git.oblomov.eu Git - git/blob - http-fetch.c

   1 #include "cache.h"
   2 #include "commit.h"
   3 #include "pack.h"
   4 #include "fetch.h"
   5 #include "http.h"
   6
   7 #ifndef NO_EXPAT
   8 #include <expat.h>
   9
  10 /* Definitions for DAV requests */
  11 #define DAV_PROPFIND "PROPFIND"
  12 #define DAV_PROPFIND_RESP ".multistatus.response"
  13 #define DAV_PROPFIND_NAME ".multistatus.response.href"
  14 #define DAV_PROPFIND_COLLECTION ".multistatus.response.propstat.prop.resourcetype.collection"
  15 #define PROPFIND_ALL_REQUEST "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<D:propfind xmlns:D=\"DAV:\">\n<D:allprop/>\n</D:propfind>"
  16
  17 /* Definitions for processing XML DAV responses */
  18 #ifndef XML_STATUS_OK
  19 enum XML_Status {
  20   XML_STATUS_OK = 1,
  21   XML_STATUS_ERROR = 0
  22 };
  23 #define XML_STATUS_OK    1
  24 #define XML_STATUS_ERROR 0
  25 #endif
  26
  27 /* Flags that control remote_ls processing */
  28 #define PROCESS_FILES (1u << 0)
  29 #define PROCESS_DIRS  (1u << 1)
  30 #define RECURSIVE     (1u << 2)
  31
  32 /* Flags that remote_ls passes to callback functions */
  33 #define IS_DIR (1u << 0)
  34 #endif
  35
  36 #define PREV_BUF_SIZE 4096
  37 #define RANGE_HEADER_SIZE 30
  38
  39 static int commits_on_stdin = 0;
  40
  41 static int got_alternates = -1;
  42 static int corrupt_object_found = 0;
  43
  44 static struct curl_slist *no_pragma_header;
  45
  46 struct alt_base
  47 {
  48         const char *base;
  49         int path_len;
  50         int got_indices;
  51         struct packed_git *packs;
  52         struct alt_base *next;
  53 };
  54
  55 static struct alt_base *alt = NULL;
  56
  57 enum object_request_state {
  58         WAITING,
  59         ABORTED,
  60         ACTIVE,
  61         COMPLETE,
  62 };
  63
  64 struct object_request
  65 {
  66         unsigned char sha1[20];
  67         struct alt_base *repo;
  68         char *url;
  69         char filename[PATH_MAX];
  70         char tmpfile[PATH_MAX];
  71         int local;
  72         enum object_request_state state;
  73         CURLcode curl_result;
  74         char errorstr[CURL_ERROR_SIZE];
  75         long http_code;
  76         unsigned char real_sha1[20];
  77         SHA_CTX c;
  78         z_stream stream;
  79         int zret;
  80         int rename;
  81         struct active_request_slot *slot;
  82         struct object_request *next;
  83 };
  84
  85 struct alternates_request {
  86         const char *base;
  87         char *url;
  88         struct buffer *buffer;
  89         struct active_request_slot *slot;
  90         int http_specific;
  91 };
  92
  93 #ifndef NO_EXPAT
  94 struct xml_ctx
  95 {
  96         char *name;
  97         int len;
  98         char *cdata;
  99         void (*userFunc)(struct xml_ctx *ctx, int tag_closed);
 100         void *userData;
 101 };
 102
 103 struct remote_ls_ctx
 104 {
 105         struct alt_base *repo;
 106         char *path;
 107         void (*userFunc)(struct remote_ls_ctx *ls);
 108         void *userData;
 109         int flags;
 110         char *dentry_name;
 111         int dentry_flags;
 112         int rc;
 113         struct remote_ls_ctx *parent;
 114 };
 115 #endif
 116
 117 static struct object_request *object_queue_head = NULL;
 118
 119 static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
 120                                void *data)
 121 {
 122         unsigned char expn[4096];
 123         size_t size = eltsize * nmemb;
 124         int posn = 0;
 125         struct object_request *obj_req = (struct object_request *)data;
 126         do {
 127                 ssize_t retval = write(obj_req->local,
 128                                        (char *) ptr + posn, size - posn);
 129                 if (retval < 0)
 130                         return posn;
 131                 posn += retval;
 132         } while (posn < size);
 133
 134         obj_req->stream.avail_in = size;
 135         obj_req->stream.next_in = ptr;
 136         do {
 137                 obj_req->stream.next_out = expn;
 138                 obj_req->stream.avail_out = sizeof(expn);
 139                 obj_req->zret = inflate(&obj_req->stream, Z_SYNC_FLUSH);
 140                 SHA1_Update(&obj_req->c, expn,
 141                             sizeof(expn) - obj_req->stream.avail_out);
 142         } while (obj_req->stream.avail_in && obj_req->zret == Z_OK);
 143         data_received++;
 144         return size;
 145 }
 146
 147 static void fetch_alternates(const char *base);
 148
 149 static void process_object_response(void *callback_data);
 150
 151 static void start_object_request(struct object_request *obj_req)
 152 {
 153         char *hex = sha1_to_hex(obj_req->sha1);
 154         char prevfile[PATH_MAX];
 155         char *url;
 156         char *posn;
 157         int prevlocal;
 158         unsigned char prev_buf[PREV_BUF_SIZE];
 159         ssize_t prev_read = 0;
 160         long prev_posn = 0;
 161         char range[RANGE_HEADER_SIZE];
 162         struct curl_slist *range_header = NULL;
 163         struct active_request_slot *slot;
 164
 165         snprintf(prevfile, sizeof(prevfile), "%s.prev", obj_req->filename);
 166         unlink(prevfile);
 167         rename(obj_req->tmpfile, prevfile);
 168         unlink(obj_req->tmpfile);
 169
 170         if (obj_req->local != -1)
 171                 error("fd leakage in start: %d", obj_req->local);
 172         obj_req->local = open(obj_req->tmpfile,
 173                               O_WRONLY | O_CREAT | O_EXCL, 0666);
 174         /* This could have failed due to the "lazy directory creation";
 175          * try to mkdir the last path component.
 176          */
 177         if (obj_req->local < 0 && errno == ENOENT) {
 178                 char *dir = strrchr(obj_req->tmpfile, '/');
 179                 if (dir) {
 180                         *dir = 0;
 181                         mkdir(obj_req->tmpfile, 0777);
 182                         *dir = '/';
 183                 }
 184                 obj_req->local = open(obj_req->tmpfile,
 185                                       O_WRONLY | O_CREAT | O_EXCL, 0666);
 186         }
 187
 188         if (obj_req->local < 0) {
 189                 obj_req->state = ABORTED;
 190                 error("Couldn't create temporary file %s for %s: %s",
 191                       obj_req->tmpfile, obj_req->filename, strerror(errno));
 192                 return;
 193         }
 194
 195         memset(&obj_req->stream, 0, sizeof(obj_req->stream));
 196
 197         inflateInit(&obj_req->stream);
 198
 199         SHA1_Init(&obj_req->c);
 200
 201         url = xmalloc(strlen(obj_req->repo->base) + 50);
 202         obj_req->url = xmalloc(strlen(obj_req->repo->base) + 50);
 203         strcpy(url, obj_req->repo->base);
 204         posn = url + strlen(obj_req->repo->base);
 205         strcpy(posn, "objects/");
 206         posn += 8;
 207         memcpy(posn, hex, 2);
 208         posn += 2;
 209         *(posn++) = '/';
 210         strcpy(posn, hex + 2);
 211         strcpy(obj_req->url, url);
 212
 213         /* If a previous temp file is present, process what was already
 214            fetched. */
 215         prevlocal = open(prevfile, O_RDONLY);
 216         if (prevlocal != -1) {
 217                 do {
 218                         prev_read = read(prevlocal, prev_buf, PREV_BUF_SIZE);
 219                         if (prev_read>0) {
 220                                 if (fwrite_sha1_file(prev_buf,
 221                                                      1,
 222                                                      prev_read,
 223                                                      obj_req) == prev_read) {
 224                                         prev_posn += prev_read;
 225                                 } else {
 226                                         prev_read = -1;
 227                                 }
 228                         }
 229                 } while (prev_read > 0);
 230                 close(prevlocal);
 231         }
 232         unlink(prevfile);
 233
 234         /* Reset inflate/SHA1 if there was an error reading the previous temp
 235            file; also rewind to the beginning of the local file. */
 236         if (prev_read == -1) {
 237                 memset(&obj_req->stream, 0, sizeof(obj_req->stream));
 238                 inflateInit(&obj_req->stream);
 239                 SHA1_Init(&obj_req->c);
 240                 if (prev_posn>0) {
 241                         prev_posn = 0;
 242                         lseek(obj_req->local, SEEK_SET, 0);
 243                         ftruncate(obj_req->local, 0);
 244                 }
 245         }
 246
 247         slot = get_active_slot();
 248         slot->callback_func = process_object_response;
 249         slot->callback_data = obj_req;
 250         obj_req->slot = slot;
 251
 252         curl_easy_setopt(slot->curl, CURLOPT_FILE, obj_req);
 253         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
 254         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, obj_req->errorstr);
 255         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 256         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 257
 258         /* If we have successfully processed data from a previous fetch
 259            attempt, only fetch the data we don't already have. */
 260         if (prev_posn>0) {
 261                 if (get_verbosely)
 262                         fprintf(stderr,
 263                                 "Resuming fetch of object %s at byte %ld\n",
 264                                 hex, prev_posn);
 265                 sprintf(range, "Range: bytes=%ld-", prev_posn);
 266                 range_header = curl_slist_append(range_header, range);
 267                 curl_easy_setopt(slot->curl,
 268                                  CURLOPT_HTTPHEADER, range_header);
 269         }
 270
 271         /* Try to get the request started, abort the request on error */
 272         obj_req->state = ACTIVE;
 273         if (!start_active_slot(slot)) {
 274                 obj_req->state = ABORTED;
 275                 obj_req->slot = NULL;
 276                 close(obj_req->local); obj_req->local = -1;
 277                 free(obj_req->url);
 278                 return;
 279         }
 280 }
 281
 282 static void finish_object_request(struct object_request *obj_req)
 283 {
 284         struct stat st;
 285
 286         fchmod(obj_req->local, 0444);
 287         close(obj_req->local); obj_req->local = -1;
 288
 289         if (obj_req->http_code == 416) {
 290                 fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
 291         } else if (obj_req->curl_result != CURLE_OK) {
 292                 if (stat(obj_req->tmpfile, &st) == 0)
 293                         if (st.st_size == 0)
 294                                 unlink(obj_req->tmpfile);
 295                 return;
 296         }
 297
 298         inflateEnd(&obj_req->stream);
 299         SHA1_Final(obj_req->real_sha1, &obj_req->c);
 300         if (obj_req->zret != Z_STREAM_END) {
 301                 unlink(obj_req->tmpfile);
 302                 return;
 303         }
 304         if (memcmp(obj_req->sha1, obj_req->real_sha1, 20)) {
 305                 unlink(obj_req->tmpfile);
 306                 return;
 307         }
 308         obj_req->rename =
 309                 move_temp_to_file(obj_req->tmpfile, obj_req->filename);
 310
 311         if (obj_req->rename == 0)
 312                 pull_say("got %s\n", sha1_to_hex(obj_req->sha1));
 313 }
 314
 315 static void process_object_response(void *callback_data)
 316 {
 317         struct object_request *obj_req =
 318                 (struct object_request *)callback_data;
 319
 320         obj_req->curl_result = obj_req->slot->curl_result;
 321         obj_req->http_code = obj_req->slot->http_code;
 322         obj_req->slot = NULL;
 323         obj_req->state = COMPLETE;
 324
 325         /* Use alternates if necessary */
 326         if (obj_req->http_code == 404 ||
 327             obj_req->curl_result == CURLE_FILE_COULDNT_READ_FILE) {
 328                 fetch_alternates(alt->base);
 329                 if (obj_req->repo->next != NULL) {
 330                         obj_req->repo =
 331                                 obj_req->repo->next;
 332                         close(obj_req->local);
 333                         obj_req->local = -1;
 334                         start_object_request(obj_req);
 335                         return;
 336                 }
 337         }
 338
 339         finish_object_request(obj_req);
 340 }
 341
 342 static void release_object_request(struct object_request *obj_req)
 343 {
 344         struct object_request *entry = object_queue_head;
 345
 346         if (obj_req->local != -1)
 347                 error("fd leakage in release: %d", obj_req->local);
 348         if (obj_req == object_queue_head) {
 349                 object_queue_head = obj_req->next;
 350         } else {
 351                 while (entry->next != NULL && entry->next != obj_req)
 352                         entry = entry->next;
 353                 if (entry->next == obj_req)
 354                         entry->next = entry->next->next;
 355         }
 356
 357         free(obj_req->url);
 358         free(obj_req);
 359 }
 360
 361 #ifdef USE_CURL_MULTI
 362 void fill_active_slots(void)
 363 {
 364         struct object_request *obj_req = object_queue_head;
 365         struct active_request_slot *slot = active_queue_head;
 366         int num_transfers;
 367
 368         while (active_requests < max_requests && obj_req != NULL) {
 369                 if (obj_req->state == WAITING) {
 370                         if (has_sha1_file(obj_req->sha1))
 371                                 obj_req->state = COMPLETE;
 372                         else
 373                                 start_object_request(obj_req);
 374                         curl_multi_perform(curlm, &num_transfers);
 375                 }
 376                 obj_req = obj_req->next;
 377         }
 378
 379         while (slot != NULL) {
 380                 if (!slot->in_use && slot->curl != NULL) {
 381                         curl_easy_cleanup(slot->curl);
 382                         slot->curl = NULL;
 383                 }
 384                 slot = slot->next;
 385         }
 386 }
 387 #endif
 388
 389 void prefetch(unsigned char *sha1)
 390 {
 391         struct object_request *newreq;
 392         struct object_request *tail;
 393         char *filename = sha1_file_name(sha1);
 394
 395         newreq = xmalloc(sizeof(*newreq));
 396         memcpy(newreq->sha1, sha1, 20);
 397         newreq->repo = alt;
 398         newreq->url = NULL;
 399         newreq->local = -1;
 400         newreq->state = WAITING;
 401         snprintf(newreq->filename, sizeof(newreq->filename), "%s", filename);
 402         snprintf(newreq->tmpfile, sizeof(newreq->tmpfile),
 403                  "%s.temp", filename);
 404         newreq->slot = NULL;
 405         newreq->next = NULL;
 406
 407         if (object_queue_head == NULL) {
 408                 object_queue_head = newreq;
 409         } else {
 410                 tail = object_queue_head;
 411                 while (tail->next != NULL) {
 412                         tail = tail->next;
 413                 }
 414                 tail->next = newreq;
 415         }
 416
 417 #ifdef USE_CURL_MULTI
 418         fill_active_slots();
 419         step_active_slots();
 420 #endif
 421 }
 422
 423 static int fetch_index(struct alt_base *repo, unsigned char *sha1)
 424 {
 425         char *hex = sha1_to_hex(sha1);
 426         char *filename;
 427         char *url;
 428         char tmpfile[PATH_MAX];
 429         long prev_posn = 0;
 430         char range[RANGE_HEADER_SIZE];
 431         struct curl_slist *range_header = NULL;
 432
 433         FILE *indexfile;
 434         struct active_request_slot *slot;
 435         struct slot_results results;
 436
 437         if (has_pack_index(sha1))
 438                 return 0;
 439
 440         if (get_verbosely)
 441                 fprintf(stderr, "Getting index for pack %s\n", hex);
 442
 443         url = xmalloc(strlen(repo->base) + 64);
 444         sprintf(url, "%s/objects/pack/pack-%s.idx", repo->base, hex);
 445
 446         filename = sha1_pack_index_name(sha1);
 447         snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
 448         indexfile = fopen(tmpfile, "a");
 449         if (!indexfile)
 450                 return error("Unable to open local file %s for pack index",
 451                              filename);
 452
 453         slot = get_active_slot();
 454         slot->results = &results;
 455         curl_easy_setopt(slot->curl, CURLOPT_FILE, indexfile);
 456         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
 457         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 458         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 459         slot->local = indexfile;
 460
 461         /* If there is data present from a previous transfer attempt,
 462            resume where it left off */
 463         prev_posn = ftell(indexfile);
 464         if (prev_posn>0) {
 465                 if (get_verbosely)
 466                         fprintf(stderr,
 467                                 "Resuming fetch of index for pack %s at byte %ld\n",
 468                                 hex, prev_posn);
 469                 sprintf(range, "Range: bytes=%ld-", prev_posn);
 470                 range_header = curl_slist_append(range_header, range);
 471                 curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
 472         }
 473
 474         if (start_active_slot(slot)) {
 475                 run_active_slot(slot);
 476                 if (results.curl_result != CURLE_OK) {
 477                         fclose(indexfile);
 478                         return error("Unable to get pack index %s\n%s", url,
 479                                      curl_errorstr);
 480                 }
 481         } else {
 482                 fclose(indexfile);
 483                 return error("Unable to start request");
 484         }
 485
 486         fclose(indexfile);
 487
 488         return move_temp_to_file(tmpfile, filename);
 489 }
 490
 491 static int setup_index(struct alt_base *repo, unsigned char *sha1)
 492 {
 493         struct packed_git *new_pack;
 494         if (has_pack_file(sha1))
 495                 return 0; /* don't list this as something we can get */
 496
 497         if (fetch_index(repo, sha1))
 498                 return -1;
 499
 500         new_pack = parse_pack_index(sha1);
 501         new_pack->next = repo->packs;
 502         repo->packs = new_pack;
 503         return 0;
 504 }
 505
 506 static void process_alternates_response(void *callback_data)
 507 {
 508         struct alternates_request *alt_req =
 509                 (struct alternates_request *)callback_data;
 510         struct active_request_slot *slot = alt_req->slot;
 511         struct alt_base *tail = alt;
 512         const char *base = alt_req->base;
 513         static const char null_byte = '\0';
 514         char *data;
 515         int i = 0;
 516
 517         if (alt_req->http_specific) {
 518                 if (slot->curl_result != CURLE_OK ||
 519                     !alt_req->buffer->posn) {
 520
 521                         /* Try reusing the slot to get non-http alternates */
 522                         alt_req->http_specific = 0;
 523                         sprintf(alt_req->url, "%s/objects/info/alternates",
 524                                 base);
 525                         curl_easy_setopt(slot->curl, CURLOPT_URL,
 526                                          alt_req->url);
 527                         active_requests++;
 528                         slot->in_use = 1;
 529                         if (slot->finished != NULL)
 530                                 (*slot->finished) = 0;
 531                         if (!start_active_slot(slot)) {
 532                                 got_alternates = -1;
 533                                 slot->in_use = 0;
 534                                 if (slot->finished != NULL)
 535                                         (*slot->finished) = 1;
 536                         }
 537                         return;
 538                 }
 539         } else if (slot->curl_result != CURLE_OK) {
 540                 if (slot->http_code != 404 &&
 541                     slot->curl_result != CURLE_FILE_COULDNT_READ_FILE) {
 542                         got_alternates = -1;
 543                         return;
 544                 }
 545         }
 546
 547         fwrite_buffer(&null_byte, 1, 1, alt_req->buffer);
 548         alt_req->buffer->posn--;
 549         data = alt_req->buffer->buffer;
 550
 551         while (i < alt_req->buffer->posn) {
 552                 int posn = i;
 553                 while (posn < alt_req->buffer->posn && data[posn] != '\n')
 554                         posn++;
 555                 if (data[posn] == '\n') {
 556                         int okay = 0;
 557                         int serverlen = 0;
 558                         struct alt_base *newalt;
 559                         char *target = NULL;
 560                         char *path;
 561                         if (data[i] == '/') {
 562                                 /* This counts
 563                                  * http://git.host/pub/scm/linux.git/
 564                                  * -----------here^
 565                                  * so memcpy(dst, base, serverlen) will
 566                                  * copy up to "...git.host".
 567                                  */
 568                                 const char *colon_ss = strstr(base,"://");
 569                                 if (colon_ss) {
 570                                         serverlen = (strchr(colon_ss + 3, '/')
 571                                                      - base);
 572                                         okay = 1;
 573                                 }
 574                         } else if (!memcmp(data + i, "../", 3)) {
 575                                 /* Relative URL; chop the corresponding
 576                                  * number of subpath from base (and ../
 577                                  * from data), and concatenate the result.
 578                                  *
 579                                  * The code first drops ../ from data, and
 580                                  * then drops one ../ from data and one path
 581                                  * from base.  IOW, one extra ../ is dropped
 582                                  * from data than path is dropped from base.
 583                                  *
 584                                  * This is not wrong.  The alternate in
 585                                  *     http://git.host/pub/scm/linux.git/
 586                                  * to borrow from
 587                                  *     http://git.host/pub/scm/linus.git/
 588                                  * is ../../linus.git/objects/.  You need
 589                                  * two ../../ to borrow from your direct
 590                                  * neighbour.
 591                                  */
 592                                 i += 3;
 593                                 serverlen = strlen(base);
 594                                 while (i + 2 < posn &&
 595                                        !memcmp(data + i, "../", 3)) {
 596                                         do {
 597                                                 serverlen--;
 598                                         } while (serverlen &&
 599                                                  base[serverlen - 1] != '/');
 600                                         i += 3;
 601                                 }
 602                                 /* If the server got removed, give up. */
 603                                 okay = strchr(base, ':') - base + 3 <
 604                                         serverlen;
 605                         } else if (alt_req->http_specific) {
 606                                 char *colon = strchr(data + i, ':');
 607                                 char *slash = strchr(data + i, '/');
 608                                 if (colon && slash && colon < data + posn &&
 609                                     slash < data + posn && colon < slash) {
 610                                         okay = 1;
 611                                 }
 612                         }
 613                         /* skip "objects\n" at end */
 614                         if (okay) {
 615                                 target = xmalloc(serverlen + posn - i - 6);
 616                                 memcpy(target, base, serverlen);
 617                                 memcpy(target + serverlen, data + i,
 618                                        posn - i - 7);
 619                                 target[serverlen + posn - i - 7] = 0;
 620                                 if (get_verbosely)
 621                                         fprintf(stderr,
 622                                                 "Also look at %s\n", target);
 623                                 newalt = xmalloc(sizeof(*newalt));
 624                                 newalt->next = NULL;
 625                                 newalt->base = target;
 626                                 newalt->got_indices = 0;
 627                                 newalt->packs = NULL;
 628                                 path = strstr(target, "//");
 629                                 if (path) {
 630                                         path = strchr(path+2, '/');
 631                                         if (path)
 632                                                 newalt->path_len = strlen(path);
 633                                 }
 634
 635                                 while (tail->next != NULL)
 636                                         tail = tail->next;
 637                                 tail->next = newalt;
 638                         }
 639                 }
 640                 i = posn + 1;
 641         }
 642
 643         got_alternates = 1;
 644 }
 645
 646 static void fetch_alternates(const char *base)
 647 {
 648         struct buffer buffer;
 649         char *url;
 650         char *data;
 651         struct active_request_slot *slot;
 652         struct alternates_request alt_req;
 653
 654         /* If another request has already started fetching alternates,
 655            wait for them to arrive and return to processing this request's
 656            curl message */
 657 #ifdef USE_CURL_MULTI
 658         while (got_alternates == 0) {
 659                 step_active_slots();
 660         }
 661 #endif
 662
 663         /* Nothing to do if they've already been fetched */
 664         if (got_alternates == 1)
 665                 return;
 666
 667         /* Start the fetch */
 668         got_alternates = 0;
 669
 670         data = xmalloc(4096);
 671         buffer.size = 4096;
 672         buffer.posn = 0;
 673         buffer.buffer = data;
 674
 675         if (get_verbosely)
 676                 fprintf(stderr, "Getting alternates list for %s\n", base);
 677
 678         url = xmalloc(strlen(base) + 31);
 679         sprintf(url, "%s/objects/info/http-alternates", base);
 680
 681         /* Use a callback to process the result, since another request
 682            may fail and need to have alternates loaded before continuing */
 683         slot = get_active_slot();
 684         slot->callback_func = process_alternates_response;
 685         slot->callback_data = &alt_req;
 686
 687         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 688         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 689         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 690
 691         alt_req.base = base;
 692         alt_req.url = url;
 693         alt_req.buffer = &buffer;
 694         alt_req.http_specific = 1;
 695         alt_req.slot = slot;
 696
 697         if (start_active_slot(slot))
 698                 run_active_slot(slot);
 699         else
 700                 got_alternates = -1;
 701
 702         free(data);
 703         free(url);
 704 }
 705
 706 #ifndef NO_EXPAT
 707 static void
 708 xml_start_tag(void *userData, const char *name, const char **atts)
 709 {
 710         struct xml_ctx *ctx = (struct xml_ctx *)userData;
 711         const char *c = strchr(name, ':');
 712         int new_len;
 713
 714         if (c == NULL)
 715                 c = name;
 716         else
 717                 c++;
 718
 719         new_len = strlen(ctx->name) + strlen(c) + 2;
 720
 721         if (new_len > ctx->len) {
 722                 ctx->name = xrealloc(ctx->name, new_len);
 723                 ctx->len = new_len;
 724         }
 725         strcat(ctx->name, ".");
 726         strcat(ctx->name, c);
 727
 728         if (ctx->cdata) {
 729                 free(ctx->cdata);
 730                 ctx->cdata = NULL;
 731         }
 732
 733         ctx->userFunc(ctx, 0);
 734 }
 735
 736 static void
 737 xml_end_tag(void *userData, const char *name)
 738 {
 739         struct xml_ctx *ctx = (struct xml_ctx *)userData;
 740         const char *c = strchr(name, ':');
 741         char *ep;
 742
 743         ctx->userFunc(ctx, 1);
 744
 745         if (c == NULL)
 746                 c = name;
 747         else
 748                 c++;
 749
 750         ep = ctx->name + strlen(ctx->name) - strlen(c) - 1;
 751         *ep = 0;
 752 }
 753
 754 static void
 755 xml_cdata(void *userData, const XML_Char *s, int len)
 756 {
 757         struct xml_ctx *ctx = (struct xml_ctx *)userData;
 758         if (ctx->cdata)
 759                 free(ctx->cdata);
 760         ctx->cdata = xmalloc(len + 1);
 761         strlcpy(ctx->cdata, s, len + 1);
 762 }
 763
 764 static int remote_ls(struct alt_base *repo, const char *path, int flags,
 765                      void (*userFunc)(struct remote_ls_ctx *ls),
 766                      void *userData);
 767
 768 static void handle_remote_ls_ctx(struct xml_ctx *ctx, int tag_closed)
 769 {
 770         struct remote_ls_ctx *ls = (struct remote_ls_ctx *)ctx->userData;
 771
 772         if (tag_closed) {
 773                 if (!strcmp(ctx->name, DAV_PROPFIND_RESP) && ls->dentry_name) {
 774                         if (ls->dentry_flags & IS_DIR) {
 775                                 if (ls->flags & PROCESS_DIRS) {
 776                                         ls->userFunc(ls);
 777                                 }
 778                                 if (strcmp(ls->dentry_name, ls->path) &&
 779                                     ls->flags & RECURSIVE) {
 780                                         ls->rc = remote_ls(ls->repo,
 781                                                            ls->dentry_name,
 782                                                            ls->flags,
 783                                                            ls->userFunc,
 784                                                            ls->userData);
 785                                 }
 786                         } else if (ls->flags & PROCESS_FILES) {
 787                                 ls->userFunc(ls);
 788                         }
 789                 } else if (!strcmp(ctx->name, DAV_PROPFIND_NAME) && ctx->cdata) {
 790                         ls->dentry_name = xmalloc(strlen(ctx->cdata) -
 791                                                   ls->repo->path_len + 1);
 792                         strcpy(ls->dentry_name, ctx->cdata + ls->repo->path_len);
 793                 } else if (!strcmp(ctx->name, DAV_PROPFIND_COLLECTION)) {
 794                         ls->dentry_flags |= IS_DIR;
 795                 }
 796         } else if (!strcmp(ctx->name, DAV_PROPFIND_RESP)) {
 797                 if (ls->dentry_name) {
 798                         free(ls->dentry_name);
 799                 }
 800                 ls->dentry_name = NULL;
 801                 ls->dentry_flags = 0;
 802         }
 803 }
 804
 805 static int remote_ls(struct alt_base *repo, const char *path, int flags,
 806                      void (*userFunc)(struct remote_ls_ctx *ls),
 807                      void *userData)
 808 {
 809         char *url = xmalloc(strlen(repo->base) + strlen(path) + 1);
 810         struct active_request_slot *slot;
 811         struct slot_results results;
 812         struct buffer in_buffer;
 813         struct buffer out_buffer;
 814         char *in_data;
 815         char *out_data;
 816         XML_Parser parser = XML_ParserCreate(NULL);
 817         enum XML_Status result;
 818         struct curl_slist *dav_headers = NULL;
 819         struct xml_ctx ctx;
 820         struct remote_ls_ctx ls;
 821
 822         ls.flags = flags;
 823         ls.repo = repo;
 824         ls.path = strdup(path);
 825         ls.dentry_name = NULL;
 826         ls.dentry_flags = 0;
 827         ls.userData = userData;
 828         ls.userFunc = userFunc;
 829         ls.rc = 0;
 830
 831         sprintf(url, "%s%s", repo->base, path);
 832
 833         out_buffer.size = strlen(PROPFIND_ALL_REQUEST);
 834         out_data = xmalloc(out_buffer.size + 1);
 835         snprintf(out_data, out_buffer.size + 1, PROPFIND_ALL_REQUEST);
 836         out_buffer.posn = 0;
 837         out_buffer.buffer = out_data;
 838
 839         in_buffer.size = 4096;
 840         in_data = xmalloc(in_buffer.size);
 841         in_buffer.posn = 0;
 842         in_buffer.buffer = in_data;
 843
 844         dav_headers = curl_slist_append(dav_headers, "Depth: 1");
 845         dav_headers = curl_slist_append(dav_headers, "Content-Type: text/xml");
 846
 847         slot = get_active_slot();
 848         slot->results = &results;
 849         curl_easy_setopt(slot->curl, CURLOPT_INFILE, &out_buffer);
 850         curl_easy_setopt(slot->curl, CURLOPT_INFILESIZE, out_buffer.size);
 851         curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, fread_buffer);
 852         curl_easy_setopt(slot->curl, CURLOPT_FILE, &in_buffer);
 853         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 854         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 855         curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 1);
 856         curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, DAV_PROPFIND);
 857         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);
 858
 859         if (start_active_slot(slot)) {
 860                 run_active_slot(slot);
 861                 if (results.curl_result == CURLE_OK) {
 862                         ctx.name = xcalloc(10, 1);
 863                         ctx.len = 0;
 864                         ctx.cdata = NULL;
 865                         ctx.userFunc = handle_remote_ls_ctx;
 866                         ctx.userData = &ls;
 867                         XML_SetUserData(parser, &ctx);
 868                         XML_SetElementHandler(parser, xml_start_tag,
 869                                               xml_end_tag);
 870                         XML_SetCharacterDataHandler(parser, xml_cdata);
 871                         result = XML_Parse(parser, in_buffer.buffer,
 872                                            in_buffer.posn, 1);
 873                         free(ctx.name);
 874
 875                         if (result != XML_STATUS_OK) {
 876                                 ls.rc = error("XML error: %s",
 877                                               XML_ErrorString(
 878                                                       XML_GetErrorCode(parser)));
 879                         }
 880                 } else {
 881                         ls.rc = -1;
 882                 }
 883         } else {
 884                 ls.rc = error("Unable to start PROPFIND request");
 885         }
 886
 887         free(ls.path);
 888         free(url);
 889         free(out_data);
 890         free(in_buffer.buffer);
 891         curl_slist_free_all(dav_headers);
 892
 893         return ls.rc;
 894 }
 895
 896 static void process_ls_pack(struct remote_ls_ctx *ls)
 897 {
 898         unsigned char sha1[20];
 899
 900         if (strlen(ls->dentry_name) == 63 &&
 901             !strncmp(ls->dentry_name, "objects/pack/pack-", 18) &&
 902             has_extension(ls->dentry_name, ".pack")) {
 903                 get_sha1_hex(ls->dentry_name + 18, sha1);
 904                 setup_index(ls->repo, sha1);
 905         }
 906 }
 907 #endif
 908
 909 static int fetch_indices(struct alt_base *repo)
 910 {
 911         unsigned char sha1[20];
 912         char *url;
 913         struct buffer buffer;
 914         char *data;
 915         int i = 0;
 916
 917         struct active_request_slot *slot;
 918         struct slot_results results;
 919
 920         if (repo->got_indices)
 921                 return 0;
 922
 923         data = xmalloc(4096);
 924         buffer.size = 4096;
 925         buffer.posn = 0;
 926         buffer.buffer = data;
 927
 928         if (get_verbosely)
 929                 fprintf(stderr, "Getting pack list for %s\n", repo->base);
 930
 931 #ifndef NO_EXPAT
 932         if (remote_ls(repo, "objects/pack/", PROCESS_FILES,
 933                       process_ls_pack, NULL) == 0)
 934                 return 0;
 935 #endif
 936
 937         url = xmalloc(strlen(repo->base) + 21);
 938         sprintf(url, "%s/objects/info/packs", repo->base);
 939
 940         slot = get_active_slot();
 941         slot->results = &results;
 942         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 943         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 944         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 945         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
 946         if (start_active_slot(slot)) {
 947                 run_active_slot(slot);
 948                 if (results.curl_result != CURLE_OK) {
 949                         if (results.http_code == 404 ||
 950                             results.curl_result == CURLE_FILE_COULDNT_READ_FILE) {
 951                                 repo->got_indices = 1;
 952                                 free(buffer.buffer);
 953                                 return 0;
 954                         } else {
 955                                 repo->got_indices = 0;
 956                                 free(buffer.buffer);
 957                                 return error("%s", curl_errorstr);
 958                         }
 959                 }
 960         } else {
 961                 repo->got_indices = 0;
 962                 free(buffer.buffer);
 963                 return error("Unable to start request");
 964         }
 965
 966         data = buffer.buffer;
 967         while (i < buffer.posn) {
 968                 switch (data[i]) {
 969                 case 'P':
 970                         i++;
 971                         if (i + 52 <= buffer.posn &&
 972                             !strncmp(data + i, " pack-", 6) &&
 973                             !strncmp(data + i + 46, ".pack\n", 6)) {
 974                                 get_sha1_hex(data + i + 6, sha1);
 975                                 setup_index(repo, sha1);
 976                                 i += 51;
 977                                 break;
 978                         }
 979                 default:
 980                         while (i < buffer.posn && data[i] != '\n')
 981                                 i++;
 982                 }
 983                 i++;
 984         }
 985
 986         free(buffer.buffer);
 987         repo->got_indices = 1;
 988         return 0;
 989 }
 990
 991 static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
 992 {
 993         char *url;
 994         struct packed_git *target;
 995         struct packed_git **lst;
 996         FILE *packfile;
 997         char *filename;
 998         char tmpfile[PATH_MAX];
 999         int ret;
1000         long prev_posn = 0;
1001         char range[RANGE_HEADER_SIZE];
1002         struct curl_slist *range_header = NULL;
1003
1004         struct active_request_slot *slot;
1005         struct slot_results results;
1006
1007         if (fetch_indices(repo))
1008                 return -1;
1009         target = find_sha1_pack(sha1, repo->packs);
1010         if (!target)
1011                 return -1;
1012
1013         if (get_verbosely) {
1014                 fprintf(stderr, "Getting pack %s\n",
1015                         sha1_to_hex(target->sha1));
1016                 fprintf(stderr, " which contains %s\n",
1017                         sha1_to_hex(sha1));
1018         }
1019
1020         url = xmalloc(strlen(repo->base) + 65);
1021         sprintf(url, "%s/objects/pack/pack-%s.pack",
1022                 repo->base, sha1_to_hex(target->sha1));
1023
1024         filename = sha1_pack_name(target->sha1);
1025         snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
1026         packfile = fopen(tmpfile, "a");
1027         if (!packfile)
1028                 return error("Unable to open local file %s for pack",
1029                              filename);
1030
1031         slot = get_active_slot();
1032         slot->results = &results;
1033         curl_easy_setopt(slot->curl, CURLOPT_FILE, packfile);
1034         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
1035         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1036         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
1037         slot->local = packfile;
1038
1039         /* If there is data present from a previous transfer attempt,
1040            resume where it left off */
1041         prev_posn = ftell(packfile);
1042         if (prev_posn>0) {
1043                 if (get_verbosely)
1044                         fprintf(stderr,
1045                                 "Resuming fetch of pack %s at byte %ld\n",
1046                                 sha1_to_hex(target->sha1), prev_posn);
1047                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1048                 range_header = curl_slist_append(range_header, range);
1049                 curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
1050         }
1051
1052         if (start_active_slot(slot)) {
1053                 run_active_slot(slot);
1054                 if (results.curl_result != CURLE_OK) {
1055                         fclose(packfile);
1056                         return error("Unable to get pack file %s\n%s", url,
1057                                      curl_errorstr);
1058                 }
1059         } else {
1060                 fclose(packfile);
1061                 return error("Unable to start request");
1062         }
1063
1064         fclose(packfile);
1065
1066         ret = move_temp_to_file(tmpfile, filename);
1067         if (ret)
1068                 return ret;
1069
1070         lst = &repo->packs;
1071         while (*lst != target)
1072                 lst = &((*lst)->next);
1073         *lst = (*lst)->next;
1074
1075         if (verify_pack(target, 0))
1076                 return -1;
1077         install_packed_git(target);
1078
1079         return 0;
1080 }
1081
1082 static void abort_object_request(struct object_request *obj_req)
1083 {
1084         if (obj_req->local >= 0) {
1085                 close(obj_req->local);
1086                 obj_req->local = -1;
1087         }
1088         unlink(obj_req->tmpfile);
1089         if (obj_req->slot) {
1090                 release_active_slot(obj_req->slot);
1091                 obj_req->slot = NULL;
1092         }
1093         release_object_request(obj_req);
1094 }
1095
1096 static int fetch_object(struct alt_base *repo, unsigned char *sha1)
1097 {
1098         char *hex = sha1_to_hex(sha1);
1099         int ret = 0;
1100         struct object_request *obj_req = object_queue_head;
1101
1102         while (obj_req != NULL && memcmp(obj_req->sha1, sha1, 20))
1103                 obj_req = obj_req->next;
1104         if (obj_req == NULL)
1105                 return error("Couldn't find request for %s in the queue", hex);
1106
1107         if (has_sha1_file(obj_req->sha1)) {
1108                 abort_object_request(obj_req);
1109                 return 0;
1110         }
1111
1112 #ifdef USE_CURL_MULTI
1113         while (obj_req->state == WAITING) {
1114                 step_active_slots();
1115         }
1116 #else
1117         start_object_request(obj_req);
1118 #endif
1119
1120         while (obj_req->state == ACTIVE) {
1121                 run_active_slot(obj_req->slot);
1122         }
1123         if (obj_req->local != -1) {
1124                 close(obj_req->local); obj_req->local = -1;
1125         }
1126
1127         if (obj_req->state == ABORTED) {
1128                 ret = error("Request for %s aborted", hex);
1129         } else if (obj_req->curl_result != CURLE_OK &&
1130                    obj_req->http_code != 416) {
1131                 if (obj_req->http_code == 404 ||
1132                     obj_req->curl_result == CURLE_FILE_COULDNT_READ_FILE)
1133                         ret = -1; /* Be silent, it is probably in a pack. */
1134                 else
1135                         ret = error("%s (curl_result = %d, http_code = %ld, sha1 = %s)",
1136                                     obj_req->errorstr, obj_req->curl_result,
1137                                     obj_req->http_code, hex);
1138         } else if (obj_req->zret != Z_STREAM_END) {
1139                 corrupt_object_found++;
1140                 ret = error("File %s (%s) corrupt", hex, obj_req->url);
1141         } else if (memcmp(obj_req->sha1, obj_req->real_sha1, 20)) {
1142                 ret = error("File %s has bad hash", hex);
1143         } else if (obj_req->rename < 0) {
1144                 ret = error("unable to write sha1 filename %s",
1145                             obj_req->filename);
1146         }
1147
1148         release_object_request(obj_req);
1149         return ret;
1150 }
1151
1152 int fetch(unsigned char *sha1)
1153 {
1154         struct alt_base *altbase = alt;
1155
1156         if (!fetch_object(altbase, sha1))
1157                 return 0;
1158         while (altbase) {
1159                 if (!fetch_pack(altbase, sha1))
1160                         return 0;
1161                 fetch_alternates(alt->base);
1162                 altbase = altbase->next;
1163         }
1164         return error("Unable to find %s under %s", sha1_to_hex(sha1),
1165                      alt->base);
1166 }
1167
1168 static inline int needs_quote(int ch)
1169 {
1170         if (((ch >= 'A') && (ch <= 'Z'))
1171                         || ((ch >= 'a') && (ch <= 'z'))
1172                         || ((ch >= '0') && (ch <= '9'))
1173                         || (ch == '/')
1174                         || (ch == '-')
1175                         || (ch == '.'))
1176                 return 0;
1177         return 1;
1178 }
1179
1180 static inline int hex(int v)
1181 {
1182         if (v < 10) return '0' + v;
1183         else return 'A' + v - 10;
1184 }
1185
1186 static char *quote_ref_url(const char *base, const char *ref)
1187 {
1188         const char *cp;
1189         char *dp, *qref;
1190         int len, baselen, ch;
1191
1192         baselen = strlen(base);
1193         len = baselen + 6; /* "refs/" + NUL */
1194         for (cp = ref; (ch = *cp) != 0; cp++, len++)
1195                 if (needs_quote(ch))
1196                         len += 2; /* extra two hex plus replacement % */
1197         qref = xmalloc(len);
1198         memcpy(qref, base, baselen);
1199         memcpy(qref + baselen, "refs/", 5);
1200         for (cp = ref, dp = qref + baselen + 5; (ch = *cp) != 0; cp++) {
1201                 if (needs_quote(ch)) {
1202                         *dp++ = '%';
1203                         *dp++ = hex((ch >> 4) & 0xF);
1204                         *dp++ = hex(ch & 0xF);
1205                 }
1206                 else
1207                         *dp++ = ch;
1208         }
1209         *dp = 0;
1210
1211         return qref;
1212 }
1213
1214 int fetch_ref(char *ref, unsigned char *sha1)
1215 {
1216         char *url;
1217         char hex[42];
1218         struct buffer buffer;
1219         const char *base = alt->base;
1220         struct active_request_slot *slot;
1221         struct slot_results results;
1222         buffer.size = 41;
1223         buffer.posn = 0;
1224         buffer.buffer = hex;
1225         hex[41] = '\0';
1226
1227         url = quote_ref_url(base, ref);
1228         slot = get_active_slot();
1229         slot->results = &results;
1230         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
1231         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
1232         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
1233         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1234         if (start_active_slot(slot)) {
1235                 run_active_slot(slot);
1236                 if (results.curl_result != CURLE_OK)
1237                         return error("Couldn't get %s for %s\n%s",
1238                                      url, ref, curl_errorstr);
1239         } else {
1240                 return error("Unable to start request");
1241         }
1242
1243         hex[40] = '\0';
1244         get_sha1_hex(hex, sha1);
1245         return 0;
1246 }
1247
1248 int main(int argc, const char **argv)
1249 {
1250         int commits;
1251         const char **write_ref = NULL;
1252         char **commit_id;
1253         const char *url;
1254         char *path;
1255         int arg = 1;
1256         int rc = 0;
1257
1258         setup_ident();
1259         setup_git_directory();
1260         git_config(git_default_config);
1261
1262         while (arg < argc && argv[arg][0] == '-') {
1263                 if (argv[arg][1] == 't') {
1264                         get_tree = 1;
1265                 } else if (argv[arg][1] == 'c') {
1266                         get_history = 1;
1267                 } else if (argv[arg][1] == 'a') {
1268                         get_all = 1;
1269                         get_tree = 1;
1270                         get_history = 1;
1271                 } else if (argv[arg][1] == 'v') {
1272                         get_verbosely = 1;
1273                 } else if (argv[arg][1] == 'w') {
1274                         write_ref = &argv[arg + 1];
1275                         arg++;
1276                 } else if (!strcmp(argv[arg], "--recover")) {
1277                         get_recover = 1;
1278                 } else if (!strcmp(argv[arg], "--stdin")) {
1279                         commits_on_stdin = 1;
1280                 }
1281                 arg++;
1282         }
1283         if (argc < arg + 2 - commits_on_stdin) {
1284                 usage("git-http-fetch [-c] [-t] [-a] [-v] [--recover] [-w ref] [--stdin] commit-id url");
1285                 return 1;
1286         }
1287         if (commits_on_stdin) {
1288                 commits = pull_targets_stdin(&commit_id, &write_ref);
1289         } else {
1290                 commit_id = (char **) &argv[arg++];
1291                 commits = 1;
1292         }
1293         url = argv[arg];
1294
1295         http_init();
1296
1297         no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
1298
1299         alt = xmalloc(sizeof(*alt));
1300         alt->base = url;
1301         alt->got_indices = 0;
1302         alt->packs = NULL;
1303         alt->next = NULL;
1304         path = strstr(url, "//");
1305         if (path) {
1306                 path = strchr(path+2, '/');
1307                 if (path)
1308                         alt->path_len = strlen(path);
1309         }
1310
1311         if (pull(commits, commit_id, write_ref, url))
1312                 rc = 1;
1313
1314         http_cleanup();
1315
1316         curl_slist_free_all(no_pragma_header);
1317
1318         if (commits_on_stdin)
1319                 pull_targets_free(commits, commit_id, write_ref);
1320
1321         if (corrupt_object_found) {
1322                 fprintf(stderr,
1323 "Some loose object were found to be corrupt, but they might be just\n"
1324 "a false '404 Not Found' error message sent with incorrect HTTP\n"
1325 "status code.  Suggest running git fsck-objects.\n");
1326         }
1327         return rc;
1328 }