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
  13 int active_requests;
  14 int http_is_verbose;
  15 size_t http_post_buffer = 16 * LARGE_PACKET_MAX;
  16
  17 #if LIBCURL_VERSION_NUM >= 0x070a06
  18 #define LIBCURL_CAN_HANDLE_AUTH_ANY
  19 #endif
  20
  21 static int min_curl_sessions = 1;
  22 static int curl_session_count;
  23 #ifdef USE_CURL_MULTI
  24 static int max_requests = -1;
  25 static CURLM *curlm;
  26 #endif
  27 #ifndef NO_CURL_EASY_DUPHANDLE
  28 static CURL *curl_default;
  29 #endif
  30
  31 #define PREV_BUF_SIZE 4096
  32 #define RANGE_HEADER_SIZE 30
  33
  34 char curl_errorstr[CURL_ERROR_SIZE];
  35
  36 static int curl_ssl_verify = -1;
  37 static int curl_ssl_try;
  38 static const char *ssl_cert;
  39 static const char *ssl_cipherlist;
  40 static const char *ssl_version;
  41 static struct {
  42         const char *name;
  43         long ssl_version;
  44 } sslversions[] = {
  45         { "sslv2", CURL_SSLVERSION_SSLv2 },
  46         { "sslv3", CURL_SSLVERSION_SSLv3 },
  47         { "tlsv1", CURL_SSLVERSION_TLSv1 },
  48 #if LIBCURL_VERSION_NUM >= 0x072200
  49         { "tlsv1.0", CURL_SSLVERSION_TLSv1_0 },
  50         { "tlsv1.1", CURL_SSLVERSION_TLSv1_1 },
  51         { "tlsv1.2", CURL_SSLVERSION_TLSv1_2 },
  52 #endif
  53 };
  54 #if LIBCURL_VERSION_NUM >= 0x070903
  55 static const char *ssl_key;
  56 #endif
  57 #if LIBCURL_VERSION_NUM >= 0x070908
  58 static const char *ssl_capath;
  59 #endif
  60 static const char *ssl_cainfo;
  61 static long curl_low_speed_limit = -1;
  62 static long curl_low_speed_time = -1;
  63 static int curl_ftp_no_epsv;
  64 static const char *curl_http_proxy;
  65 static const char *curl_cookie_file;
  66 static int curl_save_cookies;
  67 struct credential http_auth = CREDENTIAL_INIT;
  68 static int http_proactive_auth;
  69 static const char *user_agent;
  70
  71 #if LIBCURL_VERSION_NUM >= 0x071700
  72 /* Use CURLOPT_KEYPASSWD as is */
  73 #elif LIBCURL_VERSION_NUM >= 0x070903
  74 #define CURLOPT_KEYPASSWD CURLOPT_SSLKEYPASSWD
  75 #else
  76 #define CURLOPT_KEYPASSWD CURLOPT_SSLCERTPASSWD
  77 #endif
  78
  79 static struct credential cert_auth = CREDENTIAL_INIT;
  80 static int ssl_cert_password_required;
  81 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
  82 static unsigned long http_auth_methods = CURLAUTH_ANY;
  83 #endif
  84
  85 static struct curl_slist *pragma_header;
  86 static struct curl_slist *no_pragma_header;
  87
  88 static struct active_request_slot *active_queue_head;
  89
  90 static char *cached_accept_language;
  91
  92 size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
  93 {
  94         size_t size = eltsize * nmemb;
  95         struct buffer *buffer = buffer_;
  96
  97         if (size > buffer->buf.len - buffer->posn)
  98                 size = buffer->buf.len - buffer->posn;
  99         memcpy(ptr, buffer->buf.buf + buffer->posn, size);
 100         buffer->posn += size;
 101
 102         return size;
 103 }
 104
 105 #ifndef NO_CURL_IOCTL
 106 curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)
 107 {
 108         struct buffer *buffer = clientp;
 109
 110         switch (cmd) {
 111         case CURLIOCMD_NOP:
 112                 return CURLIOE_OK;
 113
 114         case CURLIOCMD_RESTARTREAD:
 115                 buffer->posn = 0;
 116                 return CURLIOE_OK;
 117
 118         default:
 119                 return CURLIOE_UNKNOWNCMD;
 120         }
 121 }
 122 #endif
 123
 124 size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
 125 {
 126         size_t size = eltsize * nmemb;
 127         struct strbuf *buffer = buffer_;
 128
 129         strbuf_add(buffer, ptr, size);
 130         return size;
 131 }
 132
 133 size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf)
 134 {
 135         return eltsize * nmemb;
 136 }
 137
 138 static void closedown_active_slot(struct active_request_slot *slot)
 139 {
 140         active_requests--;
 141         slot->in_use = 0;
 142 }
 143
 144 static void finish_active_slot(struct active_request_slot *slot)
 145 {
 146         closedown_active_slot(slot);
 147         curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
 148
 149         if (slot->finished != NULL)
 150                 (*slot->finished) = 1;
 151
 152         /* Store slot results so they can be read after the slot is reused */
 153         if (slot->results != NULL) {
 154                 slot->results->curl_result = slot->curl_result;
 155                 slot->results->http_code = slot->http_code;
 156 #if LIBCURL_VERSION_NUM >= 0x070a08
 157                 curl_easy_getinfo(slot->curl, CURLINFO_HTTPAUTH_AVAIL,
 158                                   &slot->results->auth_avail);
 159 #else
 160                 slot->results->auth_avail = 0;
 161 #endif
 162         }
 163
 164         /* Run callback if appropriate */
 165         if (slot->callback_func != NULL)
 166                 slot->callback_func(slot->callback_data);
 167 }
 168
 169 #ifdef USE_CURL_MULTI
 170 static void process_curl_messages(void)
 171 {
 172         int num_messages;
 173         struct active_request_slot *slot;
 174         CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
 175
 176         while (curl_message != NULL) {
 177                 if (curl_message->msg == CURLMSG_DONE) {
 178                         int curl_result = curl_message->data.result;
 179                         slot = active_queue_head;
 180                         while (slot != NULL &&
 181                                slot->curl != curl_message->easy_handle)
 182                                 slot = slot->next;
 183                         if (slot != NULL) {
 184                                 curl_multi_remove_handle(curlm, slot->curl);
 185                                 slot->curl_result = curl_result;
 186                                 finish_active_slot(slot);
 187                         } else {
 188                                 fprintf(stderr, "Received DONE message for unknown request!\n");
 189                         }
 190                 } else {
 191                         fprintf(stderr, "Unknown CURL message received: %d\n",
 192                                 (int)curl_message->msg);
 193                 }
 194                 curl_message = curl_multi_info_read(curlm, &num_messages);
 195         }
 196 }
 197 #endif
 198
 199 static int http_options(const char *var, const char *value, void *cb)
 200 {
 201         if (!strcmp("http.sslverify", var)) {
 202                 curl_ssl_verify = git_config_bool(var, value);
 203                 return 0;
 204         }
 205         if (!strcmp("http.sslcipherlist", var))
 206                 return git_config_string(&ssl_cipherlist, var, value);
 207         if (!strcmp("http.sslversion", var))
 208                 return git_config_string(&ssl_version, var, value);
 209         if (!strcmp("http.sslcert", var))
 210                 return git_config_string(&ssl_cert, var, value);
 211 #if LIBCURL_VERSION_NUM >= 0x070903
 212         if (!strcmp("http.sslkey", var))
 213                 return git_config_string(&ssl_key, var, value);
 214 #endif
 215 #if LIBCURL_VERSION_NUM >= 0x070908
 216         if (!strcmp("http.sslcapath", var))
 217                 return git_config_string(&ssl_capath, var, value);
 218 #endif
 219         if (!strcmp("http.sslcainfo", var))
 220                 return git_config_string(&ssl_cainfo, var, value);
 221         if (!strcmp("http.sslcertpasswordprotected", var)) {
 222                 ssl_cert_password_required = git_config_bool(var, value);
 223                 return 0;
 224         }
 225         if (!strcmp("http.ssltry", var)) {
 226                 curl_ssl_try = git_config_bool(var, value);
 227                 return 0;
 228         }
 229         if (!strcmp("http.minsessions", var)) {
 230                 min_curl_sessions = git_config_int(var, value);
 231 #ifndef USE_CURL_MULTI
 232                 if (min_curl_sessions > 1)
 233                         min_curl_sessions = 1;
 234 #endif
 235                 return 0;
 236         }
 237 #ifdef USE_CURL_MULTI
 238         if (!strcmp("http.maxrequests", var)) {
 239                 max_requests = git_config_int(var, value);
 240                 return 0;
 241         }
 242 #endif
 243         if (!strcmp("http.lowspeedlimit", var)) {
 244                 curl_low_speed_limit = (long)git_config_int(var, value);
 245                 return 0;
 246         }
 247         if (!strcmp("http.lowspeedtime", var)) {
 248                 curl_low_speed_time = (long)git_config_int(var, value);
 249                 return 0;
 250         }
 251
 252         if (!strcmp("http.noepsv", var)) {
 253                 curl_ftp_no_epsv = git_config_bool(var, value);
 254                 return 0;
 255         }
 256         if (!strcmp("http.proxy", var))
 257                 return git_config_string(&curl_http_proxy, var, value);
 258
 259         if (!strcmp("http.cookiefile", var))
 260                 return git_config_string(&curl_cookie_file, var, value);
 261         if (!strcmp("http.savecookies", var)) {
 262                 curl_save_cookies = git_config_bool(var, value);
 263                 return 0;
 264         }
 265
 266         if (!strcmp("http.postbuffer", var)) {
 267                 http_post_buffer = git_config_int(var, value);
 268                 if (http_post_buffer < LARGE_PACKET_MAX)
 269                         http_post_buffer = LARGE_PACKET_MAX;
 270                 return 0;
 271         }
 272
 273         if (!strcmp("http.useragent", var))
 274                 return git_config_string(&user_agent, var, value);
 275
 276         /* Fall back on the default ones */
 277         return git_default_config(var, value, cb);
 278 }
 279
 280 static void init_curl_http_auth(CURL *result)
 281 {
 282         if (!http_auth.username)
 283                 return;
 284
 285         credential_fill(&http_auth);
 286
 287 #if LIBCURL_VERSION_NUM >= 0x071301
 288         curl_easy_setopt(result, CURLOPT_USERNAME, http_auth.username);
 289         curl_easy_setopt(result, CURLOPT_PASSWORD, http_auth.password);
 290 #else
 291         {
 292                 static struct strbuf up = STRBUF_INIT;
 293                 /*
 294                  * Note that we assume we only ever have a single set of
 295                  * credentials in a given program run, so we do not have
 296                  * to worry about updating this buffer, only setting its
 297                  * initial value.
 298                  */
 299                 if (!up.len)
 300                         strbuf_addf(&up, "%s:%s",
 301                                 http_auth.username, http_auth.password);
 302                 curl_easy_setopt(result, CURLOPT_USERPWD, up.buf);
 303         }
 304 #endif
 305 }
 306
 307 static int has_cert_password(void)
 308 {
 309         if (ssl_cert == NULL || ssl_cert_password_required != 1)
 310                 return 0;
 311         if (!cert_auth.password) {
 312                 cert_auth.protocol = xstrdup("cert");
 313                 cert_auth.username = xstrdup("");
 314                 cert_auth.path = xstrdup(ssl_cert);
 315                 credential_fill(&cert_auth);
 316         }
 317         return 1;
 318 }
 319
 320 #if LIBCURL_VERSION_NUM >= 0x071900
 321 static void set_curl_keepalive(CURL *c)
 322 {
 323         curl_easy_setopt(c, CURLOPT_TCP_KEEPALIVE, 1);
 324 }
 325
 326 #elif LIBCURL_VERSION_NUM >= 0x071000
 327 static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
 328 {
 329         int ka = 1;
 330         int rc;
 331         socklen_t len = (socklen_t)sizeof(ka);
 332
 333         if (type != CURLSOCKTYPE_IPCXN)
 334                 return 0;
 335
 336         rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
 337         if (rc < 0)
 338                 warning("unable to set SO_KEEPALIVE on socket %s",
 339                         strerror(errno));
 340
 341         return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
 342 }
 343
 344 static void set_curl_keepalive(CURL *c)
 345 {
 346         curl_easy_setopt(c, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
 347 }
 348
 349 #else
 350 static void set_curl_keepalive(CURL *c)
 351 {
 352         /* not supported on older curl versions */
 353 }
 354 #endif
 355
 356 static CURL *get_curl_handle(void)
 357 {
 358         CURL *result = curl_easy_init();
 359
 360         if (!result)
 361                 die("curl_easy_init failed");
 362
 363         if (!curl_ssl_verify) {
 364                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
 365                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
 366         } else {
 367                 /* Verify authenticity of the peer's certificate */
 368                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
 369                 /* The name in the cert must match whom we tried to connect */
 370                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
 371         }
 372
 373 #if LIBCURL_VERSION_NUM >= 0x070907
 374         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
 375 #endif
 376 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 377         curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
 378 #endif
 379
 380         if (http_proactive_auth)
 381                 init_curl_http_auth(result);
 382
 383         if (getenv("GIT_SSL_VERSION"))
 384                 ssl_version = getenv("GIT_SSL_VERSION");
 385         if (ssl_version && *ssl_version) {
 386                 int i;
 387                 for (i = 0; i < ARRAY_SIZE(sslversions); i++) {
 388                         if (!strcmp(ssl_version, sslversions[i].name)) {
 389                                 curl_easy_setopt(result, CURLOPT_SSLVERSION,
 390                                                  sslversions[i].ssl_version);
 391                                 break;
 392                         }
 393                 }
 394                 if (i == ARRAY_SIZE(sslversions))
 395                         warning("unsupported ssl version %s: using default",
 396                                 ssl_version);
 397         }
 398
 399         if (getenv("GIT_SSL_CIPHER_LIST"))
 400                 ssl_cipherlist = getenv("GIT_SSL_CIPHER_LIST");
 401         if (ssl_cipherlist != NULL && *ssl_cipherlist)
 402                 curl_easy_setopt(result, CURLOPT_SSL_CIPHER_LIST,
 403                                 ssl_cipherlist);
 404
 405         if (ssl_cert != NULL)
 406                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
 407         if (has_cert_password())
 408                 curl_easy_setopt(result, CURLOPT_KEYPASSWD, cert_auth.password);
 409 #if LIBCURL_VERSION_NUM >= 0x070903
 410         if (ssl_key != NULL)
 411                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
 412 #endif
 413 #if LIBCURL_VERSION_NUM >= 0x070908
 414         if (ssl_capath != NULL)
 415                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
 416 #endif
 417         if (ssl_cainfo != NULL)
 418                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
 419
 420         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
 421                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
 422                                  curl_low_speed_limit);
 423                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
 424                                  curl_low_speed_time);
 425         }
 426
 427         curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
 428 #if LIBCURL_VERSION_NUM >= 0x071301
 429         curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
 430 #elif LIBCURL_VERSION_NUM >= 0x071101
 431         curl_easy_setopt(result, CURLOPT_POST301, 1);
 432 #endif
 433
 434         if (getenv("GIT_CURL_VERBOSE"))
 435                 curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
 436
 437         curl_easy_setopt(result, CURLOPT_USERAGENT,
 438                 user_agent ? user_agent : git_user_agent());
 439
 440         if (curl_ftp_no_epsv)
 441                 curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
 442
 443 #ifdef CURLOPT_USE_SSL
 444         if (curl_ssl_try)
 445                 curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
 446 #endif
 447
 448         if (curl_http_proxy) {
 449                 curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
 450         }
 451 #if LIBCURL_VERSION_NUM >= 0x070a07
 452         curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
 453 #endif
 454
 455         set_curl_keepalive(result);
 456
 457         return result;
 458 }
 459
 460 static void set_from_env(const char **var, const char *envname)
 461 {
 462         const char *val = getenv(envname);
 463         if (val)
 464                 *var = val;
 465 }
 466
 467 void http_init(struct remote *remote, const char *url, int proactive_auth)
 468 {
 469         char *low_speed_limit;
 470         char *low_speed_time;
 471         char *normalized_url;
 472         struct urlmatch_config config = { STRING_LIST_INIT_DUP };
 473
 474         config.section = "http";
 475         config.key = NULL;
 476         config.collect_fn = http_options;
 477         config.cascade_fn = git_default_config;
 478         config.cb = NULL;
 479
 480         http_is_verbose = 0;
 481         normalized_url = url_normalize(url, &config.url);
 482
 483         git_config(urlmatch_config_entry, &config);
 484         free(normalized_url);
 485
 486         if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK)
 487                 die("curl_global_init failed");
 488
 489         http_proactive_auth = proactive_auth;
 490
 491         if (remote && remote->http_proxy)
 492                 curl_http_proxy = xstrdup(remote->http_proxy);
 493
 494         pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
 495         no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
 496
 497 #ifdef USE_CURL_MULTI
 498         {
 499                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
 500                 if (http_max_requests != NULL)
 501                         max_requests = atoi(http_max_requests);
 502         }
 503
 504         curlm = curl_multi_init();
 505         if (!curlm)
 506                 die("curl_multi_init failed");
 507 #endif
 508
 509         if (getenv("GIT_SSL_NO_VERIFY"))
 510                 curl_ssl_verify = 0;
 511
 512         set_from_env(&ssl_cert, "GIT_SSL_CERT");
 513 #if LIBCURL_VERSION_NUM >= 0x070903
 514         set_from_env(&ssl_key, "GIT_SSL_KEY");
 515 #endif
 516 #if LIBCURL_VERSION_NUM >= 0x070908
 517         set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
 518 #endif
 519         set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
 520
 521         set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");
 522
 523         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
 524         if (low_speed_limit != NULL)
 525                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
 526         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
 527         if (low_speed_time != NULL)
 528                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
 529
 530         if (curl_ssl_verify == -1)
 531                 curl_ssl_verify = 1;
 532
 533         curl_session_count = 0;
 534 #ifdef USE_CURL_MULTI
 535         if (max_requests < 1)
 536                 max_requests = DEFAULT_MAX_REQUESTS;
 537 #endif
 538
 539         if (getenv("GIT_CURL_FTP_NO_EPSV"))
 540                 curl_ftp_no_epsv = 1;
 541
 542         if (url) {
 543                 credential_from_url(&http_auth, url);
 544                 if (!ssl_cert_password_required &&
 545                     getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
 546                     starts_with(url, "https://"))
 547                         ssl_cert_password_required = 1;
 548         }
 549
 550 #ifndef NO_CURL_EASY_DUPHANDLE
 551         curl_default = get_curl_handle();
 552 #endif
 553 }
 554
 555 void http_cleanup(void)
 556 {
 557         struct active_request_slot *slot = active_queue_head;
 558
 559         while (slot != NULL) {
 560                 struct active_request_slot *next = slot->next;
 561                 if (slot->curl != NULL) {
 562 #ifdef USE_CURL_MULTI
 563                         curl_multi_remove_handle(curlm, slot->curl);
 564 #endif
 565                         curl_easy_cleanup(slot->curl);
 566                 }
 567                 free(slot);
 568                 slot = next;
 569         }
 570         active_queue_head = NULL;
 571
 572 #ifndef NO_CURL_EASY_DUPHANDLE
 573         curl_easy_cleanup(curl_default);
 574 #endif
 575
 576 #ifdef USE_CURL_MULTI
 577         curl_multi_cleanup(curlm);
 578 #endif
 579         curl_global_cleanup();
 580
 581         curl_slist_free_all(pragma_header);
 582         pragma_header = NULL;
 583
 584         curl_slist_free_all(no_pragma_header);
 585         no_pragma_header = NULL;
 586
 587         if (curl_http_proxy) {
 588                 free((void *)curl_http_proxy);
 589                 curl_http_proxy = NULL;
 590         }
 591
 592         if (cert_auth.password != NULL) {
 593                 memset(cert_auth.password, 0, strlen(cert_auth.password));
 594                 free(cert_auth.password);
 595                 cert_auth.password = NULL;
 596         }
 597         ssl_cert_password_required = 0;
 598
 599         free(cached_accept_language);
 600         cached_accept_language = NULL;
 601 }
 602
 603 struct active_request_slot *get_active_slot(void)
 604 {
 605         struct active_request_slot *slot = active_queue_head;
 606         struct active_request_slot *newslot;
 607
 608 #ifdef USE_CURL_MULTI
 609         int num_transfers;
 610
 611         /* Wait for a slot to open up if the queue is full */
 612         while (active_requests >= max_requests) {
 613                 curl_multi_perform(curlm, &num_transfers);
 614                 if (num_transfers < active_requests)
 615                         process_curl_messages();
 616         }
 617 #endif
 618
 619         while (slot != NULL && slot->in_use)
 620                 slot = slot->next;
 621
 622         if (slot == NULL) {
 623                 newslot = xmalloc(sizeof(*newslot));
 624                 newslot->curl = NULL;
 625                 newslot->in_use = 0;
 626                 newslot->next = NULL;
 627
 628                 slot = active_queue_head;
 629                 if (slot == NULL) {
 630                         active_queue_head = newslot;
 631                 } else {
 632                         while (slot->next != NULL)
 633                                 slot = slot->next;
 634                         slot->next = newslot;
 635                 }
 636                 slot = newslot;
 637         }
 638
 639         if (slot->curl == NULL) {
 640 #ifdef NO_CURL_EASY_DUPHANDLE
 641                 slot->curl = get_curl_handle();
 642 #else
 643                 slot->curl = curl_easy_duphandle(curl_default);
 644 #endif
 645                 curl_session_count++;
 646         }
 647
 648         active_requests++;
 649         slot->in_use = 1;
 650         slot->results = NULL;
 651         slot->finished = NULL;
 652         slot->callback_data = NULL;
 653         slot->callback_func = NULL;
 654         curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file);
 655         if (curl_save_cookies)
 656                 curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file);
 657         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
 658         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
 659         curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
 660         curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
 661         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
 662         curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
 663         curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
 664         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
 665         curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
 666 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 667         curl_easy_setopt(slot->curl, CURLOPT_HTTPAUTH, http_auth_methods);
 668 #endif
 669         if (http_auth.password)
 670                 init_curl_http_auth(slot->curl);
 671
 672         return slot;
 673 }
 674
 675 int start_active_slot(struct active_request_slot *slot)
 676 {
 677 #ifdef USE_CURL_MULTI
 678         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
 679         int num_transfers;
 680
 681         if (curlm_result != CURLM_OK &&
 682             curlm_result != CURLM_CALL_MULTI_PERFORM) {
 683                 active_requests--;
 684                 slot->in_use = 0;
 685                 return 0;
 686         }
 687
 688         /*
 689          * We know there must be something to do, since we just added
 690          * something.
 691          */
 692         curl_multi_perform(curlm, &num_transfers);
 693 #endif
 694         return 1;
 695 }
 696
 697 #ifdef USE_CURL_MULTI
 698 struct fill_chain {
 699         void *data;
 700         int (*fill)(void *);
 701         struct fill_chain *next;
 702 };
 703
 704 static struct fill_chain *fill_cfg;
 705
 706 void add_fill_function(void *data, int (*fill)(void *))
 707 {
 708         struct fill_chain *new = xmalloc(sizeof(*new));
 709         struct fill_chain **linkp = &fill_cfg;
 710         new->data = data;
 711         new->fill = fill;
 712         new->next = NULL;
 713         while (*linkp)
 714                 linkp = &(*linkp)->next;
 715         *linkp = new;
 716 }
 717
 718 void fill_active_slots(void)
 719 {
 720         struct active_request_slot *slot = active_queue_head;
 721
 722         while (active_requests < max_requests) {
 723                 struct fill_chain *fill;
 724                 for (fill = fill_cfg; fill; fill = fill->next)
 725                         if (fill->fill(fill->data))
 726                                 break;
 727
 728                 if (!fill)
 729                         break;
 730         }
 731
 732         while (slot != NULL) {
 733                 if (!slot->in_use && slot->curl != NULL
 734                         && curl_session_count > min_curl_sessions) {
 735                         curl_easy_cleanup(slot->curl);
 736                         slot->curl = NULL;
 737                         curl_session_count--;
 738                 }
 739                 slot = slot->next;
 740         }
 741 }
 742
 743 void step_active_slots(void)
 744 {
 745         int num_transfers;
 746         CURLMcode curlm_result;
 747
 748         do {
 749                 curlm_result = curl_multi_perform(curlm, &num_transfers);
 750         } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
 751         if (num_transfers < active_requests) {
 752                 process_curl_messages();
 753                 fill_active_slots();
 754         }
 755 }
 756 #endif
 757
 758 void run_active_slot(struct active_request_slot *slot)
 759 {
 760 #ifdef USE_CURL_MULTI
 761         fd_set readfds;
 762         fd_set writefds;
 763         fd_set excfds;
 764         int max_fd;
 765         struct timeval select_timeout;
 766         int finished = 0;
 767
 768         slot->finished = &finished;
 769         while (!finished) {
 770                 step_active_slots();
 771
 772                 if (slot->in_use) {
 773 #if LIBCURL_VERSION_NUM >= 0x070f04
 774                         long curl_timeout;
 775                         curl_multi_timeout(curlm, &curl_timeout);
 776                         if (curl_timeout == 0) {
 777                                 continue;
 778                         } else if (curl_timeout == -1) {
 779                                 select_timeout.tv_sec  = 0;
 780                                 select_timeout.tv_usec = 50000;
 781                         } else {
 782                                 select_timeout.tv_sec  =  curl_timeout / 1000;
 783                                 select_timeout.tv_usec = (curl_timeout % 1000) * 1000;
 784                         }
 785 #else
 786                         select_timeout.tv_sec  = 0;
 787                         select_timeout.tv_usec = 50000;
 788 #endif
 789
 790                         max_fd = -1;
 791                         FD_ZERO(&readfds);
 792                         FD_ZERO(&writefds);
 793                         FD_ZERO(&excfds);
 794                         curl_multi_fdset(curlm, &readfds, &writefds, &excfds, &max_fd);
 795
 796                         /*
 797                          * It can happen that curl_multi_timeout returns a pathologically
 798                          * long timeout when curl_multi_fdset returns no file descriptors
 799                          * to read.  See commit message for more details.
 800                          */
 801                         if (max_fd < 0 &&
 802                             (select_timeout.tv_sec > 0 ||
 803                              select_timeout.tv_usec > 50000)) {
 804                                 select_timeout.tv_sec  = 0;
 805                                 select_timeout.tv_usec = 50000;
 806                         }
 807
 808                         select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
 809                 }
 810         }
 811 #else
 812         while (slot->in_use) {
 813                 slot->curl_result = curl_easy_perform(slot->curl);
 814                 finish_active_slot(slot);
 815         }
 816 #endif
 817 }
 818
 819 static void release_active_slot(struct active_request_slot *slot)
 820 {
 821         closedown_active_slot(slot);
 822         if (slot->curl && curl_session_count > min_curl_sessions) {
 823 #ifdef USE_CURL_MULTI
 824                 curl_multi_remove_handle(curlm, slot->curl);
 825 #endif
 826                 curl_easy_cleanup(slot->curl);
 827                 slot->curl = NULL;
 828                 curl_session_count--;
 829         }
 830 #ifdef USE_CURL_MULTI
 831         fill_active_slots();
 832 #endif
 833 }
 834
 835 void finish_all_active_slots(void)
 836 {
 837         struct active_request_slot *slot = active_queue_head;
 838
 839         while (slot != NULL)
 840                 if (slot->in_use) {
 841                         run_active_slot(slot);
 842                         slot = active_queue_head;
 843                 } else {
 844                         slot = slot->next;
 845                 }
 846 }
 847
 848 /* Helpers for modifying and creating URLs */
 849 static inline int needs_quote(int ch)
 850 {
 851         if (((ch >= 'A') && (ch <= 'Z'))
 852                         || ((ch >= 'a') && (ch <= 'z'))
 853                         || ((ch >= '0') && (ch <= '9'))
 854                         || (ch == '/')
 855                         || (ch == '-')
 856                         || (ch == '.'))
 857                 return 0;
 858         return 1;
 859 }
 860
 861 static char *quote_ref_url(const char *base, const char *ref)
 862 {
 863         struct strbuf buf = STRBUF_INIT;
 864         const char *cp;
 865         int ch;
 866
 867         end_url_with_slash(&buf, base);
 868
 869         for (cp = ref; (ch = *cp) != 0; cp++)
 870                 if (needs_quote(ch))
 871                         strbuf_addf(&buf, "%%%02x", ch);
 872                 else
 873                         strbuf_addch(&buf, *cp);
 874
 875         return strbuf_detach(&buf, NULL);
 876 }
 877
 878 void append_remote_object_url(struct strbuf *buf, const char *url,
 879                               const char *hex,
 880                               int only_two_digit_prefix)
 881 {
 882         end_url_with_slash(buf, url);
 883
 884         strbuf_addf(buf, "objects/%.*s/", 2, hex);
 885         if (!only_two_digit_prefix)
 886                 strbuf_addf(buf, "%s", hex+2);
 887 }
 888
 889 char *get_remote_object_url(const char *url, const char *hex,
 890                             int only_two_digit_prefix)
 891 {
 892         struct strbuf buf = STRBUF_INIT;
 893         append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
 894         return strbuf_detach(&buf, NULL);
 895 }
 896
 897 static int handle_curl_result(struct slot_results *results)
 898 {
 899         /*
 900          * If we see a failing http code with CURLE_OK, we have turned off
 901          * FAILONERROR (to keep the server's custom error response), and should
 902          * translate the code into failure here.
 903          */
 904         if (results->curl_result == CURLE_OK &&
 905             results->http_code >= 400) {
 906                 results->curl_result = CURLE_HTTP_RETURNED_ERROR;
 907                 /*
 908                  * Normally curl will already have put the "reason phrase"
 909                  * from the server into curl_errorstr; unfortunately without
 910                  * FAILONERROR it is lost, so we can give only the numeric
 911                  * status code.
 912                  */
 913                 snprintf(curl_errorstr, sizeof(curl_errorstr),
 914                          "The requested URL returned error: %ld",
 915                          results->http_code);
 916         }
 917
 918         if (results->curl_result == CURLE_OK) {
 919                 credential_approve(&http_auth);
 920                 return HTTP_OK;
 921         } else if (missing_target(results))
 922                 return HTTP_MISSING_TARGET;
 923         else if (results->http_code == 401) {
 924                 if (http_auth.username && http_auth.password) {
 925                         credential_reject(&http_auth);
 926                         return HTTP_NOAUTH;
 927                 } else {
 928 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 929                         http_auth_methods &= ~CURLAUTH_GSSNEGOTIATE;
 930 #endif
 931                         return HTTP_REAUTH;
 932                 }
 933         } else {
 934 #if LIBCURL_VERSION_NUM >= 0x070c00
 935                 if (!curl_errorstr[0])
 936                         strlcpy(curl_errorstr,
 937                                 curl_easy_strerror(results->curl_result),
 938                                 sizeof(curl_errorstr));
 939 #endif
 940                 return HTTP_ERROR;
 941         }
 942 }
 943
 944 int run_one_slot(struct active_request_slot *slot,
 945                  struct slot_results *results)
 946 {
 947         slot->results = results;
 948         if (!start_active_slot(slot)) {
 949                 snprintf(curl_errorstr, sizeof(curl_errorstr),
 950                          "failed to start HTTP request");
 951                 return HTTP_START_FAILED;
 952         }
 953
 954         run_active_slot(slot);
 955         return handle_curl_result(results);
 956 }
 957
 958 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
 959 {
 960         char *ptr;
 961         CURLcode ret;
 962
 963         strbuf_reset(buf);
 964         ret = curl_easy_getinfo(curl, info, &ptr);
 965         if (!ret && ptr)
 966                 strbuf_addstr(buf, ptr);
 967         return ret;
 968 }
 969
 970 /*
 971  * Check for and extract a content-type parameter. "raw"
 972  * should be positioned at the start of the potential
 973  * parameter, with any whitespace already removed.
 974  *
 975  * "name" is the name of the parameter. The value is appended
 976  * to "out".
 977  */
 978 static int extract_param(const char *raw, const char *name,
 979                          struct strbuf *out)
 980 {
 981         size_t len = strlen(name);
 982
 983         if (strncasecmp(raw, name, len))
 984                 return -1;
 985         raw += len;
 986
 987         if (*raw != '=')
 988                 return -1;
 989         raw++;
 990
 991         while (*raw && !isspace(*raw) && *raw != ';')
 992                 strbuf_addch(out, *raw++);
 993         return 0;
 994 }
 995
 996 /*
 997  * Extract a normalized version of the content type, with any
 998  * spaces suppressed, all letters lowercased, and no trailing ";"
 999  * or parameters.
1000  *
1001  * Note that we will silently remove even invalid whitespace. For
1002  * example, "text / plain" is specifically forbidden by RFC 2616,
1003  * but "text/plain" is the only reasonable output, and this keeps
1004  * our code simple.
1005  *
1006  * If the "charset" argument is not NULL, store the value of any
1007  * charset parameter there.
1008  *
1009  * Example:
1010  *   "TEXT/PLAIN; charset=utf-8" -> "text/plain", "utf-8"
1011  *   "text / plain" -> "text/plain"
1012  */
1013 static void extract_content_type(struct strbuf *raw, struct strbuf *type,
1014                                  struct strbuf *charset)
1015 {
1016         const char *p;
1017
1018         strbuf_reset(type);
1019         strbuf_grow(type, raw->len);
1020         for (p = raw->buf; *p; p++) {
1021                 if (isspace(*p))
1022                         continue;
1023                 if (*p == ';') {
1024                         p++;
1025                         break;
1026                 }
1027                 strbuf_addch(type, tolower(*p));
1028         }
1029
1030         if (!charset)
1031                 return;
1032
1033         strbuf_reset(charset);
1034         while (*p) {
1035                 while (isspace(*p) || *p == ';')
1036                         p++;
1037                 if (!extract_param(p, "charset", charset))
1038                         return;
1039                 while (*p && !isspace(*p))
1040                         p++;
1041         }
1042
1043         if (!charset->len && starts_with(type->buf, "text/"))
1044                 strbuf_addstr(charset, "ISO-8859-1");
1045 }
1046
1047 static void write_accept_language(struct strbuf *buf)
1048 {
1049         /*
1050          * MAX_DECIMAL_PLACES must not be larger than 3. If it is larger than
1051          * that, q-value will be smaller than 0.001, the minimum q-value the
1052          * HTTP specification allows. See
1053          * http://tools.ietf.org/html/rfc7231#section-5.3.1 for q-value.
1054          */
1055         const int MAX_DECIMAL_PLACES = 3;
1056         const int MAX_LANGUAGE_TAGS = 1000;
1057         const int MAX_ACCEPT_LANGUAGE_HEADER_SIZE = 4000;
1058         char **language_tags = NULL;
1059         int num_langs = 0;
1060         const char *s = get_preferred_languages();
1061         int i;
1062         struct strbuf tag = STRBUF_INIT;
1063
1064         /* Don't add Accept-Language header if no language is preferred. */
1065         if (!s)
1066                 return;
1067
1068         /*
1069          * Split the colon-separated string of preferred languages into
1070          * language_tags array.
1071          */
1072         do {
1073                 /* collect language tag */
1074                 for (; *s && (isalnum(*s) || *s == '_'); s++)
1075                         strbuf_addch(&tag, *s == '_' ? '-' : *s);
1076
1077                 /* skip .codeset, @modifier and any other unnecessary parts */
1078                 while (*s && *s != ':')
1079                         s++;
1080
1081                 if (tag.len) {
1082                         num_langs++;
1083                         REALLOC_ARRAY(language_tags, num_langs);
1084                         language_tags[num_langs - 1] = strbuf_detach(&tag, NULL);
1085                         if (num_langs >= MAX_LANGUAGE_TAGS - 1) /* -1 for '*' */
1086                                 break;
1087                 }
1088         } while (*s++);
1089
1090         /* write Accept-Language header into buf */
1091         if (num_langs) {
1092                 int last_buf_len = 0;
1093                 int max_q;
1094                 int decimal_places;
1095                 char q_format[32];
1096
1097                 /* add '*' */
1098                 REALLOC_ARRAY(language_tags, num_langs + 1);
1099                 language_tags[num_langs++] = "*"; /* it's OK; this won't be freed */
1100
1101                 /* compute decimal_places */
1102                 for (max_q = 1, decimal_places = 0;
1103                      max_q < num_langs && decimal_places <= MAX_DECIMAL_PLACES;
1104                      decimal_places++, max_q *= 10)
1105                         ;
1106
1107                 sprintf(q_format, ";q=0.%%0%dd", decimal_places);
1108
1109                 strbuf_addstr(buf, "Accept-Language: ");
1110
1111                 for (i = 0; i < num_langs; i++) {
1112                         if (i > 0)
1113                                 strbuf_addstr(buf, ", ");
1114
1115                         strbuf_addstr(buf, language_tags[i]);
1116
1117                         if (i > 0)
1118                                 strbuf_addf(buf, q_format, max_q - i);
1119
1120                         if (buf->len > MAX_ACCEPT_LANGUAGE_HEADER_SIZE) {
1121                                 strbuf_remove(buf, last_buf_len, buf->len - last_buf_len);
1122                                 break;
1123                         }
1124
1125                         last_buf_len = buf->len;
1126                 }
1127         }
1128
1129         /* free language tags -- last one is a static '*' */
1130         for (i = 0; i < num_langs - 1; i++)
1131                 free(language_tags[i]);
1132         free(language_tags);
1133 }
1134
1135 /*
1136  * Get an Accept-Language header which indicates user's preferred languages.
1137  *
1138  * Examples:
1139  *   LANGUAGE= -> ""
1140  *   LANGUAGE=ko:en -> "Accept-Language: ko, en; q=0.9, *; q=0.1"
1141  *   LANGUAGE=ko_KR.UTF-8:sr@latin -> "Accept-Language: ko-KR, sr; q=0.9, *; q=0.1"
1142  *   LANGUAGE=ko LANG=en_US.UTF-8 -> "Accept-Language: ko, *; q=0.1"
1143  *   LANGUAGE= LANG=en_US.UTF-8 -> "Accept-Language: en-US, *; q=0.1"
1144  *   LANGUAGE= LANG=C -> ""
1145  */
1146 static const char *get_accept_language(void)
1147 {
1148         if (!cached_accept_language) {
1149                 struct strbuf buf = STRBUF_INIT;
1150                 write_accept_language(&buf);
1151                 if (buf.len > 0)
1152                         cached_accept_language = strbuf_detach(&buf, NULL);
1153         }
1154
1155         return cached_accept_language;
1156 }
1157
1158 /* http_request() targets */
1159 #define HTTP_REQUEST_STRBUF     0
1160 #define HTTP_REQUEST_FILE       1
1161
1162 static int http_request(const char *url,
1163                         void *result, int target,
1164                         const struct http_get_options *options)
1165 {
1166         struct active_request_slot *slot;
1167         struct slot_results results;
1168         struct curl_slist *headers = NULL;
1169         struct strbuf buf = STRBUF_INIT;
1170         const char *accept_language;
1171         int ret;
1172
1173         slot = get_active_slot();
1174         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1175
1176         if (result == NULL) {
1177                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
1178         } else {
1179                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
1180                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
1181
1182                 if (target == HTTP_REQUEST_FILE) {
1183                         long posn = ftell(result);
1184                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1185                                          fwrite);
1186                         if (posn > 0) {
1187                                 strbuf_addf(&buf, "Range: bytes=%ld-", posn);
1188                                 headers = curl_slist_append(headers, buf.buf);
1189                                 strbuf_reset(&buf);
1190                         }
1191                 } else
1192                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1193                                          fwrite_buffer);
1194         }
1195
1196         accept_language = get_accept_language();
1197
1198         if (accept_language)
1199                 headers = curl_slist_append(headers, accept_language);
1200
1201         strbuf_addstr(&buf, "Pragma:");
1202         if (options && options->no_cache)
1203                 strbuf_addstr(&buf, " no-cache");
1204         if (options && options->keep_error)
1205                 curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
1206
1207         headers = curl_slist_append(headers, buf.buf);
1208
1209         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1210         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
1211         curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
1212
1213         ret = run_one_slot(slot, &results);
1214
1215         if (options && options->content_type) {
1216                 struct strbuf raw = STRBUF_INIT;
1217                 curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE, &raw);
1218                 extract_content_type(&raw, options->content_type,
1219                                      options->charset);
1220                 strbuf_release(&raw);
1221         }
1222
1223         if (options && options->effective_url)
1224                 curlinfo_strbuf(slot->curl, CURLINFO_EFFECTIVE_URL,
1225                                 options->effective_url);
1226
1227         curl_slist_free_all(headers);
1228         strbuf_release(&buf);
1229
1230         return ret;
1231 }
1232
1233 /*
1234  * Update the "base" url to a more appropriate value, as deduced by
1235  * redirects seen when requesting a URL starting with "url".
1236  *
1237  * The "asked" parameter is a URL that we asked curl to access, and must begin
1238  * with "base".
1239  *
1240  * The "got" parameter is the URL that curl reported to us as where we ended
1241  * up.
1242  *
1243  * Returns 1 if we updated the base url, 0 otherwise.
1244  *
1245  * Our basic strategy is to compare "base" and "asked" to find the bits
1246  * specific to our request. We then strip those bits off of "got" to yield the
1247  * new base. So for example, if our base is "http://example.com/foo.git",
1248  * and we ask for "http://example.com/foo.git/info/refs", we might end up
1249  * with "https://other.example.com/foo.git/info/refs". We would want the
1250  * new URL to become "https://other.example.com/foo.git".
1251  *
1252  * Note that this assumes a sane redirect scheme. It's entirely possible
1253  * in the example above to end up at a URL that does not even end in
1254  * "info/refs".  In such a case we simply punt, as there is not much we can
1255  * do (and such a scheme is unlikely to represent a real git repository,
1256  * which means we are likely about to abort anyway).
1257  */
1258 static int update_url_from_redirect(struct strbuf *base,
1259                                     const char *asked,
1260                                     const struct strbuf *got)
1261 {
1262         const char *tail;
1263         size_t tail_len;
1264
1265         if (!strcmp(asked, got->buf))
1266                 return 0;
1267
1268         if (!skip_prefix(asked, base->buf, &tail))
1269                 die("BUG: update_url_from_redirect: %s is not a superset of %s",
1270                     asked, base->buf);
1271
1272         tail_len = strlen(tail);
1273
1274         if (got->len < tail_len ||
1275             strcmp(tail, got->buf + got->len - tail_len))
1276                 return 0; /* insane redirect scheme */
1277
1278         strbuf_reset(base);
1279         strbuf_add(base, got->buf, got->len - tail_len);
1280         return 1;
1281 }
1282
1283 static int http_request_reauth(const char *url,
1284                                void *result, int target,
1285                                struct http_get_options *options)
1286 {
1287         int ret = http_request(url, result, target, options);
1288
1289         if (options && options->effective_url && options->base_url) {
1290                 if (update_url_from_redirect(options->base_url,
1291                                              url, options->effective_url)) {
1292                         credential_from_url(&http_auth, options->base_url->buf);
1293                         url = options->effective_url->buf;
1294                 }
1295         }
1296
1297         if (ret != HTTP_REAUTH)
1298                 return ret;
1299
1300         /*
1301          * If we are using KEEP_ERROR, the previous request may have
1302          * put cruft into our output stream; we should clear it out before
1303          * making our next request. We only know how to do this for
1304          * the strbuf case, but that is enough to satisfy current callers.
1305          */
1306         if (options && options->keep_error) {
1307                 switch (target) {
1308                 case HTTP_REQUEST_STRBUF:
1309                         strbuf_reset(result);
1310                         break;
1311                 default:
1312                         die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
1313                 }
1314         }
1315
1316         credential_fill(&http_auth);
1317
1318         return http_request(url, result, target, options);
1319 }
1320
1321 int http_get_strbuf(const char *url,
1322                     struct strbuf *result,
1323                     struct http_get_options *options)
1324 {
1325         return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
1326 }
1327
1328 /*
1329  * Downloads a URL and stores the result in the given file.
1330  *
1331  * If a previous interrupted download is detected (i.e. a previous temporary
1332  * file is still around) the download is resumed.
1333  */
1334 static int http_get_file(const char *url, const char *filename,
1335                          struct http_get_options *options)
1336 {
1337         int ret;
1338         struct strbuf tmpfile = STRBUF_INIT;
1339         FILE *result;
1340
1341         strbuf_addf(&tmpfile, "%s.temp", filename);
1342         result = fopen(tmpfile.buf, "a");
1343         if (!result) {
1344                 error("Unable to open local file %s", tmpfile.buf);
1345                 ret = HTTP_ERROR;
1346                 goto cleanup;
1347         }
1348
1349         ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
1350         fclose(result);
1351
1352         if (ret == HTTP_OK && finalize_object_file(tmpfile.buf, filename))
1353                 ret = HTTP_ERROR;
1354 cleanup:
1355         strbuf_release(&tmpfile);
1356         return ret;
1357 }
1358
1359 int http_fetch_ref(const char *base, struct ref *ref)
1360 {
1361         struct http_get_options options = {0};
1362         char *url;
1363         struct strbuf buffer = STRBUF_INIT;
1364         int ret = -1;
1365
1366         options.no_cache = 1;
1367
1368         url = quote_ref_url(base, ref->name);
1369         if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
1370                 strbuf_rtrim(&buffer);
1371                 if (buffer.len == 40)
1372                         ret = get_sha1_hex(buffer.buf, ref->old_sha1);
1373                 else if (starts_with(buffer.buf, "ref: ")) {
1374                         ref->symref = xstrdup(buffer.buf + 5);
1375                         ret = 0;
1376                 }
1377         }
1378
1379         strbuf_release(&buffer);
1380         free(url);
1381         return ret;
1382 }
1383
1384 /* Helpers for fetching packs */
1385 static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
1386 {
1387         char *url, *tmp;
1388         struct strbuf buf = STRBUF_INIT;
1389
1390         if (http_is_verbose)
1391                 fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
1392
1393         end_url_with_slash(&buf, base_url);
1394         strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
1395         url = strbuf_detach(&buf, NULL);
1396
1397         strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
1398         tmp = strbuf_detach(&buf, NULL);
1399
1400         if (http_get_file(url, tmp, NULL) != HTTP_OK) {
1401                 error("Unable to get pack index %s", url);
1402                 free(tmp);
1403                 tmp = NULL;
1404         }
1405
1406         free(url);
1407         return tmp;
1408 }
1409
1410 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
1411         unsigned char *sha1, const char *base_url)
1412 {
1413         struct packed_git *new_pack;
1414         char *tmp_idx = NULL;
1415         int ret;
1416
1417         if (has_pack_index(sha1)) {
1418                 new_pack = parse_pack_index(sha1, sha1_pack_index_name(sha1));
1419                 if (!new_pack)
1420                         return -1; /* parse_pack_index() already issued error message */
1421                 goto add_pack;
1422         }
1423
1424         tmp_idx = fetch_pack_index(sha1, base_url);
1425         if (!tmp_idx)
1426                 return -1;
1427
1428         new_pack = parse_pack_index(sha1, tmp_idx);
1429         if (!new_pack) {
1430                 unlink(tmp_idx);
1431                 free(tmp_idx);
1432
1433                 return -1; /* parse_pack_index() already issued error message */
1434         }
1435
1436         ret = verify_pack_index(new_pack);
1437         if (!ret) {
1438                 close_pack_index(new_pack);
1439                 ret = finalize_object_file(tmp_idx, sha1_pack_index_name(sha1));
1440         }
1441         free(tmp_idx);
1442         if (ret)
1443                 return -1;
1444
1445 add_pack:
1446         new_pack->next = *packs_head;
1447         *packs_head = new_pack;
1448         return 0;
1449 }
1450
1451 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
1452 {
1453         struct http_get_options options = {0};
1454         int ret = 0, i = 0;
1455         char *url, *data;
1456         struct strbuf buf = STRBUF_INIT;
1457         unsigned char sha1[20];
1458
1459         end_url_with_slash(&buf, base_url);
1460         strbuf_addstr(&buf, "objects/info/packs");
1461         url = strbuf_detach(&buf, NULL);
1462
1463         options.no_cache = 1;
1464         ret = http_get_strbuf(url, &buf, &options);
1465         if (ret != HTTP_OK)
1466                 goto cleanup;
1467
1468         data = buf.buf;
1469         while (i < buf.len) {
1470                 switch (data[i]) {
1471                 case 'P':
1472                         i++;
1473                         if (i + 52 <= buf.len &&
1474                             starts_with(data + i, " pack-") &&
1475                             starts_with(data + i + 46, ".pack\n")) {
1476                                 get_sha1_hex(data + i + 6, sha1);
1477                                 fetch_and_setup_pack_index(packs_head, sha1,
1478                                                       base_url);
1479                                 i += 51;
1480                                 break;
1481                         }
1482                 default:
1483                         while (i < buf.len && data[i] != '\n')
1484                                 i++;
1485                 }
1486                 i++;
1487         }
1488
1489 cleanup:
1490         free(url);
1491         return ret;
1492 }
1493
1494 void release_http_pack_request(struct http_pack_request *preq)
1495 {
1496         if (preq->packfile != NULL) {
1497                 fclose(preq->packfile);
1498                 preq->packfile = NULL;
1499         }
1500         if (preq->range_header != NULL) {
1501                 curl_slist_free_all(preq->range_header);
1502                 preq->range_header = NULL;
1503         }
1504         preq->slot = NULL;
1505         free(preq->url);
1506         free(preq);
1507 }
1508
1509 int finish_http_pack_request(struct http_pack_request *preq)
1510 {
1511         struct packed_git **lst;
1512         struct packed_git *p = preq->target;
1513         char *tmp_idx;
1514         struct child_process ip = CHILD_PROCESS_INIT;
1515         const char *ip_argv[8];
1516
1517         close_pack_index(p);
1518
1519         fclose(preq->packfile);
1520         preq->packfile = NULL;
1521
1522         lst = preq->lst;
1523         while (*lst != p)
1524                 lst = &((*lst)->next);
1525         *lst = (*lst)->next;
1526
1527         tmp_idx = xstrdup(preq->tmpfile);
1528         strcpy(tmp_idx + strlen(tmp_idx) - strlen(".pack.temp"),
1529                ".idx.temp");
1530
1531         ip_argv[0] = "index-pack";
1532         ip_argv[1] = "-o";
1533         ip_argv[2] = tmp_idx;
1534         ip_argv[3] = preq->tmpfile;
1535         ip_argv[4] = NULL;
1536
1537         ip.argv = ip_argv;
1538         ip.git_cmd = 1;
1539         ip.no_stdin = 1;
1540         ip.no_stdout = 1;
1541
1542         if (run_command(&ip)) {
1543                 unlink(preq->tmpfile);
1544                 unlink(tmp_idx);
1545                 free(tmp_idx);
1546                 return -1;
1547         }
1548
1549         unlink(sha1_pack_index_name(p->sha1));
1550
1551         if (finalize_object_file(preq->tmpfile, sha1_pack_name(p->sha1))
1552          || finalize_object_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
1553                 free(tmp_idx);
1554                 return -1;
1555         }
1556
1557         install_packed_git(p);
1558         free(tmp_idx);
1559         return 0;
1560 }
1561
1562 struct http_pack_request *new_http_pack_request(
1563         struct packed_git *target, const char *base_url)
1564 {
1565         long prev_posn = 0;
1566         char range[RANGE_HEADER_SIZE];
1567         struct strbuf buf = STRBUF_INIT;
1568         struct http_pack_request *preq;
1569
1570         preq = xcalloc(1, sizeof(*preq));
1571         preq->target = target;
1572
1573         end_url_with_slash(&buf, base_url);
1574         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
1575                 sha1_to_hex(target->sha1));
1576         preq->url = strbuf_detach(&buf, NULL);
1577
1578         snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
1579                 sha1_pack_name(target->sha1));
1580         preq->packfile = fopen(preq->tmpfile, "a");
1581         if (!preq->packfile) {
1582                 error("Unable to open local file %s for pack",
1583                       preq->tmpfile);
1584                 goto abort;
1585         }
1586
1587         preq->slot = get_active_slot();
1588         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
1589         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
1590         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
1591         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1592                 no_pragma_header);
1593
1594         /*
1595          * If there is data present from a previous transfer attempt,
1596          * resume where it left off
1597          */
1598         prev_posn = ftell(preq->packfile);
1599         if (prev_posn>0) {
1600                 if (http_is_verbose)
1601                         fprintf(stderr,
1602                                 "Resuming fetch of pack %s at byte %ld\n",
1603                                 sha1_to_hex(target->sha1), prev_posn);
1604                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1605                 preq->range_header = curl_slist_append(NULL, range);
1606                 curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1607                         preq->range_header);
1608         }
1609
1610         return preq;
1611
1612 abort:
1613         free(preq->url);
1614         free(preq);
1615         return NULL;
1616 }
1617
1618 /* Helpers for fetching objects (loose) */
1619 static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
1620                                void *data)
1621 {
1622         unsigned char expn[4096];
1623         size_t size = eltsize * nmemb;
1624         int posn = 0;
1625         struct http_object_request *freq =
1626                 (struct http_object_request *)data;
1627         do {
1628                 ssize_t retval = xwrite(freq->localfile,
1629                                         (char *) ptr + posn, size - posn);
1630                 if (retval < 0)
1631                         return posn;
1632                 posn += retval;
1633         } while (posn < size);
1634
1635         freq->stream.avail_in = size;
1636         freq->stream.next_in = (void *)ptr;
1637         do {
1638                 freq->stream.next_out = expn;
1639                 freq->stream.avail_out = sizeof(expn);
1640                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
1641                 git_SHA1_Update(&freq->c, expn,
1642                                 sizeof(expn) - freq->stream.avail_out);
1643         } while (freq->stream.avail_in && freq->zret == Z_OK);
1644         return size;
1645 }
1646
1647 struct http_object_request *new_http_object_request(const char *base_url,
1648         unsigned char *sha1)
1649 {
1650         char *hex = sha1_to_hex(sha1);
1651         const char *filename;
1652         char prevfile[PATH_MAX];
1653         int prevlocal;
1654         char prev_buf[PREV_BUF_SIZE];
1655         ssize_t prev_read = 0;
1656         long prev_posn = 0;
1657         char range[RANGE_HEADER_SIZE];
1658         struct curl_slist *range_header = NULL;
1659         struct http_object_request *freq;
1660
1661         freq = xcalloc(1, sizeof(*freq));
1662         hashcpy(freq->sha1, sha1);
1663         freq->localfile = -1;
1664
1665         filename = sha1_file_name(sha1);
1666         snprintf(freq->tmpfile, sizeof(freq->tmpfile),
1667                  "%s.temp", filename);
1668
1669         snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
1670         unlink_or_warn(prevfile);
1671         rename(freq->tmpfile, prevfile);
1672         unlink_or_warn(freq->tmpfile);
1673
1674         if (freq->localfile != -1)
1675                 error("fd leakage in start: %d", freq->localfile);
1676         freq->localfile = open(freq->tmpfile,
1677                                O_WRONLY | O_CREAT | O_EXCL, 0666);
1678         /*
1679          * This could have failed due to the "lazy directory creation";
1680          * try to mkdir the last path component.
1681          */
1682         if (freq->localfile < 0 && errno == ENOENT) {
1683                 char *dir = strrchr(freq->tmpfile, '/');
1684                 if (dir) {
1685                         *dir = 0;
1686                         mkdir(freq->tmpfile, 0777);
1687                         *dir = '/';
1688                 }
1689                 freq->localfile = open(freq->tmpfile,
1690                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
1691         }
1692
1693         if (freq->localfile < 0) {
1694                 error("Couldn't create temporary file %s: %s",
1695                       freq->tmpfile, strerror(errno));
1696                 goto abort;
1697         }
1698
1699         git_inflate_init(&freq->stream);
1700
1701         git_SHA1_Init(&freq->c);
1702
1703         freq->url = get_remote_object_url(base_url, hex, 0);
1704
1705         /*
1706          * If a previous temp file is present, process what was already
1707          * fetched.
1708          */
1709         prevlocal = open(prevfile, O_RDONLY);
1710         if (prevlocal != -1) {
1711                 do {
1712                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
1713                         if (prev_read>0) {
1714                                 if (fwrite_sha1_file(prev_buf,
1715                                                      1,
1716                                                      prev_read,
1717                                                      freq) == prev_read) {
1718                                         prev_posn += prev_read;
1719                                 } else {
1720                                         prev_read = -1;
1721                                 }
1722                         }
1723                 } while (prev_read > 0);
1724                 close(prevlocal);
1725         }
1726         unlink_or_warn(prevfile);
1727
1728         /*
1729          * Reset inflate/SHA1 if there was an error reading the previous temp
1730          * file; also rewind to the beginning of the local file.
1731          */
1732         if (prev_read == -1) {
1733                 memset(&freq->stream, 0, sizeof(freq->stream));
1734                 git_inflate_init(&freq->stream);
1735                 git_SHA1_Init(&freq->c);
1736                 if (prev_posn>0) {
1737                         prev_posn = 0;
1738                         lseek(freq->localfile, 0, SEEK_SET);
1739                         if (ftruncate(freq->localfile, 0) < 0) {
1740                                 error("Couldn't truncate temporary file %s: %s",
1741                                           freq->tmpfile, strerror(errno));
1742                                 goto abort;
1743                         }
1744                 }
1745         }
1746
1747         freq->slot = get_active_slot();
1748
1749         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
1750         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
1751         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
1752         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
1753         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
1754
1755         /*
1756          * If we have successfully processed data from a previous fetch
1757          * attempt, only fetch the data we don't already have.
1758          */
1759         if (prev_posn>0) {
1760                 if (http_is_verbose)
1761                         fprintf(stderr,
1762                                 "Resuming fetch of object %s at byte %ld\n",
1763                                 hex, prev_posn);
1764                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1765                 range_header = curl_slist_append(range_header, range);
1766                 curl_easy_setopt(freq->slot->curl,
1767                                  CURLOPT_HTTPHEADER, range_header);
1768         }
1769
1770         return freq;
1771
1772 abort:
1773         free(freq->url);
1774         free(freq);
1775         return NULL;
1776 }
1777
1778 void process_http_object_request(struct http_object_request *freq)
1779 {
1780         if (freq->slot == NULL)
1781                 return;
1782         freq->curl_result = freq->slot->curl_result;
1783         freq->http_code = freq->slot->http_code;
1784         freq->slot = NULL;
1785 }
1786
1787 int finish_http_object_request(struct http_object_request *freq)
1788 {
1789         struct stat st;
1790
1791         close(freq->localfile);
1792         freq->localfile = -1;
1793
1794         process_http_object_request(freq);
1795
1796         if (freq->http_code == 416) {
1797                 warning("requested range invalid; we may already have all the data.");
1798         } else if (freq->curl_result != CURLE_OK) {
1799                 if (stat(freq->tmpfile, &st) == 0)
1800                         if (st.st_size == 0)
1801                                 unlink_or_warn(freq->tmpfile);
1802                 return -1;
1803         }
1804
1805         git_inflate_end(&freq->stream);
1806         git_SHA1_Final(freq->real_sha1, &freq->c);
1807         if (freq->zret != Z_STREAM_END) {
1808                 unlink_or_warn(freq->tmpfile);
1809                 return -1;
1810         }
1811         if (hashcmp(freq->sha1, freq->real_sha1)) {
1812                 unlink_or_warn(freq->tmpfile);
1813                 return -1;
1814         }
1815         freq->rename =
1816                 finalize_object_file(freq->tmpfile, sha1_file_name(freq->sha1));
1817
1818         return freq->rename;
1819 }
1820
1821 void abort_http_object_request(struct http_object_request *freq)
1822 {
1823         unlink_or_warn(freq->tmpfile);
1824
1825         release_http_object_request(freq);
1826 }
1827
1828 void release_http_object_request(struct http_object_request *freq)
1829 {
1830         if (freq->localfile != -1) {
1831                 close(freq->localfile);
1832                 freq->localfile = -1;
1833         }
1834         if (freq->url != NULL) {
1835                 free(freq->url);
1836                 freq->url = NULL;
1837         }
1838         if (freq->slot != NULL) {
1839                 freq->slot->callback_func = NULL;
1840                 freq->slot->callback_data = NULL;
1841                 release_active_slot(freq->slot);
1842                 freq->slot = NULL;
1843         }
1844 }