Git 1.8.1.2
[git/jnareb-git.git] / transport-helper.c
blob4713b6930248d961824c9f867b10340e6278132f
1 #include "cache.h"
2 #include "transport.h"
3 #include "quote.h"
4 #include "run-command.h"
5 #include "commit.h"
6 #include "diff.h"
7 #include "revision.h"
8 #include "quote.h"
9 #include "remote.h"
10 #include "string-list.h"
11 #include "thread-utils.h"
12 #include "sigchain.h"
13 #include "argv-array.h"
15 static int debug;
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 no_disconnect_req : 1;
29 char *export_marks;
30 char *import_marks;
31 /* These go from remote name (as in "list") to private name */
32 struct refspec *refspecs;
33 int refspec_nr;
34 /* Transport options for fetch-pack/send-pack (should one of
35 * those be invoked).
37 struct git_transport_options transport_options;
40 static void sendline(struct helper_data *helper, struct strbuf *buffer)
42 if (debug)
43 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
44 if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
45 != buffer->len)
46 die_errno("Full write to remote helper failed");
49 static int recvline_fh(FILE *helper, struct strbuf *buffer)
51 strbuf_reset(buffer);
52 if (debug)
53 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
54 if (strbuf_getline(buffer, helper, '\n') == EOF) {
55 if (debug)
56 fprintf(stderr, "Debug: Remote helper quit.\n");
57 exit(128);
60 if (debug)
61 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
62 return 0;
65 static int recvline(struct helper_data *helper, struct strbuf *buffer)
67 return recvline_fh(helper->out, buffer);
70 static void xchgline(struct helper_data *helper, struct strbuf *buffer)
72 sendline(helper, buffer);
73 recvline(helper, buffer);
76 static void write_constant(int fd, const char *str)
78 if (debug)
79 fprintf(stderr, "Debug: Remote helper: -> %s", str);
80 if (write_in_full(fd, str, strlen(str)) != strlen(str))
81 die_errno("Full write to remote helper failed");
84 static const char *remove_ext_force(const char *url)
86 if (url) {
87 const char *colon = strchr(url, ':');
88 if (colon && colon[1] == ':')
89 return colon + 2;
91 return url;
94 static void do_take_over(struct transport *transport)
96 struct helper_data *data;
97 data = (struct helper_data *)transport->data;
98 transport_take_over(transport, data->helper);
99 fclose(data->out);
100 free(data);
103 static struct child_process *get_helper(struct transport *transport)
105 struct helper_data *data = transport->data;
106 struct argv_array argv = ARGV_ARRAY_INIT;
107 struct strbuf buf = STRBUF_INIT;
108 struct child_process *helper;
109 const char **refspecs = NULL;
110 int refspec_nr = 0;
111 int refspec_alloc = 0;
112 int duped;
113 int code;
114 char git_dir_buf[sizeof(GIT_DIR_ENVIRONMENT) + PATH_MAX + 1];
115 const char *helper_env[] = {
116 git_dir_buf,
117 NULL
121 if (data->helper)
122 return data->helper;
124 helper = xcalloc(1, sizeof(*helper));
125 helper->in = -1;
126 helper->out = -1;
127 helper->err = 0;
128 argv_array_pushf(&argv, "git-remote-%s", data->name);
129 argv_array_push(&argv, transport->remote->name);
130 argv_array_push(&argv, remove_ext_force(transport->url));
131 helper->argv = argv_array_detach(&argv, NULL);
132 helper->git_cmd = 0;
133 helper->silent_exec_failure = 1;
135 snprintf(git_dir_buf, sizeof(git_dir_buf), "%s=%s", GIT_DIR_ENVIRONMENT, get_git_dir());
136 helper->env = helper_env;
138 code = start_command(helper);
139 if (code < 0 && errno == ENOENT)
140 die("Unable to find remote helper for '%s'", data->name);
141 else if (code != 0)
142 exit(code);
144 data->helper = helper;
145 data->no_disconnect_req = 0;
148 * Open the output as FILE* so strbuf_getline() can be used.
149 * Do this with duped fd because fclose() will close the fd,
150 * and stuff like taking over will require the fd to remain.
152 duped = dup(helper->out);
153 if (duped < 0)
154 die_errno("Can't dup helper output fd");
155 data->out = xfdopen(duped, "r");
157 write_constant(helper->in, "capabilities\n");
159 while (1) {
160 const char *capname;
161 int mandatory = 0;
162 recvline(data, &buf);
164 if (!*buf.buf)
165 break;
167 if (*buf.buf == '*') {
168 capname = buf.buf + 1;
169 mandatory = 1;
170 } else
171 capname = buf.buf;
173 if (debug)
174 fprintf(stderr, "Debug: Got cap %s\n", capname);
175 if (!strcmp(capname, "fetch"))
176 data->fetch = 1;
177 else if (!strcmp(capname, "option"))
178 data->option = 1;
179 else if (!strcmp(capname, "push"))
180 data->push = 1;
181 else if (!strcmp(capname, "import"))
182 data->import = 1;
183 else if (!strcmp(capname, "bidi-import"))
184 data->bidi_import = 1;
185 else if (!strcmp(capname, "export"))
186 data->export = 1;
187 else if (!data->refspecs && !prefixcmp(capname, "refspec ")) {
188 ALLOC_GROW(refspecs,
189 refspec_nr + 1,
190 refspec_alloc);
191 refspecs[refspec_nr++] = xstrdup(capname + strlen("refspec "));
192 } else if (!strcmp(capname, "connect")) {
193 data->connect = 1;
194 } else if (!prefixcmp(capname, "export-marks ")) {
195 struct strbuf arg = STRBUF_INIT;
196 strbuf_addstr(&arg, "--export-marks=");
197 strbuf_addstr(&arg, capname + strlen("export-marks "));
198 data->export_marks = strbuf_detach(&arg, NULL);
199 } else if (!prefixcmp(capname, "import-marks")) {
200 struct strbuf arg = STRBUF_INIT;
201 strbuf_addstr(&arg, "--import-marks=");
202 strbuf_addstr(&arg, capname + strlen("import-marks "));
203 data->import_marks = strbuf_detach(&arg, NULL);
204 } else if (mandatory) {
205 die("Unknown mandatory capability %s. This remote "
206 "helper probably needs newer version of Git.",
207 capname);
210 if (refspecs) {
211 int i;
212 data->refspec_nr = refspec_nr;
213 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
214 for (i = 0; i < refspec_nr; i++) {
215 free((char *)refspecs[i]);
217 free(refspecs);
219 strbuf_release(&buf);
220 if (debug)
221 fprintf(stderr, "Debug: Capabilities complete.\n");
222 return data->helper;
225 static int disconnect_helper(struct transport *transport)
227 struct helper_data *data = transport->data;
228 int res = 0;
230 if (data->helper) {
231 if (debug)
232 fprintf(stderr, "Debug: Disconnecting.\n");
233 if (!data->no_disconnect_req) {
235 * Ignore write errors; there's nothing we can do,
236 * since we're about to close the pipe anyway. And the
237 * most likely error is EPIPE due to the helper dying
238 * to report an error itself.
240 sigchain_push(SIGPIPE, SIG_IGN);
241 xwrite(data->helper->in, "\n", 1);
242 sigchain_pop(SIGPIPE);
244 close(data->helper->in);
245 close(data->helper->out);
246 fclose(data->out);
247 res = finish_command(data->helper);
248 argv_array_free_detached(data->helper->argv);
249 free(data->helper);
250 data->helper = NULL;
252 return res;
255 static const char *unsupported_options[] = {
256 TRANS_OPT_UPLOADPACK,
257 TRANS_OPT_RECEIVEPACK,
258 TRANS_OPT_THIN,
259 TRANS_OPT_KEEP
261 static const char *boolean_options[] = {
262 TRANS_OPT_THIN,
263 TRANS_OPT_KEEP,
264 TRANS_OPT_FOLLOWTAGS
267 static int set_helper_option(struct transport *transport,
268 const char *name, const char *value)
270 struct helper_data *data = transport->data;
271 struct strbuf buf = STRBUF_INIT;
272 int i, ret, is_bool = 0;
274 get_helper(transport);
276 if (!data->option)
277 return 1;
279 for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
280 if (!strcmp(name, unsupported_options[i]))
281 return 1;
284 for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
285 if (!strcmp(name, boolean_options[i])) {
286 is_bool = 1;
287 break;
291 strbuf_addf(&buf, "option %s ", name);
292 if (is_bool)
293 strbuf_addstr(&buf, value ? "true" : "false");
294 else
295 quote_c_style(value, &buf, NULL, 0);
296 strbuf_addch(&buf, '\n');
298 xchgline(data, &buf);
300 if (!strcmp(buf.buf, "ok"))
301 ret = 0;
302 else if (!prefixcmp(buf.buf, "error")) {
303 ret = -1;
304 } else if (!strcmp(buf.buf, "unsupported"))
305 ret = 1;
306 else {
307 warning("%s unexpectedly said: '%s'", data->name, buf.buf);
308 ret = 1;
310 strbuf_release(&buf);
311 return ret;
314 static void standard_options(struct transport *t)
316 char buf[16];
317 int n;
318 int v = t->verbose;
320 set_helper_option(t, "progress", t->progress ? "true" : "false");
322 n = snprintf(buf, sizeof(buf), "%d", v + 1);
323 if (n >= sizeof(buf))
324 die("impossibly large verbosity value");
325 set_helper_option(t, "verbosity", buf);
328 static int release_helper(struct transport *transport)
330 int res = 0;
331 struct helper_data *data = transport->data;
332 free_refspec(data->refspec_nr, data->refspecs);
333 data->refspecs = NULL;
334 res = disconnect_helper(transport);
335 free(transport->data);
336 return res;
339 static int fetch_with_fetch(struct transport *transport,
340 int nr_heads, struct ref **to_fetch)
342 struct helper_data *data = transport->data;
343 int i;
344 struct strbuf buf = STRBUF_INIT;
346 standard_options(transport);
348 for (i = 0; i < nr_heads; i++) {
349 const struct ref *posn = to_fetch[i];
350 if (posn->status & REF_STATUS_UPTODATE)
351 continue;
353 strbuf_addf(&buf, "fetch %s %s\n",
354 sha1_to_hex(posn->old_sha1), posn->name);
357 strbuf_addch(&buf, '\n');
358 sendline(data, &buf);
360 while (1) {
361 recvline(data, &buf);
363 if (!prefixcmp(buf.buf, "lock ")) {
364 const char *name = buf.buf + 5;
365 if (transport->pack_lockfile)
366 warning("%s also locked %s", data->name, name);
367 else
368 transport->pack_lockfile = xstrdup(name);
370 else if (!buf.len)
371 break;
372 else
373 warning("%s unexpectedly said: '%s'", data->name, buf.buf);
375 strbuf_release(&buf);
376 return 0;
379 static int get_importer(struct transport *transport, struct child_process *fastimport)
381 struct child_process *helper = get_helper(transport);
382 struct helper_data *data = transport->data;
383 struct argv_array argv = ARGV_ARRAY_INIT;
384 int cat_blob_fd, code;
385 memset(fastimport, 0, sizeof(*fastimport));
386 fastimport->in = helper->out;
387 argv_array_push(&argv, "fast-import");
388 argv_array_push(&argv, debug ? "--stats" : "--quiet");
390 if (data->bidi_import) {
391 cat_blob_fd = xdup(helper->in);
392 argv_array_pushf(&argv, "--cat-blob-fd=%d", cat_blob_fd);
394 fastimport->argv = argv.argv;
395 fastimport->git_cmd = 1;
397 code = start_command(fastimport);
398 return code;
401 static int get_exporter(struct transport *transport,
402 struct child_process *fastexport,
403 struct string_list *revlist_args)
405 struct helper_data *data = transport->data;
406 struct child_process *helper = get_helper(transport);
407 int argc = 0, i;
408 memset(fastexport, 0, sizeof(*fastexport));
410 /* we need to duplicate helper->in because we want to use it after
411 * fastexport is done with it. */
412 fastexport->out = dup(helper->in);
413 fastexport->argv = xcalloc(5 + revlist_args->nr, sizeof(*fastexport->argv));
414 fastexport->argv[argc++] = "fast-export";
415 fastexport->argv[argc++] = "--use-done-feature";
416 if (data->export_marks)
417 fastexport->argv[argc++] = data->export_marks;
418 if (data->import_marks)
419 fastexport->argv[argc++] = data->import_marks;
421 for (i = 0; i < revlist_args->nr; i++)
422 fastexport->argv[argc++] = revlist_args->items[i].string;
424 fastexport->git_cmd = 1;
425 return start_command(fastexport);
428 static int fetch_with_import(struct transport *transport,
429 int nr_heads, struct ref **to_fetch)
431 struct child_process fastimport;
432 struct helper_data *data = transport->data;
433 int i;
434 struct ref *posn;
435 struct strbuf buf = STRBUF_INIT;
437 get_helper(transport);
439 if (get_importer(transport, &fastimport))
440 die("Couldn't run fast-import");
442 for (i = 0; i < nr_heads; i++) {
443 posn = to_fetch[i];
444 if (posn->status & REF_STATUS_UPTODATE)
445 continue;
447 strbuf_addf(&buf, "import %s\n", posn->name);
448 sendline(data, &buf);
449 strbuf_reset(&buf);
452 write_constant(data->helper->in, "\n");
454 * remote-helpers that advertise the bidi-import capability are required to
455 * buffer the complete batch of import commands until this newline before
456 * sending data to fast-import.
457 * These helpers read back data from fast-import on their stdin, which could
458 * be mixed with import commands, otherwise.
461 if (finish_command(&fastimport))
462 die("Error while running fast-import");
463 argv_array_free_detached(fastimport.argv);
466 * The fast-import stream of a remote helper that advertises
467 * the "refspec" capability writes to the refs named after the
468 * right hand side of the first refspec matching each ref we
469 * were fetching.
471 * (If no "refspec" capability was specified, for historical
472 * reasons we default to *:*.)
474 * Store the result in to_fetch[i].old_sha1. Callers such
475 * as "git fetch" can use the value to write feedback to the
476 * terminal, populate FETCH_HEAD, and determine what new value
477 * should be written to peer_ref if the update is a
478 * fast-forward or this is a forced update.
480 for (i = 0; i < nr_heads; i++) {
481 char *private;
482 posn = to_fetch[i];
483 if (posn->status & REF_STATUS_UPTODATE)
484 continue;
485 if (data->refspecs)
486 private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
487 else
488 private = xstrdup(posn->name);
489 if (private) {
490 read_ref(private, posn->old_sha1);
491 free(private);
494 strbuf_release(&buf);
495 return 0;
498 static int process_connect_service(struct transport *transport,
499 const char *name, const char *exec)
501 struct helper_data *data = transport->data;
502 struct strbuf cmdbuf = STRBUF_INIT;
503 struct child_process *helper;
504 int r, duped, ret = 0;
505 FILE *input;
507 helper = get_helper(transport);
510 * Yes, dup the pipe another time, as we need unbuffered version
511 * of input pipe as FILE*. fclose() closes the underlying fd and
512 * stream buffering only can be changed before first I/O operation
513 * on it.
515 duped = dup(helper->out);
516 if (duped < 0)
517 die_errno("Can't dup helper output fd");
518 input = xfdopen(duped, "r");
519 setvbuf(input, NULL, _IONBF, 0);
522 * Handle --upload-pack and friends. This is fire and forget...
523 * just warn if it fails.
525 if (strcmp(name, exec)) {
526 r = set_helper_option(transport, "servpath", exec);
527 if (r > 0)
528 warning("Setting remote service path not supported by protocol.");
529 else if (r < 0)
530 warning("Invalid remote service path.");
533 if (data->connect)
534 strbuf_addf(&cmdbuf, "connect %s\n", name);
535 else
536 goto exit;
538 sendline(data, &cmdbuf);
539 recvline_fh(input, &cmdbuf);
540 if (!strcmp(cmdbuf.buf, "")) {
541 data->no_disconnect_req = 1;
542 if (debug)
543 fprintf(stderr, "Debug: Smart transport connection "
544 "ready.\n");
545 ret = 1;
546 } else if (!strcmp(cmdbuf.buf, "fallback")) {
547 if (debug)
548 fprintf(stderr, "Debug: Falling back to dumb "
549 "transport.\n");
550 } else
551 die("Unknown response to connect: %s",
552 cmdbuf.buf);
554 exit:
555 fclose(input);
556 return ret;
559 static int process_connect(struct transport *transport,
560 int for_push)
562 struct helper_data *data = transport->data;
563 const char *name;
564 const char *exec;
566 name = for_push ? "git-receive-pack" : "git-upload-pack";
567 if (for_push)
568 exec = data->transport_options.receivepack;
569 else
570 exec = data->transport_options.uploadpack;
572 return process_connect_service(transport, name, exec);
575 static int connect_helper(struct transport *transport, const char *name,
576 const char *exec, int fd[2])
578 struct helper_data *data = transport->data;
580 /* Get_helper so connect is inited. */
581 get_helper(transport);
582 if (!data->connect)
583 die("Operation not supported by protocol.");
585 if (!process_connect_service(transport, name, exec))
586 die("Can't connect to subservice %s.", name);
588 fd[0] = data->helper->out;
589 fd[1] = data->helper->in;
590 return 0;
593 static int fetch(struct transport *transport,
594 int nr_heads, struct ref **to_fetch)
596 struct helper_data *data = transport->data;
597 int i, count;
599 if (process_connect(transport, 0)) {
600 do_take_over(transport);
601 return transport->fetch(transport, nr_heads, to_fetch);
604 count = 0;
605 for (i = 0; i < nr_heads; i++)
606 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
607 count++;
609 if (!count)
610 return 0;
612 if (data->fetch)
613 return fetch_with_fetch(transport, nr_heads, to_fetch);
615 if (data->import)
616 return fetch_with_import(transport, nr_heads, to_fetch);
618 return -1;
621 static void push_update_ref_status(struct strbuf *buf,
622 struct ref **ref,
623 struct ref *remote_refs)
625 char *refname, *msg;
626 int status;
628 if (!prefixcmp(buf->buf, "ok ")) {
629 status = REF_STATUS_OK;
630 refname = buf->buf + 3;
631 } else if (!prefixcmp(buf->buf, "error ")) {
632 status = REF_STATUS_REMOTE_REJECT;
633 refname = buf->buf + 6;
634 } else
635 die("expected ok/error, helper said '%s'", buf->buf);
637 msg = strchr(refname, ' ');
638 if (msg) {
639 struct strbuf msg_buf = STRBUF_INIT;
640 const char *end;
642 *msg++ = '\0';
643 if (!unquote_c_style(&msg_buf, msg, &end))
644 msg = strbuf_detach(&msg_buf, NULL);
645 else
646 msg = xstrdup(msg);
647 strbuf_release(&msg_buf);
649 if (!strcmp(msg, "no match")) {
650 status = REF_STATUS_NONE;
651 free(msg);
652 msg = NULL;
654 else if (!strcmp(msg, "up to date")) {
655 status = REF_STATUS_UPTODATE;
656 free(msg);
657 msg = NULL;
659 else if (!strcmp(msg, "non-fast forward")) {
660 status = REF_STATUS_REJECT_NONFASTFORWARD;
661 free(msg);
662 msg = NULL;
666 if (*ref)
667 *ref = find_ref_by_name(*ref, refname);
668 if (!*ref)
669 *ref = find_ref_by_name(remote_refs, refname);
670 if (!*ref) {
671 warning("helper reported unexpected status of %s", refname);
672 return;
675 if ((*ref)->status != REF_STATUS_NONE) {
677 * Earlier, the ref was marked not to be pushed, so ignore the ref
678 * status reported by the remote helper if the latter is 'no match'.
680 if (status == REF_STATUS_NONE)
681 return;
684 (*ref)->status = status;
685 (*ref)->remote_status = msg;
688 static void push_update_refs_status(struct helper_data *data,
689 struct ref *remote_refs)
691 struct strbuf buf = STRBUF_INIT;
692 struct ref *ref = remote_refs;
693 for (;;) {
694 recvline(data, &buf);
695 if (!buf.len)
696 break;
698 push_update_ref_status(&buf, &ref, remote_refs);
700 strbuf_release(&buf);
703 static int push_refs_with_push(struct transport *transport,
704 struct ref *remote_refs, int flags)
706 int force_all = flags & TRANSPORT_PUSH_FORCE;
707 int mirror = flags & TRANSPORT_PUSH_MIRROR;
708 struct helper_data *data = transport->data;
709 struct strbuf buf = STRBUF_INIT;
710 struct ref *ref;
712 get_helper(transport);
713 if (!data->push)
714 return 1;
716 for (ref = remote_refs; ref; ref = ref->next) {
717 if (!ref->peer_ref && !mirror)
718 continue;
720 /* Check for statuses set by set_ref_status_for_push() */
721 switch (ref->status) {
722 case REF_STATUS_REJECT_NONFASTFORWARD:
723 case REF_STATUS_UPTODATE:
724 continue;
725 default:
726 ; /* do nothing */
729 if (force_all)
730 ref->force = 1;
732 strbuf_addstr(&buf, "push ");
733 if (!ref->deletion) {
734 if (ref->force)
735 strbuf_addch(&buf, '+');
736 if (ref->peer_ref)
737 strbuf_addstr(&buf, ref->peer_ref->name);
738 else
739 strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
741 strbuf_addch(&buf, ':');
742 strbuf_addstr(&buf, ref->name);
743 strbuf_addch(&buf, '\n');
745 if (buf.len == 0)
746 return 0;
748 standard_options(transport);
750 if (flags & TRANSPORT_PUSH_DRY_RUN) {
751 if (set_helper_option(transport, "dry-run", "true") != 0)
752 die("helper %s does not support dry-run", data->name);
755 strbuf_addch(&buf, '\n');
756 sendline(data, &buf);
757 strbuf_release(&buf);
759 push_update_refs_status(data, remote_refs);
760 return 0;
763 static int push_refs_with_export(struct transport *transport,
764 struct ref *remote_refs, int flags)
766 struct ref *ref;
767 struct child_process *helper, exporter;
768 struct helper_data *data = transport->data;
769 struct string_list revlist_args = STRING_LIST_INIT_NODUP;
770 struct strbuf buf = STRBUF_INIT;
772 helper = get_helper(transport);
774 write_constant(helper->in, "export\n");
776 strbuf_reset(&buf);
778 for (ref = remote_refs; ref; ref = ref->next) {
779 char *private;
780 unsigned char sha1[20];
782 if (!data->refspecs)
783 continue;
784 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
785 if (private && !get_sha1(private, sha1)) {
786 strbuf_addf(&buf, "^%s", private);
787 string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
789 free(private);
791 if (ref->deletion) {
792 die("remote-helpers do not support ref deletion");
795 if (ref->peer_ref)
796 string_list_append(&revlist_args, ref->peer_ref->name);
800 if (get_exporter(transport, &exporter, &revlist_args))
801 die("Couldn't run fast-export");
803 if (finish_command(&exporter))
804 die("Error while running fast-export");
805 push_update_refs_status(data, remote_refs);
806 return 0;
809 static int push_refs(struct transport *transport,
810 struct ref *remote_refs, int flags)
812 struct helper_data *data = transport->data;
814 if (process_connect(transport, 1)) {
815 do_take_over(transport);
816 return transport->push_refs(transport, remote_refs, flags);
819 if (!remote_refs) {
820 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
821 "Perhaps you should specify a branch such as 'master'.\n");
822 return 0;
825 if (data->push)
826 return push_refs_with_push(transport, remote_refs, flags);
828 if (data->export)
829 return push_refs_with_export(transport, remote_refs, flags);
831 return -1;
835 static int has_attribute(const char *attrs, const char *attr) {
836 int len;
837 if (!attrs)
838 return 0;
840 len = strlen(attr);
841 for (;;) {
842 const char *space = strchrnul(attrs, ' ');
843 if (len == space - attrs && !strncmp(attrs, attr, len))
844 return 1;
845 if (!*space)
846 return 0;
847 attrs = space + 1;
851 static struct ref *get_refs_list(struct transport *transport, int for_push)
853 struct helper_data *data = transport->data;
854 struct child_process *helper;
855 struct ref *ret = NULL;
856 struct ref **tail = &ret;
857 struct ref *posn;
858 struct strbuf buf = STRBUF_INIT;
860 helper = get_helper(transport);
862 if (process_connect(transport, for_push)) {
863 do_take_over(transport);
864 return transport->get_refs_list(transport, for_push);
867 if (data->push && for_push)
868 write_str_in_full(helper->in, "list for-push\n");
869 else
870 write_str_in_full(helper->in, "list\n");
872 while (1) {
873 char *eov, *eon;
874 recvline(data, &buf);
876 if (!*buf.buf)
877 break;
879 eov = strchr(buf.buf, ' ');
880 if (!eov)
881 die("Malformed response in ref list: %s", buf.buf);
882 eon = strchr(eov + 1, ' ');
883 *eov = '\0';
884 if (eon)
885 *eon = '\0';
886 *tail = alloc_ref(eov + 1);
887 if (buf.buf[0] == '@')
888 (*tail)->symref = xstrdup(buf.buf + 1);
889 else if (buf.buf[0] != '?')
890 get_sha1_hex(buf.buf, (*tail)->old_sha1);
891 if (eon) {
892 if (has_attribute(eon + 1, "unchanged")) {
893 (*tail)->status |= REF_STATUS_UPTODATE;
894 read_ref((*tail)->name, (*tail)->old_sha1);
897 tail = &((*tail)->next);
899 if (debug)
900 fprintf(stderr, "Debug: Read ref listing.\n");
901 strbuf_release(&buf);
903 for (posn = ret; posn; posn = posn->next)
904 resolve_remote_symref(posn, ret);
906 return ret;
909 int transport_helper_init(struct transport *transport, const char *name)
911 struct helper_data *data = xcalloc(sizeof(*data), 1);
912 data->name = name;
914 if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
915 debug = 1;
917 transport->data = data;
918 transport->set_option = set_helper_option;
919 transport->get_refs_list = get_refs_list;
920 transport->fetch = fetch;
921 transport->push_refs = push_refs;
922 transport->disconnect = release_helper;
923 transport->connect = connect_helper;
924 transport->smart_options = &(data->transport_options);
925 return 0;
929 * Linux pipes can buffer 65536 bytes at once (and most platforms can
930 * buffer less), so attempt reads and writes with up to that size.
932 #define BUFFERSIZE 65536
933 /* This should be enough to hold debugging message. */
934 #define PBUFFERSIZE 8192
936 /* Print bidirectional transfer loop debug message. */
937 static void transfer_debug(const char *fmt, ...)
939 va_list args;
940 char msgbuf[PBUFFERSIZE];
941 static int debug_enabled = -1;
943 if (debug_enabled < 0)
944 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
945 if (!debug_enabled)
946 return;
948 va_start(args, fmt);
949 vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
950 va_end(args);
951 fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
954 /* Stream state: More data may be coming in this direction. */
955 #define SSTATE_TRANSFERING 0
957 * Stream state: No more data coming in this direction, flushing rest of
958 * data.
960 #define SSTATE_FLUSHING 1
961 /* Stream state: Transfer in this direction finished. */
962 #define SSTATE_FINISHED 2
964 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
965 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
966 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
968 /* Unidirectional transfer. */
969 struct unidirectional_transfer {
970 /* Source */
971 int src;
972 /* Destination */
973 int dest;
974 /* Is source socket? */
975 int src_is_sock;
976 /* Is destination socket? */
977 int dest_is_sock;
978 /* Transfer state (TRANSFERING/FLUSHING/FINISHED) */
979 int state;
980 /* Buffer. */
981 char buf[BUFFERSIZE];
982 /* Buffer used. */
983 size_t bufuse;
984 /* Name of source. */
985 const char *src_name;
986 /* Name of destination. */
987 const char *dest_name;
990 /* Closes the target (for writing) if transfer has finished. */
991 static void udt_close_if_finished(struct unidirectional_transfer *t)
993 if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
994 t->state = SSTATE_FINISHED;
995 if (t->dest_is_sock)
996 shutdown(t->dest, SHUT_WR);
997 else
998 close(t->dest);
999 transfer_debug("Closed %s.", t->dest_name);
1004 * Tries to read read data from source into buffer. If buffer is full,
1005 * no data is read. Returns 0 on success, -1 on error.
1007 static int udt_do_read(struct unidirectional_transfer *t)
1009 ssize_t bytes;
1011 if (t->bufuse == BUFFERSIZE)
1012 return 0; /* No space for more. */
1014 transfer_debug("%s is readable", t->src_name);
1015 bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1016 if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1017 errno != EINTR) {
1018 error("read(%s) failed: %s", t->src_name, strerror(errno));
1019 return -1;
1020 } else if (bytes == 0) {
1021 transfer_debug("%s EOF (with %i bytes in buffer)",
1022 t->src_name, t->bufuse);
1023 t->state = SSTATE_FLUSHING;
1024 } else if (bytes > 0) {
1025 t->bufuse += bytes;
1026 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1027 (int)bytes, t->src_name, (int)t->bufuse);
1029 return 0;
1032 /* Tries to write data from buffer into destination. If buffer is empty,
1033 * no data is written. Returns 0 on success, -1 on error.
1035 static int udt_do_write(struct unidirectional_transfer *t)
1037 ssize_t bytes;
1039 if (t->bufuse == 0)
1040 return 0; /* Nothing to write. */
1042 transfer_debug("%s is writable", t->dest_name);
1043 bytes = write(t->dest, t->buf, t->bufuse);
1044 if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1045 errno != EINTR) {
1046 error("write(%s) failed: %s", t->dest_name, strerror(errno));
1047 return -1;
1048 } else if (bytes > 0) {
1049 t->bufuse -= bytes;
1050 if (t->bufuse)
1051 memmove(t->buf, t->buf + bytes, t->bufuse);
1052 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1053 (int)bytes, t->dest_name, (int)t->bufuse);
1055 return 0;
1059 /* State of bidirectional transfer loop. */
1060 struct bidirectional_transfer_state {
1061 /* Direction from program to git. */
1062 struct unidirectional_transfer ptg;
1063 /* Direction from git to program. */
1064 struct unidirectional_transfer gtp;
1067 static void *udt_copy_task_routine(void *udt)
1069 struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1070 while (t->state != SSTATE_FINISHED) {
1071 if (STATE_NEEDS_READING(t->state))
1072 if (udt_do_read(t))
1073 return NULL;
1074 if (STATE_NEEDS_WRITING(t->state))
1075 if (udt_do_write(t))
1076 return NULL;
1077 if (STATE_NEEDS_CLOSING(t->state))
1078 udt_close_if_finished(t);
1080 return udt; /* Just some non-NULL value. */
1083 #ifndef NO_PTHREADS
1086 * Join thread, with apporiate errors on failure. Name is name for the
1087 * thread (for error messages). Returns 0 on success, 1 on failure.
1089 static int tloop_join(pthread_t thread, const char *name)
1091 int err;
1092 void *tret;
1093 err = pthread_join(thread, &tret);
1094 if (!tret) {
1095 error("%s thread failed", name);
1096 return 1;
1098 if (err) {
1099 error("%s thread failed to join: %s", name, strerror(err));
1100 return 1;
1102 return 0;
1106 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1107 * -1 on failure.
1109 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1111 pthread_t gtp_thread;
1112 pthread_t ptg_thread;
1113 int err;
1114 int ret = 0;
1115 err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1116 &s->gtp);
1117 if (err)
1118 die("Can't start thread for copying data: %s", strerror(err));
1119 err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1120 &s->ptg);
1121 if (err)
1122 die("Can't start thread for copying data: %s", strerror(err));
1124 ret |= tloop_join(gtp_thread, "Git to program copy");
1125 ret |= tloop_join(ptg_thread, "Program to git copy");
1126 return ret;
1128 #else
1130 /* Close the source and target (for writing) for transfer. */
1131 static void udt_kill_transfer(struct unidirectional_transfer *t)
1133 t->state = SSTATE_FINISHED;
1135 * Socket read end left open isn't a disaster if nobody
1136 * attempts to read from it (mingw compat headers do not
1137 * have SHUT_RD)...
1139 * We can't fully close the socket since otherwise gtp
1140 * task would first close the socket it sends data to
1141 * while closing the ptg file descriptors.
1143 if (!t->src_is_sock)
1144 close(t->src);
1145 if (t->dest_is_sock)
1146 shutdown(t->dest, SHUT_WR);
1147 else
1148 close(t->dest);
1152 * Join process, with apporiate errors on failure. Name is name for the
1153 * process (for error messages). Returns 0 on success, 1 on failure.
1155 static int tloop_join(pid_t pid, const char *name)
1157 int tret;
1158 if (waitpid(pid, &tret, 0) < 0) {
1159 error("%s process failed to wait: %s", name, strerror(errno));
1160 return 1;
1162 if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1163 error("%s process failed", name);
1164 return 1;
1166 return 0;
1170 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1171 * -1 on failure.
1173 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1175 pid_t pid1, pid2;
1176 int ret = 0;
1178 /* Fork thread #1: git to program. */
1179 pid1 = fork();
1180 if (pid1 < 0)
1181 die_errno("Can't start thread for copying data");
1182 else if (pid1 == 0) {
1183 udt_kill_transfer(&s->ptg);
1184 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1187 /* Fork thread #2: program to git. */
1188 pid2 = fork();
1189 if (pid2 < 0)
1190 die_errno("Can't start thread for copying data");
1191 else if (pid2 == 0) {
1192 udt_kill_transfer(&s->gtp);
1193 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1197 * Close both streams in parent as to not interfere with
1198 * end of file detection and wait for both tasks to finish.
1200 udt_kill_transfer(&s->gtp);
1201 udt_kill_transfer(&s->ptg);
1202 ret |= tloop_join(pid1, "Git to program copy");
1203 ret |= tloop_join(pid2, "Program to git copy");
1204 return ret;
1206 #endif
1209 * Copies data from stdin to output and from input to stdout simultaneously.
1210 * Additionally filtering through given filter. If filter is NULL, uses
1211 * identity filter.
1213 int bidirectional_transfer_loop(int input, int output)
1215 struct bidirectional_transfer_state state;
1217 /* Fill the state fields. */
1218 state.ptg.src = input;
1219 state.ptg.dest = 1;
1220 state.ptg.src_is_sock = (input == output);
1221 state.ptg.dest_is_sock = 0;
1222 state.ptg.state = SSTATE_TRANSFERING;
1223 state.ptg.bufuse = 0;
1224 state.ptg.src_name = "remote input";
1225 state.ptg.dest_name = "stdout";
1227 state.gtp.src = 0;
1228 state.gtp.dest = output;
1229 state.gtp.src_is_sock = 0;
1230 state.gtp.dest_is_sock = (input == output);
1231 state.gtp.state = SSTATE_TRANSFERING;
1232 state.gtp.bufuse = 0;
1233 state.gtp.src_name = "stdin";
1234 state.gtp.dest_name = "remote output";
1236 return tloop_spawnwait_tasks(&state);