Merge branch 'jt/t5551-protocol-v2-does-not-have-half-auth'
[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         char *export_marks;
37         char *import_marks;
38         /* These go from remote name (as in "list") to private name */
39         struct refspec rs;
40         /* Transport options for fetch-pack/send-pack (should one of
41          * those be invoked).
42          */
43         struct git_transport_options transport_options;
44 };
45
46 static void sendline(struct helper_data *helper, struct strbuf *buffer)
47 {
48         if (debug)
49                 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
50         if (write_in_full(helper->helper->in, buffer->buf, buffer->len) < 0)
51                 die_errno(_("full write to remote helper failed"));
52 }
53
54 static int recvline_fh(FILE *helper, struct strbuf *buffer)
55 {
56         strbuf_reset(buffer);
57         if (debug)
58                 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
59         if (strbuf_getline(buffer, helper) == EOF) {
60                 if (debug)
61                         fprintf(stderr, "Debug: Remote helper quit.\n");
62                 return 1;
63         }
64
65         if (debug)
66                 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
67         return 0;
68 }
69
70 static int recvline(struct helper_data *helper, struct strbuf *buffer)
71 {
72         return recvline_fh(helper->out, buffer);
73 }
74
75 static void write_constant(int fd, const char *str)
76 {
77         if (debug)
78                 fprintf(stderr, "Debug: Remote helper: -> %s", str);
79         if (write_in_full(fd, str, strlen(str)) < 0)
80                 die_errno(_("full write to remote helper failed"));
81 }
82
83 static const char *remove_ext_force(const char *url)
84 {
85         if (url) {
86                 const char *colon = strchr(url, ':');
87                 if (colon && colon[1] == ':')
88                         return colon + 2;
89         }
90         return url;
91 }
92
93 static void do_take_over(struct transport *transport)
94 {
95         struct helper_data *data;
96         data = (struct helper_data *)transport->data;
97         transport_take_over(transport, data->helper);
98         fclose(data->out);
99         free(data);
100 }
101
102 static void standard_options(struct transport *t);
103
104 static struct child_process *get_helper(struct transport *transport)
105 {
106         struct helper_data *data = transport->data;
107         struct strbuf buf = STRBUF_INIT;
108         struct child_process *helper;
109         int duped;
110         int code;
111
112         if (data->helper)
113                 return data->helper;
114
115         helper = xmalloc(sizeof(*helper));
116         child_process_init(helper);
117         helper->in = -1;
118         helper->out = -1;
119         helper->err = 0;
120         argv_array_pushf(&helper->args, "git-remote-%s", data->name);
121         argv_array_push(&helper->args, transport->remote->name);
122         argv_array_push(&helper->args, remove_ext_force(transport->url));
123         helper->git_cmd = 0;
124         helper->silent_exec_failure = 1;
125
126         if (have_git_dir())
127                 argv_array_pushf(&helper->env_array, "%s=%s",
128                                  GIT_DIR_ENVIRONMENT, get_git_dir());
129
130         helper->trace2_child_class = helper->args.argv[0]; /* "remote-<name>" */
131
132         code = start_command(helper);
133         if (code < 0 && errno == ENOENT)
134                 die(_("unable to find remote helper for '%s'"), data->name);
135         else if (code != 0)
136                 exit(code);
137
138         data->helper = helper;
139         data->no_disconnect_req = 0;
140         refspec_init(&data->rs, REFSPEC_FETCH);
141
142         /*
143          * Open the output as FILE* so strbuf_getline_*() family of
144          * functions can be used.
145          * Do this with duped fd because fclose() will close the fd,
146          * and stuff like taking over will require the fd to remain.
147          */
148         duped = dup(helper->out);
149         if (duped < 0)
150                 die_errno(_("can't dup helper output fd"));
151         data->out = xfdopen(duped, "r");
152
153         write_constant(helper->in, "capabilities\n");
154
155         while (1) {
156                 const char *capname, *arg;
157                 int mandatory = 0;
158                 if (recvline(data, &buf))
159                         exit(128);
160
161                 if (!*buf.buf)
162                         break;
163
164                 if (*buf.buf == '*') {
165                         capname = buf.buf + 1;
166                         mandatory = 1;
167                 } else
168                         capname = buf.buf;
169
170                 if (debug)
171                         fprintf(stderr, "Debug: Got cap %s\n", capname);
172                 if (!strcmp(capname, "fetch"))
173                         data->fetch = 1;
174                 else if (!strcmp(capname, "option"))
175                         data->option = 1;
176                 else if (!strcmp(capname, "push"))
177                         data->push = 1;
178                 else if (!strcmp(capname, "import"))
179                         data->import = 1;
180                 else if (!strcmp(capname, "bidi-import"))
181                         data->bidi_import = 1;
182                 else if (!strcmp(capname, "export"))
183                         data->export = 1;
184                 else if (!strcmp(capname, "check-connectivity"))
185                         data->check_connectivity = 1;
186                 else if (skip_prefix(capname, "refspec ", &arg)) {
187                         refspec_append(&data->rs, arg);
188                 } else if (!strcmp(capname, "connect")) {
189                         data->connect = 1;
190                 } else if (!strcmp(capname, "stateless-connect")) {
191                         data->stateless_connect = 1;
192                 } else if (!strcmp(capname, "signed-tags")) {
193                         data->signed_tags = 1;
194                 } else if (skip_prefix(capname, "export-marks ", &arg)) {
195                         data->export_marks = xstrdup(arg);
196                 } else if (skip_prefix(capname, "import-marks ", &arg)) {
197                         data->import_marks = xstrdup(arg);
198                 } else if (starts_with(capname, "no-private-update")) {
199                         data->no_private_update = 1;
200                 } else if (mandatory) {
201                         die(_("unknown mandatory capability %s; this remote "
202                               "helper probably needs newer version of Git"),
203                             capname);
204                 }
205         }
206         if (!data->rs.nr && (data->import || data->bidi_import || data->export)) {
207                 warning(_("this remote helper should implement refspec capability"));
208         }
209         strbuf_release(&buf);
210         if (debug)
211                 fprintf(stderr, "Debug: Capabilities complete.\n");
212         standard_options(transport);
213         return data->helper;
214 }
215
216 static int disconnect_helper(struct transport *transport)
217 {
218         struct helper_data *data = transport->data;
219         int res = 0;
220
221         if (data->helper) {
222                 if (debug)
223                         fprintf(stderr, "Debug: Disconnecting.\n");
224                 if (!data->no_disconnect_req) {
225                         /*
226                          * Ignore write errors; there's nothing we can do,
227                          * since we're about to close the pipe anyway. And the
228                          * most likely error is EPIPE due to the helper dying
229                          * to report an error itself.
230                          */
231                         sigchain_push(SIGPIPE, SIG_IGN);
232                         xwrite(data->helper->in, "\n", 1);
233                         sigchain_pop(SIGPIPE);
234                 }
235                 close(data->helper->in);
236                 close(data->helper->out);
237                 fclose(data->out);
238                 res = finish_command(data->helper);
239                 FREE_AND_NULL(data->helper);
240         }
241         return res;
242 }
243
244 static const char *unsupported_options[] = {
245         TRANS_OPT_UPLOADPACK,
246         TRANS_OPT_RECEIVEPACK,
247         TRANS_OPT_THIN,
248         TRANS_OPT_KEEP
249         };
250
251 static const char *boolean_options[] = {
252         TRANS_OPT_THIN,
253         TRANS_OPT_KEEP,
254         TRANS_OPT_FOLLOWTAGS,
255         TRANS_OPT_DEEPEN_RELATIVE
256         };
257
258 static int strbuf_set_helper_option(struct helper_data *data,
259                                     struct strbuf *buf)
260 {
261         int ret;
262
263         sendline(data, buf);
264         if (recvline(data, buf))
265                 exit(128);
266
267         if (!strcmp(buf->buf, "ok"))
268                 ret = 0;
269         else if (starts_with(buf->buf, "error"))
270                 ret = -1;
271         else if (!strcmp(buf->buf, "unsupported"))
272                 ret = 1;
273         else {
274                 warning(_("%s unexpectedly said: '%s'"), data->name, buf->buf);
275                 ret = 1;
276         }
277         return ret;
278 }
279
280 static int string_list_set_helper_option(struct helper_data *data,
281                                          const char *name,
282                                          struct string_list *list)
283 {
284         struct strbuf buf = STRBUF_INIT;
285         int i, ret = 0;
286
287         for (i = 0; i < list->nr; i++) {
288                 strbuf_addf(&buf, "option %s ", name);
289                 quote_c_style(list->items[i].string, &buf, NULL, 0);
290                 strbuf_addch(&buf, '\n');
291
292                 if ((ret = strbuf_set_helper_option(data, &buf)))
293                         break;
294                 strbuf_reset(&buf);
295         }
296         strbuf_release(&buf);
297         return ret;
298 }
299
300 static int set_helper_option(struct transport *transport,
301                           const char *name, const char *value)
302 {
303         struct helper_data *data = transport->data;
304         struct strbuf buf = STRBUF_INIT;
305         int i, ret, is_bool = 0;
306
307         get_helper(transport);
308
309         if (!data->option)
310                 return 1;
311
312         if (!strcmp(name, "deepen-not"))
313                 return string_list_set_helper_option(data, name,
314                                                      (struct string_list *)value);
315
316         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
317                 if (!strcmp(name, unsupported_options[i]))
318                         return 1;
319         }
320
321         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
322                 if (!strcmp(name, boolean_options[i])) {
323                         is_bool = 1;
324                         break;
325                 }
326         }
327
328         strbuf_addf(&buf, "option %s ", name);
329         if (is_bool)
330                 strbuf_addstr(&buf, value ? "true" : "false");
331         else
332                 quote_c_style(value, &buf, NULL, 0);
333         strbuf_addch(&buf, '\n');
334
335         ret = strbuf_set_helper_option(data, &buf);
336         strbuf_release(&buf);
337         return ret;
338 }
339
340 static void standard_options(struct transport *t)
341 {
342         char buf[16];
343         int v = t->verbose;
344
345         set_helper_option(t, "progress", t->progress ? "true" : "false");
346
347         xsnprintf(buf, sizeof(buf), "%d", v + 1);
348         set_helper_option(t, "verbosity", buf);
349
350         switch (t->family) {
351         case TRANSPORT_FAMILY_ALL:
352                 /*
353                  * this is already the default,
354                  * do not break old remote helpers by setting "all" here
355                  */
356                 break;
357         case TRANSPORT_FAMILY_IPV4:
358                 set_helper_option(t, "family", "ipv4");
359                 break;
360         case TRANSPORT_FAMILY_IPV6:
361                 set_helper_option(t, "family", "ipv6");
362                 break;
363         }
364 }
365
366 static int release_helper(struct transport *transport)
367 {
368         int res = 0;
369         struct helper_data *data = transport->data;
370         refspec_clear(&data->rs);
371         res = disconnect_helper(transport);
372         free(transport->data);
373         return res;
374 }
375
376 static int fetch_with_fetch(struct transport *transport,
377                             int nr_heads, struct ref **to_fetch)
378 {
379         struct helper_data *data = transport->data;
380         int i;
381         struct strbuf buf = STRBUF_INIT;
382
383         for (i = 0; i < nr_heads; i++) {
384                 const struct ref *posn = to_fetch[i];
385                 if (posn->status & REF_STATUS_UPTODATE)
386                         continue;
387
388                 strbuf_addf(&buf, "fetch %s %s\n",
389                             oid_to_hex(&posn->old_oid),
390                             posn->symref ? posn->symref : posn->name);
391         }
392
393         strbuf_addch(&buf, '\n');
394         sendline(data, &buf);
395
396         while (1) {
397                 if (recvline(data, &buf))
398                         exit(128);
399
400                 if (starts_with(buf.buf, "lock ")) {
401                         const char *name = buf.buf + 5;
402                         if (transport->pack_lockfile)
403                                 warning(_("%s also locked %s"), data->name, name);
404                         else
405                                 transport->pack_lockfile = xstrdup(name);
406                 }
407                 else if (data->check_connectivity &&
408                          data->transport_options.check_self_contained_and_connected &&
409                          !strcmp(buf.buf, "connectivity-ok"))
410                         data->transport_options.self_contained_and_connected = 1;
411                 else if (!buf.len)
412                         break;
413                 else
414                         warning(_("%s unexpectedly said: '%s'"), data->name, buf.buf);
415         }
416         strbuf_release(&buf);
417         return 0;
418 }
419
420 static int get_importer(struct transport *transport, struct child_process *fastimport)
421 {
422         struct child_process *helper = get_helper(transport);
423         struct helper_data *data = transport->data;
424         int cat_blob_fd, code;
425         child_process_init(fastimport);
426         fastimport->in = helper->out;
427         argv_array_push(&fastimport->args, "fast-import");
428         argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
429
430         if (data->bidi_import) {
431                 cat_blob_fd = xdup(helper->in);
432                 argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
433         }
434         fastimport->git_cmd = 1;
435
436         code = start_command(fastimport);
437         return code;
438 }
439
440 static int get_exporter(struct transport *transport,
441                         struct child_process *fastexport,
442                         struct string_list *revlist_args)
443 {
444         struct helper_data *data = transport->data;
445         struct child_process *helper = get_helper(transport);
446         int i;
447
448         child_process_init(fastexport);
449
450         /* we need to duplicate helper->in because we want to use it after
451          * fastexport is done with it. */
452         fastexport->out = dup(helper->in);
453         argv_array_push(&fastexport->args, "fast-export");
454         argv_array_push(&fastexport->args, "--use-done-feature");
455         argv_array_push(&fastexport->args, data->signed_tags ?
456                 "--signed-tags=verbatim" : "--signed-tags=warn-strip");
457         if (data->export_marks)
458                 argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
459         if (data->import_marks)
460                 argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
461
462         for (i = 0; i < revlist_args->nr; i++)
463                 argv_array_push(&fastexport->args, revlist_args->items[i].string);
464
465         fastexport->git_cmd = 1;
466         return start_command(fastexport);
467 }
468
469 static int fetch_with_import(struct transport *transport,
470                              int nr_heads, struct ref **to_fetch)
471 {
472         struct child_process fastimport;
473         struct helper_data *data = transport->data;
474         int i;
475         struct ref *posn;
476         struct strbuf buf = STRBUF_INIT;
477
478         get_helper(transport);
479
480         if (get_importer(transport, &fastimport))
481                 die(_("couldn't run fast-import"));
482
483         for (i = 0; i < nr_heads; i++) {
484                 posn = to_fetch[i];
485                 if (posn->status & REF_STATUS_UPTODATE)
486                         continue;
487
488                 strbuf_addf(&buf, "import %s\n",
489                             posn->symref ? posn->symref : posn->name);
490                 sendline(data, &buf);
491                 strbuf_reset(&buf);
492         }
493
494         write_constant(data->helper->in, "\n");
495         /*
496          * remote-helpers that advertise the bidi-import capability are required to
497          * buffer the complete batch of import commands until this newline before
498          * sending data to fast-import.
499          * These helpers read back data from fast-import on their stdin, which could
500          * be mixed with import commands, otherwise.
501          */
502
503         if (finish_command(&fastimport))
504                 die(_("error while running fast-import"));
505
506         /*
507          * The fast-import stream of a remote helper that advertises
508          * the "refspec" capability writes to the refs named after the
509          * right hand side of the first refspec matching each ref we
510          * were fetching.
511          *
512          * (If no "refspec" capability was specified, for historical
513          * reasons we default to the equivalent of *:*.)
514          *
515          * Store the result in to_fetch[i].old_sha1.  Callers such
516          * as "git fetch" can use the value to write feedback to the
517          * terminal, populate FETCH_HEAD, and determine what new value
518          * should be written to peer_ref if the update is a
519          * fast-forward or this is a forced update.
520          */
521         for (i = 0; i < nr_heads; i++) {
522                 char *private, *name;
523                 posn = to_fetch[i];
524                 if (posn->status & REF_STATUS_UPTODATE)
525                         continue;
526                 name = posn->symref ? posn->symref : posn->name;
527                 if (data->rs.nr)
528                         private = apply_refspecs(&data->rs, name);
529                 else
530                         private = xstrdup(name);
531                 if (private) {
532                         if (read_ref(private, &posn->old_oid) < 0)
533                                 die(_("could not read ref %s"), private);
534                         free(private);
535                 }
536         }
537         strbuf_release(&buf);
538         return 0;
539 }
540
541 static int run_connect(struct transport *transport, struct strbuf *cmdbuf)
542 {
543         struct helper_data *data = transport->data;
544         int ret = 0;
545         int duped;
546         FILE *input;
547         struct child_process *helper;
548
549         helper = get_helper(transport);
550
551         /*
552          * Yes, dup the pipe another time, as we need unbuffered version
553          * of input pipe as FILE*. fclose() closes the underlying fd and
554          * stream buffering only can be changed before first I/O operation
555          * on it.
556          */
557         duped = dup(helper->out);
558         if (duped < 0)
559                 die_errno(_("can't dup helper output fd"));
560         input = xfdopen(duped, "r");
561         setvbuf(input, NULL, _IONBF, 0);
562
563         sendline(data, cmdbuf);
564         if (recvline_fh(input, cmdbuf))
565                 exit(128);
566
567         if (!strcmp(cmdbuf->buf, "")) {
568                 data->no_disconnect_req = 1;
569                 if (debug)
570                         fprintf(stderr, "Debug: Smart transport connection "
571                                 "ready.\n");
572                 ret = 1;
573         } else if (!strcmp(cmdbuf->buf, "fallback")) {
574                 if (debug)
575                         fprintf(stderr, "Debug: Falling back to dumb "
576                                 "transport.\n");
577         } else {
578                 die(_("unknown response to connect: %s"),
579                     cmdbuf->buf);
580         }
581
582         fclose(input);
583         return ret;
584 }
585
586 static int process_connect_service(struct transport *transport,
587                                    const char *name, const char *exec)
588 {
589         struct helper_data *data = transport->data;
590         struct strbuf cmdbuf = STRBUF_INIT;
591         int ret = 0;
592
593         /*
594          * Handle --upload-pack and friends. This is fire and forget...
595          * just warn if it fails.
596          */
597         if (strcmp(name, exec)) {
598                 int r = set_helper_option(transport, "servpath", exec);
599                 if (r > 0)
600                         warning(_("setting remote service path not supported by protocol"));
601                 else if (r < 0)
602                         warning(_("invalid remote service path"));
603         }
604
605         if (data->connect) {
606                 strbuf_addf(&cmdbuf, "connect %s\n", name);
607                 ret = run_connect(transport, &cmdbuf);
608         } else if (data->stateless_connect &&
609                    (get_protocol_version_config() == protocol_v2) &&
610                    !strcmp("git-upload-pack", name)) {
611                 strbuf_addf(&cmdbuf, "stateless-connect %s\n", name);
612                 ret = run_connect(transport, &cmdbuf);
613                 if (ret)
614                         transport->stateless_rpc = 1;
615         }
616
617         strbuf_release(&cmdbuf);
618         return ret;
619 }
620
621 static int process_connect(struct transport *transport,
622                                      int for_push)
623 {
624         struct helper_data *data = transport->data;
625         const char *name;
626         const char *exec;
627
628         name = for_push ? "git-receive-pack" : "git-upload-pack";
629         if (for_push)
630                 exec = data->transport_options.receivepack;
631         else
632                 exec = data->transport_options.uploadpack;
633
634         return process_connect_service(transport, name, exec);
635 }
636
637 static int connect_helper(struct transport *transport, const char *name,
638                    const char *exec, int fd[2])
639 {
640         struct helper_data *data = transport->data;
641
642         /* Get_helper so connect is inited. */
643         get_helper(transport);
644         if (!data->connect)
645                 die(_("operation not supported by protocol"));
646
647         if (!process_connect_service(transport, name, exec))
648                 die(_("can't connect to subservice %s"), name);
649
650         fd[0] = data->helper->out;
651         fd[1] = data->helper->in;
652         return 0;
653 }
654
655 static int fetch(struct transport *transport,
656                  int nr_heads, struct ref **to_fetch)
657 {
658         struct helper_data *data = transport->data;
659         int i, count;
660
661         if (process_connect(transport, 0)) {
662                 do_take_over(transport);
663                 return transport->vtable->fetch(transport, nr_heads, to_fetch);
664         }
665
666         count = 0;
667         for (i = 0; i < nr_heads; i++)
668                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
669                         count++;
670
671         if (!count)
672                 return 0;
673
674         if (data->check_connectivity &&
675             data->transport_options.check_self_contained_and_connected)
676                 set_helper_option(transport, "check-connectivity", "true");
677
678         if (transport->cloning)
679                 set_helper_option(transport, "cloning", "true");
680
681         if (data->transport_options.update_shallow)
682                 set_helper_option(transport, "update-shallow", "true");
683
684         if (data->transport_options.filter_options.choice) {
685                 struct strbuf expanded_filter_spec = STRBUF_INIT;
686                 expand_list_objects_filter_spec(
687                         &data->transport_options.filter_options,
688                         &expanded_filter_spec);
689                 set_helper_option(transport, "filter",
690                                   expanded_filter_spec.buf);
691                 strbuf_release(&expanded_filter_spec);
692         }
693
694         if (data->transport_options.negotiation_tips)
695                 warning("Ignoring --negotiation-tip because the protocol does not support it.");
696
697         if (data->fetch)
698                 return fetch_with_fetch(transport, nr_heads, to_fetch);
699
700         if (data->import)
701                 return fetch_with_import(transport, nr_heads, to_fetch);
702
703         return -1;
704 }
705
706 static int push_update_ref_status(struct strbuf *buf,
707                                    struct ref **ref,
708                                    struct ref *remote_refs)
709 {
710         char *refname, *msg;
711         int status, forced = 0;
712
713         if (starts_with(buf->buf, "ok ")) {
714                 status = REF_STATUS_OK;
715                 refname = buf->buf + 3;
716         } else if (starts_with(buf->buf, "error ")) {
717                 status = REF_STATUS_REMOTE_REJECT;
718                 refname = buf->buf + 6;
719         } else
720                 die(_("expected ok/error, helper said '%s'"), buf->buf);
721
722         msg = strchr(refname, ' ');
723         if (msg) {
724                 struct strbuf msg_buf = STRBUF_INIT;
725                 const char *end;
726
727                 *msg++ = '\0';
728                 if (!unquote_c_style(&msg_buf, msg, &end))
729                         msg = strbuf_detach(&msg_buf, NULL);
730                 else
731                         msg = xstrdup(msg);
732                 strbuf_release(&msg_buf);
733
734                 if (!strcmp(msg, "no match")) {
735                         status = REF_STATUS_NONE;
736                         FREE_AND_NULL(msg);
737                 }
738                 else if (!strcmp(msg, "up to date")) {
739                         status = REF_STATUS_UPTODATE;
740                         FREE_AND_NULL(msg);
741                 }
742                 else if (!strcmp(msg, "non-fast forward")) {
743                         status = REF_STATUS_REJECT_NONFASTFORWARD;
744                         FREE_AND_NULL(msg);
745                 }
746                 else if (!strcmp(msg, "already exists")) {
747                         status = REF_STATUS_REJECT_ALREADY_EXISTS;
748                         FREE_AND_NULL(msg);
749                 }
750                 else if (!strcmp(msg, "fetch first")) {
751                         status = REF_STATUS_REJECT_FETCH_FIRST;
752                         FREE_AND_NULL(msg);
753                 }
754                 else if (!strcmp(msg, "needs force")) {
755                         status = REF_STATUS_REJECT_NEEDS_FORCE;
756                         FREE_AND_NULL(msg);
757                 }
758                 else if (!strcmp(msg, "stale info")) {
759                         status = REF_STATUS_REJECT_STALE;
760                         FREE_AND_NULL(msg);
761                 }
762                 else if (!strcmp(msg, "forced update")) {
763                         forced = 1;
764                         FREE_AND_NULL(msg);
765                 }
766         }
767
768         if (*ref)
769                 *ref = find_ref_by_name(*ref, refname);
770         if (!*ref)
771                 *ref = find_ref_by_name(remote_refs, refname);
772         if (!*ref) {
773                 warning(_("helper reported unexpected status of %s"), refname);
774                 return 1;
775         }
776
777         if ((*ref)->status != REF_STATUS_NONE) {
778                 /*
779                  * Earlier, the ref was marked not to be pushed, so ignore the ref
780                  * status reported by the remote helper if the latter is 'no match'.
781                  */
782                 if (status == REF_STATUS_NONE)
783                         return 1;
784         }
785
786         (*ref)->status = status;
787         (*ref)->forced_update |= forced;
788         (*ref)->remote_status = msg;
789         return !(status == REF_STATUS_OK);
790 }
791
792 static int push_update_refs_status(struct helper_data *data,
793                                     struct ref *remote_refs,
794                                     int flags)
795 {
796         struct strbuf buf = STRBUF_INIT;
797         struct ref *ref = remote_refs;
798         int ret = 0;
799
800         for (;;) {
801                 char *private;
802
803                 if (recvline(data, &buf)) {
804                         ret = 1;
805                         break;
806                 }
807
808                 if (!buf.len)
809                         break;
810
811                 if (push_update_ref_status(&buf, &ref, remote_refs))
812                         continue;
813
814                 if (flags & TRANSPORT_PUSH_DRY_RUN || !data->rs.nr || data->no_private_update)
815                         continue;
816
817                 /* propagate back the update to the remote namespace */
818                 private = apply_refspecs(&data->rs, ref->name);
819                 if (!private)
820                         continue;
821                 update_ref("update by helper", private, &ref->new_oid, NULL,
822                            0, 0);
823                 free(private);
824         }
825         strbuf_release(&buf);
826         return ret;
827 }
828
829 static void set_common_push_options(struct transport *transport,
830                                    const char *name, int flags)
831 {
832         if (flags & TRANSPORT_PUSH_DRY_RUN) {
833                 if (set_helper_option(transport, "dry-run", "true") != 0)
834                         die(_("helper %s does not support dry-run"), name);
835         } else if (flags & TRANSPORT_PUSH_CERT_ALWAYS) {
836                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
837                         die(_("helper %s does not support --signed"), name);
838         } else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED) {
839                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "if-asked") != 0)
840                         die(_("helper %s does not support --signed=if-asked"), name);
841         }
842
843         if (flags & TRANSPORT_PUSH_OPTIONS) {
844                 struct string_list_item *item;
845                 for_each_string_list_item(item, transport->push_options)
846                         if (set_helper_option(transport, "push-option", item->string) != 0)
847                                 die(_("helper %s does not support 'push-option'"), name);
848         }
849 }
850
851 static int push_refs_with_push(struct transport *transport,
852                                struct ref *remote_refs, int flags)
853 {
854         int force_all = flags & TRANSPORT_PUSH_FORCE;
855         int mirror = flags & TRANSPORT_PUSH_MIRROR;
856         struct helper_data *data = transport->data;
857         struct strbuf buf = STRBUF_INIT;
858         struct ref *ref;
859         struct string_list cas_options = STRING_LIST_INIT_DUP;
860         struct string_list_item *cas_option;
861
862         get_helper(transport);
863         if (!data->push)
864                 return 1;
865
866         for (ref = remote_refs; ref; ref = ref->next) {
867                 if (!ref->peer_ref && !mirror)
868                         continue;
869
870                 /* Check for statuses set by set_ref_status_for_push() */
871                 switch (ref->status) {
872                 case REF_STATUS_REJECT_NONFASTFORWARD:
873                 case REF_STATUS_REJECT_STALE:
874                 case REF_STATUS_REJECT_ALREADY_EXISTS:
875                 case REF_STATUS_UPTODATE:
876                         continue;
877                 default:
878                         ; /* do nothing */
879                 }
880
881                 if (force_all)
882                         ref->force = 1;
883
884                 strbuf_addstr(&buf, "push ");
885                 if (!ref->deletion) {
886                         if (ref->force)
887                                 strbuf_addch(&buf, '+');
888                         if (ref->peer_ref)
889                                 strbuf_addstr(&buf, ref->peer_ref->name);
890                         else
891                                 strbuf_addstr(&buf, oid_to_hex(&ref->new_oid));
892                 }
893                 strbuf_addch(&buf, ':');
894                 strbuf_addstr(&buf, ref->name);
895                 strbuf_addch(&buf, '\n');
896
897                 /*
898                  * The "--force-with-lease" options without explicit
899                  * values to expect have already been expanded into
900                  * the ref->old_oid_expect[] field; we can ignore
901                  * transport->smart_options->cas altogether and instead
902                  * can enumerate them from the refs.
903                  */
904                 if (ref->expect_old_sha1) {
905                         struct strbuf cas = STRBUF_INIT;
906                         strbuf_addf(&cas, "%s:%s",
907                                     ref->name, oid_to_hex(&ref->old_oid_expect));
908                         string_list_append_nodup(&cas_options,
909                                                  strbuf_detach(&cas, NULL));
910                 }
911         }
912         if (buf.len == 0) {
913                 string_list_clear(&cas_options, 0);
914                 return 0;
915         }
916
917         for_each_string_list_item(cas_option, &cas_options)
918                 set_helper_option(transport, "cas", cas_option->string);
919         set_common_push_options(transport, data->name, flags);
920
921         strbuf_addch(&buf, '\n');
922         sendline(data, &buf);
923         strbuf_release(&buf);
924         string_list_clear(&cas_options, 0);
925
926         return push_update_refs_status(data, remote_refs, flags);
927 }
928
929 static int push_refs_with_export(struct transport *transport,
930                 struct ref *remote_refs, int flags)
931 {
932         struct ref *ref;
933         struct child_process *helper, exporter;
934         struct helper_data *data = transport->data;
935         struct string_list revlist_args = STRING_LIST_INIT_DUP;
936         struct strbuf buf = STRBUF_INIT;
937
938         if (!data->rs.nr)
939                 die(_("remote-helper doesn't support push; refspec needed"));
940
941         set_common_push_options(transport, data->name, flags);
942         if (flags & TRANSPORT_PUSH_FORCE) {
943                 if (set_helper_option(transport, "force", "true") != 0)
944                         warning(_("helper %s does not support 'force'"), data->name);
945         }
946
947         helper = get_helper(transport);
948
949         write_constant(helper->in, "export\n");
950
951         for (ref = remote_refs; ref; ref = ref->next) {
952                 char *private;
953                 struct object_id oid;
954
955                 private = apply_refspecs(&data->rs, ref->name);
956                 if (private && !get_oid(private, &oid)) {
957                         strbuf_addf(&buf, "^%s", private);
958                         string_list_append_nodup(&revlist_args,
959                                                  strbuf_detach(&buf, NULL));
960                         oidcpy(&ref->old_oid, &oid);
961                 }
962                 free(private);
963
964                 if (ref->peer_ref) {
965                         if (strcmp(ref->name, ref->peer_ref->name)) {
966                                 if (!ref->deletion) {
967                                         const char *name;
968                                         int flag;
969
970                                         /* Follow symbolic refs (mainly for HEAD). */
971                                         name = resolve_ref_unsafe(ref->peer_ref->name,
972                                                                   RESOLVE_REF_READING,
973                                                                   &oid, &flag);
974                                         if (!name || !(flag & REF_ISSYMREF))
975                                                 name = ref->peer_ref->name;
976
977                                         strbuf_addf(&buf, "%s:%s", name, ref->name);
978                                 } else
979                                         strbuf_addf(&buf, ":%s", ref->name);
980
981                                 string_list_append(&revlist_args, "--refspec");
982                                 string_list_append(&revlist_args, buf.buf);
983                                 strbuf_release(&buf);
984                         }
985                         if (!ref->deletion)
986                                 string_list_append(&revlist_args, ref->peer_ref->name);
987                 }
988         }
989
990         if (get_exporter(transport, &exporter, &revlist_args))
991                 die(_("couldn't run fast-export"));
992
993         string_list_clear(&revlist_args, 1);
994
995         if (finish_command(&exporter))
996                 die(_("error while running fast-export"));
997         if (push_update_refs_status(data, remote_refs, flags))
998                 return 1;
999
1000         if (data->export_marks) {
1001                 strbuf_addf(&buf, "%s.tmp", data->export_marks);
1002                 rename(buf.buf, data->export_marks);
1003                 strbuf_release(&buf);
1004         }
1005
1006         return 0;
1007 }
1008
1009 static int push_refs(struct transport *transport,
1010                 struct ref *remote_refs, int flags)
1011 {
1012         struct helper_data *data = transport->data;
1013
1014         if (process_connect(transport, 1)) {
1015                 do_take_over(transport);
1016                 return transport->vtable->push_refs(transport, remote_refs, flags);
1017         }
1018
1019         if (!remote_refs) {
1020                 fprintf(stderr,
1021                         _("No refs in common and none specified; doing nothing.\n"
1022                           "Perhaps you should specify a branch such as 'master'.\n"));
1023                 return 0;
1024         }
1025
1026         if (data->push)
1027                 return push_refs_with_push(transport, remote_refs, flags);
1028
1029         if (data->export)
1030                 return push_refs_with_export(transport, remote_refs, flags);
1031
1032         return -1;
1033 }
1034
1035
1036 static int has_attribute(const char *attrs, const char *attr)
1037 {
1038         int len;
1039         if (!attrs)
1040                 return 0;
1041
1042         len = strlen(attr);
1043         for (;;) {
1044                 const char *space = strchrnul(attrs, ' ');
1045                 if (len == space - attrs && !strncmp(attrs, attr, len))
1046                         return 1;
1047                 if (!*space)
1048                         return 0;
1049                 attrs = space + 1;
1050         }
1051 }
1052
1053 static struct ref *get_refs_list(struct transport *transport, int for_push,
1054                                  const struct argv_array *ref_prefixes)
1055 {
1056         struct helper_data *data = transport->data;
1057         struct child_process *helper;
1058         struct ref *ret = NULL;
1059         struct ref **tail = &ret;
1060         struct ref *posn;
1061         struct strbuf buf = STRBUF_INIT;
1062
1063         helper = get_helper(transport);
1064
1065         if (process_connect(transport, for_push)) {
1066                 do_take_over(transport);
1067                 return transport->vtable->get_refs_list(transport, for_push, ref_prefixes);
1068         }
1069
1070         if (data->push && for_push)
1071                 write_str_in_full(helper->in, "list for-push\n");
1072         else
1073                 write_str_in_full(helper->in, "list\n");
1074
1075         while (1) {
1076                 char *eov, *eon;
1077                 if (recvline(data, &buf))
1078                         exit(128);
1079
1080                 if (!*buf.buf)
1081                         break;
1082
1083                 eov = strchr(buf.buf, ' ');
1084                 if (!eov)
1085                         die(_("malformed response in ref list: %s"), buf.buf);
1086                 eon = strchr(eov + 1, ' ');
1087                 *eov = '\0';
1088                 if (eon)
1089                         *eon = '\0';
1090                 *tail = alloc_ref(eov + 1);
1091                 if (buf.buf[0] == '@')
1092                         (*tail)->symref = xstrdup(buf.buf + 1);
1093                 else if (buf.buf[0] != '?')
1094                         get_oid_hex(buf.buf, &(*tail)->old_oid);
1095                 if (eon) {
1096                         if (has_attribute(eon + 1, "unchanged")) {
1097                                 (*tail)->status |= REF_STATUS_UPTODATE;
1098                                 if (read_ref((*tail)->name, &(*tail)->old_oid) < 0)
1099                                         die(_("could not read ref %s"),
1100                                             (*tail)->name);
1101                         }
1102                 }
1103                 tail = &((*tail)->next);
1104         }
1105         if (debug)
1106                 fprintf(stderr, "Debug: Read ref listing.\n");
1107         strbuf_release(&buf);
1108
1109         for (posn = ret; posn; posn = posn->next)
1110                 resolve_remote_symref(posn, ret);
1111
1112         return ret;
1113 }
1114
1115 static struct transport_vtable vtable = {
1116         0,
1117         set_helper_option,
1118         get_refs_list,
1119         fetch,
1120         push_refs,
1121         connect_helper,
1122         release_helper
1123 };
1124
1125 int transport_helper_init(struct transport *transport, const char *name)
1126 {
1127         struct helper_data *data = xcalloc(1, sizeof(*data));
1128         data->name = name;
1129
1130         transport_check_allowed(name);
1131
1132         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1133                 debug = 1;
1134
1135         transport->data = data;
1136         transport->vtable = &vtable;
1137         transport->smart_options = &(data->transport_options);
1138         return 0;
1139 }
1140
1141 /*
1142  * Linux pipes can buffer 65536 bytes at once (and most platforms can
1143  * buffer less), so attempt reads and writes with up to that size.
1144  */
1145 #define BUFFERSIZE 65536
1146 /* This should be enough to hold debugging message. */
1147 #define PBUFFERSIZE 8192
1148
1149 /* Print bidirectional transfer loop debug message. */
1150 __attribute__((format (printf, 1, 2)))
1151 static void transfer_debug(const char *fmt, ...)
1152 {
1153         /*
1154          * NEEDSWORK: This function is sometimes used from multiple threads, and
1155          * we end up using debug_enabled racily. That "should not matter" since
1156          * we always write the same value, but it's still wrong. This function
1157          * is listed in .tsan-suppressions for the time being.
1158          */
1159
1160         va_list args;
1161         char msgbuf[PBUFFERSIZE];
1162         static int debug_enabled = -1;
1163
1164         if (debug_enabled < 0)
1165                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1166         if (!debug_enabled)
1167                 return;
1168
1169         va_start(args, fmt);
1170         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1171         va_end(args);
1172         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1173 }
1174
1175 /* Stream state: More data may be coming in this direction. */
1176 #define SSTATE_TRANSFERRING 0
1177 /*
1178  * Stream state: No more data coming in this direction, flushing rest of
1179  * data.
1180  */
1181 #define SSTATE_FLUSHING 1
1182 /* Stream state: Transfer in this direction finished. */
1183 #define SSTATE_FINISHED 2
1184
1185 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERRING)
1186 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1187 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1188
1189 /* Unidirectional transfer. */
1190 struct unidirectional_transfer {
1191         /* Source */
1192         int src;
1193         /* Destination */
1194         int dest;
1195         /* Is source socket? */
1196         int src_is_sock;
1197         /* Is destination socket? */
1198         int dest_is_sock;
1199         /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1200         int state;
1201         /* Buffer. */
1202         char buf[BUFFERSIZE];
1203         /* Buffer used. */
1204         size_t bufuse;
1205         /* Name of source. */
1206         const char *src_name;
1207         /* Name of destination. */
1208         const char *dest_name;
1209 };
1210
1211 /* Closes the target (for writing) if transfer has finished. */
1212 static void udt_close_if_finished(struct unidirectional_transfer *t)
1213 {
1214         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1215                 t->state = SSTATE_FINISHED;
1216                 if (t->dest_is_sock)
1217                         shutdown(t->dest, SHUT_WR);
1218                 else
1219                         close(t->dest);
1220                 transfer_debug("Closed %s.", t->dest_name);
1221         }
1222 }
1223
1224 /*
1225  * Tries to read data from source into buffer. If buffer is full,
1226  * no data is read. Returns 0 on success, -1 on error.
1227  */
1228 static int udt_do_read(struct unidirectional_transfer *t)
1229 {
1230         ssize_t bytes;
1231
1232         if (t->bufuse == BUFFERSIZE)
1233                 return 0;       /* No space for more. */
1234
1235         transfer_debug("%s is readable", t->src_name);
1236         bytes = xread(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1237         if (bytes < 0) {
1238                 error_errno(_("read(%s) failed"), t->src_name);
1239                 return -1;
1240         } else if (bytes == 0) {
1241                 transfer_debug("%s EOF (with %i bytes in buffer)",
1242                         t->src_name, (int)t->bufuse);
1243                 t->state = SSTATE_FLUSHING;
1244         } else if (bytes > 0) {
1245                 t->bufuse += bytes;
1246                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1247                         (int)bytes, t->src_name, (int)t->bufuse);
1248         }
1249         return 0;
1250 }
1251
1252 /* Tries to write data from buffer into destination. If buffer is empty,
1253  * no data is written. Returns 0 on success, -1 on error.
1254  */
1255 static int udt_do_write(struct unidirectional_transfer *t)
1256 {
1257         ssize_t bytes;
1258
1259         if (t->bufuse == 0)
1260                 return 0;       /* Nothing to write. */
1261
1262         transfer_debug("%s is writable", t->dest_name);
1263         bytes = xwrite(t->dest, t->buf, t->bufuse);
1264         if (bytes < 0) {
1265                 error_errno(_("write(%s) failed"), t->dest_name);
1266                 return -1;
1267         } else if (bytes > 0) {
1268                 t->bufuse -= bytes;
1269                 if (t->bufuse)
1270                         memmove(t->buf, t->buf + bytes, t->bufuse);
1271                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1272                         (int)bytes, t->dest_name, (int)t->bufuse);
1273         }
1274         return 0;
1275 }
1276
1277
1278 /* State of bidirectional transfer loop. */
1279 struct bidirectional_transfer_state {
1280         /* Direction from program to git. */
1281         struct unidirectional_transfer ptg;
1282         /* Direction from git to program. */
1283         struct unidirectional_transfer gtp;
1284 };
1285
1286 static void *udt_copy_task_routine(void *udt)
1287 {
1288         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1289         while (t->state != SSTATE_FINISHED) {
1290                 if (STATE_NEEDS_READING(t->state))
1291                         if (udt_do_read(t))
1292                                 return NULL;
1293                 if (STATE_NEEDS_WRITING(t->state))
1294                         if (udt_do_write(t))
1295                                 return NULL;
1296                 if (STATE_NEEDS_CLOSING(t->state))
1297                         udt_close_if_finished(t);
1298         }
1299         return udt;     /* Just some non-NULL value. */
1300 }
1301
1302 #ifndef NO_PTHREADS
1303
1304 /*
1305  * Join thread, with appropriate errors on failure. Name is name for the
1306  * thread (for error messages). Returns 0 on success, 1 on failure.
1307  */
1308 static int tloop_join(pthread_t thread, const char *name)
1309 {
1310         int err;
1311         void *tret;
1312         err = pthread_join(thread, &tret);
1313         if (!tret) {
1314                 error(_("%s thread failed"), name);
1315                 return 1;
1316         }
1317         if (err) {
1318                 error(_("%s thread failed to join: %s"), name, strerror(err));
1319                 return 1;
1320         }
1321         return 0;
1322 }
1323
1324 /*
1325  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1326  * -1 on failure.
1327  */
1328 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1329 {
1330         pthread_t gtp_thread;
1331         pthread_t ptg_thread;
1332         int err;
1333         int ret = 0;
1334         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1335                 &s->gtp);
1336         if (err)
1337                 die(_("can't start thread for copying data: %s"), strerror(err));
1338         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1339                 &s->ptg);
1340         if (err)
1341                 die(_("can't start thread for copying data: %s"), strerror(err));
1342
1343         ret |= tloop_join(gtp_thread, "Git to program copy");
1344         ret |= tloop_join(ptg_thread, "Program to git copy");
1345         return ret;
1346 }
1347 #else
1348
1349 /* Close the source and target (for writing) for transfer. */
1350 static void udt_kill_transfer(struct unidirectional_transfer *t)
1351 {
1352         t->state = SSTATE_FINISHED;
1353         /*
1354          * Socket read end left open isn't a disaster if nobody
1355          * attempts to read from it (mingw compat headers do not
1356          * have SHUT_RD)...
1357          *
1358          * We can't fully close the socket since otherwise gtp
1359          * task would first close the socket it sends data to
1360          * while closing the ptg file descriptors.
1361          */
1362         if (!t->src_is_sock)
1363                 close(t->src);
1364         if (t->dest_is_sock)
1365                 shutdown(t->dest, SHUT_WR);
1366         else
1367                 close(t->dest);
1368 }
1369
1370 /*
1371  * Join process, with appropriate errors on failure. Name is name for the
1372  * process (for error messages). Returns 0 on success, 1 on failure.
1373  */
1374 static int tloop_join(pid_t pid, const char *name)
1375 {
1376         int tret;
1377         if (waitpid(pid, &tret, 0) < 0) {
1378                 error_errno(_("%s process failed to wait"), name);
1379                 return 1;
1380         }
1381         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1382                 error(_("%s process failed"), name);
1383                 return 1;
1384         }
1385         return 0;
1386 }
1387
1388 /*
1389  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1390  * -1 on failure.
1391  */
1392 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1393 {
1394         pid_t pid1, pid2;
1395         int ret = 0;
1396
1397         /* Fork thread #1: git to program. */
1398         pid1 = fork();
1399         if (pid1 < 0)
1400                 die_errno(_("can't start thread for copying data"));
1401         else if (pid1 == 0) {
1402                 udt_kill_transfer(&s->ptg);
1403                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1404         }
1405
1406         /* Fork thread #2: program to git. */
1407         pid2 = fork();
1408         if (pid2 < 0)
1409                 die_errno(_("can't start thread for copying data"));
1410         else if (pid2 == 0) {
1411                 udt_kill_transfer(&s->gtp);
1412                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1413         }
1414
1415         /*
1416          * Close both streams in parent as to not interfere with
1417          * end of file detection and wait for both tasks to finish.
1418          */
1419         udt_kill_transfer(&s->gtp);
1420         udt_kill_transfer(&s->ptg);
1421         ret |= tloop_join(pid1, "Git to program copy");
1422         ret |= tloop_join(pid2, "Program to git copy");
1423         return ret;
1424 }
1425 #endif
1426
1427 /*
1428  * Copies data from stdin to output and from input to stdout simultaneously.
1429  * Additionally filtering through given filter. If filter is NULL, uses
1430  * identity filter.
1431  */
1432 int bidirectional_transfer_loop(int input, int output)
1433 {
1434         struct bidirectional_transfer_state state;
1435
1436         /* Fill the state fields. */
1437         state.ptg.src = input;
1438         state.ptg.dest = 1;
1439         state.ptg.src_is_sock = (input == output);
1440         state.ptg.dest_is_sock = 0;
1441         state.ptg.state = SSTATE_TRANSFERRING;
1442         state.ptg.bufuse = 0;
1443         state.ptg.src_name = "remote input";
1444         state.ptg.dest_name = "stdout";
1445
1446         state.gtp.src = 0;
1447         state.gtp.dest = output;
1448         state.gtp.src_is_sock = 0;
1449         state.gtp.dest_is_sock = (input == output);
1450         state.gtp.state = SSTATE_TRANSFERRING;
1451         state.gtp.bufuse = 0;
1452         state.gtp.src_name = "stdin";
1453         state.gtp.dest_name = "remote output";
1454
1455         return tloop_spawnwait_tasks(&state);
1456 }