sparse-checkout: update working directory in-process for 'init'
[git] / transport-helper.c
1 #include "cache.h"
2 #include "transport.h"
3 #include "quote.h"
4 #include "run-command.h"
5 #include "commit.h"
6 #include "diff.h"
7 #include "revision.h"
8 #include "remote.h"
9 #include "string-list.h"
10 #include "thread-utils.h"
11 #include "sigchain.h"
12 #include "argv-array.h"
13 #include "refs.h"
14 #include "refspec.h"
15 #include "transport-internal.h"
16 #include "protocol.h"
17
18 static int debug;
19
20 struct helper_data {
21         const char *name;
22         struct child_process *helper;
23         FILE *out;
24         unsigned fetch : 1,
25                 import : 1,
26                 bidi_import : 1,
27                 export : 1,
28                 option : 1,
29                 push : 1,
30                 connect : 1,
31                 stateless_connect : 1,
32                 signed_tags : 1,
33                 check_connectivity : 1,
34                 no_disconnect_req : 1,
35                 no_private_update : 1;
36
37         /*
38          * As an optimization, the transport code may invoke fetch before
39          * get_refs_list. If this happens, and if the transport helper doesn't
40          * support connect or stateless_connect, we need to invoke
41          * get_refs_list ourselves if we haven't already done so. Keep track of
42          * whether we have invoked get_refs_list.
43          */
44         unsigned get_refs_list_called : 1;
45
46         char *export_marks;
47         char *import_marks;
48         /* These go from remote name (as in "list") to private name */
49         struct refspec rs;
50         /* Transport options for fetch-pack/send-pack (should one of
51          * those be invoked).
52          */
53         struct git_transport_options transport_options;
54 };
55
56 static void sendline(struct helper_data *helper, struct strbuf *buffer)
57 {
58         if (debug)
59                 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
60         if (write_in_full(helper->helper->in, buffer->buf, buffer->len) < 0)
61                 die_errno(_("full write to remote helper failed"));
62 }
63
64 static int recvline_fh(FILE *helper, struct strbuf *buffer)
65 {
66         strbuf_reset(buffer);
67         if (debug)
68                 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
69         if (strbuf_getline(buffer, helper) == EOF) {
70                 if (debug)
71                         fprintf(stderr, "Debug: Remote helper quit.\n");
72                 return 1;
73         }
74
75         if (debug)
76                 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
77         return 0;
78 }
79
80 static int recvline(struct helper_data *helper, struct strbuf *buffer)
81 {
82         return recvline_fh(helper->out, buffer);
83 }
84
85 static void write_constant(int fd, const char *str)
86 {
87         if (debug)
88                 fprintf(stderr, "Debug: Remote helper: -> %s", str);
89         if (write_in_full(fd, str, strlen(str)) < 0)
90                 die_errno(_("full write to remote helper failed"));
91 }
92
93 static const char *remove_ext_force(const char *url)
94 {
95         if (url) {
96                 const char *colon = strchr(url, ':');
97                 if (colon && colon[1] == ':')
98                         return colon + 2;
99         }
100         return url;
101 }
102
103 static void do_take_over(struct transport *transport)
104 {
105         struct helper_data *data;
106         data = (struct helper_data *)transport->data;
107         transport_take_over(transport, data->helper);
108         fclose(data->out);
109         free(data);
110 }
111
112 static void standard_options(struct transport *t);
113
114 static struct child_process *get_helper(struct transport *transport)
115 {
116         struct helper_data *data = transport->data;
117         struct strbuf buf = STRBUF_INIT;
118         struct child_process *helper;
119         int duped;
120         int code;
121
122         if (data->helper)
123                 return data->helper;
124
125         helper = xmalloc(sizeof(*helper));
126         child_process_init(helper);
127         helper->in = -1;
128         helper->out = -1;
129         helper->err = 0;
130         argv_array_pushf(&helper->args, "git-remote-%s", data->name);
131         argv_array_push(&helper->args, transport->remote->name);
132         argv_array_push(&helper->args, remove_ext_force(transport->url));
133         helper->git_cmd = 0;
134         helper->silent_exec_failure = 1;
135
136         if (have_git_dir())
137                 argv_array_pushf(&helper->env_array, "%s=%s",
138                                  GIT_DIR_ENVIRONMENT, get_git_dir());
139
140         helper->trace2_child_class = helper->args.argv[0]; /* "remote-<name>" */
141
142         code = start_command(helper);
143         if (code < 0 && errno == ENOENT)
144                 die(_("unable to find remote helper for '%s'"), data->name);
145         else if (code != 0)
146                 exit(code);
147
148         data->helper = helper;
149         data->no_disconnect_req = 0;
150         refspec_init(&data->rs, REFSPEC_FETCH);
151
152         /*
153          * Open the output as FILE* so strbuf_getline_*() family of
154          * functions can be used.
155          * Do this with duped fd because fclose() will close the fd,
156          * and stuff like taking over will require the fd to remain.
157          */
158         duped = dup(helper->out);
159         if (duped < 0)
160                 die_errno(_("can't dup helper output fd"));
161         data->out = xfdopen(duped, "r");
162
163         write_constant(helper->in, "capabilities\n");
164
165         while (1) {
166                 const char *capname, *arg;
167                 int mandatory = 0;
168                 if (recvline(data, &buf))
169                         exit(128);
170
171                 if (!*buf.buf)
172                         break;
173
174                 if (*buf.buf == '*') {
175                         capname = buf.buf + 1;
176                         mandatory = 1;
177                 } else
178                         capname = buf.buf;
179
180                 if (debug)
181                         fprintf(stderr, "Debug: Got cap %s\n", capname);
182                 if (!strcmp(capname, "fetch"))
183                         data->fetch = 1;
184                 else if (!strcmp(capname, "option"))
185                         data->option = 1;
186                 else if (!strcmp(capname, "push"))
187                         data->push = 1;
188                 else if (!strcmp(capname, "import"))
189                         data->import = 1;
190                 else if (!strcmp(capname, "bidi-import"))
191                         data->bidi_import = 1;
192                 else if (!strcmp(capname, "export"))
193                         data->export = 1;
194                 else if (!strcmp(capname, "check-connectivity"))
195                         data->check_connectivity = 1;
196                 else if (skip_prefix(capname, "refspec ", &arg)) {
197                         refspec_append(&data->rs, arg);
198                 } else if (!strcmp(capname, "connect")) {
199                         data->connect = 1;
200                 } else if (!strcmp(capname, "stateless-connect")) {
201                         data->stateless_connect = 1;
202                 } else if (!strcmp(capname, "signed-tags")) {
203                         data->signed_tags = 1;
204                 } else if (skip_prefix(capname, "export-marks ", &arg)) {
205                         data->export_marks = xstrdup(arg);
206                 } else if (skip_prefix(capname, "import-marks ", &arg)) {
207                         data->import_marks = xstrdup(arg);
208                 } else if (starts_with(capname, "no-private-update")) {
209                         data->no_private_update = 1;
210                 } else if (mandatory) {
211                         die(_("unknown mandatory capability %s; this remote "
212                               "helper probably needs newer version of Git"),
213                             capname);
214                 }
215         }
216         if (!data->rs.nr && (data->import || data->bidi_import || data->export)) {
217                 warning(_("this remote helper should implement refspec capability"));
218         }
219         strbuf_release(&buf);
220         if (debug)
221                 fprintf(stderr, "Debug: Capabilities complete.\n");
222         standard_options(transport);
223         return data->helper;
224 }
225
226 static int disconnect_helper(struct transport *transport)
227 {
228         struct helper_data *data = transport->data;
229         int res = 0;
230
231         if (data->helper) {
232                 if (debug)
233                         fprintf(stderr, "Debug: Disconnecting.\n");
234                 if (!data->no_disconnect_req) {
235                         /*
236                          * Ignore write errors; there's nothing we can do,
237                          * since we're about to close the pipe anyway. And the
238                          * most likely error is EPIPE due to the helper dying
239                          * to report an error itself.
240                          */
241                         sigchain_push(SIGPIPE, SIG_IGN);
242                         xwrite(data->helper->in, "\n", 1);
243                         sigchain_pop(SIGPIPE);
244                 }
245                 close(data->helper->in);
246                 close(data->helper->out);
247                 fclose(data->out);
248                 res = finish_command(data->helper);
249                 FREE_AND_NULL(data->helper);
250         }
251         return res;
252 }
253
254 static const char *unsupported_options[] = {
255         TRANS_OPT_UPLOADPACK,
256         TRANS_OPT_RECEIVEPACK,
257         TRANS_OPT_THIN,
258         TRANS_OPT_KEEP
259         };
260
261 static const char *boolean_options[] = {
262         TRANS_OPT_THIN,
263         TRANS_OPT_KEEP,
264         TRANS_OPT_FOLLOWTAGS,
265         TRANS_OPT_DEEPEN_RELATIVE
266         };
267
268 static int strbuf_set_helper_option(struct helper_data *data,
269                                     struct strbuf *buf)
270 {
271         int ret;
272
273         sendline(data, buf);
274         if (recvline(data, buf))
275                 exit(128);
276
277         if (!strcmp(buf->buf, "ok"))
278                 ret = 0;
279         else if (starts_with(buf->buf, "error"))
280                 ret = -1;
281         else if (!strcmp(buf->buf, "unsupported"))
282                 ret = 1;
283         else {
284                 warning(_("%s unexpectedly said: '%s'"), data->name, buf->buf);
285                 ret = 1;
286         }
287         return ret;
288 }
289
290 static int string_list_set_helper_option(struct helper_data *data,
291                                          const char *name,
292                                          struct string_list *list)
293 {
294         struct strbuf buf = STRBUF_INIT;
295         int i, ret = 0;
296
297         for (i = 0; i < list->nr; i++) {
298                 strbuf_addf(&buf, "option %s ", name);
299                 quote_c_style(list->items[i].string, &buf, NULL, 0);
300                 strbuf_addch(&buf, '\n');
301
302                 if ((ret = strbuf_set_helper_option(data, &buf)))
303                         break;
304                 strbuf_reset(&buf);
305         }
306         strbuf_release(&buf);
307         return ret;
308 }
309
310 static int set_helper_option(struct transport *transport,
311                           const char *name, const char *value)
312 {
313         struct helper_data *data = transport->data;
314         struct strbuf buf = STRBUF_INIT;
315         int i, ret, is_bool = 0;
316
317         get_helper(transport);
318
319         if (!data->option)
320                 return 1;
321
322         if (!strcmp(name, "deepen-not"))
323                 return string_list_set_helper_option(data, name,
324                                                      (struct string_list *)value);
325
326         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
327                 if (!strcmp(name, unsupported_options[i]))
328                         return 1;
329         }
330
331         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
332                 if (!strcmp(name, boolean_options[i])) {
333                         is_bool = 1;
334                         break;
335                 }
336         }
337
338         strbuf_addf(&buf, "option %s ", name);
339         if (is_bool)
340                 strbuf_addstr(&buf, value ? "true" : "false");
341         else
342                 quote_c_style(value, &buf, NULL, 0);
343         strbuf_addch(&buf, '\n');
344
345         ret = strbuf_set_helper_option(data, &buf);
346         strbuf_release(&buf);
347         return ret;
348 }
349
350 static void standard_options(struct transport *t)
351 {
352         char buf[16];
353         int v = t->verbose;
354
355         set_helper_option(t, "progress", t->progress ? "true" : "false");
356
357         xsnprintf(buf, sizeof(buf), "%d", v + 1);
358         set_helper_option(t, "verbosity", buf);
359
360         switch (t->family) {
361         case TRANSPORT_FAMILY_ALL:
362                 /*
363                  * this is already the default,
364                  * do not break old remote helpers by setting "all" here
365                  */
366                 break;
367         case TRANSPORT_FAMILY_IPV4:
368                 set_helper_option(t, "family", "ipv4");
369                 break;
370         case TRANSPORT_FAMILY_IPV6:
371                 set_helper_option(t, "family", "ipv6");
372                 break;
373         }
374 }
375
376 static int release_helper(struct transport *transport)
377 {
378         int res = 0;
379         struct helper_data *data = transport->data;
380         refspec_clear(&data->rs);
381         res = disconnect_helper(transport);
382         free(transport->data);
383         return res;
384 }
385
386 static int fetch_with_fetch(struct transport *transport,
387                             int nr_heads, struct ref **to_fetch)
388 {
389         struct helper_data *data = transport->data;
390         int i;
391         struct strbuf buf = STRBUF_INIT;
392
393         for (i = 0; i < nr_heads; i++) {
394                 const struct ref *posn = to_fetch[i];
395                 if (posn->status & REF_STATUS_UPTODATE)
396                         continue;
397
398                 strbuf_addf(&buf, "fetch %s %s\n",
399                             oid_to_hex(&posn->old_oid),
400                             posn->symref ? posn->symref : posn->name);
401         }
402
403         strbuf_addch(&buf, '\n');
404         sendline(data, &buf);
405
406         while (1) {
407                 if (recvline(data, &buf))
408                         exit(128);
409
410                 if (starts_with(buf.buf, "lock ")) {
411                         const char *name = buf.buf + 5;
412                         if (transport->pack_lockfile)
413                                 warning(_("%s also locked %s"), data->name, name);
414                         else
415                                 transport->pack_lockfile = xstrdup(name);
416                 }
417                 else if (data->check_connectivity &&
418                          data->transport_options.check_self_contained_and_connected &&
419                          !strcmp(buf.buf, "connectivity-ok"))
420                         data->transport_options.self_contained_and_connected = 1;
421                 else if (!buf.len)
422                         break;
423                 else
424                         warning(_("%s unexpectedly said: '%s'"), data->name, buf.buf);
425         }
426         strbuf_release(&buf);
427         return 0;
428 }
429
430 static int get_importer(struct transport *transport, struct child_process *fastimport)
431 {
432         struct child_process *helper = get_helper(transport);
433         struct helper_data *data = transport->data;
434         int cat_blob_fd, code;
435         child_process_init(fastimport);
436         fastimport->in = xdup(helper->out);
437         argv_array_push(&fastimport->args, "fast-import");
438         argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
439
440         if (data->bidi_import) {
441                 cat_blob_fd = xdup(helper->in);
442                 argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
443         }
444         fastimport->git_cmd = 1;
445
446         code = start_command(fastimport);
447         return code;
448 }
449
450 static int get_exporter(struct transport *transport,
451                         struct child_process *fastexport,
452                         struct string_list *revlist_args)
453 {
454         struct helper_data *data = transport->data;
455         struct child_process *helper = get_helper(transport);
456         int i;
457
458         child_process_init(fastexport);
459
460         /* we need to duplicate helper->in because we want to use it after
461          * fastexport is done with it. */
462         fastexport->out = dup(helper->in);
463         argv_array_push(&fastexport->args, "fast-export");
464         argv_array_push(&fastexport->args, "--use-done-feature");
465         argv_array_push(&fastexport->args, data->signed_tags ?
466                 "--signed-tags=verbatim" : "--signed-tags=warn-strip");
467         if (data->export_marks)
468                 argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
469         if (data->import_marks)
470                 argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
471
472         for (i = 0; i < revlist_args->nr; i++)
473                 argv_array_push(&fastexport->args, revlist_args->items[i].string);
474
475         fastexport->git_cmd = 1;
476         return start_command(fastexport);
477 }
478
479 static int fetch_with_import(struct transport *transport,
480                              int nr_heads, struct ref **to_fetch)
481 {
482         struct child_process fastimport;
483         struct helper_data *data = transport->data;
484         int i;
485         struct ref *posn;
486         struct strbuf buf = STRBUF_INIT;
487
488         get_helper(transport);
489
490         if (get_importer(transport, &fastimport))
491                 die(_("couldn't run fast-import"));
492
493         for (i = 0; i < nr_heads; i++) {
494                 posn = to_fetch[i];
495                 if (posn->status & REF_STATUS_UPTODATE)
496                         continue;
497
498                 strbuf_addf(&buf, "import %s\n",
499                             posn->symref ? posn->symref : posn->name);
500                 sendline(data, &buf);
501                 strbuf_reset(&buf);
502         }
503
504         write_constant(data->helper->in, "\n");
505         /*
506          * remote-helpers that advertise the bidi-import capability are required to
507          * buffer the complete batch of import commands until this newline before
508          * sending data to fast-import.
509          * These helpers read back data from fast-import on their stdin, which could
510          * be mixed with import commands, otherwise.
511          */
512
513         if (finish_command(&fastimport))
514                 die(_("error while running fast-import"));
515
516         /*
517          * The fast-import stream of a remote helper that advertises
518          * the "refspec" capability writes to the refs named after the
519          * right hand side of the first refspec matching each ref we
520          * were fetching.
521          *
522          * (If no "refspec" capability was specified, for historical
523          * reasons we default to the equivalent of *:*.)
524          *
525          * Store the result in to_fetch[i].old_sha1.  Callers such
526          * as "git fetch" can use the value to write feedback to the
527          * terminal, populate FETCH_HEAD, and determine what new value
528          * should be written to peer_ref if the update is a
529          * fast-forward or this is a forced update.
530          */
531         for (i = 0; i < nr_heads; i++) {
532                 char *private, *name;
533                 posn = to_fetch[i];
534                 if (posn->status & REF_STATUS_UPTODATE)
535                         continue;
536                 name = posn->symref ? posn->symref : posn->name;
537                 if (data->rs.nr)
538                         private = apply_refspecs(&data->rs, name);
539                 else
540                         private = xstrdup(name);
541                 if (private) {
542                         if (read_ref(private, &posn->old_oid) < 0)
543                                 die(_("could not read ref %s"), private);
544                         free(private);
545                 }
546         }
547         strbuf_release(&buf);
548         return 0;
549 }
550
551 static int run_connect(struct transport *transport, struct strbuf *cmdbuf)
552 {
553         struct helper_data *data = transport->data;
554         int ret = 0;
555         int duped;
556         FILE *input;
557         struct child_process *helper;
558
559         helper = get_helper(transport);
560
561         /*
562          * Yes, dup the pipe another time, as we need unbuffered version
563          * of input pipe as FILE*. fclose() closes the underlying fd and
564          * stream buffering only can be changed before first I/O operation
565          * on it.
566          */
567         duped = dup(helper->out);
568         if (duped < 0)
569                 die_errno(_("can't dup helper output fd"));
570         input = xfdopen(duped, "r");
571         setvbuf(input, NULL, _IONBF, 0);
572
573         sendline(data, cmdbuf);
574         if (recvline_fh(input, cmdbuf))
575                 exit(128);
576
577         if (!strcmp(cmdbuf->buf, "")) {
578                 data->no_disconnect_req = 1;
579                 if (debug)
580                         fprintf(stderr, "Debug: Smart transport connection "
581                                 "ready.\n");
582                 ret = 1;
583         } else if (!strcmp(cmdbuf->buf, "fallback")) {
584                 if (debug)
585                         fprintf(stderr, "Debug: Falling back to dumb "
586                                 "transport.\n");
587         } else {
588                 die(_("unknown response to connect: %s"),
589                     cmdbuf->buf);
590         }
591
592         fclose(input);
593         return ret;
594 }
595
596 static int process_connect_service(struct transport *transport,
597                                    const char *name, const char *exec)
598 {
599         struct helper_data *data = transport->data;
600         struct strbuf cmdbuf = STRBUF_INIT;
601         int ret = 0;
602
603         /*
604          * Handle --upload-pack and friends. This is fire and forget...
605          * just warn if it fails.
606          */
607         if (strcmp(name, exec)) {
608                 int r = set_helper_option(transport, "servpath", exec);
609                 if (r > 0)
610                         warning(_("setting remote service path not supported by protocol"));
611                 else if (r < 0)
612                         warning(_("invalid remote service path"));
613         }
614
615         if (data->connect) {
616                 strbuf_addf(&cmdbuf, "connect %s\n", name);
617                 ret = run_connect(transport, &cmdbuf);
618         } else if (data->stateless_connect &&
619                    (get_protocol_version_config() == protocol_v2) &&
620                    !strcmp("git-upload-pack", name)) {
621                 strbuf_addf(&cmdbuf, "stateless-connect %s\n", name);
622                 ret = run_connect(transport, &cmdbuf);
623                 if (ret)
624                         transport->stateless_rpc = 1;
625         }
626
627         strbuf_release(&cmdbuf);
628         return ret;
629 }
630
631 static int process_connect(struct transport *transport,
632                                      int for_push)
633 {
634         struct helper_data *data = transport->data;
635         const char *name;
636         const char *exec;
637
638         name = for_push ? "git-receive-pack" : "git-upload-pack";
639         if (for_push)
640                 exec = data->transport_options.receivepack;
641         else
642                 exec = data->transport_options.uploadpack;
643
644         return process_connect_service(transport, name, exec);
645 }
646
647 static int connect_helper(struct transport *transport, const char *name,
648                    const char *exec, int fd[2])
649 {
650         struct helper_data *data = transport->data;
651
652         /* Get_helper so connect is inited. */
653         get_helper(transport);
654         if (!data->connect)
655                 die(_("operation not supported by protocol"));
656
657         if (!process_connect_service(transport, name, exec))
658                 die(_("can't connect to subservice %s"), name);
659
660         fd[0] = data->helper->out;
661         fd[1] = data->helper->in;
662         return 0;
663 }
664
665 static struct ref *get_refs_list_using_list(struct transport *transport,
666                                             int for_push);
667
668 static int fetch(struct transport *transport,
669                  int nr_heads, struct ref **to_fetch)
670 {
671         struct helper_data *data = transport->data;
672         int i, count;
673
674         get_helper(transport);
675
676         if (process_connect(transport, 0)) {
677                 do_take_over(transport);
678                 return transport->vtable->fetch(transport, nr_heads, to_fetch);
679         }
680
681         if (!data->get_refs_list_called)
682                 get_refs_list_using_list(transport, 0);
683
684         count = 0;
685         for (i = 0; i < nr_heads; i++)
686                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
687                         count++;
688
689         if (!count)
690                 return 0;
691
692         if (data->check_connectivity &&
693             data->transport_options.check_self_contained_and_connected)
694                 set_helper_option(transport, "check-connectivity", "true");
695
696         if (transport->cloning)
697                 set_helper_option(transport, "cloning", "true");
698
699         if (data->transport_options.update_shallow)
700                 set_helper_option(transport, "update-shallow", "true");
701
702         if (data->transport_options.filter_options.choice) {
703                 const char *spec = expand_list_objects_filter_spec(
704                         &data->transport_options.filter_options);
705                 set_helper_option(transport, "filter", spec);
706         }
707
708         if (data->transport_options.negotiation_tips)
709                 warning("Ignoring --negotiation-tip because the protocol does not support it.");
710
711         if (data->fetch)
712                 return fetch_with_fetch(transport, nr_heads, to_fetch);
713
714         if (data->import)
715                 return fetch_with_import(transport, nr_heads, to_fetch);
716
717         return -1;
718 }
719
720 static int push_update_ref_status(struct strbuf *buf,
721                                    struct ref **ref,
722                                    struct ref *remote_refs)
723 {
724         char *refname, *msg;
725         int status, forced = 0;
726
727         if (starts_with(buf->buf, "ok ")) {
728                 status = REF_STATUS_OK;
729                 refname = buf->buf + 3;
730         } else if (starts_with(buf->buf, "error ")) {
731                 status = REF_STATUS_REMOTE_REJECT;
732                 refname = buf->buf + 6;
733         } else
734                 die(_("expected ok/error, helper said '%s'"), buf->buf);
735
736         msg = strchr(refname, ' ');
737         if (msg) {
738                 struct strbuf msg_buf = STRBUF_INIT;
739                 const char *end;
740
741                 *msg++ = '\0';
742                 if (!unquote_c_style(&msg_buf, msg, &end))
743                         msg = strbuf_detach(&msg_buf, NULL);
744                 else
745                         msg = xstrdup(msg);
746                 strbuf_release(&msg_buf);
747
748                 if (!strcmp(msg, "no match")) {
749                         status = REF_STATUS_NONE;
750                         FREE_AND_NULL(msg);
751                 }
752                 else if (!strcmp(msg, "up to date")) {
753                         status = REF_STATUS_UPTODATE;
754                         FREE_AND_NULL(msg);
755                 }
756                 else if (!strcmp(msg, "non-fast forward")) {
757                         status = REF_STATUS_REJECT_NONFASTFORWARD;
758                         FREE_AND_NULL(msg);
759                 }
760                 else if (!strcmp(msg, "already exists")) {
761                         status = REF_STATUS_REJECT_ALREADY_EXISTS;
762                         FREE_AND_NULL(msg);
763                 }
764                 else if (!strcmp(msg, "fetch first")) {
765                         status = REF_STATUS_REJECT_FETCH_FIRST;
766                         FREE_AND_NULL(msg);
767                 }
768                 else if (!strcmp(msg, "needs force")) {
769                         status = REF_STATUS_REJECT_NEEDS_FORCE;
770                         FREE_AND_NULL(msg);
771                 }
772                 else if (!strcmp(msg, "stale info")) {
773                         status = REF_STATUS_REJECT_STALE;
774                         FREE_AND_NULL(msg);
775                 }
776                 else if (!strcmp(msg, "forced update")) {
777                         forced = 1;
778                         FREE_AND_NULL(msg);
779                 }
780         }
781
782         if (*ref)
783                 *ref = find_ref_by_name(*ref, refname);
784         if (!*ref)
785                 *ref = find_ref_by_name(remote_refs, refname);
786         if (!*ref) {
787                 warning(_("helper reported unexpected status of %s"), refname);
788                 return 1;
789         }
790
791         if ((*ref)->status != REF_STATUS_NONE) {
792                 /*
793                  * Earlier, the ref was marked not to be pushed, so ignore the ref
794                  * status reported by the remote helper if the latter is 'no match'.
795                  */
796                 if (status == REF_STATUS_NONE)
797                         return 1;
798         }
799
800         (*ref)->status = status;
801         (*ref)->forced_update |= forced;
802         (*ref)->remote_status = msg;
803         return !(status == REF_STATUS_OK);
804 }
805
806 static int push_update_refs_status(struct helper_data *data,
807                                     struct ref *remote_refs,
808                                     int flags)
809 {
810         struct strbuf buf = STRBUF_INIT;
811         struct ref *ref = remote_refs;
812         int ret = 0;
813
814         for (;;) {
815                 char *private;
816
817                 if (recvline(data, &buf)) {
818                         ret = 1;
819                         break;
820                 }
821
822                 if (!buf.len)
823                         break;
824
825                 if (push_update_ref_status(&buf, &ref, remote_refs))
826                         continue;
827
828                 if (flags & TRANSPORT_PUSH_DRY_RUN || !data->rs.nr || data->no_private_update)
829                         continue;
830
831                 /* propagate back the update to the remote namespace */
832                 private = apply_refspecs(&data->rs, ref->name);
833                 if (!private)
834                         continue;
835                 update_ref("update by helper", private, &ref->new_oid, NULL,
836                            0, 0);
837                 free(private);
838         }
839         strbuf_release(&buf);
840         return ret;
841 }
842
843 static void set_common_push_options(struct transport *transport,
844                                    const char *name, int flags)
845 {
846         if (flags & TRANSPORT_PUSH_DRY_RUN) {
847                 if (set_helper_option(transport, "dry-run", "true") != 0)
848                         die(_("helper %s does not support dry-run"), name);
849         } else if (flags & TRANSPORT_PUSH_CERT_ALWAYS) {
850                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
851                         die(_("helper %s does not support --signed"), name);
852         } else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED) {
853                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "if-asked") != 0)
854                         die(_("helper %s does not support --signed=if-asked"), name);
855         }
856
857         if (flags & TRANSPORT_PUSH_ATOMIC)
858                 if (set_helper_option(transport, TRANS_OPT_ATOMIC, "true") != 0)
859                         die(_("helper %s does not support --atomic"), name);
860
861         if (flags & TRANSPORT_PUSH_OPTIONS) {
862                 struct string_list_item *item;
863                 for_each_string_list_item(item, transport->push_options)
864                         if (set_helper_option(transport, "push-option", item->string) != 0)
865                                 die(_("helper %s does not support 'push-option'"), name);
866         }
867 }
868
869 static int push_refs_with_push(struct transport *transport,
870                                struct ref *remote_refs, int flags)
871 {
872         int force_all = flags & TRANSPORT_PUSH_FORCE;
873         int mirror = flags & TRANSPORT_PUSH_MIRROR;
874         int atomic = flags & TRANSPORT_PUSH_ATOMIC;
875         struct helper_data *data = transport->data;
876         struct strbuf buf = STRBUF_INIT;
877         struct ref *ref;
878         struct string_list cas_options = STRING_LIST_INIT_DUP;
879         struct string_list_item *cas_option;
880
881         get_helper(transport);
882         if (!data->push)
883                 return 1;
884
885         for (ref = remote_refs; ref; ref = ref->next) {
886                 if (!ref->peer_ref && !mirror)
887                         continue;
888
889                 /* Check for statuses set by set_ref_status_for_push() */
890                 switch (ref->status) {
891                 case REF_STATUS_REJECT_NONFASTFORWARD:
892                 case REF_STATUS_REJECT_STALE:
893                 case REF_STATUS_REJECT_ALREADY_EXISTS:
894                         if (atomic) {
895                                 string_list_clear(&cas_options, 0);
896                                 return 0;
897                         } else
898                                 continue;
899                 case REF_STATUS_UPTODATE:
900                         continue;
901                 default:
902                         ; /* do nothing */
903                 }
904
905                 if (force_all)
906                         ref->force = 1;
907
908                 strbuf_addstr(&buf, "push ");
909                 if (!ref->deletion) {
910                         if (ref->force)
911                                 strbuf_addch(&buf, '+');
912                         if (ref->peer_ref)
913                                 strbuf_addstr(&buf, ref->peer_ref->name);
914                         else
915                                 strbuf_addstr(&buf, oid_to_hex(&ref->new_oid));
916                 }
917                 strbuf_addch(&buf, ':');
918                 strbuf_addstr(&buf, ref->name);
919                 strbuf_addch(&buf, '\n');
920
921                 /*
922                  * The "--force-with-lease" options without explicit
923                  * values to expect have already been expanded into
924                  * the ref->old_oid_expect[] field; we can ignore
925                  * transport->smart_options->cas altogether and instead
926                  * can enumerate them from the refs.
927                  */
928                 if (ref->expect_old_sha1) {
929                         struct strbuf cas = STRBUF_INIT;
930                         strbuf_addf(&cas, "%s:%s",
931                                     ref->name, oid_to_hex(&ref->old_oid_expect));
932                         string_list_append_nodup(&cas_options,
933                                                  strbuf_detach(&cas, NULL));
934                 }
935         }
936         if (buf.len == 0) {
937                 string_list_clear(&cas_options, 0);
938                 return 0;
939         }
940
941         for_each_string_list_item(cas_option, &cas_options)
942                 set_helper_option(transport, "cas", cas_option->string);
943         set_common_push_options(transport, data->name, flags);
944
945         strbuf_addch(&buf, '\n');
946         sendline(data, &buf);
947         strbuf_release(&buf);
948         string_list_clear(&cas_options, 0);
949
950         return push_update_refs_status(data, remote_refs, flags);
951 }
952
953 static int push_refs_with_export(struct transport *transport,
954                 struct ref *remote_refs, int flags)
955 {
956         struct ref *ref;
957         struct child_process *helper, exporter;
958         struct helper_data *data = transport->data;
959         struct string_list revlist_args = STRING_LIST_INIT_DUP;
960         struct strbuf buf = STRBUF_INIT;
961
962         if (!data->rs.nr)
963                 die(_("remote-helper doesn't support push; refspec needed"));
964
965         set_common_push_options(transport, data->name, flags);
966         if (flags & TRANSPORT_PUSH_FORCE) {
967                 if (set_helper_option(transport, "force", "true") != 0)
968                         warning(_("helper %s does not support 'force'"), data->name);
969         }
970
971         helper = get_helper(transport);
972
973         write_constant(helper->in, "export\n");
974
975         for (ref = remote_refs; ref; ref = ref->next) {
976                 char *private;
977                 struct object_id oid;
978
979                 private = apply_refspecs(&data->rs, ref->name);
980                 if (private && !get_oid(private, &oid)) {
981                         strbuf_addf(&buf, "^%s", private);
982                         string_list_append_nodup(&revlist_args,
983                                                  strbuf_detach(&buf, NULL));
984                         oidcpy(&ref->old_oid, &oid);
985                 }
986                 free(private);
987
988                 if (ref->peer_ref) {
989                         if (strcmp(ref->name, ref->peer_ref->name)) {
990                                 if (!ref->deletion) {
991                                         const char *name;
992                                         int flag;
993
994                                         /* Follow symbolic refs (mainly for HEAD). */
995                                         name = resolve_ref_unsafe(ref->peer_ref->name,
996                                                                   RESOLVE_REF_READING,
997                                                                   &oid, &flag);
998                                         if (!name || !(flag & REF_ISSYMREF))
999                                                 name = ref->peer_ref->name;
1000
1001                                         strbuf_addf(&buf, "%s:%s", name, ref->name);
1002                                 } else
1003                                         strbuf_addf(&buf, ":%s", ref->name);
1004
1005                                 string_list_append(&revlist_args, "--refspec");
1006                                 string_list_append(&revlist_args, buf.buf);
1007                                 strbuf_release(&buf);
1008                         }
1009                         if (!ref->deletion)
1010                                 string_list_append(&revlist_args, ref->peer_ref->name);
1011                 }
1012         }
1013
1014         if (get_exporter(transport, &exporter, &revlist_args))
1015                 die(_("couldn't run fast-export"));
1016
1017         string_list_clear(&revlist_args, 1);
1018
1019         if (finish_command(&exporter))
1020                 die(_("error while running fast-export"));
1021         if (push_update_refs_status(data, remote_refs, flags))
1022                 return 1;
1023
1024         if (data->export_marks) {
1025                 strbuf_addf(&buf, "%s.tmp", data->export_marks);
1026                 rename(buf.buf, data->export_marks);
1027                 strbuf_release(&buf);
1028         }
1029
1030         return 0;
1031 }
1032
1033 static int push_refs(struct transport *transport,
1034                 struct ref *remote_refs, int flags)
1035 {
1036         struct helper_data *data = transport->data;
1037
1038         if (process_connect(transport, 1)) {
1039                 do_take_over(transport);
1040                 return transport->vtable->push_refs(transport, remote_refs, flags);
1041         }
1042
1043         if (!remote_refs) {
1044                 fprintf(stderr,
1045                         _("No refs in common and none specified; doing nothing.\n"
1046                           "Perhaps you should specify a branch such as 'master'.\n"));
1047                 return 0;
1048         }
1049
1050         if (data->push)
1051                 return push_refs_with_push(transport, remote_refs, flags);
1052
1053         if (data->export)
1054                 return push_refs_with_export(transport, remote_refs, flags);
1055
1056         return -1;
1057 }
1058
1059
1060 static int has_attribute(const char *attrs, const char *attr)
1061 {
1062         int len;
1063         if (!attrs)
1064                 return 0;
1065
1066         len = strlen(attr);
1067         for (;;) {
1068                 const char *space = strchrnul(attrs, ' ');
1069                 if (len == space - attrs && !strncmp(attrs, attr, len))
1070                         return 1;
1071                 if (!*space)
1072                         return 0;
1073                 attrs = space + 1;
1074         }
1075 }
1076
1077 static struct ref *get_refs_list(struct transport *transport, int for_push,
1078                                  const struct argv_array *ref_prefixes)
1079 {
1080         get_helper(transport);
1081
1082         if (process_connect(transport, for_push)) {
1083                 do_take_over(transport);
1084                 return transport->vtable->get_refs_list(transport, for_push, ref_prefixes);
1085         }
1086
1087         return get_refs_list_using_list(transport, for_push);
1088 }
1089
1090 static struct ref *get_refs_list_using_list(struct transport *transport,
1091                                             int for_push)
1092 {
1093         struct helper_data *data = transport->data;
1094         struct child_process *helper;
1095         struct ref *ret = NULL;
1096         struct ref **tail = &ret;
1097         struct ref *posn;
1098         struct strbuf buf = STRBUF_INIT;
1099
1100         data->get_refs_list_called = 1;
1101         helper = get_helper(transport);
1102
1103         if (data->push && for_push)
1104                 write_str_in_full(helper->in, "list for-push\n");
1105         else
1106                 write_str_in_full(helper->in, "list\n");
1107
1108         while (1) {
1109                 char *eov, *eon;
1110                 if (recvline(data, &buf))
1111                         exit(128);
1112
1113                 if (!*buf.buf)
1114                         break;
1115
1116                 eov = strchr(buf.buf, ' ');
1117                 if (!eov)
1118                         die(_("malformed response in ref list: %s"), buf.buf);
1119                 eon = strchr(eov + 1, ' ');
1120                 *eov = '\0';
1121                 if (eon)
1122                         *eon = '\0';
1123                 *tail = alloc_ref(eov + 1);
1124                 if (buf.buf[0] == '@')
1125                         (*tail)->symref = xstrdup(buf.buf + 1);
1126                 else if (buf.buf[0] != '?')
1127                         get_oid_hex(buf.buf, &(*tail)->old_oid);
1128                 if (eon) {
1129                         if (has_attribute(eon + 1, "unchanged")) {
1130                                 (*tail)->status |= REF_STATUS_UPTODATE;
1131                                 if (read_ref((*tail)->name, &(*tail)->old_oid) < 0)
1132                                         die(_("could not read ref %s"),
1133                                             (*tail)->name);
1134                         }
1135                 }
1136                 tail = &((*tail)->next);
1137         }
1138         if (debug)
1139                 fprintf(stderr, "Debug: Read ref listing.\n");
1140         strbuf_release(&buf);
1141
1142         for (posn = ret; posn; posn = posn->next)
1143                 resolve_remote_symref(posn, ret);
1144
1145         return ret;
1146 }
1147
1148 static struct transport_vtable vtable = {
1149         set_helper_option,
1150         get_refs_list,
1151         fetch,
1152         push_refs,
1153         connect_helper,
1154         release_helper
1155 };
1156
1157 int transport_helper_init(struct transport *transport, const char *name)
1158 {
1159         struct helper_data *data = xcalloc(1, sizeof(*data));
1160         data->name = name;
1161
1162         transport_check_allowed(name);
1163
1164         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1165                 debug = 1;
1166
1167         transport->data = data;
1168         transport->vtable = &vtable;
1169         transport->smart_options = &(data->transport_options);
1170         return 0;
1171 }
1172
1173 /*
1174  * Linux pipes can buffer 65536 bytes at once (and most platforms can
1175  * buffer less), so attempt reads and writes with up to that size.
1176  */
1177 #define BUFFERSIZE 65536
1178 /* This should be enough to hold debugging message. */
1179 #define PBUFFERSIZE 8192
1180
1181 /* Print bidirectional transfer loop debug message. */
1182 __attribute__((format (printf, 1, 2)))
1183 static void transfer_debug(const char *fmt, ...)
1184 {
1185         /*
1186          * NEEDSWORK: This function is sometimes used from multiple threads, and
1187          * we end up using debug_enabled racily. That "should not matter" since
1188          * we always write the same value, but it's still wrong. This function
1189          * is listed in .tsan-suppressions for the time being.
1190          */
1191
1192         va_list args;
1193         char msgbuf[PBUFFERSIZE];
1194         static int debug_enabled = -1;
1195
1196         if (debug_enabled < 0)
1197                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1198         if (!debug_enabled)
1199                 return;
1200
1201         va_start(args, fmt);
1202         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1203         va_end(args);
1204         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1205 }
1206
1207 /* Stream state: More data may be coming in this direction. */
1208 #define SSTATE_TRANSFERRING 0
1209 /*
1210  * Stream state: No more data coming in this direction, flushing rest of
1211  * data.
1212  */
1213 #define SSTATE_FLUSHING 1
1214 /* Stream state: Transfer in this direction finished. */
1215 #define SSTATE_FINISHED 2
1216
1217 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERRING)
1218 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1219 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1220
1221 /* Unidirectional transfer. */
1222 struct unidirectional_transfer {
1223         /* Source */
1224         int src;
1225         /* Destination */
1226         int dest;
1227         /* Is source socket? */
1228         int src_is_sock;
1229         /* Is destination socket? */
1230         int dest_is_sock;
1231         /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1232         int state;
1233         /* Buffer. */
1234         char buf[BUFFERSIZE];
1235         /* Buffer used. */
1236         size_t bufuse;
1237         /* Name of source. */
1238         const char *src_name;
1239         /* Name of destination. */
1240         const char *dest_name;
1241 };
1242
1243 /* Closes the target (for writing) if transfer has finished. */
1244 static void udt_close_if_finished(struct unidirectional_transfer *t)
1245 {
1246         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1247                 t->state = SSTATE_FINISHED;
1248                 if (t->dest_is_sock)
1249                         shutdown(t->dest, SHUT_WR);
1250                 else
1251                         close(t->dest);
1252                 transfer_debug("Closed %s.", t->dest_name);
1253         }
1254 }
1255
1256 /*
1257  * Tries to read data from source into buffer. If buffer is full,
1258  * no data is read. Returns 0 on success, -1 on error.
1259  */
1260 static int udt_do_read(struct unidirectional_transfer *t)
1261 {
1262         ssize_t bytes;
1263
1264         if (t->bufuse == BUFFERSIZE)
1265                 return 0;       /* No space for more. */
1266
1267         transfer_debug("%s is readable", t->src_name);
1268         bytes = xread(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1269         if (bytes < 0) {
1270                 error_errno(_("read(%s) failed"), t->src_name);
1271                 return -1;
1272         } else if (bytes == 0) {
1273                 transfer_debug("%s EOF (with %i bytes in buffer)",
1274                         t->src_name, (int)t->bufuse);
1275                 t->state = SSTATE_FLUSHING;
1276         } else if (bytes > 0) {
1277                 t->bufuse += bytes;
1278                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1279                         (int)bytes, t->src_name, (int)t->bufuse);
1280         }
1281         return 0;
1282 }
1283
1284 /* Tries to write data from buffer into destination. If buffer is empty,
1285  * no data is written. Returns 0 on success, -1 on error.
1286  */
1287 static int udt_do_write(struct unidirectional_transfer *t)
1288 {
1289         ssize_t bytes;
1290
1291         if (t->bufuse == 0)
1292                 return 0;       /* Nothing to write. */
1293
1294         transfer_debug("%s is writable", t->dest_name);
1295         bytes = xwrite(t->dest, t->buf, t->bufuse);
1296         if (bytes < 0) {
1297                 error_errno(_("write(%s) failed"), t->dest_name);
1298                 return -1;
1299         } else if (bytes > 0) {
1300                 t->bufuse -= bytes;
1301                 if (t->bufuse)
1302                         memmove(t->buf, t->buf + bytes, t->bufuse);
1303                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1304                         (int)bytes, t->dest_name, (int)t->bufuse);
1305         }
1306         return 0;
1307 }
1308
1309
1310 /* State of bidirectional transfer loop. */
1311 struct bidirectional_transfer_state {
1312         /* Direction from program to git. */
1313         struct unidirectional_transfer ptg;
1314         /* Direction from git to program. */
1315         struct unidirectional_transfer gtp;
1316 };
1317
1318 static void *udt_copy_task_routine(void *udt)
1319 {
1320         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1321         while (t->state != SSTATE_FINISHED) {
1322                 if (STATE_NEEDS_READING(t->state))
1323                         if (udt_do_read(t))
1324                                 return NULL;
1325                 if (STATE_NEEDS_WRITING(t->state))
1326                         if (udt_do_write(t))
1327                                 return NULL;
1328                 if (STATE_NEEDS_CLOSING(t->state))
1329                         udt_close_if_finished(t);
1330         }
1331         return udt;     /* Just some non-NULL value. */
1332 }
1333
1334 #ifndef NO_PTHREADS
1335
1336 /*
1337  * Join thread, with appropriate errors on failure. Name is name for the
1338  * thread (for error messages). Returns 0 on success, 1 on failure.
1339  */
1340 static int tloop_join(pthread_t thread, const char *name)
1341 {
1342         int err;
1343         void *tret;
1344         err = pthread_join(thread, &tret);
1345         if (!tret) {
1346                 error(_("%s thread failed"), name);
1347                 return 1;
1348         }
1349         if (err) {
1350                 error(_("%s thread failed to join: %s"), name, strerror(err));
1351                 return 1;
1352         }
1353         return 0;
1354 }
1355
1356 /*
1357  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1358  * -1 on failure.
1359  */
1360 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1361 {
1362         pthread_t gtp_thread;
1363         pthread_t ptg_thread;
1364         int err;
1365         int ret = 0;
1366         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1367                 &s->gtp);
1368         if (err)
1369                 die(_("can't start thread for copying data: %s"), strerror(err));
1370         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1371                 &s->ptg);
1372         if (err)
1373                 die(_("can't start thread for copying data: %s"), strerror(err));
1374
1375         ret |= tloop_join(gtp_thread, "Git to program copy");
1376         ret |= tloop_join(ptg_thread, "Program to git copy");
1377         return ret;
1378 }
1379 #else
1380
1381 /* Close the source and target (for writing) for transfer. */
1382 static void udt_kill_transfer(struct unidirectional_transfer *t)
1383 {
1384         t->state = SSTATE_FINISHED;
1385         /*
1386          * Socket read end left open isn't a disaster if nobody
1387          * attempts to read from it (mingw compat headers do not
1388          * have SHUT_RD)...
1389          *
1390          * We can't fully close the socket since otherwise gtp
1391          * task would first close the socket it sends data to
1392          * while closing the ptg file descriptors.
1393          */
1394         if (!t->src_is_sock)
1395                 close(t->src);
1396         if (t->dest_is_sock)
1397                 shutdown(t->dest, SHUT_WR);
1398         else
1399                 close(t->dest);
1400 }
1401
1402 /*
1403  * Join process, with appropriate errors on failure. Name is name for the
1404  * process (for error messages). Returns 0 on success, 1 on failure.
1405  */
1406 static int tloop_join(pid_t pid, const char *name)
1407 {
1408         int tret;
1409         if (waitpid(pid, &tret, 0) < 0) {
1410                 error_errno(_("%s process failed to wait"), name);
1411                 return 1;
1412         }
1413         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1414                 error(_("%s process failed"), name);
1415                 return 1;
1416         }
1417         return 0;
1418 }
1419
1420 /*
1421  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1422  * -1 on failure.
1423  */
1424 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1425 {
1426         pid_t pid1, pid2;
1427         int ret = 0;
1428
1429         /* Fork thread #1: git to program. */
1430         pid1 = fork();
1431         if (pid1 < 0)
1432                 die_errno(_("can't start thread for copying data"));
1433         else if (pid1 == 0) {
1434                 udt_kill_transfer(&s->ptg);
1435                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1436         }
1437
1438         /* Fork thread #2: program to git. */
1439         pid2 = fork();
1440         if (pid2 < 0)
1441                 die_errno(_("can't start thread for copying data"));
1442         else if (pid2 == 0) {
1443                 udt_kill_transfer(&s->gtp);
1444                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1445         }
1446
1447         /*
1448          * Close both streams in parent as to not interfere with
1449          * end of file detection and wait for both tasks to finish.
1450          */
1451         udt_kill_transfer(&s->gtp);
1452         udt_kill_transfer(&s->ptg);
1453         ret |= tloop_join(pid1, "Git to program copy");
1454         ret |= tloop_join(pid2, "Program to git copy");
1455         return ret;
1456 }
1457 #endif
1458
1459 /*
1460  * Copies data from stdin to output and from input to stdout simultaneously.
1461  * Additionally filtering through given filter. If filter is NULL, uses
1462  * identity filter.
1463  */
1464 int bidirectional_transfer_loop(int input, int output)
1465 {
1466         struct bidirectional_transfer_state state;
1467
1468         /* Fill the state fields. */
1469         state.ptg.src = input;
1470         state.ptg.dest = 1;
1471         state.ptg.src_is_sock = (input == output);
1472         state.ptg.dest_is_sock = 0;
1473         state.ptg.state = SSTATE_TRANSFERRING;
1474         state.ptg.bufuse = 0;
1475         state.ptg.src_name = "remote input";
1476         state.ptg.dest_name = "stdout";
1477
1478         state.gtp.src = 0;
1479         state.gtp.dest = output;
1480         state.gtp.src_is_sock = 0;
1481         state.gtp.dest_is_sock = (input == output);
1482         state.gtp.state = SSTATE_TRANSFERRING;
1483         state.gtp.bufuse = 0;
1484         state.gtp.src_name = "stdin";
1485         state.gtp.dest_name = "remote output";
1486
1487         return tloop_spawnwait_tasks(&state);
1488 }