http-backend.c

   1 #include "cache.h"
   2 #include "config.h"
   3 #include "repository.h"
   4 #include "refs.h"
   5 #include "pkt-line.h"
   6 #include "object.h"
   7 #include "tag.h"
   8 #include "exec-cmd.h"
   9 #include "run-command.h"
  10 #include "string-list.h"
  11 #include "url.h"
  12 #include "strvec.h"
  13 #include "packfile.h"
  14 #include "object-store.h"
  15 #include "protocol.h"
  16 #include "date.h"
  17
  18 static const char content_type[] = "Content-Type";
  19 static const char content_length[] = "Content-Length";
  20 static const char last_modified[] = "Last-Modified";
  21 static int getanyfile = 1;
  22 static unsigned long max_request_buffer = 10 * 1024 * 1024;
  23
  24 static struct string_list *query_params;
  25
  26 struct rpc_service {
  27         const char *name;
  28         const char *config_name;
  29         unsigned buffer_input : 1;
  30         signed enabled : 2;
  31 };
  32
  33 static struct rpc_service rpc_service[] = {
  34         { "upload-pack", "uploadpack", 1, 1 },
  35         { "receive-pack", "receivepack", 0, -1 },
  36 };
  37
  38 static struct string_list *get_parameters(void)
  39 {
  40         if (!query_params) {
  41                 const char *query = getenv("QUERY_STRING");
  42
  43                 CALLOC_ARRAY(query_params, 1);
  44                 while (query && *query) {
  45                         char *name = url_decode_parameter_name(&query);
  46                         char *value = url_decode_parameter_value(&query);
  47                         struct string_list_item *i;
  48
  49                         i = string_list_lookup(query_params, name);
  50                         if (!i)
  51                                 i = string_list_insert(query_params, name);
  52                         else
  53                                 free(i->util);
  54                         i->util = value;
  55                 }
  56         }
  57         return query_params;
  58 }
  59
  60 static const char *get_parameter(const char *name)
  61 {
  62         struct string_list_item *i;
  63         i = string_list_lookup(get_parameters(), name);
  64         return i ? i->util : NULL;
  65 }
  66
  67 __attribute__((format (printf, 2, 3)))
  68 static void format_write(int fd, const char *fmt, ...)
  69 {
  70         static char buffer[1024];
  71
  72         va_list args;
  73         unsigned n;
  74
  75         va_start(args, fmt);
  76         n = vsnprintf(buffer, sizeof(buffer), fmt, args);
  77         va_end(args);
  78         if (n >= sizeof(buffer))
  79                 die("protocol error: impossibly long line");
  80
  81         write_or_die(fd, buffer, n);
  82 }
  83
  84 static void http_status(struct strbuf *hdr, unsigned code, const char *msg)
  85 {
  86         strbuf_addf(hdr, "Status: %u %s\r\n", code, msg);
  87 }
  88
  89 static void hdr_str(struct strbuf *hdr, const char *name, const char *value)
  90 {
  91         strbuf_addf(hdr, "%s: %s\r\n", name, value);
  92 }
  93
  94 static void hdr_int(struct strbuf *hdr, const char *name, uintmax_t value)
  95 {
  96         strbuf_addf(hdr, "%s: %" PRIuMAX "\r\n", name, value);
  97 }
  98
  99 static void hdr_date(struct strbuf *hdr, const char *name, timestamp_t when)
 100 {
 101         const char *value = show_date(when, 0, DATE_MODE(RFC2822));
 102         hdr_str(hdr, name, value);
 103 }
 104
 105 static void hdr_nocache(struct strbuf *hdr)
 106 {
 107         hdr_str(hdr, "Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
 108         hdr_str(hdr, "Pragma", "no-cache");
 109         hdr_str(hdr, "Cache-Control", "no-cache, max-age=0, must-revalidate");
 110 }
 111
 112 static void hdr_cache_forever(struct strbuf *hdr)
 113 {
 114         timestamp_t now = time(NULL);
 115         hdr_date(hdr, "Date", now);
 116         hdr_date(hdr, "Expires", now + 31536000);
 117         hdr_str(hdr, "Cache-Control", "public, max-age=31536000");
 118 }
 119
 120 static void end_headers(struct strbuf *hdr)
 121 {
 122         strbuf_add(hdr, "\r\n", 2);
 123         write_or_die(1, hdr->buf, hdr->len);
 124         strbuf_release(hdr);
 125 }
 126
 127 __attribute__((format (printf, 2, 3)))
 128 static NORETURN void not_found(struct strbuf *hdr, const char *err, ...)
 129 {
 130         va_list params;
 131
 132         http_status(hdr, 404, "Not Found");
 133         hdr_nocache(hdr);
 134         end_headers(hdr);
 135
 136         va_start(params, err);
 137         if (err && *err)
 138                 vfprintf(stderr, err, params);
 139         va_end(params);
 140         exit(0);
 141 }
 142
 143 __attribute__((format (printf, 2, 3)))
 144 static NORETURN void forbidden(struct strbuf *hdr, const char *err, ...)
 145 {
 146         va_list params;
 147
 148         http_status(hdr, 403, "Forbidden");
 149         hdr_nocache(hdr);
 150         end_headers(hdr);
 151
 152         va_start(params, err);
 153         if (err && *err)
 154                 vfprintf(stderr, err, params);
 155         va_end(params);
 156         exit(0);
 157 }
 158
 159 static void select_getanyfile(struct strbuf *hdr)
 160 {
 161         if (!getanyfile)
 162                 forbidden(hdr, "Unsupported service: getanyfile");
 163 }
 164
 165 static void send_strbuf(struct strbuf *hdr,
 166                         const char *type, struct strbuf *buf)
 167 {
 168         hdr_int(hdr, content_length, buf->len);
 169         hdr_str(hdr, content_type, type);
 170         end_headers(hdr);
 171         write_or_die(1, buf->buf, buf->len);
 172 }
 173
 174 static void send_local_file(struct strbuf *hdr, const char *the_type,
 175                                 const char *name)
 176 {
 177         char *p = git_pathdup("%s", name);
 178         size_t buf_alloc = 8192;
 179         char *buf = xmalloc(buf_alloc);
 180         int fd;
 181         struct stat sb;
 182
 183         fd = open(p, O_RDONLY);
 184         if (fd < 0)
 185                 not_found(hdr, "Cannot open '%s': %s", p, strerror(errno));
 186         if (fstat(fd, &sb) < 0)
 187                 die_errno("Cannot stat '%s'", p);
 188
 189         hdr_int(hdr, content_length, sb.st_size);
 190         hdr_str(hdr, content_type, the_type);
 191         hdr_date(hdr, last_modified, sb.st_mtime);
 192         end_headers(hdr);
 193
 194         for (;;) {
 195                 ssize_t n = xread(fd, buf, buf_alloc);
 196                 if (n < 0)
 197                         die_errno("Cannot read '%s'", p);
 198                 if (!n)
 199                         break;
 200                 write_or_die(1, buf, n);
 201         }
 202         close(fd);
 203         free(buf);
 204         free(p);
 205 }
 206
 207 static void get_text_file(struct strbuf *hdr, char *name)
 208 {
 209         select_getanyfile(hdr);
 210         hdr_nocache(hdr);
 211         send_local_file(hdr, "text/plain", name);
 212 }
 213
 214 static void get_loose_object(struct strbuf *hdr, char *name)
 215 {
 216         select_getanyfile(hdr);
 217         hdr_cache_forever(hdr);
 218         send_local_file(hdr, "application/x-git-loose-object", name);
 219 }
 220
 221 static void get_pack_file(struct strbuf *hdr, char *name)
 222 {
 223         select_getanyfile(hdr);
 224         hdr_cache_forever(hdr);
 225         send_local_file(hdr, "application/x-git-packed-objects", name);
 226 }
 227
 228 static void get_idx_file(struct strbuf *hdr, char *name)
 229 {
 230         select_getanyfile(hdr);
 231         hdr_cache_forever(hdr);
 232         send_local_file(hdr, "application/x-git-packed-objects-toc", name);
 233 }
 234
 235 static void http_config(void)
 236 {
 237         int i, value = 0;
 238         struct strbuf var = STRBUF_INIT;
 239
 240         git_config_get_bool("http.getanyfile", &getanyfile);
 241         git_config_get_ulong("http.maxrequestbuffer", &max_request_buffer);
 242
 243         for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 244                 struct rpc_service *svc = &rpc_service[i];
 245                 strbuf_addf(&var, "http.%s", svc->config_name);
 246                 if (!git_config_get_bool(var.buf, &value))
 247                         svc->enabled = value;
 248                 strbuf_reset(&var);
 249         }
 250
 251         strbuf_release(&var);
 252 }
 253
 254 static struct rpc_service *select_service(struct strbuf *hdr, const char *name)
 255 {
 256         const char *svc_name;
 257         struct rpc_service *svc = NULL;
 258         int i;
 259
 260         if (!skip_prefix(name, "git-", &svc_name))
 261                 forbidden(hdr, "Unsupported service: '%s'", name);
 262
 263         for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 264                 struct rpc_service *s = &rpc_service[i];
 265                 if (!strcmp(s->name, svc_name)) {
 266                         svc = s;
 267                         break;
 268                 }
 269         }
 270
 271         if (!svc)
 272                 forbidden(hdr, "Unsupported service: '%s'", name);
 273
 274         if (svc->enabled < 0) {
 275                 const char *user = getenv("REMOTE_USER");
 276                 svc->enabled = (user && *user) ? 1 : 0;
 277         }
 278         if (!svc->enabled)
 279                 forbidden(hdr, "Service not enabled: '%s'", svc->name);
 280         return svc;
 281 }
 282
 283 static void write_to_child(int out, const unsigned char *buf, ssize_t len, const char *prog_name)
 284 {
 285         if (write_in_full(out, buf, len) < 0)
 286                 die("unable to write to '%s'", prog_name);
 287 }
 288
 289 /*
 290  * This is basically strbuf_read(), except that if we
 291  * hit max_request_buffer we die (we'd rather reject a
 292  * maliciously large request than chew up infinite memory).
 293  */
 294 static ssize_t read_request_eof(int fd, unsigned char **out)
 295 {
 296         size_t len = 0, alloc = 8192;
 297         unsigned char *buf = xmalloc(alloc);
 298
 299         if (max_request_buffer < alloc)
 300                 max_request_buffer = alloc;
 301
 302         while (1) {
 303                 ssize_t cnt;
 304
 305                 cnt = read_in_full(fd, buf + len, alloc - len);
 306                 if (cnt < 0) {
 307                         free(buf);
 308                         return -1;
 309                 }
 310
 311                 /* partial read from read_in_full means we hit EOF */
 312                 len += cnt;
 313                 if (len < alloc) {
 314                         *out = buf;
 315                         return len;
 316                 }
 317
 318                 /* otherwise, grow and try again (if we can) */
 319                 if (alloc == max_request_buffer)
 320                         die("request was larger than our maximum size (%lu);"
 321                             " try setting GIT_HTTP_MAX_REQUEST_BUFFER",
 322                             max_request_buffer);
 323
 324                 alloc = alloc_nr(alloc);
 325                 if (alloc > max_request_buffer)
 326                         alloc = max_request_buffer;
 327                 REALLOC_ARRAY(buf, alloc);
 328         }
 329 }
 330
 331 static ssize_t read_request_fixed_len(int fd, ssize_t req_len, unsigned char **out)
 332 {
 333         unsigned char *buf = NULL;
 334         ssize_t cnt = 0;
 335
 336         if (max_request_buffer < req_len) {
 337                 die("request was larger than our maximum size (%lu): "
 338                     "%" PRIuMAX "; try setting GIT_HTTP_MAX_REQUEST_BUFFER",
 339                     max_request_buffer, (uintmax_t)req_len);
 340         }
 341
 342         buf = xmalloc(req_len);
 343         cnt = read_in_full(fd, buf, req_len);
 344         if (cnt < 0) {
 345                 free(buf);
 346                 return -1;
 347         }
 348         *out = buf;
 349         return cnt;
 350 }
 351
 352 static ssize_t get_content_length(void)
 353 {
 354         ssize_t val = -1;
 355         const char *str = getenv("CONTENT_LENGTH");
 356
 357         if (str && *str && !git_parse_ssize_t(str, &val))
 358                 die("failed to parse CONTENT_LENGTH: %s", str);
 359         return val;
 360 }
 361
 362 static ssize_t read_request(int fd, unsigned char **out, ssize_t req_len)
 363 {
 364         if (req_len < 0)
 365                 return read_request_eof(fd, out);
 366         else
 367                 return read_request_fixed_len(fd, req_len, out);
 368 }
 369
 370 static void inflate_request(const char *prog_name, int out, int buffer_input, ssize_t req_len)
 371 {
 372         git_zstream stream;
 373         unsigned char *full_request = NULL;
 374         unsigned char in_buf[8192];
 375         unsigned char out_buf[8192];
 376         unsigned long cnt = 0;
 377         int req_len_defined = req_len >= 0;
 378         size_t req_remaining_len = req_len;
 379
 380         memset(&stream, 0, sizeof(stream));
 381         git_inflate_init_gzip_only(&stream);
 382
 383         while (1) {
 384                 ssize_t n;
 385
 386                 if (buffer_input) {
 387                         if (full_request)
 388                                 n = 0; /* nothing left to read */
 389                         else
 390                                 n = read_request(0, &full_request, req_len);
 391                         stream.next_in = full_request;
 392                 } else {
 393                         ssize_t buffer_len;
 394                         if (req_len_defined && req_remaining_len <= sizeof(in_buf))
 395                                 buffer_len = req_remaining_len;
 396                         else
 397                                 buffer_len = sizeof(in_buf);
 398                         n = xread(0, in_buf, buffer_len);
 399                         stream.next_in = in_buf;
 400                         if (req_len_defined && n > 0)
 401                                 req_remaining_len -= n;
 402                 }
 403
 404                 if (n <= 0)
 405                         die("request ended in the middle of the gzip stream");
 406                 stream.avail_in = n;
 407
 408                 while (0 < stream.avail_in) {
 409                         int ret;
 410
 411                         stream.next_out = out_buf;
 412                         stream.avail_out = sizeof(out_buf);
 413
 414                         ret = git_inflate(&stream, Z_NO_FLUSH);
 415                         if (ret != Z_OK && ret != Z_STREAM_END)
 416                                 die("zlib error inflating request, result %d", ret);
 417
 418                         n = stream.total_out - cnt;
 419                         write_to_child(out, out_buf, stream.total_out - cnt, prog_name);
 420                         cnt = stream.total_out;
 421
 422                         if (ret == Z_STREAM_END)
 423                                 goto done;
 424                 }
 425         }
 426
 427 done:
 428         git_inflate_end(&stream);
 429         close(out);
 430         free(full_request);
 431 }
 432
 433 static void copy_request(const char *prog_name, int out, ssize_t req_len)
 434 {
 435         unsigned char *buf;
 436         ssize_t n = read_request(0, &buf, req_len);
 437         if (n < 0)
 438                 die_errno("error reading request body");
 439         write_to_child(out, buf, n, prog_name);
 440         close(out);
 441         free(buf);
 442 }
 443
 444 static void pipe_fixed_length(const char *prog_name, int out, size_t req_len)
 445 {
 446         unsigned char buf[8192];
 447         size_t remaining_len = req_len;
 448
 449         while (remaining_len > 0) {
 450                 size_t chunk_length = remaining_len > sizeof(buf) ? sizeof(buf) : remaining_len;
 451                 ssize_t n = xread(0, buf, chunk_length);
 452                 if (n < 0)
 453                         die_errno("Reading request failed");
 454                 write_to_child(out, buf, n, prog_name);
 455                 remaining_len -= n;
 456         }
 457
 458         close(out);
 459 }
 460
 461 static void run_service(const char **argv, int buffer_input)
 462 {
 463         const char *encoding = getenv("HTTP_CONTENT_ENCODING");
 464         const char *user = getenv("REMOTE_USER");
 465         const char *host = getenv("REMOTE_ADDR");
 466         int gzipped_request = 0;
 467         struct child_process cld = CHILD_PROCESS_INIT;
 468         ssize_t req_len = get_content_length();
 469
 470         if (encoding && (!strcmp(encoding, "gzip") || !strcmp(encoding, "x-gzip")))
 471                 gzipped_request = 1;
 472
 473         if (!user || !*user)
 474                 user = "anonymous";
 475         if (!host || !*host)
 476                 host = "(none)";
 477
 478         if (!getenv("GIT_COMMITTER_NAME"))
 479                 strvec_pushf(&cld.env, "GIT_COMMITTER_NAME=%s", user);
 480         if (!getenv("GIT_COMMITTER_EMAIL"))
 481                 strvec_pushf(&cld.env,
 482                              "GIT_COMMITTER_EMAIL=%s@http.%s", user, host);
 483
 484         strvec_pushv(&cld.args, argv);
 485         if (buffer_input || gzipped_request || req_len >= 0)
 486                 cld.in = -1;
 487         cld.git_cmd = 1;
 488         cld.clean_on_exit = 1;
 489         cld.wait_after_clean = 1;
 490         if (start_command(&cld))
 491                 exit(1);
 492
 493         close(1);
 494         if (gzipped_request)
 495                 inflate_request(argv[0], cld.in, buffer_input, req_len);
 496         else if (buffer_input)
 497                 copy_request(argv[0], cld.in, req_len);
 498         else if (req_len >= 0)
 499                 pipe_fixed_length(argv[0], cld.in, req_len);
 500         else
 501                 close(0);
 502
 503         if (finish_command(&cld))
 504                 exit(1);
 505 }
 506
 507 static int show_text_ref(const char *name, const struct object_id *oid,
 508                          int flag UNUSED, void *cb_data)
 509 {
 510         const char *name_nons = strip_namespace(name);
 511         struct strbuf *buf = cb_data;
 512         struct object *o = parse_object(the_repository, oid);
 513         if (!o)
 514                 return 0;
 515
 516         strbuf_addf(buf, "%s\t%s\n", oid_to_hex(oid), name_nons);
 517         if (o->type == OBJ_TAG) {
 518                 o = deref_tag(the_repository, o, name, 0);
 519                 if (!o)
 520                         return 0;
 521                 strbuf_addf(buf, "%s\t%s^{}\n", oid_to_hex(&o->oid),
 522                             name_nons);
 523         }
 524         return 0;
 525 }
 526
 527 static void get_info_refs(struct strbuf *hdr, char *arg)
 528 {
 529         const char *service_name = get_parameter("service");
 530         struct strbuf buf = STRBUF_INIT;
 531
 532         hdr_nocache(hdr);
 533
 534         if (service_name) {
 535                 const char *argv[] = {NULL /* service name */,
 536                         "--http-backend-info-refs",
 537                         ".", NULL};
 538                 struct rpc_service *svc = select_service(hdr, service_name);
 539
 540                 strbuf_addf(&buf, "application/x-git-%s-advertisement",
 541                         svc->name);
 542                 hdr_str(hdr, content_type, buf.buf);
 543                 end_headers(hdr);
 544
 545
 546                 if (determine_protocol_version_server() != protocol_v2) {
 547                         packet_write_fmt(1, "# service=git-%s\n", svc->name);
 548                         packet_flush(1);
 549                 }
 550
 551                 argv[0] = svc->name;
 552                 run_service(argv, 0);
 553
 554         } else {
 555                 select_getanyfile(hdr);
 556                 for_each_namespaced_ref(show_text_ref, &buf);
 557                 send_strbuf(hdr, "text/plain", &buf);
 558         }
 559         strbuf_release(&buf);
 560 }
 561
 562 static int show_head_ref(const char *refname, const struct object_id *oid,
 563                          int flag, void *cb_data)
 564 {
 565         struct strbuf *buf = cb_data;
 566
 567         if (flag & REF_ISSYMREF) {
 568                 const char *target = resolve_ref_unsafe(refname,
 569                                                         RESOLVE_REF_READING,
 570                                                         NULL, NULL);
 571
 572                 if (target)
 573                         strbuf_addf(buf, "ref: %s\n", strip_namespace(target));
 574         } else {
 575                 strbuf_addf(buf, "%s\n", oid_to_hex(oid));
 576         }
 577
 578         return 0;
 579 }
 580
 581 static void get_head(struct strbuf *hdr, char *arg)
 582 {
 583         struct strbuf buf = STRBUF_INIT;
 584
 585         select_getanyfile(hdr);
 586         head_ref_namespaced(show_head_ref, &buf);
 587         send_strbuf(hdr, "text/plain", &buf);
 588         strbuf_release(&buf);
 589 }
 590
 591 static void get_info_packs(struct strbuf *hdr, char *arg)
 592 {
 593         size_t objdirlen = strlen(get_object_directory());
 594         struct strbuf buf = STRBUF_INIT;
 595         struct packed_git *p;
 596         size_t cnt = 0;
 597
 598         select_getanyfile(hdr);
 599         for (p = get_all_packs(the_repository); p; p = p->next) {
 600                 if (p->pack_local)
 601                         cnt++;
 602         }
 603
 604         strbuf_grow(&buf, cnt * 53 + 2);
 605         for (p = get_all_packs(the_repository); p; p = p->next) {
 606                 if (p->pack_local)
 607                         strbuf_addf(&buf, "P %s\n", p->pack_name + objdirlen + 6);
 608         }
 609         strbuf_addch(&buf, '\n');
 610
 611         hdr_nocache(hdr);
 612         send_strbuf(hdr, "text/plain; charset=utf-8", &buf);
 613         strbuf_release(&buf);
 614 }
 615
 616 static void check_content_type(struct strbuf *hdr, const char *accepted_type)
 617 {
 618         const char *actual_type = getenv("CONTENT_TYPE");
 619
 620         if (!actual_type)
 621                 actual_type = "";
 622
 623         if (strcmp(actual_type, accepted_type)) {
 624                 http_status(hdr, 415, "Unsupported Media Type");
 625                 hdr_nocache(hdr);
 626                 end_headers(hdr);
 627                 format_write(1,
 628                         "Expected POST with Content-Type '%s',"
 629                         " but received '%s' instead.\n",
 630                         accepted_type, actual_type);
 631                 exit(0);
 632         }
 633 }
 634
 635 static void service_rpc(struct strbuf *hdr, char *service_name)
 636 {
 637         const char *argv[] = {NULL, "--stateless-rpc", ".", NULL};
 638         struct rpc_service *svc = select_service(hdr, service_name);
 639         struct strbuf buf = STRBUF_INIT;
 640
 641         strbuf_reset(&buf);
 642         strbuf_addf(&buf, "application/x-git-%s-request", svc->name);
 643         check_content_type(hdr, buf.buf);
 644
 645         hdr_nocache(hdr);
 646
 647         strbuf_reset(&buf);
 648         strbuf_addf(&buf, "application/x-git-%s-result", svc->name);
 649         hdr_str(hdr, content_type, buf.buf);
 650
 651         end_headers(hdr);
 652
 653         argv[0] = svc->name;
 654         run_service(argv, svc->buffer_input);
 655         strbuf_release(&buf);
 656 }
 657
 658 static int dead;
 659 static NORETURN void die_webcgi(const char *err, va_list params)
 660 {
 661         if (dead <= 1) {
 662                 struct strbuf hdr = STRBUF_INIT;
 663                 report_fn die_message_fn = get_die_message_routine();
 664
 665                 die_message_fn(err, params);
 666
 667                 http_status(&hdr, 500, "Internal Server Error");
 668                 hdr_nocache(&hdr);
 669                 end_headers(&hdr);
 670         }
 671         exit(0); /* we successfully reported a failure ;-) */
 672 }
 673
 674 static int die_webcgi_recursing(void)
 675 {
 676         return dead++ > 1;
 677 }
 678
 679 static char* getdir(void)
 680 {
 681         struct strbuf buf = STRBUF_INIT;
 682         char *pathinfo = getenv("PATH_INFO");
 683         char *root = getenv("GIT_PROJECT_ROOT");
 684         char *path = getenv("PATH_TRANSLATED");
 685
 686         if (root && *root) {
 687                 if (!pathinfo || !*pathinfo)
 688                         die("GIT_PROJECT_ROOT is set but PATH_INFO is not");
 689                 if (daemon_avoid_alias(pathinfo))
 690                         die("'%s': aliased", pathinfo);
 691                 end_url_with_slash(&buf, root);
 692                 if (pathinfo[0] == '/')
 693                         pathinfo++;
 694                 strbuf_addstr(&buf, pathinfo);
 695                 return strbuf_detach(&buf, NULL);
 696         } else if (path && *path) {
 697                 return xstrdup(path);
 698         } else
 699                 die("No GIT_PROJECT_ROOT or PATH_TRANSLATED from server");
 700         return NULL;
 701 }
 702
 703 static struct service_cmd {
 704         const char *method;
 705         const char *pattern;
 706         void (*imp)(struct strbuf *, char *);
 707 } services[] = {
 708         {"GET", "/HEAD$", get_head},
 709         {"GET", "/info/refs$", get_info_refs},
 710         {"GET", "/objects/info/alternates$", get_text_file},
 711         {"GET", "/objects/info/http-alternates$", get_text_file},
 712         {"GET", "/objects/info/packs$", get_info_packs},
 713         {"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{38}$", get_loose_object},
 714         {"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{62}$", get_loose_object},
 715         {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.pack$", get_pack_file},
 716         {"GET", "/objects/pack/pack-[0-9a-f]{64}\\.pack$", get_pack_file},
 717         {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.idx$", get_idx_file},
 718         {"GET", "/objects/pack/pack-[0-9a-f]{64}\\.idx$", get_idx_file},
 719
 720         {"POST", "/git-upload-pack$", service_rpc},
 721         {"POST", "/git-receive-pack$", service_rpc}
 722 };
 723
 724 static int bad_request(struct strbuf *hdr, const struct service_cmd *c)
 725 {
 726         const char *proto = getenv("SERVER_PROTOCOL");
 727
 728         if (proto && !strcmp(proto, "HTTP/1.1")) {
 729                 http_status(hdr, 405, "Method Not Allowed");
 730                 hdr_str(hdr, "Allow",
 731                         !strcmp(c->method, "GET") ? "GET, HEAD" : c->method);
 732         } else
 733                 http_status(hdr, 400, "Bad Request");
 734         hdr_nocache(hdr);
 735         end_headers(hdr);
 736         return 0;
 737 }
 738
 739 int cmd_main(int argc, const char **argv)
 740 {
 741         char *method = getenv("REQUEST_METHOD");
 742         const char *proto_header;
 743         char *dir;
 744         struct service_cmd *cmd = NULL;
 745         char *cmd_arg = NULL;
 746         int i;
 747         struct strbuf hdr = STRBUF_INIT;
 748
 749         set_die_routine(die_webcgi);
 750         set_die_is_recursing_routine(die_webcgi_recursing);
 751
 752         if (!method)
 753                 die("No REQUEST_METHOD from server");
 754         if (!strcmp(method, "HEAD"))
 755                 method = "GET";
 756         dir = getdir();
 757
 758         for (i = 0; i < ARRAY_SIZE(services); i++) {
 759                 struct service_cmd *c = &services[i];
 760                 regex_t re;
 761                 regmatch_t out[1];
 762
 763                 if (regcomp(&re, c->pattern, REG_EXTENDED))
 764                         die("Bogus regex in service table: %s", c->pattern);
 765                 if (!regexec(&re, dir, 1, out, 0)) {
 766                         size_t n;
 767
 768                         if (strcmp(method, c->method))
 769                                 return bad_request(&hdr, c);
 770
 771                         cmd = c;
 772                         n = out[0].rm_eo - out[0].rm_so;
 773                         cmd_arg = xmemdupz(dir + out[0].rm_so + 1, n - 1);
 774                         dir[out[0].rm_so] = 0;
 775                         break;
 776                 }
 777                 regfree(&re);
 778         }
 779
 780         if (!cmd)
 781                 not_found(&hdr, "Request not supported: '%s'", dir);
 782
 783         setup_path();
 784         if (!enter_repo(dir, 0))
 785                 not_found(&hdr, "Not a git repository: '%s'", dir);
 786         if (!getenv("GIT_HTTP_EXPORT_ALL") &&
 787             access("git-daemon-export-ok", F_OK) )
 788                 not_found(&hdr, "Repository not exported: '%s'", dir);
 789
 790         http_config();
 791         max_request_buffer = git_env_ulong("GIT_HTTP_MAX_REQUEST_BUFFER",
 792                                            max_request_buffer);
 793         proto_header = getenv("HTTP_GIT_PROTOCOL");
 794         if (proto_header)
 795                 setenv(GIT_PROTOCOL_ENVIRONMENT, proto_header, 0);
 796
 797         cmd->imp(&hdr, cmd_arg);
 798         return 0;
 799 }