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

   1 #include "git-compat-util.h"
   2 #include "http.h"
   3 #include "pack.h"
   4 #include "sideband.h"
   5 #include "run-command.h"
   6 #include "url.h"
   7 #include "urlmatch.h"
   8 #include "credential.h"
   9 #include "version.h"
  10 #include "pkt-line.h"
  11 #include "gettext.h"
  12 #include "transport.h"
  13
  14 int active_requests;
  15 int http_is_verbose;
  16 size_t http_post_buffer = 16 * LARGE_PACKET_MAX;
  17
  18 #if LIBCURL_VERSION_NUM >= 0x070a06
  19 #define LIBCURL_CAN_HANDLE_AUTH_ANY
  20 #endif
  21
  22 static int min_curl_sessions = 1;
  23 static int curl_session_count;
  24 #ifdef USE_CURL_MULTI
  25 static int max_requests = -1;
  26 static CURLM *curlm;
  27 #endif
  28 #ifndef NO_CURL_EASY_DUPHANDLE
  29 static CURL *curl_default;
  30 #endif
  31
  32 #define PREV_BUF_SIZE 4096
  33 #define RANGE_HEADER_SIZE 30
  34
  35 char curl_errorstr[CURL_ERROR_SIZE];
  36
  37 static int curl_ssl_verify = -1;
  38 static int curl_ssl_try;
  39 static const char *ssl_cert;
  40 static const char *ssl_cipherlist;
  41 static const char *ssl_version;
  42 static struct {
  43         const char *name;
  44         long ssl_version;
  45 } sslversions[] = {
  46         { "sslv2", CURL_SSLVERSION_SSLv2 },
  47         { "sslv3", CURL_SSLVERSION_SSLv3 },
  48         { "tlsv1", CURL_SSLVERSION_TLSv1 },
  49 #if LIBCURL_VERSION_NUM >= 0x072200
  50         { "tlsv1.0", CURL_SSLVERSION_TLSv1_0 },
  51         { "tlsv1.1", CURL_SSLVERSION_TLSv1_1 },
  52         { "tlsv1.2", CURL_SSLVERSION_TLSv1_2 },
  53 #endif
  54 };
  55 #if LIBCURL_VERSION_NUM >= 0x070903
  56 static const char *ssl_key;
  57 #endif
  58 #if LIBCURL_VERSION_NUM >= 0x070908
  59 static const char *ssl_capath;
  60 #endif
  61 static const char *ssl_cainfo;
  62 static long curl_low_speed_limit = -1;
  63 static long curl_low_speed_time = -1;
  64 static int curl_ftp_no_epsv;
  65 static const char *curl_http_proxy;
  66 static const char *curl_cookie_file;
  67 static int curl_save_cookies;
  68 struct credential http_auth = CREDENTIAL_INIT;
  69 static int http_proactive_auth;
  70 static const char *user_agent;
  71
  72 #if LIBCURL_VERSION_NUM >= 0x071700
  73 /* Use CURLOPT_KEYPASSWD as is */
  74 #elif LIBCURL_VERSION_NUM >= 0x070903
  75 #define CURLOPT_KEYPASSWD CURLOPT_SSLKEYPASSWD
  76 #else
  77 #define CURLOPT_KEYPASSWD CURLOPT_SSLCERTPASSWD
  78 #endif
  79
  80 static struct credential cert_auth = CREDENTIAL_INIT;
  81 static int ssl_cert_password_required;
  82 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
  83 static unsigned long http_auth_methods = CURLAUTH_ANY;
  84 #endif
  85
  86 static struct curl_slist *pragma_header;
  87 static struct curl_slist *no_pragma_header;
  88
  89 static struct active_request_slot *active_queue_head;
  90
  91 static char *cached_accept_language;
  92
  93 size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
  94 {
  95         size_t size = eltsize * nmemb;
  96         struct buffer *buffer = buffer_;
  97
  98         if (size > buffer->buf.len - buffer->posn)
  99                 size = buffer->buf.len - buffer->posn;
 100         memcpy(ptr, buffer->buf.buf + buffer->posn, size);
 101         buffer->posn += size;
 102
 103         return size;
 104 }
 105
 106 #ifndef NO_CURL_IOCTL
 107 curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)
 108 {
 109         struct buffer *buffer = clientp;
 110
 111         switch (cmd) {
 112         case CURLIOCMD_NOP:
 113                 return CURLIOE_OK;
 114
 115         case CURLIOCMD_RESTARTREAD:
 116                 buffer->posn = 0;
 117                 return CURLIOE_OK;
 118
 119         default:
 120                 return CURLIOE_UNKNOWNCMD;
 121         }
 122 }
 123 #endif
 124
 125 size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
 126 {
 127         size_t size = eltsize * nmemb;
 128         struct strbuf *buffer = buffer_;
 129
 130         strbuf_add(buffer, ptr, size);
 131         return size;
 132 }
 133
 134 size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf)
 135 {
 136         return eltsize * nmemb;
 137 }
 138
 139 static void closedown_active_slot(struct active_request_slot *slot)
 140 {
 141         active_requests--;
 142         slot->in_use = 0;
 143 }
 144
 145 static void finish_active_slot(struct active_request_slot *slot)
 146 {
 147         closedown_active_slot(slot);
 148         curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
 149
 150         if (slot->finished != NULL)
 151                 (*slot->finished) = 1;
 152
 153         /* Store slot results so they can be read after the slot is reused */
 154         if (slot->results != NULL) {
 155                 slot->results->curl_result = slot->curl_result;
 156                 slot->results->http_code = slot->http_code;
 157 #if LIBCURL_VERSION_NUM >= 0x070a08
 158                 curl_easy_getinfo(slot->curl, CURLINFO_HTTPAUTH_AVAIL,
 159                                   &slot->results->auth_avail);
 160 #else
 161                 slot->results->auth_avail = 0;
 162 #endif
 163         }
 164
 165         /* Run callback if appropriate */
 166         if (slot->callback_func != NULL)
 167                 slot->callback_func(slot->callback_data);
 168 }
 169
 170 #ifdef USE_CURL_MULTI
 171 static void process_curl_messages(void)
 172 {
 173         int num_messages;
 174         struct active_request_slot *slot;
 175         CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
 176
 177         while (curl_message != NULL) {
 178                 if (curl_message->msg == CURLMSG_DONE) {
 179                         int curl_result = curl_message->data.result;
 180                         slot = active_queue_head;
 181                         while (slot != NULL &&
 182                                slot->curl != curl_message->easy_handle)
 183                                 slot = slot->next;
 184                         if (slot != NULL) {
 185                                 curl_multi_remove_handle(curlm, slot->curl);
 186                                 slot->curl_result = curl_result;
 187                                 finish_active_slot(slot);
 188                         } else {
 189                                 fprintf(stderr, "Received DONE message for unknown request!\n");
 190                         }
 191                 } else {
 192                         fprintf(stderr, "Unknown CURL message received: %d\n",
 193                                 (int)curl_message->msg);
 194                 }
 195                 curl_message = curl_multi_info_read(curlm, &num_messages);
 196         }
 197 }
 198 #endif
 199
 200 static int http_options(const char *var, const char *value, void *cb)
 201 {
 202         if (!strcmp("http.sslverify", var)) {
 203                 curl_ssl_verify = git_config_bool(var, value);
 204                 return 0;
 205         }
 206         if (!strcmp("http.sslcipherlist", var))
 207                 return git_config_string(&ssl_cipherlist, var, value);
 208         if (!strcmp("http.sslversion", var))
 209                 return git_config_string(&ssl_version, var, value);
 210         if (!strcmp("http.sslcert", var))
 211                 return git_config_string(&ssl_cert, var, value);
 212 #if LIBCURL_VERSION_NUM >= 0x070903
 213         if (!strcmp("http.sslkey", var))
 214                 return git_config_string(&ssl_key, var, value);
 215 #endif
 216 #if LIBCURL_VERSION_NUM >= 0x070908
 217         if (!strcmp("http.sslcapath", var))
 218                 return git_config_pathname(&ssl_capath, var, value);
 219 #endif
 220         if (!strcmp("http.sslcainfo", var))
 221                 return git_config_pathname(&ssl_cainfo, var, value);
 222         if (!strcmp("http.sslcertpasswordprotected", var)) {
 223                 ssl_cert_password_required = git_config_bool(var, value);
 224                 return 0;
 225         }
 226         if (!strcmp("http.ssltry", var)) {
 227                 curl_ssl_try = git_config_bool(var, value);
 228                 return 0;
 229         }
 230         if (!strcmp("http.minsessions", var)) {
 231                 min_curl_sessions = git_config_int(var, value);
 232 #ifndef USE_CURL_MULTI
 233                 if (min_curl_sessions > 1)
 234                         min_curl_sessions = 1;
 235 #endif
 236                 return 0;
 237         }
 238 #ifdef USE_CURL_MULTI
 239         if (!strcmp("http.maxrequests", var)) {
 240                 max_requests = git_config_int(var, value);
 241                 return 0;
 242         }
 243 #endif
 244         if (!strcmp("http.lowspeedlimit", var)) {
 245                 curl_low_speed_limit = (long)git_config_int(var, value);
 246                 return 0;
 247         }
 248         if (!strcmp("http.lowspeedtime", var)) {
 249                 curl_low_speed_time = (long)git_config_int(var, value);
 250                 return 0;
 251         }
 252
 253         if (!strcmp("http.noepsv", var)) {
 254                 curl_ftp_no_epsv = git_config_bool(var, value);
 255                 return 0;
 256         }
 257         if (!strcmp("http.proxy", var))
 258                 return git_config_string(&curl_http_proxy, var, value);
 259
 260         if (!strcmp("http.cookiefile", var))
 261                 return git_config_string(&curl_cookie_file, var, value);
 262         if (!strcmp("http.savecookies", var)) {
 263                 curl_save_cookies = git_config_bool(var, value);
 264                 return 0;
 265         }
 266
 267         if (!strcmp("http.postbuffer", var)) {
 268                 http_post_buffer = git_config_int(var, value);
 269                 if (http_post_buffer < LARGE_PACKET_MAX)
 270                         http_post_buffer = LARGE_PACKET_MAX;
 271                 return 0;
 272         }
 273
 274         if (!strcmp("http.useragent", var))
 275                 return git_config_string(&user_agent, var, value);
 276
 277         /* Fall back on the default ones */
 278         return git_default_config(var, value, cb);
 279 }
 280
 281 static void init_curl_http_auth(CURL *result)
 282 {
 283         if (!http_auth.username)
 284                 return;
 285
 286         credential_fill(&http_auth);
 287
 288 #if LIBCURL_VERSION_NUM >= 0x071301
 289         curl_easy_setopt(result, CURLOPT_USERNAME, http_auth.username);
 290         curl_easy_setopt(result, CURLOPT_PASSWORD, http_auth.password);
 291 #else
 292         {
 293                 static struct strbuf up = STRBUF_INIT;
 294                 /*
 295                  * Note that we assume we only ever have a single set of
 296                  * credentials in a given program run, so we do not have
 297                  * to worry about updating this buffer, only setting its
 298                  * initial value.
 299                  */
 300                 if (!up.len)
 301                         strbuf_addf(&up, "%s:%s",
 302                                 http_auth.username, http_auth.password);
 303                 curl_easy_setopt(result, CURLOPT_USERPWD, up.buf);
 304         }
 305 #endif
 306 }
 307
 308 static int has_cert_password(void)
 309 {
 310         if (ssl_cert == NULL || ssl_cert_password_required != 1)
 311                 return 0;
 312         if (!cert_auth.password) {
 313                 cert_auth.protocol = xstrdup("cert");
 314                 cert_auth.username = xstrdup("");
 315                 cert_auth.path = xstrdup(ssl_cert);
 316                 credential_fill(&cert_auth);
 317         }
 318         return 1;
 319 }
 320
 321 #if LIBCURL_VERSION_NUM >= 0x071900
 322 static void set_curl_keepalive(CURL *c)
 323 {
 324         curl_easy_setopt(c, CURLOPT_TCP_KEEPALIVE, 1);
 325 }
 326
 327 #elif LIBCURL_VERSION_NUM >= 0x071000
 328 static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
 329 {
 330         int ka = 1;
 331         int rc;
 332         socklen_t len = (socklen_t)sizeof(ka);
 333
 334         if (type != CURLSOCKTYPE_IPCXN)
 335                 return 0;
 336
 337         rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
 338         if (rc < 0)
 339                 warning("unable to set SO_KEEPALIVE on socket %s",
 340                         strerror(errno));
 341
 342         return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
 343 }
 344
 345 static void set_curl_keepalive(CURL *c)
 346 {
 347         curl_easy_setopt(c, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
 348 }
 349
 350 #else
 351 static void set_curl_keepalive(CURL *c)
 352 {
 353         /* not supported on older curl versions */
 354 }
 355 #endif
 356
 357 static CURL *get_curl_handle(void)
 358 {
 359         CURL *result = curl_easy_init();
 360         long allowed_protocols = 0;
 361
 362         if (!result)
 363                 die("curl_easy_init failed");
 364
 365         if (!curl_ssl_verify) {
 366                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
 367                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
 368         } else {
 369                 /* Verify authenticity of the peer's certificate */
 370                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
 371                 /* The name in the cert must match whom we tried to connect */
 372                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
 373         }
 374
 375 #if LIBCURL_VERSION_NUM >= 0x070907
 376         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
 377 #endif
 378 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 379         curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
 380 #endif
 381
 382         if (http_proactive_auth)
 383                 init_curl_http_auth(result);
 384
 385         if (getenv("GIT_SSL_VERSION"))
 386                 ssl_version = getenv("GIT_SSL_VERSION");
 387         if (ssl_version && *ssl_version) {
 388                 int i;
 389                 for (i = 0; i < ARRAY_SIZE(sslversions); i++) {
 390                         if (!strcmp(ssl_version, sslversions[i].name)) {
 391                                 curl_easy_setopt(result, CURLOPT_SSLVERSION,
 392                                                  sslversions[i].ssl_version);
 393                                 break;
 394                         }
 395                 }
 396                 if (i == ARRAY_SIZE(sslversions))
 397                         warning("unsupported ssl version %s: using default",
 398                                 ssl_version);
 399         }
 400
 401         if (getenv("GIT_SSL_CIPHER_LIST"))
 402                 ssl_cipherlist = getenv("GIT_SSL_CIPHER_LIST");
 403         if (ssl_cipherlist != NULL && *ssl_cipherlist)
 404                 curl_easy_setopt(result, CURLOPT_SSL_CIPHER_LIST,
 405                                 ssl_cipherlist);
 406
 407         if (ssl_cert != NULL)
 408                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
 409         if (has_cert_password())
 410                 curl_easy_setopt(result, CURLOPT_KEYPASSWD, cert_auth.password);
 411 #if LIBCURL_VERSION_NUM >= 0x070903
 412         if (ssl_key != NULL)
 413                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
 414 #endif
 415 #if LIBCURL_VERSION_NUM >= 0x070908
 416         if (ssl_capath != NULL)
 417                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
 418 #endif
 419         if (ssl_cainfo != NULL)
 420                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
 421
 422         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
 423                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
 424                                  curl_low_speed_limit);
 425                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
 426                                  curl_low_speed_time);
 427         }
 428
 429         curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
 430         curl_easy_setopt(result, CURLOPT_MAXREDIRS, 20);
 431 #if LIBCURL_VERSION_NUM >= 0x071301
 432         curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
 433 #elif LIBCURL_VERSION_NUM >= 0x071101
 434         curl_easy_setopt(result, CURLOPT_POST301, 1);
 435 #endif
 436 #if LIBCURL_VERSION_NUM >= 0x071304
 437         if (is_transport_allowed("http"))
 438                 allowed_protocols |= CURLPROTO_HTTP;
 439         if (is_transport_allowed("https"))
 440                 allowed_protocols |= CURLPROTO_HTTPS;
 441         if (is_transport_allowed("ftp"))
 442                 allowed_protocols |= CURLPROTO_FTP;
 443         if (is_transport_allowed("ftps"))
 444                 allowed_protocols |= CURLPROTO_FTPS;
 445         curl_easy_setopt(result, CURLOPT_REDIR_PROTOCOLS, allowed_protocols);
 446 #else
 447         if (transport_restrict_protocols())
 448                 warning("protocol restrictions not applied to curl redirects because\n"
 449                         "your curl version is too old (>= 7.19.4)");
 450 #endif
 451
 452         if (getenv("GIT_CURL_VERBOSE"))
 453                 curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
 454
 455         curl_easy_setopt(result, CURLOPT_USERAGENT,
 456                 user_agent ? user_agent : git_user_agent());
 457
 458         if (curl_ftp_no_epsv)
 459                 curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
 460
 461 #ifdef CURLOPT_USE_SSL
 462         if (curl_ssl_try)
 463                 curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
 464 #endif
 465
 466         if (curl_http_proxy) {
 467                 curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
 468 #if LIBCURL_VERSION_NUM >= 0x071800
 469                 if (starts_with(curl_http_proxy, "socks5"))
 470                         curl_easy_setopt(result,
 471                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);
 472                 else if (starts_with(curl_http_proxy, "socks4a"))
 473                         curl_easy_setopt(result,
 474                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4A);
 475                 else if (starts_with(curl_http_proxy, "socks"))
 476                         curl_easy_setopt(result,
 477                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4);
 478 #endif
 479         }
 480 #if LIBCURL_VERSION_NUM >= 0x070a07
 481         curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
 482 #endif
 483
 484         set_curl_keepalive(result);
 485
 486         return result;
 487 }
 488
 489 static void set_from_env(const char **var, const char *envname)
 490 {
 491         const char *val = getenv(envname);
 492         if (val)
 493                 *var = val;
 494 }
 495
 496 void http_init(struct remote *remote, const char *url, int proactive_auth)
 497 {
 498         char *low_speed_limit;
 499         char *low_speed_time;
 500         char *normalized_url;
 501         struct urlmatch_config config = { STRING_LIST_INIT_DUP };
 502
 503         config.section = "http";
 504         config.key = NULL;
 505         config.collect_fn = http_options;
 506         config.cascade_fn = git_default_config;
 507         config.cb = NULL;
 508
 509         http_is_verbose = 0;
 510         normalized_url = url_normalize(url, &config.url);
 511
 512         git_config(urlmatch_config_entry, &config);
 513         free(normalized_url);
 514
 515         if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK)
 516                 die("curl_global_init failed");
 517
 518         http_proactive_auth = proactive_auth;
 519
 520         if (remote && remote->http_proxy)
 521                 curl_http_proxy = xstrdup(remote->http_proxy);
 522
 523         pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
 524         no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
 525
 526 #ifdef USE_CURL_MULTI
 527         {
 528                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
 529                 if (http_max_requests != NULL)
 530                         max_requests = atoi(http_max_requests);
 531         }
 532
 533         curlm = curl_multi_init();
 534         if (!curlm)
 535                 die("curl_multi_init failed");
 536 #endif
 537
 538         if (getenv("GIT_SSL_NO_VERIFY"))
 539                 curl_ssl_verify = 0;
 540
 541         set_from_env(&ssl_cert, "GIT_SSL_CERT");
 542 #if LIBCURL_VERSION_NUM >= 0x070903
 543         set_from_env(&ssl_key, "GIT_SSL_KEY");
 544 #endif
 545 #if LIBCURL_VERSION_NUM >= 0x070908
 546         set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
 547 #endif
 548         set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
 549
 550         set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");
 551
 552         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
 553         if (low_speed_limit != NULL)
 554                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
 555         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
 556         if (low_speed_time != NULL)
 557                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
 558
 559         if (curl_ssl_verify == -1)
 560                 curl_ssl_verify = 1;
 561
 562         curl_session_count = 0;
 563 #ifdef USE_CURL_MULTI
 564         if (max_requests < 1)
 565                 max_requests = DEFAULT_MAX_REQUESTS;
 566 #endif
 567
 568         if (getenv("GIT_CURL_FTP_NO_EPSV"))
 569                 curl_ftp_no_epsv = 1;
 570
 571         if (url) {
 572                 credential_from_url(&http_auth, url);
 573                 if (!ssl_cert_password_required &&
 574                     getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
 575                     starts_with(url, "https://"))
 576                         ssl_cert_password_required = 1;
 577         }
 578
 579 #ifndef NO_CURL_EASY_DUPHANDLE
 580         curl_default = get_curl_handle();
 581 #endif
 582 }
 583
 584 void http_cleanup(void)
 585 {
 586         struct active_request_slot *slot = active_queue_head;
 587
 588         while (slot != NULL) {
 589                 struct active_request_slot *next = slot->next;
 590                 if (slot->curl != NULL) {
 591 #ifdef USE_CURL_MULTI
 592                         curl_multi_remove_handle(curlm, slot->curl);
 593 #endif
 594                         curl_easy_cleanup(slot->curl);
 595                 }
 596                 free(slot);
 597                 slot = next;
 598         }
 599         active_queue_head = NULL;
 600
 601 #ifndef NO_CURL_EASY_DUPHANDLE
 602         curl_easy_cleanup(curl_default);
 603 #endif
 604
 605 #ifdef USE_CURL_MULTI
 606         curl_multi_cleanup(curlm);
 607 #endif
 608         curl_global_cleanup();
 609
 610         curl_slist_free_all(pragma_header);
 611         pragma_header = NULL;
 612
 613         curl_slist_free_all(no_pragma_header);
 614         no_pragma_header = NULL;
 615
 616         if (curl_http_proxy) {
 617                 free((void *)curl_http_proxy);
 618                 curl_http_proxy = NULL;
 619         }
 620
 621         if (cert_auth.password != NULL) {
 622                 memset(cert_auth.password, 0, strlen(cert_auth.password));
 623                 free(cert_auth.password);
 624                 cert_auth.password = NULL;
 625         }
 626         ssl_cert_password_required = 0;
 627
 628         free(cached_accept_language);
 629         cached_accept_language = NULL;
 630 }
 631
 632 struct active_request_slot *get_active_slot(void)
 633 {
 634         struct active_request_slot *slot = active_queue_head;
 635         struct active_request_slot *newslot;
 636
 637 #ifdef USE_CURL_MULTI
 638         int num_transfers;
 639
 640         /* Wait for a slot to open up if the queue is full */
 641         while (active_requests >= max_requests) {
 642                 curl_multi_perform(curlm, &num_transfers);
 643                 if (num_transfers < active_requests)
 644                         process_curl_messages();
 645         }
 646 #endif
 647
 648         while (slot != NULL && slot->in_use)
 649                 slot = slot->next;
 650
 651         if (slot == NULL) {
 652                 newslot = xmalloc(sizeof(*newslot));
 653                 newslot->curl = NULL;
 654                 newslot->in_use = 0;
 655                 newslot->next = NULL;
 656
 657                 slot = active_queue_head;
 658                 if (slot == NULL) {
 659                         active_queue_head = newslot;
 660                 } else {
 661                         while (slot->next != NULL)
 662                                 slot = slot->next;
 663                         slot->next = newslot;
 664                 }
 665                 slot = newslot;
 666         }
 667
 668         if (slot->curl == NULL) {
 669 #ifdef NO_CURL_EASY_DUPHANDLE
 670                 slot->curl = get_curl_handle();
 671 #else
 672                 slot->curl = curl_easy_duphandle(curl_default);
 673 #endif
 674                 curl_session_count++;
 675         }
 676
 677         active_requests++;
 678         slot->in_use = 1;
 679         slot->results = NULL;
 680         slot->finished = NULL;
 681         slot->callback_data = NULL;
 682         slot->callback_func = NULL;
 683         curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file);
 684         if (curl_save_cookies)
 685                 curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file);
 686         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
 687         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
 688         curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
 689         curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
 690         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
 691         curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
 692         curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
 693         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
 694         curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
 695 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 696         curl_easy_setopt(slot->curl, CURLOPT_HTTPAUTH, http_auth_methods);
 697 #endif
 698         if (http_auth.password)
 699                 init_curl_http_auth(slot->curl);
 700
 701         return slot;
 702 }
 703
 704 int start_active_slot(struct active_request_slot *slot)
 705 {
 706 #ifdef USE_CURL_MULTI
 707         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
 708         int num_transfers;
 709
 710         if (curlm_result != CURLM_OK &&
 711             curlm_result != CURLM_CALL_MULTI_PERFORM) {
 712                 active_requests--;
 713                 slot->in_use = 0;
 714                 return 0;
 715         }
 716
 717         /*
 718          * We know there must be something to do, since we just added
 719          * something.
 720          */
 721         curl_multi_perform(curlm, &num_transfers);
 722 #endif
 723         return 1;
 724 }
 725
 726 #ifdef USE_CURL_MULTI
 727 struct fill_chain {
 728         void *data;
 729         int (*fill)(void *);
 730         struct fill_chain *next;
 731 };
 732
 733 static struct fill_chain *fill_cfg;
 734
 735 void add_fill_function(void *data, int (*fill)(void *))
 736 {
 737         struct fill_chain *new = xmalloc(sizeof(*new));
 738         struct fill_chain **linkp = &fill_cfg;
 739         new->data = data;
 740         new->fill = fill;
 741         new->next = NULL;
 742         while (*linkp)
 743                 linkp = &(*linkp)->next;
 744         *linkp = new;
 745 }
 746
 747 void fill_active_slots(void)
 748 {
 749         struct active_request_slot *slot = active_queue_head;
 750
 751         while (active_requests < max_requests) {
 752                 struct fill_chain *fill;
 753                 for (fill = fill_cfg; fill; fill = fill->next)
 754                         if (fill->fill(fill->data))
 755                                 break;
 756
 757                 if (!fill)
 758                         break;
 759         }
 760
 761         while (slot != NULL) {
 762                 if (!slot->in_use && slot->curl != NULL
 763                         && curl_session_count > min_curl_sessions) {
 764                         curl_easy_cleanup(slot->curl);
 765                         slot->curl = NULL;
 766                         curl_session_count--;
 767                 }
 768                 slot = slot->next;
 769         }
 770 }
 771
 772 void step_active_slots(void)
 773 {
 774         int num_transfers;
 775         CURLMcode curlm_result;
 776
 777         do {
 778                 curlm_result = curl_multi_perform(curlm, &num_transfers);
 779         } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
 780         if (num_transfers < active_requests) {
 781                 process_curl_messages();
 782                 fill_active_slots();
 783         }
 784 }
 785 #endif
 786
 787 void run_active_slot(struct active_request_slot *slot)
 788 {
 789 #ifdef USE_CURL_MULTI
 790         fd_set readfds;
 791         fd_set writefds;
 792         fd_set excfds;
 793         int max_fd;
 794         struct timeval select_timeout;
 795         int finished = 0;
 796
 797         slot->finished = &finished;
 798         while (!finished) {
 799                 step_active_slots();
 800
 801                 if (slot->in_use) {
 802 #if LIBCURL_VERSION_NUM >= 0x070f04
 803                         long curl_timeout;
 804                         curl_multi_timeout(curlm, &curl_timeout);
 805                         if (curl_timeout == 0) {
 806                                 continue;
 807                         } else if (curl_timeout == -1) {
 808                                 select_timeout.tv_sec  = 0;
 809                                 select_timeout.tv_usec = 50000;
 810                         } else {
 811                                 select_timeout.tv_sec  =  curl_timeout / 1000;
 812                                 select_timeout.tv_usec = (curl_timeout % 1000) * 1000;
 813                         }
 814 #else
 815                         select_timeout.tv_sec  = 0;
 816                         select_timeout.tv_usec = 50000;
 817 #endif
 818
 819                         max_fd = -1;
 820                         FD_ZERO(&readfds);
 821                         FD_ZERO(&writefds);
 822                         FD_ZERO(&excfds);
 823                         curl_multi_fdset(curlm, &readfds, &writefds, &excfds, &max_fd);
 824
 825                         /*
 826                          * It can happen that curl_multi_timeout returns a pathologically
 827                          * long timeout when curl_multi_fdset returns no file descriptors
 828                          * to read.  See commit message for more details.
 829                          */
 830                         if (max_fd < 0 &&
 831                             (select_timeout.tv_sec > 0 ||
 832                              select_timeout.tv_usec > 50000)) {
 833                                 select_timeout.tv_sec  = 0;
 834                                 select_timeout.tv_usec = 50000;
 835                         }
 836
 837                         select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
 838                 }
 839         }
 840 #else
 841         while (slot->in_use) {
 842                 slot->curl_result = curl_easy_perform(slot->curl);
 843                 finish_active_slot(slot);
 844         }
 845 #endif
 846 }
 847
 848 static void release_active_slot(struct active_request_slot *slot)
 849 {
 850         closedown_active_slot(slot);
 851         if (slot->curl && curl_session_count > min_curl_sessions) {
 852 #ifdef USE_CURL_MULTI
 853                 curl_multi_remove_handle(curlm, slot->curl);
 854 #endif
 855                 curl_easy_cleanup(slot->curl);
 856                 slot->curl = NULL;
 857                 curl_session_count--;
 858         }
 859 #ifdef USE_CURL_MULTI
 860         fill_active_slots();
 861 #endif
 862 }
 863
 864 void finish_all_active_slots(void)
 865 {
 866         struct active_request_slot *slot = active_queue_head;
 867
 868         while (slot != NULL)
 869                 if (slot->in_use) {
 870                         run_active_slot(slot);
 871                         slot = active_queue_head;
 872                 } else {
 873                         slot = slot->next;
 874                 }
 875 }
 876
 877 /* Helpers for modifying and creating URLs */
 878 static inline int needs_quote(int ch)
 879 {
 880         if (((ch >= 'A') && (ch <= 'Z'))
 881                         || ((ch >= 'a') && (ch <= 'z'))
 882                         || ((ch >= '0') && (ch <= '9'))
 883                         || (ch == '/')
 884                         || (ch == '-')
 885                         || (ch == '.'))
 886                 return 0;
 887         return 1;
 888 }
 889
 890 static char *quote_ref_url(const char *base, const char *ref)
 891 {
 892         struct strbuf buf = STRBUF_INIT;
 893         const char *cp;
 894         int ch;
 895
 896         end_url_with_slash(&buf, base);
 897
 898         for (cp = ref; (ch = *cp) != 0; cp++)
 899                 if (needs_quote(ch))
 900                         strbuf_addf(&buf, "%%%02x", ch);
 901                 else
 902                         strbuf_addch(&buf, *cp);
 903
 904         return strbuf_detach(&buf, NULL);
 905 }
 906
 907 void append_remote_object_url(struct strbuf *buf, const char *url,
 908                               const char *hex,
 909                               int only_two_digit_prefix)
 910 {
 911         end_url_with_slash(buf, url);
 912
 913         strbuf_addf(buf, "objects/%.*s/", 2, hex);
 914         if (!only_two_digit_prefix)
 915                 strbuf_addf(buf, "%s", hex+2);
 916 }
 917
 918 char *get_remote_object_url(const char *url, const char *hex,
 919                             int only_two_digit_prefix)
 920 {
 921         struct strbuf buf = STRBUF_INIT;
 922         append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
 923         return strbuf_detach(&buf, NULL);
 924 }
 925
 926 static int handle_curl_result(struct slot_results *results)
 927 {
 928         /*
 929          * If we see a failing http code with CURLE_OK, we have turned off
 930          * FAILONERROR (to keep the server's custom error response), and should
 931          * translate the code into failure here.
 932          */
 933         if (results->curl_result == CURLE_OK &&
 934             results->http_code >= 400) {
 935                 results->curl_result = CURLE_HTTP_RETURNED_ERROR;
 936                 /*
 937                  * Normally curl will already have put the "reason phrase"
 938                  * from the server into curl_errorstr; unfortunately without
 939                  * FAILONERROR it is lost, so we can give only the numeric
 940                  * status code.
 941                  */
 942                 snprintf(curl_errorstr, sizeof(curl_errorstr),
 943                          "The requested URL returned error: %ld",
 944                          results->http_code);
 945         }
 946
 947         if (results->curl_result == CURLE_OK) {
 948                 credential_approve(&http_auth);
 949                 return HTTP_OK;
 950         } else if (missing_target(results))
 951                 return HTTP_MISSING_TARGET;
 952         else if (results->http_code == 401) {
 953                 if (http_auth.username && http_auth.password) {
 954                         credential_reject(&http_auth);
 955                         return HTTP_NOAUTH;
 956                 } else {
 957 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 958                         http_auth_methods &= ~CURLAUTH_GSSNEGOTIATE;
 959 #endif
 960                         return HTTP_REAUTH;
 961                 }
 962         } else {
 963 #if LIBCURL_VERSION_NUM >= 0x070c00
 964                 if (!curl_errorstr[0])
 965                         strlcpy(curl_errorstr,
 966                                 curl_easy_strerror(results->curl_result),
 967                                 sizeof(curl_errorstr));
 968 #endif
 969                 return HTTP_ERROR;
 970         }
 971 }
 972
 973 int run_one_slot(struct active_request_slot *slot,
 974                  struct slot_results *results)
 975 {
 976         slot->results = results;
 977         if (!start_active_slot(slot)) {
 978                 snprintf(curl_errorstr, sizeof(curl_errorstr),
 979                          "failed to start HTTP request");
 980                 return HTTP_START_FAILED;
 981         }
 982
 983         run_active_slot(slot);
 984         return handle_curl_result(results);
 985 }
 986
 987 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
 988 {
 989         char *ptr;
 990         CURLcode ret;
 991
 992         strbuf_reset(buf);
 993         ret = curl_easy_getinfo(curl, info, &ptr);
 994         if (!ret && ptr)
 995                 strbuf_addstr(buf, ptr);
 996         return ret;
 997 }
 998
 999 /*
1000  * Check for and extract a content-type parameter. "raw"
1001  * should be positioned at the start of the potential
1002  * parameter, with any whitespace already removed.
1003  *
1004  * "name" is the name of the parameter. The value is appended
1005  * to "out".
1006  */
1007 static int extract_param(const char *raw, const char *name,
1008                          struct strbuf *out)
1009 {
1010         size_t len = strlen(name);
1011
1012         if (strncasecmp(raw, name, len))
1013                 return -1;
1014         raw += len;
1015
1016         if (*raw != '=')
1017                 return -1;
1018         raw++;
1019
1020         while (*raw && !isspace(*raw) && *raw != ';')
1021                 strbuf_addch(out, *raw++);
1022         return 0;
1023 }
1024
1025 /*
1026  * Extract a normalized version of the content type, with any
1027  * spaces suppressed, all letters lowercased, and no trailing ";"
1028  * or parameters.
1029  *
1030  * Note that we will silently remove even invalid whitespace. For
1031  * example, "text / plain" is specifically forbidden by RFC 2616,
1032  * but "text/plain" is the only reasonable output, and this keeps
1033  * our code simple.
1034  *
1035  * If the "charset" argument is not NULL, store the value of any
1036  * charset parameter there.
1037  *
1038  * Example:
1039  *   "TEXT/PLAIN; charset=utf-8" -> "text/plain", "utf-8"
1040  *   "text / plain" -> "text/plain"
1041  */
1042 static void extract_content_type(struct strbuf *raw, struct strbuf *type,
1043                                  struct strbuf *charset)
1044 {
1045         const char *p;
1046
1047         strbuf_reset(type);
1048         strbuf_grow(type, raw->len);
1049         for (p = raw->buf; *p; p++) {
1050                 if (isspace(*p))
1051                         continue;
1052                 if (*p == ';') {
1053                         p++;
1054                         break;
1055                 }
1056                 strbuf_addch(type, tolower(*p));
1057         }
1058
1059         if (!charset)
1060                 return;
1061
1062         strbuf_reset(charset);
1063         while (*p) {
1064                 while (isspace(*p) || *p == ';')
1065                         p++;
1066                 if (!extract_param(p, "charset", charset))
1067                         return;
1068                 while (*p && !isspace(*p))
1069                         p++;
1070         }
1071
1072         if (!charset->len && starts_with(type->buf, "text/"))
1073                 strbuf_addstr(charset, "ISO-8859-1");
1074 }
1075
1076 static void write_accept_language(struct strbuf *buf)
1077 {
1078         /*
1079          * MAX_DECIMAL_PLACES must not be larger than 3. If it is larger than
1080          * that, q-value will be smaller than 0.001, the minimum q-value the
1081          * HTTP specification allows. See
1082          * http://tools.ietf.org/html/rfc7231#section-5.3.1 for q-value.
1083          */
1084         const int MAX_DECIMAL_PLACES = 3;
1085         const int MAX_LANGUAGE_TAGS = 1000;
1086         const int MAX_ACCEPT_LANGUAGE_HEADER_SIZE = 4000;
1087         char **language_tags = NULL;
1088         int num_langs = 0;
1089         const char *s = get_preferred_languages();
1090         int i;
1091         struct strbuf tag = STRBUF_INIT;
1092
1093         /* Don't add Accept-Language header if no language is preferred. */
1094         if (!s)
1095                 return;
1096
1097         /*
1098          * Split the colon-separated string of preferred languages into
1099          * language_tags array.
1100          */
1101         do {
1102                 /* collect language tag */
1103                 for (; *s && (isalnum(*s) || *s == '_'); s++)
1104                         strbuf_addch(&tag, *s == '_' ? '-' : *s);
1105
1106                 /* skip .codeset, @modifier and any other unnecessary parts */
1107                 while (*s && *s != ':')
1108                         s++;
1109
1110                 if (tag.len) {
1111                         num_langs++;
1112                         REALLOC_ARRAY(language_tags, num_langs);
1113                         language_tags[num_langs - 1] = strbuf_detach(&tag, NULL);
1114                         if (num_langs >= MAX_LANGUAGE_TAGS - 1) /* -1 for '*' */
1115                                 break;
1116                 }
1117         } while (*s++);
1118
1119         /* write Accept-Language header into buf */
1120         if (num_langs) {
1121                 int last_buf_len = 0;
1122                 int max_q;
1123                 int decimal_places;
1124                 char q_format[32];
1125
1126                 /* add '*' */
1127                 REALLOC_ARRAY(language_tags, num_langs + 1);
1128                 language_tags[num_langs++] = "*"; /* it's OK; this won't be freed */
1129
1130                 /* compute decimal_places */
1131                 for (max_q = 1, decimal_places = 0;
1132                      max_q < num_langs && decimal_places <= MAX_DECIMAL_PLACES;
1133                      decimal_places++, max_q *= 10)
1134                         ;
1135
1136                 sprintf(q_format, ";q=0.%%0%dd", decimal_places);
1137
1138                 strbuf_addstr(buf, "Accept-Language: ");
1139
1140                 for (i = 0; i < num_langs; i++) {
1141                         if (i > 0)
1142                                 strbuf_addstr(buf, ", ");
1143
1144                         strbuf_addstr(buf, language_tags[i]);
1145
1146                         if (i > 0)
1147                                 strbuf_addf(buf, q_format, max_q - i);
1148
1149                         if (buf->len > MAX_ACCEPT_LANGUAGE_HEADER_SIZE) {
1150                                 strbuf_remove(buf, last_buf_len, buf->len - last_buf_len);
1151                                 break;
1152                         }
1153
1154                         last_buf_len = buf->len;
1155                 }
1156         }
1157
1158         /* free language tags -- last one is a static '*' */
1159         for (i = 0; i < num_langs - 1; i++)
1160                 free(language_tags[i]);
1161         free(language_tags);
1162 }
1163
1164 /*
1165  * Get an Accept-Language header which indicates user's preferred languages.
1166  *
1167  * Examples:
1168  *   LANGUAGE= -> ""
1169  *   LANGUAGE=ko:en -> "Accept-Language: ko, en; q=0.9, *; q=0.1"
1170  *   LANGUAGE=ko_KR.UTF-8:sr@latin -> "Accept-Language: ko-KR, sr; q=0.9, *; q=0.1"
1171  *   LANGUAGE=ko LANG=en_US.UTF-8 -> "Accept-Language: ko, *; q=0.1"
1172  *   LANGUAGE= LANG=en_US.UTF-8 -> "Accept-Language: en-US, *; q=0.1"
1173  *   LANGUAGE= LANG=C -> ""
1174  */
1175 static const char *get_accept_language(void)
1176 {
1177         if (!cached_accept_language) {
1178                 struct strbuf buf = STRBUF_INIT;
1179                 write_accept_language(&buf);
1180                 if (buf.len > 0)
1181                         cached_accept_language = strbuf_detach(&buf, NULL);
1182         }
1183
1184         return cached_accept_language;
1185 }
1186
1187 /* http_request() targets */
1188 #define HTTP_REQUEST_STRBUF     0
1189 #define HTTP_REQUEST_FILE       1
1190
1191 static int http_request(const char *url,
1192                         void *result, int target,
1193                         const struct http_get_options *options)
1194 {
1195         struct active_request_slot *slot;
1196         struct slot_results results;
1197         struct curl_slist *headers = NULL;
1198         struct strbuf buf = STRBUF_INIT;
1199         const char *accept_language;
1200         int ret;
1201
1202         slot = get_active_slot();
1203         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1204
1205         if (result == NULL) {
1206                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
1207         } else {
1208                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
1209                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
1210
1211                 if (target == HTTP_REQUEST_FILE) {
1212                         long posn = ftell(result);
1213                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1214                                          fwrite);
1215                         if (posn > 0) {
1216                                 strbuf_addf(&buf, "Range: bytes=%ld-", posn);
1217                                 headers = curl_slist_append(headers, buf.buf);
1218                                 strbuf_reset(&buf);
1219                         }
1220                 } else
1221                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1222                                          fwrite_buffer);
1223         }
1224
1225         accept_language = get_accept_language();
1226
1227         if (accept_language)
1228                 headers = curl_slist_append(headers, accept_language);
1229
1230         strbuf_addstr(&buf, "Pragma:");
1231         if (options && options->no_cache)
1232                 strbuf_addstr(&buf, " no-cache");
1233         if (options && options->keep_error)
1234                 curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
1235
1236         headers = curl_slist_append(headers, buf.buf);
1237
1238         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1239         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
1240         curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
1241
1242         ret = run_one_slot(slot, &results);
1243
1244         if (options && options->content_type) {
1245                 struct strbuf raw = STRBUF_INIT;
1246                 curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE, &raw);
1247                 extract_content_type(&raw, options->content_type,
1248                                      options->charset);
1249                 strbuf_release(&raw);
1250         }
1251
1252         if (options && options->effective_url)
1253                 curlinfo_strbuf(slot->curl, CURLINFO_EFFECTIVE_URL,
1254                                 options->effective_url);
1255
1256         curl_slist_free_all(headers);
1257         strbuf_release(&buf);
1258
1259         return ret;
1260 }
1261
1262 /*
1263  * Update the "base" url to a more appropriate value, as deduced by
1264  * redirects seen when requesting a URL starting with "url".
1265  *
1266  * The "asked" parameter is a URL that we asked curl to access, and must begin
1267  * with "base".
1268  *
1269  * The "got" parameter is the URL that curl reported to us as where we ended
1270  * up.
1271  *
1272  * Returns 1 if we updated the base url, 0 otherwise.
1273  *
1274  * Our basic strategy is to compare "base" and "asked" to find the bits
1275  * specific to our request. We then strip those bits off of "got" to yield the
1276  * new base. So for example, if our base is "http://example.com/foo.git",
1277  * and we ask for "http://example.com/foo.git/info/refs", we might end up
1278  * with "https://other.example.com/foo.git/info/refs". We would want the
1279  * new URL to become "https://other.example.com/foo.git".
1280  *
1281  * Note that this assumes a sane redirect scheme. It's entirely possible
1282  * in the example above to end up at a URL that does not even end in
1283  * "info/refs".  In such a case we simply punt, as there is not much we can
1284  * do (and such a scheme is unlikely to represent a real git repository,
1285  * which means we are likely about to abort anyway).
1286  */
1287 static int update_url_from_redirect(struct strbuf *base,
1288                                     const char *asked,
1289                                     const struct strbuf *got)
1290 {
1291         const char *tail;
1292         size_t tail_len;
1293
1294         if (!strcmp(asked, got->buf))
1295                 return 0;
1296
1297         if (!skip_prefix(asked, base->buf, &tail))
1298                 die("BUG: update_url_from_redirect: %s is not a superset of %s",
1299                     asked, base->buf);
1300
1301         tail_len = strlen(tail);
1302
1303         if (got->len < tail_len ||
1304             strcmp(tail, got->buf + got->len - tail_len))
1305                 return 0; /* insane redirect scheme */
1306
1307         strbuf_reset(base);
1308         strbuf_add(base, got->buf, got->len - tail_len);
1309         return 1;
1310 }
1311
1312 static int http_request_reauth(const char *url,
1313                                void *result, int target,
1314                                struct http_get_options *options)
1315 {
1316         int ret = http_request(url, result, target, options);
1317
1318         if (options && options->effective_url && options->base_url) {
1319                 if (update_url_from_redirect(options->base_url,
1320                                              url, options->effective_url)) {
1321                         credential_from_url(&http_auth, options->base_url->buf);
1322                         url = options->effective_url->buf;
1323                 }
1324         }
1325
1326         if (ret != HTTP_REAUTH)
1327                 return ret;
1328
1329         /*
1330          * If we are using KEEP_ERROR, the previous request may have
1331          * put cruft into our output stream; we should clear it out before
1332          * making our next request. We only know how to do this for
1333          * the strbuf case, but that is enough to satisfy current callers.
1334          */
1335         if (options && options->keep_error) {
1336                 switch (target) {
1337                 case HTTP_REQUEST_STRBUF:
1338                         strbuf_reset(result);
1339                         break;
1340                 default:
1341                         die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
1342                 }
1343         }
1344
1345         credential_fill(&http_auth);
1346
1347         return http_request(url, result, target, options);
1348 }
1349
1350 int http_get_strbuf(const char *url,
1351                     struct strbuf *result,
1352                     struct http_get_options *options)
1353 {
1354         return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
1355 }
1356
1357 /*
1358  * Downloads a URL and stores the result in the given file.
1359  *
1360  * If a previous interrupted download is detected (i.e. a previous temporary
1361  * file is still around) the download is resumed.
1362  */
1363 static int http_get_file(const char *url, const char *filename,
1364                          struct http_get_options *options)
1365 {
1366         int ret;
1367         struct strbuf tmpfile = STRBUF_INIT;
1368         FILE *result;
1369
1370         strbuf_addf(&tmpfile, "%s.temp", filename);
1371         result = fopen(tmpfile.buf, "a");
1372         if (!result) {
1373                 error("Unable to open local file %s", tmpfile.buf);
1374                 ret = HTTP_ERROR;
1375                 goto cleanup;
1376         }
1377
1378         ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
1379         fclose(result);
1380
1381         if (ret == HTTP_OK && finalize_object_file(tmpfile.buf, filename))
1382                 ret = HTTP_ERROR;
1383 cleanup:
1384         strbuf_release(&tmpfile);
1385         return ret;
1386 }
1387
1388 int http_fetch_ref(const char *base, struct ref *ref)
1389 {
1390         struct http_get_options options = {0};
1391         char *url;
1392         struct strbuf buffer = STRBUF_INIT;
1393         int ret = -1;
1394
1395         options.no_cache = 1;
1396
1397         url = quote_ref_url(base, ref->name);
1398         if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
1399                 strbuf_rtrim(&buffer);
1400                 if (buffer.len == 40)
1401                         ret = get_sha1_hex(buffer.buf, ref->old_sha1);
1402                 else if (starts_with(buffer.buf, "ref: ")) {
1403                         ref->symref = xstrdup(buffer.buf + 5);
1404                         ret = 0;
1405                 }
1406         }
1407
1408         strbuf_release(&buffer);
1409         free(url);
1410         return ret;
1411 }
1412
1413 /* Helpers for fetching packs */
1414 static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
1415 {
1416         char *url, *tmp;
1417         struct strbuf buf = STRBUF_INIT;
1418
1419         if (http_is_verbose)
1420                 fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
1421
1422         end_url_with_slash(&buf, base_url);
1423         strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
1424         url = strbuf_detach(&buf, NULL);
1425
1426         strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
1427         tmp = strbuf_detach(&buf, NULL);
1428
1429         if (http_get_file(url, tmp, NULL) != HTTP_OK) {
1430                 error("Unable to get pack index %s", url);
1431                 free(tmp);
1432                 tmp = NULL;
1433         }
1434
1435         free(url);
1436         return tmp;
1437 }
1438
1439 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
1440         unsigned char *sha1, const char *base_url)
1441 {
1442         struct packed_git *new_pack;
1443         char *tmp_idx = NULL;
1444         int ret;
1445
1446         if (has_pack_index(sha1)) {
1447                 new_pack = parse_pack_index(sha1, sha1_pack_index_name(sha1));
1448                 if (!new_pack)
1449                         return -1; /* parse_pack_index() already issued error message */
1450                 goto add_pack;
1451         }
1452
1453         tmp_idx = fetch_pack_index(sha1, base_url);
1454         if (!tmp_idx)
1455                 return -1;
1456
1457         new_pack = parse_pack_index(sha1, tmp_idx);
1458         if (!new_pack) {
1459                 unlink(tmp_idx);
1460                 free(tmp_idx);
1461
1462                 return -1; /* parse_pack_index() already issued error message */
1463         }
1464
1465         ret = verify_pack_index(new_pack);
1466         if (!ret) {
1467                 close_pack_index(new_pack);
1468                 ret = finalize_object_file(tmp_idx, sha1_pack_index_name(sha1));
1469         }
1470         free(tmp_idx);
1471         if (ret)
1472                 return -1;
1473
1474 add_pack:
1475         new_pack->next = *packs_head;
1476         *packs_head = new_pack;
1477         return 0;
1478 }
1479
1480 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
1481 {
1482         struct http_get_options options = {0};
1483         int ret = 0, i = 0;
1484         char *url, *data;
1485         struct strbuf buf = STRBUF_INIT;
1486         unsigned char sha1[20];
1487
1488         end_url_with_slash(&buf, base_url);
1489         strbuf_addstr(&buf, "objects/info/packs");
1490         url = strbuf_detach(&buf, NULL);
1491
1492         options.no_cache = 1;
1493         ret = http_get_strbuf(url, &buf, &options);
1494         if (ret != HTTP_OK)
1495                 goto cleanup;
1496
1497         data = buf.buf;
1498         while (i < buf.len) {
1499                 switch (data[i]) {
1500                 case 'P':
1501                         i++;
1502                         if (i + 52 <= buf.len &&
1503                             starts_with(data + i, " pack-") &&
1504                             starts_with(data + i + 46, ".pack\n")) {
1505                                 get_sha1_hex(data + i + 6, sha1);
1506                                 fetch_and_setup_pack_index(packs_head, sha1,
1507                                                       base_url);
1508                                 i += 51;
1509                                 break;
1510                         }
1511                 default:
1512                         while (i < buf.len && data[i] != '\n')
1513                                 i++;
1514                 }
1515                 i++;
1516         }
1517
1518 cleanup:
1519         free(url);
1520         return ret;
1521 }
1522
1523 void release_http_pack_request(struct http_pack_request *preq)
1524 {
1525         if (preq->packfile != NULL) {
1526                 fclose(preq->packfile);
1527                 preq->packfile = NULL;
1528         }
1529         if (preq->range_header != NULL) {
1530                 curl_slist_free_all(preq->range_header);
1531                 preq->range_header = NULL;
1532         }
1533         preq->slot = NULL;
1534         free(preq->url);
1535         free(preq);
1536 }
1537
1538 int finish_http_pack_request(struct http_pack_request *preq)
1539 {
1540         struct packed_git **lst;
1541         struct packed_git *p = preq->target;
1542         char *tmp_idx;
1543         struct child_process ip = CHILD_PROCESS_INIT;
1544         const char *ip_argv[8];
1545
1546         close_pack_index(p);
1547
1548         fclose(preq->packfile);
1549         preq->packfile = NULL;
1550
1551         lst = preq->lst;
1552         while (*lst != p)
1553                 lst = &((*lst)->next);
1554         *lst = (*lst)->next;
1555
1556         tmp_idx = xstrdup(preq->tmpfile);
1557         strcpy(tmp_idx + strlen(tmp_idx) - strlen(".pack.temp"),
1558                ".idx.temp");
1559
1560         ip_argv[0] = "index-pack";
1561         ip_argv[1] = "-o";
1562         ip_argv[2] = tmp_idx;
1563         ip_argv[3] = preq->tmpfile;
1564         ip_argv[4] = NULL;
1565
1566         ip.argv = ip_argv;
1567         ip.git_cmd = 1;
1568         ip.no_stdin = 1;
1569         ip.no_stdout = 1;
1570
1571         if (run_command(&ip)) {
1572                 unlink(preq->tmpfile);
1573                 unlink(tmp_idx);
1574                 free(tmp_idx);
1575                 return -1;
1576         }
1577
1578         unlink(sha1_pack_index_name(p->sha1));
1579
1580         if (finalize_object_file(preq->tmpfile, sha1_pack_name(p->sha1))
1581          || finalize_object_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
1582                 free(tmp_idx);
1583                 return -1;
1584         }
1585
1586         install_packed_git(p);
1587         free(tmp_idx);
1588         return 0;
1589 }
1590
1591 struct http_pack_request *new_http_pack_request(
1592         struct packed_git *target, const char *base_url)
1593 {
1594         long prev_posn = 0;
1595         char range[RANGE_HEADER_SIZE];
1596         struct strbuf buf = STRBUF_INIT;
1597         struct http_pack_request *preq;
1598
1599         preq = xcalloc(1, sizeof(*preq));
1600         preq->target = target;
1601
1602         end_url_with_slash(&buf, base_url);
1603         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
1604                 sha1_to_hex(target->sha1));
1605         preq->url = strbuf_detach(&buf, NULL);
1606
1607         snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
1608                 sha1_pack_name(target->sha1));
1609         preq->packfile = fopen(preq->tmpfile, "a");
1610         if (!preq->packfile) {
1611                 error("Unable to open local file %s for pack",
1612                       preq->tmpfile);
1613                 goto abort;
1614         }
1615
1616         preq->slot = get_active_slot();
1617         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
1618         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
1619         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
1620         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1621                 no_pragma_header);
1622
1623         /*
1624          * If there is data present from a previous transfer attempt,
1625          * resume where it left off
1626          */
1627         prev_posn = ftell(preq->packfile);
1628         if (prev_posn>0) {
1629                 if (http_is_verbose)
1630                         fprintf(stderr,
1631                                 "Resuming fetch of pack %s at byte %ld\n",
1632                                 sha1_to_hex(target->sha1), prev_posn);
1633                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1634                 preq->range_header = curl_slist_append(NULL, range);
1635                 curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1636                         preq->range_header);
1637         }
1638
1639         return preq;
1640
1641 abort:
1642         free(preq->url);
1643         free(preq);
1644         return NULL;
1645 }
1646
1647 /* Helpers for fetching objects (loose) */
1648 static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
1649                                void *data)
1650 {
1651         unsigned char expn[4096];
1652         size_t size = eltsize * nmemb;
1653         int posn = 0;
1654         struct http_object_request *freq =
1655                 (struct http_object_request *)data;
1656         do {
1657                 ssize_t retval = xwrite(freq->localfile,
1658                                         (char *) ptr + posn, size - posn);
1659                 if (retval < 0)
1660                         return posn;
1661                 posn += retval;
1662         } while (posn < size);
1663
1664         freq->stream.avail_in = size;
1665         freq->stream.next_in = (void *)ptr;
1666         do {
1667                 freq->stream.next_out = expn;
1668                 freq->stream.avail_out = sizeof(expn);
1669                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
1670                 git_SHA1_Update(&freq->c, expn,
1671                                 sizeof(expn) - freq->stream.avail_out);
1672         } while (freq->stream.avail_in && freq->zret == Z_OK);
1673         return size;
1674 }
1675
1676 struct http_object_request *new_http_object_request(const char *base_url,
1677         unsigned char *sha1)
1678 {
1679         char *hex = sha1_to_hex(sha1);
1680         const char *filename;
1681         char prevfile[PATH_MAX];
1682         int prevlocal;
1683         char prev_buf[PREV_BUF_SIZE];
1684         ssize_t prev_read = 0;
1685         long prev_posn = 0;
1686         char range[RANGE_HEADER_SIZE];
1687         struct curl_slist *range_header = NULL;
1688         struct http_object_request *freq;
1689
1690         freq = xcalloc(1, sizeof(*freq));
1691         hashcpy(freq->sha1, sha1);
1692         freq->localfile = -1;
1693
1694         filename = sha1_file_name(sha1);
1695         snprintf(freq->tmpfile, sizeof(freq->tmpfile),
1696                  "%s.temp", filename);
1697
1698         snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
1699         unlink_or_warn(prevfile);
1700         rename(freq->tmpfile, prevfile);
1701         unlink_or_warn(freq->tmpfile);
1702
1703         if (freq->localfile != -1)
1704                 error("fd leakage in start: %d", freq->localfile);
1705         freq->localfile = open(freq->tmpfile,
1706                                O_WRONLY | O_CREAT | O_EXCL, 0666);
1707         /*
1708          * This could have failed due to the "lazy directory creation";
1709          * try to mkdir the last path component.
1710          */
1711         if (freq->localfile < 0 && errno == ENOENT) {
1712                 char *dir = strrchr(freq->tmpfile, '/');
1713                 if (dir) {
1714                         *dir = 0;
1715                         mkdir(freq->tmpfile, 0777);
1716                         *dir = '/';
1717                 }
1718                 freq->localfile = open(freq->tmpfile,
1719                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
1720         }
1721
1722         if (freq->localfile < 0) {
1723                 error("Couldn't create temporary file %s: %s",
1724                       freq->tmpfile, strerror(errno));
1725                 goto abort;
1726         }
1727
1728         git_inflate_init(&freq->stream);
1729
1730         git_SHA1_Init(&freq->c);
1731
1732         freq->url = get_remote_object_url(base_url, hex, 0);
1733
1734         /*
1735          * If a previous temp file is present, process what was already
1736          * fetched.
1737          */
1738         prevlocal = open(prevfile, O_RDONLY);
1739         if (prevlocal != -1) {
1740                 do {
1741                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
1742                         if (prev_read>0) {
1743                                 if (fwrite_sha1_file(prev_buf,
1744                                                      1,
1745                                                      prev_read,
1746                                                      freq) == prev_read) {
1747                                         prev_posn += prev_read;
1748                                 } else {
1749                                         prev_read = -1;
1750                                 }
1751                         }
1752                 } while (prev_read > 0);
1753                 close(prevlocal);
1754         }
1755         unlink_or_warn(prevfile);
1756
1757         /*
1758          * Reset inflate/SHA1 if there was an error reading the previous temp
1759          * file; also rewind to the beginning of the local file.
1760          */
1761         if (prev_read == -1) {
1762                 memset(&freq->stream, 0, sizeof(freq->stream));
1763                 git_inflate_init(&freq->stream);
1764                 git_SHA1_Init(&freq->c);
1765                 if (prev_posn>0) {
1766                         prev_posn = 0;
1767                         lseek(freq->localfile, 0, SEEK_SET);
1768                         if (ftruncate(freq->localfile, 0) < 0) {
1769                                 error("Couldn't truncate temporary file %s: %s",
1770                                           freq->tmpfile, strerror(errno));
1771                                 goto abort;
1772                         }
1773                 }
1774         }
1775
1776         freq->slot = get_active_slot();
1777
1778         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
1779         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
1780         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
1781         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
1782         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
1783
1784         /*
1785          * If we have successfully processed data from a previous fetch
1786          * attempt, only fetch the data we don't already have.
1787          */
1788         if (prev_posn>0) {
1789                 if (http_is_verbose)
1790                         fprintf(stderr,
1791                                 "Resuming fetch of object %s at byte %ld\n",
1792                                 hex, prev_posn);
1793                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1794                 range_header = curl_slist_append(range_header, range);
1795                 curl_easy_setopt(freq->slot->curl,
1796                                  CURLOPT_HTTPHEADER, range_header);
1797         }
1798
1799         return freq;
1800
1801 abort:
1802         free(freq->url);
1803         free(freq);
1804         return NULL;
1805 }
1806
1807 void process_http_object_request(struct http_object_request *freq)
1808 {
1809         if (freq->slot == NULL)
1810                 return;
1811         freq->curl_result = freq->slot->curl_result;
1812         freq->http_code = freq->slot->http_code;
1813         freq->slot = NULL;
1814 }
1815
1816 int finish_http_object_request(struct http_object_request *freq)
1817 {
1818         struct stat st;
1819
1820         close(freq->localfile);
1821         freq->localfile = -1;
1822
1823         process_http_object_request(freq);
1824
1825         if (freq->http_code == 416) {
1826                 warning("requested range invalid; we may already have all the data.");
1827         } else if (freq->curl_result != CURLE_OK) {
1828                 if (stat(freq->tmpfile, &st) == 0)
1829                         if (st.st_size == 0)
1830                                 unlink_or_warn(freq->tmpfile);
1831                 return -1;
1832         }
1833
1834         git_inflate_end(&freq->stream);
1835         git_SHA1_Final(freq->real_sha1, &freq->c);
1836         if (freq->zret != Z_STREAM_END) {
1837                 unlink_or_warn(freq->tmpfile);
1838                 return -1;
1839         }
1840         if (hashcmp(freq->sha1, freq->real_sha1)) {
1841                 unlink_or_warn(freq->tmpfile);
1842                 return -1;
1843         }
1844         freq->rename =
1845                 finalize_object_file(freq->tmpfile, sha1_file_name(freq->sha1));
1846
1847         return freq->rename;
1848 }
1849
1850 void abort_http_object_request(struct http_object_request *freq)
1851 {
1852         unlink_or_warn(freq->tmpfile);
1853
1854         release_http_object_request(freq);
1855 }
1856
1857 void release_http_object_request(struct http_object_request *freq)
1858 {
1859         if (freq->localfile != -1) {
1860                 close(freq->localfile);
1861                 freq->localfile = -1;
1862         }
1863         if (freq->url != NULL) {
1864                 free(freq->url);
1865                 freq->url = NULL;
1866         }
1867         if (freq->slot != NULL) {
1868                 freq->slot->callback_func = NULL;
1869                 freq->slot->callback_data = NULL;
1870                 release_active_slot(freq->slot);
1871                 freq->slot = NULL;
1872         }
1873 }