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