git.oblomov.eu Git - git/blob - http.c

   1 #include "git-compat-util.h"
   2 #include "http.h"
   3 #include "pack.h"
   4 #include "sideband.h"
   5 #include "run-command.h"
   6 #include "url.h"
   7 #include "urlmatch.h"
   8 #include "credential.h"
   9 #include "version.h"
  10 #include "pkt-line.h"
  11 #include "gettext.h"
  12 #include "transport.h"
  13
  14 #if LIBCURL_VERSION_NUM >= 0x070a08
  15 long int git_curl_ipresolve = CURL_IPRESOLVE_WHATEVER;
  16 #else
  17 long int git_curl_ipresolve;
  18 #endif
  19 int active_requests;
  20 int http_is_verbose;
  21 size_t http_post_buffer = 16 * LARGE_PACKET_MAX;
  22
  23 #if LIBCURL_VERSION_NUM >= 0x070a06
  24 #define LIBCURL_CAN_HANDLE_AUTH_ANY
  25 #endif
  26
  27 static int min_curl_sessions = 1;
  28 static int curl_session_count;
  29 #ifdef USE_CURL_MULTI
  30 static int max_requests = -1;
  31 static CURLM *curlm;
  32 #endif
  33 #ifndef NO_CURL_EASY_DUPHANDLE
  34 static CURL *curl_default;
  35 #endif
  36
  37 #define PREV_BUF_SIZE 4096
  38
  39 char curl_errorstr[CURL_ERROR_SIZE];
  40
  41 static int curl_ssl_verify = -1;
  42 static int curl_ssl_try;
  43 static const char *ssl_cert;
  44 static const char *ssl_cipherlist;
  45 static const char *ssl_version;
  46 static struct {
  47         const char *name;
  48         long ssl_version;
  49 } sslversions[] = {
  50         { "sslv2", CURL_SSLVERSION_SSLv2 },
  51         { "sslv3", CURL_SSLVERSION_SSLv3 },
  52         { "tlsv1", CURL_SSLVERSION_TLSv1 },
  53 #if LIBCURL_VERSION_NUM >= 0x072200
  54         { "tlsv1.0", CURL_SSLVERSION_TLSv1_0 },
  55         { "tlsv1.1", CURL_SSLVERSION_TLSv1_1 },
  56         { "tlsv1.2", CURL_SSLVERSION_TLSv1_2 },
  57 #endif
  58 };
  59 #if LIBCURL_VERSION_NUM >= 0x070903
  60 static const char *ssl_key;
  61 #endif
  62 #if LIBCURL_VERSION_NUM >= 0x070908
  63 static const char *ssl_capath;
  64 #endif
  65 #if LIBCURL_VERSION_NUM >= 0x072c00
  66 static const char *ssl_pinnedkey;
  67 #endif
  68 static const char *ssl_cainfo;
  69 static long curl_low_speed_limit = -1;
  70 static long curl_low_speed_time = -1;
  71 static int curl_ftp_no_epsv;
  72 static const char *curl_http_proxy;
  73 static const char *curl_no_proxy;
  74 static const char *http_proxy_authmethod;
  75 static struct {
  76         const char *name;
  77         long curlauth_param;
  78 } proxy_authmethods[] = {
  79         { "basic", CURLAUTH_BASIC },
  80         { "digest", CURLAUTH_DIGEST },
  81         { "negotiate", CURLAUTH_GSSNEGOTIATE },
  82         { "ntlm", CURLAUTH_NTLM },
  83 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
  84         { "anyauth", CURLAUTH_ANY },
  85 #endif
  86         /*
  87          * CURLAUTH_DIGEST_IE has no corresponding command-line option in
  88          * curl(1) and is not included in CURLAUTH_ANY, so we leave it out
  89          * here, too
  90          */
  91 };
  92 static struct credential proxy_auth = CREDENTIAL_INIT;
  93 static const char *curl_proxyuserpwd;
  94 static const char *curl_cookie_file;
  95 static int curl_save_cookies;
  96 struct credential http_auth = CREDENTIAL_INIT;
  97 static int http_proactive_auth;
  98 static const char *user_agent;
  99 static int curl_empty_auth;
 100
 101 #if LIBCURL_VERSION_NUM >= 0x071700
 102 /* Use CURLOPT_KEYPASSWD as is */
 103 #elif LIBCURL_VERSION_NUM >= 0x070903
 104 #define CURLOPT_KEYPASSWD CURLOPT_SSLKEYPASSWD
 105 #else
 106 #define CURLOPT_KEYPASSWD CURLOPT_SSLCERTPASSWD
 107 #endif
 108
 109 static struct credential cert_auth = CREDENTIAL_INIT;
 110 static int ssl_cert_password_required;
 111 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 112 static unsigned long http_auth_methods = CURLAUTH_ANY;
 113 #endif
 114
 115 static struct curl_slist *pragma_header;
 116 static struct curl_slist *no_pragma_header;
 117
 118 static struct active_request_slot *active_queue_head;
 119
 120 static char *cached_accept_language;
 121
 122 size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
 123 {
 124         size_t size = eltsize * nmemb;
 125         struct buffer *buffer = buffer_;
 126
 127         if (size > buffer->buf.len - buffer->posn)
 128                 size = buffer->buf.len - buffer->posn;
 129         memcpy(ptr, buffer->buf.buf + buffer->posn, size);
 130         buffer->posn += size;
 131
 132         return size;
 133 }
 134
 135 #ifndef NO_CURL_IOCTL
 136 curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)
 137 {
 138         struct buffer *buffer = clientp;
 139
 140         switch (cmd) {
 141         case CURLIOCMD_NOP:
 142                 return CURLIOE_OK;
 143
 144         case CURLIOCMD_RESTARTREAD:
 145                 buffer->posn = 0;
 146                 return CURLIOE_OK;
 147
 148         default:
 149                 return CURLIOE_UNKNOWNCMD;
 150         }
 151 }
 152 #endif
 153
 154 size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
 155 {
 156         size_t size = eltsize * nmemb;
 157         struct strbuf *buffer = buffer_;
 158
 159         strbuf_add(buffer, ptr, size);
 160         return size;
 161 }
 162
 163 size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf)
 164 {
 165         return eltsize * nmemb;
 166 }
 167
 168 static void closedown_active_slot(struct active_request_slot *slot)
 169 {
 170         active_requests--;
 171         slot->in_use = 0;
 172 }
 173
 174 static void finish_active_slot(struct active_request_slot *slot)
 175 {
 176         closedown_active_slot(slot);
 177         curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
 178
 179         if (slot->finished != NULL)
 180                 (*slot->finished) = 1;
 181
 182         /* Store slot results so they can be read after the slot is reused */
 183         if (slot->results != NULL) {
 184                 slot->results->curl_result = slot->curl_result;
 185                 slot->results->http_code = slot->http_code;
 186 #if LIBCURL_VERSION_NUM >= 0x070a08
 187                 curl_easy_getinfo(slot->curl, CURLINFO_HTTPAUTH_AVAIL,
 188                                   &slot->results->auth_avail);
 189 #else
 190                 slot->results->auth_avail = 0;
 191 #endif
 192
 193                 curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CONNECTCODE,
 194                         &slot->results->http_connectcode);
 195         }
 196
 197         /* Run callback if appropriate */
 198         if (slot->callback_func != NULL)
 199                 slot->callback_func(slot->callback_data);
 200 }
 201
 202 #ifdef USE_CURL_MULTI
 203 static void process_curl_messages(void)
 204 {
 205         int num_messages;
 206         struct active_request_slot *slot;
 207         CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
 208
 209         while (curl_message != NULL) {
 210                 if (curl_message->msg == CURLMSG_DONE) {
 211                         int curl_result = curl_message->data.result;
 212                         slot = active_queue_head;
 213                         while (slot != NULL &&
 214                                slot->curl != curl_message->easy_handle)
 215                                 slot = slot->next;
 216                         if (slot != NULL) {
 217                                 curl_multi_remove_handle(curlm, slot->curl);
 218                                 slot->curl_result = curl_result;
 219                                 finish_active_slot(slot);
 220                         } else {
 221                                 fprintf(stderr, "Received DONE message for unknown request!\n");
 222                         }
 223                 } else {
 224                         fprintf(stderr, "Unknown CURL message received: %d\n",
 225                                 (int)curl_message->msg);
 226                 }
 227                 curl_message = curl_multi_info_read(curlm, &num_messages);
 228         }
 229 }
 230 #endif
 231
 232 static int http_options(const char *var, const char *value, void *cb)
 233 {
 234         if (!strcmp("http.sslverify", var)) {
 235                 curl_ssl_verify = git_config_bool(var, value);
 236                 return 0;
 237         }
 238         if (!strcmp("http.sslcipherlist", var))
 239                 return git_config_string(&ssl_cipherlist, var, value);
 240         if (!strcmp("http.sslversion", var))
 241                 return git_config_string(&ssl_version, var, value);
 242         if (!strcmp("http.sslcert", var))
 243                 return git_config_string(&ssl_cert, var, value);
 244 #if LIBCURL_VERSION_NUM >= 0x070903
 245         if (!strcmp("http.sslkey", var))
 246                 return git_config_string(&ssl_key, var, value);
 247 #endif
 248 #if LIBCURL_VERSION_NUM >= 0x070908
 249         if (!strcmp("http.sslcapath", var))
 250                 return git_config_pathname(&ssl_capath, var, value);
 251 #endif
 252         if (!strcmp("http.sslcainfo", var))
 253                 return git_config_pathname(&ssl_cainfo, var, value);
 254         if (!strcmp("http.sslcertpasswordprotected", var)) {
 255                 ssl_cert_password_required = git_config_bool(var, value);
 256                 return 0;
 257         }
 258         if (!strcmp("http.ssltry", var)) {
 259                 curl_ssl_try = git_config_bool(var, value);
 260                 return 0;
 261         }
 262         if (!strcmp("http.minsessions", var)) {
 263                 min_curl_sessions = git_config_int(var, value);
 264 #ifndef USE_CURL_MULTI
 265                 if (min_curl_sessions > 1)
 266                         min_curl_sessions = 1;
 267 #endif
 268                 return 0;
 269         }
 270 #ifdef USE_CURL_MULTI
 271         if (!strcmp("http.maxrequests", var)) {
 272                 max_requests = git_config_int(var, value);
 273                 return 0;
 274         }
 275 #endif
 276         if (!strcmp("http.lowspeedlimit", var)) {
 277                 curl_low_speed_limit = (long)git_config_int(var, value);
 278                 return 0;
 279         }
 280         if (!strcmp("http.lowspeedtime", var)) {
 281                 curl_low_speed_time = (long)git_config_int(var, value);
 282                 return 0;
 283         }
 284
 285         if (!strcmp("http.noepsv", var)) {
 286                 curl_ftp_no_epsv = git_config_bool(var, value);
 287                 return 0;
 288         }
 289         if (!strcmp("http.proxy", var))
 290                 return git_config_string(&curl_http_proxy, var, value);
 291
 292         if (!strcmp("http.proxyauthmethod", var))
 293                 return git_config_string(&http_proxy_authmethod, var, value);
 294
 295         if (!strcmp("http.cookiefile", var))
 296                 return git_config_string(&curl_cookie_file, var, value);
 297         if (!strcmp("http.savecookies", var)) {
 298                 curl_save_cookies = git_config_bool(var, value);
 299                 return 0;
 300         }
 301
 302         if (!strcmp("http.postbuffer", var)) {
 303                 http_post_buffer = git_config_int(var, value);
 304                 if (http_post_buffer < LARGE_PACKET_MAX)
 305                         http_post_buffer = LARGE_PACKET_MAX;
 306                 return 0;
 307         }
 308
 309         if (!strcmp("http.useragent", var))
 310                 return git_config_string(&user_agent, var, value);
 311
 312         if (!strcmp("http.emptyauth", var)) {
 313                 curl_empty_auth = git_config_bool(var, value);
 314                 return 0;
 315         }
 316
 317         if (!strcmp("http.pinnedpubkey", var)) {
 318 #if LIBCURL_VERSION_NUM >= 0x072c00
 319                 return git_config_pathname(&ssl_pinnedkey, var, value);
 320 #else
 321                 warning(_("Public key pinning not supported with cURL < 7.44.0"));
 322                 return 0;
 323 #endif
 324         }
 325
 326         /* Fall back on the default ones */
 327         return git_default_config(var, value, cb);
 328 }
 329
 330 static void init_curl_http_auth(CURL *result)
 331 {
 332         if (!http_auth.username) {
 333                 if (curl_empty_auth)
 334                         curl_easy_setopt(result, CURLOPT_USERPWD, ":");
 335                 return;
 336         }
 337
 338         credential_fill(&http_auth);
 339
 340 #if LIBCURL_VERSION_NUM >= 0x071301
 341         curl_easy_setopt(result, CURLOPT_USERNAME, http_auth.username);
 342         curl_easy_setopt(result, CURLOPT_PASSWORD, http_auth.password);
 343 #else
 344         {
 345                 static struct strbuf up = STRBUF_INIT;
 346                 /*
 347                  * Note that we assume we only ever have a single set of
 348                  * credentials in a given program run, so we do not have
 349                  * to worry about updating this buffer, only setting its
 350                  * initial value.
 351                  */
 352                 if (!up.len)
 353                         strbuf_addf(&up, "%s:%s",
 354                                 http_auth.username, http_auth.password);
 355                 curl_easy_setopt(result, CURLOPT_USERPWD, up.buf);
 356         }
 357 #endif
 358 }
 359
 360 /* *var must be free-able */
 361 static void var_override(const char **var, char *value)
 362 {
 363         if (value) {
 364                 free((void *)*var);
 365                 *var = xstrdup(value);
 366         }
 367 }
 368
 369 static void set_proxyauth_name_password(CURL *result)
 370 {
 371 #if LIBCURL_VERSION_NUM >= 0x071301
 372                 curl_easy_setopt(result, CURLOPT_PROXYUSERNAME,
 373                         proxy_auth.username);
 374                 curl_easy_setopt(result, CURLOPT_PROXYPASSWORD,
 375                         proxy_auth.password);
 376 #else
 377                 struct strbuf s = STRBUF_INIT;
 378
 379                 strbuf_addstr_urlencode(&s, proxy_auth.username, 1);
 380                 strbuf_addch(&s, ':');
 381                 strbuf_addstr_urlencode(&s, proxy_auth.password, 1);
 382                 curl_proxyuserpwd = strbuf_detach(&s, NULL);
 383                 curl_easy_setopt(result, CURLOPT_PROXYUSERPWD, curl_proxyuserpwd);
 384 #endif
 385 }
 386
 387 static void init_curl_proxy_auth(CURL *result)
 388 {
 389         if (proxy_auth.username) {
 390                 if (!proxy_auth.password)
 391                         credential_fill(&proxy_auth);
 392                 set_proxyauth_name_password(result);
 393         }
 394
 395         var_override(&http_proxy_authmethod, getenv("GIT_HTTP_PROXY_AUTHMETHOD"));
 396
 397 #if LIBCURL_VERSION_NUM >= 0x070a07 /* CURLOPT_PROXYAUTH and CURLAUTH_ANY */
 398         if (http_proxy_authmethod) {
 399                 int i;
 400                 for (i = 0; i < ARRAY_SIZE(proxy_authmethods); i++) {
 401                         if (!strcmp(http_proxy_authmethod, proxy_authmethods[i].name)) {
 402                                 curl_easy_setopt(result, CURLOPT_PROXYAUTH,
 403                                                 proxy_authmethods[i].curlauth_param);
 404                                 break;
 405                         }
 406                 }
 407                 if (i == ARRAY_SIZE(proxy_authmethods)) {
 408                         warning("unsupported proxy authentication method %s: using anyauth",
 409                                         http_proxy_authmethod);
 410                         curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
 411                 }
 412         }
 413         else
 414                 curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
 415 #endif
 416 }
 417
 418 static int has_cert_password(void)
 419 {
 420         if (ssl_cert == NULL || ssl_cert_password_required != 1)
 421                 return 0;
 422         if (!cert_auth.password) {
 423                 cert_auth.protocol = xstrdup("cert");
 424                 cert_auth.username = xstrdup("");
 425                 cert_auth.path = xstrdup(ssl_cert);
 426                 credential_fill(&cert_auth);
 427         }
 428         return 1;
 429 }
 430
 431 #if LIBCURL_VERSION_NUM >= 0x071900
 432 static void set_curl_keepalive(CURL *c)
 433 {
 434         curl_easy_setopt(c, CURLOPT_TCP_KEEPALIVE, 1);
 435 }
 436
 437 #elif LIBCURL_VERSION_NUM >= 0x071000
 438 static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
 439 {
 440         int ka = 1;
 441         int rc;
 442         socklen_t len = (socklen_t)sizeof(ka);
 443
 444         if (type != CURLSOCKTYPE_IPCXN)
 445                 return 0;
 446
 447         rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
 448         if (rc < 0)
 449                 warning("unable to set SO_KEEPALIVE on socket %s",
 450                         strerror(errno));
 451
 452         return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
 453 }
 454
 455 static void set_curl_keepalive(CURL *c)
 456 {
 457         curl_easy_setopt(c, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
 458 }
 459
 460 #else
 461 static void set_curl_keepalive(CURL *c)
 462 {
 463         /* not supported on older curl versions */
 464 }
 465 #endif
 466
 467 static CURL *get_curl_handle(void)
 468 {
 469         CURL *result = curl_easy_init();
 470         long allowed_protocols = 0;
 471
 472         if (!result)
 473                 die("curl_easy_init failed");
 474
 475         if (!curl_ssl_verify) {
 476                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
 477                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
 478         } else {
 479                 /* Verify authenticity of the peer's certificate */
 480                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
 481                 /* The name in the cert must match whom we tried to connect */
 482                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
 483         }
 484
 485 #if LIBCURL_VERSION_NUM >= 0x070907
 486         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
 487 #endif
 488 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 489         curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
 490 #endif
 491
 492         if (http_proactive_auth)
 493                 init_curl_http_auth(result);
 494
 495         if (getenv("GIT_SSL_VERSION"))
 496                 ssl_version = getenv("GIT_SSL_VERSION");
 497         if (ssl_version && *ssl_version) {
 498                 int i;
 499                 for (i = 0; i < ARRAY_SIZE(sslversions); i++) {
 500                         if (!strcmp(ssl_version, sslversions[i].name)) {
 501                                 curl_easy_setopt(result, CURLOPT_SSLVERSION,
 502                                                  sslversions[i].ssl_version);
 503                                 break;
 504                         }
 505                 }
 506                 if (i == ARRAY_SIZE(sslversions))
 507                         warning("unsupported ssl version %s: using default",
 508                                 ssl_version);
 509         }
 510
 511         if (getenv("GIT_SSL_CIPHER_LIST"))
 512                 ssl_cipherlist = getenv("GIT_SSL_CIPHER_LIST");
 513         if (ssl_cipherlist != NULL && *ssl_cipherlist)
 514                 curl_easy_setopt(result, CURLOPT_SSL_CIPHER_LIST,
 515                                 ssl_cipherlist);
 516
 517         if (ssl_cert != NULL)
 518                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
 519         if (has_cert_password())
 520                 curl_easy_setopt(result, CURLOPT_KEYPASSWD, cert_auth.password);
 521 #if LIBCURL_VERSION_NUM >= 0x070903
 522         if (ssl_key != NULL)
 523                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
 524 #endif
 525 #if LIBCURL_VERSION_NUM >= 0x070908
 526         if (ssl_capath != NULL)
 527                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
 528 #endif
 529 #if LIBCURL_VERSION_NUM >= 0x072c00
 530         if (ssl_pinnedkey != NULL)
 531                 curl_easy_setopt(result, CURLOPT_PINNEDPUBLICKEY, ssl_pinnedkey);
 532 #endif
 533         if (ssl_cainfo != NULL)
 534                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
 535
 536         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
 537                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
 538                                  curl_low_speed_limit);
 539                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
 540                                  curl_low_speed_time);
 541         }
 542
 543         curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
 544         curl_easy_setopt(result, CURLOPT_MAXREDIRS, 20);
 545 #if LIBCURL_VERSION_NUM >= 0x071301
 546         curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
 547 #elif LIBCURL_VERSION_NUM >= 0x071101
 548         curl_easy_setopt(result, CURLOPT_POST301, 1);
 549 #endif
 550 #if LIBCURL_VERSION_NUM >= 0x071304
 551         if (is_transport_allowed("http"))
 552                 allowed_protocols |= CURLPROTO_HTTP;
 553         if (is_transport_allowed("https"))
 554                 allowed_protocols |= CURLPROTO_HTTPS;
 555         if (is_transport_allowed("ftp"))
 556                 allowed_protocols |= CURLPROTO_FTP;
 557         if (is_transport_allowed("ftps"))
 558                 allowed_protocols |= CURLPROTO_FTPS;
 559         curl_easy_setopt(result, CURLOPT_REDIR_PROTOCOLS, allowed_protocols);
 560 #else
 561         if (transport_restrict_protocols())
 562                 warning("protocol restrictions not applied to curl redirects because\n"
 563                         "your curl version is too old (>= 7.19.4)");
 564 #endif
 565
 566         if (getenv("GIT_CURL_VERBOSE"))
 567                 curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
 568
 569         curl_easy_setopt(result, CURLOPT_USERAGENT,
 570                 user_agent ? user_agent : git_user_agent());
 571
 572         if (curl_ftp_no_epsv)
 573                 curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
 574
 575 #ifdef CURLOPT_USE_SSL
 576         if (curl_ssl_try)
 577                 curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
 578 #endif
 579
 580         /*
 581          * CURL also examines these variables as a fallback; but we need to query
 582          * them here in order to decide whether to prompt for missing password (cf.
 583          * init_curl_proxy_auth()).
 584          *
 585          * Unlike many other common environment variables, these are historically
 586          * lowercase only. It appears that CURL did not know this and implemented
 587          * only uppercase variants, which was later corrected to take both - with
 588          * the exception of http_proxy, which is lowercase only also in CURL. As
 589          * the lowercase versions are the historical quasi-standard, they take
 590          * precedence here, as in CURL.
 591          */
 592         if (!curl_http_proxy) {
 593                 if (!strcmp(http_auth.protocol, "https")) {
 594                         var_override(&curl_http_proxy, getenv("HTTPS_PROXY"));
 595                         var_override(&curl_http_proxy, getenv("https_proxy"));
 596                 } else {
 597                         var_override(&curl_http_proxy, getenv("http_proxy"));
 598                 }
 599                 if (!curl_http_proxy) {
 600                         var_override(&curl_http_proxy, getenv("ALL_PROXY"));
 601                         var_override(&curl_http_proxy, getenv("all_proxy"));
 602                 }
 603         }
 604
 605         if (curl_http_proxy) {
 606                 curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
 607 #if LIBCURL_VERSION_NUM >= 0x071800
 608                 if (starts_with(curl_http_proxy, "socks5h"))
 609                         curl_easy_setopt(result,
 610                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5_HOSTNAME);
 611                 else if (starts_with(curl_http_proxy, "socks5"))
 612                         curl_easy_setopt(result,
 613                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);
 614                 else if (starts_with(curl_http_proxy, "socks4a"))
 615                         curl_easy_setopt(result,
 616                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4A);
 617                 else if (starts_with(curl_http_proxy, "socks"))
 618                         curl_easy_setopt(result,
 619                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4);
 620 #endif
 621                 if (strstr(curl_http_proxy, "://"))
 622                         credential_from_url(&proxy_auth, curl_http_proxy);
 623                 else {
 624                         struct strbuf url = STRBUF_INIT;
 625                         strbuf_addf(&url, "http://%s", curl_http_proxy);
 626                         credential_from_url(&proxy_auth, url.buf);
 627                         strbuf_release(&url);
 628                 }
 629
 630                 curl_easy_setopt(result, CURLOPT_PROXY, proxy_auth.host);
 631 #if LIBCURL_VERSION_NUM >= 0x071304
 632                 var_override(&curl_no_proxy, getenv("NO_PROXY"));
 633                 var_override(&curl_no_proxy, getenv("no_proxy"));
 634                 curl_easy_setopt(result, CURLOPT_NOPROXY, curl_no_proxy);
 635 #endif
 636         }
 637         init_curl_proxy_auth(result);
 638
 639         set_curl_keepalive(result);
 640
 641         return result;
 642 }
 643
 644 static void set_from_env(const char **var, const char *envname)
 645 {
 646         const char *val = getenv(envname);
 647         if (val)
 648                 *var = val;
 649 }
 650
 651 void http_init(struct remote *remote, const char *url, int proactive_auth)
 652 {
 653         char *low_speed_limit;
 654         char *low_speed_time;
 655         char *normalized_url;
 656         struct urlmatch_config config = { STRING_LIST_INIT_DUP };
 657
 658         config.section = "http";
 659         config.key = NULL;
 660         config.collect_fn = http_options;
 661         config.cascade_fn = git_default_config;
 662         config.cb = NULL;
 663
 664         http_is_verbose = 0;
 665         normalized_url = url_normalize(url, &config.url);
 666
 667         git_config(urlmatch_config_entry, &config);
 668         free(normalized_url);
 669
 670         if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK)
 671                 die("curl_global_init failed");
 672
 673         http_proactive_auth = proactive_auth;
 674
 675         if (remote && remote->http_proxy)
 676                 curl_http_proxy = xstrdup(remote->http_proxy);
 677
 678         if (remote)
 679                 var_override(&http_proxy_authmethod, remote->http_proxy_authmethod);
 680
 681         pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
 682         no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
 683
 684 #ifdef USE_CURL_MULTI
 685         {
 686                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
 687                 if (http_max_requests != NULL)
 688                         max_requests = atoi(http_max_requests);
 689         }
 690
 691         curlm = curl_multi_init();
 692         if (!curlm)
 693                 die("curl_multi_init failed");
 694 #endif
 695
 696         if (getenv("GIT_SSL_NO_VERIFY"))
 697                 curl_ssl_verify = 0;
 698
 699         set_from_env(&ssl_cert, "GIT_SSL_CERT");
 700 #if LIBCURL_VERSION_NUM >= 0x070903
 701         set_from_env(&ssl_key, "GIT_SSL_KEY");
 702 #endif
 703 #if LIBCURL_VERSION_NUM >= 0x070908
 704         set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
 705 #endif
 706         set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
 707
 708         set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");
 709
 710         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
 711         if (low_speed_limit != NULL)
 712                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
 713         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
 714         if (low_speed_time != NULL)
 715                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
 716
 717         if (curl_ssl_verify == -1)
 718                 curl_ssl_verify = 1;
 719
 720         curl_session_count = 0;
 721 #ifdef USE_CURL_MULTI
 722         if (max_requests < 1)
 723                 max_requests = DEFAULT_MAX_REQUESTS;
 724 #endif
 725
 726         if (getenv("GIT_CURL_FTP_NO_EPSV"))
 727                 curl_ftp_no_epsv = 1;
 728
 729         if (url) {
 730                 credential_from_url(&http_auth, url);
 731                 if (!ssl_cert_password_required &&
 732                     getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
 733                     starts_with(url, "https://"))
 734                         ssl_cert_password_required = 1;
 735         }
 736
 737 #ifndef NO_CURL_EASY_DUPHANDLE
 738         curl_default = get_curl_handle();
 739 #endif
 740 }
 741
 742 void http_cleanup(void)
 743 {
 744         struct active_request_slot *slot = active_queue_head;
 745
 746         while (slot != NULL) {
 747                 struct active_request_slot *next = slot->next;
 748                 if (slot->curl != NULL) {
 749 #ifdef USE_CURL_MULTI
 750                         curl_multi_remove_handle(curlm, slot->curl);
 751 #endif
 752                         curl_easy_cleanup(slot->curl);
 753                 }
 754                 free(slot);
 755                 slot = next;
 756         }
 757         active_queue_head = NULL;
 758
 759 #ifndef NO_CURL_EASY_DUPHANDLE
 760         curl_easy_cleanup(curl_default);
 761 #endif
 762
 763 #ifdef USE_CURL_MULTI
 764         curl_multi_cleanup(curlm);
 765 #endif
 766         curl_global_cleanup();
 767
 768         curl_slist_free_all(pragma_header);
 769         pragma_header = NULL;
 770
 771         curl_slist_free_all(no_pragma_header);
 772         no_pragma_header = NULL;
 773
 774         if (curl_http_proxy) {
 775                 free((void *)curl_http_proxy);
 776                 curl_http_proxy = NULL;
 777         }
 778
 779         if (proxy_auth.password) {
 780                 memset(proxy_auth.password, 0, strlen(proxy_auth.password));
 781                 free(proxy_auth.password);
 782                 proxy_auth.password = NULL;
 783         }
 784
 785         free((void *)curl_proxyuserpwd);
 786         curl_proxyuserpwd = NULL;
 787
 788         free((void *)http_proxy_authmethod);
 789         http_proxy_authmethod = NULL;
 790
 791         if (cert_auth.password != NULL) {
 792                 memset(cert_auth.password, 0, strlen(cert_auth.password));
 793                 free(cert_auth.password);
 794                 cert_auth.password = NULL;
 795         }
 796         ssl_cert_password_required = 0;
 797
 798         free(cached_accept_language);
 799         cached_accept_language = NULL;
 800 }
 801
 802 struct active_request_slot *get_active_slot(void)
 803 {
 804         struct active_request_slot *slot = active_queue_head;
 805         struct active_request_slot *newslot;
 806
 807 #ifdef USE_CURL_MULTI
 808         int num_transfers;
 809
 810         /* Wait for a slot to open up if the queue is full */
 811         while (active_requests >= max_requests) {
 812                 curl_multi_perform(curlm, &num_transfers);
 813                 if (num_transfers < active_requests)
 814                         process_curl_messages();
 815         }
 816 #endif
 817
 818         while (slot != NULL && slot->in_use)
 819                 slot = slot->next;
 820
 821         if (slot == NULL) {
 822                 newslot = xmalloc(sizeof(*newslot));
 823                 newslot->curl = NULL;
 824                 newslot->in_use = 0;
 825                 newslot->next = NULL;
 826
 827                 slot = active_queue_head;
 828                 if (slot == NULL) {
 829                         active_queue_head = newslot;
 830                 } else {
 831                         while (slot->next != NULL)
 832                                 slot = slot->next;
 833                         slot->next = newslot;
 834                 }
 835                 slot = newslot;
 836         }
 837
 838         if (slot->curl == NULL) {
 839 #ifdef NO_CURL_EASY_DUPHANDLE
 840                 slot->curl = get_curl_handle();
 841 #else
 842                 slot->curl = curl_easy_duphandle(curl_default);
 843 #endif
 844                 curl_session_count++;
 845         }
 846
 847         active_requests++;
 848         slot->in_use = 1;
 849         slot->results = NULL;
 850         slot->finished = NULL;
 851         slot->callback_data = NULL;
 852         slot->callback_func = NULL;
 853         curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file);
 854         if (curl_save_cookies)
 855                 curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file);
 856         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
 857         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
 858         curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
 859         curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
 860         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
 861         curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
 862         curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
 863         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
 864         curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
 865         curl_easy_setopt(slot->curl, CURLOPT_RANGE, NULL);
 866
 867 #if LIBCURL_VERSION_NUM >= 0x070a08
 868         curl_easy_setopt(slot->curl, CURLOPT_IPRESOLVE, git_curl_ipresolve);
 869 #endif
 870 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 871         curl_easy_setopt(slot->curl, CURLOPT_HTTPAUTH, http_auth_methods);
 872 #endif
 873         if (http_auth.password || curl_empty_auth)
 874                 init_curl_http_auth(slot->curl);
 875
 876         return slot;
 877 }
 878
 879 int start_active_slot(struct active_request_slot *slot)
 880 {
 881 #ifdef USE_CURL_MULTI
 882         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
 883         int num_transfers;
 884
 885         if (curlm_result != CURLM_OK &&
 886             curlm_result != CURLM_CALL_MULTI_PERFORM) {
 887                 active_requests--;
 888                 slot->in_use = 0;
 889                 return 0;
 890         }
 891
 892         /*
 893          * We know there must be something to do, since we just added
 894          * something.
 895          */
 896         curl_multi_perform(curlm, &num_transfers);
 897 #endif
 898         return 1;
 899 }
 900
 901 #ifdef USE_CURL_MULTI
 902 struct fill_chain {
 903         void *data;
 904         int (*fill)(void *);
 905         struct fill_chain *next;
 906 };
 907
 908 static struct fill_chain *fill_cfg;
 909
 910 void add_fill_function(void *data, int (*fill)(void *))
 911 {
 912         struct fill_chain *new = xmalloc(sizeof(*new));
 913         struct fill_chain **linkp = &fill_cfg;
 914         new->data = data;
 915         new->fill = fill;
 916         new->next = NULL;
 917         while (*linkp)
 918                 linkp = &(*linkp)->next;
 919         *linkp = new;
 920 }
 921
 922 void fill_active_slots(void)
 923 {
 924         struct active_request_slot *slot = active_queue_head;
 925
 926         while (active_requests < max_requests) {
 927                 struct fill_chain *fill;
 928                 for (fill = fill_cfg; fill; fill = fill->next)
 929                         if (fill->fill(fill->data))
 930                                 break;
 931
 932                 if (!fill)
 933                         break;
 934         }
 935
 936         while (slot != NULL) {
 937                 if (!slot->in_use && slot->curl != NULL
 938                         && curl_session_count > min_curl_sessions) {
 939                         curl_easy_cleanup(slot->curl);
 940                         slot->curl = NULL;
 941                         curl_session_count--;
 942                 }
 943                 slot = slot->next;
 944         }
 945 }
 946
 947 void step_active_slots(void)
 948 {
 949         int num_transfers;
 950         CURLMcode curlm_result;
 951
 952         do {
 953                 curlm_result = curl_multi_perform(curlm, &num_transfers);
 954         } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
 955         if (num_transfers < active_requests) {
 956                 process_curl_messages();
 957                 fill_active_slots();
 958         }
 959 }
 960 #endif
 961
 962 void run_active_slot(struct active_request_slot *slot)
 963 {
 964 #ifdef USE_CURL_MULTI
 965         fd_set readfds;
 966         fd_set writefds;
 967         fd_set excfds;
 968         int max_fd;
 969         struct timeval select_timeout;
 970         int finished = 0;
 971
 972         slot->finished = &finished;
 973         while (!finished) {
 974                 step_active_slots();
 975
 976                 if (slot->in_use) {
 977 #if LIBCURL_VERSION_NUM >= 0x070f04
 978                         long curl_timeout;
 979                         curl_multi_timeout(curlm, &curl_timeout);
 980                         if (curl_timeout == 0) {
 981                                 continue;
 982                         } else if (curl_timeout == -1) {
 983                                 select_timeout.tv_sec  = 0;
 984                                 select_timeout.tv_usec = 50000;
 985                         } else {
 986                                 select_timeout.tv_sec  =  curl_timeout / 1000;
 987                                 select_timeout.tv_usec = (curl_timeout % 1000) * 1000;
 988                         }
 989 #else
 990                         select_timeout.tv_sec  = 0;
 991                         select_timeout.tv_usec = 50000;
 992 #endif
 993
 994                         max_fd = -1;
 995                         FD_ZERO(&readfds);
 996                         FD_ZERO(&writefds);
 997                         FD_ZERO(&excfds);
 998                         curl_multi_fdset(curlm, &readfds, &writefds, &excfds, &max_fd);
 999
1000                         /*
1001                          * It can happen that curl_multi_timeout returns a pathologically
1002                          * long timeout when curl_multi_fdset returns no file descriptors
1003                          * to read.  See commit message for more details.
1004                          */
1005                         if (max_fd < 0 &&
1006                             (select_timeout.tv_sec > 0 ||
1007                              select_timeout.tv_usec > 50000)) {
1008                                 select_timeout.tv_sec  = 0;
1009                                 select_timeout.tv_usec = 50000;
1010                         }
1011
1012                         select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
1013                 }
1014         }
1015 #else
1016         while (slot->in_use) {
1017                 slot->curl_result = curl_easy_perform(slot->curl);
1018                 finish_active_slot(slot);
1019         }
1020 #endif
1021 }
1022
1023 static void release_active_slot(struct active_request_slot *slot)
1024 {
1025         closedown_active_slot(slot);
1026         if (slot->curl && curl_session_count > min_curl_sessions) {
1027 #ifdef USE_CURL_MULTI
1028                 curl_multi_remove_handle(curlm, slot->curl);
1029 #endif
1030                 curl_easy_cleanup(slot->curl);
1031                 slot->curl = NULL;
1032                 curl_session_count--;
1033         }
1034 #ifdef USE_CURL_MULTI
1035         fill_active_slots();
1036 #endif
1037 }
1038
1039 void finish_all_active_slots(void)
1040 {
1041         struct active_request_slot *slot = active_queue_head;
1042
1043         while (slot != NULL)
1044                 if (slot->in_use) {
1045                         run_active_slot(slot);
1046                         slot = active_queue_head;
1047                 } else {
1048                         slot = slot->next;
1049                 }
1050 }
1051
1052 /* Helpers for modifying and creating URLs */
1053 static inline int needs_quote(int ch)
1054 {
1055         if (((ch >= 'A') && (ch <= 'Z'))
1056                         || ((ch >= 'a') && (ch <= 'z'))
1057                         || ((ch >= '0') && (ch <= '9'))
1058                         || (ch == '/')
1059                         || (ch == '-')
1060                         || (ch == '.'))
1061                 return 0;
1062         return 1;
1063 }
1064
1065 static char *quote_ref_url(const char *base, const char *ref)
1066 {
1067         struct strbuf buf = STRBUF_INIT;
1068         const char *cp;
1069         int ch;
1070
1071         end_url_with_slash(&buf, base);
1072
1073         for (cp = ref; (ch = *cp) != 0; cp++)
1074                 if (needs_quote(ch))
1075                         strbuf_addf(&buf, "%%%02x", ch);
1076                 else
1077                         strbuf_addch(&buf, *cp);
1078
1079         return strbuf_detach(&buf, NULL);
1080 }
1081
1082 void append_remote_object_url(struct strbuf *buf, const char *url,
1083                               const char *hex,
1084                               int only_two_digit_prefix)
1085 {
1086         end_url_with_slash(buf, url);
1087
1088         strbuf_addf(buf, "objects/%.*s/", 2, hex);
1089         if (!only_two_digit_prefix)
1090                 strbuf_addf(buf, "%s", hex+2);
1091 }
1092
1093 char *get_remote_object_url(const char *url, const char *hex,
1094                             int only_two_digit_prefix)
1095 {
1096         struct strbuf buf = STRBUF_INIT;
1097         append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
1098         return strbuf_detach(&buf, NULL);
1099 }
1100
1101 static int handle_curl_result(struct slot_results *results)
1102 {
1103         /*
1104          * If we see a failing http code with CURLE_OK, we have turned off
1105          * FAILONERROR (to keep the server's custom error response), and should
1106          * translate the code into failure here.
1107          */
1108         if (results->curl_result == CURLE_OK &&
1109             results->http_code >= 400) {
1110                 results->curl_result = CURLE_HTTP_RETURNED_ERROR;
1111                 /*
1112                  * Normally curl will already have put the "reason phrase"
1113                  * from the server into curl_errorstr; unfortunately without
1114                  * FAILONERROR it is lost, so we can give only the numeric
1115                  * status code.
1116                  */
1117                 snprintf(curl_errorstr, sizeof(curl_errorstr),
1118                          "The requested URL returned error: %ld",
1119                          results->http_code);
1120         }
1121
1122         if (results->curl_result == CURLE_OK) {
1123                 credential_approve(&http_auth);
1124                 if (proxy_auth.password)
1125                         credential_approve(&proxy_auth);
1126                 return HTTP_OK;
1127         } else if (missing_target(results))
1128                 return HTTP_MISSING_TARGET;
1129         else if (results->http_code == 401) {
1130                 if (http_auth.username && http_auth.password) {
1131                         credential_reject(&http_auth);
1132                         return HTTP_NOAUTH;
1133                 } else {
1134 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
1135                         http_auth_methods &= ~CURLAUTH_GSSNEGOTIATE;
1136 #endif
1137                         return HTTP_REAUTH;
1138                 }
1139         } else {
1140                 if (results->http_connectcode == 407)
1141                         credential_reject(&proxy_auth);
1142 #if LIBCURL_VERSION_NUM >= 0x070c00
1143                 if (!curl_errorstr[0])
1144                         strlcpy(curl_errorstr,
1145                                 curl_easy_strerror(results->curl_result),
1146                                 sizeof(curl_errorstr));
1147 #endif
1148                 return HTTP_ERROR;
1149         }
1150 }
1151
1152 int run_one_slot(struct active_request_slot *slot,
1153                  struct slot_results *results)
1154 {
1155         slot->results = results;
1156         if (!start_active_slot(slot)) {
1157                 snprintf(curl_errorstr, sizeof(curl_errorstr),
1158                          "failed to start HTTP request");
1159                 return HTTP_START_FAILED;
1160         }
1161
1162         run_active_slot(slot);
1163         return handle_curl_result(results);
1164 }
1165
1166 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
1167 {
1168         char *ptr;
1169         CURLcode ret;
1170
1171         strbuf_reset(buf);
1172         ret = curl_easy_getinfo(curl, info, &ptr);
1173         if (!ret && ptr)
1174                 strbuf_addstr(buf, ptr);
1175         return ret;
1176 }
1177
1178 /*
1179  * Check for and extract a content-type parameter. "raw"
1180  * should be positioned at the start of the potential
1181  * parameter, with any whitespace already removed.
1182  *
1183  * "name" is the name of the parameter. The value is appended
1184  * to "out".
1185  */
1186 static int extract_param(const char *raw, const char *name,
1187                          struct strbuf *out)
1188 {
1189         size_t len = strlen(name);
1190
1191         if (strncasecmp(raw, name, len))
1192                 return -1;
1193         raw += len;
1194
1195         if (*raw != '=')
1196                 return -1;
1197         raw++;
1198
1199         while (*raw && !isspace(*raw) && *raw != ';')
1200                 strbuf_addch(out, *raw++);
1201         return 0;
1202 }
1203
1204 /*
1205  * Extract a normalized version of the content type, with any
1206  * spaces suppressed, all letters lowercased, and no trailing ";"
1207  * or parameters.
1208  *
1209  * Note that we will silently remove even invalid whitespace. For
1210  * example, "text / plain" is specifically forbidden by RFC 2616,
1211  * but "text/plain" is the only reasonable output, and this keeps
1212  * our code simple.
1213  *
1214  * If the "charset" argument is not NULL, store the value of any
1215  * charset parameter there.
1216  *
1217  * Example:
1218  *   "TEXT/PLAIN; charset=utf-8" -> "text/plain", "utf-8"
1219  *   "text / plain" -> "text/plain"
1220  */
1221 static void extract_content_type(struct strbuf *raw, struct strbuf *type,
1222                                  struct strbuf *charset)
1223 {
1224         const char *p;
1225
1226         strbuf_reset(type);
1227         strbuf_grow(type, raw->len);
1228         for (p = raw->buf; *p; p++) {
1229                 if (isspace(*p))
1230                         continue;
1231                 if (*p == ';') {
1232                         p++;
1233                         break;
1234                 }
1235                 strbuf_addch(type, tolower(*p));
1236         }
1237
1238         if (!charset)
1239                 return;
1240
1241         strbuf_reset(charset);
1242         while (*p) {
1243                 while (isspace(*p) || *p == ';')
1244                         p++;
1245                 if (!extract_param(p, "charset", charset))
1246                         return;
1247                 while (*p && !isspace(*p))
1248                         p++;
1249         }
1250
1251         if (!charset->len && starts_with(type->buf, "text/"))
1252                 strbuf_addstr(charset, "ISO-8859-1");
1253 }
1254
1255 static void write_accept_language(struct strbuf *buf)
1256 {
1257         /*
1258          * MAX_DECIMAL_PLACES must not be larger than 3. If it is larger than
1259          * that, q-value will be smaller than 0.001, the minimum q-value the
1260          * HTTP specification allows. See
1261          * http://tools.ietf.org/html/rfc7231#section-5.3.1 for q-value.
1262          */
1263         const int MAX_DECIMAL_PLACES = 3;
1264         const int MAX_LANGUAGE_TAGS = 1000;
1265         const int MAX_ACCEPT_LANGUAGE_HEADER_SIZE = 4000;
1266         char **language_tags = NULL;
1267         int num_langs = 0;
1268         const char *s = get_preferred_languages();
1269         int i;
1270         struct strbuf tag = STRBUF_INIT;
1271
1272         /* Don't add Accept-Language header if no language is preferred. */
1273         if (!s)
1274                 return;
1275
1276         /*
1277          * Split the colon-separated string of preferred languages into
1278          * language_tags array.
1279          */
1280         do {
1281                 /* collect language tag */
1282                 for (; *s && (isalnum(*s) || *s == '_'); s++)
1283                         strbuf_addch(&tag, *s == '_' ? '-' : *s);
1284
1285                 /* skip .codeset, @modifier and any other unnecessary parts */
1286                 while (*s && *s != ':')
1287                         s++;
1288
1289                 if (tag.len) {
1290                         num_langs++;
1291                         REALLOC_ARRAY(language_tags, num_langs);
1292                         language_tags[num_langs - 1] = strbuf_detach(&tag, NULL);
1293                         if (num_langs >= MAX_LANGUAGE_TAGS - 1) /* -1 for '*' */
1294                                 break;
1295                 }
1296         } while (*s++);
1297
1298         /* write Accept-Language header into buf */
1299         if (num_langs) {
1300                 int last_buf_len = 0;
1301                 int max_q;
1302                 int decimal_places;
1303                 char q_format[32];
1304
1305                 /* add '*' */
1306                 REALLOC_ARRAY(language_tags, num_langs + 1);
1307                 language_tags[num_langs++] = "*"; /* it's OK; this won't be freed */
1308
1309                 /* compute decimal_places */
1310                 for (max_q = 1, decimal_places = 0;
1311                      max_q < num_langs && decimal_places <= MAX_DECIMAL_PLACES;
1312                      decimal_places++, max_q *= 10)
1313                         ;
1314
1315                 xsnprintf(q_format, sizeof(q_format), ";q=0.%%0%dd", decimal_places);
1316
1317                 strbuf_addstr(buf, "Accept-Language: ");
1318
1319                 for (i = 0; i < num_langs; i++) {
1320                         if (i > 0)
1321                                 strbuf_addstr(buf, ", ");
1322
1323                         strbuf_addstr(buf, language_tags[i]);
1324
1325                         if (i > 0)
1326                                 strbuf_addf(buf, q_format, max_q - i);
1327
1328                         if (buf->len > MAX_ACCEPT_LANGUAGE_HEADER_SIZE) {
1329                                 strbuf_remove(buf, last_buf_len, buf->len - last_buf_len);
1330                                 break;
1331                         }
1332
1333                         last_buf_len = buf->len;
1334                 }
1335         }
1336
1337         /* free language tags -- last one is a static '*' */
1338         for (i = 0; i < num_langs - 1; i++)
1339                 free(language_tags[i]);
1340         free(language_tags);
1341 }
1342
1343 /*
1344  * Get an Accept-Language header which indicates user's preferred languages.
1345  *
1346  * Examples:
1347  *   LANGUAGE= -> ""
1348  *   LANGUAGE=ko:en -> "Accept-Language: ko, en; q=0.9, *; q=0.1"
1349  *   LANGUAGE=ko_KR.UTF-8:sr@latin -> "Accept-Language: ko-KR, sr; q=0.9, *; q=0.1"
1350  *   LANGUAGE=ko LANG=en_US.UTF-8 -> "Accept-Language: ko, *; q=0.1"
1351  *   LANGUAGE= LANG=en_US.UTF-8 -> "Accept-Language: en-US, *; q=0.1"
1352  *   LANGUAGE= LANG=C -> ""
1353  */
1354 static const char *get_accept_language(void)
1355 {
1356         if (!cached_accept_language) {
1357                 struct strbuf buf = STRBUF_INIT;
1358                 write_accept_language(&buf);
1359                 if (buf.len > 0)
1360                         cached_accept_language = strbuf_detach(&buf, NULL);
1361         }
1362
1363         return cached_accept_language;
1364 }
1365
1366 static void http_opt_request_remainder(CURL *curl, off_t pos)
1367 {
1368         char buf[128];
1369         xsnprintf(buf, sizeof(buf), "%"PRIuMAX"-", (uintmax_t)pos);
1370         curl_easy_setopt(curl, CURLOPT_RANGE, buf);
1371 }
1372
1373 /* http_request() targets */
1374 #define HTTP_REQUEST_STRBUF     0
1375 #define HTTP_REQUEST_FILE       1
1376
1377 static int http_request(const char *url,
1378                         void *result, int target,
1379                         const struct http_get_options *options)
1380 {
1381         struct active_request_slot *slot;
1382         struct slot_results results;
1383         struct curl_slist *headers = NULL;
1384         struct strbuf buf = STRBUF_INIT;
1385         const char *accept_language;
1386         int ret;
1387
1388         slot = get_active_slot();
1389         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1390
1391         if (result == NULL) {
1392                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
1393         } else {
1394                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
1395                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
1396
1397                 if (target == HTTP_REQUEST_FILE) {
1398                         off_t posn = ftello(result);
1399                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1400                                          fwrite);
1401                         if (posn > 0)
1402                                 http_opt_request_remainder(slot->curl, posn);
1403                 } else
1404                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1405                                          fwrite_buffer);
1406         }
1407
1408         accept_language = get_accept_language();
1409
1410         if (accept_language)
1411                 headers = curl_slist_append(headers, accept_language);
1412
1413         strbuf_addstr(&buf, "Pragma:");
1414         if (options && options->no_cache)
1415                 strbuf_addstr(&buf, " no-cache");
1416         if (options && options->keep_error)
1417                 curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
1418
1419         headers = curl_slist_append(headers, buf.buf);
1420
1421         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1422         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
1423         curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
1424
1425         ret = run_one_slot(slot, &results);
1426
1427         if (options && options->content_type) {
1428                 struct strbuf raw = STRBUF_INIT;
1429                 curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE, &raw);
1430                 extract_content_type(&raw, options->content_type,
1431                                      options->charset);
1432                 strbuf_release(&raw);
1433         }
1434
1435         if (options && options->effective_url)
1436                 curlinfo_strbuf(slot->curl, CURLINFO_EFFECTIVE_URL,
1437                                 options->effective_url);
1438
1439         curl_slist_free_all(headers);
1440         strbuf_release(&buf);
1441
1442         return ret;
1443 }
1444
1445 /*
1446  * Update the "base" url to a more appropriate value, as deduced by
1447  * redirects seen when requesting a URL starting with "url".
1448  *
1449  * The "asked" parameter is a URL that we asked curl to access, and must begin
1450  * with "base".
1451  *
1452  * The "got" parameter is the URL that curl reported to us as where we ended
1453  * up.
1454  *
1455  * Returns 1 if we updated the base url, 0 otherwise.
1456  *
1457  * Our basic strategy is to compare "base" and "asked" to find the bits
1458  * specific to our request. We then strip those bits off of "got" to yield the
1459  * new base. So for example, if our base is "http://example.com/foo.git",
1460  * and we ask for "http://example.com/foo.git/info/refs", we might end up
1461  * with "https://other.example.com/foo.git/info/refs". We would want the
1462  * new URL to become "https://other.example.com/foo.git".
1463  *
1464  * Note that this assumes a sane redirect scheme. It's entirely possible
1465  * in the example above to end up at a URL that does not even end in
1466  * "info/refs".  In such a case we simply punt, as there is not much we can
1467  * do (and such a scheme is unlikely to represent a real git repository,
1468  * which means we are likely about to abort anyway).
1469  */
1470 static int update_url_from_redirect(struct strbuf *base,
1471                                     const char *asked,
1472                                     const struct strbuf *got)
1473 {
1474         const char *tail;
1475         size_t tail_len;
1476
1477         if (!strcmp(asked, got->buf))
1478                 return 0;
1479
1480         if (!skip_prefix(asked, base->buf, &tail))
1481                 die("BUG: update_url_from_redirect: %s is not a superset of %s",
1482                     asked, base->buf);
1483
1484         tail_len = strlen(tail);
1485
1486         if (got->len < tail_len ||
1487             strcmp(tail, got->buf + got->len - tail_len))
1488                 return 0; /* insane redirect scheme */
1489
1490         strbuf_reset(base);
1491         strbuf_add(base, got->buf, got->len - tail_len);
1492         return 1;
1493 }
1494
1495 static int http_request_reauth(const char *url,
1496                                void *result, int target,
1497                                struct http_get_options *options)
1498 {
1499         int ret = http_request(url, result, target, options);
1500
1501         if (options && options->effective_url && options->base_url) {
1502                 if (update_url_from_redirect(options->base_url,
1503                                              url, options->effective_url)) {
1504                         credential_from_url(&http_auth, options->base_url->buf);
1505                         url = options->effective_url->buf;
1506                 }
1507         }
1508
1509         if (ret != HTTP_REAUTH)
1510                 return ret;
1511
1512         /*
1513          * If we are using KEEP_ERROR, the previous request may have
1514          * put cruft into our output stream; we should clear it out before
1515          * making our next request. We only know how to do this for
1516          * the strbuf case, but that is enough to satisfy current callers.
1517          */
1518         if (options && options->keep_error) {
1519                 switch (target) {
1520                 case HTTP_REQUEST_STRBUF:
1521                         strbuf_reset(result);
1522                         break;
1523                 default:
1524                         die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
1525                 }
1526         }
1527
1528         credential_fill(&http_auth);
1529
1530         return http_request(url, result, target, options);
1531 }
1532
1533 int http_get_strbuf(const char *url,
1534                     struct strbuf *result,
1535                     struct http_get_options *options)
1536 {
1537         return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
1538 }
1539
1540 /*
1541  * Downloads a URL and stores the result in the given file.
1542  *
1543  * If a previous interrupted download is detected (i.e. a previous temporary
1544  * file is still around) the download is resumed.
1545  */
1546 static int http_get_file(const char *url, const char *filename,
1547                          struct http_get_options *options)
1548 {
1549         int ret;
1550         struct strbuf tmpfile = STRBUF_INIT;
1551         FILE *result;
1552
1553         strbuf_addf(&tmpfile, "%s.temp", filename);
1554         result = fopen(tmpfile.buf, "a");
1555         if (!result) {
1556                 error("Unable to open local file %s", tmpfile.buf);
1557                 ret = HTTP_ERROR;
1558                 goto cleanup;
1559         }
1560
1561         ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
1562         fclose(result);
1563
1564         if (ret == HTTP_OK && finalize_object_file(tmpfile.buf, filename))
1565                 ret = HTTP_ERROR;
1566 cleanup:
1567         strbuf_release(&tmpfile);
1568         return ret;
1569 }
1570
1571 int http_fetch_ref(const char *base, struct ref *ref)
1572 {
1573         struct http_get_options options = {0};
1574         char *url;
1575         struct strbuf buffer = STRBUF_INIT;
1576         int ret = -1;
1577
1578         options.no_cache = 1;
1579
1580         url = quote_ref_url(base, ref->name);
1581         if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
1582                 strbuf_rtrim(&buffer);
1583                 if (buffer.len == 40)
1584                         ret = get_oid_hex(buffer.buf, &ref->old_oid);
1585                 else if (starts_with(buffer.buf, "ref: ")) {
1586                         ref->symref = xstrdup(buffer.buf + 5);
1587                         ret = 0;
1588                 }
1589         }
1590
1591         strbuf_release(&buffer);
1592         free(url);
1593         return ret;
1594 }
1595
1596 /* Helpers for fetching packs */
1597 static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
1598 {
1599         char *url, *tmp;
1600         struct strbuf buf = STRBUF_INIT;
1601
1602         if (http_is_verbose)
1603                 fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
1604
1605         end_url_with_slash(&buf, base_url);
1606         strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
1607         url = strbuf_detach(&buf, NULL);
1608
1609         strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
1610         tmp = strbuf_detach(&buf, NULL);
1611
1612         if (http_get_file(url, tmp, NULL) != HTTP_OK) {
1613                 error("Unable to get pack index %s", url);
1614                 free(tmp);
1615                 tmp = NULL;
1616         }
1617
1618         free(url);
1619         return tmp;
1620 }
1621
1622 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
1623         unsigned char *sha1, const char *base_url)
1624 {
1625         struct packed_git *new_pack;
1626         char *tmp_idx = NULL;
1627         int ret;
1628
1629         if (has_pack_index(sha1)) {
1630                 new_pack = parse_pack_index(sha1, sha1_pack_index_name(sha1));
1631                 if (!new_pack)
1632                         return -1; /* parse_pack_index() already issued error message */
1633                 goto add_pack;
1634         }
1635
1636         tmp_idx = fetch_pack_index(sha1, base_url);
1637         if (!tmp_idx)
1638                 return -1;
1639
1640         new_pack = parse_pack_index(sha1, tmp_idx);
1641         if (!new_pack) {
1642                 unlink(tmp_idx);
1643                 free(tmp_idx);
1644
1645                 return -1; /* parse_pack_index() already issued error message */
1646         }
1647
1648         ret = verify_pack_index(new_pack);
1649         if (!ret) {
1650                 close_pack_index(new_pack);
1651                 ret = finalize_object_file(tmp_idx, sha1_pack_index_name(sha1));
1652         }
1653         free(tmp_idx);
1654         if (ret)
1655                 return -1;
1656
1657 add_pack:
1658         new_pack->next = *packs_head;
1659         *packs_head = new_pack;
1660         return 0;
1661 }
1662
1663 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
1664 {
1665         struct http_get_options options = {0};
1666         int ret = 0, i = 0;
1667         char *url, *data;
1668         struct strbuf buf = STRBUF_INIT;
1669         unsigned char sha1[20];
1670
1671         end_url_with_slash(&buf, base_url);
1672         strbuf_addstr(&buf, "objects/info/packs");
1673         url = strbuf_detach(&buf, NULL);
1674
1675         options.no_cache = 1;
1676         ret = http_get_strbuf(url, &buf, &options);
1677         if (ret != HTTP_OK)
1678                 goto cleanup;
1679
1680         data = buf.buf;
1681         while (i < buf.len) {
1682                 switch (data[i]) {
1683                 case 'P':
1684                         i++;
1685                         if (i + 52 <= buf.len &&
1686                             starts_with(data + i, " pack-") &&
1687                             starts_with(data + i + 46, ".pack\n")) {
1688                                 get_sha1_hex(data + i + 6, sha1);
1689                                 fetch_and_setup_pack_index(packs_head, sha1,
1690                                                       base_url);
1691                                 i += 51;
1692                                 break;
1693                         }
1694                 default:
1695                         while (i < buf.len && data[i] != '\n')
1696                                 i++;
1697                 }
1698                 i++;
1699         }
1700
1701 cleanup:
1702         free(url);
1703         return ret;
1704 }
1705
1706 void release_http_pack_request(struct http_pack_request *preq)
1707 {
1708         if (preq->packfile != NULL) {
1709                 fclose(preq->packfile);
1710                 preq->packfile = NULL;
1711         }
1712         preq->slot = NULL;
1713         free(preq->url);
1714         free(preq);
1715 }
1716
1717 int finish_http_pack_request(struct http_pack_request *preq)
1718 {
1719         struct packed_git **lst;
1720         struct packed_git *p = preq->target;
1721         char *tmp_idx;
1722         size_t len;
1723         struct child_process ip = CHILD_PROCESS_INIT;
1724         const char *ip_argv[8];
1725
1726         close_pack_index(p);
1727
1728         fclose(preq->packfile);
1729         preq->packfile = NULL;
1730
1731         lst = preq->lst;
1732         while (*lst != p)
1733                 lst = &((*lst)->next);
1734         *lst = (*lst)->next;
1735
1736         if (!strip_suffix(preq->tmpfile, ".pack.temp", &len))
1737                 die("BUG: pack tmpfile does not end in .pack.temp?");
1738         tmp_idx = xstrfmt("%.*s.idx.temp", (int)len, preq->tmpfile);
1739
1740         ip_argv[0] = "index-pack";
1741         ip_argv[1] = "-o";
1742         ip_argv[2] = tmp_idx;
1743         ip_argv[3] = preq->tmpfile;
1744         ip_argv[4] = NULL;
1745
1746         ip.argv = ip_argv;
1747         ip.git_cmd = 1;
1748         ip.no_stdin = 1;
1749         ip.no_stdout = 1;
1750
1751         if (run_command(&ip)) {
1752                 unlink(preq->tmpfile);
1753                 unlink(tmp_idx);
1754                 free(tmp_idx);
1755                 return -1;
1756         }
1757
1758         unlink(sha1_pack_index_name(p->sha1));
1759
1760         if (finalize_object_file(preq->tmpfile, sha1_pack_name(p->sha1))
1761          || finalize_object_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
1762                 free(tmp_idx);
1763                 return -1;
1764         }
1765
1766         install_packed_git(p);
1767         free(tmp_idx);
1768         return 0;
1769 }
1770
1771 struct http_pack_request *new_http_pack_request(
1772         struct packed_git *target, const char *base_url)
1773 {
1774         off_t prev_posn = 0;
1775         struct strbuf buf = STRBUF_INIT;
1776         struct http_pack_request *preq;
1777
1778         preq = xcalloc(1, sizeof(*preq));
1779         preq->target = target;
1780
1781         end_url_with_slash(&buf, base_url);
1782         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
1783                 sha1_to_hex(target->sha1));
1784         preq->url = strbuf_detach(&buf, NULL);
1785
1786         snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
1787                 sha1_pack_name(target->sha1));
1788         preq->packfile = fopen(preq->tmpfile, "a");
1789         if (!preq->packfile) {
1790                 error("Unable to open local file %s for pack",
1791                       preq->tmpfile);
1792                 goto abort;
1793         }
1794
1795         preq->slot = get_active_slot();
1796         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
1797         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
1798         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
1799         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1800                 no_pragma_header);
1801
1802         /*
1803          * If there is data present from a previous transfer attempt,
1804          * resume where it left off
1805          */
1806         prev_posn = ftello(preq->packfile);
1807         if (prev_posn>0) {
1808                 if (http_is_verbose)
1809                         fprintf(stderr,
1810                                 "Resuming fetch of pack %s at byte %"PRIuMAX"\n",
1811                                 sha1_to_hex(target->sha1), (uintmax_t)prev_posn);
1812                 http_opt_request_remainder(preq->slot->curl, prev_posn);
1813         }
1814
1815         return preq;
1816
1817 abort:
1818         free(preq->url);
1819         free(preq);
1820         return NULL;
1821 }
1822
1823 /* Helpers for fetching objects (loose) */
1824 static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
1825                                void *data)
1826 {
1827         unsigned char expn[4096];
1828         size_t size = eltsize * nmemb;
1829         int posn = 0;
1830         struct http_object_request *freq =
1831                 (struct http_object_request *)data;
1832         do {
1833                 ssize_t retval = xwrite(freq->localfile,
1834                                         (char *) ptr + posn, size - posn);
1835                 if (retval < 0)
1836                         return posn;
1837                 posn += retval;
1838         } while (posn < size);
1839
1840         freq->stream.avail_in = size;
1841         freq->stream.next_in = (void *)ptr;
1842         do {
1843                 freq->stream.next_out = expn;
1844                 freq->stream.avail_out = sizeof(expn);
1845                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
1846                 git_SHA1_Update(&freq->c, expn,
1847                                 sizeof(expn) - freq->stream.avail_out);
1848         } while (freq->stream.avail_in && freq->zret == Z_OK);
1849         return size;
1850 }
1851
1852 struct http_object_request *new_http_object_request(const char *base_url,
1853         unsigned char *sha1)
1854 {
1855         char *hex = sha1_to_hex(sha1);
1856         const char *filename;
1857         char prevfile[PATH_MAX];
1858         int prevlocal;
1859         char prev_buf[PREV_BUF_SIZE];
1860         ssize_t prev_read = 0;
1861         off_t prev_posn = 0;
1862         struct http_object_request *freq;
1863
1864         freq = xcalloc(1, sizeof(*freq));
1865         hashcpy(freq->sha1, sha1);
1866         freq->localfile = -1;
1867
1868         filename = sha1_file_name(sha1);
1869         snprintf(freq->tmpfile, sizeof(freq->tmpfile),
1870                  "%s.temp", filename);
1871
1872         snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
1873         unlink_or_warn(prevfile);
1874         rename(freq->tmpfile, prevfile);
1875         unlink_or_warn(freq->tmpfile);
1876
1877         if (freq->localfile != -1)
1878                 error("fd leakage in start: %d", freq->localfile);
1879         freq->localfile = open(freq->tmpfile,
1880                                O_WRONLY | O_CREAT | O_EXCL, 0666);
1881         /*
1882          * This could have failed due to the "lazy directory creation";
1883          * try to mkdir the last path component.
1884          */
1885         if (freq->localfile < 0 && errno == ENOENT) {
1886                 char *dir = strrchr(freq->tmpfile, '/');
1887                 if (dir) {
1888                         *dir = 0;
1889                         mkdir(freq->tmpfile, 0777);
1890                         *dir = '/';
1891                 }
1892                 freq->localfile = open(freq->tmpfile,
1893                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
1894         }
1895
1896         if (freq->localfile < 0) {
1897                 error("Couldn't create temporary file %s: %s",
1898                       freq->tmpfile, strerror(errno));
1899                 goto abort;
1900         }
1901
1902         git_inflate_init(&freq->stream);
1903
1904         git_SHA1_Init(&freq->c);
1905
1906         freq->url = get_remote_object_url(base_url, hex, 0);
1907
1908         /*
1909          * If a previous temp file is present, process what was already
1910          * fetched.
1911          */
1912         prevlocal = open(prevfile, O_RDONLY);
1913         if (prevlocal != -1) {
1914                 do {
1915                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
1916                         if (prev_read>0) {
1917                                 if (fwrite_sha1_file(prev_buf,
1918                                                      1,
1919                                                      prev_read,
1920                                                      freq) == prev_read) {
1921                                         prev_posn += prev_read;
1922                                 } else {
1923                                         prev_read = -1;
1924                                 }
1925                         }
1926                 } while (prev_read > 0);
1927                 close(prevlocal);
1928         }
1929         unlink_or_warn(prevfile);
1930
1931         /*
1932          * Reset inflate/SHA1 if there was an error reading the previous temp
1933          * file; also rewind to the beginning of the local file.
1934          */
1935         if (prev_read == -1) {
1936                 memset(&freq->stream, 0, sizeof(freq->stream));
1937                 git_inflate_init(&freq->stream);
1938                 git_SHA1_Init(&freq->c);
1939                 if (prev_posn>0) {
1940                         prev_posn = 0;
1941                         lseek(freq->localfile, 0, SEEK_SET);
1942                         if (ftruncate(freq->localfile, 0) < 0) {
1943                                 error("Couldn't truncate temporary file %s: %s",
1944                                           freq->tmpfile, strerror(errno));
1945                                 goto abort;
1946                         }
1947                 }
1948         }
1949
1950         freq->slot = get_active_slot();
1951
1952         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
1953         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
1954         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
1955         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
1956         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
1957
1958         /*
1959          * If we have successfully processed data from a previous fetch
1960          * attempt, only fetch the data we don't already have.
1961          */
1962         if (prev_posn>0) {
1963                 if (http_is_verbose)
1964                         fprintf(stderr,
1965                                 "Resuming fetch of object %s at byte %"PRIuMAX"\n",
1966                                 hex, (uintmax_t)prev_posn);
1967                 http_opt_request_remainder(freq->slot->curl, prev_posn);
1968         }
1969
1970         return freq;
1971
1972 abort:
1973         free(freq->url);
1974         free(freq);
1975         return NULL;
1976 }
1977
1978 void process_http_object_request(struct http_object_request *freq)
1979 {
1980         if (freq->slot == NULL)
1981                 return;
1982         freq->curl_result = freq->slot->curl_result;
1983         freq->http_code = freq->slot->http_code;
1984         freq->slot = NULL;
1985 }
1986
1987 int finish_http_object_request(struct http_object_request *freq)
1988 {
1989         struct stat st;
1990
1991         close(freq->localfile);
1992         freq->localfile = -1;
1993
1994         process_http_object_request(freq);
1995
1996         if (freq->http_code == 416) {
1997                 warning("requested range invalid; we may already have all the data.");
1998         } else if (freq->curl_result != CURLE_OK) {
1999                 if (stat(freq->tmpfile, &st) == 0)
2000                         if (st.st_size == 0)
2001                                 unlink_or_warn(freq->tmpfile);
2002                 return -1;
2003         }
2004
2005         git_inflate_end(&freq->stream);
2006         git_SHA1_Final(freq->real_sha1, &freq->c);
2007         if (freq->zret != Z_STREAM_END) {
2008                 unlink_or_warn(freq->tmpfile);
2009                 return -1;
2010         }
2011         if (hashcmp(freq->sha1, freq->real_sha1)) {
2012                 unlink_or_warn(freq->tmpfile);
2013                 return -1;
2014         }
2015         freq->rename =
2016                 finalize_object_file(freq->tmpfile, sha1_file_name(freq->sha1));
2017
2018         return freq->rename;
2019 }
2020
2021 void abort_http_object_request(struct http_object_request *freq)
2022 {
2023         unlink_or_warn(freq->tmpfile);
2024
2025         release_http_object_request(freq);
2026 }
2027
2028 void release_http_object_request(struct http_object_request *freq)
2029 {
2030         if (freq->localfile != -1) {
2031                 close(freq->localfile);
2032                 freq->localfile = -1;
2033         }
2034         if (freq->url != NULL) {
2035                 free(freq->url);
2036                 freq->url = NULL;
2037         }
2038         if (freq->slot != NULL) {
2039                 freq->slot->callback_func = NULL;
2040                 freq->slot->callback_data = NULL;
2041                 release_active_slot(freq->slot);
2042                 freq->slot = NULL;
2043         }
2044 }