http-backend.c

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