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 static void xmulti_remove_handle(struct active_request_slot *slot)
 171 {
 172 #ifdef USE_CURL_MULTI
 173         curl_multi_remove_handle(curlm, slot->curl);
 174 #endif
 175 }
 176
 177 #ifdef USE_CURL_MULTI
 178 static void process_curl_messages(void)
 179 {
 180         int num_messages;
 181         struct active_request_slot *slot;
 182         CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
 183
 184         while (curl_message != NULL) {
 185                 if (curl_message->msg == CURLMSG_DONE) {
 186                         int curl_result = curl_message->data.result;
 187                         slot = active_queue_head;
 188                         while (slot != NULL &&
 189                                slot->curl != curl_message->easy_handle)
 190                                 slot = slot->next;
 191                         if (slot != NULL) {
 192                                 xmulti_remove_handle(slot);
 193                                 slot->curl_result = curl_result;
 194                                 finish_active_slot(slot);
 195                         } else {
 196                                 fprintf(stderr, "Received DONE message for unknown request!\n");
 197                         }
 198                 } else {
 199                         fprintf(stderr, "Unknown CURL message received: %d\n",
 200                                 (int)curl_message->msg);
 201                 }
 202                 curl_message = curl_multi_info_read(curlm, &num_messages);
 203         }
 204 }
 205 #endif
 206
 207 static int http_options(const char *var, const char *value, void *cb)
 208 {
 209         if (!strcmp("http.sslverify", var)) {
 210                 curl_ssl_verify = git_config_bool(var, value);
 211                 return 0;
 212         }
 213         if (!strcmp("http.sslcipherlist", var))
 214                 return git_config_string(&ssl_cipherlist, var, value);
 215         if (!strcmp("http.sslversion", var))
 216                 return git_config_string(&ssl_version, var, value);
 217         if (!strcmp("http.sslcert", var))
 218                 return git_config_string(&ssl_cert, var, value);
 219 #if LIBCURL_VERSION_NUM >= 0x070903
 220         if (!strcmp("http.sslkey", var))
 221                 return git_config_string(&ssl_key, var, value);
 222 #endif
 223 #if LIBCURL_VERSION_NUM >= 0x070908
 224         if (!strcmp("http.sslcapath", var))
 225                 return git_config_pathname(&ssl_capath, var, value);
 226 #endif
 227         if (!strcmp("http.sslcainfo", var))
 228                 return git_config_pathname(&ssl_cainfo, var, value);
 229         if (!strcmp("http.sslcertpasswordprotected", var)) {
 230                 ssl_cert_password_required = git_config_bool(var, value);
 231                 return 0;
 232         }
 233         if (!strcmp("http.ssltry", var)) {
 234                 curl_ssl_try = git_config_bool(var, value);
 235                 return 0;
 236         }
 237         if (!strcmp("http.minsessions", var)) {
 238                 min_curl_sessions = git_config_int(var, value);
 239 #ifndef USE_CURL_MULTI
 240                 if (min_curl_sessions > 1)
 241                         min_curl_sessions = 1;
 242 #endif
 243                 return 0;
 244         }
 245 #ifdef USE_CURL_MULTI
 246         if (!strcmp("http.maxrequests", var)) {
 247                 max_requests = git_config_int(var, value);
 248                 return 0;
 249         }
 250 #endif
 251         if (!strcmp("http.lowspeedlimit", var)) {
 252                 curl_low_speed_limit = (long)git_config_int(var, value);
 253                 return 0;
 254         }
 255         if (!strcmp("http.lowspeedtime", var)) {
 256                 curl_low_speed_time = (long)git_config_int(var, value);
 257                 return 0;
 258         }
 259
 260         if (!strcmp("http.noepsv", var)) {
 261                 curl_ftp_no_epsv = git_config_bool(var, value);
 262                 return 0;
 263         }
 264         if (!strcmp("http.proxy", var))
 265                 return git_config_string(&curl_http_proxy, var, value);
 266
 267         if (!strcmp("http.cookiefile", var))
 268                 return git_config_string(&curl_cookie_file, var, value);
 269         if (!strcmp("http.savecookies", var)) {
 270                 curl_save_cookies = git_config_bool(var, value);
 271                 return 0;
 272         }
 273
 274         if (!strcmp("http.postbuffer", var)) {
 275                 http_post_buffer = git_config_int(var, value);
 276                 if (http_post_buffer < LARGE_PACKET_MAX)
 277                         http_post_buffer = LARGE_PACKET_MAX;
 278                 return 0;
 279         }
 280
 281         if (!strcmp("http.useragent", var))
 282                 return git_config_string(&user_agent, var, value);
 283
 284         /* Fall back on the default ones */
 285         return git_default_config(var, value, cb);
 286 }
 287
 288 static void init_curl_http_auth(CURL *result)
 289 {
 290         if (!http_auth.username)
 291                 return;
 292
 293         credential_fill(&http_auth);
 294
 295 #if LIBCURL_VERSION_NUM >= 0x071301
 296         curl_easy_setopt(result, CURLOPT_USERNAME, http_auth.username);
 297         curl_easy_setopt(result, CURLOPT_PASSWORD, http_auth.password);
 298 #else
 299         {
 300                 static struct strbuf up = STRBUF_INIT;
 301                 /*
 302                  * Note that we assume we only ever have a single set of
 303                  * credentials in a given program run, so we do not have
 304                  * to worry about updating this buffer, only setting its
 305                  * initial value.
 306                  */
 307                 if (!up.len)
 308                         strbuf_addf(&up, "%s:%s",
 309                                 http_auth.username, http_auth.password);
 310                 curl_easy_setopt(result, CURLOPT_USERPWD, up.buf);
 311         }
 312 #endif
 313 }
 314
 315 static int has_cert_password(void)
 316 {
 317         if (ssl_cert == NULL || ssl_cert_password_required != 1)
 318                 return 0;
 319         if (!cert_auth.password) {
 320                 cert_auth.protocol = xstrdup("cert");
 321                 cert_auth.username = xstrdup("");
 322                 cert_auth.path = xstrdup(ssl_cert);
 323                 credential_fill(&cert_auth);
 324         }
 325         return 1;
 326 }
 327
 328 #if LIBCURL_VERSION_NUM >= 0x071900
 329 static void set_curl_keepalive(CURL *c)
 330 {
 331         curl_easy_setopt(c, CURLOPT_TCP_KEEPALIVE, 1);
 332 }
 333
 334 #elif LIBCURL_VERSION_NUM >= 0x071000
 335 static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
 336 {
 337         int ka = 1;
 338         int rc;
 339         socklen_t len = (socklen_t)sizeof(ka);
 340
 341         if (type != CURLSOCKTYPE_IPCXN)
 342                 return 0;
 343
 344         rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
 345         if (rc < 0)
 346                 warning("unable to set SO_KEEPALIVE on socket %s",
 347                         strerror(errno));
 348
 349         return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
 350 }
 351
 352 static void set_curl_keepalive(CURL *c)
 353 {
 354         curl_easy_setopt(c, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
 355 }
 356
 357 #else
 358 static void set_curl_keepalive(CURL *c)
 359 {
 360         /* not supported on older curl versions */
 361 }
 362 #endif
 363
 364 static CURL *get_curl_handle(void)
 365 {
 366         CURL *result = curl_easy_init();
 367         long allowed_protocols = 0;
 368
 369         if (!result)
 370                 die("curl_easy_init failed");
 371
 372         if (!curl_ssl_verify) {
 373                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
 374                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
 375         } else {
 376                 /* Verify authenticity of the peer's certificate */
 377                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
 378                 /* The name in the cert must match whom we tried to connect */
 379                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
 380         }
 381
 382 #if LIBCURL_VERSION_NUM >= 0x070907
 383         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
 384 #endif
 385 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 386         curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
 387 #endif
 388
 389         if (http_proactive_auth)
 390                 init_curl_http_auth(result);
 391
 392         if (getenv("GIT_SSL_VERSION"))
 393                 ssl_version = getenv("GIT_SSL_VERSION");
 394         if (ssl_version && *ssl_version) {
 395                 int i;
 396                 for (i = 0; i < ARRAY_SIZE(sslversions); i++) {
 397                         if (!strcmp(ssl_version, sslversions[i].name)) {
 398                                 curl_easy_setopt(result, CURLOPT_SSLVERSION,
 399                                                  sslversions[i].ssl_version);
 400                                 break;
 401                         }
 402                 }
 403                 if (i == ARRAY_SIZE(sslversions))
 404                         warning("unsupported ssl version %s: using default",
 405                                 ssl_version);
 406         }
 407
 408         if (getenv("GIT_SSL_CIPHER_LIST"))
 409                 ssl_cipherlist = getenv("GIT_SSL_CIPHER_LIST");
 410         if (ssl_cipherlist != NULL && *ssl_cipherlist)
 411                 curl_easy_setopt(result, CURLOPT_SSL_CIPHER_LIST,
 412                                 ssl_cipherlist);
 413
 414         if (ssl_cert != NULL)
 415                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
 416         if (has_cert_password())
 417                 curl_easy_setopt(result, CURLOPT_KEYPASSWD, cert_auth.password);
 418 #if LIBCURL_VERSION_NUM >= 0x070903
 419         if (ssl_key != NULL)
 420                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
 421 #endif
 422 #if LIBCURL_VERSION_NUM >= 0x070908
 423         if (ssl_capath != NULL)
 424                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
 425 #endif
 426         if (ssl_cainfo != NULL)
 427                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
 428
 429         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
 430                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
 431                                  curl_low_speed_limit);
 432                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
 433                                  curl_low_speed_time);
 434         }
 435
 436         curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
 437         curl_easy_setopt(result, CURLOPT_MAXREDIRS, 20);
 438 #if LIBCURL_VERSION_NUM >= 0x071301
 439         curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
 440 #elif LIBCURL_VERSION_NUM >= 0x071101
 441         curl_easy_setopt(result, CURLOPT_POST301, 1);
 442 #endif
 443 #if LIBCURL_VERSION_NUM >= 0x071304
 444         if (is_transport_allowed("http"))
 445                 allowed_protocols |= CURLPROTO_HTTP;
 446         if (is_transport_allowed("https"))
 447                 allowed_protocols |= CURLPROTO_HTTPS;
 448         if (is_transport_allowed("ftp"))
 449                 allowed_protocols |= CURLPROTO_FTP;
 450         if (is_transport_allowed("ftps"))
 451                 allowed_protocols |= CURLPROTO_FTPS;
 452         curl_easy_setopt(result, CURLOPT_REDIR_PROTOCOLS, allowed_protocols);
 453 #else
 454         if (transport_restrict_protocols())
 455                 warning("protocol restrictions not applied to curl redirects because\n"
 456                         "your curl version is too old (>= 7.19.4)");
 457 #endif
 458
 459         if (getenv("GIT_CURL_VERBOSE"))
 460                 curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
 461
 462         curl_easy_setopt(result, CURLOPT_USERAGENT,
 463                 user_agent ? user_agent : git_user_agent());
 464
 465         if (curl_ftp_no_epsv)
 466                 curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
 467
 468 #ifdef CURLOPT_USE_SSL
 469         if (curl_ssl_try)
 470                 curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
 471 #endif
 472
 473         if (curl_http_proxy) {
 474                 curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
 475 #if LIBCURL_VERSION_NUM >= 0x071800
 476                 if (starts_with(curl_http_proxy, "socks5"))
 477                         curl_easy_setopt(result,
 478                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);
 479                 else if (starts_with(curl_http_proxy, "socks4a"))
 480                         curl_easy_setopt(result,
 481                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4A);
 482                 else if (starts_with(curl_http_proxy, "socks"))
 483                         curl_easy_setopt(result,
 484                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4);
 485 #endif
 486         }
 487 #if LIBCURL_VERSION_NUM >= 0x070a07
 488         curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
 489 #endif
 490
 491         set_curl_keepalive(result);
 492
 493         return result;
 494 }
 495
 496 static void set_from_env(const char **var, const char *envname)
 497 {
 498         const char *val = getenv(envname);
 499         if (val)
 500                 *var = val;
 501 }
 502
 503 void http_init(struct remote *remote, const char *url, int proactive_auth)
 504 {
 505         char *low_speed_limit;
 506         char *low_speed_time;
 507         char *normalized_url;
 508         struct urlmatch_config config = { STRING_LIST_INIT_DUP };
 509
 510         config.section = "http";
 511         config.key = NULL;
 512         config.collect_fn = http_options;
 513         config.cascade_fn = git_default_config;
 514         config.cb = NULL;
 515
 516         http_is_verbose = 0;
 517         normalized_url = url_normalize(url, &config.url);
 518
 519         git_config(urlmatch_config_entry, &config);
 520         free(normalized_url);
 521
 522         if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK)
 523                 die("curl_global_init failed");
 524
 525         http_proactive_auth = proactive_auth;
 526
 527         if (remote && remote->http_proxy)
 528                 curl_http_proxy = xstrdup(remote->http_proxy);
 529
 530         pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
 531         no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
 532
 533 #ifdef USE_CURL_MULTI
 534         {
 535                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
 536                 if (http_max_requests != NULL)
 537                         max_requests = atoi(http_max_requests);
 538         }
 539
 540         curlm = curl_multi_init();
 541         if (!curlm)
 542                 die("curl_multi_init failed");
 543 #endif
 544
 545         if (getenv("GIT_SSL_NO_VERIFY"))
 546                 curl_ssl_verify = 0;
 547
 548         set_from_env(&ssl_cert, "GIT_SSL_CERT");
 549 #if LIBCURL_VERSION_NUM >= 0x070903
 550         set_from_env(&ssl_key, "GIT_SSL_KEY");
 551 #endif
 552 #if LIBCURL_VERSION_NUM >= 0x070908
 553         set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
 554 #endif
 555         set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
 556
 557         set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");
 558
 559         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
 560         if (low_speed_limit != NULL)
 561                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
 562         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
 563         if (low_speed_time != NULL)
 564                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
 565
 566         if (curl_ssl_verify == -1)
 567                 curl_ssl_verify = 1;
 568
 569         curl_session_count = 0;
 570 #ifdef USE_CURL_MULTI
 571         if (max_requests < 1)
 572                 max_requests = DEFAULT_MAX_REQUESTS;
 573 #endif
 574
 575         if (getenv("GIT_CURL_FTP_NO_EPSV"))
 576                 curl_ftp_no_epsv = 1;
 577
 578         if (url) {
 579                 credential_from_url(&http_auth, url);
 580                 if (!ssl_cert_password_required &&
 581                     getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
 582                     starts_with(url, "https://"))
 583                         ssl_cert_password_required = 1;
 584         }
 585
 586 #ifndef NO_CURL_EASY_DUPHANDLE
 587         curl_default = get_curl_handle();
 588 #endif
 589 }
 590
 591 void http_cleanup(void)
 592 {
 593         struct active_request_slot *slot = active_queue_head;
 594
 595         while (slot != NULL) {
 596                 struct active_request_slot *next = slot->next;
 597                 if (slot->curl != NULL) {
 598                         xmulti_remove_handle(slot);
 599                         curl_easy_cleanup(slot->curl);
 600                 }
 601                 free(slot);
 602                 slot = next;
 603         }
 604         active_queue_head = NULL;
 605
 606 #ifndef NO_CURL_EASY_DUPHANDLE
 607         curl_easy_cleanup(curl_default);
 608 #endif
 609
 610 #ifdef USE_CURL_MULTI
 611         curl_multi_cleanup(curlm);
 612 #endif
 613         curl_global_cleanup();
 614
 615         curl_slist_free_all(pragma_header);
 616         pragma_header = NULL;
 617
 618         curl_slist_free_all(no_pragma_header);
 619         no_pragma_header = NULL;
 620
 621         if (curl_http_proxy) {
 622                 free((void *)curl_http_proxy);
 623                 curl_http_proxy = NULL;
 624         }
 625
 626         if (cert_auth.password != NULL) {
 627                 memset(cert_auth.password, 0, strlen(cert_auth.password));
 628                 free(cert_auth.password);
 629                 cert_auth.password = NULL;
 630         }
 631         ssl_cert_password_required = 0;
 632
 633         free(cached_accept_language);
 634         cached_accept_language = NULL;
 635 }
 636
 637 struct active_request_slot *get_active_slot(void)
 638 {
 639         struct active_request_slot *slot = active_queue_head;
 640         struct active_request_slot *newslot;
 641
 642 #ifdef USE_CURL_MULTI
 643         int num_transfers;
 644
 645         /* Wait for a slot to open up if the queue is full */
 646         while (active_requests >= max_requests) {
 647                 curl_multi_perform(curlm, &num_transfers);
 648                 if (num_transfers < active_requests)
 649                         process_curl_messages();
 650         }
 651 #endif
 652
 653         while (slot != NULL && slot->in_use)
 654                 slot = slot->next;
 655
 656         if (slot == NULL) {
 657                 newslot = xmalloc(sizeof(*newslot));
 658                 newslot->curl = NULL;
 659                 newslot->in_use = 0;
 660                 newslot->next = NULL;
 661
 662                 slot = active_queue_head;
 663                 if (slot == NULL) {
 664                         active_queue_head = newslot;
 665                 } else {
 666                         while (slot->next != NULL)
 667                                 slot = slot->next;
 668                         slot->next = newslot;
 669                 }
 670                 slot = newslot;
 671         }
 672
 673         if (slot->curl == NULL) {
 674 #ifdef NO_CURL_EASY_DUPHANDLE
 675                 slot->curl = get_curl_handle();
 676 #else
 677                 slot->curl = curl_easy_duphandle(curl_default);
 678 #endif
 679                 curl_session_count++;
 680         }
 681
 682         active_requests++;
 683         slot->in_use = 1;
 684         slot->results = NULL;
 685         slot->finished = NULL;
 686         slot->callback_data = NULL;
 687         slot->callback_func = NULL;
 688         curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file);
 689         if (curl_save_cookies)
 690                 curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file);
 691         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
 692         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
 693         curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
 694         curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
 695         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
 696         curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
 697         curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
 698         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
 699         curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
 700 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 701         curl_easy_setopt(slot->curl, CURLOPT_HTTPAUTH, http_auth_methods);
 702 #endif
 703         if (http_auth.password)
 704                 init_curl_http_auth(slot->curl);
 705
 706         return slot;
 707 }
 708
 709 int start_active_slot(struct active_request_slot *slot)
 710 {
 711 #ifdef USE_CURL_MULTI
 712         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
 713         int num_transfers;
 714
 715         if (curlm_result != CURLM_OK &&
 716             curlm_result != CURLM_CALL_MULTI_PERFORM) {
 717                 warning("curl_multi_add_handle failed: %s",
 718                         curl_multi_strerror(curlm_result));
 719                 active_requests--;
 720                 slot->in_use = 0;
 721                 return 0;
 722         }
 723
 724         /*
 725          * We know there must be something to do, since we just added
 726          * something.
 727          */
 728         curl_multi_perform(curlm, &num_transfers);
 729 #endif
 730         return 1;
 731 }
 732
 733 #ifdef USE_CURL_MULTI
 734 struct fill_chain {
 735         void *data;
 736         int (*fill)(void *);
 737         struct fill_chain *next;
 738 };
 739
 740 static struct fill_chain *fill_cfg;
 741
 742 void add_fill_function(void *data, int (*fill)(void *))
 743 {
 744         struct fill_chain *new = xmalloc(sizeof(*new));
 745         struct fill_chain **linkp = &fill_cfg;
 746         new->data = data;
 747         new->fill = fill;
 748         new->next = NULL;
 749         while (*linkp)
 750                 linkp = &(*linkp)->next;
 751         *linkp = new;
 752 }
 753
 754 void fill_active_slots(void)
 755 {
 756         struct active_request_slot *slot = active_queue_head;
 757
 758         while (active_requests < max_requests) {
 759                 struct fill_chain *fill;
 760                 for (fill = fill_cfg; fill; fill = fill->next)
 761                         if (fill->fill(fill->data))
 762                                 break;
 763
 764                 if (!fill)
 765                         break;
 766         }
 767
 768         while (slot != NULL) {
 769                 if (!slot->in_use && slot->curl != NULL
 770                         && curl_session_count > min_curl_sessions) {
 771                         curl_easy_cleanup(slot->curl);
 772                         slot->curl = NULL;
 773                         curl_session_count--;
 774                 }
 775                 slot = slot->next;
 776         }
 777 }
 778
 779 void step_active_slots(void)
 780 {
 781         int num_transfers;
 782         CURLMcode curlm_result;
 783
 784         do {
 785                 curlm_result = curl_multi_perform(curlm, &num_transfers);
 786         } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
 787         if (num_transfers < active_requests) {
 788                 process_curl_messages();
 789                 fill_active_slots();
 790         }
 791 }
 792 #endif
 793
 794 void run_active_slot(struct active_request_slot *slot)
 795 {
 796 #ifdef USE_CURL_MULTI
 797         fd_set readfds;
 798         fd_set writefds;
 799         fd_set excfds;
 800         int max_fd;
 801         struct timeval select_timeout;
 802         int finished = 0;
 803
 804         slot->finished = &finished;
 805         while (!finished) {
 806                 step_active_slots();
 807
 808                 if (slot->in_use) {
 809 #if LIBCURL_VERSION_NUM >= 0x070f04
 810                         long curl_timeout;
 811                         curl_multi_timeout(curlm, &curl_timeout);
 812                         if (curl_timeout == 0) {
 813                                 continue;
 814                         } else if (curl_timeout == -1) {
 815                                 select_timeout.tv_sec  = 0;
 816                                 select_timeout.tv_usec = 50000;
 817                         } else {
 818                                 select_timeout.tv_sec  =  curl_timeout / 1000;
 819                                 select_timeout.tv_usec = (curl_timeout % 1000) * 1000;
 820                         }
 821 #else
 822                         select_timeout.tv_sec  = 0;
 823                         select_timeout.tv_usec = 50000;
 824 #endif
 825
 826                         max_fd = -1;
 827                         FD_ZERO(&readfds);
 828                         FD_ZERO(&writefds);
 829                         FD_ZERO(&excfds);
 830                         curl_multi_fdset(curlm, &readfds, &writefds, &excfds, &max_fd);
 831
 832                         /*
 833                          * It can happen that curl_multi_timeout returns a pathologically
 834                          * long timeout when curl_multi_fdset returns no file descriptors
 835                          * to read.  See commit message for more details.
 836                          */
 837                         if (max_fd < 0 &&
 838                             (select_timeout.tv_sec > 0 ||
 839                              select_timeout.tv_usec > 50000)) {
 840                                 select_timeout.tv_sec  = 0;
 841                                 select_timeout.tv_usec = 50000;
 842                         }
 843
 844                         select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
 845                 }
 846         }
 847 #else
 848         while (slot->in_use) {
 849                 slot->curl_result = curl_easy_perform(slot->curl);
 850                 finish_active_slot(slot);
 851         }
 852 #endif
 853 }
 854
 855 static void release_active_slot(struct active_request_slot *slot)
 856 {
 857         closedown_active_slot(slot);
 858         if (slot->curl) {
 859                 xmulti_remove_handle(slot);
 860                 if (curl_session_count > min_curl_sessions) {
 861                         curl_easy_cleanup(slot->curl);
 862                         slot->curl = NULL;
 863                         curl_session_count--;
 864                 }
 865         }
 866 #ifdef USE_CURL_MULTI
 867         fill_active_slots();
 868 #endif
 869 }
 870
 871 void finish_all_active_slots(void)
 872 {
 873         struct active_request_slot *slot = active_queue_head;
 874
 875         while (slot != NULL)
 876                 if (slot->in_use) {
 877                         run_active_slot(slot);
 878                         slot = active_queue_head;
 879                 } else {
 880                         slot = slot->next;
 881                 }
 882 }
 883
 884 /* Helpers for modifying and creating URLs */
 885 static inline int needs_quote(int ch)
 886 {
 887         if (((ch >= 'A') && (ch <= 'Z'))
 888                         || ((ch >= 'a') && (ch <= 'z'))
 889                         || ((ch >= '0') && (ch <= '9'))
 890                         || (ch == '/')
 891                         || (ch == '-')
 892                         || (ch == '.'))
 893                 return 0;
 894         return 1;
 895 }
 896
 897 static char *quote_ref_url(const char *base, const char *ref)
 898 {
 899         struct strbuf buf = STRBUF_INIT;
 900         const char *cp;
 901         int ch;
 902
 903         end_url_with_slash(&buf, base);
 904
 905         for (cp = ref; (ch = *cp) != 0; cp++)
 906                 if (needs_quote(ch))
 907                         strbuf_addf(&buf, "%%%02x", ch);
 908                 else
 909                         strbuf_addch(&buf, *cp);
 910
 911         return strbuf_detach(&buf, NULL);
 912 }
 913
 914 void append_remote_object_url(struct strbuf *buf, const char *url,
 915                               const char *hex,
 916                               int only_two_digit_prefix)
 917 {
 918         end_url_with_slash(buf, url);
 919
 920         strbuf_addf(buf, "objects/%.*s/", 2, hex);
 921         if (!only_two_digit_prefix)
 922                 strbuf_addf(buf, "%s", hex+2);
 923 }
 924
 925 char *get_remote_object_url(const char *url, const char *hex,
 926                             int only_two_digit_prefix)
 927 {
 928         struct strbuf buf = STRBUF_INIT;
 929         append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
 930         return strbuf_detach(&buf, NULL);
 931 }
 932
 933 static int handle_curl_result(struct slot_results *results)
 934 {
 935         /*
 936          * If we see a failing http code with CURLE_OK, we have turned off
 937          * FAILONERROR (to keep the server's custom error response), and should
 938          * translate the code into failure here.
 939          */
 940         if (results->curl_result == CURLE_OK &&
 941             results->http_code >= 400) {
 942                 results->curl_result = CURLE_HTTP_RETURNED_ERROR;
 943                 /*
 944                  * Normally curl will already have put the "reason phrase"
 945                  * from the server into curl_errorstr; unfortunately without
 946                  * FAILONERROR it is lost, so we can give only the numeric
 947                  * status code.
 948                  */
 949                 snprintf(curl_errorstr, sizeof(curl_errorstr),
 950                          "The requested URL returned error: %ld",
 951                          results->http_code);
 952         }
 953
 954         if (results->curl_result == CURLE_OK) {
 955                 credential_approve(&http_auth);
 956                 return HTTP_OK;
 957         } else if (missing_target(results))
 958                 return HTTP_MISSING_TARGET;
 959         else if (results->http_code == 401) {
 960                 if (http_auth.username && http_auth.password) {
 961                         credential_reject(&http_auth);
 962                         return HTTP_NOAUTH;
 963                 } else {
 964 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 965                         http_auth_methods &= ~CURLAUTH_GSSNEGOTIATE;
 966 #endif
 967                         return HTTP_REAUTH;
 968                 }
 969         } else {
 970 #if LIBCURL_VERSION_NUM >= 0x070c00
 971                 if (!curl_errorstr[0])
 972                         strlcpy(curl_errorstr,
 973                                 curl_easy_strerror(results->curl_result),
 974                                 sizeof(curl_errorstr));
 975 #endif
 976                 return HTTP_ERROR;
 977         }
 978 }
 979
 980 int run_one_slot(struct active_request_slot *slot,
 981                  struct slot_results *results)
 982 {
 983         slot->results = results;
 984         if (!start_active_slot(slot)) {
 985                 snprintf(curl_errorstr, sizeof(curl_errorstr),
 986                          "failed to start HTTP request");
 987                 return HTTP_START_FAILED;
 988         }
 989
 990         run_active_slot(slot);
 991         return handle_curl_result(results);
 992 }
 993
 994 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
 995 {
 996         char *ptr;
 997         CURLcode ret;
 998
 999         strbuf_reset(buf);
1000         ret = curl_easy_getinfo(curl, info, &ptr);
1001         if (!ret && ptr)
1002                 strbuf_addstr(buf, ptr);
1003         return ret;
1004 }
1005
1006 /*
1007  * Check for and extract a content-type parameter. "raw"
1008  * should be positioned at the start of the potential
1009  * parameter, with any whitespace already removed.
1010  *
1011  * "name" is the name of the parameter. The value is appended
1012  * to "out".
1013  */
1014 static int extract_param(const char *raw, const char *name,
1015                          struct strbuf *out)
1016 {
1017         size_t len = strlen(name);
1018
1019         if (strncasecmp(raw, name, len))
1020                 return -1;
1021         raw += len;
1022
1023         if (*raw != '=')
1024                 return -1;
1025         raw++;
1026
1027         while (*raw && !isspace(*raw) && *raw != ';')
1028                 strbuf_addch(out, *raw++);
1029         return 0;
1030 }
1031
1032 /*
1033  * Extract a normalized version of the content type, with any
1034  * spaces suppressed, all letters lowercased, and no trailing ";"
1035  * or parameters.
1036  *
1037  * Note that we will silently remove even invalid whitespace. For
1038  * example, "text / plain" is specifically forbidden by RFC 2616,
1039  * but "text/plain" is the only reasonable output, and this keeps
1040  * our code simple.
1041  *
1042  * If the "charset" argument is not NULL, store the value of any
1043  * charset parameter there.
1044  *
1045  * Example:
1046  *   "TEXT/PLAIN; charset=utf-8" -> "text/plain", "utf-8"
1047  *   "text / plain" -> "text/plain"
1048  */
1049 static void extract_content_type(struct strbuf *raw, struct strbuf *type,
1050                                  struct strbuf *charset)
1051 {
1052         const char *p;
1053
1054         strbuf_reset(type);
1055         strbuf_grow(type, raw->len);
1056         for (p = raw->buf; *p; p++) {
1057                 if (isspace(*p))
1058                         continue;
1059                 if (*p == ';') {
1060                         p++;
1061                         break;
1062                 }
1063                 strbuf_addch(type, tolower(*p));
1064         }
1065
1066         if (!charset)
1067                 return;
1068
1069         strbuf_reset(charset);
1070         while (*p) {
1071                 while (isspace(*p) || *p == ';')
1072                         p++;
1073                 if (!extract_param(p, "charset", charset))
1074                         return;
1075                 while (*p && !isspace(*p))
1076                         p++;
1077         }
1078
1079         if (!charset->len && starts_with(type->buf, "text/"))
1080                 strbuf_addstr(charset, "ISO-8859-1");
1081 }
1082
1083 static void write_accept_language(struct strbuf *buf)
1084 {
1085         /*
1086          * MAX_DECIMAL_PLACES must not be larger than 3. If it is larger than
1087          * that, q-value will be smaller than 0.001, the minimum q-value the
1088          * HTTP specification allows. See
1089          * http://tools.ietf.org/html/rfc7231#section-5.3.1 for q-value.
1090          */
1091         const int MAX_DECIMAL_PLACES = 3;
1092         const int MAX_LANGUAGE_TAGS = 1000;
1093         const int MAX_ACCEPT_LANGUAGE_HEADER_SIZE = 4000;
1094         char **language_tags = NULL;
1095         int num_langs = 0;
1096         const char *s = get_preferred_languages();
1097         int i;
1098         struct strbuf tag = STRBUF_INIT;
1099
1100         /* Don't add Accept-Language header if no language is preferred. */
1101         if (!s)
1102                 return;
1103
1104         /*
1105          * Split the colon-separated string of preferred languages into
1106          * language_tags array.
1107          */
1108         do {
1109                 /* collect language tag */
1110                 for (; *s && (isalnum(*s) || *s == '_'); s++)
1111                         strbuf_addch(&tag, *s == '_' ? '-' : *s);
1112
1113                 /* skip .codeset, @modifier and any other unnecessary parts */
1114                 while (*s && *s != ':')
1115                         s++;
1116
1117                 if (tag.len) {
1118                         num_langs++;
1119                         REALLOC_ARRAY(language_tags, num_langs);
1120                         language_tags[num_langs - 1] = strbuf_detach(&tag, NULL);
1121                         if (num_langs >= MAX_LANGUAGE_TAGS - 1) /* -1 for '*' */
1122                                 break;
1123                 }
1124         } while (*s++);
1125
1126         /* write Accept-Language header into buf */
1127         if (num_langs) {
1128                 int last_buf_len = 0;
1129                 int max_q;
1130                 int decimal_places;
1131                 char q_format[32];
1132
1133                 /* add '*' */
1134                 REALLOC_ARRAY(language_tags, num_langs + 1);
1135                 language_tags[num_langs++] = "*"; /* it's OK; this won't be freed */
1136
1137                 /* compute decimal_places */
1138                 for (max_q = 1, decimal_places = 0;
1139                      max_q < num_langs && decimal_places <= MAX_DECIMAL_PLACES;
1140                      decimal_places++, max_q *= 10)
1141                         ;
1142
1143                 sprintf(q_format, ";q=0.%%0%dd", decimal_places);
1144
1145                 strbuf_addstr(buf, "Accept-Language: ");
1146
1147                 for (i = 0; i < num_langs; i++) {
1148                         if (i > 0)
1149                                 strbuf_addstr(buf, ", ");
1150
1151                         strbuf_addstr(buf, language_tags[i]);
1152
1153                         if (i > 0)
1154                                 strbuf_addf(buf, q_format, max_q - i);
1155
1156                         if (buf->len > MAX_ACCEPT_LANGUAGE_HEADER_SIZE) {
1157                                 strbuf_remove(buf, last_buf_len, buf->len - last_buf_len);
1158                                 break;
1159                         }
1160
1161                         last_buf_len = buf->len;
1162                 }
1163         }
1164
1165         /* free language tags -- last one is a static '*' */
1166         for (i = 0; i < num_langs - 1; i++)
1167                 free(language_tags[i]);
1168         free(language_tags);
1169 }
1170
1171 /*
1172  * Get an Accept-Language header which indicates user's preferred languages.
1173  *
1174  * Examples:
1175  *   LANGUAGE= -> ""
1176  *   LANGUAGE=ko:en -> "Accept-Language: ko, en; q=0.9, *; q=0.1"
1177  *   LANGUAGE=ko_KR.UTF-8:sr@latin -> "Accept-Language: ko-KR, sr; q=0.9, *; q=0.1"
1178  *   LANGUAGE=ko LANG=en_US.UTF-8 -> "Accept-Language: ko, *; q=0.1"
1179  *   LANGUAGE= LANG=en_US.UTF-8 -> "Accept-Language: en-US, *; q=0.1"
1180  *   LANGUAGE= LANG=C -> ""
1181  */
1182 static const char *get_accept_language(void)
1183 {
1184         if (!cached_accept_language) {
1185                 struct strbuf buf = STRBUF_INIT;
1186                 write_accept_language(&buf);
1187                 if (buf.len > 0)
1188                         cached_accept_language = strbuf_detach(&buf, NULL);
1189         }
1190
1191         return cached_accept_language;
1192 }
1193
1194 /* http_request() targets */
1195 #define HTTP_REQUEST_STRBUF     0
1196 #define HTTP_REQUEST_FILE       1
1197
1198 static int http_request(const char *url,
1199                         void *result, int target,
1200                         const struct http_get_options *options)
1201 {
1202         struct active_request_slot *slot;
1203         struct slot_results results;
1204         struct curl_slist *headers = NULL;
1205         struct strbuf buf = STRBUF_INIT;
1206         const char *accept_language;
1207         int ret;
1208
1209         slot = get_active_slot();
1210         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1211
1212         if (result == NULL) {
1213                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
1214         } else {
1215                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
1216                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
1217
1218                 if (target == HTTP_REQUEST_FILE) {
1219                         long posn = ftell(result);
1220                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1221                                          fwrite);
1222                         if (posn > 0) {
1223                                 strbuf_addf(&buf, "Range: bytes=%ld-", posn);
1224                                 headers = curl_slist_append(headers, buf.buf);
1225                                 strbuf_reset(&buf);
1226                         }
1227                 } else
1228                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1229                                          fwrite_buffer);
1230         }
1231
1232         accept_language = get_accept_language();
1233
1234         if (accept_language)
1235                 headers = curl_slist_append(headers, accept_language);
1236
1237         strbuf_addstr(&buf, "Pragma:");
1238         if (options && options->no_cache)
1239                 strbuf_addstr(&buf, " no-cache");
1240         if (options && options->keep_error)
1241                 curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
1242
1243         headers = curl_slist_append(headers, buf.buf);
1244
1245         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1246         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
1247         curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
1248
1249         ret = run_one_slot(slot, &results);
1250
1251         if (options && options->content_type) {
1252                 struct strbuf raw = STRBUF_INIT;
1253                 curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE, &raw);
1254                 extract_content_type(&raw, options->content_type,
1255                                      options->charset);
1256                 strbuf_release(&raw);
1257         }
1258
1259         if (options && options->effective_url)
1260                 curlinfo_strbuf(slot->curl, CURLINFO_EFFECTIVE_URL,
1261                                 options->effective_url);
1262
1263         curl_slist_free_all(headers);
1264         strbuf_release(&buf);
1265
1266         return ret;
1267 }
1268
1269 /*
1270  * Update the "base" url to a more appropriate value, as deduced by
1271  * redirects seen when requesting a URL starting with "url".
1272  *
1273  * The "asked" parameter is a URL that we asked curl to access, and must begin
1274  * with "base".
1275  *
1276  * The "got" parameter is the URL that curl reported to us as where we ended
1277  * up.
1278  *
1279  * Returns 1 if we updated the base url, 0 otherwise.
1280  *
1281  * Our basic strategy is to compare "base" and "asked" to find the bits
1282  * specific to our request. We then strip those bits off of "got" to yield the
1283  * new base. So for example, if our base is "http://example.com/foo.git",
1284  * and we ask for "http://example.com/foo.git/info/refs", we might end up
1285  * with "https://other.example.com/foo.git/info/refs". We would want the
1286  * new URL to become "https://other.example.com/foo.git".
1287  *
1288  * Note that this assumes a sane redirect scheme. It's entirely possible
1289  * in the example above to end up at a URL that does not even end in
1290  * "info/refs".  In such a case we simply punt, as there is not much we can
1291  * do (and such a scheme is unlikely to represent a real git repository,
1292  * which means we are likely about to abort anyway).
1293  */
1294 static int update_url_from_redirect(struct strbuf *base,
1295                                     const char *asked,
1296                                     const struct strbuf *got)
1297 {
1298         const char *tail;
1299         size_t tail_len;
1300
1301         if (!strcmp(asked, got->buf))
1302                 return 0;
1303
1304         if (!skip_prefix(asked, base->buf, &tail))
1305                 die("BUG: update_url_from_redirect: %s is not a superset of %s",
1306                     asked, base->buf);
1307
1308         tail_len = strlen(tail);
1309
1310         if (got->len < tail_len ||
1311             strcmp(tail, got->buf + got->len - tail_len))
1312                 return 0; /* insane redirect scheme */
1313
1314         strbuf_reset(base);
1315         strbuf_add(base, got->buf, got->len - tail_len);
1316         return 1;
1317 }
1318
1319 static int http_request_reauth(const char *url,
1320                                void *result, int target,
1321                                struct http_get_options *options)
1322 {
1323         int ret = http_request(url, result, target, options);
1324
1325         if (options && options->effective_url && options->base_url) {
1326                 if (update_url_from_redirect(options->base_url,
1327                                              url, options->effective_url)) {
1328                         credential_from_url(&http_auth, options->base_url->buf);
1329                         url = options->effective_url->buf;
1330                 }
1331         }
1332
1333         if (ret != HTTP_REAUTH)
1334                 return ret;
1335
1336         /*
1337          * If we are using KEEP_ERROR, the previous request may have
1338          * put cruft into our output stream; we should clear it out before
1339          * making our next request. We only know how to do this for
1340          * the strbuf case, but that is enough to satisfy current callers.
1341          */
1342         if (options && options->keep_error) {
1343                 switch (target) {
1344                 case HTTP_REQUEST_STRBUF:
1345                         strbuf_reset(result);
1346                         break;
1347                 default:
1348                         die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
1349                 }
1350         }
1351
1352         credential_fill(&http_auth);
1353
1354         return http_request(url, result, target, options);
1355 }
1356
1357 int http_get_strbuf(const char *url,
1358                     struct strbuf *result,
1359                     struct http_get_options *options)
1360 {
1361         return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
1362 }
1363
1364 /*
1365  * Downloads a URL and stores the result in the given file.
1366  *
1367  * If a previous interrupted download is detected (i.e. a previous temporary
1368  * file is still around) the download is resumed.
1369  */
1370 static int http_get_file(const char *url, const char *filename,
1371                          struct http_get_options *options)
1372 {
1373         int ret;
1374         struct strbuf tmpfile = STRBUF_INIT;
1375         FILE *result;
1376
1377         strbuf_addf(&tmpfile, "%s.temp", filename);
1378         result = fopen(tmpfile.buf, "a");
1379         if (!result) {
1380                 error("Unable to open local file %s", tmpfile.buf);
1381                 ret = HTTP_ERROR;
1382                 goto cleanup;
1383         }
1384
1385         ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
1386         fclose(result);
1387
1388         if (ret == HTTP_OK && finalize_object_file(tmpfile.buf, filename))
1389                 ret = HTTP_ERROR;
1390 cleanup:
1391         strbuf_release(&tmpfile);
1392         return ret;
1393 }
1394
1395 int http_fetch_ref(const char *base, struct ref *ref)
1396 {
1397         struct http_get_options options = {0};
1398         char *url;
1399         struct strbuf buffer = STRBUF_INIT;
1400         int ret = -1;
1401
1402         options.no_cache = 1;
1403
1404         url = quote_ref_url(base, ref->name);
1405         if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
1406                 strbuf_rtrim(&buffer);
1407                 if (buffer.len == 40)
1408                         ret = get_sha1_hex(buffer.buf, ref->old_sha1);
1409                 else if (starts_with(buffer.buf, "ref: ")) {
1410                         ref->symref = xstrdup(buffer.buf + 5);
1411                         ret = 0;
1412                 }
1413         }
1414
1415         strbuf_release(&buffer);
1416         free(url);
1417         return ret;
1418 }
1419
1420 /* Helpers for fetching packs */
1421 static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
1422 {
1423         char *url, *tmp;
1424         struct strbuf buf = STRBUF_INIT;
1425
1426         if (http_is_verbose)
1427                 fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
1428
1429         end_url_with_slash(&buf, base_url);
1430         strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
1431         url = strbuf_detach(&buf, NULL);
1432
1433         strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
1434         tmp = strbuf_detach(&buf, NULL);
1435
1436         if (http_get_file(url, tmp, NULL) != HTTP_OK) {
1437                 error("Unable to get pack index %s", url);
1438                 free(tmp);
1439                 tmp = NULL;
1440         }
1441
1442         free(url);
1443         return tmp;
1444 }
1445
1446 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
1447         unsigned char *sha1, const char *base_url)
1448 {
1449         struct packed_git *new_pack;
1450         char *tmp_idx = NULL;
1451         int ret;
1452
1453         if (has_pack_index(sha1)) {
1454                 new_pack = parse_pack_index(sha1, sha1_pack_index_name(sha1));
1455                 if (!new_pack)
1456                         return -1; /* parse_pack_index() already issued error message */
1457                 goto add_pack;
1458         }
1459
1460         tmp_idx = fetch_pack_index(sha1, base_url);
1461         if (!tmp_idx)
1462                 return -1;
1463
1464         new_pack = parse_pack_index(sha1, tmp_idx);
1465         if (!new_pack) {
1466                 unlink(tmp_idx);
1467                 free(tmp_idx);
1468
1469                 return -1; /* parse_pack_index() already issued error message */
1470         }
1471
1472         ret = verify_pack_index(new_pack);
1473         if (!ret) {
1474                 close_pack_index(new_pack);
1475                 ret = finalize_object_file(tmp_idx, sha1_pack_index_name(sha1));
1476         }
1477         free(tmp_idx);
1478         if (ret)
1479                 return -1;
1480
1481 add_pack:
1482         new_pack->next = *packs_head;
1483         *packs_head = new_pack;
1484         return 0;
1485 }
1486
1487 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
1488 {
1489         struct http_get_options options = {0};
1490         int ret = 0, i = 0;
1491         char *url, *data;
1492         struct strbuf buf = STRBUF_INIT;
1493         unsigned char sha1[20];
1494
1495         end_url_with_slash(&buf, base_url);
1496         strbuf_addstr(&buf, "objects/info/packs");
1497         url = strbuf_detach(&buf, NULL);
1498
1499         options.no_cache = 1;
1500         ret = http_get_strbuf(url, &buf, &options);
1501         if (ret != HTTP_OK)
1502                 goto cleanup;
1503
1504         data = buf.buf;
1505         while (i < buf.len) {
1506                 switch (data[i]) {
1507                 case 'P':
1508                         i++;
1509                         if (i + 52 <= buf.len &&
1510                             starts_with(data + i, " pack-") &&
1511                             starts_with(data + i + 46, ".pack\n")) {
1512                                 get_sha1_hex(data + i + 6, sha1);
1513                                 fetch_and_setup_pack_index(packs_head, sha1,
1514                                                       base_url);
1515                                 i += 51;
1516                                 break;
1517                         }
1518                 default:
1519                         while (i < buf.len && data[i] != '\n')
1520                                 i++;
1521                 }
1522                 i++;
1523         }
1524
1525 cleanup:
1526         free(url);
1527         return ret;
1528 }
1529
1530 void release_http_pack_request(struct http_pack_request *preq)
1531 {
1532         if (preq->packfile != NULL) {
1533                 fclose(preq->packfile);
1534                 preq->packfile = NULL;
1535         }
1536         if (preq->range_header != NULL) {
1537                 curl_slist_free_all(preq->range_header);
1538                 preq->range_header = NULL;
1539         }
1540         preq->slot = NULL;
1541         free(preq->url);
1542         free(preq);
1543 }
1544
1545 int finish_http_pack_request(struct http_pack_request *preq)
1546 {
1547         struct packed_git **lst;
1548         struct packed_git *p = preq->target;
1549         char *tmp_idx;
1550         struct child_process ip = CHILD_PROCESS_INIT;
1551         const char *ip_argv[8];
1552
1553         close_pack_index(p);
1554
1555         fclose(preq->packfile);
1556         preq->packfile = NULL;
1557
1558         lst = preq->lst;
1559         while (*lst != p)
1560                 lst = &((*lst)->next);
1561         *lst = (*lst)->next;
1562
1563         tmp_idx = xstrdup(preq->tmpfile);
1564         strcpy(tmp_idx + strlen(tmp_idx) - strlen(".pack.temp"),
1565                ".idx.temp");
1566
1567         ip_argv[0] = "index-pack";
1568         ip_argv[1] = "-o";
1569         ip_argv[2] = tmp_idx;
1570         ip_argv[3] = preq->tmpfile;
1571         ip_argv[4] = NULL;
1572
1573         ip.argv = ip_argv;
1574         ip.git_cmd = 1;
1575         ip.no_stdin = 1;
1576         ip.no_stdout = 1;
1577
1578         if (run_command(&ip)) {
1579                 unlink(preq->tmpfile);
1580                 unlink(tmp_idx);
1581                 free(tmp_idx);
1582                 return -1;
1583         }
1584
1585         unlink(sha1_pack_index_name(p->sha1));
1586
1587         if (finalize_object_file(preq->tmpfile, sha1_pack_name(p->sha1))
1588          || finalize_object_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
1589                 free(tmp_idx);
1590                 return -1;
1591         }
1592
1593         install_packed_git(p);
1594         free(tmp_idx);
1595         return 0;
1596 }
1597
1598 struct http_pack_request *new_http_pack_request(
1599         struct packed_git *target, const char *base_url)
1600 {
1601         long prev_posn = 0;
1602         char range[RANGE_HEADER_SIZE];
1603         struct strbuf buf = STRBUF_INIT;
1604         struct http_pack_request *preq;
1605
1606         preq = xcalloc(1, sizeof(*preq));
1607         preq->target = target;
1608
1609         end_url_with_slash(&buf, base_url);
1610         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
1611                 sha1_to_hex(target->sha1));
1612         preq->url = strbuf_detach(&buf, NULL);
1613
1614         snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
1615                 sha1_pack_name(target->sha1));
1616         preq->packfile = fopen(preq->tmpfile, "a");
1617         if (!preq->packfile) {
1618                 error("Unable to open local file %s for pack",
1619                       preq->tmpfile);
1620                 goto abort;
1621         }
1622
1623         preq->slot = get_active_slot();
1624         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
1625         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
1626         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
1627         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1628                 no_pragma_header);
1629
1630         /*
1631          * If there is data present from a previous transfer attempt,
1632          * resume where it left off
1633          */
1634         prev_posn = ftell(preq->packfile);
1635         if (prev_posn>0) {
1636                 if (http_is_verbose)
1637                         fprintf(stderr,
1638                                 "Resuming fetch of pack %s at byte %ld\n",
1639                                 sha1_to_hex(target->sha1), prev_posn);
1640                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1641                 preq->range_header = curl_slist_append(NULL, range);
1642                 curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1643                         preq->range_header);
1644         }
1645
1646         return preq;
1647
1648 abort:
1649         free(preq->url);
1650         free(preq);
1651         return NULL;
1652 }
1653
1654 /* Helpers for fetching objects (loose) */
1655 static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
1656                                void *data)
1657 {
1658         unsigned char expn[4096];
1659         size_t size = eltsize * nmemb;
1660         int posn = 0;
1661         struct http_object_request *freq =
1662                 (struct http_object_request *)data;
1663         do {
1664                 ssize_t retval = xwrite(freq->localfile,
1665                                         (char *) ptr + posn, size - posn);
1666                 if (retval < 0)
1667                         return posn;
1668                 posn += retval;
1669         } while (posn < size);
1670
1671         freq->stream.avail_in = size;
1672         freq->stream.next_in = (void *)ptr;
1673         do {
1674                 freq->stream.next_out = expn;
1675                 freq->stream.avail_out = sizeof(expn);
1676                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
1677                 git_SHA1_Update(&freq->c, expn,
1678                                 sizeof(expn) - freq->stream.avail_out);
1679         } while (freq->stream.avail_in && freq->zret == Z_OK);
1680         return size;
1681 }
1682
1683 struct http_object_request *new_http_object_request(const char *base_url,
1684         unsigned char *sha1)
1685 {
1686         char *hex = sha1_to_hex(sha1);
1687         const char *filename;
1688         char prevfile[PATH_MAX];
1689         int prevlocal;
1690         char prev_buf[PREV_BUF_SIZE];
1691         ssize_t prev_read = 0;
1692         long prev_posn = 0;
1693         char range[RANGE_HEADER_SIZE];
1694         struct curl_slist *range_header = NULL;
1695         struct http_object_request *freq;
1696
1697         freq = xcalloc(1, sizeof(*freq));
1698         hashcpy(freq->sha1, sha1);
1699         freq->localfile = -1;
1700
1701         filename = sha1_file_name(sha1);
1702         snprintf(freq->tmpfile, sizeof(freq->tmpfile),
1703                  "%s.temp", filename);
1704
1705         snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
1706         unlink_or_warn(prevfile);
1707         rename(freq->tmpfile, prevfile);
1708         unlink_or_warn(freq->tmpfile);
1709
1710         if (freq->localfile != -1)
1711                 error("fd leakage in start: %d", freq->localfile);
1712         freq->localfile = open(freq->tmpfile,
1713                                O_WRONLY | O_CREAT | O_EXCL, 0666);
1714         /*
1715          * This could have failed due to the "lazy directory creation";
1716          * try to mkdir the last path component.
1717          */
1718         if (freq->localfile < 0 && errno == ENOENT) {
1719                 char *dir = strrchr(freq->tmpfile, '/');
1720                 if (dir) {
1721                         *dir = 0;
1722                         mkdir(freq->tmpfile, 0777);
1723                         *dir = '/';
1724                 }
1725                 freq->localfile = open(freq->tmpfile,
1726                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
1727         }
1728
1729         if (freq->localfile < 0) {
1730                 error("Couldn't create temporary file %s: %s",
1731                       freq->tmpfile, strerror(errno));
1732                 goto abort;
1733         }
1734
1735         git_inflate_init(&freq->stream);
1736
1737         git_SHA1_Init(&freq->c);
1738
1739         freq->url = get_remote_object_url(base_url, hex, 0);
1740
1741         /*
1742          * If a previous temp file is present, process what was already
1743          * fetched.
1744          */
1745         prevlocal = open(prevfile, O_RDONLY);
1746         if (prevlocal != -1) {
1747                 do {
1748                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
1749                         if (prev_read>0) {
1750                                 if (fwrite_sha1_file(prev_buf,
1751                                                      1,
1752                                                      prev_read,
1753                                                      freq) == prev_read) {
1754                                         prev_posn += prev_read;
1755                                 } else {
1756                                         prev_read = -1;
1757                                 }
1758                         }
1759                 } while (prev_read > 0);
1760                 close(prevlocal);
1761         }
1762         unlink_or_warn(prevfile);
1763
1764         /*
1765          * Reset inflate/SHA1 if there was an error reading the previous temp
1766          * file; also rewind to the beginning of the local file.
1767          */
1768         if (prev_read == -1) {
1769                 memset(&freq->stream, 0, sizeof(freq->stream));
1770                 git_inflate_init(&freq->stream);
1771                 git_SHA1_Init(&freq->c);
1772                 if (prev_posn>0) {
1773                         prev_posn = 0;
1774                         lseek(freq->localfile, 0, SEEK_SET);
1775                         if (ftruncate(freq->localfile, 0) < 0) {
1776                                 error("Couldn't truncate temporary file %s: %s",
1777                                           freq->tmpfile, strerror(errno));
1778                                 goto abort;
1779                         }
1780                 }
1781         }
1782
1783         freq->slot = get_active_slot();
1784
1785         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
1786         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
1787         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
1788         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
1789         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
1790
1791         /*
1792          * If we have successfully processed data from a previous fetch
1793          * attempt, only fetch the data we don't already have.
1794          */
1795         if (prev_posn>0) {
1796                 if (http_is_verbose)
1797                         fprintf(stderr,
1798                                 "Resuming fetch of object %s at byte %ld\n",
1799                                 hex, prev_posn);
1800                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1801                 range_header = curl_slist_append(range_header, range);
1802                 curl_easy_setopt(freq->slot->curl,
1803                                  CURLOPT_HTTPHEADER, range_header);
1804         }
1805
1806         return freq;
1807
1808 abort:
1809         free(freq->url);
1810         free(freq);
1811         return NULL;
1812 }
1813
1814 void process_http_object_request(struct http_object_request *freq)
1815 {
1816         if (freq->slot == NULL)
1817                 return;
1818         freq->curl_result = freq->slot->curl_result;
1819         freq->http_code = freq->slot->http_code;
1820         freq->slot = NULL;
1821 }
1822
1823 int finish_http_object_request(struct http_object_request *freq)
1824 {
1825         struct stat st;
1826
1827         close(freq->localfile);
1828         freq->localfile = -1;
1829
1830         process_http_object_request(freq);
1831
1832         if (freq->http_code == 416) {
1833                 warning("requested range invalid; we may already have all the data.");
1834         } else if (freq->curl_result != CURLE_OK) {
1835                 if (stat(freq->tmpfile, &st) == 0)
1836                         if (st.st_size == 0)
1837                                 unlink_or_warn(freq->tmpfile);
1838                 return -1;
1839         }
1840
1841         git_inflate_end(&freq->stream);
1842         git_SHA1_Final(freq->real_sha1, &freq->c);
1843         if (freq->zret != Z_STREAM_END) {
1844                 unlink_or_warn(freq->tmpfile);
1845                 return -1;
1846         }
1847         if (hashcmp(freq->sha1, freq->real_sha1)) {
1848                 unlink_or_warn(freq->tmpfile);
1849                 return -1;
1850         }
1851         freq->rename =
1852                 finalize_object_file(freq->tmpfile, sha1_file_name(freq->sha1));
1853
1854         return freq->rename;
1855 }
1856
1857 void abort_http_object_request(struct http_object_request *freq)
1858 {
1859         unlink_or_warn(freq->tmpfile);
1860
1861         release_http_object_request(freq);
1862 }
1863
1864 void release_http_object_request(struct http_object_request *freq)
1865 {
1866         if (freq->localfile != -1) {
1867                 close(freq->localfile);
1868                 freq->localfile = -1;
1869         }
1870         if (freq->url != NULL) {
1871                 free(freq->url);
1872                 freq->url = NULL;
1873         }
1874         if (freq->slot != NULL) {
1875                 freq->slot->callback_func = NULL;
1876                 freq->slot->callback_data = NULL;
1877                 release_active_slot(freq->slot);
1878                 freq->slot = NULL;
1879         }
1880 }