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 got_alternates = 0;
  29 static int active_requests = 0;
  30 static int data_received;
  31
  32 #ifdef USE_CURL_MULTI
  33 static int max_requests = -1;
  34 static CURLM *curlm;
  35 #endif
  36 #ifndef NO_CURL_EASY_DUPHANDLE
  37 static CURL *curl_default;
  38 #endif
  39 static struct curl_slist *pragma_header;
  40 static struct curl_slist *no_pragma_header;
  41 static struct curl_slist *no_range_header;
  42 static char curl_errorstr[CURL_ERROR_SIZE];
  43
  44 struct alt_base
  45 {
  46         char *base;
  47         int got_indices;
  48         struct packed_git *packs;
  49         struct alt_base *next;
  50 };
  51
  52 static struct alt_base *alt = NULL;
  53
  54 enum transfer_state {
  55         WAITING,
  56         ABORTED,
  57         ACTIVE,
  58         COMPLETE,
  59 };
  60
  61 struct transfer_request
  62 {
  63         unsigned char sha1[20];
  64         struct alt_base *repo;
  65         char *url;
  66         char filename[PATH_MAX];
  67         char tmpfile[PATH_MAX];
  68         int local;
  69         enum transfer_state state;
  70         CURLcode curl_result;
  71         char errorstr[CURL_ERROR_SIZE];
  72         long http_code;
  73         unsigned char real_sha1[20];
  74         SHA_CTX c;
  75         z_stream stream;
  76         int zret;
  77         int rename;
  78         struct active_request_slot *slot;
  79         struct transfer_request *next;
  80 };
  81
  82 struct active_request_slot
  83 {
  84         CURL *curl;
  85         FILE *local;
  86         int in_use;
  87         int done;
  88         CURLcode curl_result;
  89         long http_code;
  90         struct active_request_slot *next;
  91 };
  92
  93 static struct transfer_request *request_queue_head = NULL;
  94 static struct active_request_slot *active_queue_head = NULL;
  95
  96 static int curl_ssl_verify = -1;
  97 static char *ssl_cert = NULL;
  98 #if LIBCURL_VERSION_NUM >= 0x070902
  99 static char *ssl_key = NULL;
 100 #endif
 101 #if LIBCURL_VERSION_NUM >= 0x070908
 102 static char *ssl_capath = NULL;
 103 #endif
 104 static char *ssl_cainfo = NULL;
 105 static long curl_low_speed_limit = -1;
 106 static long curl_low_speed_time = -1;
 107
 108 struct buffer
 109 {
 110         size_t posn;
 111         size_t size;
 112         void *buffer;
 113 };
 114
 115 static int http_options(const char *var, const char *value)
 116 {
 117         if (!strcmp("http.sslverify", var)) {
 118                 if (curl_ssl_verify == -1) {
 119                         curl_ssl_verify = git_config_bool(var, value);
 120                 }
 121                 return 0;
 122         }
 123
 124         if (!strcmp("http.sslcert", var)) {
 125                 if (ssl_cert == NULL) {
 126                         ssl_cert = xmalloc(strlen(value)+1);
 127                         strcpy(ssl_cert, value);
 128                 }
 129                 return 0;
 130         }
 131 #if LIBCURL_VERSION_NUM >= 0x070902
 132         if (!strcmp("http.sslkey", var)) {
 133                 if (ssl_key == NULL) {
 134                         ssl_key = xmalloc(strlen(value)+1);
 135                         strcpy(ssl_key, value);
 136                 }
 137                 return 0;
 138         }
 139 #endif
 140 #if LIBCURL_VERSION_NUM >= 0x070908
 141         if (!strcmp("http.sslcapath", var)) {
 142                 if (ssl_capath == NULL) {
 143                         ssl_capath = xmalloc(strlen(value)+1);
 144                         strcpy(ssl_capath, value);
 145                 }
 146                 return 0;
 147         }
 148 #endif
 149         if (!strcmp("http.sslcainfo", var)) {
 150                 if (ssl_cainfo == NULL) {
 151                         ssl_cainfo = xmalloc(strlen(value)+1);
 152                         strcpy(ssl_cainfo, value);
 153                 }
 154                 return 0;
 155         }
 156
 157 #ifdef USE_CURL_MULTI
 158         if (!strcmp("http.maxrequests", var)) {
 159                 if (max_requests == -1)
 160                         max_requests = git_config_int(var, value);
 161                 return 0;
 162         }
 163 #endif
 164
 165         if (!strcmp("http.lowspeedlimit", var)) {
 166                 if (curl_low_speed_limit == -1)
 167                         curl_low_speed_limit = (long)git_config_int(var, value);
 168                 return 0;
 169         }
 170         if (!strcmp("http.lowspeedtime", var)) {
 171                 if (curl_low_speed_time == -1)
 172                         curl_low_speed_time = (long)git_config_int(var, value);
 173                 return 0;
 174         }
 175
 176         /* Fall back on the default ones */
 177         return git_default_config(var, value);
 178 }
 179
 180 static size_t fwrite_buffer(void *ptr, size_t eltsize, size_t nmemb,
 181                             struct buffer *buffer)
 182 {
 183         size_t size = eltsize * nmemb;
 184         if (size > buffer->size - buffer->posn)
 185                 size = buffer->size - buffer->posn;
 186         memcpy(buffer->buffer + buffer->posn, ptr, size);
 187         buffer->posn += size;
 188         data_received++;
 189         return size;
 190 }
 191
 192 static size_t fwrite_buffer_dynamic(const void *ptr, size_t eltsize,
 193                                     size_t nmemb, struct buffer *buffer)
 194 {
 195         size_t size = eltsize * nmemb;
 196         if (size > buffer->size - buffer->posn) {
 197                 buffer->size = buffer->size * 3 / 2;
 198                 if (buffer->size < buffer->posn + size)
 199                         buffer->size = buffer->posn + size;
 200                 buffer->buffer = xrealloc(buffer->buffer, buffer->size);
 201         }
 202         memcpy(buffer->buffer + buffer->posn, ptr, size);
 203         buffer->posn += size;
 204         data_received++;
 205         return size;
 206 }
 207
 208 static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
 209                                void *data)
 210 {
 211         unsigned char expn[4096];
 212         size_t size = eltsize * nmemb;
 213         int posn = 0;
 214         struct transfer_request *request = (struct transfer_request *)data;
 215         do {
 216                 ssize_t retval = write(request->local,
 217                                        ptr + posn, size - posn);
 218                 if (retval < 0)
 219                         return posn;
 220                 posn += retval;
 221         } while (posn < size);
 222
 223         request->stream.avail_in = size;
 224         request->stream.next_in = ptr;
 225         do {
 226                 request->stream.next_out = expn;
 227                 request->stream.avail_out = sizeof(expn);
 228                 request->zret = inflate(&request->stream, Z_SYNC_FLUSH);
 229                 SHA1_Update(&request->c, expn,
 230                             sizeof(expn) - request->stream.avail_out);
 231         } while (request->stream.avail_in && request->zret == Z_OK);
 232         data_received++;
 233         return size;
 234 }
 235
 236 #ifdef USE_CURL_MULTI
 237 static void process_curl_messages(void);
 238 static void process_request_queue(void);
 239 #endif
 240 static int fetch_alternates(char *base);
 241
 242 static CURL* get_curl_handle(void)
 243 {
 244         CURL* result = curl_easy_init();
 245
 246         curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, curl_ssl_verify);
 247 #if LIBCURL_VERSION_NUM >= 0x070907
 248         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
 249 #endif
 250
 251         if (ssl_cert != NULL)
 252                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
 253 #if LIBCURL_VERSION_NUM >= 0x070902
 254         if (ssl_key != NULL)
 255                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
 256 #endif
 257 #if LIBCURL_VERSION_NUM >= 0x070908
 258         if (ssl_capath != NULL)
 259                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
 260 #endif
 261         if (ssl_cainfo != NULL)
 262                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
 263         curl_easy_setopt(result, CURLOPT_FAILONERROR, 1);
 264
 265         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
 266                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
 267                                  curl_low_speed_limit);
 268                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
 269                                  curl_low_speed_time);
 270         }
 271
 272         return result;
 273 }
 274
 275 static struct active_request_slot *get_active_slot(void)
 276 {
 277         struct active_request_slot *slot = active_queue_head;
 278         struct active_request_slot *newslot;
 279
 280 #ifdef USE_CURL_MULTI
 281         int num_transfers;
 282
 283         /* Wait for a slot to open up if the queue is full */
 284         while (active_requests >= max_requests) {
 285                 curl_multi_perform(curlm, &num_transfers);
 286                 if (num_transfers < active_requests) {
 287                         process_curl_messages();
 288                 }
 289         }
 290 #endif
 291
 292         while (slot != NULL && slot->in_use) {
 293                 slot = slot->next;
 294         }
 295         if (slot == NULL) {
 296                 newslot = xmalloc(sizeof(*newslot));
 297                 newslot->curl = NULL;
 298                 newslot->in_use = 0;
 299                 newslot->next = NULL;
 300
 301                 slot = active_queue_head;
 302                 if (slot == NULL) {
 303                         active_queue_head = newslot;
 304                 } else {
 305                         while (slot->next != NULL) {
 306                                 slot = slot->next;
 307                         }
 308                         slot->next = newslot;
 309                 }
 310                 slot = newslot;
 311         }
 312
 313         if (slot->curl == NULL) {
 314 #ifdef NO_CURL_EASY_DUPHANDLE
 315                 slot->curl = get_curl_handle();
 316 #else
 317                 slot->curl = curl_easy_duphandle(curl_default);
 318 #endif
 319         }
 320
 321         active_requests++;
 322         slot->in_use = 1;
 323         slot->done = 0;
 324         slot->local = NULL;
 325         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
 326         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_range_header);
 327         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
 328
 329         return slot;
 330 }
 331
 332 static int start_active_slot(struct active_request_slot *slot)
 333 {
 334 #ifdef USE_CURL_MULTI
 335         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
 336
 337         if (curlm_result != CURLM_OK &&
 338             curlm_result != CURLM_CALL_MULTI_PERFORM) {
 339                 active_requests--;
 340                 slot->in_use = 0;
 341                 return 0;
 342         }
 343 #endif
 344         return 1;
 345 }
 346
 347 static void run_active_slot(struct active_request_slot *slot)
 348 {
 349 #ifdef USE_CURL_MULTI
 350         int num_transfers;
 351         long last_pos = 0;
 352         long current_pos;
 353         fd_set readfds;
 354         fd_set writefds;
 355         fd_set excfds;
 356         int max_fd;
 357         struct timeval select_timeout;
 358         CURLMcode curlm_result;
 359
 360         while (!slot->done) {
 361                 data_received = 0;
 362                 do {
 363                         curlm_result = curl_multi_perform(curlm,
 364                                                           &num_transfers);
 365                 } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
 366                 if (num_transfers < active_requests) {
 367                         process_curl_messages();
 368                         process_request_queue();
 369                 }
 370
 371                 if (!data_received && slot->local != NULL) {
 372                         current_pos = ftell(slot->local);
 373                         if (current_pos > last_pos)
 374                                 data_received++;
 375                         last_pos = current_pos;
 376                 }
 377
 378                 if (!slot->done && !data_received) {
 379                         max_fd = 0;
 380                         FD_ZERO(&readfds);
 381                         FD_ZERO(&writefds);
 382                         FD_ZERO(&excfds);
 383                         select_timeout.tv_sec = 0;
 384                         select_timeout.tv_usec = 50000;
 385                         select(max_fd, &readfds, &writefds,
 386                                &excfds, &select_timeout);
 387                 }
 388         }
 389 #else
 390         slot->curl_result = curl_easy_perform(slot->curl);
 391         active_requests--;
 392 #endif
 393 }
 394
 395 static void start_request(struct transfer_request *request)
 396 {
 397         char *hex = sha1_to_hex(request->sha1);
 398         char prevfile[PATH_MAX];
 399         char *url;
 400         char *posn;
 401         int prevlocal;
 402         unsigned char prev_buf[PREV_BUF_SIZE];
 403         ssize_t prev_read = 0;
 404         long prev_posn = 0;
 405         char range[RANGE_HEADER_SIZE];
 406         struct curl_slist *range_header = NULL;
 407         struct active_request_slot *slot;
 408
 409         snprintf(prevfile, sizeof(prevfile), "%s.prev", request->filename);
 410         unlink(prevfile);
 411         rename(request->tmpfile, prevfile);
 412         unlink(request->tmpfile);
 413
 414         request->local = open(request->tmpfile,
 415                               O_WRONLY | O_CREAT | O_EXCL, 0666);
 416         /* This could have failed due to the "lazy directory creation";
 417          * try to mkdir the last path component.
 418          */
 419         if (request->local < 0 && errno == ENOENT) {
 420                 char *dir = strrchr(request->tmpfile, '/');
 421                 if (dir) {
 422                         *dir = 0;
 423                         mkdir(request->tmpfile, 0777);
 424                         *dir = '/';
 425                 }
 426                 request->local = open(request->tmpfile,
 427                                       O_WRONLY | O_CREAT | O_EXCL, 0666);
 428         }
 429
 430         if (request->local < 0) {
 431                 request->state = ABORTED;
 432                 error("Couldn't create temporary file %s for %s: %s\n",
 433                       request->tmpfile, request->filename, strerror(errno));
 434                 return;
 435         }
 436
 437         memset(&request->stream, 0, sizeof(request->stream));
 438
 439         inflateInit(&request->stream);
 440
 441         SHA1_Init(&request->c);
 442
 443         url = xmalloc(strlen(request->repo->base) + 50);
 444         request->url = xmalloc(strlen(request->repo->base) + 50);
 445         strcpy(url, request->repo->base);
 446         posn = url + strlen(request->repo->base);
 447         strcpy(posn, "objects/");
 448         posn += 8;
 449         memcpy(posn, hex, 2);
 450         posn += 2;
 451         *(posn++) = '/';
 452         strcpy(posn, hex + 2);
 453         strcpy(request->url, url);
 454
 455         /* If a previous temp file is present, process what was already
 456            fetched. */
 457         prevlocal = open(prevfile, O_RDONLY);
 458         if (prevlocal != -1) {
 459                 do {
 460                         prev_read = read(prevlocal, prev_buf, PREV_BUF_SIZE);
 461                         if (prev_read>0) {
 462                                 if (fwrite_sha1_file(prev_buf,
 463                                                      1,
 464                                                      prev_read,
 465                                                      request) == prev_read) {
 466                                         prev_posn += prev_read;
 467                                 } else {
 468                                         prev_read = -1;
 469                                 }
 470                         }
 471                 } while (prev_read > 0);
 472                 close(prevlocal);
 473         }
 474         unlink(prevfile);
 475
 476         /* Reset inflate/SHA1 if there was an error reading the previous temp
 477            file; also rewind to the beginning of the local file. */
 478         if (prev_read == -1) {
 479                 memset(&request->stream, 0, sizeof(request->stream));
 480                 inflateInit(&request->stream);
 481                 SHA1_Init(&request->c);
 482                 if (prev_posn>0) {
 483                         prev_posn = 0;
 484                         lseek(request->local, SEEK_SET, 0);
 485                         ftruncate(request->local, 0);
 486                 }
 487         }
 488
 489         slot = get_active_slot();
 490         curl_easy_setopt(slot->curl, CURLOPT_FILE, request);
 491         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
 492         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, request->errorstr);
 493         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 494         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 495
 496         /* If we have successfully processed data from a previous fetch
 497            attempt, only fetch the data we don't already have. */
 498         if (prev_posn>0) {
 499                 if (get_verbosely)
 500                         fprintf(stderr,
 501                                 "Resuming fetch of object %s at byte %ld\n",
 502                                 hex, prev_posn);
 503                 sprintf(range, "Range: bytes=%ld-", prev_posn);
 504                 range_header = curl_slist_append(range_header, range);
 505                 curl_easy_setopt(slot->curl,
 506                                  CURLOPT_HTTPHEADER, range_header);
 507         }
 508
 509         /* Try to get the request started, abort the request on error */
 510         if (!start_active_slot(slot)) {
 511                 request->state = ABORTED;
 512                 close(request->local);
 513                 free(request->url);
 514                 return;
 515         }
 516
 517         request->slot = slot;
 518         request->state = ACTIVE;
 519 }
 520
 521 static void finish_request(struct transfer_request *request)
 522 {
 523         fchmod(request->local, 0444);
 524         close(request->local);
 525
 526         if (request->http_code == 416) {
 527                 fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
 528         } else if (request->curl_result != CURLE_OK) {
 529                 return;
 530         }
 531
 532         inflateEnd(&request->stream);
 533         SHA1_Final(request->real_sha1, &request->c);
 534         if (request->zret != Z_STREAM_END) {
 535                 unlink(request->tmpfile);
 536                 return;
 537         }
 538         if (memcmp(request->sha1, request->real_sha1, 20)) {
 539                 unlink(request->tmpfile);
 540                 return;
 541         }
 542         request->rename =
 543                 move_temp_to_file(request->tmpfile, request->filename);
 544
 545         if (request->rename == 0)
 546                 pull_say("got %s\n", sha1_to_hex(request->sha1));
 547 }
 548
 549 static void release_request(struct transfer_request *request)
 550 {
 551         struct transfer_request *entry = request_queue_head;
 552
 553         if (request == request_queue_head) {
 554                 request_queue_head = request->next;
 555         } else {
 556                 while (entry->next != NULL && entry->next != request)
 557                         entry = entry->next;
 558                 if (entry->next == request)
 559                         entry->next = entry->next->next;
 560         }
 561
 562         free(request->url);
 563         free(request);
 564 }
 565
 566 #ifdef USE_CURL_MULTI
 567 void process_curl_messages(void)
 568 {
 569         int num_messages;
 570         struct active_request_slot *slot;
 571         struct transfer_request *request = NULL;
 572         CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
 573
 574         while (curl_message != NULL) {
 575                 if (curl_message->msg == CURLMSG_DONE) {
 576                         slot = active_queue_head;
 577                         while (slot != NULL &&
 578                                slot->curl != curl_message->easy_handle)
 579                                 slot = slot->next;
 580                         if (slot != NULL) {
 581                                 curl_multi_remove_handle(curlm, slot->curl);
 582                                 active_requests--;
 583                                 slot->done = 1;
 584                                 slot->in_use = 0;
 585                                 slot->curl_result = curl_message->data.result;
 586                                 curl_easy_getinfo(slot->curl,
 587                                                   CURLINFO_HTTP_CODE,
 588                                                   &slot->http_code);
 589                                 request = request_queue_head;
 590                                 while (request != NULL &&
 591                                        request->slot != slot)
 592                                         request = request->next;
 593                         } else {
 594                                 fprintf(stderr, "Received DONE message for unknown request!\n");
 595                         }
 596                         if (request != NULL) {
 597                                 request->curl_result =
 598                                         curl_message->data.result;
 599                                 request->http_code = slot->http_code;
 600                                 request->slot = NULL;
 601                                 request->state = COMPLETE;
 602
 603                                 /* Use alternates if necessary */
 604                                 if (request->http_code == 404) {
 605                                         fetch_alternates(alt->base);
 606                                         if (request->repo->next != NULL) {
 607                                                 request->repo =
 608                                                         request->repo->next;
 609                                                 start_request(request);
 610                                         }
 611                                 } else {
 612                                         finish_request(request);
 613                                 }
 614                         }
 615                 } else {
 616                         fprintf(stderr, "Unknown CURL message received: %d\n",
 617                                 (int)curl_message->msg);
 618                 }
 619                 curl_message = curl_multi_info_read(curlm, &num_messages);
 620         }
 621 }
 622
 623 void process_request_queue(void)
 624 {
 625         struct transfer_request *request = request_queue_head;
 626         struct active_request_slot *slot = active_queue_head;
 627         int num_transfers;
 628
 629         while (active_requests < max_requests && request != NULL) {
 630                 if (request->state == WAITING) {
 631                         if (has_sha1_file(request->sha1))
 632                                 release_request(request);
 633                         else
 634                                 start_request(request);
 635                         curl_multi_perform(curlm, &num_transfers);
 636                 }
 637                 request = request->next;
 638         }
 639
 640         while (slot != NULL) {
 641                 if (!slot->in_use && slot->curl != NULL) {
 642                         curl_easy_cleanup(slot->curl);
 643                         slot->curl = NULL;
 644                 }
 645                 slot = slot->next;
 646         }
 647 }
 648 #endif
 649
 650 void prefetch(unsigned char *sha1)
 651 {
 652         struct transfer_request *newreq;
 653         struct transfer_request *tail;
 654         char *filename = sha1_file_name(sha1);
 655
 656         newreq = xmalloc(sizeof(*newreq));
 657         memcpy(newreq->sha1, sha1, 20);
 658         newreq->repo = alt;
 659         newreq->url = NULL;
 660         newreq->local = -1;
 661         newreq->state = WAITING;
 662         snprintf(newreq->filename, sizeof(newreq->filename), "%s", filename);
 663         snprintf(newreq->tmpfile, sizeof(newreq->tmpfile),
 664                  "%s.temp", filename);
 665         newreq->next = NULL;
 666
 667         if (request_queue_head == NULL) {
 668                 request_queue_head = newreq;
 669         } else {
 670                 tail = request_queue_head;
 671                 while (tail->next != NULL) {
 672                         tail = tail->next;
 673                 }
 674                 tail->next = newreq;
 675         }
 676 #ifdef USE_CURL_MULTI
 677         process_request_queue();
 678         process_curl_messages();
 679 #endif
 680 }
 681
 682 static int fetch_index(struct alt_base *repo, unsigned char *sha1)
 683 {
 684         char *hex = sha1_to_hex(sha1);
 685         char *filename;
 686         char *url;
 687         char tmpfile[PATH_MAX];
 688         long prev_posn = 0;
 689         char range[RANGE_HEADER_SIZE];
 690         struct curl_slist *range_header = NULL;
 691
 692         FILE *indexfile;
 693         struct active_request_slot *slot;
 694
 695         if (has_pack_index(sha1))
 696                 return 0;
 697
 698         if (get_verbosely)
 699                 fprintf(stderr, "Getting index for pack %s\n", hex);
 700
 701         url = xmalloc(strlen(repo->base) + 64);
 702         sprintf(url, "%s/objects/pack/pack-%s.idx", repo->base, hex);
 703
 704         filename = sha1_pack_index_name(sha1);
 705         snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
 706         indexfile = fopen(tmpfile, "a");
 707         if (!indexfile)
 708                 return error("Unable to open local file %s for pack index",
 709                              filename);
 710
 711         slot = get_active_slot();
 712         curl_easy_setopt(slot->curl, CURLOPT_FILE, indexfile);
 713         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
 714         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 715         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 716         slot->local = indexfile;
 717
 718         /* If there is data present from a previous transfer attempt,
 719            resume where it left off */
 720         prev_posn = ftell(indexfile);
 721         if (prev_posn>0) {
 722                 if (get_verbosely)
 723                         fprintf(stderr,
 724                                 "Resuming fetch of index for pack %s at byte %ld\n",
 725                                 hex, prev_posn);
 726                 sprintf(range, "Range: bytes=%ld-", prev_posn);
 727                 range_header = curl_slist_append(range_header, range);
 728                 curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
 729         }
 730
 731         if (start_active_slot(slot)) {
 732                 run_active_slot(slot);
 733                 if (slot->curl_result != CURLE_OK) {
 734                         fclose(indexfile);
 735                         return error("Unable to get pack index %s\n%s", url,
 736                                      curl_errorstr);
 737                 }
 738         } else {
 739                 return error("Unable to start request");
 740         }
 741
 742         fclose(indexfile);
 743
 744         return move_temp_to_file(tmpfile, filename);
 745 }
 746
 747 static int setup_index(struct alt_base *repo, unsigned char *sha1)
 748 {
 749         struct packed_git *new_pack;
 750         if (has_pack_file(sha1))
 751                 return 0; // don't list this as something we can get
 752
 753         if (fetch_index(repo, sha1))
 754                 return -1;
 755
 756         new_pack = parse_pack_index(sha1);
 757         new_pack->next = repo->packs;
 758         repo->packs = new_pack;
 759         return 0;
 760 }
 761
 762 static int fetch_alternates(char *base)
 763 {
 764         int ret = 0;
 765         struct buffer buffer;
 766         char *url;
 767         char *data;
 768         int i = 0;
 769         int http_specific = 1;
 770         struct alt_base *tail = alt;
 771         static const char null_byte = '\0';
 772
 773         struct active_request_slot *slot;
 774
 775         if (got_alternates)
 776                 return 0;
 777
 778         data = xmalloc(4096);
 779         buffer.size = 4096;
 780         buffer.posn = 0;
 781         buffer.buffer = data;
 782
 783         if (get_verbosely)
 784                 fprintf(stderr, "Getting alternates list\n");
 785
 786         url = xmalloc(strlen(base) + 31);
 787         sprintf(url, "%s/objects/info/http-alternates", base);
 788
 789         slot = get_active_slot();
 790         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 791         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
 792                          fwrite_buffer_dynamic);
 793         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 794         if (start_active_slot(slot)) {
 795                 run_active_slot(slot);
 796                 if (slot->curl_result != CURLE_OK || !buffer.posn) {
 797                         http_specific = 0;
 798
 799                         sprintf(url, "%s/objects/info/alternates", base);
 800
 801                         slot = get_active_slot();
 802                         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 803                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
 804                                          fwrite_buffer_dynamic);
 805                         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 806                         if (start_active_slot(slot)) {
 807                                 run_active_slot(slot);
 808                                 if (slot->curl_result != CURLE_OK) {
 809                                         free(buffer.buffer);
 810                                         if (slot->http_code == 404)
 811                                                 got_alternates = 1;
 812                                         return 0;
 813                                 }
 814                         }
 815                 }
 816         } else {
 817                 free(buffer.buffer);
 818                 return 0;
 819         }
 820
 821         fwrite_buffer_dynamic(&null_byte, 1, 1, &buffer);
 822         buffer.posn--;
 823         data = buffer.buffer;
 824
 825         while (i < buffer.posn) {
 826                 int posn = i;
 827                 while (posn < buffer.posn && data[posn] != '\n')
 828                         posn++;
 829                 if (data[posn] == '\n') {
 830                         int okay = 0;
 831                         int serverlen = 0;
 832                         struct alt_base *newalt;
 833                         char *target = NULL;
 834                         if (data[i] == '/') {
 835                                 serverlen = strchr(base + 8, '/') - base;
 836                                 okay = 1;
 837                         } else if (!memcmp(data + i, "../", 3)) {
 838                                 i += 3;
 839                                 serverlen = strlen(base);
 840                                 while (i + 2 < posn &&
 841                                        !memcmp(data + i, "../", 3)) {
 842                                         do {
 843                                                 serverlen--;
 844                                         } while (serverlen &&
 845                                                  base[serverlen - 1] != '/');
 846                                         i += 3;
 847                                 }
 848                                 // If the server got removed, give up.
 849                                 okay = strchr(base, ':') - base + 3 <
 850                                         serverlen;
 851                         } else if (http_specific) {
 852                                 char *colon = strchr(data + i, ':');
 853                                 char *slash = strchr(data + i, '/');
 854                                 if (colon && slash && colon < data + posn &&
 855                                     slash < data + posn && colon < slash) {
 856                                         okay = 1;
 857                                 }
 858                         }
 859                         // skip 'objects' at end
 860                         if (okay) {
 861                                 target = xmalloc(serverlen + posn - i - 6);
 862                                 strncpy(target, base, serverlen);
 863                                 strncpy(target + serverlen, data + i,
 864                                         posn - i - 7);
 865                                 target[serverlen + posn - i - 7] = '\0';
 866                                 if (get_verbosely)
 867                                         fprintf(stderr,
 868                                                 "Also look at %s\n", target);
 869                                 newalt = xmalloc(sizeof(*newalt));
 870                                 newalt->next = NULL;
 871                                 newalt->base = target;
 872                                 newalt->got_indices = 0;
 873                                 newalt->packs = NULL;
 874                                 while (tail->next != NULL)
 875                                         tail = tail->next;
 876                                 tail->next = newalt;
 877                                 ret++;
 878                         }
 879                 }
 880                 i = posn + 1;
 881         }
 882
 883         got_alternates = 1;
 884         free(buffer.buffer);
 885         return ret;
 886 }
 887
 888 static int fetch_indices(struct alt_base *repo)
 889 {
 890         unsigned char sha1[20];
 891         char *url;
 892         struct buffer buffer;
 893         char *data;
 894         int i = 0;
 895
 896         struct active_request_slot *slot;
 897
 898         if (repo->got_indices)
 899                 return 0;
 900
 901         data = xmalloc(4096);
 902         buffer.size = 4096;
 903         buffer.posn = 0;
 904         buffer.buffer = data;
 905
 906         if (get_verbosely)
 907                 fprintf(stderr, "Getting pack list\n");
 908
 909         url = xmalloc(strlen(repo->base) + 21);
 910         sprintf(url, "%s/objects/info/packs", repo->base);
 911
 912         slot = get_active_slot();
 913         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 914         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
 915                          fwrite_buffer_dynamic);
 916         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 917         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
 918         if (start_active_slot(slot)) {
 919                 run_active_slot(slot);
 920                 if (slot->curl_result != CURLE_OK) {
 921                         free(buffer.buffer);
 922                         return error("%s", curl_errorstr);
 923                 }
 924         } else {
 925                 free(buffer.buffer);
 926                 return error("Unable to start request");
 927         }
 928
 929         data = buffer.buffer;
 930         while (i < buffer.posn) {
 931                 switch (data[i]) {
 932                 case 'P':
 933                         i++;
 934                         if (i + 52 < buffer.posn &&
 935                             !strncmp(data + i, " pack-", 6) &&
 936                             !strncmp(data + i + 46, ".pack\n", 6)) {
 937                                 get_sha1_hex(data + i + 6, sha1);
 938                                 setup_index(repo, sha1);
 939                                 i += 51;
 940                                 break;
 941                         }
 942                 default:
 943                         while (data[i] != '\n')
 944                                 i++;
 945                 }
 946                 i++;
 947         }
 948
 949         free(buffer.buffer);
 950         repo->got_indices = 1;
 951         return 0;
 952 }
 953
 954 static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
 955 {
 956         char *url;
 957         struct packed_git *target;
 958         struct packed_git **lst;
 959         FILE *packfile;
 960         char *filename;
 961         char tmpfile[PATH_MAX];
 962         int ret;
 963         long prev_posn = 0;
 964         char range[RANGE_HEADER_SIZE];
 965         struct curl_slist *range_header = NULL;
 966
 967         struct active_request_slot *slot;
 968
 969         if (fetch_indices(repo))
 970                 return -1;
 971         target = find_sha1_pack(sha1, repo->packs);
 972         if (!target)
 973                 return -1;
 974
 975         if (get_verbosely) {
 976                 fprintf(stderr, "Getting pack %s\n",
 977                         sha1_to_hex(target->sha1));
 978                 fprintf(stderr, " which contains %s\n",
 979                         sha1_to_hex(sha1));
 980         }
 981
 982         url = xmalloc(strlen(repo->base) + 65);
 983         sprintf(url, "%s/objects/pack/pack-%s.pack",
 984                 repo->base, sha1_to_hex(target->sha1));
 985
 986         filename = sha1_pack_name(target->sha1);
 987         snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
 988         packfile = fopen(tmpfile, "a");
 989         if (!packfile)
 990                 return error("Unable to open local file %s for pack",
 991                              filename);
 992
 993         slot = get_active_slot();
 994         curl_easy_setopt(slot->curl, CURLOPT_FILE, packfile);
 995         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
 996         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 997         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
 998         slot->local = packfile;
 999
1000         /* If there is data present from a previous transfer attempt,
1001            resume where it left off */
1002         prev_posn = ftell(packfile);
1003         if (prev_posn>0) {
1004                 if (get_verbosely)
1005                         fprintf(stderr,
1006                                 "Resuming fetch of pack %s at byte %ld\n",
1007                                 sha1_to_hex(target->sha1), prev_posn);
1008                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1009                 range_header = curl_slist_append(range_header, range);
1010                 curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
1011         }
1012
1013         if (start_active_slot(slot)) {
1014                 run_active_slot(slot);
1015                 if (slot->curl_result != CURLE_OK) {
1016                         fclose(packfile);
1017                         return error("Unable to get pack file %s\n%s", url,
1018                                      curl_errorstr);
1019                 }
1020         } else {
1021                 return error("Unable to start request");
1022         }
1023
1024         fclose(packfile);
1025
1026         ret = move_temp_to_file(tmpfile, filename);
1027         if (ret)
1028                 return ret;
1029
1030         lst = &repo->packs;
1031         while (*lst != target)
1032                 lst = &((*lst)->next);
1033         *lst = (*lst)->next;
1034
1035         if (verify_pack(target, 0))
1036                 return -1;
1037         install_packed_git(target);
1038
1039         return 0;
1040 }
1041
1042 static int fetch_object(struct alt_base *repo, unsigned char *sha1)
1043 {
1044         char *hex = sha1_to_hex(sha1);
1045         int ret;
1046         struct transfer_request *request = request_queue_head;
1047
1048         while (request != NULL && memcmp(request->sha1, sha1, 20))
1049                 request = request->next;
1050         if (request == NULL)
1051                 return error("Couldn't find request for %s in the queue", hex);
1052
1053         if (has_sha1_file(request->sha1)) {
1054                 release_request(request);
1055                 return 0;
1056         }
1057
1058 #ifdef USE_CURL_MULTI
1059         while (request->state == WAITING) {
1060                 int num_transfers;
1061                 curl_multi_perform(curlm, &num_transfers);
1062                 if (num_transfers < active_requests) {
1063                         process_curl_messages();
1064                         process_request_queue();
1065                 }
1066         }
1067 #else
1068         start_request(request);
1069 #endif
1070
1071         while (request->state == ACTIVE) {
1072                 run_active_slot(request->slot);
1073 #ifndef USE_CURL_MULTI
1074                 request->curl_result = request->slot->curl_result;
1075                 request->http_code = request->slot->http_code;
1076                 request->slot = NULL;
1077
1078                 /* Use alternates if necessary */
1079                 if (request->http_code == 404) {
1080                         fetch_alternates(alt->base);
1081                         if (request->repo->next != NULL) {
1082                                 request->repo = request->repo->next;
1083                                 start_request(request);
1084                         }
1085                 } else {
1086                         finish_request(request);
1087                         request->state = COMPLETE;
1088                 }
1089 #endif
1090         }
1091
1092         if (request->state == ABORTED) {
1093                 release_request(request);
1094                 return error("Request for %s aborted", hex);
1095         }
1096
1097         if (request->curl_result != CURLE_OK && request->http_code != 416) {
1098                 ret = error("%s (curl_result = %d, http_code = %ld, sha1 = %s)",
1099                             request->errorstr, request->curl_result,
1100                             request->http_code, hex);
1101                 release_request(request);
1102                 return ret;
1103         }
1104
1105         if (request->zret != Z_STREAM_END) {
1106                 ret = error("File %s (%s) corrupt\n", hex, request->url);
1107                 release_request(request);
1108                 return ret;
1109         }
1110
1111         if (memcmp(request->sha1, request->real_sha1, 20)) {
1112                 release_request(request);
1113                 return error("File %s has bad hash\n", hex);
1114         }
1115
1116         if (request->rename < 0) {
1117                 ret = error("unable to write sha1 filename %s: %s",
1118                             request->filename,
1119                             strerror(request->rename));
1120                 release_request(request);
1121                 return ret;
1122         }
1123
1124         release_request(request);
1125         return 0;
1126 }
1127
1128 int fetch(unsigned char *sha1)
1129 {
1130         struct alt_base *altbase = alt;
1131
1132         if (!fetch_object(altbase, sha1))
1133                 return 0;
1134         while (altbase) {
1135                 if (!fetch_pack(altbase, sha1))
1136                         return 0;
1137                 fetch_alternates(alt->base);
1138                 altbase = altbase->next;
1139         }
1140         return error("Unable to find %s under %s\n", sha1_to_hex(sha1),
1141                      alt->base);
1142 }
1143
1144 static inline int needs_quote(int ch)
1145 {
1146         switch (ch) {
1147         case '/': case '-': case '.':
1148         case 'A'...'Z': case 'a'...'z': case '0'...'9':
1149                 return 0;
1150         default:
1151                 return 1;
1152         }
1153 }
1154
1155 static inline int hex(int v)
1156 {
1157         if (v < 10) return '0' + v;
1158         else return 'A' + v - 10;
1159 }
1160
1161 static char *quote_ref_url(const char *base, const char *ref)
1162 {
1163         const char *cp;
1164         char *dp, *qref;
1165         int len, baselen, ch;
1166
1167         baselen = strlen(base);
1168         len = baselen + 6; /* "refs/" + NUL */
1169         for (cp = ref; (ch = *cp) != 0; cp++, len++)
1170                 if (needs_quote(ch))
1171                         len += 2; /* extra two hex plus replacement % */
1172         qref = xmalloc(len);
1173         memcpy(qref, base, baselen);
1174         memcpy(qref + baselen, "refs/", 5);
1175         for (cp = ref, dp = qref + baselen + 5; (ch = *cp) != 0; cp++) {
1176                 if (needs_quote(ch)) {
1177                         *dp++ = '%';
1178                         *dp++ = hex((ch >> 4) & 0xF);
1179                         *dp++ = hex(ch & 0xF);
1180                 }
1181                 else
1182                         *dp++ = ch;
1183         }
1184         *dp = 0;
1185
1186         return qref;
1187 }
1188
1189 int fetch_ref(char *ref, unsigned char *sha1)
1190 {
1191         char *url;
1192         char hex[42];
1193         struct buffer buffer;
1194         char *base = alt->base;
1195         struct active_request_slot *slot;
1196         buffer.size = 41;
1197         buffer.posn = 0;
1198         buffer.buffer = hex;
1199         hex[41] = '\0';
1200
1201         url = quote_ref_url(base, ref);
1202         slot = get_active_slot();
1203         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
1204         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
1205         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
1206         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1207         if (start_active_slot(slot)) {
1208                 run_active_slot(slot);
1209                 if (slot->curl_result != CURLE_OK)
1210                         return error("Couldn't get %s for %s\n%s",
1211                                      url, ref, curl_errorstr);
1212         } else {
1213                 return error("Unable to start request");
1214         }
1215
1216         hex[40] = '\0';
1217         get_sha1_hex(hex, sha1);
1218         return 0;
1219 }
1220
1221 int main(int argc, char **argv)
1222 {
1223         char *commit_id;
1224         char *url;
1225         int arg = 1;
1226         struct active_request_slot *slot;
1227         char *low_speed_limit;
1228         char *low_speed_time;
1229         char *wait_url;
1230         int rc = 0;
1231
1232         while (arg < argc && argv[arg][0] == '-') {
1233                 if (argv[arg][1] == 't') {
1234                         get_tree = 1;
1235                 } else if (argv[arg][1] == 'c') {
1236                         get_history = 1;
1237                 } else if (argv[arg][1] == 'a') {
1238                         get_all = 1;
1239                         get_tree = 1;
1240                         get_history = 1;
1241                 } else if (argv[arg][1] == 'v') {
1242                         get_verbosely = 1;
1243                 } else if (argv[arg][1] == 'w') {
1244                         write_ref = argv[arg + 1];
1245                         arg++;
1246                 } else if (!strcmp(argv[arg], "--recover")) {
1247                         get_recover = 1;
1248                 }
1249                 arg++;
1250         }
1251         if (argc < arg + 2) {
1252                 usage("git-http-fetch [-c] [-t] [-a] [-d] [-v] [--recover] [-w ref] commit-id url");
1253                 return 1;
1254         }
1255         commit_id = argv[arg];
1256         url = argv[arg + 1];
1257
1258         curl_global_init(CURL_GLOBAL_ALL);
1259
1260 #ifdef USE_CURL_MULTI
1261         {
1262                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
1263                 if (http_max_requests != NULL)
1264                         max_requests = atoi(http_max_requests);
1265         }
1266
1267         curlm = curl_multi_init();
1268         if (curlm == NULL) {
1269                 fprintf(stderr, "Error creating curl multi handle.\n");
1270                 return 1;
1271         }
1272 #endif
1273
1274         if (getenv("GIT_SSL_NO_VERIFY"))
1275                 curl_ssl_verify = 0;
1276
1277         ssl_cert = getenv("GIT_SSL_CERT");
1278 #if LIBCURL_VERSION_NUM >= 0x070902
1279         ssl_key = getenv("GIT_SSL_KEY");
1280 #endif
1281 #if LIBCURL_VERSION_NUM >= 0x070908
1282         ssl_capath = getenv("GIT_SSL_CAPATH");
1283 #endif
1284         ssl_cainfo = getenv("GIT_SSL_CAINFO");
1285
1286         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
1287         if (low_speed_limit != NULL)
1288                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
1289         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
1290         if (low_speed_time != NULL)
1291                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
1292
1293         git_config(http_options);
1294
1295         if (curl_ssl_verify == -1)
1296                 curl_ssl_verify = 1;
1297
1298 #ifdef USE_CURL_MULTI
1299         if (max_requests < 1)
1300                 max_requests = DEFAULT_MAX_REQUESTS;
1301 #endif
1302
1303         pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
1304         no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
1305         no_range_header = curl_slist_append(no_range_header, "Range:");
1306
1307 #ifndef NO_CURL_EASY_DUPHANDLE
1308         curl_default = get_curl_handle();
1309 #endif
1310
1311         alt = xmalloc(sizeof(*alt));
1312         alt->base = url;
1313         alt->got_indices = 0;
1314         alt->packs = NULL;
1315         alt->next = NULL;
1316
1317         if (pull(commit_id))
1318                 rc = 1;
1319
1320         curl_slist_free_all(pragma_header);
1321         curl_slist_free_all(no_pragma_header);
1322         curl_slist_free_all(no_range_header);
1323 #ifndef NO_CURL_EASY_DUPHANDLE
1324         curl_easy_cleanup(curl_default);
1325 #endif
1326         slot = active_queue_head;
1327         while (slot != NULL) {
1328                 if (slot->in_use) {
1329                         if (get_verbosely) {
1330                                 curl_easy_getinfo(slot->curl,
1331                                                   CURLINFO_EFFECTIVE_URL,
1332                                                   &wait_url);
1333                                 fprintf(stderr, "Waiting for %s\n", wait_url);
1334                         }
1335                         run_active_slot(slot);
1336                 }
1337                 if (slot->curl != NULL)
1338                         curl_easy_cleanup(slot->curl);
1339                 slot = slot->next;
1340         }
1341 #ifdef USE_CURL_MULTI
1342         curl_multi_cleanup(curlm);
1343 #endif
1344         curl_global_cleanup();
1345         return rc;
1346 }