Andrew's git / gitweb.git / http.c
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http.con commit Almost -rc0 for 1.8.5 (0d6cf24)
   1#include "http.h"
   2#include "pack.h"
   3#include "sideband.h"
   4#include "run-command.h"
   5#include "url.h"
   6#include "urlmatch.h"
   7#include "credential.h"
   8#include "version.h"
   9#include "pkt-line.h"
  10
  11int active_requests;
  12int http_is_verbose;
  13size_t http_post_buffer = 16 * LARGE_PACKET_MAX;
  14
  15#if LIBCURL_VERSION_NUM >= 0x070a06
  16#define LIBCURL_CAN_HANDLE_AUTH_ANY
  17#endif
  18
  19static int min_curl_sessions = 1;
  20static int curl_session_count;
  21#ifdef USE_CURL_MULTI
  22static int max_requests = -1;
  23static CURLM *curlm;
  24#endif
  25#ifndef NO_CURL_EASY_DUPHANDLE
  26static CURL *curl_default;
  27#endif
  28
  29#define PREV_BUF_SIZE 4096
  30#define RANGE_HEADER_SIZE 30
  31
  32char curl_errorstr[CURL_ERROR_SIZE];
  33
  34static int curl_ssl_verify = -1;
  35static int curl_ssl_try;
  36static const char *ssl_cert;
  37#if LIBCURL_VERSION_NUM >= 0x070903
  38static const char *ssl_key;
  39#endif
  40#if LIBCURL_VERSION_NUM >= 0x070908
  41static const char *ssl_capath;
  42#endif
  43static const char *ssl_cainfo;
  44static long curl_low_speed_limit = -1;
  45static long curl_low_speed_time = -1;
  46static int curl_ftp_no_epsv;
  47static const char *curl_http_proxy;
  48static const char *curl_cookie_file;
  49static int curl_save_cookies;
  50static struct credential http_auth = CREDENTIAL_INIT;
  51static int http_proactive_auth;
  52static const char *user_agent;
  53
  54#if LIBCURL_VERSION_NUM >= 0x071700
  55/* Use CURLOPT_KEYPASSWD as is */
  56#elif LIBCURL_VERSION_NUM >= 0x070903
  57#define CURLOPT_KEYPASSWD CURLOPT_SSLKEYPASSWD
  58#else
  59#define CURLOPT_KEYPASSWD CURLOPT_SSLCERTPASSWD
  60#endif
  61
  62static struct credential cert_auth = CREDENTIAL_INIT;
  63static int ssl_cert_password_required;
  64
  65static struct curl_slist *pragma_header;
  66static struct curl_slist *no_pragma_header;
  67
  68static struct active_request_slot *active_queue_head;
  69
  70size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
  71{
  72        size_t size = eltsize * nmemb;
  73        struct buffer *buffer = buffer_;
  74
  75        if (size > buffer->buf.len - buffer->posn)
  76                size = buffer->buf.len - buffer->posn;
  77        memcpy(ptr, buffer->buf.buf + buffer->posn, size);
  78        buffer->posn += size;
  79
  80        return size;
  81}
  82
  83#ifndef NO_CURL_IOCTL
  84curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)
  85{
  86        struct buffer *buffer = clientp;
  87
  88        switch (cmd) {
  89        case CURLIOCMD_NOP:
  90                return CURLIOE_OK;
  91
  92        case CURLIOCMD_RESTARTREAD:
  93                buffer->posn = 0;
  94                return CURLIOE_OK;
  95
  96        default:
  97                return CURLIOE_UNKNOWNCMD;
  98        }
  99}
 100#endif
 101
 102size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
 103{
 104        size_t size = eltsize * nmemb;
 105        struct strbuf *buffer = buffer_;
 106
 107        strbuf_add(buffer, ptr, size);
 108        return size;
 109}
 110
 111size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf)
 112{
 113        return eltsize * nmemb;
 114}
 115
 116#ifdef USE_CURL_MULTI
 117static void process_curl_messages(void)
 118{
 119        int num_messages;
 120        struct active_request_slot *slot;
 121        CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
 122
 123        while (curl_message != NULL) {
 124                if (curl_message->msg == CURLMSG_DONE) {
 125                        int curl_result = curl_message->data.result;
 126                        slot = active_queue_head;
 127                        while (slot != NULL &&
 128                               slot->curl != curl_message->easy_handle)
 129                                slot = slot->next;
 130                        if (slot != NULL) {
 131                                curl_multi_remove_handle(curlm, slot->curl);
 132                                slot->curl_result = curl_result;
 133                                finish_active_slot(slot);
 134                        } else {
 135                                fprintf(stderr, "Received DONE message for unknown request!\n");
 136                        }
 137                } else {
 138                        fprintf(stderr, "Unknown CURL message received: %d\n",
 139                                (int)curl_message->msg);
 140                }
 141                curl_message = curl_multi_info_read(curlm, &num_messages);
 142        }
 143}
 144#endif
 145
 146static int http_options(const char *var, const char *value, void *cb)
 147{
 148        if (!strcmp("http.sslverify", var)) {
 149                curl_ssl_verify = git_config_bool(var, value);
 150                return 0;
 151        }
 152        if (!strcmp("http.sslcert", var))
 153                return git_config_string(&ssl_cert, var, value);
 154#if LIBCURL_VERSION_NUM >= 0x070903
 155        if (!strcmp("http.sslkey", var))
 156                return git_config_string(&ssl_key, var, value);
 157#endif
 158#if LIBCURL_VERSION_NUM >= 0x070908
 159        if (!strcmp("http.sslcapath", var))
 160                return git_config_string(&ssl_capath, var, value);
 161#endif
 162        if (!strcmp("http.sslcainfo", var))
 163                return git_config_string(&ssl_cainfo, var, value);
 164        if (!strcmp("http.sslcertpasswordprotected", var)) {
 165                ssl_cert_password_required = git_config_bool(var, value);
 166                return 0;
 167        }
 168        if (!strcmp("http.ssltry", var)) {
 169                curl_ssl_try = git_config_bool(var, value);
 170                return 0;
 171        }
 172        if (!strcmp("http.minsessions", var)) {
 173                min_curl_sessions = git_config_int(var, value);
 174#ifndef USE_CURL_MULTI
 175                if (min_curl_sessions > 1)
 176                        min_curl_sessions = 1;
 177#endif
 178                return 0;
 179        }
 180#ifdef USE_CURL_MULTI
 181        if (!strcmp("http.maxrequests", var)) {
 182                max_requests = git_config_int(var, value);
 183                return 0;
 184        }
 185#endif
 186        if (!strcmp("http.lowspeedlimit", var)) {
 187                curl_low_speed_limit = (long)git_config_int(var, value);
 188                return 0;
 189        }
 190        if (!strcmp("http.lowspeedtime", var)) {
 191                curl_low_speed_time = (long)git_config_int(var, value);
 192                return 0;
 193        }
 194
 195        if (!strcmp("http.noepsv", var)) {
 196                curl_ftp_no_epsv = git_config_bool(var, value);
 197                return 0;
 198        }
 199        if (!strcmp("http.proxy", var))
 200                return git_config_string(&curl_http_proxy, var, value);
 201
 202        if (!strcmp("http.cookiefile", var))
 203                return git_config_string(&curl_cookie_file, var, value);
 204        if (!strcmp("http.savecookies", var)) {
 205                curl_save_cookies = git_config_bool(var, value);
 206                return 0;
 207        }
 208
 209        if (!strcmp("http.postbuffer", var)) {
 210                http_post_buffer = git_config_int(var, value);
 211                if (http_post_buffer < LARGE_PACKET_MAX)
 212                        http_post_buffer = LARGE_PACKET_MAX;
 213                return 0;
 214        }
 215
 216        if (!strcmp("http.useragent", var))
 217                return git_config_string(&user_agent, var, value);
 218
 219        /* Fall back on the default ones */
 220        return git_default_config(var, value, cb);
 221}
 222
 223static void init_curl_http_auth(CURL *result)
 224{
 225        if (!http_auth.username)
 226                return;
 227
 228        credential_fill(&http_auth);
 229
 230#if LIBCURL_VERSION_NUM >= 0x071301
 231        curl_easy_setopt(result, CURLOPT_USERNAME, http_auth.username);
 232        curl_easy_setopt(result, CURLOPT_PASSWORD, http_auth.password);
 233#else
 234        {
 235                static struct strbuf up = STRBUF_INIT;
 236                /*
 237                 * Note that we assume we only ever have a single set of
 238                 * credentials in a given program run, so we do not have
 239                 * to worry about updating this buffer, only setting its
 240                 * initial value.
 241                 */
 242                if (!up.len)
 243                        strbuf_addf(&up, "%s:%s",
 244                                http_auth.username, http_auth.password);
 245                curl_easy_setopt(result, CURLOPT_USERPWD, up.buf);
 246        }
 247#endif
 248}
 249
 250static int has_cert_password(void)
 251{
 252        if (ssl_cert == NULL || ssl_cert_password_required != 1)
 253                return 0;
 254        if (!cert_auth.password) {
 255                cert_auth.protocol = xstrdup("cert");
 256                cert_auth.username = xstrdup("");
 257                cert_auth.path = xstrdup(ssl_cert);
 258                credential_fill(&cert_auth);
 259        }
 260        return 1;
 261}
 262
 263#if LIBCURL_VERSION_NUM >= 0x071900
 264static void set_curl_keepalive(CURL *c)
 265{
 266        curl_easy_setopt(c, CURLOPT_TCP_KEEPALIVE, 1);
 267}
 268
 269#elif LIBCURL_VERSION_NUM >= 0x071000
 270static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
 271{
 272        int ka = 1;
 273        int rc;
 274        socklen_t len = (socklen_t)sizeof(ka);
 275
 276        if (type != CURLSOCKTYPE_IPCXN)
 277                return 0;
 278
 279        rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
 280        if (rc < 0)
 281                warning("unable to set SO_KEEPALIVE on socket %s",
 282                        strerror(errno));
 283
 284        return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
 285}
 286
 287static void set_curl_keepalive(CURL *c)
 288{
 289        curl_easy_setopt(c, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
 290}
 291
 292#else
 293static void set_curl_keepalive(CURL *c)
 294{
 295        /* not supported on older curl versions */
 296}
 297#endif
 298
 299static CURL *get_curl_handle(void)
 300{
 301        CURL *result = curl_easy_init();
 302
 303        if (!curl_ssl_verify) {
 304                curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
 305                curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
 306        } else {
 307                /* Verify authenticity of the peer's certificate */
 308                curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
 309                /* The name in the cert must match whom we tried to connect */
 310                curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
 311        }
 312
 313#if LIBCURL_VERSION_NUM >= 0x070907
 314        curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
 315#endif
 316#ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 317        curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
 318#endif
 319
 320        if (http_proactive_auth)
 321                init_curl_http_auth(result);
 322
 323        if (ssl_cert != NULL)
 324                curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
 325        if (has_cert_password())
 326                curl_easy_setopt(result, CURLOPT_KEYPASSWD, cert_auth.password);
 327#if LIBCURL_VERSION_NUM >= 0x070903
 328        if (ssl_key != NULL)
 329                curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
 330#endif
 331#if LIBCURL_VERSION_NUM >= 0x070908
 332        if (ssl_capath != NULL)
 333                curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
 334#endif
 335        if (ssl_cainfo != NULL)
 336                curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
 337
 338        if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
 339                curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
 340                                 curl_low_speed_limit);
 341                curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
 342                                 curl_low_speed_time);
 343        }
 344
 345        curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
 346#if LIBCURL_VERSION_NUM >= 0x071301
 347        curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
 348#elif LIBCURL_VERSION_NUM >= 0x071101
 349        curl_easy_setopt(result, CURLOPT_POST301, 1);
 350#endif
 351
 352        if (getenv("GIT_CURL_VERBOSE"))
 353                curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
 354
 355        curl_easy_setopt(result, CURLOPT_USERAGENT,
 356                user_agent ? user_agent : git_user_agent());
 357
 358        if (curl_ftp_no_epsv)
 359                curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
 360
 361#ifdef CURLOPT_USE_SSL
 362        if (curl_ssl_try)
 363                curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
 364#endif
 365
 366        if (curl_http_proxy) {
 367                curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
 368                curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
 369        }
 370
 371        set_curl_keepalive(result);
 372
 373        return result;
 374}
 375
 376static void set_from_env(const char **var, const char *envname)
 377{
 378        const char *val = getenv(envname);
 379        if (val)
 380                *var = val;
 381}
 382
 383void http_init(struct remote *remote, const char *url, int proactive_auth)
 384{
 385        char *low_speed_limit;
 386        char *low_speed_time;
 387        char *normalized_url;
 388        struct urlmatch_config config = { STRING_LIST_INIT_DUP };
 389
 390        config.section = "http";
 391        config.key = NULL;
 392        config.collect_fn = http_options;
 393        config.cascade_fn = git_default_config;
 394        config.cb = NULL;
 395
 396        http_is_verbose = 0;
 397        normalized_url = url_normalize(url, &config.url);
 398
 399        git_config(urlmatch_config_entry, &config);
 400        free(normalized_url);
 401
 402        curl_global_init(CURL_GLOBAL_ALL);
 403
 404        http_proactive_auth = proactive_auth;
 405
 406        if (remote && remote->http_proxy)
 407                curl_http_proxy = xstrdup(remote->http_proxy);
 408
 409        pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
 410        no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
 411
 412#ifdef USE_CURL_MULTI
 413        {
 414                char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
 415                if (http_max_requests != NULL)
 416                        max_requests = atoi(http_max_requests);
 417        }
 418
 419        curlm = curl_multi_init();
 420        if (curlm == NULL) {
 421                fprintf(stderr, "Error creating curl multi handle.\n");
 422                exit(1);
 423        }
 424#endif
 425
 426        if (getenv("GIT_SSL_NO_VERIFY"))
 427                curl_ssl_verify = 0;
 428
 429        set_from_env(&ssl_cert, "GIT_SSL_CERT");
 430#if LIBCURL_VERSION_NUM >= 0x070903
 431        set_from_env(&ssl_key, "GIT_SSL_KEY");
 432#endif
 433#if LIBCURL_VERSION_NUM >= 0x070908
 434        set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
 435#endif
 436        set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
 437
 438        set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");
 439
 440        low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
 441        if (low_speed_limit != NULL)
 442                curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
 443        low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
 444        if (low_speed_time != NULL)
 445                curl_low_speed_time = strtol(low_speed_time, NULL, 10);
 446
 447        if (curl_ssl_verify == -1)
 448                curl_ssl_verify = 1;
 449
 450        curl_session_count = 0;
 451#ifdef USE_CURL_MULTI
 452        if (max_requests < 1)
 453                max_requests = DEFAULT_MAX_REQUESTS;
 454#endif
 455
 456        if (getenv("GIT_CURL_FTP_NO_EPSV"))
 457                curl_ftp_no_epsv = 1;
 458
 459        if (url) {
 460                credential_from_url(&http_auth, url);
 461                if (!ssl_cert_password_required &&
 462                    getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
 463                    !prefixcmp(url, "https://"))
 464                        ssl_cert_password_required = 1;
 465        }
 466
 467#ifndef NO_CURL_EASY_DUPHANDLE
 468        curl_default = get_curl_handle();
 469#endif
 470}
 471
 472void http_cleanup(void)
 473{
 474        struct active_request_slot *slot = active_queue_head;
 475
 476        while (slot != NULL) {
 477                struct active_request_slot *next = slot->next;
 478                if (slot->curl != NULL) {
 479#ifdef USE_CURL_MULTI
 480                        curl_multi_remove_handle(curlm, slot->curl);
 481#endif
 482                        curl_easy_cleanup(slot->curl);
 483                }
 484                free(slot);
 485                slot = next;
 486        }
 487        active_queue_head = NULL;
 488
 489#ifndef NO_CURL_EASY_DUPHANDLE
 490        curl_easy_cleanup(curl_default);
 491#endif
 492
 493#ifdef USE_CURL_MULTI
 494        curl_multi_cleanup(curlm);
 495#endif
 496        curl_global_cleanup();
 497
 498        curl_slist_free_all(pragma_header);
 499        pragma_header = NULL;
 500
 501        curl_slist_free_all(no_pragma_header);
 502        no_pragma_header = NULL;
 503
 504        if (curl_http_proxy) {
 505                free((void *)curl_http_proxy);
 506                curl_http_proxy = NULL;
 507        }
 508
 509        if (cert_auth.password != NULL) {
 510                memset(cert_auth.password, 0, strlen(cert_auth.password));
 511                free(cert_auth.password);
 512                cert_auth.password = NULL;
 513        }
 514        ssl_cert_password_required = 0;
 515}
 516
 517struct active_request_slot *get_active_slot(void)
 518{
 519        struct active_request_slot *slot = active_queue_head;
 520        struct active_request_slot *newslot;
 521
 522#ifdef USE_CURL_MULTI
 523        int num_transfers;
 524
 525        /* Wait for a slot to open up if the queue is full */
 526        while (active_requests >= max_requests) {
 527                curl_multi_perform(curlm, &num_transfers);
 528                if (num_transfers < active_requests)
 529                        process_curl_messages();
 530        }
 531#endif
 532
 533        while (slot != NULL && slot->in_use)
 534                slot = slot->next;
 535
 536        if (slot == NULL) {
 537                newslot = xmalloc(sizeof(*newslot));
 538                newslot->curl = NULL;
 539                newslot->in_use = 0;
 540                newslot->next = NULL;
 541
 542                slot = active_queue_head;
 543                if (slot == NULL) {
 544                        active_queue_head = newslot;
 545                } else {
 546                        while (slot->next != NULL)
 547                                slot = slot->next;
 548                        slot->next = newslot;
 549                }
 550                slot = newslot;
 551        }
 552
 553        if (slot->curl == NULL) {
 554#ifdef NO_CURL_EASY_DUPHANDLE
 555                slot->curl = get_curl_handle();
 556#else
 557                slot->curl = curl_easy_duphandle(curl_default);
 558#endif
 559                curl_session_count++;
 560        }
 561
 562        active_requests++;
 563        slot->in_use = 1;
 564        slot->results = NULL;
 565        slot->finished = NULL;
 566        slot->callback_data = NULL;
 567        slot->callback_func = NULL;
 568        curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file);
 569        if (curl_save_cookies)
 570                curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file);
 571        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
 572        curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
 573        curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
 574        curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
 575        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
 576        curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
 577        curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
 578        curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
 579        curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
 580        if (http_auth.password)
 581                init_curl_http_auth(slot->curl);
 582
 583        return slot;
 584}
 585
 586int start_active_slot(struct active_request_slot *slot)
 587{
 588#ifdef USE_CURL_MULTI
 589        CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
 590        int num_transfers;
 591
 592        if (curlm_result != CURLM_OK &&
 593            curlm_result != CURLM_CALL_MULTI_PERFORM) {
 594                active_requests--;
 595                slot->in_use = 0;
 596                return 0;
 597        }
 598
 599        /*
 600         * We know there must be something to do, since we just added
 601         * something.
 602         */
 603        curl_multi_perform(curlm, &num_transfers);
 604#endif
 605        return 1;
 606}
 607
 608#ifdef USE_CURL_MULTI
 609struct fill_chain {
 610        void *data;
 611        int (*fill)(void *);
 612        struct fill_chain *next;
 613};
 614
 615static struct fill_chain *fill_cfg;
 616
 617void add_fill_function(void *data, int (*fill)(void *))
 618{
 619        struct fill_chain *new = xmalloc(sizeof(*new));
 620        struct fill_chain **linkp = &fill_cfg;
 621        new->data = data;
 622        new->fill = fill;
 623        new->next = NULL;
 624        while (*linkp)
 625                linkp = &(*linkp)->next;
 626        *linkp = new;
 627}
 628
 629void fill_active_slots(void)
 630{
 631        struct active_request_slot *slot = active_queue_head;
 632
 633        while (active_requests < max_requests) {
 634                struct fill_chain *fill;
 635                for (fill = fill_cfg; fill; fill = fill->next)
 636                        if (fill->fill(fill->data))
 637                                break;
 638
 639                if (!fill)
 640                        break;
 641        }
 642
 643        while (slot != NULL) {
 644                if (!slot->in_use && slot->curl != NULL
 645                        && curl_session_count > min_curl_sessions) {
 646                        curl_easy_cleanup(slot->curl);
 647                        slot->curl = NULL;
 648                        curl_session_count--;
 649                }
 650                slot = slot->next;
 651        }
 652}
 653
 654void step_active_slots(void)
 655{
 656        int num_transfers;
 657        CURLMcode curlm_result;
 658
 659        do {
 660                curlm_result = curl_multi_perform(curlm, &num_transfers);
 661        } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
 662        if (num_transfers < active_requests) {
 663                process_curl_messages();
 664                fill_active_slots();
 665        }
 666}
 667#endif
 668
 669void run_active_slot(struct active_request_slot *slot)
 670{
 671#ifdef USE_CURL_MULTI
 672        fd_set readfds;
 673        fd_set writefds;
 674        fd_set excfds;
 675        int max_fd;
 676        struct timeval select_timeout;
 677        int finished = 0;
 678
 679        slot->finished = &finished;
 680        while (!finished) {
 681                step_active_slots();
 682
 683                if (slot->in_use) {
 684#if LIBCURL_VERSION_NUM >= 0x070f04
 685                        long curl_timeout;
 686                        curl_multi_timeout(curlm, &curl_timeout);
 687                        if (curl_timeout == 0) {
 688                                continue;
 689                        } else if (curl_timeout == -1) {
 690                                select_timeout.tv_sec  = 0;
 691                                select_timeout.tv_usec = 50000;
 692                        } else {
 693                                select_timeout.tv_sec  =  curl_timeout / 1000;
 694                                select_timeout.tv_usec = (curl_timeout % 1000) * 1000;
 695                        }
 696#else
 697                        select_timeout.tv_sec  = 0;
 698                        select_timeout.tv_usec = 50000;
 699#endif
 700
 701                        max_fd = -1;
 702                        FD_ZERO(&readfds);
 703                        FD_ZERO(&writefds);
 704                        FD_ZERO(&excfds);
 705                        curl_multi_fdset(curlm, &readfds, &writefds, &excfds, &max_fd);
 706
 707                        /*
 708                         * It can happen that curl_multi_timeout returns a pathologically
 709                         * long timeout when curl_multi_fdset returns no file descriptors
 710                         * to read.  See commit message for more details.
 711                         */
 712                        if (max_fd < 0 &&
 713                            (select_timeout.tv_sec > 0 ||
 714                             select_timeout.tv_usec > 50000)) {
 715                                select_timeout.tv_sec  = 0;
 716                                select_timeout.tv_usec = 50000;
 717                        }
 718
 719                        select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
 720                }
 721        }
 722#else
 723        while (slot->in_use) {
 724                slot->curl_result = curl_easy_perform(slot->curl);
 725                finish_active_slot(slot);
 726        }
 727#endif
 728}
 729
 730static void closedown_active_slot(struct active_request_slot *slot)
 731{
 732        active_requests--;
 733        slot->in_use = 0;
 734}
 735
 736static void release_active_slot(struct active_request_slot *slot)
 737{
 738        closedown_active_slot(slot);
 739        if (slot->curl && curl_session_count > min_curl_sessions) {
 740#ifdef USE_CURL_MULTI
 741                curl_multi_remove_handle(curlm, slot->curl);
 742#endif
 743                curl_easy_cleanup(slot->curl);
 744                slot->curl = NULL;
 745                curl_session_count--;
 746        }
 747#ifdef USE_CURL_MULTI
 748        fill_active_slots();
 749#endif
 750}
 751
 752void finish_active_slot(struct active_request_slot *slot)
 753{
 754        closedown_active_slot(slot);
 755        curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
 756
 757        if (slot->finished != NULL)
 758                (*slot->finished) = 1;
 759
 760        /* Store slot results so they can be read after the slot is reused */
 761        if (slot->results != NULL) {
 762                slot->results->curl_result = slot->curl_result;
 763                slot->results->http_code = slot->http_code;
 764        }
 765
 766        /* Run callback if appropriate */
 767        if (slot->callback_func != NULL)
 768                slot->callback_func(slot->callback_data);
 769}
 770
 771void finish_all_active_slots(void)
 772{
 773        struct active_request_slot *slot = active_queue_head;
 774
 775        while (slot != NULL)
 776                if (slot->in_use) {
 777                        run_active_slot(slot);
 778                        slot = active_queue_head;
 779                } else {
 780                        slot = slot->next;
 781                }
 782}
 783
 784/* Helpers for modifying and creating URLs */
 785static inline int needs_quote(int ch)
 786{
 787        if (((ch >= 'A') && (ch <= 'Z'))
 788                        || ((ch >= 'a') && (ch <= 'z'))
 789                        || ((ch >= '0') && (ch <= '9'))
 790                        || (ch == '/')
 791                        || (ch == '-')
 792                        || (ch == '.'))
 793                return 0;
 794        return 1;
 795}
 796
 797static char *quote_ref_url(const char *base, const char *ref)
 798{
 799        struct strbuf buf = STRBUF_INIT;
 800        const char *cp;
 801        int ch;
 802
 803        end_url_with_slash(&buf, base);
 804
 805        for (cp = ref; (ch = *cp) != 0; cp++)
 806                if (needs_quote(ch))
 807                        strbuf_addf(&buf, "%%%02x", ch);
 808                else
 809                        strbuf_addch(&buf, *cp);
 810
 811        return strbuf_detach(&buf, NULL);
 812}
 813
 814void append_remote_object_url(struct strbuf *buf, const char *url,
 815                              const char *hex,
 816                              int only_two_digit_prefix)
 817{
 818        end_url_with_slash(buf, url);
 819
 820        strbuf_addf(buf, "objects/%.*s/", 2, hex);
 821        if (!only_two_digit_prefix)
 822                strbuf_addf(buf, "%s", hex+2);
 823}
 824
 825char *get_remote_object_url(const char *url, const char *hex,
 826                            int only_two_digit_prefix)
 827{
 828        struct strbuf buf = STRBUF_INIT;
 829        append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
 830        return strbuf_detach(&buf, NULL);
 831}
 832
 833int handle_curl_result(struct slot_results *results)
 834{
 835        /*
 836         * If we see a failing http code with CURLE_OK, we have turned off
 837         * FAILONERROR (to keep the server's custom error response), and should
 838         * translate the code into failure here.
 839         */
 840        if (results->curl_result == CURLE_OK &&
 841            results->http_code >= 400) {
 842                results->curl_result = CURLE_HTTP_RETURNED_ERROR;
 843                /*
 844                 * Normally curl will already have put the "reason phrase"
 845                 * from the server into curl_errorstr; unfortunately without
 846                 * FAILONERROR it is lost, so we can give only the numeric
 847                 * status code.
 848                 */
 849                snprintf(curl_errorstr, sizeof(curl_errorstr),
 850                         "The requested URL returned error: %ld",
 851                         results->http_code);
 852        }
 853
 854        if (results->curl_result == CURLE_OK) {
 855                credential_approve(&http_auth);
 856                return HTTP_OK;
 857        } else if (missing_target(results))
 858                return HTTP_MISSING_TARGET;
 859        else if (results->http_code == 401) {
 860                if (http_auth.username && http_auth.password) {
 861                        credential_reject(&http_auth);
 862                        return HTTP_NOAUTH;
 863                } else {
 864                        credential_fill(&http_auth);
 865                        return HTTP_REAUTH;
 866                }
 867        } else {
 868#if LIBCURL_VERSION_NUM >= 0x070c00
 869                if (!curl_errorstr[0])
 870                        strlcpy(curl_errorstr,
 871                                curl_easy_strerror(results->curl_result),
 872                                sizeof(curl_errorstr));
 873#endif
 874                return HTTP_ERROR;
 875        }
 876}
 877
 878/* http_request() targets */
 879#define HTTP_REQUEST_STRBUF     0
 880#define HTTP_REQUEST_FILE       1
 881
 882static int http_request(const char *url, struct strbuf *type,
 883                        void *result, int target, int options)
 884{
 885        struct active_request_slot *slot;
 886        struct slot_results results;
 887        struct curl_slist *headers = NULL;
 888        struct strbuf buf = STRBUF_INIT;
 889        int ret;
 890
 891        slot = get_active_slot();
 892        slot->results = &results;
 893        curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
 894
 895        if (result == NULL) {
 896                curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
 897        } else {
 898                curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
 899                curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
 900
 901                if (target == HTTP_REQUEST_FILE) {
 902                        long posn = ftell(result);
 903                        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
 904                                         fwrite);
 905                        if (posn > 0) {
 906                                strbuf_addf(&buf, "Range: bytes=%ld-", posn);
 907                                headers = curl_slist_append(headers, buf.buf);
 908                                strbuf_reset(&buf);
 909                        }
 910                } else
 911                        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
 912                                         fwrite_buffer);
 913        }
 914
 915        strbuf_addstr(&buf, "Pragma:");
 916        if (options & HTTP_NO_CACHE)
 917                strbuf_addstr(&buf, " no-cache");
 918        if (options & HTTP_KEEP_ERROR)
 919                curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
 920
 921        headers = curl_slist_append(headers, buf.buf);
 922
 923        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 924        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
 925        curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
 926
 927        if (start_active_slot(slot)) {
 928                run_active_slot(slot);
 929                ret = handle_curl_result(&results);
 930        } else {
 931                snprintf(curl_errorstr, sizeof(curl_errorstr),
 932                         "failed to start HTTP request");
 933                ret = HTTP_START_FAILED;
 934        }
 935
 936        if (type) {
 937                char *t;
 938                strbuf_reset(type);
 939                curl_easy_getinfo(slot->curl, CURLINFO_CONTENT_TYPE, &t);
 940                if (t)
 941                        strbuf_addstr(type, t);
 942        }
 943
 944        curl_slist_free_all(headers);
 945        strbuf_release(&buf);
 946
 947        return ret;
 948}
 949
 950static int http_request_reauth(const char *url,
 951                               struct strbuf *type,
 952                               void *result, int target,
 953                               int options)
 954{
 955        int ret = http_request(url, type, result, target, options);
 956        if (ret != HTTP_REAUTH)
 957                return ret;
 958
 959        /*
 960         * If we are using KEEP_ERROR, the previous request may have
 961         * put cruft into our output stream; we should clear it out before
 962         * making our next request. We only know how to do this for
 963         * the strbuf case, but that is enough to satisfy current callers.
 964         */
 965        if (options & HTTP_KEEP_ERROR) {
 966                switch (target) {
 967                case HTTP_REQUEST_STRBUF:
 968                        strbuf_reset(result);
 969                        break;
 970                default:
 971                        die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
 972                }
 973        }
 974        return http_request(url, type, result, target, options);
 975}
 976
 977int http_get_strbuf(const char *url,
 978                    struct strbuf *type,
 979                    struct strbuf *result, int options)
 980{
 981        return http_request_reauth(url, type, result,
 982                                   HTTP_REQUEST_STRBUF, options);
 983}
 984
 985/*
 986 * Downloads a URL and stores the result in the given file.
 987 *
 988 * If a previous interrupted download is detected (i.e. a previous temporary
 989 * file is still around) the download is resumed.
 990 */
 991static int http_get_file(const char *url, const char *filename, int options)
 992{
 993        int ret;
 994        struct strbuf tmpfile = STRBUF_INIT;
 995        FILE *result;
 996
 997        strbuf_addf(&tmpfile, "%s.temp", filename);
 998        result = fopen(tmpfile.buf, "a");
 999        if (! result) {
1000                error("Unable to open local file %s", tmpfile.buf);
1001                ret = HTTP_ERROR;
1002                goto cleanup;
1003        }
1004
1005        ret = http_request_reauth(url, NULL, result, HTTP_REQUEST_FILE, options);
1006        fclose(result);
1007
1008        if ((ret == HTTP_OK) && move_temp_to_file(tmpfile.buf, filename))
1009                ret = HTTP_ERROR;
1010cleanup:
1011        strbuf_release(&tmpfile);
1012        return ret;
1013}
1014
1015int http_fetch_ref(const char *base, struct ref *ref)
1016{
1017        char *url;
1018        struct strbuf buffer = STRBUF_INIT;
1019        int ret = -1;
1020
1021        url = quote_ref_url(base, ref->name);
1022        if (http_get_strbuf(url, NULL, &buffer, HTTP_NO_CACHE) == HTTP_OK) {
1023                strbuf_rtrim(&buffer);
1024                if (buffer.len == 40)
1025                        ret = get_sha1_hex(buffer.buf, ref->old_sha1);
1026                else if (!prefixcmp(buffer.buf, "ref: ")) {
1027                        ref->symref = xstrdup(buffer.buf + 5);
1028                        ret = 0;
1029                }
1030        }
1031
1032        strbuf_release(&buffer);
1033        free(url);
1034        return ret;
1035}
1036
1037/* Helpers for fetching packs */
1038static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
1039{
1040        char *url, *tmp;
1041        struct strbuf buf = STRBUF_INIT;
1042
1043        if (http_is_verbose)
1044                fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
1045
1046        end_url_with_slash(&buf, base_url);
1047        strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
1048        url = strbuf_detach(&buf, NULL);
1049
1050        strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
1051        tmp = strbuf_detach(&buf, NULL);
1052
1053        if (http_get_file(url, tmp, 0) != HTTP_OK) {
1054                error("Unable to get pack index %s", url);
1055                free(tmp);
1056                tmp = NULL;
1057        }
1058
1059        free(url);
1060        return tmp;
1061}
1062
1063static int fetch_and_setup_pack_index(struct packed_git **packs_head,
1064        unsigned char *sha1, const char *base_url)
1065{
1066        struct packed_git *new_pack;
1067        char *tmp_idx = NULL;
1068        int ret;
1069
1070        if (has_pack_index(sha1)) {
1071                new_pack = parse_pack_index(sha1, NULL);
1072                if (!new_pack)
1073                        return -1; /* parse_pack_index() already issued error message */
1074                goto add_pack;
1075        }
1076
1077        tmp_idx = fetch_pack_index(sha1, base_url);
1078        if (!tmp_idx)
1079                return -1;
1080
1081        new_pack = parse_pack_index(sha1, tmp_idx);
1082        if (!new_pack) {
1083                unlink(tmp_idx);
1084                free(tmp_idx);
1085
1086                return -1; /* parse_pack_index() already issued error message */
1087        }
1088
1089        ret = verify_pack_index(new_pack);
1090        if (!ret) {
1091                close_pack_index(new_pack);
1092                ret = move_temp_to_file(tmp_idx, sha1_pack_index_name(sha1));
1093        }
1094        free(tmp_idx);
1095        if (ret)
1096                return -1;
1097
1098add_pack:
1099        new_pack->next = *packs_head;
1100        *packs_head = new_pack;
1101        return 0;
1102}
1103
1104int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
1105{
1106        int ret = 0, i = 0;
1107        char *url, *data;
1108        struct strbuf buf = STRBUF_INIT;
1109        unsigned char sha1[20];
1110
1111        end_url_with_slash(&buf, base_url);
1112        strbuf_addstr(&buf, "objects/info/packs");
1113        url = strbuf_detach(&buf, NULL);
1114
1115        ret = http_get_strbuf(url, NULL, &buf, HTTP_NO_CACHE);
1116        if (ret != HTTP_OK)
1117                goto cleanup;
1118
1119        data = buf.buf;
1120        while (i < buf.len) {
1121                switch (data[i]) {
1122                case 'P':
1123                        i++;
1124                        if (i + 52 <= buf.len &&
1125                            !prefixcmp(data + i, " pack-") &&
1126                            !prefixcmp(data + i + 46, ".pack\n")) {
1127                                get_sha1_hex(data + i + 6, sha1);
1128                                fetch_and_setup_pack_index(packs_head, sha1,
1129                                                      base_url);
1130                                i += 51;
1131                                break;
1132                        }
1133                default:
1134                        while (i < buf.len && data[i] != '\n')
1135                                i++;
1136                }
1137                i++;
1138        }
1139
1140cleanup:
1141        free(url);
1142        return ret;
1143}
1144
1145void release_http_pack_request(struct http_pack_request *preq)
1146{
1147        if (preq->packfile != NULL) {
1148                fclose(preq->packfile);
1149                preq->packfile = NULL;
1150        }
1151        if (preq->range_header != NULL) {
1152                curl_slist_free_all(preq->range_header);
1153                preq->range_header = NULL;
1154        }
1155        preq->slot = NULL;
1156        free(preq->url);
1157}
1158
1159int finish_http_pack_request(struct http_pack_request *preq)
1160{
1161        struct packed_git **lst;
1162        struct packed_git *p = preq->target;
1163        char *tmp_idx;
1164        struct child_process ip;
1165        const char *ip_argv[8];
1166
1167        close_pack_index(p);
1168
1169        fclose(preq->packfile);
1170        preq->packfile = NULL;
1171
1172        lst = preq->lst;
1173        while (*lst != p)
1174                lst = &((*lst)->next);
1175        *lst = (*lst)->next;
1176
1177        tmp_idx = xstrdup(preq->tmpfile);
1178        strcpy(tmp_idx + strlen(tmp_idx) - strlen(".pack.temp"),
1179               ".idx.temp");
1180
1181        ip_argv[0] = "index-pack";
1182        ip_argv[1] = "-o";
1183        ip_argv[2] = tmp_idx;
1184        ip_argv[3] = preq->tmpfile;
1185        ip_argv[4] = NULL;
1186
1187        memset(&ip, 0, sizeof(ip));
1188        ip.argv = ip_argv;
1189        ip.git_cmd = 1;
1190        ip.no_stdin = 1;
1191        ip.no_stdout = 1;
1192
1193        if (run_command(&ip)) {
1194                unlink(preq->tmpfile);
1195                unlink(tmp_idx);
1196                free(tmp_idx);
1197                return -1;
1198        }
1199
1200        unlink(sha1_pack_index_name(p->sha1));
1201
1202        if (move_temp_to_file(preq->tmpfile, sha1_pack_name(p->sha1))
1203         || move_temp_to_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
1204                free(tmp_idx);
1205                return -1;
1206        }
1207
1208        install_packed_git(p);
1209        free(tmp_idx);
1210        return 0;
1211}
1212
1213struct http_pack_request *new_http_pack_request(
1214        struct packed_git *target, const char *base_url)
1215{
1216        long prev_posn = 0;
1217        char range[RANGE_HEADER_SIZE];
1218        struct strbuf buf = STRBUF_INIT;
1219        struct http_pack_request *preq;
1220
1221        preq = xcalloc(1, sizeof(*preq));
1222        preq->target = target;
1223
1224        end_url_with_slash(&buf, base_url);
1225        strbuf_addf(&buf, "objects/pack/pack-%s.pack",
1226                sha1_to_hex(target->sha1));
1227        preq->url = strbuf_detach(&buf, NULL);
1228
1229        snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
1230                sha1_pack_name(target->sha1));
1231        preq->packfile = fopen(preq->tmpfile, "a");
1232        if (!preq->packfile) {
1233                error("Unable to open local file %s for pack",
1234                      preq->tmpfile);
1235                goto abort;
1236        }
1237
1238        preq->slot = get_active_slot();
1239        curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
1240        curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
1241        curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
1242        curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1243                no_pragma_header);
1244
1245        /*
1246         * If there is data present from a previous transfer attempt,
1247         * resume where it left off
1248         */
1249        prev_posn = ftell(preq->packfile);
1250        if (prev_posn>0) {
1251                if (http_is_verbose)
1252                        fprintf(stderr,
1253                                "Resuming fetch of pack %s at byte %ld\n",
1254                                sha1_to_hex(target->sha1), prev_posn);
1255                sprintf(range, "Range: bytes=%ld-", prev_posn);
1256                preq->range_header = curl_slist_append(NULL, range);
1257                curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1258                        preq->range_header);
1259        }
1260
1261        return preq;
1262
1263abort:
1264        free(preq->url);
1265        free(preq);
1266        return NULL;
1267}
1268
1269/* Helpers for fetching objects (loose) */
1270static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
1271                               void *data)
1272{
1273        unsigned char expn[4096];
1274        size_t size = eltsize * nmemb;
1275        int posn = 0;
1276        struct http_object_request *freq =
1277                (struct http_object_request *)data;
1278        do {
1279                ssize_t retval = xwrite(freq->localfile,
1280                                        (char *) ptr + posn, size - posn);
1281                if (retval < 0)
1282                        return posn;
1283                posn += retval;
1284        } while (posn < size);
1285
1286        freq->stream.avail_in = size;
1287        freq->stream.next_in = (void *)ptr;
1288        do {
1289                freq->stream.next_out = expn;
1290                freq->stream.avail_out = sizeof(expn);
1291                freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
1292                git_SHA1_Update(&freq->c, expn,
1293                                sizeof(expn) - freq->stream.avail_out);
1294        } while (freq->stream.avail_in && freq->zret == Z_OK);
1295        return size;
1296}
1297
1298struct http_object_request *new_http_object_request(const char *base_url,
1299        unsigned char *sha1)
1300{
1301        char *hex = sha1_to_hex(sha1);
1302        char *filename;
1303        char prevfile[PATH_MAX];
1304        int prevlocal;
1305        char prev_buf[PREV_BUF_SIZE];
1306        ssize_t prev_read = 0;
1307        long prev_posn = 0;
1308        char range[RANGE_HEADER_SIZE];
1309        struct curl_slist *range_header = NULL;
1310        struct http_object_request *freq;
1311
1312        freq = xcalloc(1, sizeof(*freq));
1313        hashcpy(freq->sha1, sha1);
1314        freq->localfile = -1;
1315
1316        filename = sha1_file_name(sha1);
1317        snprintf(freq->tmpfile, sizeof(freq->tmpfile),
1318                 "%s.temp", filename);
1319
1320        snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
1321        unlink_or_warn(prevfile);
1322        rename(freq->tmpfile, prevfile);
1323        unlink_or_warn(freq->tmpfile);
1324
1325        if (freq->localfile != -1)
1326                error("fd leakage in start: %d", freq->localfile);
1327        freq->localfile = open(freq->tmpfile,
1328                               O_WRONLY | O_CREAT | O_EXCL, 0666);
1329        /*
1330         * This could have failed due to the "lazy directory creation";
1331         * try to mkdir the last path component.
1332         */
1333        if (freq->localfile < 0 && errno == ENOENT) {
1334                char *dir = strrchr(freq->tmpfile, '/');
1335                if (dir) {
1336                        *dir = 0;
1337                        mkdir(freq->tmpfile, 0777);
1338                        *dir = '/';
1339                }
1340                freq->localfile = open(freq->tmpfile,
1341                                       O_WRONLY | O_CREAT | O_EXCL, 0666);
1342        }
1343
1344        if (freq->localfile < 0) {
1345                error("Couldn't create temporary file %s: %s",
1346                      freq->tmpfile, strerror(errno));
1347                goto abort;
1348        }
1349
1350        git_inflate_init(&freq->stream);
1351
1352        git_SHA1_Init(&freq->c);
1353
1354        freq->url = get_remote_object_url(base_url, hex, 0);
1355
1356        /*
1357         * If a previous temp file is present, process what was already
1358         * fetched.
1359         */
1360        prevlocal = open(prevfile, O_RDONLY);
1361        if (prevlocal != -1) {
1362                do {
1363                        prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
1364                        if (prev_read>0) {
1365                                if (fwrite_sha1_file(prev_buf,
1366                                                     1,
1367                                                     prev_read,
1368                                                     freq) == prev_read) {
1369                                        prev_posn += prev_read;
1370                                } else {
1371                                        prev_read = -1;
1372                                }
1373                        }
1374                } while (prev_read > 0);
1375                close(prevlocal);
1376        }
1377        unlink_or_warn(prevfile);
1378
1379        /*
1380         * Reset inflate/SHA1 if there was an error reading the previous temp
1381         * file; also rewind to the beginning of the local file.
1382         */
1383        if (prev_read == -1) {
1384                memset(&freq->stream, 0, sizeof(freq->stream));
1385                git_inflate_init(&freq->stream);
1386                git_SHA1_Init(&freq->c);
1387                if (prev_posn>0) {
1388                        prev_posn = 0;
1389                        lseek(freq->localfile, 0, SEEK_SET);
1390                        if (ftruncate(freq->localfile, 0) < 0) {
1391                                error("Couldn't truncate temporary file %s: %s",
1392                                          freq->tmpfile, strerror(errno));
1393                                goto abort;
1394                        }
1395                }
1396        }
1397
1398        freq->slot = get_active_slot();
1399
1400        curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
1401        curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
1402        curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
1403        curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
1404        curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
1405
1406        /*
1407         * If we have successfully processed data from a previous fetch
1408         * attempt, only fetch the data we don't already have.
1409         */
1410        if (prev_posn>0) {
1411                if (http_is_verbose)
1412                        fprintf(stderr,
1413                                "Resuming fetch of object %s at byte %ld\n",
1414                                hex, prev_posn);
1415                sprintf(range, "Range: bytes=%ld-", prev_posn);
1416                range_header = curl_slist_append(range_header, range);
1417                curl_easy_setopt(freq->slot->curl,
1418                                 CURLOPT_HTTPHEADER, range_header);
1419        }
1420
1421        return freq;
1422
1423abort:
1424        free(freq->url);
1425        free(freq);
1426        return NULL;
1427}
1428
1429void process_http_object_request(struct http_object_request *freq)
1430{
1431        if (freq->slot == NULL)
1432                return;
1433        freq->curl_result = freq->slot->curl_result;
1434        freq->http_code = freq->slot->http_code;
1435        freq->slot = NULL;
1436}
1437
1438int finish_http_object_request(struct http_object_request *freq)
1439{
1440        struct stat st;
1441
1442        close(freq->localfile);
1443        freq->localfile = -1;
1444
1445        process_http_object_request(freq);
1446
1447        if (freq->http_code == 416) {
1448                warning("requested range invalid; we may already have all the data.");
1449        } else if (freq->curl_result != CURLE_OK) {
1450                if (stat(freq->tmpfile, &st) == 0)
1451                        if (st.st_size == 0)
1452                                unlink_or_warn(freq->tmpfile);
1453                return -1;
1454        }
1455
1456        git_inflate_end(&freq->stream);
1457        git_SHA1_Final(freq->real_sha1, &freq->c);
1458        if (freq->zret != Z_STREAM_END) {
1459                unlink_or_warn(freq->tmpfile);
1460                return -1;
1461        }
1462        if (hashcmp(freq->sha1, freq->real_sha1)) {
1463                unlink_or_warn(freq->tmpfile);
1464                return -1;
1465        }
1466        freq->rename =
1467                move_temp_to_file(freq->tmpfile, sha1_file_name(freq->sha1));
1468
1469        return freq->rename;
1470}
1471
1472void abort_http_object_request(struct http_object_request *freq)
1473{
1474        unlink_or_warn(freq->tmpfile);
1475
1476        release_http_object_request(freq);
1477}
1478
1479void release_http_object_request(struct http_object_request *freq)
1480{
1481        if (freq->localfile != -1) {
1482                close(freq->localfile);
1483                freq->localfile = -1;
1484        }
1485        if (freq->url != NULL) {
1486                free(freq->url);
1487                freq->url = NULL;
1488        }
1489        if (freq->slot != NULL) {
1490                freq->slot->callback_func = NULL;
1491                freq->slot->callback_data = NULL;
1492                release_active_slot(freq->slot);
1493                freq->slot = NULL;
1494        }
1495}