Merge branch 'mg/cherry-pick-multi-on-unborn' into maint
[git] / transport-helper.c
1 #include "cache.h"
2 #include "transport.h"
3 #include "quote.h"
4 #include "run-command.h"
5 #include "commit.h"
6 #include "diff.h"
7 #include "revision.h"
8 #include "remote.h"
9 #include "string-list.h"
10 #include "thread-utils.h"
11 #include "sigchain.h"
12 #include "argv-array.h"
13 #include "refs.h"
14
15 static int debug;
16
17 struct helper_data {
18         const char *name;
19         struct child_process *helper;
20         FILE *out;
21         unsigned fetch : 1,
22                 import : 1,
23                 bidi_import : 1,
24                 export : 1,
25                 option : 1,
26                 push : 1,
27                 connect : 1,
28                 signed_tags : 1,
29                 check_connectivity : 1,
30                 no_disconnect_req : 1,
31                 no_private_update : 1;
32         char *export_marks;
33         char *import_marks;
34         /* These go from remote name (as in "list") to private name */
35         struct refspec *refspecs;
36         int refspec_nr;
37         /* Transport options for fetch-pack/send-pack (should one of
38          * those be invoked).
39          */
40         struct git_transport_options transport_options;
41 };
42
43 static void sendline(struct helper_data *helper, struct strbuf *buffer)
44 {
45         if (debug)
46                 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
47         if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
48                 != buffer->len)
49                 die_errno("Full write to remote helper failed");
50 }
51
52 static int recvline_fh(FILE *helper, struct strbuf *buffer, const char *name)
53 {
54         strbuf_reset(buffer);
55         if (debug)
56                 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
57         if (strbuf_getline(buffer, helper) == EOF) {
58                 if (debug)
59                         fprintf(stderr, "Debug: Remote helper quit.\n");
60                 return 1;
61         }
62
63         if (debug)
64                 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
65         return 0;
66 }
67
68 static int recvline(struct helper_data *helper, struct strbuf *buffer)
69 {
70         return recvline_fh(helper->out, buffer, helper->name);
71 }
72
73 static void write_constant(int fd, const char *str)
74 {
75         if (debug)
76                 fprintf(stderr, "Debug: Remote helper: -> %s", str);
77         if (write_in_full(fd, str, strlen(str)) != strlen(str))
78                 die_errno("Full write to remote helper failed");
79 }
80
81 static const char *remove_ext_force(const char *url)
82 {
83         if (url) {
84                 const char *colon = strchr(url, ':');
85                 if (colon && colon[1] == ':')
86                         return colon + 2;
87         }
88         return url;
89 }
90
91 static void do_take_over(struct transport *transport)
92 {
93         struct helper_data *data;
94         data = (struct helper_data *)transport->data;
95         transport_take_over(transport, data->helper);
96         fclose(data->out);
97         free(data);
98 }
99
100 static void standard_options(struct transport *t);
101
102 static struct child_process *get_helper(struct transport *transport)
103 {
104         struct helper_data *data = transport->data;
105         struct strbuf buf = STRBUF_INIT;
106         struct child_process *helper;
107         const char **refspecs = NULL;
108         int refspec_nr = 0;
109         int refspec_alloc = 0;
110         int duped;
111         int code;
112
113         if (data->helper)
114                 return data->helper;
115
116         helper = xmalloc(sizeof(*helper));
117         child_process_init(helper);
118         helper->in = -1;
119         helper->out = -1;
120         helper->err = 0;
121         argv_array_pushf(&helper->args, "git-remote-%s", data->name);
122         argv_array_push(&helper->args, transport->remote->name);
123         argv_array_push(&helper->args, remove_ext_force(transport->url));
124         helper->git_cmd = 0;
125         helper->silent_exec_failure = 1;
126
127         argv_array_pushf(&helper->env_array, "%s=%s", GIT_DIR_ENVIRONMENT,
128                          get_git_dir());
129
130         code = start_command(helper);
131         if (code < 0 && errno == ENOENT)
132                 die("Unable to find remote helper for '%s'", data->name);
133         else if (code != 0)
134                 exit(code);
135
136         data->helper = helper;
137         data->no_disconnect_req = 0;
138
139         /*
140          * Open the output as FILE* so strbuf_getline_*() family of
141          * functions can be used.
142          * Do this with duped fd because fclose() will close the fd,
143          * and stuff like taking over will require the fd to remain.
144          */
145         duped = dup(helper->out);
146         if (duped < 0)
147                 die_errno("Can't dup helper output fd");
148         data->out = xfdopen(duped, "r");
149
150         write_constant(helper->in, "capabilities\n");
151
152         while (1) {
153                 const char *capname, *arg;
154                 int mandatory = 0;
155                 if (recvline(data, &buf))
156                         exit(128);
157
158                 if (!*buf.buf)
159                         break;
160
161                 if (*buf.buf == '*') {
162                         capname = buf.buf + 1;
163                         mandatory = 1;
164                 } else
165                         capname = buf.buf;
166
167                 if (debug)
168                         fprintf(stderr, "Debug: Got cap %s\n", capname);
169                 if (!strcmp(capname, "fetch"))
170                         data->fetch = 1;
171                 else if (!strcmp(capname, "option"))
172                         data->option = 1;
173                 else if (!strcmp(capname, "push"))
174                         data->push = 1;
175                 else if (!strcmp(capname, "import"))
176                         data->import = 1;
177                 else if (!strcmp(capname, "bidi-import"))
178                         data->bidi_import = 1;
179                 else if (!strcmp(capname, "export"))
180                         data->export = 1;
181                 else if (!strcmp(capname, "check-connectivity"))
182                         data->check_connectivity = 1;
183                 else if (!data->refspecs && skip_prefix(capname, "refspec ", &arg)) {
184                         ALLOC_GROW(refspecs,
185                                    refspec_nr + 1,
186                                    refspec_alloc);
187                         refspecs[refspec_nr++] = xstrdup(arg);
188                 } else if (!strcmp(capname, "connect")) {
189                         data->connect = 1;
190                 } else if (!strcmp(capname, "signed-tags")) {
191                         data->signed_tags = 1;
192                 } else if (skip_prefix(capname, "export-marks ", &arg)) {
193                         data->export_marks = xstrdup(arg);
194                 } else if (skip_prefix(capname, "import-marks ", &arg)) {
195                         data->import_marks = xstrdup(arg);
196                 } else if (starts_with(capname, "no-private-update")) {
197                         data->no_private_update = 1;
198                 } else if (mandatory) {
199                         die("Unknown mandatory capability %s. This remote "
200                             "helper probably needs newer version of Git.",
201                             capname);
202                 }
203         }
204         if (refspecs) {
205                 int i;
206                 data->refspec_nr = refspec_nr;
207                 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
208                 for (i = 0; i < refspec_nr; i++)
209                         free((char *)refspecs[i]);
210                 free(refspecs);
211         } else if (data->import || data->bidi_import || data->export) {
212                 warning("This remote helper should implement refspec capability.");
213         }
214         strbuf_release(&buf);
215         if (debug)
216                 fprintf(stderr, "Debug: Capabilities complete.\n");
217         standard_options(transport);
218         return data->helper;
219 }
220
221 static int disconnect_helper(struct transport *transport)
222 {
223         struct helper_data *data = transport->data;
224         int res = 0;
225
226         if (data->helper) {
227                 if (debug)
228                         fprintf(stderr, "Debug: Disconnecting.\n");
229                 if (!data->no_disconnect_req) {
230                         /*
231                          * Ignore write errors; there's nothing we can do,
232                          * since we're about to close the pipe anyway. And the
233                          * most likely error is EPIPE due to the helper dying
234                          * to report an error itself.
235                          */
236                         sigchain_push(SIGPIPE, SIG_IGN);
237                         xwrite(data->helper->in, "\n", 1);
238                         sigchain_pop(SIGPIPE);
239                 }
240                 close(data->helper->in);
241                 close(data->helper->out);
242                 fclose(data->out);
243                 res = finish_command(data->helper);
244                 free(data->helper);
245                 data->helper = NULL;
246         }
247         return res;
248 }
249
250 static const char *unsupported_options[] = {
251         TRANS_OPT_UPLOADPACK,
252         TRANS_OPT_RECEIVEPACK,
253         TRANS_OPT_THIN,
254         TRANS_OPT_KEEP
255         };
256
257 static const char *boolean_options[] = {
258         TRANS_OPT_THIN,
259         TRANS_OPT_KEEP,
260         TRANS_OPT_FOLLOWTAGS,
261         };
262
263 static int set_helper_option(struct transport *transport,
264                           const char *name, const char *value)
265 {
266         struct helper_data *data = transport->data;
267         struct strbuf buf = STRBUF_INIT;
268         int i, ret, is_bool = 0;
269
270         get_helper(transport);
271
272         if (!data->option)
273                 return 1;
274
275         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
276                 if (!strcmp(name, unsupported_options[i]))
277                         return 1;
278         }
279
280         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
281                 if (!strcmp(name, boolean_options[i])) {
282                         is_bool = 1;
283                         break;
284                 }
285         }
286
287         strbuf_addf(&buf, "option %s ", name);
288         if (is_bool)
289                 strbuf_addstr(&buf, value ? "true" : "false");
290         else
291                 quote_c_style(value, &buf, NULL, 0);
292         strbuf_addch(&buf, '\n');
293
294         sendline(data, &buf);
295         if (recvline(data, &buf))
296                 exit(128);
297
298         if (!strcmp(buf.buf, "ok"))
299                 ret = 0;
300         else if (starts_with(buf.buf, "error")) {
301                 ret = -1;
302         } else if (!strcmp(buf.buf, "unsupported"))
303                 ret = 1;
304         else {
305                 warning("%s unexpectedly said: '%s'", data->name, buf.buf);
306                 ret = 1;
307         }
308         strbuf_release(&buf);
309         return ret;
310 }
311
312 static void standard_options(struct transport *t)
313 {
314         char buf[16];
315         int n;
316         int v = t->verbose;
317
318         set_helper_option(t, "progress", t->progress ? "true" : "false");
319
320         n = snprintf(buf, sizeof(buf), "%d", v + 1);
321         if (n >= sizeof(buf))
322                 die("impossibly large verbosity value");
323         set_helper_option(t, "verbosity", buf);
324
325         switch (t->family) {
326         case TRANSPORT_FAMILY_ALL:
327                 /*
328                  * this is already the default,
329                  * do not break old remote helpers by setting "all" here
330                  */
331                 break;
332         case TRANSPORT_FAMILY_IPV4:
333                 set_helper_option(t, "family", "ipv4");
334                 break;
335         case TRANSPORT_FAMILY_IPV6:
336                 set_helper_option(t, "family", "ipv6");
337                 break;
338         }
339 }
340
341 static int release_helper(struct transport *transport)
342 {
343         int res = 0;
344         struct helper_data *data = transport->data;
345         free_refspec(data->refspec_nr, data->refspecs);
346         data->refspecs = NULL;
347         res = disconnect_helper(transport);
348         free(transport->data);
349         return res;
350 }
351
352 static int fetch_with_fetch(struct transport *transport,
353                             int nr_heads, struct ref **to_fetch)
354 {
355         struct helper_data *data = transport->data;
356         int i;
357         struct strbuf buf = STRBUF_INIT;
358
359         for (i = 0; i < nr_heads; i++) {
360                 const struct ref *posn = to_fetch[i];
361                 if (posn->status & REF_STATUS_UPTODATE)
362                         continue;
363
364                 strbuf_addf(&buf, "fetch %s %s\n",
365                             oid_to_hex(&posn->old_oid),
366                             posn->symref ? posn->symref : posn->name);
367         }
368
369         strbuf_addch(&buf, '\n');
370         sendline(data, &buf);
371
372         while (1) {
373                 if (recvline(data, &buf))
374                         exit(128);
375
376                 if (starts_with(buf.buf, "lock ")) {
377                         const char *name = buf.buf + 5;
378                         if (transport->pack_lockfile)
379                                 warning("%s also locked %s", data->name, name);
380                         else
381                                 transport->pack_lockfile = xstrdup(name);
382                 }
383                 else if (data->check_connectivity &&
384                          data->transport_options.check_self_contained_and_connected &&
385                          !strcmp(buf.buf, "connectivity-ok"))
386                         data->transport_options.self_contained_and_connected = 1;
387                 else if (!buf.len)
388                         break;
389                 else
390                         warning("%s unexpectedly said: '%s'", data->name, buf.buf);
391         }
392         strbuf_release(&buf);
393         return 0;
394 }
395
396 static int get_importer(struct transport *transport, struct child_process *fastimport)
397 {
398         struct child_process *helper = get_helper(transport);
399         struct helper_data *data = transport->data;
400         int cat_blob_fd, code;
401         child_process_init(fastimport);
402         fastimport->in = helper->out;
403         argv_array_push(&fastimport->args, "fast-import");
404         argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
405
406         if (data->bidi_import) {
407                 cat_blob_fd = xdup(helper->in);
408                 argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
409         }
410         fastimport->git_cmd = 1;
411
412         code = start_command(fastimport);
413         return code;
414 }
415
416 static int get_exporter(struct transport *transport,
417                         struct child_process *fastexport,
418                         struct string_list *revlist_args)
419 {
420         struct helper_data *data = transport->data;
421         struct child_process *helper = get_helper(transport);
422         int i;
423
424         child_process_init(fastexport);
425
426         /* we need to duplicate helper->in because we want to use it after
427          * fastexport is done with it. */
428         fastexport->out = dup(helper->in);
429         argv_array_push(&fastexport->args, "fast-export");
430         argv_array_push(&fastexport->args, "--use-done-feature");
431         argv_array_push(&fastexport->args, data->signed_tags ?
432                 "--signed-tags=verbatim" : "--signed-tags=warn-strip");
433         if (data->export_marks)
434                 argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
435         if (data->import_marks)
436                 argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
437
438         for (i = 0; i < revlist_args->nr; i++)
439                 argv_array_push(&fastexport->args, revlist_args->items[i].string);
440
441         fastexport->git_cmd = 1;
442         return start_command(fastexport);
443 }
444
445 static int fetch_with_import(struct transport *transport,
446                              int nr_heads, struct ref **to_fetch)
447 {
448         struct child_process fastimport;
449         struct helper_data *data = transport->data;
450         int i;
451         struct ref *posn;
452         struct strbuf buf = STRBUF_INIT;
453
454         get_helper(transport);
455
456         if (get_importer(transport, &fastimport))
457                 die("Couldn't run fast-import");
458
459         for (i = 0; i < nr_heads; i++) {
460                 posn = to_fetch[i];
461                 if (posn->status & REF_STATUS_UPTODATE)
462                         continue;
463
464                 strbuf_addf(&buf, "import %s\n",
465                             posn->symref ? posn->symref : posn->name);
466                 sendline(data, &buf);
467                 strbuf_reset(&buf);
468         }
469
470         write_constant(data->helper->in, "\n");
471         /*
472          * remote-helpers that advertise the bidi-import capability are required to
473          * buffer the complete batch of import commands until this newline before
474          * sending data to fast-import.
475          * These helpers read back data from fast-import on their stdin, which could
476          * be mixed with import commands, otherwise.
477          */
478
479         if (finish_command(&fastimport))
480                 die("Error while running fast-import");
481
482         /*
483          * The fast-import stream of a remote helper that advertises
484          * the "refspec" capability writes to the refs named after the
485          * right hand side of the first refspec matching each ref we
486          * were fetching.
487          *
488          * (If no "refspec" capability was specified, for historical
489          * reasons we default to the equivalent of *:*.)
490          *
491          * Store the result in to_fetch[i].old_sha1.  Callers such
492          * as "git fetch" can use the value to write feedback to the
493          * terminal, populate FETCH_HEAD, and determine what new value
494          * should be written to peer_ref if the update is a
495          * fast-forward or this is a forced update.
496          */
497         for (i = 0; i < nr_heads; i++) {
498                 char *private, *name;
499                 posn = to_fetch[i];
500                 if (posn->status & REF_STATUS_UPTODATE)
501                         continue;
502                 name = posn->symref ? posn->symref : posn->name;
503                 if (data->refspecs)
504                         private = apply_refspecs(data->refspecs, data->refspec_nr, name);
505                 else
506                         private = xstrdup(name);
507                 if (private) {
508                         if (read_ref(private, posn->old_oid.hash) < 0)
509                                 die("Could not read ref %s", private);
510                         free(private);
511                 }
512         }
513         strbuf_release(&buf);
514         return 0;
515 }
516
517 static int process_connect_service(struct transport *transport,
518                                    const char *name, const char *exec)
519 {
520         struct helper_data *data = transport->data;
521         struct strbuf cmdbuf = STRBUF_INIT;
522         struct child_process *helper;
523         int r, duped, ret = 0;
524         FILE *input;
525
526         helper = get_helper(transport);
527
528         /*
529          * Yes, dup the pipe another time, as we need unbuffered version
530          * of input pipe as FILE*. fclose() closes the underlying fd and
531          * stream buffering only can be changed before first I/O operation
532          * on it.
533          */
534         duped = dup(helper->out);
535         if (duped < 0)
536                 die_errno("Can't dup helper output fd");
537         input = xfdopen(duped, "r");
538         setvbuf(input, NULL, _IONBF, 0);
539
540         /*
541          * Handle --upload-pack and friends. This is fire and forget...
542          * just warn if it fails.
543          */
544         if (strcmp(name, exec)) {
545                 r = set_helper_option(transport, "servpath", exec);
546                 if (r > 0)
547                         warning("Setting remote service path not supported by protocol.");
548                 else if (r < 0)
549                         warning("Invalid remote service path.");
550         }
551
552         if (data->connect)
553                 strbuf_addf(&cmdbuf, "connect %s\n", name);
554         else
555                 goto exit;
556
557         sendline(data, &cmdbuf);
558         if (recvline_fh(input, &cmdbuf, name))
559                 exit(128);
560
561         if (!strcmp(cmdbuf.buf, "")) {
562                 data->no_disconnect_req = 1;
563                 if (debug)
564                         fprintf(stderr, "Debug: Smart transport connection "
565                                 "ready.\n");
566                 ret = 1;
567         } else if (!strcmp(cmdbuf.buf, "fallback")) {
568                 if (debug)
569                         fprintf(stderr, "Debug: Falling back to dumb "
570                                 "transport.\n");
571         } else
572                 die("Unknown response to connect: %s",
573                         cmdbuf.buf);
574
575 exit:
576         fclose(input);
577         return ret;
578 }
579
580 static int process_connect(struct transport *transport,
581                                      int for_push)
582 {
583         struct helper_data *data = transport->data;
584         const char *name;
585         const char *exec;
586
587         name = for_push ? "git-receive-pack" : "git-upload-pack";
588         if (for_push)
589                 exec = data->transport_options.receivepack;
590         else
591                 exec = data->transport_options.uploadpack;
592
593         return process_connect_service(transport, name, exec);
594 }
595
596 static int connect_helper(struct transport *transport, const char *name,
597                    const char *exec, int fd[2])
598 {
599         struct helper_data *data = transport->data;
600
601         /* Get_helper so connect is inited. */
602         get_helper(transport);
603         if (!data->connect)
604                 die("Operation not supported by protocol.");
605
606         if (!process_connect_service(transport, name, exec))
607                 die("Can't connect to subservice %s.", name);
608
609         fd[0] = data->helper->out;
610         fd[1] = data->helper->in;
611         return 0;
612 }
613
614 static int fetch(struct transport *transport,
615                  int nr_heads, struct ref **to_fetch)
616 {
617         struct helper_data *data = transport->data;
618         int i, count;
619
620         if (process_connect(transport, 0)) {
621                 do_take_over(transport);
622                 return transport->fetch(transport, nr_heads, to_fetch);
623         }
624
625         count = 0;
626         for (i = 0; i < nr_heads; i++)
627                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
628                         count++;
629
630         if (!count)
631                 return 0;
632
633         if (data->check_connectivity &&
634             data->transport_options.check_self_contained_and_connected)
635                 set_helper_option(transport, "check-connectivity", "true");
636
637         if (transport->cloning)
638                 set_helper_option(transport, "cloning", "true");
639
640         if (data->transport_options.update_shallow)
641                 set_helper_option(transport, "update-shallow", "true");
642
643         if (data->fetch)
644                 return fetch_with_fetch(transport, nr_heads, to_fetch);
645
646         if (data->import)
647                 return fetch_with_import(transport, nr_heads, to_fetch);
648
649         return -1;
650 }
651
652 static int push_update_ref_status(struct strbuf *buf,
653                                    struct ref **ref,
654                                    struct ref *remote_refs)
655 {
656         char *refname, *msg;
657         int status, forced = 0;
658
659         if (starts_with(buf->buf, "ok ")) {
660                 status = REF_STATUS_OK;
661                 refname = buf->buf + 3;
662         } else if (starts_with(buf->buf, "error ")) {
663                 status = REF_STATUS_REMOTE_REJECT;
664                 refname = buf->buf + 6;
665         } else
666                 die("expected ok/error, helper said '%s'", buf->buf);
667
668         msg = strchr(refname, ' ');
669         if (msg) {
670                 struct strbuf msg_buf = STRBUF_INIT;
671                 const char *end;
672
673                 *msg++ = '\0';
674                 if (!unquote_c_style(&msg_buf, msg, &end))
675                         msg = strbuf_detach(&msg_buf, NULL);
676                 else
677                         msg = xstrdup(msg);
678                 strbuf_release(&msg_buf);
679
680                 if (!strcmp(msg, "no match")) {
681                         status = REF_STATUS_NONE;
682                         free(msg);
683                         msg = NULL;
684                 }
685                 else if (!strcmp(msg, "up to date")) {
686                         status = REF_STATUS_UPTODATE;
687                         free(msg);
688                         msg = NULL;
689                 }
690                 else if (!strcmp(msg, "non-fast forward")) {
691                         status = REF_STATUS_REJECT_NONFASTFORWARD;
692                         free(msg);
693                         msg = NULL;
694                 }
695                 else if (!strcmp(msg, "already exists")) {
696                         status = REF_STATUS_REJECT_ALREADY_EXISTS;
697                         free(msg);
698                         msg = NULL;
699                 }
700                 else if (!strcmp(msg, "fetch first")) {
701                         status = REF_STATUS_REJECT_FETCH_FIRST;
702                         free(msg);
703                         msg = NULL;
704                 }
705                 else if (!strcmp(msg, "needs force")) {
706                         status = REF_STATUS_REJECT_NEEDS_FORCE;
707                         free(msg);
708                         msg = NULL;
709                 }
710                 else if (!strcmp(msg, "stale info")) {
711                         status = REF_STATUS_REJECT_STALE;
712                         free(msg);
713                         msg = NULL;
714                 }
715                 else if (!strcmp(msg, "forced update")) {
716                         forced = 1;
717                         free(msg);
718                         msg = NULL;
719                 }
720         }
721
722         if (*ref)
723                 *ref = find_ref_by_name(*ref, refname);
724         if (!*ref)
725                 *ref = find_ref_by_name(remote_refs, refname);
726         if (!*ref) {
727                 warning("helper reported unexpected status of %s", refname);
728                 return 1;
729         }
730
731         if ((*ref)->status != REF_STATUS_NONE) {
732                 /*
733                  * Earlier, the ref was marked not to be pushed, so ignore the ref
734                  * status reported by the remote helper if the latter is 'no match'.
735                  */
736                 if (status == REF_STATUS_NONE)
737                         return 1;
738         }
739
740         (*ref)->status = status;
741         (*ref)->forced_update |= forced;
742         (*ref)->remote_status = msg;
743         return !(status == REF_STATUS_OK);
744 }
745
746 static int push_update_refs_status(struct helper_data *data,
747                                     struct ref *remote_refs,
748                                     int flags)
749 {
750         struct strbuf buf = STRBUF_INIT;
751         struct ref *ref = remote_refs;
752         int ret = 0;
753
754         for (;;) {
755                 char *private;
756
757                 if (recvline(data, &buf)) {
758                         ret = 1;
759                         break;
760                 }
761
762                 if (!buf.len)
763                         break;
764
765                 if (push_update_ref_status(&buf, &ref, remote_refs))
766                         continue;
767
768                 if (flags & TRANSPORT_PUSH_DRY_RUN || !data->refspecs || data->no_private_update)
769                         continue;
770
771                 /* propagate back the update to the remote namespace */
772                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
773                 if (!private)
774                         continue;
775                 update_ref("update by helper", private, ref->new_oid.hash, NULL, 0, 0);
776                 free(private);
777         }
778         strbuf_release(&buf);
779         return ret;
780 }
781
782 static void set_common_push_options(struct transport *transport,
783                                    const char *name, int flags)
784 {
785         if (flags & TRANSPORT_PUSH_DRY_RUN) {
786                 if (set_helper_option(transport, "dry-run", "true") != 0)
787                         die("helper %s does not support dry-run", name);
788         } else if (flags & TRANSPORT_PUSH_CERT_ALWAYS) {
789                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
790                         die("helper %s does not support --signed", name);
791         } else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED) {
792                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "if-asked") != 0)
793                         die("helper %s does not support --signed=if-asked", name);
794         }
795 }
796
797 static int push_refs_with_push(struct transport *transport,
798                                struct ref *remote_refs, int flags)
799 {
800         int force_all = flags & TRANSPORT_PUSH_FORCE;
801         int mirror = flags & TRANSPORT_PUSH_MIRROR;
802         struct helper_data *data = transport->data;
803         struct strbuf buf = STRBUF_INIT;
804         struct ref *ref;
805         struct string_list cas_options = STRING_LIST_INIT_DUP;
806         struct string_list_item *cas_option;
807
808         get_helper(transport);
809         if (!data->push)
810                 return 1;
811
812         for (ref = remote_refs; ref; ref = ref->next) {
813                 if (!ref->peer_ref && !mirror)
814                         continue;
815
816                 /* Check for statuses set by set_ref_status_for_push() */
817                 switch (ref->status) {
818                 case REF_STATUS_REJECT_NONFASTFORWARD:
819                 case REF_STATUS_REJECT_STALE:
820                 case REF_STATUS_REJECT_ALREADY_EXISTS:
821                 case REF_STATUS_UPTODATE:
822                         continue;
823                 default:
824                         ; /* do nothing */
825                 }
826
827                 if (force_all)
828                         ref->force = 1;
829
830                 strbuf_addstr(&buf, "push ");
831                 if (!ref->deletion) {
832                         if (ref->force)
833                                 strbuf_addch(&buf, '+');
834                         if (ref->peer_ref)
835                                 strbuf_addstr(&buf, ref->peer_ref->name);
836                         else
837                                 strbuf_addstr(&buf, oid_to_hex(&ref->new_oid));
838                 }
839                 strbuf_addch(&buf, ':');
840                 strbuf_addstr(&buf, ref->name);
841                 strbuf_addch(&buf, '\n');
842
843                 /*
844                  * The "--force-with-lease" options without explicit
845                  * values to expect have already been expanded into
846                  * the ref->old_oid_expect[] field; we can ignore
847                  * transport->smart_options->cas altogether and instead
848                  * can enumerate them from the refs.
849                  */
850                 if (ref->expect_old_sha1) {
851                         struct strbuf cas = STRBUF_INIT;
852                         strbuf_addf(&cas, "%s:%s",
853                                     ref->name, oid_to_hex(&ref->old_oid_expect));
854                         string_list_append(&cas_options, strbuf_detach(&cas, NULL));
855                 }
856         }
857         if (buf.len == 0) {
858                 string_list_clear(&cas_options, 0);
859                 return 0;
860         }
861
862         for_each_string_list_item(cas_option, &cas_options)
863                 set_helper_option(transport, "cas", cas_option->string);
864         set_common_push_options(transport, data->name, flags);
865
866         strbuf_addch(&buf, '\n');
867         sendline(data, &buf);
868         strbuf_release(&buf);
869
870         return push_update_refs_status(data, remote_refs, flags);
871 }
872
873 static int push_refs_with_export(struct transport *transport,
874                 struct ref *remote_refs, int flags)
875 {
876         struct ref *ref;
877         struct child_process *helper, exporter;
878         struct helper_data *data = transport->data;
879         struct string_list revlist_args = STRING_LIST_INIT_DUP;
880         struct strbuf buf = STRBUF_INIT;
881
882         if (!data->refspecs)
883                 die("remote-helper doesn't support push; refspec needed");
884
885         set_common_push_options(transport, data->name, flags);
886         if (flags & TRANSPORT_PUSH_FORCE) {
887                 if (set_helper_option(transport, "force", "true") != 0)
888                         warning("helper %s does not support 'force'", data->name);
889         }
890
891         helper = get_helper(transport);
892
893         write_constant(helper->in, "export\n");
894
895         for (ref = remote_refs; ref; ref = ref->next) {
896                 char *private;
897                 struct object_id oid;
898
899                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
900                 if (private && !get_sha1(private, oid.hash)) {
901                         strbuf_addf(&buf, "^%s", private);
902                         string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
903                         oidcpy(&ref->old_oid, &oid);
904                 }
905                 free(private);
906
907                 if (ref->peer_ref) {
908                         if (strcmp(ref->name, ref->peer_ref->name)) {
909                                 if (!ref->deletion) {
910                                         const char *name;
911                                         int flag;
912
913                                         /* Follow symbolic refs (mainly for HEAD). */
914                                         name = resolve_ref_unsafe(
915                                                  ref->peer_ref->name,
916                                                  RESOLVE_REF_READING,
917                                                  oid.hash, &flag);
918                                         if (!name || !(flag & REF_ISSYMREF))
919                                                 name = ref->peer_ref->name;
920
921                                         strbuf_addf(&buf, "%s:%s", name, ref->name);
922                                 } else
923                                         strbuf_addf(&buf, ":%s", ref->name);
924
925                                 string_list_append(&revlist_args, "--refspec");
926                                 string_list_append(&revlist_args, buf.buf);
927                                 strbuf_release(&buf);
928                         }
929                         if (!ref->deletion)
930                                 string_list_append(&revlist_args, ref->peer_ref->name);
931                 }
932         }
933
934         if (get_exporter(transport, &exporter, &revlist_args))
935                 die("Couldn't run fast-export");
936
937         string_list_clear(&revlist_args, 1);
938
939         if (finish_command(&exporter))
940                 die("Error while running fast-export");
941         if (push_update_refs_status(data, remote_refs, flags))
942                 return 1;
943
944         if (data->export_marks) {
945                 strbuf_addf(&buf, "%s.tmp", data->export_marks);
946                 rename(buf.buf, data->export_marks);
947                 strbuf_release(&buf);
948         }
949
950         return 0;
951 }
952
953 static int push_refs(struct transport *transport,
954                 struct ref *remote_refs, int flags)
955 {
956         struct helper_data *data = transport->data;
957
958         if (process_connect(transport, 1)) {
959                 do_take_over(transport);
960                 return transport->push_refs(transport, remote_refs, flags);
961         }
962
963         if (!remote_refs) {
964                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
965                         "Perhaps you should specify a branch such as 'master'.\n");
966                 return 0;
967         }
968
969         if (data->push)
970                 return push_refs_with_push(transport, remote_refs, flags);
971
972         if (data->export)
973                 return push_refs_with_export(transport, remote_refs, flags);
974
975         return -1;
976 }
977
978
979 static int has_attribute(const char *attrs, const char *attr) {
980         int len;
981         if (!attrs)
982                 return 0;
983
984         len = strlen(attr);
985         for (;;) {
986                 const char *space = strchrnul(attrs, ' ');
987                 if (len == space - attrs && !strncmp(attrs, attr, len))
988                         return 1;
989                 if (!*space)
990                         return 0;
991                 attrs = space + 1;
992         }
993 }
994
995 static struct ref *get_refs_list(struct transport *transport, int for_push)
996 {
997         struct helper_data *data = transport->data;
998         struct child_process *helper;
999         struct ref *ret = NULL;
1000         struct ref **tail = &ret;
1001         struct ref *posn;
1002         struct strbuf buf = STRBUF_INIT;
1003
1004         helper = get_helper(transport);
1005
1006         if (process_connect(transport, for_push)) {
1007                 do_take_over(transport);
1008                 return transport->get_refs_list(transport, for_push);
1009         }
1010
1011         if (data->push && for_push)
1012                 write_str_in_full(helper->in, "list for-push\n");
1013         else
1014                 write_str_in_full(helper->in, "list\n");
1015
1016         while (1) {
1017                 char *eov, *eon;
1018                 if (recvline(data, &buf))
1019                         exit(128);
1020
1021                 if (!*buf.buf)
1022                         break;
1023
1024                 eov = strchr(buf.buf, ' ');
1025                 if (!eov)
1026                         die("Malformed response in ref list: %s", buf.buf);
1027                 eon = strchr(eov + 1, ' ');
1028                 *eov = '\0';
1029                 if (eon)
1030                         *eon = '\0';
1031                 *tail = alloc_ref(eov + 1);
1032                 if (buf.buf[0] == '@')
1033                         (*tail)->symref = xstrdup(buf.buf + 1);
1034                 else if (buf.buf[0] != '?')
1035                         get_oid_hex(buf.buf, &(*tail)->old_oid);
1036                 if (eon) {
1037                         if (has_attribute(eon + 1, "unchanged")) {
1038                                 (*tail)->status |= REF_STATUS_UPTODATE;
1039                                 if (read_ref((*tail)->name,
1040                                              (*tail)->old_oid.hash) < 0)
1041                                         die(N_("Could not read ref %s"),
1042                                             (*tail)->name);
1043                         }
1044                 }
1045                 tail = &((*tail)->next);
1046         }
1047         if (debug)
1048                 fprintf(stderr, "Debug: Read ref listing.\n");
1049         strbuf_release(&buf);
1050
1051         for (posn = ret; posn; posn = posn->next)
1052                 resolve_remote_symref(posn, ret);
1053
1054         return ret;
1055 }
1056
1057 int transport_helper_init(struct transport *transport, const char *name)
1058 {
1059         struct helper_data *data = xcalloc(1, sizeof(*data));
1060         data->name = name;
1061
1062         transport_check_allowed(name);
1063
1064         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1065                 debug = 1;
1066
1067         transport->data = data;
1068         transport->set_option = set_helper_option;
1069         transport->get_refs_list = get_refs_list;
1070         transport->fetch = fetch;
1071         transport->push_refs = push_refs;
1072         transport->disconnect = release_helper;
1073         transport->connect = connect_helper;
1074         transport->smart_options = &(data->transport_options);
1075         return 0;
1076 }
1077
1078 /*
1079  * Linux pipes can buffer 65536 bytes at once (and most platforms can
1080  * buffer less), so attempt reads and writes with up to that size.
1081  */
1082 #define BUFFERSIZE 65536
1083 /* This should be enough to hold debugging message. */
1084 #define PBUFFERSIZE 8192
1085
1086 /* Print bidirectional transfer loop debug message. */
1087 __attribute__((format (printf, 1, 2)))
1088 static void transfer_debug(const char *fmt, ...)
1089 {
1090         va_list args;
1091         char msgbuf[PBUFFERSIZE];
1092         static int debug_enabled = -1;
1093
1094         if (debug_enabled < 0)
1095                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1096         if (!debug_enabled)
1097                 return;
1098
1099         va_start(args, fmt);
1100         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1101         va_end(args);
1102         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1103 }
1104
1105 /* Stream state: More data may be coming in this direction. */
1106 #define SSTATE_TRANSFERING 0
1107 /*
1108  * Stream state: No more data coming in this direction, flushing rest of
1109  * data.
1110  */
1111 #define SSTATE_FLUSHING 1
1112 /* Stream state: Transfer in this direction finished. */
1113 #define SSTATE_FINISHED 2
1114
1115 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
1116 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1117 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1118
1119 /* Unidirectional transfer. */
1120 struct unidirectional_transfer {
1121         /* Source */
1122         int src;
1123         /* Destination */
1124         int dest;
1125         /* Is source socket? */
1126         int src_is_sock;
1127         /* Is destination socket? */
1128         int dest_is_sock;
1129         /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1130         int state;
1131         /* Buffer. */
1132         char buf[BUFFERSIZE];
1133         /* Buffer used. */
1134         size_t bufuse;
1135         /* Name of source. */
1136         const char *src_name;
1137         /* Name of destination. */
1138         const char *dest_name;
1139 };
1140
1141 /* Closes the target (for writing) if transfer has finished. */
1142 static void udt_close_if_finished(struct unidirectional_transfer *t)
1143 {
1144         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1145                 t->state = SSTATE_FINISHED;
1146                 if (t->dest_is_sock)
1147                         shutdown(t->dest, SHUT_WR);
1148                 else
1149                         close(t->dest);
1150                 transfer_debug("Closed %s.", t->dest_name);
1151         }
1152 }
1153
1154 /*
1155  * Tries to read data from source into buffer. If buffer is full,
1156  * no data is read. Returns 0 on success, -1 on error.
1157  */
1158 static int udt_do_read(struct unidirectional_transfer *t)
1159 {
1160         ssize_t bytes;
1161
1162         if (t->bufuse == BUFFERSIZE)
1163                 return 0;       /* No space for more. */
1164
1165         transfer_debug("%s is readable", t->src_name);
1166         bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1167         if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1168                 errno != EINTR) {
1169                 error_errno("read(%s) failed", t->src_name);
1170                 return -1;
1171         } else if (bytes == 0) {
1172                 transfer_debug("%s EOF (with %i bytes in buffer)",
1173                         t->src_name, (int)t->bufuse);
1174                 t->state = SSTATE_FLUSHING;
1175         } else if (bytes > 0) {
1176                 t->bufuse += bytes;
1177                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1178                         (int)bytes, t->src_name, (int)t->bufuse);
1179         }
1180         return 0;
1181 }
1182
1183 /* Tries to write data from buffer into destination. If buffer is empty,
1184  * no data is written. Returns 0 on success, -1 on error.
1185  */
1186 static int udt_do_write(struct unidirectional_transfer *t)
1187 {
1188         ssize_t bytes;
1189
1190         if (t->bufuse == 0)
1191                 return 0;       /* Nothing to write. */
1192
1193         transfer_debug("%s is writable", t->dest_name);
1194         bytes = xwrite(t->dest, t->buf, t->bufuse);
1195         if (bytes < 0 && errno != EWOULDBLOCK) {
1196                 error_errno("write(%s) failed", t->dest_name);
1197                 return -1;
1198         } else if (bytes > 0) {
1199                 t->bufuse -= bytes;
1200                 if (t->bufuse)
1201                         memmove(t->buf, t->buf + bytes, t->bufuse);
1202                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1203                         (int)bytes, t->dest_name, (int)t->bufuse);
1204         }
1205         return 0;
1206 }
1207
1208
1209 /* State of bidirectional transfer loop. */
1210 struct bidirectional_transfer_state {
1211         /* Direction from program to git. */
1212         struct unidirectional_transfer ptg;
1213         /* Direction from git to program. */
1214         struct unidirectional_transfer gtp;
1215 };
1216
1217 static void *udt_copy_task_routine(void *udt)
1218 {
1219         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1220         while (t->state != SSTATE_FINISHED) {
1221                 if (STATE_NEEDS_READING(t->state))
1222                         if (udt_do_read(t))
1223                                 return NULL;
1224                 if (STATE_NEEDS_WRITING(t->state))
1225                         if (udt_do_write(t))
1226                                 return NULL;
1227                 if (STATE_NEEDS_CLOSING(t->state))
1228                         udt_close_if_finished(t);
1229         }
1230         return udt;     /* Just some non-NULL value. */
1231 }
1232
1233 #ifndef NO_PTHREADS
1234
1235 /*
1236  * Join thread, with appropriate errors on failure. Name is name for the
1237  * thread (for error messages). Returns 0 on success, 1 on failure.
1238  */
1239 static int tloop_join(pthread_t thread, const char *name)
1240 {
1241         int err;
1242         void *tret;
1243         err = pthread_join(thread, &tret);
1244         if (!tret) {
1245                 error("%s thread failed", name);
1246                 return 1;
1247         }
1248         if (err) {
1249                 error("%s thread failed to join: %s", name, strerror(err));
1250                 return 1;
1251         }
1252         return 0;
1253 }
1254
1255 /*
1256  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1257  * -1 on failure.
1258  */
1259 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1260 {
1261         pthread_t gtp_thread;
1262         pthread_t ptg_thread;
1263         int err;
1264         int ret = 0;
1265         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1266                 &s->gtp);
1267         if (err)
1268                 die("Can't start thread for copying data: %s", strerror(err));
1269         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1270                 &s->ptg);
1271         if (err)
1272                 die("Can't start thread for copying data: %s", strerror(err));
1273
1274         ret |= tloop_join(gtp_thread, "Git to program copy");
1275         ret |= tloop_join(ptg_thread, "Program to git copy");
1276         return ret;
1277 }
1278 #else
1279
1280 /* Close the source and target (for writing) for transfer. */
1281 static void udt_kill_transfer(struct unidirectional_transfer *t)
1282 {
1283         t->state = SSTATE_FINISHED;
1284         /*
1285          * Socket read end left open isn't a disaster if nobody
1286          * attempts to read from it (mingw compat headers do not
1287          * have SHUT_RD)...
1288          *
1289          * We can't fully close the socket since otherwise gtp
1290          * task would first close the socket it sends data to
1291          * while closing the ptg file descriptors.
1292          */
1293         if (!t->src_is_sock)
1294                 close(t->src);
1295         if (t->dest_is_sock)
1296                 shutdown(t->dest, SHUT_WR);
1297         else
1298                 close(t->dest);
1299 }
1300
1301 /*
1302  * Join process, with appropriate errors on failure. Name is name for the
1303  * process (for error messages). Returns 0 on success, 1 on failure.
1304  */
1305 static int tloop_join(pid_t pid, const char *name)
1306 {
1307         int tret;
1308         if (waitpid(pid, &tret, 0) < 0) {
1309                 error_errno("%s process failed to wait", name);
1310                 return 1;
1311         }
1312         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1313                 error("%s process failed", name);
1314                 return 1;
1315         }
1316         return 0;
1317 }
1318
1319 /*
1320  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1321  * -1 on failure.
1322  */
1323 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1324 {
1325         pid_t pid1, pid2;
1326         int ret = 0;
1327
1328         /* Fork thread #1: git to program. */
1329         pid1 = fork();
1330         if (pid1 < 0)
1331                 die_errno("Can't start thread for copying data");
1332         else if (pid1 == 0) {
1333                 udt_kill_transfer(&s->ptg);
1334                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1335         }
1336
1337         /* Fork thread #2: program to git. */
1338         pid2 = fork();
1339         if (pid2 < 0)
1340                 die_errno("Can't start thread for copying data");
1341         else if (pid2 == 0) {
1342                 udt_kill_transfer(&s->gtp);
1343                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1344         }
1345
1346         /*
1347          * Close both streams in parent as to not interfere with
1348          * end of file detection and wait for both tasks to finish.
1349          */
1350         udt_kill_transfer(&s->gtp);
1351         udt_kill_transfer(&s->ptg);
1352         ret |= tloop_join(pid1, "Git to program copy");
1353         ret |= tloop_join(pid2, "Program to git copy");
1354         return ret;
1355 }
1356 #endif
1357
1358 /*
1359  * Copies data from stdin to output and from input to stdout simultaneously.
1360  * Additionally filtering through given filter. If filter is NULL, uses
1361  * identity filter.
1362  */
1363 int bidirectional_transfer_loop(int input, int output)
1364 {
1365         struct bidirectional_transfer_state state;
1366
1367         /* Fill the state fields. */
1368         state.ptg.src = input;
1369         state.ptg.dest = 1;
1370         state.ptg.src_is_sock = (input == output);
1371         state.ptg.dest_is_sock = 0;
1372         state.ptg.state = SSTATE_TRANSFERING;
1373         state.ptg.bufuse = 0;
1374         state.ptg.src_name = "remote input";
1375         state.ptg.dest_name = "stdout";
1376
1377         state.gtp.src = 0;
1378         state.gtp.dest = output;
1379         state.gtp.src_is_sock = 0;
1380         state.gtp.dest_is_sock = (input == output);
1381         state.gtp.state = SSTATE_TRANSFERING;
1382         state.gtp.bufuse = 0;
1383         state.gtp.src_name = "stdin";
1384         state.gtp.dest_name = "remote output";
1385
1386         return tloop_spawnwait_tasks(&state);
1387 }