about summary refs log tree commit diff
path: root/third_party/git/http-backend.c
diff options
context:
space:
mode:
authorVincent Ambo <Vincent Ambo>2020-01-11T23·36+0000
committerVincent Ambo <Vincent Ambo>2020-01-11T23·40+0000
commit7ef0d62730840ded097b524104cc0a0904591a63 (patch)
treea670f96103667aeca4789a95d94ca0dff550c4ce /third_party/git/http-backend.c
parent6a2a3007077818e24a3d56fc492ada9206a10cf0 (diff)
parent1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5 (diff)
merge(third_party/git): Merge squashed git subtree at v2.23.0 r/373
Merge commit '1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5' as 'third_party/git'
Diffstat (limited to 'third_party/git/http-backend.c')
-rw-r--r--third_party/git/http-backend.c795
1 files changed, 795 insertions, 0 deletions
diff --git a/third_party/git/http-backend.c b/third_party/git/http-backend.c
new file mode 100644
index 0000000000..ec3144b444
--- /dev/null
+++ b/third_party/git/http-backend.c
@@ -0,0 +1,795 @@
+#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;
+	cld.clean_on_exit = 1;
+	cld.wait_after_clean = 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/[0-9a-f]{2}/[0-9a-f]{62}$", get_loose_object},
+	{"GET", "/objects/pack/pack-[0-9a-f]{40}\\.pack$", get_pack_file},
+	{"GET", "/objects/pack/pack-[0-9a-f]{64}\\.pack$", get_pack_file},
+	{"GET", "/objects/pack/pack-[0-9a-f]{40}\\.idx$", get_idx_file},
+	{"GET", "/objects/pack/pack-[0-9a-f]{64}\\.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;
+}