Merge branch 'jn/gitweb-time-hires-comes-with-5.8'
[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 "quote.h"
9 #include "remote.h"
10 #include "string-list.h"
11
12 #ifndef NO_PTHREADS
13 #include <pthread.h>
14 #include "thread-utils.h"
15 #endif
16
17 static int debug;
18
19 struct helper_data
20 {
21         const char *name;
22         struct child_process *helper;
23         FILE *out;
24         unsigned fetch : 1,
25                 import : 1,
26                 export : 1,
27                 option : 1,
28                 push : 1,
29                 connect : 1,
30                 no_disconnect_req : 1;
31         /* These go from remote name (as in "list") to private name */
32         struct refspec *refspecs;
33         int refspec_nr;
34         /* Transport options for fetch-pack/send-pack (should one of
35          * those be invoked).
36          */
37         struct git_transport_options transport_options;
38 };
39
40 static void sendline(struct helper_data *helper, struct strbuf *buffer)
41 {
42         if (debug)
43                 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
44         if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
45                 != buffer->len)
46                 die_errno("Full write to remote helper failed");
47 }
48
49 static int recvline_fh(FILE *helper, struct strbuf *buffer)
50 {
51         strbuf_reset(buffer);
52         if (debug)
53                 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
54         if (strbuf_getline(buffer, helper, '\n') == EOF) {
55                 if (debug)
56                         fprintf(stderr, "Debug: Remote helper quit.\n");
57                 exit(128);
58         }
59
60         if (debug)
61                 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
62         return 0;
63 }
64
65 static int recvline(struct helper_data *helper, struct strbuf *buffer)
66 {
67         return recvline_fh(helper->out, buffer);
68 }
69
70 static void xchgline(struct helper_data *helper, struct strbuf *buffer)
71 {
72         sendline(helper, buffer);
73         recvline(helper, buffer);
74 }
75
76 static void write_constant(int fd, const char *str)
77 {
78         if (debug)
79                 fprintf(stderr, "Debug: Remote helper: -> %s", str);
80         if (write_in_full(fd, str, strlen(str)) != strlen(str))
81                 die_errno("Full write to remote helper failed");
82 }
83
84 const char *remove_ext_force(const char *url)
85 {
86         if (url) {
87                 const char *colon = strchr(url, ':');
88                 if (colon && colon[1] == ':')
89                         return colon + 2;
90         }
91         return url;
92 }
93
94 static void do_take_over(struct transport *transport)
95 {
96         struct helper_data *data;
97         data = (struct helper_data *)transport->data;
98         transport_take_over(transport, data->helper);
99         fclose(data->out);
100         free(data);
101 }
102
103 static struct child_process *get_helper(struct transport *transport)
104 {
105         struct helper_data *data = transport->data;
106         struct strbuf buf = STRBUF_INIT;
107         struct child_process *helper;
108         const char **refspecs = NULL;
109         int refspec_nr = 0;
110         int refspec_alloc = 0;
111         int duped;
112         int code;
113
114         if (data->helper)
115                 return data->helper;
116
117         helper = xcalloc(1, sizeof(*helper));
118         helper->in = -1;
119         helper->out = -1;
120         helper->err = 0;
121         helper->argv = xcalloc(4, sizeof(*helper->argv));
122         strbuf_addf(&buf, "git-remote-%s", data->name);
123         helper->argv[0] = strbuf_detach(&buf, NULL);
124         helper->argv[1] = transport->remote->name;
125         helper->argv[2] = remove_ext_force(transport->url);
126         helper->git_cmd = 0;
127         helper->silent_exec_failure = 1;
128         code = start_command(helper);
129         if (code < 0 && errno == ENOENT)
130                 die("Unable to find remote helper for '%s'", data->name);
131         else if (code != 0)
132                 exit(code);
133
134         data->helper = helper;
135         data->no_disconnect_req = 0;
136
137         /*
138          * Open the output as FILE* so strbuf_getline() can be used.
139          * Do this with duped fd because fclose() will close the fd,
140          * and stuff like taking over will require the fd to remain.
141          */
142         duped = dup(helper->out);
143         if (duped < 0)
144                 die_errno("Can't dup helper output fd");
145         data->out = xfdopen(duped, "r");
146
147         write_constant(helper->in, "capabilities\n");
148
149         while (1) {
150                 const char *capname;
151                 int mandatory = 0;
152                 recvline(data, &buf);
153
154                 if (!*buf.buf)
155                         break;
156
157                 if (*buf.buf == '*') {
158                         capname = buf.buf + 1;
159                         mandatory = 1;
160                 } else
161                         capname = buf.buf;
162
163                 if (debug)
164                         fprintf(stderr, "Debug: Got cap %s\n", capname);
165                 if (!strcmp(capname, "fetch"))
166                         data->fetch = 1;
167                 else if (!strcmp(capname, "option"))
168                         data->option = 1;
169                 else if (!strcmp(capname, "push"))
170                         data->push = 1;
171                 else if (!strcmp(capname, "import"))
172                         data->import = 1;
173                 else if (!strcmp(capname, "export"))
174                         data->export = 1;
175                 else if (!data->refspecs && !prefixcmp(capname, "refspec ")) {
176                         ALLOC_GROW(refspecs,
177                                    refspec_nr + 1,
178                                    refspec_alloc);
179                         refspecs[refspec_nr++] = strdup(buf.buf + strlen("refspec "));
180                 } else if (!strcmp(capname, "connect")) {
181                         data->connect = 1;
182                 } else if (!strcmp(buf.buf, "gitdir")) {
183                         struct strbuf gitdir = STRBUF_INIT;
184                         strbuf_addf(&gitdir, "gitdir %s\n", get_git_dir());
185                         sendline(data, &gitdir);
186                         strbuf_release(&gitdir);
187                 } else if (mandatory) {
188                         die("Unknown mandatory capability %s. This remote "
189                             "helper probably needs newer version of Git.\n",
190                             capname);
191                 }
192         }
193         if (refspecs) {
194                 int i;
195                 data->refspec_nr = refspec_nr;
196                 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
197                 for (i = 0; i < refspec_nr; i++) {
198                         free((char *)refspecs[i]);
199                 }
200                 free(refspecs);
201         }
202         strbuf_release(&buf);
203         if (debug)
204                 fprintf(stderr, "Debug: Capabilities complete.\n");
205         return data->helper;
206 }
207
208 static int disconnect_helper(struct transport *transport)
209 {
210         struct helper_data *data = transport->data;
211         struct strbuf buf = STRBUF_INIT;
212
213         if (data->helper) {
214                 if (debug)
215                         fprintf(stderr, "Debug: Disconnecting.\n");
216                 if (!data->no_disconnect_req) {
217                         strbuf_addf(&buf, "\n");
218                         sendline(data, &buf);
219                 }
220                 close(data->helper->in);
221                 close(data->helper->out);
222                 fclose(data->out);
223                 finish_command(data->helper);
224                 free((char *)data->helper->argv[0]);
225                 free(data->helper->argv);
226                 free(data->helper);
227                 data->helper = NULL;
228         }
229         return 0;
230 }
231
232 static const char *unsupported_options[] = {
233         TRANS_OPT_UPLOADPACK,
234         TRANS_OPT_RECEIVEPACK,
235         TRANS_OPT_THIN,
236         TRANS_OPT_KEEP
237         };
238 static const char *boolean_options[] = {
239         TRANS_OPT_THIN,
240         TRANS_OPT_KEEP,
241         TRANS_OPT_FOLLOWTAGS
242         };
243
244 static int set_helper_option(struct transport *transport,
245                           const char *name, const char *value)
246 {
247         struct helper_data *data = transport->data;
248         struct strbuf buf = STRBUF_INIT;
249         int i, ret, is_bool = 0;
250
251         get_helper(transport);
252
253         if (!data->option)
254                 return 1;
255
256         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
257                 if (!strcmp(name, unsupported_options[i]))
258                         return 1;
259         }
260
261         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
262                 if (!strcmp(name, boolean_options[i])) {
263                         is_bool = 1;
264                         break;
265                 }
266         }
267
268         strbuf_addf(&buf, "option %s ", name);
269         if (is_bool)
270                 strbuf_addstr(&buf, value ? "true" : "false");
271         else
272                 quote_c_style(value, &buf, NULL, 0);
273         strbuf_addch(&buf, '\n');
274
275         xchgline(data, &buf);
276
277         if (!strcmp(buf.buf, "ok"))
278                 ret = 0;
279         else if (!prefixcmp(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         strbuf_release(&buf);
288         return ret;
289 }
290
291 static void standard_options(struct transport *t)
292 {
293         char buf[16];
294         int n;
295         int v = t->verbose;
296
297         set_helper_option(t, "progress", t->progress ? "true" : "false");
298
299         n = snprintf(buf, sizeof(buf), "%d", v + 1);
300         if (n >= sizeof(buf))
301                 die("impossibly large verbosity value");
302         set_helper_option(t, "verbosity", buf);
303 }
304
305 static int release_helper(struct transport *transport)
306 {
307         struct helper_data *data = transport->data;
308         free_refspec(data->refspec_nr, data->refspecs);
309         data->refspecs = NULL;
310         disconnect_helper(transport);
311         free(transport->data);
312         return 0;
313 }
314
315 static int fetch_with_fetch(struct transport *transport,
316                             int nr_heads, struct ref **to_fetch)
317 {
318         struct helper_data *data = transport->data;
319         int i;
320         struct strbuf buf = STRBUF_INIT;
321
322         standard_options(transport);
323
324         for (i = 0; i < nr_heads; i++) {
325                 const struct ref *posn = to_fetch[i];
326                 if (posn->status & REF_STATUS_UPTODATE)
327                         continue;
328
329                 strbuf_addf(&buf, "fetch %s %s\n",
330                             sha1_to_hex(posn->old_sha1), posn->name);
331         }
332
333         strbuf_addch(&buf, '\n');
334         sendline(data, &buf);
335
336         while (1) {
337                 recvline(data, &buf);
338
339                 if (!prefixcmp(buf.buf, "lock ")) {
340                         const char *name = buf.buf + 5;
341                         if (transport->pack_lockfile)
342                                 warning("%s also locked %s", data->name, name);
343                         else
344                                 transport->pack_lockfile = xstrdup(name);
345                 }
346                 else if (!buf.len)
347                         break;
348                 else
349                         warning("%s unexpectedly said: '%s'", data->name, buf.buf);
350         }
351         strbuf_release(&buf);
352         return 0;
353 }
354
355 static int get_importer(struct transport *transport, struct child_process *fastimport)
356 {
357         struct child_process *helper = get_helper(transport);
358         memset(fastimport, 0, sizeof(*fastimport));
359         fastimport->in = helper->out;
360         fastimport->argv = xcalloc(5, sizeof(*fastimport->argv));
361         fastimport->argv[0] = "fast-import";
362         fastimport->argv[1] = "--quiet";
363
364         fastimport->git_cmd = 1;
365         return start_command(fastimport);
366 }
367
368 static int get_exporter(struct transport *transport,
369                         struct child_process *fastexport,
370                         const char *export_marks,
371                         const char *import_marks,
372                         struct string_list *revlist_args)
373 {
374         struct child_process *helper = get_helper(transport);
375         int argc = 0, i;
376         memset(fastexport, 0, sizeof(*fastexport));
377
378         /* we need to duplicate helper->in because we want to use it after
379          * fastexport is done with it. */
380         fastexport->out = dup(helper->in);
381         fastexport->argv = xcalloc(4 + revlist_args->nr, sizeof(*fastexport->argv));
382         fastexport->argv[argc++] = "fast-export";
383         if (export_marks)
384                 fastexport->argv[argc++] = export_marks;
385         if (import_marks)
386                 fastexport->argv[argc++] = import_marks;
387
388         for (i = 0; i < revlist_args->nr; i++)
389                 fastexport->argv[argc++] = revlist_args->items[i].string;
390
391         fastexport->git_cmd = 1;
392         return start_command(fastexport);
393 }
394
395 static int fetch_with_import(struct transport *transport,
396                              int nr_heads, struct ref **to_fetch)
397 {
398         struct child_process fastimport;
399         struct helper_data *data = transport->data;
400         int i;
401         struct ref *posn;
402         struct strbuf buf = STRBUF_INIT;
403
404         get_helper(transport);
405
406         if (get_importer(transport, &fastimport))
407                 die("Couldn't run fast-import");
408
409         for (i = 0; i < nr_heads; i++) {
410                 posn = to_fetch[i];
411                 if (posn->status & REF_STATUS_UPTODATE)
412                         continue;
413
414                 strbuf_addf(&buf, "import %s\n", posn->name);
415                 sendline(data, &buf);
416                 strbuf_reset(&buf);
417         }
418         disconnect_helper(transport);
419         finish_command(&fastimport);
420         free(fastimport.argv);
421         fastimport.argv = NULL;
422
423         for (i = 0; i < nr_heads; i++) {
424                 char *private;
425                 posn = to_fetch[i];
426                 if (posn->status & REF_STATUS_UPTODATE)
427                         continue;
428                 if (data->refspecs)
429                         private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
430                 else
431                         private = strdup(posn->name);
432                 read_ref(private, posn->old_sha1);
433                 free(private);
434         }
435         strbuf_release(&buf);
436         return 0;
437 }
438
439 static int process_connect_service(struct transport *transport,
440                                    const char *name, const char *exec)
441 {
442         struct helper_data *data = transport->data;
443         struct strbuf cmdbuf = STRBUF_INIT;
444         struct child_process *helper;
445         int r, duped, ret = 0;
446         FILE *input;
447
448         helper = get_helper(transport);
449
450         /*
451          * Yes, dup the pipe another time, as we need unbuffered version
452          * of input pipe as FILE*. fclose() closes the underlying fd and
453          * stream buffering only can be changed before first I/O operation
454          * on it.
455          */
456         duped = dup(helper->out);
457         if (duped < 0)
458                 die_errno("Can't dup helper output fd");
459         input = xfdopen(duped, "r");
460         setvbuf(input, NULL, _IONBF, 0);
461
462         /*
463          * Handle --upload-pack and friends. This is fire and forget...
464          * just warn if it fails.
465          */
466         if (strcmp(name, exec)) {
467                 r = set_helper_option(transport, "servpath", exec);
468                 if (r > 0)
469                         warning("Setting remote service path not supported by protocol.");
470                 else if (r < 0)
471                         warning("Invalid remote service path.");
472         }
473
474         if (data->connect)
475                 strbuf_addf(&cmdbuf, "connect %s\n", name);
476         else
477                 goto exit;
478
479         sendline(data, &cmdbuf);
480         recvline_fh(input, &cmdbuf);
481         if (!strcmp(cmdbuf.buf, "")) {
482                 data->no_disconnect_req = 1;
483                 if (debug)
484                         fprintf(stderr, "Debug: Smart transport connection "
485                                 "ready.\n");
486                 ret = 1;
487         } else if (!strcmp(cmdbuf.buf, "fallback")) {
488                 if (debug)
489                         fprintf(stderr, "Debug: Falling back to dumb "
490                                 "transport.\n");
491         } else
492                 die("Unknown response to connect: %s",
493                         cmdbuf.buf);
494
495 exit:
496         fclose(input);
497         return ret;
498 }
499
500 static int process_connect(struct transport *transport,
501                                      int for_push)
502 {
503         struct helper_data *data = transport->data;
504         const char *name;
505         const char *exec;
506
507         name = for_push ? "git-receive-pack" : "git-upload-pack";
508         if (for_push)
509                 exec = data->transport_options.receivepack;
510         else
511                 exec = data->transport_options.uploadpack;
512
513         return process_connect_service(transport, name, exec);
514 }
515
516 static int connect_helper(struct transport *transport, const char *name,
517                    const char *exec, int fd[2])
518 {
519         struct helper_data *data = transport->data;
520
521         /* Get_helper so connect is inited. */
522         get_helper(transport);
523         if (!data->connect)
524                 die("Operation not supported by protocol.");
525
526         if (!process_connect_service(transport, name, exec))
527                 die("Can't connect to subservice %s.", name);
528
529         fd[0] = data->helper->out;
530         fd[1] = data->helper->in;
531         return 0;
532 }
533
534 static int fetch(struct transport *transport,
535                  int nr_heads, struct ref **to_fetch)
536 {
537         struct helper_data *data = transport->data;
538         int i, count;
539
540         if (process_connect(transport, 0)) {
541                 do_take_over(transport);
542                 return transport->fetch(transport, nr_heads, to_fetch);
543         }
544
545         count = 0;
546         for (i = 0; i < nr_heads; i++)
547                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
548                         count++;
549
550         if (!count)
551                 return 0;
552
553         if (data->fetch)
554                 return fetch_with_fetch(transport, nr_heads, to_fetch);
555
556         if (data->import)
557                 return fetch_with_import(transport, nr_heads, to_fetch);
558
559         return -1;
560 }
561
562 static int push_refs_with_push(struct transport *transport,
563                 struct ref *remote_refs, int flags)
564 {
565         int force_all = flags & TRANSPORT_PUSH_FORCE;
566         int mirror = flags & TRANSPORT_PUSH_MIRROR;
567         struct helper_data *data = transport->data;
568         struct strbuf buf = STRBUF_INIT;
569         struct child_process *helper;
570         struct ref *ref;
571
572         helper = get_helper(transport);
573         if (!data->push)
574                 return 1;
575
576         for (ref = remote_refs; ref; ref = ref->next) {
577                 if (!ref->peer_ref && !mirror)
578                         continue;
579
580                 /* Check for statuses set by set_ref_status_for_push() */
581                 switch (ref->status) {
582                 case REF_STATUS_REJECT_NONFASTFORWARD:
583                 case REF_STATUS_UPTODATE:
584                         continue;
585                 default:
586                         ; /* do nothing */
587                 }
588
589                 if (force_all)
590                         ref->force = 1;
591
592                 strbuf_addstr(&buf, "push ");
593                 if (!ref->deletion) {
594                         if (ref->force)
595                                 strbuf_addch(&buf, '+');
596                         if (ref->peer_ref)
597                                 strbuf_addstr(&buf, ref->peer_ref->name);
598                         else
599                                 strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
600                 }
601                 strbuf_addch(&buf, ':');
602                 strbuf_addstr(&buf, ref->name);
603                 strbuf_addch(&buf, '\n');
604         }
605         if (buf.len == 0)
606                 return 0;
607
608         standard_options(transport);
609
610         if (flags & TRANSPORT_PUSH_DRY_RUN) {
611                 if (set_helper_option(transport, "dry-run", "true") != 0)
612                         die("helper %s does not support dry-run", data->name);
613         }
614
615         strbuf_addch(&buf, '\n');
616         sendline(data, &buf);
617
618         ref = remote_refs;
619         while (1) {
620                 char *refname, *msg;
621                 int status;
622
623                 recvline(data, &buf);
624                 if (!buf.len)
625                         break;
626
627                 if (!prefixcmp(buf.buf, "ok ")) {
628                         status = REF_STATUS_OK;
629                         refname = buf.buf + 3;
630                 } else if (!prefixcmp(buf.buf, "error ")) {
631                         status = REF_STATUS_REMOTE_REJECT;
632                         refname = buf.buf + 6;
633                 } else
634                         die("expected ok/error, helper said '%s'\n", buf.buf);
635
636                 msg = strchr(refname, ' ');
637                 if (msg) {
638                         struct strbuf msg_buf = STRBUF_INIT;
639                         const char *end;
640
641                         *msg++ = '\0';
642                         if (!unquote_c_style(&msg_buf, msg, &end))
643                                 msg = strbuf_detach(&msg_buf, NULL);
644                         else
645                                 msg = xstrdup(msg);
646                         strbuf_release(&msg_buf);
647
648                         if (!strcmp(msg, "no match")) {
649                                 status = REF_STATUS_NONE;
650                                 free(msg);
651                                 msg = NULL;
652                         }
653                         else if (!strcmp(msg, "up to date")) {
654                                 status = REF_STATUS_UPTODATE;
655                                 free(msg);
656                                 msg = NULL;
657                         }
658                         else if (!strcmp(msg, "non-fast forward")) {
659                                 status = REF_STATUS_REJECT_NONFASTFORWARD;
660                                 free(msg);
661                                 msg = NULL;
662                         }
663                 }
664
665                 if (ref)
666                         ref = find_ref_by_name(ref, refname);
667                 if (!ref)
668                         ref = find_ref_by_name(remote_refs, refname);
669                 if (!ref) {
670                         warning("helper reported unexpected status of %s", refname);
671                         continue;
672                 }
673
674                 if (ref->status != REF_STATUS_NONE) {
675                         /*
676                          * Earlier, the ref was marked not to be pushed, so ignore the ref
677                          * status reported by the remote helper if the latter is 'no match'.
678                          */
679                         if (status == REF_STATUS_NONE)
680                                 continue;
681                 }
682
683                 ref->status = status;
684                 ref->remote_status = msg;
685         }
686         strbuf_release(&buf);
687         return 0;
688 }
689
690 static int push_refs_with_export(struct transport *transport,
691                 struct ref *remote_refs, int flags)
692 {
693         struct ref *ref;
694         struct child_process *helper, exporter;
695         struct helper_data *data = transport->data;
696         char *export_marks = NULL, *import_marks = NULL;
697         struct string_list revlist_args = STRING_LIST_INIT_NODUP;
698         struct strbuf buf = STRBUF_INIT;
699
700         helper = get_helper(transport);
701
702         write_constant(helper->in, "export\n");
703
704         recvline(data, &buf);
705         if (debug)
706                 fprintf(stderr, "Debug: Got export_marks '%s'\n", buf.buf);
707         if (buf.len) {
708                 struct strbuf arg = STRBUF_INIT;
709                 strbuf_addstr(&arg, "--export-marks=");
710                 strbuf_addbuf(&arg, &buf);
711                 export_marks = strbuf_detach(&arg, NULL);
712         }
713
714         recvline(data, &buf);
715         if (debug)
716                 fprintf(stderr, "Debug: Got import_marks '%s'\n", buf.buf);
717         if (buf.len) {
718                 struct strbuf arg = STRBUF_INIT;
719                 strbuf_addstr(&arg, "--import-marks=");
720                 strbuf_addbuf(&arg, &buf);
721                 import_marks = strbuf_detach(&arg, NULL);
722         }
723
724         strbuf_reset(&buf);
725
726         for (ref = remote_refs; ref; ref = ref->next) {
727                 char *private;
728                 unsigned char sha1[20];
729
730                 if (!data->refspecs)
731                         continue;
732                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
733                 if (private && !get_sha1(private, sha1)) {
734                         strbuf_addf(&buf, "^%s", private);
735                         string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
736                 }
737
738                 string_list_append(&revlist_args, ref->name);
739
740         }
741
742         if (get_exporter(transport, &exporter,
743                          export_marks, import_marks, &revlist_args))
744                 die("Couldn't run fast-export");
745
746         data->no_disconnect_req = 1;
747         finish_command(&exporter);
748         disconnect_helper(transport);
749         return 0;
750 }
751
752 static int push_refs(struct transport *transport,
753                 struct ref *remote_refs, int flags)
754 {
755         struct helper_data *data = transport->data;
756
757         if (process_connect(transport, 1)) {
758                 do_take_over(transport);
759                 return transport->push_refs(transport, remote_refs, flags);
760         }
761
762         if (!remote_refs) {
763                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
764                         "Perhaps you should specify a branch such as 'master'.\n");
765                 return 0;
766         }
767
768         if (data->push)
769                 return push_refs_with_push(transport, remote_refs, flags);
770
771         if (data->export)
772                 return push_refs_with_export(transport, remote_refs, flags);
773
774         return -1;
775 }
776
777
778 static int has_attribute(const char *attrs, const char *attr) {
779         int len;
780         if (!attrs)
781                 return 0;
782
783         len = strlen(attr);
784         for (;;) {
785                 const char *space = strchrnul(attrs, ' ');
786                 if (len == space - attrs && !strncmp(attrs, attr, len))
787                         return 1;
788                 if (!*space)
789                         return 0;
790                 attrs = space + 1;
791         }
792 }
793
794 static struct ref *get_refs_list(struct transport *transport, int for_push)
795 {
796         struct helper_data *data = transport->data;
797         struct child_process *helper;
798         struct ref *ret = NULL;
799         struct ref **tail = &ret;
800         struct ref *posn;
801         struct strbuf buf = STRBUF_INIT;
802
803         helper = get_helper(transport);
804
805         if (process_connect(transport, for_push)) {
806                 do_take_over(transport);
807                 return transport->get_refs_list(transport, for_push);
808         }
809
810         if (data->push && for_push)
811                 write_str_in_full(helper->in, "list for-push\n");
812         else
813                 write_str_in_full(helper->in, "list\n");
814
815         while (1) {
816                 char *eov, *eon;
817                 recvline(data, &buf);
818
819                 if (!*buf.buf)
820                         break;
821
822                 eov = strchr(buf.buf, ' ');
823                 if (!eov)
824                         die("Malformed response in ref list: %s", buf.buf);
825                 eon = strchr(eov + 1, ' ');
826                 *eov = '\0';
827                 if (eon)
828                         *eon = '\0';
829                 *tail = alloc_ref(eov + 1);
830                 if (buf.buf[0] == '@')
831                         (*tail)->symref = xstrdup(buf.buf + 1);
832                 else if (buf.buf[0] != '?')
833                         get_sha1_hex(buf.buf, (*tail)->old_sha1);
834                 if (eon) {
835                         if (has_attribute(eon + 1, "unchanged")) {
836                                 (*tail)->status |= REF_STATUS_UPTODATE;
837                                 read_ref((*tail)->name, (*tail)->old_sha1);
838                         }
839                 }
840                 tail = &((*tail)->next);
841         }
842         if (debug)
843                 fprintf(stderr, "Debug: Read ref listing.\n");
844         strbuf_release(&buf);
845
846         for (posn = ret; posn; posn = posn->next)
847                 resolve_remote_symref(posn, ret);
848
849         return ret;
850 }
851
852 int transport_helper_init(struct transport *transport, const char *name)
853 {
854         struct helper_data *data = xcalloc(sizeof(*data), 1);
855         data->name = name;
856
857         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
858                 debug = 1;
859
860         transport->data = data;
861         transport->set_option = set_helper_option;
862         transport->get_refs_list = get_refs_list;
863         transport->fetch = fetch;
864         transport->push_refs = push_refs;
865         transport->disconnect = release_helper;
866         transport->connect = connect_helper;
867         transport->smart_options = &(data->transport_options);
868         return 0;
869 }
870
871 /*
872  * Linux pipes can buffer 65536 bytes at once (and most platforms can
873  * buffer less), so attempt reads and writes with up to that size.
874  */
875 #define BUFFERSIZE 65536
876 /* This should be enough to hold debugging message. */
877 #define PBUFFERSIZE 8192
878
879 /* Print bidirectional transfer loop debug message. */
880 static void transfer_debug(const char *fmt, ...)
881 {
882         va_list args;
883         char msgbuf[PBUFFERSIZE];
884         static int debug_enabled = -1;
885
886         if (debug_enabled < 0)
887                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
888         if (!debug_enabled)
889                 return;
890
891         va_start(args, fmt);
892         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
893         va_end(args);
894         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
895 }
896
897 /* Stream state: More data may be coming in this direction. */
898 #define SSTATE_TRANSFERING 0
899 /*
900  * Stream state: No more data coming in this direction, flushing rest of
901  * data.
902  */
903 #define SSTATE_FLUSHING 1
904 /* Stream state: Transfer in this direction finished. */
905 #define SSTATE_FINISHED 2
906
907 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
908 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
909 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
910
911 /* Unidirectional transfer. */
912 struct unidirectional_transfer {
913         /* Source */
914         int src;
915         /* Destination */
916         int dest;
917         /* Is source socket? */
918         int src_is_sock;
919         /* Is destination socket? */
920         int dest_is_sock;
921         /* Transfer state (TRANSFERING/FLUSHING/FINISHED) */
922         int state;
923         /* Buffer. */
924         char buf[BUFFERSIZE];
925         /* Buffer used. */
926         size_t bufuse;
927         /* Name of source. */
928         const char *src_name;
929         /* Name of destination. */
930         const char *dest_name;
931 };
932
933 /* Closes the target (for writing) if transfer has finished. */
934 static void udt_close_if_finished(struct unidirectional_transfer *t)
935 {
936         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
937                 t->state = SSTATE_FINISHED;
938                 if (t->dest_is_sock)
939                         shutdown(t->dest, SHUT_WR);
940                 else
941                         close(t->dest);
942                 transfer_debug("Closed %s.", t->dest_name);
943         }
944 }
945
946 /*
947  * Tries to read read data from source into buffer. If buffer is full,
948  * no data is read. Returns 0 on success, -1 on error.
949  */
950 static int udt_do_read(struct unidirectional_transfer *t)
951 {
952         ssize_t bytes;
953
954         if (t->bufuse == BUFFERSIZE)
955                 return 0;       /* No space for more. */
956
957         transfer_debug("%s is readable", t->src_name);
958         bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
959         if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
960                 errno != EINTR) {
961                 error("read(%s) failed: %s", t->src_name, strerror(errno));
962                 return -1;
963         } else if (bytes == 0) {
964                 transfer_debug("%s EOF (with %i bytes in buffer)",
965                         t->src_name, t->bufuse);
966                 t->state = SSTATE_FLUSHING;
967         } else if (bytes > 0) {
968                 t->bufuse += bytes;
969                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
970                         (int)bytes, t->src_name, (int)t->bufuse);
971         }
972         return 0;
973 }
974
975 /* Tries to write data from buffer into destination. If buffer is empty,
976  * no data is written. Returns 0 on success, -1 on error.
977  */
978 static int udt_do_write(struct unidirectional_transfer *t)
979 {
980         size_t bytes;
981
982         if (t->bufuse == 0)
983                 return 0;       /* Nothing to write. */
984
985         transfer_debug("%s is writable", t->dest_name);
986         bytes = write(t->dest, t->buf, t->bufuse);
987         if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
988                 errno != EINTR) {
989                 error("write(%s) failed: %s", t->dest_name, strerror(errno));
990                 return -1;
991         } else if (bytes > 0) {
992                 t->bufuse -= bytes;
993                 if (t->bufuse)
994                         memmove(t->buf, t->buf + bytes, t->bufuse);
995                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
996                         (int)bytes, t->dest_name, (int)t->bufuse);
997         }
998         return 0;
999 }
1000
1001
1002 /* State of bidirectional transfer loop. */
1003 struct bidirectional_transfer_state {
1004         /* Direction from program to git. */
1005         struct unidirectional_transfer ptg;
1006         /* Direction from git to program. */
1007         struct unidirectional_transfer gtp;
1008 };
1009
1010 static void *udt_copy_task_routine(void *udt)
1011 {
1012         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1013         while (t->state != SSTATE_FINISHED) {
1014                 if (STATE_NEEDS_READING(t->state))
1015                         if (udt_do_read(t))
1016                                 return NULL;
1017                 if (STATE_NEEDS_WRITING(t->state))
1018                         if (udt_do_write(t))
1019                                 return NULL;
1020                 if (STATE_NEEDS_CLOSING(t->state))
1021                         udt_close_if_finished(t);
1022         }
1023         return udt;     /* Just some non-NULL value. */
1024 }
1025
1026 #ifndef NO_PTHREADS
1027
1028 /*
1029  * Join thread, with apporiate errors on failure. Name is name for the
1030  * thread (for error messages). Returns 0 on success, 1 on failure.
1031  */
1032 static int tloop_join(pthread_t thread, const char *name)
1033 {
1034         int err;
1035         void *tret;
1036         err = pthread_join(thread, &tret);
1037         if (!tret) {
1038                 error("%s thread failed", name);
1039                 return 1;
1040         }
1041         if (err) {
1042                 error("%s thread failed to join: %s", name, strerror(err));
1043                 return 1;
1044         }
1045         return 0;
1046 }
1047
1048 /*
1049  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1050  * -1 on failure.
1051  */
1052 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1053 {
1054         pthread_t gtp_thread;
1055         pthread_t ptg_thread;
1056         int err;
1057         int ret = 0;
1058         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1059                 &s->gtp);
1060         if (err)
1061                 die("Can't start thread for copying data: %s", strerror(err));
1062         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1063                 &s->ptg);
1064         if (err)
1065                 die("Can't start thread for copying data: %s", strerror(err));
1066
1067         ret |= tloop_join(gtp_thread, "Git to program copy");
1068         ret |= tloop_join(ptg_thread, "Program to git copy");
1069         return ret;
1070 }
1071 #else
1072
1073 /* Close the source and target (for writing) for transfer. */
1074 static void udt_kill_transfer(struct unidirectional_transfer *t)
1075 {
1076         t->state = SSTATE_FINISHED;
1077         /*
1078          * Socket read end left open isn't a disaster if nobody
1079          * attempts to read from it (mingw compat headers do not
1080          * have SHUT_RD)...
1081          *
1082          * We can't fully close the socket since otherwise gtp
1083          * task would first close the socket it sends data to
1084          * while closing the ptg file descriptors.
1085          */
1086         if (!t->src_is_sock)
1087                 close(t->src);
1088         if (t->dest_is_sock)
1089                 shutdown(t->dest, SHUT_WR);
1090         else
1091                 close(t->dest);
1092 }
1093
1094 /*
1095  * Join process, with apporiate errors on failure. Name is name for the
1096  * process (for error messages). Returns 0 on success, 1 on failure.
1097  */
1098 static int tloop_join(pid_t pid, const char *name)
1099 {
1100         int tret;
1101         if (waitpid(pid, &tret, 0) < 0) {
1102                 error("%s process failed to wait: %s", name, strerror(errno));
1103                 return 1;
1104         }
1105         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1106                 error("%s process failed", name);
1107                 return 1;
1108         }
1109         return 0;
1110 }
1111
1112 /*
1113  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1114  * -1 on failure.
1115  */
1116 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1117 {
1118         pid_t pid1, pid2;
1119         int ret = 0;
1120
1121         /* Fork thread #1: git to program. */
1122         pid1 = fork();
1123         if (pid1 < 0)
1124                 die_errno("Can't start thread for copying data");
1125         else if (pid1 == 0) {
1126                 udt_kill_transfer(&s->ptg);
1127                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1128         }
1129
1130         /* Fork thread #2: program to git. */
1131         pid2 = fork();
1132         if (pid2 < 0)
1133                 die_errno("Can't start thread for copying data");
1134         else if (pid2 == 0) {
1135                 udt_kill_transfer(&s->gtp);
1136                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1137         }
1138
1139         /*
1140          * Close both streams in parent as to not interfere with
1141          * end of file detection and wait for both tasks to finish.
1142          */
1143         udt_kill_transfer(&s->gtp);
1144         udt_kill_transfer(&s->ptg);
1145         ret |= tloop_join(pid1, "Git to program copy");
1146         ret |= tloop_join(pid2, "Program to git copy");
1147         return ret;
1148 }
1149 #endif
1150
1151 /*
1152  * Copies data from stdin to output and from input to stdout simultaneously.
1153  * Additionally filtering through given filter. If filter is NULL, uses
1154  * identity filter.
1155  */
1156 int bidirectional_transfer_loop(int input, int output)
1157 {
1158         struct bidirectional_transfer_state state;
1159
1160         /* Fill the state fields. */
1161         state.ptg.src = input;
1162         state.ptg.dest = 1;
1163         state.ptg.src_is_sock = (input == output);
1164         state.ptg.dest_is_sock = 0;
1165         state.ptg.state = SSTATE_TRANSFERING;
1166         state.ptg.bufuse = 0;
1167         state.ptg.src_name = "remote input";
1168         state.ptg.dest_name = "stdout";
1169
1170         state.gtp.src = 0;
1171         state.gtp.dest = output;
1172         state.gtp.src_is_sock = 0;
1173         state.gtp.dest_is_sock = (input == output);
1174         state.gtp.state = SSTATE_TRANSFERING;
1175         state.gtp.bufuse = 0;
1176         state.gtp.src_name = "stdin";
1177         state.gtp.dest_name = "remote output";
1178
1179         return tloop_spawnwait_tasks(&state);
1180 }