File: http-backend.c

package info (click to toggle)
git 1:2.20.1-2+deb10u3
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 45,676 kB
  • sloc: ansic: 210,769; sh: 180,432; perl: 29,102; tcl: 21,663; python: 6,143; makefile: 3,700; sed: 189; php: 120; asm: 98; csh: 45; ruby: 24; lisp: 12
file content (790 lines) | stat: -rw-r--r-- 19,106 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
#include "cache.h"
#include "config.h"
#include "repository.h"
#include "refs.h"
#include "pkt-line.h"
#include "object.h"
#include "tag.h"
#include "exec-cmd.h"
#include "run-command.h"
#include "string-list.h"
#include "url.h"
#include "argv-array.h"
#include "packfile.h"
#include "object-store.h"
#include "protocol.h"

static const char content_type[] = "Content-Type";
static const char content_length[] = "Content-Length";
static const char last_modified[] = "Last-Modified";
static int getanyfile = 1;
static unsigned long max_request_buffer = 10 * 1024 * 1024;

static struct string_list *query_params;

struct rpc_service {
	const char *name;
	const char *config_name;
	unsigned buffer_input : 1;
	signed enabled : 2;
};

static struct rpc_service rpc_service[] = {
	{ "upload-pack", "uploadpack", 1, 1 },
	{ "receive-pack", "receivepack", 0, -1 },
};

static struct string_list *get_parameters(void)
{
	if (!query_params) {
		const char *query = getenv("QUERY_STRING");

		query_params = xcalloc(1, sizeof(*query_params));
		while (query && *query) {
			char *name = url_decode_parameter_name(&query);
			char *value = url_decode_parameter_value(&query);
			struct string_list_item *i;

			i = string_list_lookup(query_params, name);
			if (!i)
				i = string_list_insert(query_params, name);
			else
				free(i->util);
			i->util = value;
		}
	}
	return query_params;
}

static const char *get_parameter(const char *name)
{
	struct string_list_item *i;
	i = string_list_lookup(get_parameters(), name);
	return i ? i->util : NULL;
}

__attribute__((format (printf, 2, 3)))
static void format_write(int fd, const char *fmt, ...)
{
	static char buffer[1024];

	va_list args;
	unsigned n;

	va_start(args, fmt);
	n = vsnprintf(buffer, sizeof(buffer), fmt, args);
	va_end(args);
	if (n >= sizeof(buffer))
		die("protocol error: impossibly long line");

	write_or_die(fd, buffer, n);
}

static void http_status(struct strbuf *hdr, unsigned code, const char *msg)
{
	strbuf_addf(hdr, "Status: %u %s\r\n", code, msg);
}

static void hdr_str(struct strbuf *hdr, const char *name, const char *value)
{
	strbuf_addf(hdr, "%s: %s\r\n", name, value);
}

static void hdr_int(struct strbuf *hdr, const char *name, uintmax_t value)
{
	strbuf_addf(hdr, "%s: %" PRIuMAX "\r\n", name, value);
}

static void hdr_date(struct strbuf *hdr, const char *name, timestamp_t when)
{
	const char *value = show_date(when, 0, DATE_MODE(RFC2822));
	hdr_str(hdr, name, value);
}

static void hdr_nocache(struct strbuf *hdr)
{
	hdr_str(hdr, "Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
	hdr_str(hdr, "Pragma", "no-cache");
	hdr_str(hdr, "Cache-Control", "no-cache, max-age=0, must-revalidate");
}

static void hdr_cache_forever(struct strbuf *hdr)
{
	timestamp_t now = time(NULL);
	hdr_date(hdr, "Date", now);
	hdr_date(hdr, "Expires", now + 31536000);
	hdr_str(hdr, "Cache-Control", "public, max-age=31536000");
}

static void end_headers(struct strbuf *hdr)
{
	strbuf_add(hdr, "\r\n", 2);
	write_or_die(1, hdr->buf, hdr->len);
	strbuf_release(hdr);
}

__attribute__((format (printf, 2, 3)))
static NORETURN void not_found(struct strbuf *hdr, const char *err, ...)
{
	va_list params;

	http_status(hdr, 404, "Not Found");
	hdr_nocache(hdr);
	end_headers(hdr);

	va_start(params, err);
	if (err && *err)
		vfprintf(stderr, err, params);
	va_end(params);
	exit(0);
}

__attribute__((format (printf, 2, 3)))
static NORETURN void forbidden(struct strbuf *hdr, const char *err, ...)
{
	va_list params;

	http_status(hdr, 403, "Forbidden");
	hdr_nocache(hdr);
	end_headers(hdr);

	va_start(params, err);
	if (err && *err)
		vfprintf(stderr, err, params);
	va_end(params);
	exit(0);
}

static void select_getanyfile(struct strbuf *hdr)
{
	if (!getanyfile)
		forbidden(hdr, "Unsupported service: getanyfile");
}

static void send_strbuf(struct strbuf *hdr,
			const char *type, struct strbuf *buf)
{
	hdr_int(hdr, content_length, buf->len);
	hdr_str(hdr, content_type, type);
	end_headers(hdr);
	write_or_die(1, buf->buf, buf->len);
}

static void send_local_file(struct strbuf *hdr, const char *the_type,
				const char *name)
{
	char *p = git_pathdup("%s", name);
	size_t buf_alloc = 8192;
	char *buf = xmalloc(buf_alloc);
	int fd;
	struct stat sb;

	fd = open(p, O_RDONLY);
	if (fd < 0)
		not_found(hdr, "Cannot open '%s': %s", p, strerror(errno));
	if (fstat(fd, &sb) < 0)
		die_errno("Cannot stat '%s'", p);

	hdr_int(hdr, content_length, sb.st_size);
	hdr_str(hdr, content_type, the_type);
	hdr_date(hdr, last_modified, sb.st_mtime);
	end_headers(hdr);

	for (;;) {
		ssize_t n = xread(fd, buf, buf_alloc);
		if (n < 0)
			die_errno("Cannot read '%s'", p);
		if (!n)
			break;
		write_or_die(1, buf, n);
	}
	close(fd);
	free(buf);
	free(p);
}

static void get_text_file(struct strbuf *hdr, char *name)
{
	select_getanyfile(hdr);
	hdr_nocache(hdr);
	send_local_file(hdr, "text/plain", name);
}

static void get_loose_object(struct strbuf *hdr, char *name)
{
	select_getanyfile(hdr);
	hdr_cache_forever(hdr);
	send_local_file(hdr, "application/x-git-loose-object", name);
}

static void get_pack_file(struct strbuf *hdr, char *name)
{
	select_getanyfile(hdr);
	hdr_cache_forever(hdr);
	send_local_file(hdr, "application/x-git-packed-objects", name);
}

static void get_idx_file(struct strbuf *hdr, char *name)
{
	select_getanyfile(hdr);
	hdr_cache_forever(hdr);
	send_local_file(hdr, "application/x-git-packed-objects-toc", name);
}

static void http_config(void)
{
	int i, value = 0;
	struct strbuf var = STRBUF_INIT;

	git_config_get_bool("http.getanyfile", &getanyfile);
	git_config_get_ulong("http.maxrequestbuffer", &max_request_buffer);

	for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
		struct rpc_service *svc = &rpc_service[i];
		strbuf_addf(&var, "http.%s", svc->config_name);
		if (!git_config_get_bool(var.buf, &value))
			svc->enabled = value;
		strbuf_reset(&var);
	}

	strbuf_release(&var);
}

static struct rpc_service *select_service(struct strbuf *hdr, const char *name)
{
	const char *svc_name;
	struct rpc_service *svc = NULL;
	int i;

	if (!skip_prefix(name, "git-", &svc_name))
		forbidden(hdr, "Unsupported service: '%s'", name);

	for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
		struct rpc_service *s = &rpc_service[i];
		if (!strcmp(s->name, svc_name)) {
			svc = s;
			break;
		}
	}

	if (!svc)
		forbidden(hdr, "Unsupported service: '%s'", name);

	if (svc->enabled < 0) {
		const char *user = getenv("REMOTE_USER");
		svc->enabled = (user && *user) ? 1 : 0;
	}
	if (!svc->enabled)
		forbidden(hdr, "Service not enabled: '%s'", svc->name);
	return svc;
}

static void write_to_child(int out, const unsigned char *buf, ssize_t len, const char *prog_name)
{
	if (write_in_full(out, buf, len) < 0)
		die("unable to write to '%s'", prog_name);
}

/*
 * This is basically strbuf_read(), except that if we
 * hit max_request_buffer we die (we'd rather reject a
 * maliciously large request than chew up infinite memory).
 */
static ssize_t read_request_eof(int fd, unsigned char **out)
{
	size_t len = 0, alloc = 8192;
	unsigned char *buf = xmalloc(alloc);

	if (max_request_buffer < alloc)
		max_request_buffer = alloc;

	while (1) {
		ssize_t cnt;

		cnt = read_in_full(fd, buf + len, alloc - len);
		if (cnt < 0) {
			free(buf);
			return -1;
		}

		/* partial read from read_in_full means we hit EOF */
		len += cnt;
		if (len < alloc) {
			*out = buf;
			return len;
		}

		/* otherwise, grow and try again (if we can) */
		if (alloc == max_request_buffer)
			die("request was larger than our maximum size (%lu);"
			    " try setting GIT_HTTP_MAX_REQUEST_BUFFER",
			    max_request_buffer);

		alloc = alloc_nr(alloc);
		if (alloc > max_request_buffer)
			alloc = max_request_buffer;
		REALLOC_ARRAY(buf, alloc);
	}
}

static ssize_t read_request_fixed_len(int fd, ssize_t req_len, unsigned char **out)
{
	unsigned char *buf = NULL;
	ssize_t cnt = 0;

	if (max_request_buffer < req_len) {
		die("request was larger than our maximum size (%lu): "
		    "%" PRIuMAX "; try setting GIT_HTTP_MAX_REQUEST_BUFFER",
		    max_request_buffer, (uintmax_t)req_len);
	}

	buf = xmalloc(req_len);
	cnt = read_in_full(fd, buf, req_len);
	if (cnt < 0) {
		free(buf);
		return -1;
	}
	*out = buf;
	return cnt;
}

static ssize_t get_content_length(void)
{
	ssize_t val = -1;
	const char *str = getenv("CONTENT_LENGTH");

	if (str && *str && !git_parse_ssize_t(str, &val))
		die("failed to parse CONTENT_LENGTH: %s", str);
	return val;
}

static ssize_t read_request(int fd, unsigned char **out, ssize_t req_len)
{
	if (req_len < 0)
		return read_request_eof(fd, out);
	else
		return read_request_fixed_len(fd, req_len, out);
}

static void inflate_request(const char *prog_name, int out, int buffer_input, ssize_t req_len)
{
	git_zstream stream;
	unsigned char *full_request = NULL;
	unsigned char in_buf[8192];
	unsigned char out_buf[8192];
	unsigned long cnt = 0;
	int req_len_defined = req_len >= 0;
	size_t req_remaining_len = req_len;

	memset(&stream, 0, sizeof(stream));
	git_inflate_init_gzip_only(&stream);

	while (1) {
		ssize_t n;

		if (buffer_input) {
			if (full_request)
				n = 0; /* nothing left to read */
			else
				n = read_request(0, &full_request, req_len);
			stream.next_in = full_request;
		} else {
			ssize_t buffer_len;
			if (req_len_defined && req_remaining_len <= sizeof(in_buf))
				buffer_len = req_remaining_len;
			else
				buffer_len = sizeof(in_buf);
			n = xread(0, in_buf, buffer_len);
			stream.next_in = in_buf;
			if (req_len_defined && n > 0)
				req_remaining_len -= n;
		}

		if (n <= 0)
			die("request ended in the middle of the gzip stream");
		stream.avail_in = n;

		while (0 < stream.avail_in) {
			int ret;

			stream.next_out = out_buf;
			stream.avail_out = sizeof(out_buf);

			ret = git_inflate(&stream, Z_NO_FLUSH);
			if (ret != Z_OK && ret != Z_STREAM_END)
				die("zlib error inflating request, result %d", ret);

			n = stream.total_out - cnt;
			write_to_child(out, out_buf, stream.total_out - cnt, prog_name);
			cnt = stream.total_out;

			if (ret == Z_STREAM_END)
				goto done;
		}
	}

done:
	git_inflate_end(&stream);
	close(out);
	free(full_request);
}

static void copy_request(const char *prog_name, int out, ssize_t req_len)
{
	unsigned char *buf;
	ssize_t n = read_request(0, &buf, req_len);
	if (n < 0)
		die_errno("error reading request body");
	write_to_child(out, buf, n, prog_name);
	close(out);
	free(buf);
}

static void pipe_fixed_length(const char *prog_name, int out, size_t req_len)
{
	unsigned char buf[8192];
	size_t remaining_len = req_len;

	while (remaining_len > 0) {
		size_t chunk_length = remaining_len > sizeof(buf) ? sizeof(buf) : remaining_len;
		ssize_t n = xread(0, buf, chunk_length);
		if (n < 0)
			die_errno("Reading request failed");
		write_to_child(out, buf, n, prog_name);
		remaining_len -= n;
	}

	close(out);
}

static void run_service(const char **argv, int buffer_input)
{
	const char *encoding = getenv("HTTP_CONTENT_ENCODING");
	const char *user = getenv("REMOTE_USER");
	const char *host = getenv("REMOTE_ADDR");
	int gzipped_request = 0;
	struct child_process cld = CHILD_PROCESS_INIT;
	ssize_t req_len = get_content_length();

	if (encoding && !strcmp(encoding, "gzip"))
		gzipped_request = 1;
	else if (encoding && !strcmp(encoding, "x-gzip"))
		gzipped_request = 1;

	if (!user || !*user)
		user = "anonymous";
	if (!host || !*host)
		host = "(none)";

	if (!getenv("GIT_COMMITTER_NAME"))
		argv_array_pushf(&cld.env_array, "GIT_COMMITTER_NAME=%s", user);
	if (!getenv("GIT_COMMITTER_EMAIL"))
		argv_array_pushf(&cld.env_array,
				 "GIT_COMMITTER_EMAIL=%s@http.%s", user, host);

	cld.argv = argv;
	if (buffer_input || gzipped_request || req_len >= 0)
		cld.in = -1;
	cld.git_cmd = 1;
	if (start_command(&cld))
		exit(1);

	close(1);
	if (gzipped_request)
		inflate_request(argv[0], cld.in, buffer_input, req_len);
	else if (buffer_input)
		copy_request(argv[0], cld.in, req_len);
	else if (req_len >= 0)
		pipe_fixed_length(argv[0], cld.in, req_len);
	else
		close(0);

	if (finish_command(&cld))
		exit(1);
}

static int show_text_ref(const char *name, const struct object_id *oid,
			 int flag, void *cb_data)
{
	const char *name_nons = strip_namespace(name);
	struct strbuf *buf = cb_data;
	struct object *o = parse_object(the_repository, oid);
	if (!o)
		return 0;

	strbuf_addf(buf, "%s\t%s\n", oid_to_hex(oid), name_nons);
	if (o->type == OBJ_TAG) {
		o = deref_tag(the_repository, o, name, 0);
		if (!o)
			return 0;
		strbuf_addf(buf, "%s\t%s^{}\n", oid_to_hex(&o->oid),
			    name_nons);
	}
	return 0;
}

static void get_info_refs(struct strbuf *hdr, char *arg)
{
	const char *service_name = get_parameter("service");
	struct strbuf buf = STRBUF_INIT;

	hdr_nocache(hdr);

	if (service_name) {
		const char *argv[] = {NULL /* service name */,
			"--stateless-rpc", "--advertise-refs",
			".", NULL};
		struct rpc_service *svc = select_service(hdr, service_name);

		strbuf_addf(&buf, "application/x-git-%s-advertisement",
			svc->name);
		hdr_str(hdr, content_type, buf.buf);
		end_headers(hdr);


		if (determine_protocol_version_server() != protocol_v2) {
			packet_write_fmt(1, "# service=git-%s\n", svc->name);
			packet_flush(1);
		}

		argv[0] = svc->name;
		run_service(argv, 0);

	} else {
		select_getanyfile(hdr);
		for_each_namespaced_ref(show_text_ref, &buf);
		send_strbuf(hdr, "text/plain", &buf);
	}
	strbuf_release(&buf);
}

static int show_head_ref(const char *refname, const struct object_id *oid,
			 int flag, void *cb_data)
{
	struct strbuf *buf = cb_data;

	if (flag & REF_ISSYMREF) {
		const char *target = resolve_ref_unsafe(refname,
							RESOLVE_REF_READING,
							NULL, NULL);

		if (target)
			strbuf_addf(buf, "ref: %s\n", strip_namespace(target));
	} else {
		strbuf_addf(buf, "%s\n", oid_to_hex(oid));
	}

	return 0;
}

static void get_head(struct strbuf *hdr, char *arg)
{
	struct strbuf buf = STRBUF_INIT;

	select_getanyfile(hdr);
	head_ref_namespaced(show_head_ref, &buf);
	send_strbuf(hdr, "text/plain", &buf);
	strbuf_release(&buf);
}

static void get_info_packs(struct strbuf *hdr, char *arg)
{
	size_t objdirlen = strlen(get_object_directory());
	struct strbuf buf = STRBUF_INIT;
	struct packed_git *p;
	size_t cnt = 0;

	select_getanyfile(hdr);
	for (p = get_all_packs(the_repository); p; p = p->next) {
		if (p->pack_local)
			cnt++;
	}

	strbuf_grow(&buf, cnt * 53 + 2);
	for (p = get_all_packs(the_repository); p; p = p->next) {
		if (p->pack_local)
			strbuf_addf(&buf, "P %s\n", p->pack_name + objdirlen + 6);
	}
	strbuf_addch(&buf, '\n');

	hdr_nocache(hdr);
	send_strbuf(hdr, "text/plain; charset=utf-8", &buf);
	strbuf_release(&buf);
}

static void check_content_type(struct strbuf *hdr, const char *accepted_type)
{
	const char *actual_type = getenv("CONTENT_TYPE");

	if (!actual_type)
		actual_type = "";

	if (strcmp(actual_type, accepted_type)) {
		http_status(hdr, 415, "Unsupported Media Type");
		hdr_nocache(hdr);
		end_headers(hdr);
		format_write(1,
			"Expected POST with Content-Type '%s',"
			" but received '%s' instead.\n",
			accepted_type, actual_type);
		exit(0);
	}
}

static void service_rpc(struct strbuf *hdr, char *service_name)
{
	const char *argv[] = {NULL, "--stateless-rpc", ".", NULL};
	struct rpc_service *svc = select_service(hdr, service_name);
	struct strbuf buf = STRBUF_INIT;

	strbuf_reset(&buf);
	strbuf_addf(&buf, "application/x-git-%s-request", svc->name);
	check_content_type(hdr, buf.buf);

	hdr_nocache(hdr);

	strbuf_reset(&buf);
	strbuf_addf(&buf, "application/x-git-%s-result", svc->name);
	hdr_str(hdr, content_type, buf.buf);

	end_headers(hdr);

	argv[0] = svc->name;
	run_service(argv, svc->buffer_input);
	strbuf_release(&buf);
}

static int dead;
static NORETURN void die_webcgi(const char *err, va_list params)
{
	if (dead <= 1) {
		struct strbuf hdr = STRBUF_INIT;

		vreportf("fatal: ", err, params);

		http_status(&hdr, 500, "Internal Server Error");
		hdr_nocache(&hdr);
		end_headers(&hdr);
	}
	exit(0); /* we successfully reported a failure ;-) */
}

static int die_webcgi_recursing(void)
{
	return dead++ > 1;
}

static char* getdir(void)
{
	struct strbuf buf = STRBUF_INIT;
	char *pathinfo = getenv("PATH_INFO");
	char *root = getenv("GIT_PROJECT_ROOT");
	char *path = getenv("PATH_TRANSLATED");

	if (root && *root) {
		if (!pathinfo || !*pathinfo)
			die("GIT_PROJECT_ROOT is set but PATH_INFO is not");
		if (daemon_avoid_alias(pathinfo))
			die("'%s': aliased", pathinfo);
		end_url_with_slash(&buf, root);
		if (pathinfo[0] == '/')
			pathinfo++;
		strbuf_addstr(&buf, pathinfo);
		return strbuf_detach(&buf, NULL);
	} else if (path && *path) {
		return xstrdup(path);
	} else
		die("No GIT_PROJECT_ROOT or PATH_TRANSLATED from server");
	return NULL;
}

static struct service_cmd {
	const char *method;
	const char *pattern;
	void (*imp)(struct strbuf *, char *);
} services[] = {
	{"GET", "/HEAD$", get_head},
	{"GET", "/info/refs$", get_info_refs},
	{"GET", "/objects/info/alternates$", get_text_file},
	{"GET", "/objects/info/http-alternates$", get_text_file},
	{"GET", "/objects/info/packs$", get_info_packs},
	{"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{38}$", get_loose_object},
	{"GET", "/objects/pack/pack-[0-9a-f]{40}\\.pack$", get_pack_file},
	{"GET", "/objects/pack/pack-[0-9a-f]{40}\\.idx$", get_idx_file},

	{"POST", "/git-upload-pack$", service_rpc},
	{"POST", "/git-receive-pack$", service_rpc}
};

static int bad_request(struct strbuf *hdr, const struct service_cmd *c)
{
	const char *proto = getenv("SERVER_PROTOCOL");

	if (proto && !strcmp(proto, "HTTP/1.1")) {
		http_status(hdr, 405, "Method Not Allowed");
		hdr_str(hdr, "Allow",
			!strcmp(c->method, "GET") ? "GET, HEAD" : c->method);
	} else
		http_status(hdr, 400, "Bad Request");
	hdr_nocache(hdr);
	end_headers(hdr);
	return 0;
}

int cmd_main(int argc, const char **argv)
{
	char *method = getenv("REQUEST_METHOD");
	char *dir;
	struct service_cmd *cmd = NULL;
	char *cmd_arg = NULL;
	int i;
	struct strbuf hdr = STRBUF_INIT;

	set_die_routine(die_webcgi);
	set_die_is_recursing_routine(die_webcgi_recursing);

	if (!method)
		die("No REQUEST_METHOD from server");
	if (!strcmp(method, "HEAD"))
		method = "GET";
	dir = getdir();

	for (i = 0; i < ARRAY_SIZE(services); i++) {
		struct service_cmd *c = &services[i];
		regex_t re;
		regmatch_t out[1];

		if (regcomp(&re, c->pattern, REG_EXTENDED))
			die("Bogus regex in service table: %s", c->pattern);
		if (!regexec(&re, dir, 1, out, 0)) {
			size_t n;

			if (strcmp(method, c->method))
				return bad_request(&hdr, c);

			cmd = c;
			n = out[0].rm_eo - out[0].rm_so;
			cmd_arg = xmemdupz(dir + out[0].rm_so + 1, n - 1);
			dir[out[0].rm_so] = 0;
			break;
		}
		regfree(&re);
	}

	if (!cmd)
		not_found(&hdr, "Request not supported: '%s'", dir);

	setup_path();
	if (!enter_repo(dir, 0))
		not_found(&hdr, "Not a git repository: '%s'", dir);
	if (!getenv("GIT_HTTP_EXPORT_ALL") &&
	    access("git-daemon-export-ok", F_OK) )
		not_found(&hdr, "Repository not exported: '%s'", dir);

	http_config();
	max_request_buffer = git_env_ulong("GIT_HTTP_MAX_REQUEST_BUFFER",
					   max_request_buffer);

	cmd->imp(&hdr, cmd_arg);
	return 0;
}