http.c

   1 #include "git-compat-util.h"
   2 #include "http.h"
   3 #include "pack.h"
   4 #include "sideband.h"
   5 #include "run-command.h"
   6 #include "url.h"
   7 #include "urlmatch.h"
   8 #include "credential.h"
   9 #include "version.h"
  10 #include "pkt-line.h"
  11 #include "transport.h"
  12
  13 int active_requests;
  14 int http_is_verbose;
  15 size_t http_post_buffer = 16 * LARGE_PACKET_MAX;
  16
  17 #if LIBCURL_VERSION_NUM >= 0x070a06
  18 #define LIBCURL_CAN_HANDLE_AUTH_ANY
  19 #endif
  20
  21 static int min_curl_sessions = 1;
  22 static int curl_session_count;
  23 #ifdef USE_CURL_MULTI
  24 static int max_requests = -1;
  25 static CURLM *curlm;
  26 #endif
  27 #ifndef NO_CURL_EASY_DUPHANDLE
  28 static CURL *curl_default;
  29 #endif
  30
  31 #define PREV_BUF_SIZE 4096
  32 #define RANGE_HEADER_SIZE 30
  33
  34 char curl_errorstr[CURL_ERROR_SIZE];
  35
  36 static int curl_ssl_verify = -1;
  37 static int curl_ssl_try;
  38 static const char *ssl_cert;
  39 #if LIBCURL_VERSION_NUM >= 0x070903
  40 static const char *ssl_key;
  41 #endif
  42 #if LIBCURL_VERSION_NUM >= 0x070908
  43 static const char *ssl_capath;
  44 #endif
  45 static const char *ssl_cainfo;
  46 static long curl_low_speed_limit = -1;
  47 static long curl_low_speed_time = -1;
  48 static int curl_ftp_no_epsv;
  49 static const char *curl_http_proxy;
  50 static const char *curl_cookie_file;
  51 static int curl_save_cookies;
  52 struct credential http_auth = CREDENTIAL_INIT;
  53 static int http_proactive_auth;
  54 static const char *user_agent;
  55
  56 #if LIBCURL_VERSION_NUM >= 0x071700
  57 /* Use CURLOPT_KEYPASSWD as is */
  58 #elif LIBCURL_VERSION_NUM >= 0x070903
  59 #define CURLOPT_KEYPASSWD CURLOPT_SSLKEYPASSWD
  60 #else
  61 #define CURLOPT_KEYPASSWD CURLOPT_SSLCERTPASSWD
  62 #endif
  63
  64 static struct credential cert_auth = CREDENTIAL_INIT;
  65 static int ssl_cert_password_required;
  66 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
  67 static unsigned long http_auth_methods = CURLAUTH_ANY;
  68 #endif
  69
  70 static struct curl_slist *pragma_header;
  71 static struct curl_slist *no_pragma_header;
  72
  73 static struct active_request_slot *active_queue_head;
  74
  75 size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
  76 {
  77         size_t size = eltsize * nmemb;
  78         struct buffer *buffer = buffer_;
  79
  80         if (size > buffer->buf.len - buffer->posn)
  81                 size = buffer->buf.len - buffer->posn;
  82         memcpy(ptr, buffer->buf.buf + buffer->posn, size);
  83         buffer->posn += size;
  84
  85         return size;
  86 }
  87
  88 #ifndef NO_CURL_IOCTL
  89 curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)
  90 {
  91         struct buffer *buffer = clientp;
  92
  93         switch (cmd) {
  94         case CURLIOCMD_NOP:
  95                 return CURLIOE_OK;
  96
  97         case CURLIOCMD_RESTARTREAD:
  98                 buffer->posn = 0;
  99                 return CURLIOE_OK;
 100
 101         default:
 102                 return CURLIOE_UNKNOWNCMD;
 103         }
 104 }
 105 #endif
 106
 107 size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
 108 {
 109         size_t size = eltsize * nmemb;
 110         struct strbuf *buffer = buffer_;
 111
 112         strbuf_add(buffer, ptr, size);
 113         return size;
 114 }
 115
 116 size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf)
 117 {
 118         return eltsize * nmemb;
 119 }
 120
 121 #ifdef USE_CURL_MULTI
 122 static void process_curl_messages(void)
 123 {
 124         int num_messages;
 125         struct active_request_slot *slot;
 126         CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
 127
 128         while (curl_message != NULL) {
 129                 if (curl_message->msg == CURLMSG_DONE) {
 130                         int curl_result = curl_message->data.result;
 131                         slot = active_queue_head;
 132                         while (slot != NULL &&
 133                                slot->curl != curl_message->easy_handle)
 134                                 slot = slot->next;
 135                         if (slot != NULL) {
 136                                 curl_multi_remove_handle(curlm, slot->curl);
 137                                 slot->curl_result = curl_result;
 138                                 finish_active_slot(slot);
 139                         } else {
 140                                 fprintf(stderr, "Received DONE message for unknown request!\n");
 141                         }
 142                 } else {
 143                         fprintf(stderr, "Unknown CURL message received: %d\n",
 144                                 (int)curl_message->msg);
 145                 }
 146                 curl_message = curl_multi_info_read(curlm, &num_messages);
 147         }
 148 }
 149 #endif
 150
 151 static int http_options(const char *var, const char *value, void *cb)
 152 {
 153         if (!strcmp("http.sslverify", var)) {
 154                 curl_ssl_verify = git_config_bool(var, value);
 155                 return 0;
 156         }
 157         if (!strcmp("http.sslcert", var))
 158                 return git_config_string(&ssl_cert, var, value);
 159 #if LIBCURL_VERSION_NUM >= 0x070903
 160         if (!strcmp("http.sslkey", var))
 161                 return git_config_string(&ssl_key, var, value);
 162 #endif
 163 #if LIBCURL_VERSION_NUM >= 0x070908
 164         if (!strcmp("http.sslcapath", var))
 165                 return git_config_string(&ssl_capath, var, value);
 166 #endif
 167         if (!strcmp("http.sslcainfo", var))
 168                 return git_config_string(&ssl_cainfo, var, value);
 169         if (!strcmp("http.sslcertpasswordprotected", var)) {
 170                 ssl_cert_password_required = git_config_bool(var, value);
 171                 return 0;
 172         }
 173         if (!strcmp("http.ssltry", var)) {
 174                 curl_ssl_try = git_config_bool(var, value);
 175                 return 0;
 176         }
 177         if (!strcmp("http.minsessions", var)) {
 178                 min_curl_sessions = git_config_int(var, value);
 179 #ifndef USE_CURL_MULTI
 180                 if (min_curl_sessions > 1)
 181                         min_curl_sessions = 1;
 182 #endif
 183                 return 0;
 184         }
 185 #ifdef USE_CURL_MULTI
 186         if (!strcmp("http.maxrequests", var)) {
 187                 max_requests = git_config_int(var, value);
 188                 return 0;
 189         }
 190 #endif
 191         if (!strcmp("http.lowspeedlimit", var)) {
 192                 curl_low_speed_limit = (long)git_config_int(var, value);
 193                 return 0;
 194         }
 195         if (!strcmp("http.lowspeedtime", var)) {
 196                 curl_low_speed_time = (long)git_config_int(var, value);
 197                 return 0;
 198         }
 199
 200         if (!strcmp("http.noepsv", var)) {
 201                 curl_ftp_no_epsv = git_config_bool(var, value);
 202                 return 0;
 203         }
 204         if (!strcmp("http.proxy", var))
 205                 return git_config_string(&curl_http_proxy, var, value);
 206
 207         if (!strcmp("http.cookiefile", var))
 208                 return git_config_string(&curl_cookie_file, var, value);
 209         if (!strcmp("http.savecookies", var)) {
 210                 curl_save_cookies = git_config_bool(var, value);
 211                 return 0;
 212         }
 213
 214         if (!strcmp("http.postbuffer", var)) {
 215                 http_post_buffer = git_config_int(var, value);
 216                 if (http_post_buffer < LARGE_PACKET_MAX)
 217                         http_post_buffer = LARGE_PACKET_MAX;
 218                 return 0;
 219         }
 220
 221         if (!strcmp("http.useragent", var))
 222                 return git_config_string(&user_agent, var, value);
 223
 224         /* Fall back on the default ones */
 225         return git_default_config(var, value, cb);
 226 }
 227
 228 static void init_curl_http_auth(CURL *result)
 229 {
 230         if (!http_auth.username)
 231                 return;
 232
 233         credential_fill(&http_auth);
 234
 235 #if LIBCURL_VERSION_NUM >= 0x071301
 236         curl_easy_setopt(result, CURLOPT_USERNAME, http_auth.username);
 237         curl_easy_setopt(result, CURLOPT_PASSWORD, http_auth.password);
 238 #else
 239         {
 240                 static struct strbuf up = STRBUF_INIT;
 241                 /*
 242                  * Note that we assume we only ever have a single set of
 243                  * credentials in a given program run, so we do not have
 244                  * to worry about updating this buffer, only setting its
 245                  * initial value.
 246                  */
 247                 if (!up.len)
 248                         strbuf_addf(&up, "%s:%s",
 249                                 http_auth.username, http_auth.password);
 250                 curl_easy_setopt(result, CURLOPT_USERPWD, up.buf);
 251         }
 252 #endif
 253 }
 254
 255 static int has_cert_password(void)
 256 {
 257         if (ssl_cert == NULL || ssl_cert_password_required != 1)
 258                 return 0;
 259         if (!cert_auth.password) {
 260                 cert_auth.protocol = xstrdup("cert");
 261                 cert_auth.username = xstrdup("");
 262                 cert_auth.path = xstrdup(ssl_cert);
 263                 credential_fill(&cert_auth);
 264         }
 265         return 1;
 266 }
 267
 268 #if LIBCURL_VERSION_NUM >= 0x071900
 269 static void set_curl_keepalive(CURL *c)
 270 {
 271         curl_easy_setopt(c, CURLOPT_TCP_KEEPALIVE, 1);
 272 }
 273
 274 #elif LIBCURL_VERSION_NUM >= 0x071000
 275 static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
 276 {
 277         int ka = 1;
 278         int rc;
 279         socklen_t len = (socklen_t)sizeof(ka);
 280
 281         if (type != CURLSOCKTYPE_IPCXN)
 282                 return 0;
 283
 284         rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
 285         if (rc < 0)
 286                 warning("unable to set SO_KEEPALIVE on socket %s",
 287                         strerror(errno));
 288
 289         return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
 290 }
 291
 292 static void set_curl_keepalive(CURL *c)
 293 {
 294         curl_easy_setopt(c, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
 295 }
 296
 297 #else
 298 static void set_curl_keepalive(CURL *c)
 299 {
 300         /* not supported on older curl versions */
 301 }
 302 #endif
 303
 304 static CURL *get_curl_handle(void)
 305 {
 306         CURL *result = curl_easy_init();
 307         long allowed_protocols = 0;
 308
 309         if (!result)
 310                 die("curl_easy_init failed");
 311
 312         if (!curl_ssl_verify) {
 313                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
 314                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
 315         } else {
 316                 /* Verify authenticity of the peer's certificate */
 317                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
 318                 /* The name in the cert must match whom we tried to connect */
 319                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
 320         }
 321
 322 #if LIBCURL_VERSION_NUM >= 0x070907
 323         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
 324 #endif
 325 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 326         curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
 327 #endif
 328
 329         if (http_proactive_auth)
 330                 init_curl_http_auth(result);
 331
 332         if (ssl_cert != NULL)
 333                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
 334         if (has_cert_password())
 335                 curl_easy_setopt(result, CURLOPT_KEYPASSWD, cert_auth.password);
 336 #if LIBCURL_VERSION_NUM >= 0x070903
 337         if (ssl_key != NULL)
 338                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
 339 #endif
 340 #if LIBCURL_VERSION_NUM >= 0x070908
 341         if (ssl_capath != NULL)
 342                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
 343 #endif
 344         if (ssl_cainfo != NULL)
 345                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
 346
 347         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
 348                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
 349                                  curl_low_speed_limit);
 350                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
 351                                  curl_low_speed_time);
 352         }
 353
 354         curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
 355         curl_easy_setopt(result, CURLOPT_MAXREDIRS, 20);
 356 #if LIBCURL_VERSION_NUM >= 0x071301
 357         curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
 358 #elif LIBCURL_VERSION_NUM >= 0x071101
 359         curl_easy_setopt(result, CURLOPT_POST301, 1);
 360 #endif
 361 #if LIBCURL_VERSION_NUM >= 0x071304
 362         if (is_transport_allowed("http"))
 363                 allowed_protocols |= CURLPROTO_HTTP;
 364         if (is_transport_allowed("https"))
 365                 allowed_protocols |= CURLPROTO_HTTPS;
 366         if (is_transport_allowed("ftp"))
 367                 allowed_protocols |= CURLPROTO_FTP;
 368         if (is_transport_allowed("ftps"))
 369                 allowed_protocols |= CURLPROTO_FTPS;
 370         curl_easy_setopt(result, CURLOPT_REDIR_PROTOCOLS, allowed_protocols);
 371 #else
 372         if (transport_restrict_protocols())
 373                 warning("protocol restrictions not applied to curl redirects because\n"
 374                         "your curl version is too old (>= 7.19.4)");
 375 #endif
 376
 377         if (getenv("GIT_CURL_VERBOSE"))
 378                 curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
 379
 380         curl_easy_setopt(result, CURLOPT_USERAGENT,
 381                 user_agent ? user_agent : git_user_agent());
 382
 383         if (curl_ftp_no_epsv)
 384                 curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
 385
 386 #ifdef CURLOPT_USE_SSL
 387         if (curl_ssl_try)
 388                 curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
 389 #endif
 390
 391         if (curl_http_proxy) {
 392                 curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
 393                 curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
 394         }
 395
 396         set_curl_keepalive(result);
 397
 398         return result;
 399 }
 400
 401 static void set_from_env(const char **var, const char *envname)
 402 {
 403         const char *val = getenv(envname);
 404         if (val)
 405                 *var = val;
 406 }
 407
 408 void http_init(struct remote *remote, const char *url, int proactive_auth)
 409 {
 410         char *low_speed_limit;
 411         char *low_speed_time;
 412         char *normalized_url;
 413         struct urlmatch_config config = { STRING_LIST_INIT_DUP };
 414
 415         config.section = "http";
 416         config.key = NULL;
 417         config.collect_fn = http_options;
 418         config.cascade_fn = git_default_config;
 419         config.cb = NULL;
 420
 421         http_is_verbose = 0;
 422         normalized_url = url_normalize(url, &config.url);
 423
 424         git_config(urlmatch_config_entry, &config);
 425         free(normalized_url);
 426
 427         if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK)
 428                 die("curl_global_init failed");
 429
 430         http_proactive_auth = proactive_auth;
 431
 432         if (remote && remote->http_proxy)
 433                 curl_http_proxy = xstrdup(remote->http_proxy);
 434
 435         pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
 436         no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
 437
 438 #ifdef USE_CURL_MULTI
 439         {
 440                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
 441                 if (http_max_requests != NULL)
 442                         max_requests = atoi(http_max_requests);
 443         }
 444
 445         curlm = curl_multi_init();
 446         if (!curlm)
 447                 die("curl_multi_init failed");
 448 #endif
 449
 450         if (getenv("GIT_SSL_NO_VERIFY"))
 451                 curl_ssl_verify = 0;
 452
 453         set_from_env(&ssl_cert, "GIT_SSL_CERT");
 454 #if LIBCURL_VERSION_NUM >= 0x070903
 455         set_from_env(&ssl_key, "GIT_SSL_KEY");
 456 #endif
 457 #if LIBCURL_VERSION_NUM >= 0x070908
 458         set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
 459 #endif
 460         set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
 461
 462         set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");
 463
 464         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
 465         if (low_speed_limit != NULL)
 466                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
 467         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
 468         if (low_speed_time != NULL)
 469                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
 470
 471         if (curl_ssl_verify == -1)
 472                 curl_ssl_verify = 1;
 473
 474         curl_session_count = 0;
 475 #ifdef USE_CURL_MULTI
 476         if (max_requests < 1)
 477                 max_requests = DEFAULT_MAX_REQUESTS;
 478 #endif
 479
 480         if (getenv("GIT_CURL_FTP_NO_EPSV"))
 481                 curl_ftp_no_epsv = 1;
 482
 483         if (url) {
 484                 credential_from_url(&http_auth, url);
 485                 if (!ssl_cert_password_required &&
 486                     getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
 487                     starts_with(url, "https://"))
 488                         ssl_cert_password_required = 1;
 489         }
 490
 491 #ifndef NO_CURL_EASY_DUPHANDLE
 492         curl_default = get_curl_handle();
 493 #endif
 494 }
 495
 496 void http_cleanup(void)
 497 {
 498         struct active_request_slot *slot = active_queue_head;
 499
 500         while (slot != NULL) {
 501                 struct active_request_slot *next = slot->next;
 502                 if (slot->curl != NULL) {
 503 #ifdef USE_CURL_MULTI
 504                         curl_multi_remove_handle(curlm, slot->curl);
 505 #endif
 506                         curl_easy_cleanup(slot->curl);
 507                 }
 508                 free(slot);
 509                 slot = next;
 510         }
 511         active_queue_head = NULL;
 512
 513 #ifndef NO_CURL_EASY_DUPHANDLE
 514         curl_easy_cleanup(curl_default);
 515 #endif
 516
 517 #ifdef USE_CURL_MULTI
 518         curl_multi_cleanup(curlm);
 519 #endif
 520         curl_global_cleanup();
 521
 522         curl_slist_free_all(pragma_header);
 523         pragma_header = NULL;
 524
 525         curl_slist_free_all(no_pragma_header);
 526         no_pragma_header = NULL;
 527
 528         if (curl_http_proxy) {
 529                 free((void *)curl_http_proxy);
 530                 curl_http_proxy = NULL;
 531         }
 532
 533         if (cert_auth.password != NULL) {
 534                 memset(cert_auth.password, 0, strlen(cert_auth.password));
 535                 free(cert_auth.password);
 536                 cert_auth.password = NULL;
 537         }
 538         ssl_cert_password_required = 0;
 539 }
 540
 541 struct active_request_slot *get_active_slot(void)
 542 {
 543         struct active_request_slot *slot = active_queue_head;
 544         struct active_request_slot *newslot;
 545
 546 #ifdef USE_CURL_MULTI
 547         int num_transfers;
 548
 549         /* Wait for a slot to open up if the queue is full */
 550         while (active_requests >= max_requests) {
 551                 curl_multi_perform(curlm, &num_transfers);
 552                 if (num_transfers < active_requests)
 553                         process_curl_messages();
 554         }
 555 #endif
 556
 557         while (slot != NULL && slot->in_use)
 558                 slot = slot->next;
 559
 560         if (slot == NULL) {
 561                 newslot = xmalloc(sizeof(*newslot));
 562                 newslot->curl = NULL;
 563                 newslot->in_use = 0;
 564                 newslot->next = NULL;
 565
 566                 slot = active_queue_head;
 567                 if (slot == NULL) {
 568                         active_queue_head = newslot;
 569                 } else {
 570                         while (slot->next != NULL)
 571                                 slot = slot->next;
 572                         slot->next = newslot;
 573                 }
 574                 slot = newslot;
 575         }
 576
 577         if (slot->curl == NULL) {
 578 #ifdef NO_CURL_EASY_DUPHANDLE
 579                 slot->curl = get_curl_handle();
 580 #else
 581                 slot->curl = curl_easy_duphandle(curl_default);
 582 #endif
 583                 curl_session_count++;
 584         }
 585
 586         active_requests++;
 587         slot->in_use = 1;
 588         slot->results = NULL;
 589         slot->finished = NULL;
 590         slot->callback_data = NULL;
 591         slot->callback_func = NULL;
 592         curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file);
 593         if (curl_save_cookies)
 594                 curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file);
 595         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
 596         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
 597         curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
 598         curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
 599         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
 600         curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
 601         curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
 602         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
 603         curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
 604 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 605         curl_easy_setopt(slot->curl, CURLOPT_HTTPAUTH, http_auth_methods);
 606 #endif
 607         if (http_auth.password)
 608                 init_curl_http_auth(slot->curl);
 609
 610         return slot;
 611 }
 612
 613 int start_active_slot(struct active_request_slot *slot)
 614 {
 615 #ifdef USE_CURL_MULTI
 616         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
 617         int num_transfers;
 618
 619         if (curlm_result != CURLM_OK &&
 620             curlm_result != CURLM_CALL_MULTI_PERFORM) {
 621                 active_requests--;
 622                 slot->in_use = 0;
 623                 return 0;
 624         }
 625
 626         /*
 627          * We know there must be something to do, since we just added
 628          * something.
 629          */
 630         curl_multi_perform(curlm, &num_transfers);
 631 #endif
 632         return 1;
 633 }
 634
 635 #ifdef USE_CURL_MULTI
 636 struct fill_chain {
 637         void *data;
 638         int (*fill)(void *);
 639         struct fill_chain *next;
 640 };
 641
 642 static struct fill_chain *fill_cfg;
 643
 644 void add_fill_function(void *data, int (*fill)(void *))
 645 {
 646         struct fill_chain *new = xmalloc(sizeof(*new));
 647         struct fill_chain **linkp = &fill_cfg;
 648         new->data = data;
 649         new->fill = fill;
 650         new->next = NULL;
 651         while (*linkp)
 652                 linkp = &(*linkp)->next;
 653         *linkp = new;
 654 }
 655
 656 void fill_active_slots(void)
 657 {
 658         struct active_request_slot *slot = active_queue_head;
 659
 660         while (active_requests < max_requests) {
 661                 struct fill_chain *fill;
 662                 for (fill = fill_cfg; fill; fill = fill->next)
 663                         if (fill->fill(fill->data))
 664                                 break;
 665
 666                 if (!fill)
 667                         break;
 668         }
 669
 670         while (slot != NULL) {
 671                 if (!slot->in_use && slot->curl != NULL
 672                         && curl_session_count > min_curl_sessions) {
 673                         curl_easy_cleanup(slot->curl);
 674                         slot->curl = NULL;
 675                         curl_session_count--;
 676                 }
 677                 slot = slot->next;
 678         }
 679 }
 680
 681 void step_active_slots(void)
 682 {
 683         int num_transfers;
 684         CURLMcode curlm_result;
 685
 686         do {
 687                 curlm_result = curl_multi_perform(curlm, &num_transfers);
 688         } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
 689         if (num_transfers < active_requests) {
 690                 process_curl_messages();
 691                 fill_active_slots();
 692         }
 693 }
 694 #endif
 695
 696 void run_active_slot(struct active_request_slot *slot)
 697 {
 698 #ifdef USE_CURL_MULTI
 699         fd_set readfds;
 700         fd_set writefds;
 701         fd_set excfds;
 702         int max_fd;
 703         struct timeval select_timeout;
 704         int finished = 0;
 705
 706         slot->finished = &finished;
 707         while (!finished) {
 708                 step_active_slots();
 709
 710                 if (slot->in_use) {
 711 #if LIBCURL_VERSION_NUM >= 0x070f04
 712                         long curl_timeout;
 713                         curl_multi_timeout(curlm, &curl_timeout);
 714                         if (curl_timeout == 0) {
 715                                 continue;
 716                         } else if (curl_timeout == -1) {
 717                                 select_timeout.tv_sec  = 0;
 718                                 select_timeout.tv_usec = 50000;
 719                         } else {
 720                                 select_timeout.tv_sec  =  curl_timeout / 1000;
 721                                 select_timeout.tv_usec = (curl_timeout % 1000) * 1000;
 722                         }
 723 #else
 724                         select_timeout.tv_sec  = 0;
 725                         select_timeout.tv_usec = 50000;
 726 #endif
 727
 728                         max_fd = -1;
 729                         FD_ZERO(&readfds);
 730                         FD_ZERO(&writefds);
 731                         FD_ZERO(&excfds);
 732                         curl_multi_fdset(curlm, &readfds, &writefds, &excfds, &max_fd);
 733
 734                         /*
 735                          * It can happen that curl_multi_timeout returns a pathologically
 736                          * long timeout when curl_multi_fdset returns no file descriptors
 737                          * to read.  See commit message for more details.
 738                          */
 739                         if (max_fd < 0 &&
 740                             (select_timeout.tv_sec > 0 ||
 741                              select_timeout.tv_usec > 50000)) {
 742                                 select_timeout.tv_sec  = 0;
 743                                 select_timeout.tv_usec = 50000;
 744                         }
 745
 746                         select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
 747                 }
 748         }
 749 #else
 750         while (slot->in_use) {
 751                 slot->curl_result = curl_easy_perform(slot->curl);
 752                 finish_active_slot(slot);
 753         }
 754 #endif
 755 }
 756
 757 static void closedown_active_slot(struct active_request_slot *slot)
 758 {
 759         active_requests--;
 760         slot->in_use = 0;
 761 }
 762
 763 static void release_active_slot(struct active_request_slot *slot)
 764 {
 765         closedown_active_slot(slot);
 766         if (slot->curl && curl_session_count > min_curl_sessions) {
 767 #ifdef USE_CURL_MULTI
 768                 curl_multi_remove_handle(curlm, slot->curl);
 769 #endif
 770                 curl_easy_cleanup(slot->curl);
 771                 slot->curl = NULL;
 772                 curl_session_count--;
 773         }
 774 #ifdef USE_CURL_MULTI
 775         fill_active_slots();
 776 #endif
 777 }
 778
 779 void finish_active_slot(struct active_request_slot *slot)
 780 {
 781         closedown_active_slot(slot);
 782         curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
 783
 784         if (slot->finished != NULL)
 785                 (*slot->finished) = 1;
 786
 787         /* Store slot results so they can be read after the slot is reused */
 788         if (slot->results != NULL) {
 789                 slot->results->curl_result = slot->curl_result;
 790                 slot->results->http_code = slot->http_code;
 791 #if LIBCURL_VERSION_NUM >= 0x070a08
 792                 curl_easy_getinfo(slot->curl, CURLINFO_HTTPAUTH_AVAIL,
 793                                   &slot->results->auth_avail);
 794 #else
 795                 slot->results->auth_avail = 0;
 796 #endif
 797         }
 798
 799         /* Run callback if appropriate */
 800         if (slot->callback_func != NULL)
 801                 slot->callback_func(slot->callback_data);
 802 }
 803
 804 void finish_all_active_slots(void)
 805 {
 806         struct active_request_slot *slot = active_queue_head;
 807
 808         while (slot != NULL)
 809                 if (slot->in_use) {
 810                         run_active_slot(slot);
 811                         slot = active_queue_head;
 812                 } else {
 813                         slot = slot->next;
 814                 }
 815 }
 816
 817 /* Helpers for modifying and creating URLs */
 818 static inline int needs_quote(int ch)
 819 {
 820         if (((ch >= 'A') && (ch <= 'Z'))
 821                         || ((ch >= 'a') && (ch <= 'z'))
 822                         || ((ch >= '0') && (ch <= '9'))
 823                         || (ch == '/')
 824                         || (ch == '-')
 825                         || (ch == '.'))
 826                 return 0;
 827         return 1;
 828 }
 829
 830 static char *quote_ref_url(const char *base, const char *ref)
 831 {
 832         struct strbuf buf = STRBUF_INIT;
 833         const char *cp;
 834         int ch;
 835
 836         end_url_with_slash(&buf, base);
 837
 838         for (cp = ref; (ch = *cp) != 0; cp++)
 839                 if (needs_quote(ch))
 840                         strbuf_addf(&buf, "%%%02x", ch);
 841                 else
 842                         strbuf_addch(&buf, *cp);
 843
 844         return strbuf_detach(&buf, NULL);
 845 }
 846
 847 void append_remote_object_url(struct strbuf *buf, const char *url,
 848                               const char *hex,
 849                               int only_two_digit_prefix)
 850 {
 851         end_url_with_slash(buf, url);
 852
 853         strbuf_addf(buf, "objects/%.*s/", 2, hex);
 854         if (!only_two_digit_prefix)
 855                 strbuf_addf(buf, "%s", hex+2);
 856 }
 857
 858 char *get_remote_object_url(const char *url, const char *hex,
 859                             int only_two_digit_prefix)
 860 {
 861         struct strbuf buf = STRBUF_INIT;
 862         append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
 863         return strbuf_detach(&buf, NULL);
 864 }
 865
 866 int handle_curl_result(struct slot_results *results)
 867 {
 868         /*
 869          * If we see a failing http code with CURLE_OK, we have turned off
 870          * FAILONERROR (to keep the server's custom error response), and should
 871          * translate the code into failure here.
 872          */
 873         if (results->curl_result == CURLE_OK &&
 874             results->http_code >= 400) {
 875                 results->curl_result = CURLE_HTTP_RETURNED_ERROR;
 876                 /*
 877                  * Normally curl will already have put the "reason phrase"
 878                  * from the server into curl_errorstr; unfortunately without
 879                  * FAILONERROR it is lost, so we can give only the numeric
 880                  * status code.
 881                  */
 882                 snprintf(curl_errorstr, sizeof(curl_errorstr),
 883                          "The requested URL returned error: %ld",
 884                          results->http_code);
 885         }
 886
 887         if (results->curl_result == CURLE_OK) {
 888                 credential_approve(&http_auth);
 889                 return HTTP_OK;
 890         } else if (missing_target(results))
 891                 return HTTP_MISSING_TARGET;
 892         else if (results->http_code == 401) {
 893                 if (http_auth.username && http_auth.password) {
 894                         credential_reject(&http_auth);
 895                         return HTTP_NOAUTH;
 896                 } else {
 897 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 898                         http_auth_methods &= ~CURLAUTH_GSSNEGOTIATE;
 899 #endif
 900                         return HTTP_REAUTH;
 901                 }
 902         } else {
 903 #if LIBCURL_VERSION_NUM >= 0x070c00
 904                 if (!curl_errorstr[0])
 905                         strlcpy(curl_errorstr,
 906                                 curl_easy_strerror(results->curl_result),
 907                                 sizeof(curl_errorstr));
 908 #endif
 909                 return HTTP_ERROR;
 910         }
 911 }
 912
 913 int run_one_slot(struct active_request_slot *slot,
 914                  struct slot_results *results)
 915 {
 916         slot->results = results;
 917         if (!start_active_slot(slot)) {
 918                 snprintf(curl_errorstr, sizeof(curl_errorstr),
 919                          "failed to start HTTP request");
 920                 return HTTP_START_FAILED;
 921         }
 922
 923         run_active_slot(slot);
 924         return handle_curl_result(results);
 925 }
 926
 927 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
 928 {
 929         char *ptr;
 930         CURLcode ret;
 931
 932         strbuf_reset(buf);
 933         ret = curl_easy_getinfo(curl, info, &ptr);
 934         if (!ret && ptr)
 935                 strbuf_addstr(buf, ptr);
 936         return ret;
 937 }
 938
 939 /*
 940  * Check for and extract a content-type parameter. "raw"
 941  * should be positioned at the start of the potential
 942  * parameter, with any whitespace already removed.
 943  *
 944  * "name" is the name of the parameter. The value is appended
 945  * to "out".
 946  */
 947 static int extract_param(const char *raw, const char *name,
 948                          struct strbuf *out)
 949 {
 950         size_t len = strlen(name);
 951
 952         if (strncasecmp(raw, name, len))
 953                 return -1;
 954         raw += len;
 955
 956         if (*raw != '=')
 957                 return -1;
 958         raw++;
 959
 960         while (*raw && !isspace(*raw) && *raw != ';')
 961                 strbuf_addch(out, *raw++);
 962         return 0;
 963 }
 964
 965 /*
 966  * Extract a normalized version of the content type, with any
 967  * spaces suppressed, all letters lowercased, and no trailing ";"
 968  * or parameters.
 969  *
 970  * Note that we will silently remove even invalid whitespace. For
 971  * example, "text / plain" is specifically forbidden by RFC 2616,
 972  * but "text/plain" is the only reasonable output, and this keeps
 973  * our code simple.
 974  *
 975  * If the "charset" argument is not NULL, store the value of any
 976  * charset parameter there.
 977  *
 978  * Example:
 979  *   "TEXT/PLAIN; charset=utf-8" -> "text/plain", "utf-8"
 980  *   "text / plain" -> "text/plain"
 981  */
 982 static void extract_content_type(struct strbuf *raw, struct strbuf *type,
 983                                  struct strbuf *charset)
 984 {
 985         const char *p;
 986
 987         strbuf_reset(type);
 988         strbuf_grow(type, raw->len);
 989         for (p = raw->buf; *p; p++) {
 990                 if (isspace(*p))
 991                         continue;
 992                 if (*p == ';') {
 993                         p++;
 994                         break;
 995                 }
 996                 strbuf_addch(type, tolower(*p));
 997         }
 998
 999         if (!charset)
1000                 return;
1001
1002         strbuf_reset(charset);
1003         while (*p) {
1004                 while (isspace(*p) || *p == ';')
1005                         p++;
1006                 if (!extract_param(p, "charset", charset))
1007                         return;
1008                 while (*p && !isspace(*p))
1009                         p++;
1010         }
1011
1012         if (!charset->len && starts_with(type->buf, "text/"))
1013                 strbuf_addstr(charset, "ISO-8859-1");
1014 }
1015
1016
1017 /* http_request() targets */
1018 #define HTTP_REQUEST_STRBUF     0
1019 #define HTTP_REQUEST_FILE       1
1020
1021 static int http_request(const char *url,
1022                         void *result, int target,
1023                         const struct http_get_options *options)
1024 {
1025         struct active_request_slot *slot;
1026         struct slot_results results;
1027         struct curl_slist *headers = NULL;
1028         struct strbuf buf = STRBUF_INIT;
1029         int ret;
1030
1031         slot = get_active_slot();
1032         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1033
1034         if (result == NULL) {
1035                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
1036         } else {
1037                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
1038                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
1039
1040                 if (target == HTTP_REQUEST_FILE) {
1041                         long posn = ftell(result);
1042                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1043                                          fwrite);
1044                         if (posn > 0) {
1045                                 strbuf_addf(&buf, "Range: bytes=%ld-", posn);
1046                                 headers = curl_slist_append(headers, buf.buf);
1047                                 strbuf_reset(&buf);
1048                         }
1049                 } else
1050                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1051                                          fwrite_buffer);
1052         }
1053
1054         strbuf_addstr(&buf, "Pragma:");
1055         if (options && options->no_cache)
1056                 strbuf_addstr(&buf, " no-cache");
1057         if (options && options->keep_error)
1058                 curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
1059
1060         headers = curl_slist_append(headers, buf.buf);
1061
1062         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1063         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
1064         curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
1065
1066         ret = run_one_slot(slot, &results);
1067
1068         if (options && options->content_type) {
1069                 struct strbuf raw = STRBUF_INIT;
1070                 curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE, &raw);
1071                 extract_content_type(&raw, options->content_type,
1072                                      options->charset);
1073                 strbuf_release(&raw);
1074         }
1075
1076         if (options && options->effective_url)
1077                 curlinfo_strbuf(slot->curl, CURLINFO_EFFECTIVE_URL,
1078                                 options->effective_url);
1079
1080         curl_slist_free_all(headers);
1081         strbuf_release(&buf);
1082
1083         return ret;
1084 }
1085
1086 /*
1087  * Update the "base" url to a more appropriate value, as deduced by
1088  * redirects seen when requesting a URL starting with "url".
1089  *
1090  * The "asked" parameter is a URL that we asked curl to access, and must begin
1091  * with "base".
1092  *
1093  * The "got" parameter is the URL that curl reported to us as where we ended
1094  * up.
1095  *
1096  * Returns 1 if we updated the base url, 0 otherwise.
1097  *
1098  * Our basic strategy is to compare "base" and "asked" to find the bits
1099  * specific to our request. We then strip those bits off of "got" to yield the
1100  * new base. So for example, if our base is "http://example.com/foo.git",
1101  * and we ask for "http://example.com/foo.git/info/refs", we might end up
1102  * with "https://other.example.com/foo.git/info/refs". We would want the
1103  * new URL to become "https://other.example.com/foo.git".
1104  *
1105  * Note that this assumes a sane redirect scheme. It's entirely possible
1106  * in the example above to end up at a URL that does not even end in
1107  * "info/refs".  In such a case we simply punt, as there is not much we can
1108  * do (and such a scheme is unlikely to represent a real git repository,
1109  * which means we are likely about to abort anyway).
1110  */
1111 static int update_url_from_redirect(struct strbuf *base,
1112                                     const char *asked,
1113                                     const struct strbuf *got)
1114 {
1115         const char *tail;
1116         size_t tail_len;
1117
1118         if (!strcmp(asked, got->buf))
1119                 return 0;
1120
1121         if (!skip_prefix(asked, base->buf, &tail))
1122                 die("BUG: update_url_from_redirect: %s is not a superset of %s",
1123                     asked, base->buf);
1124
1125         tail_len = strlen(tail);
1126
1127         if (got->len < tail_len ||
1128             strcmp(tail, got->buf + got->len - tail_len))
1129                 return 0; /* insane redirect scheme */
1130
1131         strbuf_reset(base);
1132         strbuf_add(base, got->buf, got->len - tail_len);
1133         return 1;
1134 }
1135
1136 static int http_request_reauth(const char *url,
1137                                void *result, int target,
1138                                struct http_get_options *options)
1139 {
1140         int ret = http_request(url, result, target, options);
1141
1142         if (options && options->effective_url && options->base_url) {
1143                 if (update_url_from_redirect(options->base_url,
1144                                              url, options->effective_url)) {
1145                         credential_from_url(&http_auth, options->base_url->buf);
1146                         url = options->effective_url->buf;
1147                 }
1148         }
1149
1150         if (ret != HTTP_REAUTH)
1151                 return ret;
1152
1153         /*
1154          * If we are using KEEP_ERROR, the previous request may have
1155          * put cruft into our output stream; we should clear it out before
1156          * making our next request. We only know how to do this for
1157          * the strbuf case, but that is enough to satisfy current callers.
1158          */
1159         if (options && options->keep_error) {
1160                 switch (target) {
1161                 case HTTP_REQUEST_STRBUF:
1162                         strbuf_reset(result);
1163                         break;
1164                 default:
1165                         die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
1166                 }
1167         }
1168
1169         credential_fill(&http_auth);
1170
1171         return http_request(url, result, target, options);
1172 }
1173
1174 int http_get_strbuf(const char *url,
1175                     struct strbuf *result,
1176                     struct http_get_options *options)
1177 {
1178         return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
1179 }
1180
1181 /*
1182  * Downloads a URL and stores the result in the given file.
1183  *
1184  * If a previous interrupted download is detected (i.e. a previous temporary
1185  * file is still around) the download is resumed.
1186  */
1187 static int http_get_file(const char *url, const char *filename,
1188                          struct http_get_options *options)
1189 {
1190         int ret;
1191         struct strbuf tmpfile = STRBUF_INIT;
1192         FILE *result;
1193
1194         strbuf_addf(&tmpfile, "%s.temp", filename);
1195         result = fopen(tmpfile.buf, "a");
1196         if (!result) {
1197                 error("Unable to open local file %s", tmpfile.buf);
1198                 ret = HTTP_ERROR;
1199                 goto cleanup;
1200         }
1201
1202         ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
1203         fclose(result);
1204
1205         if (ret == HTTP_OK && move_temp_to_file(tmpfile.buf, filename))
1206                 ret = HTTP_ERROR;
1207 cleanup:
1208         strbuf_release(&tmpfile);
1209         return ret;
1210 }
1211
1212 int http_fetch_ref(const char *base, struct ref *ref)
1213 {
1214         struct http_get_options options = {0};
1215         char *url;
1216         struct strbuf buffer = STRBUF_INIT;
1217         int ret = -1;
1218
1219         options.no_cache = 1;
1220
1221         url = quote_ref_url(base, ref->name);
1222         if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
1223                 strbuf_rtrim(&buffer);
1224                 if (buffer.len == 40)
1225                         ret = get_sha1_hex(buffer.buf, ref->old_sha1);
1226                 else if (starts_with(buffer.buf, "ref: ")) {
1227                         ref->symref = xstrdup(buffer.buf + 5);
1228                         ret = 0;
1229                 }
1230         }
1231
1232         strbuf_release(&buffer);
1233         free(url);
1234         return ret;
1235 }
1236
1237 /* Helpers for fetching packs */
1238 static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
1239 {
1240         char *url, *tmp;
1241         struct strbuf buf = STRBUF_INIT;
1242
1243         if (http_is_verbose)
1244                 fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
1245
1246         end_url_with_slash(&buf, base_url);
1247         strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
1248         url = strbuf_detach(&buf, NULL);
1249
1250         strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
1251         tmp = strbuf_detach(&buf, NULL);
1252
1253         if (http_get_file(url, tmp, NULL) != HTTP_OK) {
1254                 error("Unable to get pack index %s", url);
1255                 free(tmp);
1256                 tmp = NULL;
1257         }
1258
1259         free(url);
1260         return tmp;
1261 }
1262
1263 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
1264         unsigned char *sha1, const char *base_url)
1265 {
1266         struct packed_git *new_pack;
1267         char *tmp_idx = NULL;
1268         int ret;
1269
1270         if (has_pack_index(sha1)) {
1271                 new_pack = parse_pack_index(sha1, sha1_pack_index_name(sha1));
1272                 if (!new_pack)
1273                         return -1; /* parse_pack_index() already issued error message */
1274                 goto add_pack;
1275         }
1276
1277         tmp_idx = fetch_pack_index(sha1, base_url);
1278         if (!tmp_idx)
1279                 return -1;
1280
1281         new_pack = parse_pack_index(sha1, tmp_idx);
1282         if (!new_pack) {
1283                 unlink(tmp_idx);
1284                 free(tmp_idx);
1285
1286                 return -1; /* parse_pack_index() already issued error message */
1287         }
1288
1289         ret = verify_pack_index(new_pack);
1290         if (!ret) {
1291                 close_pack_index(new_pack);
1292                 ret = move_temp_to_file(tmp_idx, sha1_pack_index_name(sha1));
1293         }
1294         free(tmp_idx);
1295         if (ret)
1296                 return -1;
1297
1298 add_pack:
1299         new_pack->next = *packs_head;
1300         *packs_head = new_pack;
1301         return 0;
1302 }
1303
1304 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
1305 {
1306         struct http_get_options options = {0};
1307         int ret = 0, i = 0;
1308         char *url, *data;
1309         struct strbuf buf = STRBUF_INIT;
1310         unsigned char sha1[20];
1311
1312         end_url_with_slash(&buf, base_url);
1313         strbuf_addstr(&buf, "objects/info/packs");
1314         url = strbuf_detach(&buf, NULL);
1315
1316         options.no_cache = 1;
1317         ret = http_get_strbuf(url, &buf, &options);
1318         if (ret != HTTP_OK)
1319                 goto cleanup;
1320
1321         data = buf.buf;
1322         while (i < buf.len) {
1323                 switch (data[i]) {
1324                 case 'P':
1325                         i++;
1326                         if (i + 52 <= buf.len &&
1327                             starts_with(data + i, " pack-") &&
1328                             starts_with(data + i + 46, ".pack\n")) {
1329                                 get_sha1_hex(data + i + 6, sha1);
1330                                 fetch_and_setup_pack_index(packs_head, sha1,
1331                                                       base_url);
1332                                 i += 51;
1333                                 break;
1334                         }
1335                 default:
1336                         while (i < buf.len && data[i] != '\n')
1337                                 i++;
1338                 }
1339                 i++;
1340         }
1341
1342 cleanup:
1343         free(url);
1344         return ret;
1345 }
1346
1347 void release_http_pack_request(struct http_pack_request *preq)
1348 {
1349         if (preq->packfile != NULL) {
1350                 fclose(preq->packfile);
1351                 preq->packfile = NULL;
1352         }
1353         if (preq->range_header != NULL) {
1354                 curl_slist_free_all(preq->range_header);
1355                 preq->range_header = NULL;
1356         }
1357         preq->slot = NULL;
1358         free(preq->url);
1359 }
1360
1361 int finish_http_pack_request(struct http_pack_request *preq)
1362 {
1363         struct packed_git **lst;
1364         struct packed_git *p = preq->target;
1365         char *tmp_idx;
1366         struct child_process ip = CHILD_PROCESS_INIT;
1367         const char *ip_argv[8];
1368
1369         close_pack_index(p);
1370
1371         fclose(preq->packfile);
1372         preq->packfile = NULL;
1373
1374         lst = preq->lst;
1375         while (*lst != p)
1376                 lst = &((*lst)->next);
1377         *lst = (*lst)->next;
1378
1379         tmp_idx = xstrdup(preq->tmpfile);
1380         strcpy(tmp_idx + strlen(tmp_idx) - strlen(".pack.temp"),
1381                ".idx.temp");
1382
1383         ip_argv[0] = "index-pack";
1384         ip_argv[1] = "-o";
1385         ip_argv[2] = tmp_idx;
1386         ip_argv[3] = preq->tmpfile;
1387         ip_argv[4] = NULL;
1388
1389         ip.argv = ip_argv;
1390         ip.git_cmd = 1;
1391         ip.no_stdin = 1;
1392         ip.no_stdout = 1;
1393
1394         if (run_command(&ip)) {
1395                 unlink(preq->tmpfile);
1396                 unlink(tmp_idx);
1397                 free(tmp_idx);
1398                 return -1;
1399         }
1400
1401         unlink(sha1_pack_index_name(p->sha1));
1402
1403         if (move_temp_to_file(preq->tmpfile, sha1_pack_name(p->sha1))
1404          || move_temp_to_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
1405                 free(tmp_idx);
1406                 return -1;
1407         }
1408
1409         install_packed_git(p);
1410         free(tmp_idx);
1411         return 0;
1412 }
1413
1414 struct http_pack_request *new_http_pack_request(
1415         struct packed_git *target, const char *base_url)
1416 {
1417         long prev_posn = 0;
1418         char range[RANGE_HEADER_SIZE];
1419         struct strbuf buf = STRBUF_INIT;
1420         struct http_pack_request *preq;
1421
1422         preq = xcalloc(1, sizeof(*preq));
1423         preq->target = target;
1424
1425         end_url_with_slash(&buf, base_url);
1426         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
1427                 sha1_to_hex(target->sha1));
1428         preq->url = strbuf_detach(&buf, NULL);
1429
1430         snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
1431                 sha1_pack_name(target->sha1));
1432         preq->packfile = fopen(preq->tmpfile, "a");
1433         if (!preq->packfile) {
1434                 error("Unable to open local file %s for pack",
1435                       preq->tmpfile);
1436                 goto abort;
1437         }
1438
1439         preq->slot = get_active_slot();
1440         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
1441         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
1442         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
1443         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1444                 no_pragma_header);
1445
1446         /*
1447          * If there is data present from a previous transfer attempt,
1448          * resume where it left off
1449          */
1450         prev_posn = ftell(preq->packfile);
1451         if (prev_posn>0) {
1452                 if (http_is_verbose)
1453                         fprintf(stderr,
1454                                 "Resuming fetch of pack %s at byte %ld\n",
1455                                 sha1_to_hex(target->sha1), prev_posn);
1456                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1457                 preq->range_header = curl_slist_append(NULL, range);
1458                 curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1459                         preq->range_header);
1460         }
1461
1462         return preq;
1463
1464 abort:
1465         free(preq->url);
1466         free(preq);
1467         return NULL;
1468 }
1469
1470 /* Helpers for fetching objects (loose) */
1471 static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
1472                                void *data)
1473 {
1474         unsigned char expn[4096];
1475         size_t size = eltsize * nmemb;
1476         int posn = 0;
1477         struct http_object_request *freq =
1478                 (struct http_object_request *)data;
1479         do {
1480                 ssize_t retval = xwrite(freq->localfile,
1481                                         (char *) ptr + posn, size - posn);
1482                 if (retval < 0)
1483                         return posn;
1484                 posn += retval;
1485         } while (posn < size);
1486
1487         freq->stream.avail_in = size;
1488         freq->stream.next_in = (void *)ptr;
1489         do {
1490                 freq->stream.next_out = expn;
1491                 freq->stream.avail_out = sizeof(expn);
1492                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
1493                 git_SHA1_Update(&freq->c, expn,
1494                                 sizeof(expn) - freq->stream.avail_out);
1495         } while (freq->stream.avail_in && freq->zret == Z_OK);
1496         return size;
1497 }
1498
1499 struct http_object_request *new_http_object_request(const char *base_url,
1500         unsigned char *sha1)
1501 {
1502         char *hex = sha1_to_hex(sha1);
1503         const char *filename;
1504         char prevfile[PATH_MAX];
1505         int prevlocal;
1506         char prev_buf[PREV_BUF_SIZE];
1507         ssize_t prev_read = 0;
1508         long prev_posn = 0;
1509         char range[RANGE_HEADER_SIZE];
1510         struct curl_slist *range_header = NULL;
1511         struct http_object_request *freq;
1512
1513         freq = xcalloc(1, sizeof(*freq));
1514         hashcpy(freq->sha1, sha1);
1515         freq->localfile = -1;
1516
1517         filename = sha1_file_name(sha1);
1518         snprintf(freq->tmpfile, sizeof(freq->tmpfile),
1519                  "%s.temp", filename);
1520
1521         snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
1522         unlink_or_warn(prevfile);
1523         rename(freq->tmpfile, prevfile);
1524         unlink_or_warn(freq->tmpfile);
1525
1526         if (freq->localfile != -1)
1527                 error("fd leakage in start: %d", freq->localfile);
1528         freq->localfile = open(freq->tmpfile,
1529                                O_WRONLY | O_CREAT | O_EXCL, 0666);
1530         /*
1531          * This could have failed due to the "lazy directory creation";
1532          * try to mkdir the last path component.
1533          */
1534         if (freq->localfile < 0 && errno == ENOENT) {
1535                 char *dir = strrchr(freq->tmpfile, '/');
1536                 if (dir) {
1537                         *dir = 0;
1538                         mkdir(freq->tmpfile, 0777);
1539                         *dir = '/';
1540                 }
1541                 freq->localfile = open(freq->tmpfile,
1542                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
1543         }
1544
1545         if (freq->localfile < 0) {
1546                 error("Couldn't create temporary file %s: %s",
1547                       freq->tmpfile, strerror(errno));
1548                 goto abort;
1549         }
1550
1551         git_inflate_init(&freq->stream);
1552
1553         git_SHA1_Init(&freq->c);
1554
1555         freq->url = get_remote_object_url(base_url, hex, 0);
1556
1557         /*
1558          * If a previous temp file is present, process what was already
1559          * fetched.
1560          */
1561         prevlocal = open(prevfile, O_RDONLY);
1562         if (prevlocal != -1) {
1563                 do {
1564                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
1565                         if (prev_read>0) {
1566                                 if (fwrite_sha1_file(prev_buf,
1567                                                      1,
1568                                                      prev_read,
1569                                                      freq) == prev_read) {
1570                                         prev_posn += prev_read;
1571                                 } else {
1572                                         prev_read = -1;
1573                                 }
1574                         }
1575                 } while (prev_read > 0);
1576                 close(prevlocal);
1577         }
1578         unlink_or_warn(prevfile);
1579
1580         /*
1581          * Reset inflate/SHA1 if there was an error reading the previous temp
1582          * file; also rewind to the beginning of the local file.
1583          */
1584         if (prev_read == -1) {
1585                 memset(&freq->stream, 0, sizeof(freq->stream));
1586                 git_inflate_init(&freq->stream);
1587                 git_SHA1_Init(&freq->c);
1588                 if (prev_posn>0) {
1589                         prev_posn = 0;
1590                         lseek(freq->localfile, 0, SEEK_SET);
1591                         if (ftruncate(freq->localfile, 0) < 0) {
1592                                 error("Couldn't truncate temporary file %s: %s",
1593                                           freq->tmpfile, strerror(errno));
1594                                 goto abort;
1595                         }
1596                 }
1597         }
1598
1599         freq->slot = get_active_slot();
1600
1601         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
1602         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
1603         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
1604         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
1605         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
1606
1607         /*
1608          * If we have successfully processed data from a previous fetch
1609          * attempt, only fetch the data we don't already have.
1610          */
1611         if (prev_posn>0) {
1612                 if (http_is_verbose)
1613                         fprintf(stderr,
1614                                 "Resuming fetch of object %s at byte %ld\n",
1615                                 hex, prev_posn);
1616                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1617                 range_header = curl_slist_append(range_header, range);
1618                 curl_easy_setopt(freq->slot->curl,
1619                                  CURLOPT_HTTPHEADER, range_header);
1620         }
1621
1622         return freq;
1623
1624 abort:
1625         free(freq->url);
1626         free(freq);
1627         return NULL;
1628 }
1629
1630 void process_http_object_request(struct http_object_request *freq)
1631 {
1632         if (freq->slot == NULL)
1633                 return;
1634         freq->curl_result = freq->slot->curl_result;
1635         freq->http_code = freq->slot->http_code;
1636         freq->slot = NULL;
1637 }
1638
1639 int finish_http_object_request(struct http_object_request *freq)
1640 {
1641         struct stat st;
1642
1643         close(freq->localfile);
1644         freq->localfile = -1;
1645
1646         process_http_object_request(freq);
1647
1648         if (freq->http_code == 416) {
1649                 warning("requested range invalid; we may already have all the data.");
1650         } else if (freq->curl_result != CURLE_OK) {
1651                 if (stat(freq->tmpfile, &st) == 0)
1652                         if (st.st_size == 0)
1653                                 unlink_or_warn(freq->tmpfile);
1654                 return -1;
1655         }
1656
1657         git_inflate_end(&freq->stream);
1658         git_SHA1_Final(freq->real_sha1, &freq->c);
1659         if (freq->zret != Z_STREAM_END) {
1660                 unlink_or_warn(freq->tmpfile);
1661                 return -1;
1662         }
1663         if (hashcmp(freq->sha1, freq->real_sha1)) {
1664                 unlink_or_warn(freq->tmpfile);
1665                 return -1;
1666         }
1667         freq->rename =
1668                 move_temp_to_file(freq->tmpfile, sha1_file_name(freq->sha1));
1669
1670         return freq->rename;
1671 }
1672
1673 void abort_http_object_request(struct http_object_request *freq)
1674 {
1675         unlink_or_warn(freq->tmpfile);
1676
1677         release_http_object_request(freq);
1678 }
1679
1680 void release_http_object_request(struct http_object_request *freq)
1681 {
1682         if (freq->localfile != -1) {
1683                 close(freq->localfile);
1684                 freq->localfile = -1;
1685         }
1686         if (freq->url != NULL) {
1687                 free(freq->url);
1688                 freq->url = NULL;
1689         }
1690         if (freq->slot != NULL) {
1691                 freq->slot->callback_func = NULL;
1692                 freq->slot->callback_data = NULL;
1693                 release_active_slot(freq->slot);
1694                 freq->slot = NULL;
1695         }
1696 }