Andrew's git / gitweb.git / http.c
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http.con commit http.c: prompt for SSL client certificate password (30dd916)
   1#include "http.h"
   2
   3int data_received;
   4int active_requests;
   5
   6#ifdef USE_CURL_MULTI
   7static int max_requests = -1;
   8static CURLM *curlm;
   9#endif
  10#ifndef NO_CURL_EASY_DUPHANDLE
  11static CURL *curl_default;
  12#endif
  13char curl_errorstr[CURL_ERROR_SIZE];
  14
  15static int curl_ssl_verify = -1;
  16static const char *ssl_cert;
  17#if LIBCURL_VERSION_NUM >= 0x070902
  18static const char *ssl_key;
  19#endif
  20#if LIBCURL_VERSION_NUM >= 0x070908
  21static const char *ssl_capath;
  22#endif
  23static const char *ssl_cainfo;
  24static long curl_low_speed_limit = -1;
  25static long curl_low_speed_time = -1;
  26static int curl_ftp_no_epsv;
  27static const char *curl_http_proxy;
  28static char *user_name, *user_pass;
  29
  30#if LIBCURL_VERSION_NUM >= 0x071700
  31/* Use CURLOPT_KEYPASSWD as is */
  32#elif LIBCURL_VERSION_NUM >= 0x070903
  33#define CURLOPT_KEYPASSWD CURLOPT_SSLKEYPASSWD
  34#else
  35#define CURLOPT_KEYPASSWD CURLOPT_SSLCERTPASSWD
  36#endif
  37
  38static char *ssl_cert_password;
  39static int ssl_cert_password_required;
  40
  41static struct curl_slist *pragma_header;
  42
  43static struct active_request_slot *active_queue_head;
  44
  45size_t fread_buffer(void *ptr, size_t eltsize, size_t nmemb, void *buffer_)
  46{
  47        size_t size = eltsize * nmemb;
  48        struct buffer *buffer = buffer_;
  49
  50        if (size > buffer->buf.len - buffer->posn)
  51                size = buffer->buf.len - buffer->posn;
  52        memcpy(ptr, buffer->buf.buf + buffer->posn, size);
  53        buffer->posn += size;
  54
  55        return size;
  56}
  57
  58#ifndef NO_CURL_IOCTL
  59curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)
  60{
  61        struct buffer *buffer = clientp;
  62
  63        switch (cmd) {
  64        case CURLIOCMD_NOP:
  65                return CURLIOE_OK;
  66
  67        case CURLIOCMD_RESTARTREAD:
  68                buffer->posn = 0;
  69                return CURLIOE_OK;
  70
  71        default:
  72                return CURLIOE_UNKNOWNCMD;
  73        }
  74}
  75#endif
  76
  77size_t fwrite_buffer(const void *ptr, size_t eltsize, size_t nmemb, void *buffer_)
  78{
  79        size_t size = eltsize * nmemb;
  80        struct strbuf *buffer = buffer_;
  81
  82        strbuf_add(buffer, ptr, size);
  83        data_received++;
  84        return size;
  85}
  86
  87size_t fwrite_null(const void *ptr, size_t eltsize, size_t nmemb, void *strbuf)
  88{
  89        data_received++;
  90        return eltsize * nmemb;
  91}
  92
  93static void finish_active_slot(struct active_request_slot *slot);
  94
  95#ifdef USE_CURL_MULTI
  96static void process_curl_messages(void)
  97{
  98        int num_messages;
  99        struct active_request_slot *slot;
 100        CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
 101
 102        while (curl_message != NULL) {
 103                if (curl_message->msg == CURLMSG_DONE) {
 104                        int curl_result = curl_message->data.result;
 105                        slot = active_queue_head;
 106                        while (slot != NULL &&
 107                               slot->curl != curl_message->easy_handle)
 108                                slot = slot->next;
 109                        if (slot != NULL) {
 110                                curl_multi_remove_handle(curlm, slot->curl);
 111                                slot->curl_result = curl_result;
 112                                finish_active_slot(slot);
 113                        } else {
 114                                fprintf(stderr, "Received DONE message for unknown request!\n");
 115                        }
 116                } else {
 117                        fprintf(stderr, "Unknown CURL message received: %d\n",
 118                                (int)curl_message->msg);
 119                }
 120                curl_message = curl_multi_info_read(curlm, &num_messages);
 121        }
 122}
 123#endif
 124
 125static int http_options(const char *var, const char *value, void *cb)
 126{
 127        if (!strcmp("http.sslverify", var)) {
 128                curl_ssl_verify = git_config_bool(var, value);
 129                return 0;
 130        }
 131        if (!strcmp("http.sslcert", var))
 132                return git_config_string(&ssl_cert, var, value);
 133#if LIBCURL_VERSION_NUM >= 0x070902
 134        if (!strcmp("http.sslkey", var))
 135                return git_config_string(&ssl_key, var, value);
 136#endif
 137#if LIBCURL_VERSION_NUM >= 0x070908
 138        if (!strcmp("http.sslcapath", var))
 139                return git_config_string(&ssl_capath, var, value);
 140#endif
 141        if (!strcmp("http.sslcainfo", var))
 142                return git_config_string(&ssl_cainfo, var, value);
 143#ifdef USE_CURL_MULTI
 144        if (!strcmp("http.maxrequests", var)) {
 145                max_requests = git_config_int(var, value);
 146                return 0;
 147        }
 148#endif
 149        if (!strcmp("http.lowspeedlimit", var)) {
 150                curl_low_speed_limit = (long)git_config_int(var, value);
 151                return 0;
 152        }
 153        if (!strcmp("http.lowspeedtime", var)) {
 154                curl_low_speed_time = (long)git_config_int(var, value);
 155                return 0;
 156        }
 157
 158        if (!strcmp("http.noepsv", var)) {
 159                curl_ftp_no_epsv = git_config_bool(var, value);
 160                return 0;
 161        }
 162        if (!strcmp("http.proxy", var))
 163                return git_config_string(&curl_http_proxy, var, value);
 164
 165        /* Fall back on the default ones */
 166        return git_default_config(var, value, cb);
 167}
 168
 169static void init_curl_http_auth(CURL *result)
 170{
 171        if (user_name) {
 172                struct strbuf up = STRBUF_INIT;
 173                if (!user_pass)
 174                        user_pass = xstrdup(getpass("Password: "));
 175                strbuf_addf(&up, "%s:%s", user_name, user_pass);
 176                curl_easy_setopt(result, CURLOPT_USERPWD,
 177                                 strbuf_detach(&up, NULL));
 178        }
 179}
 180
 181static int has_cert_password(void)
 182{
 183        if (ssl_cert_password != NULL)
 184                return 1;
 185        if (ssl_cert == NULL || ssl_cert_password_required != 1)
 186                return 0;
 187        /* Only prompt the user once. */
 188        ssl_cert_password_required = -1;
 189        ssl_cert_password = getpass("Certificate Password: ");
 190        if (ssl_cert_password != NULL) {
 191                ssl_cert_password = xstrdup(ssl_cert_password);
 192                return 1;
 193        } else
 194                return 0;
 195}
 196
 197static CURL *get_curl_handle(void)
 198{
 199        CURL *result = curl_easy_init();
 200
 201        if (!curl_ssl_verify) {
 202                curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
 203                curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
 204        } else {
 205                /* Verify authenticity of the peer's certificate */
 206                curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
 207                /* The name in the cert must match whom we tried to connect */
 208                curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
 209        }
 210
 211#if LIBCURL_VERSION_NUM >= 0x070907
 212        curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
 213#endif
 214
 215        init_curl_http_auth(result);
 216
 217        if (ssl_cert != NULL)
 218                curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
 219        if (has_cert_password())
 220                curl_easy_setopt(result, CURLOPT_KEYPASSWD, ssl_cert_password);
 221#if LIBCURL_VERSION_NUM >= 0x070902
 222        if (ssl_key != NULL)
 223                curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
 224#endif
 225#if LIBCURL_VERSION_NUM >= 0x070908
 226        if (ssl_capath != NULL)
 227                curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
 228#endif
 229        if (ssl_cainfo != NULL)
 230                curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
 231        curl_easy_setopt(result, CURLOPT_FAILONERROR, 1);
 232
 233        if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
 234                curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
 235                                 curl_low_speed_limit);
 236                curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
 237                                 curl_low_speed_time);
 238        }
 239
 240        curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
 241
 242        if (getenv("GIT_CURL_VERBOSE"))
 243                curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
 244
 245        curl_easy_setopt(result, CURLOPT_USERAGENT, GIT_USER_AGENT);
 246
 247        if (curl_ftp_no_epsv)
 248                curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
 249
 250        if (curl_http_proxy)
 251                curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
 252
 253        return result;
 254}
 255
 256static void http_auth_init(const char *url)
 257{
 258        char *at, *colon, *cp, *slash;
 259        int len;
 260
 261        cp = strstr(url, "://");
 262        if (!cp)
 263                return;
 264
 265        /*
 266         * Ok, the URL looks like "proto://something".  Which one?
 267         * "proto://<user>:<pass>@<host>/...",
 268         * "proto://<user>@<host>/...", or just
 269         * "proto://<host>/..."?
 270         */
 271        cp += 3;
 272        at = strchr(cp, '@');
 273        colon = strchr(cp, ':');
 274        slash = strchrnul(cp, '/');
 275        if (!at || slash <= at)
 276                return; /* No credentials */
 277        if (!colon || at <= colon) {
 278                /* Only username */
 279                len = at - cp;
 280                user_name = xmalloc(len + 1);
 281                memcpy(user_name, cp, len);
 282                user_name[len] = '\0';
 283                user_pass = NULL;
 284        } else {
 285                len = colon - cp;
 286                user_name = xmalloc(len + 1);
 287                memcpy(user_name, cp, len);
 288                user_name[len] = '\0';
 289                len = at - (colon + 1);
 290                user_pass = xmalloc(len + 1);
 291                memcpy(user_pass, colon + 1, len);
 292                user_pass[len] = '\0';
 293        }
 294}
 295
 296static void set_from_env(const char **var, const char *envname)
 297{
 298        const char *val = getenv(envname);
 299        if (val)
 300                *var = val;
 301}
 302
 303void http_init(struct remote *remote)
 304{
 305        char *low_speed_limit;
 306        char *low_speed_time;
 307
 308        git_config(http_options, NULL);
 309
 310        curl_global_init(CURL_GLOBAL_ALL);
 311
 312        if (remote && remote->http_proxy)
 313                curl_http_proxy = xstrdup(remote->http_proxy);
 314
 315        pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
 316
 317#ifdef USE_CURL_MULTI
 318        {
 319                char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
 320                if (http_max_requests != NULL)
 321                        max_requests = atoi(http_max_requests);
 322        }
 323
 324        curlm = curl_multi_init();
 325        if (curlm == NULL) {
 326                fprintf(stderr, "Error creating curl multi handle.\n");
 327                exit(1);
 328        }
 329#endif
 330
 331        if (getenv("GIT_SSL_NO_VERIFY"))
 332                curl_ssl_verify = 0;
 333
 334        set_from_env(&ssl_cert, "GIT_SSL_CERT");
 335#if LIBCURL_VERSION_NUM >= 0x070902
 336        set_from_env(&ssl_key, "GIT_SSL_KEY");
 337#endif
 338#if LIBCURL_VERSION_NUM >= 0x070908
 339        set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
 340#endif
 341        set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
 342
 343        low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
 344        if (low_speed_limit != NULL)
 345                curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
 346        low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
 347        if (low_speed_time != NULL)
 348                curl_low_speed_time = strtol(low_speed_time, NULL, 10);
 349
 350        if (curl_ssl_verify == -1)
 351                curl_ssl_verify = 1;
 352
 353#ifdef USE_CURL_MULTI
 354        if (max_requests < 1)
 355                max_requests = DEFAULT_MAX_REQUESTS;
 356#endif
 357
 358        if (getenv("GIT_CURL_FTP_NO_EPSV"))
 359                curl_ftp_no_epsv = 1;
 360
 361        if (remote && remote->url && remote->url[0]) {
 362                http_auth_init(remote->url[0]);
 363                if (!prefixcmp(remote->url[0], "https://"))
 364                        ssl_cert_password_required = 1;
 365        }
 366
 367#ifndef NO_CURL_EASY_DUPHANDLE
 368        curl_default = get_curl_handle();
 369#endif
 370}
 371
 372void http_cleanup(void)
 373{
 374        struct active_request_slot *slot = active_queue_head;
 375
 376        while (slot != NULL) {
 377                struct active_request_slot *next = slot->next;
 378                if (slot->curl != NULL) {
 379#ifdef USE_CURL_MULTI
 380                        curl_multi_remove_handle(curlm, slot->curl);
 381#endif
 382                        curl_easy_cleanup(slot->curl);
 383                }
 384                free(slot);
 385                slot = next;
 386        }
 387        active_queue_head = NULL;
 388
 389#ifndef NO_CURL_EASY_DUPHANDLE
 390        curl_easy_cleanup(curl_default);
 391#endif
 392
 393#ifdef USE_CURL_MULTI
 394        curl_multi_cleanup(curlm);
 395#endif
 396        curl_global_cleanup();
 397
 398        curl_slist_free_all(pragma_header);
 399        pragma_header = NULL;
 400
 401        if (curl_http_proxy) {
 402                free((void *)curl_http_proxy);
 403                curl_http_proxy = NULL;
 404        }
 405
 406        if (ssl_cert_password != NULL) {
 407                memset(ssl_cert_password, 0, strlen(ssl_cert_password));
 408                free(ssl_cert_password);
 409                ssl_cert_password = NULL;
 410        }
 411        ssl_cert_password_required = 0;
 412}
 413
 414struct active_request_slot *get_active_slot(void)
 415{
 416        struct active_request_slot *slot = active_queue_head;
 417        struct active_request_slot *newslot;
 418
 419#ifdef USE_CURL_MULTI
 420        int num_transfers;
 421
 422        /* Wait for a slot to open up if the queue is full */
 423        while (active_requests >= max_requests) {
 424                curl_multi_perform(curlm, &num_transfers);
 425                if (num_transfers < active_requests)
 426                        process_curl_messages();
 427        }
 428#endif
 429
 430        while (slot != NULL && slot->in_use)
 431                slot = slot->next;
 432
 433        if (slot == NULL) {
 434                newslot = xmalloc(sizeof(*newslot));
 435                newslot->curl = NULL;
 436                newslot->in_use = 0;
 437                newslot->next = NULL;
 438
 439                slot = active_queue_head;
 440                if (slot == NULL) {
 441                        active_queue_head = newslot;
 442                } else {
 443                        while (slot->next != NULL)
 444                                slot = slot->next;
 445                        slot->next = newslot;
 446                }
 447                slot = newslot;
 448        }
 449
 450        if (slot->curl == NULL) {
 451#ifdef NO_CURL_EASY_DUPHANDLE
 452                slot->curl = get_curl_handle();
 453#else
 454                slot->curl = curl_easy_duphandle(curl_default);
 455#endif
 456        }
 457
 458        active_requests++;
 459        slot->in_use = 1;
 460        slot->local = NULL;
 461        slot->results = NULL;
 462        slot->finished = NULL;
 463        slot->callback_data = NULL;
 464        slot->callback_func = NULL;
 465        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
 466        curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
 467        curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
 468        curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
 469        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
 470        curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
 471        curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
 472
 473        return slot;
 474}
 475
 476int start_active_slot(struct active_request_slot *slot)
 477{
 478#ifdef USE_CURL_MULTI
 479        CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
 480        int num_transfers;
 481
 482        if (curlm_result != CURLM_OK &&
 483            curlm_result != CURLM_CALL_MULTI_PERFORM) {
 484                active_requests--;
 485                slot->in_use = 0;
 486                return 0;
 487        }
 488
 489        /*
 490         * We know there must be something to do, since we just added
 491         * something.
 492         */
 493        curl_multi_perform(curlm, &num_transfers);
 494#endif
 495        return 1;
 496}
 497
 498#ifdef USE_CURL_MULTI
 499struct fill_chain {
 500        void *data;
 501        int (*fill)(void *);
 502        struct fill_chain *next;
 503};
 504
 505static struct fill_chain *fill_cfg;
 506
 507void add_fill_function(void *data, int (*fill)(void *))
 508{
 509        struct fill_chain *new = xmalloc(sizeof(*new));
 510        struct fill_chain **linkp = &fill_cfg;
 511        new->data = data;
 512        new->fill = fill;
 513        new->next = NULL;
 514        while (*linkp)
 515                linkp = &(*linkp)->next;
 516        *linkp = new;
 517}
 518
 519void fill_active_slots(void)
 520{
 521        struct active_request_slot *slot = active_queue_head;
 522
 523        while (active_requests < max_requests) {
 524                struct fill_chain *fill;
 525                for (fill = fill_cfg; fill; fill = fill->next)
 526                        if (fill->fill(fill->data))
 527                                break;
 528
 529                if (!fill)
 530                        break;
 531        }
 532
 533        while (slot != NULL) {
 534                if (!slot->in_use && slot->curl != NULL) {
 535                        curl_easy_cleanup(slot->curl);
 536                        slot->curl = NULL;
 537                }
 538                slot = slot->next;
 539        }
 540}
 541
 542void step_active_slots(void)
 543{
 544        int num_transfers;
 545        CURLMcode curlm_result;
 546
 547        do {
 548                curlm_result = curl_multi_perform(curlm, &num_transfers);
 549        } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
 550        if (num_transfers < active_requests) {
 551                process_curl_messages();
 552                fill_active_slots();
 553        }
 554}
 555#endif
 556
 557void run_active_slot(struct active_request_slot *slot)
 558{
 559#ifdef USE_CURL_MULTI
 560        long last_pos = 0;
 561        long current_pos;
 562        fd_set readfds;
 563        fd_set writefds;
 564        fd_set excfds;
 565        int max_fd;
 566        struct timeval select_timeout;
 567        int finished = 0;
 568
 569        slot->finished = &finished;
 570        while (!finished) {
 571                data_received = 0;
 572                step_active_slots();
 573
 574                if (!data_received && slot->local != NULL) {
 575                        current_pos = ftell(slot->local);
 576                        if (current_pos > last_pos)
 577                                data_received++;
 578                        last_pos = current_pos;
 579                }
 580
 581                if (slot->in_use && !data_received) {
 582                        max_fd = 0;
 583                        FD_ZERO(&readfds);
 584                        FD_ZERO(&writefds);
 585                        FD_ZERO(&excfds);
 586                        select_timeout.tv_sec = 0;
 587                        select_timeout.tv_usec = 50000;
 588                        select(max_fd, &readfds, &writefds,
 589                               &excfds, &select_timeout);
 590                }
 591        }
 592#else
 593        while (slot->in_use) {
 594                slot->curl_result = curl_easy_perform(slot->curl);
 595                finish_active_slot(slot);
 596        }
 597#endif
 598}
 599
 600static void closedown_active_slot(struct active_request_slot *slot)
 601{
 602        active_requests--;
 603        slot->in_use = 0;
 604}
 605
 606void release_active_slot(struct active_request_slot *slot)
 607{
 608        closedown_active_slot(slot);
 609        if (slot->curl) {
 610#ifdef USE_CURL_MULTI
 611                curl_multi_remove_handle(curlm, slot->curl);
 612#endif
 613                curl_easy_cleanup(slot->curl);
 614                slot->curl = NULL;
 615        }
 616#ifdef USE_CURL_MULTI
 617        fill_active_slots();
 618#endif
 619}
 620
 621static void finish_active_slot(struct active_request_slot *slot)
 622{
 623        closedown_active_slot(slot);
 624        curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
 625
 626        if (slot->finished != NULL)
 627                (*slot->finished) = 1;
 628
 629        /* Store slot results so they can be read after the slot is reused */
 630        if (slot->results != NULL) {
 631                slot->results->curl_result = slot->curl_result;
 632                slot->results->http_code = slot->http_code;
 633        }
 634
 635        /* Run callback if appropriate */
 636        if (slot->callback_func != NULL)
 637                slot->callback_func(slot->callback_data);
 638}
 639
 640void finish_all_active_slots(void)
 641{
 642        struct active_request_slot *slot = active_queue_head;
 643
 644        while (slot != NULL)
 645                if (slot->in_use) {
 646                        run_active_slot(slot);
 647                        slot = active_queue_head;
 648                } else {
 649                        slot = slot->next;
 650                }
 651}
 652
 653static inline int needs_quote(int ch)
 654{
 655        if (((ch >= 'A') && (ch <= 'Z'))
 656                        || ((ch >= 'a') && (ch <= 'z'))
 657                        || ((ch >= '0') && (ch <= '9'))
 658                        || (ch == '/')
 659                        || (ch == '-')
 660                        || (ch == '.'))
 661                return 0;
 662        return 1;
 663}
 664
 665static inline int hex(int v)
 666{
 667        if (v < 10)
 668                return '0' + v;
 669        else
 670                return 'A' + v - 10;
 671}
 672
 673static char *quote_ref_url(const char *base, const char *ref)
 674{
 675        struct strbuf buf = STRBUF_INIT;
 676        const char *cp;
 677        int ch;
 678
 679        strbuf_addstr(&buf, base);
 680        if (buf.len && buf.buf[buf.len - 1] != '/' && *ref != '/')
 681                strbuf_addstr(&buf, "/");
 682
 683        for (cp = ref; (ch = *cp) != 0; cp++)
 684                if (needs_quote(ch))
 685                        strbuf_addf(&buf, "%%%02x", ch);
 686                else
 687                        strbuf_addch(&buf, *cp);
 688
 689        return strbuf_detach(&buf, NULL);
 690}
 691
 692int http_fetch_ref(const char *base, struct ref *ref)
 693{
 694        char *url;
 695        struct strbuf buffer = STRBUF_INIT;
 696        struct active_request_slot *slot;
 697        struct slot_results results;
 698        int ret;
 699
 700        url = quote_ref_url(base, ref->name);
 701        slot = get_active_slot();
 702        slot->results = &results;
 703        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 704        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 705        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
 706        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 707        if (start_active_slot(slot)) {
 708                run_active_slot(slot);
 709                if (results.curl_result == CURLE_OK) {
 710                        strbuf_rtrim(&buffer);
 711                        if (buffer.len == 40)
 712                                ret = get_sha1_hex(buffer.buf, ref->old_sha1);
 713                        else if (!prefixcmp(buffer.buf, "ref: ")) {
 714                                ref->symref = xstrdup(buffer.buf + 5);
 715                                ret = 0;
 716                        } else
 717                                ret = 1;
 718                } else {
 719                        ret = error("Couldn't get %s for %s\n%s",
 720                                    url, ref->name, curl_errorstr);
 721                }
 722        } else {
 723                ret = error("Unable to start request");
 724        }
 725
 726        strbuf_release(&buffer);
 727        free(url);
 728        return ret;
 729}