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

   1 #include "git-compat-util.h"
   2 #include "http.h"
   3 #include "config.h"
   4 #include "pack.h"
   5 #include "sideband.h"
   6 #include "run-command.h"
   7 #include "url.h"
   8 #include "urlmatch.h"
   9 #include "credential.h"
  10 #include "version.h"
  11 #include "pkt-line.h"
  12 #include "gettext.h"
  13 #include "transport.h"
  14 #include "packfile.h"
  15 #include "protocol.h"
  16 #include "string-list.h"
  17
  18 static struct trace_key trace_curl = TRACE_KEY_INIT(CURL);
  19 static int trace_curl_data = 1;
  20 static struct string_list cookies_to_redact = STRING_LIST_INIT_DUP;
  21 #if LIBCURL_VERSION_NUM >= 0x070a08
  22 long int git_curl_ipresolve = CURL_IPRESOLVE_WHATEVER;
  23 #else
  24 long int git_curl_ipresolve;
  25 #endif
  26 int active_requests;
  27 int http_is_verbose;
  28 ssize_t http_post_buffer = 16 * LARGE_PACKET_MAX;
  29
  30 #if LIBCURL_VERSION_NUM >= 0x070a06
  31 #define LIBCURL_CAN_HANDLE_AUTH_ANY
  32 #endif
  33
  34 static int min_curl_sessions = 1;
  35 static int curl_session_count;
  36 #ifdef USE_CURL_MULTI
  37 static int max_requests = -1;
  38 static CURLM *curlm;
  39 #endif
  40 #ifndef NO_CURL_EASY_DUPHANDLE
  41 static CURL *curl_default;
  42 #endif
  43
  44 #define PREV_BUF_SIZE 4096
  45
  46 char curl_errorstr[CURL_ERROR_SIZE];
  47
  48 static int curl_ssl_verify = -1;
  49 static int curl_ssl_try;
  50 static const char *ssl_cert;
  51 static const char *ssl_cipherlist;
  52 static const char *ssl_version;
  53 static struct {
  54         const char *name;
  55         long ssl_version;
  56 } sslversions[] = {
  57         { "sslv2", CURL_SSLVERSION_SSLv2 },
  58         { "sslv3", CURL_SSLVERSION_SSLv3 },
  59         { "tlsv1", CURL_SSLVERSION_TLSv1 },
  60 #if LIBCURL_VERSION_NUM >= 0x072200
  61         { "tlsv1.0", CURL_SSLVERSION_TLSv1_0 },
  62         { "tlsv1.1", CURL_SSLVERSION_TLSv1_1 },
  63         { "tlsv1.2", CURL_SSLVERSION_TLSv1_2 },
  64 #endif
  65 };
  66 #if LIBCURL_VERSION_NUM >= 0x070903
  67 static const char *ssl_key;
  68 #endif
  69 #if LIBCURL_VERSION_NUM >= 0x070908
  70 static const char *ssl_capath;
  71 #endif
  72 #if LIBCURL_VERSION_NUM >= 0x072c00
  73 static const char *ssl_pinnedkey;
  74 #endif
  75 static const char *ssl_cainfo;
  76 static long curl_low_speed_limit = -1;
  77 static long curl_low_speed_time = -1;
  78 static int curl_ftp_no_epsv;
  79 static const char *curl_http_proxy;
  80 static const char *curl_no_proxy;
  81 static const char *http_proxy_authmethod;
  82 static struct {
  83         const char *name;
  84         long curlauth_param;
  85 } proxy_authmethods[] = {
  86         { "basic", CURLAUTH_BASIC },
  87         { "digest", CURLAUTH_DIGEST },
  88         { "negotiate", CURLAUTH_GSSNEGOTIATE },
  89         { "ntlm", CURLAUTH_NTLM },
  90 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
  91         { "anyauth", CURLAUTH_ANY },
  92 #endif
  93         /*
  94          * CURLAUTH_DIGEST_IE has no corresponding command-line option in
  95          * curl(1) and is not included in CURLAUTH_ANY, so we leave it out
  96          * here, too
  97          */
  98 };
  99 #ifdef CURLGSSAPI_DELEGATION_FLAG
 100 static const char *curl_deleg;
 101 static struct {
 102         const char *name;
 103         long curl_deleg_param;
 104 } curl_deleg_levels[] = {
 105         { "none", CURLGSSAPI_DELEGATION_NONE },
 106         { "policy", CURLGSSAPI_DELEGATION_POLICY_FLAG },
 107         { "always", CURLGSSAPI_DELEGATION_FLAG },
 108 };
 109 #endif
 110
 111 static struct credential proxy_auth = CREDENTIAL_INIT;
 112 static const char *curl_proxyuserpwd;
 113 static const char *curl_cookie_file;
 114 static int curl_save_cookies;
 115 struct credential http_auth = CREDENTIAL_INIT;
 116 static int http_proactive_auth;
 117 static const char *user_agent;
 118 static int curl_empty_auth = -1;
 119
 120 enum http_follow_config http_follow_config = HTTP_FOLLOW_INITIAL;
 121
 122 #if LIBCURL_VERSION_NUM >= 0x071700
 123 /* Use CURLOPT_KEYPASSWD as is */
 124 #elif LIBCURL_VERSION_NUM >= 0x070903
 125 #define CURLOPT_KEYPASSWD CURLOPT_SSLKEYPASSWD
 126 #else
 127 #define CURLOPT_KEYPASSWD CURLOPT_SSLCERTPASSWD
 128 #endif
 129
 130 static struct credential cert_auth = CREDENTIAL_INIT;
 131 static int ssl_cert_password_required;
 132 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 133 static unsigned long http_auth_methods = CURLAUTH_ANY;
 134 static int http_auth_methods_restricted;
 135 /* Modes for which empty_auth cannot actually help us. */
 136 static unsigned long empty_auth_useless =
 137         CURLAUTH_BASIC
 138 #ifdef CURLAUTH_DIGEST_IE
 139         | CURLAUTH_DIGEST_IE
 140 #endif
 141         | CURLAUTH_DIGEST;
 142 #endif
 143
 144 static struct curl_slist *pragma_header;
 145 static struct curl_slist *no_pragma_header;
 146 static struct curl_slist *extra_http_headers;
 147
 148 static struct active_request_slot *active_queue_head;
 149
 150 static char *cached_accept_language;
 151
 152 size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
 153 {
 154         size_t size = eltsize * nmemb;
 155         struct buffer *buffer = buffer_;
 156
 157         if (size > buffer->buf.len - buffer->posn)
 158                 size = buffer->buf.len - buffer->posn;
 159         memcpy(ptr, buffer->buf.buf + buffer->posn, size);
 160         buffer->posn += size;
 161
 162         return size;
 163 }
 164
 165 #ifndef NO_CURL_IOCTL
 166 curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)
 167 {
 168         struct buffer *buffer = clientp;
 169
 170         switch (cmd) {
 171         case CURLIOCMD_NOP:
 172                 return CURLIOE_OK;
 173
 174         case CURLIOCMD_RESTARTREAD:
 175                 buffer->posn = 0;
 176                 return CURLIOE_OK;
 177
 178         default:
 179                 return CURLIOE_UNKNOWNCMD;
 180         }
 181 }
 182 #endif
 183
 184 size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
 185 {
 186         size_t size = eltsize * nmemb;
 187         struct strbuf *buffer = buffer_;
 188
 189         strbuf_add(buffer, ptr, size);
 190         return size;
 191 }
 192
 193 size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf)
 194 {
 195         return eltsize * nmemb;
 196 }
 197
 198 static void closedown_active_slot(struct active_request_slot *slot)
 199 {
 200         active_requests--;
 201         slot->in_use = 0;
 202 }
 203
 204 static void finish_active_slot(struct active_request_slot *slot)
 205 {
 206         closedown_active_slot(slot);
 207         curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
 208
 209         if (slot->finished != NULL)
 210                 (*slot->finished) = 1;
 211
 212         /* Store slot results so they can be read after the slot is reused */
 213         if (slot->results != NULL) {
 214                 slot->results->curl_result = slot->curl_result;
 215                 slot->results->http_code = slot->http_code;
 216 #if LIBCURL_VERSION_NUM >= 0x070a08
 217                 curl_easy_getinfo(slot->curl, CURLINFO_HTTPAUTH_AVAIL,
 218                                   &slot->results->auth_avail);
 219 #else
 220                 slot->results->auth_avail = 0;
 221 #endif
 222
 223                 curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CONNECTCODE,
 224                         &slot->results->http_connectcode);
 225         }
 226
 227         /* Run callback if appropriate */
 228         if (slot->callback_func != NULL)
 229                 slot->callback_func(slot->callback_data);
 230 }
 231
 232 static void xmulti_remove_handle(struct active_request_slot *slot)
 233 {
 234 #ifdef USE_CURL_MULTI
 235         curl_multi_remove_handle(curlm, slot->curl);
 236 #endif
 237 }
 238
 239 #ifdef USE_CURL_MULTI
 240 static void process_curl_messages(void)
 241 {
 242         int num_messages;
 243         struct active_request_slot *slot;
 244         CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
 245
 246         while (curl_message != NULL) {
 247                 if (curl_message->msg == CURLMSG_DONE) {
 248                         int curl_result = curl_message->data.result;
 249                         slot = active_queue_head;
 250                         while (slot != NULL &&
 251                                slot->curl != curl_message->easy_handle)
 252                                 slot = slot->next;
 253                         if (slot != NULL) {
 254                                 xmulti_remove_handle(slot);
 255                                 slot->curl_result = curl_result;
 256                                 finish_active_slot(slot);
 257                         } else {
 258                                 fprintf(stderr, "Received DONE message for unknown request!\n");
 259                         }
 260                 } else {
 261                         fprintf(stderr, "Unknown CURL message received: %d\n",
 262                                 (int)curl_message->msg);
 263                 }
 264                 curl_message = curl_multi_info_read(curlm, &num_messages);
 265         }
 266 }
 267 #endif
 268
 269 static int http_options(const char *var, const char *value, void *cb)
 270 {
 271         if (!strcmp("http.sslverify", var)) {
 272                 curl_ssl_verify = git_config_bool(var, value);
 273                 return 0;
 274         }
 275         if (!strcmp("http.sslcipherlist", var))
 276                 return git_config_string(&ssl_cipherlist, var, value);
 277         if (!strcmp("http.sslversion", var))
 278                 return git_config_string(&ssl_version, var, value);
 279         if (!strcmp("http.sslcert", var))
 280                 return git_config_pathname(&ssl_cert, var, value);
 281 #if LIBCURL_VERSION_NUM >= 0x070903
 282         if (!strcmp("http.sslkey", var))
 283                 return git_config_pathname(&ssl_key, var, value);
 284 #endif
 285 #if LIBCURL_VERSION_NUM >= 0x070908
 286         if (!strcmp("http.sslcapath", var))
 287                 return git_config_pathname(&ssl_capath, var, value);
 288 #endif
 289         if (!strcmp("http.sslcainfo", var))
 290                 return git_config_pathname(&ssl_cainfo, var, value);
 291         if (!strcmp("http.sslcertpasswordprotected", var)) {
 292                 ssl_cert_password_required = git_config_bool(var, value);
 293                 return 0;
 294         }
 295         if (!strcmp("http.ssltry", var)) {
 296                 curl_ssl_try = git_config_bool(var, value);
 297                 return 0;
 298         }
 299         if (!strcmp("http.minsessions", var)) {
 300                 min_curl_sessions = git_config_int(var, value);
 301 #ifndef USE_CURL_MULTI
 302                 if (min_curl_sessions > 1)
 303                         min_curl_sessions = 1;
 304 #endif
 305                 return 0;
 306         }
 307 #ifdef USE_CURL_MULTI
 308         if (!strcmp("http.maxrequests", var)) {
 309                 max_requests = git_config_int(var, value);
 310                 return 0;
 311         }
 312 #endif
 313         if (!strcmp("http.lowspeedlimit", var)) {
 314                 curl_low_speed_limit = (long)git_config_int(var, value);
 315                 return 0;
 316         }
 317         if (!strcmp("http.lowspeedtime", var)) {
 318                 curl_low_speed_time = (long)git_config_int(var, value);
 319                 return 0;
 320         }
 321
 322         if (!strcmp("http.noepsv", var)) {
 323                 curl_ftp_no_epsv = git_config_bool(var, value);
 324                 return 0;
 325         }
 326         if (!strcmp("http.proxy", var))
 327                 return git_config_string(&curl_http_proxy, var, value);
 328
 329         if (!strcmp("http.proxyauthmethod", var))
 330                 return git_config_string(&http_proxy_authmethod, var, value);
 331
 332         if (!strcmp("http.cookiefile", var))
 333                 return git_config_pathname(&curl_cookie_file, var, value);
 334         if (!strcmp("http.savecookies", var)) {
 335                 curl_save_cookies = git_config_bool(var, value);
 336                 return 0;
 337         }
 338
 339         if (!strcmp("http.postbuffer", var)) {
 340                 http_post_buffer = git_config_ssize_t(var, value);
 341                 if (http_post_buffer < 0)
 342                         warning(_("negative value for http.postbuffer; defaulting to %d"), LARGE_PACKET_MAX);
 343                 if (http_post_buffer < LARGE_PACKET_MAX)
 344                         http_post_buffer = LARGE_PACKET_MAX;
 345                 return 0;
 346         }
 347
 348         if (!strcmp("http.useragent", var))
 349                 return git_config_string(&user_agent, var, value);
 350
 351         if (!strcmp("http.emptyauth", var)) {
 352                 if (value && !strcmp("auto", value))
 353                         curl_empty_auth = -1;
 354                 else
 355                         curl_empty_auth = git_config_bool(var, value);
 356                 return 0;
 357         }
 358
 359         if (!strcmp("http.delegation", var)) {
 360 #ifdef CURLGSSAPI_DELEGATION_FLAG
 361                 return git_config_string(&curl_deleg, var, value);
 362 #else
 363                 warning(_("Delegation control is not supported with cURL < 7.22.0"));
 364                 return 0;
 365 #endif
 366         }
 367
 368         if (!strcmp("http.pinnedpubkey", var)) {
 369 #if LIBCURL_VERSION_NUM >= 0x072c00
 370                 return git_config_pathname(&ssl_pinnedkey, var, value);
 371 #else
 372                 warning(_("Public key pinning not supported with cURL < 7.44.0"));
 373                 return 0;
 374 #endif
 375         }
 376
 377         if (!strcmp("http.extraheader", var)) {
 378                 if (!value) {
 379                         return config_error_nonbool(var);
 380                 } else if (!*value) {
 381                         curl_slist_free_all(extra_http_headers);
 382                         extra_http_headers = NULL;
 383                 } else {
 384                         extra_http_headers =
 385                                 curl_slist_append(extra_http_headers, value);
 386                 }
 387                 return 0;
 388         }
 389
 390         if (!strcmp("http.followredirects", var)) {
 391                 if (value && !strcmp(value, "initial"))
 392                         http_follow_config = HTTP_FOLLOW_INITIAL;
 393                 else if (git_config_bool(var, value))
 394                         http_follow_config = HTTP_FOLLOW_ALWAYS;
 395                 else
 396                         http_follow_config = HTTP_FOLLOW_NONE;
 397                 return 0;
 398         }
 399
 400         /* Fall back on the default ones */
 401         return git_default_config(var, value, cb);
 402 }
 403
 404 static int curl_empty_auth_enabled(void)
 405 {
 406         if (curl_empty_auth >= 0)
 407                 return curl_empty_auth;
 408
 409 #ifndef LIBCURL_CAN_HANDLE_AUTH_ANY
 410         /*
 411          * Our libcurl is too old to do AUTH_ANY in the first place;
 412          * just default to turning the feature off.
 413          */
 414 #else
 415         /*
 416          * In the automatic case, kick in the empty-auth
 417          * hack as long as we would potentially try some
 418          * method more exotic than "Basic" or "Digest".
 419          *
 420          * But only do this when this is our second or
 421          * subsequent request, as by then we know what
 422          * methods are available.
 423          */
 424         if (http_auth_methods_restricted &&
 425             (http_auth_methods & ~empty_auth_useless))
 426                 return 1;
 427 #endif
 428         return 0;
 429 }
 430
 431 static void init_curl_http_auth(CURL *result)
 432 {
 433         if (!http_auth.username || !*http_auth.username) {
 434                 if (curl_empty_auth_enabled())
 435                         curl_easy_setopt(result, CURLOPT_USERPWD, ":");
 436                 return;
 437         }
 438
 439         credential_fill(&http_auth);
 440
 441 #if LIBCURL_VERSION_NUM >= 0x071301
 442         curl_easy_setopt(result, CURLOPT_USERNAME, http_auth.username);
 443         curl_easy_setopt(result, CURLOPT_PASSWORD, http_auth.password);
 444 #else
 445         {
 446                 static struct strbuf up = STRBUF_INIT;
 447                 /*
 448                  * Note that we assume we only ever have a single set of
 449                  * credentials in a given program run, so we do not have
 450                  * to worry about updating this buffer, only setting its
 451                  * initial value.
 452                  */
 453                 if (!up.len)
 454                         strbuf_addf(&up, "%s:%s",
 455                                 http_auth.username, http_auth.password);
 456                 curl_easy_setopt(result, CURLOPT_USERPWD, up.buf);
 457         }
 458 #endif
 459 }
 460
 461 /* *var must be free-able */
 462 static void var_override(const char **var, char *value)
 463 {
 464         if (value) {
 465                 free((void *)*var);
 466                 *var = xstrdup(value);
 467         }
 468 }
 469
 470 static void set_proxyauth_name_password(CURL *result)
 471 {
 472 #if LIBCURL_VERSION_NUM >= 0x071301
 473                 curl_easy_setopt(result, CURLOPT_PROXYUSERNAME,
 474                         proxy_auth.username);
 475                 curl_easy_setopt(result, CURLOPT_PROXYPASSWORD,
 476                         proxy_auth.password);
 477 #else
 478                 struct strbuf s = STRBUF_INIT;
 479
 480                 strbuf_addstr_urlencode(&s, proxy_auth.username, 1);
 481                 strbuf_addch(&s, ':');
 482                 strbuf_addstr_urlencode(&s, proxy_auth.password, 1);
 483                 curl_proxyuserpwd = strbuf_detach(&s, NULL);
 484                 curl_easy_setopt(result, CURLOPT_PROXYUSERPWD, curl_proxyuserpwd);
 485 #endif
 486 }
 487
 488 static void init_curl_proxy_auth(CURL *result)
 489 {
 490         if (proxy_auth.username) {
 491                 if (!proxy_auth.password)
 492                         credential_fill(&proxy_auth);
 493                 set_proxyauth_name_password(result);
 494         }
 495
 496         var_override(&http_proxy_authmethod, getenv("GIT_HTTP_PROXY_AUTHMETHOD"));
 497
 498 #if LIBCURL_VERSION_NUM >= 0x070a07 /* CURLOPT_PROXYAUTH and CURLAUTH_ANY */
 499         if (http_proxy_authmethod) {
 500                 int i;
 501                 for (i = 0; i < ARRAY_SIZE(proxy_authmethods); i++) {
 502                         if (!strcmp(http_proxy_authmethod, proxy_authmethods[i].name)) {
 503                                 curl_easy_setopt(result, CURLOPT_PROXYAUTH,
 504                                                 proxy_authmethods[i].curlauth_param);
 505                                 break;
 506                         }
 507                 }
 508                 if (i == ARRAY_SIZE(proxy_authmethods)) {
 509                         warning("unsupported proxy authentication method %s: using anyauth",
 510                                         http_proxy_authmethod);
 511                         curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
 512                 }
 513         }
 514         else
 515                 curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
 516 #endif
 517 }
 518
 519 static int has_cert_password(void)
 520 {
 521         if (ssl_cert == NULL || ssl_cert_password_required != 1)
 522                 return 0;
 523         if (!cert_auth.password) {
 524                 cert_auth.protocol = xstrdup("cert");
 525                 cert_auth.username = xstrdup("");
 526                 cert_auth.path = xstrdup(ssl_cert);
 527                 credential_fill(&cert_auth);
 528         }
 529         return 1;
 530 }
 531
 532 #if LIBCURL_VERSION_NUM >= 0x071900
 533 static void set_curl_keepalive(CURL *c)
 534 {
 535         curl_easy_setopt(c, CURLOPT_TCP_KEEPALIVE, 1);
 536 }
 537
 538 #elif LIBCURL_VERSION_NUM >= 0x071000
 539 static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
 540 {
 541         int ka = 1;
 542         int rc;
 543         socklen_t len = (socklen_t)sizeof(ka);
 544
 545         if (type != CURLSOCKTYPE_IPCXN)
 546                 return 0;
 547
 548         rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
 549         if (rc < 0)
 550                 warning_errno("unable to set SO_KEEPALIVE on socket");
 551
 552         return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
 553 }
 554
 555 static void set_curl_keepalive(CURL *c)
 556 {
 557         curl_easy_setopt(c, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
 558 }
 559
 560 #else
 561 static void set_curl_keepalive(CURL *c)
 562 {
 563         /* not supported on older curl versions */
 564 }
 565 #endif
 566
 567 static void redact_sensitive_header(struct strbuf *header)
 568 {
 569         const char *sensitive_header;
 570
 571         if (skip_prefix(header->buf, "Authorization:", &sensitive_header) ||
 572             skip_prefix(header->buf, "Proxy-Authorization:", &sensitive_header)) {
 573                 /* The first token is the type, which is OK to log */
 574                 while (isspace(*sensitive_header))
 575                         sensitive_header++;
 576                 while (*sensitive_header && !isspace(*sensitive_header))
 577                         sensitive_header++;
 578                 /* Everything else is opaque and possibly sensitive */
 579                 strbuf_setlen(header,  sensitive_header - header->buf);
 580                 strbuf_addstr(header, " <redacted>");
 581         } else if (cookies_to_redact.nr &&
 582                    skip_prefix(header->buf, "Cookie:", &sensitive_header)) {
 583                 struct strbuf redacted_header = STRBUF_INIT;
 584                 char *cookie;
 585
 586                 while (isspace(*sensitive_header))
 587                         sensitive_header++;
 588
 589                 /*
 590                  * The contents of header starting from sensitive_header will
 591                  * subsequently be overridden, so it is fine to mutate this
 592                  * string (hence the assignment to "char *").
 593                  */
 594                 cookie = (char *) sensitive_header;
 595
 596                 while (cookie) {
 597                         char *equals;
 598                         char *semicolon = strstr(cookie, "; ");
 599                         if (semicolon)
 600                                 *semicolon = 0;
 601                         equals = strchrnul(cookie, '=');
 602                         if (!equals) {
 603                                 /* invalid cookie, just append and continue */
 604                                 strbuf_addstr(&redacted_header, cookie);
 605                                 continue;
 606                         }
 607                         *equals = 0; /* temporarily set to NUL for lookup */
 608                         if (string_list_lookup(&cookies_to_redact, cookie)) {
 609                                 strbuf_addstr(&redacted_header, cookie);
 610                                 strbuf_addstr(&redacted_header, "=<redacted>");
 611                         } else {
 612                                 *equals = '=';
 613                                 strbuf_addstr(&redacted_header, cookie);
 614                         }
 615                         if (semicolon) {
 616                                 /*
 617                                  * There are more cookies. (Or, for some
 618                                  * reason, the input string ends in "; ".)
 619                                  */
 620                                 strbuf_addstr(&redacted_header, "; ");
 621                                 cookie = semicolon + strlen("; ");
 622                         } else {
 623                                 cookie = NULL;
 624                         }
 625                 }
 626
 627                 strbuf_setlen(header, sensitive_header - header->buf);
 628                 strbuf_addbuf(header, &redacted_header);
 629         }
 630 }
 631
 632 static void curl_dump_header(const char *text, unsigned char *ptr, size_t size, int hide_sensitive_header)
 633 {
 634         struct strbuf out = STRBUF_INIT;
 635         struct strbuf **headers, **header;
 636
 637         strbuf_addf(&out, "%s, %10.10ld bytes (0x%8.8lx)\n",
 638                 text, (long)size, (long)size);
 639         trace_strbuf(&trace_curl, &out);
 640         strbuf_reset(&out);
 641         strbuf_add(&out, ptr, size);
 642         headers = strbuf_split_max(&out, '\n', 0);
 643
 644         for (header = headers; *header; header++) {
 645                 if (hide_sensitive_header)
 646                         redact_sensitive_header(*header);
 647                 strbuf_insert((*header), 0, text, strlen(text));
 648                 strbuf_insert((*header), strlen(text), ": ", 2);
 649                 strbuf_rtrim((*header));
 650                 strbuf_addch((*header), '\n');
 651                 trace_strbuf(&trace_curl, (*header));
 652         }
 653         strbuf_list_free(headers);
 654         strbuf_release(&out);
 655 }
 656
 657 static void curl_dump_data(const char *text, unsigned char *ptr, size_t size)
 658 {
 659         size_t i;
 660         struct strbuf out = STRBUF_INIT;
 661         unsigned int width = 60;
 662
 663         strbuf_addf(&out, "%s, %10.10ld bytes (0x%8.8lx)\n",
 664                 text, (long)size, (long)size);
 665         trace_strbuf(&trace_curl, &out);
 666
 667         for (i = 0; i < size; i += width) {
 668                 size_t w;
 669
 670                 strbuf_reset(&out);
 671                 strbuf_addf(&out, "%s: ", text);
 672                 for (w = 0; (w < width) && (i + w < size); w++) {
 673                         unsigned char ch = ptr[i + w];
 674
 675                         strbuf_addch(&out,
 676                                        (ch >= 0x20) && (ch < 0x80)
 677                                        ? ch : '.');
 678                 }
 679                 strbuf_addch(&out, '\n');
 680                 trace_strbuf(&trace_curl, &out);
 681         }
 682         strbuf_release(&out);
 683 }
 684
 685 static int curl_trace(CURL *handle, curl_infotype type, char *data, size_t size, void *userp)
 686 {
 687         const char *text;
 688         enum { NO_FILTER = 0, DO_FILTER = 1 };
 689
 690         switch (type) {
 691         case CURLINFO_TEXT:
 692                 trace_printf_key(&trace_curl, "== Info: %s", data);
 693                 break;
 694         case CURLINFO_HEADER_OUT:
 695                 text = "=> Send header";
 696                 curl_dump_header(text, (unsigned char *)data, size, DO_FILTER);
 697                 break;
 698         case CURLINFO_DATA_OUT:
 699                 if (trace_curl_data) {
 700                         text = "=> Send data";
 701                         curl_dump_data(text, (unsigned char *)data, size);
 702                 }
 703                 break;
 704         case CURLINFO_SSL_DATA_OUT:
 705                 if (trace_curl_data) {
 706                         text = "=> Send SSL data";
 707                         curl_dump_data(text, (unsigned char *)data, size);
 708                 }
 709                 break;
 710         case CURLINFO_HEADER_IN:
 711                 text = "<= Recv header";
 712                 curl_dump_header(text, (unsigned char *)data, size, NO_FILTER);
 713                 break;
 714         case CURLINFO_DATA_IN:
 715                 if (trace_curl_data) {
 716                         text = "<= Recv data";
 717                         curl_dump_data(text, (unsigned char *)data, size);
 718                 }
 719                 break;
 720         case CURLINFO_SSL_DATA_IN:
 721                 if (trace_curl_data) {
 722                         text = "<= Recv SSL data";
 723                         curl_dump_data(text, (unsigned char *)data, size);
 724                 }
 725                 break;
 726
 727         default:                /* we ignore unknown types by default */
 728                 return 0;
 729         }
 730         return 0;
 731 }
 732
 733 void setup_curl_trace(CURL *handle)
 734 {
 735         if (!trace_want(&trace_curl))
 736                 return;
 737         curl_easy_setopt(handle, CURLOPT_VERBOSE, 1L);
 738         curl_easy_setopt(handle, CURLOPT_DEBUGFUNCTION, curl_trace);
 739         curl_easy_setopt(handle, CURLOPT_DEBUGDATA, NULL);
 740 }
 741
 742 #ifdef CURLPROTO_HTTP
 743 static long get_curl_allowed_protocols(int from_user)
 744 {
 745         long allowed_protocols = 0;
 746
 747         if (is_transport_allowed("http", from_user))
 748                 allowed_protocols |= CURLPROTO_HTTP;
 749         if (is_transport_allowed("https", from_user))
 750                 allowed_protocols |= CURLPROTO_HTTPS;
 751         if (is_transport_allowed("ftp", from_user))
 752                 allowed_protocols |= CURLPROTO_FTP;
 753         if (is_transport_allowed("ftps", from_user))
 754                 allowed_protocols |= CURLPROTO_FTPS;
 755
 756         return allowed_protocols;
 757 }
 758 #endif
 759
 760 static CURL *get_curl_handle(void)
 761 {
 762         CURL *result = curl_easy_init();
 763
 764         if (!result)
 765                 die("curl_easy_init failed");
 766
 767         if (!curl_ssl_verify) {
 768                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
 769                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
 770         } else {
 771                 /* Verify authenticity of the peer's certificate */
 772                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
 773                 /* The name in the cert must match whom we tried to connect */
 774                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
 775         }
 776
 777 #if LIBCURL_VERSION_NUM >= 0x070907
 778         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
 779 #endif
 780 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 781         curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
 782 #endif
 783
 784 #ifdef CURLGSSAPI_DELEGATION_FLAG
 785         if (curl_deleg) {
 786                 int i;
 787                 for (i = 0; i < ARRAY_SIZE(curl_deleg_levels); i++) {
 788                         if (!strcmp(curl_deleg, curl_deleg_levels[i].name)) {
 789                                 curl_easy_setopt(result, CURLOPT_GSSAPI_DELEGATION,
 790                                                 curl_deleg_levels[i].curl_deleg_param);
 791                                 break;
 792                         }
 793                 }
 794                 if (i == ARRAY_SIZE(curl_deleg_levels))
 795                         warning("Unknown delegation method '%s': using default",
 796                                 curl_deleg);
 797         }
 798 #endif
 799
 800         if (http_proactive_auth)
 801                 init_curl_http_auth(result);
 802
 803         if (getenv("GIT_SSL_VERSION"))
 804                 ssl_version = getenv("GIT_SSL_VERSION");
 805         if (ssl_version && *ssl_version) {
 806                 int i;
 807                 for (i = 0; i < ARRAY_SIZE(sslversions); i++) {
 808                         if (!strcmp(ssl_version, sslversions[i].name)) {
 809                                 curl_easy_setopt(result, CURLOPT_SSLVERSION,
 810                                                  sslversions[i].ssl_version);
 811                                 break;
 812                         }
 813                 }
 814                 if (i == ARRAY_SIZE(sslversions))
 815                         warning("unsupported ssl version %s: using default",
 816                                 ssl_version);
 817         }
 818
 819         if (getenv("GIT_SSL_CIPHER_LIST"))
 820                 ssl_cipherlist = getenv("GIT_SSL_CIPHER_LIST");
 821         if (ssl_cipherlist != NULL && *ssl_cipherlist)
 822                 curl_easy_setopt(result, CURLOPT_SSL_CIPHER_LIST,
 823                                 ssl_cipherlist);
 824
 825         if (ssl_cert != NULL)
 826                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
 827         if (has_cert_password())
 828                 curl_easy_setopt(result, CURLOPT_KEYPASSWD, cert_auth.password);
 829 #if LIBCURL_VERSION_NUM >= 0x070903
 830         if (ssl_key != NULL)
 831                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
 832 #endif
 833 #if LIBCURL_VERSION_NUM >= 0x070908
 834         if (ssl_capath != NULL)
 835                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
 836 #endif
 837 #if LIBCURL_VERSION_NUM >= 0x072c00
 838         if (ssl_pinnedkey != NULL)
 839                 curl_easy_setopt(result, CURLOPT_PINNEDPUBLICKEY, ssl_pinnedkey);
 840 #endif
 841         if (ssl_cainfo != NULL)
 842                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
 843
 844         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
 845                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
 846                                  curl_low_speed_limit);
 847                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
 848                                  curl_low_speed_time);
 849         }
 850
 851         curl_easy_setopt(result, CURLOPT_MAXREDIRS, 20);
 852 #if LIBCURL_VERSION_NUM >= 0x071301
 853         curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
 854 #elif LIBCURL_VERSION_NUM >= 0x071101
 855         curl_easy_setopt(result, CURLOPT_POST301, 1);
 856 #endif
 857 #ifdef CURLPROTO_HTTP
 858         curl_easy_setopt(result, CURLOPT_REDIR_PROTOCOLS,
 859                          get_curl_allowed_protocols(0));
 860         curl_easy_setopt(result, CURLOPT_PROTOCOLS,
 861                          get_curl_allowed_protocols(-1));
 862 #else
 863         warning("protocol restrictions not applied to curl redirects because\n"
 864                 "your curl version is too old (>= 7.19.4)");
 865 #endif
 866         if (getenv("GIT_CURL_VERBOSE"))
 867                 curl_easy_setopt(result, CURLOPT_VERBOSE, 1L);
 868         setup_curl_trace(result);
 869         if (getenv("GIT_TRACE_CURL_NO_DATA"))
 870                 trace_curl_data = 0;
 871         if (getenv("GIT_REDACT_COOKIES")) {
 872                 string_list_split(&cookies_to_redact,
 873                                   getenv("GIT_REDACT_COOKIES"), ',', -1);
 874                 string_list_sort(&cookies_to_redact);
 875         }
 876
 877         curl_easy_setopt(result, CURLOPT_USERAGENT,
 878                 user_agent ? user_agent : git_user_agent());
 879
 880         if (curl_ftp_no_epsv)
 881                 curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
 882
 883 #ifdef CURLOPT_USE_SSL
 884         if (curl_ssl_try)
 885                 curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
 886 #endif
 887
 888         /*
 889          * CURL also examines these variables as a fallback; but we need to query
 890          * them here in order to decide whether to prompt for missing password (cf.
 891          * init_curl_proxy_auth()).
 892          *
 893          * Unlike many other common environment variables, these are historically
 894          * lowercase only. It appears that CURL did not know this and implemented
 895          * only uppercase variants, which was later corrected to take both - with
 896          * the exception of http_proxy, which is lowercase only also in CURL. As
 897          * the lowercase versions are the historical quasi-standard, they take
 898          * precedence here, as in CURL.
 899          */
 900         if (!curl_http_proxy) {
 901                 if (http_auth.protocol && !strcmp(http_auth.protocol, "https")) {
 902                         var_override(&curl_http_proxy, getenv("HTTPS_PROXY"));
 903                         var_override(&curl_http_proxy, getenv("https_proxy"));
 904                 } else {
 905                         var_override(&curl_http_proxy, getenv("http_proxy"));
 906                 }
 907                 if (!curl_http_proxy) {
 908                         var_override(&curl_http_proxy, getenv("ALL_PROXY"));
 909                         var_override(&curl_http_proxy, getenv("all_proxy"));
 910                 }
 911         }
 912
 913         if (curl_http_proxy && curl_http_proxy[0] == '\0') {
 914                 /*
 915                  * Handle case with the empty http.proxy value here to keep
 916                  * common code clean.
 917                  * NB: empty option disables proxying at all.
 918                  */
 919                 curl_easy_setopt(result, CURLOPT_PROXY, "");
 920         } else if (curl_http_proxy) {
 921 #if LIBCURL_VERSION_NUM >= 0x071800
 922                 if (starts_with(curl_http_proxy, "socks5h"))
 923                         curl_easy_setopt(result,
 924                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5_HOSTNAME);
 925                 else if (starts_with(curl_http_proxy, "socks5"))
 926                         curl_easy_setopt(result,
 927                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);
 928                 else if (starts_with(curl_http_proxy, "socks4a"))
 929                         curl_easy_setopt(result,
 930                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4A);
 931                 else if (starts_with(curl_http_proxy, "socks"))
 932                         curl_easy_setopt(result,
 933                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4);
 934 #endif
 935 #if LIBCURL_VERSION_NUM >= 0x073400
 936                 else if (starts_with(curl_http_proxy, "https"))
 937                         curl_easy_setopt(result,
 938                                 CURLOPT_PROXYTYPE, CURLPROXY_HTTPS);
 939 #endif
 940                 if (strstr(curl_http_proxy, "://"))
 941                         credential_from_url(&proxy_auth, curl_http_proxy);
 942                 else {
 943                         struct strbuf url = STRBUF_INIT;
 944                         strbuf_addf(&url, "http://%s", curl_http_proxy);
 945                         credential_from_url(&proxy_auth, url.buf);
 946                         strbuf_release(&url);
 947                 }
 948
 949                 if (!proxy_auth.host)
 950                         die("Invalid proxy URL '%s'", curl_http_proxy);
 951
 952                 curl_easy_setopt(result, CURLOPT_PROXY, proxy_auth.host);
 953 #if LIBCURL_VERSION_NUM >= 0x071304
 954                 var_override(&curl_no_proxy, getenv("NO_PROXY"));
 955                 var_override(&curl_no_proxy, getenv("no_proxy"));
 956                 curl_easy_setopt(result, CURLOPT_NOPROXY, curl_no_proxy);
 957 #endif
 958         }
 959         init_curl_proxy_auth(result);
 960
 961         set_curl_keepalive(result);
 962
 963         return result;
 964 }
 965
 966 static void set_from_env(const char **var, const char *envname)
 967 {
 968         const char *val = getenv(envname);
 969         if (val)
 970                 *var = val;
 971 }
 972
 973 static void protocol_http_header(void)
 974 {
 975         if (get_protocol_version_config() > 0) {
 976                 struct strbuf protocol_header = STRBUF_INIT;
 977
 978                 strbuf_addf(&protocol_header, GIT_PROTOCOL_HEADER ": version=%d",
 979                             get_protocol_version_config());
 980
 981
 982                 extra_http_headers = curl_slist_append(extra_http_headers,
 983                                                        protocol_header.buf);
 984                 strbuf_release(&protocol_header);
 985         }
 986 }
 987
 988 void http_init(struct remote *remote, const char *url, int proactive_auth)
 989 {
 990         char *low_speed_limit;
 991         char *low_speed_time;
 992         char *normalized_url;
 993         struct urlmatch_config config = { STRING_LIST_INIT_DUP };
 994
 995         config.section = "http";
 996         config.key = NULL;
 997         config.collect_fn = http_options;
 998         config.cascade_fn = git_default_config;
 999         config.cb = NULL;
1000
1001         http_is_verbose = 0;
1002         normalized_url = url_normalize(url, &config.url);
1003
1004         git_config(urlmatch_config_entry, &config);
1005         free(normalized_url);
1006
1007         if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK)
1008                 die("curl_global_init failed");
1009
1010         http_proactive_auth = proactive_auth;
1011
1012         if (remote && remote->http_proxy)
1013                 curl_http_proxy = xstrdup(remote->http_proxy);
1014
1015         if (remote)
1016                 var_override(&http_proxy_authmethod, remote->http_proxy_authmethod);
1017
1018         protocol_http_header();
1019
1020         pragma_header = curl_slist_append(http_copy_default_headers(),
1021                 "Pragma: no-cache");
1022         no_pragma_header = curl_slist_append(http_copy_default_headers(),
1023                 "Pragma:");
1024
1025 #ifdef USE_CURL_MULTI
1026         {
1027                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
1028                 if (http_max_requests != NULL)
1029                         max_requests = atoi(http_max_requests);
1030         }
1031
1032         curlm = curl_multi_init();
1033         if (!curlm)
1034                 die("curl_multi_init failed");
1035 #endif
1036
1037         if (getenv("GIT_SSL_NO_VERIFY"))
1038                 curl_ssl_verify = 0;
1039
1040         set_from_env(&ssl_cert, "GIT_SSL_CERT");
1041 #if LIBCURL_VERSION_NUM >= 0x070903
1042         set_from_env(&ssl_key, "GIT_SSL_KEY");
1043 #endif
1044 #if LIBCURL_VERSION_NUM >= 0x070908
1045         set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
1046 #endif
1047         set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
1048
1049         set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");
1050
1051         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
1052         if (low_speed_limit != NULL)
1053                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
1054         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
1055         if (low_speed_time != NULL)
1056                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
1057
1058         if (curl_ssl_verify == -1)
1059                 curl_ssl_verify = 1;
1060
1061         curl_session_count = 0;
1062 #ifdef USE_CURL_MULTI
1063         if (max_requests < 1)
1064                 max_requests = DEFAULT_MAX_REQUESTS;
1065 #endif
1066
1067         if (getenv("GIT_CURL_FTP_NO_EPSV"))
1068                 curl_ftp_no_epsv = 1;
1069
1070         if (url) {
1071                 credential_from_url(&http_auth, url);
1072                 if (!ssl_cert_password_required &&
1073                     getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
1074                     starts_with(url, "https://"))
1075                         ssl_cert_password_required = 1;
1076         }
1077
1078 #ifndef NO_CURL_EASY_DUPHANDLE
1079         curl_default = get_curl_handle();
1080 #endif
1081 }
1082
1083 void http_cleanup(void)
1084 {
1085         struct active_request_slot *slot = active_queue_head;
1086
1087         while (slot != NULL) {
1088                 struct active_request_slot *next = slot->next;
1089                 if (slot->curl != NULL) {
1090                         xmulti_remove_handle(slot);
1091                         curl_easy_cleanup(slot->curl);
1092                 }
1093                 free(slot);
1094                 slot = next;
1095         }
1096         active_queue_head = NULL;
1097
1098 #ifndef NO_CURL_EASY_DUPHANDLE
1099         curl_easy_cleanup(curl_default);
1100 #endif
1101
1102 #ifdef USE_CURL_MULTI
1103         curl_multi_cleanup(curlm);
1104 #endif
1105         curl_global_cleanup();
1106
1107         curl_slist_free_all(extra_http_headers);
1108         extra_http_headers = NULL;
1109
1110         curl_slist_free_all(pragma_header);
1111         pragma_header = NULL;
1112
1113         curl_slist_free_all(no_pragma_header);
1114         no_pragma_header = NULL;
1115
1116         if (curl_http_proxy) {
1117                 free((void *)curl_http_proxy);
1118                 curl_http_proxy = NULL;
1119         }
1120
1121         if (proxy_auth.password) {
1122                 memset(proxy_auth.password, 0, strlen(proxy_auth.password));
1123                 FREE_AND_NULL(proxy_auth.password);
1124         }
1125
1126         free((void *)curl_proxyuserpwd);
1127         curl_proxyuserpwd = NULL;
1128
1129         free((void *)http_proxy_authmethod);
1130         http_proxy_authmethod = NULL;
1131
1132         if (cert_auth.password != NULL) {
1133                 memset(cert_auth.password, 0, strlen(cert_auth.password));
1134                 FREE_AND_NULL(cert_auth.password);
1135         }
1136         ssl_cert_password_required = 0;
1137
1138         FREE_AND_NULL(cached_accept_language);
1139 }
1140
1141 struct active_request_slot *get_active_slot(void)
1142 {
1143         struct active_request_slot *slot = active_queue_head;
1144         struct active_request_slot *newslot;
1145
1146 #ifdef USE_CURL_MULTI
1147         int num_transfers;
1148
1149         /* Wait for a slot to open up if the queue is full */
1150         while (active_requests >= max_requests) {
1151                 curl_multi_perform(curlm, &num_transfers);
1152                 if (num_transfers < active_requests)
1153                         process_curl_messages();
1154         }
1155 #endif
1156
1157         while (slot != NULL && slot->in_use)
1158                 slot = slot->next;
1159
1160         if (slot == NULL) {
1161                 newslot = xmalloc(sizeof(*newslot));
1162                 newslot->curl = NULL;
1163                 newslot->in_use = 0;
1164                 newslot->next = NULL;
1165
1166                 slot = active_queue_head;
1167                 if (slot == NULL) {
1168                         active_queue_head = newslot;
1169                 } else {
1170                         while (slot->next != NULL)
1171                                 slot = slot->next;
1172                         slot->next = newslot;
1173                 }
1174                 slot = newslot;
1175         }
1176
1177         if (slot->curl == NULL) {
1178 #ifdef NO_CURL_EASY_DUPHANDLE
1179                 slot->curl = get_curl_handle();
1180 #else
1181                 slot->curl = curl_easy_duphandle(curl_default);
1182 #endif
1183                 curl_session_count++;
1184         }
1185
1186         active_requests++;
1187         slot->in_use = 1;
1188         slot->results = NULL;
1189         slot->finished = NULL;
1190         slot->callback_data = NULL;
1191         slot->callback_func = NULL;
1192         curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file);
1193         if (curl_save_cookies)
1194                 curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file);
1195         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
1196         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
1197         curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
1198         curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
1199         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
1200         curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
1201         curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
1202         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1203         curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
1204         curl_easy_setopt(slot->curl, CURLOPT_RANGE, NULL);
1205
1206         /*
1207          * Default following to off unless "ALWAYS" is configured; this gives
1208          * callers a sane starting point, and they can tweak for individual
1209          * HTTP_FOLLOW_* cases themselves.
1210          */
1211         if (http_follow_config == HTTP_FOLLOW_ALWAYS)
1212                 curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 1);
1213         else
1214                 curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 0);
1215
1216 #if LIBCURL_VERSION_NUM >= 0x070a08
1217         curl_easy_setopt(slot->curl, CURLOPT_IPRESOLVE, git_curl_ipresolve);
1218 #endif
1219 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
1220         curl_easy_setopt(slot->curl, CURLOPT_HTTPAUTH, http_auth_methods);
1221 #endif
1222         if (http_auth.password || curl_empty_auth_enabled())
1223                 init_curl_http_auth(slot->curl);
1224
1225         return slot;
1226 }
1227
1228 int start_active_slot(struct active_request_slot *slot)
1229 {
1230 #ifdef USE_CURL_MULTI
1231         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
1232         int num_transfers;
1233
1234         if (curlm_result != CURLM_OK &&
1235             curlm_result != CURLM_CALL_MULTI_PERFORM) {
1236                 warning("curl_multi_add_handle failed: %s",
1237                         curl_multi_strerror(curlm_result));
1238                 active_requests--;
1239                 slot->in_use = 0;
1240                 return 0;
1241         }
1242
1243         /*
1244          * We know there must be something to do, since we just added
1245          * something.
1246          */
1247         curl_multi_perform(curlm, &num_transfers);
1248 #endif
1249         return 1;
1250 }
1251
1252 #ifdef USE_CURL_MULTI
1253 struct fill_chain {
1254         void *data;
1255         int (*fill)(void *);
1256         struct fill_chain *next;
1257 };
1258
1259 static struct fill_chain *fill_cfg;
1260
1261 void add_fill_function(void *data, int (*fill)(void *))
1262 {
1263         struct fill_chain *new = xmalloc(sizeof(*new));
1264         struct fill_chain **linkp = &fill_cfg;
1265         new->data = data;
1266         new->fill = fill;
1267         new->next = NULL;
1268         while (*linkp)
1269                 linkp = &(*linkp)->next;
1270         *linkp = new;
1271 }
1272
1273 void fill_active_slots(void)
1274 {
1275         struct active_request_slot *slot = active_queue_head;
1276
1277         while (active_requests < max_requests) {
1278                 struct fill_chain *fill;
1279                 for (fill = fill_cfg; fill; fill = fill->next)
1280                         if (fill->fill(fill->data))
1281                                 break;
1282
1283                 if (!fill)
1284                         break;
1285         }
1286
1287         while (slot != NULL) {
1288                 if (!slot->in_use && slot->curl != NULL
1289                         && curl_session_count > min_curl_sessions) {
1290                         curl_easy_cleanup(slot->curl);
1291                         slot->curl = NULL;
1292                         curl_session_count--;
1293                 }
1294                 slot = slot->next;
1295         }
1296 }
1297
1298 void step_active_slots(void)
1299 {
1300         int num_transfers;
1301         CURLMcode curlm_result;
1302
1303         do {
1304                 curlm_result = curl_multi_perform(curlm, &num_transfers);
1305         } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
1306         if (num_transfers < active_requests) {
1307                 process_curl_messages();
1308                 fill_active_slots();
1309         }
1310 }
1311 #endif
1312
1313 void run_active_slot(struct active_request_slot *slot)
1314 {
1315 #ifdef USE_CURL_MULTI
1316         fd_set readfds;
1317         fd_set writefds;
1318         fd_set excfds;
1319         int max_fd;
1320         struct timeval select_timeout;
1321         int finished = 0;
1322
1323         slot->finished = &finished;
1324         while (!finished) {
1325                 step_active_slots();
1326
1327                 if (slot->in_use) {
1328 #if LIBCURL_VERSION_NUM >= 0x070f04
1329                         long curl_timeout;
1330                         curl_multi_timeout(curlm, &curl_timeout);
1331                         if (curl_timeout == 0) {
1332                                 continue;
1333                         } else if (curl_timeout == -1) {
1334                                 select_timeout.tv_sec  = 0;
1335                                 select_timeout.tv_usec = 50000;
1336                         } else {
1337                                 select_timeout.tv_sec  =  curl_timeout / 1000;
1338                                 select_timeout.tv_usec = (curl_timeout % 1000) * 1000;
1339                         }
1340 #else
1341                         select_timeout.tv_sec  = 0;
1342                         select_timeout.tv_usec = 50000;
1343 #endif
1344
1345                         max_fd = -1;
1346                         FD_ZERO(&readfds);
1347                         FD_ZERO(&writefds);
1348                         FD_ZERO(&excfds);
1349                         curl_multi_fdset(curlm, &readfds, &writefds, &excfds, &max_fd);
1350
1351                         /*
1352                          * It can happen that curl_multi_timeout returns a pathologically
1353                          * long timeout when curl_multi_fdset returns no file descriptors
1354                          * to read.  See commit message for more details.
1355                          */
1356                         if (max_fd < 0 &&
1357                             (select_timeout.tv_sec > 0 ||
1358                              select_timeout.tv_usec > 50000)) {
1359                                 select_timeout.tv_sec  = 0;
1360                                 select_timeout.tv_usec = 50000;
1361                         }
1362
1363                         select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
1364                 }
1365         }
1366 #else
1367         while (slot->in_use) {
1368                 slot->curl_result = curl_easy_perform(slot->curl);
1369                 finish_active_slot(slot);
1370         }
1371 #endif
1372 }
1373
1374 static void release_active_slot(struct active_request_slot *slot)
1375 {
1376         closedown_active_slot(slot);
1377         if (slot->curl) {
1378                 xmulti_remove_handle(slot);
1379                 if (curl_session_count > min_curl_sessions) {
1380                         curl_easy_cleanup(slot->curl);
1381                         slot->curl = NULL;
1382                         curl_session_count--;
1383                 }
1384         }
1385 #ifdef USE_CURL_MULTI
1386         fill_active_slots();
1387 #endif
1388 }
1389
1390 void finish_all_active_slots(void)
1391 {
1392         struct active_request_slot *slot = active_queue_head;
1393
1394         while (slot != NULL)
1395                 if (slot->in_use) {
1396                         run_active_slot(slot);
1397                         slot = active_queue_head;
1398                 } else {
1399                         slot = slot->next;
1400                 }
1401 }
1402
1403 /* Helpers for modifying and creating URLs */
1404 static inline int needs_quote(int ch)
1405 {
1406         if (((ch >= 'A') && (ch <= 'Z'))
1407                         || ((ch >= 'a') && (ch <= 'z'))
1408                         || ((ch >= '0') && (ch <= '9'))
1409                         || (ch == '/')
1410                         || (ch == '-')
1411                         || (ch == '.'))
1412                 return 0;
1413         return 1;
1414 }
1415
1416 static char *quote_ref_url(const char *base, const char *ref)
1417 {
1418         struct strbuf buf = STRBUF_INIT;
1419         const char *cp;
1420         int ch;
1421
1422         end_url_with_slash(&buf, base);
1423
1424         for (cp = ref; (ch = *cp) != 0; cp++)
1425                 if (needs_quote(ch))
1426                         strbuf_addf(&buf, "%%%02x", ch);
1427                 else
1428                         strbuf_addch(&buf, *cp);
1429
1430         return strbuf_detach(&buf, NULL);
1431 }
1432
1433 void append_remote_object_url(struct strbuf *buf, const char *url,
1434                               const char *hex,
1435                               int only_two_digit_prefix)
1436 {
1437         end_url_with_slash(buf, url);
1438
1439         strbuf_addf(buf, "objects/%.*s/", 2, hex);
1440         if (!only_two_digit_prefix)
1441                 strbuf_addstr(buf, hex + 2);
1442 }
1443
1444 char *get_remote_object_url(const char *url, const char *hex,
1445                             int only_two_digit_prefix)
1446 {
1447         struct strbuf buf = STRBUF_INIT;
1448         append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
1449         return strbuf_detach(&buf, NULL);
1450 }
1451
1452 static int handle_curl_result(struct slot_results *results)
1453 {
1454         /*
1455          * If we see a failing http code with CURLE_OK, we have turned off
1456          * FAILONERROR (to keep the server's custom error response), and should
1457          * translate the code into failure here.
1458          *
1459          * Likewise, if we see a redirect (30x code), that means we turned off
1460          * redirect-following, and we should treat the result as an error.
1461          */
1462         if (results->curl_result == CURLE_OK &&
1463             results->http_code >= 300) {
1464                 results->curl_result = CURLE_HTTP_RETURNED_ERROR;
1465                 /*
1466                  * Normally curl will already have put the "reason phrase"
1467                  * from the server into curl_errorstr; unfortunately without
1468                  * FAILONERROR it is lost, so we can give only the numeric
1469                  * status code.
1470                  */
1471                 xsnprintf(curl_errorstr, sizeof(curl_errorstr),
1472                           "The requested URL returned error: %ld",
1473                           results->http_code);
1474         }
1475
1476         if (results->curl_result == CURLE_OK) {
1477                 credential_approve(&http_auth);
1478                 if (proxy_auth.password)
1479                         credential_approve(&proxy_auth);
1480                 return HTTP_OK;
1481         } else if (missing_target(results))
1482                 return HTTP_MISSING_TARGET;
1483         else if (results->http_code == 401) {
1484                 if (http_auth.username && http_auth.password) {
1485                         credential_reject(&http_auth);
1486                         return HTTP_NOAUTH;
1487                 } else {
1488 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
1489                         http_auth_methods &= ~CURLAUTH_GSSNEGOTIATE;
1490                         if (results->auth_avail) {
1491                                 http_auth_methods &= results->auth_avail;
1492                                 http_auth_methods_restricted = 1;
1493                         }
1494 #endif
1495                         return HTTP_REAUTH;
1496                 }
1497         } else {
1498                 if (results->http_connectcode == 407)
1499                         credential_reject(&proxy_auth);
1500 #if LIBCURL_VERSION_NUM >= 0x070c00
1501                 if (!curl_errorstr[0])
1502                         strlcpy(curl_errorstr,
1503                                 curl_easy_strerror(results->curl_result),
1504                                 sizeof(curl_errorstr));
1505 #endif
1506                 return HTTP_ERROR;
1507         }
1508 }
1509
1510 int run_one_slot(struct active_request_slot *slot,
1511                  struct slot_results *results)
1512 {
1513         slot->results = results;
1514         if (!start_active_slot(slot)) {
1515                 xsnprintf(curl_errorstr, sizeof(curl_errorstr),
1516                           "failed to start HTTP request");
1517                 return HTTP_START_FAILED;
1518         }
1519
1520         run_active_slot(slot);
1521         return handle_curl_result(results);
1522 }
1523
1524 struct curl_slist *http_copy_default_headers(void)
1525 {
1526         struct curl_slist *headers = NULL, *h;
1527
1528         for (h = extra_http_headers; h; h = h->next)
1529                 headers = curl_slist_append(headers, h->data);
1530
1531         return headers;
1532 }
1533
1534 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
1535 {
1536         char *ptr;
1537         CURLcode ret;
1538
1539         strbuf_reset(buf);
1540         ret = curl_easy_getinfo(curl, info, &ptr);
1541         if (!ret && ptr)
1542                 strbuf_addstr(buf, ptr);
1543         return ret;
1544 }
1545
1546 /*
1547  * Check for and extract a content-type parameter. "raw"
1548  * should be positioned at the start of the potential
1549  * parameter, with any whitespace already removed.
1550  *
1551  * "name" is the name of the parameter. The value is appended
1552  * to "out".
1553  */
1554 static int extract_param(const char *raw, const char *name,
1555                          struct strbuf *out)
1556 {
1557         size_t len = strlen(name);
1558
1559         if (strncasecmp(raw, name, len))
1560                 return -1;
1561         raw += len;
1562
1563         if (*raw != '=')
1564                 return -1;
1565         raw++;
1566
1567         while (*raw && !isspace(*raw) && *raw != ';')
1568                 strbuf_addch(out, *raw++);
1569         return 0;
1570 }
1571
1572 /*
1573  * Extract a normalized version of the content type, with any
1574  * spaces suppressed, all letters lowercased, and no trailing ";"
1575  * or parameters.
1576  *
1577  * Note that we will silently remove even invalid whitespace. For
1578  * example, "text / plain" is specifically forbidden by RFC 2616,
1579  * but "text/plain" is the only reasonable output, and this keeps
1580  * our code simple.
1581  *
1582  * If the "charset" argument is not NULL, store the value of any
1583  * charset parameter there.
1584  *
1585  * Example:
1586  *   "TEXT/PLAIN; charset=utf-8" -> "text/plain", "utf-8"
1587  *   "text / plain" -> "text/plain"
1588  */
1589 static void extract_content_type(struct strbuf *raw, struct strbuf *type,
1590                                  struct strbuf *charset)
1591 {
1592         const char *p;
1593
1594         strbuf_reset(type);
1595         strbuf_grow(type, raw->len);
1596         for (p = raw->buf; *p; p++) {
1597                 if (isspace(*p))
1598                         continue;
1599                 if (*p == ';') {
1600                         p++;
1601                         break;
1602                 }
1603                 strbuf_addch(type, tolower(*p));
1604         }
1605
1606         if (!charset)
1607                 return;
1608
1609         strbuf_reset(charset);
1610         while (*p) {
1611                 while (isspace(*p) || *p == ';')
1612                         p++;
1613                 if (!extract_param(p, "charset", charset))
1614                         return;
1615                 while (*p && !isspace(*p))
1616                         p++;
1617         }
1618
1619         if (!charset->len && starts_with(type->buf, "text/"))
1620                 strbuf_addstr(charset, "ISO-8859-1");
1621 }
1622
1623 static void write_accept_language(struct strbuf *buf)
1624 {
1625         /*
1626          * MAX_DECIMAL_PLACES must not be larger than 3. If it is larger than
1627          * that, q-value will be smaller than 0.001, the minimum q-value the
1628          * HTTP specification allows. See
1629          * http://tools.ietf.org/html/rfc7231#section-5.3.1 for q-value.
1630          */
1631         const int MAX_DECIMAL_PLACES = 3;
1632         const int MAX_LANGUAGE_TAGS = 1000;
1633         const int MAX_ACCEPT_LANGUAGE_HEADER_SIZE = 4000;
1634         char **language_tags = NULL;
1635         int num_langs = 0;
1636         const char *s = get_preferred_languages();
1637         int i;
1638         struct strbuf tag = STRBUF_INIT;
1639
1640         /* Don't add Accept-Language header if no language is preferred. */
1641         if (!s)
1642                 return;
1643
1644         /*
1645          * Split the colon-separated string of preferred languages into
1646          * language_tags array.
1647          */
1648         do {
1649                 /* collect language tag */
1650                 for (; *s && (isalnum(*s) || *s == '_'); s++)
1651                         strbuf_addch(&tag, *s == '_' ? '-' : *s);
1652
1653                 /* skip .codeset, @modifier and any other unnecessary parts */
1654                 while (*s && *s != ':')
1655                         s++;
1656
1657                 if (tag.len) {
1658                         num_langs++;
1659                         REALLOC_ARRAY(language_tags, num_langs);
1660                         language_tags[num_langs - 1] = strbuf_detach(&tag, NULL);
1661                         if (num_langs >= MAX_LANGUAGE_TAGS - 1) /* -1 for '*' */
1662                                 break;
1663                 }
1664         } while (*s++);
1665
1666         /* write Accept-Language header into buf */
1667         if (num_langs) {
1668                 int last_buf_len = 0;
1669                 int max_q;
1670                 int decimal_places;
1671                 char q_format[32];
1672
1673                 /* add '*' */
1674                 REALLOC_ARRAY(language_tags, num_langs + 1);
1675                 language_tags[num_langs++] = "*"; /* it's OK; this won't be freed */
1676
1677                 /* compute decimal_places */
1678                 for (max_q = 1, decimal_places = 0;
1679                      max_q < num_langs && decimal_places <= MAX_DECIMAL_PLACES;
1680                      decimal_places++, max_q *= 10)
1681                         ;
1682
1683                 xsnprintf(q_format, sizeof(q_format), ";q=0.%%0%dd", decimal_places);
1684
1685                 strbuf_addstr(buf, "Accept-Language: ");
1686
1687                 for (i = 0; i < num_langs; i++) {
1688                         if (i > 0)
1689                                 strbuf_addstr(buf, ", ");
1690
1691                         strbuf_addstr(buf, language_tags[i]);
1692
1693                         if (i > 0)
1694                                 strbuf_addf(buf, q_format, max_q - i);
1695
1696                         if (buf->len > MAX_ACCEPT_LANGUAGE_HEADER_SIZE) {
1697                                 strbuf_remove(buf, last_buf_len, buf->len - last_buf_len);
1698                                 break;
1699                         }
1700
1701                         last_buf_len = buf->len;
1702                 }
1703         }
1704
1705         /* free language tags -- last one is a static '*' */
1706         for (i = 0; i < num_langs - 1; i++)
1707                 free(language_tags[i]);
1708         free(language_tags);
1709 }
1710
1711 /*
1712  * Get an Accept-Language header which indicates user's preferred languages.
1713  *
1714  * Examples:
1715  *   LANGUAGE= -> ""
1716  *   LANGUAGE=ko:en -> "Accept-Language: ko, en; q=0.9, *; q=0.1"
1717  *   LANGUAGE=ko_KR.UTF-8:sr@latin -> "Accept-Language: ko-KR, sr; q=0.9, *; q=0.1"
1718  *   LANGUAGE=ko LANG=en_US.UTF-8 -> "Accept-Language: ko, *; q=0.1"
1719  *   LANGUAGE= LANG=en_US.UTF-8 -> "Accept-Language: en-US, *; q=0.1"
1720  *   LANGUAGE= LANG=C -> ""
1721  */
1722 static const char *get_accept_language(void)
1723 {
1724         if (!cached_accept_language) {
1725                 struct strbuf buf = STRBUF_INIT;
1726                 write_accept_language(&buf);
1727                 if (buf.len > 0)
1728                         cached_accept_language = strbuf_detach(&buf, NULL);
1729         }
1730
1731         return cached_accept_language;
1732 }
1733
1734 static void http_opt_request_remainder(CURL *curl, off_t pos)
1735 {
1736         char buf[128];
1737         xsnprintf(buf, sizeof(buf), "%"PRIuMAX"-", (uintmax_t)pos);
1738         curl_easy_setopt(curl, CURLOPT_RANGE, buf);
1739 }
1740
1741 /* http_request() targets */
1742 #define HTTP_REQUEST_STRBUF     0
1743 #define HTTP_REQUEST_FILE       1
1744
1745 static int http_request(const char *url,
1746                         void *result, int target,
1747                         const struct http_get_options *options)
1748 {
1749         struct active_request_slot *slot;
1750         struct slot_results results;
1751         struct curl_slist *headers = http_copy_default_headers();
1752         struct strbuf buf = STRBUF_INIT;
1753         const char *accept_language;
1754         int ret;
1755
1756         slot = get_active_slot();
1757         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1758
1759         if (result == NULL) {
1760                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
1761         } else {
1762                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
1763                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
1764
1765                 if (target == HTTP_REQUEST_FILE) {
1766                         off_t posn = ftello(result);
1767                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1768                                          fwrite);
1769                         if (posn > 0)
1770                                 http_opt_request_remainder(slot->curl, posn);
1771                 } else
1772                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1773                                          fwrite_buffer);
1774         }
1775
1776         accept_language = get_accept_language();
1777
1778         if (accept_language)
1779                 headers = curl_slist_append(headers, accept_language);
1780
1781         strbuf_addstr(&buf, "Pragma:");
1782         if (options && options->no_cache)
1783                 strbuf_addstr(&buf, " no-cache");
1784         if (options && options->keep_error)
1785                 curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
1786         if (options && options->initial_request &&
1787             http_follow_config == HTTP_FOLLOW_INITIAL)
1788                 curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 1);
1789
1790         headers = curl_slist_append(headers, buf.buf);
1791
1792         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1793         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
1794         curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
1795
1796         ret = run_one_slot(slot, &results);
1797
1798         if (options && options->content_type) {
1799                 struct strbuf raw = STRBUF_INIT;
1800                 curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE, &raw);
1801                 extract_content_type(&raw, options->content_type,
1802                                      options->charset);
1803                 strbuf_release(&raw);
1804         }
1805
1806         if (options && options->effective_url)
1807                 curlinfo_strbuf(slot->curl, CURLINFO_EFFECTIVE_URL,
1808                                 options->effective_url);
1809
1810         curl_slist_free_all(headers);
1811         strbuf_release(&buf);
1812
1813         return ret;
1814 }
1815
1816 /*
1817  * Update the "base" url to a more appropriate value, as deduced by
1818  * redirects seen when requesting a URL starting with "url".
1819  *
1820  * The "asked" parameter is a URL that we asked curl to access, and must begin
1821  * with "base".
1822  *
1823  * The "got" parameter is the URL that curl reported to us as where we ended
1824  * up.
1825  *
1826  * Returns 1 if we updated the base url, 0 otherwise.
1827  *
1828  * Our basic strategy is to compare "base" and "asked" to find the bits
1829  * specific to our request. We then strip those bits off of "got" to yield the
1830  * new base. So for example, if our base is "http://example.com/foo.git",
1831  * and we ask for "http://example.com/foo.git/info/refs", we might end up
1832  * with "https://other.example.com/foo.git/info/refs". We would want the
1833  * new URL to become "https://other.example.com/foo.git".
1834  *
1835  * Note that this assumes a sane redirect scheme. It's entirely possible
1836  * in the example above to end up at a URL that does not even end in
1837  * "info/refs".  In such a case we die. There's not much we can do, such a
1838  * scheme is unlikely to represent a real git repository, and failing to
1839  * rewrite the base opens options for malicious redirects to do funny things.
1840  */
1841 static int update_url_from_redirect(struct strbuf *base,
1842                                     const char *asked,
1843                                     const struct strbuf *got)
1844 {
1845         const char *tail;
1846         size_t new_len;
1847
1848         if (!strcmp(asked, got->buf))
1849                 return 0;
1850
1851         if (!skip_prefix(asked, base->buf, &tail))
1852                 die("BUG: update_url_from_redirect: %s is not a superset of %s",
1853                     asked, base->buf);
1854
1855         new_len = got->len;
1856         if (!strip_suffix_mem(got->buf, &new_len, tail))
1857                 die(_("unable to update url base from redirection:\n"
1858                       "  asked for: %s\n"
1859                       "   redirect: %s"),
1860                     asked, got->buf);
1861
1862         strbuf_reset(base);
1863         strbuf_add(base, got->buf, new_len);
1864
1865         return 1;
1866 }
1867
1868 static int http_request_reauth(const char *url,
1869                                void *result, int target,
1870                                struct http_get_options *options)
1871 {
1872         int ret = http_request(url, result, target, options);
1873
1874         if (ret != HTTP_OK && ret != HTTP_REAUTH)
1875                 return ret;
1876
1877         if (options && options->effective_url && options->base_url) {
1878                 if (update_url_from_redirect(options->base_url,
1879                                              url, options->effective_url)) {
1880                         credential_from_url(&http_auth, options->base_url->buf);
1881                         url = options->effective_url->buf;
1882                 }
1883         }
1884
1885         if (ret != HTTP_REAUTH)
1886                 return ret;
1887
1888         /*
1889          * If we are using KEEP_ERROR, the previous request may have
1890          * put cruft into our output stream; we should clear it out before
1891          * making our next request. We only know how to do this for
1892          * the strbuf case, but that is enough to satisfy current callers.
1893          */
1894         if (options && options->keep_error) {
1895                 switch (target) {
1896                 case HTTP_REQUEST_STRBUF:
1897                         strbuf_reset(result);
1898                         break;
1899                 default:
1900                         die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
1901                 }
1902         }
1903
1904         credential_fill(&http_auth);
1905
1906         return http_request(url, result, target, options);
1907 }
1908
1909 int http_get_strbuf(const char *url,
1910                     struct strbuf *result,
1911                     struct http_get_options *options)
1912 {
1913         return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
1914 }
1915
1916 /*
1917  * Downloads a URL and stores the result in the given file.
1918  *
1919  * If a previous interrupted download is detected (i.e. a previous temporary
1920  * file is still around) the download is resumed.
1921  */
1922 static int http_get_file(const char *url, const char *filename,
1923                          struct http_get_options *options)
1924 {
1925         int ret;
1926         struct strbuf tmpfile = STRBUF_INIT;
1927         FILE *result;
1928
1929         strbuf_addf(&tmpfile, "%s.temp", filename);
1930         result = fopen(tmpfile.buf, "a");
1931         if (!result) {
1932                 error("Unable to open local file %s", tmpfile.buf);
1933                 ret = HTTP_ERROR;
1934                 goto cleanup;
1935         }
1936
1937         ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
1938         fclose(result);
1939
1940         if (ret == HTTP_OK && finalize_object_file(tmpfile.buf, filename))
1941                 ret = HTTP_ERROR;
1942 cleanup:
1943         strbuf_release(&tmpfile);
1944         return ret;
1945 }
1946
1947 int http_fetch_ref(const char *base, struct ref *ref)
1948 {
1949         struct http_get_options options = {0};
1950         char *url;
1951         struct strbuf buffer = STRBUF_INIT;
1952         int ret = -1;
1953
1954         options.no_cache = 1;
1955
1956         url = quote_ref_url(base, ref->name);
1957         if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
1958                 strbuf_rtrim(&buffer);
1959                 if (buffer.len == 40)
1960                         ret = get_oid_hex(buffer.buf, &ref->old_oid);
1961                 else if (starts_with(buffer.buf, "ref: ")) {
1962                         ref->symref = xstrdup(buffer.buf + 5);
1963                         ret = 0;
1964                 }
1965         }
1966
1967         strbuf_release(&buffer);
1968         free(url);
1969         return ret;
1970 }
1971
1972 /* Helpers for fetching packs */
1973 static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
1974 {
1975         char *url, *tmp;
1976         struct strbuf buf = STRBUF_INIT;
1977
1978         if (http_is_verbose)
1979                 fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
1980
1981         end_url_with_slash(&buf, base_url);
1982         strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
1983         url = strbuf_detach(&buf, NULL);
1984
1985         strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
1986         tmp = strbuf_detach(&buf, NULL);
1987
1988         if (http_get_file(url, tmp, NULL) != HTTP_OK) {
1989                 error("Unable to get pack index %s", url);
1990                 FREE_AND_NULL(tmp);
1991         }
1992
1993         free(url);
1994         return tmp;
1995 }
1996
1997 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
1998         unsigned char *sha1, const char *base_url)
1999 {
2000         struct packed_git *new_pack;
2001         char *tmp_idx = NULL;
2002         int ret;
2003
2004         if (has_pack_index(sha1)) {
2005                 new_pack = parse_pack_index(sha1, sha1_pack_index_name(sha1));
2006                 if (!new_pack)
2007                         return -1; /* parse_pack_index() already issued error message */
2008                 goto add_pack;
2009         }
2010
2011         tmp_idx = fetch_pack_index(sha1, base_url);
2012         if (!tmp_idx)
2013                 return -1;
2014
2015         new_pack = parse_pack_index(sha1, tmp_idx);
2016         if (!new_pack) {
2017                 unlink(tmp_idx);
2018                 free(tmp_idx);
2019
2020                 return -1; /* parse_pack_index() already issued error message */
2021         }
2022
2023         ret = verify_pack_index(new_pack);
2024         if (!ret) {
2025                 close_pack_index(new_pack);
2026                 ret = finalize_object_file(tmp_idx, sha1_pack_index_name(sha1));
2027         }
2028         free(tmp_idx);
2029         if (ret)
2030                 return -1;
2031
2032 add_pack:
2033         new_pack->next = *packs_head;
2034         *packs_head = new_pack;
2035         return 0;
2036 }
2037
2038 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
2039 {
2040         struct http_get_options options = {0};
2041         int ret = 0, i = 0;
2042         char *url, *data;
2043         struct strbuf buf = STRBUF_INIT;
2044         unsigned char sha1[20];
2045
2046         end_url_with_slash(&buf, base_url);
2047         strbuf_addstr(&buf, "objects/info/packs");
2048         url = strbuf_detach(&buf, NULL);
2049
2050         options.no_cache = 1;
2051         ret = http_get_strbuf(url, &buf, &options);
2052         if (ret != HTTP_OK)
2053                 goto cleanup;
2054
2055         data = buf.buf;
2056         while (i < buf.len) {
2057                 switch (data[i]) {
2058                 case 'P':
2059                         i++;
2060                         if (i + 52 <= buf.len &&
2061                             starts_with(data + i, " pack-") &&
2062                             starts_with(data + i + 46, ".pack\n")) {
2063                                 get_sha1_hex(data + i + 6, sha1);
2064                                 fetch_and_setup_pack_index(packs_head, sha1,
2065                                                       base_url);
2066                                 i += 51;
2067                                 break;
2068                         }
2069                 default:
2070                         while (i < buf.len && data[i] != '\n')
2071                                 i++;
2072                 }
2073                 i++;
2074         }
2075
2076 cleanup:
2077         free(url);
2078         return ret;
2079 }
2080
2081 void release_http_pack_request(struct http_pack_request *preq)
2082 {
2083         if (preq->packfile != NULL) {
2084                 fclose(preq->packfile);
2085                 preq->packfile = NULL;
2086         }
2087         preq->slot = NULL;
2088         free(preq->url);
2089         free(preq);
2090 }
2091
2092 int finish_http_pack_request(struct http_pack_request *preq)
2093 {
2094         struct packed_git **lst;
2095         struct packed_git *p = preq->target;
2096         char *tmp_idx;
2097         size_t len;
2098         struct child_process ip = CHILD_PROCESS_INIT;
2099
2100         close_pack_index(p);
2101
2102         fclose(preq->packfile);
2103         preq->packfile = NULL;
2104
2105         lst = preq->lst;
2106         while (*lst != p)
2107                 lst = &((*lst)->next);
2108         *lst = (*lst)->next;
2109
2110         if (!strip_suffix(preq->tmpfile, ".pack.temp", &len))
2111                 die("BUG: pack tmpfile does not end in .pack.temp?");
2112         tmp_idx = xstrfmt("%.*s.idx.temp", (int)len, preq->tmpfile);
2113
2114         argv_array_push(&ip.args, "index-pack");
2115         argv_array_pushl(&ip.args, "-o", tmp_idx, NULL);
2116         argv_array_push(&ip.args, preq->tmpfile);
2117         ip.git_cmd = 1;
2118         ip.no_stdin = 1;
2119         ip.no_stdout = 1;
2120
2121         if (run_command(&ip)) {
2122                 unlink(preq->tmpfile);
2123                 unlink(tmp_idx);
2124                 free(tmp_idx);
2125                 return -1;
2126         }
2127
2128         unlink(sha1_pack_index_name(p->sha1));
2129
2130         if (finalize_object_file(preq->tmpfile, sha1_pack_name(p->sha1))
2131          || finalize_object_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
2132                 free(tmp_idx);
2133                 return -1;
2134         }
2135
2136         install_packed_git(p);
2137         free(tmp_idx);
2138         return 0;
2139 }
2140
2141 struct http_pack_request *new_http_pack_request(
2142         struct packed_git *target, const char *base_url)
2143 {
2144         off_t prev_posn = 0;
2145         struct strbuf buf = STRBUF_INIT;
2146         struct http_pack_request *preq;
2147
2148         preq = xcalloc(1, sizeof(*preq));
2149         preq->target = target;
2150
2151         end_url_with_slash(&buf, base_url);
2152         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
2153                 sha1_to_hex(target->sha1));
2154         preq->url = strbuf_detach(&buf, NULL);
2155
2156         snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
2157                 sha1_pack_name(target->sha1));
2158         preq->packfile = fopen(preq->tmpfile, "a");
2159         if (!preq->packfile) {
2160                 error("Unable to open local file %s for pack",
2161                       preq->tmpfile);
2162                 goto abort;
2163         }
2164
2165         preq->slot = get_active_slot();
2166         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
2167         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
2168         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
2169         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
2170                 no_pragma_header);
2171
2172         /*
2173          * If there is data present from a previous transfer attempt,
2174          * resume where it left off
2175          */
2176         prev_posn = ftello(preq->packfile);
2177         if (prev_posn>0) {
2178                 if (http_is_verbose)
2179                         fprintf(stderr,
2180                                 "Resuming fetch of pack %s at byte %"PRIuMAX"\n",
2181                                 sha1_to_hex(target->sha1), (uintmax_t)prev_posn);
2182                 http_opt_request_remainder(preq->slot->curl, prev_posn);
2183         }
2184
2185         return preq;
2186
2187 abort:
2188         free(preq->url);
2189         free(preq);
2190         return NULL;
2191 }
2192
2193 /* Helpers for fetching objects (loose) */
2194 static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
2195                                void *data)
2196 {
2197         unsigned char expn[4096];
2198         size_t size = eltsize * nmemb;
2199         int posn = 0;
2200         struct http_object_request *freq = data;
2201         struct active_request_slot *slot = freq->slot;
2202
2203         if (slot) {
2204                 CURLcode c = curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE,
2205                                                 &slot->http_code);
2206                 if (c != CURLE_OK)
2207                         die("BUG: curl_easy_getinfo for HTTP code failed: %s",
2208                                 curl_easy_strerror(c));
2209                 if (slot->http_code >= 300)
2210                         return size;
2211         }
2212
2213         do {
2214                 ssize_t retval = xwrite(freq->localfile,
2215                                         (char *) ptr + posn, size - posn);
2216                 if (retval < 0)
2217                         return posn;
2218                 posn += retval;
2219         } while (posn < size);
2220
2221         freq->stream.avail_in = size;
2222         freq->stream.next_in = (void *)ptr;
2223         do {
2224                 freq->stream.next_out = expn;
2225                 freq->stream.avail_out = sizeof(expn);
2226                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
2227                 git_SHA1_Update(&freq->c, expn,
2228                                 sizeof(expn) - freq->stream.avail_out);
2229         } while (freq->stream.avail_in && freq->zret == Z_OK);
2230         return size;
2231 }
2232
2233 struct http_object_request *new_http_object_request(const char *base_url,
2234         unsigned char *sha1)
2235 {
2236         char *hex = sha1_to_hex(sha1);
2237         const char *filename;
2238         char prevfile[PATH_MAX];
2239         int prevlocal;
2240         char prev_buf[PREV_BUF_SIZE];
2241         ssize_t prev_read = 0;
2242         off_t prev_posn = 0;
2243         struct http_object_request *freq;
2244
2245         freq = xcalloc(1, sizeof(*freq));
2246         hashcpy(freq->sha1, sha1);
2247         freq->localfile = -1;
2248
2249         filename = sha1_file_name(sha1);
2250         snprintf(freq->tmpfile, sizeof(freq->tmpfile),
2251                  "%s.temp", filename);
2252
2253         snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
2254         unlink_or_warn(prevfile);
2255         rename(freq->tmpfile, prevfile);
2256         unlink_or_warn(freq->tmpfile);
2257
2258         if (freq->localfile != -1)
2259                 error("fd leakage in start: %d", freq->localfile);
2260         freq->localfile = open(freq->tmpfile,
2261                                O_WRONLY | O_CREAT | O_EXCL, 0666);
2262         /*
2263          * This could have failed due to the "lazy directory creation";
2264          * try to mkdir the last path component.
2265          */
2266         if (freq->localfile < 0 && errno == ENOENT) {
2267                 char *dir = strrchr(freq->tmpfile, '/');
2268                 if (dir) {
2269                         *dir = 0;
2270                         mkdir(freq->tmpfile, 0777);
2271                         *dir = '/';
2272                 }
2273                 freq->localfile = open(freq->tmpfile,
2274                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
2275         }
2276
2277         if (freq->localfile < 0) {
2278                 error_errno("Couldn't create temporary file %s", freq->tmpfile);
2279                 goto abort;
2280         }
2281
2282         git_inflate_init(&freq->stream);
2283
2284         git_SHA1_Init(&freq->c);
2285
2286         freq->url = get_remote_object_url(base_url, hex, 0);
2287
2288         /*
2289          * If a previous temp file is present, process what was already
2290          * fetched.
2291          */
2292         prevlocal = open(prevfile, O_RDONLY);
2293         if (prevlocal != -1) {
2294                 do {
2295                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
2296                         if (prev_read>0) {
2297                                 if (fwrite_sha1_file(prev_buf,
2298                                                      1,
2299                                                      prev_read,
2300                                                      freq) == prev_read) {
2301                                         prev_posn += prev_read;
2302                                 } else {
2303                                         prev_read = -1;
2304                                 }
2305                         }
2306                 } while (prev_read > 0);
2307                 close(prevlocal);
2308         }
2309         unlink_or_warn(prevfile);
2310
2311         /*
2312          * Reset inflate/SHA1 if there was an error reading the previous temp
2313          * file; also rewind to the beginning of the local file.
2314          */
2315         if (prev_read == -1) {
2316                 memset(&freq->stream, 0, sizeof(freq->stream));
2317                 git_inflate_init(&freq->stream);
2318                 git_SHA1_Init(&freq->c);
2319                 if (prev_posn>0) {
2320                         prev_posn = 0;
2321                         lseek(freq->localfile, 0, SEEK_SET);
2322                         if (ftruncate(freq->localfile, 0) < 0) {
2323                                 error_errno("Couldn't truncate temporary file %s",
2324                                             freq->tmpfile);
2325                                 goto abort;
2326                         }
2327                 }
2328         }
2329
2330         freq->slot = get_active_slot();
2331
2332         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
2333         curl_easy_setopt(freq->slot->curl, CURLOPT_FAILONERROR, 0);
2334         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
2335         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
2336         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
2337         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
2338
2339         /*
2340          * If we have successfully processed data from a previous fetch
2341          * attempt, only fetch the data we don't already have.
2342          */
2343         if (prev_posn>0) {
2344                 if (http_is_verbose)
2345                         fprintf(stderr,
2346                                 "Resuming fetch of object %s at byte %"PRIuMAX"\n",
2347                                 hex, (uintmax_t)prev_posn);
2348                 http_opt_request_remainder(freq->slot->curl, prev_posn);
2349         }
2350
2351         return freq;
2352
2353 abort:
2354         free(freq->url);
2355         free(freq);
2356         return NULL;
2357 }
2358
2359 void process_http_object_request(struct http_object_request *freq)
2360 {
2361         if (freq->slot == NULL)
2362                 return;
2363         freq->curl_result = freq->slot->curl_result;
2364         freq->http_code = freq->slot->http_code;
2365         freq->slot = NULL;
2366 }
2367
2368 int finish_http_object_request(struct http_object_request *freq)
2369 {
2370         struct stat st;
2371
2372         close(freq->localfile);
2373         freq->localfile = -1;
2374
2375         process_http_object_request(freq);
2376
2377         if (freq->http_code == 416) {
2378                 warning("requested range invalid; we may already have all the data.");
2379         } else if (freq->curl_result != CURLE_OK) {
2380                 if (stat(freq->tmpfile, &st) == 0)
2381                         if (st.st_size == 0)
2382                                 unlink_or_warn(freq->tmpfile);
2383                 return -1;
2384         }
2385
2386         git_inflate_end(&freq->stream);
2387         git_SHA1_Final(freq->real_sha1, &freq->c);
2388         if (freq->zret != Z_STREAM_END) {
2389                 unlink_or_warn(freq->tmpfile);
2390                 return -1;
2391         }
2392         if (hashcmp(freq->sha1, freq->real_sha1)) {
2393                 unlink_or_warn(freq->tmpfile);
2394                 return -1;
2395         }
2396         freq->rename =
2397                 finalize_object_file(freq->tmpfile, sha1_file_name(freq->sha1));
2398
2399         return freq->rename;
2400 }
2401
2402 void abort_http_object_request(struct http_object_request *freq)
2403 {
2404         unlink_or_warn(freq->tmpfile);
2405
2406         release_http_object_request(freq);
2407 }
2408
2409 void release_http_object_request(struct http_object_request *freq)
2410 {
2411         if (freq->localfile != -1) {
2412                 close(freq->localfile);
2413                 freq->localfile = -1;
2414         }
2415         if (freq->url != NULL) {
2416                 FREE_AND_NULL(freq->url);
2417         }
2418         if (freq->slot != NULL) {
2419                 freq->slot->callback_func = NULL;
2420                 freq->slot->callback_data = NULL;
2421                 release_active_slot(freq->slot);
2422                 freq->slot = NULL;
2423         }
2424 }