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
15static int debug;
16
17struct 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
43static 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
52static 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
68static int recvline(struct helper_data *helper, struct strbuf *buffer)
69{
70 return recvline_fh(helper->out, buffer, helper->name);
71}
72
73static 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
81static 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
91static 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
100static void standard_options(struct transport *t);
101
102static 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
221static 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
250static const char *unsupported_options[] = {
251 TRANS_OPT_UPLOADPACK,
252 TRANS_OPT_RECEIVEPACK,
253 TRANS_OPT_THIN,
254 TRANS_OPT_KEEP
255 };
256
257static const char *boolean_options[] = {
258 TRANS_OPT_THIN,
259 TRANS_OPT_KEEP,
260 TRANS_OPT_FOLLOWTAGS,
261 };
262
263static int strbuf_set_helper_option(struct helper_data *data,
264 struct strbuf *buf)
265{
266 int ret;
267
268 sendline(data, buf);
269 if (recvline(data, buf))
270 exit(128);
271
272 if (!strcmp(buf->buf, "ok"))
273 ret = 0;
274 else if (starts_with(buf->buf, "error"))
275 ret = -1;
276 else if (!strcmp(buf->buf, "unsupported"))
277 ret = 1;
278 else {
279 warning("%s unexpectedly said: '%s'", data->name, buf->buf);
280 ret = 1;
281 }
282 return ret;
283}
284
285static int string_list_set_helper_option(struct helper_data *data,
286 const char *name,
287 struct string_list *list)
288{
289 struct strbuf buf = STRBUF_INIT;
290 int i, ret = 0;
291
292 for (i = 0; i < list->nr; i++) {
293 strbuf_addf(&buf, "option %s ", name);
294 quote_c_style(list->items[i].string, &buf, NULL, 0);
295 strbuf_addch(&buf, '\n');
296
297 if ((ret = strbuf_set_helper_option(data, &buf)))
298 break;
299 strbuf_reset(&buf);
300 }
301 strbuf_release(&buf);
302 return ret;
303}
304
305static int set_helper_option(struct transport *transport,
306 const char *name, const char *value)
307{
308 struct helper_data *data = transport->data;
309 struct strbuf buf = STRBUF_INIT;
310 int i, ret, is_bool = 0;
311
312 get_helper(transport);
313
314 if (!data->option)
315 return 1;
316
317 if (!strcmp(name, "deepen-not"))
318 return string_list_set_helper_option(data, name,
319 (struct string_list *)value);
320
321 for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
322 if (!strcmp(name, unsupported_options[i]))
323 return 1;
324 }
325
326 for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
327 if (!strcmp(name, boolean_options[i])) {
328 is_bool = 1;
329 break;
330 }
331 }
332
333 strbuf_addf(&buf, "option %s ", name);
334 if (is_bool)
335 strbuf_addstr(&buf, value ? "true" : "false");
336 else
337 quote_c_style(value, &buf, NULL, 0);
338 strbuf_addch(&buf, '\n');
339
340 ret = strbuf_set_helper_option(data, &buf);
341 strbuf_release(&buf);
342 return ret;
343}
344
345static void standard_options(struct transport *t)
346{
347 char buf[16];
348 int n;
349 int v = t->verbose;
350
351 set_helper_option(t, "progress", t->progress ? "true" : "false");
352
353 n = snprintf(buf, sizeof(buf), "%d", v + 1);
354 if (n >= sizeof(buf))
355 die("impossibly large verbosity value");
356 set_helper_option(t, "verbosity", buf);
357}
358
359static int release_helper(struct transport *transport)
360{
361 int res = 0;
362 struct helper_data *data = transport->data;
363 free_refspec(data->refspec_nr, data->refspecs);
364 data->refspecs = NULL;
365 res = disconnect_helper(transport);
366 free(transport->data);
367 return res;
368}
369
370static int fetch_with_fetch(struct transport *transport,
371 int nr_heads, struct ref **to_fetch)
372{
373 struct helper_data *data = transport->data;
374 int i;
375 struct strbuf buf = STRBUF_INIT;
376
377 for (i = 0; i < nr_heads; i++) {
378 const struct ref *posn = to_fetch[i];
379 if (posn->status & REF_STATUS_UPTODATE)
380 continue;
381
382 strbuf_addf(&buf, "fetch %s %s\n",
383 oid_to_hex(&posn->old_oid),
384 posn->symref ? posn->symref : posn->name);
385 }
386
387 strbuf_addch(&buf, '\n');
388 sendline(data, &buf);
389
390 while (1) {
391 if (recvline(data, &buf))
392 exit(128);
393
394 if (starts_with(buf.buf, "lock ")) {
395 const char *name = buf.buf + 5;
396 if (transport->pack_lockfile)
397 warning("%s also locked %s", data->name, name);
398 else
399 transport->pack_lockfile = xstrdup(name);
400 }
401 else if (data->check_connectivity &&
402 data->transport_options.check_self_contained_and_connected &&
403 !strcmp(buf.buf, "connectivity-ok"))
404 data->transport_options.self_contained_and_connected = 1;
405 else if (!buf.len)
406 break;
407 else
408 warning("%s unexpectedly said: '%s'", data->name, buf.buf);
409 }
410 strbuf_release(&buf);
411 return 0;
412}
413
414static int get_importer(struct transport *transport, struct child_process *fastimport)
415{
416 struct child_process *helper = get_helper(transport);
417 struct helper_data *data = transport->data;
418 int cat_blob_fd, code;
419 child_process_init(fastimport);
420 fastimport->in = helper->out;
421 argv_array_push(&fastimport->args, "fast-import");
422 argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
423
424 if (data->bidi_import) {
425 cat_blob_fd = xdup(helper->in);
426 argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
427 }
428 fastimport->git_cmd = 1;
429
430 code = start_command(fastimport);
431 return code;
432}
433
434static int get_exporter(struct transport *transport,
435 struct child_process *fastexport,
436 struct string_list *revlist_args)
437{
438 struct helper_data *data = transport->data;
439 struct child_process *helper = get_helper(transport);
440 int i;
441
442 child_process_init(fastexport);
443
444 /* we need to duplicate helper->in because we want to use it after
445 * fastexport is done with it. */
446 fastexport->out = dup(helper->in);
447 argv_array_push(&fastexport->args, "fast-export");
448 argv_array_push(&fastexport->args, "--use-done-feature");
449 argv_array_push(&fastexport->args, data->signed_tags ?
450 "--signed-tags=verbatim" : "--signed-tags=warn-strip");
451 if (data->export_marks)
452 argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
453 if (data->import_marks)
454 argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
455
456 for (i = 0; i < revlist_args->nr; i++)
457 argv_array_push(&fastexport->args, revlist_args->items[i].string);
458
459 fastexport->git_cmd = 1;
460 return start_command(fastexport);
461}
462
463static int fetch_with_import(struct transport *transport,
464 int nr_heads, struct ref **to_fetch)
465{
466 struct child_process fastimport;
467 struct helper_data *data = transport->data;
468 int i;
469 struct ref *posn;
470 struct strbuf buf = STRBUF_INIT;
471
472 get_helper(transport);
473
474 if (get_importer(transport, &fastimport))
475 die("Couldn't run fast-import");
476
477 for (i = 0; i < nr_heads; i++) {
478 posn = to_fetch[i];
479 if (posn->status & REF_STATUS_UPTODATE)
480 continue;
481
482 strbuf_addf(&buf, "import %s\n",
483 posn->symref ? posn->symref : posn->name);
484 sendline(data, &buf);
485 strbuf_reset(&buf);
486 }
487
488 write_constant(data->helper->in, "\n");
489 /*
490 * remote-helpers that advertise the bidi-import capability are required to
491 * buffer the complete batch of import commands until this newline before
492 * sending data to fast-import.
493 * These helpers read back data from fast-import on their stdin, which could
494 * be mixed with import commands, otherwise.
495 */
496
497 if (finish_command(&fastimport))
498 die("Error while running fast-import");
499
500 /*
501 * The fast-import stream of a remote helper that advertises
502 * the "refspec" capability writes to the refs named after the
503 * right hand side of the first refspec matching each ref we
504 * were fetching.
505 *
506 * (If no "refspec" capability was specified, for historical
507 * reasons we default to the equivalent of *:*.)
508 *
509 * Store the result in to_fetch[i].old_sha1. Callers such
510 * as "git fetch" can use the value to write feedback to the
511 * terminal, populate FETCH_HEAD, and determine what new value
512 * should be written to peer_ref if the update is a
513 * fast-forward or this is a forced update.
514 */
515 for (i = 0; i < nr_heads; i++) {
516 char *private, *name;
517 posn = to_fetch[i];
518 if (posn->status & REF_STATUS_UPTODATE)
519 continue;
520 name = posn->symref ? posn->symref : posn->name;
521 if (data->refspecs)
522 private = apply_refspecs(data->refspecs, data->refspec_nr, name);
523 else
524 private = xstrdup(name);
525 if (private) {
526 if (read_ref(private, posn->old_oid.hash) < 0)
527 die("Could not read ref %s", private);
528 free(private);
529 }
530 }
531 strbuf_release(&buf);
532 return 0;
533}
534
535static int process_connect_service(struct transport *transport,
536 const char *name, const char *exec)
537{
538 struct helper_data *data = transport->data;
539 struct strbuf cmdbuf = STRBUF_INIT;
540 struct child_process *helper;
541 int r, duped, ret = 0;
542 FILE *input;
543
544 helper = get_helper(transport);
545
546 /*
547 * Yes, dup the pipe another time, as we need unbuffered version
548 * of input pipe as FILE*. fclose() closes the underlying fd and
549 * stream buffering only can be changed before first I/O operation
550 * on it.
551 */
552 duped = dup(helper->out);
553 if (duped < 0)
554 die_errno("Can't dup helper output fd");
555 input = xfdopen(duped, "r");
556 setvbuf(input, NULL, _IONBF, 0);
557
558 /*
559 * Handle --upload-pack and friends. This is fire and forget...
560 * just warn if it fails.
561 */
562 if (strcmp(name, exec)) {
563 r = set_helper_option(transport, "servpath", exec);
564 if (r > 0)
565 warning("Setting remote service path not supported by protocol.");
566 else if (r < 0)
567 warning("Invalid remote service path.");
568 }
569
570 if (data->connect)
571 strbuf_addf(&cmdbuf, "connect %s\n", name);
572 else
573 goto exit;
574
575 sendline(data, &cmdbuf);
576 if (recvline_fh(input, &cmdbuf, name))
577 exit(128);
578
579 if (!strcmp(cmdbuf.buf, "")) {
580 data->no_disconnect_req = 1;
581 if (debug)
582 fprintf(stderr, "Debug: Smart transport connection "
583 "ready.\n");
584 ret = 1;
585 } else if (!strcmp(cmdbuf.buf, "fallback")) {
586 if (debug)
587 fprintf(stderr, "Debug: Falling back to dumb "
588 "transport.\n");
589 } else
590 die("Unknown response to connect: %s",
591 cmdbuf.buf);
592
593exit:
594 fclose(input);
595 return ret;
596}
597
598static int process_connect(struct transport *transport,
599 int for_push)
600{
601 struct helper_data *data = transport->data;
602 const char *name;
603 const char *exec;
604
605 name = for_push ? "git-receive-pack" : "git-upload-pack";
606 if (for_push)
607 exec = data->transport_options.receivepack;
608 else
609 exec = data->transport_options.uploadpack;
610
611 return process_connect_service(transport, name, exec);
612}
613
614static int connect_helper(struct transport *transport, const char *name,
615 const char *exec, int fd[2])
616{
617 struct helper_data *data = transport->data;
618
619 /* Get_helper so connect is inited. */
620 get_helper(transport);
621 if (!data->connect)
622 die("Operation not supported by protocol.");
623
624 if (!process_connect_service(transport, name, exec))
625 die("Can't connect to subservice %s.", name);
626
627 fd[0] = data->helper->out;
628 fd[1] = data->helper->in;
629 return 0;
630}
631
632static int fetch(struct transport *transport,
633 int nr_heads, struct ref **to_fetch)
634{
635 struct helper_data *data = transport->data;
636 int i, count;
637
638 if (process_connect(transport, 0)) {
639 do_take_over(transport);
640 return transport->fetch(transport, nr_heads, to_fetch);
641 }
642
643 count = 0;
644 for (i = 0; i < nr_heads; i++)
645 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
646 count++;
647
648 if (!count)
649 return 0;
650
651 if (data->check_connectivity &&
652 data->transport_options.check_self_contained_and_connected)
653 set_helper_option(transport, "check-connectivity", "true");
654
655 if (transport->cloning)
656 set_helper_option(transport, "cloning", "true");
657
658 if (data->transport_options.update_shallow)
659 set_helper_option(transport, "update-shallow", "true");
660
661 if (data->fetch)
662 return fetch_with_fetch(transport, nr_heads, to_fetch);
663
664 if (data->import)
665 return fetch_with_import(transport, nr_heads, to_fetch);
666
667 return -1;
668}
669
670static int push_update_ref_status(struct strbuf *buf,
671 struct ref **ref,
672 struct ref *remote_refs)
673{
674 char *refname, *msg;
675 int status, forced = 0;
676
677 if (starts_with(buf->buf, "ok ")) {
678 status = REF_STATUS_OK;
679 refname = buf->buf + 3;
680 } else if (starts_with(buf->buf, "error ")) {
681 status = REF_STATUS_REMOTE_REJECT;
682 refname = buf->buf + 6;
683 } else
684 die("expected ok/error, helper said '%s'", buf->buf);
685
686 msg = strchr(refname, ' ');
687 if (msg) {
688 struct strbuf msg_buf = STRBUF_INIT;
689 const char *end;
690
691 *msg++ = '\0';
692 if (!unquote_c_style(&msg_buf, msg, &end))
693 msg = strbuf_detach(&msg_buf, NULL);
694 else
695 msg = xstrdup(msg);
696 strbuf_release(&msg_buf);
697
698 if (!strcmp(msg, "no match")) {
699 status = REF_STATUS_NONE;
700 free(msg);
701 msg = NULL;
702 }
703 else if (!strcmp(msg, "up to date")) {
704 status = REF_STATUS_UPTODATE;
705 free(msg);
706 msg = NULL;
707 }
708 else if (!strcmp(msg, "non-fast forward")) {
709 status = REF_STATUS_REJECT_NONFASTFORWARD;
710 free(msg);
711 msg = NULL;
712 }
713 else if (!strcmp(msg, "already exists")) {
714 status = REF_STATUS_REJECT_ALREADY_EXISTS;
715 free(msg);
716 msg = NULL;
717 }
718 else if (!strcmp(msg, "fetch first")) {
719 status = REF_STATUS_REJECT_FETCH_FIRST;
720 free(msg);
721 msg = NULL;
722 }
723 else if (!strcmp(msg, "needs force")) {
724 status = REF_STATUS_REJECT_NEEDS_FORCE;
725 free(msg);
726 msg = NULL;
727 }
728 else if (!strcmp(msg, "stale info")) {
729 status = REF_STATUS_REJECT_STALE;
730 free(msg);
731 msg = NULL;
732 }
733 else if (!strcmp(msg, "forced update")) {
734 forced = 1;
735 free(msg);
736 msg = NULL;
737 }
738 }
739
740 if (*ref)
741 *ref = find_ref_by_name(*ref, refname);
742 if (!*ref)
743 *ref = find_ref_by_name(remote_refs, refname);
744 if (!*ref) {
745 warning("helper reported unexpected status of %s", refname);
746 return 1;
747 }
748
749 if ((*ref)->status != REF_STATUS_NONE) {
750 /*
751 * Earlier, the ref was marked not to be pushed, so ignore the ref
752 * status reported by the remote helper if the latter is 'no match'.
753 */
754 if (status == REF_STATUS_NONE)
755 return 1;
756 }
757
758 (*ref)->status = status;
759 (*ref)->forced_update |= forced;
760 (*ref)->remote_status = msg;
761 return !(status == REF_STATUS_OK);
762}
763
764static int push_update_refs_status(struct helper_data *data,
765 struct ref *remote_refs,
766 int flags)
767{
768 struct strbuf buf = STRBUF_INIT;
769 struct ref *ref = remote_refs;
770 int ret = 0;
771
772 for (;;) {
773 char *private;
774
775 if (recvline(data, &buf)) {
776 ret = 1;
777 break;
778 }
779
780 if (!buf.len)
781 break;
782
783 if (push_update_ref_status(&buf, &ref, remote_refs))
784 continue;
785
786 if (flags & TRANSPORT_PUSH_DRY_RUN || !data->refspecs || data->no_private_update)
787 continue;
788
789 /* propagate back the update to the remote namespace */
790 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
791 if (!private)
792 continue;
793 update_ref("update by helper", private, ref->new_oid.hash, NULL, 0, 0);
794 free(private);
795 }
796 strbuf_release(&buf);
797 return ret;
798}
799
800static void set_common_push_options(struct transport *transport,
801 const char *name, int flags)
802{
803 if (flags & TRANSPORT_PUSH_DRY_RUN) {
804 if (set_helper_option(transport, "dry-run", "true") != 0)
805 die("helper %s does not support dry-run", name);
806 } else if (flags & TRANSPORT_PUSH_CERT_ALWAYS) {
807 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
808 die("helper %s does not support --signed", name);
809 } else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED) {
810 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "if-asked") != 0)
811 die("helper %s does not support --signed=if-asked", name);
812 }
813}
814
815static int push_refs_with_push(struct transport *transport,
816 struct ref *remote_refs, int flags)
817{
818 int force_all = flags & TRANSPORT_PUSH_FORCE;
819 int mirror = flags & TRANSPORT_PUSH_MIRROR;
820 struct helper_data *data = transport->data;
821 struct strbuf buf = STRBUF_INIT;
822 struct ref *ref;
823 struct string_list cas_options = STRING_LIST_INIT_DUP;
824 struct string_list_item *cas_option;
825
826 get_helper(transport);
827 if (!data->push)
828 return 1;
829
830 for (ref = remote_refs; ref; ref = ref->next) {
831 if (!ref->peer_ref && !mirror)
832 continue;
833
834 /* Check for statuses set by set_ref_status_for_push() */
835 switch (ref->status) {
836 case REF_STATUS_REJECT_NONFASTFORWARD:
837 case REF_STATUS_REJECT_STALE:
838 case REF_STATUS_REJECT_ALREADY_EXISTS:
839 case REF_STATUS_UPTODATE:
840 continue;
841 default:
842 ; /* do nothing */
843 }
844
845 if (force_all)
846 ref->force = 1;
847
848 strbuf_addstr(&buf, "push ");
849 if (!ref->deletion) {
850 if (ref->force)
851 strbuf_addch(&buf, '+');
852 if (ref->peer_ref)
853 strbuf_addstr(&buf, ref->peer_ref->name);
854 else
855 strbuf_addstr(&buf, oid_to_hex(&ref->new_oid));
856 }
857 strbuf_addch(&buf, ':');
858 strbuf_addstr(&buf, ref->name);
859 strbuf_addch(&buf, '\n');
860
861 /*
862 * The "--force-with-lease" options without explicit
863 * values to expect have already been expanded into
864 * the ref->old_oid_expect[] field; we can ignore
865 * transport->smart_options->cas altogether and instead
866 * can enumerate them from the refs.
867 */
868 if (ref->expect_old_sha1) {
869 struct strbuf cas = STRBUF_INIT;
870 strbuf_addf(&cas, "%s:%s",
871 ref->name, oid_to_hex(&ref->old_oid_expect));
872 string_list_append(&cas_options, strbuf_detach(&cas, NULL));
873 }
874 }
875 if (buf.len == 0) {
876 string_list_clear(&cas_options, 0);
877 return 0;
878 }
879
880 for_each_string_list_item(cas_option, &cas_options)
881 set_helper_option(transport, "cas", cas_option->string);
882 set_common_push_options(transport, data->name, flags);
883
884 strbuf_addch(&buf, '\n');
885 sendline(data, &buf);
886 strbuf_release(&buf);
887
888 return push_update_refs_status(data, remote_refs, flags);
889}
890
891static int push_refs_with_export(struct transport *transport,
892 struct ref *remote_refs, int flags)
893{
894 struct ref *ref;
895 struct child_process *helper, exporter;
896 struct helper_data *data = transport->data;
897 struct string_list revlist_args = STRING_LIST_INIT_DUP;
898 struct strbuf buf = STRBUF_INIT;
899
900 if (!data->refspecs)
901 die("remote-helper doesn't support push; refspec needed");
902
903 set_common_push_options(transport, data->name, flags);
904 if (flags & TRANSPORT_PUSH_FORCE) {
905 if (set_helper_option(transport, "force", "true") != 0)
906 warning("helper %s does not support 'force'", data->name);
907 }
908
909 helper = get_helper(transport);
910
911 write_constant(helper->in, "export\n");
912
913 for (ref = remote_refs; ref; ref = ref->next) {
914 char *private;
915 struct object_id oid;
916
917 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
918 if (private && !get_sha1(private, oid.hash)) {
919 strbuf_addf(&buf, "^%s", private);
920 string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
921 oidcpy(&ref->old_oid, &oid);
922 }
923 free(private);
924
925 if (ref->peer_ref) {
926 if (strcmp(ref->name, ref->peer_ref->name)) {
927 if (!ref->deletion) {
928 const char *name;
929 int flag;
930
931 /* Follow symbolic refs (mainly for HEAD). */
932 name = resolve_ref_unsafe(
933 ref->peer_ref->name,
934 RESOLVE_REF_READING,
935 oid.hash, &flag);
936 if (!name || !(flag & REF_ISSYMREF))
937 name = ref->peer_ref->name;
938
939 strbuf_addf(&buf, "%s:%s", name, ref->name);
940 } else
941 strbuf_addf(&buf, ":%s", ref->name);
942
943 string_list_append(&revlist_args, "--refspec");
944 string_list_append(&revlist_args, buf.buf);
945 strbuf_release(&buf);
946 }
947 if (!ref->deletion)
948 string_list_append(&revlist_args, ref->peer_ref->name);
949 }
950 }
951
952 if (get_exporter(transport, &exporter, &revlist_args))
953 die("Couldn't run fast-export");
954
955 string_list_clear(&revlist_args, 1);
956
957 if (finish_command(&exporter))
958 die("Error while running fast-export");
959 if (push_update_refs_status(data, remote_refs, flags))
960 return 1;
961
962 if (data->export_marks) {
963 strbuf_addf(&buf, "%s.tmp", data->export_marks);
964 rename(buf.buf, data->export_marks);
965 strbuf_release(&buf);
966 }
967
968 return 0;
969}
970
971static int push_refs(struct transport *transport,
972 struct ref *remote_refs, int flags)
973{
974 struct helper_data *data = transport->data;
975
976 if (process_connect(transport, 1)) {
977 do_take_over(transport);
978 return transport->push_refs(transport, remote_refs, flags);
979 }
980
981 if (!remote_refs) {
982 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
983 "Perhaps you should specify a branch such as 'master'.\n");
984 return 0;
985 }
986
987 if (data->push)
988 return push_refs_with_push(transport, remote_refs, flags);
989
990 if (data->export)
991 return push_refs_with_export(transport, remote_refs, flags);
992
993 return -1;
994}
995
996
997static int has_attribute(const char *attrs, const char *attr) {
998 int len;
999 if (!attrs)
1000 return 0;
1001
1002 len = strlen(attr);
1003 for (;;) {
1004 const char *space = strchrnul(attrs, ' ');
1005 if (len == space - attrs && !strncmp(attrs, attr, len))
1006 return 1;
1007 if (!*space)
1008 return 0;
1009 attrs = space + 1;
1010 }
1011}
1012
1013static struct ref *get_refs_list(struct transport *transport, int for_push)
1014{
1015 struct helper_data *data = transport->data;
1016 struct child_process *helper;
1017 struct ref *ret = NULL;
1018 struct ref **tail = &ret;
1019 struct ref *posn;
1020 struct strbuf buf = STRBUF_INIT;
1021
1022 helper = get_helper(transport);
1023
1024 if (process_connect(transport, for_push)) {
1025 do_take_over(transport);
1026 return transport->get_refs_list(transport, for_push);
1027 }
1028
1029 if (data->push && for_push)
1030 write_str_in_full(helper->in, "list for-push\n");
1031 else
1032 write_str_in_full(helper->in, "list\n");
1033
1034 while (1) {
1035 char *eov, *eon;
1036 if (recvline(data, &buf))
1037 exit(128);
1038
1039 if (!*buf.buf)
1040 break;
1041
1042 eov = strchr(buf.buf, ' ');
1043 if (!eov)
1044 die("Malformed response in ref list: %s", buf.buf);
1045 eon = strchr(eov + 1, ' ');
1046 *eov = '\0';
1047 if (eon)
1048 *eon = '\0';
1049 *tail = alloc_ref(eov + 1);
1050 if (buf.buf[0] == '@')
1051 (*tail)->symref = xstrdup(buf.buf + 1);
1052 else if (buf.buf[0] != '?')
1053 get_oid_hex(buf.buf, &(*tail)->old_oid);
1054 if (eon) {
1055 if (has_attribute(eon + 1, "unchanged")) {
1056 (*tail)->status |= REF_STATUS_UPTODATE;
1057 if (read_ref((*tail)->name,
1058 (*tail)->old_oid.hash) < 0)
1059 die(N_("Could not read ref %s"),
1060 (*tail)->name);
1061 }
1062 }
1063 tail = &((*tail)->next);
1064 }
1065 if (debug)
1066 fprintf(stderr, "Debug: Read ref listing.\n");
1067 strbuf_release(&buf);
1068
1069 for (posn = ret; posn; posn = posn->next)
1070 resolve_remote_symref(posn, ret);
1071
1072 return ret;
1073}
1074
1075int transport_helper_init(struct transport *transport, const char *name)
1076{
1077 struct helper_data *data = xcalloc(1, sizeof(*data));
1078 data->name = name;
1079
1080 transport_check_allowed(name);
1081
1082 if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1083 debug = 1;
1084
1085 transport->data = data;
1086 transport->set_option = set_helper_option;
1087 transport->get_refs_list = get_refs_list;
1088 transport->fetch = fetch;
1089 transport->push_refs = push_refs;
1090 transport->disconnect = release_helper;
1091 transport->connect = connect_helper;
1092 transport->smart_options = &(data->transport_options);
1093 return 0;
1094}
1095
1096/*
1097 * Linux pipes can buffer 65536 bytes at once (and most platforms can
1098 * buffer less), so attempt reads and writes with up to that size.
1099 */
1100#define BUFFERSIZE 65536
1101/* This should be enough to hold debugging message. */
1102#define PBUFFERSIZE 8192
1103
1104/* Print bidirectional transfer loop debug message. */
1105__attribute__((format (printf, 1, 2)))
1106static void transfer_debug(const char *fmt, ...)
1107{
1108 va_list args;
1109 char msgbuf[PBUFFERSIZE];
1110 static int debug_enabled = -1;
1111
1112 if (debug_enabled < 0)
1113 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1114 if (!debug_enabled)
1115 return;
1116
1117 va_start(args, fmt);
1118 vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1119 va_end(args);
1120 fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1121}
1122
1123/* Stream state: More data may be coming in this direction. */
1124#define SSTATE_TRANSFERING 0
1125/*
1126 * Stream state: No more data coming in this direction, flushing rest of
1127 * data.
1128 */
1129#define SSTATE_FLUSHING 1
1130/* Stream state: Transfer in this direction finished. */
1131#define SSTATE_FINISHED 2
1132
1133#define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
1134#define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1135#define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1136
1137/* Unidirectional transfer. */
1138struct unidirectional_transfer {
1139 /* Source */
1140 int src;
1141 /* Destination */
1142 int dest;
1143 /* Is source socket? */
1144 int src_is_sock;
1145 /* Is destination socket? */
1146 int dest_is_sock;
1147 /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1148 int state;
1149 /* Buffer. */
1150 char buf[BUFFERSIZE];
1151 /* Buffer used. */
1152 size_t bufuse;
1153 /* Name of source. */
1154 const char *src_name;
1155 /* Name of destination. */
1156 const char *dest_name;
1157};
1158
1159/* Closes the target (for writing) if transfer has finished. */
1160static void udt_close_if_finished(struct unidirectional_transfer *t)
1161{
1162 if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1163 t->state = SSTATE_FINISHED;
1164 if (t->dest_is_sock)
1165 shutdown(t->dest, SHUT_WR);
1166 else
1167 close(t->dest);
1168 transfer_debug("Closed %s.", t->dest_name);
1169 }
1170}
1171
1172/*
1173 * Tries to read read data from source into buffer. If buffer is full,
1174 * no data is read. Returns 0 on success, -1 on error.
1175 */
1176static int udt_do_read(struct unidirectional_transfer *t)
1177{
1178 ssize_t bytes;
1179
1180 if (t->bufuse == BUFFERSIZE)
1181 return 0; /* No space for more. */
1182
1183 transfer_debug("%s is readable", t->src_name);
1184 bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1185 if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1186 errno != EINTR) {
1187 error("read(%s) failed: %s", t->src_name, strerror(errno));
1188 return -1;
1189 } else if (bytes == 0) {
1190 transfer_debug("%s EOF (with %i bytes in buffer)",
1191 t->src_name, (int)t->bufuse);
1192 t->state = SSTATE_FLUSHING;
1193 } else if (bytes > 0) {
1194 t->bufuse += bytes;
1195 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1196 (int)bytes, t->src_name, (int)t->bufuse);
1197 }
1198 return 0;
1199}
1200
1201/* Tries to write data from buffer into destination. If buffer is empty,
1202 * no data is written. Returns 0 on success, -1 on error.
1203 */
1204static int udt_do_write(struct unidirectional_transfer *t)
1205{
1206 ssize_t bytes;
1207
1208 if (t->bufuse == 0)
1209 return 0; /* Nothing to write. */
1210
1211 transfer_debug("%s is writable", t->dest_name);
1212 bytes = xwrite(t->dest, t->buf, t->bufuse);
1213 if (bytes < 0 && errno != EWOULDBLOCK) {
1214 error("write(%s) failed: %s", t->dest_name, strerror(errno));
1215 return -1;
1216 } else if (bytes > 0) {
1217 t->bufuse -= bytes;
1218 if (t->bufuse)
1219 memmove(t->buf, t->buf + bytes, t->bufuse);
1220 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1221 (int)bytes, t->dest_name, (int)t->bufuse);
1222 }
1223 return 0;
1224}
1225
1226
1227/* State of bidirectional transfer loop. */
1228struct bidirectional_transfer_state {
1229 /* Direction from program to git. */
1230 struct unidirectional_transfer ptg;
1231 /* Direction from git to program. */
1232 struct unidirectional_transfer gtp;
1233};
1234
1235static void *udt_copy_task_routine(void *udt)
1236{
1237 struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1238 while (t->state != SSTATE_FINISHED) {
1239 if (STATE_NEEDS_READING(t->state))
1240 if (udt_do_read(t))
1241 return NULL;
1242 if (STATE_NEEDS_WRITING(t->state))
1243 if (udt_do_write(t))
1244 return NULL;
1245 if (STATE_NEEDS_CLOSING(t->state))
1246 udt_close_if_finished(t);
1247 }
1248 return udt; /* Just some non-NULL value. */
1249}
1250
1251#ifndef NO_PTHREADS
1252
1253/*
1254 * Join thread, with appropriate errors on failure. Name is name for the
1255 * thread (for error messages). Returns 0 on success, 1 on failure.
1256 */
1257static int tloop_join(pthread_t thread, const char *name)
1258{
1259 int err;
1260 void *tret;
1261 err = pthread_join(thread, &tret);
1262 if (!tret) {
1263 error("%s thread failed", name);
1264 return 1;
1265 }
1266 if (err) {
1267 error("%s thread failed to join: %s", name, strerror(err));
1268 return 1;
1269 }
1270 return 0;
1271}
1272
1273/*
1274 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1275 * -1 on failure.
1276 */
1277static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1278{
1279 pthread_t gtp_thread;
1280 pthread_t ptg_thread;
1281 int err;
1282 int ret = 0;
1283 err = pthread_create(>p_thread, NULL, udt_copy_task_routine,
1284 &s->gtp);
1285 if (err)
1286 die("Can't start thread for copying data: %s", strerror(err));
1287 err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1288 &s->ptg);
1289 if (err)
1290 die("Can't start thread for copying data: %s", strerror(err));
1291
1292 ret |= tloop_join(gtp_thread, "Git to program copy");
1293 ret |= tloop_join(ptg_thread, "Program to git copy");
1294 return ret;
1295}
1296#else
1297
1298/* Close the source and target (for writing) for transfer. */
1299static void udt_kill_transfer(struct unidirectional_transfer *t)
1300{
1301 t->state = SSTATE_FINISHED;
1302 /*
1303 * Socket read end left open isn't a disaster if nobody
1304 * attempts to read from it (mingw compat headers do not
1305 * have SHUT_RD)...
1306 *
1307 * We can't fully close the socket since otherwise gtp
1308 * task would first close the socket it sends data to
1309 * while closing the ptg file descriptors.
1310 */
1311 if (!t->src_is_sock)
1312 close(t->src);
1313 if (t->dest_is_sock)
1314 shutdown(t->dest, SHUT_WR);
1315 else
1316 close(t->dest);
1317}
1318
1319/*
1320 * Join process, with appropriate errors on failure. Name is name for the
1321 * process (for error messages). Returns 0 on success, 1 on failure.
1322 */
1323static int tloop_join(pid_t pid, const char *name)
1324{
1325 int tret;
1326 if (waitpid(pid, &tret, 0) < 0) {
1327 error("%s process failed to wait: %s", name, strerror(errno));
1328 return 1;
1329 }
1330 if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1331 error("%s process failed", name);
1332 return 1;
1333 }
1334 return 0;
1335}
1336
1337/*
1338 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1339 * -1 on failure.
1340 */
1341static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1342{
1343 pid_t pid1, pid2;
1344 int ret = 0;
1345
1346 /* Fork thread #1: git to program. */
1347 pid1 = fork();
1348 if (pid1 < 0)
1349 die_errno("Can't start thread for copying data");
1350 else if (pid1 == 0) {
1351 udt_kill_transfer(&s->ptg);
1352 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1353 }
1354
1355 /* Fork thread #2: program to git. */
1356 pid2 = fork();
1357 if (pid2 < 0)
1358 die_errno("Can't start thread for copying data");
1359 else if (pid2 == 0) {
1360 udt_kill_transfer(&s->gtp);
1361 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1362 }
1363
1364 /*
1365 * Close both streams in parent as to not interfere with
1366 * end of file detection and wait for both tasks to finish.
1367 */
1368 udt_kill_transfer(&s->gtp);
1369 udt_kill_transfer(&s->ptg);
1370 ret |= tloop_join(pid1, "Git to program copy");
1371 ret |= tloop_join(pid2, "Program to git copy");
1372 return ret;
1373}
1374#endif
1375
1376/*
1377 * Copies data from stdin to output and from input to stdout simultaneously.
1378 * Additionally filtering through given filter. If filter is NULL, uses
1379 * identity filter.
1380 */
1381int bidirectional_transfer_loop(int input, int output)
1382{
1383 struct bidirectional_transfer_state state;
1384
1385 /* Fill the state fields. */
1386 state.ptg.src = input;
1387 state.ptg.dest = 1;
1388 state.ptg.src_is_sock = (input == output);
1389 state.ptg.dest_is_sock = 0;
1390 state.ptg.state = SSTATE_TRANSFERING;
1391 state.ptg.bufuse = 0;
1392 state.ptg.src_name = "remote input";
1393 state.ptg.dest_name = "stdout";
1394
1395 state.gtp.src = 0;
1396 state.gtp.dest = output;
1397 state.gtp.src_is_sock = 0;
1398 state.gtp.dest_is_sock = (input == output);
1399 state.gtp.state = SSTATE_TRANSFERING;
1400 state.gtp.bufuse = 0;
1401 state.gtp.src_name = "stdin";
1402 state.gtp.dest_name = "remote output";
1403
1404 return tloop_spawnwait_tasks(&state);
1405}