http-fetch.c

   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 #if LIBCURL_VERSION_NUM < 0x070c04
  22 #define NO_CURL_EASY_DUPHANDLE
  23 #endif
  24
  25 #define PREV_BUF_SIZE 4096
  26 #define RANGE_HEADER_SIZE 30
  27
  28 static int active_requests = 0;
  29 static int data_received;
  30
  31 #ifdef USE_CURL_MULTI
  32 static int max_requests = -1;
  33 static CURLM *curlm;
  34 #endif
  35 #ifndef NO_CURL_EASY_DUPHANDLE
  36 static CURL *curl_default;
  37 #endif
  38 static struct curl_slist *pragma_header;
  39 static struct curl_slist *no_pragma_header;
  40 static struct curl_slist *no_range_header;
  41 static char curl_errorstr[CURL_ERROR_SIZE];
  42
  43 struct alt_base
  44 {
  45         char *base;
  46         int got_indices;
  47         struct packed_git *packs;
  48         struct alt_base *next;
  49 };
  50
  51 static struct alt_base *alt = NULL;
  52
  53 enum transfer_state {
  54         WAITING,
  55         ABORTED,
  56         ACTIVE,
  57         COMPLETE,
  58 };
  59
  60 struct transfer_request
  61 {
  62         unsigned char sha1[20];
  63         struct alt_base *repo;
  64         char *url;
  65         char filename[PATH_MAX];
  66         char tmpfile[PATH_MAX];
  67         int local;
  68         enum transfer_state state;
  69         CURLcode curl_result;
  70         char errorstr[CURL_ERROR_SIZE];
  71         long http_code;
  72         unsigned char real_sha1[20];
  73         SHA_CTX c;
  74         z_stream stream;
  75         int zret;
  76         int rename;
  77         struct active_request_slot *slot;
  78         struct transfer_request *next;
  79 };
  80
  81 struct active_request_slot
  82 {
  83         CURL *curl;
  84         FILE *local;
  85         int in_use;
  86         int done;
  87         CURLcode curl_result;
  88         struct active_request_slot *next;
  89 };
  90
  91 static struct transfer_request *request_queue_head = NULL;
  92 static struct active_request_slot *active_queue_head = NULL;
  93
  94 static int curl_ssl_verify = -1;
  95 static char *ssl_cert = NULL;
  96 #if LIBCURL_VERSION_NUM >= 0x070902
  97 static char *ssl_key = NULL;
  98 #endif
  99 #if LIBCURL_VERSION_NUM >= 0x070908
 100 static char *ssl_capath = NULL;
 101 #endif
 102 static char *ssl_cainfo = NULL;
 103 static long curl_low_speed_limit = -1;
 104 static long curl_low_speed_time = -1;
 105
 106 struct buffer
 107 {
 108         size_t posn;
 109         size_t size;
 110         void *buffer;
 111 };
 112
 113 static int http_options(const char *var, const char *value)
 114 {
 115         if (!strcmp("http.sslverify", var)) {
 116                 if (curl_ssl_verify == -1) {
 117                         curl_ssl_verify = git_config_bool(var, value);
 118                 }
 119                 return 0;
 120         }
 121
 122         if (!strcmp("http.sslcert", var)) {
 123                 if (ssl_cert == NULL) {
 124                         ssl_cert = xmalloc(strlen(value)+1);
 125                         strcpy(ssl_cert, value);
 126                 }
 127                 return 0;
 128         }
 129 #if LIBCURL_VERSION_NUM >= 0x070902
 130         if (!strcmp("http.sslkey", var)) {
 131                 if (ssl_key == NULL) {
 132                         ssl_key = xmalloc(strlen(value)+1);
 133                         strcpy(ssl_key, value);
 134                 }
 135                 return 0;
 136         }
 137 #endif
 138 #if LIBCURL_VERSION_NUM >= 0x070908
 139         if (!strcmp("http.sslcapath", var)) {
 140                 if (ssl_capath == NULL) {
 141                         ssl_capath = xmalloc(strlen(value)+1);
 142                         strcpy(ssl_capath, value);
 143                 }
 144                 return 0;
 145         }
 146 #endif
 147         if (!strcmp("http.sslcainfo", var)) {
 148                 if (ssl_cainfo == NULL) {
 149                         ssl_cainfo = xmalloc(strlen(value)+1);
 150                         strcpy(ssl_cainfo, value);
 151                 }
 152                 return 0;
 153         }
 154
 155 #ifdef USE_CURL_MULTI
 156         if (!strcmp("http.maxrequests", var)) {
 157                 if (max_requests == -1)
 158                         max_requests = git_config_int(var, value);
 159                 return 0;
 160         }
 161 #endif
 162
 163         if (!strcmp("http.lowspeedlimit", var)) {
 164                 if (curl_low_speed_limit == -1)
 165                         curl_low_speed_limit = (long)git_config_int(var, value);
 166                 return 0;
 167         }
 168         if (!strcmp("http.lowspeedtime", var)) {
 169                 if (curl_low_speed_time == -1)
 170                         curl_low_speed_time = (long)git_config_int(var, value);
 171                 return 0;
 172         }
 173
 174         /* Fall back on the default ones */
 175         return git_default_config(var, value);
 176 }
 177
 178 static size_t fwrite_buffer(void *ptr, size_t eltsize, size_t nmemb,
 179                             struct buffer *buffer)
 180 {
 181         size_t size = eltsize * nmemb;
 182         if (size > buffer->size - buffer->posn)
 183                 size = buffer->size - buffer->posn;
 184         memcpy(buffer->buffer + buffer->posn, ptr, size);
 185         buffer->posn += size;
 186         data_received++;
 187         return size;
 188 }
 189
 190 static size_t fwrite_buffer_dynamic(const void *ptr, size_t eltsize,
 191                                     size_t nmemb, struct buffer *buffer)
 192 {
 193         size_t size = eltsize * nmemb;
 194         if (size > buffer->size - buffer->posn) {
 195                 buffer->size = buffer->size * 3 / 2;
 196                 if (buffer->size < buffer->posn + size)
 197                         buffer->size = buffer->posn + size;
 198                 buffer->buffer = xrealloc(buffer->buffer, buffer->size);
 199         }
 200         memcpy(buffer->buffer + buffer->posn, ptr, size);
 201         buffer->posn += size;
 202         data_received++;
 203         return size;
 204 }
 205
 206 static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
 207                                void *data)
 208 {
 209         unsigned char expn[4096];
 210         size_t size = eltsize * nmemb;
 211         int posn = 0;
 212         struct transfer_request *request = (struct transfer_request *)data;
 213         do {
 214                 ssize_t retval = write(request->local,
 215                                        ptr + posn, size - posn);
 216                 if (retval < 0)
 217                         return posn;
 218                 posn += retval;
 219         } while (posn < size);
 220
 221         request->stream.avail_in = size;
 222         request->stream.next_in = ptr;
 223         do {
 224                 request->stream.next_out = expn;
 225                 request->stream.avail_out = sizeof(expn);
 226                 request->zret = inflate(&request->stream, Z_SYNC_FLUSH);
 227                 SHA1_Update(&request->c, expn,
 228                             sizeof(expn) - request->stream.avail_out);
 229         } while (request->stream.avail_in && request->zret == Z_OK);
 230         data_received++;
 231         return size;
 232 }
 233
 234 #ifdef USE_CURL_MULTI
 235 static void process_curl_messages(void);
 236 static void process_request_queue(void);
 237 #endif
 238
 239 static CURL* get_curl_handle(void)
 240 {
 241         CURL* result = curl_easy_init();
 242
 243         curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, curl_ssl_verify);
 244 #if LIBCURL_VERSION_NUM >= 0x070907
 245         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
 246 #endif
 247
 248         if (ssl_cert != NULL)
 249                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
 250 #if LIBCURL_VERSION_NUM >= 0x070902
 251         if (ssl_key != NULL)
 252                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
 253 #endif
 254 #if LIBCURL_VERSION_NUM >= 0x070908
 255         if (ssl_capath != NULL)
 256                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
 257 #endif
 258         if (ssl_cainfo != NULL)
 259                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
 260         curl_easy_setopt(result, CURLOPT_FAILONERROR, 1);
 261
 262         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
 263                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
 264                                  curl_low_speed_limit);
 265                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
 266                                  curl_low_speed_time);
 267         }
 268
 269         return result;
 270 }
 271
 272 static struct active_request_slot *get_active_slot(void)
 273 {
 274         struct active_request_slot *slot = active_queue_head;
 275         struct active_request_slot *newslot;
 276
 277 #ifdef USE_CURL_MULTI
 278         int num_transfers;
 279
 280         /* Wait for a slot to open up if the queue is full */
 281         while (active_requests >= max_requests) {
 282                 curl_multi_perform(curlm, &num_transfers);
 283                 if (num_transfers < active_requests) {
 284                         process_curl_messages();
 285                 }
 286         }
 287 #endif
 288
 289         while (slot != NULL && slot->in_use) {
 290                 slot = slot->next;
 291         }
 292         if (slot == NULL) {
 293                 newslot = xmalloc(sizeof(*newslot));
 294 #ifdef NO_CURL_EASY_DUPHANDLE
 295                 newslot->curl = get_curl_handle();
 296 #else
 297                 newslot->curl = curl_easy_duphandle(curl_default);
 298 #endif
 299                 newslot->in_use = 0;
 300                 newslot->next = NULL;
 301
 302                 slot = active_queue_head;
 303                 if (slot == NULL) {
 304                         active_queue_head = newslot;
 305                 } else {
 306                         while (slot->next != NULL) {
 307                                 slot = slot->next;
 308                         }
 309                         slot->next = newslot;
 310                 }
 311                 slot = newslot;
 312         }
 313
 314         active_requests++;
 315         slot->in_use = 1;
 316         slot->done = 0;
 317         slot->local = NULL;
 318         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
 319         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_range_header);
 320         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
 321
 322         return slot;
 323 }
 324
 325 static int start_active_slot(struct active_request_slot *slot)
 326 {
 327 #ifdef USE_CURL_MULTI
 328         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
 329
 330         if (curlm_result != CURLM_OK &&
 331             curlm_result != CURLM_CALL_MULTI_PERFORM) {
 332                 active_requests--;
 333                 slot->in_use = 0;
 334                 return 0;
 335         }
 336 #endif
 337         return 1;
 338 }
 339
 340 static void run_active_slot(struct active_request_slot *slot)
 341 {
 342 #ifdef USE_CURL_MULTI
 343         int num_transfers;
 344         long last_pos = 0;
 345         long current_pos;
 346         fd_set readfds;
 347         fd_set writefds;
 348         fd_set excfds;
 349         int max_fd;
 350         struct timeval select_timeout;
 351         CURLMcode curlm_result;
 352
 353         while (!slot->done) {
 354                 data_received = 0;
 355                 do {
 356                         curlm_result = curl_multi_perform(curlm,
 357                                                           &num_transfers);
 358                 } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
 359                 if (num_transfers < active_requests) {
 360                         process_curl_messages();
 361                         process_request_queue();
 362                 }
 363
 364                 if (!data_received && slot->local != NULL) {
 365                         current_pos = ftell(slot->local);
 366                         if (current_pos > last_pos)
 367                                 data_received++;
 368                         last_pos = current_pos;
 369                 }
 370
 371                 if (!slot->done && !data_received) {
 372                         max_fd = 0;
 373                         FD_ZERO(&readfds);
 374                         FD_ZERO(&writefds);
 375                         FD_ZERO(&excfds);
 376                         select_timeout.tv_sec = 0;
 377                         select_timeout.tv_usec = 50000;
 378                         select(max_fd, &readfds, &writefds,
 379                                &excfds, &select_timeout);
 380                 }
 381         }
 382 #else
 383         slot->curl_result = curl_easy_perform(slot->curl);
 384         active_requests--;
 385 #endif
 386 }
 387
 388 static void start_request(struct transfer_request *request)
 389 {
 390         char *hex = sha1_to_hex(request->sha1);
 391         char prevfile[PATH_MAX];
 392         char *url;
 393         char *posn;
 394         int prevlocal;
 395         unsigned char prev_buf[PREV_BUF_SIZE];
 396         ssize_t prev_read = 0;
 397         long prev_posn = 0;
 398         char range[RANGE_HEADER_SIZE];
 399         struct curl_slist *range_header = NULL;
 400         struct active_request_slot *slot;
 401
 402         snprintf(prevfile, sizeof(prevfile), "%s.prev", request->filename);
 403         unlink(prevfile);
 404         rename(request->tmpfile, prevfile);
 405         unlink(request->tmpfile);
 406
 407         request->local = open(request->tmpfile,
 408                               O_WRONLY | O_CREAT | O_EXCL, 0666);
 409         /* This could have failed due to the "lazy directory creation";
 410          * try to mkdir the last path component.
 411          */
 412         if (request->local < 0 && errno == ENOENT) {
 413                 char *dir = strrchr(request->tmpfile, '/');
 414                 if (dir) {
 415                         *dir = 0;
 416                         mkdir(request->tmpfile, 0777);
 417                         *dir = '/';
 418                 }
 419                 request->local = open(request->tmpfile,
 420                                       O_WRONLY | O_CREAT | O_EXCL, 0666);
 421         }
 422
 423         if (request->local < 0) {
 424                 request->state = ABORTED;
 425                 error("Couldn't create temporary file %s for %s: %s\n",
 426                       request->tmpfile, request->filename, strerror(errno));
 427                 return;
 428         }
 429
 430         memset(&request->stream, 0, sizeof(request->stream));
 431
 432         inflateInit(&request->stream);
 433
 434         SHA1_Init(&request->c);
 435
 436         url = xmalloc(strlen(request->repo->base) + 50);
 437         request->url = xmalloc(strlen(request->repo->base) + 50);
 438         strcpy(url, request->repo->base);
 439         posn = url + strlen(request->repo->base);
 440         strcpy(posn, "objects/");
 441         posn += 8;
 442         memcpy(posn, hex, 2);
 443         posn += 2;
 444         *(posn++) = '/';
 445         strcpy(posn, hex + 2);
 446         strcpy(request->url, url);
 447
 448         /* If a previous temp file is present, process what was already
 449            fetched. */
 450         prevlocal = open(prevfile, O_RDONLY);
 451         if (prevlocal != -1) {
 452                 do {
 453                         prev_read = read(prevlocal, prev_buf, PREV_BUF_SIZE);
 454                         if (prev_read>0) {
 455                                 if (fwrite_sha1_file(prev_buf,
 456                                                      1,
 457                                                      prev_read,
 458                                                      request) == prev_read) {
 459                                         prev_posn += prev_read;
 460                                 } else {
 461                                         prev_read = -1;
 462                                 }
 463                         }
 464                 } while (prev_read > 0);
 465                 close(prevlocal);
 466         }
 467         unlink(prevfile);
 468
 469         /* Reset inflate/SHA1 if there was an error reading the previous temp
 470            file; also rewind to the beginning of the local file. */
 471         if (prev_read == -1) {
 472                 memset(&request->stream, 0, sizeof(request->stream));
 473                 inflateInit(&request->stream);
 474                 SHA1_Init(&request->c);
 475                 if (prev_posn>0) {
 476                         prev_posn = 0;
 477                         lseek(request->local, SEEK_SET, 0);
 478                         ftruncate(request->local, 0);
 479                 }
 480         }
 481
 482         slot = get_active_slot();
 483         curl_easy_setopt(slot->curl, CURLOPT_FILE, request);
 484         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
 485         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, request->errorstr);
 486         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 487         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 488
 489         /* If we have successfully processed data from a previous fetch
 490            attempt, only fetch the data we don't already have. */
 491         if (prev_posn>0) {
 492                 if (get_verbosely)
 493                         fprintf(stderr,
 494                                 "Resuming fetch of object %s at byte %ld\n",
 495                                 hex, prev_posn);
 496                 sprintf(range, "Range: bytes=%ld-", prev_posn);
 497                 range_header = curl_slist_append(range_header, range);
 498                 curl_easy_setopt(slot->curl,
 499                                  CURLOPT_HTTPHEADER, range_header);
 500         }
 501
 502         /* Try to get the request started, abort the request on error */
 503         if (!start_active_slot(slot)) {
 504                 request->state = ABORTED;
 505                 close(request->local);
 506                 free(request->url);
 507                 return;
 508         }
 509
 510         request->slot = slot;
 511         request->state = ACTIVE;
 512 }
 513
 514 static void finish_request(struct transfer_request *request)
 515 {
 516         fchmod(request->local, 0444);
 517         close(request->local);
 518
 519         if (request->http_code == 416) {
 520                 fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
 521         } else if (request->curl_result != CURLE_OK) {
 522                 return;
 523         }
 524
 525         inflateEnd(&request->stream);
 526         SHA1_Final(request->real_sha1, &request->c);
 527         if (request->zret != Z_STREAM_END) {
 528                 unlink(request->tmpfile);
 529                 return;
 530         }
 531         if (memcmp(request->sha1, request->real_sha1, 20)) {
 532                 unlink(request->tmpfile);
 533                 return;
 534         }
 535         request->rename =
 536                 move_temp_to_file(request->tmpfile, request->filename);
 537
 538         if (request->rename == 0)
 539                 pull_say("got %s\n", sha1_to_hex(request->sha1));
 540 }
 541
 542 static void release_request(struct transfer_request *request)
 543 {
 544         struct transfer_request *entry = request_queue_head;
 545
 546         if (request == request_queue_head) {
 547                 request_queue_head = request->next;
 548         } else {
 549                 while (entry->next != NULL && entry->next != request)
 550                         entry = entry->next;
 551                 if (entry->next == request)
 552                         entry->next = entry->next->next;
 553         }
 554
 555         free(request->url);
 556         free(request);
 557 }
 558
 559 #ifdef USE_CURL_MULTI
 560 void process_curl_messages(void)
 561 {
 562         int num_messages;
 563         struct active_request_slot *slot;
 564         struct transfer_request *request = NULL;
 565         CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
 566
 567         while (curl_message != NULL) {
 568                 if (curl_message->msg == CURLMSG_DONE) {
 569                         slot = active_queue_head;
 570                         while (slot != NULL &&
 571                                slot->curl != curl_message->easy_handle)
 572                                 slot = slot->next;
 573                         if (slot != NULL) {
 574                                 curl_multi_remove_handle(curlm, slot->curl);
 575                                 active_requests--;
 576                                 slot->done = 1;
 577                                 slot->in_use = 0;
 578                                 slot->curl_result = curl_message->data.result;
 579                                 request = request_queue_head;
 580                                 while (request != NULL &&
 581                                        request->slot != slot)
 582                                         request = request->next;
 583                         } else {
 584                                 fprintf(stderr, "Received DONE message for unknown request!\n");
 585                         }
 586                         if (request != NULL) {
 587                                 request->curl_result =
 588                                         curl_message->data.result;
 589                                 curl_easy_getinfo(slot->curl,
 590                                                   CURLINFO_HTTP_CODE,
 591                                                   &request->http_code);
 592                                 request->slot = NULL;
 593
 594                                 /* Use alternates if necessary */
 595                                 if (request->http_code == 404 &&
 596                                     request->repo->next != NULL) {
 597                                         request->repo = request->repo->next;
 598                                         start_request(request);
 599                                 } else {
 600                                         finish_request(request);
 601                                         request->state = COMPLETE;
 602                                 }
 603                         }
 604                 } else {
 605                         fprintf(stderr, "Unknown CURL message received: %d\n",
 606                                 (int)curl_message->msg);
 607                 }
 608                 curl_message = curl_multi_info_read(curlm, &num_messages);
 609         }
 610 }
 611
 612 void process_request_queue(void)
 613 {
 614         struct transfer_request *request = request_queue_head;
 615         int num_transfers;
 616
 617         while (active_requests < max_requests && request != NULL) {
 618                 if (request->state == WAITING) {
 619                         if (has_sha1_file(request->sha1))
 620                                 release_request(request);
 621                         else
 622                                 start_request(request);
 623                         curl_multi_perform(curlm, &num_transfers);
 624                 }
 625                 request = request->next;
 626         }
 627 }
 628 #endif
 629
 630 void prefetch(unsigned char *sha1)
 631 {
 632         struct transfer_request *newreq;
 633         struct transfer_request *tail;
 634         char *filename = sha1_file_name(sha1);
 635
 636         newreq = xmalloc(sizeof(*newreq));
 637         memcpy(newreq->sha1, sha1, 20);
 638         newreq->repo = alt;
 639         newreq->url = NULL;
 640         newreq->local = -1;
 641         newreq->state = WAITING;
 642         snprintf(newreq->filename, sizeof(newreq->filename), "%s", filename);
 643         snprintf(newreq->tmpfile, sizeof(newreq->tmpfile),
 644                  "%s.temp", filename);
 645         newreq->next = NULL;
 646
 647         if (request_queue_head == NULL) {
 648                 request_queue_head = newreq;
 649         } else {
 650                 tail = request_queue_head;
 651                 while (tail->next != NULL) {
 652                         tail = tail->next;
 653                 }
 654                 tail->next = newreq;
 655         }
 656 #ifdef USE_CURL_MULTI
 657         process_request_queue();
 658         process_curl_messages();
 659 #endif
 660 }
 661
 662 static int fetch_index(struct alt_base *repo, unsigned char *sha1)
 663 {
 664         char *hex = sha1_to_hex(sha1);
 665         char *filename;
 666         char *url;
 667         char tmpfile[PATH_MAX];
 668         long prev_posn = 0;
 669         char range[RANGE_HEADER_SIZE];
 670         struct curl_slist *range_header = NULL;
 671
 672         FILE *indexfile;
 673         struct active_request_slot *slot;
 674
 675         if (has_pack_index(sha1))
 676                 return 0;
 677
 678         if (get_verbosely)
 679                 fprintf(stderr, "Getting index for pack %s\n", hex);
 680
 681         url = xmalloc(strlen(repo->base) + 64);
 682         sprintf(url, "%s/objects/pack/pack-%s.idx", repo->base, hex);
 683
 684         filename = sha1_pack_index_name(sha1);
 685         snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
 686         indexfile = fopen(tmpfile, "a");
 687         if (!indexfile)
 688                 return error("Unable to open local file %s for pack index",
 689                              filename);
 690
 691         slot = get_active_slot();
 692         curl_easy_setopt(slot->curl, CURLOPT_FILE, indexfile);
 693         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
 694         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 695         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 696         slot->local = indexfile;
 697
 698         /* If there is data present from a previous transfer attempt,
 699            resume where it left off */
 700         prev_posn = ftell(indexfile);
 701         if (prev_posn>0) {
 702                 if (get_verbosely)
 703                         fprintf(stderr,
 704                                 "Resuming fetch of index for pack %s at byte %ld\n",
 705                                 hex, prev_posn);
 706                 sprintf(range, "Range: bytes=%ld-", prev_posn);
 707                 range_header = curl_slist_append(range_header, range);
 708                 curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
 709         }
 710
 711         if (start_active_slot(slot)) {
 712                 run_active_slot(slot);
 713                 if (slot->curl_result != CURLE_OK) {
 714                         fclose(indexfile);
 715                         return error("Unable to get pack index %s\n%s", url,
 716                                      curl_errorstr);
 717                 }
 718         } else {
 719                 return error("Unable to start request");
 720         }
 721
 722         fclose(indexfile);
 723
 724         return move_temp_to_file(tmpfile, filename);
 725 }
 726
 727 static int setup_index(struct alt_base *repo, unsigned char *sha1)
 728 {
 729         struct packed_git *new_pack;
 730         if (has_pack_file(sha1))
 731                 return 0; // don't list this as something we can get
 732
 733         if (fetch_index(repo, sha1))
 734                 return -1;
 735
 736         new_pack = parse_pack_index(sha1);
 737         new_pack->next = repo->packs;
 738         repo->packs = new_pack;
 739         return 0;
 740 }
 741
 742 static int fetch_alternates(char *base)
 743 {
 744         int ret = 0;
 745         struct buffer buffer;
 746         char *url;
 747         char *data;
 748         int i = 0;
 749         int http_specific = 1;
 750         struct alt_base *tail = alt;
 751         static const char null_byte = '\0';
 752
 753         struct active_request_slot *slot;
 754
 755         data = xmalloc(4096);
 756         buffer.size = 4096;
 757         buffer.posn = 0;
 758         buffer.buffer = data;
 759
 760         if (get_verbosely)
 761                 fprintf(stderr, "Getting alternates list\n");
 762
 763         url = xmalloc(strlen(base) + 31);
 764         sprintf(url, "%s/objects/info/http-alternates", base);
 765
 766         slot = get_active_slot();
 767         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 768         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
 769                          fwrite_buffer_dynamic);
 770         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 771         if (start_active_slot(slot)) {
 772                 run_active_slot(slot);
 773                 if (slot->curl_result != CURLE_OK || !buffer.posn) {
 774                         http_specific = 0;
 775
 776                         sprintf(url, "%s/objects/info/alternates", base);
 777
 778                         slot = get_active_slot();
 779                         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 780                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
 781                                          fwrite_buffer_dynamic);
 782                         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 783                         if (start_active_slot(slot)) {
 784                                 run_active_slot(slot);
 785                                 if (slot->curl_result != CURLE_OK) {
 786                                         free(buffer.buffer);
 787                                         return 0;
 788                                 }
 789                         }
 790                 }
 791         } else {
 792                 free(buffer.buffer);
 793                 return 0;
 794         }
 795
 796         fwrite_buffer_dynamic(&null_byte, 1, 1, &buffer);
 797         buffer.posn--;
 798         data = buffer.buffer;
 799
 800         while (i < buffer.posn) {
 801                 int posn = i;
 802                 while (posn < buffer.posn && data[posn] != '\n')
 803                         posn++;
 804                 if (data[posn] == '\n') {
 805                         int okay = 0;
 806                         int serverlen = 0;
 807                         struct alt_base *newalt;
 808                         char *target = NULL;
 809                         if (data[i] == '/') {
 810                                 serverlen = strchr(base + 8, '/') - base;
 811                                 okay = 1;
 812                         } else if (!memcmp(data + i, "../", 3)) {
 813                                 i += 3;
 814                                 serverlen = strlen(base);
 815                                 while (i + 2 < posn &&
 816                                        !memcmp(data + i, "../", 3)) {
 817                                         do {
 818                                                 serverlen--;
 819                                         } while (serverlen &&
 820                                                  base[serverlen - 1] != '/');
 821                                         i += 3;
 822                                 }
 823                                 // If the server got removed, give up.
 824                                 okay = strchr(base, ':') - base + 3 <
 825                                         serverlen;
 826                         } else if (http_specific) {
 827                                 char *colon = strchr(data + i, ':');
 828                                 char *slash = strchr(data + i, '/');
 829                                 if (colon && slash && colon < data + posn &&
 830                                     slash < data + posn && colon < slash) {
 831                                         okay = 1;
 832                                 }
 833                         }
 834                         // skip 'objects' at end
 835                         if (okay) {
 836                                 target = xmalloc(serverlen + posn - i - 6);
 837                                 strncpy(target, base, serverlen);
 838                                 strncpy(target + serverlen, data + i,
 839                                         posn - i - 7);
 840                                 target[serverlen + posn - i - 7] = '\0';
 841                                 if (get_verbosely)
 842                                         fprintf(stderr,
 843                                                 "Also look at %s\n", target);
 844                                 newalt = xmalloc(sizeof(*newalt));
 845                                 newalt->next = NULL;
 846                                 newalt->base = target;
 847                                 newalt->got_indices = 0;
 848                                 newalt->packs = NULL;
 849                                 while (tail->next != NULL)
 850                                         tail = tail->next;
 851                                 tail->next = newalt;
 852                                 ret++;
 853                         }
 854                 }
 855                 i = posn + 1;
 856         }
 857
 858         free(buffer.buffer);
 859         return ret;
 860 }
 861
 862 static int fetch_indices(struct alt_base *repo)
 863 {
 864         unsigned char sha1[20];
 865         char *url;
 866         struct buffer buffer;
 867         char *data;
 868         int i = 0;
 869
 870         struct active_request_slot *slot;
 871
 872         if (repo->got_indices)
 873                 return 0;
 874
 875         data = xmalloc(4096);
 876         buffer.size = 4096;
 877         buffer.posn = 0;
 878         buffer.buffer = data;
 879
 880         if (get_verbosely)
 881                 fprintf(stderr, "Getting pack list\n");
 882
 883         url = xmalloc(strlen(repo->base) + 21);
 884         sprintf(url, "%s/objects/info/packs", repo->base);
 885
 886         slot = get_active_slot();
 887         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 888         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
 889                          fwrite_buffer_dynamic);
 890         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 891         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
 892         if (start_active_slot(slot)) {
 893                 run_active_slot(slot);
 894                 if (slot->curl_result != CURLE_OK) {
 895                         free(buffer.buffer);
 896                         return error("%s", curl_errorstr);
 897                 }
 898         } else {
 899                 free(buffer.buffer);
 900                 return error("Unable to start request");
 901         }
 902
 903         data = buffer.buffer;
 904         while (i < buffer.posn) {
 905                 switch (data[i]) {
 906                 case 'P':
 907                         i++;
 908                         if (i + 52 < buffer.posn &&
 909                             !strncmp(data + i, " pack-", 6) &&
 910                             !strncmp(data + i + 46, ".pack\n", 6)) {
 911                                 get_sha1_hex(data + i + 6, sha1);
 912                                 setup_index(repo, sha1);
 913                                 i += 51;
 914                                 break;
 915                         }
 916                 default:
 917                         while (data[i] != '\n')
 918                                 i++;
 919                 }
 920                 i++;
 921         }
 922
 923         free(buffer.buffer);
 924         repo->got_indices = 1;
 925         return 0;
 926 }
 927
 928 static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
 929 {
 930         char *url;
 931         struct packed_git *target;
 932         struct packed_git **lst;
 933         FILE *packfile;
 934         char *filename;
 935         char tmpfile[PATH_MAX];
 936         int ret;
 937         long prev_posn = 0;
 938         char range[RANGE_HEADER_SIZE];
 939         struct curl_slist *range_header = NULL;
 940
 941         struct active_request_slot *slot;
 942
 943         if (fetch_indices(repo))
 944                 return -1;
 945         target = find_sha1_pack(sha1, repo->packs);
 946         if (!target)
 947                 return -1;
 948
 949         if (get_verbosely) {
 950                 fprintf(stderr, "Getting pack %s\n",
 951                         sha1_to_hex(target->sha1));
 952                 fprintf(stderr, " which contains %s\n",
 953                         sha1_to_hex(sha1));
 954         }
 955
 956         url = xmalloc(strlen(repo->base) + 65);
 957         sprintf(url, "%s/objects/pack/pack-%s.pack",
 958                 repo->base, sha1_to_hex(target->sha1));
 959
 960         filename = sha1_pack_name(target->sha1);
 961         snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
 962         packfile = fopen(tmpfile, "a");
 963         if (!packfile)
 964                 return error("Unable to open local file %s for pack",
 965                              filename);
 966
 967         slot = get_active_slot();
 968         curl_easy_setopt(slot->curl, CURLOPT_FILE, packfile);
 969         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
 970         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 971         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 972         slot->local = packfile;
 973
 974         /* If there is data present from a previous transfer attempt,
 975            resume where it left off */
 976         prev_posn = ftell(packfile);
 977         if (prev_posn>0) {
 978                 if (get_verbosely)
 979                         fprintf(stderr,
 980                                 "Resuming fetch of pack %s at byte %ld\n",
 981                                 sha1_to_hex(target->sha1), prev_posn);
 982                 sprintf(range, "Range: bytes=%ld-", prev_posn);
 983                 range_header = curl_slist_append(range_header, range);
 984                 curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
 985         }
 986
 987         if (start_active_slot(slot)) {
 988                 run_active_slot(slot);
 989                 if (slot->curl_result != CURLE_OK) {
 990                         fclose(packfile);
 991                         return error("Unable to get pack file %s\n%s", url,
 992                                      curl_errorstr);
 993                 }
 994         } else {
 995                 return error("Unable to start request");
 996         }
 997
 998         fclose(packfile);
 999
1000         ret = move_temp_to_file(tmpfile, filename);
1001         if (ret)
1002                 return ret;
1003
1004         lst = &repo->packs;
1005         while (*lst != target)
1006                 lst = &((*lst)->next);
1007         *lst = (*lst)->next;
1008
1009         if (verify_pack(target, 0))
1010                 return -1;
1011         install_packed_git(target);
1012
1013         return 0;
1014 }
1015
1016 static int fetch_object(struct alt_base *repo, unsigned char *sha1)
1017 {
1018         char *hex = sha1_to_hex(sha1);
1019         int ret;
1020         struct transfer_request *request = request_queue_head;
1021
1022         while (request != NULL && memcmp(request->sha1, sha1, 20))
1023                 request = request->next;
1024         if (request == NULL)
1025                 return error("Couldn't find request for %s in the queue", hex);
1026
1027         if (has_sha1_file(request->sha1)) {
1028                 release_request(request);
1029                 return 0;
1030         }
1031
1032 #ifdef USE_CURL_MULTI
1033         while (request->state == WAITING) {
1034                 int num_transfers;
1035                 curl_multi_perform(curlm, &num_transfers);
1036                 if (num_transfers < active_requests) {
1037                         process_curl_messages();
1038                         process_request_queue();
1039                 }
1040         }
1041 #else
1042         start_request(request);
1043 #endif
1044
1045         while (request->state == ACTIVE) {
1046                 run_active_slot(request->slot);
1047 #ifndef USE_CURL_MULTI
1048                 request->curl_result = request->slot->curl_result;
1049                 curl_easy_getinfo(request->slot->curl,
1050                                   CURLINFO_HTTP_CODE,
1051                                   &request->http_code);
1052                 request->slot = NULL;
1053
1054                 /* Use alternates if necessary */
1055                 if (request->http_code == 404 &&
1056                     request->repo->next != NULL) {
1057                         request->repo = request->repo->next;
1058                         start_request(request);
1059                 } else {
1060                         finish_request(request);
1061                         request->state = COMPLETE;
1062                 }
1063 #endif
1064         }
1065
1066         if (request->state == ABORTED) {
1067                 release_request(request);
1068                 return error("Request for %s aborted", hex);
1069         }
1070
1071         if (request->curl_result != CURLE_OK && request->http_code != 416) {
1072                 ret = error("%s (curl_result = %d, http_code = %ld, sha1 = %s)",
1073                             request->errorstr, request->curl_result,
1074                             request->http_code, hex);
1075                 release_request(request);
1076                 return ret;
1077         }
1078
1079         if (request->zret != Z_STREAM_END) {
1080                 ret = error("File %s (%s) corrupt\n", hex, request->url);
1081                 release_request(request);
1082                 return ret;
1083         }
1084
1085         if (memcmp(request->sha1, request->real_sha1, 20)) {
1086                 release_request(request);
1087                 return error("File %s has bad hash\n", hex);
1088         }
1089
1090         if (request->rename < 0) {
1091                 ret = error("unable to write sha1 filename %s: %s",
1092                             request->filename,
1093                             strerror(request->rename));
1094                 release_request(request);
1095                 return ret;
1096         }
1097
1098         release_request(request);
1099         return 0;
1100 }
1101
1102 int fetch(unsigned char *sha1)
1103 {
1104         struct alt_base *altbase = alt;
1105
1106         if (!fetch_object(altbase, sha1))
1107                 return 0;
1108         while (altbase) {
1109                 if (!fetch_pack(altbase, sha1))
1110                         return 0;
1111                 altbase = altbase->next;
1112         }
1113         return error("Unable to find %s under %s\n", sha1_to_hex(sha1),
1114                      alt->base);
1115 }
1116
1117 static inline int needs_quote(int ch)
1118 {
1119         switch (ch) {
1120         case '/': case '-': case '.':
1121         case 'A'...'Z': case 'a'...'z': case '0'...'9':
1122                 return 0;
1123         default:
1124                 return 1;
1125         }
1126 }
1127
1128 static inline int hex(int v)
1129 {
1130         if (v < 10) return '0' + v;
1131         else return 'A' + v - 10;
1132 }
1133
1134 static char *quote_ref_url(const char *base, const char *ref)
1135 {
1136         const char *cp;
1137         char *dp, *qref;
1138         int len, baselen, ch;
1139
1140         baselen = strlen(base);
1141         len = baselen + 6; /* "refs/" + NUL */
1142         for (cp = ref; (ch = *cp) != 0; cp++, len++)
1143                 if (needs_quote(ch))
1144                         len += 2; /* extra two hex plus replacement % */
1145         qref = xmalloc(len);
1146         memcpy(qref, base, baselen);
1147         memcpy(qref + baselen, "refs/", 5);
1148         for (cp = ref, dp = qref + baselen + 5; (ch = *cp) != 0; cp++) {
1149                 if (needs_quote(ch)) {
1150                         *dp++ = '%';
1151                         *dp++ = hex((ch >> 4) & 0xF);
1152                         *dp++ = hex(ch & 0xF);
1153                 }
1154                 else
1155                         *dp++ = ch;
1156         }
1157         *dp = 0;
1158
1159         return qref;
1160 }
1161
1162 int fetch_ref(char *ref, unsigned char *sha1)
1163 {
1164         char *url;
1165         char hex[42];
1166         struct buffer buffer;
1167         char *base = alt->base;
1168         struct active_request_slot *slot;
1169         buffer.size = 41;
1170         buffer.posn = 0;
1171         buffer.buffer = hex;
1172         hex[41] = '\0';
1173
1174         url = quote_ref_url(base, ref);
1175         slot = get_active_slot();
1176         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
1177         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
1178         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
1179         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1180         if (start_active_slot(slot)) {
1181                 run_active_slot(slot);
1182                 if (slot->curl_result != CURLE_OK)
1183                         return error("Couldn't get %s for %s\n%s",
1184                                      url, ref, curl_errorstr);
1185         } else {
1186                 return error("Unable to start request");
1187         }
1188
1189         hex[40] = '\0';
1190         get_sha1_hex(hex, sha1);
1191         return 0;
1192 }
1193
1194 int main(int argc, char **argv)
1195 {
1196         char *commit_id;
1197         char *url;
1198         int arg = 1;
1199         struct active_request_slot *slot;
1200         char *low_speed_limit;
1201         char *low_speed_time;
1202
1203         while (arg < argc && argv[arg][0] == '-') {
1204                 if (argv[arg][1] == 't') {
1205                         get_tree = 1;
1206                 } else if (argv[arg][1] == 'c') {
1207                         get_history = 1;
1208                 } else if (argv[arg][1] == 'a') {
1209                         get_all = 1;
1210                         get_tree = 1;
1211                         get_history = 1;
1212                 } else if (argv[arg][1] == 'v') {
1213                         get_verbosely = 1;
1214                 } else if (argv[arg][1] == 'w') {
1215                         write_ref = argv[arg + 1];
1216                         arg++;
1217                 } else if (!strcmp(argv[arg], "--recover")) {
1218                         get_recover = 1;
1219                 }
1220                 arg++;
1221         }
1222         if (argc < arg + 2) {
1223                 usage("git-http-fetch [-c] [-t] [-a] [-d] [-v] [--recover] [-w ref] commit-id url");
1224                 return 1;
1225         }
1226         commit_id = argv[arg];
1227         url = argv[arg + 1];
1228
1229         curl_global_init(CURL_GLOBAL_ALL);
1230
1231 #ifdef USE_CURL_MULTI
1232         {
1233                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
1234                 if (http_max_requests != NULL)
1235                         max_requests = atoi(http_max_requests);
1236         }
1237
1238         curlm = curl_multi_init();
1239         if (curlm == NULL) {
1240                 fprintf(stderr, "Error creating curl multi handle.\n");
1241                 return 1;
1242         }
1243 #endif
1244
1245         if (getenv("GIT_SSL_NO_VERIFY"))
1246                 curl_ssl_verify = 0;
1247
1248         ssl_cert = getenv("GIT_SSL_CERT");
1249 #if LIBCURL_VERSION_NUM >= 0x070902
1250         ssl_key = getenv("GIT_SSL_KEY");
1251 #endif
1252 #if LIBCURL_VERSION_NUM >= 0x070908
1253         ssl_capath = getenv("GIT_SSL_CAPATH");
1254 #endif
1255         ssl_cainfo = getenv("GIT_SSL_CAINFO");
1256
1257         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
1258         if (low_speed_limit != NULL)
1259                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
1260         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
1261         if (low_speed_time != NULL)
1262                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
1263
1264         git_config(http_options);
1265
1266         if (curl_ssl_verify == -1)
1267                 curl_ssl_verify = 1;
1268
1269 #ifdef USE_CURL_MULTI
1270         if (max_requests < 1)
1271                 max_requests = DEFAULT_MAX_REQUESTS;
1272 #endif
1273
1274         pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
1275         no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
1276         no_range_header = curl_slist_append(no_range_header, "Range:");
1277
1278 #ifndef NO_CURL_EASY_DUPHANDLE
1279         curl_default = get_curl_handle();
1280 #endif
1281
1282         alt = xmalloc(sizeof(*alt));
1283         alt->base = url;
1284         alt->got_indices = 0;
1285         alt->packs = NULL;
1286         alt->next = NULL;
1287         fetch_alternates(alt->base);
1288
1289         if (pull(commit_id))
1290                 return 1;
1291
1292         curl_slist_free_all(pragma_header);
1293         curl_slist_free_all(no_pragma_header);
1294         curl_slist_free_all(no_range_header);
1295 #ifndef NO_CURL_EASY_DUPHANDLE
1296         curl_easy_cleanup(curl_default);
1297 #endif
1298         slot = active_queue_head;
1299         while (slot != NULL) {
1300                 curl_easy_cleanup(slot->curl);
1301                 slot = slot->next;
1302         }
1303 #ifdef USE_CURL_MULTI
1304         curl_multi_cleanup(curlm);
1305 #endif
1306         curl_global_cleanup();
1307         return 0;
1308 }