Merge branch 'tc/missing-http-proxyauth'
[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 #include "thread-utils.h"
12 #include "sigchain.h"
13 #include "argv-array.h"
14 #include "refs.h"
15
16 static int debug;
17
18 struct helper_data {
19         const char *name;
20         struct child_process *helper;
21         FILE *out;
22         unsigned fetch : 1,
23                 import : 1,
24                 bidi_import : 1,
25                 export : 1,
26                 option : 1,
27                 push : 1,
28                 connect : 1,
29                 signed_tags : 1,
30                 check_connectivity : 1,
31                 no_disconnect_req : 1,
32                 no_private_update : 1;
33         char *export_marks;
34         char *import_marks;
35         /* These go from remote name (as in "list") to private name */
36         struct refspec *refspecs;
37         int refspec_nr;
38         /* Transport options for fetch-pack/send-pack (should one of
39          * those be invoked).
40          */
41         struct git_transport_options transport_options;
42 };
43
44 static void sendline(struct helper_data *helper, struct strbuf *buffer)
45 {
46         if (debug)
47                 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
48         if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
49                 != buffer->len)
50                 die_errno("Full write to remote helper failed");
51 }
52
53 static int recvline_fh(FILE *helper, struct strbuf *buffer, const char *name)
54 {
55         strbuf_reset(buffer);
56         if (debug)
57                 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
58         if (strbuf_getline(buffer, helper, '\n') == EOF) {
59                 if (debug)
60                         fprintf(stderr, "Debug: Remote helper quit.\n");
61                 return 1;
62         }
63
64         if (debug)
65                 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
66         return 0;
67 }
68
69 static int recvline(struct helper_data *helper, struct strbuf *buffer)
70 {
71         return recvline_fh(helper->out, buffer, helper->name);
72 }
73
74 static void write_constant(int fd, const char *str)
75 {
76         if (debug)
77                 fprintf(stderr, "Debug: Remote helper: -> %s", str);
78         if (write_in_full(fd, str, strlen(str)) != strlen(str))
79                 die_errno("Full write to remote helper failed");
80 }
81
82 static const char *remove_ext_force(const char *url)
83 {
84         if (url) {
85                 const char *colon = strchr(url, ':');
86                 if (colon && colon[1] == ':')
87                         return colon + 2;
88         }
89         return url;
90 }
91
92 static void do_take_over(struct transport *transport)
93 {
94         struct helper_data *data;
95         data = (struct helper_data *)transport->data;
96         transport_take_over(transport, data->helper);
97         fclose(data->out);
98         free(data);
99 }
100
101 static struct child_process *get_helper(struct transport *transport)
102 {
103         struct helper_data *data = transport->data;
104         struct strbuf buf = STRBUF_INIT;
105         struct child_process *helper;
106         const char **refspecs = NULL;
107         int refspec_nr = 0;
108         int refspec_alloc = 0;
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         argv_array_pushf(&helper->env_array, "%s=%s", GIT_DIR_ENVIRONMENT,
127                          get_git_dir());
128
129         code = start_command(helper);
130         if (code < 0 && errno == ENOENT)
131                 die("Unable to find remote helper for '%s'", data->name);
132         else if (code != 0)
133                 exit(code);
134
135         data->helper = helper;
136         data->no_disconnect_req = 0;
137
138         /*
139          * Open the output as FILE* so strbuf_getline() can be used.
140          * Do this with duped fd because fclose() will close the fd,
141          * and stuff like taking over will require the fd to remain.
142          */
143         duped = dup(helper->out);
144         if (duped < 0)
145                 die_errno("Can't dup helper output fd");
146         data->out = xfdopen(duped, "r");
147
148         write_constant(helper->in, "capabilities\n");
149
150         while (1) {
151                 const char *capname, *arg;
152                 int mandatory = 0;
153                 if (recvline(data, &buf))
154                         exit(128);
155
156                 if (!*buf.buf)
157                         break;
158
159                 if (*buf.buf == '*') {
160                         capname = buf.buf + 1;
161                         mandatory = 1;
162                 } else
163                         capname = buf.buf;
164
165                 if (debug)
166                         fprintf(stderr, "Debug: Got cap %s\n", capname);
167                 if (!strcmp(capname, "fetch"))
168                         data->fetch = 1;
169                 else if (!strcmp(capname, "option"))
170                         data->option = 1;
171                 else if (!strcmp(capname, "push"))
172                         data->push = 1;
173                 else if (!strcmp(capname, "import"))
174                         data->import = 1;
175                 else if (!strcmp(capname, "bidi-import"))
176                         data->bidi_import = 1;
177                 else if (!strcmp(capname, "export"))
178                         data->export = 1;
179                 else if (!strcmp(capname, "check-connectivity"))
180                         data->check_connectivity = 1;
181                 else if (!data->refspecs && skip_prefix(capname, "refspec ", &arg)) {
182                         ALLOC_GROW(refspecs,
183                                    refspec_nr + 1,
184                                    refspec_alloc);
185                         refspecs[refspec_nr++] = xstrdup(arg);
186                 } else if (!strcmp(capname, "connect")) {
187                         data->connect = 1;
188                 } else if (!strcmp(capname, "signed-tags")) {
189                         data->signed_tags = 1;
190                 } else if (skip_prefix(capname, "export-marks ", &arg)) {
191                         data->export_marks = xstrdup(arg);
192                 } else if (skip_prefix(capname, "import-marks ", &arg)) {
193                         data->import_marks = xstrdup(arg);
194                 } else if (starts_with(capname, "no-private-update")) {
195                         data->no_private_update = 1;
196                 } else if (mandatory) {
197                         die("Unknown mandatory capability %s. This remote "
198                             "helper probably needs newer version of Git.",
199                             capname);
200                 }
201         }
202         if (refspecs) {
203                 int i;
204                 data->refspec_nr = refspec_nr;
205                 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
206                 for (i = 0; i < refspec_nr; i++)
207                         free((char *)refspecs[i]);
208                 free(refspecs);
209         } else if (data->import || data->bidi_import || data->export) {
210                 warning("This remote helper should implement refspec capability.");
211         }
212         strbuf_release(&buf);
213         if (debug)
214                 fprintf(stderr, "Debug: Capabilities complete.\n");
215         return data->helper;
216 }
217
218 static int disconnect_helper(struct transport *transport)
219 {
220         struct helper_data *data = transport->data;
221         int res = 0;
222
223         if (data->helper) {
224                 if (debug)
225                         fprintf(stderr, "Debug: Disconnecting.\n");
226                 if (!data->no_disconnect_req) {
227                         /*
228                          * Ignore write errors; there's nothing we can do,
229                          * since we're about to close the pipe anyway. And the
230                          * most likely error is EPIPE due to the helper dying
231                          * to report an error itself.
232                          */
233                         sigchain_push(SIGPIPE, SIG_IGN);
234                         xwrite(data->helper->in, "\n", 1);
235                         sigchain_pop(SIGPIPE);
236                 }
237                 close(data->helper->in);
238                 close(data->helper->out);
239                 fclose(data->out);
240                 res = finish_command(data->helper);
241                 free(data->helper);
242                 data->helper = NULL;
243         }
244         return res;
245 }
246
247 static const char *unsupported_options[] = {
248         TRANS_OPT_UPLOADPACK,
249         TRANS_OPT_RECEIVEPACK,
250         TRANS_OPT_THIN,
251         TRANS_OPT_KEEP
252         };
253
254 static const char *boolean_options[] = {
255         TRANS_OPT_THIN,
256         TRANS_OPT_KEEP,
257         TRANS_OPT_FOLLOWTAGS,
258         TRANS_OPT_PUSH_CERT
259         };
260
261 static int set_helper_option(struct transport *transport,
262                           const char *name, const char *value)
263 {
264         struct helper_data *data = transport->data;
265         struct strbuf buf = STRBUF_INIT;
266         int i, ret, is_bool = 0;
267
268         get_helper(transport);
269
270         if (!data->option)
271                 return 1;
272
273         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
274                 if (!strcmp(name, unsupported_options[i]))
275                         return 1;
276         }
277
278         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
279                 if (!strcmp(name, boolean_options[i])) {
280                         is_bool = 1;
281                         break;
282                 }
283         }
284
285         strbuf_addf(&buf, "option %s ", name);
286         if (is_bool)
287                 strbuf_addstr(&buf, value ? "true" : "false");
288         else
289                 quote_c_style(value, &buf, NULL, 0);
290         strbuf_addch(&buf, '\n');
291
292         sendline(data, &buf);
293         if (recvline(data, &buf))
294                 exit(128);
295
296         if (!strcmp(buf.buf, "ok"))
297                 ret = 0;
298         else if (starts_with(buf.buf, "error")) {
299                 ret = -1;
300         } else if (!strcmp(buf.buf, "unsupported"))
301                 ret = 1;
302         else {
303                 warning("%s unexpectedly said: '%s'", data->name, buf.buf);
304                 ret = 1;
305         }
306         strbuf_release(&buf);
307         return ret;
308 }
309
310 static void standard_options(struct transport *t)
311 {
312         char buf[16];
313         int n;
314         int v = t->verbose;
315
316         set_helper_option(t, "progress", t->progress ? "true" : "false");
317
318         n = snprintf(buf, sizeof(buf), "%d", v + 1);
319         if (n >= sizeof(buf))
320                 die("impossibly large verbosity value");
321         set_helper_option(t, "verbosity", buf);
322 }
323
324 static int release_helper(struct transport *transport)
325 {
326         int res = 0;
327         struct helper_data *data = transport->data;
328         free_refspec(data->refspec_nr, data->refspecs);
329         data->refspecs = NULL;
330         res = disconnect_helper(transport);
331         free(transport->data);
332         return res;
333 }
334
335 static int fetch_with_fetch(struct transport *transport,
336                             int nr_heads, struct ref **to_fetch)
337 {
338         struct helper_data *data = transport->data;
339         int i;
340         struct strbuf buf = STRBUF_INIT;
341
342         standard_options(transport);
343         if (data->check_connectivity &&
344             data->transport_options.check_self_contained_and_connected)
345                 set_helper_option(transport, "check-connectivity", "true");
346
347         if (transport->cloning)
348                 set_helper_option(transport, "cloning", "true");
349
350         if (data->transport_options.update_shallow)
351                 set_helper_option(transport, "update-shallow", "true");
352
353         for (i = 0; i < nr_heads; i++) {
354                 const struct ref *posn = to_fetch[i];
355                 if (posn->status & REF_STATUS_UPTODATE)
356                         continue;
357
358                 strbuf_addf(&buf, "fetch %s %s\n",
359                             sha1_to_hex(posn->old_sha1),
360                             posn->symref ? posn->symref : posn->name);
361         }
362
363         strbuf_addch(&buf, '\n');
364         sendline(data, &buf);
365
366         while (1) {
367                 if (recvline(data, &buf))
368                         exit(128);
369
370                 if (starts_with(buf.buf, "lock ")) {
371                         const char *name = buf.buf + 5;
372                         if (transport->pack_lockfile)
373                                 warning("%s also locked %s", data->name, name);
374                         else
375                                 transport->pack_lockfile = xstrdup(name);
376                 }
377                 else if (data->check_connectivity &&
378                          data->transport_options.check_self_contained_and_connected &&
379                          !strcmp(buf.buf, "connectivity-ok"))
380                         data->transport_options.self_contained_and_connected = 1;
381                 else if (!buf.len)
382                         break;
383                 else
384                         warning("%s unexpectedly said: '%s'", data->name, buf.buf);
385         }
386         strbuf_release(&buf);
387         return 0;
388 }
389
390 static int get_importer(struct transport *transport, struct child_process *fastimport)
391 {
392         struct child_process *helper = get_helper(transport);
393         struct helper_data *data = transport->data;
394         int cat_blob_fd, code;
395         child_process_init(fastimport);
396         fastimport->in = helper->out;
397         argv_array_push(&fastimport->args, "fast-import");
398         argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
399
400         if (data->bidi_import) {
401                 cat_blob_fd = xdup(helper->in);
402                 argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
403         }
404         fastimport->git_cmd = 1;
405
406         code = start_command(fastimport);
407         return code;
408 }
409
410 static int get_exporter(struct transport *transport,
411                         struct child_process *fastexport,
412                         struct string_list *revlist_args)
413 {
414         struct helper_data *data = transport->data;
415         struct child_process *helper = get_helper(transport);
416         int i;
417
418         child_process_init(fastexport);
419
420         /* we need to duplicate helper->in because we want to use it after
421          * fastexport is done with it. */
422         fastexport->out = dup(helper->in);
423         argv_array_push(&fastexport->args, "fast-export");
424         argv_array_push(&fastexport->args, "--use-done-feature");
425         argv_array_push(&fastexport->args, data->signed_tags ?
426                 "--signed-tags=verbatim" : "--signed-tags=warn-strip");
427         if (data->export_marks)
428                 argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
429         if (data->import_marks)
430                 argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
431
432         for (i = 0; i < revlist_args->nr; i++)
433                 argv_array_push(&fastexport->args, revlist_args->items[i].string);
434
435         fastexport->git_cmd = 1;
436         return start_command(fastexport);
437 }
438
439 static int fetch_with_import(struct transport *transport,
440                              int nr_heads, struct ref **to_fetch)
441 {
442         struct child_process fastimport;
443         struct helper_data *data = transport->data;
444         int i;
445         struct ref *posn;
446         struct strbuf buf = STRBUF_INIT;
447
448         get_helper(transport);
449
450         if (get_importer(transport, &fastimport))
451                 die("Couldn't run fast-import");
452
453         for (i = 0; i < nr_heads; i++) {
454                 posn = to_fetch[i];
455                 if (posn->status & REF_STATUS_UPTODATE)
456                         continue;
457
458                 strbuf_addf(&buf, "import %s\n",
459                             posn->symref ? posn->symref : posn->name);
460                 sendline(data, &buf);
461                 strbuf_reset(&buf);
462         }
463
464         write_constant(data->helper->in, "\n");
465         /*
466          * remote-helpers that advertise the bidi-import capability are required to
467          * buffer the complete batch of import commands until this newline before
468          * sending data to fast-import.
469          * These helpers read back data from fast-import on their stdin, which could
470          * be mixed with import commands, otherwise.
471          */
472
473         if (finish_command(&fastimport))
474                 die("Error while running fast-import");
475
476         /*
477          * The fast-import stream of a remote helper that advertises
478          * the "refspec" capability writes to the refs named after the
479          * right hand side of the first refspec matching each ref we
480          * were fetching.
481          *
482          * (If no "refspec" capability was specified, for historical
483          * reasons we default to the equivalent of *:*.)
484          *
485          * Store the result in to_fetch[i].old_sha1.  Callers such
486          * as "git fetch" can use the value to write feedback to the
487          * terminal, populate FETCH_HEAD, and determine what new value
488          * should be written to peer_ref if the update is a
489          * fast-forward or this is a forced update.
490          */
491         for (i = 0; i < nr_heads; i++) {
492                 char *private, *name;
493                 posn = to_fetch[i];
494                 if (posn->status & REF_STATUS_UPTODATE)
495                         continue;
496                 name = posn->symref ? posn->symref : posn->name;
497                 if (data->refspecs)
498                         private = apply_refspecs(data->refspecs, data->refspec_nr, name);
499                 else
500                         private = xstrdup(name);
501                 if (private) {
502                         read_ref(private, posn->old_sha1);
503                         free(private);
504                 }
505         }
506         strbuf_release(&buf);
507         return 0;
508 }
509
510 static int process_connect_service(struct transport *transport,
511                                    const char *name, const char *exec)
512 {
513         struct helper_data *data = transport->data;
514         struct strbuf cmdbuf = STRBUF_INIT;
515         struct child_process *helper;
516         int r, duped, ret = 0;
517         FILE *input;
518
519         helper = get_helper(transport);
520
521         /*
522          * Yes, dup the pipe another time, as we need unbuffered version
523          * of input pipe as FILE*. fclose() closes the underlying fd and
524          * stream buffering only can be changed before first I/O operation
525          * on it.
526          */
527         duped = dup(helper->out);
528         if (duped < 0)
529                 die_errno("Can't dup helper output fd");
530         input = xfdopen(duped, "r");
531         setvbuf(input, NULL, _IONBF, 0);
532
533         /*
534          * Handle --upload-pack and friends. This is fire and forget...
535          * just warn if it fails.
536          */
537         if (strcmp(name, exec)) {
538                 r = set_helper_option(transport, "servpath", exec);
539                 if (r > 0)
540                         warning("Setting remote service path not supported by protocol.");
541                 else if (r < 0)
542                         warning("Invalid remote service path.");
543         }
544
545         if (data->connect)
546                 strbuf_addf(&cmdbuf, "connect %s\n", name);
547         else
548                 goto exit;
549
550         sendline(data, &cmdbuf);
551         if (recvline_fh(input, &cmdbuf, name))
552                 exit(128);
553
554         if (!strcmp(cmdbuf.buf, "")) {
555                 data->no_disconnect_req = 1;
556                 if (debug)
557                         fprintf(stderr, "Debug: Smart transport connection "
558                                 "ready.\n");
559                 ret = 1;
560         } else if (!strcmp(cmdbuf.buf, "fallback")) {
561                 if (debug)
562                         fprintf(stderr, "Debug: Falling back to dumb "
563                                 "transport.\n");
564         } else
565                 die("Unknown response to connect: %s",
566                         cmdbuf.buf);
567
568 exit:
569         fclose(input);
570         return ret;
571 }
572
573 static int process_connect(struct transport *transport,
574                                      int for_push)
575 {
576         struct helper_data *data = transport->data;
577         const char *name;
578         const char *exec;
579
580         name = for_push ? "git-receive-pack" : "git-upload-pack";
581         if (for_push)
582                 exec = data->transport_options.receivepack;
583         else
584                 exec = data->transport_options.uploadpack;
585
586         return process_connect_service(transport, name, exec);
587 }
588
589 static int connect_helper(struct transport *transport, const char *name,
590                    const char *exec, int fd[2])
591 {
592         struct helper_data *data = transport->data;
593
594         /* Get_helper so connect is inited. */
595         get_helper(transport);
596         if (!data->connect)
597                 die("Operation not supported by protocol.");
598
599         if (!process_connect_service(transport, name, exec))
600                 die("Can't connect to subservice %s.", name);
601
602         fd[0] = data->helper->out;
603         fd[1] = data->helper->in;
604         return 0;
605 }
606
607 static int fetch(struct transport *transport,
608                  int nr_heads, struct ref **to_fetch)
609 {
610         struct helper_data *data = transport->data;
611         int i, count;
612
613         if (process_connect(transport, 0)) {
614                 do_take_over(transport);
615                 return transport->fetch(transport, nr_heads, to_fetch);
616         }
617
618         count = 0;
619         for (i = 0; i < nr_heads; i++)
620                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
621                         count++;
622
623         if (!count)
624                 return 0;
625
626         if (data->fetch)
627                 return fetch_with_fetch(transport, nr_heads, to_fetch);
628
629         if (data->import)
630                 return fetch_with_import(transport, nr_heads, to_fetch);
631
632         return -1;
633 }
634
635 static int push_update_ref_status(struct strbuf *buf,
636                                    struct ref **ref,
637                                    struct ref *remote_refs)
638 {
639         char *refname, *msg;
640         int status, forced = 0;
641
642         if (starts_with(buf->buf, "ok ")) {
643                 status = REF_STATUS_OK;
644                 refname = buf->buf + 3;
645         } else if (starts_with(buf->buf, "error ")) {
646                 status = REF_STATUS_REMOTE_REJECT;
647                 refname = buf->buf + 6;
648         } else
649                 die("expected ok/error, helper said '%s'", buf->buf);
650
651         msg = strchr(refname, ' ');
652         if (msg) {
653                 struct strbuf msg_buf = STRBUF_INIT;
654                 const char *end;
655
656                 *msg++ = '\0';
657                 if (!unquote_c_style(&msg_buf, msg, &end))
658                         msg = strbuf_detach(&msg_buf, NULL);
659                 else
660                         msg = xstrdup(msg);
661                 strbuf_release(&msg_buf);
662
663                 if (!strcmp(msg, "no match")) {
664                         status = REF_STATUS_NONE;
665                         free(msg);
666                         msg = NULL;
667                 }
668                 else if (!strcmp(msg, "up to date")) {
669                         status = REF_STATUS_UPTODATE;
670                         free(msg);
671                         msg = NULL;
672                 }
673                 else if (!strcmp(msg, "non-fast forward")) {
674                         status = REF_STATUS_REJECT_NONFASTFORWARD;
675                         free(msg);
676                         msg = NULL;
677                 }
678                 else if (!strcmp(msg, "already exists")) {
679                         status = REF_STATUS_REJECT_ALREADY_EXISTS;
680                         free(msg);
681                         msg = NULL;
682                 }
683                 else if (!strcmp(msg, "fetch first")) {
684                         status = REF_STATUS_REJECT_FETCH_FIRST;
685                         free(msg);
686                         msg = NULL;
687                 }
688                 else if (!strcmp(msg, "needs force")) {
689                         status = REF_STATUS_REJECT_NEEDS_FORCE;
690                         free(msg);
691                         msg = NULL;
692                 }
693                 else if (!strcmp(msg, "stale info")) {
694                         status = REF_STATUS_REJECT_STALE;
695                         free(msg);
696                         msg = NULL;
697                 }
698                 else if (!strcmp(msg, "forced update")) {
699                         forced = 1;
700                         free(msg);
701                         msg = NULL;
702                 }
703         }
704
705         if (*ref)
706                 *ref = find_ref_by_name(*ref, refname);
707         if (!*ref)
708                 *ref = find_ref_by_name(remote_refs, refname);
709         if (!*ref) {
710                 warning("helper reported unexpected status of %s", refname);
711                 return 1;
712         }
713
714         if ((*ref)->status != REF_STATUS_NONE) {
715                 /*
716                  * Earlier, the ref was marked not to be pushed, so ignore the ref
717                  * status reported by the remote helper if the latter is 'no match'.
718                  */
719                 if (status == REF_STATUS_NONE)
720                         return 1;
721         }
722
723         (*ref)->status = status;
724         (*ref)->forced_update |= forced;
725         (*ref)->remote_status = msg;
726         return !(status == REF_STATUS_OK);
727 }
728
729 static int push_update_refs_status(struct helper_data *data,
730                                     struct ref *remote_refs,
731                                     int flags)
732 {
733         struct strbuf buf = STRBUF_INIT;
734         struct ref *ref = remote_refs;
735         int ret = 0;
736
737         for (;;) {
738                 char *private;
739
740                 if (recvline(data, &buf)) {
741                         ret = 1;
742                         break;
743                 }
744
745                 if (!buf.len)
746                         break;
747
748                 if (push_update_ref_status(&buf, &ref, remote_refs))
749                         continue;
750
751                 if (flags & TRANSPORT_PUSH_DRY_RUN || !data->refspecs || data->no_private_update)
752                         continue;
753
754                 /* propagate back the update to the remote namespace */
755                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
756                 if (!private)
757                         continue;
758                 update_ref("update by helper", private, ref->new_sha1, NULL, 0, 0);
759                 free(private);
760         }
761         strbuf_release(&buf);
762         return ret;
763 }
764
765 static int push_refs_with_push(struct transport *transport,
766                                struct ref *remote_refs, int flags)
767 {
768         int force_all = flags & TRANSPORT_PUSH_FORCE;
769         int mirror = flags & TRANSPORT_PUSH_MIRROR;
770         struct helper_data *data = transport->data;
771         struct strbuf buf = STRBUF_INIT;
772         struct ref *ref;
773         struct string_list cas_options = STRING_LIST_INIT_DUP;
774         struct string_list_item *cas_option;
775
776         get_helper(transport);
777         if (!data->push)
778                 return 1;
779
780         for (ref = remote_refs; ref; ref = ref->next) {
781                 if (!ref->peer_ref && !mirror)
782                         continue;
783
784                 /* Check for statuses set by set_ref_status_for_push() */
785                 switch (ref->status) {
786                 case REF_STATUS_REJECT_NONFASTFORWARD:
787                 case REF_STATUS_REJECT_STALE:
788                 case REF_STATUS_REJECT_ALREADY_EXISTS:
789                 case REF_STATUS_UPTODATE:
790                         continue;
791                 default:
792                         ; /* do nothing */
793                 }
794
795                 if (force_all)
796                         ref->force = 1;
797
798                 strbuf_addstr(&buf, "push ");
799                 if (!ref->deletion) {
800                         if (ref->force)
801                                 strbuf_addch(&buf, '+');
802                         if (ref->peer_ref)
803                                 strbuf_addstr(&buf, ref->peer_ref->name);
804                         else
805                                 strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
806                 }
807                 strbuf_addch(&buf, ':');
808                 strbuf_addstr(&buf, ref->name);
809                 strbuf_addch(&buf, '\n');
810
811                 /*
812                  * The "--force-with-lease" options without explicit
813                  * values to expect have already been expanded into
814                  * the ref->old_sha1_expect[] field; we can ignore
815                  * transport->smart_options->cas altogether and instead
816                  * can enumerate them from the refs.
817                  */
818                 if (ref->expect_old_sha1) {
819                         struct strbuf cas = STRBUF_INIT;
820                         strbuf_addf(&cas, "%s:%s",
821                                     ref->name, sha1_to_hex(ref->old_sha1_expect));
822                         string_list_append(&cas_options, strbuf_detach(&cas, NULL));
823                 }
824         }
825         if (buf.len == 0) {
826                 string_list_clear(&cas_options, 0);
827                 return 0;
828         }
829
830         standard_options(transport);
831         for_each_string_list_item(cas_option, &cas_options)
832                 set_helper_option(transport, "cas", cas_option->string);
833
834         if (flags & TRANSPORT_PUSH_DRY_RUN) {
835                 if (set_helper_option(transport, "dry-run", "true") != 0)
836                         die("helper %s does not support dry-run", data->name);
837         } else if (flags & TRANSPORT_PUSH_CERT) {
838                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
839                         die("helper %s does not support --signed", data->name);
840         }
841
842         strbuf_addch(&buf, '\n');
843         sendline(data, &buf);
844         strbuf_release(&buf);
845
846         return push_update_refs_status(data, remote_refs, flags);
847 }
848
849 static int push_refs_with_export(struct transport *transport,
850                 struct ref *remote_refs, int flags)
851 {
852         struct ref *ref;
853         struct child_process *helper, exporter;
854         struct helper_data *data = transport->data;
855         struct string_list revlist_args = STRING_LIST_INIT_DUP;
856         struct strbuf buf = STRBUF_INIT;
857
858         if (!data->refspecs)
859                 die("remote-helper doesn't support push; refspec needed");
860
861         if (flags & TRANSPORT_PUSH_DRY_RUN) {
862                 if (set_helper_option(transport, "dry-run", "true") != 0)
863                         die("helper %s does not support dry-run", data->name);
864         } else if (flags & TRANSPORT_PUSH_CERT) {
865                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
866                         die("helper %s does not support --signed", data->name);
867         }
868
869         if (flags & TRANSPORT_PUSH_FORCE) {
870                 if (set_helper_option(transport, "force", "true") != 0)
871                         warning("helper %s does not support 'force'", data->name);
872         }
873
874         helper = get_helper(transport);
875
876         write_constant(helper->in, "export\n");
877
878         for (ref = remote_refs; ref; ref = ref->next) {
879                 char *private;
880                 unsigned char sha1[20];
881
882                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
883                 if (private && !get_sha1(private, sha1)) {
884                         strbuf_addf(&buf, "^%s", private);
885                         string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
886                         hashcpy(ref->old_sha1, sha1);
887                 }
888                 free(private);
889
890                 if (ref->peer_ref) {
891                         if (strcmp(ref->name, ref->peer_ref->name)) {
892                                 if (!ref->deletion) {
893                                         const char *name;
894                                         int flag;
895
896                                         /* Follow symbolic refs (mainly for HEAD). */
897                                         name = resolve_ref_unsafe(
898                                                  ref->peer_ref->name,
899                                                  RESOLVE_REF_READING,
900                                                  sha1, &flag);
901                                         if (!name || !(flag & REF_ISSYMREF))
902                                                 name = ref->peer_ref->name;
903
904                                         strbuf_addf(&buf, "%s:%s", name, ref->name);
905                                 } else
906                                         strbuf_addf(&buf, ":%s", ref->name);
907
908                                 string_list_append(&revlist_args, "--refspec");
909                                 string_list_append(&revlist_args, buf.buf);
910                                 strbuf_release(&buf);
911                         }
912                         if (!ref->deletion)
913                                 string_list_append(&revlist_args, ref->peer_ref->name);
914                 }
915         }
916
917         if (get_exporter(transport, &exporter, &revlist_args))
918                 die("Couldn't run fast-export");
919
920         string_list_clear(&revlist_args, 1);
921
922         if (finish_command(&exporter))
923                 die("Error while running fast-export");
924         if (push_update_refs_status(data, remote_refs, flags))
925                 return 1;
926
927         if (data->export_marks) {
928                 strbuf_addf(&buf, "%s.tmp", data->export_marks);
929                 rename(buf.buf, data->export_marks);
930                 strbuf_release(&buf);
931         }
932
933         return 0;
934 }
935
936 static int push_refs(struct transport *transport,
937                 struct ref *remote_refs, int flags)
938 {
939         struct helper_data *data = transport->data;
940
941         if (process_connect(transport, 1)) {
942                 do_take_over(transport);
943                 return transport->push_refs(transport, remote_refs, flags);
944         }
945
946         if (!remote_refs) {
947                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
948                         "Perhaps you should specify a branch such as 'master'.\n");
949                 return 0;
950         }
951
952         if (data->push)
953                 return push_refs_with_push(transport, remote_refs, flags);
954
955         if (data->export)
956                 return push_refs_with_export(transport, remote_refs, flags);
957
958         return -1;
959 }
960
961
962 static int has_attribute(const char *attrs, const char *attr) {
963         int len;
964         if (!attrs)
965                 return 0;
966
967         len = strlen(attr);
968         for (;;) {
969                 const char *space = strchrnul(attrs, ' ');
970                 if (len == space - attrs && !strncmp(attrs, attr, len))
971                         return 1;
972                 if (!*space)
973                         return 0;
974                 attrs = space + 1;
975         }
976 }
977
978 static struct ref *get_refs_list(struct transport *transport, int for_push)
979 {
980         struct helper_data *data = transport->data;
981         struct child_process *helper;
982         struct ref *ret = NULL;
983         struct ref **tail = &ret;
984         struct ref *posn;
985         struct strbuf buf = STRBUF_INIT;
986
987         helper = get_helper(transport);
988
989         if (process_connect(transport, for_push)) {
990                 do_take_over(transport);
991                 return transport->get_refs_list(transport, for_push);
992         }
993
994         if (data->push && for_push)
995                 write_str_in_full(helper->in, "list for-push\n");
996         else
997                 write_str_in_full(helper->in, "list\n");
998
999         while (1) {
1000                 char *eov, *eon;
1001                 if (recvline(data, &buf))
1002                         exit(128);
1003
1004                 if (!*buf.buf)
1005                         break;
1006
1007                 eov = strchr(buf.buf, ' ');
1008                 if (!eov)
1009                         die("Malformed response in ref list: %s", buf.buf);
1010                 eon = strchr(eov + 1, ' ');
1011                 *eov = '\0';
1012                 if (eon)
1013                         *eon = '\0';
1014                 *tail = alloc_ref(eov + 1);
1015                 if (buf.buf[0] == '@')
1016                         (*tail)->symref = xstrdup(buf.buf + 1);
1017                 else if (buf.buf[0] != '?')
1018                         get_sha1_hex(buf.buf, (*tail)->old_sha1);
1019                 if (eon) {
1020                         if (has_attribute(eon + 1, "unchanged")) {
1021                                 (*tail)->status |= REF_STATUS_UPTODATE;
1022                                 read_ref((*tail)->name, (*tail)->old_sha1);
1023                         }
1024                 }
1025                 tail = &((*tail)->next);
1026         }
1027         if (debug)
1028                 fprintf(stderr, "Debug: Read ref listing.\n");
1029         strbuf_release(&buf);
1030
1031         for (posn = ret; posn; posn = posn->next)
1032                 resolve_remote_symref(posn, ret);
1033
1034         return ret;
1035 }
1036
1037 int transport_helper_init(struct transport *transport, const char *name)
1038 {
1039         struct helper_data *data = xcalloc(1, sizeof(*data));
1040         data->name = name;
1041
1042         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1043                 debug = 1;
1044
1045         transport->data = data;
1046         transport->set_option = set_helper_option;
1047         transport->get_refs_list = get_refs_list;
1048         transport->fetch = fetch;
1049         transport->push_refs = push_refs;
1050         transport->disconnect = release_helper;
1051         transport->connect = connect_helper;
1052         transport->smart_options = &(data->transport_options);
1053         return 0;
1054 }
1055
1056 /*
1057  * Linux pipes can buffer 65536 bytes at once (and most platforms can
1058  * buffer less), so attempt reads and writes with up to that size.
1059  */
1060 #define BUFFERSIZE 65536
1061 /* This should be enough to hold debugging message. */
1062 #define PBUFFERSIZE 8192
1063
1064 /* Print bidirectional transfer loop debug message. */
1065 __attribute__((format (printf, 1, 2)))
1066 static void transfer_debug(const char *fmt, ...)
1067 {
1068         va_list args;
1069         char msgbuf[PBUFFERSIZE];
1070         static int debug_enabled = -1;
1071
1072         if (debug_enabled < 0)
1073                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1074         if (!debug_enabled)
1075                 return;
1076
1077         va_start(args, fmt);
1078         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1079         va_end(args);
1080         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1081 }
1082
1083 /* Stream state: More data may be coming in this direction. */
1084 #define SSTATE_TRANSFERING 0
1085 /*
1086  * Stream state: No more data coming in this direction, flushing rest of
1087  * data.
1088  */
1089 #define SSTATE_FLUSHING 1
1090 /* Stream state: Transfer in this direction finished. */
1091 #define SSTATE_FINISHED 2
1092
1093 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
1094 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1095 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1096
1097 /* Unidirectional transfer. */
1098 struct unidirectional_transfer {
1099         /* Source */
1100         int src;
1101         /* Destination */
1102         int dest;
1103         /* Is source socket? */
1104         int src_is_sock;
1105         /* Is destination socket? */
1106         int dest_is_sock;
1107         /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1108         int state;
1109         /* Buffer. */
1110         char buf[BUFFERSIZE];
1111         /* Buffer used. */
1112         size_t bufuse;
1113         /* Name of source. */
1114         const char *src_name;
1115         /* Name of destination. */
1116         const char *dest_name;
1117 };
1118
1119 /* Closes the target (for writing) if transfer has finished. */
1120 static void udt_close_if_finished(struct unidirectional_transfer *t)
1121 {
1122         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1123                 t->state = SSTATE_FINISHED;
1124                 if (t->dest_is_sock)
1125                         shutdown(t->dest, SHUT_WR);
1126                 else
1127                         close(t->dest);
1128                 transfer_debug("Closed %s.", t->dest_name);
1129         }
1130 }
1131
1132 /*
1133  * Tries to read read data from source into buffer. If buffer is full,
1134  * no data is read. Returns 0 on success, -1 on error.
1135  */
1136 static int udt_do_read(struct unidirectional_transfer *t)
1137 {
1138         ssize_t bytes;
1139
1140         if (t->bufuse == BUFFERSIZE)
1141                 return 0;       /* No space for more. */
1142
1143         transfer_debug("%s is readable", t->src_name);
1144         bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1145         if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1146                 errno != EINTR) {
1147                 error("read(%s) failed: %s", t->src_name, strerror(errno));
1148                 return -1;
1149         } else if (bytes == 0) {
1150                 transfer_debug("%s EOF (with %i bytes in buffer)",
1151                         t->src_name, (int)t->bufuse);
1152                 t->state = SSTATE_FLUSHING;
1153         } else if (bytes > 0) {
1154                 t->bufuse += bytes;
1155                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1156                         (int)bytes, t->src_name, (int)t->bufuse);
1157         }
1158         return 0;
1159 }
1160
1161 /* Tries to write data from buffer into destination. If buffer is empty,
1162  * no data is written. Returns 0 on success, -1 on error.
1163  */
1164 static int udt_do_write(struct unidirectional_transfer *t)
1165 {
1166         ssize_t bytes;
1167
1168         if (t->bufuse == 0)
1169                 return 0;       /* Nothing to write. */
1170
1171         transfer_debug("%s is writable", t->dest_name);
1172         bytes = xwrite(t->dest, t->buf, t->bufuse);
1173         if (bytes < 0 && errno != EWOULDBLOCK) {
1174                 error("write(%s) failed: %s", t->dest_name, strerror(errno));
1175                 return -1;
1176         } else if (bytes > 0) {
1177                 t->bufuse -= bytes;
1178                 if (t->bufuse)
1179                         memmove(t->buf, t->buf + bytes, t->bufuse);
1180                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1181                         (int)bytes, t->dest_name, (int)t->bufuse);
1182         }
1183         return 0;
1184 }
1185
1186
1187 /* State of bidirectional transfer loop. */
1188 struct bidirectional_transfer_state {
1189         /* Direction from program to git. */
1190         struct unidirectional_transfer ptg;
1191         /* Direction from git to program. */
1192         struct unidirectional_transfer gtp;
1193 };
1194
1195 static void *udt_copy_task_routine(void *udt)
1196 {
1197         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1198         while (t->state != SSTATE_FINISHED) {
1199                 if (STATE_NEEDS_READING(t->state))
1200                         if (udt_do_read(t))
1201                                 return NULL;
1202                 if (STATE_NEEDS_WRITING(t->state))
1203                         if (udt_do_write(t))
1204                                 return NULL;
1205                 if (STATE_NEEDS_CLOSING(t->state))
1206                         udt_close_if_finished(t);
1207         }
1208         return udt;     /* Just some non-NULL value. */
1209 }
1210
1211 #ifndef NO_PTHREADS
1212
1213 /*
1214  * Join thread, with appropriate errors on failure. Name is name for the
1215  * thread (for error messages). Returns 0 on success, 1 on failure.
1216  */
1217 static int tloop_join(pthread_t thread, const char *name)
1218 {
1219         int err;
1220         void *tret;
1221         err = pthread_join(thread, &tret);
1222         if (!tret) {
1223                 error("%s thread failed", name);
1224                 return 1;
1225         }
1226         if (err) {
1227                 error("%s thread failed to join: %s", name, strerror(err));
1228                 return 1;
1229         }
1230         return 0;
1231 }
1232
1233 /*
1234  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1235  * -1 on failure.
1236  */
1237 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1238 {
1239         pthread_t gtp_thread;
1240         pthread_t ptg_thread;
1241         int err;
1242         int ret = 0;
1243         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1244                 &s->gtp);
1245         if (err)
1246                 die("Can't start thread for copying data: %s", strerror(err));
1247         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1248                 &s->ptg);
1249         if (err)
1250                 die("Can't start thread for copying data: %s", strerror(err));
1251
1252         ret |= tloop_join(gtp_thread, "Git to program copy");
1253         ret |= tloop_join(ptg_thread, "Program to git copy");
1254         return ret;
1255 }
1256 #else
1257
1258 /* Close the source and target (for writing) for transfer. */
1259 static void udt_kill_transfer(struct unidirectional_transfer *t)
1260 {
1261         t->state = SSTATE_FINISHED;
1262         /*
1263          * Socket read end left open isn't a disaster if nobody
1264          * attempts to read from it (mingw compat headers do not
1265          * have SHUT_RD)...
1266          *
1267          * We can't fully close the socket since otherwise gtp
1268          * task would first close the socket it sends data to
1269          * while closing the ptg file descriptors.
1270          */
1271         if (!t->src_is_sock)
1272                 close(t->src);
1273         if (t->dest_is_sock)
1274                 shutdown(t->dest, SHUT_WR);
1275         else
1276                 close(t->dest);
1277 }
1278
1279 /*
1280  * Join process, with appropriate errors on failure. Name is name for the
1281  * process (for error messages). Returns 0 on success, 1 on failure.
1282  */
1283 static int tloop_join(pid_t pid, const char *name)
1284 {
1285         int tret;
1286         if (waitpid(pid, &tret, 0) < 0) {
1287                 error("%s process failed to wait: %s", name, strerror(errno));
1288                 return 1;
1289         }
1290         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1291                 error("%s process failed", name);
1292                 return 1;
1293         }
1294         return 0;
1295 }
1296
1297 /*
1298  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1299  * -1 on failure.
1300  */
1301 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1302 {
1303         pid_t pid1, pid2;
1304         int ret = 0;
1305
1306         /* Fork thread #1: git to program. */
1307         pid1 = fork();
1308         if (pid1 < 0)
1309                 die_errno("Can't start thread for copying data");
1310         else if (pid1 == 0) {
1311                 udt_kill_transfer(&s->ptg);
1312                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1313         }
1314
1315         /* Fork thread #2: program to git. */
1316         pid2 = fork();
1317         if (pid2 < 0)
1318                 die_errno("Can't start thread for copying data");
1319         else if (pid2 == 0) {
1320                 udt_kill_transfer(&s->gtp);
1321                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1322         }
1323
1324         /*
1325          * Close both streams in parent as to not interfere with
1326          * end of file detection and wait for both tasks to finish.
1327          */
1328         udt_kill_transfer(&s->gtp);
1329         udt_kill_transfer(&s->ptg);
1330         ret |= tloop_join(pid1, "Git to program copy");
1331         ret |= tloop_join(pid2, "Program to git copy");
1332         return ret;
1333 }
1334 #endif
1335
1336 /*
1337  * Copies data from stdin to output and from input to stdout simultaneously.
1338  * Additionally filtering through given filter. If filter is NULL, uses
1339  * identity filter.
1340  */
1341 int bidirectional_transfer_loop(int input, int output)
1342 {
1343         struct bidirectional_transfer_state state;
1344
1345         /* Fill the state fields. */
1346         state.ptg.src = input;
1347         state.ptg.dest = 1;
1348         state.ptg.src_is_sock = (input == output);
1349         state.ptg.dest_is_sock = 0;
1350         state.ptg.state = SSTATE_TRANSFERING;
1351         state.ptg.bufuse = 0;
1352         state.ptg.src_name = "remote input";
1353         state.ptg.dest_name = "stdout";
1354
1355         state.gtp.src = 0;
1356         state.gtp.dest = output;
1357         state.gtp.src_is_sock = 0;
1358         state.gtp.dest_is_sock = (input == output);
1359         state.gtp.state = SSTATE_TRANSFERING;
1360         state.gtp.bufuse = 0;
1361         state.gtp.src_name = "stdin";
1362         state.gtp.dest_name = "remote output";
1363
1364         return tloop_spawnwait_tasks(&state);
1365 }