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

   1 #include "http.h"
   2 #include "pack.h"
   3 #include "sideband.h"
   4 #include "run-command.h"
   5 #include "url.h"
   6 #include "urlmatch.h"
   7 #include "credential.h"
   8 #include "version.h"
   9 #include "pkt-line.h"
  10
  11 int active_requests;
  12 int http_is_verbose;
  13 size_t http_post_buffer = 16 * LARGE_PACKET_MAX;
  14
  15 #if LIBCURL_VERSION_NUM >= 0x070a06
  16 #define LIBCURL_CAN_HANDLE_AUTH_ANY
  17 #endif
  18
  19 static int min_curl_sessions = 1;
  20 static int curl_session_count;
  21 #ifdef USE_CURL_MULTI
  22 static int max_requests = -1;
  23 static CURLM *curlm;
  24 #endif
  25 #ifndef NO_CURL_EASY_DUPHANDLE
  26 static CURL *curl_default;
  27 #endif
  28
  29 #define PREV_BUF_SIZE 4096
  30 #define RANGE_HEADER_SIZE 30
  31
  32 char curl_errorstr[CURL_ERROR_SIZE];
  33
  34 static int curl_ssl_verify = -1;
  35 static int curl_ssl_try;
  36 static const char *ssl_cert;
  37 #if LIBCURL_VERSION_NUM >= 0x070903
  38 static const char *ssl_key;
  39 #endif
  40 #if LIBCURL_VERSION_NUM >= 0x070908
  41 static const char *ssl_capath;
  42 #endif
  43 static const char *ssl_cainfo;
  44 static long curl_low_speed_limit = -1;
  45 static long curl_low_speed_time = -1;
  46 static int curl_ftp_no_epsv;
  47 static const char *curl_http_proxy;
  48 static const char *curl_cookie_file;
  49 static int curl_save_cookies;
  50 static struct credential http_auth = CREDENTIAL_INIT;
  51 static int http_proactive_auth;
  52 static const char *user_agent;
  53
  54 #if LIBCURL_VERSION_NUM >= 0x071700
  55 /* Use CURLOPT_KEYPASSWD as is */
  56 #elif LIBCURL_VERSION_NUM >= 0x070903
  57 #define CURLOPT_KEYPASSWD CURLOPT_SSLKEYPASSWD
  58 #else
  59 #define CURLOPT_KEYPASSWD CURLOPT_SSLCERTPASSWD
  60 #endif
  61
  62 static struct credential cert_auth = CREDENTIAL_INIT;
  63 static int ssl_cert_password_required;
  64
  65 static struct curl_slist *pragma_header;
  66 static struct curl_slist *no_pragma_header;
  67
  68 static struct active_request_slot *active_queue_head;
  69
  70 size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
  71 {
  72         size_t size = eltsize * nmemb;
  73         struct buffer *buffer = buffer_;
  74
  75         if (size > buffer->buf.len - buffer->posn)
  76                 size = buffer->buf.len - buffer->posn;
  77         memcpy(ptr, buffer->buf.buf + buffer->posn, size);
  78         buffer->posn += size;
  79
  80         return size;
  81 }
  82
  83 #ifndef NO_CURL_IOCTL
  84 curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)
  85 {
  86         struct buffer *buffer = clientp;
  87
  88         switch (cmd) {
  89         case CURLIOCMD_NOP:
  90                 return CURLIOE_OK;
  91
  92         case CURLIOCMD_RESTARTREAD:
  93                 buffer->posn = 0;
  94                 return CURLIOE_OK;
  95
  96         default:
  97                 return CURLIOE_UNKNOWNCMD;
  98         }
  99 }
 100 #endif
 101
 102 size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
 103 {
 104         size_t size = eltsize * nmemb;
 105         struct strbuf *buffer = buffer_;
 106
 107         strbuf_add(buffer, ptr, size);
 108         return size;
 109 }
 110
 111 size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf)
 112 {
 113         return eltsize * nmemb;
 114 }
 115
 116 #ifdef USE_CURL_MULTI
 117 static void process_curl_messages(void)
 118 {
 119         int num_messages;
 120         struct active_request_slot *slot;
 121         CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
 122
 123         while (curl_message != NULL) {
 124                 if (curl_message->msg == CURLMSG_DONE) {
 125                         int curl_result = curl_message->data.result;
 126                         slot = active_queue_head;
 127                         while (slot != NULL &&
 128                                slot->curl != curl_message->easy_handle)
 129                                 slot = slot->next;
 130                         if (slot != NULL) {
 131                                 curl_multi_remove_handle(curlm, slot->curl);
 132                                 slot->curl_result = curl_result;
 133                                 finish_active_slot(slot);
 134                         } else {
 135                                 fprintf(stderr, "Received DONE message for unknown request!\n");
 136                         }
 137                 } else {
 138                         fprintf(stderr, "Unknown CURL message received: %d\n",
 139                                 (int)curl_message->msg);
 140                 }
 141                 curl_message = curl_multi_info_read(curlm, &num_messages);
 142         }
 143 }
 144 #endif
 145
 146 static int http_options(const char *var, const char *value, void *cb)
 147 {
 148         if (!strcmp("http.sslverify", var)) {
 149                 curl_ssl_verify = git_config_bool(var, value);
 150                 return 0;
 151         }
 152         if (!strcmp("http.sslcert", var))
 153                 return git_config_string(&ssl_cert, var, value);
 154 #if LIBCURL_VERSION_NUM >= 0x070903
 155         if (!strcmp("http.sslkey", var))
 156                 return git_config_string(&ssl_key, var, value);
 157 #endif
 158 #if LIBCURL_VERSION_NUM >= 0x070908
 159         if (!strcmp("http.sslcapath", var))
 160                 return git_config_string(&ssl_capath, var, value);
 161 #endif
 162         if (!strcmp("http.sslcainfo", var))
 163                 return git_config_string(&ssl_cainfo, var, value);
 164         if (!strcmp("http.sslcertpasswordprotected", var)) {
 165                 ssl_cert_password_required = git_config_bool(var, value);
 166                 return 0;
 167         }
 168         if (!strcmp("http.ssltry", var)) {
 169                 curl_ssl_try = git_config_bool(var, value);
 170                 return 0;
 171         }
 172         if (!strcmp("http.minsessions", var)) {
 173                 min_curl_sessions = git_config_int(var, value);
 174 #ifndef USE_CURL_MULTI
 175                 if (min_curl_sessions > 1)
 176                         min_curl_sessions = 1;
 177 #endif
 178                 return 0;
 179         }
 180 #ifdef USE_CURL_MULTI
 181         if (!strcmp("http.maxrequests", var)) {
 182                 max_requests = git_config_int(var, value);
 183                 return 0;
 184         }
 185 #endif
 186         if (!strcmp("http.lowspeedlimit", var)) {
 187                 curl_low_speed_limit = (long)git_config_int(var, value);
 188                 return 0;
 189         }
 190         if (!strcmp("http.lowspeedtime", var)) {
 191                 curl_low_speed_time = (long)git_config_int(var, value);
 192                 return 0;
 193         }
 194
 195         if (!strcmp("http.noepsv", var)) {
 196                 curl_ftp_no_epsv = git_config_bool(var, value);
 197                 return 0;
 198         }
 199         if (!strcmp("http.proxy", var))
 200                 return git_config_string(&curl_http_proxy, var, value);
 201
 202         if (!strcmp("http.cookiefile", var))
 203                 return git_config_string(&curl_cookie_file, var, value);
 204         if (!strcmp("http.savecookies", var)) {
 205                 curl_save_cookies = git_config_bool(var, value);
 206                 return 0;
 207         }
 208
 209         if (!strcmp("http.postbuffer", var)) {
 210                 http_post_buffer = git_config_int(var, value);
 211                 if (http_post_buffer < LARGE_PACKET_MAX)
 212                         http_post_buffer = LARGE_PACKET_MAX;
 213                 return 0;
 214         }
 215
 216         if (!strcmp("http.useragent", var))
 217                 return git_config_string(&user_agent, var, value);
 218
 219         /* Fall back on the default ones */
 220         return git_default_config(var, value, cb);
 221 }
 222
 223 static void init_curl_http_auth(CURL *result)
 224 {
 225         if (!http_auth.username)
 226                 return;
 227
 228         credential_fill(&http_auth);
 229
 230 #if LIBCURL_VERSION_NUM >= 0x071301
 231         curl_easy_setopt(result, CURLOPT_USERNAME, http_auth.username);
 232         curl_easy_setopt(result, CURLOPT_PASSWORD, http_auth.password);
 233 #else
 234         {
 235                 static struct strbuf up = STRBUF_INIT;
 236                 /*
 237                  * Note that we assume we only ever have a single set of
 238                  * credentials in a given program run, so we do not have
 239                  * to worry about updating this buffer, only setting its
 240                  * initial value.
 241                  */
 242                 if (!up.len)
 243                         strbuf_addf(&up, "%s:%s",
 244                                 http_auth.username, http_auth.password);
 245                 curl_easy_setopt(result, CURLOPT_USERPWD, up.buf);
 246         }
 247 #endif
 248 }
 249
 250 static int has_cert_password(void)
 251 {
 252         if (ssl_cert == NULL || ssl_cert_password_required != 1)
 253                 return 0;
 254         if (!cert_auth.password) {
 255                 cert_auth.protocol = xstrdup("cert");
 256                 cert_auth.username = xstrdup("");
 257                 cert_auth.path = xstrdup(ssl_cert);
 258                 credential_fill(&cert_auth);
 259         }
 260         return 1;
 261 }
 262
 263 static CURL *get_curl_handle(void)
 264 {
 265         CURL *result = curl_easy_init();
 266
 267         if (!curl_ssl_verify) {
 268                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
 269                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
 270         } else {
 271                 /* Verify authenticity of the peer's certificate */
 272                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
 273                 /* The name in the cert must match whom we tried to connect */
 274                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
 275         }
 276
 277 #if LIBCURL_VERSION_NUM >= 0x070907
 278         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
 279 #endif
 280 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 281         curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
 282 #endif
 283
 284         if (http_proactive_auth)
 285                 init_curl_http_auth(result);
 286
 287         if (ssl_cert != NULL)
 288                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
 289         if (has_cert_password())
 290                 curl_easy_setopt(result, CURLOPT_KEYPASSWD, cert_auth.password);
 291 #if LIBCURL_VERSION_NUM >= 0x070903
 292         if (ssl_key != NULL)
 293                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
 294 #endif
 295 #if LIBCURL_VERSION_NUM >= 0x070908
 296         if (ssl_capath != NULL)
 297                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
 298 #endif
 299         if (ssl_cainfo != NULL)
 300                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
 301
 302         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
 303                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
 304                                  curl_low_speed_limit);
 305                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
 306                                  curl_low_speed_time);
 307         }
 308
 309         curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
 310 #if LIBCURL_VERSION_NUM >= 0x071301
 311         curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
 312 #elif LIBCURL_VERSION_NUM >= 0x071101
 313         curl_easy_setopt(result, CURLOPT_POST301, 1);
 314 #endif
 315
 316         if (getenv("GIT_CURL_VERBOSE"))
 317                 curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
 318
 319         curl_easy_setopt(result, CURLOPT_USERAGENT,
 320                 user_agent ? user_agent : git_user_agent());
 321
 322         if (curl_ftp_no_epsv)
 323                 curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
 324
 325 #ifdef CURLOPT_USE_SSL
 326         if (curl_ssl_try)
 327                 curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
 328 #endif
 329
 330         if (curl_http_proxy) {
 331                 curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
 332                 curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
 333         }
 334
 335         return result;
 336 }
 337
 338 static void set_from_env(const char **var, const char *envname)
 339 {
 340         const char *val = getenv(envname);
 341         if (val)
 342                 *var = val;
 343 }
 344
 345 void http_init(struct remote *remote, const char *url, int proactive_auth)
 346 {
 347         char *low_speed_limit;
 348         char *low_speed_time;
 349         char *normalized_url;
 350         struct urlmatch_config config = { STRING_LIST_INIT_DUP };
 351
 352         config.section = "http";
 353         config.key = NULL;
 354         config.collect_fn = http_options;
 355         config.cascade_fn = git_default_config;
 356         config.cb = NULL;
 357
 358         http_is_verbose = 0;
 359         normalized_url = url_normalize(url, &config.url);
 360
 361         git_config(urlmatch_config_entry, &config);
 362         free(normalized_url);
 363
 364         curl_global_init(CURL_GLOBAL_ALL);
 365
 366         http_proactive_auth = proactive_auth;
 367
 368         if (remote && remote->http_proxy)
 369                 curl_http_proxy = xstrdup(remote->http_proxy);
 370
 371         pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
 372         no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
 373
 374 #ifdef USE_CURL_MULTI
 375         {
 376                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
 377                 if (http_max_requests != NULL)
 378                         max_requests = atoi(http_max_requests);
 379         }
 380
 381         curlm = curl_multi_init();
 382         if (curlm == NULL) {
 383                 fprintf(stderr, "Error creating curl multi handle.\n");
 384                 exit(1);
 385         }
 386 #endif
 387
 388         if (getenv("GIT_SSL_NO_VERIFY"))
 389                 curl_ssl_verify = 0;
 390
 391         set_from_env(&ssl_cert, "GIT_SSL_CERT");
 392 #if LIBCURL_VERSION_NUM >= 0x070903
 393         set_from_env(&ssl_key, "GIT_SSL_KEY");
 394 #endif
 395 #if LIBCURL_VERSION_NUM >= 0x070908
 396         set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
 397 #endif
 398         set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
 399
 400         set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");
 401
 402         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
 403         if (low_speed_limit != NULL)
 404                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
 405         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
 406         if (low_speed_time != NULL)
 407                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
 408
 409         if (curl_ssl_verify == -1)
 410                 curl_ssl_verify = 1;
 411
 412         curl_session_count = 0;
 413 #ifdef USE_CURL_MULTI
 414         if (max_requests < 1)
 415                 max_requests = DEFAULT_MAX_REQUESTS;
 416 #endif
 417
 418         if (getenv("GIT_CURL_FTP_NO_EPSV"))
 419                 curl_ftp_no_epsv = 1;
 420
 421         if (url) {
 422                 credential_from_url(&http_auth, url);
 423                 if (!ssl_cert_password_required &&
 424                     getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
 425                     !prefixcmp(url, "https://"))
 426                         ssl_cert_password_required = 1;
 427         }
 428
 429 #ifndef NO_CURL_EASY_DUPHANDLE
 430         curl_default = get_curl_handle();
 431 #endif
 432 }
 433
 434 void http_cleanup(void)
 435 {
 436         struct active_request_slot *slot = active_queue_head;
 437
 438         while (slot != NULL) {
 439                 struct active_request_slot *next = slot->next;
 440                 if (slot->curl != NULL) {
 441 #ifdef USE_CURL_MULTI
 442                         curl_multi_remove_handle(curlm, slot->curl);
 443 #endif
 444                         curl_easy_cleanup(slot->curl);
 445                 }
 446                 free(slot);
 447                 slot = next;
 448         }
 449         active_queue_head = NULL;
 450
 451 #ifndef NO_CURL_EASY_DUPHANDLE
 452         curl_easy_cleanup(curl_default);
 453 #endif
 454
 455 #ifdef USE_CURL_MULTI
 456         curl_multi_cleanup(curlm);
 457 #endif
 458         curl_global_cleanup();
 459
 460         curl_slist_free_all(pragma_header);
 461         pragma_header = NULL;
 462
 463         curl_slist_free_all(no_pragma_header);
 464         no_pragma_header = NULL;
 465
 466         if (curl_http_proxy) {
 467                 free((void *)curl_http_proxy);
 468                 curl_http_proxy = NULL;
 469         }
 470
 471         if (cert_auth.password != NULL) {
 472                 memset(cert_auth.password, 0, strlen(cert_auth.password));
 473                 free(cert_auth.password);
 474                 cert_auth.password = NULL;
 475         }
 476         ssl_cert_password_required = 0;
 477 }
 478
 479 struct active_request_slot *get_active_slot(void)
 480 {
 481         struct active_request_slot *slot = active_queue_head;
 482         struct active_request_slot *newslot;
 483
 484 #ifdef USE_CURL_MULTI
 485         int num_transfers;
 486
 487         /* Wait for a slot to open up if the queue is full */
 488         while (active_requests >= max_requests) {
 489                 curl_multi_perform(curlm, &num_transfers);
 490                 if (num_transfers < active_requests)
 491                         process_curl_messages();
 492         }
 493 #endif
 494
 495         while (slot != NULL && slot->in_use)
 496                 slot = slot->next;
 497
 498         if (slot == NULL) {
 499                 newslot = xmalloc(sizeof(*newslot));
 500                 newslot->curl = NULL;
 501                 newslot->in_use = 0;
 502                 newslot->next = NULL;
 503
 504                 slot = active_queue_head;
 505                 if (slot == NULL) {
 506                         active_queue_head = newslot;
 507                 } else {
 508                         while (slot->next != NULL)
 509                                 slot = slot->next;
 510                         slot->next = newslot;
 511                 }
 512                 slot = newslot;
 513         }
 514
 515         if (slot->curl == NULL) {
 516 #ifdef NO_CURL_EASY_DUPHANDLE
 517                 slot->curl = get_curl_handle();
 518 #else
 519                 slot->curl = curl_easy_duphandle(curl_default);
 520 #endif
 521                 curl_session_count++;
 522         }
 523
 524         active_requests++;
 525         slot->in_use = 1;
 526         slot->results = NULL;
 527         slot->finished = NULL;
 528         slot->callback_data = NULL;
 529         slot->callback_func = NULL;
 530         curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file);
 531         if (curl_save_cookies)
 532                 curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file);
 533         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
 534         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
 535         curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
 536         curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
 537         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
 538         curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
 539         curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
 540         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
 541         curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
 542         if (http_auth.password)
 543                 init_curl_http_auth(slot->curl);
 544
 545         return slot;
 546 }
 547
 548 int start_active_slot(struct active_request_slot *slot)
 549 {
 550 #ifdef USE_CURL_MULTI
 551         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
 552         int num_transfers;
 553
 554         if (curlm_result != CURLM_OK &&
 555             curlm_result != CURLM_CALL_MULTI_PERFORM) {
 556                 active_requests--;
 557                 slot->in_use = 0;
 558                 return 0;
 559         }
 560
 561         /*
 562          * We know there must be something to do, since we just added
 563          * something.
 564          */
 565         curl_multi_perform(curlm, &num_transfers);
 566 #endif
 567         return 1;
 568 }
 569
 570 #ifdef USE_CURL_MULTI
 571 struct fill_chain {
 572         void *data;
 573         int (*fill)(void *);
 574         struct fill_chain *next;
 575 };
 576
 577 static struct fill_chain *fill_cfg;
 578
 579 void add_fill_function(void *data, int (*fill)(void *))
 580 {
 581         struct fill_chain *new = xmalloc(sizeof(*new));
 582         struct fill_chain **linkp = &fill_cfg;
 583         new->data = data;
 584         new->fill = fill;
 585         new->next = NULL;
 586         while (*linkp)
 587                 linkp = &(*linkp)->next;
 588         *linkp = new;
 589 }
 590
 591 void fill_active_slots(void)
 592 {
 593         struct active_request_slot *slot = active_queue_head;
 594
 595         while (active_requests < max_requests) {
 596                 struct fill_chain *fill;
 597                 for (fill = fill_cfg; fill; fill = fill->next)
 598                         if (fill->fill(fill->data))
 599                                 break;
 600
 601                 if (!fill)
 602                         break;
 603         }
 604
 605         while (slot != NULL) {
 606                 if (!slot->in_use && slot->curl != NULL
 607                         && curl_session_count > min_curl_sessions) {
 608                         curl_easy_cleanup(slot->curl);
 609                         slot->curl = NULL;
 610                         curl_session_count--;
 611                 }
 612                 slot = slot->next;
 613         }
 614 }
 615
 616 void step_active_slots(void)
 617 {
 618         int num_transfers;
 619         CURLMcode curlm_result;
 620
 621         do {
 622                 curlm_result = curl_multi_perform(curlm, &num_transfers);
 623         } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
 624         if (num_transfers < active_requests) {
 625                 process_curl_messages();
 626                 fill_active_slots();
 627         }
 628 }
 629 #endif
 630
 631 void run_active_slot(struct active_request_slot *slot)
 632 {
 633 #ifdef USE_CURL_MULTI
 634         fd_set readfds;
 635         fd_set writefds;
 636         fd_set excfds;
 637         int max_fd;
 638         struct timeval select_timeout;
 639         int finished = 0;
 640
 641         slot->finished = &finished;
 642         while (!finished) {
 643                 step_active_slots();
 644
 645                 if (slot->in_use) {
 646 #if LIBCURL_VERSION_NUM >= 0x070f04
 647                         long curl_timeout;
 648                         curl_multi_timeout(curlm, &curl_timeout);
 649                         if (curl_timeout == 0) {
 650                                 continue;
 651                         } else if (curl_timeout == -1) {
 652                                 select_timeout.tv_sec  = 0;
 653                                 select_timeout.tv_usec = 50000;
 654                         } else {
 655                                 select_timeout.tv_sec  =  curl_timeout / 1000;
 656                                 select_timeout.tv_usec = (curl_timeout % 1000) * 1000;
 657                         }
 658 #else
 659                         select_timeout.tv_sec  = 0;
 660                         select_timeout.tv_usec = 50000;
 661 #endif
 662
 663                         max_fd = -1;
 664                         FD_ZERO(&readfds);
 665                         FD_ZERO(&writefds);
 666                         FD_ZERO(&excfds);
 667                         curl_multi_fdset(curlm, &readfds, &writefds, &excfds, &max_fd);
 668
 669                         /*
 670                          * It can happen that curl_multi_timeout returns a pathologically
 671                          * long timeout when curl_multi_fdset returns no file descriptors
 672                          * to read.  See commit message for more details.
 673                          */
 674                         if (max_fd < 0 &&
 675                             (select_timeout.tv_sec > 0 ||
 676                              select_timeout.tv_usec > 50000)) {
 677                                 select_timeout.tv_sec  = 0;
 678                                 select_timeout.tv_usec = 50000;
 679                         }
 680
 681                         select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
 682                 }
 683         }
 684 #else
 685         while (slot->in_use) {
 686                 slot->curl_result = curl_easy_perform(slot->curl);
 687                 finish_active_slot(slot);
 688         }
 689 #endif
 690 }
 691
 692 static void closedown_active_slot(struct active_request_slot *slot)
 693 {
 694         active_requests--;
 695         slot->in_use = 0;
 696 }
 697
 698 static void release_active_slot(struct active_request_slot *slot)
 699 {
 700         closedown_active_slot(slot);
 701         if (slot->curl && curl_session_count > min_curl_sessions) {
 702 #ifdef USE_CURL_MULTI
 703                 curl_multi_remove_handle(curlm, slot->curl);
 704 #endif
 705                 curl_easy_cleanup(slot->curl);
 706                 slot->curl = NULL;
 707                 curl_session_count--;
 708         }
 709 #ifdef USE_CURL_MULTI
 710         fill_active_slots();
 711 #endif
 712 }
 713
 714 void finish_active_slot(struct active_request_slot *slot)
 715 {
 716         closedown_active_slot(slot);
 717         curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
 718
 719         if (slot->finished != NULL)
 720                 (*slot->finished) = 1;
 721
 722         /* Store slot results so they can be read after the slot is reused */
 723         if (slot->results != NULL) {
 724                 slot->results->curl_result = slot->curl_result;
 725                 slot->results->http_code = slot->http_code;
 726         }
 727
 728         /* Run callback if appropriate */
 729         if (slot->callback_func != NULL)
 730                 slot->callback_func(slot->callback_data);
 731 }
 732
 733 void finish_all_active_slots(void)
 734 {
 735         struct active_request_slot *slot = active_queue_head;
 736
 737         while (slot != NULL)
 738                 if (slot->in_use) {
 739                         run_active_slot(slot);
 740                         slot = active_queue_head;
 741                 } else {
 742                         slot = slot->next;
 743                 }
 744 }
 745
 746 /* Helpers for modifying and creating URLs */
 747 static inline int needs_quote(int ch)
 748 {
 749         if (((ch >= 'A') && (ch <= 'Z'))
 750                         || ((ch >= 'a') && (ch <= 'z'))
 751                         || ((ch >= '0') && (ch <= '9'))
 752                         || (ch == '/')
 753                         || (ch == '-')
 754                         || (ch == '.'))
 755                 return 0;
 756         return 1;
 757 }
 758
 759 static char *quote_ref_url(const char *base, const char *ref)
 760 {
 761         struct strbuf buf = STRBUF_INIT;
 762         const char *cp;
 763         int ch;
 764
 765         end_url_with_slash(&buf, base);
 766
 767         for (cp = ref; (ch = *cp) != 0; cp++)
 768                 if (needs_quote(ch))
 769                         strbuf_addf(&buf, "%%%02x", ch);
 770                 else
 771                         strbuf_addch(&buf, *cp);
 772
 773         return strbuf_detach(&buf, NULL);
 774 }
 775
 776 void append_remote_object_url(struct strbuf *buf, const char *url,
 777                               const char *hex,
 778                               int only_two_digit_prefix)
 779 {
 780         end_url_with_slash(buf, url);
 781
 782         strbuf_addf(buf, "objects/%.*s/", 2, hex);
 783         if (!only_two_digit_prefix)
 784                 strbuf_addf(buf, "%s", hex+2);
 785 }
 786
 787 char *get_remote_object_url(const char *url, const char *hex,
 788                             int only_two_digit_prefix)
 789 {
 790         struct strbuf buf = STRBUF_INIT;
 791         append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
 792         return strbuf_detach(&buf, NULL);
 793 }
 794
 795 int handle_curl_result(struct slot_results *results)
 796 {
 797         /*
 798          * If we see a failing http code with CURLE_OK, we have turned off
 799          * FAILONERROR (to keep the server's custom error response), and should
 800          * translate the code into failure here.
 801          */
 802         if (results->curl_result == CURLE_OK &&
 803             results->http_code >= 400) {
 804                 results->curl_result = CURLE_HTTP_RETURNED_ERROR;
 805                 /*
 806                  * Normally curl will already have put the "reason phrase"
 807                  * from the server into curl_errorstr; unfortunately without
 808                  * FAILONERROR it is lost, so we can give only the numeric
 809                  * status code.
 810                  */
 811                 snprintf(curl_errorstr, sizeof(curl_errorstr),
 812                          "The requested URL returned error: %ld",
 813                          results->http_code);
 814         }
 815
 816         if (results->curl_result == CURLE_OK) {
 817                 credential_approve(&http_auth);
 818                 return HTTP_OK;
 819         } else if (missing_target(results))
 820                 return HTTP_MISSING_TARGET;
 821         else if (results->http_code == 401) {
 822                 if (http_auth.username && http_auth.password) {
 823                         credential_reject(&http_auth);
 824                         return HTTP_NOAUTH;
 825                 } else {
 826                         credential_fill(&http_auth);
 827                         return HTTP_REAUTH;
 828                 }
 829         } else {
 830 #if LIBCURL_VERSION_NUM >= 0x070c00
 831                 if (!curl_errorstr[0])
 832                         strlcpy(curl_errorstr,
 833                                 curl_easy_strerror(results->curl_result),
 834                                 sizeof(curl_errorstr));
 835 #endif
 836                 return HTTP_ERROR;
 837         }
 838 }
 839
 840 /* http_request() targets */
 841 #define HTTP_REQUEST_STRBUF     0
 842 #define HTTP_REQUEST_FILE       1
 843
 844 static int http_request(const char *url, struct strbuf *type,
 845                         void *result, int target, int options)
 846 {
 847         struct active_request_slot *slot;
 848         struct slot_results results;
 849         struct curl_slist *headers = NULL;
 850         struct strbuf buf = STRBUF_INIT;
 851         int ret;
 852
 853         slot = get_active_slot();
 854         slot->results = &results;
 855         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
 856
 857         if (result == NULL) {
 858                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
 859         } else {
 860                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
 861                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
 862
 863                 if (target == HTTP_REQUEST_FILE) {
 864                         long posn = ftell(result);
 865                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
 866                                          fwrite);
 867                         if (posn > 0) {
 868                                 strbuf_addf(&buf, "Range: bytes=%ld-", posn);
 869                                 headers = curl_slist_append(headers, buf.buf);
 870                                 strbuf_reset(&buf);
 871                         }
 872                 } else
 873                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
 874                                          fwrite_buffer);
 875         }
 876
 877         strbuf_addstr(&buf, "Pragma:");
 878         if (options & HTTP_NO_CACHE)
 879                 strbuf_addstr(&buf, " no-cache");
 880         if (options & HTTP_KEEP_ERROR)
 881                 curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
 882
 883         headers = curl_slist_append(headers, buf.buf);
 884
 885         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 886         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
 887         curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
 888
 889         if (start_active_slot(slot)) {
 890                 run_active_slot(slot);
 891                 ret = handle_curl_result(&results);
 892         } else {
 893                 snprintf(curl_errorstr, sizeof(curl_errorstr),
 894                          "failed to start HTTP request");
 895                 ret = HTTP_START_FAILED;
 896         }
 897
 898         if (type) {
 899                 char *t;
 900                 strbuf_reset(type);
 901                 curl_easy_getinfo(slot->curl, CURLINFO_CONTENT_TYPE, &t);
 902                 if (t)
 903                         strbuf_addstr(type, t);
 904         }
 905
 906         curl_slist_free_all(headers);
 907         strbuf_release(&buf);
 908
 909         return ret;
 910 }
 911
 912 static int http_request_reauth(const char *url,
 913                                struct strbuf *type,
 914                                void *result, int target,
 915                                int options)
 916 {
 917         int ret = http_request(url, type, result, target, options);
 918         if (ret != HTTP_REAUTH)
 919                 return ret;
 920
 921         /*
 922          * If we are using KEEP_ERROR, the previous request may have
 923          * put cruft into our output stream; we should clear it out before
 924          * making our next request. We only know how to do this for
 925          * the strbuf case, but that is enough to satisfy current callers.
 926          */
 927         if (options & HTTP_KEEP_ERROR) {
 928                 switch (target) {
 929                 case HTTP_REQUEST_STRBUF:
 930                         strbuf_reset(result);
 931                         break;
 932                 default:
 933                         die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
 934                 }
 935         }
 936         return http_request(url, type, result, target, options);
 937 }
 938
 939 int http_get_strbuf(const char *url,
 940                     struct strbuf *type,
 941                     struct strbuf *result, int options)
 942 {
 943         return http_request_reauth(url, type, result,
 944                                    HTTP_REQUEST_STRBUF, options);
 945 }
 946
 947 /*
 948  * Downloads a URL and stores the result in the given file.
 949  *
 950  * If a previous interrupted download is detected (i.e. a previous temporary
 951  * file is still around) the download is resumed.
 952  */
 953 static int http_get_file(const char *url, const char *filename, int options)
 954 {
 955         int ret;
 956         struct strbuf tmpfile = STRBUF_INIT;
 957         FILE *result;
 958
 959         strbuf_addf(&tmpfile, "%s.temp", filename);
 960         result = fopen(tmpfile.buf, "a");
 961         if (! result) {
 962                 error("Unable to open local file %s", tmpfile.buf);
 963                 ret = HTTP_ERROR;
 964                 goto cleanup;
 965         }
 966
 967         ret = http_request_reauth(url, NULL, result, HTTP_REQUEST_FILE, options);
 968         fclose(result);
 969
 970         if ((ret == HTTP_OK) && move_temp_to_file(tmpfile.buf, filename))
 971                 ret = HTTP_ERROR;
 972 cleanup:
 973         strbuf_release(&tmpfile);
 974         return ret;
 975 }
 976
 977 int http_fetch_ref(const char *base, struct ref *ref)
 978 {
 979         char *url;
 980         struct strbuf buffer = STRBUF_INIT;
 981         int ret = -1;
 982
 983         url = quote_ref_url(base, ref->name);
 984         if (http_get_strbuf(url, NULL, &buffer, HTTP_NO_CACHE) == HTTP_OK) {
 985                 strbuf_rtrim(&buffer);
 986                 if (buffer.len == 40)
 987                         ret = get_sha1_hex(buffer.buf, ref->old_sha1);
 988                 else if (!prefixcmp(buffer.buf, "ref: ")) {
 989                         ref->symref = xstrdup(buffer.buf + 5);
 990                         ret = 0;
 991                 }
 992         }
 993
 994         strbuf_release(&buffer);
 995         free(url);
 996         return ret;
 997 }
 998
 999 /* Helpers for fetching packs */
1000 static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
1001 {
1002         char *url, *tmp;
1003         struct strbuf buf = STRBUF_INIT;
1004
1005         if (http_is_verbose)
1006                 fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
1007
1008         end_url_with_slash(&buf, base_url);
1009         strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
1010         url = strbuf_detach(&buf, NULL);
1011
1012         strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
1013         tmp = strbuf_detach(&buf, NULL);
1014
1015         if (http_get_file(url, tmp, 0) != HTTP_OK) {
1016                 error("Unable to get pack index %s", url);
1017                 free(tmp);
1018                 tmp = NULL;
1019         }
1020
1021         free(url);
1022         return tmp;
1023 }
1024
1025 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
1026         unsigned char *sha1, const char *base_url)
1027 {
1028         struct packed_git *new_pack;
1029         char *tmp_idx = NULL;
1030         int ret;
1031
1032         if (has_pack_index(sha1)) {
1033                 new_pack = parse_pack_index(sha1, NULL);
1034                 if (!new_pack)
1035                         return -1; /* parse_pack_index() already issued error message */
1036                 goto add_pack;
1037         }
1038
1039         tmp_idx = fetch_pack_index(sha1, base_url);
1040         if (!tmp_idx)
1041                 return -1;
1042
1043         new_pack = parse_pack_index(sha1, tmp_idx);
1044         if (!new_pack) {
1045                 unlink(tmp_idx);
1046                 free(tmp_idx);
1047
1048                 return -1; /* parse_pack_index() already issued error message */
1049         }
1050
1051         ret = verify_pack_index(new_pack);
1052         if (!ret) {
1053                 close_pack_index(new_pack);
1054                 ret = move_temp_to_file(tmp_idx, sha1_pack_index_name(sha1));
1055         }
1056         free(tmp_idx);
1057         if (ret)
1058                 return -1;
1059
1060 add_pack:
1061         new_pack->next = *packs_head;
1062         *packs_head = new_pack;
1063         return 0;
1064 }
1065
1066 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
1067 {
1068         int ret = 0, i = 0;
1069         char *url, *data;
1070         struct strbuf buf = STRBUF_INIT;
1071         unsigned char sha1[20];
1072
1073         end_url_with_slash(&buf, base_url);
1074         strbuf_addstr(&buf, "objects/info/packs");
1075         url = strbuf_detach(&buf, NULL);
1076
1077         ret = http_get_strbuf(url, NULL, &buf, HTTP_NO_CACHE);
1078         if (ret != HTTP_OK)
1079                 goto cleanup;
1080
1081         data = buf.buf;
1082         while (i < buf.len) {
1083                 switch (data[i]) {
1084                 case 'P':
1085                         i++;
1086                         if (i + 52 <= buf.len &&
1087                             !prefixcmp(data + i, " pack-") &&
1088                             !prefixcmp(data + i + 46, ".pack\n")) {
1089                                 get_sha1_hex(data + i + 6, sha1);
1090                                 fetch_and_setup_pack_index(packs_head, sha1,
1091                                                       base_url);
1092                                 i += 51;
1093                                 break;
1094                         }
1095                 default:
1096                         while (i < buf.len && data[i] != '\n')
1097                                 i++;
1098                 }
1099                 i++;
1100         }
1101
1102 cleanup:
1103         free(url);
1104         return ret;
1105 }
1106
1107 void release_http_pack_request(struct http_pack_request *preq)
1108 {
1109         if (preq->packfile != NULL) {
1110                 fclose(preq->packfile);
1111                 preq->packfile = NULL;
1112         }
1113         if (preq->range_header != NULL) {
1114                 curl_slist_free_all(preq->range_header);
1115                 preq->range_header = NULL;
1116         }
1117         preq->slot = NULL;
1118         free(preq->url);
1119 }
1120
1121 int finish_http_pack_request(struct http_pack_request *preq)
1122 {
1123         struct packed_git **lst;
1124         struct packed_git *p = preq->target;
1125         char *tmp_idx;
1126         struct child_process ip;
1127         const char *ip_argv[8];
1128
1129         close_pack_index(p);
1130
1131         fclose(preq->packfile);
1132         preq->packfile = NULL;
1133
1134         lst = preq->lst;
1135         while (*lst != p)
1136                 lst = &((*lst)->next);
1137         *lst = (*lst)->next;
1138
1139         tmp_idx = xstrdup(preq->tmpfile);
1140         strcpy(tmp_idx + strlen(tmp_idx) - strlen(".pack.temp"),
1141                ".idx.temp");
1142
1143         ip_argv[0] = "index-pack";
1144         ip_argv[1] = "-o";
1145         ip_argv[2] = tmp_idx;
1146         ip_argv[3] = preq->tmpfile;
1147         ip_argv[4] = NULL;
1148
1149         memset(&ip, 0, sizeof(ip));
1150         ip.argv = ip_argv;
1151         ip.git_cmd = 1;
1152         ip.no_stdin = 1;
1153         ip.no_stdout = 1;
1154
1155         if (run_command(&ip)) {
1156                 unlink(preq->tmpfile);
1157                 unlink(tmp_idx);
1158                 free(tmp_idx);
1159                 return -1;
1160         }
1161
1162         unlink(sha1_pack_index_name(p->sha1));
1163
1164         if (move_temp_to_file(preq->tmpfile, sha1_pack_name(p->sha1))
1165          || move_temp_to_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
1166                 free(tmp_idx);
1167                 return -1;
1168         }
1169
1170         install_packed_git(p);
1171         free(tmp_idx);
1172         return 0;
1173 }
1174
1175 struct http_pack_request *new_http_pack_request(
1176         struct packed_git *target, const char *base_url)
1177 {
1178         long prev_posn = 0;
1179         char range[RANGE_HEADER_SIZE];
1180         struct strbuf buf = STRBUF_INIT;
1181         struct http_pack_request *preq;
1182
1183         preq = xcalloc(1, sizeof(*preq));
1184         preq->target = target;
1185
1186         end_url_with_slash(&buf, base_url);
1187         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
1188                 sha1_to_hex(target->sha1));
1189         preq->url = strbuf_detach(&buf, NULL);
1190
1191         snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
1192                 sha1_pack_name(target->sha1));
1193         preq->packfile = fopen(preq->tmpfile, "a");
1194         if (!preq->packfile) {
1195                 error("Unable to open local file %s for pack",
1196                       preq->tmpfile);
1197                 goto abort;
1198         }
1199
1200         preq->slot = get_active_slot();
1201         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
1202         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
1203         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
1204         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1205                 no_pragma_header);
1206
1207         /*
1208          * If there is data present from a previous transfer attempt,
1209          * resume where it left off
1210          */
1211         prev_posn = ftell(preq->packfile);
1212         if (prev_posn>0) {
1213                 if (http_is_verbose)
1214                         fprintf(stderr,
1215                                 "Resuming fetch of pack %s at byte %ld\n",
1216                                 sha1_to_hex(target->sha1), prev_posn);
1217                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1218                 preq->range_header = curl_slist_append(NULL, range);
1219                 curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1220                         preq->range_header);
1221         }
1222
1223         return preq;
1224
1225 abort:
1226         free(preq->url);
1227         free(preq);
1228         return NULL;
1229 }
1230
1231 /* Helpers for fetching objects (loose) */
1232 static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
1233                                void *data)
1234 {
1235         unsigned char expn[4096];
1236         size_t size = eltsize * nmemb;
1237         int posn = 0;
1238         struct http_object_request *freq =
1239                 (struct http_object_request *)data;
1240         do {
1241                 ssize_t retval = xwrite(freq->localfile,
1242                                         (char *) ptr + posn, size - posn);
1243                 if (retval < 0)
1244                         return posn;
1245                 posn += retval;
1246         } while (posn < size);
1247
1248         freq->stream.avail_in = size;
1249         freq->stream.next_in = (void *)ptr;
1250         do {
1251                 freq->stream.next_out = expn;
1252                 freq->stream.avail_out = sizeof(expn);
1253                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
1254                 git_SHA1_Update(&freq->c, expn,
1255                                 sizeof(expn) - freq->stream.avail_out);
1256         } while (freq->stream.avail_in && freq->zret == Z_OK);
1257         return size;
1258 }
1259
1260 struct http_object_request *new_http_object_request(const char *base_url,
1261         unsigned char *sha1)
1262 {
1263         char *hex = sha1_to_hex(sha1);
1264         char *filename;
1265         char prevfile[PATH_MAX];
1266         int prevlocal;
1267         char prev_buf[PREV_BUF_SIZE];
1268         ssize_t prev_read = 0;
1269         long prev_posn = 0;
1270         char range[RANGE_HEADER_SIZE];
1271         struct curl_slist *range_header = NULL;
1272         struct http_object_request *freq;
1273
1274         freq = xcalloc(1, sizeof(*freq));
1275         hashcpy(freq->sha1, sha1);
1276         freq->localfile = -1;
1277
1278         filename = sha1_file_name(sha1);
1279         snprintf(freq->tmpfile, sizeof(freq->tmpfile),
1280                  "%s.temp", filename);
1281
1282         snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
1283         unlink_or_warn(prevfile);
1284         rename(freq->tmpfile, prevfile);
1285         unlink_or_warn(freq->tmpfile);
1286
1287         if (freq->localfile != -1)
1288                 error("fd leakage in start: %d", freq->localfile);
1289         freq->localfile = open(freq->tmpfile,
1290                                O_WRONLY | O_CREAT | O_EXCL, 0666);
1291         /*
1292          * This could have failed due to the "lazy directory creation";
1293          * try to mkdir the last path component.
1294          */
1295         if (freq->localfile < 0 && errno == ENOENT) {
1296                 char *dir = strrchr(freq->tmpfile, '/');
1297                 if (dir) {
1298                         *dir = 0;
1299                         mkdir(freq->tmpfile, 0777);
1300                         *dir = '/';
1301                 }
1302                 freq->localfile = open(freq->tmpfile,
1303                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
1304         }
1305
1306         if (freq->localfile < 0) {
1307                 error("Couldn't create temporary file %s: %s",
1308                       freq->tmpfile, strerror(errno));
1309                 goto abort;
1310         }
1311
1312         git_inflate_init(&freq->stream);
1313
1314         git_SHA1_Init(&freq->c);
1315
1316         freq->url = get_remote_object_url(base_url, hex, 0);
1317
1318         /*
1319          * If a previous temp file is present, process what was already
1320          * fetched.
1321          */
1322         prevlocal = open(prevfile, O_RDONLY);
1323         if (prevlocal != -1) {
1324                 do {
1325                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
1326                         if (prev_read>0) {
1327                                 if (fwrite_sha1_file(prev_buf,
1328                                                      1,
1329                                                      prev_read,
1330                                                      freq) == prev_read) {
1331                                         prev_posn += prev_read;
1332                                 } else {
1333                                         prev_read = -1;
1334                                 }
1335                         }
1336                 } while (prev_read > 0);
1337                 close(prevlocal);
1338         }
1339         unlink_or_warn(prevfile);
1340
1341         /*
1342          * Reset inflate/SHA1 if there was an error reading the previous temp
1343          * file; also rewind to the beginning of the local file.
1344          */
1345         if (prev_read == -1) {
1346                 memset(&freq->stream, 0, sizeof(freq->stream));
1347                 git_inflate_init(&freq->stream);
1348                 git_SHA1_Init(&freq->c);
1349                 if (prev_posn>0) {
1350                         prev_posn = 0;
1351                         lseek(freq->localfile, 0, SEEK_SET);
1352                         if (ftruncate(freq->localfile, 0) < 0) {
1353                                 error("Couldn't truncate temporary file %s: %s",
1354                                           freq->tmpfile, strerror(errno));
1355                                 goto abort;
1356                         }
1357                 }
1358         }
1359
1360         freq->slot = get_active_slot();
1361
1362         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
1363         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
1364         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
1365         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
1366         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
1367
1368         /*
1369          * If we have successfully processed data from a previous fetch
1370          * attempt, only fetch the data we don't already have.
1371          */
1372         if (prev_posn>0) {
1373                 if (http_is_verbose)
1374                         fprintf(stderr,
1375                                 "Resuming fetch of object %s at byte %ld\n",
1376                                 hex, prev_posn);
1377                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1378                 range_header = curl_slist_append(range_header, range);
1379                 curl_easy_setopt(freq->slot->curl,
1380                                  CURLOPT_HTTPHEADER, range_header);
1381         }
1382
1383         return freq;
1384
1385 abort:
1386         free(freq->url);
1387         free(freq);
1388         return NULL;
1389 }
1390
1391 void process_http_object_request(struct http_object_request *freq)
1392 {
1393         if (freq->slot == NULL)
1394                 return;
1395         freq->curl_result = freq->slot->curl_result;
1396         freq->http_code = freq->slot->http_code;
1397         freq->slot = NULL;
1398 }
1399
1400 int finish_http_object_request(struct http_object_request *freq)
1401 {
1402         struct stat st;
1403
1404         close(freq->localfile);
1405         freq->localfile = -1;
1406
1407         process_http_object_request(freq);
1408
1409         if (freq->http_code == 416) {
1410                 warning("requested range invalid; we may already have all the data.");
1411         } else if (freq->curl_result != CURLE_OK) {
1412                 if (stat(freq->tmpfile, &st) == 0)
1413                         if (st.st_size == 0)
1414                                 unlink_or_warn(freq->tmpfile);
1415                 return -1;
1416         }
1417
1418         git_inflate_end(&freq->stream);
1419         git_SHA1_Final(freq->real_sha1, &freq->c);
1420         if (freq->zret != Z_STREAM_END) {
1421                 unlink_or_warn(freq->tmpfile);
1422                 return -1;
1423         }
1424         if (hashcmp(freq->sha1, freq->real_sha1)) {
1425                 unlink_or_warn(freq->tmpfile);
1426                 return -1;
1427         }
1428         freq->rename =
1429                 move_temp_to_file(freq->tmpfile, sha1_file_name(freq->sha1));
1430
1431         return freq->rename;
1432 }
1433
1434 void abort_http_object_request(struct http_object_request *freq)
1435 {
1436         unlink_or_warn(freq->tmpfile);
1437
1438         release_http_object_request(freq);
1439 }
1440
1441 void release_http_object_request(struct http_object_request *freq)
1442 {
1443         if (freq->localfile != -1) {
1444                 close(freq->localfile);
1445                 freq->localfile = -1;
1446         }
1447         if (freq->url != NULL) {
1448                 free(freq->url);
1449                 freq->url = NULL;
1450         }
1451         if (freq->slot != NULL) {
1452                 freq->slot->callback_func = NULL;
1453                 freq->slot->callback_data = NULL;
1454                 release_active_slot(freq->slot);
1455                 freq->slot = NULL;
1456         }
1457 }