http-backend.c

   1 #define USE_THE_REPOSITORY_VARIABLE
   2
   3 #include "git-compat-util.h"
   4 #include "config.h"
   5 #include "environment.h"
   6 #include "git-zlib.h"
   7 #include "hex.h"
   8 #include "path.h"
   9 #include "repository.h"
  10 #include "refs.h"
  11 #include "pkt-line.h"
  12 #include "object.h"
  13 #include "tag.h"
  14 #include "exec-cmd.h"
  15 #include "run-command.h"
  16 #include "string-list.h"
  17 #include "url.h"
  18 #include "strvec.h"
  19 #include "packfile.h"
  20 #include "object-store-ll.h"
  21 #include "protocol.h"
  22 #include "date.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         { "upload-archive", "uploadarchive", 0, -1 },
  44 };
  45
  46 static struct string_list *get_parameters(void)
  47 {
  48         if (!query_params) {
  49                 const char *query = getenv("QUERY_STRING");
  50
  51                 CALLOC_ARRAY(query_params, 1);
  52                 while (query && *query) {
  53                         char *name = url_decode_parameter_name(&query);
  54                         char *value = url_decode_parameter_value(&query);
  55                         struct string_list_item *i;
  56
  57                         i = string_list_lookup(query_params, name);
  58                         if (!i)
  59                                 i = string_list_insert(query_params, name);
  60                         else
  61                                 free(i->util);
  62                         i->util = value;
  63                 }
  64         }
  65         return query_params;
  66 }
  67
  68 static const char *get_parameter(const char *name)
  69 {
  70         struct string_list_item *i;
  71         i = string_list_lookup(get_parameters(), name);
  72         return i ? i->util : NULL;
  73 }
  74
  75 __attribute__((format (printf, 2, 3)))
  76 static void format_write(int fd, const char *fmt, ...)
  77 {
  78         static char buffer[1024];
  79
  80         va_list args;
  81         unsigned n;
  82
  83         va_start(args, fmt);
  84         n = vsnprintf(buffer, sizeof(buffer), fmt, args);
  85         va_end(args);
  86         if (n >= sizeof(buffer))
  87                 die("protocol error: impossibly long line");
  88
  89         write_or_die(fd, buffer, n);
  90 }
  91
  92 static void http_status(struct strbuf *hdr, unsigned code, const char *msg)
  93 {
  94         strbuf_addf(hdr, "Status: %u %s\r\n", code, msg);
  95 }
  96
  97 static void hdr_str(struct strbuf *hdr, const char *name, const char *value)
  98 {
  99         strbuf_addf(hdr, "%s: %s\r\n", name, value);
 100 }
 101
 102 static void hdr_int(struct strbuf *hdr, const char *name, uintmax_t value)
 103 {
 104         strbuf_addf(hdr, "%s: %" PRIuMAX "\r\n", name, value);
 105 }
 106
 107 static void hdr_date(struct strbuf *hdr, const char *name, timestamp_t when)
 108 {
 109         const char *value = show_date(when, 0, DATE_MODE(RFC2822));
 110         hdr_str(hdr, name, value);
 111 }
 112
 113 static void hdr_nocache(struct strbuf *hdr)
 114 {
 115         hdr_str(hdr, "Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
 116         hdr_str(hdr, "Pragma", "no-cache");
 117         hdr_str(hdr, "Cache-Control", "no-cache, max-age=0, must-revalidate");
 118 }
 119
 120 static void hdr_cache_forever(struct strbuf *hdr)
 121 {
 122         timestamp_t now = time(NULL);
 123         hdr_date(hdr, "Date", now);
 124         hdr_date(hdr, "Expires", now + 31536000);
 125         hdr_str(hdr, "Cache-Control", "public, max-age=31536000");
 126 }
 127
 128 static void end_headers(struct strbuf *hdr)
 129 {
 130         strbuf_add(hdr, "\r\n", 2);
 131         write_or_die(1, hdr->buf, hdr->len);
 132         strbuf_release(hdr);
 133 }
 134
 135 __attribute__((format (printf, 2, 3)))
 136 static NORETURN void not_found(struct strbuf *hdr, const char *err, ...)
 137 {
 138         va_list params;
 139
 140         http_status(hdr, 404, "Not Found");
 141         hdr_nocache(hdr);
 142         end_headers(hdr);
 143
 144         va_start(params, err);
 145         if (err && *err)
 146                 vfprintf(stderr, err, params);
 147         va_end(params);
 148         exit(0);
 149 }
 150
 151 __attribute__((format (printf, 2, 3)))
 152 static NORETURN void forbidden(struct strbuf *hdr, const char *err, ...)
 153 {
 154         va_list params;
 155
 156         http_status(hdr, 403, "Forbidden");
 157         hdr_nocache(hdr);
 158         end_headers(hdr);
 159
 160         va_start(params, err);
 161         if (err && *err)
 162                 vfprintf(stderr, err, params);
 163         va_end(params);
 164         exit(0);
 165 }
 166
 167 static void select_getanyfile(struct strbuf *hdr)
 168 {
 169         if (!getanyfile)
 170                 forbidden(hdr, "Unsupported service: getanyfile");
 171 }
 172
 173 static void send_strbuf(struct strbuf *hdr,
 174                         const char *type, struct strbuf *buf)
 175 {
 176         hdr_int(hdr, content_length, buf->len);
 177         hdr_str(hdr, content_type, type);
 178         end_headers(hdr);
 179         write_or_die(1, buf->buf, buf->len);
 180 }
 181
 182 static void send_local_file(struct strbuf *hdr, const char *the_type,
 183                                 const char *name)
 184 {
 185         char *p = git_pathdup("%s", name);
 186         size_t buf_alloc = 8192;
 187         char *buf = xmalloc(buf_alloc);
 188         int fd;
 189         struct stat sb;
 190
 191         fd = open(p, O_RDONLY);
 192         if (fd < 0)
 193                 not_found(hdr, "Cannot open '%s': %s", p, strerror(errno));
 194         if (fstat(fd, &sb) < 0)
 195                 die_errno("Cannot stat '%s'", p);
 196
 197         hdr_int(hdr, content_length, sb.st_size);
 198         hdr_str(hdr, content_type, the_type);
 199         hdr_date(hdr, last_modified, sb.st_mtime);
 200         end_headers(hdr);
 201
 202         for (;;) {
 203                 ssize_t n = xread(fd, buf, buf_alloc);
 204                 if (n < 0)
 205                         die_errno("Cannot read '%s'", p);
 206                 if (!n)
 207                         break;
 208                 write_or_die(1, buf, n);
 209         }
 210         close(fd);
 211         free(buf);
 212         free(p);
 213 }
 214
 215 static void get_text_file(struct strbuf *hdr, char *name)
 216 {
 217         select_getanyfile(hdr);
 218         hdr_nocache(hdr);
 219         send_local_file(hdr, "text/plain", name);
 220 }
 221
 222 static void get_loose_object(struct strbuf *hdr, char *name)
 223 {
 224         select_getanyfile(hdr);
 225         hdr_cache_forever(hdr);
 226         send_local_file(hdr, "application/x-git-loose-object", name);
 227 }
 228
 229 static void get_pack_file(struct strbuf *hdr, char *name)
 230 {
 231         select_getanyfile(hdr);
 232         hdr_cache_forever(hdr);
 233         send_local_file(hdr, "application/x-git-packed-objects", name);
 234 }
 235
 236 static void get_idx_file(struct strbuf *hdr, char *name)
 237 {
 238         select_getanyfile(hdr);
 239         hdr_cache_forever(hdr);
 240         send_local_file(hdr, "application/x-git-packed-objects-toc", name);
 241 }
 242
 243 static void http_config(void)
 244 {
 245         int i, value = 0;
 246         struct strbuf var = STRBUF_INIT;
 247
 248         git_config_get_bool("http.getanyfile", &getanyfile);
 249         git_config_get_ulong("http.maxrequestbuffer", &max_request_buffer);
 250
 251         for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 252                 struct rpc_service *svc = &rpc_service[i];
 253                 strbuf_addf(&var, "http.%s", svc->config_name);
 254                 if (!git_config_get_bool(var.buf, &value))
 255                         svc->enabled = value;
 256                 strbuf_reset(&var);
 257         }
 258
 259         strbuf_release(&var);
 260 }
 261
 262 static struct rpc_service *select_service(struct strbuf *hdr, const char *name)
 263 {
 264         const char *svc_name;
 265         struct rpc_service *svc = NULL;
 266         int i;
 267
 268         if (!skip_prefix(name, "git-", &svc_name))
 269                 forbidden(hdr, "Unsupported service: '%s'", name);
 270
 271         for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 272                 struct rpc_service *s = &rpc_service[i];
 273                 if (!strcmp(s->name, svc_name)) {
 274                         svc = s;
 275                         break;
 276                 }
 277         }
 278
 279         if (!svc)
 280                 forbidden(hdr, "Unsupported service: '%s'", name);
 281
 282         if (svc->enabled < 0) {
 283                 const char *user = getenv("REMOTE_USER");
 284                 svc->enabled = (user && *user) ? 1 : 0;
 285         }
 286         if (!svc->enabled)
 287                 forbidden(hdr, "Service not enabled: '%s'", svc->name);
 288         return svc;
 289 }
 290
 291 static void write_to_child(int out, const unsigned char *buf, ssize_t len, const char *prog_name)
 292 {
 293         if (write_in_full(out, buf, len) < 0)
 294                 die("unable to write to '%s'", prog_name);
 295 }
 296
 297 /*
 298  * This is basically strbuf_read(), except that if we
 299  * hit max_request_buffer we die (we'd rather reject a
 300  * maliciously large request than chew up infinite memory).
 301  */
 302 static ssize_t read_request_eof(int fd, unsigned char **out)
 303 {
 304         size_t len = 0, alloc = 8192;
 305         unsigned char *buf = xmalloc(alloc);
 306
 307         if (max_request_buffer < alloc)
 308                 max_request_buffer = alloc;
 309
 310         while (1) {
 311                 ssize_t cnt;
 312
 313                 cnt = read_in_full(fd, buf + len, alloc - len);
 314                 if (cnt < 0) {
 315                         free(buf);
 316                         return -1;
 317                 }
 318
 319                 /* partial read from read_in_full means we hit EOF */
 320                 len += cnt;
 321                 if (len < alloc) {
 322                         *out = buf;
 323                         return len;
 324                 }
 325
 326                 /* otherwise, grow and try again (if we can) */
 327                 if (alloc == max_request_buffer)
 328                         die("request was larger than our maximum size (%lu);"
 329                             " try setting GIT_HTTP_MAX_REQUEST_BUFFER",
 330                             max_request_buffer);
 331
 332                 alloc = alloc_nr(alloc);
 333                 if (alloc > max_request_buffer)
 334                         alloc = max_request_buffer;
 335                 REALLOC_ARRAY(buf, alloc);
 336         }
 337 }
 338
 339 static ssize_t read_request_fixed_len(int fd, ssize_t req_len, unsigned char **out)
 340 {
 341         unsigned char *buf = NULL;
 342         ssize_t cnt = 0;
 343
 344         if (max_request_buffer < req_len) {
 345                 die("request was larger than our maximum size (%lu): "
 346                     "%" PRIuMAX "; try setting GIT_HTTP_MAX_REQUEST_BUFFER",
 347                     max_request_buffer, (uintmax_t)req_len);
 348         }
 349
 350         buf = xmalloc(req_len);
 351         cnt = read_in_full(fd, buf, req_len);
 352         if (cnt < 0) {
 353                 free(buf);
 354                 return -1;
 355         }
 356         *out = buf;
 357         return cnt;
 358 }
 359
 360 static ssize_t get_content_length(void)
 361 {
 362         ssize_t val = -1;
 363         const char *str = getenv("CONTENT_LENGTH");
 364
 365         if (str && *str && !git_parse_ssize_t(str, &val))
 366                 die("failed to parse CONTENT_LENGTH: %s", str);
 367         return val;
 368 }
 369
 370 static ssize_t read_request(int fd, unsigned char **out, ssize_t req_len)
 371 {
 372         if (req_len < 0)
 373                 return read_request_eof(fd, out);
 374         else
 375                 return read_request_fixed_len(fd, req_len, out);
 376 }
 377
 378 static void inflate_request(const char *prog_name, int out, int buffer_input, ssize_t req_len)
 379 {
 380         git_zstream stream;
 381         unsigned char *full_request = NULL;
 382         unsigned char in_buf[8192];
 383         unsigned char out_buf[8192];
 384         unsigned long cnt = 0;
 385         int req_len_defined = req_len >= 0;
 386         size_t req_remaining_len = req_len;
 387
 388         memset(&stream, 0, sizeof(stream));
 389         git_inflate_init_gzip_only(&stream);
 390
 391         while (1) {
 392                 ssize_t n;
 393
 394                 if (buffer_input) {
 395                         if (full_request)
 396                                 n = 0; /* nothing left to read */
 397                         else
 398                                 n = read_request(0, &full_request, req_len);
 399                         stream.next_in = full_request;
 400                 } else {
 401                         ssize_t buffer_len;
 402                         if (req_len_defined && req_remaining_len <= sizeof(in_buf))
 403                                 buffer_len = req_remaining_len;
 404                         else
 405                                 buffer_len = sizeof(in_buf);
 406                         n = xread(0, in_buf, buffer_len);
 407                         stream.next_in = in_buf;
 408                         if (req_len_defined && n > 0)
 409                                 req_remaining_len -= n;
 410                 }
 411
 412                 if (n <= 0)
 413                         die("request ended in the middle of the gzip stream");
 414                 stream.avail_in = n;
 415
 416                 while (0 < stream.avail_in) {
 417                         int ret;
 418
 419                         stream.next_out = out_buf;
 420                         stream.avail_out = sizeof(out_buf);
 421
 422                         ret = git_inflate(&stream, Z_NO_FLUSH);
 423                         if (ret != Z_OK && ret != Z_STREAM_END)
 424                                 die("zlib error inflating request, result %d", ret);
 425
 426                         n = stream.total_out - cnt;
 427                         write_to_child(out, out_buf, stream.total_out - cnt, prog_name);
 428                         cnt = stream.total_out;
 429
 430                         if (ret == Z_STREAM_END)
 431                                 goto done;
 432                 }
 433         }
 434
 435 done:
 436         git_inflate_end(&stream);
 437         close(out);
 438         free(full_request);
 439 }
 440
 441 static void copy_request(const char *prog_name, int out, ssize_t req_len)
 442 {
 443         unsigned char *buf;
 444         ssize_t n = read_request(0, &buf, req_len);
 445         if (n < 0)
 446                 die_errno("error reading request body");
 447         write_to_child(out, buf, n, prog_name);
 448         close(out);
 449         free(buf);
 450 }
 451
 452 static void pipe_fixed_length(const char *prog_name, int out, size_t req_len)
 453 {
 454         unsigned char buf[8192];
 455         size_t remaining_len = req_len;
 456
 457         while (remaining_len > 0) {
 458                 size_t chunk_length = remaining_len > sizeof(buf) ? sizeof(buf) : remaining_len;
 459                 ssize_t n = xread(0, buf, chunk_length);
 460                 if (n < 0)
 461                         die_errno("Reading request failed");
 462                 write_to_child(out, buf, n, prog_name);
 463                 remaining_len -= n;
 464         }
 465
 466         close(out);
 467 }
 468
 469 static void run_service(const char **argv, int buffer_input)
 470 {
 471         const char *encoding = getenv("HTTP_CONTENT_ENCODING");
 472         const char *user = getenv("REMOTE_USER");
 473         const char *host = getenv("REMOTE_ADDR");
 474         int gzipped_request = 0;
 475         struct child_process cld = CHILD_PROCESS_INIT;
 476         ssize_t req_len = get_content_length();
 477
 478         if (encoding && (!strcmp(encoding, "gzip") || !strcmp(encoding, "x-gzip")))
 479                 gzipped_request = 1;
 480
 481         if (!user || !*user)
 482                 user = "anonymous";
 483         if (!host || !*host)
 484                 host = "(none)";
 485
 486         if (!getenv("GIT_COMMITTER_NAME"))
 487                 strvec_pushf(&cld.env, "GIT_COMMITTER_NAME=%s", user);
 488         if (!getenv("GIT_COMMITTER_EMAIL"))
 489                 strvec_pushf(&cld.env,
 490                              "GIT_COMMITTER_EMAIL=%s@http.%s", user, host);
 491
 492         strvec_pushv(&cld.args, argv);
 493         if (buffer_input || gzipped_request || req_len >= 0)
 494                 cld.in = -1;
 495         cld.git_cmd = 1;
 496         cld.clean_on_exit = 1;
 497         cld.wait_after_clean = 1;
 498         if (start_command(&cld))
 499                 exit(1);
 500
 501         close(1);
 502         if (gzipped_request)
 503                 inflate_request(argv[0], cld.in, buffer_input, req_len);
 504         else if (buffer_input)
 505                 copy_request(argv[0], cld.in, req_len);
 506         else if (req_len >= 0)
 507                 pipe_fixed_length(argv[0], cld.in, req_len);
 508         else
 509                 close(0);
 510
 511         if (finish_command(&cld))
 512                 exit(1);
 513 }
 514
 515 static int show_text_ref(const char *name, const struct object_id *oid,
 516                          int flag UNUSED, void *cb_data)
 517 {
 518         const char *name_nons = strip_namespace(name);
 519         struct strbuf *buf = cb_data;
 520         struct object *o = parse_object(the_repository, oid);
 521         if (!o)
 522                 return 0;
 523
 524         strbuf_addf(buf, "%s\t%s\n", oid_to_hex(oid), name_nons);
 525         if (o->type == OBJ_TAG) {
 526                 o = deref_tag(the_repository, o, name, 0);
 527                 if (!o)
 528                         return 0;
 529                 strbuf_addf(buf, "%s\t%s^{}\n", oid_to_hex(&o->oid),
 530                             name_nons);
 531         }
 532         return 0;
 533 }
 534
 535 static void get_info_refs(struct strbuf *hdr, char *arg UNUSED)
 536 {
 537         const char *service_name = get_parameter("service");
 538         struct strbuf buf = STRBUF_INIT;
 539
 540         hdr_nocache(hdr);
 541
 542         if (service_name) {
 543                 const char *argv[] = {NULL /* service name */,
 544                         "--http-backend-info-refs",
 545                         ".", NULL};
 546                 struct rpc_service *svc = select_service(hdr, service_name);
 547
 548                 strbuf_addf(&buf, "application/x-git-%s-advertisement",
 549                         svc->name);
 550                 hdr_str(hdr, content_type, buf.buf);
 551                 end_headers(hdr);
 552
 553
 554                 if (determine_protocol_version_server() != protocol_v2) {
 555                         packet_write_fmt(1, "# service=git-%s\n", svc->name);
 556                         packet_flush(1);
 557                 }
 558
 559                 argv[0] = svc->name;
 560                 run_service(argv, 0);
 561
 562         } else {
 563                 select_getanyfile(hdr);
 564                 refs_for_each_namespaced_ref(get_main_ref_store(the_repository),
 565                                              NULL, show_text_ref, &buf);
 566                 send_strbuf(hdr, "text/plain", &buf);
 567         }
 568         strbuf_release(&buf);
 569 }
 570
 571 static int show_head_ref(const char *refname, const struct object_id *oid,
 572                          int flag, void *cb_data)
 573 {
 574         struct strbuf *buf = cb_data;
 575
 576         if (flag & REF_ISSYMREF) {
 577                 const char *target = refs_resolve_ref_unsafe(get_main_ref_store(the_repository),
 578                                                              refname,
 579                                                              RESOLVE_REF_READING,
 580                                                              NULL, NULL);
 581
 582                 if (target)
 583                         strbuf_addf(buf, "ref: %s\n", strip_namespace(target));
 584         } else {
 585                 strbuf_addf(buf, "%s\n", oid_to_hex(oid));
 586         }
 587
 588         return 0;
 589 }
 590
 591 static void get_head(struct strbuf *hdr, char *arg UNUSED)
 592 {
 593         struct strbuf buf = STRBUF_INIT;
 594
 595         select_getanyfile(hdr);
 596         refs_head_ref_namespaced(get_main_ref_store(the_repository),
 597                                  show_head_ref, &buf);
 598         send_strbuf(hdr, "text/plain", &buf);
 599         strbuf_release(&buf);
 600 }
 601
 602 static void get_info_packs(struct strbuf *hdr, char *arg UNUSED)
 603 {
 604         size_t objdirlen = strlen(get_object_directory());
 605         struct strbuf buf = STRBUF_INIT;
 606         struct packed_git *p;
 607         size_t cnt = 0;
 608
 609         select_getanyfile(hdr);
 610         for (p = get_all_packs(the_repository); p; p = p->next) {
 611                 if (p->pack_local)
 612                         cnt++;
 613         }
 614
 615         strbuf_grow(&buf, cnt * 53 + 2);
 616         for (p = get_all_packs(the_repository); p; p = p->next) {
 617                 if (p->pack_local)
 618                         strbuf_addf(&buf, "P %s\n", p->pack_name + objdirlen + 6);
 619         }
 620         strbuf_addch(&buf, '\n');
 621
 622         hdr_nocache(hdr);
 623         send_strbuf(hdr, "text/plain; charset=utf-8", &buf);
 624         strbuf_release(&buf);
 625 }
 626
 627 static void check_content_type(struct strbuf *hdr, const char *accepted_type)
 628 {
 629         const char *actual_type = getenv("CONTENT_TYPE");
 630
 631         if (!actual_type)
 632                 actual_type = "";
 633
 634         if (strcmp(actual_type, accepted_type)) {
 635                 http_status(hdr, 415, "Unsupported Media Type");
 636                 hdr_nocache(hdr);
 637                 end_headers(hdr);
 638                 format_write(1,
 639                         "Expected POST with Content-Type '%s',"
 640                         " but received '%s' instead.\n",
 641                         accepted_type, actual_type);
 642                 exit(0);
 643         }
 644 }
 645
 646 static void service_rpc(struct strbuf *hdr, char *service_name)
 647 {
 648         struct strvec argv = STRVEC_INIT;
 649         struct rpc_service *svc = select_service(hdr, service_name);
 650         struct strbuf buf = STRBUF_INIT;
 651
 652         strvec_push(&argv, svc->name);
 653         if (strcmp(service_name, "git-upload-archive"))
 654                 strvec_push(&argv, "--stateless-rpc");
 655         strvec_push(&argv, ".");
 656
 657         strbuf_reset(&buf);
 658         strbuf_addf(&buf, "application/x-git-%s-request", svc->name);
 659         check_content_type(hdr, buf.buf);
 660
 661         hdr_nocache(hdr);
 662
 663         strbuf_reset(&buf);
 664         strbuf_addf(&buf, "application/x-git-%s-result", svc->name);
 665         hdr_str(hdr, content_type, buf.buf);
 666
 667         end_headers(hdr);
 668
 669         run_service(argv.v, svc->buffer_input);
 670         strbuf_release(&buf);
 671         strvec_clear(&argv);
 672 }
 673
 674 static int dead;
 675 static NORETURN void die_webcgi(const char *err, va_list params)
 676 {
 677         if (dead <= 1) {
 678                 struct strbuf hdr = STRBUF_INIT;
 679                 report_fn die_message_fn = get_die_message_routine();
 680
 681                 die_message_fn(err, params);
 682
 683                 http_status(&hdr, 500, "Internal Server Error");
 684                 hdr_nocache(&hdr);
 685                 end_headers(&hdr);
 686         }
 687         exit(0); /* we successfully reported a failure ;-) */
 688 }
 689
 690 static int die_webcgi_recursing(void)
 691 {
 692         return dead++ > 1;
 693 }
 694
 695 static char* getdir(void)
 696 {
 697         struct strbuf buf = STRBUF_INIT;
 698         char *pathinfo = getenv("PATH_INFO");
 699         char *root = getenv("GIT_PROJECT_ROOT");
 700         char *path = getenv("PATH_TRANSLATED");
 701
 702         if (root && *root) {
 703                 if (!pathinfo || !*pathinfo)
 704                         die("GIT_PROJECT_ROOT is set but PATH_INFO is not");
 705                 if (daemon_avoid_alias(pathinfo))
 706                         die("'%s': aliased", pathinfo);
 707                 end_url_with_slash(&buf, root);
 708                 if (pathinfo[0] == '/')
 709                         pathinfo++;
 710                 strbuf_addstr(&buf, pathinfo);
 711                 return strbuf_detach(&buf, NULL);
 712         } else if (path && *path) {
 713                 return xstrdup(path);
 714         } else
 715                 die("No GIT_PROJECT_ROOT or PATH_TRANSLATED from server");
 716         return NULL;
 717 }
 718
 719 static struct service_cmd {
 720         const char *method;
 721         const char *pattern;
 722         void (*imp)(struct strbuf *, char *);
 723 } services[] = {
 724         {"GET", "/HEAD$", get_head},
 725         {"GET", "/info/refs$", get_info_refs},
 726         {"GET", "/objects/info/alternates$", get_text_file},
 727         {"GET", "/objects/info/http-alternates$", get_text_file},
 728         {"GET", "/objects/info/packs$", get_info_packs},
 729         {"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{38}$", get_loose_object},
 730         {"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{62}$", get_loose_object},
 731         {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.pack$", get_pack_file},
 732         {"GET", "/objects/pack/pack-[0-9a-f]{64}\\.pack$", get_pack_file},
 733         {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.idx$", get_idx_file},
 734         {"GET", "/objects/pack/pack-[0-9a-f]{64}\\.idx$", get_idx_file},
 735
 736         {"POST", "/git-upload-pack$", service_rpc},
 737         {"POST", "/git-upload-archive$", service_rpc},
 738         {"POST", "/git-receive-pack$", service_rpc}
 739 };
 740
 741 static int bad_request(struct strbuf *hdr, const struct service_cmd *c)
 742 {
 743         const char *proto = getenv("SERVER_PROTOCOL");
 744
 745         if (proto && !strcmp(proto, "HTTP/1.1")) {
 746                 http_status(hdr, 405, "Method Not Allowed");
 747                 hdr_str(hdr, "Allow",
 748                         !strcmp(c->method, "GET") ? "GET, HEAD" : c->method);
 749         } else
 750                 http_status(hdr, 400, "Bad Request");
 751         hdr_nocache(hdr);
 752         end_headers(hdr);
 753         return 0;
 754 }
 755
 756 int cmd_main(int argc UNUSED, const char **argv UNUSED)
 757 {
 758         const char *method = getenv("REQUEST_METHOD");
 759         const char *proto_header;
 760         char *dir;
 761         struct service_cmd *cmd = NULL;
 762         char *cmd_arg = NULL;
 763         int i;
 764         struct strbuf hdr = STRBUF_INIT;
 765
 766         set_die_routine(die_webcgi);
 767         set_die_is_recursing_routine(die_webcgi_recursing);
 768
 769         if (!method)
 770                 die("No REQUEST_METHOD from server");
 771         if (!strcmp(method, "HEAD"))
 772                 method = "GET";
 773         dir = getdir();
 774
 775         for (i = 0; i < ARRAY_SIZE(services); i++) {
 776                 struct service_cmd *c = &services[i];
 777                 regex_t re;
 778                 regmatch_t out[1];
 779                 int ret;
 780
 781                 if (regcomp(&re, c->pattern, REG_EXTENDED))
 782                         die("Bogus regex in service table: %s", c->pattern);
 783                 ret = regexec(&re, dir, 1, out, 0);
 784                 regfree(&re);
 785
 786                 if (!ret) {
 787                         size_t n;
 788
 789                         if (strcmp(method, c->method))
 790                                 return bad_request(&hdr, c);
 791
 792                         cmd = c;
 793                         n = out[0].rm_eo - out[0].rm_so;
 794                         cmd_arg = xmemdupz(dir + out[0].rm_so + 1, n - 1);
 795                         dir[out[0].rm_so] = 0;
 796                         break;
 797                 }
 798         }
 799
 800         if (!cmd)
 801                 not_found(&hdr, "Request not supported: '%s'", dir);
 802
 803         setup_path();
 804         if (!enter_repo(dir, 0))
 805                 not_found(&hdr, "Not a git repository: '%s'", dir);
 806         if (!getenv("GIT_HTTP_EXPORT_ALL") &&
 807             access("git-daemon-export-ok", F_OK) )
 808                 not_found(&hdr, "Repository not exported: '%s'", dir);
 809         free(dir);
 810
 811         http_config();
 812         max_request_buffer = git_env_ulong("GIT_HTTP_MAX_REQUEST_BUFFER",
 813                                            max_request_buffer);
 814         proto_header = getenv("HTTP_GIT_PROTOCOL");
 815         if (proto_header)
 816                 setenv(GIT_PROTOCOL_ENVIRONMENT, proto_header, 0);
 817
 818         cmd->imp(&hdr, cmd_arg);
 819         free(cmd_arg);
 820         return 0;
 821 }