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 && curl_session_count > min_curl_sessions) {
 859                 xmulti_remove_handle(slot);
 860                 curl_easy_cleanup(slot->curl);
 861                 slot->curl = NULL;
 862                 curl_session_count--;
 863         }
 864 #ifdef USE_CURL_MULTI
 865         fill_active_slots();
 866 #endif
 867 }
 868
 869 void finish_all_active_slots(void)
 870 {
 871         struct active_request_slot *slot = active_queue_head;
 872
 873         while (slot != NULL)
 874                 if (slot->in_use) {
 875                         run_active_slot(slot);
 876                         slot = active_queue_head;
 877                 } else {
 878                         slot = slot->next;
 879                 }
 880 }
 881
 882 /* Helpers for modifying and creating URLs */
 883 static inline int needs_quote(int ch)
 884 {
 885         if (((ch >= 'A') && (ch <= 'Z'))
 886                         || ((ch >= 'a') && (ch <= 'z'))
 887                         || ((ch >= '0') && (ch <= '9'))
 888                         || (ch == '/')
 889                         || (ch == '-')
 890                         || (ch == '.'))
 891                 return 0;
 892         return 1;
 893 }
 894
 895 static char *quote_ref_url(const char *base, const char *ref)
 896 {
 897         struct strbuf buf = STRBUF_INIT;
 898         const char *cp;
 899         int ch;
 900
 901         end_url_with_slash(&buf, base);
 902
 903         for (cp = ref; (ch = *cp) != 0; cp++)
 904                 if (needs_quote(ch))
 905                         strbuf_addf(&buf, "%%%02x", ch);
 906                 else
 907                         strbuf_addch(&buf, *cp);
 908
 909         return strbuf_detach(&buf, NULL);
 910 }
 911
 912 void append_remote_object_url(struct strbuf *buf, const char *url,
 913                               const char *hex,
 914                               int only_two_digit_prefix)
 915 {
 916         end_url_with_slash(buf, url);
 917
 918         strbuf_addf(buf, "objects/%.*s/", 2, hex);
 919         if (!only_two_digit_prefix)
 920                 strbuf_addf(buf, "%s", hex+2);
 921 }
 922
 923 char *get_remote_object_url(const char *url, const char *hex,
 924                             int only_two_digit_prefix)
 925 {
 926         struct strbuf buf = STRBUF_INIT;
 927         append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
 928         return strbuf_detach(&buf, NULL);
 929 }
 930
 931 static int handle_curl_result(struct slot_results *results)
 932 {
 933         /*
 934          * If we see a failing http code with CURLE_OK, we have turned off
 935          * FAILONERROR (to keep the server's custom error response), and should
 936          * translate the code into failure here.
 937          */
 938         if (results->curl_result == CURLE_OK &&
 939             results->http_code >= 400) {
 940                 results->curl_result = CURLE_HTTP_RETURNED_ERROR;
 941                 /*
 942                  * Normally curl will already have put the "reason phrase"
 943                  * from the server into curl_errorstr; unfortunately without
 944                  * FAILONERROR it is lost, so we can give only the numeric
 945                  * status code.
 946                  */
 947                 snprintf(curl_errorstr, sizeof(curl_errorstr),
 948                          "The requested URL returned error: %ld",
 949                          results->http_code);
 950         }
 951
 952         if (results->curl_result == CURLE_OK) {
 953                 credential_approve(&http_auth);
 954                 return HTTP_OK;
 955         } else if (missing_target(results))
 956                 return HTTP_MISSING_TARGET;
 957         else if (results->http_code == 401) {
 958                 if (http_auth.username && http_auth.password) {
 959                         credential_reject(&http_auth);
 960                         return HTTP_NOAUTH;
 961                 } else {
 962 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 963                         http_auth_methods &= ~CURLAUTH_GSSNEGOTIATE;
 964 #endif
 965                         return HTTP_REAUTH;
 966                 }
 967         } else {
 968 #if LIBCURL_VERSION_NUM >= 0x070c00
 969                 if (!curl_errorstr[0])
 970                         strlcpy(curl_errorstr,
 971                                 curl_easy_strerror(results->curl_result),
 972                                 sizeof(curl_errorstr));
 973 #endif
 974                 return HTTP_ERROR;
 975         }
 976 }
 977
 978 int run_one_slot(struct active_request_slot *slot,
 979                  struct slot_results *results)
 980 {
 981         slot->results = results;
 982         if (!start_active_slot(slot)) {
 983                 snprintf(curl_errorstr, sizeof(curl_errorstr),
 984                          "failed to start HTTP request");
 985                 return HTTP_START_FAILED;
 986         }
 987
 988         run_active_slot(slot);
 989         return handle_curl_result(results);
 990 }
 991
 992 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
 993 {
 994         char *ptr;
 995         CURLcode ret;
 996
 997         strbuf_reset(buf);
 998         ret = curl_easy_getinfo(curl, info, &ptr);
 999         if (!ret && ptr)
1000                 strbuf_addstr(buf, ptr);
1001         return ret;
1002 }
1003
1004 /*
1005  * Check for and extract a content-type parameter. "raw"
1006  * should be positioned at the start of the potential
1007  * parameter, with any whitespace already removed.
1008  *
1009  * "name" is the name of the parameter. The value is appended
1010  * to "out".
1011  */
1012 static int extract_param(const char *raw, const char *name,
1013                          struct strbuf *out)
1014 {
1015         size_t len = strlen(name);
1016
1017         if (strncasecmp(raw, name, len))
1018                 return -1;
1019         raw += len;
1020
1021         if (*raw != '=')
1022                 return -1;
1023         raw++;
1024
1025         while (*raw && !isspace(*raw) && *raw != ';')
1026                 strbuf_addch(out, *raw++);
1027         return 0;
1028 }
1029
1030 /*
1031  * Extract a normalized version of the content type, with any
1032  * spaces suppressed, all letters lowercased, and no trailing ";"
1033  * or parameters.
1034  *
1035  * Note that we will silently remove even invalid whitespace. For
1036  * example, "text / plain" is specifically forbidden by RFC 2616,
1037  * but "text/plain" is the only reasonable output, and this keeps
1038  * our code simple.
1039  *
1040  * If the "charset" argument is not NULL, store the value of any
1041  * charset parameter there.
1042  *
1043  * Example:
1044  *   "TEXT/PLAIN; charset=utf-8" -> "text/plain", "utf-8"
1045  *   "text / plain" -> "text/plain"
1046  */
1047 static void extract_content_type(struct strbuf *raw, struct strbuf *type,
1048                                  struct strbuf *charset)
1049 {
1050         const char *p;
1051
1052         strbuf_reset(type);
1053         strbuf_grow(type, raw->len);
1054         for (p = raw->buf; *p; p++) {
1055                 if (isspace(*p))
1056                         continue;
1057                 if (*p == ';') {
1058                         p++;
1059                         break;
1060                 }
1061                 strbuf_addch(type, tolower(*p));
1062         }
1063
1064         if (!charset)
1065                 return;
1066
1067         strbuf_reset(charset);
1068         while (*p) {
1069                 while (isspace(*p) || *p == ';')
1070                         p++;
1071                 if (!extract_param(p, "charset", charset))
1072                         return;
1073                 while (*p && !isspace(*p))
1074                         p++;
1075         }
1076
1077         if (!charset->len && starts_with(type->buf, "text/"))
1078                 strbuf_addstr(charset, "ISO-8859-1");
1079 }
1080
1081 static void write_accept_language(struct strbuf *buf)
1082 {
1083         /*
1084          * MAX_DECIMAL_PLACES must not be larger than 3. If it is larger than
1085          * that, q-value will be smaller than 0.001, the minimum q-value the
1086          * HTTP specification allows. See
1087          * http://tools.ietf.org/html/rfc7231#section-5.3.1 for q-value.
1088          */
1089         const int MAX_DECIMAL_PLACES = 3;
1090         const int MAX_LANGUAGE_TAGS = 1000;
1091         const int MAX_ACCEPT_LANGUAGE_HEADER_SIZE = 4000;
1092         char **language_tags = NULL;
1093         int num_langs = 0;
1094         const char *s = get_preferred_languages();
1095         int i;
1096         struct strbuf tag = STRBUF_INIT;
1097
1098         /* Don't add Accept-Language header if no language is preferred. */
1099         if (!s)
1100                 return;
1101
1102         /*
1103          * Split the colon-separated string of preferred languages into
1104          * language_tags array.
1105          */
1106         do {
1107                 /* collect language tag */
1108                 for (; *s && (isalnum(*s) || *s == '_'); s++)
1109                         strbuf_addch(&tag, *s == '_' ? '-' : *s);
1110
1111                 /* skip .codeset, @modifier and any other unnecessary parts */
1112                 while (*s && *s != ':')
1113                         s++;
1114
1115                 if (tag.len) {
1116                         num_langs++;
1117                         REALLOC_ARRAY(language_tags, num_langs);
1118                         language_tags[num_langs - 1] = strbuf_detach(&tag, NULL);
1119                         if (num_langs >= MAX_LANGUAGE_TAGS - 1) /* -1 for '*' */
1120                                 break;
1121                 }
1122         } while (*s++);
1123
1124         /* write Accept-Language header into buf */
1125         if (num_langs) {
1126                 int last_buf_len = 0;
1127                 int max_q;
1128                 int decimal_places;
1129                 char q_format[32];
1130
1131                 /* add '*' */
1132                 REALLOC_ARRAY(language_tags, num_langs + 1);
1133                 language_tags[num_langs++] = "*"; /* it's OK; this won't be freed */
1134
1135                 /* compute decimal_places */
1136                 for (max_q = 1, decimal_places = 0;
1137                      max_q < num_langs && decimal_places <= MAX_DECIMAL_PLACES;
1138                      decimal_places++, max_q *= 10)
1139                         ;
1140
1141                 sprintf(q_format, ";q=0.%%0%dd", decimal_places);
1142
1143                 strbuf_addstr(buf, "Accept-Language: ");
1144
1145                 for (i = 0; i < num_langs; i++) {
1146                         if (i > 0)
1147                                 strbuf_addstr(buf, ", ");
1148
1149                         strbuf_addstr(buf, language_tags[i]);
1150
1151                         if (i > 0)
1152                                 strbuf_addf(buf, q_format, max_q - i);
1153
1154                         if (buf->len > MAX_ACCEPT_LANGUAGE_HEADER_SIZE) {
1155                                 strbuf_remove(buf, last_buf_len, buf->len - last_buf_len);
1156                                 break;
1157                         }
1158
1159                         last_buf_len = buf->len;
1160                 }
1161         }
1162
1163         /* free language tags -- last one is a static '*' */
1164         for (i = 0; i < num_langs - 1; i++)
1165                 free(language_tags[i]);
1166         free(language_tags);
1167 }
1168
1169 /*
1170  * Get an Accept-Language header which indicates user's preferred languages.
1171  *
1172  * Examples:
1173  *   LANGUAGE= -> ""
1174  *   LANGUAGE=ko:en -> "Accept-Language: ko, en; q=0.9, *; q=0.1"
1175  *   LANGUAGE=ko_KR.UTF-8:sr@latin -> "Accept-Language: ko-KR, sr; q=0.9, *; q=0.1"
1176  *   LANGUAGE=ko LANG=en_US.UTF-8 -> "Accept-Language: ko, *; q=0.1"
1177  *   LANGUAGE= LANG=en_US.UTF-8 -> "Accept-Language: en-US, *; q=0.1"
1178  *   LANGUAGE= LANG=C -> ""
1179  */
1180 static const char *get_accept_language(void)
1181 {
1182         if (!cached_accept_language) {
1183                 struct strbuf buf = STRBUF_INIT;
1184                 write_accept_language(&buf);
1185                 if (buf.len > 0)
1186                         cached_accept_language = strbuf_detach(&buf, NULL);
1187         }
1188
1189         return cached_accept_language;
1190 }
1191
1192 /* http_request() targets */
1193 #define HTTP_REQUEST_STRBUF     0
1194 #define HTTP_REQUEST_FILE       1
1195
1196 static int http_request(const char *url,
1197                         void *result, int target,
1198                         const struct http_get_options *options)
1199 {
1200         struct active_request_slot *slot;
1201         struct slot_results results;
1202         struct curl_slist *headers = NULL;
1203         struct strbuf buf = STRBUF_INIT;
1204         const char *accept_language;
1205         int ret;
1206
1207         slot = get_active_slot();
1208         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1209
1210         if (result == NULL) {
1211                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
1212         } else {
1213                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
1214                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
1215
1216                 if (target == HTTP_REQUEST_FILE) {
1217                         long posn = ftell(result);
1218                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1219                                          fwrite);
1220                         if (posn > 0) {
1221                                 strbuf_addf(&buf, "Range: bytes=%ld-", posn);
1222                                 headers = curl_slist_append(headers, buf.buf);
1223                                 strbuf_reset(&buf);
1224                         }
1225                 } else
1226                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1227                                          fwrite_buffer);
1228         }
1229
1230         accept_language = get_accept_language();
1231
1232         if (accept_language)
1233                 headers = curl_slist_append(headers, accept_language);
1234
1235         strbuf_addstr(&buf, "Pragma:");
1236         if (options && options->no_cache)
1237                 strbuf_addstr(&buf, " no-cache");
1238         if (options && options->keep_error)
1239                 curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
1240
1241         headers = curl_slist_append(headers, buf.buf);
1242
1243         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1244         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
1245         curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
1246
1247         ret = run_one_slot(slot, &results);
1248
1249         if (options && options->content_type) {
1250                 struct strbuf raw = STRBUF_INIT;
1251                 curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE, &raw);
1252                 extract_content_type(&raw, options->content_type,
1253                                      options->charset);
1254                 strbuf_release(&raw);
1255         }
1256
1257         if (options && options->effective_url)
1258                 curlinfo_strbuf(slot->curl, CURLINFO_EFFECTIVE_URL,
1259                                 options->effective_url);
1260
1261         curl_slist_free_all(headers);
1262         strbuf_release(&buf);
1263
1264         return ret;
1265 }
1266
1267 /*
1268  * Update the "base" url to a more appropriate value, as deduced by
1269  * redirects seen when requesting a URL starting with "url".
1270  *
1271  * The "asked" parameter is a URL that we asked curl to access, and must begin
1272  * with "base".
1273  *
1274  * The "got" parameter is the URL that curl reported to us as where we ended
1275  * up.
1276  *
1277  * Returns 1 if we updated the base url, 0 otherwise.
1278  *
1279  * Our basic strategy is to compare "base" and "asked" to find the bits
1280  * specific to our request. We then strip those bits off of "got" to yield the
1281  * new base. So for example, if our base is "http://example.com/foo.git",
1282  * and we ask for "http://example.com/foo.git/info/refs", we might end up
1283  * with "https://other.example.com/foo.git/info/refs". We would want the
1284  * new URL to become "https://other.example.com/foo.git".
1285  *
1286  * Note that this assumes a sane redirect scheme. It's entirely possible
1287  * in the example above to end up at a URL that does not even end in
1288  * "info/refs".  In such a case we simply punt, as there is not much we can
1289  * do (and such a scheme is unlikely to represent a real git repository,
1290  * which means we are likely about to abort anyway).
1291  */
1292 static int update_url_from_redirect(struct strbuf *base,
1293                                     const char *asked,
1294                                     const struct strbuf *got)
1295 {
1296         const char *tail;
1297         size_t tail_len;
1298
1299         if (!strcmp(asked, got->buf))
1300                 return 0;
1301
1302         if (!skip_prefix(asked, base->buf, &tail))
1303                 die("BUG: update_url_from_redirect: %s is not a superset of %s",
1304                     asked, base->buf);
1305
1306         tail_len = strlen(tail);
1307
1308         if (got->len < tail_len ||
1309             strcmp(tail, got->buf + got->len - tail_len))
1310                 return 0; /* insane redirect scheme */
1311
1312         strbuf_reset(base);
1313         strbuf_add(base, got->buf, got->len - tail_len);
1314         return 1;
1315 }
1316
1317 static int http_request_reauth(const char *url,
1318                                void *result, int target,
1319                                struct http_get_options *options)
1320 {
1321         int ret = http_request(url, result, target, options);
1322
1323         if (options && options->effective_url && options->base_url) {
1324                 if (update_url_from_redirect(options->base_url,
1325                                              url, options->effective_url)) {
1326                         credential_from_url(&http_auth, options->base_url->buf);
1327                         url = options->effective_url->buf;
1328                 }
1329         }
1330
1331         if (ret != HTTP_REAUTH)
1332                 return ret;
1333
1334         /*
1335          * If we are using KEEP_ERROR, the previous request may have
1336          * put cruft into our output stream; we should clear it out before
1337          * making our next request. We only know how to do this for
1338          * the strbuf case, but that is enough to satisfy current callers.
1339          */
1340         if (options && options->keep_error) {
1341                 switch (target) {
1342                 case HTTP_REQUEST_STRBUF:
1343                         strbuf_reset(result);
1344                         break;
1345                 default:
1346                         die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
1347                 }
1348         }
1349
1350         credential_fill(&http_auth);
1351
1352         return http_request(url, result, target, options);
1353 }
1354
1355 int http_get_strbuf(const char *url,
1356                     struct strbuf *result,
1357                     struct http_get_options *options)
1358 {
1359         return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
1360 }
1361
1362 /*
1363  * Downloads a URL and stores the result in the given file.
1364  *
1365  * If a previous interrupted download is detected (i.e. a previous temporary
1366  * file is still around) the download is resumed.
1367  */
1368 static int http_get_file(const char *url, const char *filename,
1369                          struct http_get_options *options)
1370 {
1371         int ret;
1372         struct strbuf tmpfile = STRBUF_INIT;
1373         FILE *result;
1374
1375         strbuf_addf(&tmpfile, "%s.temp", filename);
1376         result = fopen(tmpfile.buf, "a");
1377         if (!result) {
1378                 error("Unable to open local file %s", tmpfile.buf);
1379                 ret = HTTP_ERROR;
1380                 goto cleanup;
1381         }
1382
1383         ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
1384         fclose(result);
1385
1386         if (ret == HTTP_OK && finalize_object_file(tmpfile.buf, filename))
1387                 ret = HTTP_ERROR;
1388 cleanup:
1389         strbuf_release(&tmpfile);
1390         return ret;
1391 }
1392
1393 int http_fetch_ref(const char *base, struct ref *ref)
1394 {
1395         struct http_get_options options = {0};
1396         char *url;
1397         struct strbuf buffer = STRBUF_INIT;
1398         int ret = -1;
1399
1400         options.no_cache = 1;
1401
1402         url = quote_ref_url(base, ref->name);
1403         if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
1404                 strbuf_rtrim(&buffer);
1405                 if (buffer.len == 40)
1406                         ret = get_sha1_hex(buffer.buf, ref->old_sha1);
1407                 else if (starts_with(buffer.buf, "ref: ")) {
1408                         ref->symref = xstrdup(buffer.buf + 5);
1409                         ret = 0;
1410                 }
1411         }
1412
1413         strbuf_release(&buffer);
1414         free(url);
1415         return ret;
1416 }
1417
1418 /* Helpers for fetching packs */
1419 static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
1420 {
1421         char *url, *tmp;
1422         struct strbuf buf = STRBUF_INIT;
1423
1424         if (http_is_verbose)
1425                 fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
1426
1427         end_url_with_slash(&buf, base_url);
1428         strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
1429         url = strbuf_detach(&buf, NULL);
1430
1431         strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
1432         tmp = strbuf_detach(&buf, NULL);
1433
1434         if (http_get_file(url, tmp, NULL) != HTTP_OK) {
1435                 error("Unable to get pack index %s", url);
1436                 free(tmp);
1437                 tmp = NULL;
1438         }
1439
1440         free(url);
1441         return tmp;
1442 }
1443
1444 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
1445         unsigned char *sha1, const char *base_url)
1446 {
1447         struct packed_git *new_pack;
1448         char *tmp_idx = NULL;
1449         int ret;
1450
1451         if (has_pack_index(sha1)) {
1452                 new_pack = parse_pack_index(sha1, sha1_pack_index_name(sha1));
1453                 if (!new_pack)
1454                         return -1; /* parse_pack_index() already issued error message */
1455                 goto add_pack;
1456         }
1457
1458         tmp_idx = fetch_pack_index(sha1, base_url);
1459         if (!tmp_idx)
1460                 return -1;
1461
1462         new_pack = parse_pack_index(sha1, tmp_idx);
1463         if (!new_pack) {
1464                 unlink(tmp_idx);
1465                 free(tmp_idx);
1466
1467                 return -1; /* parse_pack_index() already issued error message */
1468         }
1469
1470         ret = verify_pack_index(new_pack);
1471         if (!ret) {
1472                 close_pack_index(new_pack);
1473                 ret = finalize_object_file(tmp_idx, sha1_pack_index_name(sha1));
1474         }
1475         free(tmp_idx);
1476         if (ret)
1477                 return -1;
1478
1479 add_pack:
1480         new_pack->next = *packs_head;
1481         *packs_head = new_pack;
1482         return 0;
1483 }
1484
1485 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
1486 {
1487         struct http_get_options options = {0};
1488         int ret = 0, i = 0;
1489         char *url, *data;
1490         struct strbuf buf = STRBUF_INIT;
1491         unsigned char sha1[20];
1492
1493         end_url_with_slash(&buf, base_url);
1494         strbuf_addstr(&buf, "objects/info/packs");
1495         url = strbuf_detach(&buf, NULL);
1496
1497         options.no_cache = 1;
1498         ret = http_get_strbuf(url, &buf, &options);
1499         if (ret != HTTP_OK)
1500                 goto cleanup;
1501
1502         data = buf.buf;
1503         while (i < buf.len) {
1504                 switch (data[i]) {
1505                 case 'P':
1506                         i++;
1507                         if (i + 52 <= buf.len &&
1508                             starts_with(data + i, " pack-") &&
1509                             starts_with(data + i + 46, ".pack\n")) {
1510                                 get_sha1_hex(data + i + 6, sha1);
1511                                 fetch_and_setup_pack_index(packs_head, sha1,
1512                                                       base_url);
1513                                 i += 51;
1514                                 break;
1515                         }
1516                 default:
1517                         while (i < buf.len && data[i] != '\n')
1518                                 i++;
1519                 }
1520                 i++;
1521         }
1522
1523 cleanup:
1524         free(url);
1525         return ret;
1526 }
1527
1528 void release_http_pack_request(struct http_pack_request *preq)
1529 {
1530         if (preq->packfile != NULL) {
1531                 fclose(preq->packfile);
1532                 preq->packfile = NULL;
1533         }
1534         if (preq->range_header != NULL) {
1535                 curl_slist_free_all(preq->range_header);
1536                 preq->range_header = NULL;
1537         }
1538         preq->slot = NULL;
1539         free(preq->url);
1540         free(preq);
1541 }
1542
1543 int finish_http_pack_request(struct http_pack_request *preq)
1544 {
1545         struct packed_git **lst;
1546         struct packed_git *p = preq->target;
1547         char *tmp_idx;
1548         struct child_process ip = CHILD_PROCESS_INIT;
1549         const char *ip_argv[8];
1550
1551         close_pack_index(p);
1552
1553         fclose(preq->packfile);
1554         preq->packfile = NULL;
1555
1556         lst = preq->lst;
1557         while (*lst != p)
1558                 lst = &((*lst)->next);
1559         *lst = (*lst)->next;
1560
1561         tmp_idx = xstrdup(preq->tmpfile);
1562         strcpy(tmp_idx + strlen(tmp_idx) - strlen(".pack.temp"),
1563                ".idx.temp");
1564
1565         ip_argv[0] = "index-pack";
1566         ip_argv[1] = "-o";
1567         ip_argv[2] = tmp_idx;
1568         ip_argv[3] = preq->tmpfile;
1569         ip_argv[4] = NULL;
1570
1571         ip.argv = ip_argv;
1572         ip.git_cmd = 1;
1573         ip.no_stdin = 1;
1574         ip.no_stdout = 1;
1575
1576         if (run_command(&ip)) {
1577                 unlink(preq->tmpfile);
1578                 unlink(tmp_idx);
1579                 free(tmp_idx);
1580                 return -1;
1581         }
1582
1583         unlink(sha1_pack_index_name(p->sha1));
1584
1585         if (finalize_object_file(preq->tmpfile, sha1_pack_name(p->sha1))
1586          || finalize_object_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
1587                 free(tmp_idx);
1588                 return -1;
1589         }
1590
1591         install_packed_git(p);
1592         free(tmp_idx);
1593         return 0;
1594 }
1595
1596 struct http_pack_request *new_http_pack_request(
1597         struct packed_git *target, const char *base_url)
1598 {
1599         long prev_posn = 0;
1600         char range[RANGE_HEADER_SIZE];
1601         struct strbuf buf = STRBUF_INIT;
1602         struct http_pack_request *preq;
1603
1604         preq = xcalloc(1, sizeof(*preq));
1605         preq->target = target;
1606
1607         end_url_with_slash(&buf, base_url);
1608         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
1609                 sha1_to_hex(target->sha1));
1610         preq->url = strbuf_detach(&buf, NULL);
1611
1612         snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
1613                 sha1_pack_name(target->sha1));
1614         preq->packfile = fopen(preq->tmpfile, "a");
1615         if (!preq->packfile) {
1616                 error("Unable to open local file %s for pack",
1617                       preq->tmpfile);
1618                 goto abort;
1619         }
1620
1621         preq->slot = get_active_slot();
1622         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
1623         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
1624         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
1625         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1626                 no_pragma_header);
1627
1628         /*
1629          * If there is data present from a previous transfer attempt,
1630          * resume where it left off
1631          */
1632         prev_posn = ftell(preq->packfile);
1633         if (prev_posn>0) {
1634                 if (http_is_verbose)
1635                         fprintf(stderr,
1636                                 "Resuming fetch of pack %s at byte %ld\n",
1637                                 sha1_to_hex(target->sha1), prev_posn);
1638                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1639                 preq->range_header = curl_slist_append(NULL, range);
1640                 curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1641                         preq->range_header);
1642         }
1643
1644         return preq;
1645
1646 abort:
1647         free(preq->url);
1648         free(preq);
1649         return NULL;
1650 }
1651
1652 /* Helpers for fetching objects (loose) */
1653 static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
1654                                void *data)
1655 {
1656         unsigned char expn[4096];
1657         size_t size = eltsize * nmemb;
1658         int posn = 0;
1659         struct http_object_request *freq =
1660                 (struct http_object_request *)data;
1661         do {
1662                 ssize_t retval = xwrite(freq->localfile,
1663                                         (char *) ptr + posn, size - posn);
1664                 if (retval < 0)
1665                         return posn;
1666                 posn += retval;
1667         } while (posn < size);
1668
1669         freq->stream.avail_in = size;
1670         freq->stream.next_in = (void *)ptr;
1671         do {
1672                 freq->stream.next_out = expn;
1673                 freq->stream.avail_out = sizeof(expn);
1674                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
1675                 git_SHA1_Update(&freq->c, expn,
1676                                 sizeof(expn) - freq->stream.avail_out);
1677         } while (freq->stream.avail_in && freq->zret == Z_OK);
1678         return size;
1679 }
1680
1681 struct http_object_request *new_http_object_request(const char *base_url,
1682         unsigned char *sha1)
1683 {
1684         char *hex = sha1_to_hex(sha1);
1685         const char *filename;
1686         char prevfile[PATH_MAX];
1687         int prevlocal;
1688         char prev_buf[PREV_BUF_SIZE];
1689         ssize_t prev_read = 0;
1690         long prev_posn = 0;
1691         char range[RANGE_HEADER_SIZE];
1692         struct curl_slist *range_header = NULL;
1693         struct http_object_request *freq;
1694
1695         freq = xcalloc(1, sizeof(*freq));
1696         hashcpy(freq->sha1, sha1);
1697         freq->localfile = -1;
1698
1699         filename = sha1_file_name(sha1);
1700         snprintf(freq->tmpfile, sizeof(freq->tmpfile),
1701                  "%s.temp", filename);
1702
1703         snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
1704         unlink_or_warn(prevfile);
1705         rename(freq->tmpfile, prevfile);
1706         unlink_or_warn(freq->tmpfile);
1707
1708         if (freq->localfile != -1)
1709                 error("fd leakage in start: %d", freq->localfile);
1710         freq->localfile = open(freq->tmpfile,
1711                                O_WRONLY | O_CREAT | O_EXCL, 0666);
1712         /*
1713          * This could have failed due to the "lazy directory creation";
1714          * try to mkdir the last path component.
1715          */
1716         if (freq->localfile < 0 && errno == ENOENT) {
1717                 char *dir = strrchr(freq->tmpfile, '/');
1718                 if (dir) {
1719                         *dir = 0;
1720                         mkdir(freq->tmpfile, 0777);
1721                         *dir = '/';
1722                 }
1723                 freq->localfile = open(freq->tmpfile,
1724                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
1725         }
1726
1727         if (freq->localfile < 0) {
1728                 error("Couldn't create temporary file %s: %s",
1729                       freq->tmpfile, strerror(errno));
1730                 goto abort;
1731         }
1732
1733         git_inflate_init(&freq->stream);
1734
1735         git_SHA1_Init(&freq->c);
1736
1737         freq->url = get_remote_object_url(base_url, hex, 0);
1738
1739         /*
1740          * If a previous temp file is present, process what was already
1741          * fetched.
1742          */
1743         prevlocal = open(prevfile, O_RDONLY);
1744         if (prevlocal != -1) {
1745                 do {
1746                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
1747                         if (prev_read>0) {
1748                                 if (fwrite_sha1_file(prev_buf,
1749                                                      1,
1750                                                      prev_read,
1751                                                      freq) == prev_read) {
1752                                         prev_posn += prev_read;
1753                                 } else {
1754                                         prev_read = -1;
1755                                 }
1756                         }
1757                 } while (prev_read > 0);
1758                 close(prevlocal);
1759         }
1760         unlink_or_warn(prevfile);
1761
1762         /*
1763          * Reset inflate/SHA1 if there was an error reading the previous temp
1764          * file; also rewind to the beginning of the local file.
1765          */
1766         if (prev_read == -1) {
1767                 memset(&freq->stream, 0, sizeof(freq->stream));
1768                 git_inflate_init(&freq->stream);
1769                 git_SHA1_Init(&freq->c);
1770                 if (prev_posn>0) {
1771                         prev_posn = 0;
1772                         lseek(freq->localfile, 0, SEEK_SET);
1773                         if (ftruncate(freq->localfile, 0) < 0) {
1774                                 error("Couldn't truncate temporary file %s: %s",
1775                                           freq->tmpfile, strerror(errno));
1776                                 goto abort;
1777                         }
1778                 }
1779         }
1780
1781         freq->slot = get_active_slot();
1782
1783         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
1784         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
1785         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
1786         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
1787         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
1788
1789         /*
1790          * If we have successfully processed data from a previous fetch
1791          * attempt, only fetch the data we don't already have.
1792          */
1793         if (prev_posn>0) {
1794                 if (http_is_verbose)
1795                         fprintf(stderr,
1796                                 "Resuming fetch of object %s at byte %ld\n",
1797                                 hex, prev_posn);
1798                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1799                 range_header = curl_slist_append(range_header, range);
1800                 curl_easy_setopt(freq->slot->curl,
1801                                  CURLOPT_HTTPHEADER, range_header);
1802         }
1803
1804         return freq;
1805
1806 abort:
1807         free(freq->url);
1808         free(freq);
1809         return NULL;
1810 }
1811
1812 void process_http_object_request(struct http_object_request *freq)
1813 {
1814         if (freq->slot == NULL)
1815                 return;
1816         freq->curl_result = freq->slot->curl_result;
1817         freq->http_code = freq->slot->http_code;
1818         freq->slot = NULL;
1819 }
1820
1821 int finish_http_object_request(struct http_object_request *freq)
1822 {
1823         struct stat st;
1824
1825         close(freq->localfile);
1826         freq->localfile = -1;
1827
1828         process_http_object_request(freq);
1829
1830         if (freq->http_code == 416) {
1831                 warning("requested range invalid; we may already have all the data.");
1832         } else if (freq->curl_result != CURLE_OK) {
1833                 if (stat(freq->tmpfile, &st) == 0)
1834                         if (st.st_size == 0)
1835                                 unlink_or_warn(freq->tmpfile);
1836                 return -1;
1837         }
1838
1839         git_inflate_end(&freq->stream);
1840         git_SHA1_Final(freq->real_sha1, &freq->c);
1841         if (freq->zret != Z_STREAM_END) {
1842                 unlink_or_warn(freq->tmpfile);
1843                 return -1;
1844         }
1845         if (hashcmp(freq->sha1, freq->real_sha1)) {
1846                 unlink_or_warn(freq->tmpfile);
1847                 return -1;
1848         }
1849         freq->rename =
1850                 finalize_object_file(freq->tmpfile, sha1_file_name(freq->sha1));
1851
1852         return freq->rename;
1853 }
1854
1855 void abort_http_object_request(struct http_object_request *freq)
1856 {
1857         unlink_or_warn(freq->tmpfile);
1858
1859         release_http_object_request(freq);
1860 }
1861
1862 void release_http_object_request(struct http_object_request *freq)
1863 {
1864         if (freq->localfile != -1) {
1865                 close(freq->localfile);
1866                 freq->localfile = -1;
1867         }
1868         if (freq->url != NULL) {
1869                 free(freq->url);
1870                 freq->url = NULL;
1871         }
1872         if (freq->slot != NULL) {
1873                 freq->slot->callback_func = NULL;
1874                 freq->slot->callback_data = NULL;
1875                 release_active_slot(freq->slot);
1876                 freq->slot = NULL;
1877         }
1878 }