http-backend.c

   1 #include "git-compat-util.h"
   2 #include "config.h"
   3 #include "environment.h"
   4 #include "git-zlib.h"
   5 #include "hex.h"
   6 #include "path.h"
   7 #include "repository.h"
   8 #include "refs.h"
   9 #include "pkt-line.h"
  10 #include "object.h"
  11 #include "tag.h"
  12 #include "exec-cmd.h"
  13 #include "run-command.h"
  14 #include "string-list.h"
  15 #include "url.h"
  16 #include "strvec.h"
  17 #include "packfile.h"
  18 #include "object-store-ll.h"
  19 #include "protocol.h"
  20 #include "date.h"
  21 #include "write-or-die.h"
  22
  23 static const char content_type[] = "Content-Type";
  24 static const char content_length[] = "Content-Length";
  25 static const char last_modified[] = "Last-Modified";
  26 static int getanyfile = 1;
  27 static unsigned long max_request_buffer = 10 * 1024 * 1024;
  28
  29 static struct string_list *query_params;
  30
  31 struct rpc_service {
  32         const char *name;
  33         const char *config_name;
  34         unsigned buffer_input : 1;
  35         signed enabled : 2;
  36 };
  37
  38 static struct rpc_service rpc_service[] = {
  39         { "upload-pack", "uploadpack", 1, 1 },
  40         { "receive-pack", "receivepack", 0, -1 },
  41 };
  42
  43 static struct string_list *get_parameters(void)
  44 {
  45         if (!query_params) {
  46                 const char *query = getenv("QUERY_STRING");
  47
  48                 CALLOC_ARRAY(query_params, 1);
  49                 while (query && *query) {
  50                         char *name = url_decode_parameter_name(&query);
  51                         char *value = url_decode_parameter_value(&query);
  52                         struct string_list_item *i;
  53
  54                         i = string_list_lookup(query_params, name);
  55                         if (!i)
  56                                 i = string_list_insert(query_params, name);
  57                         else
  58                                 free(i->util);
  59                         i->util = value;
  60                 }
  61         }
  62         return query_params;
  63 }
  64
  65 static const char *get_parameter(const char *name)
  66 {
  67         struct string_list_item *i;
  68         i = string_list_lookup(get_parameters(), name);
  69         return i ? i->util : NULL;
  70 }
  71
  72 __attribute__((format (printf, 2, 3)))
  73 static void format_write(int fd, const char *fmt, ...)
  74 {
  75         static char buffer[1024];
  76
  77         va_list args;
  78         unsigned n;
  79
  80         va_start(args, fmt);
  81         n = vsnprintf(buffer, sizeof(buffer), fmt, args);
  82         va_end(args);
  83         if (n >= sizeof(buffer))
  84                 die("protocol error: impossibly long line");
  85
  86         write_or_die(fd, buffer, n);
  87 }
  88
  89 static void http_status(struct strbuf *hdr, unsigned code, const char *msg)
  90 {
  91         strbuf_addf(hdr, "Status: %u %s\r\n", code, msg);
  92 }
  93
  94 static void hdr_str(struct strbuf *hdr, const char *name, const char *value)
  95 {
  96         strbuf_addf(hdr, "%s: %s\r\n", name, value);
  97 }
  98
  99 static void hdr_int(struct strbuf *hdr, const char *name, uintmax_t value)
 100 {
 101         strbuf_addf(hdr, "%s: %" PRIuMAX "\r\n", name, value);
 102 }
 103
 104 static void hdr_date(struct strbuf *hdr, const char *name, timestamp_t when)
 105 {
 106         const char *value = show_date(when, 0, DATE_MODE(RFC2822));
 107         hdr_str(hdr, name, value);
 108 }
 109
 110 static void hdr_nocache(struct strbuf *hdr)
 111 {
 112         hdr_str(hdr, "Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
 113         hdr_str(hdr, "Pragma", "no-cache");
 114         hdr_str(hdr, "Cache-Control", "no-cache, max-age=0, must-revalidate");
 115 }
 116
 117 static void hdr_cache_forever(struct strbuf *hdr)
 118 {
 119         timestamp_t now = time(NULL);
 120         hdr_date(hdr, "Date", now);
 121         hdr_date(hdr, "Expires", now + 31536000);
 122         hdr_str(hdr, "Cache-Control", "public, max-age=31536000");
 123 }
 124
 125 static void end_headers(struct strbuf *hdr)
 126 {
 127         strbuf_add(hdr, "\r\n", 2);
 128         write_or_die(1, hdr->buf, hdr->len);
 129         strbuf_release(hdr);
 130 }
 131
 132 __attribute__((format (printf, 2, 3)))
 133 static NORETURN void not_found(struct strbuf *hdr, const char *err, ...)
 134 {
 135         va_list params;
 136
 137         http_status(hdr, 404, "Not Found");
 138         hdr_nocache(hdr);
 139         end_headers(hdr);
 140
 141         va_start(params, err);
 142         if (err && *err)
 143                 vfprintf(stderr, err, params);
 144         va_end(params);
 145         exit(0);
 146 }
 147
 148 __attribute__((format (printf, 2, 3)))
 149 static NORETURN void forbidden(struct strbuf *hdr, const char *err, ...)
 150 {
 151         va_list params;
 152
 153         http_status(hdr, 403, "Forbidden");
 154         hdr_nocache(hdr);
 155         end_headers(hdr);
 156
 157         va_start(params, err);
 158         if (err && *err)
 159                 vfprintf(stderr, err, params);
 160         va_end(params);
 161         exit(0);
 162 }
 163
 164 static void select_getanyfile(struct strbuf *hdr)
 165 {
 166         if (!getanyfile)
 167                 forbidden(hdr, "Unsupported service: getanyfile");
 168 }
 169
 170 static void send_strbuf(struct strbuf *hdr,
 171                         const char *type, struct strbuf *buf)
 172 {
 173         hdr_int(hdr, content_length, buf->len);
 174         hdr_str(hdr, content_type, type);
 175         end_headers(hdr);
 176         write_or_die(1, buf->buf, buf->len);
 177 }
 178
 179 static void send_local_file(struct strbuf *hdr, const char *the_type,
 180                                 const char *name)
 181 {
 182         char *p = git_pathdup("%s", name);
 183         size_t buf_alloc = 8192;
 184         char *buf = xmalloc(buf_alloc);
 185         int fd;
 186         struct stat sb;
 187
 188         fd = open(p, O_RDONLY);
 189         if (fd < 0)
 190                 not_found(hdr, "Cannot open '%s': %s", p, strerror(errno));
 191         if (fstat(fd, &sb) < 0)
 192                 die_errno("Cannot stat '%s'", p);
 193
 194         hdr_int(hdr, content_length, sb.st_size);
 195         hdr_str(hdr, content_type, the_type);
 196         hdr_date(hdr, last_modified, sb.st_mtime);
 197         end_headers(hdr);
 198
 199         for (;;) {
 200                 ssize_t n = xread(fd, buf, buf_alloc);
 201                 if (n < 0)
 202                         die_errno("Cannot read '%s'", p);
 203                 if (!n)
 204                         break;
 205                 write_or_die(1, buf, n);
 206         }
 207         close(fd);
 208         free(buf);
 209         free(p);
 210 }
 211
 212 static void get_text_file(struct strbuf *hdr, char *name)
 213 {
 214         select_getanyfile(hdr);
 215         hdr_nocache(hdr);
 216         send_local_file(hdr, "text/plain", name);
 217 }
 218
 219 static void get_loose_object(struct strbuf *hdr, char *name)
 220 {
 221         select_getanyfile(hdr);
 222         hdr_cache_forever(hdr);
 223         send_local_file(hdr, "application/x-git-loose-object", name);
 224 }
 225
 226 static void get_pack_file(struct strbuf *hdr, char *name)
 227 {
 228         select_getanyfile(hdr);
 229         hdr_cache_forever(hdr);
 230         send_local_file(hdr, "application/x-git-packed-objects", name);
 231 }
 232
 233 static void get_idx_file(struct strbuf *hdr, char *name)
 234 {
 235         select_getanyfile(hdr);
 236         hdr_cache_forever(hdr);
 237         send_local_file(hdr, "application/x-git-packed-objects-toc", name);
 238 }
 239
 240 static void http_config(void)
 241 {
 242         int i, value = 0;
 243         struct strbuf var = STRBUF_INIT;
 244
 245         git_config_get_bool("http.getanyfile", &getanyfile);
 246         git_config_get_ulong("http.maxrequestbuffer", &max_request_buffer);
 247
 248         for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 249                 struct rpc_service *svc = &rpc_service[i];
 250                 strbuf_addf(&var, "http.%s", svc->config_name);
 251                 if (!git_config_get_bool(var.buf, &value))
 252                         svc->enabled = value;
 253                 strbuf_reset(&var);
 254         }
 255
 256         strbuf_release(&var);
 257 }
 258
 259 static struct rpc_service *select_service(struct strbuf *hdr, const char *name)
 260 {
 261         const char *svc_name;
 262         struct rpc_service *svc = NULL;
 263         int i;
 264
 265         if (!skip_prefix(name, "git-", &svc_name))
 266                 forbidden(hdr, "Unsupported service: '%s'", name);
 267
 268         for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 269                 struct rpc_service *s = &rpc_service[i];
 270                 if (!strcmp(s->name, svc_name)) {
 271                         svc = s;
 272                         break;
 273                 }
 274         }
 275
 276         if (!svc)
 277                 forbidden(hdr, "Unsupported service: '%s'", name);
 278
 279         if (svc->enabled < 0) {
 280                 const char *user = getenv("REMOTE_USER");
 281                 svc->enabled = (user && *user) ? 1 : 0;
 282         }
 283         if (!svc->enabled)
 284                 forbidden(hdr, "Service not enabled: '%s'", svc->name);
 285         return svc;
 286 }
 287
 288 static void write_to_child(int out, const unsigned char *buf, ssize_t len, const char *prog_name)
 289 {
 290         if (write_in_full(out, buf, len) < 0)
 291                 die("unable to write to '%s'", prog_name);
 292 }
 293
 294 /*
 295  * This is basically strbuf_read(), except that if we
 296  * hit max_request_buffer we die (we'd rather reject a
 297  * maliciously large request than chew up infinite memory).
 298  */
 299 static ssize_t read_request_eof(int fd, unsigned char **out)
 300 {
 301         size_t len = 0, alloc = 8192;
 302         unsigned char *buf = xmalloc(alloc);
 303
 304         if (max_request_buffer < alloc)
 305                 max_request_buffer = alloc;
 306
 307         while (1) {
 308                 ssize_t cnt;
 309
 310                 cnt = read_in_full(fd, buf + len, alloc - len);
 311                 if (cnt < 0) {
 312                         free(buf);
 313                         return -1;
 314                 }
 315
 316                 /* partial read from read_in_full means we hit EOF */
 317                 len += cnt;
 318                 if (len < alloc) {
 319                         *out = buf;
 320                         return len;
 321                 }
 322
 323                 /* otherwise, grow and try again (if we can) */
 324                 if (alloc == max_request_buffer)
 325                         die("request was larger than our maximum size (%lu);"
 326                             " try setting GIT_HTTP_MAX_REQUEST_BUFFER",
 327                             max_request_buffer);
 328
 329                 alloc = alloc_nr(alloc);
 330                 if (alloc > max_request_buffer)
 331                         alloc = max_request_buffer;
 332                 REALLOC_ARRAY(buf, alloc);
 333         }
 334 }
 335
 336 static ssize_t read_request_fixed_len(int fd, ssize_t req_len, unsigned char **out)
 337 {
 338         unsigned char *buf = NULL;
 339         ssize_t cnt = 0;
 340
 341         if (max_request_buffer < req_len) {
 342                 die("request was larger than our maximum size (%lu): "
 343                     "%" PRIuMAX "; try setting GIT_HTTP_MAX_REQUEST_BUFFER",
 344                     max_request_buffer, (uintmax_t)req_len);
 345         }
 346
 347         buf = xmalloc(req_len);
 348         cnt = read_in_full(fd, buf, req_len);
 349         if (cnt < 0) {
 350                 free(buf);
 351                 return -1;
 352         }
 353         *out = buf;
 354         return cnt;
 355 }
 356
 357 static ssize_t get_content_length(void)
 358 {
 359         ssize_t val = -1;
 360         const char *str = getenv("CONTENT_LENGTH");
 361
 362         if (str && *str && !git_parse_ssize_t(str, &val))
 363                 die("failed to parse CONTENT_LENGTH: %s", str);
 364         return val;
 365 }
 366
 367 static ssize_t read_request(int fd, unsigned char **out, ssize_t req_len)
 368 {
 369         if (req_len < 0)
 370                 return read_request_eof(fd, out);
 371         else
 372                 return read_request_fixed_len(fd, req_len, out);
 373 }
 374
 375 static void inflate_request(const char *prog_name, int out, int buffer_input, ssize_t req_len)
 376 {
 377         git_zstream stream;
 378         unsigned char *full_request = NULL;
 379         unsigned char in_buf[8192];
 380         unsigned char out_buf[8192];
 381         unsigned long cnt = 0;
 382         int req_len_defined = req_len >= 0;
 383         size_t req_remaining_len = req_len;
 384
 385         memset(&stream, 0, sizeof(stream));
 386         git_inflate_init_gzip_only(&stream);
 387
 388         while (1) {
 389                 ssize_t n;
 390
 391                 if (buffer_input) {
 392                         if (full_request)
 393                                 n = 0; /* nothing left to read */
 394                         else
 395                                 n = read_request(0, &full_request, req_len);
 396                         stream.next_in = full_request;
 397                 } else {
 398                         ssize_t buffer_len;
 399                         if (req_len_defined && req_remaining_len <= sizeof(in_buf))
 400                                 buffer_len = req_remaining_len;
 401                         else
 402                                 buffer_len = sizeof(in_buf);
 403                         n = xread(0, in_buf, buffer_len);
 404                         stream.next_in = in_buf;
 405                         if (req_len_defined && n > 0)
 406                                 req_remaining_len -= n;
 407                 }
 408
 409                 if (n <= 0)
 410                         die("request ended in the middle of the gzip stream");
 411                 stream.avail_in = n;
 412
 413                 while (0 < stream.avail_in) {
 414                         int ret;
 415
 416                         stream.next_out = out_buf;
 417                         stream.avail_out = sizeof(out_buf);
 418
 419                         ret = git_inflate(&stream, Z_NO_FLUSH);
 420                         if (ret != Z_OK && ret != Z_STREAM_END)
 421                                 die("zlib error inflating request, result %d", ret);
 422
 423                         n = stream.total_out - cnt;
 424                         write_to_child(out, out_buf, stream.total_out - cnt, prog_name);
 425                         cnt = stream.total_out;
 426
 427                         if (ret == Z_STREAM_END)
 428                                 goto done;
 429                 }
 430         }
 431
 432 done:
 433         git_inflate_end(&stream);
 434         close(out);
 435         free(full_request);
 436 }
 437
 438 static void copy_request(const char *prog_name, int out, ssize_t req_len)
 439 {
 440         unsigned char *buf;
 441         ssize_t n = read_request(0, &buf, req_len);
 442         if (n < 0)
 443                 die_errno("error reading request body");
 444         write_to_child(out, buf, n, prog_name);
 445         close(out);
 446         free(buf);
 447 }
 448
 449 static void pipe_fixed_length(const char *prog_name, int out, size_t req_len)
 450 {
 451         unsigned char buf[8192];
 452         size_t remaining_len = req_len;
 453
 454         while (remaining_len > 0) {
 455                 size_t chunk_length = remaining_len > sizeof(buf) ? sizeof(buf) : remaining_len;
 456                 ssize_t n = xread(0, buf, chunk_length);
 457                 if (n < 0)
 458                         die_errno("Reading request failed");
 459                 write_to_child(out, buf, n, prog_name);
 460                 remaining_len -= n;
 461         }
 462
 463         close(out);
 464 }
 465
 466 static void run_service(const char **argv, int buffer_input)
 467 {
 468         const char *encoding = getenv("HTTP_CONTENT_ENCODING");
 469         const char *user = getenv("REMOTE_USER");
 470         const char *host = getenv("REMOTE_ADDR");
 471         int gzipped_request = 0;
 472         struct child_process cld = CHILD_PROCESS_INIT;
 473         ssize_t req_len = get_content_length();
 474
 475         if (encoding && (!strcmp(encoding, "gzip") || !strcmp(encoding, "x-gzip")))
 476                 gzipped_request = 1;
 477
 478         if (!user || !*user)
 479                 user = "anonymous";
 480         if (!host || !*host)
 481                 host = "(none)";
 482
 483         if (!getenv("GIT_COMMITTER_NAME"))
 484                 strvec_pushf(&cld.env, "GIT_COMMITTER_NAME=%s", user);
 485         if (!getenv("GIT_COMMITTER_EMAIL"))
 486                 strvec_pushf(&cld.env,
 487                              "GIT_COMMITTER_EMAIL=%s@http.%s", user, host);
 488
 489         strvec_pushv(&cld.args, argv);
 490         if (buffer_input || gzipped_request || req_len >= 0)
 491                 cld.in = -1;
 492         cld.git_cmd = 1;
 493         cld.clean_on_exit = 1;
 494         cld.wait_after_clean = 1;
 495         if (start_command(&cld))
 496                 exit(1);
 497
 498         close(1);
 499         if (gzipped_request)
 500                 inflate_request(argv[0], cld.in, buffer_input, req_len);
 501         else if (buffer_input)
 502                 copy_request(argv[0], cld.in, req_len);
 503         else if (req_len >= 0)
 504                 pipe_fixed_length(argv[0], cld.in, req_len);
 505         else
 506                 close(0);
 507
 508         if (finish_command(&cld))
 509                 exit(1);
 510 }
 511
 512 static int show_text_ref(const char *name, const struct object_id *oid,
 513                          int flag UNUSED, void *cb_data)
 514 {
 515         const char *name_nons = strip_namespace(name);
 516         struct strbuf *buf = cb_data;
 517         struct object *o = parse_object(the_repository, oid);
 518         if (!o)
 519                 return 0;
 520
 521         strbuf_addf(buf, "%s\t%s\n", oid_to_hex(oid), name_nons);
 522         if (o->type == OBJ_TAG) {
 523                 o = deref_tag(the_repository, o, name, 0);
 524                 if (!o)
 525                         return 0;
 526                 strbuf_addf(buf, "%s\t%s^{}\n", oid_to_hex(&o->oid),
 527                             name_nons);
 528         }
 529         return 0;
 530 }
 531
 532 static void get_info_refs(struct strbuf *hdr, char *arg UNUSED)
 533 {
 534         const char *service_name = get_parameter("service");
 535         struct strbuf buf = STRBUF_INIT;
 536
 537         hdr_nocache(hdr);
 538
 539         if (service_name) {
 540                 const char *argv[] = {NULL /* service name */,
 541                         "--http-backend-info-refs",
 542                         ".", NULL};
 543                 struct rpc_service *svc = select_service(hdr, service_name);
 544
 545                 strbuf_addf(&buf, "application/x-git-%s-advertisement",
 546                         svc->name);
 547                 hdr_str(hdr, content_type, buf.buf);
 548                 end_headers(hdr);
 549
 550
 551                 if (determine_protocol_version_server() != protocol_v2) {
 552                         packet_write_fmt(1, "# service=git-%s\n", svc->name);
 553                         packet_flush(1);
 554                 }
 555
 556                 argv[0] = svc->name;
 557                 run_service(argv, 0);
 558
 559         } else {
 560                 select_getanyfile(hdr);
 561                 for_each_namespaced_ref(NULL, show_text_ref, &buf);
 562                 send_strbuf(hdr, "text/plain", &buf);
 563         }
 564         strbuf_release(&buf);
 565 }
 566
 567 static int show_head_ref(const char *refname, const struct object_id *oid,
 568                          int flag, void *cb_data)
 569 {
 570         struct strbuf *buf = cb_data;
 571
 572         if (flag & REF_ISSYMREF) {
 573                 const char *target = resolve_ref_unsafe(refname,
 574                                                         RESOLVE_REF_READING,
 575                                                         NULL, NULL);
 576
 577                 if (target)
 578                         strbuf_addf(buf, "ref: %s\n", strip_namespace(target));
 579         } else {
 580                 strbuf_addf(buf, "%s\n", oid_to_hex(oid));
 581         }
 582
 583         return 0;
 584 }
 585
 586 static void get_head(struct strbuf *hdr, char *arg UNUSED)
 587 {
 588         struct strbuf buf = STRBUF_INIT;
 589
 590         select_getanyfile(hdr);
 591         head_ref_namespaced(show_head_ref, &buf);
 592         send_strbuf(hdr, "text/plain", &buf);
 593         strbuf_release(&buf);
 594 }
 595
 596 static void get_info_packs(struct strbuf *hdr, char *arg UNUSED)
 597 {
 598         size_t objdirlen = strlen(get_object_directory());
 599         struct strbuf buf = STRBUF_INIT;
 600         struct packed_git *p;
 601         size_t cnt = 0;
 602
 603         select_getanyfile(hdr);
 604         for (p = get_all_packs(the_repository); p; p = p->next) {
 605                 if (p->pack_local)
 606                         cnt++;
 607         }
 608
 609         strbuf_grow(&buf, cnt * 53 + 2);
 610         for (p = get_all_packs(the_repository); p; p = p->next) {
 611                 if (p->pack_local)
 612                         strbuf_addf(&buf, "P %s\n", p->pack_name + objdirlen + 6);
 613         }
 614         strbuf_addch(&buf, '\n');
 615
 616         hdr_nocache(hdr);
 617         send_strbuf(hdr, "text/plain; charset=utf-8", &buf);
 618         strbuf_release(&buf);
 619 }
 620
 621 static void check_content_type(struct strbuf *hdr, const char *accepted_type)
 622 {
 623         const char *actual_type = getenv("CONTENT_TYPE");
 624
 625         if (!actual_type)
 626                 actual_type = "";
 627
 628         if (strcmp(actual_type, accepted_type)) {
 629                 http_status(hdr, 415, "Unsupported Media Type");
 630                 hdr_nocache(hdr);
 631                 end_headers(hdr);
 632                 format_write(1,
 633                         "Expected POST with Content-Type '%s',"
 634                         " but received '%s' instead.\n",
 635                         accepted_type, actual_type);
 636                 exit(0);
 637         }
 638 }
 639
 640 static void service_rpc(struct strbuf *hdr, char *service_name)
 641 {
 642         const char *argv[] = {NULL, "--stateless-rpc", ".", NULL};
 643         struct rpc_service *svc = select_service(hdr, service_name);
 644         struct strbuf buf = STRBUF_INIT;
 645
 646         strbuf_reset(&buf);
 647         strbuf_addf(&buf, "application/x-git-%s-request", svc->name);
 648         check_content_type(hdr, buf.buf);
 649
 650         hdr_nocache(hdr);
 651
 652         strbuf_reset(&buf);
 653         strbuf_addf(&buf, "application/x-git-%s-result", svc->name);
 654         hdr_str(hdr, content_type, buf.buf);
 655
 656         end_headers(hdr);
 657
 658         argv[0] = svc->name;
 659         run_service(argv, svc->buffer_input);
 660         strbuf_release(&buf);
 661 }
 662
 663 static int dead;
 664 static NORETURN void die_webcgi(const char *err, va_list params)
 665 {
 666         if (dead <= 1) {
 667                 struct strbuf hdr = STRBUF_INIT;
 668                 report_fn die_message_fn = get_die_message_routine();
 669
 670                 die_message_fn(err, params);
 671
 672                 http_status(&hdr, 500, "Internal Server Error");
 673                 hdr_nocache(&hdr);
 674                 end_headers(&hdr);
 675         }
 676         exit(0); /* we successfully reported a failure ;-) */
 677 }
 678
 679 static int die_webcgi_recursing(void)
 680 {
 681         return dead++ > 1;
 682 }
 683
 684 static char* getdir(void)
 685 {
 686         struct strbuf buf = STRBUF_INIT;
 687         char *pathinfo = getenv("PATH_INFO");
 688         char *root = getenv("GIT_PROJECT_ROOT");
 689         char *path = getenv("PATH_TRANSLATED");
 690
 691         if (root && *root) {
 692                 if (!pathinfo || !*pathinfo)
 693                         die("GIT_PROJECT_ROOT is set but PATH_INFO is not");
 694                 if (daemon_avoid_alias(pathinfo))
 695                         die("'%s': aliased", pathinfo);
 696                 end_url_with_slash(&buf, root);
 697                 if (pathinfo[0] == '/')
 698                         pathinfo++;
 699                 strbuf_addstr(&buf, pathinfo);
 700                 return strbuf_detach(&buf, NULL);
 701         } else if (path && *path) {
 702                 return xstrdup(path);
 703         } else
 704                 die("No GIT_PROJECT_ROOT or PATH_TRANSLATED from server");
 705         return NULL;
 706 }
 707
 708 static struct service_cmd {
 709         const char *method;
 710         const char *pattern;
 711         void (*imp)(struct strbuf *, char *);
 712 } services[] = {
 713         {"GET", "/HEAD$", get_head},
 714         {"GET", "/info/refs$", get_info_refs},
 715         {"GET", "/objects/info/alternates$", get_text_file},
 716         {"GET", "/objects/info/http-alternates$", get_text_file},
 717         {"GET", "/objects/info/packs$", get_info_packs},
 718         {"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{38}$", get_loose_object},
 719         {"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{62}$", get_loose_object},
 720         {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.pack$", get_pack_file},
 721         {"GET", "/objects/pack/pack-[0-9a-f]{64}\\.pack$", get_pack_file},
 722         {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.idx$", get_idx_file},
 723         {"GET", "/objects/pack/pack-[0-9a-f]{64}\\.idx$", get_idx_file},
 724
 725         {"POST", "/git-upload-pack$", service_rpc},
 726         {"POST", "/git-receive-pack$", service_rpc}
 727 };
 728
 729 static int bad_request(struct strbuf *hdr, const struct service_cmd *c)
 730 {
 731         const char *proto = getenv("SERVER_PROTOCOL");
 732
 733         if (proto && !strcmp(proto, "HTTP/1.1")) {
 734                 http_status(hdr, 405, "Method Not Allowed");
 735                 hdr_str(hdr, "Allow",
 736                         !strcmp(c->method, "GET") ? "GET, HEAD" : c->method);
 737         } else
 738                 http_status(hdr, 400, "Bad Request");
 739         hdr_nocache(hdr);
 740         end_headers(hdr);
 741         return 0;
 742 }
 743
 744 int cmd_main(int argc UNUSED, const char **argv UNUSED)
 745 {
 746         char *method = getenv("REQUEST_METHOD");
 747         const char *proto_header;
 748         char *dir;
 749         struct service_cmd *cmd = NULL;
 750         char *cmd_arg = NULL;
 751         int i;
 752         struct strbuf hdr = STRBUF_INIT;
 753
 754         set_die_routine(die_webcgi);
 755         set_die_is_recursing_routine(die_webcgi_recursing);
 756
 757         if (!method)
 758                 die("No REQUEST_METHOD from server");
 759         if (!strcmp(method, "HEAD"))
 760                 method = "GET";
 761         dir = getdir();
 762
 763         for (i = 0; i < ARRAY_SIZE(services); i++) {
 764                 struct service_cmd *c = &services[i];
 765                 regex_t re;
 766                 regmatch_t out[1];
 767                 int ret;
 768
 769                 if (regcomp(&re, c->pattern, REG_EXTENDED))
 770                         die("Bogus regex in service table: %s", c->pattern);
 771                 ret = regexec(&re, dir, 1, out, 0);
 772                 regfree(&re);
 773
 774                 if (!ret) {
 775                         size_t n;
 776
 777                         if (strcmp(method, c->method))
 778                                 return bad_request(&hdr, c);
 779
 780                         cmd = c;
 781                         n = out[0].rm_eo - out[0].rm_so;
 782                         cmd_arg = xmemdupz(dir + out[0].rm_so + 1, n - 1);
 783                         dir[out[0].rm_so] = 0;
 784                         break;
 785                 }
 786         }
 787
 788         if (!cmd)
 789                 not_found(&hdr, "Request not supported: '%s'", dir);
 790
 791         setup_path();
 792         if (!enter_repo(dir, 0))
 793                 not_found(&hdr, "Not a git repository: '%s'", dir);
 794         if (!getenv("GIT_HTTP_EXPORT_ALL") &&
 795             access("git-daemon-export-ok", F_OK) )
 796                 not_found(&hdr, "Repository not exported: '%s'", dir);
 797         free(dir);
 798
 799         http_config();
 800         max_request_buffer = git_env_ulong("GIT_HTTP_MAX_REQUEST_BUFFER",
 801                                            max_request_buffer);
 802         proto_header = getenv("HTTP_GIT_PROTOCOL");
 803         if (proto_header)
 804                 setenv(GIT_PROTOCOL_ENVIRONMENT, proto_header, 0);
 805
 806         cmd->imp(&hdr, cmd_arg);
 807         free(cmd_arg);
 808         return 0;
 809 }