Merge branch 'js/range-diff-noprefix'
[git] / http-backend.c
1 #include "cache.h"
2 #include "config.h"
3 #include "repository.h"
4 #include "refs.h"
5 #include "pkt-line.h"
6 #include "object.h"
7 #include "tag.h"
8 #include "exec-cmd.h"
9 #include "run-command.h"
10 #include "string-list.h"
11 #include "url.h"
12 #include "argv-array.h"
13 #include "packfile.h"
14 #include "object-store.h"
15 #include "protocol.h"
16
17 static const char content_type[] = "Content-Type";
18 static const char content_length[] = "Content-Length";
19 static const char last_modified[] = "Last-Modified";
20 static int getanyfile = 1;
21 static unsigned long max_request_buffer = 10 * 1024 * 1024;
22
23 static struct string_list *query_params;
24
25 struct rpc_service {
26         const char *name;
27         const char *config_name;
28         unsigned buffer_input : 1;
29         signed enabled : 2;
30 };
31
32 static struct rpc_service rpc_service[] = {
33         { "upload-pack", "uploadpack", 1, 1 },
34         { "receive-pack", "receivepack", 0, -1 },
35 };
36
37 static struct string_list *get_parameters(void)
38 {
39         if (!query_params) {
40                 const char *query = getenv("QUERY_STRING");
41
42                 query_params = xcalloc(1, sizeof(*query_params));
43                 while (query && *query) {
44                         char *name = url_decode_parameter_name(&query);
45                         char *value = url_decode_parameter_value(&query);
46                         struct string_list_item *i;
47
48                         i = string_list_lookup(query_params, name);
49                         if (!i)
50                                 i = string_list_insert(query_params, name);
51                         else
52                                 free(i->util);
53                         i->util = value;
54                 }
55         }
56         return query_params;
57 }
58
59 static const char *get_parameter(const char *name)
60 {
61         struct string_list_item *i;
62         i = string_list_lookup(get_parameters(), name);
63         return i ? i->util : NULL;
64 }
65
66 __attribute__((format (printf, 2, 3)))
67 static void format_write(int fd, const char *fmt, ...)
68 {
69         static char buffer[1024];
70
71         va_list args;
72         unsigned n;
73
74         va_start(args, fmt);
75         n = vsnprintf(buffer, sizeof(buffer), fmt, args);
76         va_end(args);
77         if (n >= sizeof(buffer))
78                 die("protocol error: impossibly long line");
79
80         write_or_die(fd, buffer, n);
81 }
82
83 static void http_status(struct strbuf *hdr, unsigned code, const char *msg)
84 {
85         strbuf_addf(hdr, "Status: %u %s\r\n", code, msg);
86 }
87
88 static void hdr_str(struct strbuf *hdr, const char *name, const char *value)
89 {
90         strbuf_addf(hdr, "%s: %s\r\n", name, value);
91 }
92
93 static void hdr_int(struct strbuf *hdr, const char *name, uintmax_t value)
94 {
95         strbuf_addf(hdr, "%s: %" PRIuMAX "\r\n", name, value);
96 }
97
98 static void hdr_date(struct strbuf *hdr, const char *name, timestamp_t when)
99 {
100         const char *value = show_date(when, 0, DATE_MODE(RFC2822));
101         hdr_str(hdr, name, value);
102 }
103
104 static void hdr_nocache(struct strbuf *hdr)
105 {
106         hdr_str(hdr, "Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
107         hdr_str(hdr, "Pragma", "no-cache");
108         hdr_str(hdr, "Cache-Control", "no-cache, max-age=0, must-revalidate");
109 }
110
111 static void hdr_cache_forever(struct strbuf *hdr)
112 {
113         timestamp_t now = time(NULL);
114         hdr_date(hdr, "Date", now);
115         hdr_date(hdr, "Expires", now + 31536000);
116         hdr_str(hdr, "Cache-Control", "public, max-age=31536000");
117 }
118
119 static void end_headers(struct strbuf *hdr)
120 {
121         strbuf_add(hdr, "\r\n", 2);
122         write_or_die(1, hdr->buf, hdr->len);
123         strbuf_release(hdr);
124 }
125
126 __attribute__((format (printf, 2, 3)))
127 static NORETURN void not_found(struct strbuf *hdr, const char *err, ...)
128 {
129         va_list params;
130
131         http_status(hdr, 404, "Not Found");
132         hdr_nocache(hdr);
133         end_headers(hdr);
134
135         va_start(params, err);
136         if (err && *err)
137                 vfprintf(stderr, err, params);
138         va_end(params);
139         exit(0);
140 }
141
142 __attribute__((format (printf, 2, 3)))
143 static NORETURN void forbidden(struct strbuf *hdr, const char *err, ...)
144 {
145         va_list params;
146
147         http_status(hdr, 403, "Forbidden");
148         hdr_nocache(hdr);
149         end_headers(hdr);
150
151         va_start(params, err);
152         if (err && *err)
153                 vfprintf(stderr, err, params);
154         va_end(params);
155         exit(0);
156 }
157
158 static void select_getanyfile(struct strbuf *hdr)
159 {
160         if (!getanyfile)
161                 forbidden(hdr, "Unsupported service: getanyfile");
162 }
163
164 static void send_strbuf(struct strbuf *hdr,
165                         const char *type, struct strbuf *buf)
166 {
167         hdr_int(hdr, content_length, buf->len);
168         hdr_str(hdr, content_type, type);
169         end_headers(hdr);
170         write_or_die(1, buf->buf, buf->len);
171 }
172
173 static void send_local_file(struct strbuf *hdr, const char *the_type,
174                                 const char *name)
175 {
176         char *p = git_pathdup("%s", name);
177         size_t buf_alloc = 8192;
178         char *buf = xmalloc(buf_alloc);
179         int fd;
180         struct stat sb;
181
182         fd = open(p, O_RDONLY);
183         if (fd < 0)
184                 not_found(hdr, "Cannot open '%s': %s", p, strerror(errno));
185         if (fstat(fd, &sb) < 0)
186                 die_errno("Cannot stat '%s'", p);
187
188         hdr_int(hdr, content_length, sb.st_size);
189         hdr_str(hdr, content_type, the_type);
190         hdr_date(hdr, last_modified, sb.st_mtime);
191         end_headers(hdr);
192
193         for (;;) {
194                 ssize_t n = xread(fd, buf, buf_alloc);
195                 if (n < 0)
196                         die_errno("Cannot read '%s'", p);
197                 if (!n)
198                         break;
199                 write_or_die(1, buf, n);
200         }
201         close(fd);
202         free(buf);
203         free(p);
204 }
205
206 static void get_text_file(struct strbuf *hdr, char *name)
207 {
208         select_getanyfile(hdr);
209         hdr_nocache(hdr);
210         send_local_file(hdr, "text/plain", name);
211 }
212
213 static void get_loose_object(struct strbuf *hdr, char *name)
214 {
215         select_getanyfile(hdr);
216         hdr_cache_forever(hdr);
217         send_local_file(hdr, "application/x-git-loose-object", name);
218 }
219
220 static void get_pack_file(struct strbuf *hdr, char *name)
221 {
222         select_getanyfile(hdr);
223         hdr_cache_forever(hdr);
224         send_local_file(hdr, "application/x-git-packed-objects", name);
225 }
226
227 static void get_idx_file(struct strbuf *hdr, char *name)
228 {
229         select_getanyfile(hdr);
230         hdr_cache_forever(hdr);
231         send_local_file(hdr, "application/x-git-packed-objects-toc", name);
232 }
233
234 static void http_config(void)
235 {
236         int i, value = 0;
237         struct strbuf var = STRBUF_INIT;
238
239         git_config_get_bool("http.getanyfile", &getanyfile);
240         git_config_get_ulong("http.maxrequestbuffer", &max_request_buffer);
241
242         for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
243                 struct rpc_service *svc = &rpc_service[i];
244                 strbuf_addf(&var, "http.%s", svc->config_name);
245                 if (!git_config_get_bool(var.buf, &value))
246                         svc->enabled = value;
247                 strbuf_reset(&var);
248         }
249
250         strbuf_release(&var);
251 }
252
253 static struct rpc_service *select_service(struct strbuf *hdr, const char *name)
254 {
255         const char *svc_name;
256         struct rpc_service *svc = NULL;
257         int i;
258
259         if (!skip_prefix(name, "git-", &svc_name))
260                 forbidden(hdr, "Unsupported service: '%s'", name);
261
262         for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
263                 struct rpc_service *s = &rpc_service[i];
264                 if (!strcmp(s->name, svc_name)) {
265                         svc = s;
266                         break;
267                 }
268         }
269
270         if (!svc)
271                 forbidden(hdr, "Unsupported service: '%s'", name);
272
273         if (svc->enabled < 0) {
274                 const char *user = getenv("REMOTE_USER");
275                 svc->enabled = (user && *user) ? 1 : 0;
276         }
277         if (!svc->enabled)
278                 forbidden(hdr, "Service not enabled: '%s'", svc->name);
279         return svc;
280 }
281
282 static void write_to_child(int out, const unsigned char *buf, ssize_t len, const char *prog_name)
283 {
284         if (write_in_full(out, buf, len) < 0)
285                 die("unable to write to '%s'", prog_name);
286 }
287
288 /*
289  * This is basically strbuf_read(), except that if we
290  * hit max_request_buffer we die (we'd rather reject a
291  * maliciously large request than chew up infinite memory).
292  */
293 static ssize_t read_request_eof(int fd, unsigned char **out)
294 {
295         size_t len = 0, alloc = 8192;
296         unsigned char *buf = xmalloc(alloc);
297
298         if (max_request_buffer < alloc)
299                 max_request_buffer = alloc;
300
301         while (1) {
302                 ssize_t cnt;
303
304                 cnt = read_in_full(fd, buf + len, alloc - len);
305                 if (cnt < 0) {
306                         free(buf);
307                         return -1;
308                 }
309
310                 /* partial read from read_in_full means we hit EOF */
311                 len += cnt;
312                 if (len < alloc) {
313                         *out = buf;
314                         return len;
315                 }
316
317                 /* otherwise, grow and try again (if we can) */
318                 if (alloc == max_request_buffer)
319                         die("request was larger than our maximum size (%lu);"
320                             " try setting GIT_HTTP_MAX_REQUEST_BUFFER",
321                             max_request_buffer);
322
323                 alloc = alloc_nr(alloc);
324                 if (alloc > max_request_buffer)
325                         alloc = max_request_buffer;
326                 REALLOC_ARRAY(buf, alloc);
327         }
328 }
329
330 static ssize_t read_request_fixed_len(int fd, ssize_t req_len, unsigned char **out)
331 {
332         unsigned char *buf = NULL;
333         ssize_t cnt = 0;
334
335         if (max_request_buffer < req_len) {
336                 die("request was larger than our maximum size (%lu): "
337                     "%" PRIuMAX "; try setting GIT_HTTP_MAX_REQUEST_BUFFER",
338                     max_request_buffer, (uintmax_t)req_len);
339         }
340
341         buf = xmalloc(req_len);
342         cnt = read_in_full(fd, buf, req_len);
343         if (cnt < 0) {
344                 free(buf);
345                 return -1;
346         }
347         *out = buf;
348         return cnt;
349 }
350
351 static ssize_t get_content_length(void)
352 {
353         ssize_t val = -1;
354         const char *str = getenv("CONTENT_LENGTH");
355
356         if (str && *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                 argv_array_pushf(&cld.env_array, "GIT_COMMITTER_NAME=%s", user);
481         if (!getenv("GIT_COMMITTER_EMAIL"))
482                 argv_array_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 }