Merge branch 'main' of github.com:git/git
[alt-git.git] / http-backend.c
blob6eb3b2fe51c6fe839f2dec5dd584cf174d5b5f73
1 #include "cache.h"
2 #include "config.h"
3 #include "repository.h"
4 #include "refs.h"
5 #include "pkt-line.h"
6 #include "object.h"
7 #include "tag.h"
8 #include "exec-cmd.h"
9 #include "run-command.h"
10 #include "string-list.h"
11 #include "url.h"
12 #include "strvec.h"
13 #include "packfile.h"
14 #include "object-store.h"
15 #include "protocol.h"
16 #include "date.h"
18 static const char content_type[] = "Content-Type";
19 static const char content_length[] = "Content-Length";
20 static const char last_modified[] = "Last-Modified";
21 static int getanyfile = 1;
22 static unsigned long max_request_buffer = 10 * 1024 * 1024;
24 static struct string_list *query_params;
26 struct rpc_service {
27 const char *name;
28 const char *config_name;
29 unsigned buffer_input : 1;
30 signed enabled : 2;
33 static struct rpc_service rpc_service[] = {
34 { "upload-pack", "uploadpack", 1, 1 },
35 { "receive-pack", "receivepack", 0, -1 },
38 static struct string_list *get_parameters(void)
40 if (!query_params) {
41 const char *query = getenv("QUERY_STRING");
43 CALLOC_ARRAY(query_params, 1);
44 while (query && *query) {
45 char *name = url_decode_parameter_name(&query);
46 char *value = url_decode_parameter_value(&query);
47 struct string_list_item *i;
49 i = string_list_lookup(query_params, name);
50 if (!i)
51 i = string_list_insert(query_params, name);
52 else
53 free(i->util);
54 i->util = value;
57 return query_params;
60 static const char *get_parameter(const char *name)
62 struct string_list_item *i;
63 i = string_list_lookup(get_parameters(), name);
64 return i ? i->util : NULL;
67 __attribute__((format (printf, 2, 3)))
68 static void format_write(int fd, const char *fmt, ...)
70 static char buffer[1024];
72 va_list args;
73 unsigned n;
75 va_start(args, fmt);
76 n = vsnprintf(buffer, sizeof(buffer), fmt, args);
77 va_end(args);
78 if (n >= sizeof(buffer))
79 die("protocol error: impossibly long line");
81 write_or_die(fd, buffer, n);
84 static void http_status(struct strbuf *hdr, unsigned code, const char *msg)
86 strbuf_addf(hdr, "Status: %u %s\r\n", code, msg);
89 static void hdr_str(struct strbuf *hdr, const char *name, const char *value)
91 strbuf_addf(hdr, "%s: %s\r\n", name, value);
94 static void hdr_int(struct strbuf *hdr, const char *name, uintmax_t value)
96 strbuf_addf(hdr, "%s: %" PRIuMAX "\r\n", name, value);
99 static void hdr_date(struct strbuf *hdr, const char *name, timestamp_t when)
101 const char *value = show_date(when, 0, DATE_MODE(RFC2822));
102 hdr_str(hdr, name, value);
105 static void hdr_nocache(struct strbuf *hdr)
107 hdr_str(hdr, "Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
108 hdr_str(hdr, "Pragma", "no-cache");
109 hdr_str(hdr, "Cache-Control", "no-cache, max-age=0, must-revalidate");
112 static void hdr_cache_forever(struct strbuf *hdr)
114 timestamp_t now = time(NULL);
115 hdr_date(hdr, "Date", now);
116 hdr_date(hdr, "Expires", now + 31536000);
117 hdr_str(hdr, "Cache-Control", "public, max-age=31536000");
120 static void end_headers(struct strbuf *hdr)
122 strbuf_add(hdr, "\r\n", 2);
123 write_or_die(1, hdr->buf, hdr->len);
124 strbuf_release(hdr);
127 __attribute__((format (printf, 2, 3)))
128 static NORETURN void not_found(struct strbuf *hdr, const char *err, ...)
130 va_list params;
132 http_status(hdr, 404, "Not Found");
133 hdr_nocache(hdr);
134 end_headers(hdr);
136 va_start(params, err);
137 if (err && *err)
138 vfprintf(stderr, err, params);
139 va_end(params);
140 exit(0);
143 __attribute__((format (printf, 2, 3)))
144 static NORETURN void forbidden(struct strbuf *hdr, const char *err, ...)
146 va_list params;
148 http_status(hdr, 403, "Forbidden");
149 hdr_nocache(hdr);
150 end_headers(hdr);
152 va_start(params, err);
153 if (err && *err)
154 vfprintf(stderr, err, params);
155 va_end(params);
156 exit(0);
159 static void select_getanyfile(struct strbuf *hdr)
161 if (!getanyfile)
162 forbidden(hdr, "Unsupported service: getanyfile");
165 static void send_strbuf(struct strbuf *hdr,
166 const char *type, struct strbuf *buf)
168 hdr_int(hdr, content_length, buf->len);
169 hdr_str(hdr, content_type, type);
170 end_headers(hdr);
171 write_or_die(1, buf->buf, buf->len);
174 static void send_local_file(struct strbuf *hdr, const char *the_type,
175 const char *name)
177 char *p = git_pathdup("%s", name);
178 size_t buf_alloc = 8192;
179 char *buf = xmalloc(buf_alloc);
180 int fd;
181 struct stat sb;
183 fd = open(p, O_RDONLY);
184 if (fd < 0)
185 not_found(hdr, "Cannot open '%s': %s", p, strerror(errno));
186 if (fstat(fd, &sb) < 0)
187 die_errno("Cannot stat '%s'", p);
189 hdr_int(hdr, content_length, sb.st_size);
190 hdr_str(hdr, content_type, the_type);
191 hdr_date(hdr, last_modified, sb.st_mtime);
192 end_headers(hdr);
194 for (;;) {
195 ssize_t n = xread(fd, buf, buf_alloc);
196 if (n < 0)
197 die_errno("Cannot read '%s'", p);
198 if (!n)
199 break;
200 write_or_die(1, buf, n);
202 close(fd);
203 free(buf);
204 free(p);
207 static void get_text_file(struct strbuf *hdr, char *name)
209 select_getanyfile(hdr);
210 hdr_nocache(hdr);
211 send_local_file(hdr, "text/plain", name);
214 static void get_loose_object(struct strbuf *hdr, char *name)
216 select_getanyfile(hdr);
217 hdr_cache_forever(hdr);
218 send_local_file(hdr, "application/x-git-loose-object", name);
221 static void get_pack_file(struct strbuf *hdr, char *name)
223 select_getanyfile(hdr);
224 hdr_cache_forever(hdr);
225 send_local_file(hdr, "application/x-git-packed-objects", name);
228 static void get_idx_file(struct strbuf *hdr, char *name)
230 select_getanyfile(hdr);
231 hdr_cache_forever(hdr);
232 send_local_file(hdr, "application/x-git-packed-objects-toc", name);
235 static void http_config(void)
237 int i, value = 0;
238 struct strbuf var = STRBUF_INIT;
240 git_config_get_bool("http.getanyfile", &getanyfile);
241 git_config_get_ulong("http.maxrequestbuffer", &max_request_buffer);
243 for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
244 struct rpc_service *svc = &rpc_service[i];
245 strbuf_addf(&var, "http.%s", svc->config_name);
246 if (!git_config_get_bool(var.buf, &value))
247 svc->enabled = value;
248 strbuf_reset(&var);
251 strbuf_release(&var);
254 static struct rpc_service *select_service(struct strbuf *hdr, const char *name)
256 const char *svc_name;
257 struct rpc_service *svc = NULL;
258 int i;
260 if (!skip_prefix(name, "git-", &svc_name))
261 forbidden(hdr, "Unsupported service: '%s'", name);
263 for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
264 struct rpc_service *s = &rpc_service[i];
265 if (!strcmp(s->name, svc_name)) {
266 svc = s;
267 break;
271 if (!svc)
272 forbidden(hdr, "Unsupported service: '%s'", name);
274 if (svc->enabled < 0) {
275 const char *user = getenv("REMOTE_USER");
276 svc->enabled = (user && *user) ? 1 : 0;
278 if (!svc->enabled)
279 forbidden(hdr, "Service not enabled: '%s'", svc->name);
280 return svc;
283 static void write_to_child(int out, const unsigned char *buf, ssize_t len, const char *prog_name)
285 if (write_in_full(out, buf, len) < 0)
286 die("unable to write to '%s'", prog_name);
290 * This is basically strbuf_read(), except that if we
291 * hit max_request_buffer we die (we'd rather reject a
292 * maliciously large request than chew up infinite memory).
294 static ssize_t read_request_eof(int fd, unsigned char **out)
296 size_t len = 0, alloc = 8192;
297 unsigned char *buf = xmalloc(alloc);
299 if (max_request_buffer < alloc)
300 max_request_buffer = alloc;
302 while (1) {
303 ssize_t cnt;
305 cnt = read_in_full(fd, buf + len, alloc - len);
306 if (cnt < 0) {
307 free(buf);
308 return -1;
311 /* partial read from read_in_full means we hit EOF */
312 len += cnt;
313 if (len < alloc) {
314 *out = buf;
315 return len;
318 /* otherwise, grow and try again (if we can) */
319 if (alloc == max_request_buffer)
320 die("request was larger than our maximum size (%lu);"
321 " try setting GIT_HTTP_MAX_REQUEST_BUFFER",
322 max_request_buffer);
324 alloc = alloc_nr(alloc);
325 if (alloc > max_request_buffer)
326 alloc = max_request_buffer;
327 REALLOC_ARRAY(buf, alloc);
331 static ssize_t read_request_fixed_len(int fd, ssize_t req_len, unsigned char **out)
333 unsigned char *buf = NULL;
334 ssize_t cnt = 0;
336 if (max_request_buffer < req_len) {
337 die("request was larger than our maximum size (%lu): "
338 "%" PRIuMAX "; try setting GIT_HTTP_MAX_REQUEST_BUFFER",
339 max_request_buffer, (uintmax_t)req_len);
342 buf = xmalloc(req_len);
343 cnt = read_in_full(fd, buf, req_len);
344 if (cnt < 0) {
345 free(buf);
346 return -1;
348 *out = buf;
349 return cnt;
352 static ssize_t get_content_length(void)
354 ssize_t val = -1;
355 const char *str = getenv("CONTENT_LENGTH");
357 if (str && *str && !git_parse_ssize_t(str, &val))
358 die("failed to parse CONTENT_LENGTH: %s", str);
359 return val;
362 static ssize_t read_request(int fd, unsigned char **out, ssize_t req_len)
364 if (req_len < 0)
365 return read_request_eof(fd, out);
366 else
367 return read_request_fixed_len(fd, req_len, out);
370 static void inflate_request(const char *prog_name, int out, int buffer_input, ssize_t req_len)
372 git_zstream stream;
373 unsigned char *full_request = NULL;
374 unsigned char in_buf[8192];
375 unsigned char out_buf[8192];
376 unsigned long cnt = 0;
377 int req_len_defined = req_len >= 0;
378 size_t req_remaining_len = req_len;
380 memset(&stream, 0, sizeof(stream));
381 git_inflate_init_gzip_only(&stream);
383 while (1) {
384 ssize_t n;
386 if (buffer_input) {
387 if (full_request)
388 n = 0; /* nothing left to read */
389 else
390 n = read_request(0, &full_request, req_len);
391 stream.next_in = full_request;
392 } else {
393 ssize_t buffer_len;
394 if (req_len_defined && req_remaining_len <= sizeof(in_buf))
395 buffer_len = req_remaining_len;
396 else
397 buffer_len = sizeof(in_buf);
398 n = xread(0, in_buf, buffer_len);
399 stream.next_in = in_buf;
400 if (req_len_defined && n > 0)
401 req_remaining_len -= n;
404 if (n <= 0)
405 die("request ended in the middle of the gzip stream");
406 stream.avail_in = n;
408 while (0 < stream.avail_in) {
409 int ret;
411 stream.next_out = out_buf;
412 stream.avail_out = sizeof(out_buf);
414 ret = git_inflate(&stream, Z_NO_FLUSH);
415 if (ret != Z_OK && ret != Z_STREAM_END)
416 die("zlib error inflating request, result %d", ret);
418 n = stream.total_out - cnt;
419 write_to_child(out, out_buf, stream.total_out - cnt, prog_name);
420 cnt = stream.total_out;
422 if (ret == Z_STREAM_END)
423 goto done;
427 done:
428 git_inflate_end(&stream);
429 close(out);
430 free(full_request);
433 static void copy_request(const char *prog_name, int out, ssize_t req_len)
435 unsigned char *buf;
436 ssize_t n = read_request(0, &buf, req_len);
437 if (n < 0)
438 die_errno("error reading request body");
439 write_to_child(out, buf, n, prog_name);
440 close(out);
441 free(buf);
444 static void pipe_fixed_length(const char *prog_name, int out, size_t req_len)
446 unsigned char buf[8192];
447 size_t remaining_len = req_len;
449 while (remaining_len > 0) {
450 size_t chunk_length = remaining_len > sizeof(buf) ? sizeof(buf) : remaining_len;
451 ssize_t n = xread(0, buf, chunk_length);
452 if (n < 0)
453 die_errno("Reading request failed");
454 write_to_child(out, buf, n, prog_name);
455 remaining_len -= n;
458 close(out);
461 static void run_service(const char **argv, int buffer_input)
463 const char *encoding = getenv("HTTP_CONTENT_ENCODING");
464 const char *user = getenv("REMOTE_USER");
465 const char *host = getenv("REMOTE_ADDR");
466 int gzipped_request = 0;
467 struct child_process cld = CHILD_PROCESS_INIT;
468 ssize_t req_len = get_content_length();
470 if (encoding && (!strcmp(encoding, "gzip") || !strcmp(encoding, "x-gzip")))
471 gzipped_request = 1;
473 if (!user || !*user)
474 user = "anonymous";
475 if (!host || !*host)
476 host = "(none)";
478 if (!getenv("GIT_COMMITTER_NAME"))
479 strvec_pushf(&cld.env, "GIT_COMMITTER_NAME=%s", user);
480 if (!getenv("GIT_COMMITTER_EMAIL"))
481 strvec_pushf(&cld.env,
482 "GIT_COMMITTER_EMAIL=%s@http.%s", user, host);
484 strvec_pushv(&cld.args, argv);
485 if (buffer_input || gzipped_request || req_len >= 0)
486 cld.in = -1;
487 cld.git_cmd = 1;
488 cld.clean_on_exit = 1;
489 cld.wait_after_clean = 1;
490 if (start_command(&cld))
491 exit(1);
493 close(1);
494 if (gzipped_request)
495 inflate_request(argv[0], cld.in, buffer_input, req_len);
496 else if (buffer_input)
497 copy_request(argv[0], cld.in, req_len);
498 else if (req_len >= 0)
499 pipe_fixed_length(argv[0], cld.in, req_len);
500 else
501 close(0);
503 if (finish_command(&cld))
504 exit(1);
507 static int show_text_ref(const char *name, const struct object_id *oid,
508 int flag UNUSED, void *cb_data)
510 const char *name_nons = strip_namespace(name);
511 struct strbuf *buf = cb_data;
512 struct object *o = parse_object(the_repository, oid);
513 if (!o)
514 return 0;
516 strbuf_addf(buf, "%s\t%s\n", oid_to_hex(oid), name_nons);
517 if (o->type == OBJ_TAG) {
518 o = deref_tag(the_repository, o, name, 0);
519 if (!o)
520 return 0;
521 strbuf_addf(buf, "%s\t%s^{}\n", oid_to_hex(&o->oid),
522 name_nons);
524 return 0;
527 static void get_info_refs(struct strbuf *hdr, char *arg)
529 const char *service_name = get_parameter("service");
530 struct strbuf buf = STRBUF_INIT;
532 hdr_nocache(hdr);
534 if (service_name) {
535 const char *argv[] = {NULL /* service name */,
536 "--http-backend-info-refs",
537 ".", NULL};
538 struct rpc_service *svc = select_service(hdr, service_name);
540 strbuf_addf(&buf, "application/x-git-%s-advertisement",
541 svc->name);
542 hdr_str(hdr, content_type, buf.buf);
543 end_headers(hdr);
546 if (determine_protocol_version_server() != protocol_v2) {
547 packet_write_fmt(1, "# service=git-%s\n", svc->name);
548 packet_flush(1);
551 argv[0] = svc->name;
552 run_service(argv, 0);
554 } else {
555 select_getanyfile(hdr);
556 for_each_namespaced_ref(show_text_ref, &buf);
557 send_strbuf(hdr, "text/plain", &buf);
559 strbuf_release(&buf);
562 static int show_head_ref(const char *refname, const struct object_id *oid,
563 int flag, void *cb_data)
565 struct strbuf *buf = cb_data;
567 if (flag & REF_ISSYMREF) {
568 const char *target = resolve_ref_unsafe(refname,
569 RESOLVE_REF_READING,
570 NULL, NULL);
572 if (target)
573 strbuf_addf(buf, "ref: %s\n", strip_namespace(target));
574 } else {
575 strbuf_addf(buf, "%s\n", oid_to_hex(oid));
578 return 0;
581 static void get_head(struct strbuf *hdr, char *arg)
583 struct strbuf buf = STRBUF_INIT;
585 select_getanyfile(hdr);
586 head_ref_namespaced(show_head_ref, &buf);
587 send_strbuf(hdr, "text/plain", &buf);
588 strbuf_release(&buf);
591 static void get_info_packs(struct strbuf *hdr, char *arg)
593 size_t objdirlen = strlen(get_object_directory());
594 struct strbuf buf = STRBUF_INIT;
595 struct packed_git *p;
596 size_t cnt = 0;
598 select_getanyfile(hdr);
599 for (p = get_all_packs(the_repository); p; p = p->next) {
600 if (p->pack_local)
601 cnt++;
604 strbuf_grow(&buf, cnt * 53 + 2);
605 for (p = get_all_packs(the_repository); p; p = p->next) {
606 if (p->pack_local)
607 strbuf_addf(&buf, "P %s\n", p->pack_name + objdirlen + 6);
609 strbuf_addch(&buf, '\n');
611 hdr_nocache(hdr);
612 send_strbuf(hdr, "text/plain; charset=utf-8", &buf);
613 strbuf_release(&buf);
616 static void check_content_type(struct strbuf *hdr, const char *accepted_type)
618 const char *actual_type = getenv("CONTENT_TYPE");
620 if (!actual_type)
621 actual_type = "";
623 if (strcmp(actual_type, accepted_type)) {
624 http_status(hdr, 415, "Unsupported Media Type");
625 hdr_nocache(hdr);
626 end_headers(hdr);
627 format_write(1,
628 "Expected POST with Content-Type '%s',"
629 " but received '%s' instead.\n",
630 accepted_type, actual_type);
631 exit(0);
635 static void service_rpc(struct strbuf *hdr, char *service_name)
637 const char *argv[] = {NULL, "--stateless-rpc", ".", NULL};
638 struct rpc_service *svc = select_service(hdr, service_name);
639 struct strbuf buf = STRBUF_INIT;
641 strbuf_reset(&buf);
642 strbuf_addf(&buf, "application/x-git-%s-request", svc->name);
643 check_content_type(hdr, buf.buf);
645 hdr_nocache(hdr);
647 strbuf_reset(&buf);
648 strbuf_addf(&buf, "application/x-git-%s-result", svc->name);
649 hdr_str(hdr, content_type, buf.buf);
651 end_headers(hdr);
653 argv[0] = svc->name;
654 run_service(argv, svc->buffer_input);
655 strbuf_release(&buf);
658 static int dead;
659 static NORETURN void die_webcgi(const char *err, va_list params)
661 if (dead <= 1) {
662 struct strbuf hdr = STRBUF_INIT;
663 report_fn die_message_fn = get_die_message_routine();
665 die_message_fn(err, params);
667 http_status(&hdr, 500, "Internal Server Error");
668 hdr_nocache(&hdr);
669 end_headers(&hdr);
671 exit(0); /* we successfully reported a failure ;-) */
674 static int die_webcgi_recursing(void)
676 return dead++ > 1;
679 static char* getdir(void)
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");
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;
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$", get_idx_file},
720 {"POST", "/git-upload-pack$", service_rpc},
721 {"POST", "/git-receive-pack$", service_rpc}
724 static int bad_request(struct strbuf *hdr, const struct service_cmd *c)
726 const char *proto = getenv("SERVER_PROTOCOL");
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;
739 int cmd_main(int argc, const char **argv)
741 char *method = getenv("REQUEST_METHOD");
742 const char *proto_header;
743 char *dir;
744 struct service_cmd *cmd = NULL;
745 char *cmd_arg = NULL;
746 int i;
747 struct strbuf hdr = STRBUF_INIT;
749 set_die_routine(die_webcgi);
750 set_die_is_recursing_routine(die_webcgi_recursing);
752 if (!method)
753 die("No REQUEST_METHOD from server");
754 if (!strcmp(method, "HEAD"))
755 method = "GET";
756 dir = getdir();
758 for (i = 0; i < ARRAY_SIZE(services); i++) {
759 struct service_cmd *c = &services[i];
760 regex_t re;
761 regmatch_t out[1];
763 if (regcomp(&re, c->pattern, REG_EXTENDED))
764 die("Bogus regex in service table: %s", c->pattern);
765 if (!regexec(&re, dir, 1, out, 0)) {
766 size_t n;
768 if (strcmp(method, c->method))
769 return bad_request(&hdr, c);
771 cmd = c;
772 n = out[0].rm_eo - out[0].rm_so;
773 cmd_arg = xmemdupz(dir + out[0].rm_so + 1, n - 1);
774 dir[out[0].rm_so] = 0;
775 break;
777 regfree(&re);
780 if (!cmd)
781 not_found(&hdr, "Request not supported: '%s'", dir);
783 setup_path();
784 if (!enter_repo(dir, 0))
785 not_found(&hdr, "Not a git repository: '%s'", dir);
786 if (!getenv("GIT_HTTP_EXPORT_ALL") &&
787 access("git-daemon-export-ok", F_OK) )
788 not_found(&hdr, "Repository not exported: '%s'", dir);
790 http_config();
791 max_request_buffer = git_env_ulong("GIT_HTTP_MAX_REQUEST_BUFFER",
792 max_request_buffer);
793 proto_header = getenv("HTTP_GIT_PROTOCOL");
794 if (proto_header)
795 setenv(GIT_PROTOCOL_ENVIRONMENT, proto_header, 0);
797 cmd->imp(&hdr, cmd_arg);
798 return 0;