Andrew's git / gitweb.git / http-fetch.c
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http-fetch.con commit show-branch: optionally use unique prefix as name. (013f276)
   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 = DEFAULT_MAX_REQUESTS;
  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;
  89static char *ssl_cert;
  90static char *ssl_key;
  91static char *ssl_capath;
  92static char *ssl_cainfo;
  93
  94struct buffer
  95{
  96        size_t posn;
  97        size_t size;
  98        void *buffer;
  99};
 100
 101static size_t fwrite_buffer(void *ptr, size_t eltsize, size_t nmemb,
 102                            struct buffer *buffer)
 103{
 104        size_t size = eltsize * nmemb;
 105        if (size > buffer->size - buffer->posn)
 106                size = buffer->size - buffer->posn;
 107        memcpy(buffer->buffer + buffer->posn, ptr, size);
 108        buffer->posn += size;
 109        data_received++;
 110        return size;
 111}
 112
 113static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
 114                               void *data)
 115{
 116        unsigned char expn[4096];
 117        size_t size = eltsize * nmemb;
 118        int posn = 0;
 119        struct transfer_request *request = (struct transfer_request *)data;
 120        do {
 121                ssize_t retval = write(request->local,
 122                                       ptr + posn, size - posn);
 123                if (retval < 0)
 124                        return posn;
 125                posn += retval;
 126        } while (posn < size);
 127
 128        request->stream.avail_in = size;
 129        request->stream.next_in = ptr;
 130        do {
 131                request->stream.next_out = expn;
 132                request->stream.avail_out = sizeof(expn);
 133                request->zret = inflate(&request->stream, Z_SYNC_FLUSH);
 134                SHA1_Update(&request->c, expn,
 135                            sizeof(expn) - request->stream.avail_out);
 136        } while (request->stream.avail_in && request->zret == Z_OK);
 137        data_received++;
 138        return size;
 139}
 140
 141#ifdef USE_CURL_MULTI
 142void process_curl_messages();
 143void process_request_queue();
 144#endif
 145
 146struct active_request_slot *get_active_slot()
 147{
 148        struct active_request_slot *slot = active_queue_head;
 149        struct active_request_slot *newslot;
 150
 151#ifdef USE_CURL_MULTI
 152        int num_transfers;
 153
 154        /* Wait for a slot to open up if the queue is full */
 155        while (active_requests >= max_requests) {
 156                curl_multi_perform(curlm, &num_transfers);
 157                if (num_transfers < active_requests) {
 158                        process_curl_messages();
 159                }
 160        }
 161#endif
 162
 163        while (slot != NULL && slot->in_use) {
 164                slot = slot->next;
 165        }
 166        if (slot == NULL) {
 167                newslot = xmalloc(sizeof(*newslot));
 168                newslot->curl = curl_easy_duphandle(curl_default);
 169                newslot->in_use = 0;
 170                newslot->next = NULL;
 171
 172                slot = active_queue_head;
 173                if (slot == NULL) {
 174                        active_queue_head = newslot;
 175                } else {
 176                        while (slot->next != NULL) {
 177                                slot = slot->next;
 178                        }
 179                        slot->next = newslot;
 180                }
 181                slot = newslot;
 182        }
 183
 184        active_requests++;
 185        slot->in_use = 1;
 186        slot->done = 0;
 187        slot->local = NULL;
 188        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
 189        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_range_header);
 190        curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
 191
 192        return slot;
 193}
 194
 195int start_active_slot(struct active_request_slot *slot)
 196{
 197#ifdef USE_CURL_MULTI
 198        CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
 199
 200        if (curlm_result != CURLM_OK &&
 201            curlm_result != CURLM_CALL_MULTI_PERFORM) {
 202                active_requests--;
 203                slot->in_use = 0;
 204                return 0;
 205        }
 206#endif
 207        return 1;
 208}
 209
 210void run_active_slot(struct active_request_slot *slot)
 211{
 212#ifdef USE_CURL_MULTI
 213        int num_transfers;
 214        long last_pos = 0;
 215        long current_pos;
 216        fd_set readfds;
 217        fd_set writefds;
 218        fd_set excfds;
 219        int max_fd;
 220        struct timeval select_timeout;
 221        CURLMcode curlm_result;
 222
 223        while (!slot->done) {
 224                data_received = 0;
 225                do {
 226                        curlm_result = curl_multi_perform(curlm,
 227                                                          &num_transfers);
 228                } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
 229                if (num_transfers < active_requests) {
 230                        process_curl_messages();
 231                        process_request_queue();
 232                }
 233
 234                if (!data_received && slot->local != NULL) {
 235                        current_pos = ftell(slot->local);
 236                        if (current_pos > last_pos)
 237                                data_received++;
 238                        last_pos = current_pos;
 239                }
 240
 241                if (!slot->done && !data_received) {
 242                        max_fd = 0;
 243                        FD_ZERO(&readfds);
 244                        FD_ZERO(&writefds);
 245                        FD_ZERO(&excfds);
 246                        select_timeout.tv_sec = 0;
 247                        select_timeout.tv_usec = 50000;
 248                        select(max_fd, &readfds, &writefds,
 249                               &excfds, &select_timeout);
 250                }
 251        }
 252#else
 253        slot->curl_result = curl_easy_perform(slot->curl);
 254        active_requests--;
 255#endif
 256}
 257
 258void start_request(struct transfer_request *request)
 259{
 260        char *hex = sha1_to_hex(request->sha1);
 261        char prevfile[PATH_MAX];
 262        char *url;
 263        char *posn;
 264        int prevlocal;
 265        unsigned char prev_buf[PREV_BUF_SIZE];
 266        ssize_t prev_read = 0;
 267        long prev_posn = 0;
 268        char range[RANGE_HEADER_SIZE];
 269        struct curl_slist *range_header = NULL;
 270        struct active_request_slot *slot;
 271
 272        snprintf(prevfile, sizeof(prevfile), "%s.prev", request->filename);
 273        unlink(prevfile);
 274        rename(request->tmpfile, prevfile);
 275        unlink(request->tmpfile);
 276
 277        request->local = open(request->tmpfile,
 278                              O_WRONLY | O_CREAT | O_EXCL, 0666);
 279        /* This could have failed due to the "lazy directory creation";
 280         * try to mkdir the last path component.
 281         */
 282        if (request->local < 0 && errno == ENOENT) {
 283                char *dir = strrchr(request->tmpfile, '/');
 284                if (dir) {
 285                        *dir = 0;
 286                        mkdir(request->tmpfile, 0777);
 287                        *dir = '/';
 288                }
 289                request->local = open(request->tmpfile,
 290                                      O_WRONLY | O_CREAT | O_EXCL, 0666);
 291        }
 292
 293        if (request->local < 0) {
 294                request->state = ABORTED;
 295                error("Couldn't create temporary file %s for %s: %s\n",
 296                      request->tmpfile, request->filename, strerror(errno));
 297                return;
 298        }
 299
 300        memset(&request->stream, 0, sizeof(request->stream));
 301
 302        inflateInit(&request->stream);
 303
 304        SHA1_Init(&request->c);
 305
 306        url = xmalloc(strlen(request->repo->base) + 50);
 307        request->url = xmalloc(strlen(request->repo->base) + 50);
 308        strcpy(url, request->repo->base);
 309        posn = url + strlen(request->repo->base);
 310        strcpy(posn, "objects/");
 311        posn += 8;
 312        memcpy(posn, hex, 2);
 313        posn += 2;
 314        *(posn++) = '/';
 315        strcpy(posn, hex + 2);
 316        strcpy(request->url, url);
 317
 318        /* If a previous temp file is present, process what was already
 319           fetched. */
 320        prevlocal = open(prevfile, O_RDONLY);
 321        if (prevlocal != -1) {
 322                do {
 323                        prev_read = read(prevlocal, prev_buf, PREV_BUF_SIZE);
 324                        if (prev_read>0) {
 325                                if (fwrite_sha1_file(prev_buf,
 326                                                     1,
 327                                                     prev_read,
 328                                                     request) == prev_read) {
 329                                        prev_posn += prev_read;
 330                                } else {
 331                                        prev_read = -1;
 332                                }
 333                        }
 334                } while (prev_read > 0);
 335                close(prevlocal);
 336        }
 337        unlink(prevfile);
 338
 339        /* Reset inflate/SHA1 if there was an error reading the previous temp
 340           file; also rewind to the beginning of the local file. */
 341        if (prev_read == -1) {
 342                memset(&request->stream, 0, sizeof(request->stream));
 343                inflateInit(&request->stream);
 344                SHA1_Init(&request->c);
 345                if (prev_posn>0) {
 346                        prev_posn = 0;
 347                        lseek(request->local, SEEK_SET, 0);
 348                        ftruncate(request->local, 0);
 349                }
 350        }
 351
 352        slot = get_active_slot();
 353        curl_easy_setopt(slot->curl, CURLOPT_FILE, request);
 354        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
 355        curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, request->errorstr);
 356        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 357        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 358
 359        /* If we have successfully processed data from a previous fetch
 360           attempt, only fetch the data we don't already have. */
 361        if (prev_posn>0) {
 362                if (get_verbosely)
 363                        fprintf(stderr,
 364                                "Resuming fetch of object %s at byte %ld\n",
 365                                hex, prev_posn);
 366                sprintf(range, "Range: bytes=%ld-", prev_posn);
 367                range_header = curl_slist_append(range_header, range);
 368                curl_easy_setopt(slot->curl,
 369                                 CURLOPT_HTTPHEADER, range_header);
 370        }
 371
 372        /* Try to get the request started, abort the request on error */
 373        if (!start_active_slot(slot)) {
 374                request->state = ABORTED;
 375                close(request->local);
 376                free(request->url);
 377                return;
 378        }
 379        
 380        request->slot = slot;
 381        request->state = ACTIVE;
 382}
 383
 384void finish_request(struct transfer_request *request)
 385{
 386        fchmod(request->local, 0444);
 387        close(request->local);
 388
 389        if (request->http_code == 416) {
 390                fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
 391        } else if (request->curl_result != CURLE_OK) {
 392                return;
 393        }
 394
 395        inflateEnd(&request->stream);
 396        SHA1_Final(request->real_sha1, &request->c);
 397        if (request->zret != Z_STREAM_END) {
 398                unlink(request->tmpfile);
 399                return;
 400        }
 401        if (memcmp(request->sha1, request->real_sha1, 20)) {
 402                unlink(request->tmpfile);
 403                return;
 404        }
 405        request->rename =
 406                move_temp_to_file(request->tmpfile, request->filename);
 407
 408        if (request->rename == 0)
 409                pull_say("got %s\n", sha1_to_hex(request->sha1));
 410}
 411
 412void release_request(struct transfer_request *request)
 413{
 414        struct transfer_request *entry = request_queue_head;
 415
 416        if (request == request_queue_head) {
 417                request_queue_head = request->next;
 418        } else {
 419                while (entry->next != NULL && entry->next != request)
 420                        entry = entry->next;
 421                if (entry->next == request)
 422                        entry->next = entry->next->next;
 423        }
 424
 425        free(request->url);
 426        free(request);
 427}
 428
 429#ifdef USE_CURL_MULTI
 430void process_curl_messages()
 431{
 432        int num_messages;
 433        struct active_request_slot *slot;
 434        struct transfer_request *request = NULL;
 435        CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
 436
 437        while (curl_message != NULL) {
 438                if (curl_message->msg == CURLMSG_DONE) {
 439                        slot = active_queue_head;
 440                        while (slot != NULL &&
 441                               slot->curl != curl_message->easy_handle)
 442                                slot = slot->next;
 443                        if (slot != NULL) {
 444                                curl_multi_remove_handle(curlm, slot->curl);
 445                                active_requests--;
 446                                slot->done = 1;
 447                                slot->in_use = 0;
 448                                slot->curl_result = curl_message->data.result;
 449                                request = request_queue_head;
 450                                while (request != NULL &&
 451                                       request->slot != slot)
 452                                        request = request->next;
 453                        } else {
 454                                fprintf(stderr, "Received DONE message for unknown request!\n");
 455                        }
 456                        if (request != NULL) {
 457                                request->curl_result =
 458                                        curl_message->data.result;
 459                                curl_easy_getinfo(slot->curl,
 460                                                  CURLINFO_HTTP_CODE,
 461                                                  &request->http_code);
 462                                request->slot = NULL;
 463
 464                                /* Use alternates if necessary */
 465                                if (request->http_code == 404 &&
 466                                    request->repo->next != NULL) {
 467                                        request->repo = request->repo->next;
 468                                        start_request(request);
 469                                } else {
 470                                        finish_request(request);
 471                                        request->state = COMPLETE;
 472                                }
 473                        }
 474                } else {
 475                        fprintf(stderr, "Unknown CURL message received: %d\n",
 476                                (int)curl_message->msg);
 477                }
 478                curl_message = curl_multi_info_read(curlm, &num_messages);
 479        }
 480}
 481
 482void process_request_queue()
 483{
 484        struct transfer_request *request = request_queue_head;
 485        int num_transfers;
 486
 487        while (active_requests < max_requests && request != NULL) {
 488                if (request->state == WAITING) {
 489                        if (has_sha1_file(request->sha1))
 490                                release_request(request);
 491                        else
 492                                start_request(request);
 493                        curl_multi_perform(curlm, &num_transfers);
 494                }
 495                request = request->next;
 496        }
 497}
 498#endif
 499
 500void prefetch(unsigned char *sha1)
 501{
 502        struct transfer_request *newreq;
 503        struct transfer_request *tail;
 504        char *filename = sha1_file_name(sha1);
 505
 506        newreq = xmalloc(sizeof(*newreq));
 507        memcpy(newreq->sha1, sha1, 20);
 508        newreq->repo = alt;
 509        newreq->url = NULL;
 510        newreq->local = -1;
 511        newreq->state = WAITING;
 512        snprintf(newreq->filename, sizeof(newreq->filename), "%s", filename);
 513        snprintf(newreq->tmpfile, sizeof(newreq->tmpfile),
 514                 "%s.temp", filename);
 515        newreq->next = NULL;
 516
 517        if (request_queue_head == NULL) {
 518                request_queue_head = newreq;
 519        } else {
 520                tail = request_queue_head;
 521                while (tail->next != NULL) {
 522                        tail = tail->next;
 523                }
 524                tail->next = newreq;
 525        }
 526#ifdef USE_CURL_MULTI
 527        process_request_queue();
 528        process_curl_messages();
 529#endif
 530}
 531
 532static int fetch_index(struct alt_base *repo, unsigned char *sha1)
 533{
 534        char *hex = sha1_to_hex(sha1);
 535        char *filename;
 536        char *url;
 537        char tmpfile[PATH_MAX];
 538        long prev_posn = 0;
 539        char range[RANGE_HEADER_SIZE];
 540        struct curl_slist *range_header = NULL;
 541
 542        FILE *indexfile;
 543        struct active_request_slot *slot;
 544
 545        if (has_pack_index(sha1))
 546                return 0;
 547
 548        if (get_verbosely)
 549                fprintf(stderr, "Getting index for pack %s\n", hex);
 550        
 551        url = xmalloc(strlen(repo->base) + 64);
 552        sprintf(url, "%s/objects/pack/pack-%s.idx", repo->base, hex);
 553        
 554        filename = sha1_pack_index_name(sha1);
 555        snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
 556        indexfile = fopen(tmpfile, "a");
 557        if (!indexfile)
 558                return error("Unable to open local file %s for pack index",
 559                             filename);
 560
 561        slot = get_active_slot();
 562        curl_easy_setopt(slot->curl, CURLOPT_FILE, indexfile);
 563        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
 564        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 565        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 566        slot->local = indexfile;
 567
 568        /* If there is data present from a previous transfer attempt,
 569           resume where it left off */
 570        prev_posn = ftell(indexfile);
 571        if (prev_posn>0) {
 572                if (get_verbosely)
 573                        fprintf(stderr,
 574                                "Resuming fetch of index for pack %s at byte %ld\n",
 575                                hex, prev_posn);
 576                sprintf(range, "Range: bytes=%ld-", prev_posn);
 577                range_header = curl_slist_append(range_header, range);
 578                curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
 579        }
 580
 581        if (start_active_slot(slot)) {
 582                run_active_slot(slot);
 583                if (slot->curl_result != CURLE_OK) {
 584                        fclose(indexfile);
 585                        return error("Unable to get pack index %s\n%s", url,
 586                                     curl_errorstr);
 587                }
 588        } else {
 589                return error("Unable to start request");
 590        }
 591
 592        fclose(indexfile);
 593
 594        return move_temp_to_file(tmpfile, filename);
 595}
 596
 597static int setup_index(struct alt_base *repo, unsigned char *sha1)
 598{
 599        struct packed_git *new_pack;
 600        if (has_pack_file(sha1))
 601                return 0; // don't list this as something we can get
 602
 603        if (fetch_index(repo, sha1))
 604                return -1;
 605
 606        new_pack = parse_pack_index(sha1);
 607        new_pack->next = repo->packs;
 608        repo->packs = new_pack;
 609        return 0;
 610}
 611
 612static int fetch_alternates(char *base)
 613{
 614        int ret = 0;
 615        struct buffer buffer;
 616        char *url;
 617        char *data;
 618        int i = 0;
 619        int http_specific = 1;
 620        struct alt_base *tail = alt;
 621
 622        struct active_request_slot *slot;
 623
 624        data = xmalloc(4096);
 625        buffer.size = 4095;
 626        buffer.posn = 0;
 627        buffer.buffer = data;
 628
 629        if (get_verbosely)
 630                fprintf(stderr, "Getting alternates list\n");
 631        
 632        url = xmalloc(strlen(base) + 31);
 633        sprintf(url, "%s/objects/info/http-alternates", base);
 634
 635        slot = get_active_slot();
 636        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 637        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 638        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 639        if (start_active_slot(slot)) {
 640                run_active_slot(slot);
 641                if (slot->curl_result != CURLE_OK || !buffer.posn) {
 642                        http_specific = 0;
 643
 644                        sprintf(url, "%s/objects/info/alternates", base);
 645
 646                        slot = get_active_slot();
 647                        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 648                        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
 649                                         fwrite_buffer);
 650                        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 651                        if (start_active_slot(slot)) {
 652                                run_active_slot(slot);
 653                                if (slot->curl_result != CURLE_OK) {
 654                                        return 0;
 655                                }
 656                        }
 657                }
 658        } else {
 659                return 0;
 660        }
 661
 662        data[buffer.posn] = '\0';
 663
 664        while (i < buffer.posn) {
 665                int posn = i;
 666                while (posn < buffer.posn && data[posn] != '\n')
 667                        posn++;
 668                if (data[posn] == '\n') {
 669                        int okay = 0;
 670                        int serverlen = 0;
 671                        struct alt_base *newalt;
 672                        char *target = NULL;
 673                        if (data[i] == '/') {
 674                                serverlen = strchr(base + 8, '/') - base;
 675                                okay = 1;
 676                        } else if (!memcmp(data + i, "../", 3)) {
 677                                i += 3;
 678                                serverlen = strlen(base);
 679                                while (i + 2 < posn && 
 680                                       !memcmp(data + i, "../", 3)) {
 681                                        do {
 682                                                serverlen--;
 683                                        } while (serverlen &&
 684                                                 base[serverlen - 1] != '/');
 685                                        i += 3;
 686                                }
 687                                // If the server got removed, give up.
 688                                okay = strchr(base, ':') - base + 3 < 
 689                                        serverlen;
 690                        } else if (http_specific) {
 691                                char *colon = strchr(data + i, ':');
 692                                char *slash = strchr(data + i, '/');
 693                                if (colon && slash && colon < data + posn &&
 694                                    slash < data + posn && colon < slash) {
 695                                        okay = 1;
 696                                }
 697                        }
 698                        // skip 'objects' at end
 699                        if (okay) {
 700                                target = xmalloc(serverlen + posn - i - 6);
 701                                strncpy(target, base, serverlen);
 702                                strncpy(target + serverlen, data + i,
 703                                        posn - i - 7);
 704                                target[serverlen + posn - i - 7] = '\0';
 705                                if (get_verbosely)
 706                                        fprintf(stderr, 
 707                                                "Also look at %s\n", target);
 708                                newalt = xmalloc(sizeof(*newalt));
 709                                newalt->next = NULL;
 710                                newalt->base = target;
 711                                newalt->got_indices = 0;
 712                                newalt->packs = NULL;
 713                                while (tail->next != NULL)
 714                                        tail = tail->next;
 715                                tail->next = newalt;
 716                                ret++;
 717                        }
 718                }
 719                i = posn + 1;
 720        }
 721        
 722        return ret;
 723}
 724
 725static int fetch_indices(struct alt_base *repo)
 726{
 727        unsigned char sha1[20];
 728        char *url;
 729        struct buffer buffer;
 730        char *data;
 731        int i = 0;
 732
 733        struct active_request_slot *slot;
 734
 735        if (repo->got_indices)
 736                return 0;
 737
 738        data = xmalloc(4096);
 739        buffer.size = 4096;
 740        buffer.posn = 0;
 741        buffer.buffer = data;
 742
 743        if (get_verbosely)
 744                fprintf(stderr, "Getting pack list\n");
 745        
 746        url = xmalloc(strlen(repo->base) + 21);
 747        sprintf(url, "%s/objects/info/packs", repo->base);
 748
 749        slot = get_active_slot();
 750        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 751        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 752        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 753        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
 754        if (start_active_slot(slot)) {
 755                run_active_slot(slot);
 756                if (slot->curl_result != CURLE_OK)
 757                        return error("%s", curl_errorstr);
 758        } else {
 759                return error("Unable to start request");
 760        }
 761
 762        while (i < buffer.posn) {
 763                switch (data[i]) {
 764                case 'P':
 765                        i++;
 766                        if (i + 52 < buffer.posn &&
 767                            !strncmp(data + i, " pack-", 6) &&
 768                            !strncmp(data + i + 46, ".pack\n", 6)) {
 769                                get_sha1_hex(data + i + 6, sha1);
 770                                setup_index(repo, sha1);
 771                                i += 51;
 772                                break;
 773                        }
 774                default:
 775                        while (data[i] != '\n')
 776                                i++;
 777                }
 778                i++;
 779        }
 780
 781        repo->got_indices = 1;
 782        return 0;
 783}
 784
 785static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
 786{
 787        char *url;
 788        struct packed_git *target;
 789        struct packed_git **lst;
 790        FILE *packfile;
 791        char *filename;
 792        char tmpfile[PATH_MAX];
 793        int ret;
 794        long prev_posn = 0;
 795        char range[RANGE_HEADER_SIZE];
 796        struct curl_slist *range_header = NULL;
 797
 798        struct active_request_slot *slot;
 799
 800        if (fetch_indices(repo))
 801                return -1;
 802        target = find_sha1_pack(sha1, repo->packs);
 803        if (!target)
 804                return -1;
 805
 806        if (get_verbosely) {
 807                fprintf(stderr, "Getting pack %s\n",
 808                        sha1_to_hex(target->sha1));
 809                fprintf(stderr, " which contains %s\n",
 810                        sha1_to_hex(sha1));
 811        }
 812
 813        url = xmalloc(strlen(repo->base) + 65);
 814        sprintf(url, "%s/objects/pack/pack-%s.pack",
 815                repo->base, sha1_to_hex(target->sha1));
 816
 817        filename = sha1_pack_name(target->sha1);
 818        snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
 819        packfile = fopen(tmpfile, "a");
 820        if (!packfile)
 821                return error("Unable to open local file %s for pack",
 822                             filename);
 823
 824        slot = get_active_slot();
 825        curl_easy_setopt(slot->curl, CURLOPT_FILE, packfile);
 826        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
 827        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 828        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 829        slot->local = packfile;
 830
 831        /* If there is data present from a previous transfer attempt,
 832           resume where it left off */
 833        prev_posn = ftell(packfile);
 834        if (prev_posn>0) {
 835                if (get_verbosely)
 836                        fprintf(stderr,
 837                                "Resuming fetch of pack %s at byte %ld\n",
 838                                sha1_to_hex(target->sha1), prev_posn);
 839                sprintf(range, "Range: bytes=%ld-", prev_posn);
 840                range_header = curl_slist_append(range_header, range);
 841                curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
 842        }
 843
 844        if (start_active_slot(slot)) {
 845                run_active_slot(slot);
 846                if (slot->curl_result != CURLE_OK) {
 847                        fclose(packfile);
 848                        return error("Unable to get pack file %s\n%s", url,
 849                                     curl_errorstr);
 850                }
 851        } else {
 852                return error("Unable to start request");
 853        }
 854
 855        fclose(packfile);
 856
 857        ret = move_temp_to_file(tmpfile, filename);
 858        if (ret)
 859                return ret;
 860
 861        lst = &repo->packs;
 862        while (*lst != target)
 863                lst = &((*lst)->next);
 864        *lst = (*lst)->next;
 865
 866        if (verify_pack(target, 0))
 867                return -1;
 868        install_packed_git(target);
 869
 870        return 0;
 871}
 872
 873static int fetch_object(struct alt_base *repo, unsigned char *sha1)
 874{
 875        char *hex = sha1_to_hex(sha1);
 876        int ret;
 877        struct transfer_request *request = request_queue_head;
 878
 879        while (request != NULL && memcmp(request->sha1, sha1, 20))
 880                request = request->next;
 881        if (request == NULL)
 882                return error("Couldn't find request for %s in the queue", hex);
 883
 884        if (has_sha1_file(request->sha1)) {
 885                release_request(request);
 886                return 0;
 887        }
 888
 889#ifdef USE_CURL_MULTI
 890        int num_transfers;
 891        while (request->state == WAITING) {
 892                curl_multi_perform(curlm, &num_transfers);
 893                if (num_transfers < active_requests) {
 894                        process_curl_messages();
 895                        process_request_queue();
 896                }
 897        }
 898#else
 899        start_request(request);
 900#endif
 901
 902        while (request->state == ACTIVE) {
 903                run_active_slot(request->slot);
 904#ifndef USE_CURL_MULTI
 905                request->curl_result = request->slot->curl_result;
 906                curl_easy_getinfo(request->slot->curl,
 907                                  CURLINFO_HTTP_CODE,
 908                                  &request->http_code);
 909                request->slot = NULL;
 910
 911                /* Use alternates if necessary */
 912                if (request->http_code == 404 &&
 913                    request->repo->next != NULL) {
 914                        request->repo = request->repo->next;
 915                        start_request(request);
 916                } else {
 917                        finish_request(request);
 918                        request->state = COMPLETE;
 919                }
 920#endif
 921        }
 922
 923        if (request->state == ABORTED) {
 924                release_request(request);
 925                return error("Request for %s aborted", hex);
 926        }
 927
 928        if (request->curl_result != CURLE_OK && request->http_code != 416) {
 929                ret = error("%s", request->errorstr);
 930                release_request(request);
 931                return ret;
 932        }
 933
 934        if (request->zret != Z_STREAM_END) {
 935                ret = error("File %s (%s) corrupt\n", hex, request->url);
 936                release_request(request);
 937                return ret;
 938        }
 939
 940        if (memcmp(request->sha1, request->real_sha1, 20)) {
 941                release_request(request);
 942                return error("File %s has bad hash\n", hex);
 943        }
 944
 945        if (request->rename < 0) {
 946                ret = error("unable to write sha1 filename %s: %s",
 947                            request->filename,
 948                            strerror(request->rename));
 949                release_request(request);
 950                return ret;
 951        }
 952
 953        release_request(request);
 954        return 0;
 955}
 956
 957int fetch(unsigned char *sha1)
 958{
 959        struct alt_base *altbase = alt;
 960
 961        if (!fetch_object(altbase, sha1))
 962                return 0;
 963        while (altbase) {
 964                if (!fetch_pack(altbase, sha1))
 965                        return 0;
 966                altbase = altbase->next;
 967        }
 968        return error("Unable to find %s under %s\n", sha1_to_hex(sha1), 
 969                     alt->base);
 970}
 971
 972int fetch_ref(char *ref, unsigned char *sha1)
 973{
 974        char *url, *posn;
 975        char hex[42];
 976        struct buffer buffer;
 977        char *base = alt->base;
 978        struct active_request_slot *slot;
 979        buffer.size = 41;
 980        buffer.posn = 0;
 981        buffer.buffer = hex;
 982        hex[41] = '\0';
 983        
 984        url = xmalloc(strlen(base) + 6 + strlen(ref));
 985        strcpy(url, base);
 986        posn = url + strlen(base);
 987        strcpy(posn, "refs/");
 988        posn += 5;
 989        strcpy(posn, ref);
 990
 991        slot = get_active_slot();
 992        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 993        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 994        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
 995        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 996        if (start_active_slot(slot)) {
 997                run_active_slot(slot);
 998                if (slot->curl_result != CURLE_OK)
 999                        return error("Couldn't get %s for %s\n%s",
1000                                     url, ref, curl_errorstr);
1001        } else {
1002                return error("Unable to start request");
1003        }
1004
1005        hex[40] = '\0';
1006        get_sha1_hex(hex, sha1);
1007        return 0;
1008}
1009
1010int main(int argc, char **argv)
1011{
1012        char *commit_id;
1013        char *url;
1014        int arg = 1;
1015        struct active_request_slot *slot;
1016
1017        while (arg < argc && argv[arg][0] == '-') {
1018                if (argv[arg][1] == 't') {
1019                        get_tree = 1;
1020                } else if (argv[arg][1] == 'c') {
1021                        get_history = 1;
1022                } else if (argv[arg][1] == 'a') {
1023                        get_all = 1;
1024                        get_tree = 1;
1025                        get_history = 1;
1026                } else if (argv[arg][1] == 'v') {
1027                        get_verbosely = 1;
1028                } else if (argv[arg][1] == 'w') {
1029                        write_ref = argv[arg + 1];
1030                        arg++;
1031                } else if (!strcmp(argv[arg], "--recover")) {
1032                        get_recover = 1;
1033                }
1034                arg++;
1035        }
1036        if (argc < arg + 2) {
1037                usage("git-http-fetch [-c] [-t] [-a] [-d] [-v] [--recover] [-w ref] commit-id url");
1038                return 1;
1039        }
1040        commit_id = argv[arg];
1041        url = argv[arg + 1];
1042
1043        curl_global_init(CURL_GLOBAL_ALL);
1044
1045#ifdef USE_CURL_MULTI
1046        char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
1047        if (http_max_requests != NULL)
1048                max_requests = atoi(http_max_requests);
1049        if (max_requests < 1)
1050                max_requests = DEFAULT_MAX_REQUESTS;
1051
1052        curlm = curl_multi_init();
1053        if (curlm == NULL) {
1054                fprintf(stderr, "Error creating curl multi handle.\n");
1055                return 1;
1056        }
1057#endif
1058        pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
1059        no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
1060        no_range_header = curl_slist_append(no_range_header, "Range:");
1061
1062        curl_default = curl_easy_init();
1063
1064        curl_ssl_verify = getenv("GIT_SSL_NO_VERIFY") ? 0 : 1;
1065        curl_easy_setopt(curl_default, CURLOPT_SSL_VERIFYPEER, curl_ssl_verify);
1066#if LIBCURL_VERSION_NUM >= 0x070907
1067        curl_easy_setopt(curl_default, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
1068#endif
1069
1070        if ((ssl_cert = getenv("GIT_SSL_CERT")) != NULL) {
1071                curl_easy_setopt(curl_default, CURLOPT_SSLCERT, ssl_cert);
1072        }
1073#if LIBCURL_VERSION_NUM >= 0x070902
1074        if ((ssl_key = getenv("GIT_SSL_KEY")) != NULL) {
1075                curl_easy_setopt(curl_default, CURLOPT_SSLKEY, ssl_key);
1076        }
1077#endif
1078#if LIBCURL_VERSION_NUM >= 0x070908
1079        if ((ssl_capath = getenv("GIT_SSL_CAPATH")) != NULL) {
1080                curl_easy_setopt(curl_default, CURLOPT_CAPATH, ssl_capath);
1081        }
1082#endif
1083        if ((ssl_cainfo = getenv("GIT_SSL_CAINFO")) != NULL) {
1084                curl_easy_setopt(curl_default, CURLOPT_CAINFO, ssl_cainfo);
1085        }
1086        curl_easy_setopt(curl_default, CURLOPT_FAILONERROR, 1);
1087
1088        alt = xmalloc(sizeof(*alt));
1089        alt->base = url;
1090        alt->got_indices = 0;
1091        alt->packs = NULL;
1092        alt->next = NULL;
1093        fetch_alternates(alt->base);
1094
1095        if (pull(commit_id))
1096                return 1;
1097
1098        curl_slist_free_all(pragma_header);
1099        curl_slist_free_all(no_pragma_header);
1100        curl_slist_free_all(no_range_header);
1101        curl_easy_cleanup(curl_default);
1102        slot = active_queue_head;
1103        while (slot != NULL) {
1104                curl_easy_cleanup(slot->curl);
1105                slot = slot->next;
1106        }
1107#ifdef USE_CURL_MULTI
1108        curl_multi_cleanup(curlm);
1109#endif
1110        curl_global_cleanup();
1111        return 0;
1112}