http-fetch.c

   1 #include "cache.h"
   2 #include "commit.h"
   3
   4 #include "fetch.h"
   5
   6 #include <curl/curl.h>
   7 #include <curl/easy.h>
   8
   9 #if LIBCURL_VERSION_NUM < 0x070704
  10 #define curl_global_cleanup() do { /* nothing */ } while(0)
  11 #endif
  12 #if LIBCURL_VERSION_NUM < 0x070800
  13 #define curl_global_init(a) do { /* nothing */ } while(0)
  14 #endif
  15
  16 static CURL *curl;
  17 static struct curl_slist *no_pragma_header;
  18
  19 static char *initial_base;
  20
  21 struct alt_base
  22 {
  23         char *base;
  24         int got_indices;
  25         struct packed_git *packs;
  26         struct alt_base *next;
  27 };
  28
  29 struct alt_base *alt = NULL;
  30
  31 static SHA_CTX c;
  32 static z_stream stream;
  33
  34 static int local;
  35 static int zret;
  36
  37 static int curl_ssl_verify;
  38
  39 struct buffer
  40 {
  41         size_t posn;
  42         size_t size;
  43         void *buffer;
  44 };
  45
  46 static size_t fwrite_buffer(void *ptr, size_t eltsize, size_t nmemb,
  47                             struct buffer *buffer)
  48 {
  49         size_t size = eltsize * nmemb;
  50         if (size > buffer->size - buffer->posn)
  51                 size = buffer->size - buffer->posn;
  52         memcpy(buffer->buffer + buffer->posn, ptr, size);
  53         buffer->posn += size;
  54         return size;
  55 }
  56
  57 static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
  58                                void *data)
  59 {
  60         unsigned char expn[4096];
  61         size_t size = eltsize * nmemb;
  62         int posn = 0;
  63         do {
  64                 ssize_t retval = write(local, ptr + posn, size - posn);
  65                 if (retval < 0)
  66                         return posn;
  67                 posn += retval;
  68         } while (posn < size);
  69
  70         stream.avail_in = size;
  71         stream.next_in = ptr;
  72         do {
  73                 stream.next_out = expn;
  74                 stream.avail_out = sizeof(expn);
  75                 zret = inflate(&stream, Z_SYNC_FLUSH);
  76                 SHA1_Update(&c, expn, sizeof(expn) - stream.avail_out);
  77         } while (stream.avail_in && zret == Z_OK);
  78         return size;
  79 }
  80
  81 void prefetch(unsigned char *sha1)
  82 {
  83 }
  84
  85 static int got_alternates = 0;
  86
  87 static int fetch_index(struct alt_base *repo, unsigned char *sha1)
  88 {
  89         char *filename;
  90         char *url;
  91
  92         FILE *indexfile;
  93
  94         if (has_pack_index(sha1))
  95                 return 0;
  96
  97         if (get_verbosely)
  98                 fprintf(stderr, "Getting index for pack %s\n",
  99                         sha1_to_hex(sha1));
 100
 101         url = xmalloc(strlen(repo->base) + 64);
 102         sprintf(url, "%s/objects/pack/pack-%s.idx",
 103                 repo->base, sha1_to_hex(sha1));
 104
 105         filename = sha1_pack_index_name(sha1);
 106         indexfile = fopen(filename, "w");
 107         if (!indexfile)
 108                 return error("Unable to open local file %s for pack index",
 109                              filename);
 110
 111         curl_easy_setopt(curl, CURLOPT_FILE, indexfile);
 112         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite);
 113         curl_easy_setopt(curl, CURLOPT_URL, url);
 114         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, no_pragma_header);
 115
 116         if (curl_easy_perform(curl)) {
 117                 fclose(indexfile);
 118                 return error("Unable to get pack index %s", url);
 119         }
 120
 121         fclose(indexfile);
 122         return 0;
 123 }
 124
 125 static int setup_index(struct alt_base *repo, unsigned char *sha1)
 126 {
 127         struct packed_git *new_pack;
 128         if (has_pack_file(sha1))
 129                 return 0; // don't list this as something we can get
 130
 131         if (fetch_index(repo, sha1))
 132                 return -1;
 133
 134         new_pack = parse_pack_index(sha1);
 135         new_pack->next = repo->packs;
 136         repo->packs = new_pack;
 137         return 0;
 138 }
 139
 140 static int fetch_alternates(char *base)
 141 {
 142         int ret = 0;
 143         struct buffer buffer;
 144         char *url;
 145         char *data;
 146         int i = 0;
 147         if (got_alternates)
 148                 return 0;
 149         data = xmalloc(4096);
 150         buffer.size = 4096;
 151         buffer.posn = 0;
 152         buffer.buffer = data;
 153
 154         if (get_verbosely)
 155                 fprintf(stderr, "Getting alternates list\n");
 156
 157         url = xmalloc(strlen(base) + 31);
 158         sprintf(url, "%s/objects/info/http-alternates", base);
 159
 160         curl_easy_setopt(curl, CURLOPT_FILE, &buffer);
 161         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 162         curl_easy_setopt(curl, CURLOPT_URL, url);
 163
 164         if (curl_easy_perform(curl) || !buffer.posn) {
 165                 sprintf(url, "%s/objects/info/alternates", base);
 166
 167                 curl_easy_setopt(curl, CURLOPT_FILE, &buffer);
 168                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 169                 curl_easy_setopt(curl, CURLOPT_URL, url);
 170
 171                 if (curl_easy_perform(curl)) {
 172                         return 0;
 173                 }
 174         }
 175
 176         while (i < buffer.posn) {
 177                 int posn = i;
 178                 while (posn < buffer.posn && data[posn] != '\n')
 179                         posn++;
 180                 if (data[posn] == '\n') {
 181                         if (data[i] == '/') {
 182                                 int serverlen = strchr(base + 8, '/') - base;
 183                                 // skip 'objects' at end
 184                                 char *target =
 185                                         xmalloc(serverlen + posn - i - 6);
 186                                 struct alt_base *newalt;
 187                                 strncpy(target, base, serverlen);
 188                                 strncpy(target + serverlen, data + i,
 189                                         posn - i - 7);
 190                                 target[serverlen + posn - i - 7] = '\0';
 191                                 if (get_verbosely)
 192                                         fprintf(stderr,
 193                                                 "Also look at %s\n", target);
 194                                 newalt = xmalloc(sizeof(*newalt));
 195                                 newalt->next = alt;
 196                                 newalt->base = target;
 197                                 newalt->got_indices = 0;
 198                                 newalt->packs = NULL;
 199                                 alt = newalt;
 200                                 ret++;
 201                         }
 202                 }
 203                 i = posn + 1;
 204         }
 205         got_alternates = 1;
 206
 207         return ret;
 208 }
 209
 210 static int fetch_indices(struct alt_base *repo)
 211 {
 212         unsigned char sha1[20];
 213         char *url;
 214         struct buffer buffer;
 215         char *data;
 216         int i = 0;
 217
 218         if (repo->got_indices)
 219                 return 0;
 220
 221         data = xmalloc(4096);
 222         buffer.size = 4096;
 223         buffer.posn = 0;
 224         buffer.buffer = data;
 225
 226         if (get_verbosely)
 227                 fprintf(stderr, "Getting pack list\n");
 228
 229         url = xmalloc(strlen(repo->base) + 21);
 230         sprintf(url, "%s/objects/info/packs", repo->base);
 231
 232         curl_easy_setopt(curl, CURLOPT_FILE, &buffer);
 233         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 234         curl_easy_setopt(curl, CURLOPT_URL, url);
 235         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, NULL);
 236
 237         if (curl_easy_perform(curl)) {
 238                 return error("Unable to get pack index %s", url);
 239         }
 240
 241         while (i < buffer.posn) {
 242                 switch (data[i]) {
 243                 case 'P':
 244                         i++;
 245                         if (i + 52 < buffer.posn &&
 246                             !strncmp(data + i, " pack-", 6) &&
 247                             !strncmp(data + i + 46, ".pack\n", 6)) {
 248                                 get_sha1_hex(data + i + 6, sha1);
 249                                 setup_index(repo, sha1);
 250                                 i += 51;
 251                                 break;
 252                         }
 253                 default:
 254                         while (data[i] != '\n')
 255                                 i++;
 256                 }
 257                 i++;
 258         }
 259
 260         repo->got_indices = 1;
 261         return 0;
 262 }
 263
 264 static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
 265 {
 266         char *url;
 267         struct packed_git *target;
 268         struct packed_git **lst;
 269         FILE *packfile;
 270         char *filename;
 271
 272         if (fetch_indices(repo))
 273                 return -1;
 274         target = find_sha1_pack(sha1, repo->packs);
 275         if (!target)
 276                 return -1;
 277
 278         if (get_verbosely) {
 279                 fprintf(stderr, "Getting pack %s\n",
 280                         sha1_to_hex(target->sha1));
 281                 fprintf(stderr, " which contains %s\n",
 282                         sha1_to_hex(sha1));
 283         }
 284
 285         url = xmalloc(strlen(repo->base) + 65);
 286         sprintf(url, "%s/objects/pack/pack-%s.pack",
 287                 repo->base, sha1_to_hex(target->sha1));
 288
 289         filename = sha1_pack_name(target->sha1);
 290         packfile = fopen(filename, "w");
 291         if (!packfile)
 292                 return error("Unable to open local file %s for pack",
 293                              filename);
 294
 295         curl_easy_setopt(curl, CURLOPT_FILE, packfile);
 296         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite);
 297         curl_easy_setopt(curl, CURLOPT_URL, url);
 298         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, no_pragma_header);
 299
 300         if (curl_easy_perform(curl)) {
 301                 fclose(packfile);
 302                 return error("Unable to get pack file %s", url);
 303         }
 304
 305         fclose(packfile);
 306
 307         lst = &repo->packs;
 308         while (*lst != target)
 309                 lst = &((*lst)->next);
 310         *lst = (*lst)->next;
 311
 312         install_packed_git(target);
 313
 314         return 0;
 315 }
 316
 317 int fetch_object(struct alt_base *repo, unsigned char *sha1)
 318 {
 319         char *hex = sha1_to_hex(sha1);
 320         char *filename = sha1_file_name(sha1);
 321         unsigned char real_sha1[20];
 322         char *url;
 323         char *posn;
 324
 325         local = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
 326
 327         if (local < 0)
 328                 return error("Couldn't open local object %s\n", filename);
 329
 330         memset(&stream, 0, sizeof(stream));
 331
 332         inflateInit(&stream);
 333
 334         SHA1_Init(&c);
 335
 336         curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1);
 337         curl_easy_setopt(curl, CURLOPT_FILE, NULL);
 338         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
 339         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, no_pragma_header);
 340
 341         url = xmalloc(strlen(repo->base) + 50);
 342         strcpy(url, repo->base);
 343         posn = url + strlen(repo->base);
 344         strcpy(posn, "objects/");
 345         posn += 8;
 346         memcpy(posn, hex, 2);
 347         posn += 2;
 348         *(posn++) = '/';
 349         strcpy(posn, hex + 2);
 350
 351         curl_easy_setopt(curl, CURLOPT_URL, url);
 352
 353         if (curl_easy_perform(curl)) {
 354                 unlink(filename);
 355                 return -1;
 356         }
 357
 358         close(local);
 359         inflateEnd(&stream);
 360         SHA1_Final(real_sha1, &c);
 361         if (zret != Z_STREAM_END) {
 362                 unlink(filename);
 363                 return error("File %s (%s) corrupt\n", hex, url);
 364         }
 365         if (memcmp(sha1, real_sha1, 20)) {
 366                 unlink(filename);
 367                 return error("File %s has bad hash\n", hex);
 368         }
 369
 370         pull_say("got %s\n", hex);
 371         return 0;
 372 }
 373
 374 int fetch(unsigned char *sha1)
 375 {
 376         struct alt_base *altbase = alt;
 377         while (altbase) {
 378                 if (!fetch_object(altbase, sha1))
 379                         return 0;
 380                 if (!fetch_pack(altbase, sha1))
 381                         return 0;
 382                 if (fetch_alternates(altbase->base) > 0) {
 383                         altbase = alt;
 384                         continue;
 385                 }
 386                 altbase = altbase->next;
 387         }
 388         return error("Unable to find %s under %s\n", sha1_to_hex(sha1),
 389                      initial_base);
 390 }
 391
 392 int fetch_ref(char *ref, unsigned char *sha1)
 393 {
 394         char *url, *posn;
 395         char hex[42];
 396         struct buffer buffer;
 397         char *base = initial_base;
 398         buffer.size = 41;
 399         buffer.posn = 0;
 400         buffer.buffer = hex;
 401         hex[41] = '\0';
 402
 403         curl_easy_setopt(curl, CURLOPT_FILE, &buffer);
 404         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 405         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, NULL);
 406
 407         url = xmalloc(strlen(base) + 6 + strlen(ref));
 408         strcpy(url, base);
 409         posn = url + strlen(base);
 410         strcpy(posn, "refs/");
 411         posn += 5;
 412         strcpy(posn, ref);
 413
 414         curl_easy_setopt(curl, CURLOPT_URL, url);
 415
 416         if (curl_easy_perform(curl))
 417                 return error("Couldn't get %s for %s\n", url, ref);
 418
 419         hex[40] = '\0';
 420         get_sha1_hex(hex, sha1);
 421         return 0;
 422 }
 423
 424 int main(int argc, char **argv)
 425 {
 426         char *commit_id;
 427         char *url;
 428         int arg = 1;
 429
 430         while (arg < argc && argv[arg][0] == '-') {
 431                 if (argv[arg][1] == 't') {
 432                         get_tree = 1;
 433                 } else if (argv[arg][1] == 'c') {
 434                         get_history = 1;
 435                 } else if (argv[arg][1] == 'a') {
 436                         get_all = 1;
 437                         get_tree = 1;
 438                         get_history = 1;
 439                 } else if (argv[arg][1] == 'v') {
 440                         get_verbosely = 1;
 441                 } else if (argv[arg][1] == 'w') {
 442                         write_ref = argv[arg + 1];
 443                         arg++;
 444                 }
 445                 arg++;
 446         }
 447         if (argc < arg + 2) {
 448                 usage("git-http-fetch [-c] [-t] [-a] [-d] [-v] [--recover] [-w ref] commit-id url");
 449                 return 1;
 450         }
 451         commit_id = argv[arg];
 452         url = argv[arg + 1];
 453
 454         curl_global_init(CURL_GLOBAL_ALL);
 455
 456         curl = curl_easy_init();
 457         no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
 458
 459         curl_ssl_verify = getenv("GIT_SSL_NO_VERIFY") ? 0 : 1;
 460         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, curl_ssl_verify);
 461 #if LIBCURL_VERSION_NUM >= 0x070907
 462         curl_easy_setopt(curl, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
 463 #endif
 464
 465         alt = xmalloc(sizeof(*alt));
 466         alt->base = url;
 467         alt->got_indices = 0;
 468         alt->packs = NULL;
 469         alt->next = NULL;
 470         initial_base = url;
 471
 472         if (pull(commit_id))
 473                 return 1;
 474
 475         curl_slist_free_all(no_pragma_header);
 476         curl_global_cleanup();
 477         return 0;
 478 }