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 #include "object-store.h"
  18
  19 static struct trace_key trace_curl = TRACE_KEY_INIT(CURL);
  20 static int trace_curl_data = 1;
  21 static struct string_list cookies_to_redact = STRING_LIST_INIT_DUP;
  22 #if LIBCURL_VERSION_NUM >= 0x070a08
  23 long int git_curl_ipresolve = CURL_IPRESOLVE_WHATEVER;
  24 #else
  25 long int git_curl_ipresolve;
  26 #endif
  27 int active_requests;
  28 int http_is_verbose;
  29 ssize_t http_post_buffer = 16 * LARGE_PACKET_MAX;
  30
  31 #if LIBCURL_VERSION_NUM >= 0x070a06
  32 #define LIBCURL_CAN_HANDLE_AUTH_ANY
  33 #endif
  34
  35 static int min_curl_sessions = 1;
  36 static int curl_session_count;
  37 #ifdef USE_CURL_MULTI
  38 static int max_requests = -1;
  39 static CURLM *curlm;
  40 #endif
  41 #ifndef NO_CURL_EASY_DUPHANDLE
  42 static CURL *curl_default;
  43 #endif
  44
  45 #define PREV_BUF_SIZE 4096
  46
  47 char curl_errorstr[CURL_ERROR_SIZE];
  48
  49 static int curl_ssl_verify = -1;
  50 static int curl_ssl_try;
  51 static const char *ssl_cert;
  52 static const char *ssl_cipherlist;
  53 static const char *ssl_version;
  54 static struct {
  55         const char *name;
  56         long ssl_version;
  57 } sslversions[] = {
  58         { "sslv2", CURL_SSLVERSION_SSLv2 },
  59         { "sslv3", CURL_SSLVERSION_SSLv3 },
  60         { "tlsv1", CURL_SSLVERSION_TLSv1 },
  61 #if LIBCURL_VERSION_NUM >= 0x072200
  62         { "tlsv1.0", CURL_SSLVERSION_TLSv1_0 },
  63         { "tlsv1.1", CURL_SSLVERSION_TLSv1_1 },
  64         { "tlsv1.2", CURL_SSLVERSION_TLSv1_2 },
  65 #endif
  66 #if LIBCURL_VERSION_NUM >= 0x073400
  67         { "tlsv1.3", CURL_SSLVERSION_TLSv1_3 },
  68 #endif
  69 };
  70 #if LIBCURL_VERSION_NUM >= 0x070903
  71 static const char *ssl_key;
  72 #endif
  73 #if LIBCURL_VERSION_NUM >= 0x070908
  74 static const char *ssl_capath;
  75 #endif
  76 #if LIBCURL_VERSION_NUM >= 0x071304
  77 static const char *curl_no_proxy;
  78 #endif
  79 #if LIBCURL_VERSION_NUM >= 0x072c00
  80 static const char *ssl_pinnedkey;
  81 #endif
  82 static const char *ssl_cainfo;
  83 static long curl_low_speed_limit = -1;
  84 static long curl_low_speed_time = -1;
  85 static int curl_ftp_no_epsv;
  86 static const char *curl_http_proxy;
  87 static const char *http_proxy_authmethod;
  88 static struct {
  89         const char *name;
  90         long curlauth_param;
  91 } proxy_authmethods[] = {
  92         { "basic", CURLAUTH_BASIC },
  93         { "digest", CURLAUTH_DIGEST },
  94         { "negotiate", CURLAUTH_GSSNEGOTIATE },
  95         { "ntlm", CURLAUTH_NTLM },
  96 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
  97         { "anyauth", CURLAUTH_ANY },
  98 #endif
  99         /*
 100          * CURLAUTH_DIGEST_IE has no corresponding command-line option in
 101          * curl(1) and is not included in CURLAUTH_ANY, so we leave it out
 102          * here, too
 103          */
 104 };
 105 #ifdef CURLGSSAPI_DELEGATION_FLAG
 106 static const char *curl_deleg;
 107 static struct {
 108         const char *name;
 109         long curl_deleg_param;
 110 } curl_deleg_levels[] = {
 111         { "none", CURLGSSAPI_DELEGATION_NONE },
 112         { "policy", CURLGSSAPI_DELEGATION_POLICY_FLAG },
 113         { "always", CURLGSSAPI_DELEGATION_FLAG },
 114 };
 115 #endif
 116
 117 static struct credential proxy_auth = CREDENTIAL_INIT;
 118 static const char *curl_proxyuserpwd;
 119 static const char *curl_cookie_file;
 120 static int curl_save_cookies;
 121 struct credential http_auth = CREDENTIAL_INIT;
 122 static int http_proactive_auth;
 123 static const char *user_agent;
 124 static int curl_empty_auth = -1;
 125
 126 enum http_follow_config http_follow_config = HTTP_FOLLOW_INITIAL;
 127
 128 #if LIBCURL_VERSION_NUM >= 0x071700
 129 /* Use CURLOPT_KEYPASSWD as is */
 130 #elif LIBCURL_VERSION_NUM >= 0x070903
 131 #define CURLOPT_KEYPASSWD CURLOPT_SSLKEYPASSWD
 132 #else
 133 #define CURLOPT_KEYPASSWD CURLOPT_SSLCERTPASSWD
 134 #endif
 135
 136 static struct credential cert_auth = CREDENTIAL_INIT;
 137 static int ssl_cert_password_required;
 138 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 139 static unsigned long http_auth_methods = CURLAUTH_ANY;
 140 static int http_auth_methods_restricted;
 141 /* Modes for which empty_auth cannot actually help us. */
 142 static unsigned long empty_auth_useless =
 143         CURLAUTH_BASIC
 144 #ifdef CURLAUTH_DIGEST_IE
 145         | CURLAUTH_DIGEST_IE
 146 #endif
 147         | CURLAUTH_DIGEST;
 148 #endif
 149
 150 static struct curl_slist *pragma_header;
 151 static struct curl_slist *no_pragma_header;
 152 static struct curl_slist *extra_http_headers;
 153
 154 static struct active_request_slot *active_queue_head;
 155
 156 static char *cached_accept_language;
 157
 158 static char *http_ssl_backend;
 159
 160 static int http_schannel_check_revoke = 1;
 161
 162 size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
 163 {
 164         size_t size = eltsize * nmemb;
 165         struct buffer *buffer = buffer_;
 166
 167         if (size > buffer->buf.len - buffer->posn)
 168                 size = buffer->buf.len - buffer->posn;
 169         memcpy(ptr, buffer->buf.buf + buffer->posn, size);
 170         buffer->posn += size;
 171
 172         return size;
 173 }
 174
 175 #ifndef NO_CURL_IOCTL
 176 curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)
 177 {
 178         struct buffer *buffer = clientp;
 179
 180         switch (cmd) {
 181         case CURLIOCMD_NOP:
 182                 return CURLIOE_OK;
 183
 184         case CURLIOCMD_RESTARTREAD:
 185                 buffer->posn = 0;
 186                 return CURLIOE_OK;
 187
 188         default:
 189                 return CURLIOE_UNKNOWNCMD;
 190         }
 191 }
 192 #endif
 193
 194 size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
 195 {
 196         size_t size = eltsize * nmemb;
 197         struct strbuf *buffer = buffer_;
 198
 199         strbuf_add(buffer, ptr, size);
 200         return size;
 201 }
 202
 203 size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf)
 204 {
 205         return eltsize * nmemb;
 206 }
 207
 208 static void closedown_active_slot(struct active_request_slot *slot)
 209 {
 210         active_requests--;
 211         slot->in_use = 0;
 212 }
 213
 214 static void finish_active_slot(struct active_request_slot *slot)
 215 {
 216         closedown_active_slot(slot);
 217         curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
 218
 219         if (slot->finished != NULL)
 220                 (*slot->finished) = 1;
 221
 222         /* Store slot results so they can be read after the slot is reused */
 223         if (slot->results != NULL) {
 224                 slot->results->curl_result = slot->curl_result;
 225                 slot->results->http_code = slot->http_code;
 226 #if LIBCURL_VERSION_NUM >= 0x070a08
 227                 curl_easy_getinfo(slot->curl, CURLINFO_HTTPAUTH_AVAIL,
 228                                   &slot->results->auth_avail);
 229 #else
 230                 slot->results->auth_avail = 0;
 231 #endif
 232
 233                 curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CONNECTCODE,
 234                         &slot->results->http_connectcode);
 235         }
 236
 237         /* Run callback if appropriate */
 238         if (slot->callback_func != NULL)
 239                 slot->callback_func(slot->callback_data);
 240 }
 241
 242 static void xmulti_remove_handle(struct active_request_slot *slot)
 243 {
 244 #ifdef USE_CURL_MULTI
 245         curl_multi_remove_handle(curlm, slot->curl);
 246 #endif
 247 }
 248
 249 #ifdef USE_CURL_MULTI
 250 static void process_curl_messages(void)
 251 {
 252         int num_messages;
 253         struct active_request_slot *slot;
 254         CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
 255
 256         while (curl_message != NULL) {
 257                 if (curl_message->msg == CURLMSG_DONE) {
 258                         int curl_result = curl_message->data.result;
 259                         slot = active_queue_head;
 260                         while (slot != NULL &&
 261                                slot->curl != curl_message->easy_handle)
 262                                 slot = slot->next;
 263                         if (slot != NULL) {
 264                                 xmulti_remove_handle(slot);
 265                                 slot->curl_result = curl_result;
 266                                 finish_active_slot(slot);
 267                         } else {
 268                                 fprintf(stderr, "Received DONE message for unknown request!\n");
 269                         }
 270                 } else {
 271                         fprintf(stderr, "Unknown CURL message received: %d\n",
 272                                 (int)curl_message->msg);
 273                 }
 274                 curl_message = curl_multi_info_read(curlm, &num_messages);
 275         }
 276 }
 277 #endif
 278
 279 static int http_options(const char *var, const char *value, void *cb)
 280 {
 281         if (!strcmp("http.sslverify", var)) {
 282                 curl_ssl_verify = git_config_bool(var, value);
 283                 return 0;
 284         }
 285         if (!strcmp("http.sslcipherlist", var))
 286                 return git_config_string(&ssl_cipherlist, var, value);
 287         if (!strcmp("http.sslversion", var))
 288                 return git_config_string(&ssl_version, var, value);
 289         if (!strcmp("http.sslcert", var))
 290                 return git_config_pathname(&ssl_cert, var, value);
 291 #if LIBCURL_VERSION_NUM >= 0x070903
 292         if (!strcmp("http.sslkey", var))
 293                 return git_config_pathname(&ssl_key, var, value);
 294 #endif
 295 #if LIBCURL_VERSION_NUM >= 0x070908
 296         if (!strcmp("http.sslcapath", var))
 297                 return git_config_pathname(&ssl_capath, var, value);
 298 #endif
 299         if (!strcmp("http.sslcainfo", var))
 300                 return git_config_pathname(&ssl_cainfo, var, value);
 301         if (!strcmp("http.sslcertpasswordprotected", var)) {
 302                 ssl_cert_password_required = git_config_bool(var, value);
 303                 return 0;
 304         }
 305         if (!strcmp("http.ssltry", var)) {
 306                 curl_ssl_try = git_config_bool(var, value);
 307                 return 0;
 308         }
 309         if (!strcmp("http.sslbackend", var)) {
 310                 free(http_ssl_backend);
 311                 http_ssl_backend = xstrdup_or_null(value);
 312                 return 0;
 313         }
 314
 315         if (!strcmp("http.schannelcheckrevoke", var)) {
 316                 http_schannel_check_revoke = git_config_bool(var, value);
 317                 return 0;
 318         }
 319
 320         if (!strcmp("http.minsessions", var)) {
 321                 min_curl_sessions = git_config_int(var, value);
 322 #ifndef USE_CURL_MULTI
 323                 if (min_curl_sessions > 1)
 324                         min_curl_sessions = 1;
 325 #endif
 326                 return 0;
 327         }
 328 #ifdef USE_CURL_MULTI
 329         if (!strcmp("http.maxrequests", var)) {
 330                 max_requests = git_config_int(var, value);
 331                 return 0;
 332         }
 333 #endif
 334         if (!strcmp("http.lowspeedlimit", var)) {
 335                 curl_low_speed_limit = (long)git_config_int(var, value);
 336                 return 0;
 337         }
 338         if (!strcmp("http.lowspeedtime", var)) {
 339                 curl_low_speed_time = (long)git_config_int(var, value);
 340                 return 0;
 341         }
 342
 343         if (!strcmp("http.noepsv", var)) {
 344                 curl_ftp_no_epsv = git_config_bool(var, value);
 345                 return 0;
 346         }
 347         if (!strcmp("http.proxy", var))
 348                 return git_config_string(&curl_http_proxy, var, value);
 349
 350         if (!strcmp("http.proxyauthmethod", var))
 351                 return git_config_string(&http_proxy_authmethod, var, value);
 352
 353         if (!strcmp("http.cookiefile", var))
 354                 return git_config_pathname(&curl_cookie_file, var, value);
 355         if (!strcmp("http.savecookies", var)) {
 356                 curl_save_cookies = git_config_bool(var, value);
 357                 return 0;
 358         }
 359
 360         if (!strcmp("http.postbuffer", var)) {
 361                 http_post_buffer = git_config_ssize_t(var, value);
 362                 if (http_post_buffer < 0)
 363                         warning(_("negative value for http.postbuffer; defaulting to %d"), LARGE_PACKET_MAX);
 364                 if (http_post_buffer < LARGE_PACKET_MAX)
 365                         http_post_buffer = LARGE_PACKET_MAX;
 366                 return 0;
 367         }
 368
 369         if (!strcmp("http.useragent", var))
 370                 return git_config_string(&user_agent, var, value);
 371
 372         if (!strcmp("http.emptyauth", var)) {
 373                 if (value && !strcmp("auto", value))
 374                         curl_empty_auth = -1;
 375                 else
 376                         curl_empty_auth = git_config_bool(var, value);
 377                 return 0;
 378         }
 379
 380         if (!strcmp("http.delegation", var)) {
 381 #ifdef CURLGSSAPI_DELEGATION_FLAG
 382                 return git_config_string(&curl_deleg, var, value);
 383 #else
 384                 warning(_("Delegation control is not supported with cURL < 7.22.0"));
 385                 return 0;
 386 #endif
 387         }
 388
 389         if (!strcmp("http.pinnedpubkey", var)) {
 390 #if LIBCURL_VERSION_NUM >= 0x072c00
 391                 return git_config_pathname(&ssl_pinnedkey, var, value);
 392 #else
 393                 warning(_("Public key pinning not supported with cURL < 7.44.0"));
 394                 return 0;
 395 #endif
 396         }
 397
 398         if (!strcmp("http.extraheader", var)) {
 399                 if (!value) {
 400                         return config_error_nonbool(var);
 401                 } else if (!*value) {
 402                         curl_slist_free_all(extra_http_headers);
 403                         extra_http_headers = NULL;
 404                 } else {
 405                         extra_http_headers =
 406                                 curl_slist_append(extra_http_headers, value);
 407                 }
 408                 return 0;
 409         }
 410
 411         if (!strcmp("http.followredirects", var)) {
 412                 if (value && !strcmp(value, "initial"))
 413                         http_follow_config = HTTP_FOLLOW_INITIAL;
 414                 else if (git_config_bool(var, value))
 415                         http_follow_config = HTTP_FOLLOW_ALWAYS;
 416                 else
 417                         http_follow_config = HTTP_FOLLOW_NONE;
 418                 return 0;
 419         }
 420
 421         /* Fall back on the default ones */
 422         return git_default_config(var, value, cb);
 423 }
 424
 425 static int curl_empty_auth_enabled(void)
 426 {
 427         if (curl_empty_auth >= 0)
 428                 return curl_empty_auth;
 429
 430 #ifndef LIBCURL_CAN_HANDLE_AUTH_ANY
 431         /*
 432          * Our libcurl is too old to do AUTH_ANY in the first place;
 433          * just default to turning the feature off.
 434          */
 435 #else
 436         /*
 437          * In the automatic case, kick in the empty-auth
 438          * hack as long as we would potentially try some
 439          * method more exotic than "Basic" or "Digest".
 440          *
 441          * But only do this when this is our second or
 442          * subsequent request, as by then we know what
 443          * methods are available.
 444          */
 445         if (http_auth_methods_restricted &&
 446             (http_auth_methods & ~empty_auth_useless))
 447                 return 1;
 448 #endif
 449         return 0;
 450 }
 451
 452 static void init_curl_http_auth(CURL *result)
 453 {
 454         if (!http_auth.username || !*http_auth.username) {
 455                 if (curl_empty_auth_enabled())
 456                         curl_easy_setopt(result, CURLOPT_USERPWD, ":");
 457                 return;
 458         }
 459
 460         credential_fill(&http_auth);
 461
 462 #if LIBCURL_VERSION_NUM >= 0x071301
 463         curl_easy_setopt(result, CURLOPT_USERNAME, http_auth.username);
 464         curl_easy_setopt(result, CURLOPT_PASSWORD, http_auth.password);
 465 #else
 466         {
 467                 static struct strbuf up = STRBUF_INIT;
 468                 /*
 469                  * Note that we assume we only ever have a single set of
 470                  * credentials in a given program run, so we do not have
 471                  * to worry about updating this buffer, only setting its
 472                  * initial value.
 473                  */
 474                 if (!up.len)
 475                         strbuf_addf(&up, "%s:%s",
 476                                 http_auth.username, http_auth.password);
 477                 curl_easy_setopt(result, CURLOPT_USERPWD, up.buf);
 478         }
 479 #endif
 480 }
 481
 482 /* *var must be free-able */
 483 static void var_override(const char **var, char *value)
 484 {
 485         if (value) {
 486                 free((void *)*var);
 487                 *var = xstrdup(value);
 488         }
 489 }
 490
 491 static void set_proxyauth_name_password(CURL *result)
 492 {
 493 #if LIBCURL_VERSION_NUM >= 0x071301
 494                 curl_easy_setopt(result, CURLOPT_PROXYUSERNAME,
 495                         proxy_auth.username);
 496                 curl_easy_setopt(result, CURLOPT_PROXYPASSWORD,
 497                         proxy_auth.password);
 498 #else
 499                 struct strbuf s = STRBUF_INIT;
 500
 501                 strbuf_addstr_urlencode(&s, proxy_auth.username, 1);
 502                 strbuf_addch(&s, ':');
 503                 strbuf_addstr_urlencode(&s, proxy_auth.password, 1);
 504                 curl_proxyuserpwd = strbuf_detach(&s, NULL);
 505                 curl_easy_setopt(result, CURLOPT_PROXYUSERPWD, curl_proxyuserpwd);
 506 #endif
 507 }
 508
 509 static void init_curl_proxy_auth(CURL *result)
 510 {
 511         if (proxy_auth.username) {
 512                 if (!proxy_auth.password)
 513                         credential_fill(&proxy_auth);
 514                 set_proxyauth_name_password(result);
 515         }
 516
 517         var_override(&http_proxy_authmethod, getenv("GIT_HTTP_PROXY_AUTHMETHOD"));
 518
 519 #if LIBCURL_VERSION_NUM >= 0x070a07 /* CURLOPT_PROXYAUTH and CURLAUTH_ANY */
 520         if (http_proxy_authmethod) {
 521                 int i;
 522                 for (i = 0; i < ARRAY_SIZE(proxy_authmethods); i++) {
 523                         if (!strcmp(http_proxy_authmethod, proxy_authmethods[i].name)) {
 524                                 curl_easy_setopt(result, CURLOPT_PROXYAUTH,
 525                                                 proxy_authmethods[i].curlauth_param);
 526                                 break;
 527                         }
 528                 }
 529                 if (i == ARRAY_SIZE(proxy_authmethods)) {
 530                         warning("unsupported proxy authentication method %s: using anyauth",
 531                                         http_proxy_authmethod);
 532                         curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
 533                 }
 534         }
 535         else
 536                 curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
 537 #endif
 538 }
 539
 540 static int has_cert_password(void)
 541 {
 542         if (ssl_cert == NULL || ssl_cert_password_required != 1)
 543                 return 0;
 544         if (!cert_auth.password) {
 545                 cert_auth.protocol = xstrdup("cert");
 546                 cert_auth.username = xstrdup("");
 547                 cert_auth.path = xstrdup(ssl_cert);
 548                 credential_fill(&cert_auth);
 549         }
 550         return 1;
 551 }
 552
 553 #if LIBCURL_VERSION_NUM >= 0x071900
 554 static void set_curl_keepalive(CURL *c)
 555 {
 556         curl_easy_setopt(c, CURLOPT_TCP_KEEPALIVE, 1);
 557 }
 558
 559 #elif LIBCURL_VERSION_NUM >= 0x071000
 560 static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
 561 {
 562         int ka = 1;
 563         int rc;
 564         socklen_t len = (socklen_t)sizeof(ka);
 565
 566         if (type != CURLSOCKTYPE_IPCXN)
 567                 return 0;
 568
 569         rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
 570         if (rc < 0)
 571                 warning_errno("unable to set SO_KEEPALIVE on socket");
 572
 573         return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
 574 }
 575
 576 static void set_curl_keepalive(CURL *c)
 577 {
 578         curl_easy_setopt(c, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
 579 }
 580
 581 #else
 582 static void set_curl_keepalive(CURL *c)
 583 {
 584         /* not supported on older curl versions */
 585 }
 586 #endif
 587
 588 static void redact_sensitive_header(struct strbuf *header)
 589 {
 590         const char *sensitive_header;
 591
 592         if (skip_prefix(header->buf, "Authorization:", &sensitive_header) ||
 593             skip_prefix(header->buf, "Proxy-Authorization:", &sensitive_header)) {
 594                 /* The first token is the type, which is OK to log */
 595                 while (isspace(*sensitive_header))
 596                         sensitive_header++;
 597                 while (*sensitive_header && !isspace(*sensitive_header))
 598                         sensitive_header++;
 599                 /* Everything else is opaque and possibly sensitive */
 600                 strbuf_setlen(header,  sensitive_header - header->buf);
 601                 strbuf_addstr(header, " <redacted>");
 602         } else if (cookies_to_redact.nr &&
 603                    skip_prefix(header->buf, "Cookie:", &sensitive_header)) {
 604                 struct strbuf redacted_header = STRBUF_INIT;
 605                 char *cookie;
 606
 607                 while (isspace(*sensitive_header))
 608                         sensitive_header++;
 609
 610                 /*
 611                  * The contents of header starting from sensitive_header will
 612                  * subsequently be overridden, so it is fine to mutate this
 613                  * string (hence the assignment to "char *").
 614                  */
 615                 cookie = (char *) sensitive_header;
 616
 617                 while (cookie) {
 618                         char *equals;
 619                         char *semicolon = strstr(cookie, "; ");
 620                         if (semicolon)
 621                                 *semicolon = 0;
 622                         equals = strchrnul(cookie, '=');
 623                         if (!equals) {
 624                                 /* invalid cookie, just append and continue */
 625                                 strbuf_addstr(&redacted_header, cookie);
 626                                 continue;
 627                         }
 628                         *equals = 0; /* temporarily set to NUL for lookup */
 629                         if (string_list_lookup(&cookies_to_redact, cookie)) {
 630                                 strbuf_addstr(&redacted_header, cookie);
 631                                 strbuf_addstr(&redacted_header, "=<redacted>");
 632                         } else {
 633                                 *equals = '=';
 634                                 strbuf_addstr(&redacted_header, cookie);
 635                         }
 636                         if (semicolon) {
 637                                 /*
 638                                  * There are more cookies. (Or, for some
 639                                  * reason, the input string ends in "; ".)
 640                                  */
 641                                 strbuf_addstr(&redacted_header, "; ");
 642                                 cookie = semicolon + strlen("; ");
 643                         } else {
 644                                 cookie = NULL;
 645                         }
 646                 }
 647
 648                 strbuf_setlen(header, sensitive_header - header->buf);
 649                 strbuf_addbuf(header, &redacted_header);
 650         }
 651 }
 652
 653 static void curl_dump_header(const char *text, unsigned char *ptr, size_t size, int hide_sensitive_header)
 654 {
 655         struct strbuf out = STRBUF_INIT;
 656         struct strbuf **headers, **header;
 657
 658         strbuf_addf(&out, "%s, %10.10ld bytes (0x%8.8lx)\n",
 659                 text, (long)size, (long)size);
 660         trace_strbuf(&trace_curl, &out);
 661         strbuf_reset(&out);
 662         strbuf_add(&out, ptr, size);
 663         headers = strbuf_split_max(&out, '\n', 0);
 664
 665         for (header = headers; *header; header++) {
 666                 if (hide_sensitive_header)
 667                         redact_sensitive_header(*header);
 668                 strbuf_insert((*header), 0, text, strlen(text));
 669                 strbuf_insert((*header), strlen(text), ": ", 2);
 670                 strbuf_rtrim((*header));
 671                 strbuf_addch((*header), '\n');
 672                 trace_strbuf(&trace_curl, (*header));
 673         }
 674         strbuf_list_free(headers);
 675         strbuf_release(&out);
 676 }
 677
 678 static void curl_dump_data(const char *text, unsigned char *ptr, size_t size)
 679 {
 680         size_t i;
 681         struct strbuf out = STRBUF_INIT;
 682         unsigned int width = 60;
 683
 684         strbuf_addf(&out, "%s, %10.10ld bytes (0x%8.8lx)\n",
 685                 text, (long)size, (long)size);
 686         trace_strbuf(&trace_curl, &out);
 687
 688         for (i = 0; i < size; i += width) {
 689                 size_t w;
 690
 691                 strbuf_reset(&out);
 692                 strbuf_addf(&out, "%s: ", text);
 693                 for (w = 0; (w < width) && (i + w < size); w++) {
 694                         unsigned char ch = ptr[i + w];
 695
 696                         strbuf_addch(&out,
 697                                        (ch >= 0x20) && (ch < 0x80)
 698                                        ? ch : '.');
 699                 }
 700                 strbuf_addch(&out, '\n');
 701                 trace_strbuf(&trace_curl, &out);
 702         }
 703         strbuf_release(&out);
 704 }
 705
 706 static int curl_trace(CURL *handle, curl_infotype type, char *data, size_t size, void *userp)
 707 {
 708         const char *text;
 709         enum { NO_FILTER = 0, DO_FILTER = 1 };
 710
 711         switch (type) {
 712         case CURLINFO_TEXT:
 713                 trace_printf_key(&trace_curl, "== Info: %s", data);
 714                 break;
 715         case CURLINFO_HEADER_OUT:
 716                 text = "=> Send header";
 717                 curl_dump_header(text, (unsigned char *)data, size, DO_FILTER);
 718                 break;
 719         case CURLINFO_DATA_OUT:
 720                 if (trace_curl_data) {
 721                         text = "=> Send data";
 722                         curl_dump_data(text, (unsigned char *)data, size);
 723                 }
 724                 break;
 725         case CURLINFO_SSL_DATA_OUT:
 726                 if (trace_curl_data) {
 727                         text = "=> Send SSL data";
 728                         curl_dump_data(text, (unsigned char *)data, size);
 729                 }
 730                 break;
 731         case CURLINFO_HEADER_IN:
 732                 text = "<= Recv header";
 733                 curl_dump_header(text, (unsigned char *)data, size, NO_FILTER);
 734                 break;
 735         case CURLINFO_DATA_IN:
 736                 if (trace_curl_data) {
 737                         text = "<= Recv data";
 738                         curl_dump_data(text, (unsigned char *)data, size);
 739                 }
 740                 break;
 741         case CURLINFO_SSL_DATA_IN:
 742                 if (trace_curl_data) {
 743                         text = "<= Recv SSL data";
 744                         curl_dump_data(text, (unsigned char *)data, size);
 745                 }
 746                 break;
 747
 748         default:                /* we ignore unknown types by default */
 749                 return 0;
 750         }
 751         return 0;
 752 }
 753
 754 void setup_curl_trace(CURL *handle)
 755 {
 756         if (!trace_want(&trace_curl))
 757                 return;
 758         curl_easy_setopt(handle, CURLOPT_VERBOSE, 1L);
 759         curl_easy_setopt(handle, CURLOPT_DEBUGFUNCTION, curl_trace);
 760         curl_easy_setopt(handle, CURLOPT_DEBUGDATA, NULL);
 761 }
 762
 763 #ifdef CURLPROTO_HTTP
 764 static long get_curl_allowed_protocols(int from_user)
 765 {
 766         long allowed_protocols = 0;
 767
 768         if (is_transport_allowed("http", from_user))
 769                 allowed_protocols |= CURLPROTO_HTTP;
 770         if (is_transport_allowed("https", from_user))
 771                 allowed_protocols |= CURLPROTO_HTTPS;
 772         if (is_transport_allowed("ftp", from_user))
 773                 allowed_protocols |= CURLPROTO_FTP;
 774         if (is_transport_allowed("ftps", from_user))
 775                 allowed_protocols |= CURLPROTO_FTPS;
 776
 777         return allowed_protocols;
 778 }
 779 #endif
 780
 781 static CURL *get_curl_handle(void)
 782 {
 783         CURL *result = curl_easy_init();
 784
 785         if (!result)
 786                 die("curl_easy_init failed");
 787
 788         if (!curl_ssl_verify) {
 789                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
 790                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
 791         } else {
 792                 /* Verify authenticity of the peer's certificate */
 793                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
 794                 /* The name in the cert must match whom we tried to connect */
 795                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
 796         }
 797
 798 #if LIBCURL_VERSION_NUM >= 0x070907
 799         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
 800 #endif
 801 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 802         curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
 803 #endif
 804
 805 #ifdef CURLGSSAPI_DELEGATION_FLAG
 806         if (curl_deleg) {
 807                 int i;
 808                 for (i = 0; i < ARRAY_SIZE(curl_deleg_levels); i++) {
 809                         if (!strcmp(curl_deleg, curl_deleg_levels[i].name)) {
 810                                 curl_easy_setopt(result, CURLOPT_GSSAPI_DELEGATION,
 811                                                 curl_deleg_levels[i].curl_deleg_param);
 812                                 break;
 813                         }
 814                 }
 815                 if (i == ARRAY_SIZE(curl_deleg_levels))
 816                         warning("Unknown delegation method '%s': using default",
 817                                 curl_deleg);
 818         }
 819 #endif
 820
 821         if (http_ssl_backend && !strcmp("schannel", http_ssl_backend) &&
 822             !http_schannel_check_revoke) {
 823 #if LIBCURL_VERSION_NUM >= 0x072c00
 824                 curl_easy_setopt(result, CURLOPT_SSL_OPTIONS, CURLSSLOPT_NO_REVOKE);
 825 #else
 826                 warning("CURLSSLOPT_NO_REVOKE not applied to curl SSL options because\n"
 827                         "your curl version is too old (< 7.44.0)");
 828 #endif
 829         }
 830
 831         if (http_proactive_auth)
 832                 init_curl_http_auth(result);
 833
 834         if (getenv("GIT_SSL_VERSION"))
 835                 ssl_version = getenv("GIT_SSL_VERSION");
 836         if (ssl_version && *ssl_version) {
 837                 int i;
 838                 for (i = 0; i < ARRAY_SIZE(sslversions); i++) {
 839                         if (!strcmp(ssl_version, sslversions[i].name)) {
 840                                 curl_easy_setopt(result, CURLOPT_SSLVERSION,
 841                                                  sslversions[i].ssl_version);
 842                                 break;
 843                         }
 844                 }
 845                 if (i == ARRAY_SIZE(sslversions))
 846                         warning("unsupported ssl version %s: using default",
 847                                 ssl_version);
 848         }
 849
 850         if (getenv("GIT_SSL_CIPHER_LIST"))
 851                 ssl_cipherlist = getenv("GIT_SSL_CIPHER_LIST");
 852         if (ssl_cipherlist != NULL && *ssl_cipherlist)
 853                 curl_easy_setopt(result, CURLOPT_SSL_CIPHER_LIST,
 854                                 ssl_cipherlist);
 855
 856         if (ssl_cert != NULL)
 857                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
 858         if (has_cert_password())
 859                 curl_easy_setopt(result, CURLOPT_KEYPASSWD, cert_auth.password);
 860 #if LIBCURL_VERSION_NUM >= 0x070903
 861         if (ssl_key != NULL)
 862                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
 863 #endif
 864 #if LIBCURL_VERSION_NUM >= 0x070908
 865         if (ssl_capath != NULL)
 866                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
 867 #endif
 868 #if LIBCURL_VERSION_NUM >= 0x072c00
 869         if (ssl_pinnedkey != NULL)
 870                 curl_easy_setopt(result, CURLOPT_PINNEDPUBLICKEY, ssl_pinnedkey);
 871 #endif
 872         if (ssl_cainfo != NULL)
 873                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
 874
 875         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
 876                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
 877                                  curl_low_speed_limit);
 878                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
 879                                  curl_low_speed_time);
 880         }
 881
 882         curl_easy_setopt(result, CURLOPT_MAXREDIRS, 20);
 883 #if LIBCURL_VERSION_NUM >= 0x071301
 884         curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
 885 #elif LIBCURL_VERSION_NUM >= 0x071101
 886         curl_easy_setopt(result, CURLOPT_POST301, 1);
 887 #endif
 888 #ifdef CURLPROTO_HTTP
 889         curl_easy_setopt(result, CURLOPT_REDIR_PROTOCOLS,
 890                          get_curl_allowed_protocols(0));
 891         curl_easy_setopt(result, CURLOPT_PROTOCOLS,
 892                          get_curl_allowed_protocols(-1));
 893 #else
 894         warning("protocol restrictions not applied to curl redirects because\n"
 895                 "your curl version is too old (>= 7.19.4)");
 896 #endif
 897         if (getenv("GIT_CURL_VERBOSE"))
 898                 curl_easy_setopt(result, CURLOPT_VERBOSE, 1L);
 899         setup_curl_trace(result);
 900         if (getenv("GIT_TRACE_CURL_NO_DATA"))
 901                 trace_curl_data = 0;
 902         if (getenv("GIT_REDACT_COOKIES")) {
 903                 string_list_split(&cookies_to_redact,
 904                                   getenv("GIT_REDACT_COOKIES"), ',', -1);
 905                 string_list_sort(&cookies_to_redact);
 906         }
 907
 908         curl_easy_setopt(result, CURLOPT_USERAGENT,
 909                 user_agent ? user_agent : git_user_agent());
 910
 911         if (curl_ftp_no_epsv)
 912                 curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
 913
 914 #ifdef CURLOPT_USE_SSL
 915         if (curl_ssl_try)
 916                 curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
 917 #endif
 918
 919         /*
 920          * CURL also examines these variables as a fallback; but we need to query
 921          * them here in order to decide whether to prompt for missing password (cf.
 922          * init_curl_proxy_auth()).
 923          *
 924          * Unlike many other common environment variables, these are historically
 925          * lowercase only. It appears that CURL did not know this and implemented
 926          * only uppercase variants, which was later corrected to take both - with
 927          * the exception of http_proxy, which is lowercase only also in CURL. As
 928          * the lowercase versions are the historical quasi-standard, they take
 929          * precedence here, as in CURL.
 930          */
 931         if (!curl_http_proxy) {
 932                 if (http_auth.protocol && !strcmp(http_auth.protocol, "https")) {
 933                         var_override(&curl_http_proxy, getenv("HTTPS_PROXY"));
 934                         var_override(&curl_http_proxy, getenv("https_proxy"));
 935                 } else {
 936                         var_override(&curl_http_proxy, getenv("http_proxy"));
 937                 }
 938                 if (!curl_http_proxy) {
 939                         var_override(&curl_http_proxy, getenv("ALL_PROXY"));
 940                         var_override(&curl_http_proxy, getenv("all_proxy"));
 941                 }
 942         }
 943
 944         if (curl_http_proxy && curl_http_proxy[0] == '\0') {
 945                 /*
 946                  * Handle case with the empty http.proxy value here to keep
 947                  * common code clean.
 948                  * NB: empty option disables proxying at all.
 949                  */
 950                 curl_easy_setopt(result, CURLOPT_PROXY, "");
 951         } else if (curl_http_proxy) {
 952 #if LIBCURL_VERSION_NUM >= 0x071800
 953                 if (starts_with(curl_http_proxy, "socks5h"))
 954                         curl_easy_setopt(result,
 955                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5_HOSTNAME);
 956                 else if (starts_with(curl_http_proxy, "socks5"))
 957                         curl_easy_setopt(result,
 958                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);
 959                 else if (starts_with(curl_http_proxy, "socks4a"))
 960                         curl_easy_setopt(result,
 961                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4A);
 962                 else if (starts_with(curl_http_proxy, "socks"))
 963                         curl_easy_setopt(result,
 964                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4);
 965 #endif
 966 #if LIBCURL_VERSION_NUM >= 0x073400
 967                 else if (starts_with(curl_http_proxy, "https"))
 968                         curl_easy_setopt(result,
 969                                 CURLOPT_PROXYTYPE, CURLPROXY_HTTPS);
 970 #endif
 971                 if (strstr(curl_http_proxy, "://"))
 972                         credential_from_url(&proxy_auth, curl_http_proxy);
 973                 else {
 974                         struct strbuf url = STRBUF_INIT;
 975                         strbuf_addf(&url, "http://%s", curl_http_proxy);
 976                         credential_from_url(&proxy_auth, url.buf);
 977                         strbuf_release(&url);
 978                 }
 979
 980                 if (!proxy_auth.host)
 981                         die("Invalid proxy URL '%s'", curl_http_proxy);
 982
 983                 curl_easy_setopt(result, CURLOPT_PROXY, proxy_auth.host);
 984 #if LIBCURL_VERSION_NUM >= 0x071304
 985                 var_override(&curl_no_proxy, getenv("NO_PROXY"));
 986                 var_override(&curl_no_proxy, getenv("no_proxy"));
 987                 curl_easy_setopt(result, CURLOPT_NOPROXY, curl_no_proxy);
 988 #endif
 989         }
 990         init_curl_proxy_auth(result);
 991
 992         set_curl_keepalive(result);
 993
 994         return result;
 995 }
 996
 997 static void set_from_env(const char **var, const char *envname)
 998 {
 999         const char *val = getenv(envname);
1000         if (val)
1001                 *var = val;
1002 }
1003
1004 void http_init(struct remote *remote, const char *url, int proactive_auth)
1005 {
1006         char *low_speed_limit;
1007         char *low_speed_time;
1008         char *normalized_url;
1009         struct urlmatch_config config = { STRING_LIST_INIT_DUP };
1010
1011         config.section = "http";
1012         config.key = NULL;
1013         config.collect_fn = http_options;
1014         config.cascade_fn = git_default_config;
1015         config.cb = NULL;
1016
1017         http_is_verbose = 0;
1018         normalized_url = url_normalize(url, &config.url);
1019
1020         git_config(urlmatch_config_entry, &config);
1021         free(normalized_url);
1022
1023 #if LIBCURL_VERSION_NUM >= 0x073800
1024         if (http_ssl_backend) {
1025                 const curl_ssl_backend **backends;
1026                 struct strbuf buf = STRBUF_INIT;
1027                 int i;
1028
1029                 switch (curl_global_sslset(-1, http_ssl_backend, &backends)) {
1030                 case CURLSSLSET_UNKNOWN_BACKEND:
1031                         strbuf_addf(&buf, _("Unsupported SSL backend '%s'. "
1032                                             "Supported SSL backends:"),
1033                                             http_ssl_backend);
1034                         for (i = 0; backends[i]; i++)
1035                                 strbuf_addf(&buf, "\n\t%s", backends[i]->name);
1036                         die("%s", buf.buf);
1037                 case CURLSSLSET_NO_BACKENDS:
1038                         die(_("Could not set SSL backend to '%s': "
1039                               "cURL was built without SSL backends"),
1040                             http_ssl_backend);
1041                 case CURLSSLSET_TOO_LATE:
1042                         die(_("Could not set SSL backend to '%s': already set"),
1043                             http_ssl_backend);
1044                 case CURLSSLSET_OK:
1045                         break; /* Okay! */
1046                 }
1047         }
1048 #endif
1049
1050         if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK)
1051                 die("curl_global_init failed");
1052
1053         http_proactive_auth = proactive_auth;
1054
1055         if (remote && remote->http_proxy)
1056                 curl_http_proxy = xstrdup(remote->http_proxy);
1057
1058         if (remote)
1059                 var_override(&http_proxy_authmethod, remote->http_proxy_authmethod);
1060
1061         pragma_header = curl_slist_append(http_copy_default_headers(),
1062                 "Pragma: no-cache");
1063         no_pragma_header = curl_slist_append(http_copy_default_headers(),
1064                 "Pragma:");
1065
1066 #ifdef USE_CURL_MULTI
1067         {
1068                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
1069                 if (http_max_requests != NULL)
1070                         max_requests = atoi(http_max_requests);
1071         }
1072
1073         curlm = curl_multi_init();
1074         if (!curlm)
1075                 die("curl_multi_init failed");
1076 #endif
1077
1078         if (getenv("GIT_SSL_NO_VERIFY"))
1079                 curl_ssl_verify = 0;
1080
1081         set_from_env(&ssl_cert, "GIT_SSL_CERT");
1082 #if LIBCURL_VERSION_NUM >= 0x070903
1083         set_from_env(&ssl_key, "GIT_SSL_KEY");
1084 #endif
1085 #if LIBCURL_VERSION_NUM >= 0x070908
1086         set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
1087 #endif
1088         set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
1089
1090         set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");
1091
1092         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
1093         if (low_speed_limit != NULL)
1094                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
1095         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
1096         if (low_speed_time != NULL)
1097                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
1098
1099         if (curl_ssl_verify == -1)
1100                 curl_ssl_verify = 1;
1101
1102         curl_session_count = 0;
1103 #ifdef USE_CURL_MULTI
1104         if (max_requests < 1)
1105                 max_requests = DEFAULT_MAX_REQUESTS;
1106 #endif
1107
1108         if (getenv("GIT_CURL_FTP_NO_EPSV"))
1109                 curl_ftp_no_epsv = 1;
1110
1111         if (url) {
1112                 credential_from_url(&http_auth, url);
1113                 if (!ssl_cert_password_required &&
1114                     getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
1115                     starts_with(url, "https://"))
1116                         ssl_cert_password_required = 1;
1117         }
1118
1119 #ifndef NO_CURL_EASY_DUPHANDLE
1120         curl_default = get_curl_handle();
1121 #endif
1122 }
1123
1124 void http_cleanup(void)
1125 {
1126         struct active_request_slot *slot = active_queue_head;
1127
1128         while (slot != NULL) {
1129                 struct active_request_slot *next = slot->next;
1130                 if (slot->curl != NULL) {
1131                         xmulti_remove_handle(slot);
1132                         curl_easy_cleanup(slot->curl);
1133                 }
1134                 free(slot);
1135                 slot = next;
1136         }
1137         active_queue_head = NULL;
1138
1139 #ifndef NO_CURL_EASY_DUPHANDLE
1140         curl_easy_cleanup(curl_default);
1141 #endif
1142
1143 #ifdef USE_CURL_MULTI
1144         curl_multi_cleanup(curlm);
1145 #endif
1146         curl_global_cleanup();
1147
1148         curl_slist_free_all(extra_http_headers);
1149         extra_http_headers = NULL;
1150
1151         curl_slist_free_all(pragma_header);
1152         pragma_header = NULL;
1153
1154         curl_slist_free_all(no_pragma_header);
1155         no_pragma_header = NULL;
1156
1157         if (curl_http_proxy) {
1158                 free((void *)curl_http_proxy);
1159                 curl_http_proxy = NULL;
1160         }
1161
1162         if (proxy_auth.password) {
1163                 memset(proxy_auth.password, 0, strlen(proxy_auth.password));
1164                 FREE_AND_NULL(proxy_auth.password);
1165         }
1166
1167         free((void *)curl_proxyuserpwd);
1168         curl_proxyuserpwd = NULL;
1169
1170         free((void *)http_proxy_authmethod);
1171         http_proxy_authmethod = NULL;
1172
1173         if (cert_auth.password != NULL) {
1174                 memset(cert_auth.password, 0, strlen(cert_auth.password));
1175                 FREE_AND_NULL(cert_auth.password);
1176         }
1177         ssl_cert_password_required = 0;
1178
1179         FREE_AND_NULL(cached_accept_language);
1180 }
1181
1182 struct active_request_slot *get_active_slot(void)
1183 {
1184         struct active_request_slot *slot = active_queue_head;
1185         struct active_request_slot *newslot;
1186
1187 #ifdef USE_CURL_MULTI
1188         int num_transfers;
1189
1190         /* Wait for a slot to open up if the queue is full */
1191         while (active_requests >= max_requests) {
1192                 curl_multi_perform(curlm, &num_transfers);
1193                 if (num_transfers < active_requests)
1194                         process_curl_messages();
1195         }
1196 #endif
1197
1198         while (slot != NULL && slot->in_use)
1199                 slot = slot->next;
1200
1201         if (slot == NULL) {
1202                 newslot = xmalloc(sizeof(*newslot));
1203                 newslot->curl = NULL;
1204                 newslot->in_use = 0;
1205                 newslot->next = NULL;
1206
1207                 slot = active_queue_head;
1208                 if (slot == NULL) {
1209                         active_queue_head = newslot;
1210                 } else {
1211                         while (slot->next != NULL)
1212                                 slot = slot->next;
1213                         slot->next = newslot;
1214                 }
1215                 slot = newslot;
1216         }
1217
1218         if (slot->curl == NULL) {
1219 #ifdef NO_CURL_EASY_DUPHANDLE
1220                 slot->curl = get_curl_handle();
1221 #else
1222                 slot->curl = curl_easy_duphandle(curl_default);
1223 #endif
1224                 curl_session_count++;
1225         }
1226
1227         active_requests++;
1228         slot->in_use = 1;
1229         slot->results = NULL;
1230         slot->finished = NULL;
1231         slot->callback_data = NULL;
1232         slot->callback_func = NULL;
1233         curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file);
1234         if (curl_save_cookies)
1235                 curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file);
1236         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
1237         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
1238         curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
1239         curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
1240         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
1241         curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
1242         curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
1243         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1244         curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
1245         curl_easy_setopt(slot->curl, CURLOPT_RANGE, NULL);
1246
1247         /*
1248          * Default following to off unless "ALWAYS" is configured; this gives
1249          * callers a sane starting point, and they can tweak for individual
1250          * HTTP_FOLLOW_* cases themselves.
1251          */
1252         if (http_follow_config == HTTP_FOLLOW_ALWAYS)
1253                 curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 1);
1254         else
1255                 curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 0);
1256
1257 #if LIBCURL_VERSION_NUM >= 0x070a08
1258         curl_easy_setopt(slot->curl, CURLOPT_IPRESOLVE, git_curl_ipresolve);
1259 #endif
1260 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
1261         curl_easy_setopt(slot->curl, CURLOPT_HTTPAUTH, http_auth_methods);
1262 #endif
1263         if (http_auth.password || curl_empty_auth_enabled())
1264                 init_curl_http_auth(slot->curl);
1265
1266         return slot;
1267 }
1268
1269 int start_active_slot(struct active_request_slot *slot)
1270 {
1271 #ifdef USE_CURL_MULTI
1272         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
1273         int num_transfers;
1274
1275         if (curlm_result != CURLM_OK &&
1276             curlm_result != CURLM_CALL_MULTI_PERFORM) {
1277                 warning("curl_multi_add_handle failed: %s",
1278                         curl_multi_strerror(curlm_result));
1279                 active_requests--;
1280                 slot->in_use = 0;
1281                 return 0;
1282         }
1283
1284         /*
1285          * We know there must be something to do, since we just added
1286          * something.
1287          */
1288         curl_multi_perform(curlm, &num_transfers);
1289 #endif
1290         return 1;
1291 }
1292
1293 #ifdef USE_CURL_MULTI
1294 struct fill_chain {
1295         void *data;
1296         int (*fill)(void *);
1297         struct fill_chain *next;
1298 };
1299
1300 static struct fill_chain *fill_cfg;
1301
1302 void add_fill_function(void *data, int (*fill)(void *))
1303 {
1304         struct fill_chain *new_fill = xmalloc(sizeof(*new_fill));
1305         struct fill_chain **linkp = &fill_cfg;
1306         new_fill->data = data;
1307         new_fill->fill = fill;
1308         new_fill->next = NULL;
1309         while (*linkp)
1310                 linkp = &(*linkp)->next;
1311         *linkp = new_fill;
1312 }
1313
1314 void fill_active_slots(void)
1315 {
1316         struct active_request_slot *slot = active_queue_head;
1317
1318         while (active_requests < max_requests) {
1319                 struct fill_chain *fill;
1320                 for (fill = fill_cfg; fill; fill = fill->next)
1321                         if (fill->fill(fill->data))
1322                                 break;
1323
1324                 if (!fill)
1325                         break;
1326         }
1327
1328         while (slot != NULL) {
1329                 if (!slot->in_use && slot->curl != NULL
1330                         && curl_session_count > min_curl_sessions) {
1331                         curl_easy_cleanup(slot->curl);
1332                         slot->curl = NULL;
1333                         curl_session_count--;
1334                 }
1335                 slot = slot->next;
1336         }
1337 }
1338
1339 void step_active_slots(void)
1340 {
1341         int num_transfers;
1342         CURLMcode curlm_result;
1343
1344         do {
1345                 curlm_result = curl_multi_perform(curlm, &num_transfers);
1346         } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
1347         if (num_transfers < active_requests) {
1348                 process_curl_messages();
1349                 fill_active_slots();
1350         }
1351 }
1352 #endif
1353
1354 void run_active_slot(struct active_request_slot *slot)
1355 {
1356 #ifdef USE_CURL_MULTI
1357         fd_set readfds;
1358         fd_set writefds;
1359         fd_set excfds;
1360         int max_fd;
1361         struct timeval select_timeout;
1362         int finished = 0;
1363
1364         slot->finished = &finished;
1365         while (!finished) {
1366                 step_active_slots();
1367
1368                 if (slot->in_use) {
1369 #if LIBCURL_VERSION_NUM >= 0x070f04
1370                         long curl_timeout;
1371                         curl_multi_timeout(curlm, &curl_timeout);
1372                         if (curl_timeout == 0) {
1373                                 continue;
1374                         } else if (curl_timeout == -1) {
1375                                 select_timeout.tv_sec  = 0;
1376                                 select_timeout.tv_usec = 50000;
1377                         } else {
1378                                 select_timeout.tv_sec  =  curl_timeout / 1000;
1379                                 select_timeout.tv_usec = (curl_timeout % 1000) * 1000;
1380                         }
1381 #else
1382                         select_timeout.tv_sec  = 0;
1383                         select_timeout.tv_usec = 50000;
1384 #endif
1385
1386                         max_fd = -1;
1387                         FD_ZERO(&readfds);
1388                         FD_ZERO(&writefds);
1389                         FD_ZERO(&excfds);
1390                         curl_multi_fdset(curlm, &readfds, &writefds, &excfds, &max_fd);
1391
1392                         /*
1393                          * It can happen that curl_multi_timeout returns a pathologically
1394                          * long timeout when curl_multi_fdset returns no file descriptors
1395                          * to read.  See commit message for more details.
1396                          */
1397                         if (max_fd < 0 &&
1398                             (select_timeout.tv_sec > 0 ||
1399                              select_timeout.tv_usec > 50000)) {
1400                                 select_timeout.tv_sec  = 0;
1401                                 select_timeout.tv_usec = 50000;
1402                         }
1403
1404                         select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
1405                 }
1406         }
1407 #else
1408         while (slot->in_use) {
1409                 slot->curl_result = curl_easy_perform(slot->curl);
1410                 finish_active_slot(slot);
1411         }
1412 #endif
1413 }
1414
1415 static void release_active_slot(struct active_request_slot *slot)
1416 {
1417         closedown_active_slot(slot);
1418         if (slot->curl) {
1419                 xmulti_remove_handle(slot);
1420                 if (curl_session_count > min_curl_sessions) {
1421                         curl_easy_cleanup(slot->curl);
1422                         slot->curl = NULL;
1423                         curl_session_count--;
1424                 }
1425         }
1426 #ifdef USE_CURL_MULTI
1427         fill_active_slots();
1428 #endif
1429 }
1430
1431 void finish_all_active_slots(void)
1432 {
1433         struct active_request_slot *slot = active_queue_head;
1434
1435         while (slot != NULL)
1436                 if (slot->in_use) {
1437                         run_active_slot(slot);
1438                         slot = active_queue_head;
1439                 } else {
1440                         slot = slot->next;
1441                 }
1442 }
1443
1444 /* Helpers for modifying and creating URLs */
1445 static inline int needs_quote(int ch)
1446 {
1447         if (((ch >= 'A') && (ch <= 'Z'))
1448                         || ((ch >= 'a') && (ch <= 'z'))
1449                         || ((ch >= '0') && (ch <= '9'))
1450                         || (ch == '/')
1451                         || (ch == '-')
1452                         || (ch == '.'))
1453                 return 0;
1454         return 1;
1455 }
1456
1457 static char *quote_ref_url(const char *base, const char *ref)
1458 {
1459         struct strbuf buf = STRBUF_INIT;
1460         const char *cp;
1461         int ch;
1462
1463         end_url_with_slash(&buf, base);
1464
1465         for (cp = ref; (ch = *cp) != 0; cp++)
1466                 if (needs_quote(ch))
1467                         strbuf_addf(&buf, "%%%02x", ch);
1468                 else
1469                         strbuf_addch(&buf, *cp);
1470
1471         return strbuf_detach(&buf, NULL);
1472 }
1473
1474 void append_remote_object_url(struct strbuf *buf, const char *url,
1475                               const char *hex,
1476                               int only_two_digit_prefix)
1477 {
1478         end_url_with_slash(buf, url);
1479
1480         strbuf_addf(buf, "objects/%.*s/", 2, hex);
1481         if (!only_two_digit_prefix)
1482                 strbuf_addstr(buf, hex + 2);
1483 }
1484
1485 char *get_remote_object_url(const char *url, const char *hex,
1486                             int only_two_digit_prefix)
1487 {
1488         struct strbuf buf = STRBUF_INIT;
1489         append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
1490         return strbuf_detach(&buf, NULL);
1491 }
1492
1493 static int handle_curl_result(struct slot_results *results)
1494 {
1495         /*
1496          * If we see a failing http code with CURLE_OK, we have turned off
1497          * FAILONERROR (to keep the server's custom error response), and should
1498          * translate the code into failure here.
1499          *
1500          * Likewise, if we see a redirect (30x code), that means we turned off
1501          * redirect-following, and we should treat the result as an error.
1502          */
1503         if (results->curl_result == CURLE_OK &&
1504             results->http_code >= 300) {
1505                 results->curl_result = CURLE_HTTP_RETURNED_ERROR;
1506                 /*
1507                  * Normally curl will already have put the "reason phrase"
1508                  * from the server into curl_errorstr; unfortunately without
1509                  * FAILONERROR it is lost, so we can give only the numeric
1510                  * status code.
1511                  */
1512                 xsnprintf(curl_errorstr, sizeof(curl_errorstr),
1513                           "The requested URL returned error: %ld",
1514                           results->http_code);
1515         }
1516
1517         if (results->curl_result == CURLE_OK) {
1518                 credential_approve(&http_auth);
1519                 if (proxy_auth.password)
1520                         credential_approve(&proxy_auth);
1521                 return HTTP_OK;
1522         } else if (missing_target(results))
1523                 return HTTP_MISSING_TARGET;
1524         else if (results->http_code == 401) {
1525                 if (http_auth.username && http_auth.password) {
1526                         credential_reject(&http_auth);
1527                         return HTTP_NOAUTH;
1528                 } else {
1529 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
1530                         http_auth_methods &= ~CURLAUTH_GSSNEGOTIATE;
1531                         if (results->auth_avail) {
1532                                 http_auth_methods &= results->auth_avail;
1533                                 http_auth_methods_restricted = 1;
1534                         }
1535 #endif
1536                         return HTTP_REAUTH;
1537                 }
1538         } else {
1539                 if (results->http_connectcode == 407)
1540                         credential_reject(&proxy_auth);
1541 #if LIBCURL_VERSION_NUM >= 0x070c00
1542                 if (!curl_errorstr[0])
1543                         strlcpy(curl_errorstr,
1544                                 curl_easy_strerror(results->curl_result),
1545                                 sizeof(curl_errorstr));
1546 #endif
1547                 return HTTP_ERROR;
1548         }
1549 }
1550
1551 int run_one_slot(struct active_request_slot *slot,
1552                  struct slot_results *results)
1553 {
1554         slot->results = results;
1555         if (!start_active_slot(slot)) {
1556                 xsnprintf(curl_errorstr, sizeof(curl_errorstr),
1557                           "failed to start HTTP request");
1558                 return HTTP_START_FAILED;
1559         }
1560
1561         run_active_slot(slot);
1562         return handle_curl_result(results);
1563 }
1564
1565 struct curl_slist *http_copy_default_headers(void)
1566 {
1567         struct curl_slist *headers = NULL, *h;
1568
1569         for (h = extra_http_headers; h; h = h->next)
1570                 headers = curl_slist_append(headers, h->data);
1571
1572         return headers;
1573 }
1574
1575 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
1576 {
1577         char *ptr;
1578         CURLcode ret;
1579
1580         strbuf_reset(buf);
1581         ret = curl_easy_getinfo(curl, info, &ptr);
1582         if (!ret && ptr)
1583                 strbuf_addstr(buf, ptr);
1584         return ret;
1585 }
1586
1587 /*
1588  * Check for and extract a content-type parameter. "raw"
1589  * should be positioned at the start of the potential
1590  * parameter, with any whitespace already removed.
1591  *
1592  * "name" is the name of the parameter. The value is appended
1593  * to "out".
1594  */
1595 static int extract_param(const char *raw, const char *name,
1596                          struct strbuf *out)
1597 {
1598         size_t len = strlen(name);
1599
1600         if (strncasecmp(raw, name, len))
1601                 return -1;
1602         raw += len;
1603
1604         if (*raw != '=')
1605                 return -1;
1606         raw++;
1607
1608         while (*raw && !isspace(*raw) && *raw != ';')
1609                 strbuf_addch(out, *raw++);
1610         return 0;
1611 }
1612
1613 /*
1614  * Extract a normalized version of the content type, with any
1615  * spaces suppressed, all letters lowercased, and no trailing ";"
1616  * or parameters.
1617  *
1618  * Note that we will silently remove even invalid whitespace. For
1619  * example, "text / plain" is specifically forbidden by RFC 2616,
1620  * but "text/plain" is the only reasonable output, and this keeps
1621  * our code simple.
1622  *
1623  * If the "charset" argument is not NULL, store the value of any
1624  * charset parameter there.
1625  *
1626  * Example:
1627  *   "TEXT/PLAIN; charset=utf-8" -> "text/plain", "utf-8"
1628  *   "text / plain" -> "text/plain"
1629  */
1630 static void extract_content_type(struct strbuf *raw, struct strbuf *type,
1631                                  struct strbuf *charset)
1632 {
1633         const char *p;
1634
1635         strbuf_reset(type);
1636         strbuf_grow(type, raw->len);
1637         for (p = raw->buf; *p; p++) {
1638                 if (isspace(*p))
1639                         continue;
1640                 if (*p == ';') {
1641                         p++;
1642                         break;
1643                 }
1644                 strbuf_addch(type, tolower(*p));
1645         }
1646
1647         if (!charset)
1648                 return;
1649
1650         strbuf_reset(charset);
1651         while (*p) {
1652                 while (isspace(*p) || *p == ';')
1653                         p++;
1654                 if (!extract_param(p, "charset", charset))
1655                         return;
1656                 while (*p && !isspace(*p))
1657                         p++;
1658         }
1659
1660         if (!charset->len && starts_with(type->buf, "text/"))
1661                 strbuf_addstr(charset, "ISO-8859-1");
1662 }
1663
1664 static void write_accept_language(struct strbuf *buf)
1665 {
1666         /*
1667          * MAX_DECIMAL_PLACES must not be larger than 3. If it is larger than
1668          * that, q-value will be smaller than 0.001, the minimum q-value the
1669          * HTTP specification allows. See
1670          * http://tools.ietf.org/html/rfc7231#section-5.3.1 for q-value.
1671          */
1672         const int MAX_DECIMAL_PLACES = 3;
1673         const int MAX_LANGUAGE_TAGS = 1000;
1674         const int MAX_ACCEPT_LANGUAGE_HEADER_SIZE = 4000;
1675         char **language_tags = NULL;
1676         int num_langs = 0;
1677         const char *s = get_preferred_languages();
1678         int i;
1679         struct strbuf tag = STRBUF_INIT;
1680
1681         /* Don't add Accept-Language header if no language is preferred. */
1682         if (!s)
1683                 return;
1684
1685         /*
1686          * Split the colon-separated string of preferred languages into
1687          * language_tags array.
1688          */
1689         do {
1690                 /* collect language tag */
1691                 for (; *s && (isalnum(*s) || *s == '_'); s++)
1692                         strbuf_addch(&tag, *s == '_' ? '-' : *s);
1693
1694                 /* skip .codeset, @modifier and any other unnecessary parts */
1695                 while (*s && *s != ':')
1696                         s++;
1697
1698                 if (tag.len) {
1699                         num_langs++;
1700                         REALLOC_ARRAY(language_tags, num_langs);
1701                         language_tags[num_langs - 1] = strbuf_detach(&tag, NULL);
1702                         if (num_langs >= MAX_LANGUAGE_TAGS - 1) /* -1 for '*' */
1703                                 break;
1704                 }
1705         } while (*s++);
1706
1707         /* write Accept-Language header into buf */
1708         if (num_langs) {
1709                 int last_buf_len = 0;
1710                 int max_q;
1711                 int decimal_places;
1712                 char q_format[32];
1713
1714                 /* add '*' */
1715                 REALLOC_ARRAY(language_tags, num_langs + 1);
1716                 language_tags[num_langs++] = "*"; /* it's OK; this won't be freed */
1717
1718                 /* compute decimal_places */
1719                 for (max_q = 1, decimal_places = 0;
1720                      max_q < num_langs && decimal_places <= MAX_DECIMAL_PLACES;
1721                      decimal_places++, max_q *= 10)
1722                         ;
1723
1724                 xsnprintf(q_format, sizeof(q_format), ";q=0.%%0%dd", decimal_places);
1725
1726                 strbuf_addstr(buf, "Accept-Language: ");
1727
1728                 for (i = 0; i < num_langs; i++) {
1729                         if (i > 0)
1730                                 strbuf_addstr(buf, ", ");
1731
1732                         strbuf_addstr(buf, language_tags[i]);
1733
1734                         if (i > 0)
1735                                 strbuf_addf(buf, q_format, max_q - i);
1736
1737                         if (buf->len > MAX_ACCEPT_LANGUAGE_HEADER_SIZE) {
1738                                 strbuf_remove(buf, last_buf_len, buf->len - last_buf_len);
1739                                 break;
1740                         }
1741
1742                         last_buf_len = buf->len;
1743                 }
1744         }
1745
1746         /* free language tags -- last one is a static '*' */
1747         for (i = 0; i < num_langs - 1; i++)
1748                 free(language_tags[i]);
1749         free(language_tags);
1750 }
1751
1752 /*
1753  * Get an Accept-Language header which indicates user's preferred languages.
1754  *
1755  * Examples:
1756  *   LANGUAGE= -> ""
1757  *   LANGUAGE=ko:en -> "Accept-Language: ko, en; q=0.9, *; q=0.1"
1758  *   LANGUAGE=ko_KR.UTF-8:sr@latin -> "Accept-Language: ko-KR, sr; q=0.9, *; q=0.1"
1759  *   LANGUAGE=ko LANG=en_US.UTF-8 -> "Accept-Language: ko, *; q=0.1"
1760  *   LANGUAGE= LANG=en_US.UTF-8 -> "Accept-Language: en-US, *; q=0.1"
1761  *   LANGUAGE= LANG=C -> ""
1762  */
1763 static const char *get_accept_language(void)
1764 {
1765         if (!cached_accept_language) {
1766                 struct strbuf buf = STRBUF_INIT;
1767                 write_accept_language(&buf);
1768                 if (buf.len > 0)
1769                         cached_accept_language = strbuf_detach(&buf, NULL);
1770         }
1771
1772         return cached_accept_language;
1773 }
1774
1775 static void http_opt_request_remainder(CURL *curl, off_t pos)
1776 {
1777         char buf[128];
1778         xsnprintf(buf, sizeof(buf), "%"PRIuMAX"-", (uintmax_t)pos);
1779         curl_easy_setopt(curl, CURLOPT_RANGE, buf);
1780 }
1781
1782 /* http_request() targets */
1783 #define HTTP_REQUEST_STRBUF     0
1784 #define HTTP_REQUEST_FILE       1
1785
1786 static int http_request(const char *url,
1787                         void *result, int target,
1788                         const struct http_get_options *options)
1789 {
1790         struct active_request_slot *slot;
1791         struct slot_results results;
1792         struct curl_slist *headers = http_copy_default_headers();
1793         struct strbuf buf = STRBUF_INIT;
1794         const char *accept_language;
1795         int ret;
1796
1797         slot = get_active_slot();
1798         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1799
1800         if (result == NULL) {
1801                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
1802         } else {
1803                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
1804                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
1805
1806                 if (target == HTTP_REQUEST_FILE) {
1807                         off_t posn = ftello(result);
1808                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1809                                          fwrite);
1810                         if (posn > 0)
1811                                 http_opt_request_remainder(slot->curl, posn);
1812                 } else
1813                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1814                                          fwrite_buffer);
1815         }
1816
1817         accept_language = get_accept_language();
1818
1819         if (accept_language)
1820                 headers = curl_slist_append(headers, accept_language);
1821
1822         strbuf_addstr(&buf, "Pragma:");
1823         if (options && options->no_cache)
1824                 strbuf_addstr(&buf, " no-cache");
1825         if (options && options->keep_error)
1826                 curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
1827         if (options && options->initial_request &&
1828             http_follow_config == HTTP_FOLLOW_INITIAL)
1829                 curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 1);
1830
1831         headers = curl_slist_append(headers, buf.buf);
1832
1833         /* Add additional headers here */
1834         if (options && options->extra_headers) {
1835                 const struct string_list_item *item;
1836                 for_each_string_list_item(item, options->extra_headers) {
1837                         headers = curl_slist_append(headers, item->string);
1838                 }
1839         }
1840
1841         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1842         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
1843         curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "");
1844
1845         ret = run_one_slot(slot, &results);
1846
1847         if (options && options->content_type) {
1848                 struct strbuf raw = STRBUF_INIT;
1849                 curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE, &raw);
1850                 extract_content_type(&raw, options->content_type,
1851                                      options->charset);
1852                 strbuf_release(&raw);
1853         }
1854
1855         if (options && options->effective_url)
1856                 curlinfo_strbuf(slot->curl, CURLINFO_EFFECTIVE_URL,
1857                                 options->effective_url);
1858
1859         curl_slist_free_all(headers);
1860         strbuf_release(&buf);
1861
1862         return ret;
1863 }
1864
1865 /*
1866  * Update the "base" url to a more appropriate value, as deduced by
1867  * redirects seen when requesting a URL starting with "url".
1868  *
1869  * The "asked" parameter is a URL that we asked curl to access, and must begin
1870  * with "base".
1871  *
1872  * The "got" parameter is the URL that curl reported to us as where we ended
1873  * up.
1874  *
1875  * Returns 1 if we updated the base url, 0 otherwise.
1876  *
1877  * Our basic strategy is to compare "base" and "asked" to find the bits
1878  * specific to our request. We then strip those bits off of "got" to yield the
1879  * new base. So for example, if our base is "http://example.com/foo.git",
1880  * and we ask for "http://example.com/foo.git/info/refs", we might end up
1881  * with "https://other.example.com/foo.git/info/refs". We would want the
1882  * new URL to become "https://other.example.com/foo.git".
1883  *
1884  * Note that this assumes a sane redirect scheme. It's entirely possible
1885  * in the example above to end up at a URL that does not even end in
1886  * "info/refs".  In such a case we die. There's not much we can do, such a
1887  * scheme is unlikely to represent a real git repository, and failing to
1888  * rewrite the base opens options for malicious redirects to do funny things.
1889  */
1890 static int update_url_from_redirect(struct strbuf *base,
1891                                     const char *asked,
1892                                     const struct strbuf *got)
1893 {
1894         const char *tail;
1895         size_t new_len;
1896
1897         if (!strcmp(asked, got->buf))
1898                 return 0;
1899
1900         if (!skip_prefix(asked, base->buf, &tail))
1901                 BUG("update_url_from_redirect: %s is not a superset of %s",
1902                     asked, base->buf);
1903
1904         new_len = got->len;
1905         if (!strip_suffix_mem(got->buf, &new_len, tail))
1906                 die(_("unable to update url base from redirection:\n"
1907                       "  asked for: %s\n"
1908                       "   redirect: %s"),
1909                     asked, got->buf);
1910
1911         strbuf_reset(base);
1912         strbuf_add(base, got->buf, new_len);
1913
1914         return 1;
1915 }
1916
1917 static int http_request_reauth(const char *url,
1918                                void *result, int target,
1919                                struct http_get_options *options)
1920 {
1921         int ret = http_request(url, result, target, options);
1922
1923         if (ret != HTTP_OK && ret != HTTP_REAUTH)
1924                 return ret;
1925
1926         if (options && options->effective_url && options->base_url) {
1927                 if (update_url_from_redirect(options->base_url,
1928                                              url, options->effective_url)) {
1929                         credential_from_url(&http_auth, options->base_url->buf);
1930                         url = options->effective_url->buf;
1931                 }
1932         }
1933
1934         if (ret != HTTP_REAUTH)
1935                 return ret;
1936
1937         /*
1938          * If we are using KEEP_ERROR, the previous request may have
1939          * put cruft into our output stream; we should clear it out before
1940          * making our next request. We only know how to do this for
1941          * the strbuf case, but that is enough to satisfy current callers.
1942          */
1943         if (options && options->keep_error) {
1944                 switch (target) {
1945                 case HTTP_REQUEST_STRBUF:
1946                         strbuf_reset(result);
1947                         break;
1948                 default:
1949                         BUG("HTTP_KEEP_ERROR is only supported with strbufs");
1950                 }
1951         }
1952
1953         credential_fill(&http_auth);
1954
1955         return http_request(url, result, target, options);
1956 }
1957
1958 int http_get_strbuf(const char *url,
1959                     struct strbuf *result,
1960                     struct http_get_options *options)
1961 {
1962         return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
1963 }
1964
1965 /*
1966  * Downloads a URL and stores the result in the given file.
1967  *
1968  * If a previous interrupted download is detected (i.e. a previous temporary
1969  * file is still around) the download is resumed.
1970  */
1971 static int http_get_file(const char *url, const char *filename,
1972                          struct http_get_options *options)
1973 {
1974         int ret;
1975         struct strbuf tmpfile = STRBUF_INIT;
1976         FILE *result;
1977
1978         strbuf_addf(&tmpfile, "%s.temp", filename);
1979         result = fopen(tmpfile.buf, "a");
1980         if (!result) {
1981                 error("Unable to open local file %s", tmpfile.buf);
1982                 ret = HTTP_ERROR;
1983                 goto cleanup;
1984         }
1985
1986         ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
1987         fclose(result);
1988
1989         if (ret == HTTP_OK && finalize_object_file(tmpfile.buf, filename))
1990                 ret = HTTP_ERROR;
1991 cleanup:
1992         strbuf_release(&tmpfile);
1993         return ret;
1994 }
1995
1996 int http_fetch_ref(const char *base, struct ref *ref)
1997 {
1998         struct http_get_options options = {0};
1999         char *url;
2000         struct strbuf buffer = STRBUF_INIT;
2001         int ret = -1;
2002
2003         options.no_cache = 1;
2004
2005         url = quote_ref_url(base, ref->name);
2006         if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
2007                 strbuf_rtrim(&buffer);
2008                 if (buffer.len == 40)
2009                         ret = get_oid_hex(buffer.buf, &ref->old_oid);
2010                 else if (starts_with(buffer.buf, "ref: ")) {
2011                         ref->symref = xstrdup(buffer.buf + 5);
2012                         ret = 0;
2013                 }
2014         }
2015
2016         strbuf_release(&buffer);
2017         free(url);
2018         return ret;
2019 }
2020
2021 /* Helpers for fetching packs */
2022 static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
2023 {
2024         char *url, *tmp;
2025         struct strbuf buf = STRBUF_INIT;
2026
2027         if (http_is_verbose)
2028                 fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
2029
2030         end_url_with_slash(&buf, base_url);
2031         strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
2032         url = strbuf_detach(&buf, NULL);
2033
2034         strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
2035         tmp = strbuf_detach(&buf, NULL);
2036
2037         if (http_get_file(url, tmp, NULL) != HTTP_OK) {
2038                 error("Unable to get pack index %s", url);
2039                 FREE_AND_NULL(tmp);
2040         }
2041
2042         free(url);
2043         return tmp;
2044 }
2045
2046 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
2047         unsigned char *sha1, const char *base_url)
2048 {
2049         struct packed_git *new_pack;
2050         char *tmp_idx = NULL;
2051         int ret;
2052
2053         if (has_pack_index(sha1)) {
2054                 new_pack = parse_pack_index(sha1, sha1_pack_index_name(sha1));
2055                 if (!new_pack)
2056                         return -1; /* parse_pack_index() already issued error message */
2057                 goto add_pack;
2058         }
2059
2060         tmp_idx = fetch_pack_index(sha1, base_url);
2061         if (!tmp_idx)
2062                 return -1;
2063
2064         new_pack = parse_pack_index(sha1, tmp_idx);
2065         if (!new_pack) {
2066                 unlink(tmp_idx);
2067                 free(tmp_idx);
2068
2069                 return -1; /* parse_pack_index() already issued error message */
2070         }
2071
2072         ret = verify_pack_index(new_pack);
2073         if (!ret) {
2074                 close_pack_index(new_pack);
2075                 ret = finalize_object_file(tmp_idx, sha1_pack_index_name(sha1));
2076         }
2077         free(tmp_idx);
2078         if (ret)
2079                 return -1;
2080
2081 add_pack:
2082         new_pack->next = *packs_head;
2083         *packs_head = new_pack;
2084         return 0;
2085 }
2086
2087 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
2088 {
2089         struct http_get_options options = {0};
2090         int ret = 0, i = 0;
2091         char *url, *data;
2092         struct strbuf buf = STRBUF_INIT;
2093         unsigned char hash[GIT_MAX_RAWSZ];
2094         const unsigned hexsz = the_hash_algo->hexsz;
2095
2096         end_url_with_slash(&buf, base_url);
2097         strbuf_addstr(&buf, "objects/info/packs");
2098         url = strbuf_detach(&buf, NULL);
2099
2100         options.no_cache = 1;
2101         ret = http_get_strbuf(url, &buf, &options);
2102         if (ret != HTTP_OK)
2103                 goto cleanup;
2104
2105         data = buf.buf;
2106         while (i < buf.len) {
2107                 switch (data[i]) {
2108                 case 'P':
2109                         i++;
2110                         if (i + hexsz + 12 <= buf.len &&
2111                             starts_with(data + i, " pack-") &&
2112                             starts_with(data + i + hexsz + 6, ".pack\n")) {
2113                                 get_sha1_hex(data + i + 6, hash);
2114                                 fetch_and_setup_pack_index(packs_head, hash,
2115                                                       base_url);
2116                                 i += hexsz + 11;
2117                                 break;
2118                         }
2119                 default:
2120                         while (i < buf.len && data[i] != '\n')
2121                                 i++;
2122                 }
2123                 i++;
2124         }
2125
2126 cleanup:
2127         free(url);
2128         return ret;
2129 }
2130
2131 void release_http_pack_request(struct http_pack_request *preq)
2132 {
2133         if (preq->packfile != NULL) {
2134                 fclose(preq->packfile);
2135                 preq->packfile = NULL;
2136         }
2137         preq->slot = NULL;
2138         strbuf_release(&preq->tmpfile);
2139         free(preq->url);
2140         free(preq);
2141 }
2142
2143 int finish_http_pack_request(struct http_pack_request *preq)
2144 {
2145         struct packed_git **lst;
2146         struct packed_git *p = preq->target;
2147         char *tmp_idx;
2148         size_t len;
2149         struct child_process ip = CHILD_PROCESS_INIT;
2150
2151         close_pack_index(p);
2152
2153         fclose(preq->packfile);
2154         preq->packfile = NULL;
2155
2156         lst = preq->lst;
2157         while (*lst != p)
2158                 lst = &((*lst)->next);
2159         *lst = (*lst)->next;
2160
2161         if (!strip_suffix(preq->tmpfile.buf, ".pack.temp", &len))
2162                 BUG("pack tmpfile does not end in .pack.temp?");
2163         tmp_idx = xstrfmt("%.*s.idx.temp", (int)len, preq->tmpfile.buf);
2164
2165         argv_array_push(&ip.args, "index-pack");
2166         argv_array_pushl(&ip.args, "-o", tmp_idx, NULL);
2167         argv_array_push(&ip.args, preq->tmpfile.buf);
2168         ip.git_cmd = 1;
2169         ip.no_stdin = 1;
2170         ip.no_stdout = 1;
2171
2172         if (run_command(&ip)) {
2173                 unlink(preq->tmpfile.buf);
2174                 unlink(tmp_idx);
2175                 free(tmp_idx);
2176                 return -1;
2177         }
2178
2179         unlink(sha1_pack_index_name(p->sha1));
2180
2181         if (finalize_object_file(preq->tmpfile.buf, sha1_pack_name(p->sha1))
2182          || finalize_object_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
2183                 free(tmp_idx);
2184                 return -1;
2185         }
2186
2187         install_packed_git(the_repository, p);
2188         free(tmp_idx);
2189         return 0;
2190 }
2191
2192 struct http_pack_request *new_http_pack_request(
2193         struct packed_git *target, const char *base_url)
2194 {
2195         off_t prev_posn = 0;
2196         struct strbuf buf = STRBUF_INIT;
2197         struct http_pack_request *preq;
2198
2199         preq = xcalloc(1, sizeof(*preq));
2200         strbuf_init(&preq->tmpfile, 0);
2201         preq->target = target;
2202
2203         end_url_with_slash(&buf, base_url);
2204         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
2205                 sha1_to_hex(target->sha1));
2206         preq->url = strbuf_detach(&buf, NULL);
2207
2208         strbuf_addf(&preq->tmpfile, "%s.temp", sha1_pack_name(target->sha1));
2209         preq->packfile = fopen(preq->tmpfile.buf, "a");
2210         if (!preq->packfile) {
2211                 error("Unable to open local file %s for pack",
2212                       preq->tmpfile.buf);
2213                 goto abort;
2214         }
2215
2216         preq->slot = get_active_slot();
2217         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
2218         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
2219         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
2220         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
2221                 no_pragma_header);
2222
2223         /*
2224          * If there is data present from a previous transfer attempt,
2225          * resume where it left off
2226          */
2227         prev_posn = ftello(preq->packfile);
2228         if (prev_posn>0) {
2229                 if (http_is_verbose)
2230                         fprintf(stderr,
2231                                 "Resuming fetch of pack %s at byte %"PRIuMAX"\n",
2232                                 sha1_to_hex(target->sha1), (uintmax_t)prev_posn);
2233                 http_opt_request_remainder(preq->slot->curl, prev_posn);
2234         }
2235
2236         return preq;
2237
2238 abort:
2239         strbuf_release(&preq->tmpfile);
2240         free(preq->url);
2241         free(preq);
2242         return NULL;
2243 }
2244
2245 /* Helpers for fetching objects (loose) */
2246 static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
2247                                void *data)
2248 {
2249         unsigned char expn[4096];
2250         size_t size = eltsize * nmemb;
2251         int posn = 0;
2252         struct http_object_request *freq = data;
2253         struct active_request_slot *slot = freq->slot;
2254
2255         if (slot) {
2256                 CURLcode c = curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE,
2257                                                 &slot->http_code);
2258                 if (c != CURLE_OK)
2259                         BUG("curl_easy_getinfo for HTTP code failed: %s",
2260                                 curl_easy_strerror(c));
2261                 if (slot->http_code >= 300)
2262                         return size;
2263         }
2264
2265         do {
2266                 ssize_t retval = xwrite(freq->localfile,
2267                                         (char *) ptr + posn, size - posn);
2268                 if (retval < 0)
2269                         return posn;
2270                 posn += retval;
2271         } while (posn < size);
2272
2273         freq->stream.avail_in = size;
2274         freq->stream.next_in = (void *)ptr;
2275         do {
2276                 freq->stream.next_out = expn;
2277                 freq->stream.avail_out = sizeof(expn);
2278                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
2279                 git_SHA1_Update(&freq->c, expn,
2280                                 sizeof(expn) - freq->stream.avail_out);
2281         } while (freq->stream.avail_in && freq->zret == Z_OK);
2282         return size;
2283 }
2284
2285 struct http_object_request *new_http_object_request(const char *base_url,
2286         unsigned char *sha1)
2287 {
2288         char *hex = sha1_to_hex(sha1);
2289         struct strbuf filename = STRBUF_INIT;
2290         struct strbuf prevfile = STRBUF_INIT;
2291         int prevlocal;
2292         char prev_buf[PREV_BUF_SIZE];
2293         ssize_t prev_read = 0;
2294         off_t prev_posn = 0;
2295         struct http_object_request *freq;
2296
2297         freq = xcalloc(1, sizeof(*freq));
2298         strbuf_init(&freq->tmpfile, 0);
2299         hashcpy(freq->sha1, sha1);
2300         freq->localfile = -1;
2301
2302         sha1_file_name(the_repository, &filename, sha1);
2303         strbuf_addf(&freq->tmpfile, "%s.temp", filename.buf);
2304
2305         strbuf_addf(&prevfile, "%s.prev", filename.buf);
2306         unlink_or_warn(prevfile.buf);
2307         rename(freq->tmpfile.buf, prevfile.buf);
2308         unlink_or_warn(freq->tmpfile.buf);
2309         strbuf_release(&filename);
2310
2311         if (freq->localfile != -1)
2312                 error("fd leakage in start: %d", freq->localfile);
2313         freq->localfile = open(freq->tmpfile.buf,
2314                                O_WRONLY | O_CREAT | O_EXCL, 0666);
2315         /*
2316          * This could have failed due to the "lazy directory creation";
2317          * try to mkdir the last path component.
2318          */
2319         if (freq->localfile < 0 && errno == ENOENT) {
2320                 char *dir = strrchr(freq->tmpfile.buf, '/');
2321                 if (dir) {
2322                         *dir = 0;
2323                         mkdir(freq->tmpfile.buf, 0777);
2324                         *dir = '/';
2325                 }
2326                 freq->localfile = open(freq->tmpfile.buf,
2327                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
2328         }
2329
2330         if (freq->localfile < 0) {
2331                 error_errno("Couldn't create temporary file %s",
2332                             freq->tmpfile.buf);
2333                 goto abort;
2334         }
2335
2336         git_inflate_init(&freq->stream);
2337
2338         git_SHA1_Init(&freq->c);
2339
2340         freq->url = get_remote_object_url(base_url, hex, 0);
2341
2342         /*
2343          * If a previous temp file is present, process what was already
2344          * fetched.
2345          */
2346         prevlocal = open(prevfile.buf, O_RDONLY);
2347         if (prevlocal != -1) {
2348                 do {
2349                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
2350                         if (prev_read>0) {
2351                                 if (fwrite_sha1_file(prev_buf,
2352                                                      1,
2353                                                      prev_read,
2354                                                      freq) == prev_read) {
2355                                         prev_posn += prev_read;
2356                                 } else {
2357                                         prev_read = -1;
2358                                 }
2359                         }
2360                 } while (prev_read > 0);
2361                 close(prevlocal);
2362         }
2363         unlink_or_warn(prevfile.buf);
2364         strbuf_release(&prevfile);
2365
2366         /*
2367          * Reset inflate/SHA1 if there was an error reading the previous temp
2368          * file; also rewind to the beginning of the local file.
2369          */
2370         if (prev_read == -1) {
2371                 memset(&freq->stream, 0, sizeof(freq->stream));
2372                 git_inflate_init(&freq->stream);
2373                 git_SHA1_Init(&freq->c);
2374                 if (prev_posn>0) {
2375                         prev_posn = 0;
2376                         lseek(freq->localfile, 0, SEEK_SET);
2377                         if (ftruncate(freq->localfile, 0) < 0) {
2378                                 error_errno("Couldn't truncate temporary file %s",
2379                                             freq->tmpfile.buf);
2380                                 goto abort;
2381                         }
2382                 }
2383         }
2384
2385         freq->slot = get_active_slot();
2386
2387         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
2388         curl_easy_setopt(freq->slot->curl, CURLOPT_FAILONERROR, 0);
2389         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
2390         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
2391         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
2392         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
2393
2394         /*
2395          * If we have successfully processed data from a previous fetch
2396          * attempt, only fetch the data we don't already have.
2397          */
2398         if (prev_posn>0) {
2399                 if (http_is_verbose)
2400                         fprintf(stderr,
2401                                 "Resuming fetch of object %s at byte %"PRIuMAX"\n",
2402                                 hex, (uintmax_t)prev_posn);
2403                 http_opt_request_remainder(freq->slot->curl, prev_posn);
2404         }
2405
2406         return freq;
2407
2408 abort:
2409         strbuf_release(&prevfile);
2410         free(freq->url);
2411         free(freq);
2412         return NULL;
2413 }
2414
2415 void process_http_object_request(struct http_object_request *freq)
2416 {
2417         if (freq->slot == NULL)
2418                 return;
2419         freq->curl_result = freq->slot->curl_result;
2420         freq->http_code = freq->slot->http_code;
2421         freq->slot = NULL;
2422 }
2423
2424 int finish_http_object_request(struct http_object_request *freq)
2425 {
2426         struct stat st;
2427         struct strbuf filename = STRBUF_INIT;
2428
2429         close(freq->localfile);
2430         freq->localfile = -1;
2431
2432         process_http_object_request(freq);
2433
2434         if (freq->http_code == 416) {
2435                 warning("requested range invalid; we may already have all the data.");
2436         } else if (freq->curl_result != CURLE_OK) {
2437                 if (stat(freq->tmpfile.buf, &st) == 0)
2438                         if (st.st_size == 0)
2439                                 unlink_or_warn(freq->tmpfile.buf);
2440                 return -1;
2441         }
2442
2443         git_inflate_end(&freq->stream);
2444         git_SHA1_Final(freq->real_sha1, &freq->c);
2445         if (freq->zret != Z_STREAM_END) {
2446                 unlink_or_warn(freq->tmpfile.buf);
2447                 return -1;
2448         }
2449         if (hashcmp(freq->sha1, freq->real_sha1)) {
2450                 unlink_or_warn(freq->tmpfile.buf);
2451                 return -1;
2452         }
2453         sha1_file_name(the_repository, &filename, freq->sha1);
2454         freq->rename = finalize_object_file(freq->tmpfile.buf, filename.buf);
2455         strbuf_release(&filename);
2456
2457         return freq->rename;
2458 }
2459
2460 void abort_http_object_request(struct http_object_request *freq)
2461 {
2462         unlink_or_warn(freq->tmpfile.buf);
2463
2464         release_http_object_request(freq);
2465 }
2466
2467 void release_http_object_request(struct http_object_request *freq)
2468 {
2469         if (freq->localfile != -1) {
2470                 close(freq->localfile);
2471                 freq->localfile = -1;
2472         }
2473         FREE_AND_NULL(freq->url);
2474         if (freq->slot != NULL) {
2475                 freq->slot->callback_func = NULL;
2476                 freq->slot->callback_data = NULL;
2477                 release_active_slot(freq->slot);
2478                 freq->slot = NULL;
2479         }
2480         strbuf_release(&freq->tmpfile);
2481 }