Andrew's git / gitweb.git / http-fetch.c
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http-fetch.con commit Unlocalized isspace and friends (4546738)
   1#include "cache.h"
   2#include "commit.h"
   3#include "pack.h"
   4#include "fetch.h"
   5
   6#include <curl/curl.h>
   7#include <curl/easy.h>
   8
   9#if LIBCURL_VERSION_NUM >= 0x070908
  10#define USE_CURL_MULTI
  11#define DEFAULT_MAX_REQUESTS 5
  12#endif
  13
  14#if LIBCURL_VERSION_NUM < 0x070704
  15#define curl_global_cleanup() do { /* nothing */ } while(0)
  16#endif
  17#if LIBCURL_VERSION_NUM < 0x070800
  18#define curl_global_init(a) do { /* nothing */ } while(0)
  19#endif
  20
  21#define PREV_BUF_SIZE 4096
  22#define RANGE_HEADER_SIZE 30
  23
  24static int active_requests = 0;
  25static int data_received;
  26
  27#ifdef USE_CURL_MULTI
  28static int max_requests = -1;
  29static CURLM *curlm;
  30#endif
  31static CURL *curl_default;
  32static struct curl_slist *pragma_header;
  33static struct curl_slist *no_pragma_header;
  34static struct curl_slist *no_range_header;
  35static char curl_errorstr[CURL_ERROR_SIZE];
  36
  37struct alt_base
  38{
  39        char *base;
  40        int got_indices;
  41        struct packed_git *packs;
  42        struct alt_base *next;
  43};
  44
  45static struct alt_base *alt = NULL;
  46
  47enum transfer_state {
  48        WAITING,
  49        ABORTED,
  50        ACTIVE,
  51        COMPLETE,
  52};
  53
  54struct transfer_request
  55{
  56        unsigned char sha1[20];
  57        struct alt_base *repo;
  58        char *url;
  59        char filename[PATH_MAX];
  60        char tmpfile[PATH_MAX];
  61        int local;
  62        enum transfer_state state;
  63        CURLcode curl_result;
  64        char errorstr[CURL_ERROR_SIZE];
  65        long http_code;
  66        unsigned char real_sha1[20];
  67        SHA_CTX c;
  68        z_stream stream;
  69        int zret;
  70        int rename;
  71        struct active_request_slot *slot;
  72        struct transfer_request *next;
  73};
  74
  75struct active_request_slot
  76{
  77        CURL *curl;
  78        FILE *local;
  79        int in_use;
  80        int done;
  81        CURLcode curl_result;
  82        struct active_request_slot *next;
  83};
  84
  85static struct transfer_request *request_queue_head = NULL;
  86static struct active_request_slot *active_queue_head = NULL;
  87
  88static int curl_ssl_verify = -1;
  89static char *ssl_cert = NULL;
  90static char *ssl_key = NULL;
  91static char *ssl_capath = NULL;
  92static char *ssl_cainfo = NULL;
  93
  94struct buffer
  95{
  96        size_t posn;
  97        size_t size;
  98        void *buffer;
  99};
 100
 101static int http_options(const char *var, const char *value)
 102{
 103        if (!strcmp("http.sslverify", var)) {
 104                if (curl_ssl_verify == -1) {
 105                        curl_ssl_verify = git_config_bool(var, value);
 106                }
 107                return 0;
 108        }
 109
 110        if (!strcmp("http.sslcert", var)) {
 111                if (ssl_cert == NULL) {
 112                        ssl_cert = xmalloc(strlen(value)+1);
 113                        strcpy(ssl_cert, value);
 114                }
 115                return 0;
 116        }
 117#if LIBCURL_VERSION_NUM >= 0x070902
 118        if (!strcmp("http.sslkey", var)) {
 119                if (ssl_key == NULL) {
 120                        ssl_key = xmalloc(strlen(value)+1);
 121                        strcpy(ssl_key, value);
 122                }
 123                return 0;
 124        }
 125#endif
 126#if LIBCURL_VERSION_NUM >= 0x070908
 127        if (!strcmp("http.sslcapath", var)) {
 128                if (ssl_capath == NULL) {
 129                        ssl_capath = xmalloc(strlen(value)+1);
 130                        strcpy(ssl_capath, value);
 131                }
 132                return 0;
 133        }
 134#endif
 135        if (!strcmp("http.sslcainfo", var)) {
 136                if (ssl_cainfo == NULL) {
 137                        ssl_cainfo = xmalloc(strlen(value)+1);
 138                        strcpy(ssl_cainfo, value);
 139                }
 140                return 0;
 141        }
 142
 143#ifdef USE_CURL_MULTI   
 144        if (!strcmp("http.maxrequests", var)) {
 145                if (max_requests == -1)
 146                        max_requests = git_config_int(var, value);
 147                return 0;
 148        }
 149#endif
 150
 151        /* Fall back on the default ones */
 152        return git_default_config(var, value);
 153}
 154
 155static size_t fwrite_buffer(void *ptr, size_t eltsize, size_t nmemb,
 156                            struct buffer *buffer)
 157{
 158        size_t size = eltsize * nmemb;
 159        if (size > buffer->size - buffer->posn)
 160                size = buffer->size - buffer->posn;
 161        memcpy(buffer->buffer + buffer->posn, ptr, size);
 162        buffer->posn += size;
 163        data_received++;
 164        return size;
 165}
 166
 167static size_t fwrite_buffer_dynamic(const void *ptr, size_t eltsize,
 168                                    size_t nmemb, struct buffer *buffer)
 169{
 170        size_t size = eltsize * nmemb;
 171        if (size > buffer->size - buffer->posn) {
 172                buffer->size = buffer->size * 3 / 2;
 173                if (buffer->size < buffer->posn + size)
 174                        buffer->size = buffer->posn + size;
 175                buffer->buffer = xrealloc(buffer->buffer, buffer->size);
 176        }
 177        memcpy(buffer->buffer + buffer->posn, ptr, size);
 178        buffer->posn += size;
 179        data_received++;
 180        return size;
 181}
 182
 183static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
 184                               void *data)
 185{
 186        unsigned char expn[4096];
 187        size_t size = eltsize * nmemb;
 188        int posn = 0;
 189        struct transfer_request *request = (struct transfer_request *)data;
 190        do {
 191                ssize_t retval = write(request->local,
 192                                       ptr + posn, size - posn);
 193                if (retval < 0)
 194                        return posn;
 195                posn += retval;
 196        } while (posn < size);
 197
 198        request->stream.avail_in = size;
 199        request->stream.next_in = ptr;
 200        do {
 201                request->stream.next_out = expn;
 202                request->stream.avail_out = sizeof(expn);
 203                request->zret = inflate(&request->stream, Z_SYNC_FLUSH);
 204                SHA1_Update(&request->c, expn,
 205                            sizeof(expn) - request->stream.avail_out);
 206        } while (request->stream.avail_in && request->zret == Z_OK);
 207        data_received++;
 208        return size;
 209}
 210
 211#ifdef USE_CURL_MULTI
 212void process_curl_messages();
 213void process_request_queue();
 214#endif
 215
 216struct active_request_slot *get_active_slot()
 217{
 218        struct active_request_slot *slot = active_queue_head;
 219        struct active_request_slot *newslot;
 220
 221#ifdef USE_CURL_MULTI
 222        int num_transfers;
 223
 224        /* Wait for a slot to open up if the queue is full */
 225        while (active_requests >= max_requests) {
 226                curl_multi_perform(curlm, &num_transfers);
 227                if (num_transfers < active_requests) {
 228                        process_curl_messages();
 229                }
 230        }
 231#endif
 232
 233        while (slot != NULL && slot->in_use) {
 234                slot = slot->next;
 235        }
 236        if (slot == NULL) {
 237                newslot = xmalloc(sizeof(*newslot));
 238                newslot->curl = curl_easy_duphandle(curl_default);
 239                newslot->in_use = 0;
 240                newslot->next = NULL;
 241
 242                slot = active_queue_head;
 243                if (slot == NULL) {
 244                        active_queue_head = newslot;
 245                } else {
 246                        while (slot->next != NULL) {
 247                                slot = slot->next;
 248                        }
 249                        slot->next = newslot;
 250                }
 251                slot = newslot;
 252        }
 253
 254        active_requests++;
 255        slot->in_use = 1;
 256        slot->done = 0;
 257        slot->local = NULL;
 258        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
 259        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_range_header);
 260        curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
 261
 262        return slot;
 263}
 264
 265int start_active_slot(struct active_request_slot *slot)
 266{
 267#ifdef USE_CURL_MULTI
 268        CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
 269
 270        if (curlm_result != CURLM_OK &&
 271            curlm_result != CURLM_CALL_MULTI_PERFORM) {
 272                active_requests--;
 273                slot->in_use = 0;
 274                return 0;
 275        }
 276#endif
 277        return 1;
 278}
 279
 280void run_active_slot(struct active_request_slot *slot)
 281{
 282#ifdef USE_CURL_MULTI
 283        int num_transfers;
 284        long last_pos = 0;
 285        long current_pos;
 286        fd_set readfds;
 287        fd_set writefds;
 288        fd_set excfds;
 289        int max_fd;
 290        struct timeval select_timeout;
 291        CURLMcode curlm_result;
 292
 293        while (!slot->done) {
 294                data_received = 0;
 295                do {
 296                        curlm_result = curl_multi_perform(curlm,
 297                                                          &num_transfers);
 298                } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
 299                if (num_transfers < active_requests) {
 300                        process_curl_messages();
 301                        process_request_queue();
 302                }
 303
 304                if (!data_received && slot->local != NULL) {
 305                        current_pos = ftell(slot->local);
 306                        if (current_pos > last_pos)
 307                                data_received++;
 308                        last_pos = current_pos;
 309                }
 310
 311                if (!slot->done && !data_received) {
 312                        max_fd = 0;
 313                        FD_ZERO(&readfds);
 314                        FD_ZERO(&writefds);
 315                        FD_ZERO(&excfds);
 316                        select_timeout.tv_sec = 0;
 317                        select_timeout.tv_usec = 50000;
 318                        select(max_fd, &readfds, &writefds,
 319                               &excfds, &select_timeout);
 320                }
 321        }
 322#else
 323        slot->curl_result = curl_easy_perform(slot->curl);
 324        active_requests--;
 325#endif
 326}
 327
 328void start_request(struct transfer_request *request)
 329{
 330        char *hex = sha1_to_hex(request->sha1);
 331        char prevfile[PATH_MAX];
 332        char *url;
 333        char *posn;
 334        int prevlocal;
 335        unsigned char prev_buf[PREV_BUF_SIZE];
 336        ssize_t prev_read = 0;
 337        long prev_posn = 0;
 338        char range[RANGE_HEADER_SIZE];
 339        struct curl_slist *range_header = NULL;
 340        struct active_request_slot *slot;
 341
 342        snprintf(prevfile, sizeof(prevfile), "%s.prev", request->filename);
 343        unlink(prevfile);
 344        rename(request->tmpfile, prevfile);
 345        unlink(request->tmpfile);
 346
 347        request->local = open(request->tmpfile,
 348                              O_WRONLY | O_CREAT | O_EXCL, 0666);
 349        /* This could have failed due to the "lazy directory creation";
 350         * try to mkdir the last path component.
 351         */
 352        if (request->local < 0 && errno == ENOENT) {
 353                char *dir = strrchr(request->tmpfile, '/');
 354                if (dir) {
 355                        *dir = 0;
 356                        mkdir(request->tmpfile, 0777);
 357                        *dir = '/';
 358                }
 359                request->local = open(request->tmpfile,
 360                                      O_WRONLY | O_CREAT | O_EXCL, 0666);
 361        }
 362
 363        if (request->local < 0) {
 364                request->state = ABORTED;
 365                error("Couldn't create temporary file %s for %s: %s\n",
 366                      request->tmpfile, request->filename, strerror(errno));
 367                return;
 368        }
 369
 370        memset(&request->stream, 0, sizeof(request->stream));
 371
 372        inflateInit(&request->stream);
 373
 374        SHA1_Init(&request->c);
 375
 376        url = xmalloc(strlen(request->repo->base) + 50);
 377        request->url = xmalloc(strlen(request->repo->base) + 50);
 378        strcpy(url, request->repo->base);
 379        posn = url + strlen(request->repo->base);
 380        strcpy(posn, "objects/");
 381        posn += 8;
 382        memcpy(posn, hex, 2);
 383        posn += 2;
 384        *(posn++) = '/';
 385        strcpy(posn, hex + 2);
 386        strcpy(request->url, url);
 387
 388        /* If a previous temp file is present, process what was already
 389           fetched. */
 390        prevlocal = open(prevfile, O_RDONLY);
 391        if (prevlocal != -1) {
 392                do {
 393                        prev_read = read(prevlocal, prev_buf, PREV_BUF_SIZE);
 394                        if (prev_read>0) {
 395                                if (fwrite_sha1_file(prev_buf,
 396                                                     1,
 397                                                     prev_read,
 398                                                     request) == prev_read) {
 399                                        prev_posn += prev_read;
 400                                } else {
 401                                        prev_read = -1;
 402                                }
 403                        }
 404                } while (prev_read > 0);
 405                close(prevlocal);
 406        }
 407        unlink(prevfile);
 408
 409        /* Reset inflate/SHA1 if there was an error reading the previous temp
 410           file; also rewind to the beginning of the local file. */
 411        if (prev_read == -1) {
 412                memset(&request->stream, 0, sizeof(request->stream));
 413                inflateInit(&request->stream);
 414                SHA1_Init(&request->c);
 415                if (prev_posn>0) {
 416                        prev_posn = 0;
 417                        lseek(request->local, SEEK_SET, 0);
 418                        ftruncate(request->local, 0);
 419                }
 420        }
 421
 422        slot = get_active_slot();
 423        curl_easy_setopt(slot->curl, CURLOPT_FILE, request);
 424        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
 425        curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, request->errorstr);
 426        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 427        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 428
 429        /* If we have successfully processed data from a previous fetch
 430           attempt, only fetch the data we don't already have. */
 431        if (prev_posn>0) {
 432                if (get_verbosely)
 433                        fprintf(stderr,
 434                                "Resuming fetch of object %s at byte %ld\n",
 435                                hex, prev_posn);
 436                sprintf(range, "Range: bytes=%ld-", prev_posn);
 437                range_header = curl_slist_append(range_header, range);
 438                curl_easy_setopt(slot->curl,
 439                                 CURLOPT_HTTPHEADER, range_header);
 440        }
 441
 442        /* Try to get the request started, abort the request on error */
 443        if (!start_active_slot(slot)) {
 444                request->state = ABORTED;
 445                close(request->local);
 446                free(request->url);
 447                return;
 448        }
 449        
 450        request->slot = slot;
 451        request->state = ACTIVE;
 452}
 453
 454void finish_request(struct transfer_request *request)
 455{
 456        fchmod(request->local, 0444);
 457        close(request->local);
 458
 459        if (request->http_code == 416) {
 460                fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
 461        } else if (request->curl_result != CURLE_OK) {
 462                return;
 463        }
 464
 465        inflateEnd(&request->stream);
 466        SHA1_Final(request->real_sha1, &request->c);
 467        if (request->zret != Z_STREAM_END) {
 468                unlink(request->tmpfile);
 469                return;
 470        }
 471        if (memcmp(request->sha1, request->real_sha1, 20)) {
 472                unlink(request->tmpfile);
 473                return;
 474        }
 475        request->rename =
 476                move_temp_to_file(request->tmpfile, request->filename);
 477
 478        if (request->rename == 0)
 479                pull_say("got %s\n", sha1_to_hex(request->sha1));
 480}
 481
 482void release_request(struct transfer_request *request)
 483{
 484        struct transfer_request *entry = request_queue_head;
 485
 486        if (request == request_queue_head) {
 487                request_queue_head = request->next;
 488        } else {
 489                while (entry->next != NULL && entry->next != request)
 490                        entry = entry->next;
 491                if (entry->next == request)
 492                        entry->next = entry->next->next;
 493        }
 494
 495        free(request->url);
 496        free(request);
 497}
 498
 499#ifdef USE_CURL_MULTI
 500void process_curl_messages()
 501{
 502        int num_messages;
 503        struct active_request_slot *slot;
 504        struct transfer_request *request = NULL;
 505        CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
 506
 507        while (curl_message != NULL) {
 508                if (curl_message->msg == CURLMSG_DONE) {
 509                        slot = active_queue_head;
 510                        while (slot != NULL &&
 511                               slot->curl != curl_message->easy_handle)
 512                                slot = slot->next;
 513                        if (slot != NULL) {
 514                                curl_multi_remove_handle(curlm, slot->curl);
 515                                active_requests--;
 516                                slot->done = 1;
 517                                slot->in_use = 0;
 518                                slot->curl_result = curl_message->data.result;
 519                                request = request_queue_head;
 520                                while (request != NULL &&
 521                                       request->slot != slot)
 522                                        request = request->next;
 523                        } else {
 524                                fprintf(stderr, "Received DONE message for unknown request!\n");
 525                        }
 526                        if (request != NULL) {
 527                                request->curl_result =
 528                                        curl_message->data.result;
 529                                curl_easy_getinfo(slot->curl,
 530                                                  CURLINFO_HTTP_CODE,
 531                                                  &request->http_code);
 532                                request->slot = NULL;
 533
 534                                /* Use alternates if necessary */
 535                                if (request->http_code == 404 &&
 536                                    request->repo->next != NULL) {
 537                                        request->repo = request->repo->next;
 538                                        start_request(request);
 539                                } else {
 540                                        finish_request(request);
 541                                        request->state = COMPLETE;
 542                                }
 543                        }
 544                } else {
 545                        fprintf(stderr, "Unknown CURL message received: %d\n",
 546                                (int)curl_message->msg);
 547                }
 548                curl_message = curl_multi_info_read(curlm, &num_messages);
 549        }
 550}
 551
 552void process_request_queue()
 553{
 554        struct transfer_request *request = request_queue_head;
 555        int num_transfers;
 556
 557        while (active_requests < max_requests && request != NULL) {
 558                if (request->state == WAITING) {
 559                        if (has_sha1_file(request->sha1))
 560                                release_request(request);
 561                        else
 562                                start_request(request);
 563                        curl_multi_perform(curlm, &num_transfers);
 564                }
 565                request = request->next;
 566        }
 567}
 568#endif
 569
 570void prefetch(unsigned char *sha1)
 571{
 572        struct transfer_request *newreq;
 573        struct transfer_request *tail;
 574        char *filename = sha1_file_name(sha1);
 575
 576        newreq = xmalloc(sizeof(*newreq));
 577        memcpy(newreq->sha1, sha1, 20);
 578        newreq->repo = alt;
 579        newreq->url = NULL;
 580        newreq->local = -1;
 581        newreq->state = WAITING;
 582        snprintf(newreq->filename, sizeof(newreq->filename), "%s", filename);
 583        snprintf(newreq->tmpfile, sizeof(newreq->tmpfile),
 584                 "%s.temp", filename);
 585        newreq->next = NULL;
 586
 587        if (request_queue_head == NULL) {
 588                request_queue_head = newreq;
 589        } else {
 590                tail = request_queue_head;
 591                while (tail->next != NULL) {
 592                        tail = tail->next;
 593                }
 594                tail->next = newreq;
 595        }
 596#ifdef USE_CURL_MULTI
 597        process_request_queue();
 598        process_curl_messages();
 599#endif
 600}
 601
 602static int fetch_index(struct alt_base *repo, unsigned char *sha1)
 603{
 604        char *hex = sha1_to_hex(sha1);
 605        char *filename;
 606        char *url;
 607        char tmpfile[PATH_MAX];
 608        long prev_posn = 0;
 609        char range[RANGE_HEADER_SIZE];
 610        struct curl_slist *range_header = NULL;
 611
 612        FILE *indexfile;
 613        struct active_request_slot *slot;
 614
 615        if (has_pack_index(sha1))
 616                return 0;
 617
 618        if (get_verbosely)
 619                fprintf(stderr, "Getting index for pack %s\n", hex);
 620        
 621        url = xmalloc(strlen(repo->base) + 64);
 622        sprintf(url, "%s/objects/pack/pack-%s.idx", repo->base, hex);
 623        
 624        filename = sha1_pack_index_name(sha1);
 625        snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
 626        indexfile = fopen(tmpfile, "a");
 627        if (!indexfile)
 628                return error("Unable to open local file %s for pack index",
 629                             filename);
 630
 631        slot = get_active_slot();
 632        curl_easy_setopt(slot->curl, CURLOPT_FILE, indexfile);
 633        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
 634        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 635        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 636        slot->local = indexfile;
 637
 638        /* If there is data present from a previous transfer attempt,
 639           resume where it left off */
 640        prev_posn = ftell(indexfile);
 641        if (prev_posn>0) {
 642                if (get_verbosely)
 643                        fprintf(stderr,
 644                                "Resuming fetch of index for pack %s at byte %ld\n",
 645                                hex, prev_posn);
 646                sprintf(range, "Range: bytes=%ld-", prev_posn);
 647                range_header = curl_slist_append(range_header, range);
 648                curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
 649        }
 650
 651        if (start_active_slot(slot)) {
 652                run_active_slot(slot);
 653                if (slot->curl_result != CURLE_OK) {
 654                        fclose(indexfile);
 655                        return error("Unable to get pack index %s\n%s", url,
 656                                     curl_errorstr);
 657                }
 658        } else {
 659                return error("Unable to start request");
 660        }
 661
 662        fclose(indexfile);
 663
 664        return move_temp_to_file(tmpfile, filename);
 665}
 666
 667static int setup_index(struct alt_base *repo, unsigned char *sha1)
 668{
 669        struct packed_git *new_pack;
 670        if (has_pack_file(sha1))
 671                return 0; // don't list this as something we can get
 672
 673        if (fetch_index(repo, sha1))
 674                return -1;
 675
 676        new_pack = parse_pack_index(sha1);
 677        new_pack->next = repo->packs;
 678        repo->packs = new_pack;
 679        return 0;
 680}
 681
 682static int fetch_alternates(char *base)
 683{
 684        int ret = 0;
 685        struct buffer buffer;
 686        char *url;
 687        char *data;
 688        int i = 0;
 689        int http_specific = 1;
 690        struct alt_base *tail = alt;
 691        static const char null_byte = '\0';
 692
 693        struct active_request_slot *slot;
 694
 695        data = xmalloc(4096);
 696        buffer.size = 4096;
 697        buffer.posn = 0;
 698        buffer.buffer = data;
 699
 700        if (get_verbosely)
 701                fprintf(stderr, "Getting alternates list\n");
 702        
 703        url = xmalloc(strlen(base) + 31);
 704        sprintf(url, "%s/objects/info/http-alternates", base);
 705
 706        slot = get_active_slot();
 707        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 708        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
 709                         fwrite_buffer_dynamic);
 710        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 711        if (start_active_slot(slot)) {
 712                run_active_slot(slot);
 713                if (slot->curl_result != CURLE_OK || !buffer.posn) {
 714                        http_specific = 0;
 715
 716                        sprintf(url, "%s/objects/info/alternates", base);
 717
 718                        slot = get_active_slot();
 719                        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 720                        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
 721                                         fwrite_buffer_dynamic);
 722                        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 723                        if (start_active_slot(slot)) {
 724                                run_active_slot(slot);
 725                                if (slot->curl_result != CURLE_OK) {
 726                                        free(buffer.buffer);
 727                                        return 0;
 728                                }
 729                        }
 730                }
 731        } else {
 732                free(buffer.buffer);
 733                return 0;
 734        }
 735
 736        fwrite_buffer_dynamic(&null_byte, 1, 1, &buffer);
 737        buffer.posn--;
 738        data = buffer.buffer;
 739
 740        while (i < buffer.posn) {
 741                int posn = i;
 742                while (posn < buffer.posn && data[posn] != '\n')
 743                        posn++;
 744                if (data[posn] == '\n') {
 745                        int okay = 0;
 746                        int serverlen = 0;
 747                        struct alt_base *newalt;
 748                        char *target = NULL;
 749                        if (data[i] == '/') {
 750                                serverlen = strchr(base + 8, '/') - base;
 751                                okay = 1;
 752                        } else if (!memcmp(data + i, "../", 3)) {
 753                                i += 3;
 754                                serverlen = strlen(base);
 755                                while (i + 2 < posn && 
 756                                       !memcmp(data + i, "../", 3)) {
 757                                        do {
 758                                                serverlen--;
 759                                        } while (serverlen &&
 760                                                 base[serverlen - 1] != '/');
 761                                        i += 3;
 762                                }
 763                                // If the server got removed, give up.
 764                                okay = strchr(base, ':') - base + 3 < 
 765                                        serverlen;
 766                        } else if (http_specific) {
 767                                char *colon = strchr(data + i, ':');
 768                                char *slash = strchr(data + i, '/');
 769                                if (colon && slash && colon < data + posn &&
 770                                    slash < data + posn && colon < slash) {
 771                                        okay = 1;
 772                                }
 773                        }
 774                        // skip 'objects' at end
 775                        if (okay) {
 776                                target = xmalloc(serverlen + posn - i - 6);
 777                                strncpy(target, base, serverlen);
 778                                strncpy(target + serverlen, data + i,
 779                                        posn - i - 7);
 780                                target[serverlen + posn - i - 7] = '\0';
 781                                if (get_verbosely)
 782                                        fprintf(stderr, 
 783                                                "Also look at %s\n", target);
 784                                newalt = xmalloc(sizeof(*newalt));
 785                                newalt->next = NULL;
 786                                newalt->base = target;
 787                                newalt->got_indices = 0;
 788                                newalt->packs = NULL;
 789                                while (tail->next != NULL)
 790                                        tail = tail->next;
 791                                tail->next = newalt;
 792                                ret++;
 793                        }
 794                }
 795                i = posn + 1;
 796        }
 797
 798        free(buffer.buffer);
 799        return ret;
 800}
 801
 802static int fetch_indices(struct alt_base *repo)
 803{
 804        unsigned char sha1[20];
 805        char *url;
 806        struct buffer buffer;
 807        char *data;
 808        int i = 0;
 809
 810        struct active_request_slot *slot;
 811
 812        if (repo->got_indices)
 813                return 0;
 814
 815        data = xmalloc(4096);
 816        buffer.size = 4096;
 817        buffer.posn = 0;
 818        buffer.buffer = data;
 819
 820        if (get_verbosely)
 821                fprintf(stderr, "Getting pack list\n");
 822        
 823        url = xmalloc(strlen(repo->base) + 21);
 824        sprintf(url, "%s/objects/info/packs", repo->base);
 825
 826        slot = get_active_slot();
 827        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 828        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
 829                         fwrite_buffer_dynamic);
 830        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 831        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
 832        if (start_active_slot(slot)) {
 833                run_active_slot(slot);
 834                if (slot->curl_result != CURLE_OK) {
 835                        free(buffer.buffer);
 836                        return error("%s", curl_errorstr);
 837                }
 838        } else {
 839                free(buffer.buffer);
 840                return error("Unable to start request");
 841        }
 842
 843        data = buffer.buffer;
 844        while (i < buffer.posn) {
 845                switch (data[i]) {
 846                case 'P':
 847                        i++;
 848                        if (i + 52 < buffer.posn &&
 849                            !strncmp(data + i, " pack-", 6) &&
 850                            !strncmp(data + i + 46, ".pack\n", 6)) {
 851                                get_sha1_hex(data + i + 6, sha1);
 852                                setup_index(repo, sha1);
 853                                i += 51;
 854                                break;
 855                        }
 856                default:
 857                        while (data[i] != '\n')
 858                                i++;
 859                }
 860                i++;
 861        }
 862
 863        free(buffer.buffer);
 864        repo->got_indices = 1;
 865        return 0;
 866}
 867
 868static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
 869{
 870        char *url;
 871        struct packed_git *target;
 872        struct packed_git **lst;
 873        FILE *packfile;
 874        char *filename;
 875        char tmpfile[PATH_MAX];
 876        int ret;
 877        long prev_posn = 0;
 878        char range[RANGE_HEADER_SIZE];
 879        struct curl_slist *range_header = NULL;
 880
 881        struct active_request_slot *slot;
 882
 883        if (fetch_indices(repo))
 884                return -1;
 885        target = find_sha1_pack(sha1, repo->packs);
 886        if (!target)
 887                return -1;
 888
 889        if (get_verbosely) {
 890                fprintf(stderr, "Getting pack %s\n",
 891                        sha1_to_hex(target->sha1));
 892                fprintf(stderr, " which contains %s\n",
 893                        sha1_to_hex(sha1));
 894        }
 895
 896        url = xmalloc(strlen(repo->base) + 65);
 897        sprintf(url, "%s/objects/pack/pack-%s.pack",
 898                repo->base, sha1_to_hex(target->sha1));
 899
 900        filename = sha1_pack_name(target->sha1);
 901        snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
 902        packfile = fopen(tmpfile, "a");
 903        if (!packfile)
 904                return error("Unable to open local file %s for pack",
 905                             filename);
 906
 907        slot = get_active_slot();
 908        curl_easy_setopt(slot->curl, CURLOPT_FILE, packfile);
 909        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
 910        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 911        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 912        slot->local = packfile;
 913
 914        /* If there is data present from a previous transfer attempt,
 915           resume where it left off */
 916        prev_posn = ftell(packfile);
 917        if (prev_posn>0) {
 918                if (get_verbosely)
 919                        fprintf(stderr,
 920                                "Resuming fetch of pack %s at byte %ld\n",
 921                                sha1_to_hex(target->sha1), prev_posn);
 922                sprintf(range, "Range: bytes=%ld-", prev_posn);
 923                range_header = curl_slist_append(range_header, range);
 924                curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
 925        }
 926
 927        if (start_active_slot(slot)) {
 928                run_active_slot(slot);
 929                if (slot->curl_result != CURLE_OK) {
 930                        fclose(packfile);
 931                        return error("Unable to get pack file %s\n%s", url,
 932                                     curl_errorstr);
 933                }
 934        } else {
 935                return error("Unable to start request");
 936        }
 937
 938        fclose(packfile);
 939
 940        ret = move_temp_to_file(tmpfile, filename);
 941        if (ret)
 942                return ret;
 943
 944        lst = &repo->packs;
 945        while (*lst != target)
 946                lst = &((*lst)->next);
 947        *lst = (*lst)->next;
 948
 949        if (verify_pack(target, 0))
 950                return -1;
 951        install_packed_git(target);
 952
 953        return 0;
 954}
 955
 956static int fetch_object(struct alt_base *repo, unsigned char *sha1)
 957{
 958        char *hex = sha1_to_hex(sha1);
 959        int ret;
 960        struct transfer_request *request = request_queue_head;
 961
 962        while (request != NULL && memcmp(request->sha1, sha1, 20))
 963                request = request->next;
 964        if (request == NULL)
 965                return error("Couldn't find request for %s in the queue", hex);
 966
 967        if (has_sha1_file(request->sha1)) {
 968                release_request(request);
 969                return 0;
 970        }
 971
 972#ifdef USE_CURL_MULTI
 973        int num_transfers;
 974        while (request->state == WAITING) {
 975                curl_multi_perform(curlm, &num_transfers);
 976                if (num_transfers < active_requests) {
 977                        process_curl_messages();
 978                        process_request_queue();
 979                }
 980        }
 981#else
 982        start_request(request);
 983#endif
 984
 985        while (request->state == ACTIVE) {
 986                run_active_slot(request->slot);
 987#ifndef USE_CURL_MULTI
 988                request->curl_result = request->slot->curl_result;
 989                curl_easy_getinfo(request->slot->curl,
 990                                  CURLINFO_HTTP_CODE,
 991                                  &request->http_code);
 992                request->slot = NULL;
 993
 994                /* Use alternates if necessary */
 995                if (request->http_code == 404 &&
 996                    request->repo->next != NULL) {
 997                        request->repo = request->repo->next;
 998                        start_request(request);
 999                } else {
1000                        finish_request(request);
1001                        request->state = COMPLETE;
1002                }
1003#endif
1004        }
1005
1006        if (request->state == ABORTED) {
1007                release_request(request);
1008                return error("Request for %s aborted", hex);
1009        }
1010
1011        if (request->curl_result != CURLE_OK && request->http_code != 416) {
1012                ret = error("%s", request->errorstr);
1013                release_request(request);
1014                return ret;
1015        }
1016
1017        if (request->zret != Z_STREAM_END) {
1018                ret = error("File %s (%s) corrupt\n", hex, request->url);
1019                release_request(request);
1020                return ret;
1021        }
1022
1023        if (memcmp(request->sha1, request->real_sha1, 20)) {
1024                release_request(request);
1025                return error("File %s has bad hash\n", hex);
1026        }
1027
1028        if (request->rename < 0) {
1029                ret = error("unable to write sha1 filename %s: %s",
1030                            request->filename,
1031                            strerror(request->rename));
1032                release_request(request);
1033                return ret;
1034        }
1035
1036        release_request(request);
1037        return 0;
1038}
1039
1040int fetch(unsigned char *sha1)
1041{
1042        struct alt_base *altbase = alt;
1043
1044        if (!fetch_object(altbase, sha1))
1045                return 0;
1046        while (altbase) {
1047                if (!fetch_pack(altbase, sha1))
1048                        return 0;
1049                altbase = altbase->next;
1050        }
1051        return error("Unable to find %s under %s\n", sha1_to_hex(sha1), 
1052                     alt->base);
1053}
1054
1055static inline int needs_quote(int ch)
1056{
1057        switch (ch) {
1058        case '/': case '-': case '.':
1059        case 'A'...'Z': case 'a'...'z': case '0'...'9':
1060                return 0;
1061        default:
1062                return 1;
1063        }
1064}
1065
1066static inline int hex(int v)
1067{
1068        if (v < 10) return '0' + v;
1069        else return 'A' + v - 10;
1070}
1071
1072static char *quote_ref_url(const char *base, const char *ref)
1073{
1074        const char *cp;
1075        char *dp, *qref;
1076        int len, baselen, ch;
1077
1078        baselen = strlen(base);
1079        len = baselen + 6; /* "refs/" + NUL */
1080        for (cp = ref; (ch = *cp) != 0; cp++, len++)
1081                if (needs_quote(ch))
1082                        len += 2; /* extra two hex plus replacement % */
1083        qref = xmalloc(len);
1084        memcpy(qref, base, baselen);
1085        memcpy(qref + baselen, "refs/", 5);
1086        for (cp = ref, dp = qref + baselen + 5; (ch = *cp) != 0; cp++) {
1087                if (needs_quote(ch)) {
1088                        *dp++ = '%';
1089                        *dp++ = hex((ch >> 4) & 0xF);
1090                        *dp++ = hex(ch & 0xF);
1091                }
1092                else
1093                        *dp++ = ch;
1094        }
1095        *dp = 0;
1096
1097        return qref;
1098}
1099
1100int fetch_ref(char *ref, unsigned char *sha1)
1101{
1102        char *url;
1103        char hex[42];
1104        struct buffer buffer;
1105        char *base = alt->base;
1106        struct active_request_slot *slot;
1107        buffer.size = 41;
1108        buffer.posn = 0;
1109        buffer.buffer = hex;
1110        hex[41] = '\0';
1111        
1112        url = quote_ref_url(base, ref);
1113        slot = get_active_slot();
1114        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
1115        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
1116        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
1117        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1118        if (start_active_slot(slot)) {
1119                run_active_slot(slot);
1120                if (slot->curl_result != CURLE_OK)
1121                        return error("Couldn't get %s for %s\n%s",
1122                                     url, ref, curl_errorstr);
1123        } else {
1124                return error("Unable to start request");
1125        }
1126
1127        hex[40] = '\0';
1128        get_sha1_hex(hex, sha1);
1129        return 0;
1130}
1131
1132int main(int argc, char **argv)
1133{
1134        char *commit_id;
1135        char *url;
1136        int arg = 1;
1137        struct active_request_slot *slot;
1138
1139        while (arg < argc && argv[arg][0] == '-') {
1140                if (argv[arg][1] == 't') {
1141                        get_tree = 1;
1142                } else if (argv[arg][1] == 'c') {
1143                        get_history = 1;
1144                } else if (argv[arg][1] == 'a') {
1145                        get_all = 1;
1146                        get_tree = 1;
1147                        get_history = 1;
1148                } else if (argv[arg][1] == 'v') {
1149                        get_verbosely = 1;
1150                } else if (argv[arg][1] == 'w') {
1151                        write_ref = argv[arg + 1];
1152                        arg++;
1153                } else if (!strcmp(argv[arg], "--recover")) {
1154                        get_recover = 1;
1155                }
1156                arg++;
1157        }
1158        if (argc < arg + 2) {
1159                usage("git-http-fetch [-c] [-t] [-a] [-d] [-v] [--recover] [-w ref] commit-id url");
1160                return 1;
1161        }
1162        commit_id = argv[arg];
1163        url = argv[arg + 1];
1164
1165        curl_global_init(CURL_GLOBAL_ALL);
1166
1167#ifdef USE_CURL_MULTI
1168        char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
1169        if (http_max_requests != NULL)
1170                max_requests = atoi(http_max_requests);
1171
1172        curlm = curl_multi_init();
1173        if (curlm == NULL) {
1174                fprintf(stderr, "Error creating curl multi handle.\n");
1175                return 1;
1176        }
1177#endif
1178
1179        if (getenv("GIT_SSL_NO_VERIFY"))
1180                curl_ssl_verify = 0;
1181
1182        ssl_cert = getenv("GIT_SSL_CERT");
1183#if LIBCURL_VERSION_NUM >= 0x070902
1184        ssl_key = getenv("GIT_SSL_KEY");
1185#endif
1186#if LIBCURL_VERSION_NUM >= 0x070908
1187        ssl_capath = getenv("GIT_SSL_CAPATH");
1188#endif
1189        ssl_cainfo = getenv("GIT_SSL_CAINFO");
1190
1191        git_config(http_options);
1192
1193        if (curl_ssl_verify == -1)
1194                curl_ssl_verify = 1;
1195
1196#ifdef USE_CURL_MULTI
1197        if (max_requests < 1)
1198                max_requests = DEFAULT_MAX_REQUESTS;
1199#endif
1200
1201        pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
1202        no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
1203        no_range_header = curl_slist_append(no_range_header, "Range:");
1204
1205        curl_default = curl_easy_init();
1206
1207        curl_easy_setopt(curl_default, CURLOPT_SSL_VERIFYPEER, curl_ssl_verify);
1208#if LIBCURL_VERSION_NUM >= 0x070907
1209        curl_easy_setopt(curl_default, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
1210#endif
1211
1212        if (ssl_cert != NULL)
1213                curl_easy_setopt(curl_default, CURLOPT_SSLCERT, ssl_cert);
1214        if (ssl_key != NULL)
1215                curl_easy_setopt(curl_default, CURLOPT_SSLKEY, ssl_key);
1216        if (ssl_capath != NULL)
1217                curl_easy_setopt(curl_default, CURLOPT_CAPATH, ssl_capath);
1218        if (ssl_cainfo != NULL)
1219                curl_easy_setopt(curl_default, CURLOPT_CAINFO, ssl_cainfo);
1220
1221        curl_easy_setopt(curl_default, CURLOPT_FAILONERROR, 1);
1222
1223        alt = xmalloc(sizeof(*alt));
1224        alt->base = url;
1225        alt->got_indices = 0;
1226        alt->packs = NULL;
1227        alt->next = NULL;
1228        fetch_alternates(alt->base);
1229
1230        if (pull(commit_id))
1231                return 1;
1232
1233        curl_slist_free_all(pragma_header);
1234        curl_slist_free_all(no_pragma_header);
1235        curl_slist_free_all(no_range_header);
1236        curl_easy_cleanup(curl_default);
1237        slot = active_queue_head;
1238        while (slot != NULL) {
1239                curl_easy_cleanup(slot->curl);
1240                slot = slot->next;
1241        }
1242#ifdef USE_CURL_MULTI
1243        curl_multi_cleanup(curlm);
1244#endif
1245        curl_global_cleanup();
1246        return 0;
1247}