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 "path.h"
   8 #include "repository.h"
   9 #include "refs.h"
  10 #include "pkt-line.h"
  11 #include "object.h"
  12 #include "tag.h"
  13 #include "exec-cmd.h"
  14 #include "run-command.h"
  15 #include "string-list.h"
  16 #include "url.h"
  17 #include "strvec.h"
  18 #include "packfile.h"
  19 #include "object-store-ll.h"
  20 #include "protocol.h"
  21 #include "date.h"
  22 #include "wrapper.h"
  23 #include "write-or-die.h"
  24
  25 static const char content_type[] = "Content-Type";
  26 static const char content_length[] = "Content-Length";
  27 static const char last_modified[] = "Last-Modified";
  28 static int getanyfile = 1;
  29 static unsigned long max_request_buffer = 10 * 1024 * 1024;
  30
  31 static struct string_list *query_params;
  32
  33 struct rpc_service {
  34         const char *name;
  35         const char *config_name;
  36         unsigned buffer_input : 1;
  37         signed enabled : 2;
  38 };
  39
  40 static struct rpc_service rpc_service[] = {
  41         { "upload-pack", "uploadpack", 1, 1 },
  42         { "receive-pack", "receivepack", 0, -1 },
  43 };
  44
  45 static struct string_list *get_parameters(void)
  46 {
  47         if (!query_params) {
  48                 const char *query = getenv("QUERY_STRING");
  49
  50                 CALLOC_ARRAY(query_params, 1);
  51                 while (query && *query) {
  52                         char *name = url_decode_parameter_name(&query);
  53                         char *value = url_decode_parameter_value(&query);
  54                         struct string_list_item *i;
  55
  56                         i = string_list_lookup(query_params, name);
  57                         if (!i)
  58                                 i = string_list_insert(query_params, name);
  59                         else
  60                                 free(i->util);
  61                         i->util = value;
  62                 }
  63         }
  64         return query_params;
  65 }
  66
  67 static const char *get_parameter(const char *name)
  68 {
  69         struct string_list_item *i;
  70         i = string_list_lookup(get_parameters(), name);
  71         return i ? i->util : NULL;
  72 }
  73
  74 __attribute__((format (printf, 2, 3)))
  75 static void format_write(int fd, const char *fmt, ...)
  76 {
  77         static char buffer[1024];
  78
  79         va_list args;
  80         unsigned n;
  81
  82         va_start(args, fmt);
  83         n = vsnprintf(buffer, sizeof(buffer), fmt, args);
  84         va_end(args);
  85         if (n >= sizeof(buffer))
  86                 die("protocol error: impossibly long line");
  87
  88         write_or_die(fd, buffer, n);
  89 }
  90
  91 static void http_status(struct strbuf *hdr, unsigned code, const char *msg)
  92 {
  93         strbuf_addf(hdr, "Status: %u %s\r\n", code, msg);
  94 }
  95
  96 static void hdr_str(struct strbuf *hdr, const char *name, const char *value)
  97 {
  98         strbuf_addf(hdr, "%s: %s\r\n", name, value);
  99 }
 100
 101 static void hdr_int(struct strbuf *hdr, const char *name, uintmax_t value)
 102 {
 103         strbuf_addf(hdr, "%s: %" PRIuMAX "\r\n", name, value);
 104 }
 105
 106 static void hdr_date(struct strbuf *hdr, const char *name, timestamp_t when)
 107 {
 108         const char *value = show_date(when, 0, DATE_MODE(RFC2822));
 109         hdr_str(hdr, name, value);
 110 }
 111
 112 static void hdr_nocache(struct strbuf *hdr)
 113 {
 114         hdr_str(hdr, "Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
 115         hdr_str(hdr, "Pragma", "no-cache");
 116         hdr_str(hdr, "Cache-Control", "no-cache, max-age=0, must-revalidate");
 117 }
 118
 119 static void hdr_cache_forever(struct strbuf *hdr)
 120 {
 121         timestamp_t now = time(NULL);
 122         hdr_date(hdr, "Date", now);
 123         hdr_date(hdr, "Expires", now + 31536000);
 124         hdr_str(hdr, "Cache-Control", "public, max-age=31536000");
 125 }
 126
 127 static void end_headers(struct strbuf *hdr)
 128 {
 129         strbuf_add(hdr, "\r\n", 2);
 130         write_or_die(1, hdr->buf, hdr->len);
 131         strbuf_release(hdr);
 132 }
 133
 134 __attribute__((format (printf, 2, 3)))
 135 static NORETURN void not_found(struct strbuf *hdr, const char *err, ...)
 136 {
 137         va_list params;
 138
 139         http_status(hdr, 404, "Not Found");
 140         hdr_nocache(hdr);
 141         end_headers(hdr);
 142
 143         va_start(params, err);
 144         if (err && *err)
 145                 vfprintf(stderr, err, params);
 146         va_end(params);
 147         exit(0);
 148 }
 149
 150 __attribute__((format (printf, 2, 3)))
 151 static NORETURN void forbidden(struct strbuf *hdr, const char *err, ...)
 152 {
 153         va_list params;
 154
 155         http_status(hdr, 403, "Forbidden");
 156         hdr_nocache(hdr);
 157         end_headers(hdr);
 158
 159         va_start(params, err);
 160         if (err && *err)
 161                 vfprintf(stderr, err, params);
 162         va_end(params);
 163         exit(0);
 164 }
 165
 166 static void select_getanyfile(struct strbuf *hdr)
 167 {
 168         if (!getanyfile)
 169                 forbidden(hdr, "Unsupported service: getanyfile");
 170 }
 171
 172 static void send_strbuf(struct strbuf *hdr,
 173                         const char *type, struct strbuf *buf)
 174 {
 175         hdr_int(hdr, content_length, buf->len);
 176         hdr_str(hdr, content_type, type);
 177         end_headers(hdr);
 178         write_or_die(1, buf->buf, buf->len);
 179 }
 180
 181 static void send_local_file(struct strbuf *hdr, const char *the_type,
 182                                 const char *name)
 183 {
 184         char *p = git_pathdup("%s", name);
 185         size_t buf_alloc = 8192;
 186         char *buf = xmalloc(buf_alloc);
 187         int fd;
 188         struct stat sb;
 189
 190         fd = open(p, O_RDONLY);
 191         if (fd < 0)
 192                 not_found(hdr, "Cannot open '%s': %s", p, strerror(errno));
 193         if (fstat(fd, &sb) < 0)
 194                 die_errno("Cannot stat '%s'", p);
 195
 196         hdr_int(hdr, content_length, sb.st_size);
 197         hdr_str(hdr, content_type, the_type);
 198         hdr_date(hdr, last_modified, sb.st_mtime);
 199         end_headers(hdr);
 200
 201         for (;;) {
 202                 ssize_t n = xread(fd, buf, buf_alloc);
 203                 if (n < 0)
 204                         die_errno("Cannot read '%s'", p);
 205                 if (!n)
 206                         break;
 207                 write_or_die(1, buf, n);
 208         }
 209         close(fd);
 210         free(buf);
 211         free(p);
 212 }
 213
 214 static void get_text_file(struct strbuf *hdr, char *name)
 215 {
 216         select_getanyfile(hdr);
 217         hdr_nocache(hdr);
 218         send_local_file(hdr, "text/plain", name);
 219 }
 220
 221 static void get_loose_object(struct strbuf *hdr, char *name)
 222 {
 223         select_getanyfile(hdr);
 224         hdr_cache_forever(hdr);
 225         send_local_file(hdr, "application/x-git-loose-object", name);
 226 }
 227
 228 static void get_pack_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", name);
 233 }
 234
 235 static void get_idx_file(struct strbuf *hdr, char *name)
 236 {
 237         select_getanyfile(hdr);
 238         hdr_cache_forever(hdr);
 239         send_local_file(hdr, "application/x-git-packed-objects-toc", name);
 240 }
 241
 242 static void http_config(void)
 243 {
 244         int i, value = 0;
 245         struct strbuf var = STRBUF_INIT;
 246
 247         git_config_get_bool("http.getanyfile", &getanyfile);
 248         git_config_get_ulong("http.maxrequestbuffer", &max_request_buffer);
 249
 250         for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 251                 struct rpc_service *svc = &rpc_service[i];
 252                 strbuf_addf(&var, "http.%s", svc->config_name);
 253                 if (!git_config_get_bool(var.buf, &value))
 254                         svc->enabled = value;
 255                 strbuf_reset(&var);
 256         }
 257
 258         strbuf_release(&var);
 259 }
 260
 261 static struct rpc_service *select_service(struct strbuf *hdr, const char *name)
 262 {
 263         const char *svc_name;
 264         struct rpc_service *svc = NULL;
 265         int i;
 266
 267         if (!skip_prefix(name, "git-", &svc_name))
 268                 forbidden(hdr, "Unsupported service: '%s'", name);
 269
 270         for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 271                 struct rpc_service *s = &rpc_service[i];
 272                 if (!strcmp(s->name, svc_name)) {
 273                         svc = s;
 274                         break;
 275                 }
 276         }
 277
 278         if (!svc)
 279                 forbidden(hdr, "Unsupported service: '%s'", name);
 280
 281         if (svc->enabled < 0) {
 282                 const char *user = getenv("REMOTE_USER");
 283                 svc->enabled = (user && *user) ? 1 : 0;
 284         }
 285         if (!svc->enabled)
 286                 forbidden(hdr, "Service not enabled: '%s'", svc->name);
 287         return svc;
 288 }
 289
 290 static void write_to_child(int out, const unsigned char *buf, ssize_t len, const char *prog_name)
 291 {
 292         if (write_in_full(out, buf, len) < 0)
 293                 die("unable to write to '%s'", prog_name);
 294 }
 295
 296 /*
 297  * This is basically strbuf_read(), except that if we
 298  * hit max_request_buffer we die (we'd rather reject a
 299  * maliciously large request than chew up infinite memory).
 300  */
 301 static ssize_t read_request_eof(int fd, unsigned char **out)
 302 {
 303         size_t len = 0, alloc = 8192;
 304         unsigned char *buf = xmalloc(alloc);
 305
 306         if (max_request_buffer < alloc)
 307                 max_request_buffer = alloc;
 308
 309         while (1) {
 310                 ssize_t cnt;
 311
 312                 cnt = read_in_full(fd, buf + len, alloc - len);
 313                 if (cnt < 0) {
 314                         free(buf);
 315                         return -1;
 316                 }
 317
 318                 /* partial read from read_in_full means we hit EOF */
 319                 len += cnt;
 320                 if (len < alloc) {
 321                         *out = buf;
 322                         return len;
 323                 }
 324
 325                 /* otherwise, grow and try again (if we can) */
 326                 if (alloc == max_request_buffer)
 327                         die("request was larger than our maximum size (%lu);"
 328                             " try setting GIT_HTTP_MAX_REQUEST_BUFFER",
 329                             max_request_buffer);
 330
 331                 alloc = alloc_nr(alloc);
 332                 if (alloc > max_request_buffer)
 333                         alloc = max_request_buffer;
 334                 REALLOC_ARRAY(buf, alloc);
 335         }
 336 }
 337
 338 static ssize_t read_request_fixed_len(int fd, ssize_t req_len, unsigned char **out)
 339 {
 340         unsigned char *buf = NULL;
 341         ssize_t cnt = 0;
 342
 343         if (max_request_buffer < req_len) {
 344                 die("request was larger than our maximum size (%lu): "
 345                     "%" PRIuMAX "; try setting GIT_HTTP_MAX_REQUEST_BUFFER",
 346                     max_request_buffer, (uintmax_t)req_len);
 347         }
 348
 349         buf = xmalloc(req_len);
 350         cnt = read_in_full(fd, buf, req_len);
 351         if (cnt < 0) {
 352                 free(buf);
 353                 return -1;
 354         }
 355         *out = buf;
 356         return cnt;
 357 }
 358
 359 static ssize_t get_content_length(void)
 360 {
 361         ssize_t val = -1;
 362         const char *str = getenv("CONTENT_LENGTH");
 363
 364         if (str && *str && !git_parse_ssize_t(str, &val))
 365                 die("failed to parse CONTENT_LENGTH: %s", str);
 366         return val;
 367 }
 368
 369 static ssize_t read_request(int fd, unsigned char **out, ssize_t req_len)
 370 {
 371         if (req_len < 0)
 372                 return read_request_eof(fd, out);
 373         else
 374                 return read_request_fixed_len(fd, req_len, out);
 375 }
 376
 377 static void inflate_request(const char *prog_name, int out, int buffer_input, ssize_t req_len)
 378 {
 379         git_zstream stream;
 380         unsigned char *full_request = NULL;
 381         unsigned char in_buf[8192];
 382         unsigned char out_buf[8192];
 383         unsigned long cnt = 0;
 384         int req_len_defined = req_len >= 0;
 385         size_t req_remaining_len = req_len;
 386
 387         memset(&stream, 0, sizeof(stream));
 388         git_inflate_init_gzip_only(&stream);
 389
 390         while (1) {
 391                 ssize_t n;
 392
 393                 if (buffer_input) {
 394                         if (full_request)
 395                                 n = 0; /* nothing left to read */
 396                         else
 397                                 n = read_request(0, &full_request, req_len);
 398                         stream.next_in = full_request;
 399                 } else {
 400                         ssize_t buffer_len;
 401                         if (req_len_defined && req_remaining_len <= sizeof(in_buf))
 402                                 buffer_len = req_remaining_len;
 403                         else
 404                                 buffer_len = sizeof(in_buf);
 405                         n = xread(0, in_buf, buffer_len);
 406                         stream.next_in = in_buf;
 407                         if (req_len_defined && n > 0)
 408                                 req_remaining_len -= n;
 409                 }
 410
 411                 if (n <= 0)
 412                         die("request ended in the middle of the gzip stream");
 413                 stream.avail_in = n;
 414
 415                 while (0 < stream.avail_in) {
 416                         int ret;
 417
 418                         stream.next_out = out_buf;
 419                         stream.avail_out = sizeof(out_buf);
 420
 421                         ret = git_inflate(&stream, Z_NO_FLUSH);
 422                         if (ret != Z_OK && ret != Z_STREAM_END)
 423                                 die("zlib error inflating request, result %d", ret);
 424
 425                         n = stream.total_out - cnt;
 426                         write_to_child(out, out_buf, stream.total_out - cnt, prog_name);
 427                         cnt = stream.total_out;
 428
 429                         if (ret == Z_STREAM_END)
 430                                 goto done;
 431                 }
 432         }
 433
 434 done:
 435         git_inflate_end(&stream);
 436         close(out);
 437         free(full_request);
 438 }
 439
 440 static void copy_request(const char *prog_name, int out, ssize_t req_len)
 441 {
 442         unsigned char *buf;
 443         ssize_t n = read_request(0, &buf, req_len);
 444         if (n < 0)
 445                 die_errno("error reading request body");
 446         write_to_child(out, buf, n, prog_name);
 447         close(out);
 448         free(buf);
 449 }
 450
 451 static void pipe_fixed_length(const char *prog_name, int out, size_t req_len)
 452 {
 453         unsigned char buf[8192];
 454         size_t remaining_len = req_len;
 455
 456         while (remaining_len > 0) {
 457                 size_t chunk_length = remaining_len > sizeof(buf) ? sizeof(buf) : remaining_len;
 458                 ssize_t n = xread(0, buf, chunk_length);
 459                 if (n < 0)
 460                         die_errno("Reading request failed");
 461                 write_to_child(out, buf, n, prog_name);
 462                 remaining_len -= n;
 463         }
 464
 465         close(out);
 466 }
 467
 468 static void run_service(const char **argv, int buffer_input)
 469 {
 470         const char *encoding = getenv("HTTP_CONTENT_ENCODING");
 471         const char *user = getenv("REMOTE_USER");
 472         const char *host = getenv("REMOTE_ADDR");
 473         int gzipped_request = 0;
 474         struct child_process cld = CHILD_PROCESS_INIT;
 475         ssize_t req_len = get_content_length();
 476
 477         if (encoding && (!strcmp(encoding, "gzip") || !strcmp(encoding, "x-gzip")))
 478                 gzipped_request = 1;
 479
 480         if (!user || !*user)
 481                 user = "anonymous";
 482         if (!host || !*host)
 483                 host = "(none)";
 484
 485         if (!getenv("GIT_COMMITTER_NAME"))
 486                 strvec_pushf(&cld.env, "GIT_COMMITTER_NAME=%s", user);
 487         if (!getenv("GIT_COMMITTER_EMAIL"))
 488                 strvec_pushf(&cld.env,
 489                              "GIT_COMMITTER_EMAIL=%s@http.%s", user, host);
 490
 491         strvec_pushv(&cld.args, argv);
 492         if (buffer_input || gzipped_request || req_len >= 0)
 493                 cld.in = -1;
 494         cld.git_cmd = 1;
 495         cld.clean_on_exit = 1;
 496         cld.wait_after_clean = 1;
 497         if (start_command(&cld))
 498                 exit(1);
 499
 500         close(1);
 501         if (gzipped_request)
 502                 inflate_request(argv[0], cld.in, buffer_input, req_len);
 503         else if (buffer_input)
 504                 copy_request(argv[0], cld.in, req_len);
 505         else if (req_len >= 0)
 506                 pipe_fixed_length(argv[0], cld.in, req_len);
 507         else
 508                 close(0);
 509
 510         if (finish_command(&cld))
 511                 exit(1);
 512 }
 513
 514 static int show_text_ref(const char *name, const struct object_id *oid,
 515                          int flag UNUSED, void *cb_data)
 516 {
 517         const char *name_nons = strip_namespace(name);
 518         struct strbuf *buf = cb_data;
 519         struct object *o = parse_object(the_repository, oid);
 520         if (!o)
 521                 return 0;
 522
 523         strbuf_addf(buf, "%s\t%s\n", oid_to_hex(oid), name_nons);
 524         if (o->type == OBJ_TAG) {
 525                 o = deref_tag(the_repository, o, name, 0);
 526                 if (!o)
 527                         return 0;
 528                 strbuf_addf(buf, "%s\t%s^{}\n", oid_to_hex(&o->oid),
 529                             name_nons);
 530         }
 531         return 0;
 532 }
 533
 534 static void get_info_refs(struct strbuf *hdr, char *arg UNUSED)
 535 {
 536         const char *service_name = get_parameter("service");
 537         struct strbuf buf = STRBUF_INIT;
 538
 539         hdr_nocache(hdr);
 540
 541         if (service_name) {
 542                 const char *argv[] = {NULL /* service name */,
 543                         "--http-backend-info-refs",
 544                         ".", NULL};
 545                 struct rpc_service *svc = select_service(hdr, service_name);
 546
 547                 strbuf_addf(&buf, "application/x-git-%s-advertisement",
 548                         svc->name);
 549                 hdr_str(hdr, content_type, buf.buf);
 550                 end_headers(hdr);
 551
 552
 553                 if (determine_protocol_version_server() != protocol_v2) {
 554                         packet_write_fmt(1, "# service=git-%s\n", svc->name);
 555                         packet_flush(1);
 556                 }
 557
 558                 argv[0] = svc->name;
 559                 run_service(argv, 0);
 560
 561         } else {
 562                 select_getanyfile(hdr);
 563                 for_each_namespaced_ref(show_text_ref, &buf);
 564                 send_strbuf(hdr, "text/plain", &buf);
 565         }
 566         strbuf_release(&buf);
 567 }
 568
 569 static int show_head_ref(const char *refname, const struct object_id *oid,
 570                          int flag, void *cb_data)
 571 {
 572         struct strbuf *buf = cb_data;
 573
 574         if (flag & REF_ISSYMREF) {
 575                 const char *target = resolve_ref_unsafe(refname,
 576                                                         RESOLVE_REF_READING,
 577                                                         NULL, NULL);
 578
 579                 if (target)
 580                         strbuf_addf(buf, "ref: %s\n", strip_namespace(target));
 581         } else {
 582                 strbuf_addf(buf, "%s\n", oid_to_hex(oid));
 583         }
 584
 585         return 0;
 586 }
 587
 588 static void get_head(struct strbuf *hdr, char *arg UNUSED)
 589 {
 590         struct strbuf buf = STRBUF_INIT;
 591
 592         select_getanyfile(hdr);
 593         head_ref_namespaced(show_head_ref, &buf);
 594         send_strbuf(hdr, "text/plain", &buf);
 595         strbuf_release(&buf);
 596 }
 597
 598 static void get_info_packs(struct strbuf *hdr, char *arg UNUSED)
 599 {
 600         size_t objdirlen = strlen(get_object_directory());
 601         struct strbuf buf = STRBUF_INIT;
 602         struct packed_git *p;
 603         size_t cnt = 0;
 604
 605         select_getanyfile(hdr);
 606         for (p = get_all_packs(the_repository); p; p = p->next) {
 607                 if (p->pack_local)
 608                         cnt++;
 609         }
 610
 611         strbuf_grow(&buf, cnt * 53 + 2);
 612         for (p = get_all_packs(the_repository); p; p = p->next) {
 613                 if (p->pack_local)
 614                         strbuf_addf(&buf, "P %s\n", p->pack_name + objdirlen + 6);
 615         }
 616         strbuf_addch(&buf, '\n');
 617
 618         hdr_nocache(hdr);
 619         send_strbuf(hdr, "text/plain; charset=utf-8", &buf);
 620         strbuf_release(&buf);
 621 }
 622
 623 static void check_content_type(struct strbuf *hdr, const char *accepted_type)
 624 {
 625         const char *actual_type = getenv("CONTENT_TYPE");
 626
 627         if (!actual_type)
 628                 actual_type = "";
 629
 630         if (strcmp(actual_type, accepted_type)) {
 631                 http_status(hdr, 415, "Unsupported Media Type");
 632                 hdr_nocache(hdr);
 633                 end_headers(hdr);
 634                 format_write(1,
 635                         "Expected POST with Content-Type '%s',"
 636                         " but received '%s' instead.\n",
 637                         accepted_type, actual_type);
 638                 exit(0);
 639         }
 640 }
 641
 642 static void service_rpc(struct strbuf *hdr, char *service_name)
 643 {
 644         const char *argv[] = {NULL, "--stateless-rpc", ".", NULL};
 645         struct rpc_service *svc = select_service(hdr, service_name);
 646         struct strbuf buf = STRBUF_INIT;
 647
 648         strbuf_reset(&buf);
 649         strbuf_addf(&buf, "application/x-git-%s-request", svc->name);
 650         check_content_type(hdr, buf.buf);
 651
 652         hdr_nocache(hdr);
 653
 654         strbuf_reset(&buf);
 655         strbuf_addf(&buf, "application/x-git-%s-result", svc->name);
 656         hdr_str(hdr, content_type, buf.buf);
 657
 658         end_headers(hdr);
 659
 660         argv[0] = svc->name;
 661         run_service(argv, svc->buffer_input);
 662         strbuf_release(&buf);
 663 }
 664
 665 static int dead;
 666 static NORETURN void die_webcgi(const char *err, va_list params)
 667 {
 668         if (dead <= 1) {
 669                 struct strbuf hdr = STRBUF_INIT;
 670                 report_fn die_message_fn = get_die_message_routine();
 671
 672                 die_message_fn(err, params);
 673
 674                 http_status(&hdr, 500, "Internal Server Error");
 675                 hdr_nocache(&hdr);
 676                 end_headers(&hdr);
 677         }
 678         exit(0); /* we successfully reported a failure ;-) */
 679 }
 680
 681 static int die_webcgi_recursing(void)
 682 {
 683         return dead++ > 1;
 684 }
 685
 686 static char* getdir(void)
 687 {
 688         struct strbuf buf = STRBUF_INIT;
 689         char *pathinfo = getenv("PATH_INFO");
 690         char *root = getenv("GIT_PROJECT_ROOT");
 691         char *path = getenv("PATH_TRANSLATED");
 692
 693         if (root && *root) {
 694                 if (!pathinfo || !*pathinfo)
 695                         die("GIT_PROJECT_ROOT is set but PATH_INFO is not");
 696                 if (daemon_avoid_alias(pathinfo))
 697                         die("'%s': aliased", pathinfo);
 698                 end_url_with_slash(&buf, root);
 699                 if (pathinfo[0] == '/')
 700                         pathinfo++;
 701                 strbuf_addstr(&buf, pathinfo);
 702                 return strbuf_detach(&buf, NULL);
 703         } else if (path && *path) {
 704                 return xstrdup(path);
 705         } else
 706                 die("No GIT_PROJECT_ROOT or PATH_TRANSLATED from server");
 707         return NULL;
 708 }
 709
 710 static struct service_cmd {
 711         const char *method;
 712         const char *pattern;
 713         void (*imp)(struct strbuf *, char *);
 714 } services[] = {
 715         {"GET", "/HEAD$", get_head},
 716         {"GET", "/info/refs$", get_info_refs},
 717         {"GET", "/objects/info/alternates$", get_text_file},
 718         {"GET", "/objects/info/http-alternates$", get_text_file},
 719         {"GET", "/objects/info/packs$", get_info_packs},
 720         {"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{38}$", get_loose_object},
 721         {"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{62}$", get_loose_object},
 722         {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.pack$", get_pack_file},
 723         {"GET", "/objects/pack/pack-[0-9a-f]{64}\\.pack$", get_pack_file},
 724         {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.idx$", get_idx_file},
 725         {"GET", "/objects/pack/pack-[0-9a-f]{64}\\.idx$", get_idx_file},
 726
 727         {"POST", "/git-upload-pack$", service_rpc},
 728         {"POST", "/git-receive-pack$", service_rpc}
 729 };
 730
 731 static int bad_request(struct strbuf *hdr, const struct service_cmd *c)
 732 {
 733         const char *proto = getenv("SERVER_PROTOCOL");
 734
 735         if (proto && !strcmp(proto, "HTTP/1.1")) {
 736                 http_status(hdr, 405, "Method Not Allowed");
 737                 hdr_str(hdr, "Allow",
 738                         !strcmp(c->method, "GET") ? "GET, HEAD" : c->method);
 739         } else
 740                 http_status(hdr, 400, "Bad Request");
 741         hdr_nocache(hdr);
 742         end_headers(hdr);
 743         return 0;
 744 }
 745
 746 int cmd_main(int argc UNUSED, const char **argv UNUSED)
 747 {
 748         char *method = getenv("REQUEST_METHOD");
 749         const char *proto_header;
 750         char *dir;
 751         struct service_cmd *cmd = NULL;
 752         char *cmd_arg = NULL;
 753         int i;
 754         struct strbuf hdr = STRBUF_INIT;
 755
 756         set_die_routine(die_webcgi);
 757         set_die_is_recursing_routine(die_webcgi_recursing);
 758
 759         if (!method)
 760                 die("No REQUEST_METHOD from server");
 761         if (!strcmp(method, "HEAD"))
 762                 method = "GET";
 763         dir = getdir();
 764
 765         for (i = 0; i < ARRAY_SIZE(services); i++) {
 766                 struct service_cmd *c = &services[i];
 767                 regex_t re;
 768                 regmatch_t out[1];
 769                 int ret;
 770
 771                 if (regcomp(&re, c->pattern, REG_EXTENDED))
 772                         die("Bogus regex in service table: %s", c->pattern);
 773                 ret = regexec(&re, dir, 1, out, 0);
 774                 regfree(&re);
 775
 776                 if (!ret) {
 777                         size_t n;
 778
 779                         if (strcmp(method, c->method))
 780                                 return bad_request(&hdr, c);
 781
 782                         cmd = c;
 783                         n = out[0].rm_eo - out[0].rm_so;
 784                         cmd_arg = xmemdupz(dir + out[0].rm_so + 1, n - 1);
 785                         dir[out[0].rm_so] = 0;
 786                         break;
 787                 }
 788         }
 789
 790         if (!cmd)
 791                 not_found(&hdr, "Request not supported: '%s'", dir);
 792
 793         setup_path();
 794         if (!enter_repo(dir, 0))
 795                 not_found(&hdr, "Not a git repository: '%s'", dir);
 796         if (!getenv("GIT_HTTP_EXPORT_ALL") &&
 797             access("git-daemon-export-ok", F_OK) )
 798                 not_found(&hdr, "Repository not exported: '%s'", dir);
 799         free(dir);
 800
 801         http_config();
 802         max_request_buffer = git_env_ulong("GIT_HTTP_MAX_REQUEST_BUFFER",
 803                                            max_request_buffer);
 804         proto_header = getenv("HTTP_GIT_PROTOCOL");
 805         if (proto_header)
 806                 setenv(GIT_PROTOCOL_ENVIRONMENT, proto_header, 0);
 807
 808         cmd->imp(&hdr, cmd_arg);
 809         free(cmd_arg);
 810         return 0;
 811 }