builtin rebase: actions require a rebase in progress
[git] / transport.c
1 #include "cache.h"
2 #include "config.h"
3 #include "transport.h"
4 #include "run-command.h"
5 #include "pkt-line.h"
6 #include "fetch-pack.h"
7 #include "remote.h"
8 #include "connect.h"
9 #include "send-pack.h"
10 #include "walker.h"
11 #include "bundle.h"
12 #include "dir.h"
13 #include "refs.h"
14 #include "refspec.h"
15 #include "branch.h"
16 #include "url.h"
17 #include "submodule.h"
18 #include "string-list.h"
19 #include "sha1-array.h"
20 #include "sigchain.h"
21 #include "transport-internal.h"
22 #include "protocol.h"
23 #include "object-store.h"
24 #include "color.h"
25
26 static int transport_use_color = -1;
27 static char transport_colors[][COLOR_MAXLEN] = {
28         GIT_COLOR_RESET,
29         GIT_COLOR_RED           /* REJECTED */
30 };
31
32 enum color_transport {
33         TRANSPORT_COLOR_RESET = 0,
34         TRANSPORT_COLOR_REJECTED = 1
35 };
36
37 static int transport_color_config(void)
38 {
39         const char *keys[] = {
40                 "color.transport.reset",
41                 "color.transport.rejected"
42         }, *key = "color.transport";
43         char *value;
44         int i;
45         static int initialized;
46
47         if (initialized)
48                 return 0;
49         initialized = 1;
50
51         if (!git_config_get_string(key, &value))
52                 transport_use_color = git_config_colorbool(key, value);
53
54         if (!want_color_stderr(transport_use_color))
55                 return 0;
56
57         for (i = 0; i < ARRAY_SIZE(keys); i++)
58                 if (!git_config_get_string(keys[i], &value)) {
59                         if (!value)
60                                 return config_error_nonbool(keys[i]);
61                         if (color_parse(value, transport_colors[i]) < 0)
62                                 return -1;
63                 }
64
65         return 0;
66 }
67
68 static const char *transport_get_color(enum color_transport ix)
69 {
70         if (want_color_stderr(transport_use_color))
71                 return transport_colors[ix];
72         return "";
73 }
74
75 static void set_upstreams(struct transport *transport, struct ref *refs,
76         int pretend)
77 {
78         struct ref *ref;
79         for (ref = refs; ref; ref = ref->next) {
80                 const char *localname;
81                 const char *tmp;
82                 const char *remotename;
83                 int flag = 0;
84                 /*
85                  * Check suitability for tracking. Must be successful /
86                  * already up-to-date ref create/modify (not delete).
87                  */
88                 if (ref->status != REF_STATUS_OK &&
89                         ref->status != REF_STATUS_UPTODATE)
90                         continue;
91                 if (!ref->peer_ref)
92                         continue;
93                 if (is_null_oid(&ref->new_oid))
94                         continue;
95
96                 /* Follow symbolic refs (mainly for HEAD). */
97                 localname = ref->peer_ref->name;
98                 remotename = ref->name;
99                 tmp = resolve_ref_unsafe(localname, RESOLVE_REF_READING,
100                                          NULL, &flag);
101                 if (tmp && flag & REF_ISSYMREF &&
102                         starts_with(tmp, "refs/heads/"))
103                         localname = tmp;
104
105                 /* Both source and destination must be local branches. */
106                 if (!localname || !starts_with(localname, "refs/heads/"))
107                         continue;
108                 if (!remotename || !starts_with(remotename, "refs/heads/"))
109                         continue;
110
111                 if (!pretend)
112                         install_branch_config(BRANCH_CONFIG_VERBOSE,
113                                 localname + 11, transport->remote->name,
114                                 remotename);
115                 else
116                         printf(_("Would set upstream of '%s' to '%s' of '%s'\n"),
117                                 localname + 11, remotename + 11,
118                                 transport->remote->name);
119         }
120 }
121
122 struct bundle_transport_data {
123         int fd;
124         struct bundle_header header;
125 };
126
127 static struct ref *get_refs_from_bundle(struct transport *transport,
128                                         int for_push,
129                                         const struct argv_array *ref_prefixes)
130 {
131         struct bundle_transport_data *data = transport->data;
132         struct ref *result = NULL;
133         int i;
134
135         if (for_push)
136                 return NULL;
137
138         if (data->fd > 0)
139                 close(data->fd);
140         data->fd = read_bundle_header(transport->url, &data->header);
141         if (data->fd < 0)
142                 die ("Could not read bundle '%s'.", transport->url);
143         for (i = 0; i < data->header.references.nr; i++) {
144                 struct ref_list_entry *e = data->header.references.list + i;
145                 struct ref *ref = alloc_ref(e->name);
146                 oidcpy(&ref->old_oid, &e->oid);
147                 ref->next = result;
148                 result = ref;
149         }
150         return result;
151 }
152
153 static int fetch_refs_from_bundle(struct transport *transport,
154                                int nr_heads, struct ref **to_fetch,
155                                struct ref **fetched_refs)
156 {
157         struct bundle_transport_data *data = transport->data;
158         return unbundle(&data->header, data->fd,
159                         transport->progress ? BUNDLE_VERBOSE : 0);
160 }
161
162 static int close_bundle(struct transport *transport)
163 {
164         struct bundle_transport_data *data = transport->data;
165         if (data->fd > 0)
166                 close(data->fd);
167         free(data);
168         return 0;
169 }
170
171 struct git_transport_data {
172         struct git_transport_options options;
173         struct child_process *conn;
174         int fd[2];
175         unsigned got_remote_heads : 1;
176         enum protocol_version version;
177         struct oid_array extra_have;
178         struct oid_array shallow;
179 };
180
181 static int set_git_option(struct git_transport_options *opts,
182                           const char *name, const char *value)
183 {
184         if (!strcmp(name, TRANS_OPT_UPLOADPACK)) {
185                 opts->uploadpack = value;
186                 return 0;
187         } else if (!strcmp(name, TRANS_OPT_RECEIVEPACK)) {
188                 opts->receivepack = value;
189                 return 0;
190         } else if (!strcmp(name, TRANS_OPT_THIN)) {
191                 opts->thin = !!value;
192                 return 0;
193         } else if (!strcmp(name, TRANS_OPT_FOLLOWTAGS)) {
194                 opts->followtags = !!value;
195                 return 0;
196         } else if (!strcmp(name, TRANS_OPT_KEEP)) {
197                 opts->keep = !!value;
198                 return 0;
199         } else if (!strcmp(name, TRANS_OPT_UPDATE_SHALLOW)) {
200                 opts->update_shallow = !!value;
201                 return 0;
202         } else if (!strcmp(name, TRANS_OPT_DEPTH)) {
203                 if (!value)
204                         opts->depth = 0;
205                 else {
206                         char *end;
207                         opts->depth = strtol(value, &end, 0);
208                         if (*end)
209                                 die(_("transport: invalid depth option '%s'"), value);
210                 }
211                 return 0;
212         } else if (!strcmp(name, TRANS_OPT_DEEPEN_SINCE)) {
213                 opts->deepen_since = value;
214                 return 0;
215         } else if (!strcmp(name, TRANS_OPT_DEEPEN_NOT)) {
216                 opts->deepen_not = (const struct string_list *)value;
217                 return 0;
218         } else if (!strcmp(name, TRANS_OPT_DEEPEN_RELATIVE)) {
219                 opts->deepen_relative = !!value;
220                 return 0;
221         } else if (!strcmp(name, TRANS_OPT_FROM_PROMISOR)) {
222                 opts->from_promisor = !!value;
223                 return 0;
224         } else if (!strcmp(name, TRANS_OPT_NO_DEPENDENTS)) {
225                 opts->no_dependents = !!value;
226                 return 0;
227         } else if (!strcmp(name, TRANS_OPT_LIST_OBJECTS_FILTER)) {
228                 parse_list_objects_filter(&opts->filter_options, value);
229                 return 0;
230         }
231         return 1;
232 }
233
234 static int connect_setup(struct transport *transport, int for_push)
235 {
236         struct git_transport_data *data = transport->data;
237         int flags = transport->verbose > 0 ? CONNECT_VERBOSE : 0;
238
239         if (data->conn)
240                 return 0;
241
242         switch (transport->family) {
243         case TRANSPORT_FAMILY_ALL: break;
244         case TRANSPORT_FAMILY_IPV4: flags |= CONNECT_IPV4; break;
245         case TRANSPORT_FAMILY_IPV6: flags |= CONNECT_IPV6; break;
246         }
247
248         data->conn = git_connect(data->fd, transport->url,
249                                  for_push ? data->options.receivepack :
250                                  data->options.uploadpack,
251                                  flags);
252
253         return 0;
254 }
255
256 static struct ref *get_refs_via_connect(struct transport *transport, int for_push,
257                                         const struct argv_array *ref_prefixes)
258 {
259         struct git_transport_data *data = transport->data;
260         struct ref *refs = NULL;
261         struct packet_reader reader;
262
263         connect_setup(transport, for_push);
264
265         packet_reader_init(&reader, data->fd[0], NULL, 0,
266                            PACKET_READ_CHOMP_NEWLINE |
267                            PACKET_READ_GENTLE_ON_EOF);
268
269         data->version = discover_version(&reader);
270         switch (data->version) {
271         case protocol_v2:
272                 get_remote_refs(data->fd[1], &reader, &refs, for_push,
273                                 ref_prefixes, transport->server_options);
274                 break;
275         case protocol_v1:
276         case protocol_v0:
277                 get_remote_heads(&reader, &refs,
278                                  for_push ? REF_NORMAL : 0,
279                                  &data->extra_have,
280                                  &data->shallow);
281                 break;
282         case protocol_unknown_version:
283                 BUG("unknown protocol version");
284         }
285         data->got_remote_heads = 1;
286
287         return refs;
288 }
289
290 static int fetch_refs_via_pack(struct transport *transport,
291                                int nr_heads, struct ref **to_fetch,
292                                struct ref **fetched_refs)
293 {
294         int ret = 0;
295         struct git_transport_data *data = transport->data;
296         struct ref *refs = NULL;
297         char *dest = xstrdup(transport->url);
298         struct fetch_pack_args args;
299         struct ref *refs_tmp = NULL;
300
301         memset(&args, 0, sizeof(args));
302         args.uploadpack = data->options.uploadpack;
303         args.keep_pack = data->options.keep;
304         args.lock_pack = 1;
305         args.use_thin_pack = data->options.thin;
306         args.include_tag = data->options.followtags;
307         args.verbose = (transport->verbose > 1);
308         args.quiet = (transport->verbose < 0);
309         args.no_progress = !transport->progress;
310         args.depth = data->options.depth;
311         args.deepen_since = data->options.deepen_since;
312         args.deepen_not = data->options.deepen_not;
313         args.deepen_relative = data->options.deepen_relative;
314         args.check_self_contained_and_connected =
315                 data->options.check_self_contained_and_connected;
316         args.cloning = transport->cloning;
317         args.update_shallow = data->options.update_shallow;
318         args.from_promisor = data->options.from_promisor;
319         args.no_dependents = data->options.no_dependents;
320         args.filter_options = data->options.filter_options;
321         args.stateless_rpc = transport->stateless_rpc;
322         args.server_options = transport->server_options;
323         args.negotiation_tips = data->options.negotiation_tips;
324
325         if (!data->got_remote_heads)
326                 refs_tmp = get_refs_via_connect(transport, 0, NULL);
327
328         switch (data->version) {
329         case protocol_v2:
330                 refs = fetch_pack(&args, data->fd, data->conn,
331                                   refs_tmp ? refs_tmp : transport->remote_refs,
332                                   dest, to_fetch, nr_heads, &data->shallow,
333                                   &transport->pack_lockfile, data->version);
334                 break;
335         case protocol_v1:
336         case protocol_v0:
337                 refs = fetch_pack(&args, data->fd, data->conn,
338                                   refs_tmp ? refs_tmp : transport->remote_refs,
339                                   dest, to_fetch, nr_heads, &data->shallow,
340                                   &transport->pack_lockfile, data->version);
341                 break;
342         case protocol_unknown_version:
343                 BUG("unknown protocol version");
344         }
345
346         close(data->fd[0]);
347         close(data->fd[1]);
348         if (finish_connect(data->conn))
349                 ret = -1;
350         data->conn = NULL;
351         data->got_remote_heads = 0;
352         data->options.self_contained_and_connected =
353                 args.self_contained_and_connected;
354         data->options.connectivity_checked = args.connectivity_checked;
355
356         if (refs == NULL)
357                 ret = -1;
358         if (report_unmatched_refs(to_fetch, nr_heads))
359                 ret = -1;
360
361         if (fetched_refs)
362                 *fetched_refs = refs;
363         else
364                 free_refs(refs);
365
366         free_refs(refs_tmp);
367         free(dest);
368         return ret;
369 }
370
371 static int push_had_errors(struct ref *ref)
372 {
373         for (; ref; ref = ref->next) {
374                 switch (ref->status) {
375                 case REF_STATUS_NONE:
376                 case REF_STATUS_UPTODATE:
377                 case REF_STATUS_OK:
378                         break;
379                 default:
380                         return 1;
381                 }
382         }
383         return 0;
384 }
385
386 int transport_refs_pushed(struct ref *ref)
387 {
388         for (; ref; ref = ref->next) {
389                 switch(ref->status) {
390                 case REF_STATUS_NONE:
391                 case REF_STATUS_UPTODATE:
392                         break;
393                 default:
394                         return 1;
395                 }
396         }
397         return 0;
398 }
399
400 void transport_update_tracking_ref(struct remote *remote, struct ref *ref, int verbose)
401 {
402         struct refspec_item rs;
403
404         if (ref->status != REF_STATUS_OK && ref->status != REF_STATUS_UPTODATE)
405                 return;
406
407         rs.src = ref->name;
408         rs.dst = NULL;
409
410         if (!remote_find_tracking(remote, &rs)) {
411                 if (verbose)
412                         fprintf(stderr, "updating local tracking ref '%s'\n", rs.dst);
413                 if (ref->deletion) {
414                         delete_ref(NULL, rs.dst, NULL, 0);
415                 } else
416                         update_ref("update by push", rs.dst, &ref->new_oid,
417                                    NULL, 0, 0);
418                 free(rs.dst);
419         }
420 }
421
422 static void print_ref_status(char flag, const char *summary,
423                              struct ref *to, struct ref *from, const char *msg,
424                              int porcelain, int summary_width)
425 {
426         if (porcelain) {
427                 if (from)
428                         fprintf(stdout, "%c\t%s:%s\t", flag, from->name, to->name);
429                 else
430                         fprintf(stdout, "%c\t:%s\t", flag, to->name);
431                 if (msg)
432                         fprintf(stdout, "%s (%s)\n", summary, msg);
433                 else
434                         fprintf(stdout, "%s\n", summary);
435         } else {
436                 const char *red = "", *reset = "";
437                 if (push_had_errors(to)) {
438                         red = transport_get_color(TRANSPORT_COLOR_REJECTED);
439                         reset = transport_get_color(TRANSPORT_COLOR_RESET);
440                 }
441                 fprintf(stderr, " %s%c %-*s%s ", red, flag, summary_width,
442                         summary, reset);
443                 if (from)
444                         fprintf(stderr, "%s -> %s", prettify_refname(from->name), prettify_refname(to->name));
445                 else
446                         fputs(prettify_refname(to->name), stderr);
447                 if (msg) {
448                         fputs(" (", stderr);
449                         fputs(msg, stderr);
450                         fputc(')', stderr);
451                 }
452                 fputc('\n', stderr);
453         }
454 }
455
456 static void print_ok_ref_status(struct ref *ref, int porcelain, int summary_width)
457 {
458         if (ref->deletion)
459                 print_ref_status('-', "[deleted]", ref, NULL, NULL,
460                                  porcelain, summary_width);
461         else if (is_null_oid(&ref->old_oid))
462                 print_ref_status('*',
463                         (starts_with(ref->name, "refs/tags/") ? "[new tag]" :
464                         "[new branch]"),
465                         ref, ref->peer_ref, NULL, porcelain, summary_width);
466         else {
467                 struct strbuf quickref = STRBUF_INIT;
468                 char type;
469                 const char *msg;
470
471                 strbuf_add_unique_abbrev(&quickref, &ref->old_oid,
472                                          DEFAULT_ABBREV);
473                 if (ref->forced_update) {
474                         strbuf_addstr(&quickref, "...");
475                         type = '+';
476                         msg = "forced update";
477                 } else {
478                         strbuf_addstr(&quickref, "..");
479                         type = ' ';
480                         msg = NULL;
481                 }
482                 strbuf_add_unique_abbrev(&quickref, &ref->new_oid,
483                                          DEFAULT_ABBREV);
484
485                 print_ref_status(type, quickref.buf, ref, ref->peer_ref, msg,
486                                  porcelain, summary_width);
487                 strbuf_release(&quickref);
488         }
489 }
490
491 static int print_one_push_status(struct ref *ref, const char *dest, int count,
492                                  int porcelain, int summary_width)
493 {
494         if (!count) {
495                 char *url = transport_anonymize_url(dest);
496                 fprintf(porcelain ? stdout : stderr, "To %s\n", url);
497                 free(url);
498         }
499
500         switch(ref->status) {
501         case REF_STATUS_NONE:
502                 print_ref_status('X', "[no match]", ref, NULL, NULL,
503                                  porcelain, summary_width);
504                 break;
505         case REF_STATUS_REJECT_NODELETE:
506                 print_ref_status('!', "[rejected]", ref, NULL,
507                                  "remote does not support deleting refs",
508                                  porcelain, summary_width);
509                 break;
510         case REF_STATUS_UPTODATE:
511                 print_ref_status('=', "[up to date]", ref,
512                                  ref->peer_ref, NULL, porcelain, summary_width);
513                 break;
514         case REF_STATUS_REJECT_NONFASTFORWARD:
515                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
516                                  "non-fast-forward", porcelain, summary_width);
517                 break;
518         case REF_STATUS_REJECT_ALREADY_EXISTS:
519                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
520                                  "already exists", porcelain, summary_width);
521                 break;
522         case REF_STATUS_REJECT_FETCH_FIRST:
523                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
524                                  "fetch first", porcelain, summary_width);
525                 break;
526         case REF_STATUS_REJECT_NEEDS_FORCE:
527                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
528                                  "needs force", porcelain, summary_width);
529                 break;
530         case REF_STATUS_REJECT_STALE:
531                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
532                                  "stale info", porcelain, summary_width);
533                 break;
534         case REF_STATUS_REJECT_SHALLOW:
535                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
536                                  "new shallow roots not allowed",
537                                  porcelain, summary_width);
538                 break;
539         case REF_STATUS_REMOTE_REJECT:
540                 print_ref_status('!', "[remote rejected]", ref,
541                                  ref->deletion ? NULL : ref->peer_ref,
542                                  ref->remote_status, porcelain, summary_width);
543                 break;
544         case REF_STATUS_EXPECTING_REPORT:
545                 print_ref_status('!', "[remote failure]", ref,
546                                  ref->deletion ? NULL : ref->peer_ref,
547                                  "remote failed to report status",
548                                  porcelain, summary_width);
549                 break;
550         case REF_STATUS_ATOMIC_PUSH_FAILED:
551                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
552                                  "atomic push failed", porcelain, summary_width);
553                 break;
554         case REF_STATUS_OK:
555                 print_ok_ref_status(ref, porcelain, summary_width);
556                 break;
557         }
558
559         return 1;
560 }
561
562 static int measure_abbrev(const struct object_id *oid, int sofar)
563 {
564         char hex[GIT_MAX_HEXSZ + 1];
565         int w = find_unique_abbrev_r(hex, oid, DEFAULT_ABBREV);
566
567         return (w < sofar) ? sofar : w;
568 }
569
570 int transport_summary_width(const struct ref *refs)
571 {
572         int maxw = -1;
573
574         for (; refs; refs = refs->next) {
575                 maxw = measure_abbrev(&refs->old_oid, maxw);
576                 maxw = measure_abbrev(&refs->new_oid, maxw);
577         }
578         if (maxw < 0)
579                 maxw = FALLBACK_DEFAULT_ABBREV;
580         return (2 * maxw + 3);
581 }
582
583 void transport_print_push_status(const char *dest, struct ref *refs,
584                                   int verbose, int porcelain, unsigned int *reject_reasons)
585 {
586         struct ref *ref;
587         int n = 0;
588         char *head;
589         int summary_width = transport_summary_width(refs);
590
591         if (transport_color_config() < 0)
592                 warning(_("could not parse transport.color.* config"));
593
594         head = resolve_refdup("HEAD", RESOLVE_REF_READING, NULL, NULL);
595
596         if (verbose) {
597                 for (ref = refs; ref; ref = ref->next)
598                         if (ref->status == REF_STATUS_UPTODATE)
599                                 n += print_one_push_status(ref, dest, n,
600                                                            porcelain, summary_width);
601         }
602
603         for (ref = refs; ref; ref = ref->next)
604                 if (ref->status == REF_STATUS_OK)
605                         n += print_one_push_status(ref, dest, n,
606                                                    porcelain, summary_width);
607
608         *reject_reasons = 0;
609         for (ref = refs; ref; ref = ref->next) {
610                 if (ref->status != REF_STATUS_NONE &&
611                     ref->status != REF_STATUS_UPTODATE &&
612                     ref->status != REF_STATUS_OK)
613                         n += print_one_push_status(ref, dest, n,
614                                                    porcelain, summary_width);
615                 if (ref->status == REF_STATUS_REJECT_NONFASTFORWARD) {
616                         if (head != NULL && !strcmp(head, ref->name))
617                                 *reject_reasons |= REJECT_NON_FF_HEAD;
618                         else
619                                 *reject_reasons |= REJECT_NON_FF_OTHER;
620                 } else if (ref->status == REF_STATUS_REJECT_ALREADY_EXISTS) {
621                         *reject_reasons |= REJECT_ALREADY_EXISTS;
622                 } else if (ref->status == REF_STATUS_REJECT_FETCH_FIRST) {
623                         *reject_reasons |= REJECT_FETCH_FIRST;
624                 } else if (ref->status == REF_STATUS_REJECT_NEEDS_FORCE) {
625                         *reject_reasons |= REJECT_NEEDS_FORCE;
626                 }
627         }
628         free(head);
629 }
630
631 static int git_transport_push(struct transport *transport, struct ref *remote_refs, int flags)
632 {
633         struct git_transport_data *data = transport->data;
634         struct send_pack_args args;
635         int ret = 0;
636
637         if (transport_color_config() < 0)
638                 return -1;
639
640         if (!data->got_remote_heads)
641                 get_refs_via_connect(transport, 1, NULL);
642
643         memset(&args, 0, sizeof(args));
644         args.send_mirror = !!(flags & TRANSPORT_PUSH_MIRROR);
645         args.force_update = !!(flags & TRANSPORT_PUSH_FORCE);
646         args.use_thin_pack = data->options.thin;
647         args.verbose = (transport->verbose > 0);
648         args.quiet = (transport->verbose < 0);
649         args.progress = transport->progress;
650         args.dry_run = !!(flags & TRANSPORT_PUSH_DRY_RUN);
651         args.porcelain = !!(flags & TRANSPORT_PUSH_PORCELAIN);
652         args.atomic = !!(flags & TRANSPORT_PUSH_ATOMIC);
653         args.push_options = transport->push_options;
654         args.url = transport->url;
655
656         if (flags & TRANSPORT_PUSH_CERT_ALWAYS)
657                 args.push_cert = SEND_PACK_PUSH_CERT_ALWAYS;
658         else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED)
659                 args.push_cert = SEND_PACK_PUSH_CERT_IF_ASKED;
660         else
661                 args.push_cert = SEND_PACK_PUSH_CERT_NEVER;
662
663         switch (data->version) {
664         case protocol_v2:
665                 die("support for protocol v2 not implemented yet");
666                 break;
667         case protocol_v1:
668         case protocol_v0:
669                 ret = send_pack(&args, data->fd, data->conn, remote_refs,
670                                 &data->extra_have);
671                 break;
672         case protocol_unknown_version:
673                 BUG("unknown protocol version");
674         }
675
676         close(data->fd[1]);
677         close(data->fd[0]);
678         ret |= finish_connect(data->conn);
679         data->conn = NULL;
680         data->got_remote_heads = 0;
681
682         return ret;
683 }
684
685 static int connect_git(struct transport *transport, const char *name,
686                        const char *executable, int fd[2])
687 {
688         struct git_transport_data *data = transport->data;
689         data->conn = git_connect(data->fd, transport->url,
690                                  executable, 0);
691         fd[0] = data->fd[0];
692         fd[1] = data->fd[1];
693         return 0;
694 }
695
696 static int disconnect_git(struct transport *transport)
697 {
698         struct git_transport_data *data = transport->data;
699         if (data->conn) {
700                 if (data->got_remote_heads)
701                         packet_flush(data->fd[1]);
702                 close(data->fd[0]);
703                 close(data->fd[1]);
704                 finish_connect(data->conn);
705         }
706
707         free(data);
708         return 0;
709 }
710
711 static struct transport_vtable taken_over_vtable = {
712         NULL,
713         get_refs_via_connect,
714         fetch_refs_via_pack,
715         git_transport_push,
716         NULL,
717         disconnect_git
718 };
719
720 void transport_take_over(struct transport *transport,
721                          struct child_process *child)
722 {
723         struct git_transport_data *data;
724
725         if (!transport->smart_options)
726                 BUG("taking over transport requires non-NULL "
727                     "smart_options field.");
728
729         data = xcalloc(1, sizeof(*data));
730         data->options = *transport->smart_options;
731         data->conn = child;
732         data->fd[0] = data->conn->out;
733         data->fd[1] = data->conn->in;
734         data->got_remote_heads = 0;
735         transport->data = data;
736
737         transport->vtable = &taken_over_vtable;
738         transport->smart_options = &(data->options);
739
740         transport->cannot_reuse = 1;
741 }
742
743 static int is_file(const char *url)
744 {
745         struct stat buf;
746         if (stat(url, &buf))
747                 return 0;
748         return S_ISREG(buf.st_mode);
749 }
750
751 static int external_specification_len(const char *url)
752 {
753         return strchr(url, ':') - url;
754 }
755
756 static const struct string_list *protocol_whitelist(void)
757 {
758         static int enabled = -1;
759         static struct string_list allowed = STRING_LIST_INIT_DUP;
760
761         if (enabled < 0) {
762                 const char *v = getenv("GIT_ALLOW_PROTOCOL");
763                 if (v) {
764                         string_list_split(&allowed, v, ':', -1);
765                         string_list_sort(&allowed);
766                         enabled = 1;
767                 } else {
768                         enabled = 0;
769                 }
770         }
771
772         return enabled ? &allowed : NULL;
773 }
774
775 enum protocol_allow_config {
776         PROTOCOL_ALLOW_NEVER = 0,
777         PROTOCOL_ALLOW_USER_ONLY,
778         PROTOCOL_ALLOW_ALWAYS
779 };
780
781 static enum protocol_allow_config parse_protocol_config(const char *key,
782                                                         const char *value)
783 {
784         if (!strcasecmp(value, "always"))
785                 return PROTOCOL_ALLOW_ALWAYS;
786         else if (!strcasecmp(value, "never"))
787                 return PROTOCOL_ALLOW_NEVER;
788         else if (!strcasecmp(value, "user"))
789                 return PROTOCOL_ALLOW_USER_ONLY;
790
791         die("unknown value for config '%s': %s", key, value);
792 }
793
794 static enum protocol_allow_config get_protocol_config(const char *type)
795 {
796         char *key = xstrfmt("protocol.%s.allow", type);
797         char *value;
798
799         /* first check the per-protocol config */
800         if (!git_config_get_string(key, &value)) {
801                 enum protocol_allow_config ret =
802                         parse_protocol_config(key, value);
803                 free(key);
804                 free(value);
805                 return ret;
806         }
807         free(key);
808
809         /* if defined, fallback to user-defined default for unknown protocols */
810         if (!git_config_get_string("protocol.allow", &value)) {
811                 enum protocol_allow_config ret =
812                         parse_protocol_config("protocol.allow", value);
813                 free(value);
814                 return ret;
815         }
816
817         /* fallback to built-in defaults */
818         /* known safe */
819         if (!strcmp(type, "http") ||
820             !strcmp(type, "https") ||
821             !strcmp(type, "git") ||
822             !strcmp(type, "ssh") ||
823             !strcmp(type, "file"))
824                 return PROTOCOL_ALLOW_ALWAYS;
825
826         /* known scary; err on the side of caution */
827         if (!strcmp(type, "ext"))
828                 return PROTOCOL_ALLOW_NEVER;
829
830         /* unknown; by default let them be used only directly by the user */
831         return PROTOCOL_ALLOW_USER_ONLY;
832 }
833
834 int is_transport_allowed(const char *type, int from_user)
835 {
836         const struct string_list *whitelist = protocol_whitelist();
837         if (whitelist)
838                 return string_list_has_string(whitelist, type);
839
840         switch (get_protocol_config(type)) {
841         case PROTOCOL_ALLOW_ALWAYS:
842                 return 1;
843         case PROTOCOL_ALLOW_NEVER:
844                 return 0;
845         case PROTOCOL_ALLOW_USER_ONLY:
846                 if (from_user < 0)
847                         from_user = git_env_bool("GIT_PROTOCOL_FROM_USER", 1);
848                 return from_user;
849         }
850
851         BUG("invalid protocol_allow_config type");
852 }
853
854 void transport_check_allowed(const char *type)
855 {
856         if (!is_transport_allowed(type, -1))
857                 die("transport '%s' not allowed", type);
858 }
859
860 static struct transport_vtable bundle_vtable = {
861         NULL,
862         get_refs_from_bundle,
863         fetch_refs_from_bundle,
864         NULL,
865         NULL,
866         close_bundle
867 };
868
869 static struct transport_vtable builtin_smart_vtable = {
870         NULL,
871         get_refs_via_connect,
872         fetch_refs_via_pack,
873         git_transport_push,
874         connect_git,
875         disconnect_git
876 };
877
878 struct transport *transport_get(struct remote *remote, const char *url)
879 {
880         const char *helper;
881         struct transport *ret = xcalloc(1, sizeof(*ret));
882
883         ret->progress = isatty(2);
884
885         if (!remote)
886                 die("No remote provided to transport_get()");
887
888         ret->got_remote_refs = 0;
889         ret->remote = remote;
890         helper = remote->foreign_vcs;
891
892         if (!url && remote->url)
893                 url = remote->url[0];
894         ret->url = url;
895
896         /* maybe it is a foreign URL? */
897         if (url) {
898                 const char *p = url;
899
900                 while (is_urlschemechar(p == url, *p))
901                         p++;
902                 if (starts_with(p, "::"))
903                         helper = xstrndup(url, p - url);
904         }
905
906         if (helper) {
907                 transport_helper_init(ret, helper);
908         } else if (starts_with(url, "rsync:")) {
909                 die("git-over-rsync is no longer supported");
910         } else if (url_is_local_not_ssh(url) && is_file(url) && is_bundle(url, 1)) {
911                 struct bundle_transport_data *data = xcalloc(1, sizeof(*data));
912                 transport_check_allowed("file");
913                 ret->data = data;
914                 ret->vtable = &bundle_vtable;
915                 ret->smart_options = NULL;
916         } else if (!is_url(url)
917                 || starts_with(url, "file://")
918                 || starts_with(url, "git://")
919                 || starts_with(url, "ssh://")
920                 || starts_with(url, "git+ssh://") /* deprecated - do not use */
921                 || starts_with(url, "ssh+git://") /* deprecated - do not use */
922                 ) {
923                 /*
924                  * These are builtin smart transports; "allowed" transports
925                  * will be checked individually in git_connect.
926                  */
927                 struct git_transport_data *data = xcalloc(1, sizeof(*data));
928                 ret->data = data;
929                 ret->vtable = &builtin_smart_vtable;
930                 ret->smart_options = &(data->options);
931
932                 data->conn = NULL;
933                 data->got_remote_heads = 0;
934         } else {
935                 /* Unknown protocol in URL. Pass to external handler. */
936                 int len = external_specification_len(url);
937                 char *handler = xmemdupz(url, len);
938                 transport_helper_init(ret, handler);
939         }
940
941         if (ret->smart_options) {
942                 ret->smart_options->thin = 1;
943                 ret->smart_options->uploadpack = "git-upload-pack";
944                 if (remote->uploadpack)
945                         ret->smart_options->uploadpack = remote->uploadpack;
946                 ret->smart_options->receivepack = "git-receive-pack";
947                 if (remote->receivepack)
948                         ret->smart_options->receivepack = remote->receivepack;
949         }
950
951         return ret;
952 }
953
954 int transport_set_option(struct transport *transport,
955                          const char *name, const char *value)
956 {
957         int git_reports = 1, protocol_reports = 1;
958
959         if (transport->smart_options)
960                 git_reports = set_git_option(transport->smart_options,
961                                              name, value);
962
963         if (transport->vtable->set_option)
964                 protocol_reports = transport->vtable->set_option(transport,
965                                                                  name, value);
966
967         /* If either report is 0, report 0 (success). */
968         if (!git_reports || !protocol_reports)
969                 return 0;
970         /* If either reports -1 (invalid value), report -1. */
971         if ((git_reports == -1) || (protocol_reports == -1))
972                 return -1;
973         /* Otherwise if both report unknown, report unknown. */
974         return 1;
975 }
976
977 void transport_set_verbosity(struct transport *transport, int verbosity,
978         int force_progress)
979 {
980         if (verbosity >= 1)
981                 transport->verbose = verbosity <= 3 ? verbosity : 3;
982         if (verbosity < 0)
983                 transport->verbose = -1;
984
985         /**
986          * Rules used to determine whether to report progress (processing aborts
987          * when a rule is satisfied):
988          *
989          *   . Report progress, if force_progress is 1 (ie. --progress).
990          *   . Don't report progress, if force_progress is 0 (ie. --no-progress).
991          *   . Don't report progress, if verbosity < 0 (ie. -q/--quiet ).
992          *   . Report progress if isatty(2) is 1.
993          **/
994         if (force_progress >= 0)
995                 transport->progress = !!force_progress;
996         else
997                 transport->progress = verbosity >= 0 && isatty(2);
998 }
999
1000 static void die_with_unpushed_submodules(struct string_list *needs_pushing)
1001 {
1002         int i;
1003
1004         fprintf(stderr, _("The following submodule paths contain changes that can\n"
1005                         "not be found on any remote:\n"));
1006         for (i = 0; i < needs_pushing->nr; i++)
1007                 fprintf(stderr, "  %s\n", needs_pushing->items[i].string);
1008         fprintf(stderr, _("\nPlease try\n\n"
1009                           "     git push --recurse-submodules=on-demand\n\n"
1010                           "or cd to the path and use\n\n"
1011                           "     git push\n\n"
1012                           "to push them to a remote.\n\n"));
1013
1014         string_list_clear(needs_pushing, 0);
1015
1016         die(_("Aborting."));
1017 }
1018
1019 static int run_pre_push_hook(struct transport *transport,
1020                              struct ref *remote_refs)
1021 {
1022         int ret = 0, x;
1023         struct ref *r;
1024         struct child_process proc = CHILD_PROCESS_INIT;
1025         struct strbuf buf;
1026         const char *argv[4];
1027
1028         if (!(argv[0] = find_hook("pre-push")))
1029                 return 0;
1030
1031         argv[1] = transport->remote->name;
1032         argv[2] = transport->url;
1033         argv[3] = NULL;
1034
1035         proc.argv = argv;
1036         proc.in = -1;
1037
1038         if (start_command(&proc)) {
1039                 finish_command(&proc);
1040                 return -1;
1041         }
1042
1043         sigchain_push(SIGPIPE, SIG_IGN);
1044
1045         strbuf_init(&buf, 256);
1046
1047         for (r = remote_refs; r; r = r->next) {
1048                 if (!r->peer_ref) continue;
1049                 if (r->status == REF_STATUS_REJECT_NONFASTFORWARD) continue;
1050                 if (r->status == REF_STATUS_REJECT_STALE) continue;
1051                 if (r->status == REF_STATUS_UPTODATE) continue;
1052
1053                 strbuf_reset(&buf);
1054                 strbuf_addf( &buf, "%s %s %s %s\n",
1055                          r->peer_ref->name, oid_to_hex(&r->new_oid),
1056                          r->name, oid_to_hex(&r->old_oid));
1057
1058                 if (write_in_full(proc.in, buf.buf, buf.len) < 0) {
1059                         /* We do not mind if a hook does not read all refs. */
1060                         if (errno != EPIPE)
1061                                 ret = -1;
1062                         break;
1063                 }
1064         }
1065
1066         strbuf_release(&buf);
1067
1068         x = close(proc.in);
1069         if (!ret)
1070                 ret = x;
1071
1072         sigchain_pop(SIGPIPE);
1073
1074         x = finish_command(&proc);
1075         if (!ret)
1076                 ret = x;
1077
1078         return ret;
1079 }
1080
1081 int transport_push(struct transport *transport,
1082                    struct refspec *rs, int flags,
1083                    unsigned int *reject_reasons)
1084 {
1085         *reject_reasons = 0;
1086
1087         if (transport_color_config() < 0)
1088                 return -1;
1089
1090         if (transport->vtable->push_refs) {
1091                 struct ref *remote_refs;
1092                 struct ref *local_refs = get_local_heads();
1093                 int match_flags = MATCH_REFS_NONE;
1094                 int verbose = (transport->verbose > 0);
1095                 int quiet = (transport->verbose < 0);
1096                 int porcelain = flags & TRANSPORT_PUSH_PORCELAIN;
1097                 int pretend = flags & TRANSPORT_PUSH_DRY_RUN;
1098                 int push_ret, ret, err;
1099                 struct argv_array ref_prefixes = ARGV_ARRAY_INIT;
1100
1101                 if (check_push_refs(local_refs, rs) < 0)
1102                         return -1;
1103
1104                 refspec_ref_prefixes(rs, &ref_prefixes);
1105
1106                 remote_refs = transport->vtable->get_refs_list(transport, 1,
1107                                                                &ref_prefixes);
1108
1109                 argv_array_clear(&ref_prefixes);
1110
1111                 if (flags & TRANSPORT_PUSH_ALL)
1112                         match_flags |= MATCH_REFS_ALL;
1113                 if (flags & TRANSPORT_PUSH_MIRROR)
1114                         match_flags |= MATCH_REFS_MIRROR;
1115                 if (flags & TRANSPORT_PUSH_PRUNE)
1116                         match_flags |= MATCH_REFS_PRUNE;
1117                 if (flags & TRANSPORT_PUSH_FOLLOW_TAGS)
1118                         match_flags |= MATCH_REFS_FOLLOW_TAGS;
1119
1120                 if (match_push_refs(local_refs, &remote_refs, rs, match_flags))
1121                         return -1;
1122
1123                 if (transport->smart_options &&
1124                     transport->smart_options->cas &&
1125                     !is_empty_cas(transport->smart_options->cas))
1126                         apply_push_cas(transport->smart_options->cas,
1127                                        transport->remote, remote_refs);
1128
1129                 set_ref_status_for_push(remote_refs,
1130                         flags & TRANSPORT_PUSH_MIRROR,
1131                         flags & TRANSPORT_PUSH_FORCE);
1132
1133                 if (!(flags & TRANSPORT_PUSH_NO_HOOK))
1134                         if (run_pre_push_hook(transport, remote_refs))
1135                                 return -1;
1136
1137                 if ((flags & (TRANSPORT_RECURSE_SUBMODULES_ON_DEMAND |
1138                               TRANSPORT_RECURSE_SUBMODULES_ONLY)) &&
1139                     !is_bare_repository()) {
1140                         struct ref *ref = remote_refs;
1141                         struct oid_array commits = OID_ARRAY_INIT;
1142
1143                         for (; ref; ref = ref->next)
1144                                 if (!is_null_oid(&ref->new_oid))
1145                                         oid_array_append(&commits,
1146                                                           &ref->new_oid);
1147
1148                         if (!push_unpushed_submodules(&commits,
1149                                                       transport->remote,
1150                                                       rs,
1151                                                       transport->push_options,
1152                                                       pretend)) {
1153                                 oid_array_clear(&commits);
1154                                 die("Failed to push all needed submodules!");
1155                         }
1156                         oid_array_clear(&commits);
1157                 }
1158
1159                 if (((flags & TRANSPORT_RECURSE_SUBMODULES_CHECK) ||
1160                      ((flags & (TRANSPORT_RECURSE_SUBMODULES_ON_DEMAND |
1161                                 TRANSPORT_RECURSE_SUBMODULES_ONLY)) &&
1162                       !pretend)) && !is_bare_repository()) {
1163                         struct ref *ref = remote_refs;
1164                         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
1165                         struct oid_array commits = OID_ARRAY_INIT;
1166
1167                         for (; ref; ref = ref->next)
1168                                 if (!is_null_oid(&ref->new_oid))
1169                                         oid_array_append(&commits,
1170                                                           &ref->new_oid);
1171
1172                         if (find_unpushed_submodules(&commits, transport->remote->name,
1173                                                 &needs_pushing)) {
1174                                 oid_array_clear(&commits);
1175                                 die_with_unpushed_submodules(&needs_pushing);
1176                         }
1177                         string_list_clear(&needs_pushing, 0);
1178                         oid_array_clear(&commits);
1179                 }
1180
1181                 if (!(flags & TRANSPORT_RECURSE_SUBMODULES_ONLY))
1182                         push_ret = transport->vtable->push_refs(transport, remote_refs, flags);
1183                 else
1184                         push_ret = 0;
1185                 err = push_had_errors(remote_refs);
1186                 ret = push_ret | err;
1187
1188                 if (!quiet || err)
1189                         transport_print_push_status(transport->url, remote_refs,
1190                                         verbose | porcelain, porcelain,
1191                                         reject_reasons);
1192
1193                 if (flags & TRANSPORT_PUSH_SET_UPSTREAM)
1194                         set_upstreams(transport, remote_refs, pretend);
1195
1196                 if (!(flags & (TRANSPORT_PUSH_DRY_RUN |
1197                                TRANSPORT_RECURSE_SUBMODULES_ONLY))) {
1198                         struct ref *ref;
1199                         for (ref = remote_refs; ref; ref = ref->next)
1200                                 transport_update_tracking_ref(transport->remote, ref, verbose);
1201                 }
1202
1203                 if (porcelain && !push_ret)
1204                         puts("Done");
1205                 else if (!quiet && !ret && !transport_refs_pushed(remote_refs))
1206                         fprintf(stderr, "Everything up-to-date\n");
1207
1208                 return ret;
1209         }
1210         return 1;
1211 }
1212
1213 const struct ref *transport_get_remote_refs(struct transport *transport,
1214                                             const struct argv_array *ref_prefixes)
1215 {
1216         if (!transport->got_remote_refs) {
1217                 transport->remote_refs =
1218                         transport->vtable->get_refs_list(transport, 0,
1219                                                          ref_prefixes);
1220                 transport->got_remote_refs = 1;
1221         }
1222
1223         return transport->remote_refs;
1224 }
1225
1226 int transport_fetch_refs(struct transport *transport, struct ref *refs,
1227                          struct ref **fetched_refs)
1228 {
1229         int rc;
1230         int nr_heads = 0, nr_alloc = 0, nr_refs = 0;
1231         struct ref **heads = NULL;
1232         struct ref *nop_head = NULL, **nop_tail = &nop_head;
1233         struct ref *rm;
1234
1235         for (rm = refs; rm; rm = rm->next) {
1236                 nr_refs++;
1237                 if (rm->peer_ref &&
1238                     !is_null_oid(&rm->old_oid) &&
1239                     !oidcmp(&rm->peer_ref->old_oid, &rm->old_oid)) {
1240                         /*
1241                          * These need to be reported as fetched, but we don't
1242                          * actually need to fetch them.
1243                          */
1244                         if (fetched_refs) {
1245                                 struct ref *nop_ref = copy_ref(rm);
1246                                 *nop_tail = nop_ref;
1247                                 nop_tail = &nop_ref->next;
1248                         }
1249                         continue;
1250                 }
1251                 ALLOC_GROW(heads, nr_heads + 1, nr_alloc);
1252                 heads[nr_heads++] = rm;
1253         }
1254
1255         if (!nr_heads) {
1256                 /*
1257                  * When deepening of a shallow repository is requested,
1258                  * then local and remote refs are likely to still be equal.
1259                  * Just feed them all to the fetch method in that case.
1260                  * This condition shouldn't be met in a non-deepening fetch
1261                  * (see builtin/fetch.c:quickfetch()).
1262                  */
1263                 ALLOC_ARRAY(heads, nr_refs);
1264                 for (rm = refs; rm; rm = rm->next)
1265                         heads[nr_heads++] = rm;
1266         }
1267
1268         rc = transport->vtable->fetch(transport, nr_heads, heads, fetched_refs);
1269         if (fetched_refs && nop_head) {
1270                 *nop_tail = *fetched_refs;
1271                 *fetched_refs = nop_head;
1272         }
1273
1274         free(heads);
1275         return rc;
1276 }
1277
1278 void transport_unlock_pack(struct transport *transport)
1279 {
1280         if (transport->pack_lockfile) {
1281                 unlink_or_warn(transport->pack_lockfile);
1282                 FREE_AND_NULL(transport->pack_lockfile);
1283         }
1284 }
1285
1286 int transport_connect(struct transport *transport, const char *name,
1287                       const char *exec, int fd[2])
1288 {
1289         if (transport->vtable->connect)
1290                 return transport->vtable->connect(transport, name, exec, fd);
1291         else
1292                 die("Operation not supported by protocol");
1293 }
1294
1295 int transport_disconnect(struct transport *transport)
1296 {
1297         int ret = 0;
1298         if (transport->vtable->disconnect)
1299                 ret = transport->vtable->disconnect(transport);
1300         free(transport);
1301         return ret;
1302 }
1303
1304 /*
1305  * Strip username (and password) from a URL and return
1306  * it in a newly allocated string.
1307  */
1308 char *transport_anonymize_url(const char *url)
1309 {
1310         char *scheme_prefix, *anon_part;
1311         size_t anon_len, prefix_len = 0;
1312
1313         anon_part = strchr(url, '@');
1314         if (url_is_local_not_ssh(url) || !anon_part)
1315                 goto literal_copy;
1316
1317         anon_len = strlen(++anon_part);
1318         scheme_prefix = strstr(url, "://");
1319         if (!scheme_prefix) {
1320                 if (!strchr(anon_part, ':'))
1321                         /* cannot be "me@there:/path/name" */
1322                         goto literal_copy;
1323         } else {
1324                 const char *cp;
1325                 /* make sure scheme is reasonable */
1326                 for (cp = url; cp < scheme_prefix; cp++) {
1327                         switch (*cp) {
1328                                 /* RFC 1738 2.1 */
1329                         case '+': case '.': case '-':
1330                                 break; /* ok */
1331                         default:
1332                                 if (isalnum(*cp))
1333                                         break;
1334                                 /* it isn't */
1335                                 goto literal_copy;
1336                         }
1337                 }
1338                 /* @ past the first slash does not count */
1339                 cp = strchr(scheme_prefix + 3, '/');
1340                 if (cp && cp < anon_part)
1341                         goto literal_copy;
1342                 prefix_len = scheme_prefix - url + 3;
1343         }
1344         return xstrfmt("%.*s%.*s", (int)prefix_len, url,
1345                        (int)anon_len, anon_part);
1346 literal_copy:
1347         return xstrdup(url);
1348 }
1349
1350 static void read_alternate_refs(const char *path,
1351                                 alternate_ref_fn *cb,
1352                                 void *data)
1353 {
1354         struct child_process cmd = CHILD_PROCESS_INIT;
1355         struct strbuf line = STRBUF_INIT;
1356         FILE *fh;
1357
1358         cmd.git_cmd = 1;
1359         argv_array_pushf(&cmd.args, "--git-dir=%s", path);
1360         argv_array_push(&cmd.args, "for-each-ref");
1361         argv_array_push(&cmd.args, "--format=%(objectname) %(refname)");
1362         cmd.env = local_repo_env;
1363         cmd.out = -1;
1364
1365         if (start_command(&cmd))
1366                 return;
1367
1368         fh = xfdopen(cmd.out, "r");
1369         while (strbuf_getline_lf(&line, fh) != EOF) {
1370                 struct object_id oid;
1371
1372                 if (get_oid_hex(line.buf, &oid) ||
1373                     line.buf[GIT_SHA1_HEXSZ] != ' ') {
1374                         warning("invalid line while parsing alternate refs: %s",
1375                                 line.buf);
1376                         break;
1377                 }
1378
1379                 cb(line.buf + GIT_SHA1_HEXSZ + 1, &oid, data);
1380         }
1381
1382         fclose(fh);
1383         finish_command(&cmd);
1384 }
1385
1386 struct alternate_refs_data {
1387         alternate_ref_fn *fn;
1388         void *data;
1389 };
1390
1391 static int refs_from_alternate_cb(struct alternate_object_database *e,
1392                                   void *data)
1393 {
1394         struct strbuf path = STRBUF_INIT;
1395         size_t base_len;
1396         struct alternate_refs_data *cb = data;
1397
1398         if (!strbuf_realpath(&path, e->path, 0))
1399                 goto out;
1400         if (!strbuf_strip_suffix(&path, "/objects"))
1401                 goto out;
1402         base_len = path.len;
1403
1404         /* Is this a git repository with refs? */
1405         strbuf_addstr(&path, "/refs");
1406         if (!is_directory(path.buf))
1407                 goto out;
1408         strbuf_setlen(&path, base_len);
1409
1410         read_alternate_refs(path.buf, cb->fn, cb->data);
1411
1412 out:
1413         strbuf_release(&path);
1414         return 0;
1415 }
1416
1417 void for_each_alternate_ref(alternate_ref_fn fn, void *data)
1418 {
1419         struct alternate_refs_data cb;
1420         cb.fn = fn;
1421         cb.data = data;
1422         foreach_alt_odb(refs_from_alternate_cb, &cb);
1423 }