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 "strvec.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                 CALLOC_ARRAY(query_params, 1);
  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 && *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         int req_len_defined = req_len >= 0;
 377         size_t req_remaining_len = req_len;
 378
 379         memset(&stream, 0, sizeof(stream));
 380         git_inflate_init_gzip_only(&stream);
 381
 382         while (1) {
 383                 ssize_t n;
 384
 385                 if (buffer_input) {
 386                         if (full_request)
 387                                 n = 0; /* nothing left to read */
 388                         else
 389                                 n = read_request(0, &full_request, req_len);
 390                         stream.next_in = full_request;
 391                 } else {
 392                         ssize_t buffer_len;
 393                         if (req_len_defined && req_remaining_len <= sizeof(in_buf))
 394                                 buffer_len = req_remaining_len;
 395                         else
 396                                 buffer_len = sizeof(in_buf);
 397                         n = xread(0, in_buf, buffer_len);
 398                         stream.next_in = in_buf;
 399                         if (req_len_defined && n > 0)
 400                                 req_remaining_len -= n;
 401                 }
 402
 403                 if (n <= 0)
 404                         die("request ended in the middle of the gzip stream");
 405                 stream.avail_in = n;
 406
 407                 while (0 < stream.avail_in) {
 408                         int ret;
 409
 410                         stream.next_out = out_buf;
 411                         stream.avail_out = sizeof(out_buf);
 412
 413                         ret = git_inflate(&stream, Z_NO_FLUSH);
 414                         if (ret != Z_OK && ret != Z_STREAM_END)
 415                                 die("zlib error inflating request, result %d", ret);
 416
 417                         n = stream.total_out - cnt;
 418                         write_to_child(out, out_buf, stream.total_out - cnt, prog_name);
 419                         cnt = stream.total_out;
 420
 421                         if (ret == Z_STREAM_END)
 422                                 goto done;
 423                 }
 424         }
 425
 426 done:
 427         git_inflate_end(&stream);
 428         close(out);
 429         free(full_request);
 430 }
 431
 432 static void copy_request(const char *prog_name, int out, ssize_t req_len)
 433 {
 434         unsigned char *buf;
 435         ssize_t n = read_request(0, &buf, req_len);
 436         if (n < 0)
 437                 die_errno("error reading request body");
 438         write_to_child(out, buf, n, prog_name);
 439         close(out);
 440         free(buf);
 441 }
 442
 443 static void pipe_fixed_length(const char *prog_name, int out, size_t req_len)
 444 {
 445         unsigned char buf[8192];
 446         size_t remaining_len = req_len;
 447
 448         while (remaining_len > 0) {
 449                 size_t chunk_length = remaining_len > sizeof(buf) ? sizeof(buf) : remaining_len;
 450                 ssize_t n = xread(0, buf, chunk_length);
 451                 if (n < 0)
 452                         die_errno("Reading request failed");
 453                 write_to_child(out, buf, n, prog_name);
 454                 remaining_len -= n;
 455         }
 456
 457         close(out);
 458 }
 459
 460 static void run_service(const char **argv, int buffer_input)
 461 {
 462         const char *encoding = getenv("HTTP_CONTENT_ENCODING");
 463         const char *user = getenv("REMOTE_USER");
 464         const char *host = getenv("REMOTE_ADDR");
 465         int gzipped_request = 0;
 466         struct child_process cld = CHILD_PROCESS_INIT;
 467         ssize_t req_len = get_content_length();
 468
 469         if (encoding && !strcmp(encoding, "gzip"))
 470                 gzipped_request = 1;
 471         else if (encoding && !strcmp(encoding, "x-gzip"))
 472                 gzipped_request = 1;
 473
 474         if (!user || !*user)
 475                 user = "anonymous";
 476         if (!host || !*host)
 477                 host = "(none)";
 478
 479         if (!getenv("GIT_COMMITTER_NAME"))
 480                 strvec_pushf(&cld.env_array, "GIT_COMMITTER_NAME=%s", user);
 481         if (!getenv("GIT_COMMITTER_EMAIL"))
 482                 strvec_pushf(&cld.env_array,
 483                              "GIT_COMMITTER_EMAIL=%s@http.%s", user, host);
 484
 485         cld.argv = argv;
 486         if (buffer_input || gzipped_request || req_len >= 0)
 487                 cld.in = -1;
 488         cld.git_cmd = 1;
 489         cld.clean_on_exit = 1;
 490         cld.wait_after_clean = 1;
 491         if (start_command(&cld))
 492                 exit(1);
 493
 494         close(1);
 495         if (gzipped_request)
 496                 inflate_request(argv[0], cld.in, buffer_input, req_len);
 497         else if (buffer_input)
 498                 copy_request(argv[0], cld.in, req_len);
 499         else if (req_len >= 0)
 500                 pipe_fixed_length(argv[0], cld.in, req_len);
 501         else
 502                 close(0);
 503
 504         if (finish_command(&cld))
 505                 exit(1);
 506 }
 507
 508 static int show_text_ref(const char *name, const struct object_id *oid,
 509                          int flag, void *cb_data)
 510 {
 511         const char *name_nons = strip_namespace(name);
 512         struct strbuf *buf = cb_data;
 513         struct object *o = parse_object(the_repository, oid);
 514         if (!o)
 515                 return 0;
 516
 517         strbuf_addf(buf, "%s\t%s\n", oid_to_hex(oid), name_nons);
 518         if (o->type == OBJ_TAG) {
 519                 o = deref_tag(the_repository, o, name, 0);
 520                 if (!o)
 521                         return 0;
 522                 strbuf_addf(buf, "%s\t%s^{}\n", oid_to_hex(&o->oid),
 523                             name_nons);
 524         }
 525         return 0;
 526 }
 527
 528 static void get_info_refs(struct strbuf *hdr, char *arg)
 529 {
 530         const char *service_name = get_parameter("service");
 531         struct strbuf buf = STRBUF_INIT;
 532
 533         hdr_nocache(hdr);
 534
 535         if (service_name) {
 536                 const char *argv[] = {NULL /* service name */,
 537                         "--stateless-rpc", "--advertise-refs",
 538                         ".", NULL};
 539                 struct rpc_service *svc = select_service(hdr, service_name);
 540
 541                 strbuf_addf(&buf, "application/x-git-%s-advertisement",
 542                         svc->name);
 543                 hdr_str(hdr, content_type, buf.buf);
 544                 end_headers(hdr);
 545
 546
 547                 if (determine_protocol_version_server() != protocol_v2) {
 548                         packet_write_fmt(1, "# service=git-%s\n", svc->name);
 549                         packet_flush(1);
 550                 }
 551
 552                 argv[0] = svc->name;
 553                 run_service(argv, 0);
 554
 555         } else {
 556                 select_getanyfile(hdr);
 557                 for_each_namespaced_ref(show_text_ref, &buf);
 558                 send_strbuf(hdr, "text/plain", &buf);
 559         }
 560         strbuf_release(&buf);
 561 }
 562
 563 static int show_head_ref(const char *refname, const struct object_id *oid,
 564                          int flag, void *cb_data)
 565 {
 566         struct strbuf *buf = cb_data;
 567
 568         if (flag & REF_ISSYMREF) {
 569                 const char *target = resolve_ref_unsafe(refname,
 570                                                         RESOLVE_REF_READING,
 571                                                         NULL, NULL);
 572
 573                 if (target)
 574                         strbuf_addf(buf, "ref: %s\n", strip_namespace(target));
 575         } else {
 576                 strbuf_addf(buf, "%s\n", oid_to_hex(oid));
 577         }
 578
 579         return 0;
 580 }
 581
 582 static void get_head(struct strbuf *hdr, char *arg)
 583 {
 584         struct strbuf buf = STRBUF_INIT;
 585
 586         select_getanyfile(hdr);
 587         head_ref_namespaced(show_head_ref, &buf);
 588         send_strbuf(hdr, "text/plain", &buf);
 589         strbuf_release(&buf);
 590 }
 591
 592 static void get_info_packs(struct strbuf *hdr, char *arg)
 593 {
 594         size_t objdirlen = strlen(get_object_directory());
 595         struct strbuf buf = STRBUF_INIT;
 596         struct packed_git *p;
 597         size_t cnt = 0;
 598
 599         select_getanyfile(hdr);
 600         for (p = get_all_packs(the_repository); p; p = p->next) {
 601                 if (p->pack_local)
 602                         cnt++;
 603         }
 604
 605         strbuf_grow(&buf, cnt * 53 + 2);
 606         for (p = get_all_packs(the_repository); p; p = p->next) {
 607                 if (p->pack_local)
 608                         strbuf_addf(&buf, "P %s\n", p->pack_name + objdirlen + 6);
 609         }
 610         strbuf_addch(&buf, '\n');
 611
 612         hdr_nocache(hdr);
 613         send_strbuf(hdr, "text/plain; charset=utf-8", &buf);
 614         strbuf_release(&buf);
 615 }
 616
 617 static void check_content_type(struct strbuf *hdr, const char *accepted_type)
 618 {
 619         const char *actual_type = getenv("CONTENT_TYPE");
 620
 621         if (!actual_type)
 622                 actual_type = "";
 623
 624         if (strcmp(actual_type, accepted_type)) {
 625                 http_status(hdr, 415, "Unsupported Media Type");
 626                 hdr_nocache(hdr);
 627                 end_headers(hdr);
 628                 format_write(1,
 629                         "Expected POST with Content-Type '%s',"
 630                         " but received '%s' instead.\n",
 631                         accepted_type, actual_type);
 632                 exit(0);
 633         }
 634 }
 635
 636 static void service_rpc(struct strbuf *hdr, char *service_name)
 637 {
 638         const char *argv[] = {NULL, "--stateless-rpc", ".", NULL};
 639         struct rpc_service *svc = select_service(hdr, service_name);
 640         struct strbuf buf = STRBUF_INIT;
 641
 642         strbuf_reset(&buf);
 643         strbuf_addf(&buf, "application/x-git-%s-request", svc->name);
 644         check_content_type(hdr, buf.buf);
 645
 646         hdr_nocache(hdr);
 647
 648         strbuf_reset(&buf);
 649         strbuf_addf(&buf, "application/x-git-%s-result", svc->name);
 650         hdr_str(hdr, content_type, buf.buf);
 651
 652         end_headers(hdr);
 653
 654         argv[0] = svc->name;
 655         run_service(argv, svc->buffer_input);
 656         strbuf_release(&buf);
 657 }
 658
 659 static int dead;
 660 static NORETURN void die_webcgi(const char *err, va_list params)
 661 {
 662         if (dead <= 1) {
 663                 struct strbuf hdr = STRBUF_INIT;
 664
 665                 vreportf("fatal: ", err, params);
 666
 667                 http_status(&hdr, 500, "Internal Server Error");
 668                 hdr_nocache(&hdr);
 669                 end_headers(&hdr);
 670         }
 671         exit(0); /* we successfully reported a failure ;-) */
 672 }
 673
 674 static int die_webcgi_recursing(void)
 675 {
 676         return dead++ > 1;
 677 }
 678
 679 static char* getdir(void)
 680 {
 681         struct strbuf buf = STRBUF_INIT;
 682         char *pathinfo = getenv("PATH_INFO");
 683         char *root = getenv("GIT_PROJECT_ROOT");
 684         char *path = getenv("PATH_TRANSLATED");
 685
 686         if (root && *root) {
 687                 if (!pathinfo || !*pathinfo)
 688                         die("GIT_PROJECT_ROOT is set but PATH_INFO is not");
 689                 if (daemon_avoid_alias(pathinfo))
 690                         die("'%s': aliased", pathinfo);
 691                 end_url_with_slash(&buf, root);
 692                 if (pathinfo[0] == '/')
 693                         pathinfo++;
 694                 strbuf_addstr(&buf, pathinfo);
 695                 return strbuf_detach(&buf, NULL);
 696         } else if (path && *path) {
 697                 return xstrdup(path);
 698         } else
 699                 die("No GIT_PROJECT_ROOT or PATH_TRANSLATED from server");
 700         return NULL;
 701 }
 702
 703 static struct service_cmd {
 704         const char *method;
 705         const char *pattern;
 706         void (*imp)(struct strbuf *, char *);
 707 } services[] = {
 708         {"GET", "/HEAD$", get_head},
 709         {"GET", "/info/refs$", get_info_refs},
 710         {"GET", "/objects/info/alternates$", get_text_file},
 711         {"GET", "/objects/info/http-alternates$", get_text_file},
 712         {"GET", "/objects/info/packs$", get_info_packs},
 713         {"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{38}$", get_loose_object},
 714         {"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{62}$", get_loose_object},
 715         {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.pack$", get_pack_file},
 716         {"GET", "/objects/pack/pack-[0-9a-f]{64}\\.pack$", get_pack_file},
 717         {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.idx$", get_idx_file},
 718         {"GET", "/objects/pack/pack-[0-9a-f]{64}\\.idx$", get_idx_file},
 719
 720         {"POST", "/git-upload-pack$", service_rpc},
 721         {"POST", "/git-receive-pack$", service_rpc}
 722 };
 723
 724 static int bad_request(struct strbuf *hdr, const struct service_cmd *c)
 725 {
 726         const char *proto = getenv("SERVER_PROTOCOL");
 727
 728         if (proto && !strcmp(proto, "HTTP/1.1")) {
 729                 http_status(hdr, 405, "Method Not Allowed");
 730                 hdr_str(hdr, "Allow",
 731                         !strcmp(c->method, "GET") ? "GET, HEAD" : c->method);
 732         } else
 733                 http_status(hdr, 400, "Bad Request");
 734         hdr_nocache(hdr);
 735         end_headers(hdr);
 736         return 0;
 737 }
 738
 739 int cmd_main(int argc, const char **argv)
 740 {
 741         char *method = getenv("REQUEST_METHOD");
 742         char *dir;
 743         struct service_cmd *cmd = NULL;
 744         char *cmd_arg = NULL;
 745         int i;
 746         struct strbuf hdr = STRBUF_INIT;
 747
 748         set_die_routine(die_webcgi);
 749         set_die_is_recursing_routine(die_webcgi_recursing);
 750
 751         if (!method)
 752                 die("No REQUEST_METHOD from server");
 753         if (!strcmp(method, "HEAD"))
 754                 method = "GET";
 755         dir = getdir();
 756
 757         for (i = 0; i < ARRAY_SIZE(services); i++) {
 758                 struct service_cmd *c = &services[i];
 759                 regex_t re;
 760                 regmatch_t out[1];
 761
 762                 if (regcomp(&re, c->pattern, REG_EXTENDED))
 763                         die("Bogus regex in service table: %s", c->pattern);
 764                 if (!regexec(&re, dir, 1, out, 0)) {
 765                         size_t n;
 766
 767                         if (strcmp(method, c->method))
 768                                 return bad_request(&hdr, c);
 769
 770                         cmd = c;
 771                         n = out[0].rm_eo - out[0].rm_so;
 772                         cmd_arg = xmemdupz(dir + out[0].rm_so + 1, n - 1);
 773                         dir[out[0].rm_so] = 0;
 774                         break;
 775                 }
 776                 regfree(&re);
 777         }
 778
 779         if (!cmd)
 780                 not_found(&hdr, "Request not supported: '%s'", dir);
 781
 782         setup_path();
 783         if (!enter_repo(dir, 0))
 784                 not_found(&hdr, "Not a git repository: '%s'", dir);
 785         if (!getenv("GIT_HTTP_EXPORT_ALL") &&
 786             access("git-daemon-export-ok", F_OK) )
 787                 not_found(&hdr, "Repository not exported: '%s'", dir);
 788
 789         http_config();
 790         max_request_buffer = git_env_ulong("GIT_HTTP_MAX_REQUEST_BUFFER",
 791                                            max_request_buffer);
 792
 793         cmd->imp(&hdr, cmd_arg);
 794         return 0;
 795 }