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