http-backend.c

   1 #include "git-compat-util.h"
   2 #include "alloc.h"
   3 #include "config.h"
   4 #include "environment.h"
   5 #include "git-zlib.h"
   6 #include "hex.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.h"
  19 #include "protocol.h"
  20 #include "date.h"
  21 #include "wrapper.h"
  22 #include "write-or-die.h"
  23
  24 static const char content_type[] = "Content-Type";
  25 static const char content_length[] = "Content-Length";
  26 static const char last_modified[] = "Last-Modified";
  27 static int getanyfile = 1;
  28 static unsigned long max_request_buffer = 10 * 1024 * 1024;
  29
  30 static struct string_list *query_params;
  31
  32 struct rpc_service {
  33         const char *name;
  34         const char *config_name;
  35         unsigned buffer_input : 1;
  36         signed enabled : 2;
  37 };
  38
  39 static struct rpc_service rpc_service[] = {
  40         { "upload-pack", "uploadpack", 1, 1 },
  41         { "receive-pack", "receivepack", 0, -1 },
  42 };
  43
  44 static struct string_list *get_parameters(void)
  45 {
  46         if (!query_params) {
  47                 const char *query = getenv("QUERY_STRING");
  48
  49                 CALLOC_ARRAY(query_params, 1);
  50                 while (query && *query) {
  51                         char *name = url_decode_parameter_name(&query);
  52                         char *value = url_decode_parameter_value(&query);
  53                         struct string_list_item *i;
  54
  55                         i = string_list_lookup(query_params, name);
  56                         if (!i)
  57                                 i = string_list_insert(query_params, name);
  58                         else
  59                                 free(i->util);
  60                         i->util = value;
  61                 }
  62         }
  63         return query_params;
  64 }
  65
  66 static const char *get_parameter(const char *name)
  67 {
  68         struct string_list_item *i;
  69         i = string_list_lookup(get_parameters(), name);
  70         return i ? i->util : NULL;
  71 }
  72
  73 __attribute__((format (printf, 2, 3)))
  74 static void format_write(int fd, const char *fmt, ...)
  75 {
  76         static char buffer[1024];
  77
  78         va_list args;
  79         unsigned n;
  80
  81         va_start(args, fmt);
  82         n = vsnprintf(buffer, sizeof(buffer), fmt, args);
  83         va_end(args);
  84         if (n >= sizeof(buffer))
  85                 die("protocol error: impossibly long line");
  86
  87         write_or_die(fd, buffer, n);
  88 }
  89
  90 static void http_status(struct strbuf *hdr, unsigned code, const char *msg)
  91 {
  92         strbuf_addf(hdr, "Status: %u %s\r\n", code, msg);
  93 }
  94
  95 static void hdr_str(struct strbuf *hdr, const char *name, const char *value)
  96 {
  97         strbuf_addf(hdr, "%s: %s\r\n", name, value);
  98 }
  99
 100 static void hdr_int(struct strbuf *hdr, const char *name, uintmax_t value)
 101 {
 102         strbuf_addf(hdr, "%s: %" PRIuMAX "\r\n", name, value);
 103 }
 104
 105 static void hdr_date(struct strbuf *hdr, const char *name, timestamp_t when)
 106 {
 107         const char *value = show_date(when, 0, DATE_MODE(RFC2822));
 108         hdr_str(hdr, name, value);
 109 }
 110
 111 static void hdr_nocache(struct strbuf *hdr)
 112 {
 113         hdr_str(hdr, "Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
 114         hdr_str(hdr, "Pragma", "no-cache");
 115         hdr_str(hdr, "Cache-Control", "no-cache, max-age=0, must-revalidate");
 116 }
 117
 118 static void hdr_cache_forever(struct strbuf *hdr)
 119 {
 120         timestamp_t now = time(NULL);
 121         hdr_date(hdr, "Date", now);
 122         hdr_date(hdr, "Expires", now + 31536000);
 123         hdr_str(hdr, "Cache-Control", "public, max-age=31536000");
 124 }
 125
 126 static void end_headers(struct strbuf *hdr)
 127 {
 128         strbuf_add(hdr, "\r\n", 2);
 129         write_or_die(1, hdr->buf, hdr->len);
 130         strbuf_release(hdr);
 131 }
 132
 133 __attribute__((format (printf, 2, 3)))
 134 static NORETURN void not_found(struct strbuf *hdr, const char *err, ...)
 135 {
 136         va_list params;
 137
 138         http_status(hdr, 404, "Not Found");
 139         hdr_nocache(hdr);
 140         end_headers(hdr);
 141
 142         va_start(params, err);
 143         if (err && *err)
 144                 vfprintf(stderr, err, params);
 145         va_end(params);
 146         exit(0);
 147 }
 148
 149 __attribute__((format (printf, 2, 3)))
 150 static NORETURN void forbidden(struct strbuf *hdr, const char *err, ...)
 151 {
 152         va_list params;
 153
 154         http_status(hdr, 403, "Forbidden");
 155         hdr_nocache(hdr);
 156         end_headers(hdr);
 157
 158         va_start(params, err);
 159         if (err && *err)
 160                 vfprintf(stderr, err, params);
 161         va_end(params);
 162         exit(0);
 163 }
 164
 165 static void select_getanyfile(struct strbuf *hdr)
 166 {
 167         if (!getanyfile)
 168                 forbidden(hdr, "Unsupported service: getanyfile");
 169 }
 170
 171 static void send_strbuf(struct strbuf *hdr,
 172                         const char *type, struct strbuf *buf)
 173 {
 174         hdr_int(hdr, content_length, buf->len);
 175         hdr_str(hdr, content_type, type);
 176         end_headers(hdr);
 177         write_or_die(1, buf->buf, buf->len);
 178 }
 179
 180 static void send_local_file(struct strbuf *hdr, const char *the_type,
 181                                 const char *name)
 182 {
 183         char *p = git_pathdup("%s", name);
 184         size_t buf_alloc = 8192;
 185         char *buf = xmalloc(buf_alloc);
 186         int fd;
 187         struct stat sb;
 188
 189         fd = open(p, O_RDONLY);
 190         if (fd < 0)
 191                 not_found(hdr, "Cannot open '%s': %s", p, strerror(errno));
 192         if (fstat(fd, &sb) < 0)
 193                 die_errno("Cannot stat '%s'", p);
 194
 195         hdr_int(hdr, content_length, sb.st_size);
 196         hdr_str(hdr, content_type, the_type);
 197         hdr_date(hdr, last_modified, sb.st_mtime);
 198         end_headers(hdr);
 199
 200         for (;;) {
 201                 ssize_t n = xread(fd, buf, buf_alloc);
 202                 if (n < 0)
 203                         die_errno("Cannot read '%s'", p);
 204                 if (!n)
 205                         break;
 206                 write_or_die(1, buf, n);
 207         }
 208         close(fd);
 209         free(buf);
 210         free(p);
 211 }
 212
 213 static void get_text_file(struct strbuf *hdr, char *name)
 214 {
 215         select_getanyfile(hdr);
 216         hdr_nocache(hdr);
 217         send_local_file(hdr, "text/plain", name);
 218 }
 219
 220 static void get_loose_object(struct strbuf *hdr, char *name)
 221 {
 222         select_getanyfile(hdr);
 223         hdr_cache_forever(hdr);
 224         send_local_file(hdr, "application/x-git-loose-object", name);
 225 }
 226
 227 static void get_pack_file(struct strbuf *hdr, char *name)
 228 {
 229         select_getanyfile(hdr);
 230         hdr_cache_forever(hdr);
 231         send_local_file(hdr, "application/x-git-packed-objects", name);
 232 }
 233
 234 static void get_idx_file(struct strbuf *hdr, char *name)
 235 {
 236         select_getanyfile(hdr);
 237         hdr_cache_forever(hdr);
 238         send_local_file(hdr, "application/x-git-packed-objects-toc", name);
 239 }
 240
 241 static void http_config(void)
 242 {
 243         int i, value = 0;
 244         struct strbuf var = STRBUF_INIT;
 245
 246         git_config_get_bool("http.getanyfile", &getanyfile);
 247         git_config_get_ulong("http.maxrequestbuffer", &max_request_buffer);
 248
 249         for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 250                 struct rpc_service *svc = &rpc_service[i];
 251                 strbuf_addf(&var, "http.%s", svc->config_name);
 252                 if (!git_config_get_bool(var.buf, &value))
 253                         svc->enabled = value;
 254                 strbuf_reset(&var);
 255         }
 256
 257         strbuf_release(&var);
 258 }
 259
 260 static struct rpc_service *select_service(struct strbuf *hdr, const char *name)
 261 {
 262         const char *svc_name;
 263         struct rpc_service *svc = NULL;
 264         int i;
 265
 266         if (!skip_prefix(name, "git-", &svc_name))
 267                 forbidden(hdr, "Unsupported service: '%s'", name);
 268
 269         for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 270                 struct rpc_service *s = &rpc_service[i];
 271                 if (!strcmp(s->name, svc_name)) {
 272                         svc = s;
 273                         break;
 274                 }
 275         }
 276
 277         if (!svc)
 278                 forbidden(hdr, "Unsupported service: '%s'", name);
 279
 280         if (svc->enabled < 0) {
 281                 const char *user = getenv("REMOTE_USER");
 282                 svc->enabled = (user && *user) ? 1 : 0;
 283         }
 284         if (!svc->enabled)
 285                 forbidden(hdr, "Service not enabled: '%s'", svc->name);
 286         return svc;
 287 }
 288
 289 static void write_to_child(int out, const unsigned char *buf, ssize_t len, const char *prog_name)
 290 {
 291         if (write_in_full(out, buf, len) < 0)
 292                 die("unable to write to '%s'", prog_name);
 293 }
 294
 295 /*
 296  * This is basically strbuf_read(), except that if we
 297  * hit max_request_buffer we die (we'd rather reject a
 298  * maliciously large request than chew up infinite memory).
 299  */
 300 static ssize_t read_request_eof(int fd, unsigned char **out)
 301 {
 302         size_t len = 0, alloc = 8192;
 303         unsigned char *buf = xmalloc(alloc);
 304
 305         if (max_request_buffer < alloc)
 306                 max_request_buffer = alloc;
 307
 308         while (1) {
 309                 ssize_t cnt;
 310
 311                 cnt = read_in_full(fd, buf + len, alloc - len);
 312                 if (cnt < 0) {
 313                         free(buf);
 314                         return -1;
 315                 }
 316
 317                 /* partial read from read_in_full means we hit EOF */
 318                 len += cnt;
 319                 if (len < alloc) {
 320                         *out = buf;
 321                         return len;
 322                 }
 323
 324                 /* otherwise, grow and try again (if we can) */
 325                 if (alloc == max_request_buffer)
 326                         die("request was larger than our maximum size (%lu);"
 327                             " try setting GIT_HTTP_MAX_REQUEST_BUFFER",
 328                             max_request_buffer);
 329
 330                 alloc = alloc_nr(alloc);
 331                 if (alloc > max_request_buffer)
 332                         alloc = max_request_buffer;
 333                 REALLOC_ARRAY(buf, alloc);
 334         }
 335 }
 336
 337 static ssize_t read_request_fixed_len(int fd, ssize_t req_len, unsigned char **out)
 338 {
 339         unsigned char *buf = NULL;
 340         ssize_t cnt = 0;
 341
 342         if (max_request_buffer < req_len) {
 343                 die("request was larger than our maximum size (%lu): "
 344                     "%" PRIuMAX "; try setting GIT_HTTP_MAX_REQUEST_BUFFER",
 345                     max_request_buffer, (uintmax_t)req_len);
 346         }
 347
 348         buf = xmalloc(req_len);
 349         cnt = read_in_full(fd, buf, req_len);
 350         if (cnt < 0) {
 351                 free(buf);
 352                 return -1;
 353         }
 354         *out = buf;
 355         return cnt;
 356 }
 357
 358 static ssize_t get_content_length(void)
 359 {
 360         ssize_t val = -1;
 361         const char *str = getenv("CONTENT_LENGTH");
 362
 363         if (str && *str && !git_parse_ssize_t(str, &val))
 364                 die("failed to parse CONTENT_LENGTH: %s", str);
 365         return val;
 366 }
 367
 368 static ssize_t read_request(int fd, unsigned char **out, ssize_t req_len)
 369 {
 370         if (req_len < 0)
 371                 return read_request_eof(fd, out);
 372         else
 373                 return read_request_fixed_len(fd, req_len, out);
 374 }
 375
 376 static void inflate_request(const char *prog_name, int out, int buffer_input, ssize_t req_len)
 377 {
 378         git_zstream stream;
 379         unsigned char *full_request = NULL;
 380         unsigned char in_buf[8192];
 381         unsigned char out_buf[8192];
 382         unsigned long cnt = 0;
 383         int req_len_defined = req_len >= 0;
 384         size_t req_remaining_len = req_len;
 385
 386         memset(&stream, 0, sizeof(stream));
 387         git_inflate_init_gzip_only(&stream);
 388
 389         while (1) {
 390                 ssize_t n;
 391
 392                 if (buffer_input) {
 393                         if (full_request)
 394                                 n = 0; /* nothing left to read */
 395                         else
 396                                 n = read_request(0, &full_request, req_len);
 397                         stream.next_in = full_request;
 398                 } else {
 399                         ssize_t buffer_len;
 400                         if (req_len_defined && req_remaining_len <= sizeof(in_buf))
 401                                 buffer_len = req_remaining_len;
 402                         else
 403                                 buffer_len = sizeof(in_buf);
 404                         n = xread(0, in_buf, buffer_len);
 405                         stream.next_in = in_buf;
 406                         if (req_len_defined && n > 0)
 407                                 req_remaining_len -= n;
 408                 }
 409
 410                 if (n <= 0)
 411                         die("request ended in the middle of the gzip stream");
 412                 stream.avail_in = n;
 413
 414                 while (0 < stream.avail_in) {
 415                         int ret;
 416
 417                         stream.next_out = out_buf;
 418                         stream.avail_out = sizeof(out_buf);
 419
 420                         ret = git_inflate(&stream, Z_NO_FLUSH);
 421                         if (ret != Z_OK && ret != Z_STREAM_END)
 422                                 die("zlib error inflating request, result %d", ret);
 423
 424                         n = stream.total_out - cnt;
 425                         write_to_child(out, out_buf, stream.total_out - cnt, prog_name);
 426                         cnt = stream.total_out;
 427
 428                         if (ret == Z_STREAM_END)
 429                                 goto done;
 430                 }
 431         }
 432
 433 done:
 434         git_inflate_end(&stream);
 435         close(out);
 436         free(full_request);
 437 }
 438
 439 static void copy_request(const char *prog_name, int out, ssize_t req_len)
 440 {
 441         unsigned char *buf;
 442         ssize_t n = read_request(0, &buf, req_len);
 443         if (n < 0)
 444                 die_errno("error reading request body");
 445         write_to_child(out, buf, n, prog_name);
 446         close(out);
 447         free(buf);
 448 }
 449
 450 static void pipe_fixed_length(const char *prog_name, int out, size_t req_len)
 451 {
 452         unsigned char buf[8192];
 453         size_t remaining_len = req_len;
 454
 455         while (remaining_len > 0) {
 456                 size_t chunk_length = remaining_len > sizeof(buf) ? sizeof(buf) : remaining_len;
 457                 ssize_t n = xread(0, buf, chunk_length);
 458                 if (n < 0)
 459                         die_errno("Reading request failed");
 460                 write_to_child(out, buf, n, prog_name);
 461                 remaining_len -= n;
 462         }
 463
 464         close(out);
 465 }
 466
 467 static void run_service(const char **argv, int buffer_input)
 468 {
 469         const char *encoding = getenv("HTTP_CONTENT_ENCODING");
 470         const char *user = getenv("REMOTE_USER");
 471         const char *host = getenv("REMOTE_ADDR");
 472         int gzipped_request = 0;
 473         struct child_process cld = CHILD_PROCESS_INIT;
 474         ssize_t req_len = get_content_length();
 475
 476         if (encoding && (!strcmp(encoding, "gzip") || !strcmp(encoding, "x-gzip")))
 477                 gzipped_request = 1;
 478
 479         if (!user || !*user)
 480                 user = "anonymous";
 481         if (!host || !*host)
 482                 host = "(none)";
 483
 484         if (!getenv("GIT_COMMITTER_NAME"))
 485                 strvec_pushf(&cld.env, "GIT_COMMITTER_NAME=%s", user);
 486         if (!getenv("GIT_COMMITTER_EMAIL"))
 487                 strvec_pushf(&cld.env,
 488                              "GIT_COMMITTER_EMAIL=%s@http.%s", user, host);
 489
 490         strvec_pushv(&cld.args, argv);
 491         if (buffer_input || gzipped_request || req_len >= 0)
 492                 cld.in = -1;
 493         cld.git_cmd = 1;
 494         cld.clean_on_exit = 1;
 495         cld.wait_after_clean = 1;
 496         if (start_command(&cld))
 497                 exit(1);
 498
 499         close(1);
 500         if (gzipped_request)
 501                 inflate_request(argv[0], cld.in, buffer_input, req_len);
 502         else if (buffer_input)
 503                 copy_request(argv[0], cld.in, req_len);
 504         else if (req_len >= 0)
 505                 pipe_fixed_length(argv[0], cld.in, req_len);
 506         else
 507                 close(0);
 508
 509         if (finish_command(&cld))
 510                 exit(1);
 511 }
 512
 513 static int show_text_ref(const char *name, const struct object_id *oid,
 514                          int flag UNUSED, void *cb_data)
 515 {
 516         const char *name_nons = strip_namespace(name);
 517         struct strbuf *buf = cb_data;
 518         struct object *o = parse_object(the_repository, oid);
 519         if (!o)
 520                 return 0;
 521
 522         strbuf_addf(buf, "%s\t%s\n", oid_to_hex(oid), name_nons);
 523         if (o->type == OBJ_TAG) {
 524                 o = deref_tag(the_repository, o, name, 0);
 525                 if (!o)
 526                         return 0;
 527                 strbuf_addf(buf, "%s\t%s^{}\n", oid_to_hex(&o->oid),
 528                             name_nons);
 529         }
 530         return 0;
 531 }
 532
 533 static void get_info_refs(struct strbuf *hdr, char *arg UNUSED)
 534 {
 535         const char *service_name = get_parameter("service");
 536         struct strbuf buf = STRBUF_INIT;
 537
 538         hdr_nocache(hdr);
 539
 540         if (service_name) {
 541                 const char *argv[] = {NULL /* service name */,
 542                         "--http-backend-info-refs",
 543                         ".", NULL};
 544                 struct rpc_service *svc = select_service(hdr, service_name);
 545
 546                 strbuf_addf(&buf, "application/x-git-%s-advertisement",
 547                         svc->name);
 548                 hdr_str(hdr, content_type, buf.buf);
 549                 end_headers(hdr);
 550
 551
 552                 if (determine_protocol_version_server() != protocol_v2) {
 553                         packet_write_fmt(1, "# service=git-%s\n", svc->name);
 554                         packet_flush(1);
 555                 }
 556
 557                 argv[0] = svc->name;
 558                 run_service(argv, 0);
 559
 560         } else {
 561                 select_getanyfile(hdr);
 562                 for_each_namespaced_ref(show_text_ref, &buf);
 563                 send_strbuf(hdr, "text/plain", &buf);
 564         }
 565         strbuf_release(&buf);
 566 }
 567
 568 static int show_head_ref(const char *refname, const struct object_id *oid,
 569                          int flag, void *cb_data)
 570 {
 571         struct strbuf *buf = cb_data;
 572
 573         if (flag & REF_ISSYMREF) {
 574                 const char *target = resolve_ref_unsafe(refname,
 575                                                         RESOLVE_REF_READING,
 576                                                         NULL, NULL);
 577
 578                 if (target)
 579                         strbuf_addf(buf, "ref: %s\n", strip_namespace(target));
 580         } else {
 581                 strbuf_addf(buf, "%s\n", oid_to_hex(oid));
 582         }
 583
 584         return 0;
 585 }
 586
 587 static void get_head(struct strbuf *hdr, char *arg UNUSED)
 588 {
 589         struct strbuf buf = STRBUF_INIT;
 590
 591         select_getanyfile(hdr);
 592         head_ref_namespaced(show_head_ref, &buf);
 593         send_strbuf(hdr, "text/plain", &buf);
 594         strbuf_release(&buf);
 595 }
 596
 597 static void get_info_packs(struct strbuf *hdr, char *arg UNUSED)
 598 {
 599         size_t objdirlen = strlen(get_object_directory());
 600         struct strbuf buf = STRBUF_INIT;
 601         struct packed_git *p;
 602         size_t cnt = 0;
 603
 604         select_getanyfile(hdr);
 605         for (p = get_all_packs(the_repository); p; p = p->next) {
 606                 if (p->pack_local)
 607                         cnt++;
 608         }
 609
 610         strbuf_grow(&buf, cnt * 53 + 2);
 611         for (p = get_all_packs(the_repository); p; p = p->next) {
 612                 if (p->pack_local)
 613                         strbuf_addf(&buf, "P %s\n", p->pack_name + objdirlen + 6);
 614         }
 615         strbuf_addch(&buf, '\n');
 616
 617         hdr_nocache(hdr);
 618         send_strbuf(hdr, "text/plain; charset=utf-8", &buf);
 619         strbuf_release(&buf);
 620 }
 621
 622 static void check_content_type(struct strbuf *hdr, const char *accepted_type)
 623 {
 624         const char *actual_type = getenv("CONTENT_TYPE");
 625
 626         if (!actual_type)
 627                 actual_type = "";
 628
 629         if (strcmp(actual_type, accepted_type)) {
 630                 http_status(hdr, 415, "Unsupported Media Type");
 631                 hdr_nocache(hdr);
 632                 end_headers(hdr);
 633                 format_write(1,
 634                         "Expected POST with Content-Type '%s',"
 635                         " but received '%s' instead.\n",
 636                         accepted_type, actual_type);
 637                 exit(0);
 638         }
 639 }
 640
 641 static void service_rpc(struct strbuf *hdr, char *service_name)
 642 {
 643         const char *argv[] = {NULL, "--stateless-rpc", ".", NULL};
 644         struct rpc_service *svc = select_service(hdr, service_name);
 645         struct strbuf buf = STRBUF_INIT;
 646
 647         strbuf_reset(&buf);
 648         strbuf_addf(&buf, "application/x-git-%s-request", svc->name);
 649         check_content_type(hdr, buf.buf);
 650
 651         hdr_nocache(hdr);
 652
 653         strbuf_reset(&buf);
 654         strbuf_addf(&buf, "application/x-git-%s-result", svc->name);
 655         hdr_str(hdr, content_type, buf.buf);
 656
 657         end_headers(hdr);
 658
 659         argv[0] = svc->name;
 660         run_service(argv, svc->buffer_input);
 661         strbuf_release(&buf);
 662 }
 663
 664 static int dead;
 665 static NORETURN void die_webcgi(const char *err, va_list params)
 666 {
 667         if (dead <= 1) {
 668                 struct strbuf hdr = STRBUF_INIT;
 669                 report_fn die_message_fn = get_die_message_routine();
 670
 671                 die_message_fn(err, params);
 672
 673                 http_status(&hdr, 500, "Internal Server Error");
 674                 hdr_nocache(&hdr);
 675                 end_headers(&hdr);
 676         }
 677         exit(0); /* we successfully reported a failure ;-) */
 678 }
 679
 680 static int die_webcgi_recursing(void)
 681 {
 682         return dead++ > 1;
 683 }
 684
 685 static char* getdir(void)
 686 {
 687         struct strbuf buf = STRBUF_INIT;
 688         char *pathinfo = getenv("PATH_INFO");
 689         char *root = getenv("GIT_PROJECT_ROOT");
 690         char *path = getenv("PATH_TRANSLATED");
 691
 692         if (root && *root) {
 693                 if (!pathinfo || !*pathinfo)
 694                         die("GIT_PROJECT_ROOT is set but PATH_INFO is not");
 695                 if (daemon_avoid_alias(pathinfo))
 696                         die("'%s': aliased", pathinfo);
 697                 end_url_with_slash(&buf, root);
 698                 if (pathinfo[0] == '/')
 699                         pathinfo++;
 700                 strbuf_addstr(&buf, pathinfo);
 701                 return strbuf_detach(&buf, NULL);
 702         } else if (path && *path) {
 703                 return xstrdup(path);
 704         } else
 705                 die("No GIT_PROJECT_ROOT or PATH_TRANSLATED from server");
 706         return NULL;
 707 }
 708
 709 static struct service_cmd {
 710         const char *method;
 711         const char *pattern;
 712         void (*imp)(struct strbuf *, char *);
 713 } services[] = {
 714         {"GET", "/HEAD$", get_head},
 715         {"GET", "/info/refs$", get_info_refs},
 716         {"GET", "/objects/info/alternates$", get_text_file},
 717         {"GET", "/objects/info/http-alternates$", get_text_file},
 718         {"GET", "/objects/info/packs$", get_info_packs},
 719         {"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{38}$", get_loose_object},
 720         {"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{62}$", get_loose_object},
 721         {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.pack$", get_pack_file},
 722         {"GET", "/objects/pack/pack-[0-9a-f]{64}\\.pack$", get_pack_file},
 723         {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.idx$", get_idx_file},
 724         {"GET", "/objects/pack/pack-[0-9a-f]{64}\\.idx$", get_idx_file},
 725
 726         {"POST", "/git-upload-pack$", service_rpc},
 727         {"POST", "/git-receive-pack$", service_rpc}
 728 };
 729
 730 static int bad_request(struct strbuf *hdr, const struct service_cmd *c)
 731 {
 732         const char *proto = getenv("SERVER_PROTOCOL");
 733
 734         if (proto && !strcmp(proto, "HTTP/1.1")) {
 735                 http_status(hdr, 405, "Method Not Allowed");
 736                 hdr_str(hdr, "Allow",
 737                         !strcmp(c->method, "GET") ? "GET, HEAD" : c->method);
 738         } else
 739                 http_status(hdr, 400, "Bad Request");
 740         hdr_nocache(hdr);
 741         end_headers(hdr);
 742         return 0;
 743 }
 744
 745 int cmd_main(int argc UNUSED, const char **argv UNUSED)
 746 {
 747         char *method = getenv("REQUEST_METHOD");
 748         const char *proto_header;
 749         char *dir;
 750         struct service_cmd *cmd = NULL;
 751         char *cmd_arg = NULL;
 752         int i;
 753         struct strbuf hdr = STRBUF_INIT;
 754
 755         set_die_routine(die_webcgi);
 756         set_die_is_recursing_routine(die_webcgi_recursing);
 757
 758         if (!method)
 759                 die("No REQUEST_METHOD from server");
 760         if (!strcmp(method, "HEAD"))
 761                 method = "GET";
 762         dir = getdir();
 763
 764         for (i = 0; i < ARRAY_SIZE(services); i++) {
 765                 struct service_cmd *c = &services[i];
 766                 regex_t re;
 767                 regmatch_t out[1];
 768                 int ret;
 769
 770                 if (regcomp(&re, c->pattern, REG_EXTENDED))
 771                         die("Bogus regex in service table: %s", c->pattern);
 772                 ret = regexec(&re, dir, 1, out, 0);
 773                 regfree(&re);
 774
 775                 if (!ret) {
 776                         size_t n;
 777
 778                         if (strcmp(method, c->method))
 779                                 return bad_request(&hdr, c);
 780
 781                         cmd = c;
 782                         n = out[0].rm_eo - out[0].rm_so;
 783                         cmd_arg = xmemdupz(dir + out[0].rm_so + 1, n - 1);
 784                         dir[out[0].rm_so] = 0;
 785                         break;
 786                 }
 787         }
 788
 789         if (!cmd)
 790                 not_found(&hdr, "Request not supported: '%s'", dir);
 791
 792         setup_path();
 793         if (!enter_repo(dir, 0))
 794                 not_found(&hdr, "Not a git repository: '%s'", dir);
 795         if (!getenv("GIT_HTTP_EXPORT_ALL") &&
 796             access("git-daemon-export-ok", F_OK) )
 797                 not_found(&hdr, "Repository not exported: '%s'", dir);
 798         free(dir);
 799
 800         http_config();
 801         max_request_buffer = git_env_ulong("GIT_HTTP_MAX_REQUEST_BUFFER",
 802                                            max_request_buffer);
 803         proto_header = getenv("HTTP_GIT_PROTOCOL");
 804         if (proto_header)
 805                 setenv(GIT_PROTOCOL_ENVIRONMENT, proto_header, 0);
 806
 807         cmd->imp(&hdr, cmd_arg);
 808         free(cmd_arg);
 809         return 0;
 810 }