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