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<u64, 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         u64 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(u64 caller);
  63
  64 u64 httpfetch_caller_alloc()
  65 {
  66         MutexAutoLock lock(g_httpfetch_mutex);
  67
  68         // Check each caller ID except reserved ones
  69         for (u64 caller = HTTPFETCH_CID_START; caller != 0; ++caller) {
  70                 auto it = g_httpfetch_results.find(caller);
  71                 if (it == g_httpfetch_results.end()) {
  72                         verbosestream << "httpfetch_caller_alloc: allocating "
  73                                         << caller << std::endl;
  74                         // Access element to create it
  75                         g_httpfetch_results[caller];
  76                         return caller;
  77                 }
  78         }
  79
  80         FATAL_ERROR("httpfetch_caller_alloc: ran out of caller IDs");
  81 }
  82
  83 u64 httpfetch_caller_alloc_secure()
  84 {
  85         MutexAutoLock lock(g_httpfetch_mutex);
  86
  87         // Generate random caller IDs and make sure they're not
  88         // already used or reserved.
  89         // Give up after 100 tries to prevent infinite loop
  90         size_t tries = 100;
  91         u64 caller;
  92
  93         do {
  94                 caller = (((u64) g_callerid_randomness.next()) << 32) |
  95                                 g_callerid_randomness.next();
  96
  97                 if (--tries < 1) {
  98                         FATAL_ERROR("httpfetch_caller_alloc_secure: ran out of caller IDs");
  99                         return HTTPFETCH_DISCARD;
 100                 }
 101         } while (caller >= HTTPFETCH_CID_START &&
 102                 g_httpfetch_results.find(caller) != g_httpfetch_results.end());
 103
 104         verbosestream << "httpfetch_caller_alloc_secure: allocating "
 105                 << caller << std::endl;
 106
 107         // Access element to create it
 108         g_httpfetch_results[caller];
 109         return caller;
 110 }
 111
 112 void httpfetch_caller_free(u64 caller)
 113 {
 114         verbosestream<<"httpfetch_caller_free: freeing "
 115                         <<caller<<std::endl;
 116
 117         httpfetch_request_clear(caller);
 118         if (caller != HTTPFETCH_DISCARD) {
 119                 MutexAutoLock lock(g_httpfetch_mutex);
 120                 g_httpfetch_results.erase(caller);
 121         }
 122 }
 123
 124 bool httpfetch_async_get(u64 caller, HTTPFetchResult &fetch_result)
 125 {
 126         MutexAutoLock lock(g_httpfetch_mutex);
 127
 128         // Check that caller exists
 129         auto it = g_httpfetch_results.find(caller);
 130         if (it == g_httpfetch_results.end())
 131                 return false;
 132
 133         // Check that result queue is nonempty
 134         std::queue<HTTPFetchResult> &caller_results = it->second;
 135         if (caller_results.empty())
 136                 return false;
 137
 138         // Pop first result
 139         fetch_result = std::move(caller_results.front());
 140         caller_results.pop();
 141         return true;
 142 }
 143
 144 #if USE_CURL
 145 #include <curl/curl.h>
 146
 147 /*
 148         USE_CURL is on: use cURL based httpfetch implementation
 149 */
 150
 151 static size_t httpfetch_writefunction(
 152                 char *ptr, size_t size, size_t nmemb, void *userdata)
 153 {
 154         std::ostringstream *stream = (std::ostringstream*)userdata;
 155         size_t count = size * nmemb;
 156         stream->write(ptr, count);
 157         return count;
 158 }
 159
 160 static size_t httpfetch_discardfunction(
 161                 char *ptr, size_t size, size_t nmemb, void *userdata)
 162 {
 163         return size * nmemb;
 164 }
 165
 166 class CurlHandlePool
 167 {
 168         std::list<CURL*> handles;
 169
 170 public:
 171         CurlHandlePool() = default;
 172
 173         ~CurlHandlePool()
 174         {
 175                 for (std::list<CURL*>::iterator it = handles.begin();
 176                                 it != handles.end(); ++it) {
 177                         curl_easy_cleanup(*it);
 178                 }
 179         }
 180         CURL * alloc()
 181         {
 182                 CURL *curl;
 183                 if (handles.empty()) {
 184                         curl = curl_easy_init();
 185                         if (curl == NULL) {
 186                                 errorstream<<"curl_easy_init returned NULL"<<std::endl;
 187                         }
 188                 }
 189                 else {
 190                         curl = handles.front();
 191                         handles.pop_front();
 192                 }
 193                 return curl;
 194         }
 195         void free(CURL *handle)
 196         {
 197                 if (handle)
 198                         handles.push_back(handle);
 199         }
 200 };
 201
 202 class HTTPFetchOngoing
 203 {
 204 public:
 205         HTTPFetchOngoing(const HTTPFetchRequest &request, CurlHandlePool *pool);
 206         ~HTTPFetchOngoing();
 207
 208         CURLcode start(CURLM *multi);
 209         const HTTPFetchResult * complete(CURLcode res);
 210
 211         const HTTPFetchRequest &getRequest()    const { return request; };
 212         const CURL             *getEasyHandle() const { return curl; };
 213
 214 private:
 215         CurlHandlePool *pool;
 216         CURL *curl;
 217         CURLM *multi;
 218         HTTPFetchRequest request;
 219         HTTPFetchResult result;
 220         std::ostringstream oss;
 221         struct curl_slist *http_header;
 222         curl_httppost *post;
 223 };
 224
 225
 226 HTTPFetchOngoing::HTTPFetchOngoing(const HTTPFetchRequest &request_,
 227                 CurlHandlePool *pool_):
 228         pool(pool_),
 229         curl(NULL),
 230         multi(NULL),
 231         request(request_),
 232         result(request_),
 233         oss(std::ios::binary),
 234         http_header(NULL),
 235         post(NULL)
 236 {
 237         curl = pool->alloc();
 238         if (curl == NULL) {
 239                 return;
 240         }
 241
 242         // Set static cURL options
 243         curl_easy_setopt(curl, CURLOPT_NOSIGNAL, 1);
 244         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 245         curl_easy_setopt(curl, CURLOPT_MAXREDIRS, 3);
 246         curl_easy_setopt(curl, CURLOPT_ENCODING, "gzip");
 247
 248         std::string bind_address = g_settings->get("bind_address");
 249         if (!bind_address.empty()) {
 250                 curl_easy_setopt(curl, CURLOPT_INTERFACE, bind_address.c_str());
 251         }
 252
 253         if (!g_settings->getBool("enable_ipv6")) {
 254                 curl_easy_setopt(curl, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4);
 255         }
 256
 257 #if LIBCURL_VERSION_NUM >= 0x071304
 258         // Restrict protocols so that curl vulnerabilities in
 259         // other protocols don't affect us.
 260         // These settings were introduced in curl 7.19.4.
 261         long protocols =
 262                 CURLPROTO_HTTP |
 263                 CURLPROTO_HTTPS |
 264                 CURLPROTO_FTP |
 265                 CURLPROTO_FTPS;
 266         curl_easy_setopt(curl, CURLOPT_PROTOCOLS, protocols);
 267         curl_easy_setopt(curl, CURLOPT_REDIR_PROTOCOLS, protocols);
 268 #endif
 269
 270         // Set cURL options based on HTTPFetchRequest
 271         curl_easy_setopt(curl, CURLOPT_URL,
 272                         request.url.c_str());
 273         curl_easy_setopt(curl, CURLOPT_TIMEOUT_MS,
 274                         request.timeout);
 275         curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT_MS,
 276                         request.connect_timeout);
 277
 278         if (!request.useragent.empty())
 279                 curl_easy_setopt(curl, CURLOPT_USERAGENT, request.useragent.c_str());
 280
 281         // Set up a write callback that writes to the
 282         // ostringstream ongoing->oss, unless the data
 283         // is to be discarded
 284         if (request.caller == HTTPFETCH_DISCARD) {
 285                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 286                                 httpfetch_discardfunction);
 287                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
 288         } else {
 289                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 290                                 httpfetch_writefunction);
 291                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, &oss);
 292         }
 293
 294         // Set data from fields or raw_data
 295         if (request.multipart) {
 296                 curl_httppost *last = NULL;
 297                 for (StringMap::iterator it = request.fields.begin();
 298                                 it != request.fields.end(); ++it) {
 299                         curl_formadd(&post, &last,
 300                                         CURLFORM_NAMELENGTH, it->first.size(),
 301                                         CURLFORM_PTRNAME, it->first.c_str(),
 302                                         CURLFORM_CONTENTSLENGTH, it->second.size(),
 303                                         CURLFORM_PTRCONTENTS, it->second.c_str(),
 304                                         CURLFORM_END);
 305                 }
 306                 curl_easy_setopt(curl, CURLOPT_HTTPPOST, post);
 307                 // request.post_fields must now *never* be
 308                 // modified until CURLOPT_HTTPPOST is cleared
 309         } else {
 310                 switch (request.method) {
 311                 case HTTP_GET:
 312                         curl_easy_setopt(curl, CURLOPT_HTTPGET, 1);
 313                         break;
 314                 case HTTP_POST:
 315                         curl_easy_setopt(curl, CURLOPT_POST, 1);
 316                         break;
 317                 case HTTP_PUT:
 318                         curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "PUT");
 319                         break;
 320                 case HTTP_DELETE:
 321                         curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "DELETE");
 322                         break;
 323                 }
 324                 if (request.method != HTTP_GET) {
 325                         if (!request.raw_data.empty()) {
 326                                 curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE,
 327                                                 request.raw_data.size());
 328                                 curl_easy_setopt(curl, CURLOPT_POSTFIELDS,
 329                                                 request.raw_data.c_str());
 330                         } else if (!request.fields.empty()) {
 331                                 std::string str;
 332                                 for (auto &field : request.fields) {
 333                                         if (!str.empty())
 334                                                 str += "&";
 335                                         str += urlencode(field.first);
 336                                         str += "=";
 337                                         str += urlencode(field.second);
 338                                 }
 339                                 curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE,
 340                                                 str.size());
 341                                 curl_easy_setopt(curl, CURLOPT_COPYPOSTFIELDS,
 342                                                 str.c_str());
 343                         }
 344                 }
 345         }
 346         // Set additional HTTP headers
 347         for (const std::string &extra_header : request.extra_headers) {
 348                 http_header = curl_slist_append(http_header, extra_header.c_str());
 349         }
 350         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, http_header);
 351
 352         if (!g_settings->getBool("curl_verify_cert")) {
 353                 curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, false);
 354         }
 355 }
 356
 357 CURLcode HTTPFetchOngoing::start(CURLM *multi_)
 358 {
 359         if (!curl)
 360                 return CURLE_FAILED_INIT;
 361
 362         if (!multi_) {
 363                 // Easy interface (sync)
 364                 return curl_easy_perform(curl);
 365         }
 366
 367         // Multi interface (async)
 368         CURLMcode mres = curl_multi_add_handle(multi_, curl);
 369         if (mres != CURLM_OK) {
 370                 errorstream << "curl_multi_add_handle"
 371                         << " returned error code " << mres
 372                         << std::endl;
 373                 return CURLE_FAILED_INIT;
 374         }
 375         multi = multi_; // store for curl_multi_remove_handle
 376         return CURLE_OK;
 377 }
 378
 379 const HTTPFetchResult * HTTPFetchOngoing::complete(CURLcode res)
 380 {
 381         result.succeeded = (res == CURLE_OK);
 382         result.timeout = (res == CURLE_OPERATION_TIMEDOUT);
 383         result.data = oss.str();
 384
 385         // Get HTTP/FTP response code
 386         result.response_code = 0;
 387         if (curl && (curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE,
 388                                 &result.response_code) != CURLE_OK)) {
 389                 // We failed to get a return code, make sure it is still 0
 390                 result.response_code = 0;
 391         }
 392
 393         if (res != CURLE_OK) {
 394                 errorstream << "HTTPFetch for " << request.url << " failed ("
 395                         << curl_easy_strerror(res) << ")" << std::endl;
 396         } else if (result.response_code >= 400) {
 397                 errorstream << "HTTPFetch for " << request.url
 398                         << " returned response code " << result.response_code
 399                         << std::endl;
 400                 if (result.caller == HTTPFETCH_PRINT_ERR && !result.data.empty()) {
 401                         errorstream << "Response body:" << std::endl;
 402                         safe_print_string(errorstream, result.data);
 403                         errorstream << std::endl;
 404                 }
 405         }
 406
 407         return &result;
 408 }
 409
 410 HTTPFetchOngoing::~HTTPFetchOngoing()
 411 {
 412         if (multi) {
 413                 CURLMcode mres = curl_multi_remove_handle(multi, curl);
 414                 if (mres != CURLM_OK) {
 415                         errorstream << "curl_multi_remove_handle"
 416                                 << " returned error code " << mres
 417                                 << std::endl;
 418                 }
 419         }
 420
 421         // Set safe options for the reusable cURL handle
 422         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 423                         httpfetch_discardfunction);
 424         curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
 425         curl_easy_setopt(curl, CURLOPT_POSTFIELDS, NULL);
 426         if (http_header) {
 427                 curl_easy_setopt(curl, CURLOPT_HTTPHEADER, NULL);
 428                 curl_slist_free_all(http_header);
 429         }
 430         if (post) {
 431                 curl_easy_setopt(curl, CURLOPT_HTTPPOST, NULL);
 432                 curl_formfree(post);
 433         }
 434
 435         // Store the cURL handle for reuse
 436         pool->free(curl);
 437 }
 438
 439
 440 class CurlFetchThread : public Thread
 441 {
 442 protected:
 443         enum RequestType {
 444                 RT_FETCH,
 445                 RT_CLEAR,
 446                 RT_WAKEUP,
 447         };
 448
 449         struct Request {
 450                 RequestType type;
 451                 HTTPFetchRequest fetch_request;
 452                 Event *event;
 453         };
 454
 455         CURLM *m_multi;
 456         MutexedQueue<Request> m_requests;
 457         size_t m_parallel_limit;
 458
 459         // Variables exclusively used within thread
 460         std::vector<HTTPFetchOngoing*> m_all_ongoing;
 461         std::list<HTTPFetchRequest> m_queued_fetches;
 462
 463 public:
 464         CurlFetchThread(int parallel_limit) :
 465                 Thread("CurlFetch")
 466         {
 467                 if (parallel_limit >= 1)
 468                         m_parallel_limit = parallel_limit;
 469                 else
 470                         m_parallel_limit = 1;
 471         }
 472
 473         void requestFetch(const HTTPFetchRequest &fetch_request)
 474         {
 475                 Request req;
 476                 req.type = RT_FETCH;
 477                 req.fetch_request = fetch_request;
 478                 req.event = NULL;
 479                 m_requests.push_back(req);
 480         }
 481
 482         void requestClear(u64 caller, Event *event)
 483         {
 484                 Request req;
 485                 req.type = RT_CLEAR;
 486                 req.fetch_request.caller = caller;
 487                 req.event = event;
 488                 m_requests.push_back(req);
 489         }
 490
 491         void requestWakeUp()
 492         {
 493                 Request req;
 494                 req.type = RT_WAKEUP;
 495                 req.event = NULL;
 496                 m_requests.push_back(req);
 497         }
 498
 499 protected:
 500         // Handle a request from some other thread
 501         // E.g. new fetch; clear fetches for one caller; wake up
 502         void processRequest(const Request &req)
 503         {
 504                 if (req.type == RT_FETCH) {
 505                         // New fetch, queue until there are less
 506                         // than m_parallel_limit ongoing fetches
 507                         m_queued_fetches.push_back(req.fetch_request);
 508
 509                         // see processQueued() for what happens next
 510
 511                 }
 512                 else if (req.type == RT_CLEAR) {
 513                         u64 caller = req.fetch_request.caller;
 514
 515                         // Abort all ongoing fetches for the caller
 516                         for (std::vector<HTTPFetchOngoing*>::iterator
 517                                         it = m_all_ongoing.begin();
 518                                         it != m_all_ongoing.end();) {
 519                                 if ((*it)->getRequest().caller == caller) {
 520                                         delete (*it);
 521                                         it = m_all_ongoing.erase(it);
 522                                 } else {
 523                                         ++it;
 524                                 }
 525                         }
 526
 527                         // Also abort all queued fetches for the caller
 528                         for (std::list<HTTPFetchRequest>::iterator
 529                                         it = m_queued_fetches.begin();
 530                                         it != m_queued_fetches.end();) {
 531                                 if ((*it).caller == caller)
 532                                         it = m_queued_fetches.erase(it);
 533                                 else
 534                                         ++it;
 535                         }
 536                 }
 537                 else if (req.type == RT_WAKEUP) {
 538                         // Wakeup: Nothing to do, thread is awake at this point
 539                 }
 540
 541                 if (req.event != NULL)
 542                         req.event->signal();
 543         }
 544
 545         // Start new ongoing fetches if m_parallel_limit allows
 546         void processQueued(CurlHandlePool *pool)
 547         {
 548                 while (m_all_ongoing.size() < m_parallel_limit &&
 549                                 !m_queued_fetches.empty()) {
 550                         HTTPFetchRequest request = m_queued_fetches.front();
 551                         m_queued_fetches.pop_front();
 552
 553                         // Create ongoing fetch data and make a cURL handle
 554                         // Set cURL options based on HTTPFetchRequest
 555                         HTTPFetchOngoing *ongoing =
 556                                 new HTTPFetchOngoing(request, pool);
 557
 558                         // Initiate the connection (curl_multi_add_handle)
 559                         CURLcode res = ongoing->start(m_multi);
 560                         if (res == CURLE_OK) {
 561                                 m_all_ongoing.push_back(ongoing);
 562                         }
 563                         else {
 564                                 httpfetch_deliver_result(*ongoing->complete(res));
 565                                 delete ongoing;
 566                         }
 567                 }
 568         }
 569
 570         // Process CURLMsg (indicates completion of a fetch)
 571         void processCurlMessage(CURLMsg *msg)
 572         {
 573                 // Determine which ongoing fetch the message pertains to
 574                 size_t i = 0;
 575                 bool found = false;
 576                 for (i = 0; i < m_all_ongoing.size(); ++i) {
 577                         if (m_all_ongoing[i]->getEasyHandle() == msg->easy_handle) {
 578                                 found = true;
 579                                 break;
 580                         }
 581                 }
 582                 if (msg->msg == CURLMSG_DONE && found) {
 583                         // m_all_ongoing[i] succeeded or failed.
 584                         HTTPFetchOngoing *ongoing = m_all_ongoing[i];
 585                         httpfetch_deliver_result(*ongoing->complete(msg->data.result));
 586                         delete ongoing;
 587                         m_all_ongoing.erase(m_all_ongoing.begin() + i);
 588                 }
 589         }
 590
 591         // Wait for a request from another thread, or timeout elapses
 592         void waitForRequest(long timeout)
 593         {
 594                 if (m_queued_fetches.empty()) {
 595                         try {
 596                                 Request req = m_requests.pop_front(timeout);
 597                                 processRequest(req);
 598                         }
 599                         catch (ItemNotFoundException &e) {}
 600                 }
 601         }
 602
 603         // Wait until some IO happens, or timeout elapses
 604         void waitForIO(long timeout)
 605         {
 606                 fd_set read_fd_set;
 607                 fd_set write_fd_set;
 608                 fd_set exc_fd_set;
 609                 int max_fd;
 610                 long select_timeout = -1;
 611                 struct timeval select_tv;
 612                 CURLMcode mres;
 613
 614                 FD_ZERO(&read_fd_set);
 615                 FD_ZERO(&write_fd_set);
 616                 FD_ZERO(&exc_fd_set);
 617
 618                 mres = curl_multi_fdset(m_multi, &read_fd_set,
 619                                 &write_fd_set, &exc_fd_set, &max_fd);
 620                 if (mres != CURLM_OK) {
 621                         errorstream<<"curl_multi_fdset"
 622                                 <<" returned error code "<<mres
 623                                 <<std::endl;
 624                         select_timeout = 0;
 625                 }
 626
 627                 mres = curl_multi_timeout(m_multi, &select_timeout);
 628                 if (mres != CURLM_OK) {
 629                         errorstream<<"curl_multi_timeout"
 630                                 <<" returned error code "<<mres
 631                                 <<std::endl;
 632                         select_timeout = 0;
 633                 }
 634
 635                 // Limit timeout so new requests get through
 636                 if (select_timeout < 0 || select_timeout > timeout)
 637                         select_timeout = timeout;
 638
 639                 if (select_timeout > 0) {
 640                         // in Winsock it is forbidden to pass three empty
 641                         // fd_sets to select(), so in that case use sleep_ms
 642                         if (max_fd != -1) {
 643                                 select_tv.tv_sec = select_timeout / 1000;
 644                                 select_tv.tv_usec = (select_timeout % 1000) * 1000;
 645                                 int retval = select(max_fd + 1, &read_fd_set,
 646                                                 &write_fd_set, &exc_fd_set,
 647                                                 &select_tv);
 648                                 if (retval == -1) {
 649                                         #ifdef _WIN32
 650                                         errorstream<<"select returned error code "
 651                                                 <<WSAGetLastError()<<std::endl;
 652                                         #else
 653                                         errorstream<<"select returned error code "
 654                                                 <<errno<<std::endl;
 655                                         #endif
 656                                 }
 657                         }
 658                         else {
 659                                 sleep_ms(select_timeout);
 660                         }
 661                 }
 662         }
 663
 664         void *run()
 665         {
 666                 CurlHandlePool pool;
 667
 668                 m_multi = curl_multi_init();
 669                 if (m_multi == NULL) {
 670                         errorstream<<"curl_multi_init returned NULL\n";
 671                         return NULL;
 672                 }
 673
 674                 FATAL_ERROR_IF(!m_all_ongoing.empty(), "Expected empty");
 675
 676                 while (!stopRequested()) {
 677                         BEGIN_DEBUG_EXCEPTION_HANDLER
 678
 679                         /*
 680                                 Handle new async requests
 681                         */
 682
 683                         while (!m_requests.empty()) {
 684                                 Request req = m_requests.pop_frontNoEx();
 685                                 processRequest(req);
 686                         }
 687                         processQueued(&pool);
 688
 689                         /*
 690                                 Handle ongoing async requests
 691                         */
 692
 693                         int still_ongoing = 0;
 694                         while (curl_multi_perform(m_multi, &still_ongoing) ==
 695                                         CURLM_CALL_MULTI_PERFORM)
 696                                 /* noop */;
 697
 698                         /*
 699                                 Handle completed async requests
 700                         */
 701                         if (still_ongoing < (int) m_all_ongoing.size()) {
 702                                 CURLMsg *msg;
 703                                 int msgs_in_queue;
 704                                 msg = curl_multi_info_read(m_multi, &msgs_in_queue);
 705                                 while (msg != NULL) {
 706                                         processCurlMessage(msg);
 707                                         msg = curl_multi_info_read(m_multi, &msgs_in_queue);
 708                                 }
 709                         }
 710
 711                         /*
 712                                 If there are ongoing requests, wait for data
 713                                 (with a timeout of 100ms so that new requests
 714                                 can be processed).
 715
 716                                 If no ongoing requests, wait for a new request.
 717                                 (Possibly an empty request that signals
 718                                 that the thread should be stopped.)
 719                         */
 720                         if (m_all_ongoing.empty())
 721                                 waitForRequest(100000000);
 722                         else
 723                                 waitForIO(100);
 724
 725                         END_DEBUG_EXCEPTION_HANDLER
 726                 }
 727
 728                 // Call curl_multi_remove_handle and cleanup easy handles
 729                 for (HTTPFetchOngoing *i : m_all_ongoing) {
 730                         delete i;
 731                 }
 732                 m_all_ongoing.clear();
 733
 734                 m_queued_fetches.clear();
 735
 736                 CURLMcode mres = curl_multi_cleanup(m_multi);
 737                 if (mres != CURLM_OK) {
 738                         errorstream<<"curl_multi_cleanup"
 739                                 <<" returned error code "<<mres
 740                                 <<std::endl;
 741                 }
 742
 743                 return NULL;
 744         }
 745 };
 746
 747 CurlFetchThread *g_httpfetch_thread = NULL;
 748
 749 void httpfetch_init(int parallel_limit)
 750 {
 751         verbosestream<<"httpfetch_init: parallel_limit="<<parallel_limit
 752                         <<std::endl;
 753
 754         CURLcode res = curl_global_init(CURL_GLOBAL_DEFAULT);
 755         FATAL_ERROR_IF(res != CURLE_OK, "CURL init failed");
 756
 757         g_httpfetch_thread = new CurlFetchThread(parallel_limit);
 758
 759         // Initialize g_callerid_randomness for httpfetch_caller_alloc_secure
 760         u64 randbuf[2];
 761         porting::secure_rand_fill_buf(randbuf, sizeof(u64) * 2);
 762         g_callerid_randomness = PcgRandom(randbuf[0], randbuf[1]);
 763 }
 764
 765 void httpfetch_cleanup()
 766 {
 767         verbosestream<<"httpfetch_cleanup: cleaning up"<<std::endl;
 768
 769         if (g_httpfetch_thread) {
 770                 g_httpfetch_thread->stop();
 771                 g_httpfetch_thread->requestWakeUp();
 772                 g_httpfetch_thread->wait();
 773                 delete g_httpfetch_thread;
 774         }
 775
 776         curl_global_cleanup();
 777 }
 778
 779 void httpfetch_async(const HTTPFetchRequest &fetch_request)
 780 {
 781         g_httpfetch_thread->requestFetch(fetch_request);
 782         if (!g_httpfetch_thread->isRunning())
 783                 g_httpfetch_thread->start();
 784 }
 785
 786 static void httpfetch_request_clear(u64 caller)
 787 {
 788         if (g_httpfetch_thread->isRunning()) {
 789                 Event event;
 790                 g_httpfetch_thread->requestClear(caller, &event);
 791                 event.wait();
 792         } else {
 793                 g_httpfetch_thread->requestClear(caller, NULL);
 794         }
 795 }
 796
 797 void httpfetch_sync(const HTTPFetchRequest &fetch_request,
 798                 HTTPFetchResult &fetch_result)
 799 {
 800         // Create ongoing fetch data and make a cURL handle
 801         // Set cURL options based on HTTPFetchRequest
 802         CurlHandlePool pool;
 803         HTTPFetchOngoing ongoing(fetch_request, &pool);
 804         // Do the fetch (curl_easy_perform)
 805         CURLcode res = ongoing.start(NULL);
 806         // Update fetch result
 807         fetch_result = *ongoing.complete(res);
 808 }
 809
 810 #else  // USE_CURL
 811
 812 /*
 813         USE_CURL is off:
 814
 815         Dummy httpfetch implementation that always returns an error.
 816 */
 817
 818 void httpfetch_init(int parallel_limit)
 819 {
 820 }
 821
 822 void httpfetch_cleanup()
 823 {
 824 }
 825
 826 void httpfetch_async(const HTTPFetchRequest &fetch_request)
 827 {
 828         errorstream << "httpfetch_async: unable to fetch " << fetch_request.url
 829                         << " because USE_CURL=0" << std::endl;
 830
 831         HTTPFetchResult fetch_result(fetch_request); // sets succeeded = false etc.
 832         httpfetch_deliver_result(fetch_result);
 833 }
 834
 835 static void httpfetch_request_clear(u64 caller)
 836 {
 837 }
 838
 839 void httpfetch_sync(const HTTPFetchRequest &fetch_request,
 840                 HTTPFetchResult &fetch_result)
 841 {
 842         errorstream << "httpfetch_sync: unable to fetch " << fetch_request.url
 843                         << " because USE_CURL=0" << std::endl;
 844
 845         fetch_result = HTTPFetchResult(fetch_request); // sets succeeded = false etc.
 846 }
 847
 848 #endif  // USE_CURL