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