_set, &max_fd);
 615                 if (mres != CURLM_OK) {
 616                         errorstream<<"curl_multi_fdset"
 617                                 <<" returned error code "<<mres
 618                                 <<std::endl;
 619                         select_timeout = 0;
 620                 }
 621
 622                 mres = curl_multi_timeout(m_multi, &select_timeout);
 623                 if (mres != CURLM_OK) {
 624                         errorstream<<"curl_multi_timeout"
 625                                 <<" returned error code "<<mres
 626                                 <<std::endl;
 627                         select_timeout = 0;
 628                 }
 629
 630                 // Limit timeout so new requests get through
 631                 if (select_timeout < 0 || select_timeout > timeout)
 632                         select_timeout = timeout;
 633
 634                 if (select_timeout > 0) {
 635                         // in Winsock it is forbidden to pass three empty
 636                         // fd_sets to select(), so in that case use sleep_ms
 637                         if (max_fd != -1) {
 638                                 select_tv.tv_sec = select_timeout / 1000;
 639                                 select_tv.tv_usec = (select_timeout % 1000) * 1000;
 640                                 int retval = select(max_fd + 1, &read_fd_set,
 641                                                 &write_fd_set, &exc_fd_set,
 642                                                 &select_tv);
 643                                 if (retval == -1) {
 644                                         #ifdef _WIN32
 645                                         errorstream<<"select returned error code "
 646                                                 <<WSAGetLastError()<<std::endl;
 647                                         #else
 648                                         errorstream<<"select returned error code "
 649                                                 <<errno<<std::endl;
 650                                         #endif
 651                                 }
 652                         }
 653                         else {
 654                                 sleep_ms(select_timeout);
 655                         }
 656                 }
 657         }
 658
 659         void *run()
 660         {
 661                 CurlHandlePool pool;
 662
 663                 m_multi = curl_multi_init();
 664                 if (m_multi == NULL) {
 665                         errorstream<<"curl_multi_init returned NULL\n";
 666                         return NULL;
 667                 }
 668
 669                 FATAL_ERROR_IF(!m_all_ongoing.empty(), "Expected empty");
 670
 671                 while (!stopRequested()) {
 672                         BEGIN_DEBUG_EXCEPTION_HANDLER
 673
 674                         /*
 675                                 Handle new async requests
 676                         */
 677
 678                         while (!m_requests.empty()) {
 679                                 Request req = m_requests.pop_frontNoEx();
 680                                 processRequest(req);
 681                         }
 682                         processQueued(&pool);
 683
 684                         /*
 685                                 Handle ongoing async requests
 686                         */
 687
 688                         int still_ongoing = 0;
 689                         while (curl_multi_perform(m_multi, &still_ongoing) ==
 690                                         CURLM_CALL_MULTI_PERFORM)
 691                                 /* noop */;
 692
 693                         /*
 694                                 Handle completed async requests
 695                         */
 696                         if (still_ongoing < (int) m_all_ongoing.size()) {
 697                                 CURLMsg *msg;
 698                                 int msgs_in_queue;
 699                                 msg = curl_multi_info_read(m_multi, &msgs_in_queue);
 700                                 while (msg != NULL) {
 701                                         processCurlMessage(msg);
 702                                         msg = curl_multi_info_read(m_multi, &msgs_in_queue);
 703                                 }
 704                         }
 705
 706                         /*
 707                                 If there are ongoing requests, wait for data
 708                                 (with a timeout of 100ms so that new requests
 709                                 can be processed).
 710
 711                                 If no ongoing requests, wait for a new request.
 712                                 (Possibly an empty request that signals
 713                                 that the thread should be stopped.)
 714                         */
 715                         if (m_all_ongoing.empty())
 716                                 waitForRequest(100000000);
 717                         else
 718                                 waitForIO(100);
 719
 720                         END_DEBUG_EXCEPTION_HANDLER
 721                 }
 722
 723                 // Call curl_multi_remove_handle and cleanup easy handles
 724                 for (HTTPFetchOngoing *i : m_all_ongoing) {
 725                         delete i;
 726                 }
 727                 m_all_ongoing.clear();
 728
 729                 m_queued_fetches.clear();
 730
 731                 CURLMcode mres = curl_multi_cleanup(m_multi);
 732                 if (mres != CURLM_OK) {
 733                         errorstream<<"curl_multi_cleanup"
 734                                 <<" returned error code "<<mres
 735                                 <<std::endl;
 736                 }
 737
 738                 return NULL;
 739         }
 740 };
 741
 742 CurlFetchThread *g_httpfetch_thread = NULL;
 743
 744 void httpfetch_init(int parallel_limit)
 745 {
 746         verbosestream<<"httpfetch_init: parallel_limit="<<parallel_limit
 747                         <<std::endl;
 748
 749         CURLcode res = curl_global_init(CURL_GLOBAL_DEFAULT);
 750         FATAL_ERROR_IF(res != CURLE_OK, "CURL init failed");
 751
 752         g_httpfetch_thread = new CurlFetchThread(parallel_limit);
 753
 754         // Initialize g_callerid_randomness for httpfetch_caller_alloc_secure
 755         u64 randbuf[2];
 756         porting::secure_rand_fill_buf(randbuf, sizeof(u64) * 2);
 757         g_callerid_randomness = PcgRandom(randbuf[0], randbuf[1]);
 758 }
 759
 760 void httpfetch_cleanup()
 761 {
 762         verbosestream<<"httpfetch_cleanup: cleaning up"<<std::endl;
 763
 764         g_httpfetch_thread->stop();
 765         g_httpfetch_thread->requestWakeUp();
 766         g_httpfetch_thread->wait();
 767         delete g_httpfetch_thread;
 768
 769         curl_global_cleanup();
 770 }
 771
 772 void httpfetch_async(const HTTPFetchRequest &fetch_request)
 773 {
 774         g_httpfetch_thread->requestFetch(fetch_request);
 775         if (!g_httpfetch_thread->isRunning())
 776                 g_httpfetch_thread->start();
 777 }
 778
 779 static void httpfetch_request_clear(unsigned long caller)
 780 {
 781         if (g_httpfetch_thread->isRunning()) {
 782                 Event event;
 783                 g_httpfetch_thread->requestClear(caller, &event);
 784                 event.wait();
 785         } else {
 786                 g_httpfetch_thread->requestClear(caller, NULL);
 787         }
 788 }
 789
 790 void httpfetch_sync(const HTTPFetchRequest &fetch_request,
 791                 HTTPFetchResult &fetch_result)
 792 {
 793         // Create ongoing fetch data and make a cURL handle
 794         // Set cURL options based on HTTPFetchRequest
 795         CurlHandlePool pool;
 796         HTTPFetchOngoing ongoing(fetch_request, &pool);
 797         // Do the fetch (curl_easy_perform)
 798         CURLcode res = ongoing.start(NULL);
 799         // Update fetch result
 800         fetch_result = *ongoing.complete(res);
 801 }
 802
 803 #else  // USE_CURL
 804
 805 /*
 806         USE_CURL is off:
 807
 808         Dummy httpfetch implementation that always returns an error.
 809 */
 810
 811 void httpfetch_init(int parallel_limit)
 812 {
 813 }
 814
 815 void httpfetch_cleanup()
 816 {
 817 }
 818
 819 void httpfetch_async(const HTTPFetchRequest &fetch_request)
 820 {
 821         errorstream << "httpfetch_async: unable to fetch " << fetch_request.url
 822                         << " because USE_CURL=0" << std::endl;
 823
 824         HTTPFetchResult fetch_result(fetch_request); // sets succeeded = false etc.
 825         httpfetch_deliver_result(fetch_result);
 826 }
 827
 828 static void httpfetch_request_clear(unsigned long caller)
 829 {
 830 }
 831
 832 void httpfetch_sync(const HTTPFetchRequest &fetch_request,
 833                 HTTPFetchResult &fetch_result)
 834 {
 835         errorstream << "httpfetch_sync: unable to fetch " << fetch_request.url
 836                         << " because USE_CURL=0" << std::endl;
 837
 838         fetch_result = HTTPFetchResult(fetch_request); // sets succeeded = false etc.
 839 }
 840
 841 #endif  // USE_CURL