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 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 #if LIBCURL_VERSION_NUM >= 0x071900
 264 static void set_curl_keepalive(CURL *c)
 265 {
 266         curl_easy_setopt(c, CURLOPT_TCP_KEEPALIVE, 1);
 267 }
 268
 269 #elif LIBCURL_VERSION_NUM >= 0x071000
 270 static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
 271 {
 272         int ka = 1;
 273         int rc;
 274         socklen_t len = (socklen_t)sizeof(ka);
 275
 276         if (type != CURLSOCKTYPE_IPCXN)
 277                 return 0;
 278
 279         rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
 280         if (rc < 0)
 281                 warning("unable to set SO_KEEPALIVE on socket %s",
 282                         strerror(errno));
 283
 284         return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
 285 }
 286
 287 static void set_curl_keepalive(CURL *c)
 288 {
 289         curl_easy_setopt(c, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
 290 }
 291
 292 #else
 293 static void set_curl_keepalive(CURL *c)
 294 {
 295         /* not supported on older curl versions */
 296 }
 297 #endif
 298
 299 static CURL *get_curl_handle(void)
 300 {
 301         CURL *result = curl_easy_init();
 302
 303         if (!result)
 304                 die("curl_easy_init failed");
 305
 306         if (!curl_ssl_verify) {
 307                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
 308                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
 309         } else {
 310                 /* Verify authenticity of the peer's certificate */
 311                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
 312                 /* The name in the cert must match whom we tried to connect */
 313                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
 314         }
 315
 316 #if LIBCURL_VERSION_NUM >= 0x070907
 317         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
 318 #endif
 319 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 320         curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
 321 #endif
 322
 323         if (http_proactive_auth)
 324                 init_curl_http_auth(result);
 325
 326         if (ssl_cert != NULL)
 327                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
 328         if (has_cert_password())
 329                 curl_easy_setopt(result, CURLOPT_KEYPASSWD, cert_auth.password);
 330 #if LIBCURL_VERSION_NUM >= 0x070903
 331         if (ssl_key != NULL)
 332                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
 333 #endif
 334 #if LIBCURL_VERSION_NUM >= 0x070908
 335         if (ssl_capath != NULL)
 336                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
 337 #endif
 338         if (ssl_cainfo != NULL)
 339                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
 340
 341         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
 342                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
 343                                  curl_low_speed_limit);
 344                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
 345                                  curl_low_speed_time);
 346         }
 347
 348         curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
 349 #if LIBCURL_VERSION_NUM >= 0x071301
 350         curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
 351 #elif LIBCURL_VERSION_NUM >= 0x071101
 352         curl_easy_setopt(result, CURLOPT_POST301, 1);
 353 #endif
 354
 355         if (getenv("GIT_CURL_VERBOSE"))
 356                 curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
 357
 358         curl_easy_setopt(result, CURLOPT_USERAGENT,
 359                 user_agent ? user_agent : git_user_agent());
 360
 361         if (curl_ftp_no_epsv)
 362                 curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
 363
 364 #ifdef CURLOPT_USE_SSL
 365         if (curl_ssl_try)
 366                 curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
 367 #endif
 368
 369         if (curl_http_proxy) {
 370                 curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
 371                 curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
 372         }
 373
 374         set_curl_keepalive(result);
 375
 376         return result;
 377 }
 378
 379 static void set_from_env(const char **var, const char *envname)
 380 {
 381         const char *val = getenv(envname);
 382         if (val)
 383                 *var = val;
 384 }
 385
 386 void http_init(struct remote *remote, const char *url, int proactive_auth)
 387 {
 388         char *low_speed_limit;
 389         char *low_speed_time;
 390         char *normalized_url;
 391         struct urlmatch_config config = { STRING_LIST_INIT_DUP };
 392
 393         config.section = "http";
 394         config.key = NULL;
 395         config.collect_fn = http_options;
 396         config.cascade_fn = git_default_config;
 397         config.cb = NULL;
 398
 399         http_is_verbose = 0;
 400         normalized_url = url_normalize(url, &config.url);
 401
 402         git_config(urlmatch_config_entry, &config);
 403         free(normalized_url);
 404
 405         if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK)
 406                 die("curl_global_init failed");
 407
 408         http_proactive_auth = proactive_auth;
 409
 410         if (remote && remote->http_proxy)
 411                 curl_http_proxy = xstrdup(remote->http_proxy);
 412
 413         pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
 414         no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
 415
 416 #ifdef USE_CURL_MULTI
 417         {
 418                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
 419                 if (http_max_requests != NULL)
 420                         max_requests = atoi(http_max_requests);
 421         }
 422
 423         curlm = curl_multi_init();
 424         if (curlm == NULL) {
 425                 fprintf(stderr, "Error creating curl multi handle.\n");
 426                 exit(1);
 427         }
 428 #endif
 429
 430         if (getenv("GIT_SSL_NO_VERIFY"))
 431                 curl_ssl_verify = 0;
 432
 433         set_from_env(&ssl_cert, "GIT_SSL_CERT");
 434 #if LIBCURL_VERSION_NUM >= 0x070903
 435         set_from_env(&ssl_key, "GIT_SSL_KEY");
 436 #endif
 437 #if LIBCURL_VERSION_NUM >= 0x070908
 438         set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
 439 #endif
 440         set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
 441
 442         set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");
 443
 444         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
 445         if (low_speed_limit != NULL)
 446                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
 447         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
 448         if (low_speed_time != NULL)
 449                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
 450
 451         if (curl_ssl_verify == -1)
 452                 curl_ssl_verify = 1;
 453
 454         curl_session_count = 0;
 455 #ifdef USE_CURL_MULTI
 456         if (max_requests < 1)
 457                 max_requests = DEFAULT_MAX_REQUESTS;
 458 #endif
 459
 460         if (getenv("GIT_CURL_FTP_NO_EPSV"))
 461                 curl_ftp_no_epsv = 1;
 462
 463         if (url) {
 464                 credential_from_url(&http_auth, url);
 465                 if (!ssl_cert_password_required &&
 466                     getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
 467                     starts_with(url, "https://"))
 468                         ssl_cert_password_required = 1;
 469         }
 470
 471 #ifndef NO_CURL_EASY_DUPHANDLE
 472         curl_default = get_curl_handle();
 473 #endif
 474 }
 475
 476 void http_cleanup(void)
 477 {
 478         struct active_request_slot *slot = active_queue_head;
 479
 480         while (slot != NULL) {
 481                 struct active_request_slot *next = slot->next;
 482                 if (slot->curl != NULL) {
 483 #ifdef USE_CURL_MULTI
 484                         curl_multi_remove_handle(curlm, slot->curl);
 485 #endif
 486                         curl_easy_cleanup(slot->curl);
 487                 }
 488                 free(slot);
 489                 slot = next;
 490         }
 491         active_queue_head = NULL;
 492
 493 #ifndef NO_CURL_EASY_DUPHANDLE
 494         curl_easy_cleanup(curl_default);
 495 #endif
 496
 497 #ifdef USE_CURL_MULTI
 498         curl_multi_cleanup(curlm);
 499 #endif
 500         curl_global_cleanup();
 501
 502         curl_slist_free_all(pragma_header);
 503         pragma_header = NULL;
 504
 505         curl_slist_free_all(no_pragma_header);
 506         no_pragma_header = NULL;
 507
 508         if (curl_http_proxy) {
 509                 free((void *)curl_http_proxy);
 510                 curl_http_proxy = NULL;
 511         }
 512
 513         if (cert_auth.password != NULL) {
 514                 memset(cert_auth.password, 0, strlen(cert_auth.password));
 515                 free(cert_auth.password);
 516                 cert_auth.password = NULL;
 517         }
 518         ssl_cert_password_required = 0;
 519 }
 520
 521 struct active_request_slot *get_active_slot(void)
 522 {
 523         struct active_request_slot *slot = active_queue_head;
 524         struct active_request_slot *newslot;
 525
 526 #ifdef USE_CURL_MULTI
 527         int num_transfers;
 528
 529         /* Wait for a slot to open up if the queue is full */
 530         while (active_requests >= max_requests) {
 531                 curl_multi_perform(curlm, &num_transfers);
 532                 if (num_transfers < active_requests)
 533                         process_curl_messages();
 534         }
 535 #endif
 536
 537         while (slot != NULL && slot->in_use)
 538                 slot = slot->next;
 539
 540         if (slot == NULL) {
 541                 newslot = xmalloc(sizeof(*newslot));
 542                 newslot->curl = NULL;
 543                 newslot->in_use = 0;
 544                 newslot->next = NULL;
 545
 546                 slot = active_queue_head;
 547                 if (slot == NULL) {
 548                         active_queue_head = newslot;
 549                 } else {
 550                         while (slot->next != NULL)
 551                                 slot = slot->next;
 552                         slot->next = newslot;
 553                 }
 554                 slot = newslot;
 555         }
 556
 557         if (slot->curl == NULL) {
 558 #ifdef NO_CURL_EASY_DUPHANDLE
 559                 slot->curl = get_curl_handle();
 560 #else
 561                 slot->curl = curl_easy_duphandle(curl_default);
 562 #endif
 563                 curl_session_count++;
 564         }
 565
 566         active_requests++;
 567         slot->in_use = 1;
 568         slot->results = NULL;
 569         slot->finished = NULL;
 570         slot->callback_data = NULL;
 571         slot->callback_func = NULL;
 572         curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file);
 573         if (curl_save_cookies)
 574                 curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file);
 575         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
 576         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
 577         curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
 578         curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
 579         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
 580         curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
 581         curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
 582         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
 583         curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
 584         if (http_auth.password)
 585                 init_curl_http_auth(slot->curl);
 586
 587         return slot;
 588 }
 589
 590 int start_active_slot(struct active_request_slot *slot)
 591 {
 592 #ifdef USE_CURL_MULTI
 593         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
 594         int num_transfers;
 595
 596         if (curlm_result != CURLM_OK &&
 597             curlm_result != CURLM_CALL_MULTI_PERFORM) {
 598                 active_requests--;
 599                 slot->in_use = 0;
 600                 return 0;
 601         }
 602
 603         /*
 604          * We know there must be something to do, since we just added
 605          * something.
 606          */
 607         curl_multi_perform(curlm, &num_transfers);
 608 #endif
 609         return 1;
 610 }
 611
 612 #ifdef USE_CURL_MULTI
 613 struct fill_chain {
 614         void *data;
 615         int (*fill)(void *);
 616         struct fill_chain *next;
 617 };
 618
 619 static struct fill_chain *fill_cfg;
 620
 621 void add_fill_function(void *data, int (*fill)(void *))
 622 {
 623         struct fill_chain *new = xmalloc(sizeof(*new));
 624         struct fill_chain **linkp = &fill_cfg;
 625         new->data = data;
 626         new->fill = fill;
 627         new->next = NULL;
 628         while (*linkp)
 629                 linkp = &(*linkp)->next;
 630         *linkp = new;
 631 }
 632
 633 void fill_active_slots(void)
 634 {
 635         struct active_request_slot *slot = active_queue_head;
 636
 637         while (active_requests < max_requests) {
 638                 struct fill_chain *fill;
 639                 for (fill = fill_cfg; fill; fill = fill->next)
 640                         if (fill->fill(fill->data))
 641                                 break;
 642
 643                 if (!fill)
 644                         break;
 645         }
 646
 647         while (slot != NULL) {
 648                 if (!slot->in_use && slot->curl != NULL
 649                         && curl_session_count > min_curl_sessions) {
 650                         curl_easy_cleanup(slot->curl);
 651                         slot->curl = NULL;
 652                         curl_session_count--;
 653                 }
 654                 slot = slot->next;
 655         }
 656 }
 657
 658 void step_active_slots(void)
 659 {
 660         int num_transfers;
 661         CURLMcode curlm_result;
 662
 663         do {
 664                 curlm_result = curl_multi_perform(curlm, &num_transfers);
 665         } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
 666         if (num_transfers < active_requests) {
 667                 process_curl_messages();
 668                 fill_active_slots();
 669         }
 670 }
 671 #endif
 672
 673 void run_active_slot(struct active_request_slot *slot)
 674 {
 675 #ifdef USE_CURL_MULTI
 676         fd_set readfds;
 677         fd_set writefds;
 678         fd_set excfds;
 679         int max_fd;
 680         struct timeval select_timeout;
 681         int finished = 0;
 682
 683         slot->finished = &finished;
 684         while (!finished) {
 685                 step_active_slots();
 686
 687                 if (slot->in_use) {
 688 #if LIBCURL_VERSION_NUM >= 0x070f04
 689                         long curl_timeout;
 690                         curl_multi_timeout(curlm, &curl_timeout);
 691                         if (curl_timeout == 0) {
 692                                 continue;
 693                         } else if (curl_timeout == -1) {
 694                                 select_timeout.tv_sec  = 0;
 695                                 select_timeout.tv_usec = 50000;
 696                         } else {
 697                                 select_timeout.tv_sec  =  curl_timeout / 1000;
 698                                 select_timeout.tv_usec = (curl_timeout % 1000) * 1000;
 699                         }
 700 #else
 701                         select_timeout.tv_sec  = 0;
 702                         select_timeout.tv_usec = 50000;
 703 #endif
 704
 705                         max_fd = -1;
 706                         FD_ZERO(&readfds);
 707                         FD_ZERO(&writefds);
 708                         FD_ZERO(&excfds);
 709                         curl_multi_fdset(curlm, &readfds, &writefds, &excfds, &max_fd);
 710
 711                         /*
 712                          * It can happen that curl_multi_timeout returns a pathologically
 713                          * long timeout when curl_multi_fdset returns no file descriptors
 714                          * to read.  See commit message for more details.
 715                          */
 716                         if (max_fd < 0 &&
 717                             (select_timeout.tv_sec > 0 ||
 718                              select_timeout.tv_usec > 50000)) {
 719                                 select_timeout.tv_sec  = 0;
 720                                 select_timeout.tv_usec = 50000;
 721                         }
 722
 723                         select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
 724                 }
 725         }
 726 #else
 727         while (slot->in_use) {
 728                 slot->curl_result = curl_easy_perform(slot->curl);
 729                 finish_active_slot(slot);
 730         }
 731 #endif
 732 }
 733
 734 static void closedown_active_slot(struct active_request_slot *slot)
 735 {
 736         active_requests--;
 737         slot->in_use = 0;
 738 }
 739
 740 static void release_active_slot(struct active_request_slot *slot)
 741 {
 742         closedown_active_slot(slot);
 743         if (slot->curl && curl_session_count > min_curl_sessions) {
 744 #ifdef USE_CURL_MULTI
 745                 curl_multi_remove_handle(curlm, slot->curl);
 746 #endif
 747                 curl_easy_cleanup(slot->curl);
 748                 slot->curl = NULL;
 749                 curl_session_count--;
 750         }
 751 #ifdef USE_CURL_MULTI
 752         fill_active_slots();
 753 #endif
 754 }
 755
 756 void finish_active_slot(struct active_request_slot *slot)
 757 {
 758         closedown_active_slot(slot);
 759         curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
 760
 761         if (slot->finished != NULL)
 762                 (*slot->finished) = 1;
 763
 764         /* Store slot results so they can be read after the slot is reused */
 765         if (slot->results != NULL) {
 766                 slot->results->curl_result = slot->curl_result;
 767                 slot->results->http_code = slot->http_code;
 768 #if LIBCURL_VERSION_NUM >= 0x070a08
 769                 curl_easy_getinfo(slot->curl, CURLINFO_HTTPAUTH_AVAIL,
 770                                   &slot->results->auth_avail);
 771 #else
 772                 slot->results->auth_avail = 0;
 773 #endif
 774         }
 775
 776         /* Run callback if appropriate */
 777         if (slot->callback_func != NULL)
 778                 slot->callback_func(slot->callback_data);
 779 }
 780
 781 void finish_all_active_slots(void)
 782 {
 783         struct active_request_slot *slot = active_queue_head;
 784
 785         while (slot != NULL)
 786                 if (slot->in_use) {
 787                         run_active_slot(slot);
 788                         slot = active_queue_head;
 789                 } else {
 790                         slot = slot->next;
 791                 }
 792 }
 793
 794 /* Helpers for modifying and creating URLs */
 795 static inline int needs_quote(int ch)
 796 {
 797         if (((ch >= 'A') && (ch <= 'Z'))
 798                         || ((ch >= 'a') && (ch <= 'z'))
 799                         || ((ch >= '0') && (ch <= '9'))
 800                         || (ch == '/')
 801                         || (ch == '-')
 802                         || (ch == '.'))
 803                 return 0;
 804         return 1;
 805 }
 806
 807 static char *quote_ref_url(const char *base, const char *ref)
 808 {
 809         struct strbuf buf = STRBUF_INIT;
 810         const char *cp;
 811         int ch;
 812
 813         end_url_with_slash(&buf, base);
 814
 815         for (cp = ref; (ch = *cp) != 0; cp++)
 816                 if (needs_quote(ch))
 817                         strbuf_addf(&buf, "%%%02x", ch);
 818                 else
 819                         strbuf_addch(&buf, *cp);
 820
 821         return strbuf_detach(&buf, NULL);
 822 }
 823
 824 void append_remote_object_url(struct strbuf *buf, const char *url,
 825                               const char *hex,
 826                               int only_two_digit_prefix)
 827 {
 828         end_url_with_slash(buf, url);
 829
 830         strbuf_addf(buf, "objects/%.*s/", 2, hex);
 831         if (!only_two_digit_prefix)
 832                 strbuf_addf(buf, "%s", hex+2);
 833 }
 834
 835 char *get_remote_object_url(const char *url, const char *hex,
 836                             int only_two_digit_prefix)
 837 {
 838         struct strbuf buf = STRBUF_INIT;
 839         append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
 840         return strbuf_detach(&buf, NULL);
 841 }
 842
 843 int handle_curl_result(struct slot_results *results)
 844 {
 845         /*
 846          * If we see a failing http code with CURLE_OK, we have turned off
 847          * FAILONERROR (to keep the server's custom error response), and should
 848          * translate the code into failure here.
 849          */
 850         if (results->curl_result == CURLE_OK &&
 851             results->http_code >= 400) {
 852                 results->curl_result = CURLE_HTTP_RETURNED_ERROR;
 853                 /*
 854                  * Normally curl will already have put the "reason phrase"
 855                  * from the server into curl_errorstr; unfortunately without
 856                  * FAILONERROR it is lost, so we can give only the numeric
 857                  * status code.
 858                  */
 859                 snprintf(curl_errorstr, sizeof(curl_errorstr),
 860                          "The requested URL returned error: %ld",
 861                          results->http_code);
 862         }
 863
 864         if (results->curl_result == CURLE_OK) {
 865                 credential_approve(&http_auth);
 866                 return HTTP_OK;
 867         } else if (missing_target(results))
 868                 return HTTP_MISSING_TARGET;
 869         else if (results->http_code == 401) {
 870                 if (http_auth.username && http_auth.password) {
 871                         credential_reject(&http_auth);
 872                         return HTTP_NOAUTH;
 873                 } else {
 874                         return HTTP_REAUTH;
 875                 }
 876         } else {
 877 #if LIBCURL_VERSION_NUM >= 0x070c00
 878                 if (!curl_errorstr[0])
 879                         strlcpy(curl_errorstr,
 880                                 curl_easy_strerror(results->curl_result),
 881                                 sizeof(curl_errorstr));
 882 #endif
 883                 return HTTP_ERROR;
 884         }
 885 }
 886
 887 int run_one_slot(struct active_request_slot *slot,
 888                  struct slot_results *results)
 889 {
 890         slot->results = results;
 891         if (!start_active_slot(slot)) {
 892                 snprintf(curl_errorstr, sizeof(curl_errorstr),
 893                          "failed to start HTTP request");
 894                 return HTTP_START_FAILED;
 895         }
 896
 897         run_active_slot(slot);
 898         return handle_curl_result(results);
 899 }
 900
 901 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
 902 {
 903         char *ptr;
 904         CURLcode ret;
 905
 906         strbuf_reset(buf);
 907         ret = curl_easy_getinfo(curl, info, &ptr);
 908         if (!ret && ptr)
 909                 strbuf_addstr(buf, ptr);
 910         return ret;
 911 }
 912
 913 /* http_request() targets */
 914 #define HTTP_REQUEST_STRBUF     0
 915 #define HTTP_REQUEST_FILE       1
 916
 917 static int http_request(const char *url,
 918                         void *result, int target,
 919                         const struct http_get_options *options)
 920 {
 921         struct active_request_slot *slot;
 922         struct slot_results results;
 923         struct curl_slist *headers = NULL;
 924         struct strbuf buf = STRBUF_INIT;
 925         int ret;
 926
 927         slot = get_active_slot();
 928         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
 929
 930         if (result == NULL) {
 931                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
 932         } else {
 933                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
 934                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
 935
 936                 if (target == HTTP_REQUEST_FILE) {
 937                         long posn = ftell(result);
 938                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
 939                                          fwrite);
 940                         if (posn > 0) {
 941                                 strbuf_addf(&buf, "Range: bytes=%ld-", posn);
 942                                 headers = curl_slist_append(headers, buf.buf);
 943                                 strbuf_reset(&buf);
 944                         }
 945                 } else
 946                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
 947                                          fwrite_buffer);
 948         }
 949
 950         strbuf_addstr(&buf, "Pragma:");
 951         if (options && options->no_cache)
 952                 strbuf_addstr(&buf, " no-cache");
 953         if (options && options->keep_error)
 954                 curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
 955
 956         headers = curl_slist_append(headers, buf.buf);
 957
 958         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 959         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
 960         curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
 961
 962         ret = run_one_slot(slot, &results);
 963
 964         if (options && options->content_type)
 965                 curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE,
 966                                 options->content_type);
 967
 968         if (options && options->effective_url)
 969                 curlinfo_strbuf(slot->curl, CURLINFO_EFFECTIVE_URL,
 970                                 options->effective_url);
 971
 972         curl_slist_free_all(headers);
 973         strbuf_release(&buf);
 974
 975         return ret;
 976 }
 977
 978 /*
 979  * Update the "base" url to a more appropriate value, as deduced by
 980  * redirects seen when requesting a URL starting with "url".
 981  *
 982  * The "asked" parameter is a URL that we asked curl to access, and must begin
 983  * with "base".
 984  *
 985  * The "got" parameter is the URL that curl reported to us as where we ended
 986  * up.
 987  *
 988  * Returns 1 if we updated the base url, 0 otherwise.
 989  *
 990  * Our basic strategy is to compare "base" and "asked" to find the bits
 991  * specific to our request. We then strip those bits off of "got" to yield the
 992  * new base. So for example, if our base is "http://example.com/foo.git",
 993  * and we ask for "http://example.com/foo.git/info/refs", we might end up
 994  * with "https://other.example.com/foo.git/info/refs". We would want the
 995  * new URL to become "https://other.example.com/foo.git".
 996  *
 997  * Note that this assumes a sane redirect scheme. It's entirely possible
 998  * in the example above to end up at a URL that does not even end in
 999  * "info/refs".  In such a case we simply punt, as there is not much we can
1000  * do (and such a scheme is unlikely to represent a real git repository,
1001  * which means we are likely about to abort anyway).
1002  */
1003 static int update_url_from_redirect(struct strbuf *base,
1004                                     const char *asked,
1005                                     const struct strbuf *got)
1006 {
1007         const char *tail;
1008         size_t tail_len;
1009
1010         if (!strcmp(asked, got->buf))
1011                 return 0;
1012
1013         if (!starts_with(asked, base->buf))
1014                 die("BUG: update_url_from_redirect: %s is not a superset of %s",
1015                     asked, base->buf);
1016
1017         tail = asked + base->len;
1018         tail_len = strlen(tail);
1019
1020         if (got->len < tail_len ||
1021             strcmp(tail, got->buf + got->len - tail_len))
1022                 return 0; /* insane redirect scheme */
1023
1024         strbuf_reset(base);
1025         strbuf_add(base, got->buf, got->len - tail_len);
1026         return 1;
1027 }
1028
1029 static int http_request_reauth(const char *url,
1030                                void *result, int target,
1031                                struct http_get_options *options)
1032 {
1033         int ret = http_request(url, result, target, options);
1034
1035         if (options && options->effective_url && options->base_url) {
1036                 if (update_url_from_redirect(options->base_url,
1037                                              url, options->effective_url)) {
1038                         credential_from_url(&http_auth, options->base_url->buf);
1039                         url = options->effective_url->buf;
1040                 }
1041         }
1042
1043         if (ret != HTTP_REAUTH)
1044                 return ret;
1045
1046         /*
1047          * If we are using KEEP_ERROR, the previous request may have
1048          * put cruft into our output stream; we should clear it out before
1049          * making our next request. We only know how to do this for
1050          * the strbuf case, but that is enough to satisfy current callers.
1051          */
1052         if (options && options->keep_error) {
1053                 switch (target) {
1054                 case HTTP_REQUEST_STRBUF:
1055                         strbuf_reset(result);
1056                         break;
1057                 default:
1058                         die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
1059                 }
1060         }
1061
1062         credential_fill(&http_auth);
1063
1064         return http_request(url, result, target, options);
1065 }
1066
1067 int http_get_strbuf(const char *url,
1068                     struct strbuf *result,
1069                     struct http_get_options *options)
1070 {
1071         return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
1072 }
1073
1074 /*
1075  * Downloads a URL and stores the result in the given file.
1076  *
1077  * If a previous interrupted download is detected (i.e. a previous temporary
1078  * file is still around) the download is resumed.
1079  */
1080 static int http_get_file(const char *url, const char *filename,
1081                          struct http_get_options *options)
1082 {
1083         int ret;
1084         struct strbuf tmpfile = STRBUF_INIT;
1085         FILE *result;
1086
1087         strbuf_addf(&tmpfile, "%s.temp", filename);
1088         result = fopen(tmpfile.buf, "a");
1089         if (!result) {
1090                 error("Unable to open local file %s", tmpfile.buf);
1091                 ret = HTTP_ERROR;
1092                 goto cleanup;
1093         }
1094
1095         ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
1096         fclose(result);
1097
1098         if (ret == HTTP_OK && move_temp_to_file(tmpfile.buf, filename))
1099                 ret = HTTP_ERROR;
1100 cleanup:
1101         strbuf_release(&tmpfile);
1102         return ret;
1103 }
1104
1105 int http_fetch_ref(const char *base, struct ref *ref)
1106 {
1107         struct http_get_options options = {0};
1108         char *url;
1109         struct strbuf buffer = STRBUF_INIT;
1110         int ret = -1;
1111
1112         options.no_cache = 1;
1113
1114         url = quote_ref_url(base, ref->name);
1115         if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
1116                 strbuf_rtrim(&buffer);
1117                 if (buffer.len == 40)
1118                         ret = get_sha1_hex(buffer.buf, ref->old_sha1);
1119                 else if (starts_with(buffer.buf, "ref: ")) {
1120                         ref->symref = xstrdup(buffer.buf + 5);
1121                         ret = 0;
1122                 }
1123         }
1124
1125         strbuf_release(&buffer);
1126         free(url);
1127         return ret;
1128 }
1129
1130 /* Helpers for fetching packs */
1131 static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
1132 {
1133         char *url, *tmp;
1134         struct strbuf buf = STRBUF_INIT;
1135
1136         if (http_is_verbose)
1137                 fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
1138
1139         end_url_with_slash(&buf, base_url);
1140         strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
1141         url = strbuf_detach(&buf, NULL);
1142
1143         strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
1144         tmp = strbuf_detach(&buf, NULL);
1145
1146         if (http_get_file(url, tmp, NULL) != HTTP_OK) {
1147                 error("Unable to get pack index %s", url);
1148                 free(tmp);
1149                 tmp = NULL;
1150         }
1151
1152         free(url);
1153         return tmp;
1154 }
1155
1156 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
1157         unsigned char *sha1, const char *base_url)
1158 {
1159         struct packed_git *new_pack;
1160         char *tmp_idx = NULL;
1161         int ret;
1162
1163         if (has_pack_index(sha1)) {
1164                 new_pack = parse_pack_index(sha1, NULL);
1165                 if (!new_pack)
1166                         return -1; /* parse_pack_index() already issued error message */
1167                 goto add_pack;
1168         }
1169
1170         tmp_idx = fetch_pack_index(sha1, base_url);
1171         if (!tmp_idx)
1172                 return -1;
1173
1174         new_pack = parse_pack_index(sha1, tmp_idx);
1175         if (!new_pack) {
1176                 unlink(tmp_idx);
1177                 free(tmp_idx);
1178
1179                 return -1; /* parse_pack_index() already issued error message */
1180         }
1181
1182         ret = verify_pack_index(new_pack);
1183         if (!ret) {
1184                 close_pack_index(new_pack);
1185                 ret = move_temp_to_file(tmp_idx, sha1_pack_index_name(sha1));
1186         }
1187         free(tmp_idx);
1188         if (ret)
1189                 return -1;
1190
1191 add_pack:
1192         new_pack->next = *packs_head;
1193         *packs_head = new_pack;
1194         return 0;
1195 }
1196
1197 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
1198 {
1199         struct http_get_options options = {0};
1200         int ret = 0, i = 0;
1201         char *url, *data;
1202         struct strbuf buf = STRBUF_INIT;
1203         unsigned char sha1[20];
1204
1205         end_url_with_slash(&buf, base_url);
1206         strbuf_addstr(&buf, "objects/info/packs");
1207         url = strbuf_detach(&buf, NULL);
1208
1209         options.no_cache = 1;
1210         ret = http_get_strbuf(url, &buf, &options);
1211         if (ret != HTTP_OK)
1212                 goto cleanup;
1213
1214         data = buf.buf;
1215         while (i < buf.len) {
1216                 switch (data[i]) {
1217                 case 'P':
1218                         i++;
1219                         if (i + 52 <= buf.len &&
1220                             starts_with(data + i, " pack-") &&
1221                             starts_with(data + i + 46, ".pack\n")) {
1222                                 get_sha1_hex(data + i + 6, sha1);
1223                                 fetch_and_setup_pack_index(packs_head, sha1,
1224                                                       base_url);
1225                                 i += 51;
1226                                 break;
1227                         }
1228                 default:
1229                         while (i < buf.len && data[i] != '\n')
1230                                 i++;
1231                 }
1232                 i++;
1233         }
1234
1235 cleanup:
1236         free(url);
1237         return ret;
1238 }
1239
1240 void release_http_pack_request(struct http_pack_request *preq)
1241 {
1242         if (preq->packfile != NULL) {
1243                 fclose(preq->packfile);
1244                 preq->packfile = NULL;
1245         }
1246         if (preq->range_header != NULL) {
1247                 curl_slist_free_all(preq->range_header);
1248                 preq->range_header = NULL;
1249         }
1250         preq->slot = NULL;
1251         free(preq->url);
1252 }
1253
1254 int finish_http_pack_request(struct http_pack_request *preq)
1255 {
1256         struct packed_git **lst;
1257         struct packed_git *p = preq->target;
1258         char *tmp_idx;
1259         struct child_process ip;
1260         const char *ip_argv[8];
1261
1262         close_pack_index(p);
1263
1264         fclose(preq->packfile);
1265         preq->packfile = NULL;
1266
1267         lst = preq->lst;
1268         while (*lst != p)
1269                 lst = &((*lst)->next);
1270         *lst = (*lst)->next;
1271
1272         tmp_idx = xstrdup(preq->tmpfile);
1273         strcpy(tmp_idx + strlen(tmp_idx) - strlen(".pack.temp"),
1274                ".idx.temp");
1275
1276         ip_argv[0] = "index-pack";
1277         ip_argv[1] = "-o";
1278         ip_argv[2] = tmp_idx;
1279         ip_argv[3] = preq->tmpfile;
1280         ip_argv[4] = NULL;
1281
1282         memset(&ip, 0, sizeof(ip));
1283         ip.argv = ip_argv;
1284         ip.git_cmd = 1;
1285         ip.no_stdin = 1;
1286         ip.no_stdout = 1;
1287
1288         if (run_command(&ip)) {
1289                 unlink(preq->tmpfile);
1290                 unlink(tmp_idx);
1291                 free(tmp_idx);
1292                 return -1;
1293         }
1294
1295         unlink(sha1_pack_index_name(p->sha1));
1296
1297         if (move_temp_to_file(preq->tmpfile, sha1_pack_name(p->sha1))
1298          || move_temp_to_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
1299                 free(tmp_idx);
1300                 return -1;
1301         }
1302
1303         install_packed_git(p);
1304         free(tmp_idx);
1305         return 0;
1306 }
1307
1308 struct http_pack_request *new_http_pack_request(
1309         struct packed_git *target, const char *base_url)
1310 {
1311         long prev_posn = 0;
1312         char range[RANGE_HEADER_SIZE];
1313         struct strbuf buf = STRBUF_INIT;
1314         struct http_pack_request *preq;
1315
1316         preq = xcalloc(1, sizeof(*preq));
1317         preq->target = target;
1318
1319         end_url_with_slash(&buf, base_url);
1320         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
1321                 sha1_to_hex(target->sha1));
1322         preq->url = strbuf_detach(&buf, NULL);
1323
1324         snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
1325                 sha1_pack_name(target->sha1));
1326         preq->packfile = fopen(preq->tmpfile, "a");
1327         if (!preq->packfile) {
1328                 error("Unable to open local file %s for pack",
1329                       preq->tmpfile);
1330                 goto abort;
1331         }
1332
1333         preq->slot = get_active_slot();
1334         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
1335         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
1336         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
1337         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1338                 no_pragma_header);
1339
1340         /*
1341          * If there is data present from a previous transfer attempt,
1342          * resume where it left off
1343          */
1344         prev_posn = ftell(preq->packfile);
1345         if (prev_posn>0) {
1346                 if (http_is_verbose)
1347                         fprintf(stderr,
1348                                 "Resuming fetch of pack %s at byte %ld\n",
1349                                 sha1_to_hex(target->sha1), prev_posn);
1350                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1351                 preq->range_header = curl_slist_append(NULL, range);
1352                 curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1353                         preq->range_header);
1354         }
1355
1356         return preq;
1357
1358 abort:
1359         free(preq->url);
1360         free(preq);
1361         return NULL;
1362 }
1363
1364 /* Helpers for fetching objects (loose) */
1365 static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
1366                                void *data)
1367 {
1368         unsigned char expn[4096];
1369         size_t size = eltsize * nmemb;
1370         int posn = 0;
1371         struct http_object_request *freq =
1372                 (struct http_object_request *)data;
1373         do {
1374                 ssize_t retval = xwrite(freq->localfile,
1375                                         (char *) ptr + posn, size - posn);
1376                 if (retval < 0)
1377                         return posn;
1378                 posn += retval;
1379         } while (posn < size);
1380
1381         freq->stream.avail_in = size;
1382         freq->stream.next_in = (void *)ptr;
1383         do {
1384                 freq->stream.next_out = expn;
1385                 freq->stream.avail_out = sizeof(expn);
1386                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
1387                 git_SHA1_Update(&freq->c, expn,
1388                                 sizeof(expn) - freq->stream.avail_out);
1389         } while (freq->stream.avail_in && freq->zret == Z_OK);
1390         return size;
1391 }
1392
1393 struct http_object_request *new_http_object_request(const char *base_url,
1394         unsigned char *sha1)
1395 {
1396         char *hex = sha1_to_hex(sha1);
1397         const char *filename;
1398         char prevfile[PATH_MAX];
1399         int prevlocal;
1400         char prev_buf[PREV_BUF_SIZE];
1401         ssize_t prev_read = 0;
1402         long prev_posn = 0;
1403         char range[RANGE_HEADER_SIZE];
1404         struct curl_slist *range_header = NULL;
1405         struct http_object_request *freq;
1406
1407         freq = xcalloc(1, sizeof(*freq));
1408         hashcpy(freq->sha1, sha1);
1409         freq->localfile = -1;
1410
1411         filename = sha1_file_name(sha1);
1412         snprintf(freq->tmpfile, sizeof(freq->tmpfile),
1413                  "%s.temp", filename);
1414
1415         snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
1416         unlink_or_warn(prevfile);
1417         rename(freq->tmpfile, prevfile);
1418         unlink_or_warn(freq->tmpfile);
1419
1420         if (freq->localfile != -1)
1421                 error("fd leakage in start: %d", freq->localfile);
1422         freq->localfile = open(freq->tmpfile,
1423                                O_WRONLY | O_CREAT | O_EXCL, 0666);
1424         /*
1425          * This could have failed due to the "lazy directory creation";
1426          * try to mkdir the last path component.
1427          */
1428         if (freq->localfile < 0 && errno == ENOENT) {
1429                 char *dir = strrchr(freq->tmpfile, '/');
1430                 if (dir) {
1431                         *dir = 0;
1432                         mkdir(freq->tmpfile, 0777);
1433                         *dir = '/';
1434                 }
1435                 freq->localfile = open(freq->tmpfile,
1436                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
1437         }
1438
1439         if (freq->localfile < 0) {
1440                 error("Couldn't create temporary file %s: %s",
1441                       freq->tmpfile, strerror(errno));
1442                 goto abort;
1443         }
1444
1445         git_inflate_init(&freq->stream);
1446
1447         git_SHA1_Init(&freq->c);
1448
1449         freq->url = get_remote_object_url(base_url, hex, 0);
1450
1451         /*
1452          * If a previous temp file is present, process what was already
1453          * fetched.
1454          */
1455         prevlocal = open(prevfile, O_RDONLY);
1456         if (prevlocal != -1) {
1457                 do {
1458                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
1459                         if (prev_read>0) {
1460                                 if (fwrite_sha1_file(prev_buf,
1461                                                      1,
1462                                                      prev_read,
1463                                                      freq) == prev_read) {
1464                                         prev_posn += prev_read;
1465                                 } else {
1466                                         prev_read = -1;
1467                                 }
1468                         }
1469                 } while (prev_read > 0);
1470                 close(prevlocal);
1471         }
1472         unlink_or_warn(prevfile);
1473
1474         /*
1475          * Reset inflate/SHA1 if there was an error reading the previous temp
1476          * file; also rewind to the beginning of the local file.
1477          */
1478         if (prev_read == -1) {
1479                 memset(&freq->stream, 0, sizeof(freq->stream));
1480                 git_inflate_init(&freq->stream);
1481                 git_SHA1_Init(&freq->c);
1482                 if (prev_posn>0) {
1483                         prev_posn = 0;
1484                         lseek(freq->localfile, 0, SEEK_SET);
1485                         if (ftruncate(freq->localfile, 0) < 0) {
1486                                 error("Couldn't truncate temporary file %s: %s",
1487                                           freq->tmpfile, strerror(errno));
1488                                 goto abort;
1489                         }
1490                 }
1491         }
1492
1493         freq->slot = get_active_slot();
1494
1495         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
1496         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
1497         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
1498         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
1499         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
1500
1501         /*
1502          * If we have successfully processed data from a previous fetch
1503          * attempt, only fetch the data we don't already have.
1504          */
1505         if (prev_posn>0) {
1506                 if (http_is_verbose)
1507                         fprintf(stderr,
1508                                 "Resuming fetch of object %s at byte %ld\n",
1509                                 hex, prev_posn);
1510                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1511                 range_header = curl_slist_append(range_header, range);
1512                 curl_easy_setopt(freq->slot->curl,
1513                                  CURLOPT_HTTPHEADER, range_header);
1514         }
1515
1516         return freq;
1517
1518 abort:
1519         free(freq->url);
1520         free(freq);
1521         return NULL;
1522 }
1523
1524 void process_http_object_request(struct http_object_request *freq)
1525 {
1526         if (freq->slot == NULL)
1527                 return;
1528         freq->curl_result = freq->slot->curl_result;
1529         freq->http_code = freq->slot->http_code;
1530         freq->slot = NULL;
1531 }
1532
1533 int finish_http_object_request(struct http_object_request *freq)
1534 {
1535         struct stat st;
1536
1537         close(freq->localfile);
1538         freq->localfile = -1;
1539
1540         process_http_object_request(freq);
1541
1542         if (freq->http_code == 416) {
1543                 warning("requested range invalid; we may already have all the data.");
1544         } else if (freq->curl_result != CURLE_OK) {
1545                 if (stat(freq->tmpfile, &st) == 0)
1546                         if (st.st_size == 0)
1547                                 unlink_or_warn(freq->tmpfile);
1548                 return -1;
1549         }
1550
1551         git_inflate_end(&freq->stream);
1552         git_SHA1_Final(freq->real_sha1, &freq->c);
1553         if (freq->zret != Z_STREAM_END) {
1554                 unlink_or_warn(freq->tmpfile);
1555                 return -1;
1556         }
1557         if (hashcmp(freq->sha1, freq->real_sha1)) {
1558                 unlink_or_warn(freq->tmpfile);
1559                 return -1;
1560         }
1561         freq->rename =
1562                 move_temp_to_file(freq->tmpfile, sha1_file_name(freq->sha1));
1563
1564         return freq->rename;
1565 }
1566
1567 void abort_http_object_request(struct http_object_request *freq)
1568 {
1569         unlink_or_warn(freq->tmpfile);
1570
1571         release_http_object_request(freq);
1572 }
1573
1574 void release_http_object_request(struct http_object_request *freq)
1575 {
1576         if (freq->localfile != -1) {
1577                 close(freq->localfile);
1578                 freq->localfile = -1;
1579         }
1580         if (freq->url != NULL) {
1581                 free(freq->url);
1582                 freq->url = NULL;
1583         }
1584         if (freq->slot != NULL) {
1585                 freq->slot->callback_func = NULL;
1586                 freq->slot->callback_data = NULL;
1587                 release_active_slot(freq->slot);
1588                 freq->slot = NULL;
1589         }
1590 }