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